JP5240119B2 - solenoid valve - Google Patents

Description

  The present invention relates to an electromagnetic valve, and more particularly to an electromagnetic valve suitable as a hydraulic control valve used in a hydraulic circuit such as a brake device.

  2. Description of the Related Art In recent years, there has been known a brake device that applies a braking force to a wheel by generating a hydraulic pressure in a hydraulic circuit according to an operation force of a brake pedal and supplying the hydraulic pressure to a wheel cylinder. Such a brake device is provided with an electromagnetic valve such as a pressure increasing valve or a pressure reducing valve in front of the wheel cylinder. By controlling the opening and closing of these electromagnetic valves, the amount of hydraulic fluid supplied to and discharged from the wheel cylinder can be reduced. The hydraulic pressure is controlled by adjusting, and an appropriate braking force is applied to each wheel.

  Such a solenoid valve is configured by integrally assembling a body incorporating a valve portion and a solenoid. A valve seat is provided in a passage through which hydraulic fluid is introduced and led out inside the body, and a valve body that can be attached to and detached from the valve seat to open and close the valve portion is disposed. The valve body is supported by a plunger constituting a solenoid so as to be able to operate integrally.

  For example, in the case of a normally closed solenoid valve, when the solenoid is energized, a suction force (hereinafter also referred to as “solenoid force”) is generated between the fixed iron core of the solenoid and the plunger, and the valve element is the valve. Operates in the valve opening direction away from the seat. Between the plunger and the fixed iron core is mounted a spring that urges the plunger, and thus the valve body, against the solenoid force in the valve closing direction to move away from the fixed iron core. For this reason, when the energization to the solenoid is interrupted, the valve body is seated on the valve seat and maintains the valve closed state. During the control in which the solenoid is energized, the valve opening is adjusted so that the force due to the differential pressure applied to the valve body, the solenoid force, and the load due to the spring are balanced.

  By the way, such a solenoid valve generally has a problem of self-excited vibration due to fluctuations in the differential pressure between the front and rear due to operation of a brake pedal or the like. For example, when attempting to start from a state where the vehicle is stopped with the brake applied, when the operation of the brake pedal is loosened, the hydraulic fluid flows from the brake cylinder into the reservoir by opening control of the pressure reducing valve. In this case, if the differential pressure before and after the pressure reducing valve is large, the flow rate of the working fluid flowing through the pressure reducing valve per unit time increases, so that stable pressure reduction is difficult to be performed at a constant rate, and the pressure reducing valve vibrates by itself. There is a case. Also in other solenoid valves such as a pressure booster valve, the problem of self-excited vibration can similarly occur due to the large fluctuation in the differential pressure across the valve. This self-excited vibration is promoted by bubbles precipitated from the working fluid.

  That is, when the solenoid is energized and the valve element is separated from the valve seat along with the operation of the plunger, the hydraulic fluid flows from the high pressure primary pressure side to the low pressure secondary pressure side through the valve portion. At this time, the hydraulic fluid introduced from the valve portion into the valve chamber passes through the communication passage formed in the plunger and flows into the spring chamber on the opposite side of the valve chamber so that the pressure before and after the plunger is eventually balanced. Works. However, when the hydraulic fluid is thus released from the high pressure side to the low pressure side via the valve portion, the gas dissolved under high pressure in the hydraulic fluid may precipitate and become bubbles. When the bubbles are introduced into the spring chamber together with the hydraulic fluid, the oil amount rigidity on the spring chamber side of the plunger is lowered, and a differential pressure acts on the plunger, so that self-excited vibration is likely to occur.

  Therefore, a liquid pressure that suppresses the entry of bubbles into the spring chamber by providing a baffle plate between the flow channel and the communication path so that bubbles generated in the flow path do not enter the spring chamber through the communication path. A valve has been proposed (see Patent Document 1).

JP 2005-308156 A

  However, since the above-described hydraulic valve does not have a structure that positively discharges the bubbles in the spring chamber to the outside, if the bubbles enter the spring chamber, the bubbles may remain as they are. Therefore, further improvement has been demanded from the viewpoint of suppressing self-excited vibration.

  This invention is made | formed in view of such a condition, The place made into the objective is providing the solenoid valve which can suppress the self-excited vibration resulting from a bubble.

  In order to solve the above problems, an electromagnetic valve according to an aspect of the present invention is an electromagnetic valve including a valve portion that is controlled to be opened and closed by a solenoid, and the valve portion is provided inside, and the valve portion is externally provided. A housing in which an inflow port through which hydraulic fluid flows in and an outflow port through which hydraulic fluid that has passed through the valve section flows out, and a valve seat provided inside the housing are arranged so as to be able to come into contact with and separate from, A valve body capable of opening and closing the valve portion; and the inside of the housing is partitioned into a valve chamber on the valve portion side and a back pressure chamber on the opposite side of the valve portion, and the valve A predetermined communication path that connects the chamber and the back pressure chamber is formed, a mover having the valve body attached to an end portion on the valve chamber side, and sandwiching the mover and the back pressure chamber Energized solenoids placed opposite each other A stator that sucks the movable element in the valve opening direction of the valve body by operation, a biasing member that biases the movable element in the valve closing direction of the valve body, and the stator of the movable element. And a gap filling member that fills a gap that has occurred in the back pressure chamber when the mover moves toward the stator.

  According to this aspect, even if bubbles are accumulated in the back pressure chamber, the gaps in the back pressure chamber are filled by the gap filling member, so that the bubbles are easily discharged from the back pressure chamber. As a result, self-excited vibration caused by bubbles is suppressed.

  The gap filling member may be a washer. Thereby, a gap filling member having a simple shape can be realized.

  The washer may be non-magnetic and may define a stroke amount of the valve body by contacting the stator with the valve portion being opened. As a result, even when the washer abuts against the stator, the washer is sandwiched between the stator and the mover, so that the magnetic stator and the mover are in close contact with each other more than necessary. Is prevented. Further, since the washer itself defines the stroke amount of the valve body, it is not necessary to provide a stopper member in the other part of the mover.

  The face of the washer that contacts the stator may have a shape that meets the face of the stator that comes into contact with at least an area outside the communication path. This substantially eliminates the space between the washer and the stator, thereby further reducing the possibility of bubbles remaining on the surface of the stator. In particular, by eliminating the gap in the region outside the communication path, the bubbles pushed out from the gap can easily go to the communication path.

  The communication path may have a first communication path and a second communication path. The first communication path is formed so that a cross-sectional area increases from the valve chamber toward the back pressure chamber, and the second communication path extends from the valve chamber toward the back pressure chamber. Therefore, it may be formed so that the cross-sectional area becomes small. As a result, a flow of hydraulic fluid that circulates between the valve chamber and the back pressure chamber is generated, so that bubbles in the back pressure chamber are easily discharged to the valve chamber side through the communication path.

  The stator may have an R shape at a stepped portion on the surface thereof. Thereby, bubbles existing in the back pressure chamber are less likely to be caught in the troughs than when the stepped troughs are at right angles, and are easily moved by the flow of hydraulic fluid in the back pressure chamber. As a result, the frequency of reaching the vicinity of the communication portion is increased, and the air is easily discharged from the back pressure chamber toward the valve chamber.

  The solenoid valve according to the present invention can suppress self-excited vibration caused by bubbles.

It is a systematic diagram of the brake control device concerning a 1st embodiment. It is sectional drawing which shows in detail the structure of the solenoid valve mounted in the brake control apparatus which concerns on 1st Embodiment. FIG. 3 is an enlarged view including a region A in FIG. 2. It is principal part sectional drawing which shows the spring chamber vicinity in the state which supplied with electricity to the solenoid valve shown in FIG. It is sectional drawing which shows the structure of the solenoid valve which concerns on 2nd Embodiment in detail. It is a perspective view of the plunger which concerns on 2nd Embodiment. It is sectional drawing to which the spring chamber vicinity of the solenoid valve as a comparative example was expanded. It is the figure which showed typically the force received with the flow of a hydraulic fluid when a bubble exists in the trough part of a level | step difference. It is sectional drawing which expanded the spring chamber vicinity which processed the trough part into R shape in the solenoid valve which concerns on 3rd Embodiment. It is the schematic diagram which expanded the trough part vicinity shown in FIG.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. The electromagnetic valve described in the following embodiments can be applied to a hydraulic circuit that controls hydraulic pressure, and is preferably used, for example, in a hydraulic circuit of an electronically controlled brake system for a vehicle. In the description of the drawings, the same elements are denoted by the same reference numerals, and repeated descriptions are omitted as appropriate.

(First embodiment)
FIG. 1 is a system diagram of a brake control device 10 according to the first embodiment. The brake control device 10 employs an electronically controlled brake system (ECB), and independently and optimally sets the four-wheel brakes of the vehicle according to the operation of the brake pedal 12 as a brake operation member by the driver.

  The brake pedal 12 is connected to a master cylinder 14 that sends out brake oil as hydraulic fluid in response to a depression operation by the driver. The brake pedal 12 is provided with a stroke sensor 46 that detects the depression stroke. Further, a reservoir tank 26 is connected to the master cylinder 14, and a reaction force corresponding to the operating force of the brake pedal 12 by the driver is created at one output port of the master cylinder 14 via the electromagnetic valve 23. A stroke simulator 24 is connected. The electromagnetic valve 23 is a so-called normally closed linear valve that closes when no current is supplied, and is supplied with current when the driver depresses the brake pedal 12 and is opened.

  A brake hydraulic pressure control pipe 16 for the right front wheel is connected to one output port of the master cylinder 14. The brake hydraulic pressure control pipe 16 is connected to a right front wheel wheel cylinder 20FR that applies a braking force to the right front wheel. A brake hydraulic pressure control pipe 18 for the left front wheel is connected to the other output port of the master cylinder 14. The brake hydraulic control pipe 18 is connected to a left front wheel wheel cylinder 20FL that applies a braking force to the left front wheel.

  A right master valve 22FR is provided in the middle of the brake hydraulic pressure control pipe 16, and a left master valve 22FL is provided in the middle of the brake hydraulic pressure control pipe 18. Each of the right master valve 22FR and the left master valve 22FL is a so-called normally open linear valve, which is closed in a state where current is supplied, and closes the master cylinder 14 and the right front wheel wheel cylinder 20FR or the left front wheel. The communication with the cylinder 20FL is prevented. Further, the right master valve 22FR and the left master valve 22FL are opened when current supply is reduced or stopped, and the master cylinder 14 and the right front wheel wheel cylinder 20FR or the left front wheel wheel cylinder 20FL communicate with each other. Hereinafter, the right master valve 22FR and the left master valve 22FL are collectively referred to as a master valve 22 as necessary.

  A right master pressure sensor 48FR for detecting the master cylinder pressure on the right front wheel side is provided in the middle of the brake hydraulic pressure control pipe 16. A left master pressure sensor 48FL that detects the master cylinder pressure on the left front wheel side is provided in the middle of the brake hydraulic pressure control pipe 18 for the left front wheel. In the brake control device 10, when the brake pedal 12 is depressed by the driver, the stroke operation amount is detected by the stroke sensor 46. The brake control device 10 can also obtain the depression operation force (depression force) of the brake pedal 12 from the master cylinder pressure detected by the right master pressure sensor 48FR and the left master pressure sensor 48FL. The electronic control unit (hereinafter referred to as “ECU”) 90 monitors the master cylinder pressure from the detection results of the right master pressure sensor 48FR and the left master pressure sensor 48FL from the viewpoint of fail-safe in consideration of the failure of the stroke sensor 46 and the like. To do.

  One end of a hydraulic supply / discharge pipe 28 is connected to the reservoir tank 26. A suction port of a pump 34 driven by a motor 32 is connected to the other end of the hydraulic supply / discharge pipe 28. The discharge port of the pump 34 is connected to a high pressure pipe 30, and an accumulator 50 and a relief valve 53 are connected to the high pressure pipe 30. In the present embodiment, a reciprocating pump including two or more pistons (not shown) that are reciprocated by a motor 32 is employed as the pump 34. Further, as the accumulator 50, an accumulator that converts the pressure energy of the brake oil into the pressure energy of an enclosed gas such as nitrogen is stored.

  The accumulator 50 stores brake oil whose pressure has been increased to, for example, about 14 to 22 MPa by the pump 34. Further, the valve outlet of the relief valve 53 is connected to the hydraulic supply / discharge pipe 28. When the pressure of the brake oil in the accumulator 50 is abnormally increased to about 25 MPa, for example, the relief valve 53 is opened and the high-pressure brake is opened. The oil is returned to the hydraulic supply / discharge pipe 28. Further, the high-pressure pipe 30 is provided with an accumulator pressure sensor 51 that detects the outlet pressure of the accumulator 50, that is, the pressure of the brake oil in the accumulator 50.

  The high pressure pipe 30 includes a right front wheel pressure increasing valve 40FR, a left front wheel pressure increasing valve 40FL, a right rear wheel pressure increasing valve 40RR, and a left rear wheel pressure increasing valve 40RL (hereinafter collectively referred to as “pressure increasing valve” as necessary. 40 ”), the right front wheel wheel cylinder 20FL, the left front wheel wheel cylinder 20FL, the right rear wheel wheel cylinder 20RR, and the left rear wheel wheel cylinder 20RL (hereinafter collectively referred to as necessary). (Referred to as “wheel cylinder 20”). Each of the pressure increasing valves 40 is a so-called normally closed linear valve (solenoid valve), which is closed when no current is supplied to open the wheel cylinder pressure without increasing the wheel cylinder pressure. Then, increase the wheel cylinder pressure.

  The right front wheel wheel cylinder 20FR to the right rear wheel wheel cylinder 20RR are respectively a right front wheel pressure reducing valve 42FR, a left front wheel pressure reducing valve 42FL, a right rear wheel pressure reducing valve 42RR, and a left rear wheel pressure reducing valve 42RL (hereinafter, These are collectively referred to as “reducing valve 42” as necessary.

  The right front wheel pressure reducing valve 42FR and the left front wheel pressure reducing valve 42FL are so-called normally-closed linear valves (solenoid valves). When the current is not supplied, the valve is closed and the wheel cylinder pressure is not reduced. When supplied, the valve opens to reduce the wheel cylinder pressure. On the other hand, the left rear wheel pressure reducing valve 42RL and the right rear wheel pressure reducing valve 42RR are so-called normally open linear valves (solenoid valves), which are closed when the current is supplied to reduce the wheel cylinder pressure. First, when the current supply is reduced or stopped, the valve is opened to reduce the wheel cylinder pressure.

  The right front wheel wheel cylinder 20FR, the left front wheel wheel cylinder 20FL, the right rear wheel wheel cylinder 20RR, and the hydraulic piping in the vicinity of the left rear wheel wheel cylinder 20RL respectively detect the hydraulic pressure of the corresponding wheel cylinder 20 respectively. Front wheel wheel cylinder pressure sensor 44FR, left front wheel wheel cylinder pressure sensor 44FL, right rear wheel wheel cylinder pressure sensor 44RR, and left rear wheel wheel cylinder pressure sensor 44RL (hereinafter collectively referred to as “ A wheel cylinder pressure sensor 44 ") is provided.

  The above-described master valve 22, pressure increasing valve 40, pressure reducing valve 42, pump 34, accumulator 50, master pressure sensor 48, wheel cylinder pressure sensor 44, accumulator pressure sensor 51 and the like constitute a hydraulic actuator 80. The operation of the hydraulic actuator 80 is controlled by the ECU 90.

  FIG. 2 is a cross-sectional view showing in detail the configuration of the electromagnetic valve 100 mounted on the brake control device 10 according to the first embodiment. The solenoid valve 100 is employed for the right front wheel pressure reducing valve 42FR and the left front wheel pressure reducing valve 42FL. In addition, the solenoid valve 100 may be employ | adopted as another normally closed solenoid valve. The electromagnetic valve 100 includes a valve body unit 104, a seat 106, a sleeve 108, a spring 110, a coil yoke 112, a ring yoke 114, and a coil 116.

  The valve body unit 104 includes a rod 120 and a plunger (mover) 122. The rod 120 is provided with an insertion portion 120a having a smaller diameter than the other portion over a predetermined length from one end portion. The other end portion of the rod 120 is provided with a tip portion 120b which is formed in a hemispherical shape so as to be seated on a valve seat which will be described later and prevent communication of hydraulic fluid.

  The plunger 122 is a magnetic body formed in a cylindrical shape, and a shaft fitting hole 122a in which the rod 120 is fitted and fixed is provided coaxially with the central axis. The plunger 122 is disposed inside the sleeve 108 and divides the inside of the sleeve 108 into a valve chamber 102 and a spring chamber 118. The valve chamber 102 includes a valve portion composed of a rod 120 and a seat 106. The spring chamber 118 functioning as a back pressure chamber is formed on the opposite side of the valve chamber 102 with the plunger 122 in between, and a spring 110 is provided. Plunger 122 is formed with a plurality of communication passages 122 b that allow communication between valve chamber 102 and spring chamber 118. In the plunger 122, the rod 120 is fixed to the end on the valve chamber 102 side by inserting and fitting the insertion portion 120a of the rod 120 into the shaft fitting hole 122a.

  The sheet 106 is a nonmagnetic material formed in a cylindrical shape. The seat 106 is provided with a working fluid path 106a as an inflow port through which the working fluid flows coaxially with the central axis. The hydraulic fluid passage 106 a is narrow at the deep portion, and a valve seat 106 b is formed at the boundary between the narrowed hydraulic fluid passage 106 a and the end of the seat 106. The valve seat 106b is in contact with the valve body unit 104 so that the flow of hydraulic fluid in the flow path is blocked. The seat 106 is press-fitted into an opening, which will be described later, of the sleeve 108 from the end where the valve seat 106b is provided, and is firmly fitted so as not to come out of the sleeve 108.

  The sleeve 108 functions as a stator, and is formed in a shape in which a cylindrical portion 108b having a small thickness is integrally coupled to a main body portion 108a that is a magnetic body formed in a columnar shape. . The cylindrical portion 108b is provided over a predetermined length from the opening end portion, and guides the movement of the plunger 122 in the axial direction. The sleeve 108 is provided with a hydraulic fluid passage 108e as an outflow port through which the hydraulic fluid flows out from the inner wall of the opening 108d at the end to the outer surface in the radial direction. The hydraulic fluid passage 108e communicates with the hydraulic supply / discharge pipe 28 (see FIG. 1), and guides the hydraulic fluid flowing from the hydraulic fluid passage 106a to the reservoir tank 26 via the hydraulic supply / discharge pipe 28.

  The valve body unit 104 is inserted into the cylindrical portion 108b with the plunger 122 at the top of the sleeve 108. Thereafter, the sheet 106 is fitted into the cylindrical portion 108 b of the sleeve 108, and the sheet 106 is fixed to the sleeve 108. Thereby, the valve body unit 104 is provided so that the front-end | tip part 120b of the rod 120 can move in the direction which goes to the valve seat 106b, and the direction spaced apart from the valve seat 106b.

  The tip 120b of the rod 120 prevents communication between the hydraulic fluid passage 106a and the hydraulic fluid passage 108e by being seated on the valve seat 106b, and the hydraulic fluid passage 106a and the hydraulic fluid passage 108e are separated from the valve seat 106b. To communicate. Hereinafter, the direction in which the tip 120b of the rod 120 is separated from the valve seat 106b is referred to as a “first direction”, and the direction in which the tip 120b of the rod 120 faces the valve seat 106b is referred to as a “second direction”.

  The body 108a of the sleeve 108 is provided with a bottomed spring accommodating hole 108f. In the compressed state, one end of the spring 110 abuts against the bottom 108f1 of the spring accommodating hole 108f of the sleeve 108, and the other end abuts against the bottom of the plunger 122, so that the plunger 122 moves in the second direction (valve closing direction). Give the energizing force to go. That is, the spring 110 urges the valve body unit 104 toward the valve seat 106b. Therefore, normally, the tip portion 120b of the rod 120 is seated on the valve seat 106b by the biasing force of the spring 110.

  The coil 116 is a solenoid wound outside the sleeve 108 so as to surround the outside of the plunger 122. The coil yoke 112 is a magnetic body formed in a cup shape. The coil yoke 112 is disposed outside the coil 116 in the radial direction so as to surround the coil 116. The ring yoke 114 is a disk-shaped magnetic body, and is fixed to the sleeve 108 by fitting a central insertion hole into the outer periphery of the sleeve 108. The coil yoke 112 is attached to the main body portion 108 a of the sleeve 108 and the ring yoke 114. Thus, the outer periphery of the coil 116 is covered with the coil yoke 112 and the ring yoke 114 which are magnetic materials.

  FIG. 3 is an enlarged view including a region A in FIG. The plunger 122 is formed with an annular first end 122c in the vicinity of the outer periphery as an end on the second direction side. The bottom portion 108g of the sleeve 108 is provided with a first end portion 122c of the plunger 122 so as to apply a suction force to the plunger 122 in the first direction by a magnetic flux generated by supplying a current to the coil 116. It is formed in the position facing. Hereinafter, the force in the first direction generated between the first end portion 122c of the plunger 122 and the bottom portion 108g of the sleeve 108 is referred to as “suction force”. Note that “attraction force” in the present embodiment refers to a force applied by electromagnetic force or magnetic force.

  When a current larger than the valve opening current is supplied to the coil 116, the solenoid valve 100 is opened by separating the rod 120 from the valve seat 106b of the seat 106, and the operation of the sleeve 108 from the hydraulic fluid path 106a of the seat 106 is performed. The working fluid flows out to the liquid passage 108e. For this reason, immediately after the valve is opened, the hydraulic pressure inside the hydraulic fluid passage 106a is temporarily reduced, the valve body unit 104 is pushed back by the spring 110, and the tip 120b of the rod 120 is seated on the valve seat 106b again. As a result, the hydraulic pressure inside the hydraulic fluid passage 106a increases and the electromagnetic valve 100 is opened again. Immediately after the solenoid valve 100 is opened, there is a possibility that “self-excited vibration” in which the tip 120b of the rod 120 repeatedly contacts the valve seat 106b as described above may occur, which may lead to the generation of abnormal noise.

  Such self-excited vibration may be further promoted by the presence of bubbles in the spring chamber 118. Therefore, it is desirable that the bubbles X present in the spring chamber 118 as shown in FIG. Therefore, the electromagnetic valve 100 according to the present embodiment includes a ring-shaped washer 124 as a gap filling member that fills the gap generated in the spring chamber 118 when the plunger 122 moves toward the sleeve 108. The washer 124 is provided so as to cover the annular first end 122c formed on the end surface of the plunger 122 facing the sleeve 108.

  FIG. 4 is a cross-sectional view of the main part showing the vicinity of the spring chamber in a state where the solenoid valve 100 shown in FIG. 3 is energized. When the coil 116 is energized, the solenoid valve 100 generates a suction force between the first end portion 122 c of the plunger 122 and the bottom portion 108 g of the sleeve 108, and the plunger 122 rises against the biasing force of the spring 110. The washer 124 abuts against the bottom 108 g of the sleeve 108 and is held between the sleeve 108 and the plunger 122.

  At this time, the bubbles X existing in the gaps of the spring chamber 118 as shown in FIG. 3 are forcibly moved toward the communication path 122b by the washer 124 filling a part of the gaps of the spring chamber 118, for example. Be made. As described above, even when bubbles are accumulated in the spring chamber 118, the bubbles are easily discharged from the spring chamber 118 by filling at least a part of the gap of the spring chamber 118 with the washer 124. As a result, self-excited vibration caused by bubbles is suppressed.

  In addition, the washer 124 according to the present embodiment is non-magnetic and has a thickness that comes into contact with the sleeve 108 in a state where the valve portion is opened when the coil 116 is energized. The thickness of the washer 124 is set based on a prescribed stroke amount of the valve body unit 104. Thus, even when the washer 124 contacts the sleeve 108, the washer 124 is sandwiched between the sleeve 108 and the plunger 122. Is prevented from adhering more than necessary. Further, since the washer 124 itself defines the stroke amount of the valve body, it is not necessary to provide a stopper member in the other part of the plunger 122.

  Further, the end surface 124a of the washer 124 on the side in contact with the sleeve 108 may have a shape that is combined with the bottom 108g of the sleeve 108 with which the washer 124 contacts at least in a region outside the communication path 122b. Thereby, since the space between the washer 124 and the sleeve 108 is almost eliminated, the possibility that the bubbles X stay on the surface of the sleeve 108 is further reduced. In particular, by eliminating the gap in the outer region of the communication path 122b, the bubbles X pushed out from the gap are easily directed to the communication path 122b. Note that the “mating” shape means that the washer 124 and the sleeve 108 are similar to each other to such an extent that the bubble X is pushed out from between the sleeve 108 and the washer 124 while the washer 124 is in contact with the sleeve 108. Good.

  In the electromagnetic valve 100 according to the present embodiment, a housing is mainly constituted by a seat 106 and a sleeve 108. The sleeve 108 is disposed opposite to the plunger 122 with the spring chamber 118 interposed therebetween, and functions as a stator that attracts the plunger 122 in the valve opening direction of the rod 120 by the action of an energized solenoid. In the space surrounded by the sleeve 108 and the sheet 106, a flow path that connects the hydraulic fluid path 106a and the hydraulic fluid path 108e is formed. The valve body unit 104 is provided in such a space inside the housing, and moves inside the housing in the axial direction by the action of the energized coil 116. Thus, the valve part of the solenoid valve 100 is controlled to open and close by the solenoid.

(Second Embodiment)
FIG. 5 is a cross-sectional view showing in detail the configuration of the solenoid valve 200 according to the second embodiment. FIG. 6 is a perspective view of the plunger 222 according to the second embodiment. In addition, the same code | symbol is attached | subjected about the structure similar to 1st Embodiment, and description is abbreviate | omitted suitably.

  In the electromagnetic valve 200 according to the present embodiment, the hydraulic fluid circulates in accordance with the opening / closing operation of the valve portion by making the plurality of communication passages have different shapes. By circulating the hydraulic fluid, even if bubbles are present in the spring chamber, the bubbles are easily discharged from the spring chamber through the communication path.

  The solenoid valve 200 according to the present embodiment is different from the communication passage 122b of the plunger 122 according to the first embodiment in the shape of a plurality of communication passages formed in the plunger 222. Specifically, the plunger 222 includes a first communication path 222a and a second communication path 222b. The first communication passage 222 a is formed so that its cross-sectional area increases from the valve chamber 102 toward the spring chamber 118. The second communication path 222b is formed so that the cross-sectional area decreases from the valve chamber 102 toward the spring chamber 118.

  Therefore, the diameter L2 of the hole on the valve chamber side of the second communication path 222b is larger than the diameter L1 of the hole on the valve chamber side of the first communication path 222a. Therefore, when the hydraulic fluid flows from the valve chamber 102 to the spring chamber 118, the flow rate of the hydraulic fluid flowing through the second communication passage 222b is larger than the flow rate of the hydraulic fluid flowing through the first communication passage 222a. The diameter L4 of the hole on the spring chamber side of the first communication path 222a is larger than the diameter L3 of the hole on the spring chamber side of the second communication path 222b. Therefore, when hydraulic fluid flows from the spring chamber 118 to the valve chamber 102, the flow rate flowing through the first communication passage 222a is greater than the flow rate flowing through the second communication passage 222b.

  Therefore, as shown by the arrows in FIG. 5, the hydraulic fluid in the valve chamber 102 passes through the second communication passage 222b and reaches the spring chamber 118, and then passes through the first communication passage 222a and enters the valve chamber 102. It returns and is discharged to the outside from the hydraulic fluid passage 108e. In this way, a flow of hydraulic fluid that circulates between the valve chamber 102 and the spring chamber 118 is generated. Therefore, the bubbles in the spring chamber 118 are easily discharged to the valve chamber 102 side through the communication path. In particular, the gap is filled by the presence of the washer 124 described in the first embodiment, and the bubbles existing in the gap are pushed out to the communication path side, so that the bubbles are moved from the spring chamber 118 to the valve chamber 102 side. It becomes easy to be discharged.

  Note that the first communication passage 222a and the second communication passage 222b according to the present embodiment are formed in opposite shapes with respect to changes in the cross-sectional areas of the respective axial directions, but the hydraulic fluid circulates. However, the present invention is not limited to this as long as a smooth flow is obtained. For example, if the shape of each of the plurality of communication passages is different, there is a high possibility that the pressure applied to each of the communication passages is different, and a plurality of such communication passages may be provided. Moreover, even if the shape of a some communicating path is respectively the same, a hydraulic fluid can also be circulated by devising the formation position. For example, the plurality of communication paths may be formed at positions that are asymmetric with respect to the axial direction of the plunger.

(Third embodiment)
In the present embodiment, a solenoid valve is devised in which the shape of the inside of the spring chamber is devised so that the bubbles staying in the spring chamber are easily moved by the flow of the working fluid. In addition, since it is the same as that of each above-mentioned embodiment about a structure other than a spring chamber, description is abbreviate | omitted and the structure of a spring chamber vicinity is explained in full detail below.

  FIG. 7 is an enlarged cross-sectional view of the vicinity of a spring chamber of a solenoid valve as a comparative example. According to the study by the inventors of the present application, it was found that the bubbles X tend to stay in the corners of the spring chamber 500 as shown in FIG. Specifically, when a bubble X exists in the gap between the first end 502a or the second end 502b of the plunger 502 and the first bottom 504a or the second bottom 504b of the sleeve 504, it is formed on the inner wall of the sleeve 504. The bubble X tends to stay in the valley (corner) 504c of the step.

  FIG. 8 is a diagram schematically showing the force received by the flow of hydraulic fluid when bubbles are present in the valley of the step. As shown in FIG. 8, the bubble X remaining in the valley portion 504 c is in a position deep with respect to the flow F of the hydraulic fluid indicated by the arrow. In particular, as shown in FIG. 8, when the valley portion 504 c inside the spring chamber 500 is processed into a substantially right-angled shape, the bubbles are located on the deeper side. Therefore, in some cases, the bubble X is pressed against the trough 504c with the force indicated by the arrow Y due to the flow of the hydraulic fluid.

  Therefore, in the solenoid valve according to the present embodiment, the valley is processed into an R shape or a taper shape. FIG. 9 is an enlarged cross-sectional view of the vicinity of a spring chamber in which a trough is processed into an R shape in the solenoid valve according to the third embodiment. FIG. 10 is an enlarged schematic view of the vicinity of the valley shown in FIG.

  As shown in FIG. 9, in the electromagnetic valve 300, a washer 324 is attached to the end of the plunger 122 on the spring chamber 318 side in the same manner as the electromagnetic valve according to each of the above-described embodiments. A plurality of valleys 308a provided on the inner surface of the sleeve 308 forming a part of the spring chamber 318 are processed into an R shape. Therefore, compared with the case where the trough 504c as shown in FIG. 8 is processed at a right angle, the bubble X remaining in the vicinity of the trough 308a processed into the R shape shown in FIG. 10 is closer to the communication path 122b. Since it exists in a position, it becomes easy to move with the flow F of hydraulic fluid. Further, by processing the valley portion 308a into an R shape, the trapping at the valley portion when the bubble X moves due to the flow F of the hydraulic fluid is suppressed.

  More preferably, the size of the R shape is larger than the diameter of the bubbles. Specifically, the valley portion R is preferably 0.5 mm or more. Further, the shape of the valley portion may be a taper shape, and C in that case is preferably 0.5 mm or more.

  As described above, since the valley of the step in the spring chamber has an R shape or a tapered shape, bubbles existing in the spring chamber are less likely to be caught in the valley compared to the case where the valley of the step is perpendicular. It becomes easy to move by the flow of hydraulic fluid in the spring chamber. As a result, the frequency of reaching the vicinity of the communication portion is increased, and the air is easily discharged from the spring chamber toward the valve chamber.

  As described above, the present invention has been described with reference to the above-described embodiments. However, the present invention is not limited to the above-described embodiments, and the configurations of the embodiments are appropriately combined or replaced. Those are also included in the present invention. Further, it is possible to appropriately change the combination and processing order in each embodiment based on the knowledge of those skilled in the art and to add various modifications such as various design changes to each embodiment. Embodiments to which is added can also be included in the scope of the present invention.

  DESCRIPTION OF SYMBOLS 10 Brake control apparatus, 100 Solenoid valve, 102 Valve chamber, 104 Valve body unit, 106 Seat, 106a Hydraulic fluid path, 106b Valve seat, 108 Sleeve, 108a Main body part, 108b Cylindrical part, 108d Opening part, 108e Hydraulic fluid path, 108g bottom, 110 spring, 112 coil yoke, 114 ring yoke, 116 coil, 118 spring chamber, 120 rod, 122 plunger, 122b communication path, 122c first end, 124 washer, 124a end face, 222a first communication path, 222b second communication path, 308a valley, 318 spring chamber, 324 washer.

Claims (6)

An electromagnetic valve having a valve portion that is controlled to open and close by a solenoid,
A housing in which the valve portion is provided, an inflow port through which hydraulic fluid flows into the valve portion from the outside, and an outflow port through which hydraulic fluid that has passed through the valve portion flows out;
A valve body that is arranged so as to be able to contact and separate from a valve seat provided inside the housing and can open and close the valve portion;
A predetermined part which is arranged inside the housing and divides the inside of the housing into a valve chamber on the valve portion side and a back pressure chamber on the opposite side of the valve portion, and communicates the valve chamber with the back pressure chamber. A movable passage in which the valve body is attached to an end portion on the valve chamber side,
A stator that is disposed opposite to the movable element across the back pressure chamber, and sucks the movable element in a valve opening direction of the valve body by the action of an energized solenoid;
An urging member for urging the movable element in a valve closing direction of the valve body;
A gap filling member that is provided on an end surface of the movable element facing the stator, and fills a gap generated in the back pressure chamber when the movable element moves toward the stator;
Equipped with a,
The gap filling member is a non-magnetic washer, and defines the stroke amount of the valve body by contacting the stator in a state where the valve portion is opened,
The surface of the stator side abutting on said washer in the region outside the at least the communication passage, the solenoid valves, wherein the shape der Rukoto that the washer of the stator mate with side abutting surface. An electromagnetic valve having a valve portion that is controlled to open and close by a solenoid,
  A housing in which the valve portion is provided, an inflow port through which hydraulic fluid flows into the valve portion from the outside, and an outflow port through which hydraulic fluid that has passed through the valve portion flows out;
  A valve body that is arranged so as to be able to contact and separate from a valve seat provided inside the housing and can open and close the valve portion;
  A predetermined part which is arranged inside the housing and divides the inside of the housing into a valve chamber on the valve portion side and a back pressure chamber on the opposite side of the valve portion, and communicates the valve chamber with the back pressure chamber. A movable passage in which the valve body is attached to an end portion on the valve chamber side,
  A stator that is disposed opposite to the movable element across the back pressure chamber, and sucks the movable element in a valve opening direction of the valve body by the action of an energized solenoid;
  An urging member for urging the movable element in a valve closing direction of the valve body;
  A gap filling member that is provided on an end surface of the movable element facing the stator, and fills a gap generated in the back pressure chamber when the movable element moves toward the stator;
With
  The communication path has a first communication path and a second communication path,
  The first communication path is formed so that a cross-sectional area increases from the valve chamber toward the back pressure chamber,
  The electromagnetic valve according to claim 2, wherein the second communication path is formed so that a cross-sectional area decreases from the valve chamber toward the back pressure chamber. The electromagnetic valve according to claim 2 , wherein the gap filling member is a washer. The electromagnetic valve according to claim 3 , wherein the washer is non-magnetic and defines a stroke amount of the valve body by contacting the stator in a state where the valve portion is opened. The surface of the stator side abutting on said washer in the region outside the at least the communication passage, it in claim 4, wherein said washer of said stator has a shape mating with side abutting surface The solenoid valve described. The stator solenoid valve according to any one of claims 1 to 5 valleys of the step of the surface, characterized in that it has a R-shape.

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