Information
-
Patent Grant
-
6808086
-
Patent Number
6,808,086
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Date Filed
Thursday, September 25, 200320 years ago
-
Date Issued
Tuesday, October 26, 200419 years ago
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Inventors
-
Original Assignees
-
Examiners
Agents
-
CPC
-
US Classifications
Field of Search
US
- 417 269
- 417 470
- 417 510
- 417 512
- 091 499
- 222 136
- 222 137
- 222 138
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International Classifications
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Abstract
In a seal mechanism which constitutes a port switching portion in a pump mechanism of a paste ejection apparatus that ejects paste, and which prevents leakage of the paste from a seal portion between a plunger block rotating with a plunger and a fixed seal block (between a seal surface and a sliding surface), a housing portion is formed by opposing an outer surface provided for the seal block to an inner surface extending axially from the cylinder block, and a ring-shaped external seal member formed by combination of an O-ring and self-lubricant material such as PTFE is attached into the housing portion. Hereby, it is possible to prevent the paste that has leaked from the seal portion from leaking to the outside of the housing portion by the external seal member.
Description
BACKGROUND OF THE INVENTION
The present invention relates to a paste ejection apparatus for ejecting slurry-like paste in which a viscous substance and a filler component are mixed, such as conductive paste.
As a method of joining electronic parts such as a semi-conductive chip to a print board or a lead frame, a resin adhesive is used much. As a kind of resin adhesive, conductive paste has been known, in which a conductive component such as metal powder is added in the resin thereby to apply conductivity to the joint. Since the conductive paste has a function of the adhesive, and also can cause the joint to conduct electrically, it is much used in order to secure a semi-conductive element onto the board and cause the semi-conductive element to conduct to an electrode of the board.
This conductive paste is obtained by mixing a main component as a resin adhesive such as epoxy resin, curing agent for curing the epoxy resin, or cure accelerator, with metal powder having conductivity. As the metal powder, silver powder is much used. The conductive paste is supplied in the shape of slurry in which silver powder having each kind of shape in order to improve the conductivity, for example, a grain-shaped silver powder or flake-shaped silver powder, is mixed with the resin adhesive.
For an applying apparatus of applying this conductive paste, an ejection apparatus for ejecting the conductive paste is provided. A plunger type ejection apparatus has been known, which sucks the conductive paste into a cylinder room and ejects it by a reciprocating movement of a plunger. Since the ejection by the reciprocating of the plunger is performed only intermittently, in case that it is necessary to perform paste applying of high efficiency by performing the ejection incessantly, a multi-plunger type paste apparatus having plural plungers is generally used, for example disclosed in JP-U-02-078773 (Japanese Utility Model Application Publication Number: Hei02-078773).
For such the multi-plunger type paste ejection apparatus, it is necessary to eject the paste ejected from the respective plungers in order from one fixed ejection port. Therefore, its ejection apparatus has aport switching function. Regarding this port switching, generally, an opening surface of a cylinder block for which a plunger hole is provided is brought into slide-contact with a fixed block for which an ejection port is provided, and the opening portion of each plunger is communicated with the ejection port in order. In this type, the slide-contacting surface between the opening surface of the cylinder block and the fixed block function as a seal portion for preventing the paste from leaking between the two members. Therefore, such paste leakage preventing measures are adopted that surface-finishing of high accuracy for this slide-contact surface in parts working in order to prevent occurrence of clearance, and use of a mechanism which applies the predetermined surface pressure at the operation time.
However, since the conductive paste is the slurry including a large amount of filler components such as silver powder and solid particles, in the conventional paste ejection apparatus, depending on constituent parts, the solid particles interposed between the slide clearance of the seal portion are easy to be attached onto the sliding surface, so that closeness of the sliding surface is hindered and it is not prevented that the paste leaks from the seal portion to the outside.
In addition, in such the paste ejection apparatus, the slurry-like liquid that is high in viscous and includes the metal powder is ejected. Therefore, since leakage of the liquid inside the ejection mechanism causes a bad operation and parts wear, the plunger sliding portion and the port switching portion require high sealing ability. However, generally to secure the high sealing ability increases sliding resistance of the plunger. Therefore, a load onto the drive mechanism which reciprocates the plunger increases, so that a large-sized drive mechanism is required. As described above, it was difficult to realize a compact paste ejection apparatus which secures the high sealing ability.
SUMMARY OF THE INVENTION
Therefore, an object of the invention is to provide a paste ejection apparatus which can prevent the paste from excessively leaking from the seal portion.
Furthermore, another object of the invention is to provide a small-sized and compact paste ejection apparatus which can secure the high sealing ability.
In accordance with the invention, there is provided a paste ejection apparatus for ejecting slurry-like paste in which a viscous substance and a filler component are mixed, comprising: a cylinder block being rotatable about a rotational axis by a rotation drive means, and contacting slidably with a seal surface of a seal member through a slide surface orthogonal to the rotational axis; plural cylinder holes provided in the direction of the rotational axis of the cylinder block and including opening portions formed at equal intervals on the same circumference of a circle having the rotational axis of the slide surface as a center; a plunger inserted into each cylinder hole; a plunger drive means reciprocating this plunger in synchronization with the rotation of said cylinder block; first and second communicating ports provided on the seal surface and communicating with the opening portions of the cylinder holes in the predetermined rotary position of the cylinder block; first and second external ports communicating respectively with the first and second communicating ports through the seal member; a housing portion located on the peripheral side of the seal surface, closed and surrounded by the seal member and the cylinder block to be a circular ring-shaped space; and a ring-shaped external seal member attached into the housing portion, including a first seal material having self-lubrication and a second seal material being rich in elasticity.
Furthermore, in the paste ejection apparatus according to the invention, the housing portion is formed by opposing an outer surface of the seal member to an inner surface extending axially from the cylinder block.
Furthermore, in the paste ejection apparatus according to the invention, the second seal material of the external seal member is fitted onto the outer surface of the seal member, and the first seal member of the external seal member slidably contacts with the inner surface of the cylinder block.
In another aspect of the invention, the housing portion is formed by opposing an inner surface extending axially from the seal member to an outer surface of cylinder block.
Furthermore, in the paste ejection apparatus according to the invention of the above aspect, the first seal member of the external seal member slidably contacts with the outer surface of the cylinder block, and the second seal material of the external seal member is fitted onto the inner surface of the seal member.
Preferably, the first seal member has a recess portion, and the second seal member is held by the recess portion of the first seal member.
In another aspect of the invention, the paste ejection apparatus comprises cylinder block being rotatable about a rotational axis by a rotation drive means, and contacting slidably with a seal surface of a seal member through a slide surface orthogonal to the rotational axis; plural cylinder holes provided in the direction of the rotational axis of the cylinder block and including opening portions formed at equal intervals on the same circumference of a circle having the rotational axis of the slide surface as a center; a plunger inserted into each cylinder hole; a plunger drive means reciprocating this plunger in synchronization with the rotation of said cylinder block; first and second communicating ports provided on the seal surface and communicating with the opening portions of the cylinder holes in the predetermined rotary position of the cylinder block; first and second external ports communicating respectively with the first and second communicating ports through the seal member; a housing portion located on the peripheral side of the seal surface, closed and surrounded by the seal member and the cylinder block to be a circular ring-shaped space; a ring-shaped external seal member attached into this housing portion; and a run-out constraining means for constraining run-out displacement in the diameter direction of the cylinder block near the external seal portion slidably contacts with the cylinder block.
Preferably, the housing portion is formed by opposing an outer surface of the seal member to an inner surface extending axially from said cylinder block; the inner surface side of the external seal member is fitted onto the outer surface of the seal member; and the outer surface side of the external seal member slidably contacts with the inner surface of the cylinder block.
In another aspect of the invention, the paste ejection apparatus for ejecting slurry-like paste in which a viscous substance and a filler component are mixed, comprises: a cylinder block being rotatable about a rotational axis by a rotation drive means, and contacting slidably with a seal surface of a seal member through a slide surface orthogonal to the rotational axis; plural cylinder holes provided in the direction of the rotational axis of the cylinder block and including opening portions formed at equal intervals on the same circumference of a circle having the rotational axis of the slide surface as a center; a plunger inserted into each cylinder hole; a plunger drive means reciprocating this plunger in synchronization with the rotation of said cylinder block; first and second communicating ports provided on the seal surface and communicating with the opening portions of the cylinder holes in the predetermined rotary position of the cylinder block; and first and second external ports communicating respectively with the first and second communicating ports through the seal member; furthermore the plunger drive means includes; a cam portion provided on the rotation drive means side of the cylinder block, and having cylindrical recess portions formed so that the drive end sides of the plural plungers can enter therein; a cam groove formed on the inner surface of said cylindrical recess portion and converting the relative rotating movement for the cam portion of said cylinder block into the reciprocating movement of the plunger in the direction of the rotational axis; and a cam follower coupled to the drive end side of each of the plural plungers, and rotating and moving into the cam groove thereby to transmit the reciprocating movement to the plunger.
Furthermore, the cam portion is constituted by combining two end cams each having a cam surface in the direction of the rotational axis in a state where the cam surfaces are opposed to each other.
According to the invention, on the peripheral side of the seal surface between the fixed seal member and the rotating cylinder block, the housing portion which is circular ring-shaped space closed and surrounded by the seal member and the cylinder block is provided, and the nearly ring-shaped external seal member comprising the self-lubricant material and the material that is rich in elasticity is attached into this housing portion, whereby it is possible to prevent the paste which has leaked from the seal surface from leaking to the outside of the housing by the external seal member.
Further, according to the invention, such the constitution is adopted that on the peripheral side of the seal surface between the fixed seal member and the rotating cylinder block, the housing portion which is circular ring-shaped space closed and surrounded by the seal member and the cylinder block is provided, the nearly ring-shaped external seal member is attached into this housing portion, and the run-out displacement is constrained in the diameter direction of this cylinder block near this external seal portion, whereby sealing ability when the paste that has leaked from the seal surface is prevented from leaking to the outside of the housing by the external seal member is improved, and wear of the external seal member can be reduced.
Further, according to the invention, as the plunger drive means for reciprocating the plural plungers, there are the cam portion which has therein cylindrical recess portions which the drive end sides of the plural plungers can enter; the cam groove for converting the rotating movement into the reciprocating displacement in the direction of the rotational axis, which is formed on the inner surface of the cylindrical recess portion; and the cam follower rotating and moving into this cam groove, which is coupled to the drive end side of the plunger, where by under the high sliding resistance condition, in either case of the going movement and the returning movement of the plunger, the drive power can be surely transmitted, high sealing ability is secured, and the dimension in the diameter direction can be reduced, so that a small and compact paste ejection apparatus is realized.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1
is a perspective view of a die bonding apparatus according to a first embodiment of the invention;
FIG. 2
is a sectional view of a paste ejection apparatus according to the first embodiment of the invention;
FIG. 3
is a perspective view of a plunger disc of the paste ejection apparatus according to the first embodiment of the invention;
FIG. 4
is a perspective view of a seal disc of the paste ejection apparatus according to the first embodiment of the invention;
FIG. 5
is a diagram for explaining the shape of an external seal of the paste ejection apparatus according to the first embodiment of the invention;
FIG. 6
is a diagram for explaining the attachment state of the external seal of the paste ejection apparatus according to the first embodiment of the invention;
FIG. 7
is a diagram for explaining an operation of the paste ejection apparatus according to the first embodiment of the invention;
FIG. 8
is a sectional view of a paste ejection apparatus according to a second embodiment of the invention;
FIG. 9
is a perspective view of a plunger disc of the paste ejection apparatus according to the second embodiment of the invention;
FIG. 10
is a perspective view of a seal disc of the paste ejection apparatus according to the second embodiment of the invention;
FIG. 11
is a diagram for explaining the shape of an external seal of the paste ejection apparatus according to the second embodiment of the invention;
FIG. 12
is a diagram for explaining the attachment state of the external seal of the paste ejection apparatus according to the second embodiment of the invention;
FIG. 13
is a sectional view of a paste ejection apparatus according to a third embodiment of the invention;
FIG. 14
is a perspective view of a cam portion of the paste ejection apparatus according to the third embodiment of the invention;
FIG. 15
is a sectional view of the cam portion of the paste ejection apparatus according to the third embodiment of the invention;
FIG. 16
is a perspective view of a plunger disc of the paste ejection apparatus according to the third embodiment of the invention;
FIG. 17
is a perspective view of a seal disc of the paste ejection apparatus according to the third embodiment of the invention;
FIG. 18
is a diagram for explaining the attachment state of an external seal of the paste ejection apparatus according to the third embodiment of the invention; and
FIG. 19
is a diagram for explaining an operation of the paste ejection apparatus according to the third embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
First Embodiment
FIG. 1
is a perspective view of a die bonding apparatus according to a first embodiment of the invention,
FIG. 2
is a sectional view of a paste ejection apparatus according to the first embodiment of the invention,
FIG. 3
is a perspective view of a plunger disc of the paste ejection apparatus according to the first embodiment of the invention,
FIG. 4
is a perspective view of a seal disc of the paste ejection apparatus according to the first embodiment of the invention,
FIG. 5
is a diagram for explaining the shape of an external seal of the paste ejection apparatus according to the first embodiment of the invention,
FIG. 6
is a diagram for explaining the attachment state of the external seal of the paste ejection apparatus according to the first embodiment of the invention, and
FIG. 7
is a diagram for explaining an operation of the paste ejection apparatus according to the first embodiment of the invention.
Referring first to
FIG. 1
, the structure of the die bonding apparatus will be described. In
FIG. 1
, on a chip supply portion
1
, a wafer sheet
2
is held by a not shown holding table. To the wafer sheet
2
, many chips
3
that are semi-conductive elements are bonded. To a side of the chip supply portion
1
, a transporting path
5
is arranged, which transports a lead frame
6
that is a substrate, and positions the lead frame
6
in a paste applying position and a bonding position. Above the chip supply portion
1
, a bonding head
4
is arranged, which moves horizontally and vertically by a not shown moving mechanism.
On a side of the transporting path
5
, a paste applying portion
9
is arranged. The paste applying portion
9
is so constituted that an applying nozzle
18
is attached to a moving table
10
through an L-shaped bracket
15
. The applying nozzle
18
is coupled to a paste ejection apparatus
16
secured onto a fixed plate
16
a
by a tube
17
made of flexible material.
The paste ejection apparatus
16
is further coupled to a syringe
19
through a tube
20
. Into the syringe
19
, conductive paste (hereinafter simply referred to as paste) in which a viscous substance such as epoxy resin and a conductive filler component such as silver powder are mixed is stored. By driving the paste ejection apparatus
16
, the paste into the syringe
19
is sucked and ejected by the paste ejection apparatus
16
, and press-fed through the tube
17
to the applying nozzle
18
. Next, the paste is ejected from an applying port provided for a lower end portion of the applying nozzle
18
and applied into an applying area
6
a
of the lead frame
6
.
The moving table
10
comprises a Y-axis table
11
, an X-axis table
12
placed on the Y-axis table
11
, a Z-axis table
14
vertically coupled onto the X-axis table
12
through an L-shaped bracket
13
. The Y-axis table
11
, the X-axis table
12
, and the Z-axis table
14
have respectively a Y-axis motor
11
a
, an X-axis motor
12
a
, and a Z-axis motor
14
a
. By driving the X-axis motor
12
a
, the Y-axis motor
11
a
, and the Z-axis motor
14
a
, the applying nozzle
18
moves on the lead frame
6
horizontally and vertically. Accordingly, the moving table
10
is a moving means for moving the applying nozzle
18
in relation to the lead frame
6
.
A mounting position of the chip
3
on the upper surface of the lead frame
6
is the applying area
6
a
into which the paste
7
is applied. The applying nozzle
18
is located into the applying area
6
a
, and the applying nozzle
18
is moved while the paste
7
is being ejected from the applying nozzle
18
, whereby the paste
7
for chip bonding is drawn and applied into the applying area
6
a
at a predetermined drawn pattern.
After this paste applying, the lead frame
6
is fed in a bonding position on the transporting path
5
and positioned. Next, on the paste
7
applied into the applying area
6
a
, the chip
3
picked up from the chip supplying portion
1
by a nozzle
4
a
of the bonding head
4
is bonded.
Referring next to
FIG. 2
, the structure of the paste ejection apparatus
16
will be described.
In
FIG. 2
, the paste ejection apparatus
16
is constituted so that a shaft type multi-plunger pump which is driven by a motor
22
used as a rotation drive means is included in an outer cylinder portion
21
. To a rotary shaft
23
of the motor
22
, a cylindrical rotator
28
is coupled. The rotator
28
is supported by a bearing
29
rotatably, and to an inner diameter portion
28
a
of the rotator
28
, a plunger holder
31
is attached. The plunger holder
31
is permitted to slide in a direction of an rotational axis in relation to the rotator
28
, and receives the rotation from the rotator
28
.
To a leading end of the plunger holder
31
, a plunger disc
32
is secured. The plunger holder
31
and the plunger disc
32
have respectively plural cylinder holes
31
b
and
32
b
, and each cylinder hole
31
b
and each cylinder hole
32
communicate with each other in the direction of the rotational axis. Into the cylinder holes
31
b
and
32
b
, plungers
26
are inserted. The plunger holder
31
and the plunger disc
32
constitute a cylinder block in which the plural cylinder holes are formed.
The upper end of each plunger
26
becomes a coupling end
26
b
which protrudes upward through an opening
28
provided for a base portion of the rotator
28
, and the plunger
26
is energized upward by a spring
27
attached between a flange portion
26
a
and the plunger holder
31
. To the coupling end
26
b
, a cam follower
25
is attached, and comes into contact with a cylindrical cam
24
secured to the outer cylinder portion
21
.
The rotator
28
is rotation-driven by the motor
22
, whereby the plunger holder
31
and the plunger disc
32
rotate, and the plunger
26
rotates together with the plunger holder
31
and the plunger disc
32
about the rotational axis. With this rotation, each plunger
26
reciprocates axially in accordance with the cam shape of the cylindrical cam
24
in synchronization with the rotation of the plunger holder
31
and plunger disc
32
. The motor
22
and the cylindrical cam
24
become a plunger drive means which reciprocates the plunger
26
in synchronization with the rotation of the cylinder block. The cam shape of the cylindrical cam
24
is such a shape that three plungers
26
are reciprocated in the predetermined order and at the predetermined timing, whereby suction and ejection of paste, which will be described later, are performed continuously.
Referring to
FIG. 3
, the plunger disc
32
will be described. The plunger disc
32
is made of hard ceramic such as alumina or hard material such as cemented carbide, and is provided with a cylindrical portion
32
d
extending axially from the outer edge portion of the disc body. For the disc body, the plural cylinder holes
32
b
are provided in the direction of the rotational axis. The upper surface of the disc body becomes a slide surface
32
a
orthogonal to the rotational axis, and the slide surface
32
a
comes into slide-contact with a seal surface
33
a
of a seal disc
33
that is a seal member secured to the outer cylinder portion
21
. The cylinder holes
32
b
open at equal intervals on the same circumference of a circle having the rotational axis of the slide surface
32
a
as a center. With an inner surface
32
e
of the cylindrical portion
32
d
, a periphery slide portion
36
a
of an external seal member
36
described later comes into slide contact.
Around the opening of the cylinder hole
32
b
, a scratch-off groove
32
c
is formed. The scratch-off groove
32
c
is used in order to prevent the excessive leakage of paste from the slide-contact surface between the plunger disc
32
and the seal disk
33
by scratching off a particle component in the paste attached onto the seal surface
33
a
in a pumping operation which performs the suction and ejection of paste by rotation of the plunger disc
32
in relation to the seal disc
32
.
Referring to
FIG. 4
, the shape of the seal disc
33
will be described. The seal disc
33
is made of the similar hard material to the material of the plunger disc, and it is a disc member having on its upside a step-like convex portion formed in the shape of a step. An upper surface of the step-like convex portion is the seal surface
33
a
coming into slide-contact with the plunger disc
32
, and two circular arc-shaped recess portions
33
b
and
33
c
are formed in the seal surface
33
a
. In the seal disc
33
, through-holes
34
a
and
34
b
are formed in two positions on the circumference of a circle at equal intervals, and each of the positions corresponds to the position in the diameter direction of the cylinder hole
32
b
. The through-holes
34
a
and
34
b
communicate respectively with the recess portions
33
b
and
33
c.
When the plunger disc
32
rotates in a state where the slide surface
32
a
of the plunger disc
32
comes into slide-contact with the seal surface
33
a
of the seal disc
33
, the recess portions
33
b
and
33
c
communicate with the opening portions of the cylinder holes
32
b
in the position of the predetermined rotation of the plunger disc
32
. Therefore, the recess portions
33
b
and
33
c
function as a first communicating port and a second communicating port which are provided on the seal surface
33
a
and communicate with the opening portions of the cylinder holes
32
b
in the predetermined rotational position of the cylinder block.
An outer surface
33
e
of the step-like convex portion becomes a fitting surface to which an inner fixing portion
36
b
of the external seal member
36
described later fits. A step-like surface
33
f
becomes a seal holding surface which comes into contact with an end surface of the periphery slide portion
36
a
of the external seal member
36
and holds the axial position of the periphery slide portion
36
a
. Further, a periphery edge
33
d
of the seal surface
33
a
is kept in the shape of a sharp edge in which chamfering is not performed, and prevents opening of seal gap from being made in the state where the seal surface
33
a
comes into slide-contact with the slide-contact surface
32
a
, as described later.
In
FIG. 2
, the plunger holder
31
is provided with a flange portion
31
a
protruding in the diameter direction, and between the flange portion
31
a
and the end surface of the rotator
28
, a coned disc spring
30
is attached. The coned disc spring
30
, by pressing the plunger holder
31
downward, presses the sliding surface of the plunger disc
32
against the seal surface of the seal disc
33
at the predetermined surface pressure. By this surface pressure, the close attachment between the sliding surface
32
a
and the seal surface
33
a
is secured.
In the state where the plunger disc
32
is brought into slide-contact with the seal disc
33
, on the peripheral side of the seal surface
33
a
, a housing portion
37
(refer to
FIG. 6
) is formed, which is nearly circle ring-shaped space formed by opposing the outer surface
33
e
provided for the seal dick
33
to the inner surface
32
e
of the cylindrical portion
32
d
extending axially from the plunger disc
32
. In the housing portion
37
, the external seal member
36
is attached.
The external seal member
36
, as shown in
FIG. 5
, is a nearly ring-shaped seal member, which comprises two seal members, that is, an outer slide portion
36
a
and an inner fixing portion
36
b
. The outer slide portion
36
a
is obtained by forming a first seal material of self-lubrication (for example, PTFE (4-fluorinated-ethylene resin)) in the shape of a ring having a rectangular section. Since this seal material has self-lubrication, its coefficient of friction when it comes into slid-contact with and is attached to a seal surface of another member is low, and it is rich in wear-resistance and superior in sliding performance.
For the inner fixing portion
36
b
, an O-ring made of a second seal material (rubber material) that is rich in elasticity is used, and it applies seal surface pressure to the seal surface by the elastic power in the attachment state. On the inner surface of the peripheral slide portion
36
a
, recess portions are provided throughout the entire periphery accordingly to the sectional shape of the inner fixing portion
36
b
, whereby position holding is facilitated when the inner fixing portion
36
b
is combined with the inner surface of the peripheral slide portion
36
a.
In the state where the external seal member
36
is attached in the housing portion
37
, as shown in
FIG. 6
, the inner fixing portion
36
b
fits to the outer surface
33
e
of the seal disc
33
, and an axial end surface on one side of the peripheral slide portion
36
a
comes into contact with the step-like surface
33
f
. Further, the outer surface of the peripheral slide portion
36
a
comes into slide-contact with the inner surface
32
e
of the plunger block
32
. In the operating state of the paste ejection apparatus
16
, the inner fixing portion
36
is kept fixed to the seal disc
33
by the elastic power, and the peripheral slide portion
36
a
is in the good slide-contact state with the inner surface portion
32
e
of the rotating plunger block
32
.
In this operating state, from the seal gap between the seal surface
33
a
and the slide surface
32
a
, the paste leaks into the housing portion
37
a little. The leakage of this paste to the outside of the housing portion
37
is prevented by the external seal member
36
. The paste stored in the housing portion
37
at this time acts so as to push the inner fixing portion
36
b
of the external seal
36
to the outer surface
33
e
and push the peripheral slide portion
36
a
to the step-like surface
33
f
and the inner surface
32
e
, whereby the sealing ability of the paste is improved by the external seal member
36
. Further, since the peripheral edge
33
of the seal surface
33
a
is sharp edge-shaped as describe before, the paste in the housing portion
37
is difficult to enter into the seal gap, so that opening by the increase of the seal gap is prevented.
The through-holes
34
a
and
34
b
of the seal disc
33
communicate respectively with a first external port
35
a
and a second external port
35
b
which are provided on an end surface of the outer cylinder portion
21
. The first external port
35
a
is connected through the tube
20
to the syringe
19
(FIG.
1
), and the second external port
35
b
is connected through the tube
17
to the applying nozzle
18
(FIG.
1
).
In the state where the through-hole
34
communicates with the cylinder hole
32
b
through the recess portion
33
b
, the plunger
26
moves in the pulling-into direction (upward in FIG.
2
), whereby the paste stored in the syringe
19
is supplied through the tube
20
into the cylinder hole
32
b
. The first external port
35
a
is used as a supply port to which the paste supplied from the syringe
19
is introduced.
Next, in the state where the cylinder hole
32
b
that has sucked the paste communicates with the through-hole
34
b
through the recess portion
33
c
, the plunger
26
moves in the pushing-out direction (downward in FIG.
2
), whereby the paste in the cylinder hole
32
b
is ejected from the second external port
35
b
. The second external port
35
b
is used as an ejection port from which the paste is ejected to the outside.
Referring next to
FIG. 7
, the positional relation between the recess portions
33
b
,
33
c
and the cylinder hole
32
bs
in the suction and ejection operations of the paste by the paste ejection apparatus
16
will be described. In the embodiment, by port-switching in which the three plungers
26
are alternately communicated through the recess portion
33
b
or
33
c
that is the communicating port with the two external ports
35
a
and
35
b
, the paste ejection is continuously performed.
FIG. 7A
shows a state where, in a process where the three cylinder holes
32
b
-A,
32
b
-B, and
32
b
-C rotate and move in the direction of an arrow, the position of the cylinder hole
32
b
-A matches with that of the through-hole
34
a
, and supply of the paste to the cylinder hole
32
b
-A is being performed. At this time, the cylinder hole
32
b
-C finishes the ejection of paste and is about to separate from the recess portion
33
c
, and the cylinder
32
-B reaches the end portion of the recess portion
33
c
and is about to start the ejection of paste newly. Between the state shown in FIG.
7
A and the state shown in
FIG. 7B
, the supply of paste to the cylinder hole
32
b
-A and the ejection of paste from the cylinder hole
32
b
-B are continuously performed.
Thereafter, in a timing shown in
FIG. 7C
, the cylinder hole
32
b
-A reaches the end portion of the recess portion
33
c
and starts the ejection of paste newly. At this time, the cylinder hole
32
b
-B separates from the recess portion
33
c
and finishes the ejection of paste. As described above, any one of the three cylinder holes
32
b
is always in the state of ejecting the paste, whereby the paste is ejected from the external port
35
b
(ejection port) incessantly.
Regarding this paste ejecting operation, also in case that the slurry-like paste including a large amount of filler components and solid particles is used, the paste that has leaked from the seal gap between the seal disc
33
and the plunger
32
is prevented from leaking to the outside by the external seal member
36
. Therefore, it is possible to suppress the paste leakage in the paste ejecting operation to the minimum, and a disadvantage that the inside of the apparatus is stained with the paste that has leaked can be prevented.
Second Embodiment
FIG. 8
is a sectional view of a paste ejection apparatus according to a second embodiment of the invention,
FIG. 9
is a perspective view of a plunger disc of the paste ejection apparatus according to the second embodiment of the invention,
FIG. 10
is a perspective view of a seal disc of the paste ejection apparatus according to the second embodiment of the invention,
FIG. 11
is a diagram for explaining the shape of an external seal of the paste ejection apparatus according to the second embodiment of the invention, and
FIG. 12
is a diagram for explaining the attachment state of the external seal of the paste ejection apparatus according to the second embodiment of the invention.
In the second embodiment, a modified example of the constitution of the external seal member
36
in the first embodiment is indicated. In
FIG. 8
, a paste ejection apparatus
161
is provided with the similar paste ejection mechanism to that of the paste ejection apparatus
16
indicated in the first embodiment, and the ejection apparatus in
FIG. 8
is different from that in
FIG. 2
only in a plunger disc
132
, a seal disc
133
, and an external seal member
136
.
As shown in
FIG. 9
, a plunger disc
132
is a disc member which is step-shaped and has a convex portion at its upside, and the upper surface of the step-like convex portion becomes a slide surface
132
a
orthogonal to an rotational axis. The slide surface
132
a
comes into slide-contact with a seal surface
133
a
(refer to
FIG. 8
) of a seal disc
133
that is a seal member fixed to an outer cylinder portion
21
. On the slide surface
132
a
, a cylinder hole
132
is opened, which has the same arrangement and the same function as the cylinder hole
32
b
shown in the first embodiment has. Around an opening portion of the cylinder hole
32
b
, a scratch-off groove
32
c
is formed.
An outer surface
132
e
of the step-like convex portion becomes a slide surface with which an inner slide portion
136
b
of an external seal member
136
described later comes into slide-contact. A step-like surface
132
f
becomes a seal holding surface which comes into contact with an end surface of the inner slide portion
136
a
and holds the axial position of the inner slide portion
136
a
. Further, a periphery edge
132
d
of the slide surface
132
a
is kept in the shape of a sharp edge which is not subjected to chamfering, which prevents opening by the increase of the seal gap.
Referring to
FIG. 10
, the shape of the seal disc
133
will be described. The seal disc
133
is provided with a cylindrical portion
133
d
protruding axially from an outer edge of a disc body, and on the upper surface of the disc body, a seal surface
133
a
coming into slide-contact with the plunger disc
132
is provided. On the seal surface
133
a
, recess portions
133
b
and
133
c
are formed, which have the same arrangement and the same function as the recess portions
33
b
and
33
c
shown in the first embodiment have. With the recess portions
133
b
and
133
c
, through-holes
134
a
and
134
b
communicate respectively. An inner surface
133
e
of the cylindrical portion
133
d
becomes a fitting surface to which a periphery fixing portion
136
a
of the external seal member
136
fits.
In the state where the plunger disc
132
is brought into slide-contact with the seal disc
133
, on the peripheral side of the seal surface
133
a
, a housing portion
137
is formed, which is nearly circle ring-shaped space formed by opposing the inner surface
133
e
of the cylindrical portion
133
d
protruding axially from the seal disc
133
to the outer surface
132
e
provided for the plunger disc. In the housing portion
137
, the external seal member
16
is attached.
The external seal member
136
, as shown in
FIG. 11
, is a nearly ring-shaped seal member, which comprises two seal members, that is, an outer fixing portion
136
a
and an inner slide portion
136
b
. For the outer fixing portion
136
a
, an O-ring made of a second seal material having the same property and the same function as the inner fixing portion
36
b
shown in the first embodiment has is used. The inner slide portion
136
b
is formed of a first seal material having the same property and the same function as the periphery slide portion
36
a
shown in the first embodiment has, and formed in the shape of a ring having a rectangular section. On the outer surface side of the inner slide portion
136
b
, recess portions are provided throughout the entire periphery accordingly to the sectional shape of the outer fixing portion
136
a
, whereby position holding is facilitated when the outer fixing portion
136
a
is combined with the inner slide portion
136
b.
In the state where the external seal member
136
is attached in the housing portion
137
, as shown in
FIG. 12
, the inner slide portion
136
b
firstly comes into slide-contact with the outer surface
132
e
of the plunger disc
132
, and an axial end surface on one side of the inner slide portion
136
b
comes into contact with the step-like surface
132
f
. Further, the outer surface of the outer fixing portion
136
a
fits to the inner surface
133
e
of a seal block
133
.
In the operating state of the paste ejection apparatus
161
, the outer fixing portion
136
a
is kept fixed to the inner surface
133
e
of the seal disc
133
by the elastic power, and the inner slide portion
136
b
is in the good slide-contact state with the outer surface
132
e
of the rotating plunger block
32
. In this operating state, the paste that has leaked out of the seal gap between the seal surface
133
a
and the slide surface
132
a
is prevented from leaking from the housing portion
137
to the outside by the external seal member
36
.
According to the first and second embodiments of the invention, the housing portion which is the circle ring-shaped space, and which is closed and surrounded by the seal member and the cylinder block is provided on the peripheral side of the seal surface between the fixed seal member and the rotating cylinder block; and the nearly ring-shaped external seal member composed of the self lubricant material and the material that is rich in elasticity is attached to this housing member. Hereby, it is possible to prevent the paste that has leaked from the seal surface from leaking to the outside of the housing portion by the external seal member.
Third Embodiment
Referring next to drawings, a third embodiment of the invention will be described.
FIG. 13
is a sectional view of a paste ejection apparatus according to a third embodiment of the invention,
FIG. 14
is a perspective view of a cam portion of the paste ejection apparatus according to the third embodiment of the invention,
FIG. 15
is a sectional view of the cam portion of the paste ejection apparatus according to the third embodiment of the invention,
FIG. 16
is a perspective view of a plunger disc of the paste ejection apparatus according to the third embodiment of the invention,
FIG. 17
is a perspective view of a seal disc of the paste ejection apparatus according to the third embodiment of the invention,
FIG. 18
is a diagram for explaining the attachment state of an external seal of the paste ejection apparatus according to the third embodiment of the invention, and
FIG. 19
is a diagram for explaining an operation of the paste ejection apparatus according to the third embodiment of the invention.
The third embodiment of the invention shows a modified example of the constitution of the paste ejection apparatus
16
or
161
in the first embodiment 1 or the second embodiment 2. The constitution of other parts is similar to that shown in FIG.
1
.
Referring next to
FIG. 13
, the structure of a paste ejection apparatus
216
will be described. In
FIG. 13
, the paste ejection apparatus
216
includes in an outer cylinder portion
221
a shaft-type multi-plunger pump which is driven by a motor
222
used as a rotation drive means. To an output shaft
223
of the motor
222
, a cylindrical rotator
228
is coupled with an axis A of rotation matched. The rotator
228
is supported by a bearing
229
rotatably, and a plunger holder
231
is attached to an inner diameter portion
228
of the rotator
228
. The plunger holder
231
is permitted to slide in the direction of the axis A of rotation in relation to the rotator
228
, and receives transmission of the rotation from the rotator
228
.
For the plunger holder
231
, plural plunger holes
231
are provided in the direction of the axis A of rotation at equal intervals, and a slide bearing
231
c
is attached to each plunger hole
231
b
. To a leading end portion of the plunger holder
231
, a plunger disc
233
is secured through a disc-shaped collar plate
232
. In the collar plate
232
, plural through-holes
232
a
are formed in positions corresponding to the positions of the plunger holes
231
b
. Further, in the plunger disc
233
, plural cylinder holes
233
b
are formed in positions corresponding to the positions of the through-holes
232
a
. The outer surface of the plunger disc
233
is slidably held by a cylindrical holding member
235
. The holding member
235
is made of material having self-lubrication such as resin or oil retaining metal.
The plunger
226
passes through the slide bearing
231
c
, the through-hole
232
a
and the cylinder hole
233
b
in the state where its movement in the direction of the axis A of rotation is permitted, and a seal member
234
is attached to the upside of the cylinder hole
233
b
. The plunger is inserted into the cylinder hole
233
b
through this seal member
234
, and the lower end portion of the plunger
226
reciprocates into the cylinder hole
233
b
thereby to perform the suction and ejection of paste, which will be described later. The plunger holder
231
, the collar plate
232
, and the plunger disc
233
constitute a cylinder block having the plural cylinder holes
233
b.
The upper end of each plunger
226
protrudes upward through a slide bearing
228
b
attached to a base portion of the rotator
228
and is coupled to a coupling block
226
a
, and a cam follower
225
is attached to the coupling block
226
a
. Each cam follower
225
reciprocates in the direction of the axis A of rotation by a cam portion
224
described below.
Above the rotator
228
, that is, on the motor
222
side of the cylinder block, the cam portion
224
is arranged. The cam portion
224
comprises two end cams (first end cam
224
A and second end cam
22
B) having cam surfaces
224
a
(refer to
FIG. 14
) in the direction of an axis A of rotation, the end cams are combined so that their cam surfaces
224
a
are opposed to each other, and registration of the end cams is performed by a spacer member
227
to fit them.
As shown in
FIG. 14
, either of the first end cam
224
A and the second end cam
22
B is nearly cylindrical, and inside of each end cam, a cylindrical recess portion
224
b
which the drive end sides of the three plungers
226
inserted into the plunger holder
231
can enter is provided. In the state where the first end cam
224
A and the second end cam
224
B are opposed to each other and combined, in the inner surface of the cylindrical recess portion
224
b
, a cam groove interposed between the two cam surfaces
224
a
is formed. The drive ends of the three plungers
226
inserted into the plunger holder
231
, as shown in
FIG. 15
, enter the cylindrical recess portion
224
b
in three positions at equal intervals about the axis A of rotation, and the cam follower
225
coupled to the coupling block
226
a
fits to the cam groove.
When the motor
222
is rotation-driven under this state, the cylinder block comprising the plunger holder
231
, the collar plate
232
, and the plunger disc
233
rotates through the rotator
228
, whereby each plunger
226
revolves about the axis A of rotation relatively to the cam portion
224
. By this relative rotation, the cam follower
225
fitting to the cam grove rotates and moves into the cam groove along the line of the cam surface, and reciprocates in the direction of the axis A of rotation in accordance with cam characteristic of the cam surface
224
a
. The cam follower
225
transmits this reciprocating movement through the coupling block
226
a
to the plunger
226
, whereby while the plunger
226
is rotating about the axis A of rotation, it reciprocates in the direction of the axis A of rotation in synchronization with this rotation.
Namely, the cam groove formed in the inner surface of the cylindrical recess portion
224
b
converts the relative rotating movement of the cylinder block for the cam portion
224
into the reciprocating movement of the plunger
226
in the direction of the axis A of rotation. The motor
222
and the cam portion
224
function as a plunger drive means which reciprocates the plunger
226
in synchronization with the rotation of the cylinder block. The shape of the cam groove provided fro the cam portion
224
is such a shape that the three plungers
226
are reciprocated in the predetermined order and at the predetermined timing, whereby a paste sucking operation and a paste ejecting operation are continuously performed.
In the above constitution, in case of either of the going movement and the returning movement, the plunger
226
is driven by the cam portion
224
. Accordingly, by adopting the above constitution as the plunger drive means, slurry-like liquid that is high in viscosity and includes metal powder can be ejected, and the drive power can be transmitted to the plunger surely also in case that the reciprocating movement of the plunger must be performed under the condition of high slide resistance.
Hereby, the problem in the same kind of the conventional apparatus which adopts the general cam mechanism, that is, unsteadiness of operation caused due to high slide resistance in reciprocation of a plunger driven by a cam mechanism which performs a returning operation by the energizing force of a spring is eliminated, so that the stable sucking and ejecting operations can be performed. Further, since the high slide resistance is permitted, a member having high sealing ability can be used for the slide seal portion of the seal member
234
, so that the leakage of paste during the operation can be reduced.
Further, in the embodiment, the cam portion
224
which drives the three plungers
226
is constituted so that the cylindrical recess portion
224
b
which the drive end side of each plunger
226
can enter is provided in the cam portion
224
, and also the cam groove is formed in the inner surface of the cylindrical recess portion
224
b
. Therefore, as shown in
FIG. 15
, the three plungers
226
can be arranged closely to one another around the axis A of rotation. Hereby, the paste ejection apparatus which secures high sealing ability, and is small and compact-sized by making the dimension in the diameter direction as small as possible is realized.
Such the constitution of the cam portion
224
is realized readily by opposing the two end cams, the first end cam
224
A and the second end cam
224
B to each other. Namely, in case that the above cam portion
224
is constituted by an integrated cam member usually used, it is necessary to form a cam groove in an inner surface of a cylindrical recess portion by machining, a parts cost increases because of machining difficulty, and increase of parts size is not avoided due to a limit on machining. On the contrary, in case that the cam portion
224
is constituted by opposing and combining the two end cams, the parts size and the cost can be reduced.
Referring to
FIG. 16
, the plunger disc
233
will be described. The plunger disc
233
is made of hard ceramic such as alumina or hard material such as cemented carbide, and is provided with a cylindrical portion
233
d
extending axially from the outer edge portion of the disc body. For the disc body, plural cylinder holes
233
b
are provided in the direction of the rotational axis. The upper surface of the disc body becomes a slide surface orthogonal to the rotational axis, and the slide surface comes into slide contact with a seal surface
236
a
of a seal disc
236
that is a seal member secured to the outer cylinder portion
221
. The cylinder holes
233
b
open at equal intervals on the same circumference of a circle having the rotational axis of the slide surface
32
a
as a center. With an inner surface
233
e
of the cylindrical portion
233
d
, an external seal member
237
described later comes into slide-contact.
Around the opening portion of the cylinder hole
233
b
, a scratch-off groove
233
c
is formed. The scratch-off groove
233
c
is used in order to prevent the excessive leakage of paste from the slide-contact surface between the plunger disc
233
and the seal disk
236
by scratching off a particle component in the paste attached onto the seal surface
236
a
(refer to
FIG. 17
) in a pumping operation which performs suction and ejection of paste by rotation of the plunger disc
233
in relation to the seal disc
236
.
Referring to
FIG. 17
, the shape of the seal disc
236
will be described. The seal disc
236
is made of the similar hard material to the material of the plunger disc, and it is a disc member having on its upside a step-like convex portion formed in the shape of a step. An upper surface of the step-like convex portion becomes the seal surface
236
a
coming into slide-contact with the plunger disc
233
, and two circular arc-shaped recess portions
236
b
and
236
c
are formed in the seal surface
236
a
. In the seal disc
236
, through-holes
238
a
and
238
b
are formed in two positions on the circumference of a circle at equal intervals, and each of the positions corresponds to the position in the diameter direction of the cylinder hole
236
b
. The through-holes
238
a
and
238
b
communicate respectively with the recess portions
236
b
and
236
c.
When the plunger disc
233
rotates in the state where the slide surface
233
a
of the plunger disc
233
comes into slide-contact with the seal surface
236
a
of the seal disc
236
, the recess portions
236
b
and
236
c
communicate with the opening portions of the cylinder holes
233
b
in the position of the predetermined rotation of the plunger disc
233
. Therefore, the recess portions
236
b
and
236
c
function as a first communicating port and a second communicating port which are provided on the seal surface
236
a
and communicate with the opening portions of the cylinder holes
233
b
in the predetermined rotational position of the cylinder block.
An outer surface
236
e
of the step-like convex portion becomes a fitting surface to which the external seal member
237
described later fits. A step-like surface
236
f
becomes a seal holding surface which comes into contact with an end surface of the external seal member
237
and holds the axial position of the external seal member
237
. Further, a periphery edge
236
d
of the seal surface
236
a
is kept in the shape of a sharp edge which is not subjected to chamfering, and prevents opening of the seal gap from being made in the state where the seal surface
236
a
comes into slide-contact with the slide-contact surface
233
a
, as described later.
In
FIG. 13
, the plunger holder
231
is provided with a flange portion
231
a
protruding in the diameter direction, and between the flange portion
231
a
and the end surface of the rotator
228
, a coned disc spring
230
is attached. The coned disc spring
230
, by pressing the plunger holder
231
downward, presses the slide surface of the plunger disc
233
against the seal surface
236
a
of the seal disc
236
at the predetermined surface pressure. By this surface pressure, the close attachment between the slide surface
233
a
and the seal surface
236
a
is secured.
In the state where the plunger disc
233
is brought into slide-contact with the seal disc
236
, on the peripheral side of the seal surface
236
a
, a housing portion
240
(refer to
FIG. 18
) is formed, which is nearly circle ring-shaped space in which the outer surface
236
e
provided for the seal dick
236
is opposed to the inner surface
233
e
of the cylindrical portion
233
d
extending axially from the plunger disc
233
. In the housing portion
240
, the external seal member
237
is attached.
The external seal member
237
is a nearly ring-shaped seal member, which comprises a first seal material
237
A having a V-shaped section and a second seal material
237
B held by the first seal material in the interposed state. Namely, the first seal material
237
A has a recess portion
237
A-a, and the second seal material
237
B is held in the recess portion
237
A-a. In the state where the external seal member
237
is attached into the housing portion
240
, as shown in
FIG. 18
, the inner surface side of the external seal member
237
fits to the outer surface
236
e
of the seal disc
236
, and the outer surface side thereof comes into slide-contact with the inner surface
233
e
of the plunger block
233
. The axial end on one side of the external seal member
237
comes into contact with the step-like surface
236
f
(refer to
FIG. 17
) and the axial position of the external seal member
237
is kept. Further, the first seal material
237
A is made of self-lubricant material such as 4-fluorinated ethylene resin, and the second seal material
237
B is made of material that is rich in elasticity such as rubber material/spring.
In the operating state of the paste ejection apparatus
216
, in which the cylinder block is rotate to reciprocate the plunger
226
, from the seal gap between the seal surface
236
a
and the slide surface
233
a
, the paste leaks into the housing portion
240
a little. The leakage of this paste to the outside of the housing portion
240
is prevented by the external seal member
237
. The paste stored in the housing portion
240
at this time acts so as to push the external seal
237
to the outer surface
236
e
and the inner surface
233
e
, whereby the sealing ability of the paste is improved by the external seal member
237
. Further, since the peripheral edge
236
d
of the seal surface
236
a
is sharp edge-shaped as described above, the paste in the housing portion
240
is difficult to enter into the seal gap, so that opening by the increase of the seal gap is prevented.
In seal of the paste by the external seal member
237
, the periphery side of the cylindrical portion
233
d
extending axially from the plunger disc
233
is held slidably by the cylindrical holding member
235
fitted in the outer cylinder portion
221
. Therefore, the run-out in the diameter direction of the plunger disc
233
at the rotating time is constrained by the holding member
235
. Namely, the holding means
235
functions as a run-out constraining means which constrains the run-out displacement in the diameter direction of the plunger disc
233
in the vicinity of the external seal portion in which the plunger disc
233
constituting the cylinder block and the external seal member
237
come into slide-contact with each other.
Hereby, in slide between the external seal
237
and the inner surface
233
e
with the rotation of the plunger disc
233
, the stable sliding state is kept, and the sealing ability of preventing the leakage of paste to the outside is improved. Further, wear of the external seal member
237
in the slide portion is reduced, so that a parts life can be elongated.
In
FIG. 13
, the through-holes
238
a
and
238
b
of the seal disc
236
communicate respectively with a first external port
239
a
and a second external port
239
b
which are provided on an end surface of the outer cylinder portion
221
. The first external port
239
a
is connected through the tube
20
to the syringe
19
(FIG.
1
), and the second external port
239
b
is connected through the tube
17
to the applying nozzle
18
(FIG.
1
).
In the state where the through-hole
238
a
communicates with the cylinder hole
233
b
through the recess portion
236
b
, the plunger
226
moves in the pulling-into direction (upward in FIG.
13
), whereby the paste stored in the syringe
19
is supplied through the tube
20
into the cylinder hole
233
b
. The first external port
239
a
functions as a supply port to which the paste supplied from the syringe
19
is introduced.
Next, in the state where the cylinder hole
233
b
from which the paste has been sucked communicates with the through-hole
238
b
through the recess portion
236
c
, the plunger
226
moves in the pushing-out direction (downward in FIG.
13
), whereby the paste in the cylinder hole
233
b
is ejected from the second external port
239
b
. The second external port
239
b
functions as an ejection port from which the paste is ejected to the outside
Referring next to
FIG. 19
, the positional relation between the recess portions
233
b
,
23
c
and the cylinder holes
233
b
in the sucking and ejecting operations of the paste by the paste ejection apparatus
216
will be described. In the embodiment, by port switching in which the three plungers
226
are communicated through the recess portion
236
b
or
236
c
that is the communicating port with the two external ports
239
a
and
239
b
alternately, the paste ejection is continuously performed.
FIG. 19A
shows a state where, in a process where the three cylinder holes
233
b
-A,
233
b
-B, and
233
b
-C rotate and move in the direction of an arrow, the position of the cylinder hole
233
b
-A matches with that of the through-hole
238
a
, and supply of the paste to the cylinder hole
233
b
-A is being performed. At this time, the cylinder hole
233
b
-C finishes the ejection of paste and is about to separate from the recess portion
236
c
, and the cylinder
233
-B reaches the end portion of the recess portion
236
c
and is about to start the ejection of paste newly Between the state shown in FIG.
19
A and the state shown in
FIG. 19B
, the supply of paste to the cylinder hole
233
b
-A and the ejection of paste from the cylinder hole
233
b
-B are continuously performed.
Thereafter, in a timing shown in
FIG. 19C
, the cylinder hole
233
b
-A reaches the end portion of the recess portion
236
c
and starts the ejection of paste newly. At this time, the cylinder hole
233
b
-B separates from the recess portion
236
c
and finishes the ejection of paste. As described above, any one of the three cylinder holes
233
b
is always in the state of ejecting the paste, whereby the paste is ejected from the external port
239
b
(ejection port) incessantly.
Regarding this paste ejecting operation, also in case that the slurry-like paste including a large amount of filler components and solid particles is used, the paste that has leaked from the seal gap between the seal disc
236
and the plunger
233
is prevented from leaking to the outside by the external seal member
237
. Therefore, it is possible to suppress the paste leakage in the paste ejecting operation to the minimum, and a disadvantage that the inside of the apparatus is stained with the paste that has leaked can be prevented.
Further, the constitution shown in the third embodiment can be applied to the first embodiment or the second embodiment. Similarly, the external seal member shown in the first embodiment or the second embodiment can be applied to the third embodiment.
Claims
- 1. A paste ejection apparatus for ejecting slurry-like paste in which a viscous substance and a filler component are mixed, comprising:a cylinder block being rotatable about a rotational axis by a rotation drive means, and contacting slidably with a seal surface of a seal member through a slide surface orthogonal to the rotational axis; plural cylinder holes provided in the direction of the rotational axis of the cylinder block and including opening portions formed at equal intervals on the same circumference of a circle having the rotational axis of the slide surface as a center; a plunger inserted into each cylinder hole; a plunger drive means reciprocating said plunger in synchronization with the rotation of said cylinder block; first and second communicating ports provided on the seal surface and communicating with the opening portions of the cylinder holes in the predetermined rotary position of the cylinder block; first and second external ports communicating respectively with the first and second communicating ports through the seal member; a housing portion located on the peripheral side of the seal surface, closed and surrounded by the seal member and the cylinder block to be a circular ring-shaped space; and a ring-shaped external seal member attached into the housing portion, including a first seal material having self-lubrication and a second seal material being rich in elasticity.
- 2. The paste ejection apparatus according to claim 1, wherein the housing portion is formed by opposing an outer surface of the seal member to an inner surface extending axially from the cylinder block.
- 3. The paste ejection apparatus according to claim 2, wherein the second seal material of the external seal member is fitted onto the outer surface of the seal member, and the first seal member of the external seal member slidably contacts with the inner surface of the cylinder block.
- 4. The paste ejection apparatus according to claim 2, wherein the first seal member has a recess portion, and the second seal member is held by the recess portion of the first seal member.
- 5. The paste ejection apparatus according to claim 1, wherein the housing portion is formed by opposing an inner surface extending axially from the seal member to an outer surface of cylinder block.
- 6. The paste ejection apparatus according to claim 5, wherein the first seal member of the external seal member slidably contacts with the outer surface of the cylinder block, and the second seal material of the external seal member is fitted onto the inner surface of the seal member.
- 7. The paste ejection apparatus according to claim 5, wherein the first seal member has a recess portion, and the second seal member is held by the recess portion of the first seal member.
- 8. A paste ejection apparatus for ejecting slurry-like paste in which a viscous substance and a filler component are mixed, comprising:a cylinder block being rotatable about a rotational axis by a rotation drive means, and contacting slidably with a seal surface of a seal member through a slide surface orthogonal to the rotational axis; plural cylinder holes provided in the direction of the rotational axis of the cylinder block and including opening portions formed at equal intervals on the same circumference of a circle having the rotational axis of the slide surface as a center; a plunger inserted into each cylinder hole; a plunger drive means reciprocating said plunger in synchronization with the rotation of said cylinder block; first and second communicating ports provided on the seal surface and communicating with the opening portions of the cylinder holes in the predetermined rotary position of the cylinder block; first and second external ports communicating respectively with the first and second communicating ports through the seal member; a housing portion located on the peripheral side of the seal surface, closed and surrounded by the seal member and the cylinder block to be a circular ring-shaped space; a ring-shaped external seal member attached into this housing portion; and a run-out constraining means for constraining run-out displacement in the diameter direction of the cylinder block near the external seal portion slidably contacts with the cylinder block.
- 9. The paste ejection apparatus according to claim 8,wherein the housing portion is formed by opposing an outer surface of the seal member to an inner surface extending axially from said cylinder block; the inner surface side of the external seal member is fitted onto the outer surface of the seal member; and the outer surface side of the external seal member slidably contacts with the inner surface of the cylinder block.
- 10. A paste ejection apparatus for ejecting slurry-like paste in which a viscous substance and a filler component are mixed, comprising:a cylinder block being rotatable about a rotational axis by a rotation drive means, and contacting slidably with a seal surface of a seal member through a slide surface orthogonal to the rotational axis; plural cylinder holes provided in the direction of the rotational axis of the cylinder block and including opening portions formed at equal intervals on the same circumference of a circle having the rotational axis of the slide surface as a center; a plunger inserted into each cylinder hole; a plunger drive means reciprocating said plunger in synchronization with the rotation of said cylinder block; first and second communicating ports provided on the seal surface and communicating with the opening portions of the cylinder holes in the predetermined rotary position of the cylinder block; and first and second external ports communicating respectively with the first and second communicating ports through the seal member; wherein the plunger drive means includes; a cam portion provided on the rotation drive means side of the cylinder block, and having cylindrical recess portions formed so that the drive end sides of the plural plungers can enter therein; a cam groove formed on the inner surface of said cylindrical recess portion and converting the relative rotating movement for the cam portion of said cylinder block into the reciprocating movement of the plunger in the direction of the rotational axis; and a cam follower coupled to the drive end side of each of the plural plungers, and rotating and moving into the cam groove thereby to transmit the reciprocating movement to the plunger.
- 11. The paste ejection apparatus according to claim 10, wherein the cam portion is constituted by combining two end cams each having a cam surface in the direction of the rotational axis in a state where the cam surfaces are opposed to each other.
Priority Claims (3)
Number |
Date |
Country |
Kind |
P. 2002-300097 |
Oct 2002 |
JP |
|
P. 2003-088448 |
Mar 2003 |
JP |
|
P. 2003-088449 |
Mar 2003 |
JP |
|
US Referenced Citations (4)
Foreign Referenced Citations (2)
Number |
Date |
Country |
2-78773 |
Jun 1990 |
JP |
2002-346462 |
Dec 2002 |
JP |