JP4131754B2 - Vacuum valve for automatic delay vent and automatic delay vent mechanism of vacuum equipment using the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vacuum valve used in an industrial field using vacuum, and more particularly to a vacuum valve used when a vacuum pump or the like is automatically delayed and vented.
[0002]
[Prior art]
The conventional technique will be described with reference to FIG. Reference numeral 31 denotes a vacuum vessel of a vacuum apparatus, in which various processes performed in a vacuum atmosphere such as sputtering or CVD are performed. The vacuum vessel 31 is evacuated from a turbo molecular pump 34 having an exhaust capability in a relatively low pressure region (10 ⁻¹ Pa to 10 ⁻⁵ Pa) and a relatively high pressure region (atmospheric pressure to 10 ⁻¹ Pa). This is an oil rotary vacuum pump 32 suitable for evacuation.
[0003]
When evacuating the vacuum vessel 31 from the atmospheric pressure state, the main valve 33 is closed, the roughing valve 35 is opened, the turbo molecular pump 34 is stopped, and only the oil rotary vacuum pump 32 is used to first evacuate the vacuum vessel. Rough.
[0004]
When the pressure in the vacuum vessel 31 drops to the evacuable region of the turbo molecular pump 34, the roughing valve 35 is closed, the main valve 33 is opened, the turbo molecular pump 34 is activated, and evacuation is continued. In this case, the oil rotary vacuum pump 32 is used as a booster pump of the turbo molecular pump 34 to lower the back pressure of the turbo molecular pump 34.
[0005]
When some trouble occurs in such an exhaust system and the oil rotary vacuum pump 32 and the turbo molecular pump 34 are automatically stopped or when they are intentionally stopped, the oil rotary vacuum pump 32 is lubricated and sealed. The oil flows back in the pipe (oil back) and reaches the turbo pump 34 and further to the main valve 33, and the inside of the vacuum container 31 may be contaminated with oil when the main valve 33 is opened and closed.
[0006]
In order to prevent this trouble, it has been widely practiced to increase the pressure in the vacuum apparatus by introducing gas to the suction side of the oil rotary vacuum pump 32 when the oil rotary vacuum pump 32 is stopped. This gas introduction is called a vent, and the atmosphere is generally used as the introduction gas, but nitrogen gas may be used when the gas to be exhausted is mixed with oxygen and there is a risk of ignition. .
[0007]
In FIG. 3, a branch pipe 36 is provided on the upstream side of the oil rotary vacuum pump 32 for introducing the vent gas, and a vent valve 37 is provided at the end thereof. The vent valve 37 must be operated with a delay after the oil rotary vacuum pump 32 is stopped in conjunction with the oil rotary vacuum pump 32. For this reason, this valve is called a delay vent valve and is opened and closed using an electromagnet. There were many things to do. In this case, wire the power to the solenoid valve to operate the delay vent valve and the power to the motor of the vacuum pump at the same time to supply and stop, and wait for the pump to stop before venting. It is common.
[0008]
Although this delay operation has been performed automatically in the past, the conventional vacuum valve for automatic delay vent is a combination of a capacitor and a solenoid valve, and the capacitor is used for several tens of seconds after the power supply is stopped. The solenoid valve was kept closed by the stored electric power, and then the vent gas was introduced with a delay by opening the solenoid valve as the capacitor was discharged.
[0009]
[Problems to be solved by the invention]
By the way, this delay time is not uniform depending on the type and conditions of the members to be processed in the vacuum vessel, and there are cases where it is desired to finely adjust the delay time.
[0010]
For example, in the evacuation system of FIG. 3, the evacuation stop procedure is normally performed by closing the main valve 33 and then stopping the power supply to the turbo molecular pump 34 and the oil rotary vacuum pump 32, and then using the delay vent valve 37. Vent with air. However, the turbo molecular pump 34 is weak against backflow from the back pressure side, and the turbo molecular pump 34 rotates at a high speed even while decelerating. If venting is started immediately after the power supply is stopped, a large load is applied to the bearing part and rotor part of the turbo molecular pump 34. Will be applied. In order to reduce this load as much as possible, it is necessary to make the delay vent time as long as possible.
[0011]
In some cases, it is desirable to shorten the vent time. For example, strictly speaking, the oil back starts immediately after the oil rotary vacuum pump 32 is stopped. In the case of a vacuum apparatus that hates oil back very much, it is necessary to shorten the time from the stop of the oil rotary vacuum pump 32 to the venting as much as possible.
[0012]
However, the conventional vacuum valve for automatic delay vent as described above has a drawback that the delay time is determined by the capacitor capacity, and the delay time until venting cannot be arbitrarily changed according to the configuration of the vacuum exhaust device. It was.
An object of the present invention is to solve the above problems, and to provide an automatic delay vent vacuum valve capable of arbitrarily setting a vent time and an automatic delay vent mechanism of a vacuum apparatus using the same.
[0013]
Means and Action for Solving the Invention
In order to achieve the above object, the present invention is configured as follows.
[0014]
In order to achieve the above object, a delay vent vacuum valve according to a first aspect of the present invention (corresponding to claim 1) is provided with a cylinder chamber in a valve body, and has a piston in the cylinder chamber. At one side, atmospheric pressure is always applied, and the other surface is subjected to a force that is a combination of spring force and vent gas pressure or vacuum pressure. A piston shaft part is provided integrally with the piston on the atmospheric pressure side of the piston moving to the piston, and the piston shaft part passes through a partition part connected to one end of the cylinder and reaches a port space provided in the port part. The piston is provided with a communication hole from one end of the piston to the middle of the piston shaft portion, and when the piston is moved by the vacuum pressure in the cylinder, Although the communication hole is closed, when the piston moves with the vent gas pressure, the communication hole is opened, and vent gas flows into the port space through the opened communication hole, and adjustment of the timing of introducing the vent gas into the port space Is a vacuum valve for automatic delay venting performed by controlling the flow rate of the vent gas using a flow rate adjusting valve.
[0015]
According to the present invention, the vent time can be arbitrarily set by changing the pressure difference received by the both end faces of the piston using the vent gas pressure and adjusting the changing speed with the vent gas flow rate adjusting valve.
[0016]
According to a second aspect of the present invention (corresponding to claim 2), in the delay vent vacuum valve according to the first aspect, switching between the vacuum pressure and the vent gas pressure is performed using a three-port solenoid valve, and the three-port solenoid valve When supplying power to the valve, the vent gas introduction path is closed and the vacuum pressure introduction path is opened, and when supplying power to the three-port solenoid valve is stopped, the vent gas introduction path is opened and the vacuum pressure introduction path is closed.
[0017]
According to a third aspect of the present invention (corresponding to claim 3), the port portion of the vacuum valve for automatic delay vent according to claim 2 is provided in a branch pipe provided near the suction port of an oil rotary vacuum pump for exhausting the vacuum vessel. This is an automatic delay vent mechanism of a vacuum device that is connected to a pipe and performs switching between power supply to the three-port solenoid valve of the automatic delay vent vacuum valve and power supply stop in conjunction with power supply to the oil rotary vacuum pump and power supply stop.
[0018]
By using the automatic delay vent vacuum valve according to claims 1 and 2, an automatic delay vent mechanism capable of supporting vacuum processing apparatuses under various processing conditions is provided.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. 1 and 2 show an embodiment of the present invention, and FIG. 1 is a longitudinal sectional view of an automatic delay vent vacuum valve according to the present invention (excluding a solenoid valve portion), and shows an operating state when energized. Show. FIG. 2 shows an operating state when the automatic delay vent is working after the energization of the solenoid valve is stopped in the vacuum valve of FIG. FIG. 3 is a piping diagram illustrating a case where the vacuum valve for automatic delay vent according to the present invention is used in a system for exhausting a vacuum vessel of a vacuum apparatus.
[0020]
First, the vacuum valve configuration of the present invention will be described with reference to FIG.
The embodiment of FIG. 1 is roughly composed of a valve portion 101 and an electromagnetic valve portion 102, and a cylinder body 2 is provided in a valve main body 1 that constitutes a main component of the valve portion 101. Inside the cylinder chamber 2 is a piston 4 that is always pushed in one direction (bent direction) by a compression spring 3. Reference numeral 5 denotes a piston seal, and an O-ring is used in this example. The cylinder chamber 2 is divided into a cylinder A chamber 6 and a cylinder B chamber 7 by a piston seal 5.
In the valve body 1, a port portion 10 and a port space 8 are provided in the axial direction of the cylinder chamber 2, and the cylinder chamber 2 and the port space 8 are separated by a partition portion 9. A flange for connecting to a pipe such as a vacuum pump is provided at the tip of the port space 8.
[0021]
Incidentally, at one end of the piston 4, an axial piston shaft part 11 is formed on the extension of the piston shaft, and the piston shaft part 11 penetrates the partition part 9 and reaches the port space 8. The piston 4 is provided with a communication hole 12 along its central axis, and the communication hole extends through the piston portion and further to the middle of the piston shaft portion 11. One opening A13 of the communication hole 12 is directed to a shaft end in a direction where the piston shaft portion 11 is not provided, and the other opening B14 is directed to a direction substantially perpendicular to the shaft before reaching the shaft end of the piston shaft portion 11. is open. The position of the opening B14 of the communication hole 12 provided in the piston shaft portion 11 is opened in the port space 8 when the compression spring 3 is in the longest state, and when the compression spring 3 is most compressed and shortest, the partition portion 9 between the shaft seal A15 and the shaft seal B16.
[0022]
The three-port solenoid valve mounted on the valve body 1 and shown as the solenoid valve portion 102 includes a solenoid valve first port 17, a solenoid valve second port 18, and a solenoid valve third port 19. The provided vent gas introduction path 20 is a flow path connecting the first solenoid valve port 17 and the flow rate adjustment valve 21. The other end of the flow rate adjusting valve 21 is connected to a vent gas supply source (generally, there are many cases in the atmosphere). The electromagnetic valve communication path A22 is a communication path connecting the cylinder A chamber 6 and the electromagnetic valve second port 18. The electromagnetic valve communication path B <b> 23 is a communication path connecting the port space 8 and the electromagnetic valve third port 19.
[0023]
When supplying power to the electromagnet (not shown), the three-port solenoid valve 102 closes the solenoid valve first port 17, while opening the solenoid valve second port 18 and the solenoid valve third port 19 to further open the electromagnetic valve. The second valve port 18 and the third solenoid valve port 19 are connected. Thereby, the cylinder A chamber 6 and the port space 8 communicate with each other.
[0024]
When the power supply is stopped, the three-port solenoid valve 102 connects the solenoid valve first port 17 and the solenoid valve second port 18 while closing the solenoid valve third port 19. Thus, the vent gas introduction path 20 and the electromagnetic valve communication path A22 are communicated, while the electromagnetic valve communication path B23 is closed.
In addition, an air opening hole 24 is formed so that the cylinder B chamber 7 is always in an atmospheric pressure state.
[0025]
FIG. 3 shows an example in which the automatic delay vent vacuum valve of the present invention constructed as described above is incorporated in an evacuation system. Reference numeral 31 denotes a vacuum vessel of a vacuum apparatus, in which a vacuum atmosphere such as sputtering or CVD is provided. Various processes performed in the above are performed.
A turbo molecular pump 34 is connected to the vacuum vessel 31 and an oil rotary vacuum pump 32 is connected to the discharge side thereof by piping. A main valve 33 is provided between the vacuum vessel 31 and the turbo molecular pump 34 to enable opening and closing of the flow path. A bypass pipe is further provided between the vacuum vessel 31 and the oil rotary pump 32, and a roughing valve 35 is provided in the middle of the pipe to enable opening and closing of the bypass pipe.
[0026]
Reference numeral 100 denotes a vacuum valve for automatic delay venting according to the present invention, and the port portion 10 is connected to a branch pipe extending from between the discharge side of the turbo molecular pump 34 and the suction side of the oil rotary vacuum pump 32.
[0027]
The operation of the automatic delay vent vacuum valve 100 having the above-described configuration will be described with reference to FIGS. 1 and 3 at the start-up operation.
[0028]
If the supply power of the three-port solenoid valve 102 and the oil rotary vacuum pump 32 is supplied in conjunction, the first solenoid valve connected to the vent gas introduction path 20 by the three-port solenoid valve 102 when the oil rotary vacuum pump 32 is activated. The port 17 is closed and the vent gas introduction is stopped. On the other hand, since the port space 8 being evacuated by the vacuum pump and the cylinder A chamber 6 are connected, the cylinder A chamber 6 is in a low pressure state. As a result, a pressure difference is generated between the cylinder B chamber 7 and the cylinder A chamber 6, and the force due to the pressure difference exceeds the pressing force of the compression spring 3 pushing the piston 4 in the vent direction, and the compression spring 3 contracts. When the piston 4 is moved in the opposite direction to the piston shaft portion 11 and the opening B14 of the communication hole 12 exists between the two shaft seals attached to the partition portion 9, the piston is placed on the upper wall portion of the cylinder A chamber 6. 4 touches and stops.
[0029]
A case where the oil rotary vacuum pump 32 shifts to a stop from this state will be described with reference to FIGS.
When the oil rotary vacuum pump 32 is stopped, the power supplied to the three-port solenoid valve 102 is also stopped in conjunction with it, so that the three-port solenoid valve 102 closes the solenoid valve third port 19 connected to the port space 8, By connecting the first solenoid valve port 17 and the second solenoid valve port 18, the cylinder A chamber 6 and the vent gas introduction path 20 are communicated. For this reason, vent gas is introduced into the cylinder A chamber 6 through the flow rate control valve 21. Then, the pressure difference between the cylinder A chamber 6 and the cylinder B chamber 7 decreases with time, and when the pressing force of the compression spring 3 is superior to the force due to the pressure difference, the piston 4 moves in the direction of the compression spring pressing force. Stops in contact with the lower wall surface of the cylinder B chamber 7. As a result, the opening B14 of the communication hole 12 of the piston shaft portion 11 protrudes into the port space 8, the vent gas in the cylinder A chamber 6 is introduced into the port space 8, and the oil rotary vacuum pump 32 communicating with the port space 8 is vented. Is done.
[0030]
In order to adjust the time until the vacuum pump vents, the flow rate adjusting valve 21 may be adjusted to change the introduction speed of the vent gas.
[0031]
In this way, when the vacuum device is automatically stopped due to some trouble or when it is intentionally stopped, the lubrication and sealing oil of the vacuum pump connected to the vacuum device is put into the vacuum vessel. Backflow (oil back) can be prevented from causing contamination in the vacuum vessel.
[0032]
【The invention's effect】
In the vacuum valve for automatic venting according to the present invention, the difference in pressure received at both ends of the piston is changed by using the vent gas pressure. By adjusting the changing speed with the flow rate adjusting valve, the delay time until the start of venting is arbitrarily set. By using this valve, it is possible to cope with an automatic delay vent of a vacuum processing apparatus used under various processing conditions.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a vacuum valve for automatic delay venting according to an embodiment of the present invention, showing an operating state during energization.
FIG. 2 is a vertical cross-sectional view of an automatic delay vent vacuum valve according to an embodiment of the present invention, showing an operating state when the automatic delay vent is operating after the energization is stopped.
FIG. 3 shows an example of a piping diagram of a vacuum apparatus to which an automatic delay vent valve is attached.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Valve body 2 Cylinder chamber 3 Compression spring 4 Piston 5 Piston seal 6 Cylinder A chamber 7 Cylinder B chamber 8 Port space 9 Partition part 10 Port part 11 Piston shaft part 12 Communication hole 13 Opening A
14 Opening B
15 Shaft seal A
16 Shaft seal B
17 Solenoid valve 1st port 18 Solenoid valve 2nd port 19 Solenoid valve 3rd port 20 Vent gas introduction path 21 Flow control valve 22 Solenoid valve communication path A
23 Solenoid valve communication path B
31 Vacuum container 32 Oil rotary vacuum pump 33 Main valve 34 Turbo molecular pump 35 Roughing valve 36 Branch pipe 37 Automatic delay vent vacuum valve 100 Automatic delay vent vacuum valve 101 Valve section 102 Solenoid valve section (three-port solenoid valve)

Claims (3)

A cylinder chamber is provided in the valve body, and it has a piston. One side of the piston is always subjected to atmospheric pressure, and the other side is subjected to a force that is a combination of spring pressure and vent gas pressure or vacuum pressure. The piston shaft portion is provided integrally with the piston on the atmospheric pressure side of the piston that moves to the atmospheric pressure side when the vent gas pressure is applied, and moves to the vacuum pressure side when the vacuum pressure is applied. The piston passes through a partition portion connected to one end and reaches a port space provided in the port portion, and the piston has a communication hole from one end of the piston to the middle of the piston shaft portion. In this case, the communication hole is closed when moved by vacuum pressure, but the communication hole is opened when the piston moves by vent gas pressure. The flows are vent gas in port space, adjustment of the vent gas introduction period to the port space, the vacuum valve for automatic delay vent performed by controlling the vent gas flow rate using a flow control valve through a communication hole. Switching between vacuum pressure and vent gas pressure using a three-port solenoid valve. When supplying power to the three-port solenoid valve, close the vent gas introduction path and open the vacuum pressure introduction path, and stop feeding to the three-port solenoid valve The vacuum valve for automatic delay vents according to claim 1, wherein the vent gas introduction passage is opened and the vacuum pressure introduction passage is closed. The port portion of the automatic delay vent vacuum valve according to claim 2 is connected to a branch pipe provided near the suction port of an oil rotary vacuum pump for exhausting the vacuum vessel, and the automatic delay vent vacuum valve Automatic delay venting mechanism of vacuum device that performs switching between power supply to the three-port solenoid valve and power supply stop in conjunction with power supply to the oil rotary vacuum pump and power supply stop.

Images