Vehicle brake device

Abstract

The linear motion conversion unit (40) is held by a caliper (5) that holds the pad (4), and is capable of converting rotation from the speed reducer (30) into linear motion, and pressing the pad (4) against the disk (3). The electronic circuit (50) is capable of controlling the rotation of the electric motor (20). The caliper-side speed reducer housing (60) is provided so as to accommodate a part of the speed reducer (30), and is connected to the caliper (5). The motor-side speed reducer housing (70) is provided so as to accommodate a part of the speed reducer (30), and is connected to the caliper-side speed reducer housing (60). The motor (20) is provided on the caliper-side speed reducer housing (60) side with respect to the motor-side speed reducer housing (70). The electronic circuit (50) is provided on the opposite side of the caliper-side speed reducer housing (60) with respect to the motor-side speed reducer housing (70). The thermal conductivity of the caliper-side speed reducer housing is lower than the thermal conductivity of the motor-side speed reducer housing.

Description

[0001] Cross-reference to related applications

[0002] This application is based on Japanese Patent Application No. 2022-089069 filed on May 31, 2022, and the contents thereof are incorporated herein by reference. Technical Field

[0003] The present invention relates to a braking device for a vehicle. Background Art

[0004] Conventionally, there is known an electric vehicle brake device that converts the rotation of a motor reduced by a speed reducer into a linear motion and presses a pad against a wheel disc. For example, the vehicle brake device of Patent Document 1 integrally includes a motor, a speed reducer, a linear motion conversion unit, and an electronic circuit capable of controlling the rotation of the motor.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2007-278311

[0008] In the vehicle brake device of Patent Document 1, the heat dissipation surface of the power module of the electronic circuit is arranged opposite to the metal housing to improve the heat dissipation of the power module. In addition, a resin housing or the like having a lower thermal conductivity than the metal housing is arranged between the power module and the speed reducer, the motor and the linear motion converter to suppress heat transfer between the power module and the speed reducer, the motor and the linear motion converter.

[0009] However, in the vehicle brake device of Patent Document 1, the speed reducer, the motor, and the linear motion converter are arranged close to each other in the same housing, and no consideration is given to suppressing heat transfer between the speed reducer, the motor, and the linear motion converter. Therefore, there is a concern that friction heat between the pad and the disc will be transferred to the motor and the speed reducer via the linear motion converter. Summary of the invention

[0010] An object of the present invention is to provide a vehicle brake device capable of suppressing heat transfer between parts and ensuring heat dissipation of the parts.

[0011] The present invention relates to a vehicle brake device, which can limit the rotation of the wheel by pressing a pad against a disk that is set to rotate together with the wheel, and comprises a motor, a speed reducer, a linear motion conversion unit, an electronic circuit, a caliper-side speed reducer housing, and a motor-side speed reducer housing. The motor rotates by energizing. The speed reducer reduces the speed of rotation from the motor and outputs the rotation. The linear motion conversion unit is held by a caliper that holds the pad, and can convert the rotation from the speed reducer into linear motion and press the pad against the disk.

[0012] The electronic circuit can control the rotation of the motor. The caliper-side reducer housing is configured to accommodate a portion of the reducer and is connected to the caliper. The motor-side reducer housing is configured to accommodate a portion of the reducer and is connected to the caliper-side reducer housing. The motor is disposed on the caliper-side reducer housing side or on the side opposite to the caliper-side reducer housing relative to the motor-side reducer housing. The electronic circuit is disposed on the caliper-side reducer housing side or on the other side of the caliper-side reducer housing side or on the other side of the caliper-side reducer housing relative to the motor-side reducer housing.

[0013] The thermal conductivity of the caliper-side reducer housing is lower than that of the motor-side reducer housing. Therefore, it is possible to suppress heat transfer between the caliper connected to the caliper-side reducer housing and the motor and electronic circuit provided on both sides of the motor-side reducer housing connected to the caliper-side reducer housing. As a result, it is possible to suppress the friction heat between the pad and the disc from being transferred to the reducer, the motor, and the electronic circuit. Therefore, it is possible to suppress the temperature rise of the reducer, the motor, and the electronic circuit when the vehicle brake device is working.

[0014] In addition, the motor and the electronic circuit are arranged on both sides of the motor-side reducer housing, which has a higher thermal conductivity than the caliper-side reducer housing, so that heat dissipation of the motor and the heat generating components of the electronic circuit can be ensured. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description made with reference to the accompanying drawings.

[0016] Figure 1 It is a cross-sectional view showing a vehicle brake device according to an embodiment.

[0017] Figure 2 It is a perspective view showing a vehicle brake device according to an embodiment. DETAILED DESCRIPTION

[0018] Hereinafter, a vehicle brake device according to an embodiment will be described based on the drawings. In the embodiment, substantially the same components are denoted by the same reference numerals and description thereof will be omitted.

[0019] (One embodiment)

[0020] Figure 1 , Figure 2 1 shows a vehicle brake device according to an embodiment. The vehicle brake device 10 is provided, for example, on a vehicle 1. The vehicle brake device 10 can restrict the rotation of the wheel 2 by pressing the pad 4 against the disk 3 provided to rotate together with the wheel 2. Thus, the vehicle 1 can be kept parked or the vehicle 1 can be decelerated or stopped while in motion.

[0021] The vehicle 1 is provided with a caliper 5. The caliper 5 is formed of, for example, metal, and is fixed to the vehicle 1 so as to be movable according to the wear of the pads 4. The caliper 5 holds the two pads 4. The disc 3 is located between the two pads 4.

[0022] The vehicle brake device 10 includes a motor 20, a speed reducer 30, a linear motion conversion unit 40, an electronic circuit 50, a caliper-side speed reducer housing 60, a motor-side speed reducer housing 70, a motor housing 72, an electronic circuit housing 74, a fastening member 80, a heat insulating member 90, a heat insulating member 92, a heat transfer member 94, and the like. The motor 20 rotates by energizing. The speed reducer 30 reduces the rotation from the motor 20 and outputs the rotation. The linear motion conversion unit 40 is held by the caliper 5 that holds the pad 4, and can convert the rotation from the speed reducer 30 into linear motion to press the pad 4 against the disk 3.

[0023] In more detail, the motor 20 is, for example, a three-phase brushless motor, and includes a stator 21 and a rotor 22. The stator 21 is fixed to a motor housing 72 described later. The rotor 22 is provided so as to be relatively rotatable relative to the stator 21. A shaft 23 is provided at the center of the rotor 22. The shaft 23 rotates together with the rotor 22 to output torque.

[0024] The speed reducer 30 includes a first pinion 31, a first large gear 32, a second pinion 33, a second large gear 34, a gear shaft 35, a gear shaft 36, a connecting member 37, etc. The first pinion 31 is formed of, for example, metal. The first large gear 32 is formed of, for example, metal, and the outer diameter of the first large gear 32 is set larger than that of the first pinion 31, and meshes with the first pinion 31.

[0025] The second small gear 33 is formed of, for example, resin, has an outer diameter set smaller than that of the first large gear 32, and is provided coaxially with the first large gear 32 so as to be rotatable together with the first large gear 32. The second large gear 34 is formed of, for example, resin, has an outer diameter set larger than that of the second small gear 33, and meshes with the second small gear 33.

[0026] The gear shaft 35 is formed of, for example, metal, and is rotatably supported by a motor-side speed reducer housing 70 described later. The gear shaft 36 is formed of, for example, metal, and is rotatably supported by a caliper-side speed reducer housing 60 described later. The connecting member 37 is formed of, for example, resin, and connects a rotating member 41 of a linear motion conversion unit 40 described later and the gear shaft 36, and is provided so that rotation can be transmitted between the gear shaft 36 and the rotating member 41.

[0027] The first pinion gear 31 is provided on the side of the shaft 23 opposite to the rotor 22 so as to rotate together with the shaft 23. The first large gear 32 meshes with the first pinion gear 31, and the first large gear 32 is provided coaxially with the gear shaft 35 so as to rotate together with the gear shaft 35. The second pinion gear 33 is provided coaxially with the gear shaft 35 so as to be rotatable together with the first large gear 32 and the gear shaft 35. The second large gear 34 meshes with the second pinion gear 33, and the second large gear 34 is provided coaxially with the gear shaft 36 so as to be rotatable together with the gear shaft 36.

[0028] With the above structure, when the rotor 22 of the motor 20 rotates and the shaft 23 rotates, the first pinion 31 rotates, the first large gear 32 and the second pinion 33 meshing with the first pinion 31 rotate, and the second large gear 34 meshing with the second pinion 33 rotates. Thus, the rotation from the motor 20 is decelerated and output from the gear shaft 36.

[0029] The linear motion conversion unit 40 includes a rotating member 41, a linear motion member 42, and a piston 43. The rotating member 41 is formed of metal in a substantially cylindrical shape, for example, and is rotatably supported by the caliper 5. One end of the rotating member 41 is connected to the gear shaft 36 via a connecting member 37.

[0030] The linear motion member 42 is formed of metal, for example, and is provided on the other end side of the rotating member 41. The linear motion member 42 is provided so as to be relatively movable in the axial direction with respect to the caliper 5 when the rotating member 41 rotates. Thus, the rotating member 41 can convert the input rotation into linear motion.

[0031] The piston 43 is formed in a bottomed cylindrical shape, for example. The piston 43 is provided so that the inner wall of the bottom portion can come into contact with the linear motion member 42. The piston 43 is provided so as to be relatively movable in the axial direction with respect to the caliper 5.

[0032] The vehicle brake device 10 is provided on the vehicle 1 so that the side of the piston 43 opposite to the linear motion member 42 can abut against the pad 4. When the motor 20 rotates in the forward direction by power supply, the reduced rotation is output from the gear shaft 36 of the speed reducer 30. As a result, the rotating member 41 rotates relative to the caliper 5. As a result, the linear motion member 42 moves toward the pad 4 side, and the piston 43 is pressed against the pad 4. As a result, the pad 4 is pressed against the disc 3, and the rotation of the wheel 2 is restricted.

[0033] On the other hand, when the motor 20 rotates in the reverse direction, the reduced rotation is output from the gear shaft 36 of the speed reducer 30. As a result, the rotating member 41 rotates relative to the caliper 5 in the opposite direction to the above. As a result, the linear motion member 42 moves to the side opposite to the pad 4. As a result, the pressing of the piston 43 against the pad 4 and the pressing of the pad 4 against the disc 3 are released, and the rotation of the wheel 2 is allowed.

[0034] The electronic circuit 50 can control the rotation of the motor 20. The caliper-side reducer housing 60 is provided to accommodate a portion of the reducer 30 and is connected to the caliper 5. The motor-side reducer housing 70 is provided to accommodate a portion of the reducer 30 and is connected to the caliper-side reducer housing 60. The motor 20 is provided on the caliper-side reducer housing 60 side relative to the motor-side reducer housing 70. The electronic circuit 50 is provided on the side opposite to the caliper-side reducer housing 60 relative to the motor-side reducer housing 70.

[0035] In more detail, the electronic circuit 50 includes a substrate 51, a microcomputer 52, a switching element 53, and the like. The substrate 51 is formed into a plate shape by, for example, resin. The microcomputer 52 is, for example, mounted on one surface of the substrate 51. A plurality of switching elements 53 are, for example, mounted on one surface of the substrate 51. The microcomputer 52 is a small computer having a CPU, a memory, an input / output unit, and the like, and can control the operation of the switching element 53 based on signals from various sensors mounted on the vehicle 1, thereby controlling the power supply to the motor 20.

[0036] The caliper-side speed reducer housing 60 is formed into a flat box shape by resin, for example. The caliper-side speed reducer housing 60 forms a space 600 inside. The caliper-side speed reducer housing 60 accommodates the second pinion 33, the second large gear 34, the gear shaft 36, and the connecting member 37 among the parts constituting the speed reducer 30 in the space 600. In addition, a portion of the gear shaft 35 is located in the space 600.

[0037] The caliper-side speed reducer housing 60 is arranged so that one end surface is connected to the end surface of the caliper 5 on the side opposite to the piston 43. Here, "connection" means not only a state where two components are connected in a direct contact manner, but also a state where two components are indirectly connected with other components in between (the same applies below).

[0038] The motor-side speed reducer housing 70 is formed into a flat box shape by metal, for example. The motor-side speed reducer housing 70 forms a space 700 inside. The motor-side speed reducer housing 70 accommodates the first pinion 31 and the first large gear 32 of the parts constituting the speed reducer 30 in the space 700. In addition, a portion of the shaft 23 and a portion of the gear shaft 35 are located in the space 700.

[0039] The motor-side speed reducer case 70 is provided so that a part of one end surface is connected to the end surface of the caliper-side speed reducer case 60 on the side opposite to the caliper 5 .

[0040] The electric motor 20 is disposed on the caliper-side reducer housing 60 side relative to the end surface of the motor-side reducer housing 70 connected to the caliper-side reducer housing 60. The electronic circuit 50 is disposed on the side opposite to the caliper-side reducer housing 60 relative to the end surface of the motor-side reducer housing 70 opposite to the end surface connected to the caliper-side reducer housing 60.

[0041] The thermal conductivity of the reducer housing on the caliper side is lower than the thermal conductivity of the reducer housing on the motor side.

[0042] More specifically, the caliper-side speed reducer case 60 is formed of resin, and the thermal conductivity of the caliper-side speed reducer case 60 is lower than the thermal conductivity of the motor-side speed reducer case 70 formed of metal.

[0043] The motor housing 72 is provided to house the electric motor 20 and is connected to the motor-side speed reducer housing 70. The electronic circuit housing 74 is provided to house the electronic circuit 50 and is connected to the motor-side speed reducer housing 70. The thermal conductivity of the motor housing 72 and the electronic circuit housing 74 is higher than the thermal conductivity of the caliper-side speed reducer housing 60.

[0044] More specifically, the motor housing 72 is formed into a box shape by metal, for example. The motor housing 72 forms a space 720 inside. The motor housing 72 accommodates the stator 21 and the rotor 22 of the electric motor 20 in the space 720. The stator 21 is fixed to the inner wall of the motor housing 72. In addition, a part of the shaft 23 is located in the space 720.

[0045] The motor case 72 is provided so that one end surface is connected to the end surface of the motor-side speed reducer case 70 on the caliper-side speed reducer case 60 side. Here, the motor case 72 and the motor-side speed reducer case 70 are directly in contact and connected.

[0046] The electronic circuit case 74 is formed of metal, for example, in a flat box shape. The electronic circuit case 74 forms a space 740 inside. The electronic circuit case 74 accommodates the substrate 51 , the microcomputer 52 , and the switch element 53 of the electronic circuit 50 in the space 740 .

[0047] The electronic circuit case 74 is provided so that one end surface is connected to the end surface of the motor-side speed reducer case 70 on the opposite side to the caliper-side speed reducer case 60. Here, the electronic circuit case 74 is directly in contact with and connected to the motor-side speed reducer case 70.

[0048] The motor case 72 and the electronic circuit case 74 are formed of metal, and the thermal conductivity of the motor case 72 and the electronic circuit case 74 is higher than the thermal conductivity of the caliper-side speed reducer case 60 formed of resin.

[0049] The coil (not shown) wound around the stator 21 of the motor 20 and the switching element 53 of the electronic circuit 50 are electrically connected via the conductive wire 24. The conductive wire 24 is formed into a linear shape by metal, for example, and extends from the space 600 to the space 700 through the space 740.

[0050] One or more fastening members 80 are provided, and the fastening members 80 fasten the motor case 72 and the electronic circuit case 74 integrally via the motor-side speed reducer case 70 .

[0051] In more detail, the fastening member 80 is formed into a long thread shape by metal, for example. The fastening member 80 is screwed with the motor housing 72 in a manner that penetrates the electronic circuit housing 74 and the motor-side reducer housing 70 while the motor-side reducer housing 70 is sandwiched between the motor housing 72 and the electronic circuit housing 74. In this way, the motor housing 72 and the electronic circuit housing 74 are fastened together by one or more fastening members 80 via the motor-side reducer housing 70. The thermal conductivity of the fastening member 80 is higher than that of the caliper-side reducer housing 60.

[0052] The thermal conductivity of a part of the components constituting the reduction gear 30 is lower than the thermal conductivity of the motor-side reduction gear case 70 .

[0053] More specifically, the second pinion 33 , the second large gear 34 , and the connecting member 37 of the components constituting the reducer 30 are formed of resin, and the thermal conductivity of the second pinion 33 , the second large gear 34 , and the connecting member 37 is lower than the thermal conductivity of the motor-side reducer housing 70 formed of metal.

[0054] The reducer 30 has two or more reduction mechanisms. The caliper-side reducer housing 60 accommodates one or more reduction mechanisms from the caliper 5 side of the reduction mechanism. The motor-side reducer housing 70 accommodates one or more reduction mechanisms from the motor 20 side of the reduction mechanism.

[0055] In more detail, the reducer 30 has a two-stage reduction mechanism, namely, a reduction mechanism composed of a first pinion 31 and a first large gear 32 and a reduction mechanism composed of a second pinion 33 and a second large gear 34. The caliper-side reduction mechanism housing 60 accommodates the first-stage reduction mechanism from the caliper 5 side, namely, the second pinion 33 and the second large gear 34. The motor-side reduction mechanism housing 70 accommodates the first-stage reduction mechanism from the motor 20 side, namely, the first pinion 31 and the first large gear 32, of the two reduction mechanisms.

[0056] The heat insulating components 90 and 92 are made of a material having a lower thermal conductivity than the thermal conductivity of the caliper-side reducer housing 60, and are arranged between the caliper 5 and the caliper-side reducer housing 60, or between the caliper-side reducer housing 60 and the motor-side reducer housing 70 in such a manner that the thermal resistance between the caliper 5 and the motor 20 is greater than the thermal resistance between the motor 20 and the electronic circuit 50.

[0057] In more detail, the heat insulating member 90 and the heat insulating member 92 are formed into a plate shape by resin, for example. The thermal conductivity of the heat insulating member 90 and the heat insulating member 92 is lower than the thermal conductivity of the caliper side reducer housing 60 formed by resin. The heat insulating member 90 is provided between the end surface of the caliper side reducer housing 60 side of the caliper 5 and the end surface of the caliper side reducer housing 60 on the caliper 5 side. As a result, the thermal resistance between the caliper 5 and the motor 20 is greater than the thermal resistance between the motor 20 and the electronic circuit 50.

[0058] The heat transfer member 94 is made of a material having a higher thermal conductivity than the caliper-side speed reducer case 60 , and is provided between the motor 20 and the electronic circuit 50 so that the thermal resistance between the caliper 5 and the motor 20 is greater than the thermal resistance between the motor 20 and the electronic circuit 50 .

[0059] In more detail, the heat transfer member 94 is formed of metal, for example, in a rod shape. The heat transfer member 94 is formed of metal, and the thermal conductivity of the heat transfer member 94 is higher than the thermal conductivity of the caliper-side speed reducer housing 60 formed of metal. The heat transfer member 94 is provided to connect the motor housing 72 and the electronic circuit housing 74 between the motor 20 and the electronic circuit 50. As a result, the thermal resistance between the caliper 5 and the motor 20 is greater than the thermal resistance between the motor 20 and the electronic circuit 50.

[0060] As described above, in the present embodiment, the linear motion conversion portion 40 is held by the caliper 5 that holds the pad 4, and can convert the rotation from the reducer 30 into linear motion, pressing the pad 4 against the disk 3. The electronic circuit 50 can control the rotation of the motor 20. The caliper-side reducer housing 60 is configured to accommodate a portion of the reducer 30 and is connected to the caliper 5. The motor-side reducer housing 70 is configured to accommodate a portion of the reducer 30 and is connected to the caliper-side reducer housing 60. The motor 20 is disposed on the caliper-side reducer housing 60 side relative to the motor-side reducer housing 70. The electronic circuit 50 is disposed on the side opposite to the caliper-side reducer housing 60 relative to the motor-side reducer housing 70. The thermal conductivity of the caliper-side reducer housing is lower than the thermal conductivity of the motor-side reducer housing.

[0061] Therefore, it is possible to suppress heat transfer between the caliper 5 connected to the caliper-side reducer housing 60 and the motor 20 and the electronic circuit 50 provided on both sides of the motor-side reducer housing 70 connected to the caliper-side reducer housing 60. Thus, it is possible to suppress the friction heat between the pad 4 and the disc 3 from being transferred to the reducer 30, the motor 20, and the electronic circuit 50. Therefore, it is possible to suppress the temperature increase of the reducer 30, the motor 20, and the electronic circuit 50 when the vehicle brake device 10 is in operation.

[0062] Furthermore, the motor 20 and the electronic circuit 50 are provided on both sides of the motor-side reducer case 70 having a higher thermal conductivity than the caliper-side reducer case 60. Therefore, heat dissipation of the switching element 53 and the like, which are heat generating components of the motor 20 and the electronic circuit 50, can be ensured.

[0063] The motor housing 72 is provided to house the electric motor 20 and is connected to the motor-side speed reducer housing 70. The electronic circuit housing 74 is provided to house the electronic circuit 50 and is connected to the motor-side speed reducer housing 70. The thermal conductivity of the motor housing 72 and the electronic circuit housing 74 is higher than the thermal conductivity of the caliper-side speed reducer housing 60.

[0064] Therefore, heat dissipation of the motor 20 and the electronic circuit 50 can be promoted.

[0065] One or more fastening members 80 are provided, and the fastening members 80 fasten the motor case 72 and the electronic circuit case 74 integrally via the motor-side speed reducer case 70 .

[0066] Therefore, heat transfer between the motor case 72 and the electronic circuit case 74 can be promoted, and when there is a temperature difference between the electric motor 20 and the electronic circuit 50 , heat is transferred to the lower temperature side, thereby suppressing a temperature increase.

[0067] In addition, in the present embodiment, the thermal conductivity of the fastening member 80 is higher than the thermal conductivity of the caliper-side speed reducer case 60. Therefore, the fastening member 80 can effectively promote heat transfer between the motor case 72 and the electronic circuit case 74.

[0068] The thermal conductivity of a part of the components constituting the reduction gear 30 is lower than the thermal conductivity of the motor-side reduction gear case 70 .

[0069] Therefore, it is possible to effectively suppress the friction heat between the pad 4 and the disk 3 from being transferred to the motor 20 and the electronic circuit 50 via the speed reducer 30 .

[0070] The reducer 30 has two or more reduction mechanisms. The caliper-side reducer housing 60 accommodates one or more reduction mechanisms from the caliper 5 side. The motor-side reducer housing 70 accommodates one or more reduction mechanisms from the motor 20 side.

[0071] Thus, by arranging the caliper-side speed reducer case 60 between the caliper 5 and the motor-side speed reducer case 70 at a position where the influence of heat transfer from the caliper 5 is small, heat transfer between the caliper 5 and the electric motor 20 and the electronic circuit 50 can be effectively suppressed.

[0072] The heat insulating components 90 and 92 are made of a material having a lower thermal conductivity than the thermal conductivity of the caliper-side reducer housing 60, and are arranged between the caliper 5 and the caliper-side reducer housing 60, or between the caliper-side reducer housing 60 and the motor-side reducer housing 70 in such a manner that the thermal resistance between the caliper 5 and the motor 20 is greater than the thermal resistance between the motor 20 and the electronic circuit 50.

[0073] The heat transfer member 94 is made of a material having a higher thermal conductivity than the caliper-side speed reducer case 60 , and is provided between the motor 20 and the electronic circuit 50 so that the thermal resistance between the caliper 5 and the motor 20 is greater than the thermal resistance between the motor 20 and the electronic circuit 50 .

[0074] Therefore, when there is a temperature difference between the motor 20 and the electronic circuit 50 , the temperature rise can be suppressed by transferring heat to the side with the lower temperature.

[0075] (Other embodiments)

[0076] In the above-mentioned embodiment, an example is shown in which the electric motor is arranged on the caliper side reducer housing side relative to the motor side reducer housing, and the electronic circuit is arranged on the side opposite to the caliper side reducer housing relative to the motor side reducer housing. In contrast, in other embodiments, the electric motor may be arranged on the side opposite to the caliper side reducer housing relative to the motor side reducer housing, and the electronic circuit may be arranged on the caliper side reducer housing side relative to the motor side reducer housing.

[0077] In other embodiments, the caliper-side speed reducer case and the motor-side speed reducer case may be formed of any material such as metal or resin as long as the thermal conductivity of the caliper-side speed reducer case is lower than that of the motor-side speed reducer case.

[0078] In other embodiments, the thermal conductivity of the motor case and the electronic circuit case may be lower than the thermal conductivity of the caliper-side speed reducer case.

[0079] In other embodiments, only one fastening member may be provided. In other embodiments, no fastening member may be provided.

[0080] In other embodiments, the thermal conductivity of all the members constituting the speed reducer may be equal to or higher than the thermal conductivity of the motor-side speed reducer case.

[0081] In other embodiments, the reducer may have three or more reduction mechanisms. In this case, the caliper-side reduction mechanism housing accommodates at least one reduction mechanism.

[0082] In other embodiments, the heat insulating member may be provided only between the caliper and the caliper-side speed reducer housing, or between the caliper-side speed reducer housing and the motor-side speed reducer housing. In other embodiments, the heat insulating member may not be provided.

[0083] In other embodiments, a plurality of heat transfer members may be provided. In other embodiments, the heat transfer member 94 may be formed integrally with the motor-side speed reducer housing 70. In other embodiments, no heat transfer member may be provided.

[0084] In other embodiments, the electric motor may be a motor other than a three-phase brushless motor.

[0085] In other embodiments, the linear motion conversion portion may have any configuration as long as it can convert the rotation from the speed reducer into a linear motion and press the pad against the disk.

[0086] The vehicle braking device of the present invention may be applied to all wheels among a plurality of wheels of a vehicle, or may be applied to only a part of the wheels.

[0087] The vehicle brake device of the present invention can be used as a parking brake as well as a braking brake for decelerating or stopping a traveling vehicle.

[0088] Thus, the present invention is not limited to the above-described embodiment, and can be implemented in various forms without departing from the gist of the invention.

[0089] The features of the present invention are as follows.

[0090] [Invention 1]

[0091] A vehicle brake device capable of limiting the rotation of a wheel (2) by pressing a pad (4) against a disk (3) arranged to rotate together with the wheel (2), comprising:

[0092] an electric motor (20) which rotates by supplying electricity;

[0093] a speed reducer (30) which reduces the speed of rotation from the motor and outputs the rotation;

[0094] a linear motion conversion unit (40) held by a caliper (5) holding the pad, capable of converting the rotation from the speed reducer into linear motion and pressing the pad against the disk;

[0095] an electronic circuit (50) capable of controlling the rotation of the electric motor;

[0096] A caliper-side reducer housing (60), which is configured to accommodate a portion of the reducer and is connected to the caliper; and

[0097] A motor-side reducer housing (70) is configured to accommodate a portion of the reducer and is connected to the caliper-side reducer housing.

[0098] The electric motor is provided on one of the caliper-side speed reducer housing side or the side opposite to the caliper-side speed reducer housing with respect to the motor-side speed reducer housing.

[0099] The electronic circuit is provided on the other of the caliper side reducer housing side or the side opposite to the caliper side reducer housing with respect to the motor side reducer housing.

[0100] The thermal conductivity of the caliper-side speed reducer housing is lower than the thermal conductivity of the motor-side speed reducer housing.

[0101] [Invention 2]

[0102] The vehicle brake device according to the first aspect of the present invention further comprises:

[0103] A motor housing (72) configured to accommodate the electric motor and connected to the motor-side reducer housing; and

[0104] An electronic circuit housing (74) is configured to accommodate the electronic circuit and is connected to the motor-side reducer housing.

[0105] The thermal conductivity of the motor housing and the electronic circuit housing is higher than the thermal conductivity of the caliper-side speed reducer housing.

[0106] [Invention 3]

[0107] The vehicle brake device according to the second aspect of the present invention further comprises one or more fastening members (80) for fastening the motor housing and the electronic circuit housing integrally via the motor-side speed reducer housing.

[0108] [Invention 4]

[0109] According to the vehicle brake device described in any one of Inventions 1 to 3, the thermal conductivity of a portion (33, 34, 37) of the components constituting the speed reducer is lower than the thermal conductivity of the motor-side speed reducer case.

[0110] [Invention 5]

[0111] According to the vehicle brake device described in any one of Inventions 1 to 4,

[0112] The reducer has a reduction mechanism of more than two stages.

[0113] The caliper-side speed reducer housing accommodates the speed reducing mechanisms of the speed reducing mechanisms one level or more from the caliper side.

[0114] The motor-side speed reducer housing accommodates the speed reduction mechanisms of one or more stages from the motor side among the speed reduction mechanisms.

[0115] [Invention 6]

[0116] The vehicle braking device according to any one of Inventions 1 to 5 further comprises a heat insulating component (90, 92), which is made of a material having a thermal conductivity lower than that of the caliper side reducer housing, and the heat insulating component is arranged between the caliper and the caliper side reducer housing, or between the caliper side reducer housing and the motor side reducer housing in such a manner that the thermal resistance between the caliper and the motor is greater than the thermal resistance between the motor and the electronic circuit.

[0117] [Invention 7]

[0118] The vehicle braking device according to any one of Inventions 1 to 6 further comprises a heat transfer component (94), which is made of a material having a higher thermal conductivity than the thermal conductivity of the reducer housing on the caliper side, and the heat transfer component is arranged between the motor and the electronic circuit in such a way that the thermal resistance between the caliper and the motor is greater than the thermal resistance between the motor and the electronic circuit.

[0119] The present invention has been described according to the embodiments. However, it should be understood that the present invention is not limited to the embodiments and structures. The present invention also includes various modifications and variations within the equivalent range. In addition, various combinations and modes, and including only one element among these, or including more than one element or the following other combinations and modes are all within the scope and thought of the present invention.

Claims

1. A vehicle brake device capable of limiting the rotation of a wheel (2) by pressing a pad (4) against a disk (3) arranged to rotate together with the wheel (2), characterized in that: have: an electric motor (20) which rotates by supplying electricity; a speed reducer (30) which reduces the speed of rotation from the motor and outputs the rotation; a linear motion conversion unit (40) held by a caliper (5) holding the pad, capable of converting the rotation from the speed reducer into linear motion and pressing the pad against the disk; an electronic circuit (50) capable of controlling the rotation of the electric motor; A caliper-side reducer housing (60), which is configured to accommodate a portion of the reducer and is connected to the caliper; as well as A motor-side reducer housing (70) is configured to accommodate a portion of the reducer and is connected to the caliper-side reducer housing. The electric motor is provided on one of the caliper-side speed reducer housing side or the side opposite to the caliper-side speed reducer housing with respect to the motor-side speed reducer housing. The electronic circuit is provided on the other of the caliper side reducer housing side or the side opposite to the caliper side reducer housing with respect to the motor side reducer housing. The thermal conductivity of the caliper-side speed reducer housing is lower than the thermal conductivity of the motor-side speed reducer housing.

2. The vehicle braking device according to claim 1, characterized in that: Also available: A motor housing (72) configured to accommodate the electric motor and connected to the motor-side reducer housing; and An electronic circuit housing (74) is configured to accommodate the electronic circuit and is connected to the motor-side reducer housing. The thermal conductivity of the motor housing and the electronic circuit housing is higher than the thermal conductivity of the caliper-side speed reducer housing.

3. The vehicle braking device according to claim 2, characterized in that: It also includes one or more fastening components (80) for fastening the motor housing and the electronic circuit housing into one piece via the motor-side speed reducer housing.

4. The vehicle brake device according to any one of claims 1 to 3, characterized in that: The thermal conductivity of a portion (33, 34, 37) of the components constituting the speed reducer is lower than the thermal conductivity of the motor-side speed reducer housing.

5. The vehicle brake device according to any one of claims 1 to 3, characterized in that: The reducer has a reduction mechanism of more than two stages. The caliper-side speed reducer housing accommodates the speed reducing mechanisms of the speed reducing mechanisms one level or more from the caliper side. The motor-side speed reducer housing accommodates the speed reduction mechanisms of one or more stages from the motor side among the speed reduction mechanisms.

6. The vehicle brake device according to any one of claims 1 to 3, characterized in that: It also has a heat insulating component (90, 92), which is made of a material with a lower thermal conductivity than the thermal conductivity of the caliper side reducer housing. The heat insulating component is arranged between the caliper and the caliper side reducer housing, or between the caliper side reducer housing and the motor side reducer housing in a manner that makes the thermal resistance between the caliper and the motor greater than the thermal resistance between the motor and the electronic circuit.

7. The vehicle brake device according to any one of claims 1 to 3, characterized in that: It also includes a heat transfer component (94) made of a material having a higher thermal conductivity than the thermal conductivity of the reducer housing on the caliper side, and the heat transfer component is arranged between the motor and the electronic circuit in a manner that makes the thermal resistance between the caliper and the motor greater than the thermal resistance between the motor and the electronic circuit.

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