WO2024053158A1

WO2024053158A1 - Bellows pump

Info

Publication number: WO2024053158A1
Application number: PCT/JP2023/017054
Authority: WO
Inventors: 大輔浦田; 敦文木下
Original assignee: 日本ピラー工業株式会社
Priority date: 2022-09-08
Filing date: 2023-05-01
Publication date: 2024-03-14
Also published as: JP2024038629A

Abstract

Check valves 15, 16 of a bellows pump 10 each have a cylindrical valve case 15a, 16a in which a male thread 15e, 16e to be screwed into a female thread hole 111, 112 of a pump head 11 is formed on an end section 15d, 16d located on one side in the axial direction. The bellows pump 10 is equipped with engaging grooves 113, 114 which are respectively provided in a floor surface 111a, 112a of the female thread hole 111, 112 of the pump head 11, and engaging parts 151, 161 which respectively engage the inner-circumferential surface 113a, 114a of the engaging grooves 113, 114 and are provided to the end sections 15d, 16d of the valve cases 15a, 16a.

Description

bellows pump

The present invention relates to a bellows pump.

In semiconductor manufacturing, chemical industry, etc., a bellows pump described in Patent Document 1, for example, is known as a pump for delivering a transfer fluid such as a chemical solution or a solvent. The bellows pump described in Patent Document 1 has a pump case connected to the left and right sides of a pump head to form two air chambers, and a pair of bellows that can be expanded and contracted in the left and right directions is provided inside each air chamber. Each bellows is configured to contract or expand by alternately supplying pressurized air to each air chamber.

The pump head is formed with a suction passage and a discharge passage for the transfer fluid, which communicate with the inside of each bellows. The pump head is also provided with a plurality of check valves that allow the transfer fluid to flow in one direction with respect to the suction passage or the discharge passage and prevent the transfer fluid from flowing in the other direction. Each check valve includes a valve case, a valve body housed in the valve case, and a spring that biases the valve body in the valve closing direction. One end of the valve case is attached to the pump head by tightening a male thread formed on the outer periphery of the valve case into a female threaded hole formed in the pump head.

The check valve for the suction passage opens when the bellows expands to allow the flow of transfer fluid from the suction passage into the bellows, and closes when the bellows contracts to allow the flow of transfer fluid from the inside of the bellows to the suction passage. configured to prevent it. In addition, the check valve for the discharge passage is closed by extension of the bellows to prevent the flow of transfer fluid from the discharge passage into the bellows, and opened by contraction of the bellows to prevent the flow of transfer fluid from the inside of the bellows to the discharge passage. It is constructed to allow the flow of

Japanese Patent Application Publication No. 2018-003709

In the above bellows pump, when the valve case of the check valve is attached to the pump head, one end of the male thread side of the valve case comes into contact with the bottom of the female thread hole of the pump case, so that the one end of the valve case is radially There is a risk that it will deform and fall inward. When the valve case is deformed in this way, the valve body and spring of the check valve may malfunction, worsening the pulsation on the discharge side, and causing impact pressure and cavitation called "water hammer", which can cause damage to the bellows. This may adversely affect the pump.

The present disclosure has been made in view of the above circumstances, and an object of the present disclosure is to provide a bellows pump that can suppress deformation of a valve case of a check valve.

(1) The present disclosure includes a pump head having a suction passage and a discharge passage for transfer fluid, and a bottomed female screw hole formed therein; A bellows that sucks the transfer fluid and discharges the transfer fluid from the inside to the discharge passage by contraction, and allows the transfer fluid to flow in one direction with respect to the suction passage or the discharge passage, and transfers the transfer fluid in the other direction. a check valve for blocking fluid flow, the check valve having a cylindrical valve case with a male thread formed at one axial end thereof to be screwed into the female threaded hole of the pump head. , a bellows comprising: an engagement groove provided on the bottom surface of the female threaded hole of the pump head; and an engagement part provided at the end of the valve case and engaged with the inner peripheral surface of the engagement groove. It's a pump.

According to the bellows pump of the present disclosure, when the male thread formed at the end of the valve case of the check valve is tightened into the female threaded hole of the pump head, the engaging portion provided at the end of the valve case engages the female threaded hole. It engages with the inner peripheral surface of an engagement groove provided on the bottom surface. By this engagement, when the valve case of the check valve is attached to the pump head, it is possible to suppress the end portion of the valve case from being deformed so as to collapse inward in the radial direction.

(2) In the bellows pump of (1) above, it is preferable that the inner peripheral surface of the engagement groove is a tapered surface whose diameter increases toward the one side in the axial direction.
In this case, the end portion of the valve case is pushed outward in the radial direction by the engaging portion engaging with the tapered surface that is the inner circumferential surface of the engaging groove. Thereby, the degree to which the male thread of the valve case engages with the female thread hole of the pump head can be improved.

According to the bellows pump of the present disclosure, deformation of the valve case of the check valve can be suppressed.

1 is a schematic configuration diagram of a bellows pump device including a bellows pump according to an embodiment of the present disclosure. It is a sectional view of a bellows pump. FIG. 3 is an enlarged sectional view of the main part of FIG. 2 showing the vicinity of the left suction check valve. FIG. 3 is an enlarged cross-sectional view of the main part of FIG. 2 showing the vicinity of the discharge check valve on the left side. It is an explanatory view showing operation of a bellows pump. It is an explanatory view showing operation of a bellows pump. FIG. 7 is an enlarged sectional view showing the vicinity of a left discharge check valve in a bellows pump according to a second embodiment of the present disclosure. FIG. 7 is an enlarged sectional view showing the vicinity of a left discharge check valve in a bellows pump according to a third embodiment of the present disclosure.

Next, preferred embodiments of the present disclosure will be described with reference to the accompanying drawings. Note that at least some of the embodiments described below may be combined arbitrarily.
[First embodiment]
<Overall configuration>
FIG. 1 is a schematic configuration diagram of a bellows pump device 1 including a bellows pump according to a first embodiment of the present disclosure. The bellows pump device 1 is used, for example, in semiconductor manufacturing equipment to supply a fixed amount of a transfer fluid such as a chemical solution or a solvent. The bellows pump device 1 includes an air supply device (fluid supply device) 2, a mechanical regulator 3, a first solenoid valve 4, a second solenoid valve 5, a control section 6, a bellows pump 10, a first electropneumatic regulator (first fluid A pressure adjustment section) 51 and a second electro-pneumatic regulator (second fluid pressure adjustment section) 52 are provided.

The air supply device 2 is composed of, for example, an air compressor, and generates pressurized air (pressurized fluid) to be supplied to the bellows pump 10. The mechanical regulator 3 adjusts the air pressure (fluid pressure) of pressurized air generated by the air supply device 2. The first electro-pneumatic regulator 51 and the second electro-pneumatic regulator 52 will be described later.

FIG. 2 is a cross-sectional view of the bellows pump 10. The bellows pump 10 of this embodiment includes a pump head 11, a pair of pump cases 12, a pair of bellows, a first bellows 13 and a second bellows 14, and a pair of suction check valves (check valves) 15. A pair of discharge check valves (check valves) 16 are provided.

The pump head 11 is arranged at the center of the bellows pump 10. A pair of pump cases 12 are attached to both left and right sides of the pump head 11. The first bellows 13 and the second bellows 14 are attached to the left and right side surfaces of the pump head 11 inside each pump case 12 . A pair of suction check valves 15 are attached to the left and right sides of the pump head 11 inside each of the first and

second bellows

13 and 14. Similarly, a pair of discharge check valves 16 are attached to the left and right sides of the pump head 11 inside each of the first and

second bellows

13 and 14.

<Bellows>
The first bellows 13 and the second bellows 14 are made of a fluororesin such as polytetrafluoroethylene (PTFE) or tetrafluoroethylene/perfluoroalkyl vinyl ether copolymer (PFA), and are formed into a cylindrical shape with a bottom. A flange portion 13a integrally formed on the open side end portion of the first bellows 13 is fixed to the side surface of the pump head 11 by being pressed in an airtight manner. Similarly, a flange portion 14a integrally formed at the open end of the second bellows 14 is fixed to the side surface of the pump head 11 in an airtight manner. Each peripheral wall of the first and

second bellows

13, 14 is formed in a bellows shape, and is configured to be able to expand and contract in the left and right direction independently of each other.

An actuating plate 19 is fixed to the outer surface of the closed end portions of the first and

second bellows

13 and 14 by bolts 17 and nuts 18. The first and

second bellows

13 and 14 are in the most extended state where the outer surface of the actuating plate 19 is in contact with the inner surface of the bottom wall portion 121 of the bottomed cylindrical pump case 12, and in the fully extended state where the inner surface of the piston body 23 (to be described later) is in contact with the bottom wall. It can be expanded and contracted between the most contracted state where it abuts the outer surface of the portion 121.

<Pump case>
The opening peripheral portion of the pump case 12 (hereinafter also referred to as “first pump case 12A”) is fixed to the flange portion 13a of the first bellows 13 by pressing it in an airtight manner. As a result, a first discharge side air chamber (first discharge side fluid chamber) 21A, which is maintained in an airtight state, is formed outside the first bellows 13 inside the first pump case 12A.

The first pump case 12A is provided with a first intake/exhaust port 22A. 2 (see Figure 1). As a result, when pressurized air is supplied from the air supply device 2 into the first discharge air chamber 21A, the first bellows 13 contracts to a predetermined contracted state (hereinafter simply referred to as "contracted state"). The contracted state of the first bellows 13 may be the most contracted state or a state before the most contracted state.

The periphery of the opening of the pump case 12 (hereinafter also referred to as "second pump case 12B") is fixed to the flange portion 14a of the second bellows 14 in an airtight manner. As a result, a second discharge side air chamber (second discharge side fluid chamber) 21B, which is maintained in an airtight state, is formed outside the second bellows 14 inside the second pump case 12B.

The second pump case 12B is provided with a second intake/exhaust port 22B, and the second intake/exhaust port 22B is connected to the air supply device via the second electromagnetic valve 5, the second electropneumatic regulator 52, and the mechanical regulator 3. 2 (see Figure 1). Thereby, when pressurized air is supplied from the air supply device 2 into the second discharge side air chamber 21B, the second bellows 14 contracts to a predetermined contracted state (hereinafter simply referred to as "contracted state"). The contracted state of the second bellows 14 may be the most contracted state or a state before the most contracted state.

A rod-shaped connecting member 20 is passed through the bottom wall portion 121 of each

pump case

12A, 12B. The connecting member 20 is supported so as to be slidable in the left-right direction with respect to the bottom wall portion 121. A piston body 23 is fixed to the outer end of the connecting member 20 with a nut 24 . The piston body 23 is supported so as to be slidable in the left-right direction while maintaining an airtight state on the inner peripheral surface of a cylindrical cylinder body 25 that is integrally provided on the outside of the bottom wall portion 121 .

Thereby, on the first pump case 12A side, the space surrounded by the bottom wall part 121, the cylinder body 25, and the piston body 23 is a first suction side air chamber (first suction side fluid chamber) that is kept airtight. )26A. Further, on the second pump case 12B side, a space surrounded by the bottom wall portion 121, the cylinder body 25, and the piston body 23 is a second suction side air chamber (second suction side fluid chamber) in which an airtight state is maintained. It is said to be 26B.

The cylinder body 25 on the first pump case 12A side is formed with an intake/exhaust port 251 that communicates with the first suction side air chamber 26A. This intake/exhaust port 251 is connected to the air supply device 2 via the first electromagnetic valve 4, the first electropneumatic regulator 51, and the mechanical regulator 3 (see FIG. 1). As a result, when pressurized air is supplied from the air supply device 2 to the inside of the first suction side air chamber 26A through the intake/exhaust port 251, the first bellows 13 is brought into a predetermined extended state (hereinafter simply referred to as an "extended state"). ”). The extended state of the first bellows 13 may be the most extended state, or may be a state before the most extended state.

The cylinder body 25 on the second pump case 12B side is formed with an intake/exhaust port 252 that communicates with the second suction side air chamber 26B. This intake/exhaust port 252 is connected to the air supply device 2 via the second electromagnetic valve 5, the second electropneumatic regulator 52, and the mechanical regulator 3 (see FIG. 1). As a result, when pressurized air is supplied from the air supply device 2 to the inside of the second suction side air chamber 26B via the intake/exhaust port 252, the second bellows 14 is brought into a predetermined extended state (hereinafter simply referred to as an "extended state"). ”). The extended state of the second bellows 14 may be the most extended state, or may be a state before the most extended state.

With the above configuration, the first bellows 13 is operated by the first pump case 12A in which the first discharge side air chamber 21A is formed, and the piston body 23 and cylinder body 25 that form the first suction side air chamber 26A. A first drive section 27 is configured to continuously extend and retract between an extended state and a contracted state. Further, the second bellows 14 is in an extended state by the second pump case 12B in which the second discharge side air chamber 21B is formed, and the piston body 23 and cylinder body 25 that form the second suction side air chamber 26B. A second drive unit 28 is configured to continuously expand and contract between the contracted state and the contracted state.

Although the first drive unit 27 and the second drive unit 28 are driven by pressurized air, they may be driven by other fluids.

<Detection part>
A proximity sensor 29A and a proximity sensor 29B are attached to the cylinder body 25 of the first drive section 27. A detection plate 30 is attached to the piston body 23 of the first drive unit 27 to be detected by each of the

proximity sensors

29A and 29B. The detection target plate 30 reciprocates together with the piston body 23, thereby approaching the

proximity sensors

29A and 29B alternately.

The proximity sensor 29A is arranged at a position to detect the detection plate 30 when the first bellows 13 is in the middle of contraction, just before the first bellows 13 is in the contraction state. The proximity sensor 29B is arranged at a position to detect the detection target plate 30 when the first bellows 13 is in an extended state. When each

proximity sensor

29A, 29B detects the detection target plate 30, it outputs the detection signal to the control unit 6. The pair of

proximity sensors

29A and 29B function as a first detection section 29 that detects the expansion/contraction state of the first bellows 13.

A proximity sensor 31A and a proximity sensor 31B are attached to the cylinder body 25 of the second drive unit 28. A detection plate 32 that is detected by each of the

proximity sensors

31A and 31B is attached to the piston body 23 of the second drive unit 28. The detection target plate 32 reciprocates together with the piston body 23, thereby approaching the

proximity sensors

31A and 31B alternately.

The proximity sensor 31A is arranged at a position to detect the detection plate 32 when the second bellows 14 is in the middle of contraction, just before the second bellows 14 is in the contraction state. The proximity sensor 31B is arranged at a position to detect the detection target plate 32 when the second bellows 14 is in an extended state. When each

proximity sensor

31A, 31B detects the detection target plate 30, it outputs the detection signal to the control unit 6. The pair of

proximity sensors

31A and 31B function as a second detection section 31 that detects the expansion/contraction state of the second bellows 14.

Here, the "state in the middle of contraction" of the first bellows 13 (second bellows 14) means that the contraction progress position of the first bellows 13 (second bellows 14) is lower than the contraction start position (extended state) at the contraction end position ( This means that the first bellows 13 (second bellows 14) has contracted to 50% to 90% of the contracted length from the extended state to the contracted state. means location.

Note that the first detection unit 29 is composed of

proximity sensors

29A and 29B, but is not limited to this, and may be composed of a displacement sensor using a laser beam or the like, for example. Similarly, the second detection unit 31 is configured by

proximity sensors

31A and 31B, but is not limited to this, and may be configured by a displacement sensor using a laser beam or the like, for example.

<Pump head>
The pump head 11 is made of fluororesin such as PTFE or PFA. A suction passage 34 and a discharge passage 35 for the transfer fluid are formed inside the pump head 11 . The suction passage 34 opens on the outer peripheral surface of the pump head 11 and is connected to a suction port (not shown) provided on the outer peripheral surface. The suction port is connected to a storage tank or the like for the transfer fluid. The discharge passage 35 opens on the outer peripheral surface of the pump head 11 and is connected to a discharge port (not shown) provided on the outer peripheral surface. The discharge port is connected to a destination of the transfer fluid.

The suction passage 34 branches toward the left and right sides inside the pump head 11 and has a suction port 36 that opens on both the left and right sides of the pump head 11. Each suction port 36 communicates with the inside of the

bellows

13, 14 via the suction check valve 15. The discharge passage 35 branches toward both left and right sides inside the pump head 11 and has a discharge port 37 that opens on both left and right sides of the pump head 11 . Each discharge port 37 communicates with the inside of the

bellows

13 and 14 via the discharge check valve 16.

<Check valve>
FIG. 3 is an enlarged sectional view of the main part of FIG. 2 showing the vicinity of the left suction check valve 15. In FIGS. 2 and 3, a bottomed female screw hole 111 is formed in each of the left and right side walls of the pump head 11. A suction port 36 of the suction passage 34 is opened in the bottom surface 111a of each female screw hole 111. Each female screw hole 111 is formed concentrically with the suction port 36. A suction check valve 15 is provided in each female threaded hole 111 of the pump head 11 .

The suction check valve 15 includes a valve case 15a, a valve body 15b, and a spring 15c. The valve case 15a is formed into a cylindrical shape. A male thread 15e is formed on the outer periphery of an end 15d on one axial side of the valve case 15a. The male screw 15e of the valve case 15a is screwed into the female screw hole 111 of the pump head 11. Thereby, the end 15d of the valve case 15a on one axial side is attached to the pump head 11.

An engagement groove 113 is formed in the bottom surface 111a of each female threaded hole 111 of the pump head 11. The engagement groove 113 is formed in an annular shape concentric with the suction port 36 on the radially outward side of the suction port 36 on the bottom surface 111a. In cross-sectional view, the engagement groove 113 is formed in a substantially concave shape so as to be depressed toward one side in the axial direction from the bottom surface 111a. Moreover, the inner circumferential surface 113a of the engagement groove 113 is a linear tapered surface whose diameter increases from the other axial side toward the one axial side in cross-sectional view. The outer circumferential surface 113b of the engagement groove 113 is a circumferential surface that extends straight in the axial direction when viewed in cross section. The outer diameter of the engagement groove 113 (the diameter of the outer peripheral surface 113b) is the same as the inner diameter of the female screw hole 111.

An engagement portion 151 that engages with the engagement groove 113 of the pump head 11 is provided at the end 15d of the valve case 15a. The engaging portion 151 of this embodiment is formed in an annular shape over the entire circumference of the end portion 15d of the valve case 15a. The engaging portion 151 is formed in a substantially convex shape so as to protrude toward one side in the axial direction from the end portion 15d in a cross-sectional view. The inner circumferential surface 151a of the engaging portion 151 is a linear tapered surface whose diameter increases along the inner circumferential surface (tapered surface) 113a of the engagement groove 113 in a cross-sectional view. The outer circumferential surface 151b of the engaging portion 151 is a linear tapered surface whose diameter decreases from the other axial side toward the one axial side in cross-sectional view. The maximum outer diameter of the engagement portion 151 (the maximum diameter of the outer circumferential surface 151b) is approximately the same as the outer diameter of the engagement groove 113 (the diameter of the outer circumferential surface 113b).

As described above, the inner peripheral surface 151a of the engaging portion 151 is engaged with the inner peripheral surface 113a of the engaging groove 113. Further, an annular space S1 is formed between the outer peripheral surface 151b of the engaging portion 151 and the outer peripheral surface 113b of the engaging groove 113. The space S1 functions as a space for allowing the engaging portion 151 to escape radially outward when the inner peripheral surface 151a of the engaging portion 151 engages with the inner peripheral surface 113a of the engaging groove 113.

The valve body 15b of the suction check valve 15 is provided movably in the valve case 15a in the valve closing direction (one axial side in FIG. 3) and the valve opening direction (the other axial side in FIG. 3). . The spring 15c is made of, for example, a compression coil spring, and is housed within the valve case 15a. The spring 15c biases the valve body 15b in the valve closing direction. The valve element 15b closes (closes) the suction port 36 due to the urging force of the spring 15c, and opens the suction port (opens) when back pressure is applied due to the flow of the transfer fluid as the

bellows

13, 14 expand and contract. It is supposed to be done.

Thereby, the suction check valve 15 opens when the

bellows

13, 14 in which it is disposed expands, and transfers fluid from the suction passage 34 toward the inside of the bellows 13, 14 (one direction). may be inhaled. In addition, the suction check valve 15 closes when the

bellows

13 and 14 in which it is disposed contracts, and transfers the fluid from the inside of the

bellows

13 and 14 toward the suction passage 34 (the other direction). Prevent backflow.

Note that the right side suction check valve 15 and the corresponding engagement portion 151 and engagement groove 113 are the same as the left side suction check valve 15 described above, with the left-right center line X of the pump head 11 interposed therebetween. It is formed symmetrically with the corresponding engaging portion 151 and engaging groove 113.

FIG. 4 is an enlarged sectional view of the main part of FIG. 2 showing the vicinity of the discharge check valve 16 on the left side. In FIGS. 2 and 4, a bottomed female screw hole 112 is formed in each of the left and right side walls of the pump head 11. A discharge port 37 of a discharge passage 35 is opened in the bottom surface 112a of each female threaded hole 112. Each female screw hole 112 is formed concentrically with the discharge port 37. A discharge check valve 16 is provided in each female threaded hole 112 of the pump head 11 .

The discharge check valve 16 includes a valve case 16a, a valve body 16b, and a spring 16c. The valve case 16a is formed into a cylindrical shape. A male thread 16e is formed on the outer periphery of an end 16d on one axial side of the valve case 16a. The male screw 16e of the valve case 16a is screwed into the female screw hole 112 of the pump head 11. Thereby, the end 16d on one axial side of the valve case 16a is attached to the pump head 11.

An engagement groove 114 is formed in the bottom surface 112a of each female threaded hole 112 of the pump head 11. The engagement groove 114 is formed in an annular shape concentric with the discharge port 37 on the bottom surface 112a radially outward of the discharge port 37. In cross-sectional view, the engagement groove 114 is formed in a substantially concave shape so as to be depressed toward one side in the axial direction from the bottom surface 112a. Moreover, the inner circumferential surface 114a of the engagement groove 114 is a linear tapered surface whose diameter increases from the other axial side toward the one axial side in cross-sectional view. The outer circumferential surface 114b of the engagement groove 114 is a circumferential surface that extends straight in the axial direction when viewed in cross section. The outer diameter of the engagement groove 114 (the diameter of the outer peripheral surface 114b) is the same as the inner diameter of the female screw hole 112.

An engagement portion 161 that engages with the engagement groove 114 of the pump head 11 is provided at the end 16d of the valve case 16a. The engaging portion 161 of this embodiment is formed in an annular shape over the entire circumference of the end portion 16d of the valve case 16a. The engaging portion 161 is formed in a substantially convex shape so as to protrude toward one side in the axial direction from the end portion 16d in a cross-sectional view. The inner peripheral surface 161a of the engaging portion 161 is a linear tapered surface whose diameter increases along the inner peripheral surface (tapered surface) 114a of the engaging groove 114 in a cross-sectional view. The outer circumferential surface 161b of the engaging portion 161 is a linear tapered surface whose diameter decreases from the other axial side toward the one axial side in cross-sectional view. The maximum outer diameter of the engagement portion 161 (the maximum diameter of the outer circumferential surface 161b) is approximately the same as the outer diameter of the engagement groove 114 (the diameter of the outer circumferential surface 114b).

As described above, the inner peripheral surface 161a of the engaging portion 161 is engaged with the inner peripheral surface 114a of the engaging groove 114. Further, an annular space S2 is formed between the outer peripheral surface 161b of the engaging portion 161 and the outer peripheral surface 114b of the engaging groove 114. The space S2 functions as a space for allowing the engaging portion 161 to escape radially outward when the inner peripheral surface 161a of the engaging portion 161 engages with the inner peripheral surface 114a of the engaging groove 114.

The valve body 16b of the discharge check valve 16 is provided so as to be movable in the valve case 16a in the valve closing direction (one axial side in FIG. 4) and the valve opening direction (the other axial side in FIG. 4). . The spring 16c is made of, for example, a compression coil spring, and is housed within the valve case 16a. The spring 16c biases the valve body 16b in the valve closing direction. The valve body 16b closes (closes) the opening 16f on the other axial side of the valve case 16a due to the biasing force of the spring 16c, and when back pressure is applied due to the flow of the transfer fluid as the

bellows

13 and 14 expand and contract, The opening 16f is opened (opened).

Thereby, the discharge check valve 16 opens when the

bellows

13 and 14 in which it is disposed contracts, and transfers fluid from the inside of the

bellows

13 and 14 toward the discharge passage 35 (one direction). Allow for outflow. Further, the discharge check valve 16 closes when the

bellows

13 and 14 in which it is disposed expands, and transfers the fluid from the discharge passage 35 to the inside of the bellows 13 and 14 (in the other direction). Prevent backflow.

Note that the right side discharge check valve 16 and the corresponding engagement portion 161 and engagement groove 114 are connected to the left side discharge check valve 16 described above, with the left-right center line X of the pump head 11 interposed therebetween. and is formed symmetrically with the corresponding engaging portion 151 and engaging groove 114.

<Bellows pump operation>
Next, the operation of the bellows pump 10 of this embodiment will be explained with reference to FIGS. 5 and 6. Note that in FIGS. 5 and 6, the configurations of the first and second bellows 13 and 14 are shown in a simplified manner. As shown in FIG. 5, when the first bellows 13 contracts and the second bellows 14 expands, each valve body of the suction check valve 15 and the discharge check valve 16 mounted on the left side of the pump head 11 in the figure 15b and 16b receive pressure from the transfer fluid within the first bellows 13, and move to the right side of each

valve case

15a and 16a in the figure. As a result, the suction check valve 15 is closed, and the discharge check valve 16 is opened, so that the transfer fluid in the first bellows 13 is discharged from the discharge passage 35 to the outside of the pump.

On the other hand, the valve element 15b of the suction check valve 15 mounted on the right side of the pump head 11 in the figure moves to the right side of the valve case 15a due to the suction action of the second bellows 14. The valve body 16b of the discharge check valve 16 mounted on the right side of the pump head 11 in the drawing is moved by the suction action by the second bellows 14 and the pressing action by the transfer fluid discharged from the first bellows 13 into the discharge passage 35. Move the valve case 16a to the right side in the figure. As a result, the suction check valve 15 opens, the discharge check valve 16 closes, and the transfer fluid is sucked into the second bellows 14 from the suction passage 34.

Next, as shown in FIG. 6, when the first bellows 13 is expanded and the second bellows 14 is contracted, the suction check valve 15 and the discharge check valve 16 installed on the right side of the pump head 11 in the figure are closed. Each

valve body

15b, 16b receives pressure from the transfer fluid within the second bellows 14, and moves to the left side of each

valve case

15a, 16a in the drawing. As a result, the suction check valve 15 is closed, and the discharge check valve 16 is opened, and the transfer fluid in the second bellows 14 is discharged from the discharge passage 35 to the outside of the pump.

On the other hand, the valve element 15b of the suction check valve 15 mounted on the left side of the pump head 11 in the figure moves to the left side of the valve case 15a due to the suction action of the first bellows 13. The valve body 16b of the discharge check valve 16 mounted on the left side of the pump head 11 in the figure is caused by the suction action by the first bellows 13 and the pressing action by the transfer fluid discharged from the first bellows 13 into the discharge passage 35. Move the valve case 16a to the left side in the figure. As a result, the suction check valve 15 opens, the discharge check valve 16 closes, and the transfer fluid is sucked into the first bellows 13 from the suction passage 34.
By repeating the above operations, the left and right bellows 13 and 14 can alternately suck in and discharge the transfer fluid.

<Solenoid valve>
In FIG. 1, the first solenoid valve 4 is, for example, a three-position solenoid switching valve having a pair of

solenoids

4a and 4b. Each

solenoid

4a, 4b is energized based on a command signal received from the control section 6. Thereby, the first electromagnetic valve 4 is switched and controlled by the control section 6. The first electromagnetic valve 4 switches the supply and discharge of pressurized air to and from the first discharge side air chamber 21A and the supply and discharge of pressurized air to and from the first suction side air chamber 26A in the first drive unit 27.

Specifically, when the solenoid 4a is excited, the first solenoid valve 4 supplies pressurized air to the first discharge air chamber 21A and discharges pressurized air from the first suction air chamber 26A. Switch to state. Further, when the solenoid 4b is excited, the first solenoid valve 4 is in a state of discharging the pressurized air in the first discharge side air chamber 21A and supplying pressurized air to the first suction side air chamber 26A. Switch.

The second solenoid valve 5 is, for example, a three-position solenoid switching valve having a pair of

solenoids

5a and 5b. Each

solenoid

5a, 5b is configured to receive a command signal from the control section 6 and to be excited. Thereby, the second electromagnetic valve 5 is switched and controlled by the control section 6. The second electromagnetic valve 5 switches the supply and discharge of pressurized air to and from the second discharge side air chamber 21B and the supply and discharge of pressurized air to and from the second suction side air chamber 26B in the second drive unit 28.

Specifically, when the solenoid 5a is excited, the second solenoid valve 5 supplies pressurized air to the second discharge air chamber 21B and discharges pressurized air from the second suction air chamber 26B. Switch to state. Further, when the solenoid 5b is excited, the second solenoid valve 5 is in a state of discharging the pressurized air in the second discharge side air chamber 21B and supplying pressurized air to the second suction side air chamber 26B. Switch. Although the first and second electromagnetic valves 4 and 5 of this embodiment are three-position electromagnetic switching valves, they may be two-position electromagnetic switching valves that do not have a neutral position.

<Electro-pneumatic regulator>
The first electropneumatic regulator 51 is arranged between the mechanical regulator 3 and the first electromagnetic valve 4. The first electro-pneumatic regulator 51 controls the air pressure of pressurized air supplied to the first suction side air chamber 26A of the first drive section 27 and the pressurized air pressure supplied to the first discharge side air chamber 21A of the first drive section 27. Adjust the air pressure of each compressed air.

The second electropneumatic regulator 52 is arranged between the mechanical regulator 3 and the second solenoid valve 5. The second electro-pneumatic regulator 52 controls the air pressure of pressurized air supplied to the second suction side air chamber 26B of the second drive section 28 and the pressurized air pressure supplied to the second discharge side air chamber 21B of the second drive section 28. Adjust the air pressure of each compressed air.

Note that the electro-

pneumatic regulators

51 and 52 may be used as long as they adjust at least the air pressure of the pressurized air supplied to the suction

side air chambers

26A and 26B. Further, in this embodiment, the

electropneumatic regulators

51 and 52 that directly adjust the air pressure are used as the fluid pressure adjustment section, but the air pressure is indirectly adjusted using an air flow rate adjustment valve that adjusts the air flow rate. Alternatively, a device that adjusts the pressure or flow rate of a gas other than air (for example, nitrogen) or a liquid may be used.

<Control unit>
In FIGS. 1 and 2, the control unit 6 includes a computer including a CPU and the like. Each function of the control unit 6 is performed by the CPU executing a control program stored in the storage device of the computer. The control unit 6 controls the first drive unit 27 and the second drive unit by switching the first solenoid valve 4 and the second solenoid valve 5 based on the detection results of the first detection unit 29 and the second detection unit 31. 28 drive controls are performed.

Specifically, the control unit 6 contracts the second bellows 14 from the extended state before the first bellows 13 enters the contracted state, based on the detection results of the first detection unit 29 and the second detection unit 31. At the same time, each drive of the first drive unit 27 and the second drive unit 28 is controlled so that the first bellows 13 is contracted from the extended state before the second bellows 14 is set to the contracted state.

By controlling the drive by the control unit 6 as described above, at the timing when one of the first bellows 13 and the second bellows 14 is switched from contraction to expansion (from discharge to suction of the transfer fluid), the other bellows has already contracted and discharged the transfer fluid, so it is possible to reduce a large drop in the discharge pressure of the transfer fluid at the above timing. As a result, pulsation on the discharge side of the bellows pump 10 can be reduced.

The control unit 6 controls the first bellows 13 and the second bellows 14 so that after one of the bellows 13 (bellows 14) is in the contracted state, the other bellows 14 (bellows 13) is contracted from the extended state. , each drive of the first air cylinder 41 and the second air cylinder 42 may be controlled. The bellows pump 10 also has an engaging portion 151 and an engaging groove 113 (see FIG. 3) corresponding to the suction check valve 15, and an engaging portion 161 and an engaging groove 114 (see FIG. 3) corresponding to the discharge check valve 16. 4), but it is also possible to include only an engaging portion and an engaging groove corresponding to either one of these

check valves

15, 16.

<Actions and effects of this embodiment>
As described above, according to the bellows pump 10 of the first embodiment, when the

male screws

15e, 16e of the

valve cases

15a, 16a of the

check valves

15, 16 are tightened into the female screw holes 111, 112 of the pump head 11, the

valve cases

15a,

16a Engagement portions

151, 161 provided at

ends

15d, 16d engage with inner

circumferential surfaces

113a, 114a of

engagement grooves

113, 114 formed in

bottom surfaces

111a, 112a of female threaded

holes

111, 112. This engagement prevents the

ends

15d, 16d of the

valve cases

15a, 16a from deforming radially inward when the

valve cases

15a, 16a of the

check valves

15, 16 are attached to the pump head 11. can do.

The inner

circumferential surfaces

113a and 114a of the

engagement grooves

113 and 114 are tapered surfaces whose diameter increases toward one side in the axial direction. Therefore, when the engaging

portions

151, 161 engage with the tapered surfaces (inner peripheral surfaces) 113a, 114a, the

end portions

15d, 16d of the

valve cases

15a, 16a are pushed outward in the radial direction. Thereby, the degree to which the

male threads

15e, 16e of the

valve cases

15a, 16a engage with the female threaded

holes

111, 112 of the pump head 11 can be improved.

Annular spaces S1 and S2 are formed between the outer

peripheral surfaces

151b and 161b of the engaging

portions

151 and 161 and the outer

peripheral surfaces

113b and 114b of the engaging

grooves

113 and 114, respectively. Therefore, when the inner

peripheral surfaces

151a, 161a of the engaging

portions

151, 161 engage with the inner

peripheral surfaces

113a, 114a of the engaging

grooves

113, 114, the engaging

portions

151, 161 are It can escape radially outward. Thereby, the

end portions

15d, 16d of the

valve cases

15a, 16a can be reliably pushed outward in the radial direction.

[Second embodiment]
FIG. 7 is an enlarged sectional view showing the vicinity of the left discharge check valve 16 in the bellows pump 10 according to the second embodiment of the present disclosure. In the second embodiment, the cross-sectional shapes of the engagement groove 114 of the pump head 11 and the engagement portion 161 of the discharge check valve 16 are different from those of the first embodiment.

The engagement groove 114 of the pump head 11 of this embodiment is formed in a concave arc shape so as to be depressed toward one side in the axial direction from the bottom surface 112a of the female threaded hole 112 when viewed in cross section. The inner circumferential surface 114a of the engagement groove 114 on the radially inner side (discharge port 37 side) of the lowest point 114c has a curved taper whose diameter increases from the other axial side toward the one axial side in cross-sectional view. It is a surface. The outer circumferential surface 114b on the radially outer side of the lowest point 114c in the engagement groove 114 is a curved tapered surface whose diameter increases from one axial side to the other axial side in cross-sectional view.

The engaging portion 161 provided at the end 16d of the valve case 16a of the discharge check valve 16 is formed in a convex arc shape so as to protrude from the end 16d toward one side in the axial direction when viewed in cross section. The inner circumferential surface 161a on the radially inner side (discharge port 37 side) of the highest apex 161c in the engaging portion 161 is a curved tapered surface whose diameter increases from the other axial side toward the one axial side in cross-sectional view. It is. The outer circumferential surface 161b on the radially outer side of the highest apex 161c of the engaging portion 161 is a curved tapered surface whose diameter increases from one axial side to the other axial side in cross-sectional view.

The radius of curvature R2 of the engaging portion 161 is smaller than the radius of curvature R1 of the engaging groove 114, which has a concave arcuate cross section. Further, a center point C2 of the engaging portion 161 having a convex arc cross section is located radially inward (on the discharge port 37 side) than a center point C1 of the engaging groove 114 having a concave arc cross section.

The other configurations of the second embodiment are the same as those of the first embodiment, so the same reference numerals are given and the description thereof will be omitted. The bellows pump 10 of the second embodiment also has the same effects as the first embodiment. In the second embodiment, the cross-sectional shapes of the engaging portion 161 of the discharge check valve 16 and the engaging groove 114 to which the engaging portion 161 is engaged are formed into a convex arc shape and a concave arc shape, respectively. However, the cross-sectional shapes of the engaging portion 151 of the suction check valve 15 and the engaging groove 113 to which the engaging portion 151 is engaged are as follows, similar to the engaging portion 161 and the engaging groove 114. They may be formed into a convex arc shape and a concave arc shape, respectively.

[Third embodiment]
FIG. 8 is an enlarged sectional view showing the vicinity of the left discharge check valve 16 in the bellows pump 10 according to the third embodiment of the present disclosure. In the third embodiment, the cross-sectional shapes of the engagement groove 114 of the pump head 11 and the engagement portion 161 of the discharge check valve 16 are different from those of the first and second embodiments.

The engagement groove 114 of the pump head 11 in this embodiment is formed in a concave shape so as to be depressed toward one side in the axial direction from the bottom surface 112a of the female threaded hole 112 when viewed in cross section. The inner circumferential surface 114a and the outer circumferential surface 114b of the engagement groove 114 are each a circumferential surface extending straight in the axial direction in a cross-sectional view. The outer diameter of the engagement groove 114 (the diameter of the outer peripheral surface 114b) is smaller than the inner diameter of the female threaded hole 112.

The engaging portion 161 provided at the end 16d of the valve case 16a of the discharge check valve 16 is formed in a convex shape so as to protrude from the end 16d toward one side in the axial direction when viewed in cross section. The inner circumferential surface 161a and the outer circumferential surface 161b of the engaging portion 161 are each a circumferential surface extending straight in the axial direction in a cross-sectional view. The inner diameter of the engaging portion 161 (the diameter of the inner peripheral surface 161a) is approximately the same as the inner diameter of the engaging groove 114 (the diameter of the inner peripheral surface 114a). The outer diameter of the engaging portion 161 (the diameter of the outer peripheral surface 161b) is approximately the same as the outer diameter of the engaging groove 114 (the diameter of the outer peripheral surface 114b). Thereby, the inner circumferential surface 161a and the outer circumferential surface 161b of the engaging portion 161 are engaged with the inner circumferential surface 114a and the outer circumferential surface 114b of the engaging groove 114, respectively.

The other configurations of the third embodiment are the same as those of the first embodiment, so the same reference numerals are given and the description thereof will be omitted. Also in the bellows pump 10 of the third embodiment, the engaging portion 161 provided at the end 16d of the valve case 16a engages with the inner circumferential surface 114a of the engaging groove 114 formed in the bottom surface 112a of the female threaded hole 112. do. By this engagement, when the valve case 16a of the check valve 16 is attached to the pump head 11, it is possible to suppress the end portion 16d of the valve case 16a from being deformed so as to collapse inward in the radial direction.

In the third embodiment, the cross-sectional shapes of the engaging portion 161 of the discharge check valve 16 and the engaging groove 114 to which the engaging portion 161 is engaged are formed into a convex shape and a concave shape, respectively. However, the cross-sectional shapes of the engaging portion 151 of the suction check valve 15 and the engaging groove 113 to which the engaging portion 151 is engaged are respectively convex like the engaging portion 161 and the engaging groove 114. It may also be formed in a concave shape.

[others]
The bellows pump 10 of each of the embodiments described above is not limited to use in semiconductor manufacturing equipment. Further, although the bellows pump 10 includes a pair of

bellows

13 and 14, it may include only a single bellows. For example, a bellows pump may be constructed by replacing one of a pair of bellows with an accumulator.

The engaging

portions

151, 161 in each of the above embodiments are provided over the entire circumference of the

end portions

15d, 16d of the

valve cases

15a, 16a, but are provided only on a portion of the

end portions

15d, 16d in the circumferential direction. You can leave it there.

The spaces S1, S2 between the outer

circumferential surfaces

151b, 161b of the engaging

portions

151, 161 and the outer

circumferential surfaces

113b, 114b of the engaging

grooves

113, 114 in each of the above embodiments correspond to the outer circumferential surfaces 151b of the engaging

portions

151, 161. , 161b are tapered surfaces, but the outer

circumferential surfaces

151b and 161b are circumferential surfaces that extend straight in the axial direction, and the tapered surfaces that expand radially outward from the circumferential surfaces are engaged. The spaces S1 and S2 may be formed by forming them on the outer

peripheral surfaces

113b and 114b of the matching

grooves

113 and 114.

The embodiments disclosed this time should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is indicated by the scope of the claims, not the meaning described above, and is intended to include meanings equivalent to the scope of the claims and all changes within the scope.

10 Bellows Pump 11 Pump Head 13 First Bellows (Bellows)
14 Second bellows (bellows)
15 Suction check valve (check valve)

15a Valve case 15d End

15e Male thread 16 Discharge check valve (check valve)

16a Valve case 16d End

16e Male thread 34 Suction passage 35 Discharge passage 111 Female threaded hole 111a Bottom surface 112 Female threaded hole 112a Bottom surface 113 Engagement groove 113a Inner peripheral surface (tapered surface)
114 Engagement groove 114a Inner peripheral surface (tapered surface)
151 Engagement part 161 Engagement part

Claims

a pump head having a suction passage and a discharge passage for transfer fluid, and a bottomed female threaded hole;
a bellows that is telescopically attached to the pump head, and that expands to draw transfer fluid from the suction passage into the interior, and contracts to discharge the transfer fluid from the interior to the discharge passage;
A check valve that allows the transfer fluid to flow in one direction with respect to the suction passage or the discharge passage and prevents the transfer fluid from flowing in the other direction,
The check valve has a cylindrical valve case with a male thread formed at one end in the axial direction to be screwed into the female threaded hole of the pump head,
an engagement groove provided on the bottom surface of the female threaded hole of the pump head;
A bellows pump, comprising: an engagement part provided at the end of the valve case and engaged with an inner circumferential surface of the engagement groove.
The bellows pump according to claim 1, wherein the inner peripheral surface of the engagement groove is a tapered surface whose diameter increases toward the one side in the axial direction.