JP2998083B2 - Pump pulsation suppressor - Google Patents

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
When the volume of the liquid chamber increases or decreases beyond a predetermined range due to fluctuations in the discharge pressure of the pump, a supply / exhaust switching valve mechanism for supplying gas pressure to the air chamber or exhausting air from the air chamber is provided. The switching operation is automatically performed via an axial operating rod that reciprocates in the axial direction in conjunction with the displacement of the diaphragm.

[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.

In this type of pump, it is more effective to increase the pulsation suppressing function as the inner volume of the air chamber is increased. However, when the air chamber is lengthened in the direction of expansion and contraction of the diaphragm to increase the internal volume of the air chamber, an axial operation for moving the valve element of the supply / exhaust switching valve mechanism in conjunction with the displacement of the diaphragm. When the axial length of the rod is increased, and as a result, when the pressure balance between the hydraulic pressure and the gas pressure is performed, the axial operating rod is tilted or the diaphragm is urged in the axial direction to decrease the liquid chamber volume. The spring that is deformed causes the shaft-shaped operating rod to not act vertically on the diaphragm, and the amount of movement of the valve body of the supply / exhaust switching valve mechanism changes, or the movement itself becomes slippery. There remains a problem that a predetermined supply / exhaust function cannot be performed normally.

[0005] The present invention has been made in view of the above circumstances, and by simply adding a simple structure, while ensuring a large internal volume of the air chamber to enhance the pulsation suppression function,
It is an object of the present invention to provide a pump pulsation suppressing device capable of reliably and normally performing a supply / exhaust action by a supply / exhaust switching valve mechanism linked to expansion and contraction of a diaphragm.

[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. With such a configuration, 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 side, and the capacity of the liquid chamber exceeds a predetermined range. When the pressure increases, the air supply / exhaust passage communicating with the air chamber through the shaft operation rod communicates with the air supply port, and when the capacity of the liquid chamber decreases beyond a predetermined range, the shaft operation rod That connects the supply / exhaust passage to an exhaust port through a valve In the pulsation suppression device for a pump made by mounting the switching valve mechanism for air supply and exhaust on the outside of the apparatus body with, on the wall of the apparatus main body, toward the air chamber projecting
Cylindrical member uses the internal space as the supply / exhaust switching valve mechanism.
This circle is fixed so that it communicates with the supply and exhaust passages
A middle of the axial direction of the shaft-shaped operating rod in the protruding end portion of the air chamber of the cylindrical member, and a monitor guide for slidably guided axial operation of the shaft-shaped operating rod is formed, This cylindrical part
The material has air that allows air to flow between its internal space and the air chamber.
An air circulation hole is formed .

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 increase in the volume of the liquid chamber exceeds a predetermined range due to the fluctuation of the discharge pressure of the pump, the air supply / exhaust valve mechanism supplies air into the air chamber and increases the sealing pressure, thereby restricting the expansion deformation of the diaphragm, When the decrease in the volume of the liquid chamber exceeds a predetermined range, the air is exhausted from the air chamber by the air supply / exhaust valve mechanism, and the sealing pressure is reduced. Constant expansion and contraction of diaphragm regardless of Constrained by pulsation width can be reduced to.

In addition, even if the inner volume of the air chamber is increased in order to enhance the pulsation suppressing function as described above, and the axial length of the axial operating rod is accordingly increased, the axial operating rod can be increased. A guide provided in the air chamber in the middle of the axial direction slides and guides the axial operation of the axial operating rod, so that a shaft for performing pressure balance between the liquid pressure and the gas pressure is provided. It is possible to prevent the axial operating rod from acting on the diaphragm perpendicularly by preventing the operating rod from tilting or deforming the spring that urges the diaphragm in the contracting direction. The movement of the valve element of the air supply / exhaust switching valve mechanism linked to the displacement can be smoothly performed, and the predetermined air supply / exhaust action can always be normally performed while maintaining a constant amount.

Further , the guide is formed at a protruding end of a cylindrical member arranged to protrude into the air chamber, and an air flow hole is formed in the cylindrical member to allow gas to flow between the cylindrical member and the air chamber. As a result, the guide volume (particularly, the radial dimension) occupied in the air chamber is reduced as compared with the case of using a rectangular tube member, so that it is easy to reduce the size of the entire apparatus. Irrespective of the presence, the gas pressure supply / exhaust action to the air chamber can be reliably and smoothly performed without any trouble.

Further, the pulsation suppression device for a pump having the above configuration, as described in claim 2, the planar locus for holding one end of a spring which operates urging the diaphragm to the guide in the decreasing direction of the liquid chamber volume By having the formed configuration, the axial length of the spring is made as short as possible to prevent the spring from deforming at the time of the pressure balance action,
The predetermined air supply / exhaust action can be performed more smoothly and reliably.

Furthermore, the pulsation suppression device for a pump having the above configuration, as described in claim 3, the guide P
P, PVC, PE, POM, PA, PC, PTFE, E
By being composed of at least one material selected from the group consisting of TFE, PVDF and PFA,
Even if a special sliding guide such as a bearing is not used, the frictional resistance during the operation of the shaft-shaped operating rod in the axial direction can be reduced and the predetermined operation function can be stably exhibited.

[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 located at the center of the closed end 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.
2 is a supply / exhaust switching valve mechanism provided on the outer surface of the device, and the supply / exhaust switching valve mechanism 7 is configured as shown in FIG. In FIG. 2, reference numeral 8 denotes a bottomed cylindrical casing. A slide valve element 10 is fitted in a cylinder portion 9 accommodated in the casing 8 so as to be slidable along the axial direction (vertical direction). Have been. Reference numeral 11 denotes an axial operating rod inserted through the hole 1b formed in the upper wall 1a of the apparatus main body 1 and inserted into the air chamber 4, the upper end of which is coaxial with the lower end of the slide valve body 10. The connecting flange 11a on the lower end side of the shaft-like operating rod 11 is connected to a reference position in the cylindrical connecting member 6.

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 increase in the capacity of the liquid chamber 3 exceeds a predetermined range due to the fluctuation of the pump discharge pressure, the slide valve body 10 is displaced upward to communicate the supply / exhaust passage 16a with the space S1, and the capacity of the liquid chamber 3 decreases. Exceeds the specified range,
The exhaust passage 16a is configured to communicate with the space S2.

The upper wall 1a of the apparatus main body 1 has a flange 19a facing the lower end flange 8a of the bottomed cylindrical casing 8 in the switching valve mechanism 7 for air supply and exhaust, and is located closer to the position of the air supply and exhaust passage 16a. Has a large inner diameter
A cylindrical member 19 whose internal space communicates with the air supply / exhaust passage 16a is fixed via a common bolt 20 in a state in which the flanges 8a, 19a face each other. Reference numeral 19 is disposed in the upper air chamber 4 in the apparatus main body 1 so as to protrude downward from the upper portion. This cylindrical member 19 is made of PP, PVC, PE, POM, PA,
PC, PTFE, ETFE, PVDF and PFA are made of at least one or more low-friction resin materials selected from the group consisting of: A guide 21 for slidingly guiding the movement in the axial direction (vertical direction) is formed.

An air flow hole 19b having a size that does not impede air flow with the air chamber 4 is formed in a substantially intermediate peripheral wall portion of the cylindrical member 19 in the axial direction. The lower surface is formed on a flat seat 22 for interlocking and holding the upper end of the spring 18 which is interposed between the cylindrical connecting member 6 and elastically urges the bellows 5 in the direction of decreasing the capacity of the liquid chamber 4. . In the figure, 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 2a. 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. When the amount of extension deformation of the bellows 5 exceeds a predetermined range, the slide valve body 10 is slid upwardly via the shaft-shaped operating rod 11, and the supply / exhaust passage 16a is connected to the supply port 12 via the space S1. Communicated. Therefore, high air pressure is supplied from the air supply port 12 to the air chamber 4 through the space S1, the air supply / exhaust passage 16a, the inside of the cylindrical member 19, and the circulation hole 19b, so that the air pressure sealed in the air chamber 4 is increased. Accordingly, the amount of extension 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. When the amount of contraction deformation of the bellows 5 exceeds a predetermined range, the slide valve element 10 is slid downwardly via the shaft-like operating rod 11 and the supply / exhaust passage 1 is displaced.
6a is communicated 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 circulation hole 19b, the inside of the cylindrical member 19, the supply / exhaust passage 16a and the space S2, and the air pressure in the air chamber 4 is reduced. This will cause the bellows 5
Of the liquid chamber 3 is suppressed from being excessively reduced. As a result, regardless of fluctuations in the discharge pressure of the pump, the pulsation can be efficiently absorbed and the pulsation width can be reduced.

When the pulsation is suppressed by the pressure balance between the liquid pressure and the gas pressure as described above, the axial operating rod reciprocates in the axial direction according to the expansion and contraction deformation of the bellows 5 corresponding to the fluctuation of the discharge pressure of the pump. 11 reciprocates in the axial direction below the cylindrical member 19 provided in the middle of the shaft-like operating rod 11.
Since the sliding guide is provided by the guide 21 at the end, the air chamber 4 is elongated in the direction of expansion and contraction of the bellows 5 to increase the internal volume of the air chamber 4 in order to enhance the pulsation suppressing function. Accordingly, even if the axial direction length of the shaft-like operating rod 11 becomes longer, the shaft-like operating rod 11 may be inclined during the pulsation suppressing action due to the pressure balance, or the bellows 5 may be tilted.
The spring 18 for urging the shaft 11 in the contracting direction thereof is prevented from being deformed, and the shaft-like operating rod 11 is moved to the bellows 5.
, The sliding displacement of the slide valve body 10 in the supply / exhaust switching valve mechanism 7 interlocked with the displacement of the bellows 5, and
The predetermined supply / exhaust action can always be performed normally while maintaining a fixed amount.

The upper end of the spring 18, which elastically urges the bellows 5 in the direction of decreasing the volume of the liquid chamber 4, is locked and held by a flat seat 22 formed on the lower surface of the guide 21. The spring 1 at the time of pressure balance by shortening the axial length of
8 can be prevented, and the predetermined air supply / exhaust action can be performed more smoothly and reliably.

Further, the cylindrical member 1 including the guide 21
9 is PP, PVC, PE, POM, PA, PC, PTF
E, ETFE, PVDF, PFA, and is made of one low-friction resin material. Therefore, even if a special sliding guide such as a bearing is not used, the axial operation rod 11 can be moved in the axial direction. The predetermined pulsation suppressing function can be stably performed by reducing the frictional resistance during operation.

FIG. 3 shows another embodiment of the present invention, and is an overall vertical 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. And partition wall 3
0 and a reciprocating pump unit B is integrally disposed on the other side. The configuration of the pulsation suppressing unit A is the same as that shown in FIGS. The same reference numerals are used to denote the same parts, detailed description thereof is omitted, and 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
3 is extended in the x direction in FIG. 3, the transfer liquid Q in the inflow port 2a passes through the suction check valve 41a and the pump action 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. At this time, the pump discharge pressure 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. .

In the air-driven bellows-type pump having such a configuration, the same effect as that described in the above-described embodiment can be obtained for suppressing the pulsation with respect to the fluctuation of the discharge pressure from the reciprocating pump portion B. Since the axial operation rod 11 is used as a horizontal type so that the axial direction of the operation rod 11 is along the horizontal plane, when the axial operation rod 11 is long, it tends to be inclined obliquely due to its own weight. Therefore, the effect of normalizing the air supply / exhaust action by adopting the configuration in which the long shaft-like operating rod 11 is slid and guided by the guide 21 is greater than that of the vertical type shown in the above embodiment.

[0032] Incidentally, as described above as a cylindrical member 19 forming the guide 21, used as cylindrical, in the case of forming the flow hole 19b on its peripheral wall portion occupies the air chamber 4 the guide 21 and the cylindrical The volume (particularly the radial dimension) of the member 19 is minimized to facilitate miniaturization of the entire apparatus, and the air pressure supply / exhaust action to the air chamber 4 is not affected regardless of the presence of the cylindrical member 19 for the guide 21. The advantage is that it can be performed smoothly without fail
is there.

As shown in the above embodiment, the lower end flange 8a of the bottomed cylindrical casing 8 and the cylindrical member 19 forming the guide 21 in the switching valve mechanism 7 for supply / exhaust.
With the upper end flange 19a facing the common bolt 2
0, the cylindrical connecting member 6 and the spring 18 are passed through the shaft-shaped operating rod 11 in advance, and the shaft-shaped operating rod 1
1 is connected to the slide valve body 10 through the cylindrical member 19, and these can be integrally fixed to the upper wall 1a of the apparatus main body 1 or can be unlocked.
Maintenance such as overall assembly and repair and replacement of parts can be facilitated.

[0034]

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 axial length of the axial operating rod is long, the axial operation of the axial operating rod can be prevented.
A sliding operation guide is formed on a protruding end of a cylindrical member protruding into the air chamber through a guide formed so that a shaft- shaped operating rod can be operated during a pulsation suppressing operation based on a pressure balance between hydraulic pressure and gas pressure. To prevent the spring from acting on the diaphragm in the direction of contraction from being deformed, thereby allowing the shaft-shaped operating rod to act on the diaphragm perpendicularly, thus enhancing the pulsation suppression function. While ensuring a large internal volume of the air chamber, the movement of the valve body of the air supply / exhaust switching valve mechanism linked to the expansion and contraction deformation of the diaphragm is smooth, and a predetermined air supply / exhaust action is maintained even when used for a long period of time by maintaining a constant amount. Can be surely and normally maintained .

[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 front view of a main part of the device.

FIG. 3 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 Apparatus main body 3 Liquid chamber 4 Air chamber 5 Bellows (an example of a diaphragm) 5b Closed end 7 Supply / exhaust switching valve mechanism 10 Slide valve body 11 Shaft operating rod 12 Supply port 13 Exhaust port 16a Supply / exhaust passage 18 Spring 19 Cylindrical Member 19b Flow hole 21 Guide 22 Flat seat Q Transfer liquid

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F04B 1/00-23/14

Claims (3)

(57) [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 pulsation due to the discharge pressure of the transfer liquid by a change in the capacity of the liquid chamber, and is inserted into the air chamber and displaced toward the closed end of the diaphragm. An axial operating rod reciprocating in the axial direction in conjunction therewith, and an air supply / exhaust passage communicating with the air chamber via the axial operating rod when the capacity of the liquid chamber increases beyond a predetermined range. A supply / exhaust switching valve provided with a valve body that communicates with the opening and that connects the supply / exhaust passage to the exhaust port via the shaft-shaped operating rod when the capacity of the liquid chamber is reduced beyond a predetermined range. Suppression of pulsation of a pump with a mechanism mounted outside the device body In location, the wall of the apparatus main body, a cylindrical projecting toward the air chamber
The member has its internal space in the supply / exhaust switching valve mechanism.
The cylindrical member is fixed so as to communicate with the supply / exhaust passage.
A middle projecting end of the air chamber in the axial direction of the shaft-shaped operating rod of the guide sliding guide axial operation of the shaft-shaped operating rod is formed in the cylindrical member
Air circulation that allows air to flow between the internal space and the air chamber
A pulsation suppression device for a pump, wherein a hole is formed . 2. The pulsation suppressing device for a pump according to claim 1, wherein the guide has a flat seat that holds one end of a spring that urges the diaphragm in a direction of decreasing the volume of the liquid chamber. . 3. The guide according to claim 1, wherein the guide is PP, PVC, PE, P
4. The pulsation suppression device for a pump according to claim 1, comprising at least one material selected from the group consisting of OM, PA, PC, PTFE, ETFE, PVDF, and PFA.