JP6808440B2 - Electromagnetic pump - Google Patents

Description

The present invention relates to an electromagnetic pump capable of discharging a liquid into a low pressure large flow rate and a high pressure small flow rate by operating a solenoid unit.

This type of electromagnetic pump has a stepped hole formed in the pump body by engaging the pump part with a solenoid part (electromagnetic valve), and a stepped piston slidably inserted into the stepped hole. In the direction of the high-pressure pump chamber formed by the stepped hole, the large-diameter shaft portion of the stepped piston, and the stepped portion of the small-diameter shaft portion, and the small-diameter shaft portion of the stepped piston and the small-diameter shaft portion of the stepped piston. It is provided with a low-pressure pump chamber formed by a hole in the pump body bored. Then, when the solenoid section (electromagnetic valve) is energized to discharge a large low-pressure flow rate at which the liquid in the high-pressure pump chamber and the liquid in the low-pressure pump chamber merge, and the pressure on the discharge side rises, the discharge path in the low-pressure pump chamber is discharged. The liquid in the low-pressure pump chamber is returned to the suction path from the provided pressure control valve (safety valve), and only the liquid in the high-pressure pump chamber is discharged as a high-pressure small flow rate.

JP-A-2007-126974 (paragraphs 0011, 0017, FIG. 1)

However, in such a conventional electromagnetic pump, the liquid leaks from the high-pressure pump chamber to the low-pressure pump chamber through the gap between the stepped hole and the sliding portion of the small-diameter shaft portion of the stepped piston. When it is desired to increase the flow rate of the liquid discharged from the low-pressure pump chamber, it is necessary to increase the diameter of the small-diameter shaft portion of the stepped piston. However, if the small-diameter shaft portion has a large diameter, the amount of liquid leakage increases. The amount of liquid leaking from the high-pressure pump chamber to the low-pressure pump chamber further increases, and there is a problem that a sufficient flow rate of the liquid discharged from the high-pressure pump chamber cannot be secured.

An object of the present invention is to provide an electromagnetic pump capable of suppressing an increase in the amount of liquid leaking from the high-pressure pump chamber to the low-pressure pump chamber and ensuring a sufficient flow rate of the liquid discharged from the high-pressure pump chamber.

In order to achieve such a problem, the present invention has taken the following measures. That is,
It is equipped with a solenoid part that slides the movable iron core by the suction force generated by energization and a pump part that operates by the solenoid part. The pump part has a large-diameter shaft part and a small-diameter shaft part connected in series and slides by energization of the solenoid part. It has a moving piston member, and the piston member is slidably fitted into the large-diameter hole and the small-diameter hole in which the large-diameter shaft portion and the small-diameter shaft portion are connected to the pump portion, respectively. A low-pressure pump chamber is partitioned, and a high-pressure pump chamber is partitioned by a small-diameter shaft and a small-diameter hole. The low-pressure pump chamber has a pressure control valve that controls the pressure of the low-pressure pump chamber to a set value, and a low-pressure pump from the low-pressure side. The first check valve that allows the flow of liquid to the chamber and blocks the flow of liquid from the low-pressure pump chamber to the low-pressure side, and the low-pressure pump chamber that allows the flow of liquid from the load side to the low-pressure pump chamber By connecting to the second check valve that blocks the flow of liquid, the high-pressure pump chamber allows the flow of liquid from the low-pressure side to the high-pressure pump chamber, and blocks the flow of liquid from the high-pressure pump chamber to the low-pressure side. 3 Check valve and 4th check valve that allows the flow of liquid from the high pressure pump chamber to the load side and blocks the flow of liquid from the load side to the high pressure pump chamber are connected, and the pressure control valve pumps the valve body. It is slidably inserted into the valve hole of the main body, and the valve body has two lands, and the pressure of the liquid discharged from the second check valve to the load side acts as a pilot pressure on one of the lands. provided, electromagnetic pump, wherein an external pilot der Rukoto for discharging the liquid of the low-pressure pump chamber other land portion is opened by the action of the pilot pressure to the low pressure side is it.

As described in detail above, in the invention according to claim 1, the pump portion has a piston member in which a large-diameter shaft portion and a small-diameter shaft portion are connected in series and slides by energization of the solenoid portion, and the piston member is large. The diameter shaft part and the small diameter shaft part are slidably inserted into the large diameter hole and the small diameter hole which are connected to the pump part, respectively, and the low pressure pump chamber is partitioned by the large diameter shaft part and the large diameter hole, and the small diameter shaft part is formed. The high-pressure pump chamber is partitioned by the small diameter hole. Therefore, when it is desired to increase the flow rate of the liquid discharged from the low-pressure pump chamber, only the large-diameter shaft portion of the piston member needs to have a large diameter, and the small-diameter shaft portion is not affected. Therefore, the small-diameter shaft portion and the small-diameter hole slide. It is possible to suppress an increase in the amount of liquid leaking from the high-pressure pump chamber to the low-pressure pump chamber through the gap between the portions, and a sufficient flow rate of the liquid discharged from the high-pressure pump chamber can be secured.

The invention according to claim 1, the pressure control valve, the valve body and slidably inserted into the pump body of the valve hole, the valve body has two land portions, the second check valve provided by acting the pressure of the liquid to be discharged more to the load side to one of the land portion as a pilot pressure, external pilot for discharging the liquid from the low pressure pump chamber into the low pressure side the other land portion is opened by the action of the pilot pressure It is used as a pressure control valve. Therefore, when the pilot pressure reaches the set value and the pressure control valve is opened, the liquid is discharged from the low pressure pump chamber to the low pressure side, and the pressure in the low pressure pump chamber becomes substantially zero. Then, unless the pressure of the liquid discharged from the second check valve to the load side drops below the set value, the pressure in the low-pressure pump chamber is maintained at substantially zero, so that the large-diameter shaft portion of the piston member that partitions the low-pressure pump chamber is formed. The resistance based on the pressure at the time of operation can be reduced, and the operability can be improved.

It is the hydraulic circuit diagram of the electromagnetic pump which showed the reference example . It is sectional drawing which follows the line CC of FIG. 3 of a reference example . It is sectional drawing which follows the line ABA of FIG. It is a hydraulic circuit diagram which showed the modification of FIG. It is a hydraulic circuit diagram which showed the other modification of FIG. It is a hydraulic circuit diagram of the electromagnetic pump which showed one Embodiment of this invention . It is sectional drawing which follows the line ZZ of FIG. 8 of one Embodiment. It is sectional drawing which follows the line XYX of FIG. It is a hydraulic circuit diagram which showed the modification of FIG. It is a hydraulic circuit diagram which showed the other modification of FIG.

Hereinafter, a reference example will be described with reference to the drawings.
In FIGS. 1 to 3, reference numeral 1 denotes a solenoid portion, in which a substantially cylindrical movable iron core 3 is slidably fitted into a bottomed storage hole 2A formed in a yoke 2 and is fitted into a coil 4. The suction force generated by energization is used to suck the fixed iron core 5 having a substantially disk shape. The fixed iron core 5 has a through hole 5A through which the movable iron core 3 is inserted. The yoke 2 has an opening 2B on one end side in the axial direction.

Reference numeral 6 denotes a pump portion, in which the convex portion 7A of the pump main body 7 is fitted into the through hole 5A of the fixed iron core 5, and the pump main body 7 is connected to the opening 2B of the yoke 2 by caulking. A large-diameter hole 8A and a small-diameter hole 8B are connected to the pump main body 7. Reference numeral 9 denotes a first bearing member, which is press-fitted into the open end of the large-diameter hole 8A. Reference numeral 10 denotes a second bearing member, which is press-fitted into a portion of the small-diameter hole 8B connected to the large-diameter hole 8A. Reference numeral 11 denotes a piston member, which is configured by connecting the large-diameter shaft portion 12 and the small-diameter shaft portion 13 in succession. The large-diameter shaft portion 12 has a recess 12A at the lower end, and the upper end is fixed to the movable iron core 3 and operates integrally with the movable iron core 3. The small diameter shaft portion 13 is inserted through the axis of the large diameter shaft portion 12 and fixed to the large diameter shaft portion 12. The large-diameter shaft portion 12 and the small-diameter shaft portion 13 of the piston member 11 are slidably fitted and inserted into the first bearing member 9 and the second bearing member 10, respectively. Reference numeral 14 denotes a low pressure pump chamber, which is partitioned by a large diameter shaft portion 12 and a large diameter hole 8A. Reference numeral 15 denotes a high-pressure pump chamber, which is partitioned by a small-diameter shaft portion 13 and a small-diameter hole 8B. The pressure receiving area of the large diameter shaft portion 12 is larger than the pressure receiving area of the small diameter shaft portion 13. Reference numeral 16 denotes a first elastic member, which is housed in the hollow of the movable iron core 3. Reference numeral 17 denotes a second elastic member, which is housed in the recess 12A of the large-diameter shaft portion 12. The piston member 11 is urged by the elastic force downward in the axial direction of the first elastic member 16 and the elastic force upward in the axial direction of the second elastic member 17, and the elastic force of the first elastic member 16 and the second elasticity. It stops at a position in equilibrium with the elastic force of the member 17.

Reference numeral 18 denotes a suction port, which sucks the liquid from the tank T as the low pressure side into the low pressure pump chamber 14 and the high pressure pump chamber 15. Reference numeral 19 denotes a discharge port, which discharges liquid from the low-pressure pump chamber 14 and the high-pressure pump chamber 15 to an actuator as a load side (not shown). Reference numeral 20 denotes a first suction path, which connects the suction port 18 and the low pressure pump chamber 14. Reference numeral 21 denotes a first discharge path, which connects the low pressure pump chamber 14 and the discharge port 19. Reference numeral 22 denotes a second suction path, which connects the suction port 18 and the high-pressure pump chamber 15. Reference numeral 23 denotes a second discharge path, which connects the high pressure pump chamber 15 and the discharge port 19. Reference numeral 24 denotes a first discharge path, which connects the low pressure pump chamber 14 and the suction port 18.

Reference numeral 25 denotes a first check valve provided in the first suction passage 20, in which the valve body 25A is seated on the valve seat 25C by the elastic force of the spring 25B. In the first check valve 25, the valve body 25A is separated from the valve seat 25C to allow the liquid to flow from the tank T to the low pressure pump chamber 14, and the valve body 25A is seated on the valve seat 25C and the tank is sent from the low pressure pump chamber 14. It is arranged so as to prevent the flow of liquid to T. Reference numeral 26 denotes a second check valve provided in the first discharge path 21, in which the valve body 26A is seated on the valve seat 26C by the elastic force of the spring 26B. In the second check valve 26, the valve body 26A is separated from the valve seat 26C to allow the liquid to flow from the low pressure pump chamber 14 to the actuator, and the valve body 26A is seated on the valve seat 26C from the actuator to the low pressure pump chamber 14. It is arranged so as to block the flow of the liquid. Reference numeral 27 denotes a third check valve provided in the second suction path 22, in which the valve body 27A is seated on the valve seat 27C by the elastic force of the spring 27B. In the third check valve 27, the valve body 27A is separated from the valve seat 27C to allow the liquid to flow from the tank T to the high pressure pump chamber 15, and the valve body 27A is seated on the valve seat 27C and the tank is from the high pressure pump chamber 15. It is arranged in a direction that blocks the flow of liquid to T. Reference numeral 28 denotes a fourth check valve provided in the second discharge path 23, in which the valve body 28A is seated on the valve seat 28C by the elastic force of the spring 28B. In the fourth check valve 28, the valve body 28A is separated from the valve seat 28C to allow the liquid to flow from the high pressure pump chamber 15 to the actuator, and the valve body 28A is seated on the valve seat 28C from the actuator to the high pressure pump chamber 15. It is arranged so as to block the flow of the liquid.

Reference numeral 29 denotes a relief valve as a pressure control valve provided in the first discharge passage 24. The valve body 29A is seated on the valve seat 29C by the elastic force of the spring 29B to close the first discharge passage 24. When the pressure in the low-pressure pump chamber 14 rises above the set value based on the elastic force of the spring 29B, the relief valve 29 separates the valve body 29A from the valve seat 29C against the elastic force of the spring 29B and separates the low-pressure pump chamber 14 from the low-pressure pump chamber 14. The liquid is discharged to the tank T.

Next, the operation of such a configuration will be described.
1 to 3 show a non-energized state of the coil 4, and the movable iron core 3 is stopped at an equilibrium position between the elastic force of the first elastic member 16 and the elastic force of the second elastic member 17. The first check valve 25 to the fourth check valve 28 are closed.

When the coil 4 is energized in this state, the movable iron core 3 slides downward in the axial direction against the elastic force of the second elastic member 17 and is attracted to the fixed iron core 5. As a result, the large-diameter shaft portion 12 of the piston member 11 pressurizes the liquid in the low-pressure pump chamber 14, the second check valve 26 opens, and the liquid is discharged from the low-pressure pump chamber 14. Further, in the high-pressure pump chamber 15, the small-diameter shaft portion 13 of the piston member 11 pressurizes the liquid in the high-pressure pump chamber 15, the fourth check valve 28 opens, and the liquid is discharged from the high-pressure pump chamber 15. The liquid discharged from the low-pressure pump chamber 14 and the liquid discharged from the high-pressure pump chamber 15 merge at the discharge port 19 and are discharged to the actuator.

When the coil 4 is de-energized in this state, the movable iron core 3 slides upward in the axial direction due to the elastic force of the second elastic member 17 and is separated from the fixed core 5. As a result, in the low pressure pump chamber 14, the large diameter shaft portion 12 of the piston member 11 slides upward and becomes a negative pressure. Then, the first check valve 25 is opened, the second check valve 26 is closed, and the liquid is sucked from the tank T into the low pressure pump chamber 14. Further, in the high pressure pump chamber 15, the small diameter shaft portion 13 of the piston member 11 slides upward and becomes a negative pressure. Then, the third check valve 27 opens, the fourth check valve 28 closes, and the liquid is sucked from the tank T into the high-pressure pump chamber 15. Then, the coil 4 is repeatedly energized and de-energized at high speed to discharge a low-pressure, large-flow liquid to the actuator.

When the pressure in the low-pressure pump chamber 14 rises above the set value based on the elastic force of the spring 29B of the relief valve 29 due to repeated energization and de-energization of the coil 4, the valve body 29A opens and operates in the low-pressure pump chamber 14. The liquid is discharged to the tank T, and only the liquid in the high pressure pump chamber 15 is discharged to the actuator from the discharge port 19 as a high pressure small flow rate liquid.

In such an operation, the pump portion 6 has a piston member 11 in which a large-diameter shaft portion 12 and a small-diameter shaft portion 13 are connected in series and slides by energization of the solenoid portion 1, and the piston member 11 has a small diameter with the large-diameter shaft portion 12. The shaft portion 13 is slidably fitted into the first bearing member 9 of the large diameter hole 8A and the second bearing member 10 of the small diameter hole 8B, which are connected to the pump portion 6, respectively, and the large diameter shaft portion 12 and the large diameter hole 8A are inserted. The low-pressure pump chamber 14 was partitioned, and the high-pressure pump chamber 15 was partitioned by the small-diameter shaft portion 13 and the small-diameter hole 8B. Therefore, when it is desired to increase the flow rate of the liquid discharged from the low-pressure pump chamber 14, only the large-diameter shaft portion 12 of the piston member 11 needs to have a large diameter, and the small-diameter shaft portion 13 is not affected. It is possible to suppress an increase in the amount of liquid leaking from the high-pressure pump chamber 15 to the low-pressure pump chamber 14 through the gap of the sliding portion of the second bearing member 10, and the flow rate of the liquid discharged from the high-pressure pump chamber 15 is sufficient. Can be secured.

FIG. 4 shows a modified example of the reference example , and different parts will be described. A third suction passage 30 was provided in place of the first suction passage 20 of FIGS. 1 to 3. The third suction passage 30 sucks the liquid from the tank T via the high pressure pump chamber 15 and connects to the low pressure pump chamber 14. The third suction passage 30 allows the flow of liquid from the tank T through the high-pressure pump chamber 15 to the low-pressure pump chamber 14, and allows the flow of liquid from the low-pressure pump chamber 14 to the tank T via the high-pressure pump chamber 15. A first check valve 31 for blocking is provided.

FIG. 5 shows another modified example of the reference example , and different parts will be described. A fourth suction passage 32 was provided in place of the second suction passage 22 of FIGS. 1 to 3. The fourth suction passage 32 sucks the liquid from the tank T via the low pressure pump chamber 14 and connects to the high pressure pump chamber 15. The fourth suction passage 32 allows the flow of liquid from the tank T through the low-pressure pump chamber 14 to the high-pressure pump chamber 15, and allows the flow of liquid from the high-pressure pump chamber 15 to the tank T via the low-pressure pump chamber 14. A third check valve 33 for blocking is provided.

6 to 8 show an embodiment of the present invention, the same parts as those in the reference example are designated by the same reference numerals, description thereof will be omitted, and only different parts will be described.
Reference numeral 34 denotes a valve hole formed in the pump main body 6, which connects the suction port 18 and the discharge port 19 and connects the low pressure pump chamber 14 to the intermediate portion connecting the suction port 18 and the discharge port 19. .. Reference numeral 35 denotes a second discharge passage, which corresponds to a portion connecting the low pressure pump chamber 14 of the valve hole 34 and the suction port 18. Reference numeral 36 denotes a pressure control valve of an external pilot as a pressure control valve arranged in the second discharge passage 35, and the pilot flow path 37 is connected to the actuator side from the second check valve 26 arrangement portion of the first discharge passage 21. The pressure of the liquid discharged to the actuator acts as the pilot pressure. Reference numeral 36A is a spool valve body of the pressure control valve 36, which has land portions 36B and 36C and is slidably inserted into the valve hole 34. The spool valve body 36A is urged to the left in the axial direction by the elastic force of the spring 36D, and the low pressure pump chamber 14 and the suction port 18 are closed by the land portion 36C. Then, when the pilot pressure acting on the land portion 36B rises above the set value based on the elastic force of the spring 36D, the spool valve body 36A moves to the right in the axial direction of FIG. 8 against the elastic force of the spring 36D. The land portion 36C opens between the low pressure pump chamber 14 and the suction port 18, and the liquid is discharged to the tank T.

The operation is repeated energization and de-energization of the coil 4, and when the pilot pressure rises above the set value based on the elastic force of the spring 36D of the pressure control valve 36, the spool valve body 36A opens and the low-pressure pump chamber 14 operates. Is discharged to the tank T, and only the liquid in the high-pressure pump chamber 15 is discharged to the actuator as a high-pressure small-flow liquid through the discharge port 19.

In such operation, it is possible to suppress the leakage amount of liquid leaking into the low-pressure pump chamber 14 from the high-pressure pump chamber 15 through the clearance of the sliding portion of the small-diameter shaft portion 13 and the second bearing member 10 is increased, the high-pressure pump chamber A sufficient flow rate of the liquid discharged from 15 can be secured. Further, the pressure control valve 36 is provided by acting as a pilot pressure on the pressure of the liquid discharged from the second check valve 26 to the actuator side, and is opened by the action of the pilot pressure to tank the liquid from the low pressure pump chamber 14. Discharge to T. Therefore, when the pilot pressure rises above the set value based on the elastic force of the spring 36D of the pressure control valve 36 and the spool valve body 36A opens, the liquid is discharged from the low pressure pump chamber 14 to the tank T and the low pressure pump chamber. The pressure of 14 becomes almost zero. Then, as long as the pressure of the liquid discharged from the second check valve 26 to the actuator side does not drop below the set value, the pressure in the low pressure pump chamber 14 is maintained at substantially zero, so that the piston member 11 for partitioning the low pressure pump chamber 14 The resistance based on the pressure when the large-diameter shaft portion 12 operates can be reduced, and the operability can be improved.

FIG. 9 shows a modified example of one embodiment and describes different parts. Reference numeral 38 denotes a first discharge path, and a second check valve 26 is arranged. Then, the first discharge passage 38 is connected to the second discharge passage 23 on the high-pressure pump chamber 15 side from the location where the fourth check valve 28 is arranged in the second discharge passage 23, and the second check valve 26 and the fourth check valve 28 are connected. It is connected to the actuator side in series.

FIG. 10 shows another modification of one embodiment and describes different parts. Reference numeral 39 denotes a pilot flow path of the pressure control valve 36, which is connected to the high pressure pump chamber 15 and acts as a pilot pressure using the pressure of the liquid discharged from the high pressure pump chamber 15 to the actuator.

In each of the above-described embodiments, the liquid discharged from the low-pressure pump chamber 14 and the liquid discharged from the high-pressure pump chamber 15 merge at the discharge port 19 and are discharged to the actuator, but the present invention is not limited to this. The liquid discharged from the low-pressure pump chamber 14 and the liquid discharged from the high-pressure pump chamber 15 may be discharged to separate actuators without merging at the discharge port 19. Further, the first bearing member 9 and the second bearing member 10 were press-fitted into the large-diameter hole 8A and the small-diameter hole 8B, respectively, but the first bearing member 9 and the second bearing member 10 were inserted into the large-diameter hole 8A and the small-diameter hole 8B, respectively. It does not have to be provided. Further, the piston member 11 is urged by the elastic force downward in the axial direction of the first elastic member 16 and the elastic force upward in the axial direction of the second elastic member 17, and the elastic force of the first elastic member 16 and the first elastic force. 2 Although it stopped at a position in equilibrium with the elastic force of the elastic member 17, the piston member 11 may be positioned only by the elastic force upward in the axial direction of the second elastic member 17 without the first elastic member 16. Although the pressure control valve 36 is a spool valve, it may be a poppet valve. Further, the first discharge passage 38 is connected to the second discharge passage 23 on the high pressure pump chamber 15 side from the location where the fourth check valve 28 is arranged in the second discharge passage 23, but the present invention is not limited to this, and the first discharge passage 38 is not limited to this. Of course, the discharge path 38 may be connected to the second discharge path 23 on the actuator side from the location where the fourth check valve 28 is arranged on the second discharge path 23.

1: Solenoid part 3: Movable iron core 6: Pump part 8A: Large diameter hole 8B: Small diameter hole 11: Piston member 12: Large diameter shaft part 13: Small diameter shaft part 14: Low pressure pump chamber 15: High pressure pump chamber 20: First Suction path 22: 2nd suction path 21, 38: 1st discharge path 23: 2nd discharge path 25, 31: 1st check valve 26: 2nd check valve 27, 33: 3rd check valve 28: 4th check valve 29: Relief valve 30: Third suction path 32: Fourth suction path 36: Pressure control valve T: Tank

Claims (1)

In an electromagnetic pump equipped with a low-pressure pump chamber that discharges a low-pressure large-flow liquid to the load side and a high-pressure pump chamber that discharges a high-pressure small-flow liquid to the load side, a solenoid that slides a movable iron core by an attractive force generated by energization. It is provided with a portion and a pump portion operated by a solenoid portion, and the pump portion has a piston member in which a large-diameter shaft portion and a small-diameter shaft portion are connected in series and slides by energization of the solenoid portion, and the piston member is a large-diameter shaft. The small-diameter shaft and the small-diameter shaft are slidably fitted into the large-diameter and small-diameter holes that are connected to the pump, respectively. A high-pressure pump chamber is partitioned by holes, and the low-pressure pump chamber has a pressure control valve that controls the pressure in the low-pressure pump chamber to a set value, and allows the flow of liquid from the low-pressure side to the low-pressure pump chamber to allow low pressure from the low-pressure pump chamber. Connect the first check valve that blocks the flow of liquid to the side and the second check valve that allows the flow of liquid from the low-pressure pump chamber to the load side and blocks the flow of liquid from the load side to the low-pressure pump chamber. However, the high-pressure pump chamber has a third check valve that allows the flow of liquid from the low-pressure side to the high-pressure pump chamber and blocks the flow of liquid from the high-pressure pump chamber to the low-pressure side, and the liquid from the high-pressure pump chamber to the load side. A fourth check valve is connected to allow the flow of liquid to prevent the flow of liquid from the load side to the high-pressure pump chamber, and the pressure control valve is a valve body in which the valve body is slidably inserted into the valve hole of the pump body. Has two land portions, and the pressure of the liquid discharged from the second check valve to the load side acts as a pilot pressure on one land portion, and the other land portion is opened by the action of this pilot pressure. electromagnetic pump, wherein the external pilot der Rukoto for discharging the liquid of the low-pressure pump chamber to the low pressure side Te.

Images