JP7365147B2 - Small diameter actuator for high temperature valves and high temperature valves - Google Patents

Description

The present invention relates to a small-diameter actuator for a high-temperature valve and a high-temperature valve, and in particular to a small-diameter actuator for a high-temperature valve that is extremely suitable for mounting on a fluid control valve used in a semiconductor manufacturing device for an ALD (Atomic Layer Deposition) process. Regarding high temperature valves.

In recent years, demand for the so-called ALD process as a thin film growth process continues to increase due to miniaturization and higher integration of semiconductor device design rules and further demands for thin film deposition control at the Å level. In this ALD process, thin film growth is controlled by stacking layers one at a time at the atomic/nano level, so different fluids are switched at extremely high speeds in the gas supply line to continuously repeat the cycle of supplying and discharging the fluid to the chamber. Since it is necessary to control the growth at the atomic layer level, a valve opening/closing life of about 10 million times is usually required in order to grow a thin film on a wafer at the level required for the product.

Therefore, it is essential for the valves and actuators used in the ALD process to have high durability that can withstand use far beyond what was previously expected, as well as high-speed response to open and close the valve. becomes. In addition, since the supply gas is a special fluid made of metal compounds with extremely low vapor pressure, it is necessary to maintain the temperature at approximately 200 degrees in order to ensure a stable supply of gas. It is also essential to have high temperature resistance so that it can function well even in a temperature environment of (preferably about 250 to 300 degrees).

On the other hand, in recent years, semiconductor devices are required to be increasingly miniaturized and highly integrated, and the diversification of semiconductor manufacturing processes has progressed significantly, and the various process gases used in manufacturing processes have also changed depending on individual applications. In addition to diversification, higher temperatures, and higher pressures, there is also an increase in the size of silicon wafers, liquid crystal panels, and production systems, as well as changes to special gas supply methods. These require at least the flow rate of the supply gas and the switching and control of various types of gases, and therefore at least increase the overall installation area such as larger valves and an increase in the number of installed valves, which in turn leads to further enlargement of semiconductor manufacturing equipment. Connected demand continues. In particular, since semiconductor manufacturing equipment usually manufactures high-quality precision equipment such as semiconductor elements, at least the gas supply system consisting of valves and actuators is all housed in a clean room, but even in this clean room, the volume In addition to the initial equipment costs that increase as the production progresses, running costs for maintenance and constant operation are required, which becomes a large burden on production equipment costs.

Under these circumstances, if the valves and actuators of semiconductor manufacturing equipment are made even slightly larger, the space they occupy will also increase as a large number of them are installed, making it difficult to integrate the entire equipment. In addition to compromising the requirements for the gas supply system, the optimization of the space occupied by the entire gas supply system is also impaired, and the volume of the clean room that accommodates the gas supply system must also be increased, leading to an increase in semiconductor manufacturing equipment costs and, ultimately, the cost of manufacturing semiconductor products. The problem arises that the situation gets worse. Therefore, at least valves and actuators must be optimally designed to maintain or further improve their performance while minimizing their size, that is, to minimize waste depending on the application.

On the other hand, so-called direct-touch type diaphragm valves are usually used as control valves for gas supply systems in semiconductor manufacturing equipment. Air-operated actuators with excellent performance are often installed. Such valves and actuators are typically made as compact as possible to avoid creating dead space, and in typical integrated gas systems, the valve body has fittings along with other equipment. It is not integrated into a compact base block. In recent years, for example, valve bodies have been used that are integrated into a rectangular shape within a footprint that has been significantly compacted to the extent that the flow path diameter is on the order of several millimeters and fits in the shape of a rectangular parallelepiped with sides of about 3 cm.

The basic performance of such air-operated actuators is the driving force that moves the piston (rod) up and down, and specifically, the elastic force of the diaphragm valve body by a predetermined elastic member such as a spring, and the elastic force that is applied to this elastic force. On the other hand, it is the air pressure in the air chamber that expands and contracts with the supplied air. In addition, the footprint area mentioned above is allocated as the space occupied by each actuator, and in order to fit within that area and integrate it with ease of handling and maintenance, a specified connection part is installed at the top of the base block. A structure that is removably attached via a cylinder and has a narrow cylindrical appearance is often used.

However, in reality, the demand for reducing the size and space occupied by actuators is basically a restriction on the footprint area that determines the width direction, and there are often relatively loose restrictions on the height direction. For this reason, while it is necessary to further reduce the width direction size of the actuator volume, the height direction size may often be maintained or increased to some extent. Therefore, by making the actuator smaller in diameter while maintaining or slightly increasing the height, it is possible to reduce the footprint and secure (maintain or increase) the driving force that may be lost due to this miniaturization. I can do it.

In this case, there are basically two methods/directions that can be considered. One way is to secure the necessary driving force by increasing the number of air chambers and the corresponding number of elastic members. By increasing the number of pistons in the height direction, the piston also has a multi-stage piston structure. Patent Document 1 is one of this type of conventional technology.

Patent Document 1 is an example of a prior art related to a multi-stage piston structure, and specifically, a plurality of coaxially driving pistons are provided on the upper part of one valve body piston that drives a valve body and is biased by a return spring. The pistons are stacked in multiple stages, and by introducing a return spring that urges the valve body piston, the piston's high-speed response is ensured. Since a plurality of rubber O-rings are interposed between these and interior parts, for example, when the actuator of the same document is used in an ALD process, these O-rings are exposed to high-temperature environments. As each piston moves up and down, the parts slide at high speed over a long period of time many times.

The other method is to change the drive source to some structure that has stronger driving force, such as changing the resilient spring member, while maintaining the occupied volume or making it more compact.In this case, the cam of a predetermined structure A typical example is the introduction of a booster mechanism that can appropriately amplify the actuator driving force. One of this type of prior art is Patent Document 2.

Patent Document 2 introduces a boosting mechanism that consolidates the necessary functions in the height direction while keeping the size compact in the width direction. The actuator has a rolling part that moves and an actuating part that moves the stem at the other end, and a plurality of cams that rotate around the shaft part are built into the actuator.

These cams are pivoted to a fulcrum in a substantially vertical direction along the moving direction of the piston, and are prevented from increasing in diameter in the width direction as much as possible. In the same document, a large valve closing force is ensured by introducing a disc spring that has a small diameter but exerts a strong elastic force, and the cam doubles the valve opening force due to the air supply to the bellows. The cam rotates in response to the force point action between the inclined surface of the lower surface of the actuating body and the rolling portion of the cam, and the actuating portion moves the stem up and down via the point of action.

Further, the boosting mechanism in the same document amplifies the air driving force (valve opening force) of the bellows, but the conventional technology amplifies the valve closing force by the elastic member through the principle of leverage in a cam, for example. In any case, there are many prior art proposals regarding actuators with built-in predetermined boosting mechanisms in order to compensate for the decrease in driving force due to the miniaturization of actuators.

Furthermore, as another structure, there is a so-called bellows actuator structure as shown in Patent Document 3. In this document, a double bellows is provided between the piston and the partition plate, and by supplying and discharging driving gas to the internal space between the double bellows through a flow path, a coil spring is generated. The piston, which is in a resilient state, moves up and down to open and close the valve head relative to the valve seat. The rod in this document passes through a sleeve fitted into a through hole in the center of the partition plate, so that the sleeve and rod slide as the piston moves up and down.

Furthermore, as another structure, a so-called multi-stage diaphragm actuator structure as shown in Patent Document 4 is also known. In the same document, in order to solve the problems with the conventional structure, such as the O-ring used in the piston becoming sticky and brittle at high temperatures of about 350 degrees, at least the variable air chamber volume is made possible by a diaphragm. A structure has been proposed in which, by partitioning, a dynamic sealing part such as an O-ring can be eliminated, and the air chamber can also be appropriately multi-staged in the height direction.

Japanese Patent Application Publication No. 2018-84272 Japanese Patent Application Publication No. 2016-183749 Utility Model Publication No. 6-37670 US Patent Registration No. 9476516

However, in Patent Document 1 or this type of actuator with a multi-stage piston structure, in principle, a large number of O-rings attached to the piston slide depending on the use of the valve or actuator, so at least during sliding. The frictional force impairs the vertical movement of the piston that slides with the O-ring, and thus the opening/closing response of the valve, and since there are a large number of O-rings, this effect is likely to be amplified.

In addition, in high-temperature environments, rubber O-rings tend to deteriorate, wear out, or become stuck, which tends to impair good sliding performance and high-speed response while maintaining sealing performance, especially when using grease. After being applied and left in a stationary state for a long period of time, there is a risk that the grease may stick to the grease, which also poses a problem in long-term durability.

In particular, when used in the ALD process, in addition to heat resistance against high-temperature environments as described above, high standards are also required for high-speed response and durability in this environment, so multiple O-rings are installed in the piston. The actuator of the same document, which has a structure in which such use is unavoidable, or the conventional multi-stage piston structure of this type has at least a fundamental problem with the piston's motion characteristics, and it is difficult to use it with sufficient reliability. I have to say that it is not possible.

The actuator of Patent Document 2 has a structure in which thrust from the bellows is transmitted to the stem via a cam, which is a boosting mechanism, in order to compensate for the air thrust that has weakened due to the reduction in air chamber volume due to compactness. Specifically, the presence of this cam causes a delay in air thrust transmission, and there is a risk that the valve opening/closing responsiveness may not be fully demonstrated. Furthermore, since wear between the actuating body and other parts that act on the cam is unavoidable, there is a risk that the boost balance will be disrupted and the valve performance will deteriorate.In addition, such wear may reduce the durability of the parts. It can be said that the structure is easily damaged. Furthermore, since the boost mechanism generally has a complex structure, it requires a lot of cost in terms of productivity and maintenance, and it also requires high costs to be built into the compact actuator body and function properly. Accurate component dimensions, placement, and assembly are also required.

On the other hand, in the bellows actuator structure as in Patent Document 3, first, the flow path (supply means) structure for supplying the driving gas to the bellows internal space is a structure in which the inside and outside of the actuator body are horizontally connected, so the main body is Since it is impossible to configure it compactly within the footprint area, and it has only one air chamber (piston), it cannot meet the demands for a smaller diameter or more compact main body. Furthermore, since this document basically does not take into consideration the above-mentioned ALD process, it does not provide any information on measures for high temperature resistance required for the actuator body. In particular, as mentioned above, the rod slides on the sleeve, and if such a sliding part exists even in one place, it will be a big drawback for high-speed response and high durability for many times, and above all, This is a fatal defect when used in an ALD process.

In addition, in the multi-stage bellows actuator structure as in Patent Document 4, regardless of the details of the structure, considering the principle that the air chamber volume is defined by the diaphragm that interlocks with the piston, in order to ensure sufficient driving force, When trying to secure a sufficiently large air chamber volume, there are significant restrictions on the shape of one diaphragm (one air chamber) that bulges in the height direction, so increasing the volume of the actuator body in the height direction is difficult. This is practically impossible, and it can be said that this structure inevitably increases in size at least in the lateral direction. In fact, the drawings in the same document disclose an actuator in which the inner diameter of the air chamber volume is about 10 times the outer diameter of the stem.

Therefore, the structure as described in the above document cannot sufficiently cope with the problem of compacting the size within the footprint area as described above. It should be noted that instead of enlarging the size in the lateral direction, it may be possible to achieve this by stacking multiple air chambers, but from the viewpoint of actuator operability and productivity, it is not practical to increase the size of the air chambers in this way. There are limitations; for example, a structure with 10 or more air chambers is not realistic. In fact, the drawings in this document only show a multilayer structure of up to three stages.

Therefore, the present invention was developed to solve the above problems, and its purpose is to eliminate the need for complex structures such as boosting mechanisms, and to eliminate sliding parts such as O-rings. In addition to eliminating all of the above, the multi-layer structure of the air chamber makes it possible to easily secure and adjust the driving force even though the diameter is small and small, and it can demonstrate extremely good high-speed response, heat resistance, and durability. In particular, it is an object of the present invention to provide a small-diameter actuator for a high-temperature valve and a high-temperature valve that are extremely suitable for ALD processes.

In order to achieve the above object, the invention according to claim 1 constructs a bellows unit by stacking bellows and bellows flanges in a multi-tiered state in the vertical direction, and passing a rod through the center of the bellows and bellows flange. This is a small-diameter actuator for a high-temperature valve in which a bellows unit is housed in a small cylindrical case, and a rod fixed to each bellows is moved up and down by expansion and contraction of each bellows due to supply and exhaust of air in each bellows.

In the invention according to claim 2, the air chamber of the bellows is an inner space of a large-diameter bellows of a size that can be stored in a small cylindrical case, and the inside of this inner space and the air flow path of the rod are connected through a communication part. This is a small-diameter actuator for high-temperature valves that communicates with each other.

In the invention according to claim 3, the bellows flange is composed of a fixed flange sealed on one side of the bellows and a movable flange sealed sealed on the small cylindrical case , and a movable flange sealed on the other side of the bellows and the rod. The section is a small-diameter actuator for high-temperature valves, which is a communication hole drilled in the rod.

The invention according to claim 4 is a small-diameter actuator for a high-temperature valve, in which a small-diameter bellows with an expandable structure is provided between a fixed flange and a movable flange.

In the invention according to claim 5, the air chamber of the bellows is an inner and outer bellows space configured by disposing an inner bellows coaxially within an outer bellows, and an air flow path provided in the rod and inside this inner and outer bellows space. This is a small-diameter actuator for high temperature valves that communicates with the valve through a communication portion.

In the invention according to claim 6, the bellows flange is composed of a fixed flange sealedly fixed to a small cylindrical case on one side of the inner and outer bellows, and a movable flange sealedly fixed to the rod on the other side of the inner and outer bellows, and a communicating portion. is a small-diameter actuator for a high-temperature valve, which has a communication path provided in a movable flange.

The invention according to claim 7 is a small-diameter actuator for a high-temperature valve, in which a stopper for restricting the upward movement of the movable flange is provided on the fixed flange side.

The invention according to claim 8 is a high-temperature valve in which a small-diameter actuator for a high-temperature valve is mounted on a valve body.

According to the invention set forth in claim 1, the bellows and the bellows flange are stacked vertically in multiple stages, and the center of these is penetrated by a rod to form a bellows unit, and this bellows unit is housed in a small cylindrical case. Since the rods fixed to each bellows are moved up and down by the expansion and contraction of each bellows due to the supply and exhaust of air within each bellows , parts such as O-rings on pistons that slide between members as they move are eliminated. However, it is possible to realize an actuator structure in which air chambers are stacked vertically in multiple stages.

Therefore, the actuator can be constructed using only materials that can sufficiently withstand high temperatures of at least about 300 degrees, such as an all-metal structure, and can have extremely good high temperature resistance especially for use in ALD processes. In addition, by stacking the air chambers in multiple stages in the vertical direction, it is possible to easily increase or decrease the number of air chambers, making it possible to amplify and adjust the driving force without increasing the size of the actuator in the horizontal direction. It is possible to easily secure and adjust the necessary driving force within the small footprint while maintaining compactness.

Furthermore, unlike the conventional multi-stage piston structure, there is no sliding part consisting of a large number of O-rings, and the expansion and contraction of the air chamber in the present invention is accompanied by the contraction of the bellows. No wear occurs, and no deterioration or sticking of the O-ring occurs. Therefore, it is possible to achieve extremely good high-speed response, especially for use in ALD processes, and also to have good durability that can withstand an extremely large number of operations. Furthermore, since the natural contraction force of the bellows can be used for the expansion and contraction operations of the air chamber, the structure is more advantageous for at least the high-speed response of the actuator.

According to the invention set forth in claim 2, since the air chamber of the bellows is an inner space of a large diameter bellows that is large enough to be stored in a small cylindrical case, one air chamber can be used without wasting space within the main body. Since the maximum permissible volume can be secured and the bellows is formed to have a large diameter, the expansion and contraction properties of the air chamber, that is, the operability of the actuator are also improved. In addition, since this inner space and the air flow path of the rod are communicated via the communication part, the air flow path can be housed within the rod in the axial direction of the main body in an extremely compact manner without wasting space. Therefore, the size reduction or compactness of the actuator body is not impaired due to the configuration of the air flow path, such as protrusion toward the outer circumferential side of the housing.

According to the invention set forth in claim 3, the bellows flange includes a fixed flange sealedly fixed to the small cylindrical case on one side of the bellows, and a movable flange sealedly fixed to the rod on the other side of the bellows. Since the communicating portion is a communicating hole drilled in the rod, the air chamber can be easily configured with a single bellows that seals a portion of the rod from the outside, and the actuator also has good operability.

According to the invention set forth in claim 4, since the small diameter bellows with an expandable structure is provided between the fixed flange and the movable flange, the sealing performance of the air chamber in the bellows is improved, especially air leakage from the rod shaft mounting part of the fixed flange is improved. , can be reliably prevented by the small diameter bellows, thus ensuring good actuator operability.

According to the invention set forth in claim 5, the bellows is constructed by coaxially disposing the inner bellows within the outer bellows, and the air chamber of the bellows is a space between the inner and outer bellows, and the air chamber and the rod are provided with a space between the inner and outer bellows. Since the air flow path is communicated with the air passage through the communication portion, the sealing performance of at least the air chamber within the bellows can be ensured by the double inner and outer bellows. Further, compared to the case of a single bellows, the contribution of the bellows characteristics to the air chamber expansion and contraction properties, that is, the contribution to the actuator operability can be increased.

According to the invention set forth in claim 6, the bellows flange includes a fixed flange sealedly fixed to the small cylindrical case on one side of the inner and outer bellows, and a movable flange sealedly fixed to the rod on the other side of the inner and outer bellows. Since the communication part is a communication path provided in the movable flange, air can be supplied and discharged from the movable flange side into the air chamber of the annular space partitioned by the inner and outer double bellows. This can contribute to improving the operability of the actuator, that is, the operability of the actuator.

According to the invention set forth in claim 7, since the stopper that limits the rise of the movable flange is provided on the fixed flange side, the top dead center of the movable flange can be set with a simple structure, and the operability of the actuator is also improved. Contribute.

According to the invention set forth in claim 8, since the high temperature valve is equipped with a small-diameter actuator for high temperature valves, the high temperature valve is equipped with an actuator that is extremely compact at least in the width direction while ensuring necessary and sufficient driving force and operability. It becomes possible to provide valves.

FIG. 2 is a side view showing a state in which the actuator main body according to the first embodiment of the present invention is attached to a valve body. FIG. 2 is a cross-sectional view taken along line AA in FIG. 1 and showing the valve in an open state. FIG. 3 is a cross-sectional view of FIG. 2 showing a valve closed state. FIG. 1 is a side view showing the appearance of a bellows unit according to a first embodiment of the present invention. 5 is a sectional view taken along the line BB in FIG. 4. FIG. FIG. 7 is a vertical sectional view showing the actuator main body of the second embodiment of the present invention attached to the valve body, with the right side of the center line showing the valve open state and the left side showing the valve closed state. 7 is a sectional view taken along line CC in FIG. 6. FIG. (a) is a perspective view of a holding member, (b) is a perspective view of a retaining member provided with a screw hole, and (c) is a perspective view of a main part showing a state in which the holding member is attached to the upper part of the actuator body. It is a diagram. FIG. 3 is a partially omitted main part cross-sectional view showing a state in which the presser member is attached to the upper part of the actuator main body.

Hereinafter, the structure of an embodiment of the present invention will be described in detail based on the drawings. 1 to 5 show a first embodiment (this example) of the present invention, FIG. 1 is a side view of the actuator main body 1 attached to the valve body 3, and FIG. 3 is a cross-sectional view taken along the line A-A, showing a fully open state of the valve, and FIG. 3 is a cross-sectional view showing a fully closed state of the valve.

1 to 3, the valve body 2 of the present invention is the body of a high temperature valve on which the small diameter actuator body 1 of the present invention is mounted, and this example is a direct touch type diaphragm valve. Also, although this figure is a sectional view perpendicular to the primary flow path 4, in FIG. 6, which will be described later, the primary flow path 4, This is a cross-sectional view taken along the axial direction of the side flow path 5.

1 to 3, the valve body 2 has a compact rectangular outer shape with a width comparable to the outer diameter of the actuator body 1 mounted on the upper part, and the valve body 2 has a compact rectangular outer shape with a width comparable to the outer diameter of the actuator body 1 mounted on the upper part. A flow path 4 and a secondary flow path 5 are bored to allow connection of these flow paths with the outside. The primary flow path 4 bends upward and communicates with the valve chamber 8 space through a circular valve opening, and a seat ring 6 (valve seat) is installed in a mounting groove around the valve opening. The lower surface of the diaphragm 7, which is fixed by caulking and provided above the sealing surface, can be flexibly deformed to allow close contact (seating). An annular groove having a substantially U-shaped cross section is formed on the bottom surface of the valve chamber 8, and a circular outlet portion communicating with the secondary flow path 5 is provided in this annular groove.

In FIGS. 2 and 3, the diaphragm 7, which is a valve body, is formed in a substantially circular shape and is made up of a predetermined number of metal diaphragm members stacked one on top of the other. The outer circumferential edge of the diaphragm 7 is narrowly fixed between an annular convex portion formed protruding from the outer circumferential portion of the valve chamber 8 space and an annular receiving portion at the lower end of the bonnet 9 to form an outer circumferential seal portion. .

The bonnet 9 is formed into a substantially cylindrical shape, and is provided between the base bodies 10, 34 and the body 3 when the body 3 is assembled, and is connected between the female threaded portion 3a of the body 3 and the base bodies 10, 34. The lower end surfaces of the base bodies 10 and 34 push down the bonnet 9 due to the tightening force when screwing together the male threads provided on the outer periphery of the lower part, and this pushing down force causes the receiving part of the bonnet 9 to rest on the annular convex part. It is fixed by pinching the outer peripheral edge of the placed diaphragm 7. Further, the inner circumferential surface of the bonnet 9 is a cylindrical space formed with approximately the same diameter, and a substantially cylindrical diaphragm piece 11 is inserted into this inner circumferential surface. The surface and the inner circumferential surface of the bonnet 9 can slide with almost no resistance. Further, rod portions 32 and 42 (lower end portions of bellows units 15 and 35), which will be described later, are provided on the upper surface of the diaphragm piece 11 so as to be able to come into contact therewith.

In FIGS. 1 to 3, the small cylindrical case 12 is formed into a long cylindrical shape with respect to its outer diameter, and is a housing capable of housing a bellows unit 15 (FIGS. 4 and 5), which will be described later. In this example, it is made of a predetermined metal and is formed to have a thin wall and a small diameter of, for example, φ38 mm or less so as to fit compactly within the foot space area. In FIG. 1, a breathing port 12a and a set screw 13, which will be described later, are lined up in a straight line, and the lower inner circumferential surface is fixed (screwed) to the upper outer circumferential surface of the base body 10.

The base body 10 has an outer diameter that is about the same as the outer diameter of the small cylindrical case 12, and is formed of a predetermined metal into a substantially cylindrical shape, and is connected to the small cylindrical case 12 at the upper side and The side is connected to the upper side of the body 3 by screwing, and an engaging portion 10c having a width across flats is formed on the outer peripheral surface for rotating the base body 10 with a tool such as a wrench when screwing the base body 10. ing. Further, as will be described later, inside the base body 10, a breathing port 10b and a stepped portion 10a are provided in the upper inner peripheral space formed in a cylindrical shape, and a hole portion 10d is provided in the center position of the lower portion. It will be done.

4 and 5, the bellows unit 15 of the present invention is constructed by vertically stacking bellows and bellows flanges in multiple stages, and a rod 14 is passed through the center of the bellows and bellows flanges. . The actuator of the present invention is an air-driven actuator equipped with a bellows unit 15 configured by joining a plurality of metal bellows, and a plurality of bellows and bellows flanges are vertically joined by welding, and a stem penetrates through the center. When air is supplied from the top, the inside of each bellows is filled with air, creating a sealed state, and the total thrust of each bellows trying to expand due to the air creates an air cylinder that opens the valve by pushing up the spring. ing. Valves equipped with this actuator have excellent high temperature, high durability, and high-speed opening/closing properties.

4 and 5, the rod 14 (stem) is provided with an air flow path 14a, and this air flow path 14a communicates with an air chamber 16, which will be described later, via a communication portion 17. It is built in so that it can move in the axial direction at the axial center position. The air flow path 14a is formed as an internal flow path within the pipe-shaped rod 14, and the inner diameter of this flow path is ensured to be as large as possible. In the communication portion 17 of this example, two communication holes 17 per one air chamber are provided at opposing positions as holes of a predetermined diameter drilled in the rod 14.

As shown in FIGS. 2 to 5, the bellows flange of this example consists of a fixed flange 18 and a movable flange 19. The rod 14 is moved up and down by the expansion and contraction of each bellows due to the supply and exhaust of air within these bellows.

The movable flange 19 is fixed to the other side of the bellows and the rod 14 in a sealed manner. The movable flange 19 in this example is made of metal, and the inner diameter side is fixed to the outer diameter side of the rod 14 by welding so that it can move integrally with the rod 14. The outer diameter of the movable flange 19 is formed slightly smaller than the inner diameter of the small cylindrical case 12, so that it can move up and down in the axial direction of the small cylindrical case 12 without coming into contact with the inner peripheral surface of the small cylindrical case 12. It is possible. Note that the lowermost movable flange 19' has an outer diameter slightly smaller than the other movable flange 19' in order to be housed in the inner circumferential space in the upper part of the base body 10.

The fixed flange 18 is fixed on one side of the bellows in a sealed manner. The fixed flange 18 in this example is also made of metal, and the outer diameter side faces (fits into) the inner diameter side of the small cylindrical case 12, and the set screw 13 is inserted from the outside of the small cylindrical case 12 and screwed. and is fixed to the small cylindrical case 12 side. A hole with a predetermined diameter is provided at the inner axis of the fixed flange 18 so that the rod 14 can be inserted therethrough and moved up and down. The vertical movement of the rod 14 is aligned and guided. Note that the lower surface side of the lowermost fixing flange 18' is placed so as to conform to the shape of the stepped portion 10a at the bottom of the inner circumferential space in the upper part of the base body 10.

In this example, a total of three set screws 13 are fixed to the small cylindrical case 12 at symmetrical positions at 120 degree intervals in the circumferential direction for each fixed flange 18, but due to design strength and If there is no problem in terms of cost, etc., the fixing flange 18 may be installed at multiple locations per fixed flange 18, for example, at two locations in total at 90 degrees apart from each other in the circumferential direction, or at only one location (for example, the set screws shown in the figure). 13 position only)).

The stopper 20 is provided on the fixed flange 18 side as a part that restricts the upward movement of the movable flange 19. Specifically, a pin 20 having a predetermined diameter and length is attached to the lower surface of the fixed flange 18. It is screwed and fixed vertically. As will be described later, the tip of the pin 20 comes into contact with the upper surface of the movable flange 19, which rises as the air chamber 16 expands due to air supply, and stops the movable flange 19 from rising.

As shown in FIGS. 4 and 5, the stopper 20 of this example has three pins 20 provided at 90 degree intervals in the circumferential direction for each fixed flange 18, but there is no limit to the number of pins 20, and they are placed in symmetrical positions. It may be provided as appropriate, and its shape may be selected as appropriate. Further, as in the second embodiment described later, in this example as well, if it is structurally possible, the fixed flange 18 may be integrally formed to protrude downward instead of a separate member such as the pin 20. good.

Further, in view of design strength and cost, it is not necessary to provide the stopper 20 for all the fixed flanges 18, and for example, it is sufficient to provide the stopper 20 for only one fixed flange 18. For example, the vertical strokes of the multiple movable flanges 19 are all set to be the same due to dimensions, but if there is a slight difference between them, when the movable flanges 19 operate as described below, whichever has the shortest stroke will be used. When the stopper 20 comes into contact with the upper surface of the movable flange 19, the entire bellows unit 15 is stopped from rising, so the stoppers 20 other than the stopper 20 that came into contact become functionally unnecessary. . Therefore, for example, a bellows unit structure may be adopted in which only the bottom stopper 20a is provided and the other stoppers 20 are not provided.

In FIGS. 2 to 5, the connection member 21 at the upper end of the bellows unit 15 is made of metal and formed into a substantially cylindrical shape, and has an air passage 21a provided therein. The lower end of the connection member 21 is connected to the upper end member 22. The air passages 21a and 22a are fixedly fixed (welded) in a sealed state to the upper end of the air passages 21a and 22a to communicate with each other. The upper end member 22 is also made of metal and has a substantially cylindrical shape, and has an air passage 22a provided inside. The outer diameter side of this upper end member 22 fits into the inner diameter side of the cap body 23, and at this fitting portion, upward movement is stopped by engagement of the engagement convex portion 22b, and downward movement is prevented. By being restricted by the retaining ring 24, it is positioned so that it cannot move up and down relative to the cap body 23.

The cap body 23 (top plate member) is made of metal and formed in a ring shape, the lower surface side is a receiving surface that biases the upper end side of the spring 25, and the outer diameter side is fitted into the upper inner peripheral surface of the small cylindrical case 12. At the same time, it is fixed to the upper end side of the small cylindrical case 12 by the retaining member 26, thereby closing the upper end surface side of the actuator main body 1. The retaining member 26 has a male screw portion formed on the outer diameter side and is fixed to a female screw portion on the inner peripheral surface of the upper end portion of the small cylindrical case 12 by screwing.

The spring 25 is an elastic member that is built into the actuator body 1 and serves as a driving source for closing the valve. Although the spring 25 can be selected arbitrarily, in this example, a spring 25 consisting of a small diameter and a large diameter, which are arranged inside and outside, is arranged at the top of the main body, and the upper end biases the lower surface side of the cap body 23. The lower end side is provided so that the bellows unit 15 can be biased downward by biasing the upper surface side of the uppermost movable flange 19.

The upper end member 22 and the uppermost movable flange 19 are connected by a telescopic structure using a small-diameter bellows 28, and the internal air flow path 14a is connected to the air flow path 22a in a sealed state. That is, the upper end portion of the small diameter bellows 28 is welded and fixed to the lower end surface side of the upper end member 22, and the lower end portion is also welded and fixed to the upper end surface side of the uppermost movable flange 19, so that the internal space of the small diameter bellows 28 is The space between the air channels 14a and 22a is made expandable and retractable while maintaining a sealed state from the outside, so as to absorb the movement of the rod 14 which moves up and down as described later. Further, the small-diameter bellows 28 is made of metal, and has a small diameter comparable to the outer diameter of the rod 14.

The bellows in this example is a large-diameter bellows 29, and is provided in a size that can be stored in the small cylindrical case 12. Specifically, the bellows is slightly larger than the inner peripheral surface of the small cylindrical case 12 (the outer diameter of the movable flange 19). A single heavy metal bellows with a small outer diameter is used. The upper end of the large-diameter bellows 29 is fixed to the lower surface of the movable flange 19 by welding, and the lower end is fixed to the upper surface of the fixed flange 18 by welding. An air chamber 16 is connected to an air flow path 14a inside. Note that only the lowermost large-diameter bellows 29' has a slightly smaller diameter than the others so that it can be accommodated in the inner circumferential space above the base body 10.

In this example, a small-diameter bellows 27 with an expandable structure is used between the fixed flange 18 and the movable flange 19. The small-diameter bellows 27 is made of metal and has a diameter about half that of the large-diameter bellows 29. is fixed to the lower surface of the fixed flange 18 by welding, and its lower end is fixed to the upper surface of the movable flange 19 by welding, so that at least a portion of the outer periphery of the rod 14 can be sealed. The lowermost small-diameter bellows 27 has an upper end fixed to the lower surface of the fixed flange 18' by welding, and a lower end fixed to the upper surface of the lower end member 30 by welding.

The lower end member 30 has the lower end of the rod 14 passing through its center, and the upper surface of the disk member 31 is fixed to the lower surface by welding to close the end portion of the air flow path 14a, and the lower end of the bellows unit 15 It consists of A rod-shaped rod portion 32 protrudes from the lower surface of the disk member 31, and the rod portion 32 is inserted into the hole 10d at the bottom of the base body 10 so as to be movable up and down. , can be brought into contact with and pressed against the upper surface side of the diaphragm piece 11.

As shown in FIGS. 2 to 5, in this example, air chambers 16 are provided at five locations in a multi-stage stacked manner. The actuator of the present invention has a main body that is extremely compact and has a small diameter, and can easily realize such a five-stage configuration, so the driving force can be adjusted and secured over a wide range, and can be used in various situations. In addition, in this example, the types of movable flanges 19, 19', fixed flanges 18, 18', large diameter bellows 29, 29', and small diameter bellows 27, 28 are different, but these are made as common as possible. By configuring this, it is possible to reduce the cost of the actuator.

Next, the operation of the first embodiment will be explained. First, we will explain the valve open state shown in FIG. 2 when the actuator main body 1 of this example is mounted on a valve and is in use, that is, until the air chamber 16 is filled with air and the diaphragm 7 assumes the bulging shape by self-returning. do.

Air from an air supply source (not shown) flows from the air passage 21a in the connecting member 21 through the air passage 14a of the rod 14, through each communication portion (communication hole 17), and into each air chamber 16. As each air chamber 16 expands due to the inflow pressure, the plurality of movable flanges 19, 19' rise while resisting the biasing force of the spring 25 biased from the top of the main body, and each bellows (large diameter bellows 29 , 29') will also grow.

In the actuator of this example, when the air chamber 16 expands, the thrust of the upward movement of the rod 14 is used to reduce the expansion force that each bellows (large-diameter bellows 29, 29') naturally has to extend in the vertical direction. Since it can be used for many purposes, it has excellent high-speed response at least in the valve opening direction.

Further, in this example, the small diameter bellows 27 and 28 also contract, contrary to the rise of the rod 14 due to this expansion. A loss may occur in the upward thrust of the rod 14 due to the repulsive force of each small diameter bellows 27, 28 that resists this contraction.

Specifically, when the bellows unit 15 rises, the repulsive force of the small-diameter bellows 28 includes, in addition to its own natural expansion force, an internal force between the air channels 22a and 14a filled with air pressure. Since it is connected with the air pressure, the air pressure received at this time is also added. In addition, as will be described later, the repulsive force of the small-diameter bellows 27 also includes the air pressure that passes through the shaft mounted portion of the fixed flange 18 when the air chamber 16 is filled with air pressure. Therefore, this air pressure is added to the body's own natural expansion force. Therefore, in order to minimize the respective repulsive forces, the small-diameter bellows 27 and 28 should have at least as small a diameter as possible to reduce the pressure receiving area of air pressure, and a spring constant (expansion force when contracted) as small as possible. It is preferable to use

Furthermore, since the repulsive force from the small-diameter bellows 27 and 28 depends on the material and type, especially the diameter, the upward thrust of the rod 14 due to the expansion of each air chamber 16 can be combined with the operating performance and high speed required for the actuator. It is also possible to appropriately set and ensure operability in the design of the bellows unit 15 of this example so as not to impair responsiveness.

Each of the movable flanges raised as described above is locked when reaching the top dead center where the upper surface side contacts the stopper (pin 20). In this state, the upper surface of the diaphragm piece 11 is released due to the rise of the rod portion 32, and the diaphragm 7 naturally returns to its bulging shape upwards due to its own shape restoring force, and lifts the diaphragm piece 11. The lower surface is separated from the seat ring 6. In this state, the valve is fully open, resulting in the state shown in FIG. 2 (first embodiment). In this state, the uppermost movable flanges 19 are each in a state of being resiliently urged by the springs 25.

Here, as shown in FIGS. 2 and 3, in this example, the portion where the fixed flange 18 on the lower side of the air chamber 16 supports the rod 14 (the portion where the convex portion 18a is formed) is not sealed. Although compressed air leaks from this part, this air can be hermetically captured in the small diameter bellows 27 that seals the shaft of the rod 14 at the bottom. substantially hermetically sealed.

Next, a description will be given of the state from the valve fully open state to the valve closed state shown in FIG.

As the air pressure is discharged from the air passage 14a, the air in the air chamber 16 is also discharged. Accordingly, the uppermost movable flange 19, which is biased by the spring 25, is forced downward, and the entire rod 14 descends as a unit. Along with this, each bellows (large diameter bellows 29, 29') also contracts. In this example, contrary to the case described above, the expansion force of the small-diameter bellows 27 and 28, which tends to extend up and down, is applied together with the air pressure received inside each of them, as described above. It can be used for the downward thrust of the rod 14.

As the rod 14 descends, the lower end of the rod portion 32 also descends, pushing down the upper surface of the diaphragm piece 11, and the lower surface of the diaphragm piece 11 presses the upper surface of the diaphragm 7, causing the diaphragm 7 to flexibly deform so as to concave downward. The lower surface side contacts the sealing surface on the upper surface of the seat ring 6. Finally, the rod 14 is lowered until the lower surface of the diaphragm piece 11 comes into close contact with the sealing surface with the diaphragm 7 in between, and the valve is fully closed.

Next, FIGS. 6 and 7 show the structure of an actuator body 33 according to a second embodiment (another example) of the present invention, and the right side of the center line in FIG. 6 shows the structure of the actuator body 33 attached to the valve body 3. Fig. 7 is a longitudinal cross-sectional view of the valve in the open state, and the left side of the center line in the figure is a cross-sectional view showing the valve in a fully closed state, and Fig. 7 is a cross-sectional view taken along the line CC in Fig. 6. . In addition, in this other example, the same parts as in the first embodiment are given the same reference numerals, and the description thereof will be omitted.

In FIG. 6, the small cylindrical case 37 of another example is also formed into a long cylindrical shape with respect to the outer diameter, and is a housing capable of housing the bellows unit 35. This small cylindrical case 37 is also made of a predetermined metal, and is formed with a thin wall and a small diameter of φ38 mm or less so as to fit compactly within the foot space area, and the lower inner circumferential surface is fixed (screwed) to the upper outer circumferential surface of the base body 34. wearing).

The base body 34 has an outer diameter that is approximately the same as the outer diameter of the small cylindrical case 37, is made of a predetermined metal, and is formed into a substantially cylindrical shape, and is connected to the small cylindrical case 37 at the upper side, and is connected to the lower part. The side is connected to the female threaded portion 3a on the upper side of the body 3 by screwing. Furthermore, as will be described later, inside the base body 34, in order to accommodate the lower part of the bellows unit 35, at least a breathing port 34b and a stepped portion 34a are provided in the upper inner circumferential space formed in a cylindrical shape. Further, a hole 34d is provided at the lower axial center position, into which the rod portion 42 (lower end portion of the bellows unit 35) can be inserted and moved up and down.

As shown in FIG. 6, the bellows unit 35 of the present invention is also constructed by vertically stacking bellows and bellows flanges in multiple stages, and a rod 38 is passed through the center of the bellows and bellows flanges. There is. The actuator of the present invention is an air-driven actuator equipped with a bellows unit 35 configured by combining a plurality of metal bellows, and a plurality of bellows and bellows flanges are vertically connected by welding, and a stem penetrates through the center. When air is supplied from the top, the inside of each bellows is filled with air, creating a sealed state, and the total thrust of each bellows trying to expand due to the air creates an air cylinder that opens the valve by pushing up the spring. ing. A valve equipped with this actuator can have good high temperature, high durability, and high-speed opening/closing properties.

In FIG. 6, the rod 38 (stem) is provided with an air passage 38a, and this air passage 38a communicates with an air chamber 39, which will be described later, via a communication portion 52. Built-in so that it can move in the axial direction at the axial center position. The air flow path 38a is formed as an internal flow path within a rod 38 formed in a pipe shape, and the inner diameter of this flow path is ensured as large as possible. The communication portion 52 (52') of another example is a communication path 52 (52') provided in the movable flange 40, which will be described later, and two communication paths 52 (52') per one air chamber are used to air the air in the axial direction. They are provided so as to face and branch from the flow path 38a.

As shown in FIG. 6, the bellows flange of the other example also includes a fixed flange 41 and a movable flange 40. The rod 38 is moved up and down by the expansion and contraction of each bellows due to the supply and exhaust of air within these bellows.

In this other example, the movable flange 40 is a part of the metal rod 38 that is integrally formed so as to protrude in a flange shape in the radial direction of the metal rod 38. Specifically, the rod 38 is A portion of the movable flange 40 and a passage portion 38b, which is a part of the rod 38, are formed for each air chamber 39, and three are welded vertically so that they communicate with the air passage 38a. It is fixed and configured. The outer diameter of the movable flange 40 is slightly smaller than the inner diameter of the small cylindrical case 37, so that it can move up and down in the axial direction of the small cylindrical case 37 without coming into contact with the inner peripheral surface of the small cylindrical case 37. It is possible. Note that the lowermost movable flange 40' has a slightly smaller outer diameter than the others in order to be housed in the inner circumferential space above the base body 34, and since it is the terminal part of the air flow path 38a, it is attached to the lower end of the rod 38. No flow path is formed, and the rod portion 42 is inserted into the hole 34d of the base body 34 and can come into contact with and press the upper surface of the diaphragm piece 11.

In this other example as well, the fixed flange 41 is made of metal and is a separate member from the rod 38 , and its outer diameter side faces (fits into) the inner diameter side of the small cylindrical case 37 . It is fixed to the small cylindrical case 37 side by inserting and screwing a set screw 43 from the outside. A hole with a predetermined diameter is provided at the axial center position on the inner diameter side of the fixed flange 41 so that the rod 38 can be inserted therethrough and guided for vertical movement. Further, the lower surface side of the lowermost fixing flange 41' is placed so as to match the shape of the stepped portion 34a at the bottom of the inner circumferential space above the base body 34. Furthermore, the set screw 43 is not used to fix the fixing flange 41'' one above the fixing flange 41', and instead, the outer diameter side is connected to the lower inner periphery of the small cylindrical case 37 and the upper end of the base body 34. The small cylindrical case 37 is sandwiched between the small cylindrical case 37 and fixed therebetween.

In other examples, the set screws 43 are fixed to the small cylindrical case 37 with one set screw 43 for each fixed flange 41, but if there is no problem in terms of design strength or cost, Each fixed flange 41 may be provided at a plurality of locations, for example, at six locations in total at 60 degree intervals around the outer circumference.

The stopper 44 may be provided on the fixed flange 41 side to limit the upward movement of the movable flange 40, but in another example, a protrusion with a predetermined width and length is provided only on the lower surface side of the fixed flange 41''. The protruding portion 44 is formed to protrude vertically.As will be described later, the tip of this protruding portion 44 comes into contact with the upper surface side of the lowermost movable flange 40' that rises as the air chamber 39 expands due to air supply. The bellows unit 35 is stopped from rising by contacting the bellows unit 35.

The protruding portion 44 is formed as an annular protruding portion concentrically protruding from the lower surface side of the fixed flange 41'' with an appropriate diameter, but there is no particular restriction on its form. Two (or four) protrusions may be formed at symmetrical positions, or any number may be provided at symmetrical positions of the fixed flange 41'', and the shape thereof may also be selected as appropriate. Further, if it is structurally possible, it may be a separate member such as the pin 20 as in the first embodiment, or it may be provided on all the fixing flanges 41, 41' as appropriate. Alternatively, they may be formed to protrude upward from the movable flanges 40, 40' as appropriate.

In FIG. 6, the connection member 45 at the upper end of the bellows unit 35 is fixed (welded) in a sealed manner to the upper end of the upper end member 46 to connect the air flow path 46a and the air flow path 45a. are provided so that they can communicate with each other. Further, the upper structure of the actuator main body 33 in other examples, that is, the structure of the upper end member 46 and the cap body 47, or the structure of the spring 48 interposed between the cap body 47 and the uppermost movable flange 40, is also the same as described above. This is similar to the first embodiment. Further, the upper end member 46 and the uppermost movable flange 40 are connected by a telescopic structure using a small-diameter bellows 49, and the internal air passage 38a is communicated in a sealed manner.

As shown in FIGS. 6 and 7, the bellows of the other example has an internal bellows 51 disposed coaxially within an external bellows 50. It consists of a double metal bellows in which an internal bellows 51, which has an internal diameter slightly larger than the outer peripheral surface of the rod 38, is coaxially provided inside an external bellows 50, which has an outer diameter slightly smaller than the outer diameter of the flange 40. There is. Although this configuration may increase the manufacturing cost or reduce the air chamber volume compared to the configuration of the first embodiment with the same performance, it ensures the sealing performance of the air chamber 39 and It is also possible to improve the responsiveness of the expansion and contraction (operability of the actuator).

The upper end portions of the inner and outer bellows 51 and 50 are fixed by welding to the lower surface side of the movable flange 40, and the lower end portions are fixed to the upper surface side of the fixed flange 41 by welding. The cylindrical inner and outer bellows spaces in a sealed state become an air chamber 39 that communicates with the air passage 38a in the rod 38 via the communication passage 52 (52') opened in the movable flange 40 (40'). ing. Note that only the lowermost inner and outer bellows 51', 50' have a slightly smaller diameter than the others so that they can be accommodated in the inner circumferential space above the base body 34.

In the other example, unlike the first embodiment described above, the small diameter bellows 27 having an expandable structure is not used between the fixed flange 41 and the movable flange 40. This is because the air chamber 39 of the other examples is tightly divided into the inner and outer bellows spaces, so as in the case of the first embodiment described later, the air chamber 39 from the part where the fixed flange 41 supports the rod 38 is One of the reasons is that there is no risk of air leakage within the shaft 39, and therefore there is no need to seal this shaft mounting part. Therefore, compared to the first embodiment, the height of the actuator body 33 can be kept low at least by eliminating the need for the small-diameter bellows 27. In particular, since the bellows unit 35 does not have the small diameter bellows 27 at the bottom, the rod part 42 can be directly connected to the movable flange 40' without the need for the lower end member 30 or the disk member 31. The height of the body 34 can also be suppressed.

As shown in FIG. 6, in this example, air chambers 39 are provided at four locations in a stacked manner. The actuator of the present invention has a main body that is extremely compact and has a small diameter, and can easily realize such a four-stage configuration, so the driving force can be adjusted and secured over a wide range, and can be used in a variety of situations. In addition, in this example, the types of movable flanges 40, 40', fixed flanges 41, 41', 41'', inner and outer bellows 51, 50, and small diameter bellows 49 are different, but these are made common as much as possible. This can lead to reductions in actuator costs.

Next, the operation of the second embodiment will be explained. First, when the actuator main body 33 of the present invention is mounted on a valve and is in use, the valve is opened in the open state shown on the right side of FIG. explain.

Air from an air supply source (not shown) flows from the air passage 45a in the connecting member 45, through the air passage 38a of the rod 38, through each communication section (communication passage 52), and into each air chamber 39. As each air chamber 39 expands due to the inflow pressure, the plurality of movable flanges 40, 40' rise while resisting the biasing force of the spring 48 biased from the top of the main body, and the respective bellows (internal and external bellows 51, 50, 51', 50') will also grow.

In this other example, as shown in FIG. 6, the communication passage 52 opens to the upper side of the inner and outer bellows space (air chamber 39), which is a substantially cylindrical space, so that the inner and outer bellows 51, 50 Air pressure can be supplied or exhausted along the direction of expansion and contraction. Furthermore, when the actuators have the same diameter, the volume is smaller than the air chamber 16 of the first embodiment described above, and the bellows is a double bellows. Therefore, in this other example, the bellows is configured to have an even better expansion and contraction response in response to supply and exhaust of air pressure.

Each of the movable flanges raised as described above is locked when the upper surface side reaches the top dead center where it abuts the stopper (protruding portion 44). In this state, the upper surface of the diaphragm piece 11 is released due to the rise of the rod part 42, and the diaphragm 7 naturally returns upward to its bulging shape due to its own shape restoring force and lifts the diaphragm piece 11. The lower surface is separated from the seat ring 6. In this state, the valve is fully open, resulting in the state shown on the right side of FIG. In this state, the uppermost movable flanges 40 are each in a state of being resiliently urged by the springs 48.

Next, a description will be given of the state from the fully open state of the valve to the closed state shown on the left side of FIG.

As the air pressure in the air passage 38a is discharged, the air in the air chamber 39 is also discharged. Accordingly, the uppermost movable flange 40, which is biased by the spring 48, is forced downward, and the entire rod 38 is lowered as one unit. Along with this, each bellows (inner and outer bellows 51, 50, 51', 50') also contracts.

As the rod 38 descends, the lower end of the rod portion 42 also descends, pushing down the upper surface of the diaphragm piece 11, and the lower surface of the diaphragm piece 11 presses the upper surface of the diaphragm 7, causing the diaphragm 7 to flexibly deform so as to concave downward. The lower surface side contacts the sealing surface on the upper surface of the seat ring 6. Finally, the rod 38 is lowered until the lower surface side of the diaphragm piece 11 comes into close contact with the sealing surface with the diaphragm 7 in between, and the valve is in a fully closed state.

In particular, in the bellows unit 35 of the second embodiment, only the small-diameter bellows 49 is used as a bellows other than the inner and outer bellows 51 and 50 constituting the air chamber 39, and the small-diameter bellows 27 of the bellows unit 15 of the first embodiment is used. It does not have a corresponding bellows. Therefore, at least since there is no repulsive force due to the small diameter bellows 27 when the bellows unit 15 rises, it can be said that the structure is excellent in operability and high-speed response.

As described above, the actuator of the present invention includes bellows units 15 and 35 in which at least rods 14 and 38 and movable flanges 19 and 40 are integrally constructed, respectively, and all the air chambers 16 stacked in multiple stages, 39 have a structure in which they are maintained in communication with each other via the air channels 14a and 38a, so the supplied air pressure is applied to all the movable flanges 19 and 40 without any time difference or deviation for each movable flange. can be simultaneously and evenly pushed up, and this is also the case when each movable flange 19, 40 is lowered by discharging the air.

Furthermore, the total air volume consisting of the air channels 14a, 38a and the air chambers 16, 39 inside the actuator is kept as compact as possible as a whole, and for example, in the case of the first embodiment, the valve stroke is 1.2 mm. Therefore, the expansion and contraction rate of the air chamber is also small. Furthermore, as described above, in the action of the actuator of the present invention, there is almost no sliding or frictional movement between the members, instead of the telescopic movement of the members. Therefore, the actuator can respond to the supply and discharge of air into and out of the actuator with almost no time difference, and can achieve extremely good high-speed response as well as exhibit extremely high durability.

Therefore, the actuator of the present invention has a structure that can be manufactured from all metal, and can operate the valve without any trouble even in a high-temperature atmosphere such as 300 degrees Celsius. It has extremely good durability because it has no wear parts, and the multi-stage structure of the bellows allows it to be easily constructed as a small-diameter actuator (valve).

Next, a third embodiment (another example) of the present invention will be described. In the third embodiment, the retaining ring 24 in the first embodiment is abolished, and a presser member 60 is attached instead, and the presser member 60 restricts the rotation of the connecting member 21 and allows the upper end member 22 to rotate. It prevents it from moving.

In the first embodiment of the present invention, the small-diameter bellows 28 located between the upper end member 22 and the uppermost movable flange 19 absorbs the movement so that the piping side does not move up or down when the multi-stage bellows located below moves up or down. There is a role to play. The upper end member 22 is fitted with a cap body 23, and in this fitting part, movement in the vertical direction is regulated by engagement of the engagement protrusion 22b and restriction by the retaining ring 24. .

By the way, as shown in FIGS. 2 to 5, the lower end of the connecting member 21 at the upper end of the bellows unit 15 is sealed (welded) to the upper end of the upper end member 22. If a strong rotational force is applied to the lower end of the connecting member 21 when tightening with a tool such as a spanner, the upper end member 22 fixed (welded) to the lower end of the connecting member 21 may rotate. Furthermore, when the upper end member 22 rotates, the rotational force is transmitted to the small diameter bellows 28 welded to the upper end member 22, and the small diameter bellows 28 may become twisted. If the actuator is operated with the small-diameter bellows 28 twisted, the small-diameter bellows 28 will be easily torn and will not be able to withstand multiple operations.

Therefore, in the third embodiment, in order to compensate for the above-mentioned drawbacks, a holding member 60 is attached to prevent the upper end member 22 from rotating and to prevent twisting of the small diameter bellows 28.

8(a) is a perspective view of the holding member 60, FIG. 8(b) is a perspective view of the retaining member 26 provided with a screw hole 26a, and FIG. 8(c) is a perspective view of the holding member 60. FIG. 9 is a perspective view of a main part showing a state in which the presser member 60 is attached to the upper part of the actuator body 1, and FIG. In the following description, the same parts are given the same reference numerals and the description thereof will be omitted.

As shown in FIG. 8A, the holding member 60 has a substantially rectangular base 61, a short cylindrical portion 62, a long hole portion 63, and a screw hole portion 65.
In this example, the elongated hole portions 63 are elongated holes, and a total of four elongated hole portions 63 are provided at 90 degree intervals in the circumferential direction on the substantially rectangular base 61, and the first screws 71 pass through the elongated holes to screw the retaining member 26. It is provided so that it can be screwed into the hole 26a. Note that as long as the first screws 71 can be screwed into the screw holes 26a of the retaining member 26, there may be a total of three screws at intervals of 120 degrees in the circumferential direction, or a total of two screws at symmetrical positions. Furthermore, since the elongated hole portion 63 of the holding member 60 is formed into an elongated hole shape, the first screw 71 can be screwed into the screw hole 26a of the retaining member 26 after the holding member 60 is temporarily attached at an arbitrary position. can be aligned.
The short cylindrical portion 62 is provided with a penetrating portion 64 having a substantially rectangular shape, and the penetrating portion 64 has an engaging parallel surface 66 that engages with the width across flats of the hexagonal nut portion on the lower end side of the connecting member 21. are doing. The parallel engagement surfaces 66 are provided with screw holes 65 at symmetrical positions into which the second screws 72 are screwed.

As shown in FIG. 8(b), the retaining member 26 in the third embodiment has an additional screw hole 26a. As shown in FIG. 8(b), the retaining member 26 has a screw hole 26a, a locking hole 26b, and a male screw portion 26c. The screw hole 26a is provided so as to be screwed into the first screw 71. A male screw portion 26c is provided so that the retaining member 26 can be screwed onto the small cylindrical case 12 using a jig (not shown), and a jig locking hole 26b is provided so that it can be locked with a jig (not shown).

As shown in FIGS. 8(c) and 9, after assembling the actuator body 1, a presser member 60 is attached to the upper part of the actuator body 1 to restrict rotation of the connecting member 21 and allow the upper end member 22 to rotate. It prevents you from doing so.
The holding member 60 is temporarily attached by passing the connecting member 21 through the penetration portion 64 so that the engagement parallel surface 66 of the holding member 60 and the width across flats of the hexagonal nut portion on the lower end side of the connecting member 21 are engaged. When the first screw 71 is fixed (screwed) from the elongated hole portion 63 into the screw hole 26a provided in the retaining member 26, the presser member 60 is fixed.
Then, with the engagement parallel surface 66 of the holding member 60 engaged with the width across flats of the hexagonal nut portion on the lower end side of the connecting member 21, the connecting member 21 is passed through the penetration portion 64, and the holding member 60 is fixed. Then, the width across flats of the hexagonal nut portion on the lower end side of the connecting member 21 matches and engages with the engagement parallel surface 66 of the presser member 60, and this engagement causes the lower end of the connecting member 21 to Rotation can be suppressed.

Furthermore, when using only the presser member 60, the engagement between the lower end portion of the connecting member 21 and the engaging parallel surface 66 of the presser member 60 may be somewhat wobbly. Therefore, in order to securely fix the connecting member 21, the second screw 72 is fixed (screwed) into the screw hole 65 of the holding member 60.
Further, when the second screw 72 is fixed (screwed) into the screw hole 65 of the holding member 60, one end of the second screw 72 is connected to one end of the width across flats of the hexagonal nut portion on the lower end side of the connecting member 21. By abutting against each other, rotation of the connecting member 21 can be more effectively prevented.
That is, by engaging the parallel engagement surface 66 of the holding member 60 with the hexagonal nut portion on the lower end side of the connecting member 21 and fixing the second screw 72 to the holding member 60, rotation of the connecting member 21 is prevented. Since this is controlled, it is possible to prevent the lower end portion of the connecting member 21 from rotating when the connecting member 21 is tightened with the nut. Further, rotation of the upper end member 22 fixed to the lower end of the connecting member 21 can also be prevented.

In this way, when the connecting member 21 is tightened with the nut, excessive rotation is prevented from occurring at the lower end of the connecting member 21, and since the lower end of the connecting member 21 does not rotate, it is fixed to the connecting member 21. The (welded) upper end member 22 also does not rotate, and furthermore, the rotational force is not transmitted to the small diameter bellows 28 welded to the upper end member 22. With this structure, it is possible to prevent twisting of the small diameter bellows 28 when tightening the connecting member 21 with a nut.

In addition, when the second screw 72 is fixed, the downward movement of the upper end member 22 fixed to the lower end of the connecting member 21 is restricted. Note that, similarly to the first embodiment, upward movement of the upper end member 22 is regulated by the engagement convex portion 22b. Therefore, in this example, even if the retaining ring 24 is eliminated, the vertical movement of the upper end member 22 can be restricted.

As described above, in the third embodiment, the holding member 60, the retaining member 26, and the screw members (first screw 71, second screw 72) restrict the rotation of the upper end member 22, and the connecting member 21 When the hexagonal nut portion of the small diameter bellows 28 is tightened and fixed, no rotational load is applied to the small diameter bellows 28, so the small diameter bellows 28 is not twisted in the rotational direction. Therefore, there is no risk that the small diameter bellows 28 will be torn by operating the actuator while the small diameter bellows 28 is twisted, so that sufficient operability and durability can be ensured.

Furthermore, the present invention is not limited to the description of the embodiments described above, and various changes can be made without departing from the gist of the invention as set forth in the claims of the present invention.

1 33 Actuator body 2 Valve body 3 Body 4 5 Flow path 6 Seat ring (valve seat)
7 Diaphragm (valve body)
8 Valve chamber 12 37 Small cylindrical case 14 38 Rod 14a 21a 22a 38a 45a 46a Air flow path 15 35 Bellows unit 16 Air chamber (inner space)
17 Communication hole (communication part)
18 41 Fixed flange (bellows flange)
19 40 Movable flange (bellows flange)
20 20a Pin (stopper)
27 Small diameter bellows 29 Large diameter bellows (bellows)
39 Air chamber (inner and outer bellows space)
50 External bellows (bellows)
51 Internal bellows (bellows)
44 Projection part (stopper)
52 Communication path (communication part)

Claims (8)

A bellows unit is constructed by stacking bellows and bellows flanges vertically in multiple stages, and passing a rod through the center of the bellows and bellows flange.This bellows unit is housed in a small cylindrical case, and the A small-diameter actuator for a high-temperature valve, characterized in that the rod fixed to each bellows is moved up and down by expansion and contraction of each bellows due to air supply and exhaust. The air chamber of the bellows is an inner space of a large-diameter bellows of a size that can be stored in the small cylindrical case, and the inside of this inner space and the air flow path of the rod are communicated through a communication part. 1. The small-diameter actuator for high-temperature valves according to 1. The bellows flange consists of a fixed flange sealed on one side of the bellows and fixed to the small cylindrical case , and a movable flange sealed sealed on the other side of the bellows and the rod, and the communication portion is 3. The small-diameter actuator for a high-temperature valve according to claim 2 , which is a communication hole formed in the rod. 4. The small-diameter actuator for a high-temperature valve according to claim 3, further comprising a small-diameter bellows with an expandable structure provided between the fixed flange and the movable flange. The air chamber of the bellows is an inner and outer bellows space configured by disposing an inner bellows coaxially within an outer bellows, and this inner and outer bellows space is connected to the air passage provided in the rod through a communication part. 2. The small diameter actuator for a high temperature valve according to claim 1, wherein the small diameter actuator is in communication with the high temperature valve. The bellows flange consists of a fixed flange that is fixed to one side of the inner and outer bellows in a sealed state to the small cylindrical case , and a movable flange that is fixed to the other side of the inner and outer bellows and the rod in a sealed state, and the communication portion The small-diameter actuator for a high-temperature valve according to claim 5 , wherein is a communication passage provided in the movable flange. The small-diameter actuator for a high temperature valve according to any one of claims 3, 4, or 6, further comprising a stopper provided on the fixed flange side to limit the upward movement of the movable flange. A high-temperature valve, characterized in that the small-diameter actuator for high-temperature valves according to any one of claims 1 to 7 is mounted on a valve body.

Images