JP3328591B2 - Pump with pulsation reduction device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pump with a pulsation reducing device which is suitably applied to a circulating transport of a chemical solution used for various processes such as surface cleaning of an IC or a liquid crystal in a semiconductor manufacturing apparatus.

[0002]

2. Description of the Related Art As a pulsation reducing device of a pump having such a pulsation reducing device, the present applicant has disclosed, for example, Japanese Patent Application Laid-Open No. 8-159.
No. 016 has already been proposed. There, a liquid chamber capable of temporarily storing a transfer liquid by a reciprocating pump and an air chamber in which air for reducing pulsation is enclosed by being separated from the above liquid chamber such as a bellows and a diaphragm by an elastically deformable diaphragm. The capacity of the liquid chamber is changed by the balance between the pressure of the transfer liquid flowing into and out of the liquid chamber in 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. When the liquid chamber volume increases or decreases beyond a predetermined range due to fluctuations in the discharge pressure of the pump, air is supplied to the air chamber or exhausted from the air chamber to keep the diaphragm displacement within the predetermined range. The switching valve mechanism for supply / exhaust is automatically switched via a shaft that reciprocates in the axial direction in conjunction with the displacement of the diaphragm. According to the pulsation reducing device configured as described above, not only can the pulsation due to the discharge pressure of the transfer liquid be reduced, but also the change in the volume of the liquid chamber when the discharge pressure of the pump fluctuates can be reduced or increased by the transfer liquid pressure and the gas pressure. It is possible to keep the pulsation width small irrespective of the fluctuation of the discharge pressure of the pump by keeping the pressure within a predetermined range by the pressure balance.

[0003]

In this kind of pump, the pulsation reducing action of the pump is, for example, when a high transfer fluid pressure discharged from the pump is received by the diaphragm, the diaphragm is extended into the liquid chamber of the diaphragm while the diaphragm is extended. This is performed by absorbing the high transfer liquid pressure by flowing the transfer liquid, storing the transfer liquid in the liquid chamber of the temporary diaphragm, and discharging the transfer liquid from the outflow passage while reducing the transfer liquid pressure. Then, in this case, the elongating operation of the diaphragm is performed by the transfer hydraulic pressure flowing into the liquid chamber of the diaphragm,
Although it depends on the balance with the air chamber pressure acting against the transfer liquid pressure through the diaphragm, the pressure in the air chamber generally increases due to the compression of the air chamber by the extension displacement of the diaphragm in accordance with the extension of the diaphragm. As much as possible, the diaphragm can be freely extended in accordance with the transfer liquid pressure without being affected as much as possible. For this reason, when the volume of the air chamber is small, the compression allowance of the air chamber due to the extension of the diaphragm becomes relatively larger than that of the air chamber, and the pressure of the air chamber increases. Since the pressure acts in the direction opposite to the diaphragm elongation direction and prevents the elongation of the diaphragm, the effect of the increase in the pressure of the air chamber is consequently large, and the effect of reducing the high transfer liquid pressure is reduced. That is, in this type of pump, as the volume of the air chamber is increased, the compression ratio of the air chamber can be reduced, and the increase in the pressure of the air chamber can be suppressed, and the action of preventing the diaphragm from extending can be reduced. In order to reduce the pulsation, it is more advantageous that the volume in the air chamber is larger. However, when the volume in the air chamber is increased, the entire apparatus also becomes large, and the occupied installation space increases. In particular, since a clean room provided for cleaning the surface of an IC or a liquid crystal in a semiconductor manufacturing apparatus is expensive, the installation space for this type of pump is naturally limited, and the size of the air chamber is limited. . In addition, when the volume of the air chamber is increased, the shaft of the supply / exhaust switching valve mechanism becomes longer. Therefore, when the pressure balance between the liquid pressure and the gas pressure is performed, the shaft may be tilted or the diaphragm may be moved in the axial direction. As a result, the spring for urging the operation in the direction of decreasing the liquid chamber capacity is deformed and the shaft does not act perpendicular to the diaphragm, and the supply / exhaust switching valve linked to the shaft does not open and close normally. There was a problem.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem. By adopting a structure in which the air chamber is separated into two or more, the volume of the air chamber is increased so that the pulsation reduction effect is enhanced. It is an object of the present invention to provide a pump with a pulsation reducing device capable of reducing the size of the entire pump and reducing the installation space while achieving the above. Another object of the present invention is to provide a pump with a pulsation reducing device that can shorten the shaft of a switching valve mechanism for air supply and exhaust, and achieve stable and reliable operation of air supply and exhaust.

[0005]

SUMMARY OF THE INVENTION According to the present invention, there is provided a partition wall provided with an inflow passage and an outflow passage of a liquid, and an inside of a casing fixedly connected to one side of the partition wall, which is elastically deformable along an axial direction. a first bellows possible, the air cylinder portion which the first bellows drives elastic exercise, the first bellows elastic suction action of the liquid opening and closing operation alternately with the movement and inside the first bellows An air-driven reciprocating pump unit having a pump action chamber provided with a check valve for performing a discharge operation, and a first bellows opposed to the first bellows in a casing fixedly connected to the other side of the partition wall. And the first
A second bellows which can be expanded and contracted in the direction of expansion and contraction of the bellows, and a liquid formed inside the second bellows and temporarily discharged from the pump working chamber through a discharge check valve. a liquid chamber to allow, and a device-side air chamber air pulsation reduction is isolated form with respect to the liquid chamber on the outer side of the second bellows is sealed, the expansion and contraction deformation movement of the second bellows A pulsation reducing unit configured to absorb pulsation due to a discharge pressure of the liquid discharged from the pump action chamber due to a change in volume of the liquid chamber accompanying the pulsation reducing device. In addition to the chamber, one or more separated air chambers are characterized by being provided in communication with the apparatus-side air chamber. The apparatus side air chamber and the separated air chamber are connected by piping so that the internal pressures are equal. The volume of the separation air chamber is preferably set to a range up to 20 times the volume of the liquid chamber. This is because no remarkable effect on pulsation reduction is recognized even if the setting is 20 times or more.

The pump with the pulsation reducing device further includes:
A shaft that is inserted into the apparatus-side air chamber and reciprocates in the axial direction in conjunction with the displacement of the second bellows on the closed end side; and the shaft when the capacity of the liquid chamber increases beyond a predetermined range. When the capacity of the liquid chamber is reduced beyond a predetermined range, the supply / exhaust passage communicating with the supply / exhaust passage communicating with the apparatus-side air chamber through the shaft is connected to the supply / exhaust passage via the shaft. A supply / exhaust switching valve mechanism having a valve body communicating with the exhaust port. The air supply / exhaust switching valve is not limited to the air supply / exhaust switching valve as long as it is a valve for regulating the change in the capacity of the liquid chamber within a predetermined range of the displacement of the liquid chamber.

[0007]

The operation of the first reciprocating pump unit via the air cylinder unit
When the bellows is driven to expand and contract, the check valve for suction and the check valve for discharge in the pump working chamber are alternately opened and closed to suck the liquid from the inflow passage of the liquid into the pump working chamber and from the pump working chamber. The discharge of the liquid to the outflow path is repeated, and a predetermined pump action is performed. At this time, the liquid discharged from the pump action chamber through the discharge check valve flows out to the outflow path through the liquid chamber of the pulsation reducing unit, and at this time, at the peak of the pulsation of the discharge pressure of the discharged liquid, Means that the second bellows moves in the direction of increasing the volume of the liquid chamber to absorb the pressure, and
In the valley of the pulsation, the second bellows moves in the direction of decreasing the volume of the liquid chamber to increase the pressure of the discharged liquid and absorb the pulsation, so that the liquid can be continuously and smoothly discharged without pulsation. Become.

In the pump with a pulsation reducing device that operates as described above, one or more separated air chambers are provided in communication with the device-side air chamber, separately from the device-side air chamber. The pulsation reduction performance can be satisfied by the total volume of the volume of the device-side air chamber and the volume of the separated air chamber. In addition, by separating the separation air chamber from the pump with the pulsation reduction device, not only can the whole pump be miniaturized, but also the separation air chamber can be freely installed in an empty space away from the installation location of the pump or in a dead space on the pump. And the effective use of empty space and dead space can be achieved.

According to the pump with the pulsation reducing device provided with the supply / exhaust switching valve mechanism, if the increase in the liquid chamber volume exceeds a predetermined range due to the fluctuation of the discharge pressure in the reciprocating pump, the supply / exhaust switching valve mechanism is used. When air is supplied to the device-side air chamber and the separation air chamber, the sealing pressure is increased, the expansion and deformation of the second bellows is regulated, and when the capacity of the liquid chamber exceeds a predetermined range, The air supply / exhaust switching valve mechanism exhausts air from the apparatus-side air chamber and the separation air chamber, lowers the sealing pressure, and regulates the contraction deformation of the second bellows , thereby reducing the fluctuation of the discharge pressure of the reciprocating pump. the second base regardless
The amount of expansion and contraction of the rose is regulated within a certain range, and the pulsation width can be suppressed to a small value.

In addition, as described above, it is not necessary to lengthen the shaft of the supply / exhaust switching valve mechanism with the downsizing of the pump as a whole, so that the shaft is inclined even when the pressure balance between the liquid pressure and the gas pressure is performed. Or a second velo
It becomes possible to act vertically shaft to the second bellows can be prevented that the spring is deformed or operating biases the over's the contraction direction, whereby the second Vero
The movement of the valve element of the air supply / exhaust switching valve mechanism in conjunction with the displacement of the dose can be smoothly performed, and a predetermined air supply / exhaust action can always be normally performed while maintaining a constant amount.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. 1 is an overall vertical sectional front view of an air-driven bellows type pump for a semiconductor manufacturing apparatus applied as an embodiment of a pump with a pulsation reducing device according to the present invention, and FIG. 2 is an enlarged vertical sectional front view of a supply / exhaust switching valve mechanism. In FIG. 1, reference numeral 1 denotes a partition wall in which a liquid inflow path 2 and an outflow path 3 are formed, and a reciprocating pump section 4 and a pulsation reduction section 5 are integrally disposed on both sides of the partition wall 1 so as to face each other. Has been established.

A bottomed tubular bellows 7, which is a first bellows which can be expanded and contracted along the cylinder axis direction, is provided in a bottomed tubular casing 6 fixedly connected to one side of the partition wall 1. An inner peripheral space 7a of the bellows 7 is air-tightly pressed and fixed to one side surface of the partition plate 1 by an annular fixing plate 8, so that the inner space of the casing 6 is reduced.
Pump working chamber 9a inside and pump working chamber 9 outside bellows 7
b. Bottom wall 6a of casing 6
Is connected to the closed end member 7b of the bellows 7 by the connecting member 1
A cylinder body 12 which slidably houses a piston body 11 fixedly connected through a cylinder 0 is fixed, and through this cylinder body 12 and air holes 13a, 13b formed in the bottom wall 6a of the casing 6, By supplying pressurized air supplied from a pressurized air supply device (not shown) such as a compressor to the inside of the cylinder body 12 or the pump operating chamber 9b, the air cylinder portion 14 for driving the bellows 7 to expand and contract is formed. It is configured.

A suction port 15a and a discharge port 15b formed to open in the pump action chamber 9a, respectively.
Are connected to the inflow passage 2 and the outflow passage 3, and are connected to the suction port 15 a and the discharge port 15 b, respectively, by a suction check valve 16 a and a suction check valve 16 a, which alternately open and close according to the drive expansion and contraction deformation of the bellows 7. A discharge check valve 16b is provided, and the above-described components constitute the pump unit 4.

On the other hand, a bottomed cylindrical casing 17 which is coaxially fixedly connected to the casing 6 on the other side of the partition wall 1 is opposed to the bellows 7 of the pump section 4 and has a cylindrical shape. A second tongue that can be expanded and contracted along the axial direction
Over a bottomed cylindrical bellows 18 is disposed in the figure,
The opening peripheral portion 18 a of the bellows 18 is
By pressurizing and fixing the partition wall 1 to the other side surface in an airtight manner, the internal space of the casing 17 is reduced by the bellows 18.
A liquid chamber 20a for temporarily storing liquid discharged through a discharge check valve 16b of the pump unit 4 and a communication passage 21 formed through the thickness of the partition wall 1;
Device side air chamber 20b in which air for reducing pulsation is sealed outside
And is formed in isolation.

The bellows 18 are formed by the above-described components.
The pulsation reducing unit 5 is configured to absorb a pulsation due to a discharge pressure of the liquid discharged from the pump action chamber 9a of the pump unit 4 due to a change in the capacity of the liquid chamber 20a due to the expansion and contraction of the liquid chamber 20a.

A supply / exhaust switching valve mechanism 22 is provided at the center of the outer surface of the bottom wall 17a of the casing 17 in the pulsation reducing section 5. As shown in FIG. 2, the supply / exhaust switching valve mechanism 22 includes a bottomed cylindrical casing 23 and a bolt 24 at a substantially central portion of an outer surface of a bottom wall 17 a of the casing 17.
And the like.
The valve body 26 is accommodated in the cylinder portion 25 so as to be slidable along the axial direction. A shaft 27 is coaxially connected to one end of the valve body 26, and this shaft 2
7 is inserted into the apparatus-side air chamber 20b through a hole 17b formed substantially in the center of the bottom wall 17a, and a flange 28 provided at the insertion end is substantially at the center of the closed end 18b of the bellows 18. It is connected to a reference position in the cylindrical connecting member 30 pressed against the portion by the elastic force of the spring 29.

On the peripheral wall of the casing 23, an air supply port 31 is formed near the bottom wall 17a of the casing 17, and an exhaust port 32 is formed near the other side. The air supply port 31 is configured to supply air having a pressure equal to or higher than the maximum pressure value of the transfer liquid, and the exhaust port 32 is open to the atmosphere. Ports 33 and 34 are formed on the peripheral wall of the cylinder portion 25 corresponding to the air supply port 31 and the exhaust port 32. A supply / exhaust passage 35 is formed in the peripheral wall of the casing 23, and the supply / exhaust passage 35 allows the apparatus-side air chamber 20 b and the cylinder 2
5 inside. The supply / exhaust passage 35 is provided with a passage 36 through which the region surrounded by the device-side air chamber 20b, the flange 28, the cylinder 25, and the casing 23 is communicated. By simultaneously applying the air pressure in the device-side air chamber 20b to the space surrounded by the sliding flange portion 37c (described later) and the cylinder portion 25 through the passage 36, the device-side air acting on the valve body 26 The influence of air pressure fluctuation in the chamber 20b can be canceled, and the bellows 18
It is possible to accurately transmit the displacement of the shaft 27 that operates when the amount of expansion / contraction deformation exceeds a predetermined range to the valve body 26.

As shown in FIG. 2, the valve body 26 is provided with three sliding flanges 37a at predetermined intervals in the axial direction thereof.
37b and 37c are formed, and the center sliding flange 3 is formed.
7b and the sliding flange 37a on one end side provide an air supply space S.
The space between the center sliding flange 37b and the other sliding flange 37c is defined as an exhaust space S2. When the increase in the capacity of the liquid chamber 20a exceeds a predetermined range due to the fluctuation of the pump discharge pressure, the valve body 26
5 so that the supply / exhaust passage 35 communicates with the space S1 by sliding displacement, and when the capacity reduction of the liquid chamber 20a exceeds a predetermined range, the supply / exhaust passage 35 communicates with the space S2. ing. A spring 3 for pressing and urging the valve body 26 at a reference position is provided in the casing 23.
8 are installed.

As shown in FIG. 1, a separated air chamber 39 composed of a pressure vessel or the like is formed separately and independently from the above-described apparatus side air chamber 20b, and is connected to a part of the peripheral wall of the casing 17, for example. By providing a port 41 and connecting and connecting the connection port 41 and the separation air chamber 39 with a tube 40, the separation air chamber 39 communicates with the inside of the apparatus-side air chamber 20b so as to have the same pressure.

Next, the operation of the pump with a pulsation device having the above configuration will be described. The pressurized air supplied from a pressurized air supply device (not shown) such as a compressor is supplied to the cylinder body 12 of the air cylinder section 14 of the reciprocating pump section 4.
Of the piston body 11 through the air holes 13b.
When the bellows 7 is extended in the x-direction in FIG. 1 by displacing the connecting member 10 in the x-direction in FIG. 1, the transfer liquid in the inflow passage 2 passes through the suction check valve 16a into the pump action chamber 9a. After the compressed air is supplied into the pump working chamber 9b of the air cylinder portion 14 through the air hole 13b, the bellows 7 is contracted in the y direction in FIG. Then, the pump action chamber 9
The bellows 7 of the reciprocating pump unit 4 is driven to expand and contract through the air cylinder unit 14 such that the transfer liquid sucked into the a is discharged through the discharge check valve 16b. The check valve 16a and the discharge check valve 16b are alternately opened and closed, and the suction of the liquid from the inflow passage 2 to the pump working chamber 9a and the discharge of the liquid from the inside of the pump working chamber 9a to the outflow passage 3 are repeated. Then, a predetermined pump action is performed. When the transfer liquid is fed toward a predetermined portion by the operation of the reciprocating pump unit 4, the pump discharge pressure generates pulsation due to repetition of peaks and valleys.

The transfer liquid discharged from the pump action chamber 9a of the pump section 4 through the discharge check valve 16b is sent to the liquid chamber 20a of the pulsation reducing section 5 through the communication passage 21. The liquid is temporarily stored in the liquid chamber 20a and then flows out to the outflow path 3. At this time, if the discharge pressure of the transfer liquid is at the peak of the discharge pressure curve, the transfer liquid expands and deforms the bellows 18 so as to increase the capacity of the liquid chamber 20a, so that the pressure is absorbed. At this time,
The flow rate of the transfer liquid flowing out of the liquid chamber 20a is smaller than the flow rate sent from the reciprocating pump unit 4.

When the discharge pressure of the transfer liquid reaches the valley of the discharge pressure curve, the inside of the apparatus-side air chamber 20b and the separated air chamber 3 which are compressed as the bellows 18 expands and deforms.
Since the pressure of the transfer liquid is lower than the sealing pressure in 9, the bellows 18 contracts and deforms. At this time, the reciprocating pump unit 4
The flow rate of the transfer liquid flowing out of the liquid chamber 20a is larger than the flow rate of the transfer liquid flowing into the liquid chamber 20a. The pulsation is absorbed and reduced by the repetitive operation, that is, the change in the capacity of the liquid chamber 20a.

By the way, during the above operation,
When the discharge pressure from the reciprocating pump unit 4 rises and fluctuates, the volume of the liquid chamber 20a increases due to the liquid to be transferred, and the bellows 1
8 is greatly extended and deformed. This bellows 18
When the amount of extension deformation exceeds a predetermined range A, the valve element 26 slides and displaces outward a via the shaft 27, and the supply / exhaust passage 35 communicates with the supply port 31 via the space S1. You. Therefore, a high air pressure is supplied from the air supply port 31 to the apparatus-side air chamber 20b and the separation air chamber 39 through the space S1 and the air-supply / discharge passage 35, and the inside of the apparatus-side air chamber 20b and the inside of the separation air chamber 39 The sealing pressure is increased, whereby the amount of elongation deformation of the bellows 18 is regulated, and the liquid chamber 20
Excessive increase in the capacity of a is avoided.

On the other hand, when the discharge pressure from the reciprocating pump unit 4 fluctuates, the capacity of the liquid chamber 20a is reduced by the transferred liquid, and the bellows 18 is largely contracted and deformed. When the amount of contraction deformation of the bellows 18 exceeds a predetermined range B, the valve element 26 slides inward b through the shaft 27, and the supply / exhaust passage 35 is connected to the exhaust port 32 through the space S2. Communicated. For this reason, the sealed air in the apparatus side air chamber 20b and the separation air chamber 39 is discharged into the atmosphere from the exhaust port 32 through the air supply / discharge passage 35 and the space S2, and the inside of the apparatus side air chamber 20b and the separation air chamber The sealing pressure in 39 is reduced, whereby the amount of shrinkage and deformation of the bellows 18 is restricted, and the capacity of the liquid chamber 20a is prevented from being excessively reduced. As a result, the pulsation is efficiently absorbed and the pulsation width is suppressed to be small irrespective of the fluctuation of the discharge pressure from the pump action chamber 9a of the reciprocating pump section 4.

As described above, the separate air chamber 39 is provided separately from the apparatus-side air chamber 20b formed integrally with the pulsation reducing section 5, and the two are communicated with each other. A chamber can be obtained and the effect of reducing pulsation can be enhanced, and the entire pump can be reduced in size by the volume of the separation air chamber 39, so that the occupied area of the pump can be reduced. And the separation air chamber 39 can be installed in an empty place different from the installation place of the present pump, and the dead space can be effectively utilized. For example, the main pump for a semiconductor manufacturing apparatus can be installed at a desired position in a clean room, and the separation air chamber 39 can be installed in a dead space in the clean room or outside the clean room, so that the expensive clean room can be economically used effectively. It is possible to do.

In addition, since the shaft 27 of the supply / exhaust switching valve mechanism 22 does not need to be long and needs to be short with the downsizing of the whole pump, the pulsation reduction operation by the pressure balance between the liquid pressure and the gas pressure is required. The inclination of the shaft 27 and the deformation of the spring 29 can be prevented. Therefore, the shaft 27 can always act vertically on the bellows 18, and the movement of the valve element 26 of the air supply / exhaust switching valve mechanism 22 in conjunction with the displacement of the bellows 18 can always be performed stably and smoothly.

The number of the separated air chambers 39 is not limited to one, but may be two.
More than one can be provided. The connection location of the separation air chamber 39 may be any location as long as it is in communication with the device-side air chamber 20b. For example, as shown by a virtual line in FIG. You can also. The air separation chamber 39 is not limited to a pressure vessel, and may be formed of a flexible long pipe or a thick pipe, which may be wound around the casing 23 in order to use the dead space on the outer periphery of the casing 23 .

[0028]

As described above, according to the present invention,
While the internal volume of the pulsation reducing air chamber can be increased so as to enhance the pulsation reducing effect, the whole pump can be reduced in size and the installation area can be reduced. In addition, there is an effect that the operation of the supply / exhaust switching valve mechanism of the pulsation reducing unit can always be performed smoothly and stably.

[Brief description of the drawings]

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

FIG. 2 is an enlarged vertical sectional front view of a supply / exhaust switching valve mechanism of the pump.

[Description of Signs] 1 Partition wall 2 Inflow path 3 Outflow path 4 Reciprocating pump section 5 Pulsation reduction section 6,17 Casing 7 First bellows 9a Pump action chamber 14 Air cylinder section 16a, 16b Check valve 18 Second bellows 18 Second bellows 20a Liquid chamber 20b Device side air chamber 22 Supply / exhaust switching valve mechanism 26 Valve element 27 Shaft 31 Air supply port 32 Exhaust port 35 Supply / exhaust passage 39 Separated air chamber 40 tube

Continuation of the front page (72) Inventor Ryo Imanishi 541-1, Shimouchi Shinto bat, Mita City, Hyogo Prefecture Inside the Mita Plant of Nippon Pillar Industry Co., Ltd. (56) References JP-A-10-196521 (JP, A) 2-186101 (JP, A) Japanese Utility Model 60-137156 (JP, U) Japanese Utility Model Utility Model 57-8902 (JP, U)

Claims (3)

(57) [Claims] A partition provided with an inflow passage and an outflow passage for a liquid; a first bellows capable of expanding and contracting in an axial direction within a casing disposed on one side of the partition; 1 base
An air cylinder portion for driving the expansion and contraction of the rose is provided, and a check valve is provided inside the first bellows for alternately opening and closing in accordance with the expansion and contraction of the first bellows to perform a liquid suction operation and a discharge operation. and an air-driven reciprocal pump portion comprising a pumping chamber, of the the partition wall of the other side to the arranged the casing being disposed opposite to said first bellows first bellows a second bellows that can stretch deformation in expansion and contraction deformation direction, the second base
A liquid chamber formed inside the rose and capable of temporarily storing liquid discharged from the pump action chamber via the discharge check valve, and formed separately from the liquid chamber outside the second bellows ; And a device-side air chamber in which air for reducing pulsation is sealed, and pulsation due to discharge pressure of the liquid discharged from the pump action chamber due to a change in the capacity of the liquid chamber due to the expansion and contraction movement of the second bellows. And a pulsation reducing unit configured to absorb the pulsation reducing device, comprising: a pump having one or two or more separated air chambers separately from the device-side air chamber. It provided in the communication form
The internal pressure of the device-side air chamber and the separation air chamber is equalized.
A pump with a pulsation reducing device, characterized in that the pump is connected to a pipe in such a manner as to be connected . 2. The apparatus according to claim 1, wherein said second chamber is inserted into said apparatus-side air chamber.
In conjunction with the displacement of the closed end side of the two bellows,
When the capacity of the reciprocating shaft and the liquid chamber increases beyond a predetermined range,
For air supply / exhaust through the shaft to the device side air chamber
Make the passage communicate with the air supply port, and
If it decreases beyond the specified range,
Supply / discharge with a valve that connects the supply / exhaust passage to the exhaust port
The pump with a pulsation reducing device according to claim 1 , further comprising an air switching valve mechanism . 3. The one or more separated air chambers.
Is set to a range up to 20 times the volume of the liquid chamber.
The pump with a pulsation reducing device according to claim 1 or 2 , wherein