JP2549914Y2 - Parent-child valve for vacuum equipment - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a parent-child valve for a vacuum device provided in an exhaust passage in, for example, a semiconductor manufacturing facility.

[0002]

2. Description of the Related Art Since a vacuum chamber in a semiconductor manufacturing facility needs to be set to a high vacuum in a short time, it is desired that a stop valve provided in an exhaust passage has as low resistance and large capacity as possible. However, when such a stop valve is used, turbulence is likely to occur due to a high evacuation speed at the start of the vacuum pump, and fine particles adhering to the flow path wall and the like are separated and scattered. .

Therefore, conventionally, a large-capacity parent valve and a small-capacity child valve are provided in parallel, and at the beginning of evacuation, only the child valve is opened to perform low-speed evacuation. I was Therefore, not only is the equipment cost high, but the required space is large, and the operability is poor.

In order to eliminate such difficulties, the inventor of the present invention has previously proposed an integrated master valve and child valve (Japanese Utility Model Application No. 2-96449). In this proposal, the disclosed embodiment (see FIG. 3, hereinafter referred to as a conventional example) includes a common valve shaft c for opening and closing the parent valve a and the child valve b, and the valve shaft c corresponds to the parent valve a. It is configured to be controlled in two stages of a wide range and a narrow range corresponding to the child valve b. The means for controlling the exhaust capacity of the slave valve b in accordance with the target vacuum device includes forming an inclined portion e on the piston d frictionally engaging with the valve shaft c, and adjusting screw f which comes into contact with the inclined portion e. Is configured to regulate the amount of movement of the piston d in the opening direction in accordance with the amount of protrusion of the piston d.

[0005]

According to the above prior art, the problems relating to equipment cost, required space, operability, etc. can be solved. However, in the adjusting means constructed as described above, the inclined portion e is adjusted by the adjusting screw f. When it comes into contact with the piston, the piston d may be inclined to hinder the smooth operation of the valve shaft c. In order to prevent this, a plurality of adjusting screws f are arranged in the circumferential direction and these are evenly adjusted. Must. Therefore, it takes time and effort to perform the adjustment work, and it is difficult to make an accurate adjustment, particularly when the equipment space is small.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and provides a parent-child valve for a vacuum device having a child-valve exhaust displacement control means which operates smoothly and is easily adjusted. The purpose is to:

[0007]

According to the present invention, there is provided a main valve body which is openably and closably opposed to a main valve hole and supported by a valve shaft so as to be relatively displaceable, and a sub valve hole formed in the main valve body. A sub-valve supported by the valve shaft so as to be openable and closable, a driving body frictionally engaged with the valve shaft for driving the sub-valve, and a control means for regulating the amount of movement of the driving body in the opening direction. Wherein the control means comprises a pair of wedge-shaped cams that are axially superposed facing the driver and a means for adjusting and setting the superimposed thickness of these cams. It is characterized by the following.

[0008]

In the above construction, at the beginning of the exhaust, the moving amount of the driving body is restricted by the wedge-shaped cam, so that the moving amount of the valve shaft is also restricted. Will be In this case, since the driving body does not tilt even when pressed against the wedge-shaped cam, a smooth operation is performed, and the overlapping thickness of the cam can be adjusted with only one of the cams, so that the operation is simple and easy. Done. Then, after the degree of vacuum of the target device reaches the desired level, the valve shaft is further moved to open the main valve hole, and high-speed exhaust is performed by the master valve.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to one embodiment shown in FIGS. In FIG.
Includes a main body 2, a cylindrical portion 3 and a lid 4 connected to the main body 2 in the axial direction, and a valve shaft 5 is provided inside the main body 2 so as to be able to reciprocate in the axial direction.

The main body 2 is formed with an inflow passage 6, an outflow passage 7, and a large-diameter main valve hole 8 interposed therebetween, and a main valve seat 9 is formed around the periphery of the main valve hole 8. Is provided. A main valve body 10 which forms a parent valve together with the main valve seat 9
The spring 1 is supported by the valve shaft 5 via the support member 11 so as to be relatively displaceable in the axial direction, and is interposed between the spring seat 12 locked to the valve shaft 5 and the support member 11.
In a state of being urged in the closing direction by 3, it opposes the main valve seat 9 in a detachable manner.

The main valve body 10 is provided with a small-diameter sub-valve hole 14, and a sub-valve seat 15 is provided at a peripheral portion thereof. A sub-valve element 16 that constitutes a child valve together with the sub-valve seat 15 is fixed to one end of the valve shaft 5. Sub-valve 16
Is provided with a locking portion 17 having an outer diameter larger than the valve shaft 5 and coming into contact with the support member 11 so as to be able to freely contact and separate therefrom. Further, a diaphragm 18 having an outer peripheral portion sandwiched between the main valve body 10 and the support member 11 has a center portion attached to the sub-valve body 16 and a bellows 19 having one end connected to the support member 11. The other end flange portion 20 is sandwiched between the main body 2 and the tubular portion 3. The main valve body 10 has an auxiliary valve hole 1
When the opening 4 is in the open state, a communication hole 21 that connects the inflow path 6 and the outflow path 7 is opened. An axial through hole 22 is formed in the support member 11, and the flange portion 20 is formed.
A communication passage 23 is provided between the main body 2 and the cylindrical portion 3 for communicating the inside of the bellows 19 with the outside air.

A flange portion 25 of a guide tube 24 is attached to one end of the tubular portion 3, and the valve shaft 5 is connected to the guide tube 2.
4 and extends inside the lid 4. Cylindrical part 3
Is a piston 2 mounted therein and frictionally engaged with the valve shaft 5.
6 together with a drive unit for a child valve, and is provided with a compressed air circulation hole 27 that opens toward the flange 25. And
Between the other end wall 28 of the cylindrical portion 3 and the piston 26, there is provided a control means 29 for regulating and setting the amount of movement of the piston 26 in the opening direction in order to adjust the opening of the child valve as described later. I have.

A spring seat 30 is attached to the other end of the valve shaft 5 so as to be located in the lid 4. A spring 31 (two pairs in the figure) is provided between the spring seat 30 and the lid 4. Is interposed). The outer periphery and the inner periphery of the diaphragm 32 are sandwiched between the cylindrical portion 3 and the lid 4 and between the spring seat 30 and the holding plate 33, respectively. These springs 31
The diaphragm 32 and the like constitute a parent valve drive unit, and include a compressed air circulation hole 34 formed in the tubular portion 3.

The control means 29 comprises a pair of axially superposed wedge-shaped cams 35 located between the other end wall 28 of the cylindrical part 3 and the piston 26 and the cylindrical part 3.
And an adjusting screw 36 to be screwed with the screw hole opened in the first embodiment. As shown in FIG. 2, the cam 35 has a triangular shape in cross section with inclined surfaces 37 slidably contacting each other, is formed so as not to interfere with the valve shaft 5, and is long on the side wall 38 in the axial direction. An oval through hole 39 is provided. The inner end of the adjusting screw 36 is connected to the through hole 39 via a washer 40 and an E-ring 41, and the cam 35 and the adjusting screw 3
6 are movable in the diametric direction of the valve shaft 5 and relatively displaceable in the axial direction. Therefore, when the adjusting screw 36 is rotated, the cam 35 is moved in parallel in the diameter direction of the valve shaft 5, and the overlap thickness t is variably set according to the relative movement amount of both cams. The amount of movement of the cam 35 in the diameter direction by the adjusting screw 36 and the angle of inclination of the inclined surface 37 can cover a desired range of the superposed thickness only with the other cam when one of the cams is set at the outermost position. It is configured as follows. Therefore, it is preferable to set the cam which is considered to be difficult to operate after the equipment to the outermost position in advance. Note that a lock nut 42 (see FIG. 1) is attached to the adjustment screw 36 so as to be located outside the cylindrical portion 3.

Next, the operation of the above embodiment will be described. The inflow passage 3 and the outflow passage 4 are respectively connected to a vacuum chamber and a vacuum pump (both not shown), and the control means 29 controls the exhaust capacity of the slave valve, that is, the overlapping thickness t of the cam 35 to the above-mentioned. It is assumed that the adjustment screw 36 is set so as to be adapted to the vacuum chamber.

When the vacuum pump is not in use, the main valve body 10 and the sub-valve body 16 are pressed against the main valve seat 9 and the sub-valve seat 15 by the restoring force of the springs 13 and 31, respectively. 8 and the auxiliary valve hole 14 are both in a closed state,
The inflow channel 3 and the outflow channel 4 are shut off from each other. When the vacuum pump is in the operating state, compressed air is injected from the compressed air flow hole 27 of the child valve driving unit 27 to the piston 26.
At the same time, the valve shaft 5 is moved in the compression direction of the spring 31, the sub-valve element 16 is separated from the sub-valve seat 15, and the sub-valve hole 14 is opened. Then, when the piston 26 is moved until it comes into contact with the cam 35, the sub-valve hole 14, that is, the child valve has the opening degree set by the control means 29 in advance. In this case, the spring 13 is slightly extended, but the main valve body 10 is connected to the main valve seat 9.
The main valve hole 8 is maintained in a closed state because it has a sufficient restoring force to press against the main valve hole 8. Therefore, in this state, low-speed exhaust is performed in the direction of the inflow path 6 → the sub-valve hole 14 → the communication hole 21 → the outflow path 7.

When the degree of vacuum in the vacuum chamber reaches a desired level, the compressed air flow hole 3
When pressurized air is press-fitted from the diaphragm 4, the pressing plate 33 and the spring seat 30 are moved by the thrust acting on the diaphragm 32.
The valve shaft 5 is also moved in the same direction. As a result, when the locking portion 17 provided on the sub-valve body 16 comes into contact with the support member 11, the main valve body 10 moves together with the valve shaft 5 and is separated from the main valve seat 9, and the main valve hole 8 is opened. The degree is set to a desired level according to the pressure of the compressed air. In this case, high-speed exhaust is performed with the valve hole 8 and the sub-valve hole 14 connected in parallel.

That is, in the device constructed as described above, the main valve body 10 can be driven over a wide range and the sub-valve body 16 can be driven over a narrow range by means of the common valve shaft 15, so that the parent valve and the child valve are connected to these components. It can be incorporated in parallel into one valve box 1 having a common inflow path 6 and a common outflow path 7, so that the installation work including the piping is simple and easy, and the required space is small. Is also very simple. Further, since the opening degree of the child valve can be set sufficiently small, the flow rate is limited at the beginning of the operation, and the occurrence of separation and scattering of fine particles in the vacuum apparatus can be effectively prevented.

Further, since the control means 29 is provided with a pair of wedge-shaped cams 35 superposed in the axial direction and an adjusting screw 36 for variably setting the superposed thickness t of these cams 35,
Even when the piston 26 is pressed against the cam 35, the piston 26 does not tilt and a smooth operation is performed. Further, since the above-mentioned superposed thickness t can be set with only one of the adjusting screws 36, the adjusting operation is simple and easy, and the adjusting operation can be correctly adjusted especially even when the working place is narrow.

The present invention is not limited to the above-described embodiment. For example, the control means 29 may be a combination of a plurality of wedge cams. In addition, various modifications and applications are possible within the scope of the gist of the present invention.

[0021]

As described above, according to the present invention, it is possible to provide a parent-child valve for a vacuum apparatus having a child valve exhaust capacity control means which operates smoothly and is easy to adjust.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIGS. 2A and 2B show control means in the embodiment, wherein FIG. 2A is an exploded perspective view and FIG.

FIG. 3 is a sectional view showing a conventional example.

[Explanation of symbols]

5 ... valve shaft, 8 ... main valve hole, 10 ... main valve body, 14 ... sub valve hole,
16: Sub-valve element, 26: Piston (drive body), 29: Control means, 35: Wedge cam, 36: Adjustment screw (Adjustment means).

Claims (1)

(57) [Scope of request for utility model registration] 1. A main valve body which is openably and closably opposed to a main valve hole and supported by a valve shaft so as to be relatively displaceable, and said valve which is openably and closably opposed to an auxiliary valve hole formed in the main valve body. Vacuum device parent and child provided with a sub-valve supported by a shaft, a driving body that frictionally engages with the valve shaft to drive the sub-valve, and a control unit that regulates the amount of movement of the driving body in the opening direction. In the valve, the control means includes a pair of wedge-shaped cams, which are axially overlapped with the driving body, and means for adjusting the overlap thickness of the cams, wherein the parent-child valve for a vacuum device is provided. .