Solenoid valve and brake control device

Abstract

To provide a solenoid valve and a brake control device, capable of suppressing increase of a pressure in a housing chamber.SOLUTION: A solenoid valve 21 includes: a housing 31 which is provided with a first flow channel 81, a housing chamber 82 separated from the first flow channel, a second flow channel 85 positioned between the first flow channel and the housing chamber, and an insertion hole 70 and a first circulation flow channel 75 for causing the second flow channel to communicate with the housing chamber, and which housing has a seat 43; a coil 34; a plunger 32 which is provided with a second circulation flow channel 95 for causing a first end surface 91 to communicate with a second end surface 92, and which plunger is energized by magnetic field of the coil; a valve member 33 which is positioned between the seat and the plunger inside of the housing, closing the first flow channel by passing through the insertion hole to contact with the seat, or causing the first flow channel to communicate with the second flow channel by being separated from the seat, and which valve member is energized by the plunger energized by the magnetic field; and an energization member 35 for energizing the valve member.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] An embodiment of the present invention relates to a solenoid valve and a brake control device. [Background technology]

[0002] In conventional solenoid valves, a magnetic field generated by an energized coil attracts a plunger, which then displaces the valve member, causing the valve member to close the flow path (Patent Document 1).

[0003] The magnetic field generates an attractive force that urges the plunger in a direction that closes the flow path, while the reaction force generated by the brake fluid flowing through the flow path and the spring urges the valve member in a direction that opens the flow path. The valve member moves to a position where the attractive force and reaction force are balanced. Therefore, the solenoid valve adjusts the degree to which the flow path is open depending on the current flowing through the coil. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2013-515217 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in conventional designs, the flow path blocked by the valve member and the insertion hole through which the valve member is inserted face each other. The insertion hole and the housing chamber that houses the plunger are also connected to each other. Therefore, brake fluid flowing through the flow path can flow down the valve member, pass through the insertion hole, and enter the housing chamber. The brake fluid that enters the housing chamber increases the pressure in the housing chamber, potentially biasing the valve member in a direction that closes the flow path.

[0006] Therefore, the present invention has been made in view of the above, and provides a solenoid valve and a brake control device that can suppress an increase in pressure in an accommodation chamber. [Means for solving the problem]

[0007] As an example, a solenoid valve according to an embodiment of the present invention includes a housing provided with a first flow path, a storage chamber spaced apart from the first flow path in a first direction, a second flow path located between the first flow path and the storage chamber and capable of communicating with the first flow path, an insertion hole that communicates the second flow path and the storage chamber, and a first circulation flow path that is spaced apart from the insertion hole and communicates the second flow path and the storage chamber, the housing having a sheet through which the first flow path opens; a coil that generates a magnetic field when a current is passed through it; a plunger having a first end face facing the first direction and a second end face located opposite the first end face and facing a second direction opposite to the first direction, each of which is provided with a plurality of second circulation flow paths communicating between the first end face and the second end face, the plunger being located in the accommodation chamber and biased in the second direction by the magnetic field; and a plunger located inside the housing between the seat and the plunger, which passes through the insertion hole and comes into contact with the seat to block the first flow path and move away from the seat. in a valve member that connects the first flow path to the second flow path and is urged in the second direction by the plunger that is urged by the magnetic field; and a biasing member that urges the valve member in the first direction by elastic force. The housing has an outer cylinder and an inner cylinder fitted inside the outer cylinder, the insertion hole is provided inside the inner cylinder, the first circulation flow path is provided between the outer cylinder and the inner cylinder, and the inner cylinder has a support surface that supports the biasing member. Therefore, as an example, the fluid that flows into the accommodating chamber through the insertion hole flows through at least one of the plurality of second circulation channels in a first direction through the accommodating chamber, and flows through at least another of the plurality of second circulation channels in a second direction through the accommodating chamber, thereby circulating. The fluid also flows through the first circulation channel and returns from the accommodating chamber to the second channel. This allows the solenoid valve of this embodiment to prevent an increase in pressure in the accommodating chamber and the generation of a pressure difference between the accommodating chamber and the second channel. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a cross-sectional view showing a solenoid valve of a brake control device according to a first embodiment. [Figure 2]FIG. 2 is an exploded perspective view of the guide and the plate of the first embodiment. [Figure 3] FIG. 3 is a cross-sectional view showing a solenoid valve of a brake control device according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] (First embodiment) The first embodiment will be described below with reference to FIGS. 1 and 2. In this specification, components according to the embodiment and descriptions of the components may be described using multiple expressions. The components and their descriptions are merely examples and are not limited by the expressions in this specification. The components may also be identified by names different from those in this specification. Furthermore, the components may also be described using expressions different from those in this specification.

[0010] 1 is a cross-sectional view showing an electromagnetic valve 21 of a brake control device 10 according to a first embodiment. The brake control device 10 is mounted on a vehicle 1 such as an automobile. However, the brake control device 10 is not limited to this example.

[0011] 1, the brake control device 10 includes a master cylinder (M / C) 11, a wheel cylinder (W / C) 12, an actuator 13, and an ECU (electronic control unit) 15. However, the brake control device 10 is not limited to this example.

[0012] 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 in the path of the flow path C between the M / C 11 and the W / C 12, and controls the pressure of the brake fluid.

[0013] The actuator 13 includes a solenoid valve 21 and a pump 22. The solenoid valve 21 is, for example, a differential pressure control valve in the actuator 13. The actuator 13 further includes various components such as a pressure increase control valve, a pressure decrease control valve, a reservoir, a check valve, and a fixed displacement damper. The solenoid valve 21 is not limited to a differential pressure control valve, but may be a pressure increase control valve, a pressure decrease control valve, or another valve.

[0014] The solenoid valve 21 is provided between the M / C 11 and the W / C 12 in the path of the flow path C. Note that the flow path C may have a flow path that bypasses the solenoid valve 21. The solenoid valve 21 has a housing 31, a plunger 32, a valve member 33, a coil 34, and a biasing member 35.

[0015] The solenoid valve 21 can be controlled, for example, between a communication state and a differential pressure state. In normal operation when the driver operates the brake pedal of the vehicle 1, no current flows through the coil 34 of the solenoid valve 21, and the solenoid valve 21 is in a communication state. On the other hand, when a current flows through the coil 34 of the solenoid valve 21, the magnetic field generated by the coil 34 urges the plunger 32 and the valve member 33 in a valve closing direction. This causes the solenoid valve 21 to function like a relief valve and be in a differential pressure state.

[0016] The differential pressure value generated by the solenoid valve 21 changes depending on the current value of the current flowing through the coil 34 of the solenoid valve 21. The differential pressure value generated by the solenoid valve 21 increases as the current value increases.

[0017] The solenoid valve 21 in the differential state allows the brake fluid to flow from the W / C 12 side to the M / C 11 side when the pressure of the brake fluid (hereinafter referred to as W / C pressure) in the portion connected to the W / C 12 via the flow path C (hereinafter referred to as W / C 12 side) becomes higher by 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 M / C 11 side). Therefore, the solenoid valve 21 in the differential state maintains the W / C pressure so that it does not become higher than the M / C pressure by more than a predetermined value.

[0018] The solenoid valve 21 is provided with a check valve 21a that allows the flow of brake fluid from the M / C 11 side to the W / C 12 side. The check valve 21a allows the M / C pressure to be transmitted to the W / C 12 when the driver depresses the brake pedal.

[0019] The structure of the solenoid valve 21 will be described in detail below. The housing 31 has a guide 41, a plate 42, a seat 43, a sleeve 44, and a filter 45. That is, the guide 41, the plate 42, the seat 43, the sleeve 44, and the filter 45 are provided in the housing 31. The guide 41 is an example of an outer cylinder. The plate 42 is an example of an inner cylinder.

[0020] The guide 41 is made of a magnetic material such as metal. The guide 41 is, for example, caulked to a substantially cylindrical recess 13b provided in the housing 13a of the actuator 13. A portion of the guide 41 protrudes from the housing 13a of the actuator 13 to the outside.

[0021] The guide 41 is formed in a substantially cylindrical shape extending along a central axis Ax. The central axis Ax passes through substantially the center of the guide 41 and extends in the longitudinal direction of the guide 41. Note that the central axis Ax may be offset from the center of the guide 41.

[0022] Hereinafter, for convenience, the direction along the central axis Ax will be referred to as the axial direction, the direction perpendicular to the central axis Ax as the radial direction, and the direction rotating around the central axis Ax as the circumferential direction. The axial direction is the longitudinal direction of the guide 41.

[0023] The axial direction includes a first direction D1 and a second direction D2 shown in Figure 1. The first direction D1 is a 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 to the first direction D1 and may also be referred to as a valve closing direction.

[0024] 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 opens to an end 41a of the guide 41 in the first direction D1 and an end 41b of the guide 41 in the second direction D2. The end 41a is located outside the housing 13a of the actuator 13. The end 41b is located inside the recess 13b of the actuator 13.

[0025] The inner hole 50 has a first fitting hole 51 and a second fitting hole 52. The first fitting hole 51 and the second fitting hole 52 are each a part of the inner hole 50. The first fitting hole 51 and the second fitting hole 52 are in axial communication with each other.

[0026] The first fitting hole 51 opens to the end portion 41a of the guide 41. The cross section of the first fitting hole 51 perpendicular to the central axis Ax is formed, for example, in a substantially circular shape. However, the cross section of the first fitting hole 51 perpendicular to the central axis Ax may have another shape.

[0027] The second fitting hole 52 opens to the end portion 41b of the guide 41. The cross section of the second fitting hole 52 perpendicular to the central axis Ax is formed, for example, in a substantially circular shape. However, the cross section of the second fitting hole 52 perpendicular to the central axis Ax may have another shape.

[0028] The cross section of the second fitting hole 52 perpendicular to the central axis Ax is larger than the cross section of the first fitting hole 51 perpendicular to the central axis Ax. The first fitting hole 51 and the second fitting hole 52 communicate with each other. Therefore, a step is formed between the first fitting hole 51 and the second fitting hole 52. Note that the first fitting hole 51 and the second fitting hole 52 are not limited to this example.

[0029] A plurality of through holes 55 are provided in the guide 41. The through holes 55 penetrate the guide 41 in the radial direction and communicate with the second fitting hole 52. The through holes 55 are located near the first fitting hole 51, for example.

[0030] FIG. 2 is an exploded perspective view of the guide 41 and the plate 42 of the first embodiment. FIG. 2 shows a cross section of the plate 42. The plate 42 is made of a magnetic material such as metal. However, the plate 42 may be made of other materials. As shown in FIG. 2, the plate 42 has a cylindrical portion 61 and a support portion 62.

[0031] The tubular portion 61 is a substantially cylindrical wall extending along the central axis Ax. The tubular portion 61 has end faces 65, 66, an outer circumferential surface 67, and an inner circumferential surface 68. One end face 65 is located at an end of the tubular portion 61 in the first direction D1. The end face 65 is formed substantially flat and faces the first direction D1. The other end face 66 is located at an end of the tubular portion 61 in the second direction D2. In other words, the end face 66 is located opposite the end face 65. The end face 66 is formed substantially flat and faces the second direction D2.

[0032] The outer peripheral surface 67 faces radially outward. The inner peripheral surface 68 is located on the opposite side of the outer peripheral surface 67 and faces radially inward. The inner peripheral surface 68 faces the central axis Ax. The outer peripheral surface 67 has multiple curved surfaces 67a and multiple flat surfaces 67b. In this embodiment, the outer peripheral surface 67 has four curved surfaces 67a and four flat surfaces 67b. However, the outer peripheral surface 67 is not limited to this example.

[0033] The curved surface 67a is a substantially cylindrical curved surface extending along the central axis Ax. The flat surfaces 67b are substantially flat surfaces facing in the radial direction. The four flat surfaces 67b are arranged at 90° intervals around the central axis Ax. The curved surfaces 67a and the flat surfaces 67b are arranged alternately in the circumferential direction.

[0034] The flat surface 67b is formed, for example, by cutting the substantially cylindrical outer peripheral surface 67. The flat surface 67b may be formed by other methods. Instead of the flat surface 67b, the outer peripheral surface 67 may have a concave surface recessed from the curved surface 67a toward the central axis Ax, or a curved surface with a larger radius than the curved surface 67a.

[0035] The support portion 62 is a substantially annular wall that protrudes from the inner circumferential surface 68 of the tubular portion 61 toward the central axis Ax. In the axial direction, the length of the support portion 62 is shorter than the length of the tubular portion 61. The support portion 62 is provided adjacent to the end face 66. Therefore, the end face of the tubular portion 61 in the second direction D2 and the end face of the support portion 62 in the second direction D2 form the end face 66 of the seat 43. Note that the support portion 62 is not limited to this example.

[0036] The support portion 62 has a support surface 69. The support surface 69 is an end surface of the support portion 62 in the first direction D1. The support surface 69 is formed in a substantially flat, annular shape and faces the first direction D1. The support surface 69 is spaced apart from the end surface 65 of the plate 42 in the second direction D2.

[0037] An insertion hole 70 is provided on the inner side of the plate 42. The insertion hole 70 extends along the central axis Ax and penetrates the plate 42 in the axial direction. Therefore, the insertion hole 70 opens to the end faces 65, 66 of the plate 42. The insertion hole 70 has a first insertion hole 71 and a second insertion hole 72.

[0038] The first insertion hole 71 is a part of the insertion hole 70 provided inside the tubular portion 61. The first insertion hole 71 is formed (defined) by the inner circumferential surface 68 of the tubular portion 61. Therefore, the inner circumferential surface 68 is the inner circumferential surface of the first insertion hole 71.

[0039] The first insertion hole 71 opens to the end face 65. The cross section of the first insertion hole 71 perpendicular to the central axis Ax is formed to be approximately circular. However, the cross section of the first insertion hole 71 perpendicular to the central axis Ax may have another shape.

[0040] The second insertion hole 72 is a part of the insertion hole 70 provided inside the support portion 62. The second insertion hole 72 opens to the end face 66. The cross section of the second insertion hole 72 perpendicular to the central axis Ax is formed to be approximately circular. However, the cross section of the second insertion hole 72 perpendicular to the central axis Ax may have another shape.

[0041] The first insertion hole 71 and the second insertion hole 72 communicate with each other. The cross section of the second insertion hole 72 perpendicular to the central axis Ax is smaller than the cross section of the first insertion hole 71 perpendicular to the central axis Ax. Therefore, a support surface 69 serving as a step is provided between the first insertion hole 71 and the second insertion hole 72.

[0042] As shown in FIG. 1 , the plate 42 is fitted into the first fitting hole 51 on the inside of the guide 41. In the axial direction, the length of the first fitting hole 51 is approximately equal to the length of the plate 42. An end face 65 of the plate 42 is positioned on approximately the same plane as the end portion 41 a of the guide 41. An end face 66 of the plate 42 faces the second fitting hole 52 of the guide 41.

[0043] A curved surface 67a of an outer peripheral surface 67 of the plate 42 shown in FIG. 2 contacts an inner peripheral surface 51a of the first fitting hole 51 of the guide 41. The inner peripheral surface 51a is a substantially cylindrical curved surface that is provided in the guide 41 and forms the first fitting hole 51. The radius of the curved surface 67a is slightly larger than that of the inner peripheral surface 51a. The plate 42 is fixed to the guide 41 by being press-fitted into the first fitting hole 51 of the guide 41. However, the plate 42 is not limited to this example.

[0044] As shown in FIG. 1 , a plurality of first circulation channels 75 are provided between the guide 41 and the plate 42. The plurality of first circulation channels 75 are an example of a first circulation channel and a plurality of holes. The plurality of first circulation channels 75 are formed (defined) by the inner circumferential surface 51 a of the first fitting hole 51 of the guide 41 and the four flat surfaces 67 b of the outer circumferential surface 67 of the plate 42. Therefore, in this embodiment, four first circulation channels 75 are provided in the housing 31. Note that the number of first circulation channels 75 is not limited to this example.

[0045] The four first circulation channels 75 are arranged at 90° intervals around the central axis Ax. In other words, the four first circulation channels 75 are arranged at approximately equal intervals in the circumferential direction. That is, the first circulation channels 75 are arranged to be spaced apart from the insertion hole 70 and to surround the insertion hole 70.

[0046] As described above, in this embodiment, the first circulation flow path 75 is provided between the guide 41 and the plate 42. However, the first circulation flow path 75 is not limited to this example. For example, the first circulation flow path 75 may be formed by a hole provided in the housing 31.

[0047] As described above, in this embodiment, the first circulation flow path 75 is defined by the substantially cylindrical inner circumferential surface 51a and the flat surface 67b of the outer circumferential surface 67. However, the first circulation flow path 75 is not limited to this example, and may be defined (defined) by a concave surface recessed radially outward from the inner circumferential surface 51a and the substantially cylindrical outer circumferential surface 67.

[0048] The sheet 43 is fitted into the second fitting hole 52 at a position spaced apart in the second direction D2 from the first fitting hole 51 and the second insertion hole 72. As a result, a space 78 is formed between the sheet 43 and the second insertion hole 72 in the axial direction. The space 78 is included in the second fitting hole 52. The through hole 55 connects the space 78 to the outside of the guide 41.

[0049] The sheet 43 is made of metal and formed into a substantially cylindrical shape. A first flow path 81 is provided inside the substantially cylindrical sheet 43. The first flow path 81 penetrates the sheet 43 in the axial direction along the central axis Ax. Therefore, the first flow path 81, the inner hole 50, the first through-hole 71, and the second through-hole 72 are arranged coaxially. The first flow path 81 and the second through-hole 72 face each other with a space 78 interposed therebetween.

[0050] The first flow path 81 opens to an end face 43a of the sheet 43 in the first direction D1 and an end face 43b of the sheet 43 in the second direction D2. The end face 43a faces the space 78 and faces the first fitting hole 51 and the second insertion hole 72. The end face 43b is located on the opposite side of the end face 43a. The first flow path 81 can communicate with the space 78.

[0051] An orifice 81a is provided in the first flow path 81. The orifice 81a is a portion having a smaller cross section perpendicular to the central axis Ax than other portions of the first flow path 81. Furthermore, the seat 43 has a substantially conical seating surface 43c that tapers from the end surface 43a toward the orifice 81a.

[0052] The sleeve 44 is formed in a generally cylindrical shape that is open in the second direction D2 and has a bottom. The sleeve 44 is made of a non-magnetic metal such as stainless steel. However, the material of the sleeve 44 is not limited to this example.

[0053] The end portion 41a of the guide 41 is inserted into the sleeve 44. The sleeve 44 is fixed to the guide 41 by welding or other means. As a result, an accommodating chamber 82 communicating with the first fitting hole 51 and the insertion hole 70 of the guide 41 is provided inside the sleeve 44. The accommodating chamber 82 is spaced apart from the first flow path 81 in the first direction D1.

[0054] The sleeve 44 has an inner circumferential surface 44a and a bottom surface 44b. The inner circumferential surface 44a is a substantially cylindrical surface extending along the central axis Ax. The inner circumferential surface 44a faces the central axis Ax. For example, a portion of the inner circumferential surface 44a is welded to the guide 41. The bottom surface 44b is a substantially hemispherical surface facing the end portion 41a of the guide 41. Note that the shapes of the inner circumferential surface 44a and the bottom surface 44b are not limited to this example.

[0055] The inner circumferential surface 44a, the bottom surface 44b, the end 41a of the guide 41, and the end surface 65 of the sleeve 44 form (define) the accommodation chamber 82. Note that the accommodation chamber 82 is not limited to this example. The inner circumferential surface 44a, the bottom surface 44b, the end 41a of the guide 41, and the end surface 65 of the sleeve 44 face inward of the accommodation chamber 82.

[0056] The filter 45 is formed in a substantially cylindrical shape extending along the central axis Ax. The guide 41 is fitted inside the filter 45. The filter 45 covers a plurality of through holes 55 provided in the guide 41 from the outside of the guide 41.

[0057] A plurality of through holes 83 are provided in the filter 45. Each of the plurality of through holes 83 penetrates the filter 45 in the radial direction. Each of the plurality of through holes 83 in the filter 45 is smaller than each of the plurality of through holes 55 in the guide 41. The through holes 83 in the filter 45 communicate with the through holes 55 in the guide 41. In this way, the filter 45 prevents foreign matter larger than the through holes 83 from flowing into the space 78.

[0058] An internal flow path Cv through which brake fluid flows is provided inside the housing 31. The internal flow path Cv includes the above-mentioned first flow path 81 and second flow path 85. The second flow path 85 includes the through holes 55, 83, and the space 78. Therefore, the first flow path 81 and the second flow path 85 can communicate with each other.

[0059] The internal flow path Cv is connected to the M / C11 and the W / C12 through the flow path C. The first flow path 81 is connected to the W / C12 through the flow path C. Furthermore, the first flow path 81 is connected to the pump 22 through the flow path C. The second flow path 85 is connected to the M / C11 through the flow path C. In this way, the first flow path 81 is on the W / C12 side of the internal flow path Cv, and the second flow path 85 is on the M / C11 side of the internal flow path Cv. Note that the first flow path 81 and the second flow path 85 are not limited to this example.

[0060] The second flow path 85 is located between the first flow path 81 and the storage chamber 82. The insertion hole 70 is located between the second flow path 85 and the storage chamber 82, and connects the second flow path 85 to the storage chamber 82. The first insertion hole 71 communicates with the storage chamber 82. The second insertion hole 72 communicates with the second flow path 85.

[0061] Each of the multiple first circulation channels 75 is also located between the second channel 85 and the accommodating chamber 82, and connects the second channel 85 to the accommodating chamber 82. That is, the insertion hole 70 and the multiple first circulation channels 75 connect the second channel 85 to the accommodating chamber 82 in parallel. Therefore, the brake fluid flowing through the second channel 85 passes through the insertion hole 70 and the first circulation channel 75 and flows into the accommodating chamber 82. Therefore, the accommodating chamber 82 is filled with brake fluid.

[0062] For example, the sheet 43 is provided with a check valve 21a. The check valve 21a connects a second flow path 85 to the W / C 12 and the pump 22 in parallel with the first flow path 81. The check valve 21a blocks the flow of brake fluid from the W / C 12 and the pump 22 toward the second flow path 85. On the other hand, the check valve 21a allows the flow of brake fluid from the second flow path 85 toward the W / C 12 and the pump 22.

[0063] The plunger 32 is made of a magnetic material such as metal and is formed in a generally cylindrical shape extending along the central axis Ax. The plunger 32 is positioned in the housing chamber 82 of the sleeve 44. Therefore, the plunger 32 is spaced apart from the seat 43 in the first direction D1. The plunger 32 has a first end face 91, a second end face 92, and a side face 93.

[0064] The first end surface 91 is an end surface of the plunger 32 in the first direction D1. Note that the first end surface 91 is not limited to this example. The first end surface 91 faces the bottom surface 44b of the sleeve 44.

[0065] The first end surface 91 has a flat surface 91a and a curved surface 91b. The flat surface 91a is formed to be substantially flat and faces the first direction D1. The curved surface 91b is a substantially hemispherical surface provided between the flat surface 91a and the side surface 93. The radius of at least a portion of the curved surface 91b is substantially equal to the radius of the bottom surface 44b of the sleeve 44.

[0066] The second end face 92 is the end face of the plunger 32 in the second direction D2. The second end face 92 is located on the opposite side of the first end face 91. Note that the second end face 92 is not limited to this example. For example, the plunger 32 may have a portion that protrudes from the second end face 92 in the second direction D2.

[0067] The second end face 92 is formed to be approximately flat and faces the second direction D2. Note that the second end face 92 is not limited to this example and may have other shapes. The second end face 92 faces the end 41 a of the guide 41 and the end face 65 of the plate 42 via a gap. The second end face 92 also faces the end face 43 a of the seat 43 via the guide 41 and the plate 42. The second end face 92 may be able to come into contact with the end 41 a of the guide 41 and the end face 65 of the plate 42 by moving the plunger 32 in the second direction D2.

[0068] The side surface 93 is a substantially cylindrical surface extending along the central axis Ax between the first end face 91 and the second end face 92. The center of the side surface 93 may be slightly offset from the central axis Ax. The side surface 93 faces the inner circumferential surface 44a of the sleeve 44. The diameter of the side surface 93 is slightly smaller than the diameter of the inner circumferential surface 44a of the sleeve 44. Therefore, a small gap is provided between at least a portion of the side surface 93 and the inner circumferential surface 44a.

[0069] The side surface 93 of the plunger 32 is supported by the inner circumferential surface 44a of the sleeve 44 so as to be axially movable relative to the housing 31. In other words, the plunger 32 is guided in the axial direction by the inner circumferential surface 44a of the sleeve 44.

[0070] For example, the inner circumferential surface 44a of the sleeve 44 abuts against a portion of the side surface 93, thereby restricting radial movement of the plunger 32. Furthermore, the inner circumferential surface 44a is slightly spaced apart from another portion of the side surface 93, thereby allowing the plunger 32 to move smoothly in the axial direction.

[0071] A plurality of second circulation channels 95 are provided in the plunger 32. The second circulation channels 95 are grooves recessed from the side surface 93 toward the central axis Ax. Note that the second circulation channels 95 are not limited to this example and may be holes, for example.

[0072] Each of the multiple second circulation channels 95 extends substantially in the axial direction between the flat surface 91a of the first end face 91 and the second end face 92. Therefore, the second circulation channels 95 open to the side surface 93, the first end face 91, and the second end face 92. In other words, each of the multiple second circulation channels 95 communicates between the first end face 91 and the second end face 92.

[0073] In this embodiment, four second circulation channels 95 are provided in the plunger 32. The number of second circulation channels 95 is not limited to this example, and may be two, three, five or more. The multiple second circulation channels 95 are arranged at approximately equal intervals in the circumferential direction.

[0074] The solenoid valve 21 is disposed so that the central axis Ax faces a substantially horizontal direction. Therefore, at least one of the plurality of first circulation flow paths 75 is located above the insertion hole 70 regardless of the manner (phase) of assembly of the plate 42 to the guide 41. In addition, at least one of the plurality of second circulation flow paths 95 is located above the insertion hole 70.

[0075] The valve member 33 is located inside the housing 31 between the seat 43 and the plunger 32. The valve member 33 passes through the insertion hole 70 and is able to move axially relative to the seat 43. The valve member 33 has a shaft 101 and a valve body 102.

[0076] The shaft 101 is made of a non-magnetic metal such as stainless steel. The shaft 101 has a first sliding portion 105 and a second sliding portion 106. The first sliding portion 105 and the second sliding portion 106 are formed in a generally cylindrical shape extending along the central axis Ax. The cross section of the first sliding portion 105 perpendicular to the central axis Ax is larger than the cross section of the second sliding portion 106 perpendicular to the central axis Ax.

[0077] The first sliding portion 105 is housed in the first insertion hole 71. The first sliding portion 105 is supported by the inner peripheral surface 68 of the plate 42 in the first insertion hole 71 so as to be movable in the axial direction. A small gap is provided between the first sliding portion 105 and the inner peripheral surface 68.

[0078] The second sliding portion 106 protrudes from the first sliding portion 105 through the second insertion hole 72 into the space 78. The second sliding portion 106 is supported in the second insertion hole 72 by an inner circumferential surface 72a of the second insertion hole 72 so as to be axially movable. The inner circumferential surface 72a is provided on the plate 42 and is a substantially cylindrical curved surface that forms the second insertion hole 72. A small gap is provided between the second sliding portion 106 and the inner circumferential surface 72a of the second insertion hole 72.

[0079] The valve element 102 is formed, for example, in a substantially hemispherical shape. However, the shape of the valve element 102 is not limited to this example. The valve element 102 is located in the space 78 and is provided at the end of the second sliding part 106 in the second direction D2. The valve element 102 can move axially together with the shaft 101.

[0080] An end of the first sliding portion 105 of the shaft 101 in the first direction D1 abuts against the second end face 92 of the plunger 32. The shaft 101 can move in the axial direction integrally with the plunger 32. The shaft 101 may be fixed to the plunger 32.

[0081] The valve element 102 of the valve member 33 abuts against the seat surface 43c of the seat 43 to block the first flow path 81. In other words, the valve element 102 blocks communication between the first flow path 81 and the second flow path 85 by abutting against the seat surface 43c.

[0082] On the other hand, the valve element 102 opens the first flow path 81 by moving away from the seating surface 43c, and connects the first flow path 81 to the second flow path 85. In this manner, the valve member 33 can move between a position where the first flow path 81 is blocked and a position where the first flow path 81 is connected to the second flow path 85.

[0083] The coil 34 is, for example, a solenoid wound around a central axis Ax. The coil 34 is located outside the sleeve 44 and surrounds the sleeve 44. The coil 34 generates a magnetic field when a current is passed through it. The ECU 15 controls the current passed through the coil 34.

[0084] The coil 34 is housed in a cylindrical spool made of a non-magnetic material such as resin. Furthermore, a yoke made of a magnetic material holds the spool and the coil 34. The spool and the yoke may be included in the housing 31.

[0085] The biasing member 35 is, for example, a coil spring wound around the central axis Ax. However, the biasing member 35 may be another elastic body. The biasing member 35 is housed in the first insertion hole 71 and is positioned between the support surface 69 of the plate 42 and the first sliding portion 105 of the shaft 101.

[0086] The biasing member 35 is supported by the support surface 69 and the first sliding portion 105, and is compressed between the support surface 69 and the first sliding portion 105. Therefore, the biasing member 35 is supported by the support surface 69, and biases the first sliding portion 105 in the first direction D1 by elastic force.

[0087] The biasing member 35 may be supported not only by the support surface 69 but also by, for example, the end surface 43 a of the sheet 43. In this case, for example, the plate 42 does not have the support portion 62, and the biasing member 35 is supported by the end surface 43 a and the first sliding portion 105.

[0088] When the first sliding portion 105 of the shaft 101, which is biased by the biasing member 35, moves in the first direction D1, the valve body 102 and the plunger 32 also move in the first direction D1 together with the shaft 101. As a result, the valve member 33 moves away from the seat 43.

[0089] When the valve member 33 moves away from the seat 43 to a predetermined position (fully open position), the curved surface 91b of the first end face 91 of the plunger 32 abuts against the bottom surface 44b of the sleeve 44. When the valve member 33 is located in the fully open position, the bottom surface 44b supports the curved surface 91b of the plunger 32 and restricts the plunger 32 from moving further away from the seat 43.

[0090] When the valve member 33 is in the fully open position, the flat surface 91a of the first end face 91 of the plunger 32 is spaced from the bottom surface 44b of the sleeve 44. Therefore, a gap is provided between the flat surface 91a and the bottom surface 44b. Also, as described above, a small gap is provided between at least a portion of the side surface 93 of the plunger 32 and the inner circumferential surface 44a of the sleeve 44.

[0091] The ECU 15 controls the solenoid valve 21 and the pump 22 to control the W / C pressure generated in each W / C 12. For example, under normal circumstances, the ECU 15 does not apply current to the coil 34. The valve member 33 is biased by the biasing member 35 to be in the fully open position. This causes the valve body 102 of the valve member 33 to separate from the seat surface 43c of the seat 43, and the solenoid valve 21 enters a communicating state.

[0092] When the solenoid valve 21 is in a connected state, the first flow path 81 is connected to the second flow path 85. In other words, the solenoid valve 21 opens, and the flow path C on the M / C 11 side is connected to the flow path C on the W / C 12 side. This allows brake fluid to flow between the M / C 11 side and the W / C 12 side.

[0093] When the brake pedal of the vehicle 1 is depressed, the brake fluid flows from the M / C 11 to the W / C 12 through the first flow path 81. On the other hand, when the depression of the brake pedal is stopped, the brake fluid is quickly returned from the W / C 12 to the M / C 11 through the first flow path 81.

[0094] On the other hand, when the ECU 15 increases the pressure of the W / C 12 by the pump 22, the ECU 15 drives the pump 22 and controls the solenoid valve 21 to the differential pressure state. The ECU 15 applies a current to the coil 34, causing the coil 34 to generate a magnetic field.

[0095] The coil 34 generates a magnetic field, and thereby attracts the plunger 32 in the second direction D2 by electromagnetic force. In other words, the plunger 32 is urged in the second direction D2 toward the seat 43 by the magnetic field generated by the coil 34.

[0096] The plunger 32 attracted by the magnetic field pushes the shaft 101 in the second direction D2, bringing the valve body 102 closer to the seat surface 43c of the seat 43. In this way, the valve member 33 is biased in the second direction D2 by the plunger 32 biased by the magnetic field.

[0097] The brake fluid discharged by the pump 22 flows from the flow path C on the W / C 12 side into the first flow path 81. The brake fluid pushes the valve disc 102 of the valve member 33, which is biased by the magnetic field of the coil 34, in the first direction D1. The brake fluid separates the valve disc 102 from the seating surface 43c of the seat 43 and flows from the first flow path 81 into the space 78 of the second flow path 85 through the gap between the valve disc 102 and the seating surface 43c. In this way, the pump 22 causes the brake fluid to flow from the first flow path 81 to the second flow path 85.

[0098] An attractive force generated by the magnetic field urges the valve member 33 in a second direction D2 (valve closing direction) toward the seat 43, while a reaction force generated by the brake fluid and the urging member 35 urges the valve member 33 in a first direction D1 (valve opening direction) away from the seat 43. The valve member 33 moves to a position where the attractive force and the reaction force are balanced, thereby adjusting the degree of opening of the first flow path 81 (valve opening degree).

[0099] The attractive force varies depending on the current value of the current flowing through the coil 34. Therefore, the ECU 15 adjusts the position of the valve member 33 by adjusting the current flowing through the coil 34. By adjusting the position of the valve member 33, the flow rate of the brake fluid flowing from the first flow path 81 to the second flow path 85 and the pressure in the first flow path 81 and the W / C 12 are adjusted.

[0100] As described above, in the solenoid valve 21, the valve member 33 is moved axially relative to the seat 43. Furthermore, the plunger 32 urges the valve member 33 in the second direction D2, or is urged by the valve member 33 in the first direction D1, and moves integrally with the valve member 33.

[0101] As described above, when the pump 22 discharges brake fluid and the solenoid valve 21 is controlled to the differential pressure state, the brake fluid flows from the first flow path 81 to the second flow path 85. When at least a portion of the brake fluid hits the valve body 102 of the valve member 33, it flows along the valve member 33.

[0102] 1, the flow F1 of brake fluid flows down the valve member 33 and passes through the gap between the second sliding portion 106 and the inner circumferential surface 72a of the second insertion hole 72. Furthermore, the flow F1 of brake fluid passes through the first insertion hole 71 and flows into the accommodating chamber 82.

[0103] Generally, when brake fluid flows into the storage chamber 82, there is a risk that the pressure in the storage chamber 82 will increase. In this case, the valve member 33 will be urged in the second direction D2 due to the pressure difference between the storage chamber 82 and the second flow path 85. In other words, there is a risk that the direction of the fluid force urging the valve member 33 will be reversed from the first direction D1 (valve-opening direction) to the second direction D2 (valve-closing direction).

[0104] However, the solenoid valve 21 of this embodiment can suppress the increase in pressure in the accommodating chamber 82 as follows: First, the flow Fl of brake fluid that has flowed into the accommodating chamber 82 passes through at least one of the plurality of second circulation paths 95 and reaches the innermost portion 82a of the accommodating chamber 82 between the plunger 32 and the bottom surface 44b of the sleeve 44.

[0105] The flow F1 of brake fluid flows from the innermost portion 82a through at least one other of the plurality of second circulation paths 95 and returns to the opening portion 82b of the accommodation chamber 82 between the plunger 32 and the guide 41 and between the plunger 32 and the plate 42. In this manner, the flow F1 of brake fluid circulates inside the accommodation chamber 82.

[0106] Furthermore, the flow of brake fluid F1 passes through the plurality of first circulation flow paths 75 and returns to the second flow path 85. In this manner, the flow of brake fluid F1 circulates between the second flow path 85 and the accommodation chamber 82 through the insertion hole 70 and the first circulation flow path 75.

[0107] The storage chamber 82 does not have a dead end and is connected to the second flow path 85 so that the flow F1 of brake fluid passes through the first circulation flow path 75 and returns to the second flow path 85. Therefore, the pressure in the storage chamber 82 into which the brake fluid flows approaches the pressure in the second flow path 85. Therefore, the first circulation flow path 75 prevents a pressure difference from occurring between the storage chamber 82 and the second flow path 85, and thus prevents the pressure difference from biasing the valve member 33 in the second direction D2.

[0108] Furthermore, external disturbances such as pressure fluctuations in the internal flow path Cv or changes in the discharge rate of the pump 22 may be input to the plunger 32 and the valve member 33. These external disturbances may cause self-excited vibrations in the plunger 32 and the valve member 33. However, the brake fluid filled in the accommodation chamber 82 generates a damping force due to fluid resistance, which can suppress the self-excited vibrations of the plunger 32 and the valve member 33.

[0109] On the other hand, air may be present in the accommodating chamber 82. For example, air flowing together with the brake fluid in the internal flow path Cv may pass through a gap between the inner circumferential surface 72a of the second insertion hole 72 and the second sliding portion 106 of the shaft 101 and flow into the accommodating chamber 82. In addition, air contained in the brake fluid filling the accommodating chamber 82 may precipitate due to, for example, a temperature change. If air gets mixed into the brake fluid in the accommodating chamber 82, the fluid resistance in the accommodating chamber 82 may decrease.

[0110] As described above, in the solenoid valve 21 of the present embodiment, the flow Fl of brake fluid circulates through the innermost portion 82a of the storage chamber 82. Therefore, even if air is present in the innermost portion 82a, the flow Fl of brake fluid can discharge the air present in the storage chamber 82 to the second flow path 85 through the first circulation flow path 75 and the second circulation flow path 95.

[0111] At least one of the plurality of first circulation flow paths 75 and at least one of the plurality of second circulation flow paths 95 are located above the insertion hole 70. Air in the accommodating chamber 82 tends to collect at the upper end of the accommodating chamber 82 due to buoyancy. Therefore, the flow Fl of brake fluid passing through the first circulation flow path 75 and the second circulation flow path 95, which are located above the insertion hole 70, can discharge the air from the accommodating chamber 82.

[0112] As described above, the air in the accommodation chamber 82 is discharged by the flow Fl of the brake fluid, eliminating the reduction in the fluid resistance of the brake fluid due to the air. Therefore, the solenoid valve 21 can suppress the reduction in the damping force due to the fluid resistance caused by the air, and can suppress the self-excited vibration of the plunger 32 and the valve member 33.

[0113] In the brake control device 10 according to the first embodiment described above, the housing 31 is provided with: a first flow path 81; a storage chamber 82 spaced from the first flow path 81 in the first direction D1; a second flow path 85 located between the first flow path 81 and the storage chamber 82 and capable of communicating with the first flow path 81; an insertion hole 70 connecting the second flow path 85 with the storage chamber 82; and a first circulation flow path 75 spaced from the insertion hole 70 and connecting the second flow path 85 with the storage chamber 82. The housing 31 has a seat 43 through which the first flow path 81 opens. The plunger 32 has a first end face 91 facing the first direction D1 and a second end face 92 located opposite the first end face 91 and facing the second direction D2. The plunger 32 is provided with a plurality of second circulation flow paths 95 that communicate between the first end face 91 and the second end face 92. The plunger 32 is located in the accommodation chamber 82 and is urged in the second direction D2 by the magnetic field generated by the coil 34. The valve member 33 is located inside the housing 31 between the seat 43 and the plunger 32 and passes through the insertion hole 70. The valve member 33 blocks the first flow path 81 when it comes into contact with the seat 43, and connects the first flow path 81 to the second flow path 85 when it moves away from the seat 43. The valve member 33 is urged in the second direction D2 by the plunger 32, which is urged by the magnetic field. The urging member 35 urges the valve member 33 in the first direction D1.

[0114] The brake fluid flowing from the first flow path 81 to the second flow path 85 may flow along the valve member 33. In this case, there is a risk that the brake fluid or air mixed in the brake fluid may flow into the accommodating chamber 82 through a gap between the inner circumferential surface of the insertion hole 70 and the valve member 33. However, in the solenoid valve 21 of this embodiment, the housing 31 is provided with a first circulation flow path 75 that connects the second flow path 85 and the accommodating chamber 82, and the plunger 32 is provided with a second circulation flow path 95 that connects the first end face 91 and the second end face 92. As a result, the brake fluid that has flowed into the accommodating chamber 82 through the insertion hole 70 flows through at least one of the plurality of second circulation flow paths 95 in the first direction D1 through the accommodating chamber 82 and flows through at least another of the plurality of second circulation flow paths 95 in the second direction D2 through the accommodating chamber 82, thereby circulating. Furthermore, the brake fluid returns from the storage chamber 82 to the second flow path 85 through the first circulation flow path 75. As a result, the solenoid valve 21 of this embodiment can suppress an increase in pressure in the storage chamber 82 and the generation of a pressure difference between the storage chamber 82 and the second flow path 85, and can thereby suppress the pressure difference from urging the valve member 33 in the second direction. Therefore, the solenoid valve 21 can easily balance the attractive force and the reactive force. Furthermore, by circulating the brake fluid, the air in the storage chamber 82 can be discharged to the second flow path 85. As a result, the solenoid valve 21 of this embodiment can suppress the air in the storage chamber 82 from reducing the fluid resistance of the brake fluid in the storage chamber 82, and can suppress self-excited vibration of the valve member 33 and the plunger 32 due to external disturbances.

[0115] The housing 31 has a guide 41 and a plate 42 fitted inside the guide 41. The insertion hole 70 is provided inside the plate 42. The first circulation flow path 75 is provided between the guide 41 and the plate 42. As a result, the solenoid valve 21 of this embodiment can easily provide the insertion hole 70 and the first circulation flow path 75 in the housing 31.

[0116] The plate 42 has a support surface 69 that supports the biasing member 35. This allows the biasing member 35 to be disposed outside the second flow path 85. Therefore, the solenoid valve 21 of this embodiment can suppress the biasing member 35 from affecting the flow of brake fluid in the second flow path 85.

[0117] A plurality of first circulation channels 75 are provided in the housing 31. Each of the plurality of first circulation channels 75 communicates with the second channel 85 and the accommodating chamber 82 and is arranged to surround the insertion hole 70. When the solenoid valve 21 is arranged so that the first channels 81 are substantially horizontal, at least one of the plurality of first circulation channels 75 is located above the insertion hole 70. The air in the accommodating chamber 82 moves upward due to buoyancy and moves to the vicinity of the first circulation channel 75 located above the insertion hole 70. The brake fluid discharges the air from the accommodating chamber 82 through the first circulation channel 75. As a result, the solenoid valve 21 of this embodiment can discharge the air in the accommodating chamber 82 to the second channel 85 through the first circulation channel 75 located above the insertion hole 70.

[0118] The first flow path 81 and the second flow path 85 are connected to the M / C 11 and the W / C 12 through the flow path C. For example, brake fluid in the M / C 11 or the W / C 12 flows from one of the first flow path 81 and the second flow path 85 to the other. As described above, the brake fluid and air may flow along the valve member 33. However, in the brake control device 10 of this embodiment, the brake fluid that flows into the storage chamber 82 through the insertion hole 70 circulates within the storage chamber 82. The brake fluid also returns from the storage chamber 82 to the second flow path 85 through the first circulation flow path 75. This allows the brake control device 10 of this embodiment to suppress a pressure difference between the storage chamber 82 and the second flow path 85, thereby making it easier to balance the suction force and the reaction force. Furthermore, by circulating the brake fluid, air in the storage chamber 82 can be discharged to the second flow path 85. As a result, the brake control device 10 of this embodiment can prevent the air in the storage chamber 82 from reducing the fluid resistance of the brake fluid in the storage chamber 82, and can prevent the valve member 33 and plunger 32 from vibrating self-excited due to external disturbances.

[0119] (Second embodiment) The second embodiment will be described below with reference to Fig. 3. In the following description of the embodiment, components having the same functions as components already described are given the same reference numerals as the components already described, and further description may be omitted. Furthermore, multiple components given the same reference numerals do not necessarily have all the same functions and properties, and may have different functions and properties according to each embodiment.

[0120] 3 is a cross-sectional view showing an electromagnetic valve 211 of a brake control device 200 according to the second embodiment. The brake control device 200 is mounted on a vehicle 1 and includes an M / C 11, a W / C 12, an actuator 201, a reservoir 202, and an ECU 15.

[0121] Similar to the actuator 13 of the first embodiment, the actuator 201 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 reservoir 202 is provided in the flow path C and stores the brake fluid. The reservoir 202 is, for example, open to the atmosphere. Therefore, the pressure of the brake fluid in the reservoir 202 is approximately equal to atmospheric pressure.

[0122] The actuator 201 has a solenoid valve 211 and a pump 22. Similar to the solenoid valve 21 of the first embodiment, the solenoid valve 211 is provided between the M / C 11 and the W / C 12. The solenoid valve 211 has a housing 221, a plunger 222, a valve member 223, a coil 34, and a biasing member 35.

[0123] The housing 221 includes a guide 231, a sheet 43, a sleeve 44, and a filter 45. The guide 231 is a single member made of a magnetic material such as metal. The guide 231 is formed in a substantially cylindrical shape extending along the central axis Ax.

[0124] An inner hole 240 is provided inside the guide 231. The inner hole 240 extends along the central axis Ax and axially penetrates the guide 231. Therefore, the inner hole 240 is open to an end 231a of the guide 231 in the first direction D1 and an end 231b of the guide 231 in the second direction D2.

[0125] The inner hole 240 has a fitting hole 241 and an insertion hole 242. The fitting hole 241 and the insertion hole 242 are each part of the inner hole 240. The fitting hole 241 and the insertion hole 242 communicate with each other in the axial direction.

[0126] The fitting hole 241 opens to an end portion 231b of the guide 231. The housing 221 has an inner peripheral surface 241a and a bottom surface 241b of the fitting hole 241. The inner peripheral surface 241a is a generally cylindrical curved surface facing inward in the radial direction. The bottom surface 241b is a generally flat, generally circular plane surface facing the second direction D2.

[0127] The sheet 43 is fitted into the fitting hole 241 at a position spaced apart from the insertion hole 242 in the second direction D2. This attaches the sheet 43 to the guide 231. The sheet 43 contacts an inner circumferential surface 241a of the fitting hole 241. An end surface 43a of the sheet 43 faces a bottom surface 241b of the fitting hole 241 via a gap.

[0128] Similar to the housing 31 of the first embodiment, an internal flow path Cv through which brake fluid flows is provided in the housing 221. The internal flow path Cv has a first flow path 81 and a second flow path 250. The second flow path 250 has an inner chamber 251 and a plurality of through holes 252.

[0129] The inner chamber 251 is a space provided inside the housing 221. The inner chamber 251 is a part of the fitting hole 241, and is formed (defined, partitioned) by the end surface 43a of the sheet 43 and the inner circumferential surface 241a and bottom surface 241b of the fitting hole 241. The first flow path 81 of the sheet 43 can communicate with the inner chamber 251.

[0130] A plurality of through holes 252 are provided in the guide 231. The through holes 252 penetrate the guide 231 in the radial direction and open to the inner circumferential surface 241a of the fitting hole 241. The through holes 252 communicate between the inner chamber 251 and the outside of the guide 231.

[0131] The insertion hole 242 opens to an end portion 231a of the guide 231. The insertion hole 242 has a third flow path 255 and a first communication hole 256. The third flow path 255 and the first communication hole 256 are in communication with each other in the axial direction.

[0132] The third flow path 255 opens to an end portion 231a of the guide 231. The guide 231 has an inner circumferential surface 255a and a bottom surface 255b of the third flow path 255. The inner circumferential surface 255a is a substantially cylindrical curved surface facing radially inward. The bottom surface 255b is a substantially flat, circular plane surface facing the first direction D1. The bottom surface 255b of the third flow path 255 is located on the opposite side to the bottom surface 241b of the fitting hole 241.

[0133] The first communication hole 256 opens to the bottom surface 241b of the fitting hole 241 and to the bottom surface 255b of the third flow path 255. Therefore, the first communication hole 256 communicates the inner chamber 251 of the second flow path 250 with the third flow path 255. In other words, the first communication hole 256 separates the inner chamber 251 from the third flow path 255.

[0134] The guide 231 has an inner circumferential surface 256a of the first communication hole 256. The inner circumferential surface 256a is a substantially cylindrical curved surface facing radially inward. The diameter of the inner circumferential surface 256a of the first communication hole 256 is shorter than the diameter of the inner circumferential surface 241a of the fitting hole 241 and is also shorter than the diameter of the inner circumferential surface 255a of the third flow path 255. Therefore, in the guide 231, a support portion 257 is formed between the inner chamber 251 and the third flow path 255.

[0135] The support portion 257 protrudes radially inward from an inner circumferential surface 241a of the fitting hole 241 and an inner circumferential surface 255a of the third flow path 255. A bottom surface 255b of the third flow path 255 is provided at an end of the support portion 257 in the first direction D1. The bottom surface 241b of the fitting hole 241 is provided at an end of the support portion 257 in the second direction D2. The first communication hole 256 is provided inside the support portion 257 in the radial direction.

[0136] The end portion 231a of the guide 231 is inserted into the sleeve 44. As a result, a storage chamber 258 communicating with the third flow path 255 of the guide 231 is provided inside the sleeve 44. The storage chamber 258 is spaced apart from the first flow path 81 in the first direction D1.

[0137] An inner circumferential surface 44a of the sleeve 44 is welded to the guide 231. A bottom surface 44b of the sleeve 44 faces the end portion 231a of the guide 231. The inner circumferential surface 44a and the bottom surface 44b of the sleeve 44 and the end portion 231a of the guide 231 form (define, partition) an accommodation chamber 258.

[0138] The second flow path 250 is located between the first flow path 250 and the storage chamber 258. Furthermore, the third flow path 255 is located between the inner chamber 251 of the second flow path 250 and the storage chamber 258. The inner chamber 251 and the storage chamber 258 are in communication with each other via the third flow path 255 and the first communication hole 256.

[0139] The guide 231 of the second embodiment is further provided with a fourth flow path 261 and a second communication hole 262. The fourth flow path 261 has a vertical discharge hole 265 and a horizontal discharge hole 266. Note that the fourth flow path 261 is not limited to this example.

[0140] The vertical discharge hole 265 extends in the axial direction at a position radially spaced from the third flow path 255. The vertical discharge hole 265 may extend in another direction. One end of the vertical discharge hole 265 opens to the end portion 231a of the guide 231. Therefore, the vertical discharge hole 265 communicates with the storage chamber 258. The other end of the vertical discharge hole 265 communicates with the horizontal discharge hole 266.

[0141] The lateral discharge hole 266 is located between the second flow passage 250 and the storage chamber 258. Furthermore, the lateral discharge hole 266 is spaced radially outward from the third flow passage 255. Therefore, the fourth flow passage 261 is spaced apart from the second flow passage 250 and the third flow passage 255. The lateral discharge hole 266 extends radially and connects the vertical discharge hole 265 to the outside of the guide 231.

[0142] The side discharge hole 266 is in communication with the through hole 252 of the second flow path 250 outside the guide 231. For example, a merging chamber 267 is provided between the filter 45 and the guide 231. The merging chamber 267 is an example of a space outside the second flow path. The merging chamber 267 is located outside the guide 231 and the second flow path 250. Both the through hole 252 and the side discharge hole 266 are in communication with the merging chamber 267. Therefore, the through hole 252 is in communication with the side discharge hole 266 via the merging chamber 267.

[0143] The junction chamber 267 communicates with the flow path C via the filter 45. The junction chamber 267 is connected to the reservoir 202, for example, through the flow path C. Therefore, the pressure of the brake fluid in the junction chamber 267 is approximately equal to atmospheric pressure. However, the pressure of the brake fluid in the junction chamber 267 is not limited to this example. The connection between the junction chamber 267 and the reservoir 202 may be blocked by a valve.

[0144] The second communication hole 262 communicates between the third flow path 255 and the fourth flow path 261. For example, the second communication hole 262 continues from the side discharge hole 266 of the fourth flow path 261 and opens to the inner circumferential surface 255a of the third flow path 255. In this way, the second communication hole 262 communicates between the third flow path 255 and the side discharge hole 266.

[0145] The diameters of the second communication hole 262, the side discharge hole 266, and the through hole 252 of the second flow path 250 are approximately equal to one another. However, the diameters of the second communication hole 262, the side discharge hole 266, and the through hole 252 are not limited to this example.

[0146] The solenoid valve 211 is disposed so that the central axis Ax faces a substantially horizontal direction. The fourth flow path 261 is located above the third flow path 255. Note that the position of the fourth flow path 261 is not limited to this example.

[0147] The plunger 222 is made of a magnetic material such as metal and is formed in a generally cylindrical shape extending along the central axis Ax. The plunger 222 is positioned in the accommodation chamber 258 of the sleeve 44. Therefore, the plunger 222 is spaced apart from the seat 43 in the first direction D1. The plunger 222 has a first end face 271, a second end face 272, and a side face 273.

[0148] The first end surface 271 is an end surface of the plunger 222 in the first direction D1 and faces the first direction D1. Note that the first end surface 271 is not limited to this example. The first end surface 271 faces the bottom surface 44b of the sleeve 44.

[0149] The first end surface 271 is formed in a substantially hemispherical shape. The radius of at least a portion of the first end surface 271 is substantially equal to the radius of the bottom surface 44b of the sleeve 44. However, the first end surface 271 is not limited to this example.

[0150] The second end face 272 is the end face of the plunger 222 in the second direction D2. The second end face 272 is located on the opposite side of the first end face 271. Note that the second end face 272 is not limited to this example. For example, the plunger 222 may have a portion that protrudes from the second end face 272 in the second direction D2.

[0151] The second end surface 272 is formed to be approximately flat and faces the second direction D2. Note that the second end surface 272 is not limited to this example and may have other shapes. The second end surface 272 faces the end 231a of the guide 231 via a gap. The second end surface 272 also faces the end surface 43a of the seat 43 via the guide 231. The second end surface 272 may be able to come into contact with the end 231a of the guide 231 as the plunger 222 moves in the second direction D2.

[0152] The side surface 273 is a substantially cylindrical curved surface extending along the central axis Ax between the first end face 271 and the second end face 272. The center of the side surface 273 may be slightly offset from the central axis Ax. The side surface 273 faces the inner circumferential surface 44a of the sleeve 44. The side surface 273 is supported by the inner circumferential surface 44a so as to be movable in the axial direction (first direction D1 and second direction D2) relative to the housing 221.

[0153] Plunger 222 is provided with a plurality of fifth flow paths 275. The plurality of fifth flow paths 275 includes a first hole 276 and a plurality of grooves 277. That is, first hole 276 is one of the plurality of fifth flow paths 275. Also, each of the plurality of grooves 277 is one of the plurality of fifth flow paths 275.

[0154] The first hole 276 axially penetrates the plunger 222. The first hole 276 opens to the first end face 271 and the second end face 272. Therefore, the first hole 276 communicates between the first end face 271 and the second end face 272.

[0155] The plurality of grooves 277 are recessed from the first end face 271 and the side face 273 of the plunger 222. The plurality of grooves 277 each extend substantially in the axial direction between the first end face 271 and the second end face 272. Therefore, the grooves 277 open to the first end face 271, the second end face 272, and the side face 273. In other words, the grooves 277 communicate with the first end face 271 and the second end face 272.

[0156] In this embodiment, two grooves 277 are provided in the plunger 222. Note that the number of grooves 277 is not limited to this example and may be one or three or more. The multiple grooves 277 are arranged at approximately equal intervals in the circumferential direction.

[0157] The valve member 223 is positioned between the seat 43 and the plunger 222 through the third flow path 255 and the first communication hole 256. The valve member 223 is able to move axially relative to the seat 43. The valve member 223 has a shaft 281 and a valve body 282.

[0158] The shaft 281 is made of a non-magnetic metal such as stainless steel. The shaft 281 has a first sliding portion 285 and a second sliding portion 286. The first sliding portion 285 and the second sliding portion 286 are formed in a generally cylindrical shape extending along the central axis Ax. The cross section of the first sliding portion 285 perpendicular to the central axis Ax is larger than the cross section of the second sliding portion 286 perpendicular to the central axis Ax.

[0159] The first sliding portion 285 is housed in the third flow path 255. The first sliding portion 285 has end faces 285a and 285b, an outer circumferential surface 285c, and two concave surfaces 285d. The end face 285a is an example of a third end face.

[0160] The end surface 285a is provided at an end of the valve member 223 in the first direction D1. The end surface 285a faces the first direction D1. The end surface 285a also faces the second end surface 272 of the plunger 222 and is in contact with the second end surface 272. This allows the shaft 281 to move axially together with the plunger 222. The end surface 285b is provided at an end of the first sliding portion 285 in the second direction D2.

[0161] The outer peripheral surface 285c is a substantially cylindrical curved surface that extends along the central axis Ax between the end surfaces 285a and 285b and faces radially outward. The outer peripheral surface 285c is supported by the inner peripheral surface 255a of the third flow path 255 so as to be movable in the axial direction. A small gap is provided between the outer peripheral surface 285c and the inner peripheral surface 255a.

[0162] Concave surface 285d is a flat surface recessed from outer circumferential surface 285c and facing radially outward. Concave surface 285d is connected to end surface 285b and spaced apart from end surface 285a. That is, a portion of substantially cylindrical outer circumferential surface 285c is provided between end surface 285a and concave surface 285d in the axial direction.

[0163] A gap flow path 255c is formed (defined, partitioned) between the concave surface 285d and the inner circumferential surface 255a. The gap flow path 255c is part of the third flow path 255. A cross section of the gap flow path 255c perpendicular to the central axis Ax is larger than a cross section of the gap between the outer circumferential surface 285c and the inner circumferential surface 255a perpendicular to the central axis Ax.

[0164] A second hole 290 is provided in the first sliding part 285. The second hole 290 has a horizontal hole 291 and a vertical hole 292. The horizontal hole 291 penetrates the first sliding part 285 in the radial direction and opens to the two concave surfaces 285d. Therefore, the horizontal hole 291 communicates with the gap flow path 255c of the third flow path 255. The vertical hole 292 extends in the axial direction and opens to the end surface 285a of the first sliding part 285 and the inner surface of the horizontal hole 291.

[0165] Vertical hole 292 opening in end face 285a faces first hole 276 opening in second end face 272 of plunger 222. Vertical hole 292 communicates with first hole 276. Therefore, second hole 290 communicates between third flow path 255 and first hole 276.

[0166] The second sliding portion 286 protrudes from the end surface 285b of the first sliding portion 285 through the first communicating hole 256 to the inner chamber 251. The second sliding portion 286 is supported by the inner circumferential surface 256a of the first communicating hole 256 so as to be axially movable. A small gap is provided between the second sliding portion 286 and the inner circumferential surface 256a of the first communicating hole 256.

[0167] The valve element 282 is located in the inner chamber 251 and is provided at an end of the valve member 223 in the second direction D2. The valve element 282 faces the seat surface 43c of the seat 43. The valve element 282 is formed, for example, in a substantially hemispherical shape. However, the shape of the valve element 282 is not limited to this example. The valve element 282 can move axially together with the shaft 281.

[0168] The valve element 282 blocks the first flow path 81 by abutting against the seat surface 43c of the seat 43. In other words, the valve element 282 blocks communication between the first flow path 81 and the second flow path 250 by abutting against the seat surface 43c.

[0169] On the other hand, the valve element 282 opens the first flow path 81 by moving away from the seat surface 43c, thereby connecting the first flow path 81 to the second flow path 250. In this manner, the valve member 223 can move between a position where the first flow path 81 is blocked and a position where the first flow path 81 is connected to the second flow path 250.

[0170] The biasing member 35 is housed in the third flow path 255 and is located between a bottom surface 255b of the third flow path 255 and an end surface 285b of the first sliding portion 285. The biasing member 35 is supported by the bottom surface 255b and the end surface 285b, and is compressed between the bottom surface 255b and the end surface 285b. Therefore, the biasing member 35 is supported by the bottom surface 255b, and biases the first sliding portion 285 in the first direction D1 by elastic force.

[0171] When the first sliding portion 285 of the shaft 281, which is biased by the biasing member 35, moves in the first direction D1, the valve body 282 and the plunger 222 also move in the first direction D1 integrally with the shaft 281. As a result, the valve member 223 moves away from the seat 43.

[0172] For example, when the ECU 15 increases the pressure of the W / C 12 by the pump 22, the ECU 15 drives the pump 22 and controls the solenoid valve 211 to the differential pressure state. The ECU 15 applies a current to the coil 34, thereby causing the coil 34 to generate a magnetic field.

[0173] The plunger 222 is urged in the second direction D2 toward the seat 43 by the magnetic field generated by the coil 34. The valve member 223 is urged in the second direction D2 by the plunger 222 urged by the magnetic field.

[0174] The brake fluid discharged from the pump 22 flows into the first flow path 81 and pushes the valve body 282 of the valve member 223, which is biased by the magnetic field of the coil 34, in the first direction D1. The brake fluid separates the valve body 282 from the seating surface 43c of the seat 43 and flows from the first flow path 81 into the inner chamber 251 of the second flow path 250 through the gap between the valve body 282 and the seating surface 43c.

[0175] The valve member 223 moves to a position where the attractive force generated by the magnetic field and the reactive force generated by the brake fluid and the biasing member 35 are balanced, and adjusts the degree of opening (valve opening degree) of the first flow path 81. The ECU 15 adjusts the current flowing through the coil 34 to adjust the position of the valve member 223.

[0176] A portion of the brake fluid that has flowed from the first flow path 81 into the inner chamber 251 flows through the through-hole 252 toward the reservoir 202. On the other hand, another portion of the brake fluid hits the valve body 282 of the valve member 223 and flows along the valve member 223.

[0177] The brake fluid flows down the valve member 223, passes through the gap between the second sliding portion 286 and the inner circumferential surface 256a of the first communication hole 256, and flows into the third flow path 255. The size of the gap between the second sliding portion 286 and the inner circumferential surface 256a of the first communication hole 256 is set so as to prevent a large amount of brake fluid from flowing into the third flow path 255, and is smaller than the through hole 252.

[0178] The flow of brake fluid may branch in the third flow path 255. For example, in the third flow path 255, the brake fluid branches into a flow Fl1 that flows along the valve member 223 and a flow Fl2 that flows toward the second communication hole 262.

[0179] The flow Fl1 of brake fluid flows from the gap flow path 255c of the third flow path 255 into the horizontal hole 291 of the second hole 290. Note that a portion of the brake fluid may flow into the gap between the outer circumferential surface 285c and the inner circumferential surface 255a.

[0180] The flow Fl1 of brake fluid passes from the horizontal hole 291 through the vertical hole 292 of the second hole 290 and the first hole 276 of the plunger 222, and reaches the innermost portion 258a of the accommodating chamber 258 between the plunger 222 and the bottom surface 44b of the sleeve 44.

[0181] The flow Fl1 of brake fluid flows from the deepest portion 258a through at least one of the grooves 277 to the space 258b between the plunger 222 and the guide 231 in the accommodation chamber 258. In this way, the flow Fl1 of brake fluid passes through the deepest portion 258a and turns back.

[0182] The flow Fl1 of brake fluid flows from the space 258b into the vertical discharge hole 265 of the fourth flow path 261. Note that even if the groove 277 is away from the vertical discharge hole 265, the flow Fl1 of brake fluid can pass through the space 258b and flow into the vertical discharge hole 265. The flow Fl1 of brake fluid is discharged from the vertical discharge hole 265 through the horizontal discharge hole 266 to the junction chamber 267 outside the guide 231.

[0183] On the other hand, the flow Fl2 of brake fluid flows from the third flow path 255 through the second communication hole 262 into the lateral discharge hole 266. The flow Fl2 of brake fluid merges with the flow Fl1 and is discharged into the merge chamber 267.

[0184] As described above, the brake fluid flows Fl1 and Fl2 do not return to the second flow path 250 but are discharged to the outside of the guide 231. The brake fluid flows Fl1 and Fl2 merge with the brake fluid discharged from the through-hole 252 in the merging chamber 267 and flow toward the reservoir 202.

[0185] When the brake fluid in the inner chamber 251 of the second flow path 250 passes through the through-hole 252 or the gap between the second sliding portion 286 and the inner circumferential surface 256a of the first communication hole 256, a pressure loss occurs. In addition, the junction chamber 267 is connected to the reservoir 202 through the flow path C. Therefore, the pressure of the brake fluid in the inner chamber 251 becomes higher than the pressure of the brake fluid in each of the third flow path 255, the storage chamber 258, the fourth flow path 261, and the junction chamber 267.

[0186] The pressure difference allows the brake fluid in the inner chamber 251 to pass through the gap between the second sliding portion 286 and the inner circumferential surface 256a of the first communication hole 256 and flow into the third flow path 255. In addition to the pressure difference, other factors such as the inertia of the brake fluid flowing through the valve member 223 and the Coanda effect can also cause the brake fluid to flow into the third flow path 255.

[0187] As described above, the pressure in the storage chamber 258 is lower than the pressure in the inner chamber 251. Furthermore, the brake fluid in the third flow path 255 branches into a flow Fl1 toward the storage chamber 258 and a flow Fl2 toward the second communication hole 262. That is, only a portion of the brake fluid in the third flow path 255 flows into the storage chamber 258. This allows the solenoid valve 211 to suppress an increase in the pressure in the storage chamber 258, and ultimately suppresses the pressure in the storage chamber 258 from urging the valve member 223 in the second direction D2.

[0188] Furthermore, as described above, the flow Fl1 of brake fluid passes through the innermost portion 258a of the storage chamber 258. Therefore, even if air is present in the innermost portion 258a, the flow Fl1 of brake fluid can discharge the air present in the storage chamber 258 to the outside of the guide 231 through the fifth flow path 275 and the fourth flow path 261.

[0189] The fourth flow path 261 is located above the third flow path 255. At least one of the plurality of grooves 277 is also located above the third flow path 255. The air in the storage chamber 258 tends to collect at the upper end of the storage chamber 258 due to buoyancy. Therefore, the flow Fl1 of brake fluid passing through the groove 277 located above the third flow path 255 and the fourth flow path 261 can discharge the air from the storage chamber 258.

[0190] As described above, the air in the accommodation chamber 258 is discharged by the flow Fl1 of the brake fluid, eliminating the reduction in the fluid resistance of the brake fluid due to the air. Therefore, the solenoid valve 211 can suppress the reduction in the damping force due to the fluid resistance caused by the air, and can suppress the self-excited vibration of the plunger 222 and the valve member 223.

[0191] The brake fluid that flows from the first communication hole 256 into the third flow path 255 is discharged to the outside of the guide 231 without returning to the second flow path 250. Therefore, the solenoid valve 211 can prevent the pressure in the second flow path 250 from interfering with the flow Fl1 of the brake fluid that discharges the air from the accommodation chamber 258.

[0192] In the brake control device 200 of the second embodiment described above, the housing 221 is provided with a fourth flow path 261 that is spaced apart from the second flow path 250 and the third flow path 255 and that is in communication with the storage chamber 258, and the plunger 222 is provided with a plurality of fifth flow paths 275 that are in communication with the first end face 271 and the second end face 272. As a result, the brake fluid that has flowed into the storage chamber 258 through the first communication hole 256 and the third flow path 255 flows through the storage chamber 258 in the first direction D1 through at least one of the plurality of fifth flow paths 275 and also flows through the storage chamber 258 in the second direction D2 through at least another of the plurality of fifth flow paths 275. In addition, the brake fluid can flow into the fourth flow path 261 through the third flow path 255 and the first communication hole 256 without returning to the second flow path 250. As a result, the solenoid valve 211 can make the pressure in the second flow path 250 different from the pressure in the third flow path 255, the housing chamber 258, and the fourth flow path 261. By making the pressure in the third flow path 255, the housing chamber 258, and the fourth flow path 261 lower than the pressure in the second flow path 250, the solenoid valve 211 can suppress an increase in the pressure in the housing chamber 258, which in turn makes it easier to adjust the position of the valve member 223. Furthermore, the brake fluid can pass near the first end face 271 of the plunger 222 in the housing chamber 258 and be discharged from the fourth flow path 261. As a result, the solenoid valve 211 can discharge air in the deepest portion 258a of the housing chamber 258 to the fourth flow path 261. Therefore, the solenoid valve 211 can prevent the air in the accommodation chamber 258 from reducing the fluid resistance of the brake fluid in the accommodation chamber 258, and can prevent the valve member 223 and the plunger 222 from vibrating self-excited due to disturbances.

[0193] The second flow path 250 has an internal chamber 251 and a through hole 252. The through hole 252 is connected to the fourth flow path 261 via an external junction chamber 267. When the brake fluid flows from the internal chamber 251 to the junction chamber 267, a pressure loss occurs in the through hole 252, and when the brake fluid flows from the internal chamber 251 to the third flow path 255, a pressure loss occurs in the first communication hole 256. Therefore, the pressure in the internal chamber 251 becomes higher than the pressures in the third flow path 255, the storage chamber 258, and the fourth flow path 261, and also becomes higher than the pressure in the junction chamber 267. As a result, a portion of the brake fluid in the inner chamber 251 can flow from the first communication hole 256 through the third flow path 255, the storage chamber 258, and the fifth flow path 275 to the fourth flow path 261, and thus the air in the innermost portion 258a of the storage chamber 258 can be discharged to the fourth flow path 261.

[0194] The plurality of fifth flow paths 275 include a first hole 276 that penetrates the plunger 222 and opens to the first end face 271 and the second end face 272, and a groove 277 that is recessed from the side surface 273 and opens to the first end face 271 and the second end face 272. A second hole 290 that connects the third flow path 255 and the first hole 276 is provided in the valve member 223. For example, brake fluid flowing in the first direction D1 passes through the second hole 290 and the first hole 276, and brake fluid flowing in the second direction D2 passes through the groove 277. In this way, the first hole 276 and the groove 277 each allow the brake fluid to flow in a fixed direction. Therefore, the solenoid valve 211 can generate a stable flow of brake fluid through the third flow path 255, the second hole 290, the first hole 276, the groove 277, and the fourth flow path 261, and can discharge air from the innermost portion 258a of the storage chamber 258 to the fourth flow path 261.

[0195] The valve member 223 has an outer circumferential surface 285c and a recessed surface 285d recessed from the outer circumferential surface 285c. The second hole 290 opens into the recessed surface 285d. This allows the second hole 290 to open to the side of the valve member 223, and also forms a gap flow path 255c that communicates with the second hole 290 between the inner circumferential surface 255a of the third flow path 255 and the recessed surface 285d. This improves the degree of freedom in designing the second hole 290.

[0196] A second communication hole 262 that communicates third flow path 255 and fourth flow path 261 is provided in housing 221. A portion of the brake fluid that flows from second flow path 250 through first communication hole 256 into third flow path 255 flows through fifth flow path 275 to fourth flow path 261. Meanwhile, another portion of the brake fluid flows through second communication hole 262 to fourth flow path 261. In other words, solenoid valve 211 can prevent a large amount of brake fluid from flowing into storage chamber 258, and can therefore prevent the pressure in storage chamber 258 from increasing.

[0197] The third flow path 255 and the fourth flow path 261 are provided in the guide 231. That is, the third flow path 255 and the fourth flow path 261 are provided in one member. As a result, compared to a case where the third flow path 255 and the fourth flow path 261 are formed by a plurality of members, the solenoid valve 211 of the present embodiment can reduce the number of parts and the number of assembly steps, and thus can suppress an increase in costs.

[0198] In the above embodiment, the magnetic field generated by the coil 34 urges the plunger 32, 222 in the second direction D2, and the urging member 35 urges the valve member 33, 223 in the first direction D1. However, the magnetic field generated by the coil may urge the plunger in the first direction D1, and the urging member may urge the valve member in the second direction D2.

[0199] The solenoid valve according to at least one embodiment described above may, for example, include a housing provided with a first flow path, a storage chamber spaced apart from the first flow path in a first direction from the first flow path, a second flow path located between the first flow path and the storage chamber and capable of communicating with the first flow path, an insertion hole that communicates the second flow path with the storage chamber, and a first circulation flow path that is spaced apart from the insertion hole and communicates the second flow path with the storage chamber, the housing having a sheet through which the first flow path opens; a coil that generates a magnetic field when a current is passed through it; a first end surface facing the first direction; The housing includes a plunger positioned in the housing and biased in the second direction by the magnetic field, a valve member positioned inside the housing between the seat and the plunger, passing through the insertion hole and contacting the seat to block the first flow path, and communicating the first flow path with the second flow path by separating from the seat, and biased in the second direction by the plunger biased by the magnetic field, and a biasing member that elastically biases the valve member in the first direction. Thus, for example, a fluid flowing into the housing through the insertion hole flows through at least one of the plurality of second circulation flow paths in the first direction and flows through at least another of the plurality of second circulation flow paths in the second direction, thereby circulating. The fluid also flows through the first circulation flow path and returns to the second flow path from the housing. As a result, the solenoid valve of this embodiment can suppress an increase in pressure in the storage chamber, which would otherwise cause a pressure difference between the storage chamber and the second flow path.

[0200] In the solenoid valve, as an example, the housing has an outer cylinder and an inner cylinder fitted inside the outer cylinder, the insertion hole is provided inside the inner cylinder, and the first circulation flow path is provided between the outer cylinder and the inner cylinder. Therefore, as an example, the solenoid valve of this embodiment can easily provide the insertion hole and the first circulation flow path in the housing.

[0201] In the solenoid valve, for example, the inner cylinder has a support surface that supports the biasing member. Therefore, for example, the biasing member is disposed outside the second flow path. Therefore, the solenoid valve of this embodiment can suppress the biasing member from affecting the flow of brake fluid in the second flow path.

[0202] In the above solenoid valve, as one example, the first circulation flow path includes a plurality of holes that each connect the second flow path and the storage chamber and are arranged to surround the insertion hole. Therefore, as one example, when the solenoid valve is arranged so that the first flow path is approximately horizontal, at least one of the plurality of holes is located above the insertion hole. As a result, the solenoid valve of this embodiment can discharge air that has risen due to buoyancy in the storage chamber to the second flow path through the hole located above the insertion hole.

[0203] The solenoid valve according to at least one embodiment described above may, for example, include a housing provided with a first flow path, a storage chamber spaced apart from the first flow path in a first direction from the first flow path, a second flow path located between the first flow path and the storage chamber and capable of communicating with the first flow path, a third flow path located between the second flow path and the storage chamber and communicating with the storage chamber, a fourth flow path spaced apart from the second flow path and the third flow path and communicating with the storage chamber, and a first communication hole communicating between the second flow path and the third flow path, and the housing has a sheet through which the first flow path opens; a coil that generates a magnetic field when a current is passed through it; a first end surface facing the first direction; a second end face facing a second direction opposite to the first direction, the second end face being provided with a plurality of fifth flow paths each communicating between the first end face and the second end face, the plunger being positioned in the accommodating chamber and biased by the magnetic field in one of the first direction and the second direction, a valve member being positioned between the seat and the plunger through the third flow path and the first communication hole, the valve member contacting the seat to block the first flow path and separating from the seat to connect the first flow path to the second flow path, and biased in the second direction by the plunger biased by the magnetic field, and a biasing member biasing the valve member in the other of the first direction and the second direction. Thus, for example, brake fluid flowing into the accommodating chamber through the communication hole and the third flow path flows through at least one of the plurality of fifth flow paths in the first direction and through at least another of the plurality of fifth flow paths in the second direction. Furthermore, the brake fluid can flow into the fourth flow path without returning to the second flow path through the third flow path and the communication hole. This allows the solenoid valve to make the pressure in the second flow path different from the pressure in the third flow path, the housing chamber, and the fourth flow path. By making the pressure in the third flow path, the housing chamber, and the fourth flow path lower than the pressure in the second flow path, the solenoid valve can suppress an increase in pressure in the housing chamber, which in turn makes it easier to adjust the position of the valve member. Furthermore, the brake fluid can pass near the first end face of the plunger in the housing chamber and be discharged from the fourth flow path.Therefore, the solenoid valve can discharge air deep inside the housing to the fourth flow path, thereby preventing the air in the housing from reducing the fluid resistance of the brake fluid in the housing, and preventing the valve member and plunger from vibrating self-excited by disturbances.

[0204] In the above-described solenoid valve, for example, the second flow path includes an inner chamber that can communicate with the first flow path and a through hole that connects the inner chamber to a space outside the second flow path. The first communication hole connects the inner chamber to the third flow path, and the through hole connects the inner chamber to the fourth flow path via the external space. Therefore, for example, when brake fluid flows from the inner chamber to the external space, a pressure loss occurs at the through hole, and when brake fluid flows from the inner chamber to the third flow path, a pressure loss occurs at the first communication hole. Therefore, the pressure in the inner chamber is higher than the pressure in the third flow path, the storage chamber, and the fourth flow path, and is also higher than the pressure in the external space. Therefore, a portion of the brake fluid in the inner chamber can flow from the first communication hole through the third flow path, the storage chamber, and the fifth flow path to the fourth flow path, thereby discharging air deep inside the storage chamber to the fourth flow path.

[0205] In the above-described solenoid valve, for example, the plunger has a side surface supported by the inner surface of the accommodating chamber so as to be movable in the first direction and the second direction, the plurality of fifth flow paths include a first hole penetrating the plunger and opening to the first end face and the second end face, and a groove recessed from the side surface and opening to the first end face and the second end face, and the valve member has a third end face facing the second end face of the plunger and is provided with a second hole opening to the third end face and communicating the third flow path with the first hole. Thus, for example, the first hole and the groove can each allow brake fluid to flow in a constant direction. Therefore, the solenoid valve can generate a stable flow of brake fluid through the third flow path, the second hole, the first hole, the groove, and the fourth flow path, and can exhaust air deep within the accommodating chamber to the fourth flow path.

[0206] In the above solenoid valve, as one example, the valve member has an outer surface supported on an inner surface of the third flow path so as to be movable in the first direction and the second direction, and a concave surface recessed from the outer surface, and the second hole opens into the concave surface. Thus, as one example, the second hole can open to a side of the valve member, and a flow path leading to the second hole is formed between the inner surface of the third flow path and the concave surface. This improves the degree of freedom in designing the second hole.

[0207] In the above solenoid valve, for example, a second communication hole is provided in the housing, connecting the third flow path and the fourth flow path. Therefore, for example, a portion of the brake fluid that flows from the second flow path through the first communication hole to the third flow path flows to the fourth flow path through the fifth flow path. Meanwhile, another portion of the brake fluid flows to the fourth flow path through the second communication hole. In other words, the solenoid valve can prevent a large amount of brake fluid from flowing into the storage chamber, and thus can prevent an increase in pressure in the storage chamber.

[0208] In the above solenoid valve, as an example, the housing has a guide to which the seat is attached, and the third flow path and the fourth flow path are provided in the guide. Therefore, as an example, the third flow path and the fourth flow path are provided in a single member. As a result, compared to, for example, a case in which the third flow path and the fourth flow path are formed by a plurality of members, the solenoid valve of this embodiment can reduce the number of parts and the number of assembly steps, and ultimately suppress an increase in costs.

[0209] The brake control device according to at least one embodiment described above includes, for example, a master cylinder, a wheel cylinder, and the solenoid valve, in which the first flow path is connected to one of the master cylinder and the wheel cylinder through a flow path through which brake fluid flows, and the second flow path is connected to the other of the master cylinder and the wheel cylinder through the flow path. Therefore, for example, the brake control device according to this embodiment can suppress the occurrence of a pressure difference between the brake fluid in the accommodation chamber and the brake fluid in the second flow path.

[0210] In the above description, suppression is defined as, for example, preventing an event, action, or influence from occurring, or reducing the degree of an event, action, or influence. Also, in the above description, restriction is defined as, for example, preventing movement or rotation, or allowing movement or rotation within a predetermined range and preventing movement or rotation beyond the predetermined range.

[0211] While the embodiments of the present invention have been described above, the above-described embodiments and modifications are merely examples and are not intended to limit the scope of the invention. The above-described embodiments and modifications can be implemented in various other forms, and various omissions, substitutions, combinations, and modifications can be made without departing from the spirit of the invention. Furthermore, the configurations and shapes of each embodiment and each modification can be partially interchanged. [Explanation of symbols]

[0212] 10,200...Brake control device, 11...Master cylinder, 12...Wheel cylinder, 21,211...Solenoid valve, 31,221...Housing, 32,222...Plunger, 33,223...Valve member, 34...Coil, 35...Biasing member, 41,231...Guide (outer cylinder), 42...Plate (inner cylinder), 43...Seat, 69...Support surface, 70...Through-hole, 75...First circulation flow path, 81...First flow path, 82...Accommodation chamber, 85...Second flow path, 91,271...First end surface, 92,272...Second end surface, 95...Second circulation flow path , 250...second flow path, 251...inner chamber, 252...through hole, 255...third flow path, 255a...inner surface (inner surface), 256...first communicating hole, 258...storage chamber, 261...fourth flow path, 262...second communicating hole, 267...merging chamber (external space), 273...side surface, 275...fifth flow path, 276...first hole, 277...groove, 282...valve body (third end face), 285a...end face (third end face), 285c...outer surface (outer surface), 285d...concave surface, 290...second hole, D1...first direction, D2...second direction, C...flow path.

Claims

1. a housing having a sheet in which a first flow path, a storage chamber spaced from the first flow path in a first direction, a second flow path located between the first flow path and the storage chamber and capable of communicating with the first flow path, an insertion hole that communicates the second flow path and the storage chamber, and a first circulation flow path that is spaced from the insertion hole and communicates the second flow path and the storage chamber, and in which the first flow path opens; A coil that generates a magnetic field when a current is passed through it; a plunger having a first end face facing the first direction and a second end face located opposite the first end face and facing a second direction opposite to the first direction, a plurality of second circulation flow paths each communicating between the first end face and the second end face are provided, the plunger being located in the accommodation chamber and biased by the magnetic field; a valve member located inside the housing between the seat and the plunger, passing through the insertion hole, contacting the seat to block the first flow path, and separating from the seat to connect the first flow path to the second flow path, and being biased in the second direction by the plunger biased by the magnetic field; a biasing member that biases the valve member in the first direction by elastic force; Equipped with The housing has an outer cylinder and an inner cylinder fitted inside the outer cylinder, The insertion hole is provided on the inside of the inner cylinder, The first circulation flow path is provided between the outer cylinder and the inner cylinder, The inner cylinder has a support surface that supports the urging member. Solenoid valve.

2. a housing having a sheet in which a first flow path, a storage chamber spaced from the first flow path in a first direction, a second flow path located between the first flow path and the storage chamber and capable of communicating with the first flow path, a third flow path located between the second flow path and the storage chamber and communicating with the storage chamber, a fourth flow path spaced from the second flow path and the third flow path and communicating with the storage chamber, and a first communication hole communicating between the second flow path and the third flow path, and in which the first flow path opens; A coil that generates a magnetic field when a current is passed through it; a plunger having a first end face facing the first direction and a second end face located opposite the first end face and facing a second direction opposite to the first direction, a plurality of fifth flow paths each communicating between the first end face and the second end face are provided, the plunger is located in the accommodation chamber, and is biased in one of the first direction and the second direction by the magnetic field; a valve member that is positioned between the seat and the plunger through the third flow path and the first communication hole, that blocks the first flow path when in contact with the seat, and that connects the first flow path to the second flow path when separated from the seat, and that is urged in the second direction by the plunger that is urged by the magnetic field; a biasing member that biases the valve member in the other of the first direction and the second direction; Equipped with The second flow path has an inner chamber that can communicate with the first flow path, and a through hole that communicates an external space of the second flow path with the inner chamber, The first communication hole communicates the inner chamber with the third flow path, The through hole is in communication with the fourth flow path via the external space. Solenoid valve.

3. the plunger has a side surface supported by an inner surface of the accommodation chamber so as to be movable in the first direction and the second direction; the plurality of fifth flow paths include a first hole penetrating the plunger and opening to the first end face and the second end face, and a groove recessed from the side surface and opening to the first end face and the second end face, the valve member has a third end surface facing the second end surface of the plunger, and a second hole is provided which opens into the third end surface and communicates the third flow path with the first hole; The solenoid valve of claim 2.

4. A housing having a sheet in which a first flow path, a storage chamber spaced from the first flow path in a first direction, a second flow path located between the first flow path and the storage chamber and capable of communicating with the first flow path, a third flow path located between the second flow path and the storage chamber and communicating with the storage chamber, a fourth flow path spaced from the second flow path and the third flow path and communicating with the storage chamber, and a first communication hole communicating between the second flow path and the third flow path, and the first flow path is opened; A coil that generates a magnetic field when a current is passed through it; a plunger having a first end face facing the first direction and a second end face located opposite the first end face and facing a second direction opposite to the first direction, a plurality of fifth flow paths each communicating between the first end face and the second end face are provided, the plunger is located in the accommodation chamber, and is biased in one of the first direction and the second direction by the magnetic field; a valve member that is positioned between the seat and the plunger through the third flow path and the first communication hole, that blocks the first flow path when in contact with the seat, and that connects the first flow path to the second flow path when separated from the seat, and that is urged in the second direction by the plunger that is urged by the magnetic field; a biasing member that biases the valve member in the other of the first direction and the second direction; Equipped with the plunger has a side surface supported by an inner surface of the accommodation chamber so as to be movable in the first direction and the second direction; the plurality of fifth flow paths include a first hole penetrating the plunger and opening to the first end face and the second end face, and a groove recessed from the side surface and opening to the first end face and the second end face, the valve member has a third end surface facing the second end surface of the plunger, and a second hole is provided which opens into the third end surface and communicates the third flow path with the first hole; Solenoid valve.

5. the valve member has an outer surface supported on an inner surface of the third flow passage so as to be movable in the first direction and the second direction, and a concave surface recessed from the outer surface, The second hole opens into the concave surface. The solenoid valve according to claim 3 or 4.

6. 5. The solenoid valve according to claim 2, wherein the housing is provided with a second communication hole that communicates the third flow path and the fourth flow path.

7. the housing has a guide to which the sheet is attached, The third flow path and the fourth flow path are provided in the guide.

5. A solenoid valve according to claim 2.

8. A master cylinder; A wheel cylinder; 5. The solenoid valve according to claim 1, wherein the first flow path is connected to one of the master cylinder and the wheel cylinder through a flow path through which brake fluid flows, and the second flow path is connected to the other of the master cylinder and the wheel cylinder through the flow path; A brake control device comprising:

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