Information
-
Patent Grant
-
6176282
-
Patent Number
6,176,282
-
Date Filed
Friday, June 25, 199925 years ago
-
Date Issued
Tuesday, January 23, 200123 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
- Armstrong, Westerman, Hattori, McLeland & Naughton
-
CPC
-
US Classifications
Field of Search
US
- 144 2091
- 144 211
- 144 212
- 144 213
- 144 356
- 144 357
- 144 362
- 144 365
- 144 408
- 700 160
- 700 167
- 702 169
- 702 167
-
International Classifications
-
Abstract
A pair of centering spindles are disposed away from cutting spindles and movably in the direction of Z or parallel with the axial center line of cutting spindles. A plurality of log center detecting means are disposed along the Z direction in relative to a log chucked by the centering spindles. A pair of holding members are mounted movably in the directions of X, Z, and Y including components orthogonally intersecting the X and Z. By way of controlling means, the centering spindle holding a log is caused to rotate at least one revolution thereby enabling the log center detecting means to determine each position of axial center which is assumed to constitute the axial centers at both end faces of the log, the virtual line passing through every positions of axial centers in Z direction is aligned with the Y, and the holding members are moved in the Z direction to hold the log, after which the chucking of log by the centering spindles are released. The holding members are moved in the X direction toward the cutting spindle, as well as in the Y direction to align every axial centers with the rotational center of cutting spindles, thus allowing the log to be chucked by the cutting spindle.
Description
BACKGROUND OF THE INVENTION
This invention relates to an apparatus for centering and feeding a log and to a method for centering and feeding a log, which are adapted to be used in combination with a working machine for turning a log while chucking the log by means of cutting spindles.
There is known a veneer lathe provided with cutting spindles having, in the direction of Z thereof, an axial center for chucking a log to be cut or peeled into a monolithic veneer (hereinafter referred simply to as a veneer). There is also known an apparatus for centering and feeding a log (or a log centering and feeding apparatus), which is designed to feed a log to the cutting spindles of the veneer lathe in such a manner that the log can be properly centered.
FIG. 23
shows part of one example of the conventional log centering and feeding apparatus which is disclosed in Japanese Patent Unexamined Publication H4-60001, wherein one side portion of the log-chucking section of the apparatus is illustrated. According to this log centering and feeding apparatus, a pair of centering spindles
100
(only one of them is shown) having an axial center in the same Z direction as that of the cutting spindles (not shown) of the veneer lathe are disposed away from the cutting spindles by a predetermined distance in the direction of X. The centering spindles
100
are mounted on a guiding shaft
103
which is horizontally interposed between a pair of frames
101
erected vertically (in the direction of Y), and the position of centering spindles
100
is made adjustable by means of an X-axis adjustor comprising a fluid cylinder (not shown), etc. A pair of transporting claws
104
(only one of them is shown) are disposed over the centering spindles
100
in such a manner that the position of each of the transporting claws
104
can be adjusted in the vertical direction (in the direction of Y) by means of a Y-axis adjustor comprising a fluid cylinder
105
, etc. and the transporting claws
104
are made entirely movable along the rail
110
or in the direction of X toward the cutting spindles of the veneer lathe.
Further, a plurality of log center detecting means each provided with a displacement detector
121
for detecting the position of center of a log (not shown) while the log is being kept chucked by the centering spindle
100
is mounted on a proximal end of each rocking arm
120
which is positioned at a desired interval along the longitudinal direction (in the direction of Z) of the log. In this case, the centering spindle
100
holding the log is rotated at least one revolution thereby enabling each log center detecting means to determine, through processing, each position of axial center which is assumed to constitute the axial centers at both end faces of the log, thus obtaining coordinate values on the axial center throughout the full length of log, on the basis of which the pair of centering spindles
100
are respectively shifted along the horizontal guiding shaft
103
by making use of the X-axis adjustor thereby performing the positional correction in the direction of X. Thereafter, each of the transporting claws
104
is moved downward to a predetermined degree so as to allow the log (that has been determined regarding the positional correction in the direction of X) to be held using the transporting claws
104
, after which the log is moved in the vertical direction (in the direction of Y) up to a predetermined position by making use of the Y-axis adjustor (comprising the fluid cylinder
105
), thereby performing the positional correction in the direction of Y. After finishing the alignment of axial center of log in both X and Y directions, the transporting claws
104
is moved, while maintaining this state of log. in the direction of X toward the cutting spindle of the veneer lathe so as to transfer the log to the cutting spindle.
As described above, according to the conventional log centering device, the adjustment data is output to the X-axis adjustor as well as to the Y-axis adjustor on the basis of data of axial center of log which have been obtained through the processing of data obtained from the displacement detector and from the rotation angle detector, whereby the log is shifted in the directions of X-axis and Y-axis so as to make the axial center of the log agree or align with the cutting spindle, thus performing the centering of the log.
However, since the aforementioned conventional centering device requires not only the X-axis adjustor for moving the holding claw (centering spindle
100
) in the direction of X-axis but also the Y-axis adjustor for moving the transporting claw
104
in the direction of Y-axis, the log centering device itself inevitably becomes large in size and at the same time, becomes complicated in structure, thus inviting an increase in cost.
BRIEF SUMMARY OF THE INVENTION
The present invention has been accomplished with a view to overcome the aforementioned drawbacks of the prior art, and therefore, the object of the present invention is to provide an apparatus and a method for centering and feeding a log, which are capable of omitting the aforementioned exclusive X-axis adjustor, capable of miniaturizing the apparatus, and capable of simplifying the structure of the apparatus, thus making it possible to save the manufacturing cost of the apparatus.
With a view to achieve the aforementioned problems, the present invention provides a log centering and feeding apparatus which is fundamentally featured in that a reference virtual line in the direction of Y is set in a pair of log transporting members which correspond to the aforementioned transporting claw
104
, in that the centering spindle holding a log is rotated at least one revolution thereby enabling each log center detecting means to determine, through processing, each position of axial center which is assumed to constitute the axial centers at both end faces of the log, and in that the centering spindle is further rotated so as to render the direction of the virtual line passing through every positions of axial centers as viewed from the aforementioned direction of Z to align with the reference virtual line that has been set in advance to the pair of the log transporting members, thus making it possible to omit the X-axis adjustor comprising the fluid cylinder, etc. which is provided in the conventional log centering apparatus.
The means for further rotating the centering spindle so as to render the direction of the virtual line passing through every positions of axial centers as viewed from the direction of Z to align with the reference virtual line that has been set in advance to the pair of the log transporting members can be substituted by making use of a centering spindle-rotating means that has been attached in advance to the log centering and feeding apparatus, so that any additional device is not required, thus making it possible to miniaturize the apparatus and to simplify the construction of the apparatus.
Namely, the present invention provides a log centering and feeding apparatus which is designed to be employed in combination with a veneer lathe provided at least with a cutting spindle having an axial center in the direction of Z for chucking a log constituting a raw material for producing a veneer, said log centering and feeding apparatus being used for feeding the log to the cutting spindle under a condition where the centering of the log has been determined, and comprising a centering spindle disposed away from the cutting spindle by a predetermined distance in the direction of X and having an axial center in the same Z direction as that of said cutting spindle, log center detecting means for detecting the position of axial center of the log under a condition where the log is kept chucked by said centering spindle, a pair of log transporting members which are rendered movable in the direction of Z as well as in the direction of Y including a component orthogonally intersecting the direction of Z thereby enabling the log transporting members to receive the log from said centering spindle and to deliver the log to said cutting spindle, and control means for controlling the operation of each log transporting member; wherein
said log transporting members are provided with a setting of reference virtual line in the direction of Y; and
said control means comprises means for forcing the centering spindle holding the log to rotate at least one revolution thereby enabling said log center detecting means to determine, through processing, each position of axial center which is assumed to constitute the axial centers at both end faces of the log, means for further rotating the centering spindle so as to make the direction of the virtual line passing through every positions of axial centers as viewed from the direction of Z agree or parallel with the reference virtual line that has been set in advance to the pair of the log transporting members, means for controlling said pair of log transporting members, after the log has been transferred from said centering spindle to said log transporting members while maintaining the directions of said virtual lines in agreement or parallel with each other, in such a manner that each center position of the log that has already been kept in place in the direction of X where the virtual line passing through said axial center of the log is made in agreement with the axial center line of said cutting spindle can be made in agreement with the direction of z constituting the axial center line of said cutting spindle, and means for controlling said log transporting members in a manner to allow said log to be chucked from said log transporting members to said cutting spindle while the state of the log adjusted in the direction of z is maintained. As a result of the aforementioned structure, it is possible to feed the log in an axially centered state thereof to the cutting spindle.
Although the log transporting members may be entirely constituted by a single member, it is more preferable that they comprise a pair of holders which are movable in the direction of Z, and a holding member mounted on the holder which is movable in the direction of Z and being made movable in the direction of the reference virtual line in relative to the holder movable in the direction of Z. It is possible with this preferable embodiment to increase the degree of freedom in designing the log transporting members and the log centering and feeding apparatus. In this case, the aforementioned reference virtual line may be set on the basis of these holding members.
Further, the log transporting members may be allowed to move linearly and reciprocatively in the direction of X, or to rotate about any desired point.
The present invention also provides a method of centering and feeding a log, which comprises the steps of:
determining, through processing by making use of log center detecting means, each position of axial center which is assumed to constitute the axial centers at both end faces of the log by forcing the centering spindle to rotate at least one revolution while both ends of the log are kept chucked with a pair of centering spindles;
further rotating the pair of centering spindles until the virtual line passing through the positions of axial centers as viewed from the direction of Z parallel with the axial center line of the centering spindle is aligned with a predetermined position in the direction of Y;
moving a pair of holding members in the direction of Z and close to both end faces of the log thereby to hold the log with the holding members;
moving said centering spindles away from each end face of the log;
integrally moving said pair of holding members in the direction of X including a directional component extending from said centering spindle to said cutting spindle of veneer lathe until the log is chucked by said cutting spindle; and
moving said holding members respectively in the direction of Y thereby rendering each position of axial center at both end faces of the log to become in agreement with the rotational center of said cutting spindle of veneer lathe.
By the way, the expression of “axial center line” means a virtual line passing through the rotational centers of a rotational body, i.e. a virtual line passing through the rotational center of each cross-section intersecting orthogonally with the longitudinal direction of a rotational body.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
FIG. 1
is a front view schematically showing one example of a log centering apparatus including a veneer lathe according to the present invention;
FIG. 2
is a side view as viewed from the left side of
FIG. 1
;
FIG. 3
is a block diagram illustrating the controlling means of a log centering apparatus;
FIG. 4
is an enlarged front view illustrating a centering and feeding mechanism;
FIG. 5
is an enlarged front view illustrating a centering and feeding mechanism;
FIG. 6
is an enlarged front view illustrating a centering and feeding mechanism;
FIG. 7
is an enlarged front view illustrating a centering and feeding mechanism;
FIG. 8
is an enlarged front view illustrating a centering and feeding mechanism;
FIG. 9
is an enlarged front view illustrating a centering and feeding mechanism;
FIG. 10
is an enlarged front view illustrating a centering and feeding mechanism;
FIG. 11
is a front view schematically showing a log centering apparatus including a veneer lathe according to a second embodiment of the present invention;
FIG. 12
is a front view schematically showing a log centering apparatus including a veneer lathe according to a third embodiment of the present invention;
FIG. 13
is an enlarged side view taken along a dot and dash line A—A of FIG.
12
and viewed from the direction of arrow;
FIG. 14
is an enlarged front view illustrating a centering and feeding mechanism;
FIG. 15
is an enlarged front view illustrating a centering and feeding mechanism;
FIG. 16
is an enlarged front view illustrating a centering and feeding mechanism;
FIG. 17
is an enlarged front view illustrating a centering and feeding mechanism;
FIG. 18
is an enlarged front view illustrating a centering and feeding mechanism according to a fourth embodiment of the present invention;
FIG. 19
is an enlarged front view illustrating a centering and feeding mechanism;
FIG. 20
is an enlarged front view illustrating a centering and feeding mechanism;
FIG. 21
is an enlarged front view illustrating a centering and feeding mechanism according to a modified embodiment of the present invention;
FIG. 22
is a front view schematically illustrating a centering and feeding mechanism wherein a cutter is employed as a working machine; and
FIG. 23
is a from view illustrating one example of the conventional log centering apparatus.
DETAILED DESCRIPTION OF THE INVENTION
This invention will be further explained with reference various embodiments of this invention.
Embodiment 1
FIG. 1
is a front view schematically showing a log centering apparatus including a veneer lathe.
FIG. 2
is a side view as viewed from the left side of
FIG. 1
Referring to these FIGS. , a veneer lathe
1
is constructed in the same manner as that of the conventional lathe, and comprises a frame
3
on which a cutter
3
a
for peeling (or cutting) a log
7
(see
FIG. 4
, etc.) to produce a veneer, and a pair of cutting spindles
9
for chucking and rotating the log
7
are mounted. At the portions of the frame
3
located over the cutting spindles
9
, there are provided a pair (right and left) of horizontal frames
5
extending in the direction orthogonally intersecting with the direction of the axial center line of the cutting spindles
9
, i.e. orthogonally intersecting with a virtual line passing through the rotational centers P of each cross-section orthogonally intersecting with the longitudinal direction of the cutting spindles
9
. The pair of horizontal frames
5
have at least a sufficient length to extend from the cutting spindles
9
to the centering position of log to be explained below and are extended in the direction of X or in the horizontal direction.
On this horizontal frames
5
, there is also supported a movable frame
11
extending in the direction of Z or in parallel with the axial center line P of the cutting spindles
9
. More specifically, the movable frame
11
is supported through the opposite end portions thereof on the horizontal frames
5
and is permitted to move in the direction of X orthogonally intersecting with the axial center line P of the cutting spindles
9
. Namely, a screw
15
a
is attached respectively to the opposite end portions of the movable frame
11
and engaged with moving members
15
(such as a feed screw) having an axial center line extending in the direction of X orthogonally intersecting with the axial center line P of the cutting spindles
9
and being axially supported by the frame
3
. This moving members
15
are coupled with an electric motor
13
which is mounted on the horizontal frame
5
. Accordingly, the movable frame
11
is enabled to reciprocatively move within a region between the log feeding position located over the cutting spindles
9
and the log centering position located over the centering spindles
29
to be explained hereinafter.
By the way, the electric motor
13
is provided with a rotational angle detector
13
a
such as a rotary encoder, thereby making it possible to numerically control the magnitude of movement of the movable frame
11
in conformity with the magnitude of rotation of the electric motor
13
.
A pair of holders
17
facing to each other are movably supported by the movable frame
11
, thus permitting the holders
17
to move in the direction of Z or along the longitudinal direction of the movable frame
11
. Each holder
17
is coupled with a first operating member
19
such as a hydraulic cylinder which is attached to a mounting plate
11
a
suspended from an intermediate portion of the movable frame
11
. As a result, these holders
17
are enabled, through the operation of each first operating member
19
, to move in the direction of Z to come close to each other or go away from each other.
Although each holder
17
is shown in
FIG. 2
as being perpendicularly suspended, each holder
17
may be inclined toward the cutting spindles
9
or toward the centering spindles
29
.
Each holder
17
is provided, on the surface thereof facing the other holder
17
, with a holding member
21
, which is permitted to move in the vertical direction or in the direction of Y as shown in FIG.
2
. Namely, each holding member
21
is coupled with a vertically movable member
25
such as a feed screw which is connected with an electric motor
23
fixed to the holder
17
, thus enabling each holding member
21
to vertically move along the direction of Y by means of the vertically movable member
25
to be driven by the electric motor
23
.
By the way, a virtual line VL
1
functioning as a reference (base) line for moving the holding members
21
to a predetermined position is set in advance to the holding members
21
in such a manner that the line is parallel with the vertical moving direction of the holding members
21
in relative to the holders
17
and passes through a given point that has been fixedly set in relative to the holding members
21
, for example a central in the lateral direction of the holding members
21
in
FIG. 4
in this -embodiment. Therefore, if it is desired to move the holding members
21
through a movement of the movable frame
11
, the movement of the holding members
21
is controlled such that, on the basis of information from the rotational angle detector
13
a
, the position of the virtual line VL
1
of the holding members
21
is positioned at a desired point.
By the way, each holding member
21
is provided at a lower portion of the facing surface with a claw
21
a
to be pierced into the end face of log so as to hold the log
7
. Further, the electric motor
23
is provided with a rotational angle detector
23
a
such as a rotary encoder, thereby making it possible to numerically control the magnitude of the vertical movement of the holding members
21
in conformity with the magnitude of rotation of the electric motor
23
.
A pair of centering spindles
29
, facing to each other, are mounted on a portion of the frame
3
which is located away from the axial center line of the cutting spindle
9
by a predetermined distance toward the centering position, these centering spindles
29
having an axial center line parallel with the axial center line of the cutting spindle
9
, and being rotatable and movable in the direction of the axial center line thereof or in the direction of Z. Specifically, spline grooves
29
b
having a predetermined width are formed on the outer circumferential wall of an intermediate portion of the centering spindle
29
positioned on the left side of
FIG. 2
, and the centering spindle
29
is coupled with a rotational body
33
which is connected with an electric motor
31
attached to the frame
3
. Since the rotational body
3
is engaged with the spline grooves
29
b
, the centering spindle
29
is prevented from being rotated about the axial center line thereof, but is permitted to slide in the direction of the axial center line or in the direction of Z. Accordingly, the centering spindle
29
is allowed to rotate only through the driving force of the electric motor
31
. On the other hand, a second operating member
35
such as a hydraulic cylinder is rotatably mounted on the external end portion of the centering spindle
29
, thereby enabling the centering spindle
29
to move in the direction of the axial center line or in the direction of Z through an actuation of this second operating member
35
so as to chuck the both end faces
7
a
and
7
b
of the log
7
.
In the embodiment shown
FIG. 2
, only one out of the pair of centering spindles
29
is coupled with the electric motor
31
, while allowing the other centering spindle
29
to be acted as a follower. However, it is also possible to adopt a structure where both centering spindles
29
are coupled with the electric motor
31
. The electric motor
31
is provided with a rotational angle detector
31
a
such as a rotary encoder for detecting a turning angle of the centering spindle
29
.
On the left side of the frame
3
shown in
FIG. 2
, there are disposed for instance three log center detectors
37
, which are positioned at a level which is almost identical with the height of the centering spindles
29
and are spaced apart from the centering spindle
29
by a predetermined distance L
1
. In this embodiment, these three log center detectors
37
are disposed to face the outer circumferential surfaces of both end portions and an intermediate portion (all in relative to the direction of Z) of the log
7
being chucked by the centering spindle
29
. Each log center detector
37
is provided with a light source for irradiating a light toward each outer circumferential surface of the log, and a light-receiving member for receiving a light reflected from each outer circumferential surface of the log
7
(these components are not shown). This log center detector
37
is designed to measure the maximum and minimum diameters of the log
7
from the center of the centering spindle
29
at each location on the basis of a distance L
2
between each outer circumferential surface of the log
7
and the log center detector
37
that can be calculated based on the distance L
1
between the axial center line of the centering spindle
29
which has been set in advance and the log center detector
37
, and on the time interval required for the light starting from the irradiation thereof from each log center detector
37
and finishing upon receipt of the light reflected from each outer circumferential surface of the log
7
. The control means to be discussed hereinafter determines, through processing of data measured in this manner, the positions of axial center
7
c
and
7
d
, thus estimating the positions of axial center at the opposite end faces of the log
7
.
FIG. 3
shows an electric block diagram illustrating the controlling means of the log centering and feeding apparatus.
The program data for performing the centering of the log
7
and the feeding of the log
7
to the cutting spindle
9
are stored in the ROM
43
of the CPU
41
constituting the control means. The RAM
45
of the CPU
41
is provided with a first to third memory regions
45
a
to
45
c
, wherein the first memory region
45
a
is designed to store the positional data on the rotational center P of the cutting spindle
9
, and on the positions of the centering spindle
29
and the log axial center detector
37
; the second memory region
45
b
is designed to store the distance data L
2
between each log axial center detector
37
and the outer circumferential surface of the log
7
at each turning angle of the centering spindle
29
; and the third memory region
45
c
is designed to store the data on the positions of axial center which are assumed to constitute the axial centers at both end faces
7
a
and
7
b
of the log
7
that can be calculated from the data stored in the first memory region
45
a
and the second memory region
45
b
. By the way, the reference numeral
47
represents a buffer memory designed to temporarily store the control data that have been processed based on the data stored in the first to third memory regions
45
a
to
45
c.
The CPU
41
is connected with a drive control circuit
49
, which is designed to control the operation of electric motors
13
,
23
and
31
on the basis of control data stored in the buffer memory
47
, or to control the operation of the moving member
15
or of the first and second operating members
19
and
35
. Next, the operation of centering and feeding a log will be explained.
FIGS. 4
to
10
illustrate the operation of centering and feeding a log.
The movable frame
11
is moved in advance to the cutting spindle
9
and kept in a state of stand-by so as not to interfere with the log
7
to be centered. Under this condition, the log
7
is fed to a space between a pair of the centering spindles
29
after the log
7
is temporarily centered by means of V-shaped frames (not shown) which are descendibly disposed at the centering section of the veneer lathe and near opposite end faces
7
a
,
7
b
and an intermediate portion of the log
7
(alternatively, the log
7
is fed to a space between a pair of the centering spindles
29
by means of a known log charger (not shown)). Thereafter, the second operating member
35
is actuated based on a signal from the CPU
41
, thereby causing the centering spindles
29
to move toward each other so as to chuck the opposite end faces
7
a
,
7
b
of the log
7
(see
FIG. 4
, the centering spindles
29
are not shown in FIG.
4
).
Then, the electric motor
31
is actuated based on a signal (hereinafter referred to as signal from the CPU
41
) from the drive control circuit
49
actuated based on a signal from the CPU
41
, thereby rotating the centering spindles
29
and hence to cause the log
7
to be rotated at least one revolution, during which the distance L
2
between each outer circumferential surface (the portions of the opposite end faces
7
a
,
7
b
and intermediate portion) of the log
7
and the log center detector
37
is measured, thus detecting the positions of axial centers
7
c
and
7
d
of the opposite end faces
7
a
and
7
b
of the log
7
.
Namely, the distance between the axial center line of the centering spindles
29
and the log center detector
37
is set in advance to a predetermined distance L
1
. Under this condition, the distance L
2
between each outer circumferential surface (the portions of the opposite end faces
7
a
,
7
b
and intermediate portion) of the log
7
and the log center detector
37
at each turning angle of the centering spindles
29
is measured by making use of the log center detector
37
while the log
7
is allowed to rotate. The data on the maximum and minimum outer diameters of each portion of the log
7
as measured from the center of the centering spindles
29
, which have been obtained in this manner are stored in the second memory region
45
b
. As the log
7
is turned at least one revolution, the positions of axial centers
7
c
and
7
d
of the log is calculated based on the data concerning the turning angle and the maximum and minimum outer diameters at each portion of the log that have been stored in the second memory region
45
b
according to the signals from the CPU
41
, the resultant data on the positions of axial centers
7
c
and
7
d
of the log are stored in the third memory region
45
c
(see
FIGS. 5 and 6
, wherein the solid line denotes the front end face
7
a
and the prospective position of axial center
7
c
at the front end face
7
a
; while the broken line denotes the rear end face
7
b
and the prospective position of axial center
7
d
at the rear end face
7
b
).
Then, according to the signals from the CPU
41
, the electric motor
31
is actuated to further rotate the log
7
on the basis of the data of the prospective positions of axial centers
7
c
and
7
d
at the opposite end faces
7
a
and
7
b
of log that have been stored in the third memory region
45
c
, thereby rendering the virtual line ML
1
passing through the prospective axial centers
7
c
and
7
d
at the opposite end faces
7
a
and
7
b
of log
7
to agree or align (as viewed from the Z direction which is parallel with the axial center line of the centering spindle
29
) with the vertical line, i.e. the moving direction of the holding members
21
in relative to the holders
17
(see FIG.
7
). Concurrently, the distance from the center P of the spindle
9
to the virtual line ML
1
is calculated by the CPU
41
to obtain data, the signal of which is then utilized to drive the electric motor
13
and hence, to obtain the information on the positions by making use of the rotational angle detector
13
a
. On the basis of the information on the positions, the movable frame
11
is moved from the cutting spindle
9
side so as to render the vertical line VL
1
that has been preset in the holding member
21
to align with the aforementioned virtual line ML
1
(see FIG.
8
).
In the above embodiment, the log
7
is further rotated based on the data of the positions of axial center so as to render the virtual line ML
1
passing through every axial centers at various portions of the log to agree or align with the vertical line, after which the holding members
21
are moved toward the centering region of the apparatus so as to render the virtual line ML
1
to align with the vertical line VL
1
passing through the center of the holding members
21
. Alternatively, it may be controlled such that the virtual line ML
1
is orientated to the vertical direction during the holding members
21
are being moved toward the centering region after the data on the axial centers are calculated by the CPU
41
, or after the holding members
21
are moved to the region of the centering spindle
29
.
Next, the first operating member
19
is actuated based on a signal from the CPU
41
so as to move the holders
17
toward each other thereby causing the holding members
21
to press-contact with and hold the opposite end faces
7
a
and
7
b
of the log
7
that has been chucked by the centering spindles
29
. Thereafter, the second operating member
35
is allowed to return, and the centering spindles
29
are also moved away from each other, whereby the log
7
is released from the chucking by the centering spindles
29
.
Thereafter, upon receipt of a signal from the CPU
41
, each electric motor
23
is independently actuated based on the data of the prospective axial centers
7
c
and
7
d
at the opposite end faces of the log
7
and on the positional data of the rotational center P of the cutting spindle
9
, thereby rendering each of the holding members
21
to move in the vertical direction so as to align the prospective axial centers
7
c
and
7
d
of the opposite end faces of the log
7
with the height of the rotational center P of the cutting spindle
9
(see FIG.
9
).
By the way, this operation of aligning the prospective axial centers
7
c
and
7
d
of the opposite end faces of the log
7
chucked by means of the holding members
21
with the rotational center P of the cutting spindle
9
may be performed as mentioned later during the holding members
21
are being moved toward the cutting spindle
9
, or after holding members
21
have been moved to the cutting spindle side.
Then, based on a signal from the CPU
41
, the electric motor
13
is driven to move the movable frame
11
holding the log
7
by means of holding members
21
to such an extent that the prospective axial centers
7
c
and
7
d
of the opposite end faces of the log
7
reach the vertical line VL
2
passing through the rotational center P of the spindle
9
. Thereafter, a spindle-operating member (not shown) is actuated causing the cutting spindles
9
to move toward each other so as to chuck the opposite end faces
7
a
,
7
b
of the log
7
in alignment with the axial centers
7
c
and
7
d
(see FIG.
10
).
After the log
7
is chucked by making use of the cutting spindles
9
, a signal is transmitted from the CPU
41
to the first operating member
19
thereby to move the first operating member
19
to return, and hence, the holding of the log
7
by means of the holding members
21
is released, after which the electric motor
23
is actuated to move each holding member
21
back to the original position, thus finishing the centering and feeding operation of the log
7
.
In the above embodiment 1, the virtual line VL
1
to be set in the holding members
21
as a reference line for moving the holding members
21
to a predetermined position is selected as passing through a predetermined position in relative to the holding members, i.e. the central point in the lateral direction of the holding members
21
as shown in FIG.
4
. Therefore, the virtual line VL
1
is selected to be the one which passes through the aforementioned central point and is parallel with the vertical moving direction of the holding members
21
in relative to the holders
17
. However, there is not any particular limitation regarding this point as long as this point is located at any definite position in relative to the holding members
21
. Therefore, if there is no problem in holding the log
7
by means of the holding members
21
, this point may be set at a point located outside the holding members
21
.
For example, a virtual line may be selected in such a way that the virtual line passes through a point other than the aforementioned central point and is made parallel with the vertical moving direction of the holding members
21
, thereby setting a virtual line VL
3
in the holding members
21
as shown in
FIG. 4
, which is displaced right-ward from the virtual line VL
1
. At the occasion of moving the holders
17
, the holders
17
are moved based on a signal from the CPU
41
so as to make the virtual line VL
3
align with the virtual line ML
1
as illustrated in
FIG. 7
, thereby allowing the log
7
to be held by the holding members
21
. Thereafter, the holders
17
are further moved until the virtual line VL
3
is aligned with the virtual line VL
2
. During or after this movement of the holder
17
, each of the holding members
21
is moved in the vertical direction so as to align the prospective axial centers
7
c
and
7
d
of the opposite end faces of the log
7
with the height of the center P of the cutting spindle
9
, after which the log
7
is allowed to be chucked by making use of the cutting spindle
9
.
Embodiment 2
According to Embodiment 1, the holder
17
is linearly and reciprocatively moved between the position where the reference virtual line VL
1
of the holding members
21
passes through the rotational center P of the cutting spindle
9
and a desired position on the centering spindle (
29
) side. However, according to Embodiment 2, the holder
17
is linearly and reciprocatively moved between a desired position on the cutting spindle (
9
) side and the position where the reference virtual line of the holding members
21
on the centering spindle (
29
) side passes through a point which is located away by a predetermined distance from the rotational center P of the cutting spindle
9
.
Namely, although Embodiment 2 is the same in construction of every members with Embodiment 1, the reference virtual line to be set in the holder
17
and the manner of controlling by means of the CPU functioning as control means are altered from Embodiment 1 as explained below.
In the same manner as explained in Embodiment 1, based on a signal from the CPU
41
, the log
7
is caused to rotate at least one revolution by making use of the centering spindles
29
, thus detecting the prospective positions of axial centers
7
c
and
7
d
of the opposite end faces
7
a
and
7
b
of the log
7
.
Then, the log
7
is further rotated so as to render the virtual line ML
1
passing through the prospective axial centers
7
c
and
7
d
of the opposite end faces
7
a
and
7
b
of log
7
to agree or align (as viewed from the Z direction) with the vertical direction.
On the other hand, at the occasion of moving the holders
17
toward the centering spindle
29
through the movement of the movable frame
11
on the basis of a signal from the CPU
41
, the reference virtual line VL
1
of the holder
17
is always positioned at a predetermined location which is displaced by a predetermined distance L
4
from the rotational center P of the cutting spindle
9
toward the centering spindle
29
as shown in
FIG. 11
, and is kept in a state of stand-by.
After the virtual line ML
1
has been aligned with the vertical direction and the holder
17
has been kept in a state of stand-by at a predetermined position, the distance L
5
between the reference virtual line VL
1
that has been preset in the holder
17
and the virtual line ML
1
is calculated by means of the CPU
41
, and the holding member
21
is moved in the Z direction so as to hold the opposite end faces
7
a
and
7
b
of the log
7
, after which the chucking of the log
7
by means of the centering spindles
29
is released.
Thereafter, based on a signal from the CPU
41
, the movable frame
11
is moved toward the cutting spindle
9
to such an extent that the reference virtual line VL
1
of the holder
17
is positioned at a place which is displaced by a distance of L
5
toward the right side of the vertical line VL
2
passing through the rotational center P of the cutting spindle
9
as shown in FIG.
11
. When the movable frame
11
is moved up to this place, the movement of the movable frame
11
is stopped.
In the same manner as in Embodiment 1, during or after the movement of this movable frame
11
, each electric motor
23
is independently actuated based on the data of the prospective axial centers
7
c
and
7
d
at the opposite end faces of the log
7
and on the positional data of the rotational center P of the cutting spindle
9
, thereby rendering each of the holding members
21
to move in the vertical direction so as to align the prospective axial centers
7
c
and
7
d
of the opposite end faces of the log
7
with the height of the rotational center P of the cutting spindle
9
.
After finishing these operations, a spindle-operating member (not shown) is actuated causing the cutting spindles
9
to move toward each other so as to chuck the opposite end faces
7
a
,
7
b
of the log
7
in alignment with the axial centers
7
c
and
7
d.
Embodiment 3
FIG. 12
shows a front view schematically illustrating a log centering apparatus according to a third embodiment of the present invention, while
FIG. 13
shows an enlarged side view taken along a dot and dash line A—A of FIG.
12
and viewed from the direction of arrow.
Referring to these FIGS. , horizontal frames
5
is positioned extending over the cutting spindle
9
and over the second operating member
35
, and a shaft
51
coupled with an electric motor
53
is rotatably and axially supported on this horizontal frame
5
. A rotatable frame
54
is fixed to this shaft
51
.
This electric motor
53
is provided with a rotational angle detector
53
a
such as a rotary encoder, thereby making it possible to numerically control the rotation of the shaft
51
on the basis of detected signals from the rotational angle detector
53
a
as explained below.
As shown in
FIG. 13
, a pair of holders
57
facing to each other and spaced apart from each other are supported by the rotatable frame
54
in such a manner that the holders
57
are prevented from being rotated about the axial center line thereof but is permitted to move in the direction of the axial center line (longitudinal direction) of the shaft
51
. Each holder
57
is coupled with a first operating member
19
such as a hydraulic cylinder which is attached to the rotatable frame
54
. As a result, these holders
57
are enabled, through the operation of corresponding first operating member
19
, to move in the direction of Z to come close to each other or go away from each other.
A holding member
55
having a claw
55
a
is movably supported by each holder
57
in the same manner as illustrated in Embodiment 1, so that the holding member
55
is enabled to move vertically in relative to the holder
57
. Namely, each holding member
55
is coupled with a vertically movable member
25
such as a feed screw which is connected with an electric motor
23
fixed to the holder
57
, thus enabling each holding member
55
to vertically move along the direction of Y by means of the vertically movable member
25
to be driven by the electric motor
23
.
By the way, a line functioning as a reference for rotating the holding members
55
, i.e. a virtual line ML
2
passing through a central point in the lateral direction of the holding member
55
and extending in the radial direction of the shaft
51
as shown in
FIG. 12
of the present invention is preset. Therefore, if it is desired to rotate the holding members
55
through a rotation of the rotatable frame
54
in the direction of X, the rotation of the holding members
55
is controlled such that, on the basis of information from the rotational angle detector
53
a
, the position of the virtual line ML
2
of the holding members
55
is positioned at a desired point as described below.
By the way, the electric motor
23
is provided with a rotational angle detector
23
a
such as a rotary encoder, thereby making it possible to numerically control the magnitude of the movement of the holding members
55
in accordance with the detected signals from the rotational angle detector
23
a
. Since other structure of this embodiment is the same as that of Embodiment 1, the same reference numerals are employed for the same parts thereby to omit the explanation thereof.
A pair of centering spindles
29
, facing to each other, are mounted on a portion of the frame
3
which is located away from the axial center line of the cutting spindle
9
by a predetermined distance toward the centering position, these centering spindles
29
having an axial center line parallel with the axial center line of the cutting spindle
9
, and being rotatable and movable in the direction of the axial center line thereof or in the direction of Z. Specifically, spline grooves
29
b
having a predetermined width are formed on the outer circumferential wall of an intermediate portion of the centering spindle
29
positioned on the left side of
FIG. 2
, and the centering spindle
29
is coupled with a rotational body
33
which is connected with an electric motor
31
attached to the frame
Next, the operation of centering and feeding a log according to this embodiment will be explained.
FIGS. 14
to
17
illustrate the operation of centering and feeding a log.
The holders
57
and holding members
55
are rotated in advance by means of the shaft
51
so as to be placed to take a position, for example, a position where the virtual line ML
2
in the holding members
55
is orientated in the vertical direction, which does not interfere with the log
7
to be centered, and are left in a state of stand-by (see FIG.
12
). By the way, the holders
57
and holding members
55
may be kept in a stand-by state by orienting the virtual line ML
2
to a direction inclined toward the cutting spindle
9
.
By the way, the value of distance “r” between the center R of the shaft
51
and the center P of the cutting spindle
9
, as well as the value of angle θ1 between the virtual line ML
4
passing through the centers R and P and the virtual line ML
2
are input, in advance, in the CPU
41
.
Then, in the same manner as explained in Embodiment 1, the log
7
is fed to a space between a pair of centering spindles
29
by means of V-shaped frames (not shown) or a log charger (not shown), and then, based on a signal from the CPU
41
under this condition, the centering spindles
29
are moved toward each other so as to chuck the opposite end faces
7
a
,
7
b
of the log
7
.
Then, the electric motor
31
is actuated thereby to rotate the centering spindles
29
and hence to cause the log
7
to be rotated at least one revolution, during which the maximum diameter and minimum diameter (as measured from the center of the centering spindles
29
) of the regions of opposite end faces
7
a
,
7
b
and intermediate portion of the log
7
are measured. Then, the CPU
41
is operated so as to perform the processing of the data on these maximum diameter and minimum diameter at each portion of the log
7
and to determine the position of axial centers
7
c
and
7
d
of the opposite end faces
7
a
and
7
b
of the log
7
.
Then, according to the signals from the CPU
41
, the electric motor
31
is actuated on the basis of the data of the prospective positions of axial centers
7
c
and
7
d
at the opposite end faces
7
a
and
7
b
of log
7
that have been stored in the third memory region
45
c
. As a result, the log
7
is caused to further rotate in such a manner that the virtual line ML
3
passing through the prospective axial centers
7
c
and
7
d
of the opposite end faces
7
a
and
7
b
of log
7
passes through the center R of the shaft
51
, i.e. the virtual line ML
3
is aligned with the virtual line in the radial direction of the shaft
51
(as viewed from the Z direction which is parallel with the axial center line of the centering spindle
29
) (see FIG.
14
). Concurrently, the CPU
41
is operated so as to calculate the angle θ2 between the virtual line ML
2
and the virtual line ML
3
under the condition shown in
FIG. 14
, thereby output a signal, on the basis of which the electric motor
53
is driven to rotate the shaft
51
, and hence, to rotate the holders
57
and the holding members
55
from the position shown in
FIG. 14
toward the left side. Further, when a detection signal from the rotational angle detector
53
a
indicating that the shaft
51
has been rotated by an angle of θ2 is detected by the CPU
41
, a signal is output by the CPU
41
so as to stop the operation of the electric motor
53
. As a result of these operations, the virtual line ML
2
of the holding members
55
is rendered to agree or align with the aforementioned virtual line ML
3
(see FIG.
15
).
Next, the first operating member
19
is actuated based on a signal from the CPU
41
so as to move the holders
57
toward each other thereby causing the holding members
55
to hold the opposite end faces
7
a
and
7
b
of the log
7
that has been chucked by the centering spindles
29
. Thereafter, the second operating member
35
is allowed to return, and the centering spindles
29
are also moved away from each other, whereby the log
7
is released from the chucking by the centering spindles
29
.
Thereafter, based upon the data on each distance between the center R of the shaft
51
to the prospective axial centers
7
c
and
7
d
of the opposite end faces of the log
7
and upon the data of aforementioned “r”, the CPU
41
is operated to calculate the magnitude of movement in radial direction of each holding member
55
, which is required for make each distance identical with the aforementioned “r”. Based on the calculated results, signals are output so as to independently actuate each electric motor
23
thereby to move each holding member
55
. When the movement of each holding member
55
to a calculated distance is confirmed by the rotational angle detector
23
a
, a signal is emitted from the CPU
41
so as to stop the operation of each electric motor
23
. As a result, the prospective axial centers
7
c
and
7
d
of the opposite end faces of the log
7
which is held by the holding members
55
are positioned on the circular arc having its center at the R of the shaft
51
and passing through the rotational center P of the cutting spindle
9
(FIG.
16
).
By the way, the operation of rendering the prospective axial centers
7
c
and
7
d
of the opposite end faces of the log
7
which is held by the holding members
55
to agree or align with the circular arc having its center at the R of the shaft
51
and passing through the rotational center P of the cutting spindle
9
may be performed, as mentioned hereinafter, after or during the rotation of the holder
57
with the log
7
being held by means of the holding members
55
.
Next, the electric motor
53
is driven according to a signal from the CPU
41
, thereby to rotate the shaft
51
in counterclockwise and hence, to rotate the holder
57
as shown in FIG.
16
. When the rotation of the virtual line ML
2
to an angle corresponding to the total angle of θ1 and θ2 is confirmed by the rotational angle detector
23
a
, a signal is emitted from the CPU
41
so as to stop the operation of each electric motor
53
. As a result, the holder
57
is positioned such that the virtual line ML
2
is aligned with the virtual line ML
4
passing through the aforementioned centers R and P, while the prospective axial centers
7
c
and
7
d
of the opposite end faces of the log
7
are aligned with the rotational center P of the cutting spindle
9
(FIG.
17
).
Next, a spindle operating member (not shown) is actuated so as to move each cutting spindle
9
toward the opposite end faces
7
a
and
7
b
of the log
7
, thereby causing each cutting spindle
9
being press-contacted with the opposite end faces
7
a
and
7
b
of the log
7
. As a result, the log
7
is chucked by the cutting spindle
9
with the prospective axial centers
7
c
and
7
d
thereof being aligned with the rotational center P of the cutting spindles
9
.
Thereafter, upon receipt of a signal from the CPU
41
, the first operating member
19
is caused to return, whereby the log
7
is released from the chucking by the holding members
55
, after which each electric motor
53
is actuated to turn the shaft
51
in counterclockwise as shown in FIG.
17
. When the rotation of the shaft
51
to an angle of θ1 is confirmed by the rotational angle detector
53
a
, a signal is emitted from the CPU
41
so as to stop the operation of each electric motor
53
, thereby causing each holding member
55
to return to the initial position as shown in
FIG. 12
, thus finishing the centering and feeding operation of the log
7
.
Embodiment 4
FIGS. 18
to
21
illustrate the operation of centering and feeding a log.
According to Example 3, the log
7
is caused to rotate by means of the centering spindle
29
at the occasion of rendering the log
7
to be held by the holding members
55
so as to align the virtual line ML
3
passing through the prospective axial centers
7
c
and
7
d
of the opposite end faces of the log
7
with the reference virtual line ML
2
passing through the center of the holding members
55
. Alternatively, after the log
7
is allowed to be held by the holding members
55
, the holding members
55
are moved in the direction of the reference virtual line ML
2
so as to align the prospective axial centers
7
c
and
7
d
of the opposite end faces of the log
7
with a point on the circular arc having its center at the R of the shaft
51
and passing through the rotational center P of the cutting spindle
9
.
By contrast, according to this embodiment (Embodiment 4), the log
7
is caused to rotate by means of the centering spindle
29
at the occasion of rendering the log
7
to be held by the holding members
55
so as to render the virtual line ML
3
passing through the prospective axial centers
7
c
and
7
d
of the opposite end faces of the log
7
not to align but to become parallel with the reference virtual line ML
2
passing through the center of the holding members
55
.
Namely, the holding members
55
are arranged to reciprocatively rotate within a region interposed between the position where the reference virtual line ML
2
is displaced by a required angle of a as measured clock-wise from the virtual line ML
5
passing through both of the rotational center S of the centering spindle
29
and the center R of the shaft
51
and the position where the reference virtual line ML
2
is displaced by a desired angle as measured counterclockwise from the aforementioned position which is displaced by said required angle of a from the virtual line ML
5
. By the way, this required angle of a should be set in a range which makes it possible to hold the log
7
being chucked by the centering spindle
29
.
By the way, the value of angle θ3 between the virtual line ML
4
and the virtual line ML
5
shown in
FIG. 18
is input, in advance, in the CPU
41
.
Then, in the same manner as explained in Embodiment 3, the log
7
is allowed to be chucked by means of the centering spindles
29
and then caused to turn at least one revolution, during which the positions of axial centers
7
c
and
7
d
of the opposite end faces
7
a
and
7
b
of the log
7
are determined through a processing of data. Then, according to the signals from the CPU
41
, the electric motor
53
is actuated so as to rotate the shaft
51
in clock-wise from the initial state shown in FIG.
12
.
When the rotation of the reference virtual line ML
2
that has been set in the holding members
55
to the position which is displaced from the virtual line ML
5
by an angle of θ1 is confirmed by the rotational angle detector
53
a
as shown in
FIG. 18
, a signal is emitted from the CPU
41
so as to stop the operation of each electric motor
53
. Thereafter, as shown in
FIG. 18
, the electric motor
31
is actuated, thereby causing the log
7
held by the centering spindles
29
to rotate such that the virtual line ML
3
passing through the prospective axial centers
7
c
and
7
d
of the opposite end faces
7
a
and
7
b
of log
7
is made parallel with the reference virtual line ML
2
.
By the way, the reference virtual line ML
2
that has been set in the holding members
55
at the occasion when the holder
57
is rotated to set in a state of stand-by in the region of centering spindle
29
is always a fixed position as in the cases of the above embodiments. Therefore, after the log
7
is caused to turn by means of the centering spindle
29
so as to determine, through processing, the positions of axial centers
7
c
and
7
d
of the opposite end faces
7
a
and
7
b
of the log
7
, the log
7
may be further rotated by means of the centering spindle
29
thereby to render the virtual line ML
3
passing through the prospective axial centers
7
c
and
7
d
to become parallel with the reference virtual line ML
2
.
Then, the first operating member
19
is actuated based on a signal from the CPU
41
so as to move the holding members
55
to hold the opposite end faces
7
a
and
7
b
of the log
7
as in the case of Embodiment 3. Thereafter, the centering spindles
29
are moved away from each other to release the chucking of the log
7
.
Thereafter, based upon the control data that have been obtained through the processing of the data of the positions of the axial centers of the end faces
7
a
and
7
b
of the log
7
, each electric motor
23
is actuated and at the same time, the magnitude of movement of the holding members
55
is detected by making use of the rotational angle detector
23
a
. By doing so, the holding member
55
are respectively moved in the radial direction of the shaft
51
, and at the same time, the prospective axial centers
7
c
and
7
d
of the opposite end faces of the log
7
which is held by the holding members
55
are positioned on the circular arc having its center at the R of the shaft
51
and passing through the rotational center P of the cutting spindle
9
(FIG.
19
).
Further, under this condition, the angle
6
formed between the virtual line ML
2
and the virtual line ML
6
passing through the axial centers
7
c
and
7
d
and the R is calculated by the CPU
41
.
Then, according to the signals from the CPU
41
, the electric motor
53
is actuated thereby to rotate the shaft
51
and also to turn the holder
57
in clock-wise.
When the rotation of the shaft
51
to an angle of α+θ3−β is detected from a signal form the rotational angle detector
53
a
, signal is emitted from the CPU
41
so as to stop the operation of each electric motor
53
, and hence, the rotation of the shaft
51
is also stopped. As a result, as shown in
FIG. 20
, the prospective axial centers
7
c
and
7
d
of the log
7
are aligned with the rotational center P of the cutting spindle
9
. Under this condition, the cutting spindle
9
is moved toward the axial center line thereof so as to chuck the log
7
.
In Embodiments 3 and 4, the reference virtual line ML
2
passing through the center of the holding member
55
is assumed as passing the rotational center R of the shaft
51
. However, it is also possible to assume a line which does not pass through the rotational center R of the shaft
51
as shown in
FIG. 21
, and hence to make the holding members
55
movable, in relative to the holder
57
, parallel with the reference virtual line ML
2
.
Namely, the holding members
55
may be controlled so as to make the reference virtual line ML
2
parallel or align with the virtual line ML
3
passing through the axial centers
7
c
and
7
d
. Thereafter, based upon the control data that have been obtained through the processing of the data of the positions of the axial centers of the end faces
7
a
and
7
b
of the log
7
, each electric motor
23
is actuated and at the same time, the magnitude of movement of the holding members
55
is detected by making use of the rotational angle detector
23
a
. By doing so, the holding member
55
are respectively moved in the radial direction of the shaft
51
, and at the same time, the prospective axial centers
7
c
and
7
d
of the opposite end faces of the log
7
are positioned on the circular arc having its center at the R of the shaft
51
and passing through the rotational center P of the cutting spindle
9
.
Then, the angle formed between the virtual line ML
4
and the virtual line passing through the axial centers
7
c
and the R is calculated by the CPU
41
. Then, the shaft
51
is rotated counterclock-wise by an angle calculated in this manner. Thereafter, the log is chucked by means of the cutting spindles
9
in the same manner as mentioned above.
By the way, there is known another type of veneer lathe which is constructed such that a back-up roll to be press-contacted with the circumferential surface of log for preventing the deflection of log during the peeling of the log, and a device for supporting and moving the back-up roll are interposed between the cutting spindle
9
and the centering spindle
29
of the apparatus of Embodiment 3 shown in
FIG. 14
for instance.
If the holder
57
is rotated from the position shown in
FIG. 16
to the position shown in
FIG. 17
in such a veneer lathe, the log
7
may be contacted with the back-up roll, etc.
Therefore, it may be required in such a veneer lathe that a device composed of the shaft
51
, the holding members
55
, the holders
57
, etc. for moving a log from the centering spindle
29
to the cutting spindle
9
is positioned at an upper portion of the apparatus shown in
FIG. 14
, i.e. at a portion which is far over the centering spindle
29
and cutting spindle
9
. It may be also required that the moving distance of the holding members
55
in the direction of the virtual line ML
2
in relative to the holder
57
is made sufficiently longer so as to make it possible for the holding members
55
to hold the log
7
being chucked by the centering spindle
29
, and at the same time, the log held by the holding members
55
can be fed to a predetermined portion of the cutting spindle
9
even if the aforementioned device is disposed at an upper portion of the apparatus.
This apparatus may be operated as follows. Namely, in the same manner as the apparatus of Embodiment 3 shown in
FIG. 15
, a log
7
which is being chucked using the centering spindle
29
under the condition where the virtual line ML
3
passing through the axial centers
7
a
and
7
b
is aligned with the center R of the shaft
51
is allowed to be held by the holding members
55
which is being sufficiently extended in the direction of the virtual line ML
2
in relative to the holder
57
. Then, after the centering spindles
29
are moved away from the log
7
, the holding members
55
are moved back in the direction of the virtual line ML
2
toward the center R of the shaft
51
and to such an extent that even if the shaft
51
is turned toward the cutting spindle
9
, the log
7
is prevented from being contacted with the back-up roll, etc. Then, the shaft
51
is continued to be rotated until the rotational center P of the cutting spindle
9
is aligned with the virtual line ML
2
of the holding members
55
. Upon finishing the rotation of the shaft
51
, the holding members
55
are extended in the direction of each virtual line ML
2
until the axial centers
7
c
and
7
d
of the log
7
are aligned with the aforementioned rotational center P. After the movement of each holding member
55
is stopped, the cutting spindles
9
are moved toward the log
7
so as to chuck the log
7
.
In the cases of Embodiments 1 and 2 also, after the log
7
is held by the holding members
21
with the virtual line ML
1
passing the axial centers
7
c
and
7
d
being orientated in the vertical direction, the holding members
21
are moved back in the direction of the virtual line VL
1
toward an upper portion of the apparatus to such an extent that even if the holder
17
is moved toward the cutting spindle
9
, the log
7
is prevented from being contacted with the back-up roll, etc. Then, the holder
17
is moved until the virtual line ML
1
is aligned with the rotational center P of the cutting spindle
9
. Upon finishing the movement of the holder
17
, the holding members
21
are extended in the direction of each virtual line VL
1
until the axial centers
7
c
and
7
d
of the log
7
are aligned with the aforementioned rotational center P. After the movement of each holding member
21
is stopped, the cutting spindles
9
are moved toward the log
7
so as to chuck the log
7
.
In Embodiments 1 to 4, although the log
7
is fed to the cutting spindle of a veneer lathe employed as a working machine, the log
7
may be fed to a working machine such as an apparatus provided with a cutter
59
as explained below.
Namely, the log
7
is often partially accompanied with radially projected portions which are protruded from the surface of the log
7
due to an influence of knots, so that if the log
7
is turned or cut as it is by means of a veneer lathe, the following problems are raised. Namely, in the turning of such a log, only the projected portions are turned by a cutter in the initial stage of turning. The veneer thus produced is useless due to an insufficiency in the orientation of fibers. This useless turning operation of veneer is required to be continued until the projected portions are completely cut off, thus deteriorating the productivity of veneer using a veneer lathe.
Therefore, such a log may be treated at first by a working machine provided with a cutter as shown in FIG.
22
. Namely, in the same manner as illustrated with reference to Embodiments 1 to 4, the log
7
is allowed to be chucked by a cutting spindle
9
in such a manner that the axial center
7
c
and
7
d
of the log
7
are aligned with the rotational center P of the cutting spindle
9
of the working machine. Then, the cutting spindle
9
is rotated in the direction indicated by the arrow and at the same time, reciprocatively moved in the radial direction of the log
7
while allowing the log
7
to rotate in the direction indicated by the allow, thereby cutting out the projected portions of the log
7
.
In this case, the reciprocative movement of the cutting spindle
9
in the radial direction of the log
7
may be performed manually by an operator, or may be automatically performed by a control signal to be transmitted from the control means on the basis of information to be derived from the employment of the log center detectors
37
as explained with reference to Embodiment 1.
If the log
7
which is preliminarily turned to remove the projected portions in this manner by a working machined provided with a cutter is then turned or cut by means of a veneer lathe, the time loss required for turning the useless veneer by making use of the veneer lathe can be minimized, thus making it possible to improve the productivity of veneer in the employment of a veneer lathe.
Therefore, it is possible according to the present invention to omit the conventional exclusive x-axis adjustor, to miniaturize the apparatus, and to simplify the structure of the apparatus, thus making it possible to save the manufacturing cost of the apparatus.
Claims
- 1. A log centering and feeding apparatus which is designed to be employed in combination with a working machine provided at least with a cutting spindle having an axial center in the direction of Z for chucking a log, said log centering and feeding apparatus being used for feeding the log to the cutting spindle under a condition where the centering of the log has been determined; said log centering and feeding apparatus comprising;a centering spindle disposed away from the cutting spindle by a predetermined distance in the direction of X and having an axial center in the same Z direction as that of said cutting spindle; log center detecting means for detecting the position of axial center of the log under a condition where the log is kept chucked by said centering spindle; a pair of log transporting members which are rendered movable in the direction of Z as well as in the direction of Y including a component orthogonally intersecting the direction of Z thereby enabling the log transporting members to receive the log from said centering spindle and to deliver the log to said cutting spindle; and control means for controlling the operation of each log transporting member; wherein said log transporting members are provided with a setting of reference virtual line in the direction of Y; and said control means comprises; means for forcing the centering spindle holding the log to rotate at least one revolution thereby enabling said log center detecting means to determine, through processing, each position of axial center which is assumed to constitute the axial centers at both end faces of the log; means for further rotating the centering spindle so as to make the direction of the virtual line passing through every positions of axial centers as viewed from the direction of Z agree or parallel with the reference virtual line that has been set in advance to the pair of the log transporting members; means for controlling said pair of log transporting members, after the log has been transferred from said centering spindle to said log transporting members while maintaining the directions of said virtual lines in agreement or parallel with each other, in such a manner that each center position of the log that has already been kept in place in the direction of X where the virtual line passing through said axial center of the log is made in agreement with the axial center line of said cutting spindle can be made in agreement with the direction of Z constituting the axial center line of said cutting spindle; and means for controlling said log transporting members in a manner to allow said log to be chucked from said log transporting members to said cutting spindle while the state of the log adjusted in the direction of Z is maintained, thereby making it possible to feed the log in an axially centered state thereof to the cutting spindle.
- 2. The log centering and feeding apparatus according to claim 1, wherein each of said pair of log transporting members comprise a holder which is movable in the direction of Z, and a holding member mounted on said holder and rendered movable in the direction of the reference virtual line in relative to said movable holder.
- 3. The log centering and feeding apparatus according to claim 2, wherein said reference virtual line of said pair of log transporting members is set on the basis of said holding member.
- 4. The log centering and feeding apparatus according to claim 2, wherein said pair of log transporting members are permitted to linearly and reciprocatively move in the direction of X.
- 5. The log centering and feeding apparatus according to claim 2, wherein said pair of log transporting members are permitted to rotate about a given point.
- 6. A log centering and feeding apparatus which is designed to be employed in combination with a working machine for turning a log while chucking the log by means of cutting spindles thereby to produce a veneer, said log centering and feeding apparatus comprising;a pair of centering spindles facing to each other, each being made rotatable at a place distanced away from the cutting spindles by a predetermined distance and movable in the direction of Z which is parallel with an axial center line of said cutting spindles; a plurality of log center detecting means for detecting the position of axial center of the log, said plurality of log center detecting means being disposed along the Z direction in relative to the log chucked by said centering spindle; a movable frame which is linearly and reciprocatively movable in the direction of X including a component of direction between a predetermined position of said cutting spindle or a position where a reference virtual line of holding members to be mentioned later passes through the axial center line of said butting spindle and a given position of said centering spindle; a pair of holding members which are mounted on said movable frame and rendered movable in the direction of Z in relative to said movable frame as well as in the direction of Y including a component orthogonally intersecting the direction of Z, said pair of holding members being assigned with a reference virtual line which is parallel with said Y direction; and control means for controlling the operation of each holding member; wherein said control means is designed to be operated such that; the centering spindle holding the log is caused to rotate at least one revolution thereby enabling said log center detecting means to determine, through processing, each position of axial center which is assumed to constitute the axial centers at both end faces of the log; the centering spindles are further rotated so as to make the virtual line passing through every positions of axial centers as viewed from the direction of Z parallel with the Y direction, and at the same time, a distance in the X direction between a waiting position of said movable frame and a virtual line passing through every positions of axial centers is calculated to obtain a value, on the basis of which said movable is moved until the reference virtual line of said holding members is rendered to agree with said virtual line passing through every positions of axial centers; said holding members are moved in the Z direction so as to render said holding members to come close to each other thereby to permit both end faces of said log to be held between said holding members, after which the chucking of said log by said centering spindles are released; said movable frame is moved in the X direction until the reference virtual line of said holding member is aligned with the axial center line of said cutting spindle, and said holding members are moved in the Y direction in relative to said movable frame during or after said movable frame is moved in the X direction, thereby enabling every positions of axial centers to become aligned with the rotational center of said cutting spindle; and said log is then allowed to be chucked by said cutting spindle.
- 7. A log centering and feeding apparatus which is designed to be employed in combination with a working machine for turning a log while chucking the log by means of cutting spindles thereby to produce a veneer, said log centering and feeding apparatus comprising;a pair of centering spindles facing to each other, each being made rotatable at a place distanced away from the cutting spindles by a predetermined distance and movable in the direction of Z which is parallel with an axial center line of said cutting spindles; a plurality of log center detecting means for detecting the position of axial center of the log, said plurality of log center detecting means being disposed along the Z direction in relative to the log chucked by said centering spindle; a movable frame which is linearly and reciprocatively movable in the direction of X including a component of direction between a given position of said cutting spindle and a predetermined position of said centering spindles or a position where a reference virtual line of holding members to be mentioned later displaced from the axial center line of said cutting spindle by a predetermined distance; a pair of holding members which are mounted on said movable frame and rendered movable in the direction of Z in relative to said movable frame as well as in the direction of Y including a component orthogonally intersecting the direction of Z, said pair of holding members being assigned with a reference virtual line which is parallel with said Y direction; and control means for controlling the operation of each holding member; wherein said control means is designed to be operated such that; the centering spindle holding the log is caused to rotate at least one revolution at the latest before the holding members of said movable frame which have been moved to a predetermined position in the vicinity of the centering spindle are permitted to hold both end faces of the log, thereby enabling said log center detecting means to determine, through processing, each position of axial center which is assumed to constitute the axial centers at both end faces of the log; the centering spindles are further rotated so as to make the virtual line passing through every positions of axial centers as viewed from the direction of Z parallel with the Y direction, and at the same time, a distance between a virtual line passing through every positions of axial centers which is parallel with the Y direction and the axial center line of the cutting spindle is calculated; said holding members are moved in the Z direction so as to permit both end faces of said log to be held between said holding members, after which the chucking of said log by said centering spindles are released; said movable frame is moved in the X direction until the reference virtual line of said holding member is moved to a distance that has been determined by the aforementioned processing, and said holding members are moved in the Y direction in relative to said movable frame during or after said movable frame is moved in the X direction, thereby enabling every positions of axial centers to become aligned with the rotational center of said cutting spindle; and said log is then allowed to be chucked by said cutting spindle.
- 8. A log centering and feeding apparatus which is designed to be employed in combination with a working machine for turning a log while chucking the log by means of cutting spindles thereby to produce a veneer, said log centering and feeding apparatus comprising;a pair of centering spindles facing to each other, each being made rotatable at a place distanced away from the cutting spindles by a predetermined distance and movable in the direction of Z which is parallel with an axial center line of said cutting spindles; a plurality of log center detecting means for detecting the position of axial center of the log, said plurality of log center detecting means being disposed along the Z direction in relative to the log chucked by said centering spindle; a rotatable frame which is rotatable about a given point; a pair of holding members which are mounted on said rotatable frame and rendered movable in the direction of Z in relative to said rotatable frame as well as in a predetermined radial direction from a rotational center of said rotatable frame, said pair of holding members being assigned with a reference virtual line in conformity with said radial direction; and control means for controlling the operation of each holding member; wherein said control means is designed to be operated such that; the centering spindle holding the log is caused to rotate at least one revolution thereby enabling said log center detecting means to determine, through processing, each position of axial center which is assumed to constitute the axial centers at both end faces of the log; the centering spindles are further rotated so as to align the virtual line passing through every positions of axial centers as viewed from the direction of Z with said rotational center; the rotatable frame is further rotated until the reference virtual line of said holding members is aligned with a virtual line passing through every positions of axial centers; said holding members are moved in the Z direction so as to render said holding members to come close to each other thereby to permit both end faces of said log to be held between said holding members, after which the chucking of said log by said centering spindles are released; said rotatable frame is rotated until the reference virtual line of said holding member is aligned with the axial center line of said cutting spindle, and said holding members are moved in said radial direction, thereby enabling every positions of axial centers to become aligned with the rotational center of said cutting spindle; and said log is then allowed to be chucked by said cutting spindle.
- 9. A log centering and feeding apparatus which is designed to be employed in combination with a working machine for turning a log while chucking the log by means of cutting spindles thereby to produce a veneer, said log centering and feeding apparatus comprising;a pair of centering spindles facing to each other, each being made rotatable at a place distanced away from the cutting spindles by a predetermined distance and movable in the direction of Z which is parallel with an axial center line of said cutting spindles; a plurality of log center detecting means for detecting the position of axial center of the log, said plurality of log center detecting means being disposed along the Z direction in relative to the log chucked by said centering spindle; a rotatable frame which is rotatable about a given point and in a range between a position where a reference virtual line of holding members to be mentioned later is inclined toward the centering spindle by a predetermined angle in relative to a first virtual line connecting a rotational center with the axial center line of said cutting spindle and a position where the reference virtual line is inclined at a desired angle toward the first virtual line from said predetermined angle; a pair of holding members which are mounted on said rotatable frame and rendered movable in the direction of Z in relative to said rotatable frame as well as in a predetermined radial direction from a rotational center of said rotatable frame, said pair of holding members being assigned with a reference virtual line in conformity with said radial direction; and control means for controlling the operation of each holding member; wherein said control means is designed to be operated such that; the centering spindle holding the log is caused to rotate at least one revolution at the latest before the holding members of said holder are moved toward each other so as to hold both end faces of the log after the rotatable frame is rotated to stand by at a position where the reference virtual line of the holding members is turned to a predetermined angle, thereby enabling said log center detecting means to determine, through processing, each position of axial center which is assumed to constitute the axial centers at both end faces of the log; the centering spindles are further rotated so as to render the virtual line passing through every positions of axial centers as viewed from the direction of Z to become parallel with the reference virtual line; further, a distance between a virtual line passing through every positions of axial centers and the reference virtual line is calculated; said holding members are then moved toward each other in the Z direction so as to permit both end faces of said log to be held between said holding members, after which the chucking of said log by said centering spindles are released; said rotatable frame is then moved toward said cutting spindle and at the same time, said holding members are moved in the radial direction, thereby enabling every positions of axial centers to become aligned with the rotational center of said cutting spindle; and said log is then allowed to be chucked by said cutting spindle.
- 10. The log centering and feeding apparatus according to any one of claims 1 to 9, wherein said working machine is a veneer lathe.
- 11. The log centering and feeding apparatus according to any one of claims 1 to 9, wherein said working machine is a log-cutting apparatus provided with a cutter.
- 12. A method of centering and feeding a log, which comprises the steps of:determining, through processing by making use of log center detecting means, each position of axial center which is assumed to constitute the axial centers at both end faces of the log by forcing the centering spindle to rotate at least one revolution while both ends of the log are kept chucked with a pair of centering spindles; further rotating the pair of centering spindles until the virtual line passing through the positions of axial centers as viewed from the direction of Z parallel with the axial center line of the centering spindle is aligned with a predetermined position in the direction of Y; moving a pair of holding members in the direction of Z and close to both end faces of the log thereby to hold the log with the holding members; moving said centering spindles away from each end face of the log; integrally moving said pair of holding members in the direction of X including a directional component extending from said centering spindle to a cutting spindle of a working machine for turning the log until the log is chucked by said cutting spindle; and moving said holding members respectively in the direction of Y thereby rendering each position of axial center at both end faces of the log to become in agreement with the rotational center of said cutting spindle.
- 13. The log centering and feeding apparatus according to claim 1, wherein said pair of log transporting members are permitted to linearly and reciprocatively move in the direction of X.
- 14. The log centering and feeding apparatus according to claim 13, wherein said working machine is a veneer lathe.
- 15. The log centering and feeding apparatus according to claim 13, wherein said working machine is a log-cutting apparatus provided with a cutter.
- 16. The log centering and feeding apparatus according to claim 1, wherein said pair of log transporting members are permitted to rotate about a given point.
- 17. The log centering and feeding apparatus according to claim 16, wherein said working machine is a veneer lathe.
- 18. The log centering and feeding apparatus according to claim 16, wherein said working machine is a log-cutting apparatus provided with a cutter.
Priority Claims (1)
Number |
Date |
Country |
Kind |
10-180845 |
Jun 1998 |
JP |
|
US Referenced Citations (4)