JP4088301B2 - Differential pressure actuated valve device for pump - Google Patents

Description

  The present invention relates to a differential pressure actuated valve device for a pump that can be applied to various pump devices such as a reciprocating pump.

Conventionally, various ink supply pump devices for supplying commercial printing ink, newspaper ink, and the like are known (for example, see Patent Document 1).
"Printing ink supply system" (YAMADA CATALOG), publisher: Yamada Corporation, published August 1999, revised October 2001

  The ink supply pump device is used to supply ink stored in a container such as a drum to a supply system. When the remaining amount of ink stored in the container is reduced, the load on the pump device is reduced. As a result, the reciprocating speed (stroke speed) of the piston of the pump is increased and so-called idling occurs. When the idle driving occurs, various parts are adversely affected. Therefore, the conventional ink supply pump device is provided with an operation stop unit that stops the operation of the pump when the idle driving occurs. . This operation stop part is comprised by the machine part provided with components, such as a spring, and the control part using the sequence control etc. which electrically control this machine part. The operation stop portion having such a configuration has a problem that the durability of the mechanical portion is deteriorated due to mechanical fatigue, and power other than air such as electricity (compressed air) is required.

  The present invention has been made in view of the above-mentioned problems of the prior art, and is a pump drive source without using a deterioration in durability compared to the prior art by utilizing the differential pressure of air. An object of the present invention is to provide a differential pressure actuated valve device for a pump capable of preventing the above-mentioned idling without using other power such as electricity by using air.

The present invention is a differential pressure actuated valve device for a pump provided in a pump device having a piston attached to a reciprocating piston rod,
A cap assembly provided on one end side of the piston rod of the pump device;
An air valve assembly connected to the cap assembly and connected to the pump device,
The cap assembly part is
An accommodating cylinder for accommodating one end of the piston rod of the pump device;
A suction port with a check valve and a discharge port with a check valve provided in the accommodating cylindrical portion;
As the piston rod moves outward from the accommodating cylinder, air at atmospheric pressure is sucked into the accommodating cylinder from the suction port with a check valve, while the piston rod moves toward the accommodating cylinder. By doing so, the intake air sucked into the accommodating cylindrical portion is discharged from the discharge port with the check valve,
The air valve assembly is
A space connected to the discharge port with the check valve and into which the intake air discharged from the discharge port with the check valve flows;
A space outlet provided in the space for discharging the intake air flowing into the space to the outside air;
A supply flow path connected to a compressed air source and the pump device, and supplying the compressed air flowing from the compressed air source to the pump device as compressed air for operating the pump device;
An intermediate space portion for a supply channel that is provided between the upstream side and the downstream side of the supply channel and into which the compressed air flows from the upstream side of the supply channel;
A first branch channel branched from the supply channel and into which the compressed air flows from the supply channel;
An intermediate space portion for a first branch flow path connected to the first branch flow path and into which the compressed air that has flowed into the first branch flow path flows;
A branch channel outlet connected to the first branch channel intermediate space and for discharging the compressed air flowing into the first branch channel intermediate space to the outside air;
A second branch channel connected to the first branch channel intermediate space and into which the compressed air that has flowed into the first branch channel intermediate space is introduced;
An intermediate space for a second branch flow path connected to the second branch flow path and into which the compressed air that has flowed into the second branch flow path flows;
The suction rod in which the piston rod of the pump device operates at a speed higher than a normal stroke speed, is discharged from the discharge port with the check valve of the accommodating cylindrical portion of the cap assembly portion, and flows into the space portion. In the case of abnormal operation in which the pressure of the air is greater than the pressure of the compressed air from the compressed air source, the compressed air that has flowed into the intermediate space for the supply flow path is caused to flow by the differential pressure. Provided is a differential pressure actuated valve device for a pump which is prevented from being supplied to the pump device as compressed air for operating the device.

Further, the present invention is a pump differential pressure actuated valve device provided in a pump device having a piston attached to a reciprocating piston rod,
A cap assembly provided on one end side of the piston rod of the pump device;
An air valve assembly connected to the cap assembly and connected to the pump device,
The cap assembly part is
An accommodating cylinder for accommodating one end of the piston rod of the pump device;
A suction port with a check valve and a discharge port with a check valve provided in the accommodating cylindrical portion;
As the piston rod moves outward from the accommodating cylinder, air at atmospheric pressure is sucked into the accommodating cylinder from the suction port with a check valve, while the piston rod moves toward the accommodating cylinder. By doing so, the intake air sucked into the accommodating cylindrical portion is discharged from the discharge port with the check valve,
The air valve assembly is
A space connected to the discharge port with the check valve and into which the intake air discharged from the discharge port with the check valve flows;
A space outlet provided in the space for discharging the intake air flowing into the space to the outside air;
A supply flow path connected to a compressed air source and the pump device, and supplying the compressed air flowing from the compressed air source to the pump device as compressed air for operating the pump device;
An intermediate space portion for a supply channel that is provided between the upstream side and the downstream side of the supply channel and into which the compressed air flows from the upstream side of the supply channel;
A first branch channel branched from the supply channel and into which the compressed air flows from the supply channel;
An intermediate space portion for a first branch flow path connected to the first branch flow path and into which the compressed air that has flowed into the first branch flow path flows;
A branch channel outlet connected to the first branch channel intermediate space and for discharging the compressed air flowing into the first branch channel intermediate space to the outside air;
A second branch channel connected to the first branch channel intermediate space and into which the compressed air that has flowed into the first branch channel intermediate space is introduced;
An intermediate space portion for a second branch flow path connected to the second branch flow path and into which the compressed air that has flowed into the second branch flow path flows;
A first movable shaft extending into the space of both the space and the intermediate space for the first branch channel, and extending into the outlet for the branch channel;
A second movable shaft extending into the space of both the supply channel intermediate space and the second branch channel intermediate space;
The first movable shaft is
A hermetically sealed cap portion that prevents the intake air that has flowed into the space portion from being discharged to outside air from other than the space portion discharge port;
A first restriction seal valve that restricts the compressed air that has flowed into the intermediate space for the first branch flow path from flowing into the second branch flow path;
A second restriction seal valve for restricting the compressed air that has flowed into the first branch flow path intermediate space from flowing into the branch flow path outlet;
The second movable shaft is
A third restriction seal valve for restricting the compressed air that has flowed into the supply flow path intermediate space from flowing downstream of the supply flow path;
A regulation piston provided on the second movable shaft located in the intermediate space for the first branch flow path and having a diameter larger than the diameter of the third regulation seal valve;
In the case of normal operation in which the piston rod of the pump device operates at a normal stroke speed, the pump rod is discharged from the discharge port with the check valve of the accommodating cylindrical portion of the cap assembly portion and flows into the space portion. The pressure of the intake air is set to be smaller than the pressure of the compressed air from the compressed air source, the first restriction seal valve is closed, the second restriction seal valve is opened, and the third restriction is set. The seal valve is in an open state, thereby preventing the compressed air that has flowed into the intermediate space for the first branch flow path from flowing into the second branch flow path, and the supply flow The compressed air that has flowed into the intermediate space portion for the road flows into the downstream side of the supply flow path and is supplied to the pump device as compressed air for operating the pump device,
On the other hand, the piston rod of the pump device operates at a speed higher than the normal stroke speed, and is discharged from the discharge port with the check valve of the accommodating cylindrical portion of the cap assembly portion and flows into the space portion. In the case of an abnormal operation in which the pressure of the intake air is greater than the pressure of the compressed air from the compressed air source, the first capable portion is moved by the differential pressure causing the sealing cap portion to move outward. The shaft is moved, and with this movement, the first restriction seal valve is opened and the second restriction seal valve is closed, and flows into the intermediate space portion for the first branch flow path. Compressed air flows into the second branch flow path intermediate space through the second branch flow path, and the compressed piston flows into the second branch flow path intermediate space to move the regulating piston forward. The second movable shaft is moved, the third restriction seal valve is closed, and the compressed air that has flowed into the intermediate space for the supply flow path is supplied to the pump device as compressed air for operating the pump device. Provided is a differential pressure actuated valve device for a pump which is prevented from being supplied.

  Further, a throttle valve can be provided at the space outlet. Moreover, when the said sealing cap part moves outside, it is possible to move the said sealing cap part to an original position by manual operation. Furthermore, the differential pressure actuated valve device for a pump can be applied to a reciprocating pump device.

  According to the present invention, by utilizing the differential pressure of air, durability is not deteriorated as compared with the prior art, and by driving only with air (compressed air), no other power source such as electricity is required. In addition, it is possible to prevent idling.

  The best mode for carrying out a differential pressure actuated valve device for a pump according to the present invention will be described below with reference to the drawings. FIG. 1 is a top view of a differential pressure actuated valve device 1 for a pump according to the present invention that can be applied to a reciprocating pump device or the like, and FIGS. 2-A, 2-B, and 2-C show 3 of the device. One side view is shown. The pump differential pressure actuated valve device 1 is provided in an ink supply pump device 60 having a piston 71 attached to a reciprocating piston rod 70, and is provided on one end side of the piston rod 70 of the pump device 60. It is mainly comprised from the cap assembly part 2 and the air valve assembly part 3 connected with the cap assembly part 2 and connected with the pump apparatus 60.

  6A shows a front view of the ink supply pump device 60, and FIG. 6B shows a cross-sectional view. As shown in FIG. 6, the ink supply pump device 60 has a piston 71 attached to a piston rod 70 that reciprocates in the center, and compressed air (for operating the pump device 60) on both sides of the piston 71. An upper supply chamber 72 and a lower supply chamber 73 to which compressed air) is supplied are provided. When the compressed air is supplied to the upper supply chamber 72, the piston rod 70 and the piston 71 move downward (rightward in FIG. 6), while the compressed air is supplied to the lower supply chamber 73, so that the piston The rod 70 and the piston 71 can move upward (to the left in FIG. 6). That is, by switching the supply destination of the compressed air to the upper supply chamber 72 or the lower supply chamber 73, the piston rod 70 and the piston 71 can reciprocate, and the pump device 60 operates. The pump device 60 has a configuration of a normal reciprocating pump, and a detailed description thereof will be omitted.

  As shown in FIGS. 3 and 6B, the cap assembly 2 is provided on one end side (left side in FIG. 6B) of the piston rod 70 of the pump device 60. As shown well in FIG. 3, the cap assembly 2 includes an accommodating cylindrical portion 20 that accommodates one end portion of the piston rod 70 of the pump device 60, an inlet 21 with a check valve provided in the accommodating cylindrical portion 20, and the reverse. A discharge port 22 with a stop valve is provided. When the piston rod 70 moves outward (rightward in FIG. 3) of the accommodating cylindrical portion 20, air at atmospheric pressure is sucked into the accommodating cylindrical portion 20 from the suction port 21 with a check valve. As 70 moves inward of the accommodating cylinder (leftward in FIG. 3), the intake air sucked into the accommodating cylinder 20 is discharged from the discharge port 22 with a check valve. That is, when the pump device 60 is operated and the piston rod 70 and the piston 71 reciprocate, the above suction and discharge are performed. Further, the intake air discharged from the discharge port 22 with the check valve flows into the space 30 described later through the connecting portion 24 (see FIGS. 1, 2-A, 2-B and 2-C). Is done.

  The air valve assembly 3 is connected to the cap assembly 2 and is connected to the pump device 60. More specific description will be given below. As shown in FIG. 4-A, FIG. 4-B, FIG. 4-C and FIG. 4-D, the air valve assembly 3 is connected to the discharge port 22 with a check valve in the connecting portion 24 (FIG. 1, FIG. 2-A, 2B, FIG. 2-C, and FIG. 4-D), and has a space portion 30 into which the intake air discharged from the check valve discharge port 22 flows. As shown in FIG. 4-D, a pressure gauge 31 is provided on the space portion 30 side of the connecting portion 24. The space part 30 is provided with a space part discharge port 32 for discharging the intake air flowing into the space part 30 to the outside air at a position facing the pressure gauge 31. A throttle valve 33 is provided in the space portion discharge port 32, and the amount of intake air discharged from the space portion discharge port 32 can be adjusted by the throttle valve 33.

  Reference numeral 34 denotes a supply channel. The supply flow path 34 is connected to the compressed air source 35 and the upper supply chamber 72 and the lower supply chamber 73 (see FIG. 6) of the pump device 60, and pumps compressed air flowing from the compressed air source 35. 60 is supplied to the pump device 60 as compressed air for operation to the upper supply chamber 72 and the lower supply chamber 73.

  A supply flow path intermediate space 36 is provided between the upstream side and the downstream side of the supply flow path 34. Compressed air flows into the supply channel intermediate space 36 from the upstream side of the supply channel 35. Moreover, the code | symbol 37 has shown the 1st branch flow path. The first branch channel 37 is branched from the supply channel 34, and compressed air flows from the supply channel 34. The first branch channel 37 is connected to a first branch channel intermediate space 38 into which compressed air that has flowed into the first branch channel 37 flows.

  A branch passage discharge port 39 for discharging the compressed air flowing into the first branch passage intermediate space 38 to the outside air is connected to the first branch passage intermediate space 38. Similarly, a second branch channel 40 into which the compressed air that has flowed into the first branch channel intermediate space 38 is introduced is connected to the first branch channel intermediate space 38. The second branch channel 40 is connected to a second branch channel intermediate space 41 into which the compressed air that has flowed into the second branch channel 40 flows.

  Reference numeral 42 denotes a first movable shaft. The first movable shaft 42 extends into both the space 30 and the first branch flow path intermediate space 38 and also into the branch flow path discharge port 39, and extends in the left-right direction (FIG. 4). It can move in the horizontal direction in C). The first movable shaft 42 includes a sealing cap portion 43 that prevents the intake air that has flowed into the space portion 30 from being discharged outside the space portion discharge port 39 to the outside air, and a first branch flow passage intermediate space portion. The first restriction seal valve 44 that restricts the compressed air that has flowed into the second branch flow path 40 from flowing into the second branch flow path 40 and the compressed air that has flowed into the first branch flow intermediate space 38 branch off. And a second restriction seal valve 45 that restricts the flow into the flow path discharge port 39. Further, as will be described later, the sealing cap portion 43 can be manually moved to the original position when the sealing cap portion 43 moves outward.

  Reference numeral 46 denotes a second movable shaft. The second movable shaft 46 extends in both the supply channel intermediate space 36 and the second branch channel intermediate space 41 and moves in the vertical direction (vertical direction in FIG. 4-A). Is possible. The second movable shaft 46 includes a third restriction seal valve 47 that restricts the compressed air that has flowed into the supply flow path intermediate space 36 from flowing into the downstream side of the supply flow path 34, and a supply flow path. And a restriction piston 48 provided on the second movable shaft 46 located in the intermediate space 36 and having a diameter larger than the diameter of the third restriction seal valve 47.

  Next, the operation of the above embodiment will be described. In the case of normal operation in which the piston rod 70 of the pump device 60 operates at a normal stroke speed, the piston rod 70 is discharged from the discharge port 22 with a check valve of the accommodating cylindrical portion 20 of the cap assembly portion 2 and flows into the space portion 30. The pressure of the intake air is set to be smaller than the pressure of the compressed air from the compressed air source 35, and the first restriction seal valve 44 is closed, the second restriction seal valve 45 is open, and the third restriction seal. The valve 47 is in an open state, thereby preventing the compressed air that has flowed into the first branch flow path intermediate space 38 from flowing into the second branch flow path 40 and the supply flow path. The compressed air that has flowed into the intermediate space portion 36 flows into the downstream side of the supply flow path 34 and serves as compressed air for operation of the pump device 60. The upper supply chamber 72 and the lower supply chamber 73 of the pump device 60 (FIG. 6). reference) It is supplied.

  On the other hand, as shown in FIG. 5-A, FIG. 5-B, FIG. 5-C, and FIG. 5-D, a problem such as idling occurs, and the piston rod 70 of the pump device 60 becomes faster than the normal stroke speed. The pressure of the intake air that operates at a high speed and is discharged from the discharge port 22 with the check valve of the accommodating cylindrical portion 20 of the cap assembly portion 2 and flows into the space portion 30 is reduced by the compressed air from the compressed air source 35. In the case of an abnormal operation that becomes greater than the pressure, due to this differential pressure, the first movable shaft 42 is moved outward (rightward in FIG. 5C) by moving the sealing cap portion 43 outward, Along with this movement, the first restriction seal valve 44 is opened and the second restriction seal valve 45 is closed, and the compressed air that has flowed into the first branch flow passage intermediate space 38 is second. Intermediate for second branch channel via branch channel 40 The restriction piston 48 moves the second movable shaft 46 upward by the compressed air flowing into the intermediate portion 41 and into the second branch flow passage intermediate space 41, and the third restriction seal valve 47 is closed. The compressed air that has flowed into the intermediate space portion 36 for the supply flow path is supplied to the upper supply chamber 72 and the lower supply chamber 73 (see FIG. 6) of the pump device 60 as compressed air for operating the pump device 60. Therefore, the operation of the pump device 60 is stopped. For example, after replacing the ink container (drum) attached to the pump device 60, the normal operation can be started by manually moving the sealing cap portion 43 moved outward to the original position. it can.

  This invention is applicable not only to pumps that supply ink, but also to reciprocating pumps in general, such as pumps that supply high-viscosity materials such as low-viscosity oils such as spindle oil and adhesives from high-viscosity oils such as grease. can do.

FIG. 1 is a top view showing an embodiment of a differential pressure actuated valve device for a pump according to the present invention. FIG. 2 is a side view showing a differential pressure actuated valve device for a pump. FIG. 2 is a side view showing a differential pressure actuated valve device for a pump. FIG. 2 is a side view showing a differential pressure actuated valve device for a pump. FIG. 3 is a partial cross-sectional view showing a cap assembly portion of a differential pressure actuated valve device for a pump. FIG. 4-A is a cross-sectional view showing the air valve assembly in the normal operation. FIG. 4-B is a side view showing the air valve assembly in the normal operation. FIG. 4-C is another cross-sectional view showing the air valve assembly in the normal operation. FIG. 4-D is still another cross-sectional view showing the air valve assembly in the normal operation. FIG. 5-A is a cross-sectional view showing the air valve assembly in the case of abnormal operation. FIG. 5-B is a side view showing the air valve assembly in the case of abnormal operation. FIG. 5C is another cross-sectional view showing the air valve assembly in the case of abnormal operation. FIG. 5-D is still another cross-sectional view showing the air valve assembly in the case of abnormal operation. FIG. 6 is a schematic view showing an ink supply pump device to which a differential pressure actuated valve device for a pump can be applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Differential pressure actuated valve apparatus for pumps 2 Cap assembly part 3 Air valve assembly part 20 Accommodating cylindrical part 21 Inlet port with check valve 22 Exhaust port with check valve 24 Connection part 30 Space part 31 Pressure gauge 32 Outlet for space part 33 Throttle valve 34 Supply channel 35 Compressed air source 36 Supply channel intermediate space 37 First branch channel 38 First branch channel intermediate space 39 Branch channel outlet 40 Second branch channel 41 First Intermediate space portion for two branch flow paths 42 First movable shaft 43 Sealing cap portion 44 First restriction seal valve 45 Second restriction seal valve 46 Second movable shaft 47 Third restriction seal valve 48 Restriction piston 60 Ink supply pump device 70 Piston Rod 71 Piston 72 Upper supply chamber 73 Lower supply chamber

Claims (5)

A differential pressure actuated valve device for a pump provided in a pump device having a piston attached to a reciprocating piston rod,
A cap assembly provided on one end side of the piston rod of the pump device;
An air valve assembly connected to the cap assembly and connected to the pump device,
The cap assembly part is
An accommodating cylinder for accommodating one end of the piston rod of the pump device;
A suction port with a check valve and a discharge port with a check valve provided in the accommodating cylindrical portion;
As the piston rod moves outward from the accommodating cylinder, air at atmospheric pressure is sucked into the accommodating cylinder from the suction port with a check valve, while the piston rod moves toward the accommodating cylinder. By doing so, the intake air sucked into the accommodating cylindrical portion is discharged from the discharge port with the check valve,
The air valve assembly is
A space connected to the discharge port with the check valve and into which the intake air discharged from the discharge port with the check valve flows;
A space outlet provided in the space for discharging the intake air flowing into the space to the outside air;
A supply flow path connected to a compressed air source and the pump device, and supplying the compressed air flowing from the compressed air source to the pump device as compressed air for operating the pump device;
An intermediate space portion for a supply channel that is provided between the upstream side and the downstream side of the supply channel and into which the compressed air flows from the upstream side of the supply channel;
A first branch channel branched from the supply channel and into which the compressed air flows from the supply channel;
An intermediate space portion for a first branch flow path connected to the first branch flow path and into which the compressed air that has flowed into the first branch flow path flows;
A branch channel outlet connected to the first branch channel intermediate space and for discharging the compressed air flowing into the first branch channel intermediate space to the outside air;
A second branch channel connected to the first branch channel intermediate space and into which the compressed air that has flowed into the first branch channel intermediate space is introduced;
An intermediate space for a second branch flow path connected to the second branch flow path and into which the compressed air that has flowed into the second branch flow path flows;
The suction rod in which the piston rod of the pump device operates at a speed higher than a normal stroke speed, is discharged from the discharge port with the check valve of the accommodating cylindrical portion of the cap assembly portion, and flows into the space portion. In the case of abnormal operation in which the pressure of the air is greater than the pressure of the compressed air from the compressed air source, the compressed air that has flowed into the intermediate space for the supply flow path is caused to flow by the differential pressure. A differential pressure actuated valve device for a pump, wherein the pump device is prevented from being supplied as compressed air for operating the device. A differential pressure actuated valve device for a pump provided in a pump device having a piston attached to a reciprocating piston rod,
A cap assembly provided on one end side of the piston rod of the pump device;
An air valve assembly connected to the cap assembly and connected to the pump device,
The cap assembly part is
An accommodating cylinder for accommodating one end of the piston rod of the pump device;
A suction port with a check valve and a discharge port with a check valve provided in the accommodating cylindrical portion;
As the piston rod moves outward from the accommodating cylinder, air at atmospheric pressure is sucked into the accommodating cylinder from the suction port with a check valve, while the piston rod moves toward the accommodating cylinder. By doing so, the intake air sucked into the accommodating cylindrical portion is discharged from the discharge port with the check valve,
The air valve assembly is
A space connected to the discharge port with the check valve and into which the intake air discharged from the discharge port with the check valve flows;
A space outlet provided in the space for discharging the intake air flowing into the space to the outside air;
A supply flow path connected to a compressed air source and the pump device, and supplying the compressed air flowing from the compressed air source to the pump device as compressed air for operating the pump device;
An intermediate space portion for a supply channel that is provided between the upstream side and the downstream side of the supply channel and into which the compressed air flows from the upstream side of the supply channel;
A first branch channel branched from the supply channel and into which the compressed air flows from the supply channel;
An intermediate space portion for a first branch flow path connected to the first branch flow path and into which the compressed air that has flowed into the first branch flow path flows;
A branch channel outlet connected to the first branch channel intermediate space and for discharging the compressed air flowing into the first branch channel intermediate space to the outside air;
A second branch channel connected to the first branch channel intermediate space and into which the compressed air that has flowed into the first branch channel intermediate space is introduced;
An intermediate space portion for a second branch flow path connected to the second branch flow path and into which the compressed air that has flowed into the second branch flow path flows;
A first movable shaft extending into the space of both the space and the intermediate space for the first branch channel, and extending into the outlet for the branch channel;
A second movable shaft extending into the space of both the supply channel intermediate space and the second branch channel intermediate space;
The first movable shaft is
A hermetically sealed cap portion that prevents the intake air that has flowed into the space portion from being discharged to outside air from other than the space portion discharge port;
A first restriction seal valve that restricts the compressed air that has flowed into the intermediate space for the first branch flow path from flowing into the second branch flow path;
A second restriction seal valve for restricting the compressed air that has flowed into the first branch flow path intermediate space from flowing into the branch flow path outlet;
The second movable shaft is
A third restriction seal valve for restricting the compressed air that has flowed into the supply flow path intermediate space from flowing downstream of the supply flow path;
A regulation piston provided on the second movable shaft located in the intermediate space for the first branch flow path and having a diameter larger than the diameter of the third regulation seal valve;
In the case of normal operation in which the piston rod of the pump device operates at a normal stroke speed, the pump rod is discharged from the discharge port with the check valve of the accommodating cylindrical portion of the cap assembly portion and flows into the space portion. The pressure of the intake air is set to be smaller than the pressure of the compressed air from the compressed air source, the first restriction seal valve is closed, the second restriction seal valve is opened, and the third restriction is set. The seal valve is in an open state, thereby preventing the compressed air that has flowed into the intermediate space for the first branch flow path from flowing into the second branch flow path, and the supply flow The compressed air that has flowed into the intermediate space portion for the road flows into the downstream side of the supply flow path and is supplied to the pump device as compressed air for operating the pump device,
On the other hand, the piston rod of the pump device operates at a speed higher than the normal stroke speed, and is discharged from the discharge port with the check valve of the accommodating cylindrical portion of the cap assembly portion and flows into the space portion. In the case of an abnormal operation in which the pressure of the intake air is greater than the pressure of the compressed air from the compressed air source, the first capable portion is moved by the differential pressure causing the sealing cap portion to move outward. The shaft is moved, and with this movement, the first restriction seal valve is opened and the second restriction seal valve is closed, and flows into the intermediate space portion for the first branch flow path. Compressed air flows into the second branch flow path intermediate space through the second branch flow path, and the compressed piston flows into the second branch flow path intermediate space to move the regulating piston forward. The second movable shaft is moved, the third restriction seal valve is closed, and the compressed air that has flowed into the intermediate space for the supply flow path is supplied to the pump device as compressed air for operating the pump device. A differential pressure actuated valve device for a pump, characterized in that it is prevented from being supplied.   The differential pressure actuated valve device for a pump according to claim 1 or 2, wherein a throttle valve is provided at the space outlet.   3. The differential pressure-operated valve for a pump according to claim 2, wherein when the sealing cap part moves outward, the sealing cap part can be manually moved to the original position. apparatus.   The differential pressure-actuated valve device for pumps according to any one of claims 1 to 4, wherein the differential pressure-actuated valve device for pumps is applied to a reciprocating pump device.

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