JP2021055725A - Valve and flow control device - Google Patents

Abstract

To provide a valve and a flow control device capable of easily discharging internal gas even when failure occurs in a piezoelectric element.SOLUTION: A valve includes: a body block 2B in which an inflow passage 2f and an outflow passage 2g are formed; a diaphragm 21 opening/closing the inflow passage 2f and the outflow passage 2g; a spacer case 12 and an element case 13 which are provided so that they can come close to the diaphragm 21 and separate from a valve element; a coil spring 16 energizing the spacer case 12 and the element case 13 so that they come close to the diaphragm 21; a piezoelectric element 18 provided in the element case 13 and extended to move the spacer case 12 and the element case 13 to the side separated from the diaphragm 21; and an extension member 19A extended by heating or cooling and moving the spacer case 12 and the element case 13 to the side separated from the diaphragm 21.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to valves and flow control devices used in semiconductor manufacturing devices and the like.

A mass flow rate control device has been proposed in which a valve body is operated by a laminated piezoelectric actuator to open and close a flow path (see, for example, Patent Document 1).

International Publication No. 2015/045987

In the mass flow rate control device of Patent Document 1, when the laminated piezoelectric actuator fails, the device is closed and gas stays inside the device. Therefore, when removing the device, it is necessary to perform a purge to replace the gas inside. However, since the laminated piezoelectric actuator is out of order, it is necessary for the operator to go to the device and mechanically open the device.

Therefore, an object of the present disclosure is to provide a valve and a flow rate control device capable of easily discharging the internal gas even when the piezoelectric element fails.

In order to solve the above object, the valve according to one aspect of the present disclosure can have a body in which a fluid passage is formed, a valve body that opens and closes the fluid passage, and a valve body that is close to the valve body and can be separated from the valve body. The case provided in the case, the urging member for urging the case so as to be close to the valve body, and the case provided in the case and extended to move the case away from the valve body. It includes a piezoelectric element to be moved and an extension member which is extended by heating or cooling and moves the case to a side away from the valve body.

The extension member may be composed of a member made of a positive thermal expansion material or a member made of a negative thermal expansion material.

The extension member may be interposed between the case and the piezoelectric element at an end portion of the piezoelectric element opposite to the end portion on the valve body side.

The flow rate control device according to one aspect of the present disclosure includes a body in which a fluid passage is formed, a valve body that opens and closes the fluid passage, an orifice portion provided in the fluid passage on the downstream side of the valve body, and the valve. A pressure detector that detects the pressure in the fluid passage between the body and the orifice portion, a case provided close to the valve body and separable from the valve body, and the case with respect to the valve body. An urging member that urges the case close to each other, a piezoelectric element provided in the case and extended to move the case away from the valve body, and an extension by heating or cooling. An extension member for moving the case away from the valve body is provided.

The extension member may be composed of a member made of a positive thermal expansion material or a member made of a negative thermal expansion material.

The extension member may be interposed between the case and the piezoelectric element at an end portion of the piezoelectric element opposite to the end portion on the valve body side.

According to the present disclosure, it is possible to provide a valve and a flow rate control device capable of easily discharging the internal gas even when the piezoelectric element fails.

It is sectional drawing of the flow rate control apparatus provided with the valve which concerns on embodiment of this disclosure. It is an enlarged view near the extension part which concerns on embodiment. It is an enlarged view of the vicinity of the extension part which concerns on the modification.

The valve and the flow rate control device according to the embodiment of the present disclosure will be described with reference to the drawings.

FIG. 1 is a cross-sectional view of a flow rate control device 1 including a valve according to the present embodiment.
FIG. 2 is an enlarged view of the vicinity of the extension portion according to the present embodiment.

The flow rate control device 1 of the present embodiment is a known flow rate control device called a high temperature pressure type flow rate control device. As shown in FIG. 1, the flow rate control device 1 includes a valve block body 2, a housing 3, an opening / closing unit 10, and a second pressure detector 4.

The valve block body 2 which is a body is made of, for example, stainless steel. The valve block body 2 is integrated by connecting the inlet side block 2A, the main body block 2B, and the outlet side block 2C with bolts.

A gas flow path 2d is formed in the inlet side block 2A. The main body block 2B is formed with a valve chamber 2e, an inflow passage 2f and an outflow passage 2g communicating with the valve chamber 2e. An annular valve seat 2H protruding toward the opening / closing portion 10 is provided on the peripheral edge (opening of the inflow path 2f) where the inflow path 2f of the main body block 2B and the valve chamber 2e communicate with each other. A gas flow path 2i is formed in the outlet side block 2C. The gas flow path 2d of the inlet side block 2A communicates with the inflow path 2f of the main body block 2B. The gas flow path 2i of the outlet side block 2C communicates with the outflow path 2g of the main body block 2B. The valve block body 2 is heated to a predetermined temperature by a heating device (not shown).

The housing 3 has a substantially rectangular parallelepiped shape and is installed on the main body block 2B. A plurality of vents (not shown) are formed on the side surfaces 3A and 3B of the housing 3 along the vertical direction.

As shown in FIG. 1, the opening / closing portion 10 is provided in the main body block 2B and the housing 3. The opening / closing portion 10 includes a guide member 11, a spacer case 12, an element case 13, a bridge 14, a flange portion 15, a coil spring 16, a spacer 17, a piezoelectric element 18, an extension portion 19, and a pressing portion 20. A diaphragm 21, a first pressure detector 22, and an orifice portion 23 are provided. The main body block 2B, the guide member 11, the spacer case 12, the element case 13, the bridge 14, the flange portion 15, the coil spring 16, the spacer 17, the piezoelectric element 18, the extension portion 19, and the pressing portion 20. And the diaphragm 21 constitute a valve. The valve is a valve that is always closed.

The guide member 11 has a cylindrical shape, extends along the vertical direction, and is fixed to the main body block 2B. A flange 11A is provided at the upper end of the guide member 11. The spacer case 12 has a cylindrical shape, extends along the vertical direction, and is provided in the guide member 11 so as to be slidable in the vertical direction. The element case 13 has a cylindrical shape and extends in the vertical direction, and its lower end is fixed to the upper end of the spacer case 12. A cover 13A is attached to the upper end of the element case 13. The cover 13A is made of a bag nut, and an opening 13b is formed at the upper end thereof. The bridge 14 is inserted into a slit 12a formed at the lower end of the spacer case 12. The bridge 14 is pressed from above by the guide member 11 and fixed to the main body block 2B. The element case 13, the cover 13A, and the spacer case 12 correspond to the case.

The collar portion 15 includes a collar receiver 15A and a collar body 15B. The flange receiver 15A is provided on the outer periphery of the spacer case 12 and penetrates through the through hole 11b formed in the guide member 11. The collar body 15B is provided on the collar receiver 15A. The coil spring 16 which is an urging member is provided between the flange 11A and the flange body 15B in a compressed state. The coil spring 16 always presses the spacer case 12 and the element case 13 downward via the flange portion 15.

The spacer 17 is made of a material such as metal (for example, Invar material) or resin, has a columnar shape, and is provided in the spacer case 12. The lower end of the spacer 17 is in contact with the upper end of the bridge 14. The piezoelectric element 18 is a laminated piezoelectric element, and has a substantially cylindrical shape as a whole. The piezoelectric element 18 is located above the spacer 17 and is provided in the element case 13. Since the piezoelectric element 18 is separated from the valve block body 2 by the spacer 17, even if a high temperature gas flows through the inflow path 2f and the outflow path 2g of the main body block 2B, the piezoelectric element 18 reaches a predetermined temperature or higher. Is suppressed.

The extension portion 19 is located at an end portion of the piezoelectric element 18 opposite to the end portion on the diaphragm 21 side. As shown in FIG. 2, the extension portion 19 is composed of a cylindrical aluminum member 19A and a heater 19B. The aluminum member 19A is located on the piezoelectric element 18, and the upper end of the aluminum member 19A is in contact with the cover 13A. That is, the aluminum member 19A is interposed between the cover 13A of the element case 13 and the piezoelectric element 18 along the vertical direction. The aluminum member 19A corresponds to an extension member. The heater 19B is provided in the aluminum member 19A.

As shown in FIG. 1, the pressing portion 20 is located below the spacer case 12. The lower end of the spacer case 12 is in contact with the pressing portion 20. The diaphragm 21 is made of, for example, a nickel-cobalt alloy, is provided in the valve chamber 2e, and has an outer peripheral edge held with respect to the main body block 2B. The diaphragm 21 has a substantially spherical shell shape, and the substantially spherical shell shape that is convex upward is in a natural state. When the diaphragm 21 abuts and separates from the valve seat 2H, communication or blocking between the inflow path 2f and the outflow path 2g is performed. The diaphragm 21 corresponds to a valve body. The first pressure detector 22 detects the pressure of the gas in the outflow passage 2g. A microhole (orifice) is formed in the orifice portion 23, and is located at the downstream end portion of the outflow passage 2g.

When the piezoelectric element 18 is not energized, the spacer case 12 and the element case 13 are pushed downward in the figure by the coil spring 16, the diaphragm 21 is in contact with the valve seat 2H, and the inflow path 2f and the outflow path 2g are blocked. When the piezoelectric element 18 is energized, the piezoelectric element 18 is extended, and when the spacer case 12 and the element case 13 are lifted upward in FIG. 1 against the elastic force of the coil spring 16, the diaphragm 21 is convex upward by the self-elastic force. The inflow path 2f and the outflow path 2g communicate with each other by returning to a substantially spherical shell shape.

When it is desired to open the flow rate control device 1 (valve) when the piezoelectric element 18 fails, the heater 19B is energized to heat the aluminum member 19A, thereby extending the aluminum member 19A. As a result, the spacer case 12 and the element case 13 are lifted upward in FIG. 1 against the elastic force of the coil spring 16, and the diaphragm 21 is returned to the upward convex substantially spherical shell shape by the self-elastic force to form the inflow path 2f. It communicates with the outflow channel 2g. As a result, even if the piezoelectric element 18 is out of order, the flow rate control device 1 (valve) can be opened and the gas in the flow rate control device 1 (valve) can be easily discharged to the outside.

The flow rate control device 1 detects the gas pressure at least on the upstream side of the orifice portion 23 by the first pressure detector 22, and controls the gas flow rate by operating the diaphragm 21 by the piezoelectric element 18 based on the detected pressure signal. .. When the absolute pressure of the gas on the upstream side of the orifice portion 23 becomes about twice or more the absolute pressure of the gas on the downstream side of the orifice portion 23 (critical expansion condition), the velocity of the gas passing through the micropores of the orifice portion 23 becomes the speed of sound. , No more flow velocity. Therefore, the principle that the flow rate of the gas depends only on the pressure of the gas on the upstream side of the micropores and the flow rate of the gas passing through the micropores of the orifice portion 23 is proportional to the pressure of the gas is used.

Although not shown, it is also possible to detect the pressure of the gas on the downstream side of the microhole of the orifice portion 23 and control the gas flow rate based on the differential pressure of the gas on the upstream side and the downstream side of the microhole. .. The hole of the orifice portion 23 is not limited to the orifice and may have a structure for squeezing the fluid.

The pressure detector 4 is provided in the inflow path 2f of the main body block 2B, can measure the pressure of the gas supplied from a gas supply device (for example, a raw material vaporizer) (not shown), and can be used for controlling the raw material supply amount. ..

As described above, the valve of the present embodiment has the main body block 2B in which the inflow path 2f and the outflow path 2g are formed, the diaphragm 21 that opens and closes the inflow path 2f and the outflow path 2g, and the valve that is close to the diaphragm 21 and said. A spacer case 12 and an element case 13 provided so as to be separated from the body, a coil spring 16 for urging the spacer case 12 and the element case 13 so as to be close to the diaphragm 21, and a coil spring 16 provided in the element case 13 and extending. Thereby, the piezoelectric element 18 that moves the spacer case 12 and the element case 13 to the side separated from the diaphragm 21 and the piezoelectric element 18 that is extended by heating or cooling and the spacer case 12 and the element case 13 are moved to the side separated from the diaphragm 21. An extension member 19A for making the extension member 19A is provided.

According to this configuration, when it is desired to open the valve (flow control device 1) when the piezoelectric element 18 fails, the heater 19B is energized to heat the aluminum member 19A, thereby extending the aluminum member 19A. .. As a result, the spacer case 12 and the element case 13 are lifted upward in FIG. 1 against the elastic force of the coil spring 16, and the diaphragm 21 is returned to the upward convex substantially spherical shell shape by the self-elastic force to form the inflow path 2f. It communicates with the outflow channel 2g. As a result, even if the piezoelectric element 18 is out of order, the valve can be opened and the gas in the valve can be easily discharged to the outside.

Since the extension member 19A is interposed between the cover 13A of the element case 13 and the piezoelectric element 18 at the end of the piezoelectric element 18 opposite to the end on the diaphragm 21 side, the spacer case 12 and the element case The valve can be opened by only lifting 13 and the gas in the valve can be easily discharged to the outside.

This is the end of the description of one embodiment of the present disclosure, but the present disclosure is not limited to the above embodiment, and various changes can be made without departing from the spirit of the present disclosure.

FIG. 3 is an enlarged view of the vicinity of the extension portion 119 according to the modified example.

The extension portion 119 of this modification is composed of a cylindrical extension member 119A made of a negative thermal expansion material. Examples of the negative thermal expansion material include zirconium tungate (ZrW ₂ O ₈ ), bismuth lanthanum nickel oxide (Bi _0.95 La _0.05 NiO ₃ ) and the like. By cooling the temperature of the extension member 119A from a predetermined temperature, the extension member 119A can be extended and the flow rate control device 1 (valve) can be opened. Cooling of the extension member 119A is performed, for example, by mounting a fan on the side surface 3A of the housing 3 and sending fan air to the inside of the housing 3 through a plurality of vents on the side surface 3A.

As described above, since the extension member 119A is made of a negative thermal expansion material, it is not necessary to raise the temperature in order to extend the extension member 119A. Therefore, no load is applied to the piezoelectric element 18, and the flow control device 1 (valve) can be opened by the extension member 119A even when the piezoelectric element 18 is not out of order. Therefore, by opening the flow rate control device 1 (valve) instead of the piezoelectric element 18, the load on the piezoelectric element 18 can be reduced, and the life of the flow rate control device 1 (valve) can be extended. it can.

In the above embodiment, the extension member is the aluminum member 19A, but may be another material as long as it is made of a positive thermal expansion material. The flow rate control device 1 includes the second pressure detector 4, but the second pressure detector 4 may not be provided. The pressing portion 20 is separate from the spacer case 12, but may be integrated. The extension portions 19 and 119 are interposed between the cover 13A of the element case 13 and the piezoelectric element 18, but may be interposed between the spacer 17 and the piezoelectric element 18. The flow rate control device 1 of the above embodiment is a high temperature type pressure type flow rate control device, but the flow rate control device may be a general known flow rate control device that is not a high temperature type.

1: Flow control device 2: Valve block body 2B: Main body block 12: Spacer case 13: Element case 13A: Cover 16: Coil spring 18: Piezoelectric element 19, 119: Extension part 19A: Aluminum member 119A: Extension member 21: Diaphragm 22 : 1st pressure detector 23: Orifice

Claims (6)

With the body in which the fluid passage is formed,
A valve body that opens and closes the fluid passage,
A case provided so as to be close to the valve body and separable from the valve body,
An urging member that urges the case so as to be close to the valve body,
A piezoelectric element provided in the case and extended to move the case away from the valve body.
A valve comprising an extension member that extends by heating or cooling and moves the case away from the valve body. The valve according to claim 1, wherein the extension member is composed of a member made of a positive thermal expansion material or a member made of a negative thermal expansion material. The valve according to claim 1 or 2, wherein the extension member is interposed between the case and the piezoelectric element at an end of the piezoelectric element opposite to the valve body side end. .. With the body in which the fluid passage is formed,
A valve body that opens and closes the fluid passage,
An orifice provided in the fluid passage on the downstream side of the valve body and
A pressure detector that detects the pressure in the fluid passage between the valve body and the orifice portion, and
A case provided so as to be close to the valve body and separable from the valve body,
An urging member that urges the case so as to be close to the valve body,
A piezoelectric element provided in the case and extended to move the case away from the valve body.
A flow rate control device including an extension member that extends by heating or cooling and moves the case to a side away from the valve body. The flow rate control device according to claim 4, wherein the extension member is composed of a member made of a positive thermal expansion material or a member made of a negative thermal expansion material. The flow rate according to claim 4 or 5, wherein the extension member is interposed between the case and the piezoelectric element at an end of the piezoelectric element opposite to the valve body side end. Control device.

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