JP2007178004A - Liquid pressure generator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid pressure generator capable of removing foreign matter adhering to a filter adequately without replacing the filter to maintain permeation capability. <P>SOLUTION: This liquid pressure generator has: a gear pump 2 for raising pressure of working fluid passing through the filter 5; and a high pressure pump 3 for raising pressure of the working fluid whose pressure is raised by the gear pump 2 to higher pressure, increases amount of discharge of the gear pump 2 more than amount of discharge of the high pressure pump 3, and connects a relief valve 8 between the gear pump 2 and the high pressure pump 3. A blow-out side of the relief valve 8 is communicated between the filter 5 and the gear pump. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a hydraulic pressure generating device used for a power circuit breaker and the like, and more particularly to a hydraulic pressure generating device capable of removing foreign matters from a filter.

  BACKGROUND ART A fluid pressure generating device using a fluid is used in various fields, and is one of important devices in equipment using fluid pressure. Therefore, if the hydraulic pressure generating device fails, the operation of the device becomes impossible, and there are many cases where another hydraulic pressure generating device can be attached from the outside.

  However, the usage method and maintenance method of the hydraulic pressure generator vary greatly depending on the field of use, and there are some that cannot be easily replaced at the time of failure or attached to the hydraulic pressure generator from the outside.

  For example, some electric power gas circuit breakers use a hydraulic operating device as a drive source. Generally, electric power equipment cannot be easily stopped due to its public utility, and basically, there is an opportunity to perform maintenance only at regular inspections every 6 years or 12 years. Therefore, it is desirable to extend the period of use by improving the performance of the hydraulic pressure generating device or to attach an external hydraulic pressure generating device without stopping the device at the time of failure.

  FIG. 5 is a diagram showing a configuration example of a hydraulic pressure generating device that can connect a conventional external hydraulic pressure generating device. As shown in FIG. 5, the hydraulic pressure generating device 1 includes a gear pump 2 and a high pressure pump 3. Thus, the liquid is pressurized in two stages, and the suction of the high-pressure pump 3 is assisted by increasing the discharge of the gear pump 2. That is, when the gear pump 2 is rotated, the working liquid is sucked from the low-pressure liquid tank 4 through the filter 5 and is discharged after being increased in pressure. The working fluid boosted by the gear pump 2 is further boosted to a high pressure by the high-pressure pump 3, discharged to the actuator 6 side, and accumulated by the accumulator 7.

  Here, since the discharge amount of the gear pump 2 is larger than the discharge amount of the high-pressure pump 3, the relief valve 8 is connected to the discharge side when the gear pump 2 rotates. The discharge side of the relief valve 8 communicates with the low pressure liquid tank 4. On the other hand, a return valve 10 is provided in the flow path 9 that communicates from the high pressure portion on the actuator 6 side to the low pressure liquid tank 4, and the low pressure portion on the actuator 6 side communicates with the low pressure liquid tank 4. Further, a first connecting member 11 of a hydraulic joint is provided between the high-pressure pump 3 and the actuator 6 so as to be connectable / fixable to the second connecting member 13 in the external hydraulic pressure generating device 12.

  The external hydraulic pressure generator 12 is used as an emergency when the hydraulic pressure generator 1 becomes unusable due to a failure or the like. When the high-pressure pump 14 is operated, the external hydraulic pressure generating device 12 sucks and raises the working liquid from the low-pressure liquid tank 4 via the filter 15 and then increases the pressure, and the second connecting member provided on the discharge side of the high-pressure pump 14. Discharge to the 13th side. The high-pressure pump 14 and the second connecting member 13 branch in two directions, one is provided with a relief valve 16 and the other is provided with a return valve 17, each communicating with the low-pressure liquid tank 4. ing.

  FIG. 6 is a view showing an example of the hydraulic joint, and a valve 21 is provided in the case 20 of the first connecting member 11 so as to be movable in the axial direction. The valve 21 is urged against the seat portion 23 by a spring 22 in the pressure contact direction, and the valve 21 is normally closed so that liquid does not flow out of the case 20 of the first connecting member 11. It is configured. On the other hand, the second connecting member 13 has a case 25 to which the case 20 of the first connecting member 11 can be connected, and the case 25 has a distal end portion of the case 20 of the first connecting member 11. A recess 26 for insertion and fixing is provided, and a packing 27 is provided on the inner periphery of the recess 26.

  Thus, by inserting and fixing the tip of the case 20 in the first connecting member 11 into the case 25 of the second connecting member 13, both connecting members are liquid-tight as shown in FIG. Connected to the state. At this time, since the valve 21 is kept closed, the hydraulic joint can be connected regardless of whether the pressure on the actuator 6 side is high or low. Therefore, when the high pressure pump 14 of the external hydraulic pressure generator 12 is operated, the pressure between the high pressure pump 14 and the valve 21 becomes high, and the valve 21 is opened to discharge the working liquid to the actuator 6 side. When the return valve 17 of the external hydraulic pressure generator 12 is opened, the valve 21 is closed, and the pressure between the high-pressure pump 14 and the valve 21 decreases while the pressure on the actuator 6 side is maintained. Therefore, in this state, the first connection member 11 and the second connection member 13 can be detached.

  FIG. 7 is a view showing another fluid coupling, and a valve 21a is provided in the case 20a of the first connecting member 11a so as to be movable in the axial direction. The valve 21a is urged by the spring 22a in the pressure contact direction with respect to the seat portion 23a, and the valve 21a is normally closed so that no liquid flows out from the case 20a of the first connecting member 11a. It is configured.

  On the other hand, the second connecting member 13a has a case 25a to which the case 20a of the first connecting member 11a can be connected, and the case 25a has a tip portion of the case 20a of the first connecting member 11a. A recess 26a for insertion and fixing is provided, and a packing 27a is provided on the inner periphery of the recess 26a. Further, a valve 30a urged in the press-contact direction with respect to the seat portion 29a by the spring 28a is also provided in the case 25a so as to be movable in the axial direction.

  Thus, when the first connecting member 11a and the second connecting member 13a are connected, when the distal end portion of the first connecting member 11a is inserted into the recess 26a of the second connecting member 13a, ( As shown in b), the valve stems of the valves 21a and 30a abut against each other. Therefore, when the distal end portion of the first connecting member 11a is further inserted into the recessed portion of the second connecting member 13a to fix the connection, the valves 21a and 30a resist the springs 22a and 28a, respectively, as shown in FIG. Then, they come into contact with the stoppers 24a and 31a provided on the cases 20a and 25a, respectively, and both are opened, and the external hydraulic pressure generator 12 is connected to the hydraulic pressure generator 1.

  Therefore, when the gear pump 2 rotates, the pressure between the gear pump 2 and the high-pressure pump 3 rises due to the difference in discharge amount between the gear pump 2 and the high-pressure pump 3, and when the pressure reaches a certain pressure, the relief valve 8 operates and the low-pressure liquid tank Blow out working fluid to 4 In addition, when the hydraulic pressure generating device fails, the external hydraulic pressure generating device is connected to the hydraulic pressure generating device 1 and is pressurized by the external hydraulic pressure generating device by connecting the first and second connecting members. Liquid can be used.

However, in the conventional hydraulic pressure generating apparatus as described above, there is a problem that the filter 5 needs to be replaced with a new one because the permeation ability is reduced if a certain amount of foreign matter adheres.
Further, when the hydraulic joint shown in FIG. 6 is used and the hydraulic joint is connected and fixed, when the high-pressure pump 14 of the external hydraulic pressure generator 12 is operated, the high-pressure pump 14 and the valve 21 are operated. The pressure becomes high, and the valve 21 is opened to discharge the working liquid to the actuator 6 side.
Further, when the return valve 17 is opened, the valve 21 comes into contact with the seat portion 23, so that the pressure between the first connecting member 11 and the high-pressure pump 14 decreases while maintaining the pressure on the actuator 6 side.
Therefore, it is possible to detach the second connecting member 13 from the first connecting member 11 with the return valve 17 opened. In this case, the working liquid flows out from the second connecting member 13. There are problems such as.

Further, when the external hydraulic pressure generator 12 is connected to the hydraulic pressure generator 1 using the hydraulic joint shown in FIG. 7, when the high pressure pump 14 of the external hydraulic pressure generator 12 is operated, the valve 21a And the valve 29a are both open, the working liquid is discharged to the actuator 6 side.
When the return valve 17 of the external hydraulic pressure generator 12 is opened, the pressure on the actuator 6 side also drops because the valves 21a and 29a are open.
Therefore, it is possible to detach the second connection member 13a from the first connection member 11a with the return valve 17 opened.
That is, when the second connection member 13a is to be detached from the first connection member 11a, the valves 21a and 29a are closed as shown in FIG.
However, when the actuator 6 side has a high pressure, the valve 21a of the first connecting member 11a is closed with an excessive force and cannot be pushed open by the valve 29a of the second connecting member 13a. Connection is impossible, and connection / fixation is impossible unless the hydraulic pressure generator 1 is low pressure.
Further, when the return valve 17 of the external hydraulic pressure generator 12 is opened, there is a problem that the pressure on the hydraulic pressure generator 1 side also drops.

  In view of such a point, the present invention can appropriately remove foreign matters adhering to the filter without changing the filter to maintain the permeation ability and extend the use period of the filter. The object is to obtain a pressure generator.

  The invention according to claim 1 includes a gear pump that boosts the working fluid through the first filter, and a high-pressure pump that boosts the working fluid boosted by the gear pump to a higher pressure. The discharge amount of the gear pump is In the hydraulic pressure generator in which a relief valve is connected between the gear pump and the high-pressure pump, the discharge side of the relief valve is communicated between the filter and the gear pump. It is characterized by.

  The invention according to claim 2 is characterized in that, in the hydraulic pressure generator according to claim 1, an external hydraulic pressure generator is connectable to the discharge side of the high-pressure pump via a hydraulic joint.

According to a third aspect of the present invention, in the hydraulic pressure generating device according to the first aspect, the first connecting member is connected to the discharge side of the high pressure pump of the hydraulic pressure generating device, and the working liquid is boosted through the filter from the low pressure side. A second connecting member is provided on the discharge side of the pump of the external hydraulic pressure generating device, and the first connecting member and the second connecting member are respectively springs against the seat portion provided in the case. A hydraulic joint that has a valve that is biased in the pressure-contact direction by the first and second connection member cases and is capable of being fluid-tightly connected to each other.
When connecting the two connection members, the valve rods of the two connection members are in contact with each other, and the valve of the first connection member is kept closed while the valve of the second connection member is separated from the seat portion. A hydraulic joint in which the spring of the first connecting member is stronger than the spring of the second connecting member is used.

According to a fourth aspect of the present invention, in the hydraulic pressure generating device according to the first aspect, the first connecting member is connected to the discharge side of the high pressure pump of the hydraulic pressure generating device, and the working liquid is boosted through the filter from the low pressure side. A second connecting member is provided on the discharge side of the pump of the external hydraulic pressure generator, and the first connecting member and the second connecting member are respectively spring-loaded with respect to the seat portions provided in the case. A hydraulic joint having a valve biased in the pressure contact direction and capable of liquid-tightly connecting the cases of the first and second connection members to each other;
When connecting the two connection members, the valve balances of the valves in both connection members are in contact with each other, and the valve in the second connection member is kept away from the seat portion while the valve in the first connection member is closed. The spring of the first connecting member is stronger than the spring of the second connecting member, and the opening degree restricting portion of the valve is provided in the first connecting member, so that the valve of the first connecting member opens. The hydraulic joint is used in which the valve of the second connecting member is also kept open when it moves to the position and comes into contact with the opening restricting portion.

Since the present invention is configured as described above, the adhered foreign matter can be removed or reduced, and the replacement of the filter can be reduced.
In addition, by configuring the hydraulic joint with the external hydraulic pressure generator as described above, the first connecting member and the second connecting member can be connected and disconnected regardless of whether the first connecting member side is high or low. In addition, at the time of detachment, the hydraulic fluid does not flow out and the hydraulic joint can be safely removed.

  Hereinafter, two reference examples and one embodiment of the present invention will be described with reference to FIGS. In the figure, the same parts as those in FIG.

First Reference Example FIG. 1 is a diagram showing a first reference example relating to the hydraulic pressure generating device of the present invention. The hydraulic pressure generating device 1 pressurizes liquid in two stages by a gear pump 2 and a high pressure pump 3, and the gear pump 2 The suction of the high-pressure pump 3 is assisted by increasing the amount of discharge. The high pressure pump 3 is connected to an actuator 6 that is operated by the working fluid pressurized by the high pressure pump 3, and an accumulator 7 is connected to the discharge side of the high pressure pump 3. A first filter 5 is provided on the suction side of the gear pump 2, and a relief valve 8 is connected between the gear pump 2 and the high-pressure pump 3. On the other hand, a return valve 10 is provided in the flow path 9 that communicates from the high-pressure portion on the actuator 6 side to the low-pressure liquid tank 4, and the low-pressure portion on the actuator 6 side communicates with the low-pressure liquid tank 4 by a conduit 6 a.

  The above-described configuration is the same as the conventional one. However, in the present invention, the gear pump 2 can be rotated forward and backward, and the discharge port is reversed by the forward and reverse rotation. Further, a second filter 35 is provided on the low pressure liquid layer 4 side from the relief valve 8, and a check that allows only the flow from the second filter 35 toward the gear pump 2 to pass in parallel with the relief valve 8. A valve 36 is provided. A first pressure sensor 37 is provided between the first filter 5 and the gear pump 2, and a second pressure sensor 38 is provided between the second filter 35 and the check valve 36.

  Further, a first connecting member 41 of a hydraulic joint is provided between the high-pressure pump 3 and the actuator 6 so as to be connectable / fixable to the second connecting member 51 in the external hydraulic pressure generator 12.

  FIG. 2 is a view showing a hydraulic joint composed of the first connecting member 41 and the second connecting member 51, and the valve 43 is movable in the axial direction in the case 42 of the first connecting member 41. Is provided. The valve 43 is urged toward the opening side of the case 42 in a pressure-contact direction by the spring 44 toward the opening side of the case 42, and the valve 43 is normally closed so that the liquid is in the first connection member. It is comprised so that it may not flow out of the case 42 of 41. FIG. Also, an opening degree restricting portion 46 of the valve 43 is provided in the case 42, and a predetermined valve opening degree is maintained when the valve 43 contacts the opening degree restricting portion 46.

  On the other hand, the second connecting member 51 has a case 52 to which the case 42 of the first connecting member 41 can be connected. A valve 53 is also provided in the case 52 so as to be movable in the axial direction. The valve 53 is urged toward the opening side of the case 52 in the press-contact direction with respect to the seat portion 55 by the spring 54, and the valve 53 is normally closed so that the liquid is in the first connection member. 51 so as not to flow out of the case 52. Further, the second connecting member 52 is provided with a concave portion 52a for inserting and fixing the tip small diameter portion 42a of the case 42 of the first connecting member 41, and a packing 56 is provided on the inner peripheral portion of the concave portion 52a. Is provided.

  Here, when connecting the first connection member 41 and the second connection member 51, first, the tip small diameter portion 42 a of the case 42 in the first connection member 41 is connected to the case 52 of the second connection member 51. The first connecting member 41 and the second connecting member 51 are fixed in a liquid-tight manner through the packing 56 by being inserted into the recess 52a. In this case, as shown in FIG. 2 (b), the valve rods 43a and 53a protruding so as to face both the valves 43 and 53 until the both cases 42 and 52 are completely inserted and fixed are The two valves 43 and 53 are in a closed state without contact. Therefore, as shown in FIG. 2C, when the cases 42 and 52 are completely inserted and fixed, the valve rod 43a of the valve 43 and the valve rod 53a of the valve 53 come into contact with each other. However, since the spring 44 of the first connecting member 41 is stronger than the spring 54 of the second connecting member 51, only the valve 53 of the second connecting member 51 is opened due to the difference in force. Therefore, the hydraulic joint can be connected regardless of whether the pressure on the actuator 6 side is high or low, and the working liquid does not flow out at the time of separation.

  Further, when the first connecting member 41 and the second connecting member 51 are detached, the valve 53 is in contact with the seat portion 55 in a state where the case 42 and the case 52 are sealed by the packing 56.

  Thus, in the hydraulic pressure generating apparatus configured as described above, when the gear pump 2 rotates forward, the working liquid pressurized by both the gear pump 2 and the high-pressure pump 3 is supplied to the actuator 6 or the accumulator 7. At the same time, the pressure between the gear pump 2 and the high-pressure pump 3 increases due to the difference in the discharge amounts of the two pumps. When the pressure reaches a certain pressure, the relief valve 8 operates and the low-pressure liquid tank 4 passes through the second filter 35. The hydraulic fluid corresponding to the flow rate corresponding to the discharge amount difference between the high pressure pump 3 and the gear pump 2 is blown out.

  When the gear pump 2 rotates in the reverse direction, the check valve 36 opens because the pressure between the gear pump 2 and the check valve 36 becomes negative, and the high-pressure pump 3 sucks the working liquid through the second filter 35. The working liquid is discharged to the side. In addition, the working liquid discharged from the gear pump 2 flows into the low-pressure liquid tank 4 through the first filter 5. In addition, when foreign matter adheres to the first filter 5 or the second filter 35, the liquid permeability of the filter is reduced, so that the discharge side of the filter becomes negative pressure. This pressure difference is sensed by the first pressure sensor 37 or the second pressure sensor 38 and taken out as a signal. When the return valve 10 is opened, the working liquid is returned to the low-pressure liquid tank 4 through the first filter 5 and the pressure on the actuator 6 side is reduced.

  When the first connecting member 42 and the second connecting member 52 are connected and fixed, when the high-pressure pump 14 of the external hydraulic pressure generator 12 is operated, the high-pressure pump 14 and the valve 43 of the first connecting member are connected. Becomes a high pressure, the valve 43 is opened, and the working liquid is discharged to the actuator 6 side. In addition, when the pressure on the actuator 6 side reaches a certain value, the relief valve 16 operates to blow the working liquid into the low-pressure liquid tank 4. Further, when the return valve 17 is opened, the valve 43 of the first connecting member 41 is in contact with the seat portion 45, so that the pressure on the actuator 6 side is maintained and the first connecting member 41 and the high-pressure pump 14 are maintained. The pressure in between decreases. Therefore, the first connecting member 41 and the second connecting member 51 can be detached while the return valve 17 is opened, and the working liquid from the first connecting member 41 and the second connecting member 51 can be detached when the return valve 17 is opened. There is no outflow.

  Thus, according to the present reference example, the foreign matter adhering to the first filter 5 or the second filter 35 is removed by discharging the gear pump 2 or blowing the relief valve 8 by changing the rotation direction of the gear pump 2. Can do.

  Further, the foreign matter attached to the first filter 5 can be removed by opening the return valve 10.

  Further, the second connecting member 51 can be connected and fixed regardless of whether the first connecting member 41 side is high or low, and the high pressure pump 14 can increase the pressure on the actuator 6 side. When the return valve 17 is opened, the pressure between the first connecting member 41 and the high-pressure pump 14 can be reduced while maintaining the pressure on the actuator 6 side, and the first connecting member 41 can be safely and without outflow of the working liquid. And the second connecting member 51 can be detached.

  In addition, since the rotation direction of the gear pump 2 can be appropriately controlled using the signal of the first pressure sensor 37 or the second pressure sensor 38, it is possible to avoid the discharge failure and the first filter 5 or the second filter 35. The foreign matter can be removed.

Second Reference Example FIG. 3 is a diagram showing a second reference example relating to the present invention, and a second check that allows only the flow from the first filter 5 side to pass between the gear pump 2 and the first filter 5. A parallel circuit of a valve 61 and a relief valve 62 that blows out from the gear pump 2 side to the first filter 5 side is provided. A third check valve 63 that allows only the flow in the direction of the high pressure pump 3 is provided on the suction side of the high pressure pump 3, and a third reverse valve is provided between the gear pump 2 and the second check valve 61. A pipe 64 connected between the stop valve 63 and the high pressure pump 3 is provided with a fourth check valve 65 that allows only the flow toward the high pressure pump 3 to pass therethrough.

  Thus, when the gear pump 2 rotates in the forward direction, the pressure between the gear pump 2 and the high-pressure pump 3 increases due to the difference in discharge amount between the gear pump 2 and the high-pressure pump 3, and when the pressure reaches a certain level, the relief valve 8 operates. The working liquid corresponding to the flow rate corresponding to the difference in discharge amount between the high-pressure pump 3 and the gear pump 2 is discharged to the low-pressure liquid tank 4 through the second filter 35.

  When the gear pump 2 rotates in the reverse direction, the pressure between the gear pump 2 and the check valve 36 becomes negative, so that the check valve 36 opens and sucks the working liquid through the second filter 35. The third check valve 63 is closed due to the difference in discharge amount between the gear pump 2 and the high pressure pump 3, and the working liquid discharged from the gear pump 2 flows to the high pressure pump 3 through the fourth check valve 65 and is on the side of the actuator 6. To discharge. Here, the pressure between the high pressure pump 3 via the gear pump 2 and the fourth check valve 65 rises due to the difference in the discharge amount between the gear pump 2 and the high pressure pump 3, and when the pressure reaches a certain pressure, the relief valve 62 operates. Then, the working liquid corresponding to the flow rate corresponding to the discharge amount difference between the high pressure pump 3 and the gear pump 2 is blown out to the low pressure liquid tank 4 through the first filter 5.

  As described above, according to this reference example, the foreign matter adhering to the first filter 5 or the second filter 35 can be removed by blowing the relief valve 62 or the relief valve 8 by changing the rotation direction of the gear pump 2. it can.

  Further, since both forward and reverse rotations flow to the high-pressure pump 3 via the gear pump 2, the auxiliary function of the gear pump 2 can be maintained in both forward and reverse rotations.

FIG. 4 is a diagram showing an embodiment of a hydraulic pressure generating device according to the present invention. In this embodiment, the discharge side of the relief valve 8 in the hydraulic pressure generating device shown in FIG. It is connected between the first filter 5 and the gear pump 2.

  Thus, when the gear pump 2 is rotated, the working liquid is sucked from the low-pressure liquid tank 4 through the filter 5 and discharged after being pressurized. The working fluid boosted by the gear pump 2 is further boosted to a high pressure by the high-pressure pump 3, discharged to the actuator 6 side, and accumulated by the accumulator 7. That is, when the gear pump 2 rotates, the pressure between the gear pump 2 and the high-pressure pump 3 increases due to the difference in discharge amount between the gear pump 2 and the high-pressure pump 3, and when the pressure reaches a certain pressure, the relief valve 8 operates and the filter 5 And blown out between the gear pump 2. The hydraulic fluid blown out is again pressurized by the gear pump 2.

  According to the present embodiment, since the working liquid blown out from the relief valve 8 can be returned to the gear pump 2 again, the suction of the filter 5 can be suppressed, and foreign matter adhering to the filter 5 can be reduced. In the second reference example and the present embodiment, the connection portion with the external hydraulic pressure generator is omitted, but it is needless to say that a hydraulic joint may be provided as in the first reference example.

The figure which shows the structure of the hydraulic-pressure generator of the 1st reference example regarding this invention. (A) (b) (c) (d) is a figure which shows the structure of the hydraulic coupling in the 1st Embodiment of this invention, and its operating state. The figure which shows the structure of the hydraulic-pressure generator of the 2nd reference example of this invention. The figure which shows the structure of the hydraulic-pressure generator of one Embodiment of this invention. The figure which shows the structure of the conventional hydraulic pressure generator. (A) (b) (c) is a figure which shows the structure and operating state of the conventional hydraulic coupling. (A) (b) (c) is a figure which shows the other example and operation state of the conventional hydraulic coupling.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hydraulic pressure generator 2 Gear pump 3 High pressure pump 4 Low pressure liquid tank 5 Filter 6 Actuator 7 Accumulator 8, 16 Relief valve 10, 17 Return valve 11, 41 First connection member 12 External hydraulic pressure generator 13, 51 Connecting member 14 High pressure pump 15 Filter 35 Second filter 36 Check valve 37 First pressure sensor 38 Second pressure sensor 42, 52 Case 43, 53 Valve 44, 54 Spring 45, 55 Seat portion 46 Opening restriction portion 61 Second check valve 62 Relief valve 63 Third check valve 65 Fourth check valve

Claims (4)

A gear pump that boosts the working fluid through the first filter; and a high-pressure pump that boosts the working fluid boosted by the gear pump to a higher pressure. The discharge amount of the gear pump is larger than the discharge amount of the high-pressure pump. In the hydraulic pressure generator in which a relief valve is connected between the gear pump and the high-pressure pump,
A hydraulic pressure generating device, wherein a blow-out side of the relief valve is communicated between the filter and the gear pump.   2. The hydraulic pressure generator according to claim 1, wherein an external hydraulic pressure generator is connectable to a discharge side of the high pressure pump via a hydraulic joint. A first connecting member is connected to the discharge side of the high pressure pump of the hydraulic pressure generating device, and a second connecting member is connected to the discharge side of the pump of the external hydraulic pressure generating device that pressurizes the working liquid through the filter from the low pressure side. The first connecting member and the second connecting member each have a valve that is urged in a press-contact direction by a spring with respect to a seat portion provided in the case. 2 is a hydraulic joint that enables the cases of the connecting members to be connected in a liquid-tight manner to each other;
When connecting the two connection members, the valve rods of the two connection members are in contact with each other, and the valve of the first connection member is kept closed while the valve of the second connection member is separated from the seat portion. 2. The hydraulic pressure generator according to claim 1, wherein a hydraulic joint is used in which the spring of the first connecting member is stronger than the spring of the second connecting member. A first connecting member is connected to the discharge side of the high pressure pump of the hydraulic pressure generating device, and a second connecting member is connected to the discharge side of the pump of the external hydraulic pressure generating device that pressurizes the working liquid through the filter from the low pressure side. The first connection member and the second connection member each have a valve that is biased in a pressure-contact direction by a spring with respect to a seat portion provided in the case. Is a hydraulic joint that enables the cases of the connecting members to be connected in a liquid-tight manner to each other,
When connecting the two connection members, the valve balances of the valves in both connection members are in contact with each other, and the valve in the second connection member is kept away from the seat portion while the valve in the first connection member is closed. The spring of the first connecting member is stronger than the spring of the second connecting member, and the opening degree restricting portion of the valve is provided in the first connecting member, so that the valve of the first connecting member opens. 2. The hydraulic pressure generating device according to claim 1, wherein a hydraulic joint is used in which the valve of the second connecting member is also kept open when the valve moves to contact with the opening restriction portion.

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