JPH11270459A - Pump pulsation suppressing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure the specified pulsation suppressing function and avoid occurrence of a serious situation such as leak of a transport liquid to the outside even in the course of long period of service in the condition that the elongation amount of a diaphragm is restricted in the safety range free of deformation or damage. SOLUTION: A device body 1 is structured so that a liquid chamber 3 to store a transport liquid Q temporarily and an air chamber 4 are provided in isolation from each other with bellows 5 interposed which can make expansion and contraction, wherein a changeover valve mechanism 7 for air supply and exhaust to/from the air chamber 4 is installed with the aid of a shaft-form operating rod 11 which makes reciprocation in the axial direction in linkage with the displacement of the bellows 5 complying with the increment/decrement of the capacity of the liquid chamber 3. The air chamber 4 is internally furnished with an elongation restricting mechanism 19 which comes in parallel contact with the closed end face 5b of the bellows 5 and restricts further elongation when they 5 elongate to the specified value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer liquid pipe for supplying a transfer liquid such as a chemical liquid for various treatments for cleaning a surface of an IC or a liquid crystal in a semiconductor manufacturing apparatus to each part by a reciprocating pump. The present invention relates to a pulsation suppressing device for a pump configured to suppress pulsation (pulse pressure) generated due to fluctuations in flow rate and pressure caused by reciprocation of the pump.

[0002]

2. Description of the Related Art As a pulsation suppressing device of this kind of pump,
The present applicant has already proposed a configuration as disclosed in, for example, JP-A-8-159016. The pulsation suppressor that has been proposed in the above-mentioned publications and the like is provided with a pulsation that is isolated via a diaphragm capable of temporarily storing a transfer liquid by a reciprocating pump and a liquid chamber such as a bellows and a diaphragm that is elastically deformable. An air chamber in which a gas for suppression is sealed is provided, and the capacity of the liquid chamber is changed by the balance between the diaphragm and the pressure of the sealed gas in the air chamber to absorb pulsation due to the discharge pressure of the transfer liquid. Along with
A state in which a supply / exhaust passage leading to the air chamber is communicated with an air supply port through an axial operation rod that reciprocates in the axial direction in conjunction with displacement of the closed end side of the diaphragm, and a state in which the supply / exhaust port communicates with the exhaust port. And a supply / exhaust switching valve mechanism having a valve body that can be automatically switched.

[0003]

The pump pulsation suppressing device proposed by the present applicant having the above-described configuration has the following features.
In addition to suppressing the pulsation due to the discharge pressure of the transfer liquid, the pump discharge is performed by maintaining the change in the volume of the liquid chamber when the discharge pressure of the pump fluctuates within a predetermined range by the pressure balance between the liquid pressure and the gas pressure. It is possible to keep the pulsation width small irrespective of pressure fluctuation.

However, in all pulsation suppressors conventionally used, including the pump pulsation suppressor already proposed by the present applicant, for example, when the supply of gas into the air chamber is forgotten, the apparatus is not used. When the pressure of the transfer liquid is high, when the pressure of the transfer liquid is high, the diaphragm expands to a predetermined value or more due to the collapse of the pressure balance, and the closed end face of the diaphragm is installed in the air chamber. The diaphragm is reciprocally moved in the axial direction in conjunction with the displacement of the diaphragm on the closed end surface side, so that the diaphragm comes into contact with the end of the shaft-like operating rod for automatically switching the supply / exhaust switching valve mechanism with a strong force. Is easily deformed or damaged, and an excessive force is applied to the shaft-shaped operating rod, so that the operating rod is easily deformed or damaged. When such a situation occurs, not only does it hinder subsequent operations and cannot exert a predetermined pulsation suppressing function, but also, depending on the degree of damage to the closed end face of the diaphragm, a transfer liquid such as a drug solution leaks to the outside. There was a problem that could fall into such a serious situation.

[0005] The present invention has been made in view of the above-described circumstances, and by using a simple configuration, the amount of elongation of the diaphragm is kept within a safe range where there is no deformation or damage.
It is an object of the present invention to provide a pump pulsation suppressing device capable of securing a predetermined pulsation suppressing function and avoiding a serious situation such as external leakage of a transfer liquid.

[0006]

In order to achieve the above object, a pump pulsation suppressing apparatus according to the present invention comprises a liquid chamber capable of temporarily storing a transfer liquid by a reciprocating pump in a sealed container-shaped apparatus main body. An air chamber, which is isolated from the liquid chamber via a stretchable and deformable diaphragm and is filled with a pulsation suppressing gas, and absorbs the pulsation due to the discharge pressure of the transfer liquid by changing the capacity of the liquid chamber. And a supply / exhaust passage communicating with the air chamber through an axial operating rod that is inserted into the air chamber and reciprocates in the axial direction in conjunction with the displacement of the diaphragm on the closed end face side. In the pulsation suppression device for a pump provided with a supply / exhaust switching valve mechanism having a valve body capable of automatically switching between a state communicating with an air port and a state communicating with an exhaust port, when the diaphragm expands to a predetermined value. The closed end face of this diaphragm Extension limiting mechanism for limiting further extension of the septum in parallel contact and is characterized in that it is installed in a room the vapor.

According to the present invention, when the transfer liquid flows out through the liquid chamber in the main body of the apparatus by the reciprocating pump, the capacity of the liquid chamber increases at the peak portion of the pulsation of the discharge pressure of the transfer liquid, and the diaphragm increases. Expands and absorbs pressure, and at the valley of the pulsation, the volume of the liquid chamber decreases, the diaphragm contracts and deforms, and the pressure of the transfer liquid rises to absorb the pulsation. When the volume of the liquid chamber increases due to fluctuations in the discharge pressure of the pump, the air supply / exhaust valve mechanism supplies air to the air chamber to increase the sealing pressure, and when the volume of the liquid chamber decreases, The expansion and contraction of the diaphragm is achieved by automatically supplying and exhausting air to the air chamber in response to fluctuations in the discharge pressure of the pump, such as exhausting air from the air chamber by the air supply and exhaust valve mechanism to lower the sealing pressure. Constrain deformation within a certain range to reduce pulsation width It can be suppressed.

In addition, in the above-described pulsation suppressing operation, even if the apparatus is driven in a state where the air supply to the air chamber is forgotten, for example, when the diaphragm has expanded to a predetermined value due to the increase in the fluid pressure, Since the extension restricting mechanism contacts the closed end face of the diaphragm in parallel and further extension is restricted, the diaphragm is deformed or damaged due to the contact between the diaphragm and the end of the shaft operating rod. Further, it is possible to prevent deformation and breakage of the shaft-like operation rod. Thereby, while maintaining the state where the shaft-shaped operating rod always acts perpendicularly to the diaphragm, a predetermined air supply / exhaust action and a pulsation suppressing function can be ensured, and the closed end face of the diaphragm is damaged, and the transfer liquid leaks to the outside. Such a serious situation can be avoided.

In the pulsation suppressing device for a pump having the above structure, the extension limiting mechanism has a cylindrical end face in parallel with a closed end face of the diaphragm, and has a concentric shape. A plurality of cylindrical bodies arranged in the air chamber and disposed in the air chamber;
As described in the above, any of a circular plate fixedly installed in the air chamber so as to contact the whole or almost the whole surface in parallel to the closed end face of the diaphragm may be, in short, a cylinder It is only necessary that the length of the body and the installation position of the circular plate be set to a safe value such that the amount of extension of the diaphragm does not break.

Further, in the pulsation suppressing device for a pump having the above-mentioned structure, the extension limiting mechanism has a size that does not impair the strength of a cylindrical body or a circular plate constituting the mechanism. By forming a gas flow section such as a notch or a hole that does not hinder gas flow in the air chamber,
Although the extension restricting mechanism is installed in the air chamber, it is possible to keep the gas pressure in the air chamber uniform over the entire area and to expand and contract the diaphragm without distortion.

Further, in the case where the pulsation suppressing device for a pump having the above-mentioned structure is configured so as to be horizontally placed so as to expand and contract the diaphragm in the horizontal direction, the bottom portion in the air chamber may be provided. By installing a liquid leak detection sensor at the position, if liquid leaks into the air chamber due to breakage of the diaphragm, etc., the liquid leak is detected as soon as possible, It is possible to prevent the development of a serious situation such as leakage to the public.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall longitudinal front view of a pulsation suppression device for a pump according to the present invention.
Is a sealed container-shaped device main body, and a liquid chamber 3 is formed in the lower side of the device main body 1 to take in a transfer liquid Q by a pump from an inflow port 2a, temporarily store the liquid, and flow out from an outflow port 2b. ing.

Reference numeral 4 denotes an air chamber formed on the upper side in the apparatus main body 1. The air chamber 4 is isolated from the liquid chamber 3 by a diaphragm which can be expanded and contracted, for example, a bellows 5;
The central portion 5a forms a part of the liquid chamber 3. A cylindrical connecting member 6 positioned at the center of the closed end face 5b of the bellows 5 and directed in a direction in which the volume of the liquid chamber 3 increases, that is, in a direction in which the bellows 5 extends, is pressed by the elastic biasing force of a spring 18. ing.

Reference numeral 7 denotes an upper wall 1a of the apparatus main body 1 on the air chamber 4 side.
The supply / exhaust switching valve mechanism 7 is provided on the outer surface of the device, and the supply / exhaust switching valve mechanism 7 is configured as follows. That is, a cylinder part 9 is housed in a bottomed cylindrical casing 8, and a slide valve body 10 is fitted into the cylinder part 9 so as to be slidable along the axial direction (vertical direction). ing. Reference numeral 11 denotes a shaft-like operating rod inserted into the air chamber 4 through a hole 1b formed in the upper wall 1a of the apparatus main body 1, and an upper end thereof is integrally formed with a lower end of the slide valve body 10. The connection flange 11a is coaxially connected and is connected to a reference position in the cylindrical connection member 6 at a lower end side of the shaft-like operation rod 11.

The peripheral wall of the casing 8 has an air supply port 12 formed at a lower portion thereof and an exhaust port 13 formed at an upper portion thereof. The supply port 12 is provided with the transfer liquid Q.
Is supplied at a pressure equal to or higher than the maximum pressure value, and the exhaust port 13 is open to the atmosphere. Ports 14 and 15 are formed on the peripheral wall of the cylinder section 9 corresponding to the air supply port 12 and the exhaust port 13. 1
Reference numeral 6a denotes a supply / exhaust passage formed in the peripheral wall of the casing 8, which communicates the air chamber 4 with the inside of the cylinder portion 9.

The slide valve body 10 has three sliding flanges 10a, 10b,
10c is formed, a space between the center brim portion 10b and the lower brim portion 10c is configured as an air supply space S1, and a space between the center brim portion 10b and the upper brim portion 10a is configured as an exhaust space S2. I have. When the capacity of the liquid chamber 3 increases according to the fluctuation of the pump discharge pressure, the slide valve element 10 is displaced upward to communicate the supply / exhaust passage 16a with the space S1 and when the capacity of the liquid chamber 3 decreases, The exhaust passage 16a is configured to communicate with the space S2 by descending and displacing.

On the upper wall 1a of the apparatus main body 1, two cylindrical bodies 19A and 19B which are concentric with the axial operating rod 11 and protrude to the same length in the air chamber 4 are integrally formed. Have been. The lower ends of these cylindrical bodies 19A, 19B are parallel to the closed end faces 5b of the bellows 5, respectively.
When the bellows 5 is extended to a predetermined value by the cylindrical bodies 19A and 19B, the cylindrical end faces 19a and 19b come into parallel contact with the closed end face 5b of the bellows 5 so as to come into contact with the bellows 5. Constitutes an extension limiting mechanism 19 for limiting further extension. The number of the cylindrical bodies is determined so that the closed end face 5b of the bellows 5 does not extend beyond the design allowable value when the bellows 5 expands and deforms and comes into contact with the cylindrical end face. The number is not limited to three and may be three or more.

As shown in FIG. 2, the lower end of the peripheral wall of the cylindrical body 19A, 19B constituting the extension limiting mechanism 19 is cut into a size not to impair the strength of the cylindrical body 19A, 19B. The air circulation portions 20A and 20B are formed by the notches. These air circulation units 20A and 20B
As shown in FIG. 3, even when the bellows 5 is extended to a predetermined value and the closed end face 5b is in contact with the cylindrical end faces 19a, 19b at the lower ends of the cylindrical bodies 19A, 19B constituting the extension limiting mechanism 19. The air in the chamber 4 is circulated inward and outward as indicated by the arrows in the figure to fulfill the function of keeping the air pressure uniform throughout the air chamber 4. The air circulation portions 20A and 20B may be through holes other than the cutouts. In FIG. 1, reference numeral 17 denotes a spring member which is installed in the casing 8 and applies a spring force upward to the slide valve body 10 to hold the slide valve body 10 at a reference position.

Next, the operation of the pulsation suppression device for a pump having the above configuration will be described. When the transfer liquid Q is fed toward a predetermined portion by the operation of the reciprocating pump, the pump discharge pressure generates a pulsation due to the repetition of peaks and valleys.

The transfer liquid Q is taken in from the inlet 2a, temporarily stored in the liquid chamber 3, and then flows out from the outlet 2b. At this time, when the discharge pressure of the transfer liquid Q is at the peak of the discharge pressure curve, the transfer liquid Q expands and deforms the bellows 5 so as to increase the capacity of the liquid chamber 3, so that the pressure is absorbed. At this time, the flow rate of the transfer liquid Q flowing out of the liquid chamber 3 is smaller than the flow rate sent from the pump.

On the other hand, when the discharge pressure of the transfer liquid Q approaches the valley of the discharge pressure curve, the pressure of the transfer liquid Q becomes lower than the compressed air pressure in the air chamber 4 compressed by the expansion deformation of the bellows 5. Therefore, the bellows 5 contracts and deforms. At this time, the flow rate flowing out of the liquid chamber 3 is larger than the flow rate of the transfer liquid Q flowing into the liquid chamber 3 from the pump. The pulsation is absorbed and suppressed by this repetitive operation, that is, a change in the capacity of the liquid chamber 3.

Further, during the above operation, when the discharge pressure of the pump rises and fluctuates, the transfer liquid Q
The bellows 5 is greatly expanded and deformed. At this time, the slide valve body 10 is slid and displaced upward via the shaft-like operating rod 11, and the supply / exhaust passage 16a is
1 is connected to the air supply port 12. Therefore, a high air pressure from the air supply port 12 causes the space S <b> 1 and the air supply / exhaust passage 1.
The air is supplied to the air chamber 4 via 6a, and the air pressure sealed in the air chamber 4 is increased, whereby the amount of expansion deformation of the bellows 5 is restricted and the capacity of the liquid chamber 3 is prevented from being excessively increased.

On the other hand, when the discharge pressure of the pump fluctuates,
The volume of the liquid chamber 3 is reduced by the transfer liquid Q, and the bellows 5 is largely contracted and deformed. At this time, the slide valve body 10 is slid downwardly via the shaft-shaped operation rod 11,
The supply / exhaust passage 16a communicates with the exhaust port 13 via the space S2. Therefore, the enclosed air a in the air chamber 4 is discharged to the atmosphere from the exhaust port 13 through the air supply / exhaust passage 16a and the space S2, and the air pressure in the air chamber 4 is reduced. The amount is restricted and the capacity of the liquid chamber 3 is prevented from being excessively reduced. As a result, even if the discharge pressure of the pump fluctuates, the pulsation can be efficiently absorbed and the pulsation width can be reduced.

In the above-described pulsation suppressing operation based on the pressure balance between the liquid pressure and the gas pressure, for example, even if the apparatus is driven in a state in which the supply of air into the air chamber 4 is forgotten, the increase in the liquid pressure causes When the bellows 5 has expanded to a predetermined value,
As shown in FIG. 3, the closed end face 5b of the bellows 5 comes into parallel contact with the cylindrical end faces 19a, 19b at the lower ends of the cylindrical bodies 19A, 19B in the extension limiting mechanism 19, so that further extension is restricted. , Bellows 5 and axial operating rod 1
It is possible to prevent the bellows 5 from being deformed or damaged due to the contact with the lower end of the shaft 1, and further prevent the shaft-shaped operating rod 11 from being deformed or damaged. As a result, the shaft-like operating rod 11 is
In the case of using for a long period of time while maintaining the state of acting vertically to the closed end face 5b, the predetermined air supply / exhaust action and the pulsation suppressing function can be stably secured, and the bellows 5
Can prevent the occurrence of a serious situation in which the closed end face 5b of the first member is damaged and the transfer liquid Q leaks to the outside.

Also, in the state of FIG. 3 in which the bellows 5 has been extended to a predetermined value and its closed end face 5b has come into contact with the cylindrical end faces 19a, 19b at the lower ends of the cylindrical bodies 19A, 19B constituting the extension limiting mechanism 19. The air in the air chamber 4 flows inward and outward as shown by arrows in FIG. 1 through air cut-out portions 20A and 20B formed by cutouts formed at the lower ends of the peripheral walls of the cylindrical bodies 19A and 19B. Since the air pressure in the entire area of the bellows 4 is kept uniform, no distortion occurs in the bellows 5.

FIGS. 4 and 5 show another embodiment of the present invention. In this embodiment, the extension restricting mechanism 19 of the bellows 5 is replaced with a plurality of cylindrical bodies described above.
A single circular plate 19C is horizontally disposed at a predetermined height position in the air chamber 4 and is integrally fixed to the inner peripheral surface of the apparatus main body 1. In this case, the bellows 5 Is extended to a predetermined value, the closed end face 5b of the circular plate 19C
The entire surface or almost the entire surface is contacted in parallel with the lower surface 19c of the second member to restrict further extension of the bellows 5. Also in this embodiment, the circular plate 19C is formed with a notched or through-hole air circulation portion 20C in order to keep the air pressure in the entire region inside the air chamber 4 uniform in the expansion limited state. Since other configurations are the same as those of the above-described embodiment, corresponding portions are denoted by the same reference numerals, and detailed description thereof will be omitted.

FIG. 6 shows another embodiment of the present invention, and is an overall longitudinal sectional front view of a pulsation suppressing device of an air-driven bellows type pump. This air-driven bellows type pump is provided with a pulsation suppressor A having a configuration similar to that described in the above-described embodiment on one side of a partition wall 30 where an inlet 2a and an outlet 2b of the transfer liquid Q are formed. In addition, the reciprocating pump unit B is integrally provided on the other side of the partition wall 30. Since the configuration of the pulsation suppressing unit A is the same as that shown in FIG. Corresponding parts have the same reference characters allotted, and detailed description thereof will be omitted. The configuration of the reciprocating pump unit B will be described below.

A bellows 32 serving as a pump acting body capable of expanding and contracting along the axis of the cylinder is disposed in a bottomed cylindrical casing 31 fixedly connected to the partition wall 30. The inner space of the casing 31 is hermetically partitioned into a pump working chamber 34a inside the bellows 32 and a pump working chamber 34b outside the bellows 32 by pressing and fixing the portion 32a to the partition wall 30 in an airtight manner by the annular fixing plate 33. I have. The bottom wall 3 of the bottomed cylindrical casing 31
1a, the bellows 32 is connected via a connecting member 35.
A cylinder body 37 for slidably housing a piston body 36 fixedly connected to the closed end member 32b of
Pressurized air supplied from a pressurized air supply device (not shown) such as a compressor is supplied to the inside of the cylinder body 37 or through the air holes 38a and 38b formed in the bottom wall portion 31a of the cylinder body 37 and the casing 31. An air cylinder section 39 for driving and expanding and contracting the bellows 32 is formed by supplying the bellows 32 to the pump working chamber 34b.

Further, a suction port 40a and a discharge port 40 formed to open in the pump action chamber 34a, respectively.
b is connected to the inflow port 2a and the outflow port 2b, and the suction port 40a and the discharge port 40b are each provided with a movable valve body 41a1 which is alternately opened and closed in accordance with the drive expansion and contraction of the bellows 32. The check valve 41a for discharge and the check valve 41b for discharge with the movable valve body 41b1 are provided, and the above-mentioned components constitute the reciprocating pump section B.

In the air-driven bellows type pump having the above-described structure, pressurized air supplied from a pressurized air supply device (not shown) such as a compressor is supplied to the inside of the cylinder body 37 of the air cylinder portion 39. Supply bellows 3
When the valve 2 is extended in the x direction in FIG. 6, the transfer liquid Q in the inflow port 2a passes through the check valve 41a for suction and the pump working chamber 34.
a, and then supplies the pressurized air into the pump working chamber 34b of the air cylinder portion 37 so that the bellows 32
Is contracted in the y direction of FIG.
The bellows 32 of the reciprocating pump unit B is driven to expand and contract through the air cylinder unit 39 so that the transfer liquid sucked into the a is discharged through the discharge check valve 41b. The check valve 41a and the discharge check valve 41b are alternately opened and closed, so that suction of liquid from the inlet 2a to the pump working chamber 34a and discharge of liquid from inside the pump working chamber 34a to the outlet 2b are repeated. Then, a predetermined pump action is performed. With the operation of the reciprocating pump portion B, the check valve 41b for discharge from the pump action chamber 34a is discharged.
Is transferred into the liquid chamber 3 in the pulsation suppressing section A through the communication passage 42 formed in the partition wall 30, is temporarily stored in the liquid chamber 3, and then flows out of the outlet 2b. Spilled out to. The pump discharge pressure at this time generates a pulsation due to the repetition of the peak and the valley, and the pulsation is absorbed and suppressed by the change in the capacity of the liquid chamber 3 as described in the above embodiment. When the bellows 5 has expanded to a predetermined value, further expansion is restricted by the expansion restricting mechanism 19 to prevent deformation and damage of the bellows 5 and the shaft-like operating rod 11.

In the pneumatically driven bellows type pump having such a configuration, the same effects as those described in the above-described embodiment can be obtained with respect to the pulsation suppression for the fluctuation of the discharge pressure from the reciprocating pump portion B and the extension restricting operation of the bellows 5. But
This type of pump is generally used as a horizontal type so that the bellows 5, 32 can be expanded and contracted in the horizontal direction. Therefore, a sensor 21 for detecting a liquid leak is installed at the bottom of the air chamber 4 in the pulsation suppressor A. In this case, the air leaks from the liquid chamber 3 due to breakage of the bellows 5 or the like. When the liquid leaks into the chamber 4, the sensor 21 promptly detects and notifies the sensor of the liquid leak, so that it is possible to prevent the liquid from leaking to the outside of the apparatus main body 1, and thereby to prevent a serious situation from occurring. Becomes

[0032]

As described above, according to the present invention, not only the pulsation due to the discharge pressure of the pumping liquid is absorbed, but also the fluctuation of the liquid chamber capacity when the discharge pressure fluctuates occurs. The pulsation width can be suppressed small by keeping the pressure within a predetermined range by the pressure balance. In addition, even if the apparatus is driven in a state where the air supply to the air chamber is forgotten, for example, the amount of extension of the diaphragm is set to a safe value without deformation or breakage of the axial operation rod provided in the diaphragm or the air chamber. Can be restricted to
Therefore, while maintaining the state in which the shaft-shaped operating rod always acts perpendicularly to the diaphragm, the air supply / exhaust action is maintained normally, a predetermined pulsation suppressing function can be secured, and the closed end face of the diaphragm is damaged and transported. This has the effect that a serious situation in which the liquid leaks to the outside can be reliably avoided.

In particular, when the structure of claim 5 is adopted,
In the unlikely event that a liquid leaks into the air chamber due to damage to the diaphragm, etc., the liquid leak is detected as soon as possible,
The development to a serious situation such as leakage to the outside of the apparatus main body can be prevented.

[Brief description of the drawings]

FIG. 1 is an overall vertical sectional front view of a pump pulsation suppressing device according to an embodiment of the present invention.

FIG. 2 is an enlarged vertical sectional side view of a main part of the device.

FIG. 3 is a longitudinal sectional front view of a main part of the device, showing a state in which extension of a diaphragm is restricted.

FIG. 4 is an enlarged vertical sectional front view of a main part of a pulsation suppression device for a pump according to another embodiment of the present invention.

FIG. 5 is a plan view of FIG. 4;

FIG. 6 is an overall vertical sectional front view of a pulsation suppressing device of an air-driven bellows type pump according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Device main body 3 Liquid chamber 4 Air chamber 5 Bellows (an example of a diaphragm) 5b Closed end face 7 Supply / exhaust switching valve mechanism 10 Slide valve body 11 Axial operation rod 12 Supply port 13 Exhaust port 16a Supply / exhaust passage 19 Extension restriction mechanism 19A, 19B Cylindrical body 19C Circular disk 19a, 19b Cylindrical end surface 20A, 20B, 20C Air circulation unit 21 Liquid leak detection sensor Q Transfer liquid

Claims (5)

[Claims] 1. A liquid chamber capable of temporarily storing a liquid to be transferred by a reciprocating pump in a sealed container-shaped apparatus main body, and a pulsation suppressing gas which is isolated from the liquid chamber via a diaphragm which can expand and contract. A sealed air chamber is provided to absorb the pulsation due to the discharge pressure of the transfer liquid due to a change in the capacity of the liquid chamber, and is inserted into the air chamber and displaced on the closed end face side of the diaphragm. It has a valve body that can be automatically switched between a state in which a supply / exhaust passage communicating with the air chamber is communicated with an air supply port and a state in which the supply / exhaust path is communicated with the exhaust port via an axial operation rod that reciprocates in the axial direction in conjunction therewith. A pulsation suppressing device for a pump, provided with a supply / exhaust switching valve mechanism, wherein when the diaphragm extends to a predetermined value, the diaphragm contacts the closed end face of the diaphragm in parallel to limit further extension of the diaphragm. A restriction mechanism is installed in the air chamber. Pulsation suppression device of the pump, characterized in that it is. 2. The extension restricting mechanism has a cylindrical end face in parallel with a closed end face of the diaphragm, and is constituted by a plurality of cylinders arranged concentrically and installed in the air chamber. The pulsation suppression device for a pump according to claim 1, wherein 3. The expansion limiting mechanism according to claim 1, wherein the extension restricting mechanism comprises a circular plate fixedly installed in the air chamber so as to contact the whole or almost the entire surface in parallel with the closed end face of the diaphragm. Pump pulsation suppressor. 4. The pulsation suppression device for a pump according to claim 1, wherein a gas flow portion that does not hinder gas flow in the air chamber is formed in the extension restriction mechanism. 5. The apparatus main body according to claim 1, wherein the apparatus main body is configured to be horizontally placed so as to expand and contract the diaphragm in a horizontal direction, and a liquid leakage detection sensor is provided at a bottom position in the air chamber. 5. The pulsation suppression device for a pump according to any one of claims 4 to 4.