JP3126924B2 - Valve unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve unit which is mounted in a fluid conduit to open and close a flow path.
Although it can be used for various applications, it is particularly suitable for use where heat and chemical resistance is required and where electrostatic and mechanically stable performance is required. In the manufacturing field, the present invention can be used for a valve unit of vacuum tweezers for holding a semiconductor wafer by suction under vacuum pressure.

[0002]

2. Description of the Related Art As a valve unit of this type, for example, a valve unit used in vacuum tweezers previously proposed by the present applicant and disclosed in Japanese Patent Publication Nos. 3-50672 and 5-75554 is disclosed. There is. In these valve units, the flow passage is opened and closed by an opening / closing valve mechanism in which a valve slides along a valve seat surface formed in the valve body, so that the opening / closing valve mechanism does not impair airtightness. Smooth operation, mechanical strength that does not impair the operation of the above-mentioned on-off valve mechanism due to external force, material of component parts adapted to the type of fluid to be handled, ambient atmosphere used and other usage conditions Can be selected as desired,
Is required.

In particular, in the case of the above-described valve unit for vacuum tweezers, which is the most preferred embodiment of the present applicant, damage to the member to be attracted such as a silicon wafer which impairs the electrostatic and mechanical performance. It is necessary to consider the following points in order not to give It must have conductivity that does not cause static electricity charging and dust adhesion due to charging. The wafer must be resistant to chemicals that do not deteriorate or generate metal ions even when exposed to chemicals or cleaning solutions that chemically process the wafer. It has self-lubricating properties with a low friction coefficient that does not generate particles from sliding friction parts even during long-term use. Therefore, in the case of these valve units for vacuum tweezers, a main component is a fluororesin material, particularly ethylene tetrafluoride, which has particularly excellent heat resistance and chemical resistance, a small friction coefficient and self-lubricating properties. It was often used for valve bodies.

[0004]

However, in the case of fluororesin, there is a drawback in mechanical rigidity, so that it is deformed when subjected to an external force, thereby impairing the operation of the opening / closing valve mechanism or reducing airtightness. When a screw member or the like is used for retaining and locking the on-off valve mechanism mounted in the valve body, the mechanical strength of the fluororesin material is small, so that the screw member is May easily fall off due to the influence of the fluid pressure of the fluid, and may deteriorate in the atmosphere of chemicals, such as rusting. It is not enough even if it is attached to the point, and it is necessary to solve the problem that if the fluororesin material is exposed to the outside, static electricity may be generated due to friction when holding the tweezers body by hand To be There was a variety of challenges.

As a means for solving the above problems, the present applicant has made a synthetic resin material such as a fluororesin material which is excellent in frictional sliding property important for an on-off valve mechanism as a synthetic resin material forming a valve body. Use the valve in the same manner as before, so that the valve body made of this synthetic resin material is not exposed to the outside and adversely affected by static electricity, and that the valve body is not deformed by external force and impairs the operation of the on-off valve mechanism. The outer periphery of the valve block forming the main body is covered with a valve case formed of another synthetic resin material having high rigidity and sufficient conductivity and generating no static electricity. A valve unit has been conceived which constitutes an integral valve housing. Here, the valve block is an intermediate form of a valve body in which an opening / closing valve structure including a valve body for opening / closing a flow path is mounted, and is a valve body used as an insert member when injection molding a valve case. That is, additional processing is performed after molding to form the valve body, but both are substantially the same.

However, even in the case of the valve unit according to the above concept, a halved cylindrical valve case is attached to the outer periphery of the valve body by screwing, or the cylindrical valve case is attached to the valve body by screwing. When a valve housing is constructed, it is difficult to secure the required performance in terms of connection strength and airtightness between the two members, and it is also necessary to use metal screw members or rubber O-rings. Is not desirable in terms of heat resistance and chemical resistance. Therefore, it has a small coefficient of sliding friction and excellent self-lubricating properties, so it is suitable for sliding valve bodies.
In addition to using synthetic resin material such as fluororesin for the valve body which has some difficulty in injection molding and mechanical rigidity,
Synthetic resin material having good heat resistance and chemical resistance and excellent mechanical rigidity and good conductivity, for example, PEEK containing carbon fiber
Using a material or the like as a valve case, an integral valve housing is constituted by a valve case injection-molded using a valve body on which an opening / closing valve mechanism is mounted as an insert member, thereby making use of the characteristics of each member and compensating for defects. I did it.

Further, even when a different kind of synthetic resin material is integrated by injection molding like the valve unit based on the above idea, the integrality is impaired due to the difference in the properties of the two and the characteristics of both cannot be sufficiently brought out. In particular, if the thermal expansion coefficients of the synthetic resin material forming the valve body and the synthetic resin material forming the valve case are different, voids due to shrinkage are generated at the joint surface between the two when injection molding and cooling are performed. It is necessary to solve the problem that the mechanical integrity is reduced and the strength is reduced, and the airtightness is reduced and the suction force is reduced due to air leakage.

For example, when the valve body is made of a fluororesin material having a particularly large thermal expansion coefficient among synthetic resin materials and the valve case is made of a carbon fiber-containing PEEK material having a very small thermal expansion coefficient, the valve expands during injection molding. A valve case made of PEEK material containing carbon fiber is formed on the outer periphery of the valve body made of fluororesin. However, when the valve body is cooled and shrunk after molding, a gap is generated at the joint surface with the valve case, and mechanically. This causes a reduction in strength and suction power.

Therefore, the present invention solves the above-mentioned problems of the prior art, and maintains mechanical accuracy and strength for a long period of time without being affected by external force, surrounding atmosphere, and the like. It is another object of the present invention to provide a valve unit improved so that the airtightness is reduced.

[0010]

Means for Solving the Problems To achieve the above object, the valve unit of the present invention is devised as follows which is different from the prior art. The first valve unit is
A valve body provided with a valve guide hole serving as a valve seat surface in a manner orthogonal to the flow path in a tubular body having a flow path communicating the upstream side and the downstream side formed therein; and an outer periphery of the valve body. A valve housing is formed with a valve case covering the valve case, an opening / closing valve mechanism is mounted in the valve guide hole, and the valve body is formed of a heat- and chemical-resistant, self-lubricating synthetic resin material. Is formed of a synthetic resin material different from the above-mentioned valve body having high heat resistance and chemical resistance and high rigidity, and the valve case is integrally formed by injection molding using a valve block forming the valve body as an insert member.

In the second valve unit, the valve body of the first valve unit has annular locking grooves formed in the outer peripheral surface at positions upstream and downstream of the valve guide hole, respectively. A sealing projection that fits into the annular locking groove protrudes from the inner peripheral surface of the case, and the sealing projection is formed integrally when the valve case is injection-molded.

[0012] The third valve unit is provided with the first or second valve unit.
An annular locking groove is recessed in the valve main body of the valve unit adjacent to the upper end side where the valve guide hole is opened, and a reinforcement fitting in the annular locking groove is formed on an inner peripheral surface of the valve case. Projections are provided so that the reinforcing projections are integrally formed when the valve case is injection-molded.

In the fourth valve unit, the valve body of the third valve unit is provided with a circular projection on an upper end side where the valve guide hole is opened, and the annular locking groove is formed on an outer periphery of a base portion of the circular projection. An outer screw cylinder is formed on the outer periphery of the circular projection on the valve case, and the opening / closing valve mechanism mounted on the valve guide hole is locked by a screw cap screwed onto the outer screw cylinder. I was doing it.

In the fifth valve unit, the valve case of the third valve unit is formed with an inner threaded cylinder protruding from the outside of the reinforcing projection to the outer periphery of the upper end side where the valve guide hole is opened. A holding member of the on-off valve mechanism mounted in the valve guide hole is mounted in the inner screw cylinder, and a screw cap is screwed onto the inner screw cylinder so that the on-off valve mechanism is locked. I made it.

In a sixth valve unit, the opening / closing valve mechanism in the first to fifth valve units includes a valve body that slides up and down along the valve guide hole to open and close a flow path; A valve spring elastically biased to one of an open state and a closed state, and a valve for moving the valve body up and down to the other of the open state and the closed state against the valve spring It is composed of operating means.

In a seventh valve unit, the opening / closing valve mechanism in the first to fifth valve units is configured to rotate along the valve guide hole to open and close the flow path, and to open the valve body. It is constituted by a valve operating means for performing a rotational movement operation to a state or a valve closed state.

In an eighth valve unit, the valve case in the first to seventh valve units is formed of a synthetic resin material having conductivity.

In a ninth valve unit, the valve body of the first to eighth valve units is formed of a tetrafluoroethylene material, and the valve case is formed of polyetheretherketone containing carbon fibers.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a valve unit according to the present invention will be described in detail based on an embodiment applied to vacuum tweezers. As shown in FIG. 1, the vacuum tweezers include a tweezers body 1 provided with an operation button 3 of an on-off valve that is gripped by hand to open and close a flow path, and a suction port for adsorbing or releasing an object to be adsorbed. And a suction adapter 2 having a suction tip 5 of various shapes with an opening at the tip.

The tweezer body 1 is provided with a valve unit 6 equipped with an opening / closing valve mechanism including an operation button 3 for opening / closing a flow path.
An extension tube 7 having a suction flow passage formed therein and screwed to the rear end of the valve unit 6; and a connection tube 8 screwed to the front end of the valve unit 6 for mounting the suction adapter 2. It has. The vacuum tweezers are connected to a vacuum pressure source such as a vacuum pump via a connector 9 which is attached to and detached from a connector 7a provided on the rear end side of the extension tube 7 and a suction hose 10 attached to the connector 9. When the operation button 3 is operated with the hand 1 gripped by hand, the flow path is opened or closed by the opening / closing valve mechanism built in the valve unit 6, so that a negative pressure or an atmospheric pressure is generated in the suction port 4 of the suction adapter 2. Then, the adsorption or desorption of the adsorption object is performed.

As shown in FIG. 2, the valve unit 6 has a valve housing 13 formed by a valve body 11 and a valve case 12, and an upstream passage 14 formed in the valve housing 13.
A and the downstream side flow path 14B, there is a communication hole 15 along the axis.
A valve guide hole 16 serving as a valve chamber is provided in the middle of the communication hole 15 so as to cross the communication hole 15 at right angles. The valve guide hole 16 has a valve body 17 and a valve spring 1 which constitute a manual open / close valve.
8 is attached. The valve element 17 is provided with an annular groove 19 on the outer periphery of an intermediate portion and a concave fitting portion 2 serving as a spring receiver on a lower end surface.
0, and is formed of a cylindrical body having a concave fitting portion 20 and a breathing hole 21.
A valve spring 18 that elastically urges the valve body 17 upward is stretched between the outer peripheral wall and the valve body 17.
The screw cap 23 is screwed into a screw cylinder 22 formed at the opening edge of the upper end of the valve body.
A valve stem 24 is attached to an upper end of the valve stem so as to slidably insert a screw cap 23, and an operation button 3 is attached to an upper end of the valve stem 24.

The opening / closing valve mechanism in the vacuum tweezers includes:
There are a normally open type in which the flow path is always connected to be able to be adsorbed and a normally closed type in which the flow path is shut off and the normally closed type in which the flow path is blocked, but in the latter case shown in FIG. A bypass passage 25 is provided between a valve chamber formed below the valve guide hole 16 and the upstream passage 14A.
The bypass flow passage 25 communicates with the breathing hole 21 through the valve guide hole 16 when the valve is closed, and is blocked by the outer peripheral wall of the concave fitting portion 20 of the valve body 17 when the valve is opened.

In the valve unit 6 having the above structure, the valve body 17 is normally urged upward by the valve spring 18 as shown in FIG. 2 so that the flow passage is cut off at a position where the annular groove 19 is not aligned with the communication hole 15. The operation of the operation button 3 causes the valve spring 18 to move.
When the valve element 17 is pressed down against the elastic force of
When the upstream flow path 14A and the downstream flow path 14B communicate with each other at a position aligned with the communication hole 15, and the vacuum pressure source connected to the vacuum tweezers main body 1 is operated, a negative pressure is applied to the suction port 4 of the suction adapter 2. Is generated and the object to be adsorbed brought into contact with the adsorption surface 5 can be adsorbed and held.

The valve unit 6 is a valve block 1 which has been subjected to preliminary processing as shown in FIG. 3 by machining such as cutting.
1A is manufactured separately, and the valve block 11A is mounted on a molding die device 26 as shown in FIG.
The outer periphery of 1A is integrally covered with a valve case 12 made of an injection-molded injection-molded resin material to form a valve housing 13. The valve block 11A of the valve housing 13 is subjected to additional machining by drilling or cutting. After the valve body 11 is formed, necessary components for the valve mechanism are assembled into the valve guide hole 16 of the valve housing 13 as shown in FIG.

The valve block 11A is made of a synthetic resin material such as a fluororesin material having heat resistance and chemical resistance and particularly having a small sliding friction coefficient. In this embodiment, ethylene tetrafluoride (PTFE material) is used. It is desirable to use a synthetic resin material having heat resistance, chemical resistance and sufficient conductivity to prevent generation of static electricity for the injection resin material forming the valve case 12. In this embodiment, about 15% of carbon is used. A PEEK material containing fibers is used. The PEEK material containing the carbon fiber is extremely suitable as a synthetic resin material used for the valve case 12 because the conductivity, heat resistance, and mechanical strength are remarkably improved as compared with a general PEEK material.

The valve block 11A is, as shown in FIG.
A circular projection 27 is provided on the upper surface of the intermediate portion, and is formed of a columnar or prismatic body having circular slots 28 and 29 formed on both sides in the axial direction. U-shaped annular locking grooves 30 and 31 having a U-shaped cross section are formed along the horizontal plane, and the outer locking portion has a U-shaped cross-sectionally formed annular locking groove on the outer periphery thereof. 32,33
Are drilled along the vertical plane.

As shown in a schematic enlarged view of a main part of FIG. 4, a molding die device 26 for molding the valve housing 13 has a fixed die 26A and a movable die 2 similar to a general die device.
6B, the fixed mold 26A includes an ejector plate 34, a fixed mold plate 35, an angular pin 36, and the like. The movable mold 26B includes a movable mold plate 37, left and right split mold blocks 38 and 39, and ejector pins. 40, etc., and the left and right split mold blocks 38 and 39 are provided with guide holes 41 into which the angular pins 36 are inserted when the molds are clamped.

In addition to the general configuration described above, the fixed type 26
A is provided with fixed support pins 42 vertically projecting downward from the ejector plate 34, and the movable mold 26B is provided with movable support pins 43 vertically projecting upward from the movable mold plate 37. The support pin 42 and the movable-side support pin 43 are vertically opposed to each other so as to be aligned with the center of the mold. A thread groove 44 is formed on the inner surface of each of the split mold blocks 38 and 39 at the upper end. In order to form the molding space 45 conforming to the outer shape of the valve housing 13, molding grooves 45a and 45b required are formed.

The valve block 11A is attached to the molding apparatus 26 with one of the circular slots 29 fitted into the movable support pin 43 and one end thereof being supported on the movable support pin 43. Then, when the split mold blocks 38 and 39 are pushed into the fixed mold plate 35 of the fixed mold 26A by the ejector pins 40 attached to the ejector plate of the movable mold 26B, the angular pins 36 inserted in the guide holes 41 The mold is clamped by the split mold blocks 38 and 39 while being guided. By this mold clamping, the outer periphery of the valve block 11A is surrounded by the molding space 45 formed by the molding grooves 45a and 45b, and the fixed-side support pin 42 is fitted into the other circular slot 28 of the valve block 11A. The other end is also supported in the combined state.

The fixed mold 26A and the movable mold 26B, which have been clamped, are heated to a predetermined temperature in advance, and are injected with a carbon fiber-containing polyetheretherketone (PEEK material) which is heated and melted at a higher molding temperature from a gate (not shown). Is filled from the gate into the molding space 45 of the mold via the spool runner and the runner, and the injected resin material is applied to the outer periphery of the valve block 11A and the valve case 12 integrally joined thereto is injection-molded. The valve case 12 has an outer peripheral screw 12a formed on the outer periphery on the upper end side by a screw groove 44,
The upper surface of the circular projection 27 of the valve block 11A is exposed at the middle outer periphery, and the inner annular locking grooves 30, 31 and the outer annular locking grooves 32, 33 formed in advance on the outer circumference of the valve block 11A are filled. The annular locking groove 3 is formed by the injected resin material.
Reinforcement protrusions 46 and 47 projecting annularly into 0 and 31 and sealing projections 48 and 4 projecting annularly into annular locking grooves 32 and 33.
9 are respectively formed, and the upstream flow path 14A and the downstream flow path 14B are respectively formed by the resin material covering the outer periphery of the fixed-side support pin 42 and the movable-side support pin 43.

In this embodiment, a polyether ether ketone (P) containing carbon fiber, which is heated and melted at about 380 ° C., to a mold heated to about 180 ° C.
The injection resin material is filled with an EEK material, and the injection resin material is applied to the outer periphery of the valve block 11A made of ethylene tetrafluoride (PTFE material) mounted in the mold, and the valve is formed of a molded resin material. A valve housing 13 as shown in FIG. 5 in which the case 12 and the valve block 11A as an insert material are integrated is formed.

The valve housing 13 is formed by attaching a valve case 12 made of a fiber-containing PEEK material to the outer periphery of a fluororesin valve block 11A expanded at the time of injection molding. At the time when cooling is started and heat shrinkage is started at the same time, and when the mold is taken out of the mold and cooled to room temperature, a gap is likely to be generated in the joint surface between the valve block 11A and the valve case 12 due to the difference in the heat shrinkage ratio between the two. However, the annular reinforcing projections 46, 47 and the sealing projections 48, 49 fitted in the annular locking grooves 30, 31 and the annular locking grooves 32, 33 formed in the outer periphery of the valve block 11A are simultaneously injection-molded. By doing so, the valve block 11A and the valve case 12 maintain the mechanical integrity and reinforce the strength for the reason described below, and also maintain the airtightness of the joint surface to prevent air leakage. It is integrally molded with no decrease in the adsorption force due.

In the molding of the valve housing 13, the valve block 11 A inserted into the molding space 45 of the molding die device 26 first starts expanding by heating the molding die device 26, and the valve block 11 A enters the molding space 45. It is further heated by the high-temperature injection resin material filled in the molten state, and the volume expands and acts to expand the dimensions. Therefore, the dimensions are expanded by pressing the valve block 11A from the outer periphery with the injection pressure of the injection resin material. In some cases, the molding conditions are set so that the valve block 11A is heated to a temperature equal to or higher than the melting point with an injection resin material so that the surface is melted, and the external dimensions of the block 11A are slightly compressed from those at normal temperature. It is desirable to perform pressure molding, and if the injection pressure is increased further, the block released from the above-mentioned suppression will be opened when the mold is opened after molding. 11A there is a risk of causing a crack from the split surface of the mold to be a valve casing 12 formed by the expansion of, there is a risk of causing fluid leakage from the joint surface can not be obtained sufficient injection when the injection pressure is too low.

When the valve housing 13 formed by the injection-molded valve block 11A and the valve case 12 is opened and separated from the mold, the valve case 12 cooled by contact with the outside air immediately starts to contract and is set in a short time. Although the surface of the valve block 11A reaches room temperature, latent heat remains inside the valve block 11A. Therefore, the valve block 11A does not immediately start contracting, but once expands and then contracts sequentially to determine the predetermined size. And
In the meantime, the valve case 12 elastically surrounds the outer periphery so as to follow the expanding / contracting valve block 11A, so that there is no gap at the boundary surface as much as the difference in thermal shrinkage between the two. Is integrated. In addition, since the valve case 12 after the completion of the molding slightly contracts from that at the time of the pressure molding, the molding space 45 of the mold is formed in anticipation of the contraction.
Needs to be set slightly larger than the outer shape of.

The contraction of the valve block 11A is described with reference to FIG.
As shown by, in the X-axis direction along the horizontal plane and in the Y-axis direction along the vertical plane, each shrinks inward as indicated by the arrow, and the space due to this shrinkage is extremely small in size. However, this is an important problem that cannot be ignored for the valve unit that controls the opening and closing of the flow path of the high-pressure fluid. That is, when the injection molding is performed on the valve block 11A in the above embodiment without the annular locking grooves 30, 31 and the annular locking grooves 32, 33, the synthetic resin material having a small heat shrinkage is used. As shown in FIG. 6, gaps 52 and 53 are formed between the inner peripheral side of the valve case 12 formed by the above and the outer peripheral side of the valve block 11A formed of a synthetic resin material having a high heat shrinkage. Since the joints are loosely fitted, the gaps 52, 5
There is a possibility that the fluid in the flow path leaks to the outside via the flow path 3.

The valve block 11A has a circular projection 27.
The valve body 11 is formed by drilling a valve guide hole 16 from the portion of the valve body 1, and the valve body 1 sliding on the valve seat surface is provided in the valve guide hole 16.
Since the valve opening / closing mechanism including the valve 7 is mounted, it is indispensable for the valve guide hole 16 to be always kept in a constant shape in order to perform a stable valve opening / closing operation. Needless to say, the valve body 11 itself is not easily deformed, and it is necessary to protect the valve body 11 from being deformed by the valve case 12. However, when the valve body 11 is formed of a flexible synthetic resin material having a large heat shrinkage rate such as a fluororesin material, the valve body 11 expands or contracts depending on the ambient temperature conditions used. Also, when the valve case 12 is gripped and the operation button 3 is operated to open and close the valve, the valve case 12 and the valve block 11A may be deformed due to an external force.

However, the valve block 1 as an insert member
1A are provided with annular locking grooves 32, 33, and sealing projections 48, 49 protrudingly formed in the annular locking grooves 32, 33.
Is provided in the valve case 12 formed of a molding resin material, for example, as shown in FIG. 6A in which the region V in FIG. 5 is enlarged, the valve block 11A is positioned on a horizontal plane in the Y-axis direction. When contracted inward in the X-axis direction along
Since the pressure contact portion 54 in which the inner wall surface on one side of the second 2 is pressed against the outer wall surface on one side of the sealing projections 48 and 49 is formed, even if a gap is formed at another boundary portion, the fluid is blocked by the pressure contact portion 54 and fluid leakage is prevented. Does not occur.

The valve block 1 as an insert member
1A are provided with annular locking grooves 30 and 31, and reinforcing projections 46 and 47 formed to project into the annular locking grooves 30 and 31.
Is provided in the valve case 12 formed of a molding resin material, for example, as shown in FIG. 6B in which a region H in FIG. 5 is enlarged, the valve block 11A is positioned on a horizontal plane in the Y-axis direction. When contracted inward in the X-axis direction along
2 has a pressure contact portion 55 in which the inner wall surface on one side is pressed against the outer wall surface on one side of the reinforcing projections 46 and 47.
8, 49, the valve case 12 is drawn in the Y-axis direction by this press-contact portion 55, and the contraction of the outer peripheral surface of the circular projection 27 is restricted. Are joined at a boundary where no gap 53 is formed, thereby reinforcing the valve case 12 and preventing deformation of the valve block 11A, and strengthening the outer periphery of the on-off valve mechanism to be mounted later. it can.
Therefore, the reinforcing projections 4 fitted into the annular locking grooves 30, 31
6 and 47 prevent the valve guide hole 16 forming the valve seat surface from expanding and contracting under ambient temperature conditions. Since there is no deformation, stable operation of the on-off valve is ensured for a long period of time.

The valve housing 13 is taken out of the molding die device 26 after molding, and subjected to additional processing such as drilling and cutting using a machine tool such as a drilling machine or a lathe equipped with necessary jigs and tools. You. As these additional processes, a valve guide hole 16 is formed in the valve block 11A so as to be orthogonal to the axial direction from the circular projection 27 side, and thereby the injection molding is performed on the outer periphery of the circular projection 27 which has become a cylindrical body. An outer peripheral screw 22 a is engraved on the outer peripheral surface of the cylindrical body to form a screw cylinder 22, and a breathing hole 21 is formed in the valve case 12 at an axial position of the valve guide hole 16. Also,
A communication hole 15 that is orthogonal to the valve guide hole 16 and communicates between the upstream flow path 14A and the downstream flow path 14B is formed in the valve block 11A.
And a lower end thereof, a bypass flow passage 25 communicating between the upstream flow passage 14A and the valve guide hole 15 and one end of the valve case 12 forming the downstream flow passage 14B. An inner peripheral screw 12b for connection is engraved on the inner wall surface on the side, and an outer peripheral screw 12a formed on the outer wall surface on the other end side of the valve case 12 forming the upstream flow path 14A is subjected to finish processing, whereby an insert member is used. A certain valve block 11A is finished in the form of the final valve body 11.

As shown in FIG. 7, in the valve housing 13 on which additional processing has been performed, the valve guide hole 16 accommodates the upper end of the valve spring 18 in the concave fitting portion 20 provided on the lower end of the valve body 17. The valve spring 18 and the valve body 17 are mounted in a manner, and the external thread 22 of the screw cylinder 22 formed at the upper end opening of the valve guide hole 16 is mounted.
a screw cap 23 is screwed onto the screw cap 23 to prevent the valve element 17 from coming off and locked.
Of the valve body 17 protruding upward through the slidably inserted
2, the valve stem 24 is inserted, and the operation button 3 attached to the upper end side of the valve stem 24 is connected by a locking shaft 51 such as a pin or a screw shaft, and is integrally unitized as shown in FIG. The valve unit 6 is configured.

The external thread 2 of the screw cylinder 22 shown in FIG.
Instead of the structure in which the screw cap 23 is attached to the valve body 2a to hold down the valve element 17, the valve guide hole 1 as shown in FIG.
6 is provided with a screw cylinder 56 provided with an internal screw 56a at the upper end opening thereof. After a holding member 57 such as a flanged bush is mounted in the screw cylinder 56, an external screw 58a screwed to the internal screw 56a is provided. Screw the applied cylindrical screw 58,
As a result, there is also a mode in which the valve element 17 housed in the valve guide hole 16 is stopped and locked.

Further, in the above-described embodiment, the present invention is applied to an opening / closing valve structure in which a flow path is opened and closed by sliding a valve body as a closing member up and down along a valve thrust hole formed with a valve seat. However, the present invention is not limited to such an on-off valve structure, and the flow passage is formed by rotating a valve body along a valve seat as in a known ball valve or, for example, as shown in FIG. The present invention is also applicable to a valve unit using a cock-type on-off valve structure for opening and closing.

The valve unit 106 shown in FIG. 9 is similar to the valve unit 6 of the above-described embodiment in that the valve body 1
11 is used as an insert member, and a valve case 112 is injection-molded around its outer periphery to form an integral valve housing 113.
Is formed, and the valve body 1 inserted by the injection molding
11, the annular locking grooves 130, 131, 132, 1
33, the reinforcing projections 146, 147 and the sealing projections 148, 149, which are respectively fitted into the annular locking grooves during injection molding, are formed so as to protrude from the inner surface of the valve case 112. It is configured such that the same effect as that of the embodiment can be obtained.

In the on-off valve structure according to this embodiment, a communication hole 115 for communicating the upstream flow path 114A and the downstream flow path 114B is provided at the axis of the valve body 111 constituting the valve housing 113. A frustoconical valve guide hole 116 is provided in a manner orthogonal to the communication hole 115,
The valve guide hole 116 rotatably accommodates a frusto-conical valve element 117 having a horizontal through-hole 119 formed in an intermediate portion. When the valve element 117 is rotated, the through-hole 119 is connected to the communication hole 1.
When the position is adjusted to 15, the upstream channel 114A and the downstream channel 114B are configured to communicate with each other. Valve body 1
A valve stem 127 protrudes from the upper end of the valve stem 17.
Of the valve guide hole 116, and the screw cap 123 is screwed into the screw tube 122 formed on the outer periphery of the upper end opening.
The valve body 117 and the valve rod 124 are rotatably retained and locked, and the operation button 103 is provided on the upper end of the valve rod 124 with the locking shaft 1.
51 is attached.

[0045]

As is apparent from the above description, in the valve unit of the present invention, the valve in which the opening / closing valve mechanism is mounted using a synthetic resin material having a small sliding friction coefficient and suitable for sliding the valve body. Since the main body is formed and the valve main body is integrally buried in a valve case having heat and chemical resistance and injection-molded with a rigid synthetic resin material, the built-in opening / closing valve mechanism is provided for the valve main body. By utilizing the self-lubricating property, accurate and stable operation of the opening / closing valve can be performed, and at the same time, the valve is protected by a rigid valve case and deformation due to external force is prevented.

As the synthetic resin material constituting the valve case, for example, a synthetic resin material having conductivity, such as a PEEK material containing fiber, is used. Generation of static electricity that damages the object to be adsorbed is suppressed by the coated valve case.

Further, the valve body is integrally joined to the valve case without using a member which is easily deteriorated or deteriorated under the influence of heat or chemical, for example, a metal member such as a screw or a rubber seal member such as an O-ring. As a result, stable performance is ensured for a long time regardless of the fluid to be handled and the external atmosphere.Particularly, when used as a valve unit for vacuum tweezers, particles generated from damaged parts may cause wafers, etc. The risk of contaminating is reduced.

Further, when the valve case is injection-molded, a synthetic resin for forming the valve body is formed by simultaneously injection-molding an annular sealing projection fitted into an annular locking groove formed in the outer periphery of the valve body. Even when the material and the synthetic resin material forming the valve case have different coefficients of thermal expansion, a gap due to shrinkage is prevented from being formed at the joint surface between the two when injection molded and cooled, so that mechanical Risks such as loss of strength due to loss of integrity and loss of suction due to air leakage due to loss of airtightness are also eliminated.

In particular, as the synthetic resin material forming the valve body, a fluororesin material having a particularly high thermal expansion coefficient is used among the synthetic resin materials, and as a synthetic resin material forming the valve case, a fiber-containing PEEK having an extremely low thermal expansion coefficient is used. It has been confirmed by the present applicant that the sealing projection functions effectively even when there is a large difference in the molding heat shrinkage as in the case of using a material.

When the valve case is injection-molded, an annular reinforcing projection fitted into an annular locking groove formed in the outer periphery of the valve guide hole in which the opening / closing valve mechanism is mounted is simultaneously injection-molded and reinforced. By constructing an integrated valve housing,
Prevents the valve guide hole, which forms the valve seat surface on which the valve slides, from expanding and contracting due to ambient temperature conditions and external forces due to the gripping operation, and makes the opening and closing valve operation by the valve stable over a long period of time. be able to.

Further, a screw cylinder having a valve case provided with an external thread or an internal thread is protrudingly provided on the outer periphery of the upper end edge of the valve guide hole, and a screw cap is attached to the screw cylinder for locking the valve. By doing so, it is possible to prevent the opening / closing valve mechanism from falling off due to the fluid pressure and prevent the valve seat formed in the valve guide hole from being deformed by an external force.

Further, the valve unit of the present invention not only has a valve structure for opening and closing the flow path by sliding the valve element up and down with respect to the flow path, but also rotates the valve element mounted in the flow path. It can be applied to various valve structures including a cock type that opens and closes a flow path, and its application is not limited to vacuum tweezers described in the embodiment, but a wide range of applications where the features of the present invention can be utilized It can be applied to

[Brief description of the drawings]

FIG. 1 is a front view showing the overall shape of vacuum tweezers in which a valve unit of the present invention is applied to an on-off valve for a suction passage by vacuum pressure.

FIG. 2 is a central longitudinal sectional view showing an embodiment of the valve unit according to the present invention.

3A and 3B are valve blocks used as inserts of a valve housing in the valve unit of FIG. 2, wherein FIG. 3A is a perspective view and FIG. 3B is a longitudinal sectional view.

FIG. 4 is a longitudinal sectional view of a main part of a mold apparatus for manufacturing a valve housing by injection molding a valve case on the outer periphery of the valve block of FIG. 3;

5 shows a front view in cross section of the upper half of the valve housing taken out of the mold apparatus of FIG. 3 by injection molding.

FIGS. 6A and 6B are enlarged cross-sectional views of main parts of FIG. 5, wherein FIG. 6A is an enlarged cross-sectional view of main parts of a V portion, and FIG.

FIG. 7 is an exploded perspective view illustrating an assembled state of a valve mechanism in the valve unit of FIG. 2;

FIG. 8 shows another embodiment of the valve body pressing structure in the valve unit of the present invention.

FIG. 9 shows an embodiment of another valve structure in the valve unit of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Tweezer main body 2 Suction adapter 3,103 Operation button 4 Suction port 5 Suction tip 6 Valve unit 7 Extension cylinder 7a, 9 Connector 8 Connecting cylinder 10 Suction hose 11,111 Valve body 11A Valve block 12,112 Valve case 13,113 Valve Housing 14A Upstream flow path 14B Downstream flow path 15 Communication hole 16 Valve guide hole 17,117 Valve body 18 Valve spring 19,119 Annular groove 20 Recessed portion 21 Respiration hole 22,122 Screw cylinder 23,123 Screw cap 24, 124 Valve stem 25 Bypass flow path 26 Mold device 26A Fixed type 26B Movable type 27 Circular projection 28,29 Circular slot 30.31 (Inner) annular locking groove 32,33 (outer) annular locking groove 34 Ejector plate 35 Fixed side plate 36 Angular pin 37 Movable side plate 38, 39% Block 40 ejector pin 41 guide holes 42 the fixed support pins 43 movable support pins 44 thread groove 45 forming space 45a, 45b
Molding grooves 46, 47 Reinforcement protrusions 48, 49 Sealing protrusions 50 Shaft cylinder 51 Locking shaft 52, 53 Void portion 54, 55 Press-contact portion 56 Screw cylinder 57, 157 Holding member 58 Cylindrical screw 130, 131 (Inside) annular Locking grooves 132, 133 (Outer) annular locking grooves 146, 147 Reinforcement protrusions 148, 149 Sealing protrusions 114A Upstream flow path 114B Downstream flow path

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-105879 (JP, A) JP-A-62-1115581 (JP, U) JP-B-8-15709 (JP, B2) JP-B 5-5- 75554 (JP, B2) JP 4-57916 (JP, B2) JP 63-9151 (JP, B2) JP 3-50672 (JP, B2) JP 4-18179 (JP, B2) Japanese Patent Publication No. 7-30845 (JP, B2) (58) Fields surveyed (Int. Cl. ⁷ , DB name) F16K 27/00-27/12 F16K 5/00-5/20 H01L 21/68

Claims (9)

(57) [Claims] 1. A valve body having a valve guide hole serving as a valve seat surface in a manner orthogonal to the flow path, wherein the valve body has a cylindrical body in which a flow path communicating the upstream side and the downstream side is formed. A valve housing is formed by a valve case that covers the outer periphery of the valve body,
An on-off valve mechanism is mounted in the valve guide hole, the valve body is formed of a heat-resistant and chemical-resistant, self-lubricating synthetic resin material, and the valve case is heat-resistant, chemical-resistant and highly rigid. The valve unit is made of a synthetic resin material different from the above, and the valve case is integrally formed by injection molding using a valve block forming the valve body as an insert member. 2. An annular locking groove is formed in an outer peripheral surface of the valve body at a position upstream and downstream of the valve guide hole, and the annular locking groove is formed in an inner peripheral surface of the valve case. 2. The valve unit according to claim 1, wherein a sealing projection is provided so as to fit into the valve case, and the sealing projection is formed integrally when the valve case is injection-molded. 3. An annular locking groove is recessed in the valve body adjacent to an upper end side where the valve guide hole is opened, and is fitted in the annular locking groove on an inner peripheral surface of the valve case. 3. The valve unit according to claim 1, wherein a reinforcing projection is provided so as to be integrally formed when the valve case is injection-molded. 4. 4. The valve body has a circular projection on the upper end side where the valve guide hole is opened, the annular locking groove is recessed on the outer periphery of the circular projection on the base side, and the circular shape is provided on the valve case. 4. The valve unit according to claim 3, wherein an outer screw cylinder is formed on an outer periphery of the projection, and the opening / closing valve mechanism mounted in the valve guide hole is locked by a screw cap screwed to the outer screw cylinder. 5. An inner screw cylinder is formed in the valve case so as to protrude from an outer side of the reinforcing protrusion to an outer periphery on an upper end side where the valve guide hole is opened, and the valve guide hole is formed in the inner screw cylinder. 4. The valve unit according to claim 3, wherein a holding member of the opening / closing valve mechanism mounted on the inner screw cylinder is mounted, and a screw cap is screwed onto the inner screw cylinder to lock the opening / closing valve mechanism. 6. The valve mechanism according to claim 6, wherein the valve mechanism slides up and down along the valve guide hole to open and close the flow path, and the valve element is resilient in one of an open state and a closed state. 6. A valve spring according to claim 1, wherein said valve spring is biased and said valve operating means moves said valve body up and down to one of a valve-open state and a valve-close state in opposition to said valve spring. The valve unit described in crab. 7. The open / close valve mechanism includes a valve body that rotates along the valve guide hole to open and close a flow path, and a valve operating unit that rotationally operates the valve body to open or close the valve. The valve unit according to any one of claims 1 to 5, which is configured. 8. The valve unit according to claim 1, wherein the valve case is formed of a conductive synthetic resin material. 9. The valve unit according to claim 1, wherein the valve body is formed of a tetrafluoroethylene material, and the valve case is formed of carbon fiber-containing polyetheretherketone.