JP2022057883A - Solenoid valve and brake control device - Google Patents

Abstract

To provide a solenoid valve enabling easily adjusting a position of a movable member, as an example.SOLUTION: A solenoid valve includes: a housing provided with an internal flow channel; a seat disposed in the housing and provided with a first flow channel included in the internal flow channel; a movable member positioned inside the housing, movable with respect to the seat, closing the first flow channel by contacting with the seat, and causing the first flow channel to communicate with a second flow channel included in the internal flow channel by being separated from the seat; a coil generating magnetic field for energizing the movable member toward the seat by application of electric current; and an energization member which energizes the movable member in a direction separating from the seat by elastic force, and in which a spring constant at a time when the movable member is positioned in a first section farther from the seat with respect to the first position, is lower than a spring constant at a time when the movable member is positioned in a second section closer to the seat with respect to the first position.SELECTED DRAWING: Figure 2

Description

Embodiments of the present invention relate to solenoid valves and brake control devices.

In a conventional brake control device, a solenoid valve such as a differential pressure control valve attracts a plunger by a magnetic field generated by an energized coil. When the magnetic field attracts the plunger, the movable member including the plunger and the valve body is urged in the direction of closing the flow path. On the other hand, the movable member is urged by a spring in the direction of opening the flow path.

As described above, the attractive force generated by the magnetic field urges the movable member in the direction of closing the flow path, while the reaction force generated by the brake fluid and the spring flowing in the flow path urges the movable member in the direction of opening the flow path. .. The movable member moves to a position where the suction force and the reaction force are balanced. Therefore, the solenoid valve adjusts the degree of opening of the flow path according to the current flowing through the coil (Patent Document 1).

Japanese Unexamined Patent Publication No. 2007-022129

However, in the conventional configuration, if the spring constant of the spring is constant and low, a section may occur in which the suction force and the reaction force are difficult to balance and the position of the movable member is difficult to adjust. However, when the spring constant of the spring is constant and high, the reaction force becomes high, and the power consumption of the coil that generates the suction force corresponding to the reaction force increases.

Therefore, the present invention has been made in view of the above, and provides an electromagnetic valve and a brake control device that can easily adjust the position of a movable member.

As an example, the solenoid valve according to the embodiment of the present invention includes a housing provided with an internal flow path and a sheet provided in the housing and provided with a first flow path included in the internal flow path. It is located inside the housing, is movable with respect to the sheet, closes the first flow path by coming into contact with the sheet, and is included in the internal flow path by separating from the sheet. A movable member that allows the first flow path to communicate with the second flow path, a coil that generates a magnetic field that urges the movable member toward the seat by passing an electric current, and the movable member. The spring constant when the movable member is urged by an elastic force in a direction away from the seat and the movable member is located in a first section farther from the seat than the first position is such that the movable member is located in the first position. Also includes an urging member, which is lower than the spring constant when located in the second section close to the seat. Therefore, as an example, when the movable member goes beyond the first position and approaches the seat, the spring constant of the urging member increases. Therefore, when the movable member is located near the seat, the attractive force that the magnetic field attracts the movable member and the urging member and the fluid flowing from the first flow path to the second flow path push the movable member. It becomes easier to balance the force. Therefore, the solenoid valve of the present embodiment can more precisely adjust the position of the movable member and the pressure of the first flow path and its upstream. Further, in the solenoid valve of the present embodiment, even if the movable distance of the movable member is set to be long, the attractive force corresponding to the reaction force when the movable member is located near the seat becomes low, and the attractive force is generated. It is possible to reduce the power consumption of the coil for making the coil.

In the solenoid valve, as an example, the urging member has a coil spring, and the coil spring is connected to a first coil portion and the first coil portion, and is connected to the first coil portion. The second coil portion also has a second coil portion having a narrow pitch, and the lines of the second coil portion are separated from each other when the movable member is located in the first section, and the movable member is the second coil portion. The lines are in close contact with each other when they are located in the section of. Therefore, as an example, when the movable member exceeds the first position, the wires of the second coil portion are separated or brought into close contact with each other, so that the spring constant of the urging member changes. Thereby, the solenoid valve of the present embodiment can easily change the spring constant of the urging member.

In the solenoid valve, as an example, the housing has a stopper for supporting the movable member located at a second position away from the seat, and the urging member is located at the second position. The movable member is urged by an elastic force in a direction away from the seat. Therefore, as an example, the urging member further urges the movable member separated from the seat to the second position supported by the stopper in the direction away from the seat. As a result, the urging member can reliably move (retract) the movable member to a position as far as possible from the seat.

The brake control device according to the embodiment of the present invention has, for example, the electromagnetic wave in which the internal flow path is connected to the master cylinder and the wheel cylinder through a master cylinder, a wheel cylinder, and a flow path through which brake fluid flows. It is equipped with a valve. As described above, in the solenoid valve of the present embodiment, when the movable member is located in the vicinity of the seat, it is easy to balance the attractive force and the reaction force, and the position of the movable member can be precisely adjusted. Therefore, as an example, the brake control device of the present embodiment can adjust the pressure of the first flow path and its upstream more precisely.

As an example, the brake control device further includes a pump for flowing the brake fluid from the first flow path to the second flow path, and the second section includes the third position and the second section. When the brake fluid flows from the flow path 1 to the second flow path, the pressure of the brake fluid in the first flow path increases as the movable member approaches the seat from the third position. Rise. Therefore, as an example, the position of the movable member is adjusted in the section where the pressure of the brake fluid in the first flow path rises, so that the flow rate of the brake fluid flowing from the first flow path to the second flow path can be adjusted. , The pressure of the brake fluid in the first flow path and its upstream is adjusted. In the present embodiment, the section is included in the second section in which the spring constant of the urging member becomes high. As a result, the brake control device of the present embodiment can easily balance the suction force and the reaction force when the movable member is located near the seat, and by extension, the position of the movable member, the first flow path, and the first flow path thereof. The upstream pressure can be adjusted more precisely.

FIG. 1 is a schematic diagram showing the configuration of the brake control device according to the first embodiment. FIG. 2 is a cross-sectional view showing a differential pressure control valve according to the first embodiment. FIG. 3 is a side view showing the urging member of the first embodiment. FIG. 4 is a graph showing an example of the relationship between the position and the force of the movable member of the first embodiment. FIG. 5 is a cross-sectional view showing a differential pressure control valve according to the second embodiment. FIG. 6 is a cross-sectional view showing a differential pressure control valve according to the third embodiment.

(First Embodiment)
Hereinafter, the first embodiment will be described with reference to FIGS. 1 to 4. In this specification, the constituent elements according to the embodiment and the description of the elements may be described in a plurality of expressions. The components and their description are examples and are not limited by the representations herein. The components may also be identified by names different from those herein. The components may also be described by expressions different from those herein.

FIG. 1 is a schematic diagram showing the configuration of the brake control device 10 according to the first embodiment. The brake control device 10 is mounted on a vehicle 1 such as an automobile. The brake control device 10 is not limited to this example.

As shown in FIG. 1, the brake control device 10 includes a master cylinder (M / C) 11, a wheel cylinder (W / C) 12, an actuator 13, a brake pedal 14, and an ECU (electronic control unit) 15. Has. The brake control device 10 is not limited to this example.

A flow path C through which the brake fluid flows is provided between the M / C 11 and the W / C 12. The actuator 13 is provided between the M / C 11 and the W / C 12 in the path of the flow path C, and controls the pressure of the brake fluid.

The flow path C includes flow paths C1, C2, and C3. The flow path C1 connects the M / C 11 and the actuator 13. The flow path C2 connects the W / C 12 and the actuator 13. The flow path C3 is provided in the actuator 13.

The actuator 13 has a differential pressure control valve 21, a pressure boost control valve 22, a reservoir 23, a pressure reducing control valve 24, a pump 25, a check valve 26, and a fixed capacity damper 27. The differential pressure control valve 21 is an example of a solenoid valve.

The differential pressure control valve 21 is provided between the M / C 11 and the W / C 12 in the path of the flow path C3. The differential pressure control valve 21 is, for example, a solenoid valve that can control a communication state and a differential pressure state. In the differential pressure control valve 21, no current flows through the solenoid in the normal state when the driver operates the brake pedal 14, and the differential pressure control valve 21 is in a communicating state. On the other hand, in the differential pressure control valve 21, the valve body is urged in the valve closing direction by the magnetic field generated by the solenoid by passing a current through the solenoid. As a result, the differential pressure control valve 21 functions like a relief valve and is in a differential pressure state.

The differential pressure value generated by the differential pressure control valve 21 changes according to the current value of the current flowing through the solenoid of the differential pressure control valve 21. The differential pressure value generated by the differential pressure control valve 21 increases as the current value increases.

The differential pressure control valve 21 in the differential state is the pressure of the brake fluid (hereinafter referred to as W / C pressure) in the portion (hereinafter referred to as W / C12 side) connected to W / C12 via the flow path C. Is higher than a predetermined value or more than the pressure of the brake fluid (hereinafter referred to as M / C pressure) in the portion connected to the M / C 11 via the flow path C (hereinafter referred to as the M / C 11 side). Brake fluid is flowed from the W / C12 side to the M / C11 side. Therefore, the differential pressure control valve 21 in the differential state maintains the W / C pressure so as not to be higher than the predetermined value than the M / C pressure.

The differential pressure control valve 21 is provided with a check valve 21a that allows the flow of brake fluid from the M / C11 side to the W / C12 side in parallel with the flow path C3. The check valve 21a makes it possible to transmit the M / C pressure to the W / C 12 when the brake pedal 14 is depressed by the driver.

The pressure boost control valve 22 is provided between the differential pressure control valve 21 and the W / C 12 in the path of the flow path C3. The pressure boost control valve 22 controls an increase in the pressure of the brake fluid in the W / C 12. The pressure boost control valve 22 is, for example, a linear control valve similar to the two-position valve or the differential pressure control valve 21 that can control the communication state and the cutoff state.

In the normal state, the pressure boost control valve 22 is always in communication. The pressure boost control valve 22 in the communicating state can apply the M / C pressure or the pressure due to the discharge of the brake fluid from the pump 25 to the W / C 12.

The pressure boosting control valve 22 is provided with a check valve 22a that allows the flow of brake fluid from the W / C12 side to the M / C11 side in parallel with the flow path C3. The check valve 22a assists in reducing the W / C pressure corresponding to the return operation of the brake pedal 14.

A relief flow path Ca is connected to the flow path C3 between the pressure boosting control valve 22 and the W / C 12. The escape flow path Ca connects the flow path C3 to the reservoir 23. The reservoir 23 temporarily stores the brake fluid.

The pressure reducing control valve 24 is provided between the flow path C3 and the reservoir 23 in the path of the relief flow path Ca. The pressure reducing control valve 24 controls the communication state and the shutoff state of the relief flow path Ca. The pressure reducing control valve 24 is normally shut off. The pressure reducing control valve 24 is, for example, in a communication state at the time of reducing pressure during ABS control, allows the brake fluid in the flow path C3 to escape to the reservoir 23, and reduces the W / C pressure.

A recirculation flow path Cb is connected to the flow path C3 between the differential pressure control valve 21 and the pressure increase control valve 22. The reservoir 23 is connected to the flow path C3 through the return flow path Cb. The pump 25 is provided between the reservoir 23 and the flow path C3 in the path of the return flow path Cb.

The pump 25 is an electric pump. The driven pump 25 sucks the brake fluid from the reservoir 23 and discharges the brake fluid into the flow path C3 between the differential pressure control valve 21 and the pressure increasing control valve 22.

The check valve 26 and the fixed capacity damper 27 are provided between the pump 25 and the flow path C3 in the path of the return flow path Cb. The check valve 26 suppresses the inflow of high-pressure brake fluid into the pump 25. The fixed capacity damper 27 alleviates the pulsation of the brake fluid discharged by the pump 25.

A suction flow path Ci is connected to the flow path C3 between the differential control valve 21 and the M / C 11. The reservoir 23 is connected to the flow path C3 through the suction flow path Ci. For example, during TCS control, the pump 25 sucks the brake fluid from the M / C 11 through the suction flow path Ci, discharges the brake fluid to the flow path C3 through the return flow path Cb, and sets the W / C pressure of the target wheel. Can be increased.

When a predetermined amount of brake fluid is stored in the reservoir 23, the ball valve 23a comes into contact with the valve seat 23b, thereby limiting the inflow of the brake fluid into the reservoir 23. As a result, the reservoir 23 suppresses the inflow of more brake fluid into the reservoir 23 than the suction capacity of the pump 25, and suppresses the application of high pressure to the pump 25.

The ECU 15 controls the W / C pressure generated in each W / C 12 by controlling the differential pressure control valve 21, the pressure increase control valve 22, the pressure reducing control valve 24, and the pump 25. For example, during ABS control, a control voltage is applied from the ECU 15 to the solenoid of the differential pressure control valve 21, the pressure increase control valve 22, and the pressure reduction control valve 24 and the motor of the pump 25. As a result, the differential pressure control valve 21, the pressure increasing control valve 22, the depressurizing control valve 24, and the pump 25 are driven according to the control voltage, and the path of the brake fluid flowing through the flow path C is set. Then, the pressure of the brake fluid corresponding to the set path is generated in the W / C 12, and the braking force generated in each wheel is controlled.

Further, in the actuator 13, the differential pressure control valve 21 is put into a differential pressure state and a voltage is applied to the motor of the pump 25 when the driver is not operating the brake pedal 14 during non-braking. As a result, the pump 25 sucks and discharges the brake fluid of the M / C 11, and the actuator 13 adjusts the pressure of each W / C 12. At this time, for example, the pressure boosting control valve 22 corresponding to the drive wheel is in a communicating state, and the pressure boosting control valve 22 corresponding to the driven wheel is in a shutoff state. As a result, braking force is generated only on the drive wheels.

FIG. 2 is a cross-sectional view showing the differential pressure control valve 21 of the first embodiment. The pressure increasing control valve 22 and the pressure reducing control valve 24 may have substantially the same structure as the differential pressure control valve 21 of FIG. As shown in FIG. 2, the differential pressure control valve 21 has a housing 31, a movable member 32, a coil 33, and an urging member 34.

The housing 31 has a guide 41, a seat 42, a sleeve 43, and a filter 44. That is, the guide 41, the seat 42, the sleeve 43, and the filter 44 are provided in the housing 31. The sleeve 43 is an example of a stopper.

The guide 41 is made of a magnetic material such as metal. The guide 41 is crimped to, for example, a substantially cylindrical recess 13b provided in the housing 13a of the actuator 13. A part of the guide 41 projects outward from the housing 13a of the actuator 13.

The guide 41 is formed in a substantially cylindrical shape extending along the central axis Ax. The central axis Ax passes through the substantially center of the guide 41 and extends in the longitudinal direction of the guide 41. The central axis Ax may be deviated from the center of the guide 41.

Hereinafter, for convenience, the direction along the central axis Ax is referred to as an axial direction, the direction orthogonal to the central axis Ax is referred to as a radial direction, and the direction rotating around the central axis Ax is referred to as a circumferential direction. The axial direction is the longitudinal direction of the guide 41.

The axial direction includes the first direction D1 and the second direction D2 shown in FIG. The first direction D1 is one direction along the central axis Ax, and may also be referred to as a valve opening direction. The second direction D2 is the opposite direction of the first direction D1 and may also be referred to as a valve closing direction.

An inner hole 50 is provided inside the substantially cylindrical guide 41. The inner hole 50 extends along the central axis Ax and penetrates the guide 41 in the axial direction. Therefore, the inner hole 50 is open to the end portion 41a of the guide 41 in the first direction D1 and the end portion 41b of the guide 41 in the second direction D2. The end portion 41a is located outside the housing 13a of the actuator 13. The end portion 41b is located inside the recess 13b of the actuator 13.

The inner hole 50 has a first insertion hole 51, a second insertion hole 52, and a third insertion hole 53. The first insertion hole 51, the second insertion hole 52, and the third insertion hole 53 are each a part of the inner hole 50. The first insertion hole 51, the second insertion hole 52, and the third insertion hole 53 communicate with each other in the axial direction.

The first insertion hole 51 is open to the end portion 41a of the guide 41. The cross section of the first insertion hole 51 orthogonal to the central axis Ax is formed, for example, in a substantially polygonal shape. The cross section of the first insertion hole 51 orthogonal to the central axis Ax may have another shape such as a circle.

The second insertion hole 52 is open to the end portion 41b of the guide 41. The cross section of the second insertion hole 52 orthogonal to the central axis Ax is formed, for example, in a substantially circular shape. The cross section of the second insertion hole 52 orthogonal to the central axis Ax may have another shape.

The third insertion hole 53 is located between the first insertion hole 51 and the second insertion hole 52. The cross section of the third insertion hole 53 orthogonal to the central axis Ax is formed, for example, in a substantially circular shape. The cross section of the third insertion hole 53 orthogonal to the central axis Ax is not limited to this example.

The cross section of the third insertion hole 53 orthogonal to the central axis Ax is smaller than the cross section of the first insertion hole 51 orthogonal to the central axis Ax. Further, the cross section of the third insertion hole 53 orthogonal to the central axis Ax is smaller than the cross section of the second insertion hole 52 orthogonal to the central axis Ax.

The guide 41 is provided with a plurality of through holes 55. The through hole 55 penetrates the guide 41 in the radial direction and communicates with the second insertion hole 52. The through hole 55 is located, for example, in the vicinity of the third insertion hole 53.

The sheet 42 is fitted into the second insertion hole 52 at a position separated from the third insertion hole 53 in the second direction D2. As a result, a space 56 is formed between the sheet 42 and the third insertion hole 53 in the axial direction. The space 56 is included in the second insertion hole 52. The through hole 55 communicates the space 56 with the outside of the guide 41.

The sheet 42 is made of metal and is formed in a substantially cylindrical shape. A first flow path 61 is provided inside the substantially cylindrical sheet 42. The first flow path 61 penetrates the sheet 42 in the axial direction along the central axis Ax. Therefore, the first flow path 61 and the inner hole 50 are arranged coaxially.

The first flow path 61 opens to the end surface 42a of the sheet 42 in the first direction D1 and the end surface 42b of the sheet 42 in the second direction D2. The end face 42a faces the space 56 and faces the third insertion hole 53. The end face 42b is located on the opposite side of the end face 42a. The first flow path 61 can communicate with the space 56.

An orifice 61a is provided in the first flow path 61. The orifice 61a is a portion having a smaller cross section orthogonal to the central axis Ax than the other portion of the first flow path 61. Further, the seat 42 has a substantially conical seat surface 42c that tapers from the end surface 42a toward the orifice 61a.

The sleeve 43 is opened in the second direction D2 and is formed in a substantially cylindrical shape with a bottom. The sleeve 43 is made of a non-magnetic metal such as stainless steel. The sleeve 43 is not limited to this example.

The end portion 41a of the guide 41 is inserted into the inside of the sleeve 43. The sleeve 43 is fixed to the guide 41 by welding or other means. As a result, a storage chamber 62 communicating with the first insertion hole 51 of the guide 41 is provided inside the sleeve 43.

The filter 44 is formed in a substantially cylindrical shape. The guide 41 is fitted inside the filter 44. The filter 44 covers a plurality of through holes 55 provided in the guide 41 from the outside of the guide 41.

The filter 44 is provided with a plurality of through holes 63. Each of the plurality of through holes 63 penetrates the filter 44 in the radial direction. Each of the plurality of through holes 63 of the filter 44 is smaller than each of the plurality of through holes 55 of the guide 41. The through hole 63 of the filter 44 communicates with the through hole 55 of the guide 41. As a result, the filter 44 suppresses the inflow of foreign matter larger than the through hole 63 into the space 56.

An internal flow path Cv through which the brake fluid flows is provided inside the housing 31. The internal flow path Cv includes the above-mentioned first flow path 61 and the second flow path 65. The second flow path 65 includes through holes 55, 63 and a space 56. Therefore, the first flow path 61 and the second flow path 65 can communicate with each other.

The internal flow path Cv is connected to the M / C 11 and the W / C 12 through the flow path C. The first flow path 61 is connected to the W / C 12 through the flow path C. Further, the first flow path 61 is connected to the pump 25 through the flow path C. The second flow path 65 is connected to the M / C 11 through the flow path C. As described above, the first flow path 61 is on the W / C12 side of the internal flow path Cv, and the second flow path 65 is on the M / C11 side of the internal flow path Cv.

The movable member 32 is located inside the housing 31. The movable member 32 can move in the axial direction with respect to the seat 42. The movable member 32 has a shaft 71, a valve body 72, and a plunger 73.

The shaft 71 is made of a non-magnetic metal such as stainless steel. The shaft 71 has a fitting portion 75 and a sliding portion 76. The fitting portion 75 is formed in a polygonal columnar shape extending along the central axis Ax. The sliding portion 76 is formed in a substantially columnar shape extending along the central axis Ax. The cross section of the fitting portion 75 orthogonal to the central axis Ax is larger than the cross section of the sliding portion 76 orthogonal to the central axis Ax.

The fitting portion 75 is accommodated in the first insertion hole 51. The fitting portion 75 is supported in the first insertion hole 51 so as to be movable in the axial direction by the guide 41. A slight gap is provided between the fitting portion 75 and the inner surface of the first insertion hole 51. Further, the guide 41 limits the fitting portion 75 from rotating around the central axis Ax.

The sliding portion 76 projects from the fitting portion 75 through the third insertion hole 53 to the space 56. The sliding portion 76 is supported by a guide 41 so as to be movable in the axial direction in the third insertion hole 53. A slight gap is provided between the sliding portion 76 and the inner surface of the third insertion hole 53.

The valve body 72 is formed, for example, in a substantially hemispherical shape. The shape of the valve body 72 is not limited to this example. The valve body 72 is located in the space 56 and is provided at the end of the sliding portion 76 in the second direction D2. The valve body 72 can move in the axial direction integrally with the shaft 71.

The plunger 73 is made of a magnetic material such as metal and is formed in a substantially columnar shape extending along the central axis Ax. The plunger 73 is housed in the storage chamber 62 of the sleeve 43. The plunger 73 is supported by the sleeve 43 so as to be movable in the axial direction.

The plunger 73 abuts on the end of the fitting portion 75 of the shaft 71 in the first direction D1. The plunger 73 can move in the axial direction integrally with the shaft 71. The plunger 73 may be fixed to the shaft 71.

The valve body 72 of the movable member 32 abuts on the seat surface 42c of the seat 42 to block the first flow path 61. In other words, the valve body 72 abuts on the seat surface 42c to block between the first flow path 61 and the second flow path 65.

On the other hand, the valve body 72 opens the first flow path 61 by separating from the seat surface 42c, and allows the first flow path 61 to communicate with the second flow path 65. In this way, the movable member 32 can move between the position where the first flow path 61 is closed and the position where the first flow path 61 communicates with the second flow path 65.

The coil 33 is, for example, a solenoid wound around the central axis Ax. The coil 33 is located on the outside of the sleeve 43 and surrounds the sleeve 43. The coil 33 generates a magnetic field by passing an electric current. The ECU 15 controls the current flowing through the coil 33.

The coil 33 is housed in a cylindrical spool made of, for example, a non-magnetic material such as resin. Further, a yoke made of magnetic material holds the spool and coil 33. The spool and yoke may be included in the housing 31.

The urging member 34 is, for example, a coil spring wound around the central axis Ax. The urging member 34 may be another elastic body. The urging member 34 is housed in the first insertion hole 51 and is located between the support surface 41c of the guide 41 and the fitting portion 75 of the shaft 71. The support surface 41c is located between the inner surface of the first insertion hole 51 and the inner surface of the third insertion hole 53, and faces the first direction D1.

The urging member 34 is supported by the support surface 41c and the fitting portion 75, and is compressed between the support surface 41c and the fitting portion 75. Therefore, the urging member 34 is supported by the support surface 41c and urges the fitting portion 75 in the first direction D1.

The urging member 34 is not limited to the support surface 41c, and may be supported by, for example, the end surface 42a of the sheet 42. In this case, for example, the first insertion hole 51 and the second insertion hole 52 communicate with each other, the third insertion hole 53 is omitted, and the urging member 34 is supported by the end surface 42a and the fitting portion 75. ..

When the fitting portion 75 of the shaft 71 urged by the urging member 34 moves in the first direction D1, the valve body 72 and the plunger 73 also move integrally with the shaft 71 in the first direction D1. As a result, the movable member 32 is separated from the seat 42. That is, the urging member 34 urges the movable member 32 by an elastic force in a direction away from the seat 42.

As shown in FIG. 2, when the movable member 32 moves from the seat 42 to the fully open position Pf separated by a predetermined distance in the first direction D1, the plunger 73 comes into contact with the bottom of the sleeve 43. As a result, the sleeve 43 supports the movable member 32 located at the fully open position Pf, and restricts the movable member 32 from further moving from the fully open position Pf in the first direction D1. The fully open position Pf is an example of the second position.

The urging member 34 further urges the movable member 32 located at the fully open position Pf in the first direction D1. That is, even when the movable member 32 is located at the fully open position Pf, the urging member 34 is compressed between the support surface 41c and the fitting portion 75. Therefore, the urging member 34 can move the movable member 32 to the fully open position Pf. The urging member 34 is not limited to this example.

FIG. 3 is a side view showing the urging member 34 of the first embodiment. As shown in FIG. 3, the urging member 34 has a first coil portion 81 and a second coil portion 82. In the present embodiment, the first coil portion 81 and the second coil portion 82 are each a part of an urging member 34 which is a coil spring made of continuous wires. The first coil portion 81 and the second coil portion 82 are continuous with each other and connected to each other.

The first coil portion 81 and the second coil portion 82 are each formed in a coil shape. The number of turns in each of the first coil portion 81 and the second coil portion 82 is larger than 1. The first coil portion 81 and the second coil portion 82 are not limited to this example.

The pitch Pt2 of the second coil portion 82 is narrower than the pitch Pt1 of the first coil portion 81. Pitch is the distance between adjacent lines. In other words, the spacing between the wires in the second coil portion 82 is narrower than the spacing between the wires in the first coil portion 81. As described above, in the urging member 34, the pitch is not constant.

The average diameter of the first coil portion 81 and the average diameter of the second coil portion 82 are substantially constant and substantially equal to each other. Therefore, the first coil portion 81 and the second coil portion 82 overlap in the axial direction. Further, in the first coil portion 81 and the second coil portion 82, the adjacent lines and the lines are at least partially overlapped in the axial direction. The average diameter of the first coil portion 81 and the average diameter of the second coil portion 82 may be different from each other or may not be constant.

In the above differential pressure control valve 21, as described above, no current normally flows through the coil 33. As shown in FIG. 2, the movable member 32 is urged by the urging member 34 and is located at the fully open position Pf. As a result, the valve body 72 of the movable member 32 is separated from the seat surface 42c of the seat 42, and the differential pressure control valve 21 is in a communicating state.

In the differential pressure control valve 21 in the communicating state, the first flow path 61 communicates with the second flow path 65. In other words, the differential pressure control valve 21 opens, and the flow path C3 on the M / C11 side and the flow path C3 on the W / C12 side communicate with each other.

When the brake pedal 14 is depressed, the brake fluid flows from the M / C 11 to the W / C 12 through the first flow path 61. On the other hand, when the depression of the brake pedal 14 is stopped, the brake fluid is quickly returned from the W / C 12 to the M / C 11 through the first flow path 61.

On the other hand, when the pressure of the W / C 12 is increased by the pump 25, the ECU 15 drives the pump 25 and controls the differential pressure control valve 21 to the differential pressure state. The ECU 15 generates a magnetic field in the coil 33 by passing an electric current through the coil 33.

By generating a magnetic field, the coil 33 attracts the plunger 73 in the second direction D2 by an electromagnetic force. The sucked plunger 73 pushes the shaft 71 in the second direction D2 and brings the valve body 72 closer to the seat surface 42c of the seat 42. In this way, the coil 33 urges the movable member 32 toward the seat 42 by passing an electric current.

The brake fluid discharged by the pump 25 flows into the first flow path 61 from the W / C12 side. The brake fluid pushes the valve body 72 of the movable member 32 urged by the magnetic field of the coil 33 in the first direction D1. The brake fluid separates the valve body 72 from the seat surface 42c of the seat 42, passes through the gap between the valve body 72 and the seat surface 42c, and enters the space 56 of the first flow path 61 to the second flow path 65. Inflow. In this way, the pump 25 causes the brake fluid to flow from the first flow path 61 to the second flow path 65.

The attractive force generated by the magnetic field urges the movable member 32 in the second direction D2 toward the seat 42, while the reaction force generated by the brake fluid and the urging member 34 moves the movable member 32 away from the seat 42 in the first direction. Encourage D1. The movable member 32 moves to a position where the suction force and the reaction force are balanced, and adjusts the degree of opening (valve opening degree) of the first flow path 61.

The suction force changes depending on the current value of the current flowing through the coil 33. Therefore, the ECU 15 adjusts the position of the movable member 32 by adjusting the current flowing through the coil 33. By adjusting the position of the movable member 32, the flow rate of the brake fluid flowing from the first flow path 61 to the second flow path 65 and the pressure in the first flow path 61 and W / C 12 are adjusted. ..

The pressure in the first flow path 61 and W / C 12 increases when the movable member 32 is located in the vicinity of the seat 42. For example, when the cross-sectional area of the gap between the movable member 32 and the seat surface 42c of the seat 42 is substantially the same as or smaller than the cross-sectional area of the orifice 61a of the first flow path 61, the first flow path 61 and W The pressure at / C12 rises. Therefore, for pressure adjustment, the position of the movable member 32 is adjusted in the vicinity of the seat 42. The position of the movable member 32 in which the pressure rises in the first flow path 61 and W / C 12 is not limited to the above example.

FIG. 4 is a graph showing an example of the relationship between the position and the force of the movable member 32 of the first embodiment. The horizontal axis of FIG. 4 indicates the position of the movable member 32. The position of the movable member 32 is set to 0 at the position where the valve body 72 abuts on the seat surface 42c of the seat 42, and becomes larger as the movable member 32 is separated from the seat 42. The vertical axis of FIG. 4 indicates the magnitude of a force such as an attractive force and a reaction force.

In FIG. 4, the solid line shows the elastic force FE of the urging member 34. The two-dot chain line indicates the reaction force FR. The reaction force FR is the sum of the elastic force FE of the urging member 34 and the fluid force that the brake fluid flowing from the first flow path 61 to the second flow path 65 pushes the valve body 72.

As shown in FIG. 4, the reaction force FR is substantially equal to the elastic force FE in the non-pressure adjusting region Rn where the movable member 32 is farther from the seat 42 than the boundary position Pb. The boundary position Pb is an example of the third position. The boundary position Pb is, for example, a position where the cross-sectional area of the gap between the movable member 32 and the seat surface 42c of the seat 42 is substantially equal to the cross-sectional area of the orifice 61a of the first flow path 61. The boundary position Pb is not limited to this example.

On the other hand, the reaction force FR is larger than the elastic force FE in the pressure adjusting region Rc where the movable member 32 is closer to the seat 42 than the boundary position Pb. That is, when the movable member 32 is closer to the seat 42 than the boundary position Pb, the brake fluid flowing through the first flow path 61 pushes the valve body 72, and fluid force is generated. The fluid force and the reaction force FR increase as the movable member 32 approaches the seat 42 from the boundary position Pb.

When the movable member 32 is located in the pressure adjusting region Rc, the valve body 72 of the movable member 32 narrows the first flow path 61, and the resistance of the brake fluid flowing from the first flow path 61 to the second flow path 65. Functions as. As the movable member 32 approaches the seat 42, the gap between the seat surface 42c of the seat 42 and the valve body 72 becomes narrower, and it becomes difficult for the brake fluid to flow from the first flow path 61 to the second flow path 65. Therefore, when the brake fluid flows from the first flow path 61 to the second flow path 65, the first flow path 61 and W / C 12 become closer to the seat 42 than the boundary position Pb when the movable member 32 flows. Pressure rises in.

On the other hand, as described above, the urging member 34 further urges the movable member 32 located at the fully open position Pf in the first direction D1. Therefore, even when the movable member 32 is located at the fully open position Pf, the elastic force FE and the reaction force FR are larger than 0.

In FIG. 4, the broken line indicates the attractive force FI in which the magnetic field generated by the coil 33 attracts the movable member 32. FIG. 4 shows a plurality of attractive force FIs corresponding to a plurality of current values of the current flowing through the coil 33. The larger the current value passed through the coil 33, the larger the suction force FI.

As shown in FIG. 4, the graph of the plurality of attractive force FI and the graph of the reaction force FR intersect at the intersection Pc. When the movable member 32 is located at the position corresponding to the intersection Pc, the suction force FI and the reaction force FR are balanced. Therefore, when a current is passed through the coil 33, the movable member 32 moves to a position corresponding to the intersection Pc of the graph of the attractive force FI corresponding to the current value of the current and the graph of the reaction force FR.

When the movable member 32 is located in the first section Int1 farther from the seat 42 than the close contact position Pa shown in FIG. 4, in any of the first coil portion 81 and the second coil portion 82 of the urging member 34, The lines are separated from each other. The close contact position Pa is an example of the first position.

On the other hand, when the movable member 32 is located in the second section Int2, which is closer to the seat 42 than the close contact position Pa, the wires are in close contact with each other in the second coil portion 82. On the other hand, in the first coil portion 81, the wires are separated from each other.

From the above, in the urging member 34, the spring constant when the movable member 32 is located in the first section Int1 is lower than the spring constant when the movable member 32 is located in the second section Int2. The spring constant can be represented by the slope of the graph of elastic force FE.

If the spring constant of the urging member 34 is low, an uncontrollable region Ru may occur. The uncontrollable region Ru is a section between the intersection Pc and the contact Pt when the graph of one attraction force FI has the graph of the reaction force FR and the intersection Pc and the contact Pt.

In the uncontrollable region Ru, the suction force FI is larger than the reaction force FR. Therefore, when the suction force FI having the intersection point Pc and the contact point Pt acts on the movable member 32, the movable member 32 moves not only in the uncontrollable region Ru but also to the position corresponding to the intersection point Pc. Therefore, even if the current flowing through the coil 33 is adjusted steplessly by the ECU 15, it is difficult for the movable member 32 to be arranged in the uncontrollable region Ru. As described above, in the uncontrollable region Ru, the suction force FI and the reaction force FR are difficult to balance, and it is difficult to adjust the position of the movable member 32.

By setting the spring constant of the urging member 34 high, the generation of the uncontrollable region Ru is suppressed. That is, when the spring constant of the urging member 34 is set high, the graph of the attractive force FI has an intersection point Pc with the graph of the reaction force FR, regardless of the current value of the current flowing through the coil 33, but the contact point. Does not have Pt.

On the other hand, in the present embodiment, the fully open position Pf is set relatively far from the seat 42. In other words, the stroke of the movable member 32 is set to be relatively long. As a result, the gap between the valve body 72 of the movable member 32 and the seat surface 42c of the seat 42 becomes large in the communicating state, and the flow rate of the brake fluid flowing from the first flow path 61 to the second flow path 65 becomes large. Become.

Generally, when the spring constant of the urging member 34 is constant and high and the stroke of the movable member 32 is long, the reaction force FR when the movable member 32 is located in the vicinity of the seat 42 becomes high. Therefore, there is a possibility that the power consumption of the coil 33 that generates the suction force FI that balances with the reaction force FR increases.

In the urging member 34 of the present embodiment, the spring constant when the movable member 32 is located in the first section Int1 is set lower than the spring constant when the movable member 32 is located in the second section Int2. .. That is, when the movable member 32 exceeds the close contact position Pa and approaches the seat 42, the spring constant of the urging member 34 increases.

As shown in FIG. 4, the boundary position Pb is included in the second section Int2. In other words, the close contact position Pa is set at a position farther from the seat 42 than the boundary position Pb and the pressure adjusting region Rc. Therefore, the spring constant of the urging member 34 becomes high in the pressure adjusting region Rc, and it is suppressed that the uncontrollable region Ru is generated in the pressure adjusting region Rc. Therefore, the ECU 15 can steplessly adjust the position of the movable member 32 in the pressure adjusting region Rc by adjusting the current value of the current flowing through the coil 33 steplessly, and thus the pressure of the W / C 12 is absent. It can be adjusted in stages.

On the other hand, in the first section Int1, the spring constant of the urging member 34 becomes low. Therefore, there is a possibility that an uncontrollable region Ru may occur in the non-pressure adjusting region Rn. However, the position of the movable member 32 in the non-pressure adjusting region Rn has a small influence on the pressure of the W / C 12. Therefore, even if an uncontrollable region Ru occurs in the non-pressure adjusting region Rn, the differential pressure control ability by the differential pressure control valve 21 is unlikely to deteriorate.

Since the spring constant of the urging member 34 in the first section Int1 is low, the reaction force FR when the movable member 32 is located in the vicinity of the seat 42 is low even if the stroke is set long. Therefore, the suction force FI balanced with the reaction force FR when the movable member 32 is located in the vicinity of the seat 42 becomes low, and the power consumption of the coil 33 for generating the suction force FI also becomes low.

In the brake control device 10 according to the first embodiment described above, the movable member 32 closes the first flow path 61 by coming into contact with the seat 42, and the second flow path by separating from the seat 42. The first flow path 61 is communicated with 65. The coil 33 generates a magnetic field that urges the movable member 32 toward the seat 42 by passing an electric current. The urging member 34 urges the movable member 32 in the first direction D1 away from the seat 42 by the elastic force FE. The spring constant of the urging member 34 when the movable member 32 is located in the first section Int1 farther from the seat 42 than the close contact position Pa is the second section Int2 in which the movable member 32 is closer to the seat 42 than the close contact position Pa. It is lower than the spring constant of the urging member 34 when it is located at. That is, when the movable member 32 exceeds the close contact position Pa and approaches the seat 42, the spring constant of the urging member 34 increases. Therefore, in the differential pressure control valve 21 of the present embodiment, when the movable member 32 is located in the vicinity of the seat 42, it becomes easy to balance the suction force FI and the reaction force FR, and the position of the movable member 32 and the position of the movable member 32 and the second. The pressure of the flow path 61 of 1 and the pressure of the W / C 12 upstream thereof can be adjusted more precisely. Further, the differential pressure control valve 21 of the present embodiment has a suction force FI that balances the reaction force FR when the movable member 32 is located in the vicinity of the seat 42 even if the movable member 32 is set to have a long movable distance. It becomes low, and the power consumption of the coil 33 for generating the suction force FI can be reduced.

The urging member 34 is a coil spring. The urging member 34 has a first coil portion 81 and a second coil portion 82 connected to the first coil portion 81 and having a narrower pitch than the first coil portion 81. In the second coil portion 82, the wires are separated from each other when the movable member 32 is located in the first section Int1, and the wires are brought into close contact with each other when the movable member 32 is located in the second section Int2. That is, when the movable member 32 exceeds the close contact position Pa, the wires of the second coil portion 82 are separated or brought into close contact with each other, so that the spring constant of the urging member 34 changes. Thereby, the spring constant of the urging member 34 can be easily changed.

The housing 31 has a sleeve 43 that supports the movable member 32 located at the fully open position Pf away from the seat 42. The urging member 34 urges the movable member 32 located at the fully open position Pf in the first direction D1 by an elastic force. That is, the urging member 34 further urges the movable member 32 separated from the seat 42 to the fully open position Pf supported by the sleeve 43 in the first direction D1. As a result, the urging member 34 can reliably move (retract) the movable member 32 to the fully open position Pf farthest from the seat 42, and eventually from the first flow path 61 to the second flow path 65. It is possible to suppress a decrease in the flow rate of the flowing brake fluid.

The internal flow path Cv of the differential pressure control valve 21 is connected to the M / C 11 and the W / C 12 through the flow path C through which the brake fluid flows. As described above, in the differential pressure control valve 21 of the present embodiment, when the movable member 32 is located in the vicinity of the seat 42, it is easy to balance the suction force FI and the reaction force FR, and by extension, the position of the movable member 32 can be determined. It can be adjusted more precisely. Therefore, the brake control device 10 of the present embodiment can adjust the pressure of the first flow path 61 and the W / C 12 upstream thereof more precisely.

The second section Int2 includes the boundary position Pb. When the brake fluid flows from the first flow path 61 to the second flow path 65, the pressure of the brake fluid in the first flow path 61 increases as the movable member 32 approaches the seat 42 rather than the boundary position Pb. .. By adjusting the position of the movable member 32 in the pressure adjusting region Rc where the pressure of the brake fluid in the first flow path 61 rises, the flow rate of the brake fluid flowing from the first flow path 61 to the second flow path 65. And the pressure of the brake fluid in the first flow path 61 and the W / C 12 upstream of the first flow path 61 are adjusted. In the present embodiment, the pressure adjusting region Rc is included in the second section Int2 in which the spring constant of the urging member 34 becomes high. As a result, in the brake control device 10 of the present embodiment, when the movable member 32 is located in the vicinity of the seat 42, it becomes easy to balance the suction force FI and the reaction force FR, and the position of the movable member 32 and the position of the movable member 32 and the second. The pressure of the flow path 61 of 1 and the pressure of the W / C 12 upstream thereof can be adjusted more precisely.

(Second embodiment)
The second embodiment will be described below with reference to FIG. In the following description of the plurality of embodiments, the components having the same functions as the components already described may be designated by the same reference numerals as those described above, and the description may be omitted. .. Further, the plurality of components with the same reference numerals do not necessarily have all the functions and properties in common, and may have different functions and properties according to each embodiment.

FIG. 5 is a cross-sectional view showing the differential pressure control valve 21 according to the second embodiment. As shown in FIG. 5, the urging member 34 of the second embodiment has a first coil spring 101, a second coil spring 102, and an intervening member 103.

The first coil spring 101 and the second coil spring 102 are coil springs wound around the central axis Ax, respectively. The first coil spring 101 and the second coil spring 102 are arranged in the axial direction.

An intervening member 103 is arranged between the first coil spring 101 and the second coil spring 102. The first coil spring 101 is supported by, for example, the support surface 41c of the guide 41 and the intervening member 103, and is compressed between the support surface 41c and the intervening member 103. The second coil spring 102 is supported by, for example, the fitting portion 75 of the shaft 71 and the intervening member 103, and is compressed between the fitting portion 75 and the intervening member 103. In this way, the first coil spring 101 and the second coil spring 102 are arranged in series.

The pitch of the second coil spring 102 is narrower than the pitch of the first coil spring 101. In the second embodiment, when the movable member 32 is located in the first section Int1, the wires are separated from each other in both the first coil spring 101 and the second coil spring 102. On the other hand, when the movable member 32 is located in the second section Int2, the wires are in close contact with each other in the second coil spring 102. On the other hand, in the first coil spring 101, the wires are separated from each other.

In the brake control device 10 of the second embodiment described above, the urging member 34 has a first coil spring 101 and a second coil spring 102 arranged in series. The pitch of the second coil spring 102 is narrower than the pitch of the first coil spring 101. As a result, the urging member 34 springs between the first section Int1 and the second section Int2 even if the pitches of the first coil spring 101 and the second coil spring 102 are constant. The constant can be changed.

(Third embodiment)

The third embodiment will be described below with reference to FIG. FIG. 6 is a cross-sectional view showing the differential pressure control valve 21 according to the third embodiment. As shown in FIG. 6, the urging member 34 of the third embodiment has a first coil spring 201 and a second coil spring 202.

The first coil spring 201 and the second coil spring 202 are coil springs wound around the central axis Ax, respectively. The outer diameter of the first coil spring 201 is smaller than the inner diameter of the second coil spring 202. The second coil spring 202 surrounds the first coil spring 201. In this way, the first coil spring 201 and the second coil spring 202 are arranged in parallel.

The length of the first coil spring 201 in the axial direction is longer than the length of the second coil spring 202 in the axial direction. The first coil spring 201 is supported by the support surface 41c of the guide 41 and the fitting portion 75 of the shaft 71, and is compressed between the support surface 41c and the fitting portion 75.

In the axial direction, the length of the second coil spring 202 is shorter than the distance between the support surface 41c of the guide 41 and the fitting portion 75 of the shaft 71 when the movable member 32 is located at the fully open position Pf. Therefore, when the movable member 32 is located at the fully open position Pf, the second coil spring 202 is separated from at least one of the support surface 41c and the fitting portion 75.

When the movable member 32 moves by a distance Dg from the fully open position Pf in the second direction D2, the support surface 41c of the guide 41 and the fitting portion 75 of the shaft 71 come into contact with the second coil spring 202. The distance Dg is the difference between the distance between the support surface 41c of the guide 41 and the fitting portion 75 of the shaft 71 when the movable member 32 is located at the fully open position Pf, and the length of the second coil spring 202. be.

In the third embodiment, it is movable in a section (hereinafter referred to as a first section) between the fully open position Pf and a position closer to the seat 42 by a distance Dg (hereinafter referred to as a contact position) than the fully open position Pf. When the member 32 is located, the first coil spring 201 exerts an elastic force on the movable member 32. The contact position is an example of the first position. The first section is farther from the seat 42 than the contact position. On the other hand, in the first section, the second coil spring 202 does not exert an elastic force on the movable member 32.

When the movable member 32 is located in a section (hereinafter referred to as a second section) between the contact position and the position where the valve body 72 contacts the seat surface 42c of the seat 42, the first coil spring 201 and The second coil spring 202 exerts an elastic force on the movable member 32. That is, the spring constant of the urging member 34 when the movable member 32 is located in the first section farther from the seat 42 than the contact position is located in the second section where the movable member 32 is closer to the seat 42 than the contact position. It becomes lower than the spring constant of the urging member 34 at the time of.

In the brake control device 10 of the third embodiment described above, the urging member 34 has a first coil spring 201 and a second coil spring 202 arranged in parallel. The first coil spring 201 urges the movable member 32 in the first direction D1. The second coil spring 202 is separated from at least one of the housing 31 and the movable member 32 when the movable member 32 is located in the first section farther from the seat 42 than the contact position. The second coil spring 202 urges the movable member 32 in the first direction D1 when the movable member 32 is located in the second section closer to the seat 42 than the contact position. As a result, the urging member 34 sets the spring constant between the first section and the second section even if the pitches of the first coil spring 201 and the second coil spring 202 are constant. Can be changed.

In the above plurality of embodiments, the spring constant of the urging member 34 changes in two stages. However, the spring constant of the urging member 34 is not limited to this example, and may be changed in three steps or more steps.

According to the plurality of embodiments described above, the movable member closes the first flow path by contacting with the seat, and communicates the first flow path with the second flow path by separating from the sheet. .. The coil generates a magnetic field that urges the movable member toward the seat by passing an electric current. The urging member urges the movable member by an elastic force in a direction away from the seat. For example, when the brake fluid flows from the first flow path to the second flow path and a current is passed through the coil, the attractive force generated by the magnetic field urges the movable member toward the seat, while the brake fluid. The reaction force generated by the urging member and the urging member urges the movable member in the direction away from the seat. The movable member moves to a position where the suction force and the reaction force are balanced, and adjusts the degree of opening of the first flow path. By adjusting the position of the movable member, the flow rate of the brake fluid flowing from the first flow path to the second flow path and the pressure of the brake fluid in the first flow path and its upstream are adjusted. For pressure adjustment, the position of the movable member is adjusted in the vicinity of the seat. On the other hand, if the spring constant of the urging member is constant and low, a section may occur in which the suction force and the reaction force are difficult to balance and the position of the movable member is difficult to adjust. However, when the spring constant of the urging member is constant and high, the reaction force when the movable member is located near the seat increases, and the power consumption of the coil that generates the suction force commensurate with the reaction force increases. In the present embodiment, the spring constant of the urging member when the movable member is located in the first section farther from the seat than the first position is the second section in which the movable member is closer to the seat than the first position. It is lower than the spring constant of the urging member when it is located at. That is, when the movable member goes beyond the first position and approaches the seat, the spring constant of the urging member increases. Therefore, the solenoid valve of the present embodiment makes it easy to balance the attractive force and the reaction force when the movable member is located near the seat, and by extension, the position of the movable member and the first flow path and its upstream. The pressure can be adjusted more precisely. Further, in the solenoid valve of the present embodiment, even if the movable distance of the movable member is set to be long, the attractive force corresponding to the reaction force when the movable member is located near the seat becomes low, and the attractive force is generated. It is possible to reduce the power consumption of the coil for making the coil.

Although the embodiments of the present invention have been illustrated above, the above-described embodiments and modifications are merely examples, and the scope of the invention is not intended to be limited. The above-described embodiment and modification can be implemented in various other forms, and various omissions, replacements, combinations, and changes can be made without departing from the gist of the invention. Further, the configuration and shape of each embodiment and each modification can be partially replaced.

10 ... brake control device, 11 ... master cylinder, 12 ... wheel cylinder, 21 ... differential pressure control valve (solenoid valve), 25 ... pump, 31 ... housing, 32 ... movable member, 33 ... coil, 34 ... urging member , 42 ... sheet, 61 ... first flow path, 65 ... second flow path, 81 ... first coil section, 82 ... second coil section, C, C1, C2, C3 ... flow path, Cv ... Internal flow path, Pf ... fully open position (second position), Pt1, Pt2 ... pitch, Pb ... boundary position (third position), Pa ... close contact position (first position), Int1 ... first section, Int2 ... Second section.

Claims (5)

A housing with an internal flow path and
A sheet provided in the housing and provided with a first flow path included in the internal flow path, and a sheet.
A second that is located inside the housing, is movable with respect to the sheet, closes the first flow path by contacting the sheet, and is included in the internal flow path by separating from the sheet. A movable member that allows the first flow path to communicate with the second flow path,
A coil that generates a magnetic field that urges the movable member toward the seat by passing an electric current.
The movable member is urged by an elastic force in a direction away from the seat, and the spring constant when the movable member is located in a first section farther from the seat than the first position is the spring constant of the movable member. The urging member, which is lower than the spring constant when it is located in the second section closer to the seat than the first position,
Solenoid valve equipped with. The urging member has a coil spring and has a coil spring.
The coil spring has a first coil portion and a second coil portion connected to the first coil portion and having a narrower pitch than the first coil portion.
In the second coil portion, the lines are separated from each other when the movable member is located in the first section, and the lines are in close contact with each other when the movable member is located in the second section.
The solenoid valve of claim 1. The housing has a stopper that supports the movable member located at a second position away from the seat.
The urging member urges the movable member located at the second position by an elastic force in a direction away from the seat.
The solenoid valve of claim 1 or claim 2. With the master cylinder
Wheel cylinder and
The solenoid valve according to any one of claims 1 to 3, wherein the internal flow path is connected to the master cylinder and the wheel cylinder through the flow path through which the brake fluid flows.
Brake control device. A pump that flows the brake fluid from the first flow path to the second flow path.
Further prepare
The second section includes a third position.
When the brake fluid flows from the first flow path to the second flow path, as the movable member approaches the seat from the third position, the brake fluid in the first flow path The pressure rises,
The brake control device according to claim 4.

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