JP3239166B2 - Flow control valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flow control valve installed in a pipe between a pump and a vessel of a vacuum apparatus for shutting off the vacuum pump and the vacuum vessel and controlling the flow rate when the vacuum pump is operated.

[0002]

2. Description of the Related Art In a vacuum apparatus, for example, a vacuum evaporation apparatus used to form a metal deposition film on the surface of a semiconductor wafer, first, the inside of a deposition chamber is evacuated to a high vacuum by a vacuum pump, and after the deposition is completed, the deposition is completed. The pressure in the room is returned to the atmospheric pressure.

[0003] First, when a vacuum device in an atmospheric pressure state is evacuated by a rotary pump or the like, the load is too large to suck the gas in a large-capacity vacuum chamber by the rotary pump. A valve is provided between the valves, the valve is first closed, the rotary pump is started, a small amount of air is sucked between the valve and the rotary pump, the valve is started with a small load, and the valve is gradually opened to open the vacuum chamber. Try to get closer to vacuum. The valves used at this time consist of a total of three valves in which a roughing valve and a slow exhaust valve are connected in parallel and a flow control valve is further provided in series with the slow exhaust valve. It has been proposed that the flow rate of the gas in the viscous flow region is reduced to such an extent that the gas is not disturbed, and then the roughing rotary pump is started after the flow rate is roughly reduced by the slow exhaust valve. This makes it easier to start the rotary pump with a light load, and also removes dust from the bottom of the chamber when sucking and exhausting gas in the vacuum chamber, especially when a large amount of gas is removed in a viscous region where gas is large. It is prevented from being wound up by viscous gas and attached to a wafer or the like.

As a valve used in such a vacuum device, for example, a valve element which is opened by a predetermined suction force or more is connected to a bellows to act as a slow exhaust valve used for a vacuum exhaust unit and a flow control valve, and acts on the bellows. There has been proposed a valve configured to operate its valve body in the opening direction according to the degree of vacuum in the vacuum chamber. When the pump is started by using this valve, the valve body does not open until a predetermined vacuum pressure, the pump is easily started, and when the vacuum chamber gradually becomes low pressure due to the vacuum leaking from the gap of the valve body, Due to the low pressure, the bellows operates the valve pressure in the opening direction, and opens the valve body in proportion to the decrease in the pressure.

When the above-described proportional valve is used, the valve body must be kept closed until a predetermined vacuum is reached by one valve body. Therefore, a spring for urging the valve body in the closing direction is increased. I had to. Correspondingly, the bellows operating against the spring must be enlarged, and there is a disadvantage that the valve itself becomes large. In addition, since the valve is opened in accordance with the pressure in the vacuum chamber, the time until the maximum opening of the valve is long, and the operating speed is low.

In order to eliminate the drawbacks of such a valve, a main valve and an auxiliary valve are provided in a valve body, and when evacuating the vacuum chamber in the atmospheric state, the bellows is operated by the vacuum generated by the operation of the pump. The sub-valve is gradually opened, and as a result, the pressure in the vacuum chamber is reduced. As a result of the decrease in the differential pressure across the main valve, the applicant has previously proposed a valve for opening the main valve. I have.

[0007]

In the above valve, a part of the valve is opened in accordance with the vacuum pressure at the initial stage of the operation of the pump using the auxiliary valve, so that the valve body is urged in the valve closing direction. The size of the spring can be reduced, and the bellows that operates against the spring can be reduced in size. The overall size of the valve can also be reduced. Therefore, accurate adjustment is difficult, and the adjustment range is limited. Further, since the pressure when the main valve is opened is affected by the weight of the valve, the exhaust time tends to be prolonged.

In addition, since the sealing property when the valve is fully closed is not always sufficient, means for closing a separately provided shut-off valve is required when the valve is fully closed, and the apparatus tends to be complicated and expensive.

Accordingly, the present invention provides a flow control capable of adjusting the opening and closing characteristics of a valve in a wide and accurate range, eliminating the need for a separate shut-off valve, and simplifying the apparatus and reducing the cost. The purpose is to provide a valve.

[0010]

According to the present invention, a first opening communicating with the vacuum pump and a second opening communicating with the vacuum container are provided in a connecting line between the vacuum pump and the vacuum container. A valve body provided with a valve body, the valve body being urged by a spring to close the valve seat from the second opening side, and a difference between the first opening and the atmospheric pressure engaged with the valve body. A bellows arranged to open the valve body in response to pressure, and a shut-off lever for holding the valve body at a fully closed position and a closed release position are connected to the valve body, and the valve body is A bypass path communicating the first opening and the second opening is provided separately from the valve seat, and a proportional control valve provided with an adjustment valve in the bypass path and a connection pipe line between the vacuum pump and the vacuum vessel, The first opening communicating with the second opening communicating with the vacuum vessel
A valve body provided with a valve seat in the valve body having an opening, and a valve body urged by a spring to close the valve seat from the second opening side;
A first bellows arranged to engage with a sub-valve inside the valve body to open the sub-valve in response to a pressure difference between the pressure of the first opening and the atmospheric pressure; A second bellows arranged to open the valve body in response to a pressure difference from the atmospheric pressure, and a shut-off lever for holding the valve body and the sub-valve in a fully closed position and a closed release position. And a proportional control valve provided with a bypass communication hole communicating the first opening and the second opening through the sub-valve opening in the valve body. The range of adjustment of the opening and closing characteristics can be widened and accurately performed, there is no need to separately provide a shut-off valve, and the apparatus can be simplified and inexpensive.

[0011]

According to the present invention, when the inside of the vacuum vessel is evacuated by the operation of the pump, the shut-off lever is set to the release position to operate the pump. At first, a predetermined amount of gas is sucked through the regulating valve provided in the bypass passage, and when the pressure in the pipeline between the valve body and the pump falls to a set value or less, the bellows operates according to the pressure and the valve body is opened. Opening up. After the inside of the vacuum container reaches a predetermined vacuum, the operation of the pump is stopped, and the shut-off lever is operated to hold the pipe in a fully closed state.

[0012]

An embodiment of the present invention will be described with reference to the drawings. 1 to 4 show a first embodiment of the present invention, in which a first opening 1 communicating with a vacuum pump and a second opening 2 communicating with a vacuum vessel.
The pump-side joint 4 and the container-side joint 5 are fixed to each opening of the valve body 3 having the following. A valve seat 6 is provided between each of the openings 1 and 2, and a valve body 7 is provided on the valve seat 6 so as to be able to freely contact and detach.

A bypass passage 10 is provided so as to bypass the opening 8 of the valve seat 6 closed by the valve body 7. The bypass passage 10 has a first communication hole 11 with the first opening 1 and a second communication hole 2.
The bypass passage 10 is provided in the needle valve support 13. The needle valve support 13 has a needle part 14 at the tip and an adjusting screw part 1 at the center outer periphery.
5. A needle valve 17 having an adjustment knob 16 at the rear end is provided.

The rod 20 of the valve body 7 is connected to the partition wall 2 of the valve body 3.
1, and is fixed to a rotation shaft 24 of a shut-off lever 23, which will be described later, provided above the valve body. The upper part of the rod 20 has a screw part 25, a retainer 26 screwed to the screw part, and a support cylinder 28 extending downward at the center of an upper lid 27 closing the upper part of the main body 3.
The valve body 7 is constantly urged to close upward from the lower side of the valve seat 6 by a spring 31 contracted between the lower end supporting portions 30 of the valve body 7.

A receiving plate 32 is fixed to the rod 20,
A bellows 35 is provided between the lower support member 33 fixed to the receiving plate 32 and the upper support member 34 fixed to the lower surface of the upper lid 27 so as to surround the support tube 28. An opening 36 provided in the cylinder 28 communicates with the atmosphere. The chamber 37 outside the bellows 35 communicates with the first opening 1 side through the through hole 22, and the bellows 35 is operated by a pressure difference between the atmospheric pressure and the pressure inside the pump-side passage of the valve 7. . Between the receiving plate 32 and the rod 20, the receiving plate 32 and the lower support member 33, the upper lid 27 and the upper support member 3
The four spaces are sealed so that gas does not leak into the chamber 37.

A substantially U-shaped arm 3 is provided on the upper part of the valve body 3.
8 is fixed, and a shut-off lever 23 that rotates around the rotation shaft 24 is provided above the arm 38.
The shut-off lever 23 has a flat first holding surface 40,
A second holding surface 41 orthogonal to the first holding surface 40 and a lever portion 42 are provided. The axis of the rotation shaft 24 and the first holding surface 40
The distance l ₁ is set to be greater than the distance l ₂ between the axis of the rotation shaft 24 and the second holding surface 41. At a position where the first holding surface 40 abuts on the upper surface of the arm 38 as shown in FIG.
0 is lifted, and the valve element 7 is set to be in close contact with the valve seat 6. Further, at a position where the second holding surface 41 abuts on the upper surface of the arm 38 as shown in FIG. 4, the rotation shaft 24 is located below, and the rod 20 can be lowered,
The valve body 7 is separated from the valve seat 6, and the opening 8 is opened.

In the operation of the flow control valve having the above configuration,
When the vacuum vessel is in a gas pressure state and the pump is operated to evacuate, the valve body 7 is first fully closed by the shut-off lever 23 held at the position shown in FIG. Is also closed.

Prior to the start of operation of the pump, the shut-off lever 23 is rotated as shown in FIG.
1 is a position opposing the upper surface of the arm 38. As a result, the rod 20 can be lowered, and the valve element 7 is in the closed release state via the rod 20.
Since 1 is pulling up the rod 20 via the retainer 26, the valve body 7 is pressed by the valve seat 6 and maintains the valve closed state. Next, the adjustment knob 16 is rotated to retract the needle portion 14 from the valve seat 9 to a preset position by the action of the adjustment screw portion 15, thereby setting the flow path characteristics of the bypass 10.

Next, when the vacuum pump is operated, the pressure on the first opening 1 side communicating with the vacuum pump decreases, and the pressure in the chamber 37 outside the bellows 35 communicating with the first opening 1 also decreases. The bellows 35 tries to extend due to the pressure difference between the bellows 35 and the atmospheric pressure inside the bellows 35 communicating with the atmospheric pressure,
Lower support member 34 connected to bellows 35, receiving plate 32
The force which pushes down the rod 20 and the valve body 7 is generated through this.
The valve element 7 closes until the expansion force of the bellows 35 due to the differential pressure becomes larger than the force of the spring 31 and the valve closing force due to the differential pressure between the first opening 1 and the second opening 2 around the valve element 7. The gas in the vacuum vessel on the second opening 2 side is
Aspirated through 0. Since the passage of the bypass passage 10 is set to be sufficiently small, the vacuum pump performs a small amount of exhausting action, the load at the time of startup is reduced, and dust accumulated in the vacuum vessel is rapidly exhausted. Dust is prevented from floating in the vacuum container.

[0020] By continuing the operation of the vacuum pump, the first
When the pressure in the opening 1 decreases and the extension force of the bellows due to the pressure difference between the pressure in the first opening 1 and the atmospheric pressure exceeds the valve closing force due to the pressure difference between the spring 31 and the valve element 7, the rod 20 is moved by the spring. 31 descends while compressing, the valve element 7 is lowered, and the opening 8 is opened. By opening the opening 8, a large amount of gas in the vacuum vessel is exhausted, and the bypass passage 10
The proportion of exhaust from the air is reduced. In addition, since the gas density is low even when a large amount of evacuation is performed, the load of the pump does not become too large, and the viscosity of the fluid becomes small due to the gas density decrease in the vacuum vessel. Floating dust on the bottom of the container is reduced. When the vacuum pump continues to operate further, as shown in FIG. 4, the pressure in the exhaust passage further decreases, and the valve body 7 further lowers.
The second holding surface 41 abuts on the upper surface of the arm 38, and the maximum opening of the valve body 7 is held at this position.

When the inside of the vacuum vessel has reached a predetermined vacuum state, the operation of the pump is stopped and the shut-off lever 23 is rotated to the position shown in FIG. Adhere to the lower surface. In addition, the adjustment knob 16 is rotated to close the needle valve, close the bypass passage 10, and keep the inside of the vacuum vessel in a sealed state.

In the above device, the operating characteristics of the valve element 7 are as follows:
It can be adjusted by rotating the retainer 26 to adjust the compression force of the spring 31, so that, as shown in FIG. any pressure such as operating point a ₁ to a ₈ in becomes possible to operate the valve body has, after actuation of the valve body becomes a predetermined vacuum state by the operation characteristic curve of such B ₁ to B _8.

By making the opening of the needle valve 17 arbitrarily adjustable, as shown in FIG.
It is possible to adjust the C ₁ to C ₄ by 6 regulation. In this case, at the time of closure of the valve body, the flow characteristics by adjusting the amount of bypass air becomes possible to vary the D ₁ to D ₄ and the like.

A second embodiment of the present invention will be described with reference to FIGS. 7 and 8. Also in this flow control valve, a valve seat 88 is provided on a valve body 65 having a first opening 66 communicating with the vacuum pump and a second opening 68 communicating with the vacuum container in a connecting line between the vacuum pump and the vacuum container. And a valve body 50 urged by a spring 75 described later so as to close the valve seat 88 from the second opening 68 side. In addition, a bypass communication hole 51 formed at the center of the valve body 50 is provided as a bypass passage of the valve body 50.

The bypass communication hole 51 is provided with a sub-valve 52, and a rod 53 of the sub-valve 52 extends upward through a hollow portion in a hollow rod 54 of the valve body 50, and has an upper end provided with a shut-off lever 55. The rotating shaft 56 is fixed. The upper part of the rod 53 is provided with an upper support plate 57,
A first bellows 61 is provided between a lower support plate 60 having an adjustment ring 58 slidable in a sealed state at an upper end of the lower support plate 60. The inside of the first bellows 61 communicates with the gap space 63 of the rod 53 via the upper end opening 62 of the hollow rod 54, and the gap space 63 has a hole 6 formed in the hollow rod 54 below.
4 communicates with the first opening 66 side of the valve body 65, and causes the pump-side pressure of the valve body 50 to act inside the first bellows 61.

A screw 67 formed on the outer periphery of the lower support plate 60
, An adjusting ring 58 is screwed therein, and the contact gap between the upper end surface 70 and the lower end surface 71 of the upper support plate 57 can be adjusted. A spring 75 is provided between the lower support plate 60 and a step 74 formed in the central cylindrical portion 73 of the upper lid 72 covering the upper part of the valve body 65, and the first bellows 61 and the lower support plate 6 are provided.
0, supporting the weight of the adjustment ring 58.

A lower support 77 of the second bellows 76 is fixed to an intermediate portion of the hollow rod 54, and the second bellows 76 is provided between the upper lids 72. The internal space 78 of the second bellows 76 communicates with the atmosphere through the hole 80 of the central cylindrical portion 73 and the support portion of the central cylindrical portion 73 for supporting the spring 75,
The outside of the bellows is connected to the first through a through hole 81 of the valve body 65.
It communicates with the opening side.

As shown in FIG. 8, an arm 82 is fixed to an upper portion of the valve body 65, and a shut-off lever 55 is provided on an upper surface 83 of the arm 82 so that a cam surface 84 can abut. The cam surface 84 of the shut-off lever 55 is
A first cam surface 85 at a distance of l ₁ from 6;
_It has a second cam surface 86 with a distance l ₂ smaller than ₁ and a continuous cam surface 87 therebetween. As shown in FIG. 8, when the first cam surface 85 is in contact with the upper surface 83 of the arm 82, the valve 53 is raised and the sub-valve 52 is raised, so that the valve body 50 is placed on the lower surface of the valve seat 88. Press to close opening 90. When the shut-off lever 55 is tilted to the opposite side to position the second cam surface 86 on the upper surface 83 side, the rod 53 can move the sub-valve 52 by the difference between the distances l ₁ and l ₂ , The valve body 50 can be moved similarly.

When the inside of the vacuum vessel near the atmospheric pressure is evacuated by the operation of the vacuum pump, the flow control valve is operated by the shut-off lever 55 as shown in FIGS.
The main valve 50 is pressed against the valve seat 88 via the sub-valve 52 by raising the rod 53 to seal the opening 90. In this state, the shut-off lever 55 is turned 180
When the sub-valve 52 is rotated by a degree, the sub-valve 52 and the valve body 50 are in a free state, but the spring 75 pushes up the hollow rod 54 of the valve body 50, so that the valve body 50 closes the opening 90.

When the vacuum pump is operated from this state,
The pressure on the first opening 66 side decreases, and this pressure is transmitted to the inside of the first bellows 61 through the hole 64, the gap space 63, and the opening 62, and the first bellows 61 contracts. At that time, the first
Since the lower support plate 60 of the bellows 61 is supported by the spring 75 and the differential pressure across the valve body 50, the upper support plate 57 descends, and the sub-valve 52 descends via the rod 53, and the valve body The bypass communication hole 51 at the center of 50 is opened.
At this time, the pressure at which the sub-valve 52 is opened need only be a very small pressure drop because there is almost no closing force of the sub-valve 52. Therefore, the bypass communication hole 51 is opened almost simultaneously with the operation of the pump. Performs substantially the same function as the bypass communication hole. At this time, the pressure of the first opening 66 also acts on the outer periphery of the second bellows 76, and due to the pressure difference from the atmospheric pressure of the internal chamber 78, the hollow rod 54 is passed through the lower support 77.
, The spring 75 and the valve body 50
It is blocked by the differential pressure before and after, so that the valve body 50 does not open.

When the vacuum pump is further operated to further reduce the pressure in the first opening 66, and the pressure difference between the second bellows 76 and the atmospheric pressure becomes larger than the pressure difference between the spring 75 and the valve body 50, the valve is opened. The body 50 descends gradually, and opening the opening 90 allows a large amount of exhaust. Valve body 50
Descends until it contacts the auxiliary valve 52, the descending stops,
At this time, the second cam surface 86 of the shut-off lever 55 comes into contact with the upper surface 83, and holds the position of the valve body 50.

When the vacuum pump is stopped, the sub-valve 52 closes the bypass communication hole 51 and the valve body 50 closes the opening 90 by rotating the shut-off lever to the original position shown in FIGS. Thus, one operation shuts off all conduits.

Since the flow control valve of the above embodiment does not include the needle valve of the valve of the first embodiment, no error is caused by the set of the valve when the needle valve is opened and closed, and the shutoff is not performed. With one operation of the off lever, all the pipelines can be closed.

[0034]

Since the present invention is constructed and operates as described above, it is possible to exhaust a predetermined small amount at the start of operation of the vacuum pump, and the dust accumulated on the bottom of the container due to the large amount of exhaust in the vacuum container. Can be prevented, and the starting load of the pump can be reduced. Further, since a regulating valve that can maintain a predetermined opening degree is provided in the passage that bypasses the valve body when the pump is started, the bypass passage can be kept constant irrespective of the pressure drop in the pipeline, so that the valve body can be maintained. It is possible to set the opening timing of the exhaust gas accurately, and it is possible to accurately adjust the opening timing and the exhaust gas flow rate.

Further, since the valve body can be forcibly closed by the shut-off lever, there is no need to provide a separate shut-off valve in the pipeline, and the apparatus can be simplified and inexpensive.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a first embodiment of the present invention when a valve body is closed by a shut-off lever.

FIG. 2 is a side view of the same.

FIG. 3 is a sectional view showing a state before the valve body opening operation.

FIG. 4 is a sectional view showing a state when the valve body is opened.

FIG. 5 is a time-pressure characteristic diagram of the flow control valve according to the present invention.

FIG. 6 is a pressure difference-valve opening degree characteristic diagram.

FIG. 7 is a cross-sectional view of another embodiment of the present invention.

FIG. 8 is a side view of the same.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st opening 2 2nd opening 3 Valve main body 6 Valve seat 7 Valve 8 Opening 10 Bypass path 11 1st communication hole 12 2nd communication hole 13 Needle valve support 17 Needle valve 20 Rod 23 Shut-off lever 24 Rotation axis Reference Signs 26 Retainer 27 Upper lid 28 Support tube 30 Lower end support 31 Spring 32 Receiving plate 35 Bellows 38 Arm

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-56-73269 (JP, A) JP-A-57-22485 (JP, A) JP-A-57-22484 (JP, A) JP-A-2- 298690 (JP, A) JP-A-2-298689 (JP, A) JP-A-57-186290 (JP, A) JP-A-4-138166 (JP, U) JP-A-4-54381 (JP, U) Japanese Utility Model No. 3-107572 (JP, U) Japanese Utility Model No. 2-125285 (JP, U) Japanese Utility Model No. 63-1971 (JP, U) Japanese Utility Model No. 60-114380 (JP, U) Japanese Utility Model No. 58-130350 (JP, U) JP-A 56-75378 (JP, U) JP-B 50-24446 (JP, B2) JP-B 59-19183 (JP, Y2) (58) Fields investigated (Int. Cl. ⁷⁾ F16K 51/02 F16K 35/00-35/16 F16K 31/44-31/60 F16K 17/18-17/34

Claims (2)

(57) [Claims] 1. A connecting line between a vacuum pump and a vacuum container,
A valve body provided with a valve seat in a valve body having a first opening communicating with the vacuum pump and a second opening communicating with a vacuum vessel, and a valve body biased by a spring to close the valve seat from the second opening side. And a bellows arranged to be engaged with the valve body to open the valve body in accordance with a pressure difference between the pressure of the first opening and the atmospheric pressure, and to close the valve body to a fully closed position. A shut-off lever that is held at a release position is connected to the valve body, and a bypass path that connects the first opening and the second opening is provided separately from the valve seat in the valve body, and the bypass path is adjusted. A proportional control valve having a valve. 2. A connecting line between a vacuum pump and a vacuum vessel,
A valve body provided with a valve seat in a valve body having a first opening communicating with the vacuum pump and a second opening communicating with the vacuum vessel, and a valve body biased by a spring to close the valve seat from the second opening side; A first bellows arranged to engage with a sub-valve inside the valve body to open the sub-valve according to a pressure difference between the pressure of the first opening and the atmospheric pressure; and a pressure of the first opening. A second valve disposed so as to open the valve element in accordance with the pressure difference between the pressure and the atmospheric pressure.
A bellows is provided, and a shut-off lever for holding the valve body and the sub-valve in the fully closed position and the close release position is connected to the valve body, and the second valve body is provided in the valve body through a sub-valve opening. A proportional control valve having a bypass communication hole communicating between the first opening and the second opening.