JP5505347B2 - Electromagnetic pump - Google Patents

Description

  The present invention provides a cylinder, a piston capable of reciprocating in the cylinder, an electromagnetic part for moving the piston forward, a biasing member for returning the piston, and supporting the biasing member, the cylinder, A support member that divides the pump chamber together with the piston, a suction opening / closing valve that is incorporated in the support member and permits movement of the working fluid from the suction port to the pump chamber and prohibits movement in the reverse direction; and discharge from the pump chamber The present invention relates to an electromagnetic pump comprising a discharge on-off valve that permits movement of a working fluid to an outlet and prohibits movement in the reverse direction.

  Conventionally, this type of electromagnetic pump includes a cylinder, a piston that reciprocates in the cylinder to change the volume in the pump chamber, a solenoid that moves the piston forward, a spring that moves the piston back, and a suction port. A check valve for suction that allows the flow of hydraulic oil to the pump chamber and prohibits reverse flow, and a check for discharge that allows the flow of hydraulic oil from the pump chamber to the discharge port and prohibits reverse flow A thing provided with a valve is proposed (for example, refer to patent documents 1). In this electromagnetic pump, a suction check valve and a discharge check valve are accommodated in a cylinder. The suction check valve accommodates a ball and an inner diameter smaller than the outer diameter of the ball. And a hollow cylindrical main body having a central hole formed at the center of the shaft to communicate with the suction port and the pump chamber, and the working oil is supplied from the suction port to the suction port. A spring that is biased in the direction opposite to the flowing direction and a spring receiver that receives the spring are configured. In the check valve for suction, the spring receiver faces the pump chamber, and the spring for returning the piston is supported by the surface of the spring receiver on the pump chamber side.

JP 2011-21593 A

  The electromagnetic pump of the type described above is housed in a cylinder so that the piston and the suction check valve face each other, and the pump chamber is partitioned by the cylinder, the piston, and the suction check valve. The configuration is considered to be a very important issue in determining the volume of the pump chamber and the urging force of the spring accommodated in the pump chamber.

  The main purpose of the electromagnetic pump of the present invention is to further improve the discharge performance.

  The electromagnetic pump of the present invention employs the following means in order to achieve the main object described above.

The electromagnetic pump of the present invention is
A cylinder, a piston capable of reciprocating in the cylinder, an electromagnetic part for moving the piston forward, an urging member for returning the piston, and a pump chamber together with the cylinder and the piston supporting the urging member A support member for partitioning, a suction on-off valve that is incorporated in the support member and permits movement of the working fluid from the suction port to the pump chamber and prohibits movement in the reverse direction, and operation from the pump chamber to the discharge port A discharge on-off valve that permits movement of fluid and prohibits movement in the reverse direction,
The inside of the support member includes a bottomed hollow portion that accommodates at least a part of the suction opening / closing valve from the suction port side, and a communication hole that communicates the pump chamber side bottom portion of the hollow portion with the pump chamber. Have
The gist of the support member is that a support portion that supports the biasing member, and a protruding portion that communicates with the communication hole and protrudes toward the piston side than the support portion are formed.

In the electromagnetic pump of the present invention, a cylinder, a piston capable of reciprocating in the cylinder, an electromagnetic part for moving the piston forward, an urging member for moving the piston backward, and a urging member for supporting the urging member together with the cylinder and the piston A support member that divides the pump chamber, an intake on-off valve that is incorporated in the support member and permits movement of the working fluid from the suction port to the pump chamber and prohibits reverse movement; and a working fluid from the pump chamber to the discharge port And a discharge opening / closing valve that prohibits movement in the reverse direction, and a hollow portion with a bottom that accommodates at least a part of the opening / closing valve for suction from the inlet side inside the support member, The hollow portion has a communication hole communicating with the pump chamber side bottom and the pump chamber, and the support member supports the urging member, and the communication hole communicates with the support portion and protrudes more to the piston side than the support portion. Form with protrusion That. Thereby, since the space | interval which supports a biasing member by a support part can be set and the volume in a pump chamber can be managed by a protrusion part, discharge performance can be improved more.

  In such an electromagnetic pump of the present invention, the protruding portion may be formed such that the diameter on the piston side is smaller than the diameter on the support portion side. In this aspect of the electromagnetic pump of the present invention, the projecting portion may be formed in a truncated cone shape. If it carries out like this, the process of a supporting member can be made easier.

  In the electromagnetic pump according to the present invention, the working fluid may be discharged by the backward movement of the piston by the biasing member. Since the biasing force of the biasing member is less due to temperature than the electromagnetic force, the axial length of the electromagnetic pump can be further shortened by discharging the working fluid by the biasing force. Furthermore, the axial length can be shortened.

  Furthermore, in the electromagnetic pump of the present invention, the hollow portion of the support member may be formed so that the bottom portion is deeper on the piston side than the support surface of the support portion. If it carries out like this, the length of the axial direction of a support member can be shortened, and the whole pump can be reduced in size.

It is a block diagram which shows the outline of a structure of the electromagnetic pump 20 as one Example of this invention. 4 is a perspective view of a suction check valve 60 and a piston 50 inserted into a cylinder 42. FIG. It is an external view which shows the external appearance of the valve main body.

  Next, embodiments of the present invention will be described using examples.

  FIG. 1 is a configuration diagram showing an outline of a configuration of an electromagnetic pump 20 as an embodiment of the present invention. As shown in the figure, the electromagnetic pump 20 of the embodiment is configured as a piston pump that reciprocally moves a piston 50 to pressure-feed hydraulic oil, and a solenoid unit 30 that generates electromagnetic force, and an electromagnetic force of the solenoid unit 30 A pump unit 40 that operates. For example, the electromagnetic pump 20 is incorporated in a valve body as a part of a hydraulic circuit for turning on and off a clutch and a brake included in an automatic transmission mounted on an automobile.

  In the solenoid unit 30, an electromagnetic coil 32, a plunger 34 as a mover, and a core 36 as a stator are arranged in a case 31 as a bottomed cylindrical member, and a magnetic flux is generated by applying a current to the electromagnetic coil 32. A magnetic circuit that goes around the case 31, the plunger 34, and the core 36 is formed, the plunger 34 is attracted, and the shaft 38 that contacts the tip of the plunger 34 is pushed out.

  The pump unit 40 includes a hollow cylindrical cylinder 42 joined to the solenoid unit 30, and a piston 50 that is slidably disposed in the cylinder 42 and has a proximal end surface coaxially contacting the tip of the shaft 38 of the solenoid unit 30. A spring 46 that abuts the piston 50 against the tip surface and applies a biasing force in a direction opposite to the direction in which the electromagnetic force from the solenoid unit 30 acts, and supports the spring 46 from the side opposite to the tip surface of the piston 50 A check valve 60 for suction that permits the flow of hydraulic oil in the suction direction to the chamber 41 and prohibits the flow in the reverse direction; and permits the flow of hydraulic oil in the direction of discharge from the pump chamber 41 built in the piston 50. Discharge check valve 70 that prohibits reverse flow, and a strainer that is disposed on the upstream side of suction check valve 60 and that traps foreign matter contained in the hydraulic oil sucked into pump chamber 41 7 and the piston 42, the discharge check valve 70, the spring 46, the suction check valve 60, and the strainer 47 in this order from the opening 42a on the opposite side of the solenoid portion 30 in the cylinder 42. A cylinder cover 48 covering the opening 42a. A spiral groove is formed in the circumferential direction on the inner peripheral surface of the cylinder cover 48 and the outer peripheral surface of the opening 42a of the cylinder 42. By tightening the cylinder cover 48 over the opening 42a of the cylinder 42, the cylinder cover 48 is tightened. A cover 48 is attached to the opening 42 a of the cylinder 42. In the pump unit 40, a suction port 49 for sucking hydraulic oil is formed in the center of the cylinder cover 48, and a discharge port 43 for discharging the sucked hydraulic oil is formed on the side surface of the cylinder 42. .

  The piston 50 is formed by a cylindrical piston main body 52 and a cylindrical shaft portion 54b having an outer diameter smaller than that of the piston main body 52 and having an end surface in contact with the tip of the shaft 38 of the solenoid portion 30. The cylinder 42 reciprocates in conjunction with the shaft 38 of the portion 30. The piston 50 is formed with a cylindrical bottomed hollow portion 52a at the center of the shaft so as to accommodate the check valve 70 for discharge. The hollow portion 52 a of the piston 50 penetrates the inside of the piston main body 52 from the distal end surface of the piston 50 and extends partway inside the shaft portion 54. The shaft portion 54 is formed with two through holes 54a and 54b that intersect each other at an angle of 90 degrees in the radial direction. A discharge port 43 is formed around the shaft portion 54, and the hollow portion 52a of the piston 50 communicates with the discharge port 43 through two through holes 54a and 54b.

  The suction check valve 60 is inserted into the inner peripheral surface of the opening 42a of the cylinder 42 to form a hollow portion 62a with a bottom inside, and at the bottom of the hollow portion 62a, the hollow portion 62a and pump A valve main body 62 having a central hole 62 b communicating with the chamber 41, a ball 64, a spring 66 for applying a biasing force to the ball 64, and the ball 64 and the spring 66 are incorporated in the hollow portion 62 a of the valve main body 62. And a plug 68 that is fitted into the inner peripheral surface of the hollow portion 62a.

  FIG. 2 is a perspective view of the suction check valve 60 and the piston 50 inserted into the cylinder 42, and FIG. 3 is an external view showing the appearance of the valve main body 62. As shown in the figure, the valve body 62 is formed by a stepped structure including a cylindrical pedestal 63a and a truncated cone 63b protruding from the seating surface of the pedestal 63a. The pedestal portion 63a supports the spring 46 by an annular surface at the peripheral edge of the seat surface, and the height of the seat surface is adjusted to be a spring interval for realizing a necessary biasing force. The protruding portion 63b is formed so as to protrude into the pump chamber 41, and the protruding height and diameter are adjusted so that the volume in the pump chamber 41 becomes a volume for realizing a necessary discharge pressure. That is, the valve main body 62 adjusts the urging force of the spring 46 and the volume of the pump chamber 41 by the pedestal portion 63a and the protruding portion 63b.

  The hollow portion 62a formed inside the valve body 62 extends from the back surface of the pedestal portion 63a through the inside of the pedestal portion 63a and extends to the vicinity of the tip inside the protruding portion 63b. A spring 66 and a plug 68 are assembled in this order. Accordingly, the axial length of the valve main body 62 needs to be secured by the length necessary for incorporating the ball 64, the spring 66, and the plug 68, so that the suction check valve 60 can be made compact.

  The suction check valve 60 is configured such that when the pressure difference (P1-P2) between the pressure P1 on the suction port 49 side and the pressure P2 on the pump chamber 41 side is equal to or higher than a predetermined pressure that overcomes the biasing force of the spring 66, When the ball 64 is released from the central hole 69 of the plug 68 with contraction and the above-described differential pressure (P1-P2) is less than a predetermined pressure, the ball 64 is expanded with the extension of the spring 66. The valve is closed by being pressed against the central hole 69 and closing the central hole 69.

  The discharge check valve 70 includes a ball 74, a spring 76 that applies a biasing force to the ball 74, and a plug 78 as an annular member having a center hole 79 having an inner diameter smaller than the outer diameter of the ball 74. These are assembled in the hollow portion 52 a of the piston 50 in the order of the spring 76, the ball 74, and the plug 78 from the opening 52 b and fixed by a snap ring 79.

  The discharge check valve 70 is configured such that when the differential pressure (P2−P3) between the pressure P2 on the pump chamber 41 side and the pressure P3 on the discharge port side 43 is equal to or higher than a predetermined pressure that overcomes the urging force of the spring 76, When the ball 74 is released from the center hole 79 of the plug 78 with contraction, and the differential pressure (P2-P3) is less than a predetermined pressure, the ball 74 is expanded with the extension of the spring 76. The central hole 79 is pressed to close the central hole 79 to close the valve.

Cylinder 42, the pump chamber by a space in which the piston body 52 is surrounded by the surface of the spring 46 side of the inner wall 42 b and the piston body 52 of the spring 46 side of the plane as the suction check valve 6 0 of the valve body 62 to slide 41 is formed. In the pump chamber 41, when the piston 50 is moved by the urging force of the spring 46, the suction check valve 60 opens and the discharge check valve 70 closes as the volume in the pump chamber 41 increases. When the hydraulic oil is sucked through the suction port 49 and the piston 50 is moved by the electromagnetic force of the solenoid portion 30, the suction check valve 60 is closed and the discharge reverse valve is reduced as the volume in the pump chamber 41 is reduced. The stop valve 70 is opened to discharge the hydraulic oil sucked through the discharge port 43.

Further, the cylinder 42 is an inner wall 42 b of the piston body 52 slides, the inner wall 42 c of the shaft portion 54 slides is formed with a step, the discharge port 43 is formed in the step portion. The step portion forms a space surrounded by the annular surface of the step portion between the piston main body 52 and the shaft portion 54 and the outer peripheral surface of the shaft portion 54. Since this space is formed on the opposite side of the pump chamber 41 across the piston body 52, the volume decreases when the volume of the pump chamber 41 increases, and the volume decreases when the volume of the pump chamber 41 decreases. Expanding. At this time, the volume change of the space is such that the area (pressure receiving area) that receives the pressure from the pump chamber 41 side of the piston body 52 is larger than the area (pressure receiving area) that receives the pressure from the discharge port 43 side. It becomes smaller than the volume change. For this reason, this space functions as the second pump chamber 56. That is, when the piston 50 is moved by the electromagnetic force of the solenoid unit 30, an amount of hydraulic oil corresponding to the difference between the reduced volume of the pump chamber 41 and the increased volume of the second pump chamber 56 is discharged from the pump chamber 41. When the piston 50 is moved by the urging force of the spring 46 and sent to the second pump chamber 56 through the discharge check valve 70 and discharged through the discharge port 43, the volume of the pump chamber 41 is increased. A corresponding amount of hydraulic fluid is sucked into the pump chamber 41 from the suction port 49 via the suction check valve 60, while an amount of hydraulic fluid corresponding to the reduced volume of the second pump chamber 56 is second. The liquid is discharged from the pump chamber 56 through the discharge port 43. Therefore, since the hydraulic oil is discharged twice from the discharge port 43 by one reciprocating motion of the piston 50, discharge unevenness can be reduced and the discharge performance can be improved.

  According to the electromagnetic pump 20 of the embodiment described above, the valve main body 62 of the suction check valve 60 includes a cylindrical pedestal portion 63a, and a truncated cone-shaped protruding portion 63b protruding from the seating surface of the pedestal portion 63a. Since the base portion 63a is formed so that the spring 46 is supported by the annular surface of the peripheral portion of the seat surface and the protruding portion 63b protrudes into the pump chamber 41, the seat surface of the base portion 63a is formed. The spring interval can be adjusted by adjusting the height, and the volume in the pump chamber 41 can be adjusted by adjusting the protruding height and diameter of the protruding portion 63b. As a result, the biasing force of the spring 46 and the volume of the pump chamber 41 can be optimized with a simple configuration, and the discharge performance can be further improved. Moreover, the hollow portion 62a formed inside the valve body 62 extends from the back surface of the pedestal portion 63a to the vicinity of the tip inside the protruding portion 63b from the back surface of the pedestal portion 63a around the shaft center. 64, the spring 66, and the plug 68 are incorporated, so that the axial length of the valve body 62 only needs to be ensured by the length necessary for incorporating the ball 64, the spring 66, and the plug 68. Can be made more compact.

  In the electromagnetic pump 20 of the embodiment, the discharge check valve 70 is built in the piston 50. However, the discharge check valve 70 may be built in a valve body outside the cylinder 42 and not built in the piston 50, for example.

  In the electromagnetic pump 20 of the embodiment, the protruding portion 63b of the valve body 62 has a truncated cone shape. However, the invention is not limited thereto. For example, the protruding portion 63b protrudes into the pump chamber 41 such as a cylindrical shape. Any shape can be used.

  In the electromagnetic pump 20 of the embodiment, the hollow portion 62a of the valve body 62 extends from the back surface of the pedestal portion 63b through the inside of the pedestal portion 63a to the vicinity of the tip inside the protruding portion 63b. It is good also as what does not extend to. In this case, the height of the pedestal 63a may be increased in order to incorporate the ball 64, the spring 66, and the plug 68 into the hollow portion.

  The electromagnetic pump 20 of the embodiment is configured as an electromagnetic pump of a type that discharges hydraulic oil twice from the discharge port 43 by one reciprocating motion of the piston 50. However, the present invention is not limited to this. When the piston is moved forward by electromagnetic force from the part, the hydraulic oil is sucked into the pump chamber from the suction port, and when the piston is moved backward by the biasing force of the spring, the hydraulic oil in the pump chamber is discharged from the discharge port. , When returning the piston by the biasing force of the spring, the hydraulic oil is drawn into the pump chamber from the suction port, and the hydraulic oil in the pump chamber is discharged from the discharge port when the piston is moved forward by the electromagnetic force from the solenoid section Any type of electromagnetic pump can be used as long as it can discharge the working fluid as the piston reciprocates. It does not.

  The electromagnetic pump 20 of the embodiment is used to supply hydraulic pressure for turning on and off a clutch and a brake of an automatic transmission mounted on an automobile. However, the invention is not limited to this. The present invention may be applied to any system such as transferring a liquid.

  Here, the correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems will be described. In the embodiment, the cylinder 42 corresponds to the “cylinder”, the piston 50 corresponds to the “piston”, the solenoid part 30 corresponds to the “electromagnetic part”, the spring 46 corresponds to the “biasing member”, and the valve body 62 corresponds to the “support member”, the ball 64, the spring 66, and the plug 68 constituting the suction check valve 60 correspond to the “suction open / close valve”, and the discharge check valve 70 corresponds to the “discharge open / close valve”. The pedestal 63a of the valve main body 62 corresponds to the “support”, and the protrusion 63b corresponds to the “protrusion”. The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem is the same as that of the embodiment described in the column of means for solving the problem. It is an example for specifically explaining the best mode for doing so, and does not limit the elements of the invention described in the column of means for solving the problem. That is, the interpretation of the invention described in the column of means for solving the problems should be made based on the description of the column, and the examples are those of the invention described in the column of means for solving the problems. It is only a specific example.

  The embodiments of the present invention have been described using the embodiments. However, the present invention is not limited to these embodiments, and can be implemented in various forms without departing from the gist of the present invention. Of course you get.

  The present invention can be used in the manufacturing industry of electromagnetic pumps.

  20 Electromagnetic pump, 30 Solenoid part, 31 Case, 32 Electromagnetic coil, 34 Plunger, 36 Core, 38 Shaft, 40 Pump part, 41 Pump chamber, 42 Cylinder, 42a Opening part, 42b, 42c Inner wall, 43 Discharge port, 44 pin Groove, 46 Spring, 47 Strainer, 48 Cylinder cover, 49 Suction port, 50 Piston, 52 Piston body, 52a Hollow part, 52b Opening part, 54 Shaft part, 54a, 54b Through hole, 56 Second pump chamber, 60 Suction Check valve, 62 valve body, 62a hollow portion, 62b center hole, 63a protrusion, 63b pedestal portion, 64 balls, 66 spring, 68 plug, 69 center hole, 70 discharge check valve, 74 balls, 76 spring 78 Plug, 79 Center hole.

Claims (5)

A cylinder, a piston capable of reciprocating in the cylinder, an electromagnetic part for moving the piston forward, an urging member for returning the piston, and a pump chamber together with the cylinder and the piston supporting the urging member A support member for partitioning, a suction on-off valve that is incorporated in the support member and permits movement of the working fluid from the suction port to the pump chamber and prohibits movement in the reverse direction, and operation from the pump chamber to the discharge port A discharge on-off valve that permits movement of fluid and prohibits movement in the reverse direction,
The inside of the support member includes a bottomed hollow portion that accommodates at least a part of the suction opening / closing valve from the suction port side, and a communication hole that communicates the pump chamber side bottom portion of the hollow portion with the pump chamber. Have
The electromagnetic pump according to claim 1, wherein the support member includes a support portion that supports the biasing member, and a protruding portion that communicates with the communication hole and protrudes toward the piston from the support portion.   2. The electromagnetic pump according to claim 1, wherein the protruding portion is formed so that a diameter on the piston side is smaller than a diameter on the support portion side.   The electromagnetic pump according to claim 2, wherein the protrusion is formed in a truncated cone shape.   The electromagnetic pump according to any one of claims 1 to 3, wherein the working fluid is discharged by the backward movement of the piston by the biasing member.   The electromagnetic pump according to any one of claims 1 to 4, wherein the hollow portion of the support member is formed such that a bottom portion is deeper toward the piston side than a support surface of the support portion.