JP3777254B2 - Solenoid pump device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a solenoid including a fixed core, a movable core that can be moved toward and away from the fixed core, and a coil that exhibits an electromagnetic force that attracts the movable core toward the fixed core; And a plunger whose one end faces the pump chamber formed between the pump housing and the other end side of the pump core is coaxially connected to the movable housing. And a pump that is movably fitted to the solenoid pump device.
[0002]
[Prior art]
Conventionally, such a solenoid pump device is already known, for example, from JP-A-6-288341.
[0003]
[Problems to be solved by the invention]
By the way, in the conventional solenoid pump device, the pump housing is formed of a heat resistant resin to which carbon fiber for increasing mechanical strength and fluororesin powder for reducing sliding resistance are added, and the plunger is Although it is made of hard chrome or liquid nitrocarburized stainless steel to increase surface hardness, materials with carbon fiber added to heat-resistant resin are generally expensive and increase processing costs. Resulting in.
[0004]
In order to solve such a problem, it is conceivable that the pump housing and the plunger are formed of carbon steel that has been hardened. In the above-described conventional one, the pump housing and the plunger are disposed in the fixed core. ing. Therefore, in the same arrangement as the conventional pump housing, the pump housing and the plunger are formed of carbon steel that has been subjected to the hardening treatment, and the influence of the magnetic field from the fixed core side is exerted on the pump housing and the plunger. There is a possibility that the pump housing and the plunger may be magnetically fixed to deteriorate the operability of the pump.
[0005]
The present invention has been made in view of such circumstances, and an object thereof is to provide a solenoid pump device capable of forming a pump housing and a plunger from a low-cost material while ensuring the operability of the pump. And
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention includes a fixed core, a movable core that can be moved toward and away from the fixed core, and a coil that exhibits an electromagnetic force that attracts the movable core toward the fixed core. A solenoid; a pump housing that is coaxially connected to the fixed core and disabled in an axial relative position, and has one end facing a pump chamber formed between the pump housing and the other end of the movable core A solenoid pump device configured to slidably fit a plunger that is coaxially connected, and the coil is disposed so as to surround the fixed core and the movable core formed in a cylindrical shape, The other end of the connecting tube portion to which one end of a carbon steel pump housing subjected to hardening treatment is coupled is coaxial with the end portion of the fixed core on the side opposite to the movable core, and One end of a rod made of a non-magnetic material, which is connected to the body and is inserted into the fixed core so as to be movable in the axial direction, is coaxially abutted with a carbon steel plunger whose surface is hardened, and the rod The other end is abutted coaxially with the movable core.
[0007]
According to such a configuration, since the other end of the connecting cylinder portion having the pump housing coupled to one end is coaxially and integrally connected to the end portion of the fixed core on the side opposite to the movable core, at least the pump The housing will be placed at a position away from the fixed core, and the rod made of non-magnetic material that is inserted in the fixed core so as to be movable in the axial direction is in contact with the plunger coaxially, so that it is fixed by exciting the coil. The influence of the magnetic field generated in the core is suppressed as much as possible to the pump housing and the plunger. For this reason, the pump housing and the plunger slidably fitted in the pump housing are made of carbon steel whose surface is hardened to ensure strength and wear resistance. Even if it contains a relatively large amount of carbon, it is possible to suppress magnetic remanence due to the influence of the magnetic field from the fixed core as much as possible, and to prevent the pump housing and the plunger from being magnetically fixed. Therefore, even if the pump housing and plunger are made of carbon steel, which is excellent in workability and low in cost, it is possible to maintain the pump operability satisfactorily. Can be secured.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on one embodiment of the present invention shown in the accompanying drawings.
[0009]
FIG. 1 shows an embodiment of the present invention. This solenoid pump device is used, for example, in a brake fluid pressure control device for a vehicle, and includes a pump 5 and a solenoid 6 for driving the pump 5. Consists of.
[0010]
The pump 5 includes a bottomed cylindrical pump housing 8 having an end wall 7 at one end, and a rod-shaped plunger 9 slidably fitted to the pump housing 8.
[0011]
The pump housing 8 is subjected to hardening treatment such as carburizing, quenching and tempering in order to ensure strength and wear resistance after carbon steel having excellent workability is processed according to the shape of the pump housing 8. The plunger 9 is also carburized, quenched and tempered to ensure strength and wear resistance after the carbon steel having excellent workability is processed according to the shape of the plunger 9. Etc. are subjected to curing treatment.
[0012]
A discharge port 10 is provided at the center of the end wall 7 in the pump housing 8, and a pump chamber 11 is formed between one end of the plunger 9 and the end wall 7. The other end of the plunger 9 protrudes from the other end of the pump housing 8. The other end of the plunger 9 extends along one diameter line of the plunger 9 and both ends are open to the outer surface of the plunger 9. A squeezed inlet 12 is provided. Further, a communication passage 14 is provided coaxially with the plunger 9 so that the opening of one end faces a tapered valve seat 13 provided at the center of one end of the plunger 9, and the other end of the communication passage 14 communicates with the suction port 12.
[0013]
A suction valve 15 capable of closing one end opening of the communication passage 14 is housed in the pump chamber 11. The suction valve 15 includes the valve seat 13 and a spherical valve that can be seated on the valve seat 13. A body 16 and a spring 17 that is provided between the end wall 7 of the pump housing 8 and the valve body 16 and that exerts a spring force that urges the valve body 16 in a direction in which the valve body 16 is seated on the valve seat 13 are provided.
[0014]
The suction valve 15 opens as the pressure of the pump chamber 11 is reduced as the plunger 9 moves in the direction of increasing the volume of the pump chamber 11 (the right direction in FIG. 1). Brake fluid is sucked into the pump chamber 11 from the opening 12 through the communication passage 14, and the pressure in the pump chamber 11 is increased as the plunger 9 moves in a direction to reduce the volume of the pump chamber 11. In response to this, the valve is closed to prevent the brake fluid from flowing into the pump chamber 11 from the communication passage 14.
[0015]
By the way, the pump 5 is attached to the base 18, and the base 18 is provided with a bottomed first fitting hole 19 for fitting and fixing the pump housing 8 of the pump 5. The pump housing 8 is fitted into the first fitting hole 19 so as to form a discharge liquid chamber 20 between one end thereof and the closed end of the first fitting hole 19, and is disposed on the outer periphery of the pump housing 8. An annular seal member 21 that elastically contacts the inner peripheral surface of the first fitting hole 19 is mounted.
[0016]
A discharge valve 22 is mounted on the pump housing 8 in the discharge liquid chamber 20. The discharge valve 22 faces the discharge port 10 leading to the pump chamber 11 toward the center, and the discharge liquid chamber 20 on the end wall 7. A tapered valve seat 23 provided on the side surface, a spherical valve body 24 seatable on the valve seat 23, a retainer 26 attached to one end of the pump housing 8, and a valve body 24. A spring 25 that exerts a spring force that urges the body 24 in the seating direction to the valve seat 23, and a communication for preventing the discharge liquid chamber 20 from being partitioned by the retainer 26 at the center of the retainer 26. A hole 27 is provided.
[0017]
Such a discharge valve 22 closes in response to the pressure in the pump chamber 11 being reduced as the plunger 9 moves in the direction of increasing the volume of the pump chamber 11, and discharges from the discharge liquid chamber 20. Although the brake fluid is prevented from flowing into the pump chamber 11 via the outlet 10, the pressure in the pump chamber 11 is increased as the plunger 9 moves in the direction of decreasing the volume of the pump chamber 11. In response to this, the valve is opened, and the brake fluid is discharged from the pump chamber 11 through the discharge port 10 to the discharge fluid chamber 20. Thus, the base 18 is provided with a discharge passage 28 whose one end communicates with the discharge liquid chamber 20.
[0018]
The solenoid 5 has a fixed core 30, a movable core 31 that can be moved toward and away from the fixed core 30, and is coaxially connected to the plunger 9 of the pump 5, and attracts the movable core 31 toward the fixed core 30 during excitation. And a coil 32 that exhibits electromagnetic force.
[0019]
The fixed core 30 is formed in a cylindrical shape by a magnetic metal such as free-cutting steel having excellent workability, and the other end of the connecting tube portion 33 with one end extending to the pump 5 side is the movable core 31. The other end of the fixed core 30 is coaxially and integrally connected to the end of the fixed core 30. The other end of the pump housing 8 in the pump 5 is coupled to one end of the connection cylinder 33 by press-fitting or the like. Further, a flange portion 34 projecting radially outward from the connecting portion of the fixed core 30 and the connecting cylinder portion 33 is provided integrally with the fixed core 30 and the connecting cylinder portion 33.
[0020]
In addition, the other end portion of the plunger 9 in the pump 5 protrudes from the other end of the pump housing 8 and is slidably fitted into the connection tube portion 33. An annular seal member 35 that is elastically slidably brought into contact with the outer surface of the other end is attached.
[0021]
Incidentally, the base 18 has a second fitting hole 36 having a larger diameter than the first fitting hole 19 into which the pump housing 8 is fitted, and an annular stepped portion 37 between the fitting holes 19, 36. It is provided coaxially with the first fitting hole 19 so as to be formed, and the outer end of the second fitting hole 36 is opened on the outer surface of the base 18. Thus, the connecting tube portion 33 is fitted into the second fitting hole 36 and the flange portion 34 is fastened to the outer surface of the base 18, and one end portion of the connecting tube portion 33 and the other end portion of the pump housing 8. An annular chamber 38 is formed between the inner peripheral surface of the second fitting hole 36 and the stepped portion 37, and the inner surface of the second fitting hole 36 is formed on the outer surface near the flange portion 34 of the connecting tube portion 33. An annular seal member 39 that is elastically contacted is attached.
[0022]
A guide member 40 formed in a cylindrical shape with a magnetic metal is fitted to the fixed core 30 and the connecting cylinder portion 33, and an inner end is fitted into an annular groove 41 provided on the outer periphery of the guide member 40. A pin 42 that determines the axial position of the guide member 40 is fitted to the fixed core 30 with an axis line along the radial direction of the guide member 40. Thus, the plunger 9 is interposed between one end of the guide member 40 whose axial position is fixed in the fixed core 30 and the connecting cylinder portion 33, and the other end portion of the plunger 9 and one end portion of the connecting cylinder portion 33. An inhalation liquid chamber 43 that communicates with the inhalation port 12 is formed, and the other end position of the guide member 40 is arranged so as not to protrude from the fixed core 30 to the movable core 31 side. Further, the outer end of the pin 42 does not protrude from the outer surface of the fixed core 30 in the fitted state to the fixed core 30.
[0023]
The connecting tube portion 33 is provided with a plurality of communication passages 44 that allow the annular chamber 38 to communicate with the suction liquid chamber 43, and the base 18 is provided with a suction passage 45 that allows one end to pass through the annular chamber 38.
[0024]
The fixed core 30 is assembled to the guide tube 46. The guide tube 46 includes a cylindrical portion 46a in which the fixed core 30 is fitted to one end side, and a bottomed cylindrical portion 46b that is coaxially connected to the other end of the cylindrical portion 46a. Is formed thinner than the thickness of the cylindrical portion 46a, but the cylindrical portion 46a and the bottomed cylindrical portion 46b are integrally connected in such a manner that the inner surfaces are connected to be flush with each other. Moreover, an annular seal member 47 that elastically contacts the inner surface of the cylindrical portion 46 a of the guide tube 46 is attached to the outer periphery of the fixed core 30.
[0025]
The movable core 31 is slidably fitted into the guide tube 46 so as to face the fixed core 30. One end of the movable core 31 is in contact with the other end of a rod 48 made of a non-magnetic material whose one end is in coaxial contact with the other end of the plunger 9 in the pump 5. It is slidably fitted. Further, in the suction liquid chamber 43, a spring 49 is provided between the plunger 9 and the connecting cylinder portion 33 to exert a spring force in a direction in which the plunger 9 abuts against the rod 48. The spring force of the spring 49 is as follows. The movable core 31 acts on the movable core 31 via the rod 48, and the movable core 31 is urged away from the fixed core 30 by the spring force of the spring 49. Note that the spring force of the spring 17 in the suction valve 15 also acts on the plunger 9 in the direction in which it abuts against the rod 48, but the spring load of the spring 17 is set smaller than the spring load of the spring 49.
[0026]
In order to prevent the movable core 31 from moving away from the fixed core 30 due to magnetic fixation between the movable core 31 and the fixed core 30 due to the direct contact between the movable core 31 and the fixed core 30. The spacer 50 made of a non-magnetic material is interposed so as to have a sufficient distance from the movable core 31 separated from the fixed core 30.
[0027]
A cylindrical portion 46 a of the guide tube 46 is coaxially surrounded by a synthetic resin bobbin 51, and the coil 32 is wound around the bobbin 51. That is, the coil 32 is disposed so as to surround the fixed core 30 and the movable core 31.
[0028]
Further, the bobbin 51 and the coil 32 and the protruding portion of the guide tube 46 from the bobbin 51 are covered with a yoke 52 made of magnetic metal, and the yoke 52 is coupled to the flange portion 34.
[0029]
The yoke 52 is formed, for example, in a stepped bottomed cylindrical shape, and has a first cylindrical portion 52a in which one end faces the outer surface of the base 18 and the flange portion 34 is fitted, and an outer portion of the flange portion 34. A first annular step 52b projecting radially inward from the other end of the first cylindrical portion 52a so as to contact the peripheral portion, a bobbin 51 and the coil 32 are coaxially surrounded, and the first annular step 52b A second cylindrical portion 52c having one end coaxially connected to the inner peripheral portion, and a second annular stage projecting radially inward from the other end of the second cylindrical portion 52c and holding the bobbin 51 between the flange portion 34 52d, a third cylindrical portion 52e that coaxially surrounds the protruding portion from the bobbin 51 of the guide tube 46 by connecting one end coaxially to the inner peripheral portion of the second annular stepped portion 52d, and a third cylindrical portion 52e. And an end plate portion 52f for closing the other end of the first circle. Parts 52a and the flange portion 34 is bonded to each other by press-fitting or the like.
[0030]
In such a solenoid pump device including the pump 5 and the solenoid 6, when the coil 32 is in a demagnetized state, the movable core 31 is moved away from the fixed core 30 by the spring force of the spring 49 (shown position). The plunger 9 of the pump 5 has moved to a position where the volume of the pump chamber 11 is increased. When the coil 32 is energized, the movable core 31 moves in the direction close to the fixed core 30 against the spring force of the spring 49, and the plunger 9 of the pump 5 moves toward the side that reduces the volume of the pump chamber 11. Driven by pressing. That is, by switching the demagnetization / excitation of the coil 32, the movable core 31 is reciprocated in the axial direction, and the plunger 9 is reciprocated in the axial direction accordingly, and the pump 5 is pumped.
[0031]
By the way, when the space between the movable core 31 and the fixed core 30 and the closed end of the guide tube 46 and the space between the movable cores 31 are sealed, respectively, the addition of each space according to the reciprocating movement of the movable core 31, The pressure is reduced and the smooth reciprocation of the movable core 31 is hindered. Therefore, a communication groove 53 connecting the two spaces is provided on the outer surface of the movable core 31 over the entire length in the axial direction. Further, a groove 54 along one diameter line of the rod 48 is provided on one end face of the rod 48 facing the suction liquid chamber 43, and one diameter of the rod 48 is provided on the other end face of the rod 48 contacting the movable core 31. A groove 55 along the line is provided, and the rod 48 is provided with a communication hole 56 connecting the grooves 54 and 55 coaxially. That is, the suction liquid chamber 43 communicates with the space between the movable core 31 and the fixed core 30 via the groove 54, the communication hole 56 and the groove 55, and the space between the movable core 31 and the fixed core 30 passes through the communication groove 53. The guide cylinder 46 communicates with the space between the closed end and the movable core 31.
[0032]
Next, the operation of this embodiment will be described. In the pump 5, a plunger 9 having one end facing the pump chamber 11 is slidably fitted to the pump housing 8 so that a solenoid 6 that reciprocates is provided. The plungers 9 are coaxially connected to each other, the connection structure of the pump 5 and the solenoid 6 can be simplified, and the operation efficiency of the pump 5 and the solenoid 6 can be improved.
[0033]
In addition, the solenoid 6 includes a fixed core 30, a movable core 31 that is coaxially connected to the plunger 9 so as to be close to and away from the fixed core 30, and an electromagnetic force that attracts the movable core 31 toward the fixed core 30 during excitation. The coil 32 that exhibits the above is provided, and the cost can be reduced as an actuator for driving the pump 5.
[0034]
Further, since the other end of the connecting tube portion 33 in which the pump housing 8 is coupled to one end is coaxially and integrally connected to the end portion of the fixed core 30 on the side opposite to the movable core 31, at least the pump housing 8. Is disposed at a position separated from the fixed core 30. Further, since the rod 48 made of a non-magnetic material that is inserted into the fixed core 30 so as to be movable in the axial direction is abutted on the plunger 9 coaxially, the influence of the magnetic field generated in the fixed core 30 by the excitation of the coil 32 is affected by the pump housing 8 and Covering the plunger 9 is suppressed as much as possible. For this reason, the pump housing 8 and the plunger 9 slidably fitted in the pump housing 8 are made of carbon steel whose surface is hardened to ensure strength and wear resistance. As a result, even if it contains a relatively large amount of carbon, the residual magnetism due to the influence of the magnetic field from the fixed core 30 side is suppressed as much as possible, and magnetic sticking of the pump housing 8 and the plunger 9 is suppressed. can do. Therefore, even if the pump housing 8 and the plunger 9 are formed of carbon steel having excellent workability and low cost, the operability of the pump 5 can be maintained satisfactorily, and the pump 5 can be achieved while reducing costs. Operability can be ensured.
[0035]
On the other hand, since the rod 48 is slidably fitted to the guide member 40 that is fitted and fixed to the fixed core 30 that is a separate body from the pump housing 8, the surface of the fixed core 30 is not cured. It is not necessary, and the fixed core 30 is not deformed after the fixed core 30 is processed, and the fixed core 30 does not need to be processed with an excessive processing accuracy.
[0036]
Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the present invention described in the claims. Is possible.
[0037]
【The invention's effect】
As described above, according to the present invention, the influence of the magnetic field generated in the fixed core is suppressed as much as possible to the pump housing and the plunger, and the pump housing and the plunger are hardened on the surface to ensure strength and wear resistance. Due to the fact that it is made of carbon steel that has been subjected to the treatment, even if it contains a relatively large amount of carbon, it is possible to suppress magnetic sticking of the pump housing and the plunger, and to reduce costs. The operability of the pump can be ensured.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a solenoid pump device.
[Explanation of symbols]
5 ... Pump 6 ... Solenoid 8 ... Pump housing 9 ... Plunger 11 ... Pump chamber 30 ... Fixed core 31 ... Movable core 32 ... Coil 33 ... Connection cylinder Part 48 ... Rod

Claims (1)

A fixed core (30), a movable core (31) that can be moved toward and away from the fixed core (30), and a coil that exhibits an electromagnetic force that attracts the movable core (31) toward the fixed core (30). A solenoid (6) comprising: (32); between the pump housing (8) and the pump housing (8) connected to the fixed core (30) coaxially and in an axially relative position disabled. And a pump (5) having a plunger (9) slidably fitted to the movable core (31) and having the other end coaxially connected to the movable core (31). In the solenoid pump device, the coil (32) is disposed so as to surround the fixed core (30) formed in a cylindrical shape and the movable core (31), and the surface is subjected to hardening treatment. Pump housing 8) is connected to the end of the fixed core (30) on the side opposite to the movable core (31), and the other end of the connecting cylinder (33) coupled to one end is coaxially and integrally connected. One end of a rod (48) made of a non-magnetic material that is inserted into the fixed core (30) so as to be movable in the axial direction is coaxially abutted with a plunger (9) made of carbon steel whose surface is hardened, A solenoid pump device, wherein the other end of the rod (48) abuts on the movable core (31) coaxially.

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