JP2013174257A - Electromagnetic valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of uncomfortable operation noise generated by the self-exciting vibration of a moving member at an abrupt change of pressure, in an electromagnetic valve which controls a pressure difference between fluid pressure at an upstream side and fluid pressure at a downstream side by adjusting an electricity carrying amount to a coil.SOLUTION: Irregularities for increasing slide resistance are formed at least at one of slide faces 402a, 411b of a plunger 411 being a movable member and a shaft-shaft 402. By this, the movement of the movable member becomes mild at an abrupt change of pressure, and the self-exciting vibration of the movable member is hardly generated.

Description

  The present invention relates to an electromagnetic valve that controls a differential pressure between an upstream fluid pressure and a downstream fluid pressure by adjusting an energization amount to a coil.

  Conventionally, in Patent Document 1, an electromagnetic valve applied to an actuator of a vehicle brake device has been proposed. In the electromagnetic valve shown in Patent Document 1, a plunger that is attracted by electromagnetic force when energizing a coil is slidably accommodated in a bottomed cylindrical sleeve, and a shaft that follows the plunger is operated. It is slidably held in a guide hole provided in the guide. The shaft is integrally formed with a valve member that contacts and separates from the valve seat to open and close the flow path. Further, the plunger and the shaft are biased by a spring in a direction that opposes the suction direction by electromagnetic force.

  The distance between the valve element and the valve seat (that is, the valve opening) is determined by the balance of electromagnetic force, fluid force, and spring force, and the electromagnetic force is adjusted by adjusting the energization amount to the coil. By controlling the valve opening, the desired differential pressure is generated between the upstream and downstream of the electromagnetic valve.

JP-A-11-108230

  However, in the conventional solenoid valve, when the electromagnetic force is suddenly changed in order to suddenly change the pressure, the fluid force suddenly changes and the balance of the above forces is lost, so that the plunger and the shaft which are movable members repeat reciprocating motion at high speed. There has been a problem that an unpleasant operating sound is generated due to a self-excited vibration state.

  In view of the above points, an object of the present invention is to prevent generation of unpleasant operating noise due to self-excited vibration of a movable member.

  In order to achieve the above object, according to the invention described in claim 1, in the valve seat (403b), the seat (403) having the first flow path (403a) formed on the fluid flow upstream side of the valve seat, A valve body (404) that opens and closes between the second flow path (401d) and the first flow path on the fluid flow downstream side of the seat, a coil (413) that forms a magnetic field when energized, and energization of the coil A plunger (411) that is moved in a direction in which the valve body comes into contact with the valve seat or a direction in which the valve body is separated from the valve seat, a shaft (402) that has the valve body and is moved as the plunger moves, and the plunger and the shaft Holding member (401, 410) that slidably holds the coil, and the distance between the valve element and the valve seat is controlled by adjusting the amount of current supplied to the coil, and the fluid in the first flow path Pressure and fluid in the second flow path An electromagnetic valve that controls a differential pressure between a force and a sliding resistance (401a, 402a, 410a, 411b) on at least one of a plunger, a shaft, and a holding member. Unevenness is formed.

  According to this, since the sliding resistance between the plunger or shaft, which is a movable member, and the holding member increases, the movement of the movable member when the pressure is suddenly changed becomes slow, and self-excited vibration of the movable member occurs. It becomes difficult. Therefore, it is possible to suppress generation of unpleasant operating noise due to self-excited vibration of the movable member.

  According to a second aspect of the present invention, in the electromagnetic valve according to the first aspect, the shaft is made of resin and the unevenness is a texture. According to this, irregularities can be easily formed by embossing during molding.

  As in the invention according to claim 3, in the solenoid valve according to claim 1, a groove is formed in at least one sliding surface (401a, 402a, 410a, 411b) of the plunger, the shaft, and the holding member. It can be formed to form irregularities.

  According to a fourth aspect of the present invention, in the electromagnetic valve according to the third aspect, the groove is spiral. According to this, the groove can be easily formed by cutting.

  In addition, the code | symbol in the bracket | parenthesis of each means described in this column and the claim shows the correspondence with the specific means as described in embodiment mentioned later.

It is front sectional drawing which shows the state by which the solenoid valve which concerns on one Embodiment of this invention was assembled | attached to the housing of the actuator. It is an enlarged front view of the shaft in the solenoid valve of FIG. It is a front view of the shaft which shows a 1st modification. It is a front view of the shaft which shows a 2nd modification.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  As shown in FIG. 1 and FIG. 2, for hydraulic pressure control for controlling brake hydraulic pressure between a master cylinder (hereinafter referred to as M / C) 2 and a wheel cylinder (hereinafter referred to as W / C) 1 of a vehicle. An actuator 3 is provided. The hydraulic pressure control actuator 3 includes an aluminum alloy housing 3a. The housing 3a has a stepped cylindrical recess 3b into which the electromagnetic valve 4 is inserted, and a brake between the M / C2 and the W / C1. A flow path 3c for flowing the liquid is formed.

  The electromagnetic valve 4 includes a stepped cylindrical guide 401 made of a magnetic material. One end of the guide 401 is inserted into the recess 3b of the housing 3a, and the other end protrudes outside the housing 3a. And the guide 401 is liquid-tightly fixed to the housing 3a by caulking the opening end part of the recessed part 3b.

  In the guide 401, a guide hole 401a for slidably holding the shaft 402, a sheet insertion hole 401b into which the sheet 403 is press-fitted, and a space 401c which is a part of the sheet insertion hole 401b are flown on the M / C2 side. A communication hole 401d communicating with the path 3c is formed. More specifically, the space 401c is a space defined by the guide 401, the shaft 402, and the sheet 403 in the sheet insertion hole 401b. The communication hole 401d corresponds to the second flow path of the present invention. The guide 401 corresponds to the holding member of the present invention. Further, the guide hole 401a corresponds to the sliding surface of the present invention.

  The columnar shaft 402 can reciprocate along the axial direction of the guide hole 401a. A portion of the shaft 402 on the side of the seat 403 protrudes from the guide hole 401a and extends into the space 401c, and a spherical main valve body 404 is integrally formed at the tip thereof.

  An uneven portion is formed in a portion 402a of the shaft 402 that slides while being held in the guide hole 401a (hereinafter referred to as a shaft sliding surface 402a) in order to increase sliding resistance. More specifically, by forming irregularities on the shaft sliding surface 402a, the sliding resistance between the guide 401 and the shaft 402 is increased as compared with the case where irregularities are not formed. The shaft 402 is made of resin and is molded with a mold. The unevenness of the shaft sliding surface 402a is formed of a texture, and this texture can be easily formed by, for example, forming a texture on a mold. Specifically, a texture pattern such as a leather pattern, a satin pattern, a wood pattern, a texture pattern, or a texture pattern is formed over the entire shaft sliding surface 402a.

  The material of the shaft 402 is not limited to resin. For example, you may form using a metal. In this case, the shaft 402 can be formed by cutting or cold forging. The embossing can also be performed by metal surface processing such as etching.

  The metal cylindrical sheet 403 is formed with a main flow path 403a communicating with the space 401c in the guide 401 and the flow path 3c on the W / C1 side at the center in the radial direction. A tapered main valve seat 403b with which the main valve body 404 comes into contact with and separates from is formed at the end of the main flow path 403a on the space 401c side. 403c is formed. The main valve body 404 is brought into and out of contact with the main valve seat 403b, so that the space 401c in the guide 401 (or the communication hole 401d of the guide 401 or the flow path 3c on the M / C2 side) and the main flow path 403a are separated. Open and close. The main channel 403a corresponds to the first channel of the present invention. The discharge port of the pump 6 is connected to the flow path 3c on the W / C1 side between the recess 3b and W / C1.

  Further, a sub-flow path 403d that connects the space 401c in the guide 401 and the flow path 3c on the W / C1 side is formed in parallel with the main flow path 403a at a position shifted from the radial center of the sheet 403. ing. In other words, the sub flow path 403d bypasses the main flow path 403a and is connected to the W / C1 side flow path 3c and the M / C2 side flow path 3c.

  A tapered secondary valve seat 403e is formed in the middle of the secondary flow path 403d. In the sub flow path 403d, a metal spherical sub valve body 405 is movably inserted on the side closer to the flow path 3c on the W / C1 side than the sub valve seat 403e. The sub-valve body 405 opens and closes between the sub-channel 403d and the W / C1-side channel 3c by moving due to the pressure difference and coming into contact with and separating from the sub-valve seat 403e.

  Further, a sheet portion spring receiving surface 403f that receives one end of a spring 412 described later is formed at the end of the seat 403 on the space 401c side so as to surround the main flow path 403a.

  A filter 407 for preventing foreign matter inflow is inserted on the opening end side of the sheet insertion hole 401 b in the guide 401. The position of the auxiliary valve body 405 when the valve is opened is determined by the filter 407. Further, a foreign substance inflow prevention filter 408 is also disposed on the outer periphery of the guide 401 so as to surround the communication hole 401d.

  A sleeve 410 is fitted on the outer peripheral side of the other end of the guide 401. The sleeve 410 is formed of a non-magnetic metal (for example, stainless steel) and has a bottomed cylindrical shape with one end opened. Has a substantially spherical shape.

  A substantially columnar plunger 411 made of a magnetic metal is disposed in a space defined by the sleeve 410 and the guide 401 (hereinafter referred to as an inner space of the sleeve). The plunger 411 is formed on the inner peripheral surface of the cylindrical portion of the sleeve 410. The sleeve sliding surface 410a is slidably held. Further, when the plunger 411 is in contact with the bottom surface of the sleeve 410, the upward movement of the plunger 411 is restricted. The sleeve 410 corresponds to the holding member of the present invention.

  A plunger groove 411 a that extends continuously from one end to the other end of the plunger 411 is formed on the outer peripheral surface of the plunger 411. The space on the bottom surface side of the sleeve 410 in the inner space of the sleeve and the space between the opposing surfaces of the plunger 411 and the guide 401 in the inner space of the sleeve are communicated with each other by the plunger groove 411a.

  Of the outer peripheral surface of the plunger 411 having a constant outer diameter, a portion 411b excluding the plunger groove 411a is slid while being held by the sleeve 410. Hereinafter, the portion 411b is referred to as a plunger sliding surface 411b.

  A spool 414 around which a coil 413 that forms a magnetic field when energized is wound is disposed around the sleeve 410. A yoke 415 forming a magnetic path member is disposed on the outer periphery of the spool 414. The plunger 411 is driven by electromagnetic force generated by energization of the coil 413 from the ECU (electronic control unit) 5. The ECU 5 controls the energization state of the coil 413 so as to execute ABS control or the like based on the motion state of the vehicle.

  The shaft 402 is urged toward the plunger 411 by the spring 412 sandwiched between the shaft 402 and the seat 403, and the shaft 402 and the plunger 411 are always in contact with each other so as to operate integrally.

  The spring 412 is a compression coil spring, and biases the plunger 411 and the shaft 402 in a direction in which the main valve body 404 is separated from the main valve seat 403b, that is, in a valve opening direction. In addition, the plunger 411 and the shaft 402 are biased in the direction in which the main valve body 404 approaches the main valve seat 403b, that is, in the valve closing direction, by the electromagnetic force generated by energizing the coil 413.

  The main flow path 403 a communicates with an inner space located inside the spring 412 in the space 401 c in the guide 401. The communication hole 401 d communicates with an outer space located outside the spring 412 in the space 401 c in the guide 401.

  Next, the basic operation of the solenoid valve 4 having the above configuration will be described. Normally, the solenoid valve 4 is not energized from the ECU 5 to the coil 413, that is, is not energized. When not energized, the shaft 402 and the plunger 411 are moved toward the bottom surface of the sleeve 410 by the spring 412. The plunger 411 is in contact with the bottom surface of the sleeve 410. Then, the main valve body 404 of the shaft 402 is separated from the main valve seat 403b of the seat 403, and the main flow path 403a of the seat 403 is interposed between the W / C1 side flow path 3c and the M / C2 side flow path 3c. A communication state is established through the space 401 c in the guide 401 and the communication hole 401 d of the guide 401.

  When the pump 6 operates in this state, the sub valve body 405 is moved toward the sub valve seat 403e side of the seat 403 due to the pressure difference between the W / C1 side and the M / C2 side, and the sub valve body 405 is moved to the sub valve seat. The auxiliary flow path 403d of the sheet 403 is closed in contact with 403e. Therefore, when the pump 6 is operated, the brake fluid flows from the W / C1 side to the M / C2 side only through the main channel 403a of the main channel 403a and the sub channel 403d of the seat 403.

  When the operation of the pump 6 is stopped, the auxiliary valve body 405 moves due to the pressure difference between the W / C1 side and the M / C2 side, and is separated from the auxiliary valve seat 403e of the seat 403. The flow path 3c on the / C1 side and the flow path 3c on the M / C2 side are in communication with each other via the sub-flow path 403d of the sheet 403, the space 401c in the guide 401, and the communication hole 401d of the guide 401. Therefore, when the operation of the pump 6 is stopped, the brake fluid can be quickly returned from the M / C2 side to the W / C1 side via the main flow path 403a and the sub flow path 403d of the seat 403. .

  When W / C1 pressure increase due to the operation of the pump 6 is necessary, the ECU 5 operates the pump 6 and energizes the coil 413 to close the main flow path 403a. As a result, the W / C pressure increases.

  Here, the distance between the main valve body 404 and the main valve seat 403b (that is, the balance between the electromagnetic force generated by energizing the coil 413, the fluid force acting on the shaft 402, and the spring force of the spring 412 (that is, the main valve seat 403b) , Valve opening) is determined. The distance between the main valve body 404 and the main valve seat 403b is controlled by adjusting the amount of current supplied to the coil 413, and the amount of differential pressure generated between the upstream and downstream of the electromagnetic valve 4 is linearly adjusted. The As a result, the W / C pressure is controlled in accordance with the energization amount to the coil 413.

  In this embodiment, since the sliding resistance between the guide 401 and the shaft 402 is increased by the unevenness of the shaft sliding surface 402a, when the electromagnetic force is suddenly changed in order to change the pressure suddenly, that is, the electromagnetic force and the flow. Even when the balance between the physical force and the spring force is lost, the movement of the shaft 402 becomes slow, and the self-excited vibration of the plunger 411 and the shaft 402 which are movable members is less likely to occur. Therefore, generation of unpleasant operating noise due to self-excited vibration of the plunger 411 and the shaft 402 can be suppressed.

  In addition, the shaft 402 is made of resin, and the unevenness can be easily formed by forming the unevenness on the shaft sliding surface 402a by embossing.

  In the above-described embodiment, the unevenness of the shaft sliding surface 402a is embossed, but the unevenness of the shaft sliding surface 402a may be scale-like as in the first modification shown in FIG.

  Further, in the above embodiment, the unevenness of the shaft sliding surface 402a is embossed. However, as in the second modified example shown in FIG. 4, the shaft sliding surface 402a is formed with a spiral groove so that the shaft The sliding surface 402a may be uneven, or the shaft sliding surface 402a may be uneven by forming a large number of annular grooves on the shaft sliding surface 402a (not shown). In the second modification, when the material is resin, the shaft 402 can be formed by a mold, and when the material is metal, the shaft 402 can be formed by cutting or cold forging. .

(Other embodiments)
In the said embodiment, although the example which applies the solenoid valve 4 to the system which generates a differential pressure | voltage in brake fluid between W / C1 and M / C2 was shown, the solenoid valve 4 of this invention is applied also to another system. Can be applied.

  Although the normally open type electromagnetic valve 4 is shown in the above embodiment, the present invention can also be applied to a normally closed type electromagnetic valve. Incidentally, in the case of a normally closed solenoid valve, the plunger 411 and the shaft 402 are moved in a direction in which the main valve body 404 is separated from the main valve seat 403b by the electromagnetic force generated by energizing the coil 413, that is, in the valve opening direction. The plunger 411 and the shaft 402 are urged by the spring 412 in a direction in which the main valve body 404 approaches the main valve seat 403b, that is, in a valve closing direction.

  The shaft 402 in the above embodiment can be formed by resin molding, sintering, metal melt molding, cutting, cold forging, or the like.

  In the above embodiment, the unevenness is formed in the entire region of the shaft sliding surface 402a. However, the unevenness may be formed in only a part of the shaft sliding surface 402a in the circumferential direction.

  In the above embodiment, the unevenness is formed only on the shaft sliding surface 402a, but the unevenness may be formed only on the plunger sliding surface 411b, or the unevenness is formed on both the shaft sliding surface 402a and the plunger sliding surface 411b. May be.

  In the above embodiment, irregularities are formed on the shaft sliding surface 402a and the plunger sliding surface 411b. However, irregularities may be formed on the guide hole 401a and the sleeve sliding surface 410a.

401 Guide (holding member)
402 Shaft 403 Seat 404 Main valve element (valve element)
410 Sleeve (holding member)
411 Plunger 413 Coil 401a Guide hole (sliding surface)
401d Communication hole (second flow path)
402a Sliding surface 403a Main channel (first channel)
403b Main valve seat (valve seat)
410a sliding surface 411b sliding surface

Claims (4)

A seat (403) having a valve seat (403b) and a first flow path (403a) formed on the fluid flow upstream side of the valve seat;
A valve body (404) for opening and closing between the second flow path (401d) on the fluid flow downstream side of the valve seat and the first flow path;
A coil (413) that forms a magnetic field when energized;
A plunger (411) that is moved in a direction in which the valve body is in contact with the valve seat or in a direction in which the valve body is separated from the valve seat by energization of the coil;
A shaft (402) having the valve body and moved in accordance with the movement of the plunger;
A holding member (401, 410) for slidably holding the plunger and the shaft;
By adjusting the energization amount to the coil, the distance between the valve body and the valve seat is controlled, and between the fluid pressure of the first flow path and the fluid pressure of the second flow path. A solenoid valve for controlling the differential pressure,
An electromagnetic valve characterized in that unevenness for increasing sliding resistance is formed on at least one sliding surface (401a, 402a, 410a, 411b) of the plunger, the shaft and the holding member. .   The electromagnetic valve according to claim 1, wherein the shaft is made of resin, and the unevenness is a texture.   The groove is formed in at least one sliding surface (401a, 402a, 410a, 411b) of the plunger, the shaft, and the holding member to form the unevenness. The solenoid valve according to 1.   The electromagnetic valve according to claim 3, wherein the groove has a spiral shape.

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