Electric brake device

Abstract

An electric brake device (1) is provided with: a lever member (70) to which a reaction force of a pressing load of a friction member (40) is input via a rotating part (31), the lever member (70) extending and protruding to the outside of a projection region (R) in which a linear motion conversion mechanism (30) is projected in the direction of the rotational axis of the rotating part (31); and a load sensor (80) that detects a reaction force input to the lever member (70) by coming into contact with a portion of the lever member (70) that extends and protrudes to the outside of the projection region (R).

Description

Technical Field

[0001] The invention relates to an electric brake device. Background Art

[0002] In the past, a disc brake device that applies braking force to a wheel by pressing a brake pad against a brake disc that rotates together with the wheel using an electric motor is known, as described in Patent Document 1. The disc brake device includes a detection device that detects a reaction force of a pressing load generated on the brake pad when the brake pad is pressed against the brake disc.

[0003] Patent Document 1: WO2020 / 229989

[0004] However, the detection device is equipped with a sensor for detecting the load. The sensor equipped in the detection device is a wheel-shaped sensor, and a shaft component that transmits the reaction force of the pressing load generated on the brake pad is inserted into the through hole in the center. The wheel-shaped sensor detects the reaction force of the pressing load generated on the brake pad via the shaft component.

[0005] However, in such a wheel-shaped sensor, in order to detect the load transmitted from the shaft member, a plurality of detection parts for detecting the reaction force need to be provided along the circumferential direction of the sensor, which increases the cost of the sensor and the cost of the disc brake device. Summary of the invention

[0006] An object of one aspect of the present invention is to provide an inexpensive electric brake device.

[0007] In order to solve the above-mentioned problems, an electric brake device of one embodiment of the present invention is an electric brake device that transmits the rotational motion of an electric motor to a rotating part of a direct-acting conversion mechanism, converts the rotational motion of the above-mentioned rotating part into linear motion of the direct-acting part of the above-mentioned direct-acting conversion mechanism, and presses a friction component to a rotating body that rotates together with the wheel according to the linear motion of the above-mentioned direct-acting part, thereby generating a braking force on the above-mentioned wheel. The electric brake device comprises: an input component, to which a reaction force of a pressing load of the above-mentioned friction component is input via the above-mentioned rotating part, and the input component extends to the outside of a projection area, and the above-mentioned projection area is an area where the above-mentioned direct-acting conversion mechanism is projected in the direction of the rotation axis of the above-mentioned rotating part; and a load sensor, which detects the above-mentioned reaction force input to the above-mentioned input component by contacting a portion of the above-mentioned input component that extends to the outside of the above-mentioned projection area.

[0008] According to one aspect of the present invention, an inexpensive electric brake device can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is a schematic cross-sectional view showing an outline of the electric brake device according to the first embodiment of the present invention.

[0010] Figure 2 It is magnified Figure 1 A schematic cross-sectional view of the dashed portion is shown.

[0011] Figure 3 Observed from the X2 direction Figure 1 Schematic diagram of the lever components shown.

[0012] Figure 4 This is a diagram for explaining the deflection of the caliper that occurs when the reaction force of the pressing load of the friction member acts.

[0013] Figure 5 This is a schematic cross-sectional view schematically showing a main part of an electric brake device according to a second embodiment of the present invention. DETAILED DESCRIPTION

[0014] [Implementation method 1]

[0015] Below, refer to Figure 1 to Figure 4 Embodiment 1 of the present invention will be described in detail. In the following description, Figure 1 The description will be made with reference to coordinate axes such as the X (X1-X2) direction, the Y (Y1-Y2) direction, and the Z (Z1-Z2) direction as shown in FIG.

[0016] [Overview of electric brake device]

[0017] Reference Figure 1 , an overview of the electric brake device 1 will be described. Figure 1 1 is a schematic cross-sectional view showing the outline of the electric brake device 1. As an example of a device to which the electric brake device 1 is applied, an electromechanical brake called EMB (ElectroMechanical Brake) can be cited. Figure 1 As shown, the electric brake device 1 includes an electric motor 10, a direct-acting conversion mechanism 30, a friction member 40, a lever member 70, and a load sensor 80. In addition, the electric brake device 1 may further include a transmission mechanism 20, a caliper 50, a piston 60, a thrust bearing 61, a pressure applying unit 85, and an ECU (Electronic Control Unit) 90.

[0018] The electric motor 10 is a power source of the electric brake device 1. The electric motor 10 may also be electrically connected to the ECU 90 and driven based on the control of the ECU 90. The electric motor 10 is disposed outside the caliper 50 so as to be adjacent to the caliper 50. The electric motor 10 has a rotating shaft 11 provided with a spur gear that meshes with the gear 22A of the transmission mechanism 20. When the electric motor 10 is driven, the rotating shaft 11 rotates, and the rotational motion is transmitted to the transmission mechanism 20 connected to the rotating shaft 11.

[0019] The transmission mechanism 20 is a mechanism for transmitting the rotational motion of the electric motor 10. The transmission mechanism 20 is arranged outside the caliper 50. Inside the housing 21 of the transmission mechanism 20, one or more gears 22 for transmitting the rotational motion from the electric motor 10 are provided. The transmission mechanism 20 transmits the rotational motion of the electric motor 10 to the rotating part 31 of the direct-acting conversion mechanism 30 via the one or more gears 22. Figure 1 In the example shown, the transmission mechanism 20 has three gears 22A to 22C. The transmission mechanism 20 may also serve as a speed reduction mechanism for reducing the speed of the rotational motion transmitted from the electric motor 10. However, the transmission mechanism 20 is not an essential component of the electric brake device 1.

[0020] The direct motion conversion mechanism 30 is a mechanism for converting the rotational motion of the electric motor 10 into a linear motion. The direct motion conversion mechanism 30 includes a rotating portion 31 for transmitting the rotational motion of the electric motor 10 and a linear motion portion 35 for converting the rotational motion of the rotating portion 31 into a linear motion.

[0021] The rotating portion 31 of the direct-acting conversion mechanism 30 includes a rotating shaft portion 32 and a flange portion 33. The rotating shaft portion 32 has the X direction as the rotation center A. In the present embodiment, the X direction is the rotation axis direction of the rotating portion 31. The flange portion 33 is provided between a first end portion 32A on the friction member 40 side of the rotating shaft portion 32 and a second end portion 32B on the transmission mechanism 20 side of the rotating shaft portion 32. The flange portion 33 extends from the rotating shaft portion 32 toward the outside of the rotating shaft portion 32 in the radial direction of the rotating shaft portion 32. A spur gear is provided at the second end portion 32B of the rotating shaft portion 32, and meshes with the internal teeth of the gear 22C of the transmission mechanism 20. In the rotating shaft portion 32, an external thread structure 34 is formed in the region from the flange portion 33 to the first end portion 32A of the rotating shaft portion 32.

[0022] The direct-acting part 35 of the direct-acting conversion mechanism 30 is a cylindrical component having an insertion hole 37 for inserting the rotating part 31. An internal thread structure 36 that is screwed with the external thread structure 34 of the rotating part 31 is formed on the inner circumferential surface of the insertion hole 37. The external thread structure 34 and the internal thread structure 36 are screwed together, and the rotational motion of the rotating part 31 is converted into the linear motion in the direct-acting part 35. In more detail, if the rotational motion of the electric motor 10 in the first rotation direction is transmitted to the rotating part 31, the direct-acting part 35 performs linear motion in the X1 direction, and if the rotational motion of the electric motor 10 in the second rotation direction opposite to the first rotation direction is transmitted to the rotating part 31, it performs linear motion in the X2 direction. The piston 60 provided at the front end of the friction member 40 side of the direct-acting part 35 is linked with the linear motion of the direct-acting part 35.

[0023] In addition, it is also possible to configure the direct-acting portion 35 to have an external thread structure and the rotating portion 31 to have an internal thread structure. The thread structure provided by the direct-acting conversion mechanism 30 is an example of a structure that converts rotational motion into linear motion. In addition, the direct-acting portion 35 may also be provided with a rotation-stop mechanism that prevents the direct-acting portion 35 from rotating in the cylinder portion 57 due to the rotational motion of the rotating portion 31.

[0024] The friction member 40 presses the disc rotor DR that rotates together with the wheel according to the linear motion of the direct-acting portion 35, thereby generating a braking force on the wheel. The disc rotor DR is an example of a rotating body. The friction member 40 includes a first friction member 41 and a second friction member 42 that are arranged opposite to each other in the axial direction (X direction) of the disc rotor DR across the disc rotor DR. The first friction member 41 is arranged on the direct-acting conversion mechanism 30 side. The second friction member 42 is arranged on the opposite side of the first friction member 41 with the disc rotor DR sandwiched therebetween. The first friction member 41 is mounted on the piston 60 via a mounting plate 43. The second friction member 42 is mounted on the caliper 50 via a mounting plate 44.

[0025] The first friction member 41 is linked to the linear motion of the piston 60. That is, the first friction member 41 is a member that generates a braking force on the wheel by pressing the disc rotor DR in conjunction with the linear motion of the direct motion portion 35. When the first friction member 41 linearly moves in the direction X1, which is the direction toward the disc rotor DR, the disc rotor DR is sandwiched between the first friction member 41 and the second friction member 42 and the disc rotor DR is pressed. When the disc rotor DR is pressed by the first friction member 41 and the second friction member 42, friction force is generated between the first friction member 41 and the disc rotor DR and between the second friction member 42 and the disc rotor DR. This friction force acts on the wheel as a force in the opposite direction to the rotation direction of the disc rotor DR. Thus, the friction member 40 applies a braking force to the wheel. When the pressing load by the friction member 40 increases, the friction force on the disc rotor DR increases, and the braking force on the wheel increases. When the pressing load by the friction member 40 decreases, the friction force on the disc rotor DR decreases, and the braking force on the wheel decreases.

[0026] On the other hand, if the first friction member 41 moves in the direction X2 away from the disk rotor DR, the first friction member 41 and the second friction member 42 release the pressure on the disk rotor DR. Since no friction force is generated on the disk rotor DR, the braking force on the wheel by the friction member 40 disappears.

[0027] The caliper 50 is a member that accommodates or supports a part of the members constituting the electric brake device 1. The caliper 50 has a shape that straddles the outer circumference of the disc rotor DR while sandwiching the first friction member 41 and the second friction member 42.

[0028] The caliper 50 includes a base wall 51, a first extending protruding wall 52, a second extending protruding wall 55, a third extending protruding wall 56, and a cylinder portion 57. The base wall 51 is provided along the X direction. The first extending protruding wall 52 is a wall extending from the base wall 51 and along the Y direction. More specifically, it is formed to extend from the end of the base wall 51 on the X2 direction side to the Y2 direction. In addition, the first extending protruding wall 52 may also be configured to extend from a portion other than the end of the base wall 51 on the X2 direction side. An opening 53 and an opening 54 are formed in the first extending protruding wall 52. The opening 53 is an opening formed to connect the load sensor 80 located inside the caliper 50 with the ECU 90 located outside the caliper 50. The opening 54 is an opening for connecting the direct-acting conversion mechanism 30 inside the caliper 50 with the transmission mechanism 20 outside the caliper 50.

[0029] The second extended protruding wall 55 of the caliper 50 is a wall extending from the first extended protruding wall 52 and extending in the X direction. More specifically, the second extended protruding wall 55 is a wall extending from the end of the first extended protruding wall 52 on the Y2 direction side to the X1 direction. In addition, the second extended protruding wall 55 may be configured to extend from a portion other than the end of the first extended protruding wall 52 on the Y2 direction side. The third extended protruding wall 56 of the caliper 50 is a wall extending from the base wall 51 on the side opposite to the side from which the first extended protruding wall 52 extends and extending in the Y direction. In more detail, the third extended protruding wall 56 is formed to extend from the end of the base wall 51 on the X1 direction side to the Y2 direction. In addition, the third extended protruding wall 56 may be configured to extend from a portion other than the end of the base wall 51 on the X1 direction side. The second friction member 42 is mounted on the X2 direction side of the third extended protruding wall 56 via the mounting plate 44.

[0030] The cylinder portion 57 is provided in the caliper 50. The cylinder portion 57 is a portion constituting a cylindrical space with the X direction as the axial direction. The base wall 51, the first extended protruding wall 52, and the second extended protruding wall 55 of the caliper 50 constitute a part of the cylinder portion 57. The direct-acting conversion mechanism 30 is accommodated in the space of the cylinder portion 57. In addition, the piston 60 is accommodated in the space of the cylinder portion 57. The piston 60 performs linear motion in the X direction in the space of the cylinder portion 57. In addition, the cylinder portion 57 may be provided in the caliper 50 as another component having a cylindrical space.

[0031] ECU90 is a control unit for controlling the electric brake device 1. ECU90 is an example of a control unit. ECU90 is an electronic control unit composed of a computer having a processor such as a CPU (Central Processing Unit) and a memory such as a RAM or a ROM. ECU90 has a drive circuit for driving the electric motor 10 and an input / output interface for obtaining data related to the load detected by the load sensor 80. ECU90 is arranged outside the caliper 50. ECU90 can also be arranged on the opposite side of the lever member 70 in the X direction, sandwiching the load sensor 80. ECU90 is electrically connected to the electric motor 10 and the load sensor 80. ECU90 can also control the drive of the electric motor 10 based on the data from the load sensor 80.

[0032] [Composition of load cell and lever parts]

[0033] Reference Figure 2 as well as Figure 3 , the structure of the lever member 70 and the load sensor 80 will be described. Figure 2 It is magnified Figure 1 A schematic cross-sectional view of the dashed portion is shown. Figure 3Observed from the X2 direction Figure 1 Schematic diagram of the lever components shown.

[0034] like Figure 2 As shown, the lever member 70 is an input member for the reaction force (load) of the pressing load input to the first friction member 41 via the rotating portion 31 of the direct-acting conversion mechanism 30. The lever member 70 extends and protrudes to the outside of the projection area R, which is the area projected in the X direction by the rotating portion 31. In addition, in the following description, when only the reaction force is referred to, it refers to the reaction force of the pressing load of the first friction member 41. The portion of the lever member 70 that contacts the load sensor 80 may have the same rigidity as the portion of the caliper 50 that spans the outer periphery of the disc rotor DR. The lever member 70 is arranged between the flange portion 33 of the rotating portion 31 and the second end portion 32B of the rotating shaft portion 32 of the rotating portion 31 in the X direction. The lever member 70 has a base 71, a first protrusion 73, and a second protrusion 76.

[0035] like Figure 3 As shown, the base 71 of the lever member 70 is a disc-shaped member, and a through hole 72 is formed in the center. In addition, the base 71 is not limited to the disc-shaped shape. The base 71 is a portion that inputs a reaction force to the lever member 70. The base 71 has a portion located on the inner side of the projection area R. The rotating shaft portion 32 of the rotating portion 31 of the direct-acting conversion mechanism 30 is inserted into the through hole 72. The through hole 72 is larger than the outer diameter of the rotating shaft portion 32 of the rotating portion 31, and has a size that has a space between the through hole 72 and the rotating shaft portion 32. As shown in FIG. Figure 2 As shown, the base portion 71 is in contact with the thrust bearing 61 disposed between the lever member 70 and the flange portion 33 in the X direction.

[0036] In addition, the base 71 may be configured to contact an eccentric load reduction mechanism that reduces the bias of the reaction force input from the flange 33 of the rotating part 31 to the base 71. As an example of the eccentric load reduction mechanism, a spherical support member can be cited in which the surface on the flange 33 side of the rotating part 31 is a surface in a direction orthogonal to the X direction and the surface in contact with the base 71 is a curved surface. In addition, the base 71 may be configured to contact the flange 33 of the rotating part 31.

[0037] The first protrusion (protrusion) 73 of the lever member 70 is a portion in contact with the load sensor 80. The first protrusion 73 is a portion protruding from the base 71 outside the projection region R. The first protrusion 73 may be configured to partially protrude from the base 71 to the outside of the projection region R. In addition, the lever member 70 may be configured without the first protrusion 73, and the base 71 may be in contact with the load sensor 80.

[0038] As described above, by the first protrusion 73 of the lever member 70 contacting the load sensor 80, the lever member 70 is miniaturized compared to a structure that protrudes from all directions around the base 71 to the outside of the projection area R in the X direction, and other components of the electric brake device 1 can be arranged in the portion where the first protrusion 73 does not exist. As a result, the electric brake device 1 can be miniaturized.

[0039] The first protrusion 73 may be configured to be located closer to the friction member 40 than the base 71 in the X direction. With the above configuration, the load sensor 80 can be brought closer to the friction member 40 in the X direction. Thus, the electric brake device 1 can be miniaturized in the X direction.

[0040] The first protrusion 73 of the lever member 70 has a first wall 74 and a second wall 75. The first wall 74 is a wall extending in the direction toward the first friction member 41 in the X direction. Figure 2 As shown, the first wall 74 extends from the peripheral portion of the base 71 toward the X1 direction. In addition, the first wall 74 may be configured to extend from a portion other than the peripheral portion of the base 71. In other words, the first protrusion 73 may be configured to protrude from a portion other than the peripheral portion of the base 71. In addition, a wall extending in the Y direction orthogonal to the X direction may be formed between the base 71 and the first wall 74.

[0041] like Figure 2 As shown, the second wall 75 of the first protrusion 73 is a wall extending in the Y direction at the front end side of the first protrusion 73 compared with the first wall 74. More specifically, the second wall 75 extends from the end of the first wall 74 on the X1 direction side to the Y1 direction. The load sensor 80 is in contact with the second wall 75. More specifically, the load sensor 80 is in contact with the surface 75A on the X2 direction side of the second wall. In addition, it is also possible to form a wall extending and protruding in the X direction and a wall extending and protruding in the Y direction between the second wall 75 and the first wall 74. In addition, the first protrusion 73 may also be configured without the second wall 75, and the first wall 74 is in contact with the load sensor 80.

[0042] The first protrusion 73 of the lever member 70 is pressed in the X2 direction by the pressing portion 85 supported by the caliper 50. More specifically, the first protrusion 73 is pressed in the direction of contact with the load sensor 80 by the pressing portion 85. The pressing portion 85 is provided on the X1 direction side relative to the first protrusion 73, and contacts the surface 75B on the X1 direction side of the first protrusion 73. Thus, the first protrusion 73 can be brought into contact with the load sensor 80 in a stable state.

[0043] The second protrusion 76 of the lever member 70 is a portion supported by the caliper 50. The second protrusion 76 is a portion protruding from the base 71 outside the projection area R. Figure 2 as well as Figure 3 As shown, the second protrusion 76 is located on the opposite side of the first protrusion 73 with the rotating part 31 in the Y direction. The second protrusion 76 and the first protrusion 73 are provided on the same straight line passing through the rotation center A of the rotating part 31 in the Y direction. That is, the portion of the lever member 70 supported by the caliper 50 and the portion of the lever member 70 in contact with the load sensor 80 are provided on the same straight line passing through the rotation center A in a direction orthogonal to the X direction.

[0044] The second protrusion 76 of the lever member 70 has a third wall 77 and a fourth wall 78. Figure 3 As shown in FIG. 1 , the third wall 77 extends from the peripheral portion of the base 71 toward the X1 direction. In addition, the third wall 77 may be configured to extend from a portion other than the peripheral portion of the base 71. In other words, the second protrusion 76 may be configured to protrude from a portion other than the peripheral portion of the base 71. In addition, a wall extending toward the Y direction may be formed between the base 71 and the third wall 77. Figure 2 As shown, the fourth wall 78 extends from the end of the third wall 77 on the X1 direction side to the Y2 direction side. The fourth wall 78 is supported by the support portion 58 provided on the caliper 50. In addition, it is also possible to form a wall extending and protruding in the X direction and a wall facing the Y direction between the fourth wall 78 and the third wall 77. In addition, the lever member 70 may be configured without the second protrusion 76, and the base 71 may be supported by the caliper 50.

[0045] The load sensor 80 is a sensor that detects the reaction force input to the lever member 70 by contacting a portion of the lever member 70 that extends outward from the projection region R. Figure 2 As shown, the load sensor 80 has an abutment portion 81, which is a portion in contact with the lever member 70. The load sensor 80 detects the reaction force input to the lever member 70. The load sensor 80 detects the reaction force input to the lever member 70 by contacting the first protrusion 73. The load sensor 80 is located outside the projection area R. The load sensor 80 is arranged to be located on the opposite side of the electric motor 10 with the rotating portion 31 sandwiched therebetween in the Y direction.

[0046] In addition, the load sensor 80 is configured so that a terminal 82 for electrical connection with the ECU 90 is located on the X2 direction side. The terminal 82 is provided on the ECU 90 side in the X direction. The ECU 90 is arranged on the opposite side of the lever member 70 with the load sensor 80 sandwiched therebetween in the X direction. By providing the terminal 82 on the ECU 90 side in the X direction, the terminal 82 and the ECU 90 are in a relative positional relationship, and the electrical connection between the load sensor 80 and the ECU 90 can be simplified.

[0047] The load sensor 80 is supported by the caliper 50 in the space of the cylinder portion 57 of the caliper 50. Alternatively, the load sensor 80 may be supported outside the caliper 50. Alternatively, a plurality of load sensors 80 may be in contact with the lever member 70. Alternatively, the load sensor 80 may have the same rigidity as the portion of the caliper 50 that straddles the outer periphery of the disc rotor DR.

[0048] According to the above-mentioned electric brake device 1, the electric brake device 1 includes a lever member 70 in contact with the load sensor 80, so that the load sensor 80 can be arranged outside the projection area R. In addition, the load sensor 80 only needs to detect the reaction force of the portion in contact with the lever member 70. Therefore, it is not necessary to use a wheel-shaped load sensor 80, and an inexpensive load sensor 80 with fewer detection parts can be used for the electric brake device 1. Thus, an inexpensive electric brake device 1 can be provided. In addition, by being configured to be in contact with the lever member 70, the shape of the load sensor 80 can be freely selected. Thus, the degree of freedom of the load sensor 80 used can be increased.

[0049] [Flow until detection of reaction force]

[0050] Reference Figure 1 , the flow until the load sensor 80 of the electric brake device 1 detects the reaction force is described. When the electric motor 10 is driven, the rotational motion of the electric motor 10 is transmitted to the direct-acting conversion mechanism 30 via the transmission mechanism 20. By transmitting the rotational motion of the electric motor 10 in the first rotational direction to the direct-acting conversion mechanism 30, the first friction member 41 and the piston 60 perform linear motion in the X1 direction in conjunction. When the first friction member 41 performs linear motion in the X1 direction, the disc rotor DR of the wheel is pressed in a manner of clamping the disc rotor DR with the second friction member 42. When the disc rotor DR of the wheel is pressed, a reaction force of the pressing load is generated in the first friction member 41.

[0051] The reaction force is transmitted to the direct motion conversion mechanism 30 via the mounting plate 43 and the piston 60. In the direct motion conversion mechanism 30, the reaction force transmitted to the direct motion portion 35 is transmitted to the rotating portion 31. The reaction force transmitted to the rotating portion 31 is input to the lever member 70 via the rotating portion 31. More specifically, the reaction force is input from the flange portion 33 of the rotating portion 31 to the base 71 of the lever member 70 via the thrust bearing 61.

[0052] When a reaction force is input to the base 71 of the lever member 70, a force applied in a direction tilted toward the X2 direction side with the fourth wall 78 of the second protrusion 76 as a fulcrum acts on the lever member 70. When a force tilting toward the X2 direction side is generated on the lever member 70, the reaction force is input to the load sensor 80 via the lever member 70. More specifically, the reaction force is input to the load sensor 80 via the second wall 75 of the first protrusion 73 of the lever member 70. That is, the lever member 70 is configured such that the portion supported by the caliper 50 functions as a fulcrum, the portion to which the reaction force is input functions as a force point, and the portion in contact with the load sensor 80 functions as a point of action.

[0053] According to the above configuration, by applying the principle of a lever, the magnitude of the reaction force detected by the load sensor 80 can be changed. Therefore, the type of the load sensor 80 can be appropriately selected according to the magnitude of the reaction force detected by the load sensor 80. Thus, the type of load sensor 80 to be used generates a degree of freedom.

[0054] In addition, in the Y direction, the portion of the lever member 70 to which the reaction force is input may be located between the portion supported by the caliper 50 and the portion in contact with the load sensor 80. More specifically, in the Y direction, the portion to which the reaction force is input to the base 71 of the lever member 70 may be located between the fourth wall 78 of the second protrusion 76 supported by the cylinder portion 57 of the caliper 50 and the second wall 75 of the first protrusion wall in contact with the load sensor 80. That is, in the lever member 70, the distance between the portion that functions as a fulcrum and the portion that functions as a point of action is longer than the distance between the portion that functions as a fulcrum and the portion that functions as a point of force. Therefore, the magnitude of the reaction force detected by the load sensor 80 can be made smaller than the magnitude of the reaction force input to the lever member 70. Therefore, the electric brake device 1 can adopt the load sensor 80 whose magnitude of the load that can be detected is smaller. Thus, an inexpensive electric brake device 1 can be provided.

[0055] [Deflection of the caliper when receiving reaction force]

[0056] Reference Figure 4 Next, the relationship between the deflection of the caliper 50 and the lever member 70 when receiving the reaction force will be described. Figure 42 is a diagram for explaining the deflection of the caliper 50 generated when the reaction force acts. Figure 4 In the figure, the projection area R and the rotation center A of the rotating part 31 are omitted for the sake of visibility of the drawings.

[0057] like Figure 4 As shown, when a reaction force RF1 of the pressing load of the first friction member 41 is generated, the reaction force RF1 is transmitted to the base wall 51, the first extension wall 52, and the second extension wall 55 of the caliper 50 via the piston 60 and the direct-acting conversion mechanism 30. When a reaction force RF2 of the pressing load of the second friction member 42 is generated, the reaction force RF2 is transmitted to the third extension wall 56 of the caliper 50 via the mounting plate 44.

[0058] When the reaction force RF1 is transmitted to the caliper 50, a rotational moment M acts on the caliper 50. More specifically, a rotational moment M centered on the end of the base wall 51 on the X1 direction side acts on the base wall 51. When the rotational moment M acts on the caliper 50, the caliper 50 bends in the Y1 direction.

[0059] When the caliper 50 is bent in the Y1 direction, at least one of the lever member 70 and the load sensor 80 is deformed due to the bending of the caliper 50. Here, by configuring the portion of the lever member 70 that contacts the load sensor 80 or at least one of the load sensor 80 and the portion of the caliper 50 that crosses the outer periphery of the disc rotor DR to have the same rigidity, the amount of deformation of the portion of the caliper 50 that crosses the outer periphery of the disc rotor DR (the beam portion of the caliper) can be made substantially equal to the amount of deformation of the lever member 70 that contacts the load sensor 80 or the amount of deformation of the load sensor 80 caused by the bending of the caliper 50. Therefore, the contact state of the external thread structure 34 and the internal thread structure 36, or the contact state of the thrust bearing 61 and the lever member 70 does not change depending on whether the braking force is applied to the wheel. As a result, the eccentric load on the thread structures 34, 36 or the thrust bearing 61 is suppressed, and the durability of the electric brake device 1 is improved.

[0060] [Implementation method 2]

[0061] The following reference Figure 5 Embodiment 2 of the present invention will be described. Figure 51 is a schematic diagram showing an outline of the main parts of the electric brake device 1A according to the second embodiment of the present invention. In addition, for the convenience of description, the same reference numerals are attached to the components having the same functions as the components described in the above embodiment, and the description thereof will not be repeated. The electric brake device 1A according to the second embodiment is different from the electric brake device 1 according to the first embodiment in that the input member 79 is supported in the caliper 50 through the load sensor 80A and the support member 95. That is, the input member 79 of the electric brake device 1A does not apply the principle of a lever.

[0062] The electric brake device 1A includes a support member 95 that supports the input member 79. The support member 95 is supported by the caliper 50. More specifically, the support member 95 is supported by the first extended protruding wall 52 of the caliper 50. The support member 95 is arranged at a position different from that of the load sensor 80 in a direction orthogonal to the X direction. More specifically, the support member 95 is arranged on the opposite side of the load sensor 80A with the rotating portion 31 sandwiched in the Y direction. The support member 95 is a member having the same rigidity as the load sensor 80A.

[0063] The electric brake device 1A includes a flat plate-shaped input member 79 that inputs a reaction force via the rotating portion 31. The input member 79 is supported in the caliper 50 by a supporting member 95 and a load sensor 80A. The load sensor 80A includes a contact portion 81A that is a portion in contact with the input member 79. The contact portion 81A is located outside the projection area R. The reaction force input to the input member 79 is dispersed to the supporting member 95 and the load sensor 80A. Therefore, the electric brake device 1A can adopt a load sensor 80A with a smaller size of load that can be detected. In addition, the input member 79 is not limited to a flat plate shape.

[0064] According to the above configuration, by making the rigidity of the support member 95 equal to the rigidity of the load sensor 80A, even if a reaction force is input to the input member 79, the contact angle between the input member 79 and the load sensor 80A is not easily changed. This can reduce the concern that the detection accuracy of the load sensor 80A for the reaction force is reduced.

[0065] [Other implementation methods]

[0066] In the above-mentioned embodiment, the first friction member 41 of the friction member 40 is described as being linked to the direct-acting portion 35 of the direct-acting conversion mechanism 30, but the present invention is not limited thereto. The second friction member 42 of the friction member 40 may be linked to the direct-acting portion of the direct-acting conversion mechanism. That is, the first friction member 41 and the second friction member 42 may both perform linear motion.

[0067] The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims. Embodiments obtained by appropriately combining technical means disclosed in different embodiments are also included in the technical scope of the present invention.

Claims

1. An electric brake device, which transmits the rotational motion of an electric motor to a rotating part of a direct-acting conversion mechanism, converts the rotational motion of the rotating part into a linear motion of the direct-acting conversion mechanism, and presses a friction member against a rotating body rotating with a wheel according to the linear motion of the direct-acting part, thereby generating a braking force on the wheel, wherein: The electric brake device comprises: an input member to which a reaction force of a pressing load of the friction member is input via the rotating portion, the input member extending to the outside of a projection area, the projection area being an area where the direct-acting conversion mechanism is projected in a rotation axis direction of the rotating portion; as well as The load sensor detects the reaction force input to the input member by contacting a portion of the input member extending and protruding outside the projection area.

2. The electric brake device according to claim 1, wherein: The above input component has: A base portion, to which the reaction force is input and which is within the projection area; as well as a protrusion partially protruding from the base to the outside of the projection area, The load sensor detects the reaction force input to the input member by contacting the protrusion.

3. The electric brake device according to claim 2, wherein: The protrusion is configured to be located closer to the friction member than the base in the rotation axis direction.

4. The electric brake device according to claim 1, wherein: The electric brake device further comprises a caliper for accommodating the direct-acting conversion mechanism. The input member is supported by the caliper, and a portion supported by the caliper functions as a fulcrum, a portion to which the reaction force is input functions as a force point, and a portion in contact with the load sensor functions as an action point.

5. The electric brake device according to claim 4, wherein: The input member is configured such that a portion of the input member to which the reaction force is input is located between a portion supported by the caliper and a portion in contact with the load cell in a direction orthogonal to the rotation axis.

6. The electric brake device according to claim 1, wherein: The electric brake device further comprises: A caliper accommodating the direct-acting conversion mechanism; and a support member supported by the caliper and arranged at a position different from that of the load sensor in a direction orthogonal to the rotation axis, The input member is supported in the caliper via the support member and the load sensor supported by the caliper. The support member has the same rigidity as that of the load sensor.

7. The electric brake device according to claim 1, wherein: The electric brake device further includes a control unit, which is arranged on the opposite side of the input member with the load sensor sandwiched therebetween in the direction of the rotation axis and controls the driving of the electric motor. The load sensor is provided on the control unit side in the rotation axis direction, and includes a terminal for electrically connecting the load sensor and the control unit.

8. The electric brake device according to claim 1, wherein: The friction member includes a first friction member and a second friction member which are arranged to face each other in the axial direction of the rotating body with the rotating body interposed therebetween. The electric brake device further includes a caliper having a shape that sandwiches the first friction member and the second friction member and straddles the outer circumference of the rotating body, and the caliper accommodates the direct-acting conversion mechanism. A portion of the input member that contacts the load sensor or at least one of the load sensors and a portion of the caliper that straddles the outer circumference of the rotating body have equivalent rigidity.

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