JPH03630Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a vacuum valve interposed between a vacuum chamber and a vacuum pump for opening and closing a conduit between them.

(Prior Art) For example, a vacuum chamber and a vacuum pump for evacuating the chamber are normally connected as shown in FIG. Closed. First, the on-off valve V is opened to operate the oil rotary pump P2, and after raising the degree of vacuum in the vacuum chamber C to a certain degree by so-called rough pumping, the vacuum valve 1 is opened and the oil diffusion pump P2 is operated.
1 to obtain the desired degree of vacuum. The vacuum valve 1 used in such cases is
Normally, there is a valve plate 5 that is opened and closed by an actuator operated by pneumatic pressure, but when closing the valve plate 5 after the desired degree of vacuum is obtained, there is no resistance in the pipe line, so conventional methods In a vacuum valve that only operates on and off, the valve plate 5 closes suddenly. For this reason, the valve plate 5 violently abuts against a sealing material (not shown) applied to the valve seat surface, which tends to damage the sealing material and also generates a loud operating noise, which is troublesome. In addition, recently, when processing and manufacturing products in a vacuum chamber, it has become necessary to perform suction while injecting a special gas after obtaining a vacuum state. In this case, after a vacuum condition is obtained and the vacuum valve is closed, it is necessary to gently open the valve plate a little.

In order to meet these needs, pneumatically operated, hydraulically operated or electric servo valves can easily be used to meet these needs, but the servo valves themselves have a complex and expensive structure, making them uneconomical. be.

(Problems to be Solved) This invention aims to provide a vacuum valve with a simple structure and low cost, which can quietly open and close a valve plate in addition to normal opening and closing.

(Means for solving the problem) This invention connects two actuators to a drive member that opens and closes the valve plate of a vacuum valve, applies these separate operating pressures, and adjusts the pressure difference or sum of these operating pressures. Therefore, the driving member of the valve plate can be operated. (Function) Apply operating force to two actuators separately,
When opening and closing quietly, by applying the operating force due to the difference between these operating pressures, the valve plate is opened and closed quietly without sudden opening and closing, and large operations such as after the valve plate contacts the sealing material are avoided. When force is required, the valve plate can be closed using the operating force resulting from the sum of these operating pressures.

(Embodiment) An embodiment in which rotary actuators are used as two actuators and a valve plate is opened and closed by operating an electric switch will be described with reference to the drawings.

In FIGS. 1 and 2, a valve seat 3 having the same outer diameter as the flange of the case 2 is attached to an O-ring 4 at the upper left end of a cylindrical case 2 having outward flanges at both ends. They are connected via bolts (not shown). Valve seat 3 is
It is a donut-shaped plate that has been bored out leaving the mating surface with the valve plate 5, and the O-ring 4 seals the valve seat 3 and the entire periphery of the flange surface of the case 2.

The valve plate 5 is a circular plate having an outer diameter slightly smaller than the inner diameter of the case 2, and is in close contact with the valve seat 3 via an O-ring 6 in the closed position. A U-shaped arm 6 protrudes from the center of the valve plate 5. A first link 7 is inserted into the U-shaped gap, and the arm 6
It is pivotably supported 8 to be freely rotatable. A drive shaft 9 is fixed through the other end of the first link 7, and the drive shaft 9 passes through the case 2 and connects rotary actuators attached to the through parts on both sides of the case 2, respectively. The rotary actuator is coupled to the actuators 10a and 10b and driven by these rotary actuators.

As shown in FIG. 3, the rotary actuators 10a and 10b are both pneumatic actuators each having two input ports for providing clockwise and counterclockwise rotation.

At the tip of the arm 6, second links 11, 11, which are shorter than the first link 7, are rotatably supported 12, and the other ends of the second links 11, 11 are
It is rotatably supported by a shaft 13 on a part of the case 2.

The structure of the vacuum valve 1 is as described above, and operating pressure is applied to the rotary actuators 10a and 10b separately, and the drive shaft 9 is driven by the differential pressure between them to open and close the valve plate 5. Since the arm 6, the first link 7, and the second link 11 form a four-bar link, unlike those that are opened and closed by hinges, the valve plate 5 is approximately open and closed as shown by the two-dot chain line in FIG. It can be fully opened. Further, the rotary actuators 10a and 10b are controlled by a circuit as shown in FIG.

In FIG. 3, the air pressure source 15 is connected to the inputs of two sets of regulators. One set of regulators 16a and 17a are pneumatic regulators of 5 kg and 4 kg, respectively, and the rotary actuator 10
a, and another set of regulators 16b,
17b are also 5Kg and 4Kg pneumatic regulators, respectively, for the rotary actuator 10b.

The output of the regulator 16a is connected via a control valve 18, and the output of the regulator 17b is connected via a control valve 19 to one input port of the rotary actuator 10a. Regulator 16
The output of b is sent to one input power port of the rotary actuator 10b via the control valve 20, and
It is connected to the other input port via the control valve 21, and the output of the regulator 17b is connected to the other input port of the rotary actuator 10b via the control valve 22 and the control valve 23 in sequence. has been done.

The vacuum valve opening/closing switch 24 is a two-way switch that opens and closes the control valve and selects the output of the opening sensor 25.
In the closed position, the control valves 18 and 22 are closed, and the circuit connection from the opening sensor 25 to the control valves 20 and 23 is connected. Further, the control valves 19 and 21 are closed in the open position.

The opening sensor 25 is, for example, a limit switch that detects the position of the valve plate when the valve plate 5 contacts the O-ring 6 by detecting the rotational position of the drive shaft 9, although its installation is not shown in detail. When the valve plate 5 is detected while the on/off switch 24 is in the closed position, the control valve 20 is closed and the control valve 23 is opened.

When the on/off switch 24 is set to the closed position to close the vacuum valve 1, the rotary actuators 10a, 10
Air pressure is applied to b, the valve plate 5 is quietly closed, and when it comes into contact with the O-ring 6, the valve plate 5 is closed with a strong operating force. As long as the vacuum pump is connected and operating, even if you turn off the on/off switch here,
Since the valve plate 5 is suctioned by a vacuum, it will not open.

When the valve plate 5 is in the closed state, the open/close switch 2
When the valve plate 4 is opened, air pressure is applied to the rotary actuators 10a and 10b, and the valve plate 5 is opened gently, as shown in the time chart of FIG. 4b.

In this embodiment, the vacuum valve was opened and closed using a manual switch, but it can also be operated by commands based on a program from a control device with a built-in computer, allowing processing and production lines in vacuum chambers. For example, it is more common. Further, as described above, opening the valve plate 5 a little and performing such a small opening in steps can be done as appropriate depending on the control device. The opening sensor in this case is not limited to a limit switch, but may be an encoder or the like. Further, the opening sensor is generally a simple limit switch, but it may also be an encoder, a pressure gauge, or the like.

In addition, the actuator is not limited to a rotary type, but can also be a cylinder, and can be driven by connecting a link mechanism to a drive shaft, and the valve plate operating mechanism can be of various types in addition to a link or a hinge. You can also do it. The operating pressure applied to the actuator can also be selected as appropriate, and the regulator can be shared by two actuators.

Furthermore, the actuator is not limited to a pneumatic type, but can also be a hydraulic type, an electric type, etc., but in the case of a hydraulic type, the flow rate will be throttled and the pressure will be increased. Depending on how the operating pressure is applied to the two actuators, simple on/off operation is also possible.

(Effects) As described above, according to this invention, it is possible to provide a vacuum valve with a simple structure and low cost, which can perform quiet opening and closing operations in addition to normal opening and closing operations.

[Brief explanation of the drawing]

The drawings show a conventional example and an embodiment of this invention, in which Fig. 1 is a longitudinal sectional view, Fig. 2 is an arrow view, Fig. 3 is a circuit diagram, Fig. 4 is a time chart, and Fig. 5 is a diagram.
The figure is a schematic diagram. In the drawing, 1 is a vacuum valve, 2 is a case,
5 is a valve plate, 9 is a drive shaft (drive member), 10a, 1
0b is a rotary actuator (actuator).

Claims (1)

[Claims for Utility Model Registration] (1) Two actuators that can operate in two directions are connected to a driving member of a valve plate that is connected to a valve plate that comes into contact with a valve seat when closed in a case. A vacuum valve characterized in that the driving member can be driven by a difference or a sum of operating pressures applied to each actuator. (2) The vacuum valve according to claim 1, wherein the actuator is a fluid-operated rotary actuator. (3) The vacuum valve according to claim 1, wherein the actuator is a fluid-operated cylinder.