JPH1182807A - Fluid pressure control valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluid pressure control valve preventing the deterioration of sealing performance at a valve closed time resulting from the adhesion of a product inside a main body by heating so that no local low temperature part occurs inside the main body. SOLUTION: A vacuum valve 1 is so heated that a temperature gradient is formed from the inside of the main body 10 toward the outside of the main body 10 by a flexible heater 20 fitted into the valve rod 11 subsisting in the main body 10, and the heat of the flexible heater 20 moves from the inside of the main body 10 to the outside of the main body 10 so that the whole body is heated and the occurrence of a local low temperature part inside the main body 10 is not allowed. Thereby, no adhesion of a product inside a main body 10 is allowed, and the deterioration of sealing performance at a valve closed time resulting from the adhesion of such a product can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid pressure control valve for controlling the pressure, flow rate or direction of a flow of a working fluid in a piping line, or for stopping the flow, and more particularly, for keeping the working fluid in the piping line warm. The present invention relates to a fluid pressure control valve that ensures that no product adheres to the inside of a main body.

[0002]

2. Description of the Related Art Conventionally, an exhaust system of a semiconductor manufacturing apparatus is provided with, for example, a vacuum valve as one of fluid pressure control valves as shown in FIG. The vacuum valve 100 shown in FIG.
The valve stem (not shown) included in 01 is operated by a driving unit 104 directly fixed to the main body 101 to open and close. Further, if the high-temperature exhaust gas is cooled inside the main body 101, the product adheres and the sealing performance at the time of closing the valve deteriorates. Therefore, by attaching the heater 102 to the outer wall of the main body 101, the temperature inside the main body 101 becomes high. To keep the exhaust air cool.

[0003]

However, in the vacuum valve 100 shown in FIG. 5, since the entirety is heated by the heat conduction of the heater 102 attached to the outer wall of the main body 101, the main body 101 is moved from the outer wall of the main body 101. While a temperature gradient is formed inclining toward the inside, the temperature of the outer wall of the main body 101 is measured by a thermoelectric body (not shown).
It was difficult to grasp the temperature inside. further,
A considerable amount of heat is released from a portion that comes into contact with the outside air, such as the joint portion 103 and the driving portion 104, and the inside of the main body 101 has a complicated three-dimensional shape. A low-temperature portion having a locally low temperature (a portion lower than the product formation temperature) was easily generated.
As a result, the case where the product adheres to the inside of the main body 101 and the sealing performance at the time of closing the valve is reduced may not be prevented beforehand.

Accordingly, the present invention has been made to solve the above-mentioned problems, and by performing heating so that a locally low-temperature portion is not generated inside the main body, the inside of the main body is heated. An object of the present invention is to provide a fluid pressure control valve that prevents a decrease in sealing performance when a valve is closed due to adhesion of a product.

[0005]

According to a first aspect of the present invention, there is provided a fluid pressure control valve comprising: a valve stem which is provided in a main body and urged by a spring in a valve opening direction; A fluid pressure control valve that opens and closes a valve by being pushed in a valve closing direction by a drive unit external to the main body, and freely forms a temperature gradient inclined from the inside of the main body to the outside. A first heater is mounted inside the valve stem.

A fluid pressure control valve according to a second aspect of the present invention is the fluid pressure control valve according to the first aspect, wherein the drive unit, which is separated from the valve rod when the valve is opened, is connected to the drive unit via a support member. It is characterized by being fixed to the main body. A fluid pressure control valve according to a third aspect is the fluid pressure control valve according to the first or second aspect, wherein a second cover is provided around the body.
A heater is attached.

A fluid pressure control valve according to a fourth aspect is the fluid pressure control valve according to the third aspect, wherein the main body is surrounded by a heat insulating material. A fluid pressure control valve according to a fifth aspect is the fluid pressure control valve according to any one of the first to fourth aspects, further comprising a temperature measuring unit that measures a temperature of an outer wall of the main body. It is characterized by having.

[0008] The fluid pressure control valve according to claim 6 is claim 1.
6. The fluid pressure control valve according to claim 5, further comprising a vacuum clamp joint.

In the fluid pressure control valve of the present invention having such a configuration, the valve stem inside the main body is urged in the valve opening direction by the spring. In state. On the other hand, when the drive unit is driven, the valve stem inside the main body is pushed in the valve closing direction, so that
The valve is closed. And the first mounted inside the valve stem
When the valve stem inside the main body is heated by the heater, the inside of the main body (including the inner wall of the main body; the same applies hereinafter) is applied to the outside of the main body (not including the outer wall of the main body; the same applies hereinafter).
The temperature of the first heater moves from the inside of the main body to the outside of the main body, and the entire body is heated.

[0010] At this time, when the valve is opened, the drive unit for pushing the valve stem heated by the first heater is separated from the valve stem, and loses the contact surface with the valve stem, so-called thermal resistance. Is increased, the amount of heat conducted from the valve stem to the drive unit can be reduced. Further, such a drive unit
Since it is fixed to the main body via the support member, the contact surface with the main body is eliminated and the so-called thermal resistance is increased compared to the conventional art which is directly fixed to the outer wall of the main body, so that the The amount of heat conducted to the drive unit can be further reduced.

Further, if a cover is installed outside the main body and the cover is heated by the second heater, the gradient of the temperature gradient formed from the inside of the main body toward the outside of the main body is reduced or the inclination is reduced. Because it can be in the opposite direction,
The amount of heat radiated from the inside of the main body to the outside of the main body can be reduced.

Further, if a heat insulating material is provided outside the main body, the gradient of the temperature gradient formed from the inside of the main body toward the outside of the main body can be further reduced, so that the inside of the main body can be moved to the outside of the main body. The amount of heat radiated to the motor can be further reduced.

Further, if a cover with a heat insulating material or the like is interposed between the outer wall of the main body and the driving section, the gradient of the temperature gradient formed from the outer wall of the main body toward the heat insulating material becomes smaller, and Since the gradient of the temperature gradient formed from the heat insulating material toward the drive unit becomes larger, the amount of heat moving from the outer wall of the main body to the drive unit can be reduced.

That is, the fluid pressure control valve of the present invention
A temperature gradient is formed from the inside of the main body to the outside of the main body by the heater, and the entirety is heated by the heat of the first heater moving from the inside of the main body toward the outside of the main body. Since the heating is performed such that the low portion does not occur inside the main body, the product does not adhere to the inside of the main body, and it is possible to prevent the deterioration of the sealing performance when the valve is closed due to the adhesion of the product. it can.

Further, since the drive unit is fixed to the main body via the support member, the amount of heat conducted from the main body to the drive unit is further reduced. Therefore, switches which are necessary for control of the drive unit and have poor heat resistance. Can be attached to the drive unit. In particular, at the time of opening the valve, it is necessary to perform heating by the first heater so that a flow of the working fluid is formed inside the main body and a locally low temperature portion is not generated inside the main body. Sometimes, the drive unit is separated from the valve stem heated by the first heater, so that heat of the first heater is not transmitted to the switches attached to the drive unit via the valve stem.

A cover provided with a second heater, a heat insulating material, and the like is provided outside the main body to reduce a temperature gradient formed from the inside of the main body toward the outside of the main body by the first heater. In addition, the inclination can be reversed, so that heating can be performed more reliably so that a locally low temperature portion does not occur inside the main body.

Further, when a temperature gradient is formed from the inside of the main body toward the outer wall of the main body by the first heater attached to the valve stem inside the main body, the temperature of the outer wall of the main body is measured by the temperature measuring means. Then, since the temperature inside the main body does not fall below the temperature measured by the temperature measuring means and the temperature inside the main body can be estimated, the first heater and the second heater can be estimated.
By controlling the input of the heater, it is possible to perform heating such that a locally low temperature portion does not occur inside the main body.

Further, when a vacuum clamp joint is provided and the fluid pressure control valve of the present invention is used as a vacuum valve, the portion of the vacuum clamp joint that comes into contact with the outside air is narrower than the conventional joint. Since a considerable amount of heat is not released from the vacuum clamp joint, it is possible to perform heating such that a locally low-temperature portion does not occur inside the main body.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an arrow A of FIG.
1 shows a cross-sectional view of the vacuum valve 1 of the present embodiment as viewed from above. FIG.
The cross section on the right side of FIG. 1 is when the valve is open, and the cross section on the left side of FIG. 1 is when the valve is closed. FIG. 2 is a front view of the vacuum valve 1 according to the present embodiment when the valve is closed. FIG. 3 shows a top view of the vacuum valve 1 of the present embodiment. Further, FIG. 4 shows a bottom view of the vacuum valve 1 of the present embodiment.

The vacuum valve 1 of the present embodiment is one of the fluid pressure control valves and is provided in an exhaust system of a semiconductor manufacturing apparatus, and a valve stem 11 provided in a main body 10 is driven by a driving unit. It is operated by a certain cylinder 12 to open and close.

The cylinder 12 is driven by compressed air supplied to a connection port 14, and its appearance is shown in FIG. Further, two cylinder switches 13 for magnetically detecting the upper end of the rod 14 of the cylinder 12 are attached. Furthermore, four support members 1
6 and is fixed to the main body 10.

Since the valve stem 11 inside the main body 10 is urged upward by the spring 30 in the valve opening direction, when the cylinder 12 is not driven, as shown in the right side of FIG. The vacuum valve 1 is in a valve open state. At this time,
The rod 15 of the cylinder 12 and the valve stem 12 are separated.
On the other hand, when the cylinder 12 is driven, the valve rod 11 inside the main body 10 is pushed downward by the rod 15 of the cylinder 12 in the valve closing direction, and as shown in the left side of FIG. 1 is in a valve closed state.

A flexible heater 20 as a first heater is mounted in the valve stem 11 inside the main body 10 through the insertion port 31.
Alternatively, since the valve rod 11 does not move up and down by the rod 15 of the cylinder 12 and the flexible heater 20 expands and contracts, the valve rod 11 can be uniformly heated.

The body 10 is surrounded by a cover 21, and a heat insulating material 22 is provided inside the cover 21. And
On the back side (the right side in FIG. 1) of the vacuum valve 1, a silicon rubber heater 23 as a second heater is connected to a heat insulating material 22.
It is installed inside. Further, a sheath-type thermoelectric body 24 which is a temperature measuring means for measuring the temperature of the outer wall of the main body 10 is provided. Further, the coupling 25 and the clamp 2
6, two vacuum clamp joints are provided. The input of the flexible heater 20 and the silicon rubber heater 23 is controlled by the thermostat 32.

[0027] Further, a vacuum clamp joint comprising a coupling 25 and a clamp 26 is provided. When connected to a pipe of an exhaust system of a semiconductor manufacturing apparatus, the cup is formed of a heat insulating material provided outside the pipe. Ring 25 and clamp 2
6 can be easily covered, so that the main body 10 of the vacuum valve 1
Will not come into contact with the outside air.

As described above in detail, in the vacuum valve 1 of the present embodiment, the valve rod 11 inside the main body 10 is urged upward by the spring 30, so that the cylinder 12 is driven. If not, the valve is open. On the other hand, when the cylinder 12 is driven, the valve stem 11 inside the main body 10 is pushed downward, so that the valve is in a closed state.
Then, the main body 10 is
Is heated, a temperature gradient is formed from the inside of the main body 10 to the outside of the main body 10, and the heat of the flexible heater 20 is transferred from the inside of the main body 10 to the main body 1.
0 moves toward the outer wall, and the whole is heated.

At this time, the rod 15 of the cylinder 12 for pushing the valve rod 11 heated by the flexible heater 20 is used.
When the valve is open, it is separated from the valve rod 11 and has no contact surface with the valve rod 11 to increase the so-called thermal resistance. Therefore, the amount of heat conducted from the valve rod 11 to the cylinder 12 is reduced. can do. Further, since the cylinder 12 is fixed to the main body 10 through the support member 16, the conventional cylinder which is directly fixed to the outer wall of the main body 101 like the prior art vacuum valve 100 of FIG. Since the so-called thermal resistance is increased by eliminating the contact surface with the main body 10, the amount of heat conducted from the main body 10 to the cylinder 12 can be further reduced.

Further, a cover 21 is provided outside the main body 10 and the cover 21 is heated by a silicon rubber heater 23, so that a gradient of a temperature gradient formed from the inside of the main body 10 to the outside of the main body 10 is reduced. Since the inclination can be reduced or the inclination can be reversed, the amount of heat radiated from the inside of the main body 10 to the outside of the main body can be reduced.

Further, since the heat insulating material 22 is provided outside the main body 10, the gradient of the temperature gradient formed from the inside of the main body 10 toward the outside of the main body 10 can be further reduced. The amount of heat radiated from the inside to the outside of the main body 10 can be further reduced.

A cover 21 having a heat insulating material 22 or the like is interposed between the outer wall of the main body 10 and the cylinder 12, and a temperature gradient formed from the outer wall of the main body 10 toward the heat insulating material 22. Prior art vacuum valve 1 with inclination of FIG.
5 and the gradient of the temperature gradient formed from the heat insulating material 22 toward the cylinder 12 is larger than that of the prior art vacuum valve 100 of FIG.
The amount of heat that moves from the outer wall of the cylinder to the cylinder 12 can be reduced.

That is, the vacuum valve 1 according to the present embodiment is
A temperature gradient is formed toward the outside of the main body 10, and the heat of the flexible heater 20 moves from the inside of the main body 10 to the outside of the main body 10, so that the whole is heated,
Since the heating is performed such that a locally low temperature portion is not generated inside the main body 10, the product does not adhere to the inside of the main body 10, and the sealing performance when the valve is closed due to the adhesion of the product is performed. Can be prevented from decreasing.

Further, since the amount of heat conducted from the main body 10 to the cylinder 12 is further reduced by fixing the cylinder 12 to the main body 10 via the support member 16, the cylinder 12 is necessary for controlling the cylinder 12 and has heat resistance. The poor cylinder switch 13 can be attached to the cylinder 12. In particular, when the valve is opened, it is necessary to perform heating by the flexible heater 20 so that a flow of the working fluid is formed inside the main body 10 and a locally low temperature portion is not generated inside the main body 10. By separating the rod 15 of the cylinder 12 from the valve rod 11 heated by the flexible heater 20 when the valve is opened, the heat of the flexible heater 20 can be transmitted to the cylinder switch 13 attached to the cylinder 12 via the valve rod 11. Absent.

A cover 21 to which a silicon rubber heater 23 and a heat insulating material 22 are attached is provided outside the main body 10, so that the flexible heater 20 is formed from the inside of the main body 10 to the outside of the main body 10. The temperature gradient can be reduced or the gradient can be reversed.
Heating that does not occur inside 0 can be performed more reliably.

The flexible heater 20 attached to the valve stem 11 inside the main body 10 allows the
When the temperature of the outer wall of the main body 10 is measured by the sheath-type thermoelectric body 24 when a temperature gradient is formed from the inside of the main body 10 toward the outer wall of the main body 10, the temperature inside the main body 10 is Since the temperature inside the main body 10 can be estimated without falling below the measured temperature, the inputs of the flexible heater 20 and the silicon rubber heater 23 are controlled by the thermostat 31 so that a locally low temperature part is the main body 10. Can be performed so as not to be generated inside.

Further, a coupling 25 and a clamp 26 are provided.
The coupling 25 and the clamp 26 have a narrower portion in contact with the outside air than the coupling 25 and the clamp 2 do.
Since a considerable amount of heat is not released from 6, the heating can be performed such that a locally low-temperature portion is not generated inside the main body 10.

It should be noted that the present invention is not limited to the above embodiment, and various changes can be made without departing from the gist of the present invention. For example, the vacuum valve 1 of the present embodiment is an example in which the present invention is applied to a fluid pressure control valve, and the present invention can be applied to other fluid pressure control valves. Further, in the vacuum valve 1 of the present embodiment, the cylinder 12 using compressed air as a driving source is used, but an electromagnetic coil using electric power as a driving source, a handle using manual operation as a driving source, and the like are driven. It may be used as a unit.

[0037]

According to the fluid pressure control valve of the present invention, a temperature gradient is formed from the inside of the main body to the outside of the main body by the first heater, and the heat of the first heater is transferred from the inside of the main body to the outside of the main body. The whole is heated by moving,
Heating is performed so that locally low-temperature parts are not generated inside the main body, so that products do not adhere to the inside of the main body, and the sealing performance when closing the valve due to the adhesion of such products is reduced Can be prevented.

Further, since the amount of heat conducted from the main body to the drive unit is further reduced by fixing the drive unit to the main body via the support member, switches that are necessary for control of the drive unit and have poor heat resistance. Can be attached to the drive unit. In particular, at the time of opening the valve, it is necessary to perform heating by the first heater so that a flow of the working fluid is formed inside the main body and a locally low temperature portion is not generated inside the main body. Sometimes, the drive unit is separated from the valve stem heated by the first heater, so that heat of the first heater is not transmitted to the switches attached to the drive unit via the valve stem.

Further, by providing a cover to which a second heater and a heat insulating material are attached outside the main body, it is possible to reduce the temperature gradient formed from the inside of the main body toward the outside of the main body by the first heater. In addition, the inclination can be reversed, so that heating can be performed more reliably so that a locally low temperature portion does not occur inside the main body.

Further, when a temperature gradient is formed from the inside of the main body to the outer wall of the main body by the first heater attached to the valve stem inside the main body, the temperature of the outer wall of the main body is measured by the temperature measuring means. Then, since the temperature inside the main body does not fall below the temperature measured by the temperature measuring means and the temperature inside the main body can be estimated, the first heater and the second heater can be estimated.
By controlling the input of the heater, it is possible to perform heating such that a locally low temperature portion does not occur inside the main body.

Further, if a vacuum clamp joint is provided and the fluid pressure control valve of the present invention is used as a vacuum valve, the portion of the vacuum clamp joint that comes in contact with the outside air is narrower than the conventional joint. Since a considerable amount of heat is not released from the vacuum clamp joint, it is possible to perform heating such that a locally low-temperature portion does not occur inside the main body.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of the vacuum valve of the present embodiment viewed from an arrow A in FIG.

FIG. 2 shows a front view of the vacuum valve of the present embodiment.

FIG. 3 shows a top view of the vacuum valve of the present embodiment.

FIG. 4 shows a bottom view of the vacuum valve of the present embodiment.

FIG. 5 is a front view of a prior art vacuum valve.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vacuum valve 10 Main body 11 Valve rod 12 Cylinder 16 Support member 20 Flexible heater 21 Cover 22 Insulation material 23 Silicon rubber heater 25 Coupling 26 Clamp 30 Spring

Claims (6)

[Claims] 1. A valve stem which is internal to a main body and urged in a valve opening direction by a spring is pushed in a valve closing direction by a driving unit external to the main body to open and close the valve. A fluid pressure control valve, wherein a first heater that freely forms a temperature gradient that is inclined from the inside of the main body toward the outside is mounted in the valve stem. 2. The fluid pressure control valve according to claim 1, wherein the drive unit, which is separated from the valve rod when the valve is opened, is fixed to the main body via a support member. . 3. The fluid pressure control valve according to claim 1, wherein a second heater is attached to a cover surrounding the main body. 4. The fluid pressure control valve according to claim 3, wherein the main body is surrounded by a heat insulating material. 5. The fluid pressure control valve according to claim 1, further comprising a temperature measuring means for measuring a temperature of an outer wall of the main body. . 6. The fluid pressure control valve according to claim 1, further comprising a vacuum clamp joint.