Information
-
Patent Grant
-
6308821
-
Patent Number
6,308,821
-
Date Filed
Friday, April 14, 200024 years ago
-
Date Issued
Tuesday, October 30, 200123 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
-
CPC
-
US Classifications
Field of Search
US
- 198 4689
- 198 7501
- 198 7507
- 414 7491
-
International Classifications
-
Abstract
A rail member and a rodless cylinder are arranged closely substantially in parallel to one another, and shock absorbers and the rail member are arranged closely substantially in parallel to one another. Accordingly, it is possible to arrange, in an ideal layout, the three components of the rail member, the rodless cylinder, and the shock absorbers. Further, it is possible to realize a compact size of the entire apparatus.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a linear working apparatus which functions, for example, as a workpiece transport means by operating a slider in a reciprocating manner.
2. Description of the Related Art
In recent years, a variety of linear working machines including, for example, rodless cylinders are adopted as workpiece transport means in the factory or the like. Such a linear working machine concerning the conventional technique is shown in
FIG. 9
(see Japanese Laid-Open Patent Publication No. 9-177717).
The linear working machine
1
includes a base plate
2
which has a flat plate-shaped configuration, a pair of end blocks
3
a
,
3
b
which are connected to both ends in the axial direction of the base plate
2
, and a rodless cylinder
4
which is fixed between the end blocks
3
a
,
3
b.
A guide rail
5
, which is disposed substantially in parallel to the axis of the rodless cylinder
4
, is fixed to the base plate
2
. A pair of shock absorbers
6
a
,
6
b
are arranged opposingly substantially in parallel to the axis of the rodless cylinder
4
between the guide rail
5
and the rodless cylinder
4
. A slide table
7
, which makes linear reciprocating movement along the guide rail
5
in accordance with the driving action of the rodless cylinder
4
, is provided on the base plate
2
.
However, in the case of the linear working machine
1
concerning the conventional technique described above, the pair of shock absorbers
6
a
,
6
b
are interposed between the rodless cylinder
4
and the guide rail
5
which are arranged substantially in parallel to one another. Therefore, a problem arises in that the distance of separation is inevitably increased between the rodless cylinder
4
and the guide rail
5
.
That is, when the kinetic energy (thrust force) is transmitted from the rodless cylinder
4
to the slide table
7
in order to start the movement of the slide table
7
, the reaction force is generated on the guide rail
5
on which the slide table
7
is displaced. The larger the separation distance between the rodless cylinder
4
and the guide rail
5
is, the more the reaction force is increased. In other words, the smaller the separation distance between the rodless cylinder
4
and the guide rail
5
is, the more the reaction force is repressed. Therefore, ideally, it is desirable that the rodless cylinder
4
and the guide rail
5
are arranged as closely to one another as possible.
When the shock absorber
6
a
,
6
b
absorbs the impact force at the terminal end of the displacement of the slide table
7
, the reaction force of the shock absorber
6
a
,
6
b
is applied to the guide rail
5
. The larger the separation distance between the shock absorbers
6
a
,
6
b
and the guide rail
5
is, the more the reaction force is increased. Therefore, in order to suppress the reaction force applied to the guide rail
5
, ideally, it is desirable that the shock absorbers
6
a
,
6
b
and the guide rail
5
are arranged as closely to one another as possible.
SUMMARY OF THE INVENTION
A general object of the present invention is to provide a linear working apparatus comprising three components of a driving mechanism, a track mechanism, and a buffering mechanism which are arranged in an ideal layout, making it possible to realize a compact size of the entire apparatus.
The above and other objects, features, and advantages of the present invention will become more apparent from the following description when taken in conjunction with the accompanying drawings in which a preferred embodiment of the present invention is shown by way of illustrative example.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
shows a perspective view illustrating a linear working apparatus according to an embodiment of the present invention;
FIG. 2
shows an exploded perspective view illustrating a base plate and a rodless cylinder for constructing the linear working apparatus;
FIG. 3
shows a plan view illustrating the linear working apparatus shown in
FIG. 1
;
FIG. 4
shows a cross-sectional view taken along a line IV—IV shown in
FIG. 1
;
FIG. 5
shows a perspective view illustrating a piston for constructing the rodless cylinder;
FIG. 6
shows, with partial omission, a magnified perspective view illustrating a shock absorber;
FIG. 7
shows, with partial omission, a longitudinal sectional view illustrating an engaging state of a first seal member and a slit;
FIG. 8
shows, with partial omission, a longitudinal sectional view taken along a line VIII—VIII shown in
FIG. 3
; and
FIG. 9
shows a perspective view illustrating a linear working machine concerning the conventional technique.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In
FIG. 1
, reference numeral
10
indicates a linear working apparatus according to an embodiment of the present invention.
The linear working apparatus
10
comprises a base plate (base member)
12
which has a flat plate-shaped configuration, a pair of end blocks
14
a
,
14
b
which are connected to both ends in the axial direction of the base plate
12
respectively, a linear guide mechanism (track mechanism)
16
which is secured in the axial direction to a substantially central portion of the base plate
12
, and a slider
20
which is formed with a substantially flat workpiece attachment surface
18
on its upper surface and which makes reciprocating movement in the axial direction of the base plate
12
along the linear guide mechanism
16
. The workpiece attachment surface
18
of the slider
20
may be used in any way including, for example, a case in which an unillustrated workpiece is directly attached thereto or placed thereon, and a case in which the workpiece is indirectly attached thereto or placed thereon by the aid of any member.
The linear working apparatus
10
further comprises a rodless cylinder (driving mechanism)
24
which is connected to a side portion of the base plate
12
by the aid of attachment mechanisms
22
and which is arranged substantially in parallel to the linear guide mechanism
16
, and a pair of shock absorbers (buffering mechanisms)
26
a
,
26
b
which are arranged opposingly on a side opposite to the rodless cylinder
24
with the linear guide mechanism
16
interposed therebetween. A sensor attachment long groove
28
having a rectangular cross section is formed in the axial direction on a side of the base plate
12
opposite to the side on which the rodless cylinder
24
is connected. The shock absorbers
26
a
,
26
b
function such that the terminal end of the displacement of the slider
20
is regulated, and the shock applied to the slider
20
is absorbed.
The linear guide mechanism
16
has a lengthy rail member
30
which is secured to an upper surface portion of the base plate
12
by the aid of screw members, and a pair of guide blocks (sliding members)
32
which are slidably displaceable along the rail member
30
in accordance with the rolling action of a plurality of unillustrated ball bearings. The slider
20
is secured to the upper surfaces of the pair of guide blocks
32
by the aid of screw members. The slider
20
is provided displaceably along the rail member
30
by the aid of the guide blocks
32
. A plurality of unillustrated roller members (rolling members) having a cylindrical configuration are provided rollably on a bottom surface portion of the slider
20
in place of the guide blocks
32
so that the slider
20
may be displaced along the rail member
30
in accordance with the rolling action of the roller members.
As shown in
FIG. 6
, the shock absorber
26
a
,
26
b
is fixed to the base plate
12
by the aid of a block member
34
. A screw member
38
for controlling the buffering force is provided through the end block
14
a
,
14
b
with a cutout
36
having a semielliptic cross section. In this arrangement, the pair of shock absorbers
26
a
,
26
b
are arranged opposingly by being separated from each other by a predetermined spacing distance, and they are arranged such that a phantom line obtained by connecting the pair of shock absorbers
26
a
,
26
b
is substantially parallel to the axis of the rail member
30
. The pair of shock absorbers
26
a
,
26
b
are arranged as closely as possible with respect to the rail member
30
.
As shown in
FIG. 2
, the attachment mechanism
22
for detachably connecting the base plate
12
and the rodless cylinder
24
is provided at the connecting portion between the end block
14
a
,
14
b
and the rodless cylinder
24
. The attachment mechanism
22
includes a recess
40
which is formed on the end block
14
a
,
14
b
, a projection
44
which is provided on an end cap
42
a
,
42
b
of the rodless cylinder
24
and which is connected to the recess
40
, and screw members
46
for fastening the projection
44
to the recess
40
by means of screws. In this arrangement, the screw members
46
are provided so that they may be screwed in a direction substantially perpendicular to the workpiece attachment surface
18
of the slider
20
(from an upward position).
A positioning mechanism
48
is provided at the connecting portion between the end block
14
a
(
14
b
) and the rodless cylinder
24
. The positioning mechanism
48
includes a small hole
50
which is formed on one side surface of the end block
14
a
(
14
b
), and a projection
52
which protrudes outwardly from the end cap
42
a
(
42
b
) of the rodless cylinder
24
. In this arrangement, the base plate
12
and the rodless cylinder
24
are connected in a positioned state by inserting the projection
52
into the small hole
50
.
A pair of end plates
54
a
,
54
b
, which extend in a direction substantially perpendicular to the axis, are connected to both ends of the slider
20
. The end plate
54
a
,
54
b
has an engaging section
58
which protrudes laterally from the end surface of the slider
20
for making engagement with a piston yoke
56
a
,
56
b
(see
FIG. 5
) as described later on, and a substantially flat abutment surface
60
for making abutment against the shock absorber
26
a
,
26
b.
As shown in
FIG. 8
, the rodless cylinder
24
has a cylinder tube
64
with a slit
62
which is formed at an end surface portion, the slit
62
extending in the axial direction. A bore
66
, which extends in the longitudinal direction, is provided at the inside of the cylinder tube
64
. The bore
66
is in a state of communication with the outside via the slit
62
which is formed at the end surface portion of the cylinder tube
64
.
Both ends of the cylinder tube
64
are closed in an air-tight manner by the rectangular parallelepiped-shaped end caps
42
a
,
42
b
(see
FIG. 1
) which are formed with a pair of pressure fluid inlet/outlet ports
68
respectively. Step sections
70
a
,
70
b
, which are expanded toward the bore
66
, are provided on side walls for forming the slit
62
(see FIG.
7
).
FIG. 5
shows a piston
72
. The piston
72
has a main piston body
74
having a substantially cylindrical configuration. A first pressure-receiving surface
76
is formed at one end of the main piston body
74
in the axial direction, and a second pressure-receiving surface
78
is formed on a side opposite thereto. A cushion seal
80
is provided at the inside thereof. A pair of belt separators
86
for separating a first seal member
82
from a second seal member
84
as described later on are arranged opposingly in the axial direction on the cylindrical main piston body
74
. A parallel pin
88
, which slidably contacts with the second seal member
84
, is provided at a central portion between the pair of belt separators
86
.
The main piston body
74
has the pair of piston yokes (displacement members)
56
a
,
56
b
which are formed in an integrated manner in the axial direction. The piston yokes
56
a
,
56
b
are provided so that they are engaged with the engaging sections
58
of the pair of end plates
54
a
,
54
b
of the slider
20
. As shown in
FIG. 4
, a flat plate-shaped top cover
90
is installed to the pair of piston yokes
56
a
,
56
b
. A pair of end covers
92
, which extend in a direction substantially perpendicular to the axis, are installed to both ends of the piston yokes
56
a
,
56
b
respectively. A scraper
94
is held via a groove on one narrow side surface of the end cover
92
. The scraper
94
slidably contacts with the second seal member
84
, and thus any dust or the like is removed.
As shown in
FIG. 8
, recesses, which extend in the axial direction, are formed on side surface portions in the lateral direction of the pair of piston yokes
56
a
,
56
b
. A pair of lengthy bearing members
96
, which are made of a resin material and which slidably contact with the side surface of the cylinder tube
64
to support the piston
72
, are installed to the recesses. The provision of the bearing members
96
makes it possible to avoid rotation of the piston
72
and avoid any contact between the piston yokes
56
a
,
56
b
and the cylinder tube
64
.
In
FIG. 4
, reference numeral
98
indicates a passage for the first seal member
82
to enter the inside of the piston
72
, and reference numeral
100
indicates cushion rings connected to the end caps
42
a
,
42
b.
FIG. 7
shows the seal member for being fitted to the step sections
70
a
,
70
b
which are formed at the slit
62
of the cylinder tube
64
. The first seal member
82
has tongues
102
a
,
102
b
, and it further includes expanded sections
104
a
,
104
b
which are disposed in the lateral direction of the tongues
102
a
,
102
b
. Engaging tabs
106
a
,
106
b
extend laterally from the expanded sections
104
a
,
104
b
to make slight expansion. The expanded sections
104
a
,
104
b
are provided in order that they make engagement with the step sections
70
a
,
70
b
when the internal pressure is applied to the piston
72
. The engaging tabs
106
a
,
106
b
are engaged with inner surfaces
108
a
,
108
b
for forming the slit
62
. The first seal member
82
is made of a flexible synthetic resin material in an integrated manner as a whole.
On the other hand, the second seal member
84
is provided in order to close the slit
62
. The second seal member
84
is engaged with a groove
110
which extends in the longitudinal direction on the side surface of the cylinder tube
64
. The first seal member
82
enters the inside of the passage
98
of the piston
72
, and it has both ends which are secured to the end caps
42
a
,
42
b
together with the second seal member
84
.
The linear working apparatus
10
according to the embodiment of the present invention is basically constructed as described above. Next, its operation, function, and effect will be explained.
When the compressed air is introduced from the first pressure fluid inlet/outlet port
68
formed on the end cap
42
, then the compressed air passes through the passage formed at the inside of the cushion ring
100
, and it presses the first pressure-receiving surface
76
. The piston
72
is displaced rightwardly (in the direction of the arrow X) as viewed in
FIG. 4
in accordance with the pressing action of the compressed air. During this process, the piston
72
is displaced integrally with the pair of piston yokes
56
a
,
56
b
. The belt separator
86
functions to separate the first seal member
82
from the second seal member
84
when the piston yokes
56
a
,
56
b
are displaced.
When the piston yokes
56
a
,
56
b
are displaced in the longitudinal direction of the cylinder tube
64
, the slider
20
is displaced integrally with the piston yokes
56
a
,
56
b
in accordance with the guiding action of the rail member
30
by the aid of the pair of end plates
54
a
,
54
b
which are substantially engaged with the piston yokes
56
a
,
56
b.
The pin of the shock absorber
26
a
(
26
b
) abuts against the abutment surface
60
formed on the end plate
54
a
(
54
b
) of the slider
20
to arrive at the displacement terminal position thereby. During this process, the shock generated upon the abutment is absorbed in accordance with the buffering action of the shock absorber
26
a
,
26
b.
On the other hand, when the compressed air is introduced into the second pressure fluid inlet/outlet port
68
formed on the end cap
42
a
, the operation is performed in a way opposite to the above.
In the embodiment of the present invention, the rodless cylinder
24
is arranged closely substantially in parallel to the axis of the rail member
30
with the rail member
30
disposed therebetween. The pair of shock absorbers
26
a
,
26
b
are arranged closely to be substantially parallel to the axis of the rail member
30
on the side opposite to the rodless cylinder
24
. In other words, with reference to the rail member
30
disposed substantially centrally, the rodless cylinder
24
and the shock absorbers
26
a
,
26
b
are arranged closely to be substantially parallel to one another on the both sides thereof.
Therefore, owing to the arrangement in which the rail member
30
and the rodless cylinder
24
are arranged closely substantially in parallel to one another, and the shock absorbers
26
a
,
26
b
and the rail member
30
are arranged closely substantially in parallel to one another, it is possible to arrange, in the ideal layout, the three components of the rail member
30
which functions as the track mechanism, the rodless cylinder
24
which functions as the driving mechanism, and the shock absorbers
26
a
,
26
b
which function as the buffering mechanism. Further, it is possible to realize a compact size of the entire apparatus. As a result, the load on the rail member
30
can be reduced and mitigated by suppressing the reaction force generated, for example, when the operation of the slider
20
is started.
In the embodiment of the present invention, the rodless cylinder
24
and the base plate
12
provided with the rail member
30
and the shock absorbers
26
a
,
26
b
are provided detachably by the aid of the attachment mechanism
22
. Accordingly, it is easy to exchange the driving mechanism. Further, it is possible to increase the degree of freedom of selection of the driving mechanism, and it is possible to improve the versatile property. In this arrangement, the screw member
46
, which is used to connect the base plate
12
and the rodless cylinder
24
, can be screwed from the upward position in the direction perpendicular to the workpiece attachment surface
18
of the slider
20
. Accordingly, the apparatus is advantageous in that the attachment and the detachment can be conveniently performed with ease.
The driving force of the rodless cylinder
24
can be transmitted to the slider
20
by allowing the piston yokes
56
a
,
56
b
to make the engagement between the engaging sections
58
of the pair of end plates
54
a
,
54
b
. Therefore, the driving force can be smoothly transmitted by using the simple arrangement. In this case, a predetermined clearance (not shown) is provided between the piston yoke
56
a
(
56
b
) and the engaging section
58
of the end plate
54
a
(
54
b
). The floating function to permit the displacement of the piston yoke
56
a
(
56
b
) is effected by the aid of the clearance.
The abutment surface
60
for making the abutment against the pin of the shock absorber
26
a
(
26
b
) is simultaneously provided on the end plate
54
a
(
54
b
) in addition to the engaging section
58
for making the engagement with the piston yoke
56
a
(
56
b
). Accordingly, it is possible to reduce the number of parts.
The embodiment of the present invention has been explained based on the use of the rodless cylinder
24
in which the piston
72
is displaced in accordance with the action of the pressure fluid as the driving mechanism. However, there is no limitation thereto. It is a matter of course that other driving mechanisms are usable, including, for example, a magnet type rodless cylinder in which an external movable member is displaced in accordance with the action of a magnet, a linear actuator which includes a fluid pressure-operated cylinder, and an electric actuator in which an external movable member is displaced in accordance with the transmission of a rotary driving force of a rotary driving source.
Claims
- 1. A linear working apparatus comprising:a base member; a linear track mechanism secured to said base member in its axial direction; a slider for making reciprocating movement along said track mechanism; a driving mechanism arranged substantially in parallel to said axis of said track mechanism, for transmitting rectilinear motion to said slider; and a buffering mechanism arranged on a side opposite to said driving mechanism with said track mechanism interposed therebetween, for regulating a displacement terminal end of said slider and absorbing shock applied to said slider.
- 2. The linear working apparatus according to claim 1, wherein said driving mechanism is provided detachably with respect to said base member by the aid of an attachment mechanism.
- 3. The linear working apparatus according to claim 1, wherein said slider is provided with a pair of end plates for making engagement with displacement members of said driving mechanism for transmitting said rectilinear motion, and said end plate is formed with an abutment surface for making abutment against said buffering mechanism.
- 4. The linear working apparatus according to claim 2, wherein said attachment mechanism includes a screw member for connecting said base member and said driving mechanism, and said screw member is capable of being screwed in a direction substantially perpendicular to a workpiece attachment surface of said slider.
- 5. The linear working apparatus according to claim 2, wherein a positioning mechanism for connecting said base member and said driving mechanism in a positioned state is provided at a connecting portion between said base member and said driving mechanism.
- 6. The linear working apparatus according to claim 1, wherein said driving mechanism is composed any one of a fluid pressure-operated rodless cylinder in which a piston is displaced in accordance with an action of a pressure fluid, a magnet type rodless cylinder in which an external movable member is displaced in accordance with an action of a magnet, a linear actuator, and an electric actuator.
- 7. The linear working apparatus according to claim 1, wherein said track mechanism is composed of a linear guide mechanism, and said linear guide mechanism includes a lengthy rail member and a rolling member or a sliding member for making displacement along said rail member.
- 8. The linear working apparatus according to claim 1, wherein said buffering mechanism is composed of a plurality of shock absorbers, and said shock absorbers are arranged substantially in parallel to said axis of said track mechanism at ends of said base member.
- 9. The linear working apparatus according to claim 3, wherein a predetermined clearance is provided between said end plate and said displacement member, and a floating function to permit displacement of said displacement member is effected by the aid of said clearance.
- 10. The linear working apparatus according to claim 5, wherein said positioning mechanism includes a small hole formed on one side surface of an end block connected to an end of said base member, and a projection protruding from an end cap of said driving mechanism, for being inserted into said small hole.
Priority Claims (1)
Number |
Date |
Country |
Kind |
11-110158 |
Apr 1999 |
JP |
|
US Referenced Citations (3)
Number |
Name |
Date |
Kind |
5211279 |
Abbestam et al. |
May 1993 |
|
5469775 |
Stoll et al. |
Nov 1995 |
|
5484051 |
Nagai et al. |
Jan 1996 |
|
Foreign Referenced Citations (3)
Number |
Date |
Country |
41 37 789 |
May 1993 |
DE |
0 346 504 |
Dec 1989 |
EP |
09-177717 |
Jul 1997 |
JP |