Electric brake and electric brake assembling method

Abstract

To provide an electric brake that can be effectively assembled without requiring heat countermeasures or the like.SOLUTION: A disc brake as an electric brake includes: an electric motor 25; a reduction mechanism 26 to which rotation from the electric motor 25 is transmitted; a braking mechanism 27 that generates a braking force by using the rotation from the reduction mechanism 26 and pressing inner brake pads 2 and outer brake pads 3 against a disc rotor D; and an electronic control unit 35 that controls driving of the electric motor 25. A reduction mechanism / control unit 107 in which the reduction mechanism 26 and the electronic control unit 35 are integrated is provided inside a motor housing 18 in which the electric motor 25 is disposed. This eliminates the need for heat countermeasures and enables efficient assembly of the present disc brake.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an electric brake used for braking a vehicle, and to a method for assembling the electric brake. [Background technology]

[0002] Conventionally, when assembling an MGU (Motor Gear Unit) in a disc brake, which is an electric brake, it has been necessary to assemble the motor, reduction mechanism, and electronic control unit (ECU) to the housing in that order, which has resulted in issues such as long assembly time, reduced productivity, and layout restrictions. Therefore, for disc brakes equipped with an MGU, efficient assembly methods have been investigated to improve productivity.

[0003] Therefore, Patent Document 1 describes an electric disc brake that includes a caliper that is configured with a pressing member that presses the brake pad, a motor, and a rotation-to-linear motion conversion mechanism that converts the rotation of the motor into linear motion and transmits it to the pressing member, and that propels the pressing member in accordance with the rotation of the motor and presses the brake pad against a disc rotor to generate braking force, and that integrates the motor and a control device that controls the motor to form a motor / control device unit. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-89646 Summary of the Invention [Problem to be solved by the invention]

[0005] The electric disc brake described in Patent Document 1 is equipped with a motor / controller unit that integrates a motor and a controller that controls the motor, making it easy to assemble the caliper. However, in order to provide this motor / controller unit, the electric motor and the controller must be arranged side by side, which necessitates measures to deal with heat generated by the proximity of heat-generating components and also creates new challenges such as layout restrictions.

[0006] In view of the above-mentioned problems, an object of the present invention is to provide an electric brake and an assembling method for the electric brake that do not require measures against heat or the like and that allow efficient assembly. [Means for solving the problem]

[0007] As a means for solving the above problem, the electric brake of the present invention is an electric brake comprising an electric motor, a reduction mechanism to which rotation from the electric motor is transmitted, a braking mechanism that generates a braking force by pressing a braking member against a member to be braked using the rotation from the reduction mechanism, and a control unit that controls the drive of the electric motor, and is characterized in that a reduction mechanism / control unit unit in which the reduction mechanism and the control unit are integrated is provided within a motor housing in which the electric motor is disposed.

[0008] In addition, the method for assembling an electric brake according to the present invention is a method for assembling an electric brake that includes an electric motor, a reduction mechanism to which rotation from the electric motor is transmitted, a braking mechanism that uses the rotation from the reduction mechanism to press a braking member against a member to be braked, thereby generating a braking force, and a control unit that controls the drive of the electric motor, and is characterized by including a first assembly process of assembling the reduction mechanism and the control unit into a reduction mechanism / control unit unit, a second assembly process of assembling the electric motor into a motor housing, and a third assembly process of assembling the reduction mechanism / control unit into the motor housing. [Effects of the Invention]

[0009] According to the electric brake and the method for assembling the electric brake of the present invention, no heat countermeasures or the like are required, and assembly can be carried out efficiently. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a cross-sectional view of a disc brake according to an embodiment of the present invention. [Figure 2] 1 is a cross-sectional view of a disc brake according to an embodiment of the present invention. [Figure 3] FIG. 2 is a side view of a speed reduction mechanism / control unit unit employed in the disc brake according to the embodiment of the present invention. [Figure 4] 1 is an exploded perspective view of a motor housing including an electric motor, a reduction mechanism / control unit unit, and a cover member employed in a disc brake according to an embodiment of the present invention. [Figure 5] FIG. 2 is a perspective view of a one-end plate member that is a component of the speed reduction mechanism / control unit unit of the disc brake according to the embodiment of the present invention. [Figure 6] FIG. 4 is a perspective view of the other end side plate member that is part of the speed reduction mechanism / control unit unit of the disc brake according to the embodiment of the present invention. [Figure 7] FIG. 2 is a plan view of a holding member that is a component of the speed reduction mechanism / control unit unit of the disc brake according to the embodiment of the present invention. [Figure 8] FIG. 2 is a plan view showing the configuration of the speed reduction mechanism / control unit unit of the disc brake according to the embodiment of the present invention, with a holding member and an internal gear attached to the other end side plate member. [Figure 9] FIG. 1 is a perspective view of the configuration of a reduction mechanism / control unit unit of a disc brake according to an embodiment of the present invention, showing a state in which an internal gear is arranged between a one-end plate member and an other-end plate member including a retaining member. DETAILED DESCRIPTION OF THE INVENTION

[0011] This embodiment will be described in detail below with reference to Figs. 1 to 9. The electric brake according to this embodiment, specifically the disc brake 1, generates a braking force by driving an electric motor 25 during normal driving. In the following description, the inside of the vehicle (inner side) will be referred to as one end side (cover member 20 side), and the outside of the vehicle (outer side) will be referred to as the other end side (disc rotor D side), as appropriate. That is, in Figs. 1, 2, 3, and 4, the right side will be referred to as one end side, and the left side will be referred to as the other end side, as appropriate.

[0012] 1 and 2, the disc brake 1 according to this embodiment is an electric brake, and includes a pair of inner and outer brake pads 2, 3, and a caliper 4, which are arranged on both axial sides of a disc rotor D attached to a rotating part (not shown) of a vehicle. The inner and outer brake pads 2, 3 correspond to the braking members. The disc rotor D corresponds to the member to be braked. The disc brake 1 according to this embodiment is configured as a floating caliper. The pair of inner and outer brake pads 2, 3, and the caliper 4 are supported by a carrier 5 so as to be movable in the axial direction of the disc rotor D. The carrier 5 is fixed to a non-rotating part (not shown), such as a knuckle, of the vehicle, and is provided so as to straddle the outer periphery of the disc rotor D.

[0013] The caliper body 8, which is the main body of the caliper 4, is arranged at a base end facing the inner brake pad 2 and includes a cylindrical cylinder portion 9 that opens facing the inner brake pad 2, and a pair of claws 10 that extend from the cylinder portion 9 to the outer side across the disc rotor D and are arranged at a tip end facing the outer brake pad 3 on the outer side. A piston 14 is accommodated in the cylinder portion 9 of the caliper body 8, i.e., in a cylinder bore 11 of the cylinder portion 9, so as to be non-rotatable relative to the cylinder portion 9 but movable in the axial direction. The piston 14 presses against the inner brake pad 2 and is formed in a cup shape with a bottom. The piston 14 is accommodated in the cylinder bore 11 of the cylinder portion 9 so that its bottom faces the inner brake pad 2. A seal member (not shown) is arranged on the inner circumferential surface of the other end of the cylinder bore 11 of the cylinder portion 9. The piston 14 is accommodated in the cylinder bore 11 so as to be movable in the axial direction while in contact with the seal member.

[0014] A dust boot 15 is interposed between the outer peripheral surface of the bottom side of the piston 14 and the other end side of the cylinder portion 9. These sealing members and the dust boot 15 prevent foreign matter from entering the cylinder bore 11 of the cylinder portion 9. A motor housing 18 is attached to the bottom of the cylinder portion 9 of the caliper body 8. An open portion on one end side of the motor housing 18 is airtightly closed by a cover member 20. That is, the cover member 20 is fixed with a plurality of fastening members 23, 23 so as to airtightly close the open portion on one end side of the motor housing 18.

[0015] 2 and 4, a positioning opening 22 having a generally rectangular shape in plan view is formed in the cover member 20. A positioning protrusion 85 provided on a one-end plate member 74 (described later) is airtightly fitted into this positioning opening 22. The motor housing 18 is kept airtight. Referring to FIGS. 1, 2 and 4, the motor housing 18 is configured to cover the outer periphery of the bottom of the cylinder portion 9 and to house a speed reduction mechanism 26 (described later). An electric motor 25 is integrally connected to the motor housing 18 and aligned with the cylinder portion 9.

[0016] 1 and 2, the caliper body 8 is equipped with an electric motor 25, a speed reduction mechanism 26 that reduces the speed of rotation from the electric motor 25 and outputs the reduced speed, and a braking mechanism 27 that generates a braking force by using the rotation from the speed reduction mechanism 26 to press the piston 14 against the inner brake pad 2. A brushless DC motor including a rotor main body (permanent magnet), a stator, etc. may be used as the electric motor 25. However, other known motors, such as a brushed DC motor, may also be used as the electric motor 25.

[0017] 1, 2, and 4, the electric motor 25 is integrally connected to the motor housing 18. That is, the electric motor 25 is fixed to the motor housing 18 by a plurality of fastening members 28, 28. A rotating shaft 29 of the electric motor 25 extends toward one end. The rotating shaft 29 is inside the motor housing 18 and extends through a small-diameter opening 90 of a plate member 75 on the other end side, which will be described later. A disk-shaped magnet member 32 that constitutes a rotation angle detection means 31 that detects the rotation angle of the rotating shaft 29 of the electric motor 25 is attached to the tip of the rotating shaft 29. For example, the rotation angle detection means 31 includes the magnet member 32 and a magnetic detection IC chip (not shown). The magnetic detection IC chip is electrically connected to an electronic control unit (control board) 35 that is disposed in a position facing the tip surface of the rotating shaft 29. Then, by detecting the change in magnetic flux from the magnet member 32, which rotates in accordance with the rotation of the rotating shaft 29 of the electric motor 25, using a magnetic detection IC chip, the electronic control unit 35 calculates and detects the rotation angle of the rotating shaft 29 of the electric motor 25.

[0018] A control board, a so-called electronic control unit 35, for controlling the rotation of the electric motor 25 is electrically connected to the electric motor 25. The electronic control unit 35 corresponds to a control unit. The electronic control unit 35 is one component of a reduction mechanism / control unit unit 107, which will be described later. During braking during normal driving, the electronic control unit 35 controls the driving of the electric motor 25 based on detection signals from a detection sensor (not shown) corresponding to a driver's request, various detection sensors (not shown) that detect various situations in which braking is necessary, and the like, as well as detection signals from a rotation angle detection means 31 for the electric motor 25 and a thrust sensor (not shown). A parking switch (not shown) that is operated to turn the parking brake on and off is also electrically connected to the electronic control unit 35. The electronic control unit 35 can also activate the parking brake based on a signal from the vehicle side, regardless of the operation of the parking switch.

[0019] 1 to 3, the reduction mechanism 26 is composed of a multi-stage gear reduction mechanism 37 made up of spur gears or helical gears, and a planetary gear reduction mechanism 38. The multi-stage gear reduction mechanism 37 and the planetary gear reduction mechanism 38 are housed in the motor housing 18. The multi-stage gear reduction mechanism 37 includes a first reduction gear 41, a second reduction gear 42, and a third reduction gear 43. The second and third reduction gears 42 and 43 of the multi-stage gear reduction mechanism 37 and the planetary gear reduction mechanism 38 are components of a reduction mechanism / control unit unit 107, which will be described later. The first to third reduction gears 41 to 43 are made of, for example, sintered or forged metal members, or resin-molded members. The first reduction gear 41 is formed in a cylindrical shape and is press-fitted and fixed to the rotary shaft 29 of the electric motor 25.

[0020] Referring also to Figure 4, the second reduction gear 42 is a stepped gear. A support hole 45 is formed in the axial direction through the radial center of the second reduction gear 42. A support shaft portion 81 protruding from a one-end plate member 74 (described later) is inserted into the support hole 45 of the second reduction gear 42 so as to be relatively rotatable. The second reduction gear 42 is formed by integrally connecting a large-diameter gear 47 that meshes with the first reduction gear 41 and a small-diameter shaft gear 48 that extends concentrically from the large-diameter gear 47 toward the one end. The small-diameter shaft gear 48 of the second reduction gear 42 meshes with the third reduction gear 43.

[0021] 1 to 4, the third reduction gear 43 includes a large-diameter gear 51 that meshes with the small-diameter shaft gear 48 of the second reduction gear 42, and a small-diameter sun gear 52 that is concentrically disposed inside the large-diameter gear 51. The third reduction gear 43 has a through-hole 54 that penetrates along the axial direction at its radial center. The sun gear 52 is configured as part of the planetary gear reduction mechanism 38. One end of the large-diameter gear 51 of the third reduction gear 43 and one end of the sun gear 52 are connected by an annular wall portion 58. An annular space 56 is formed between the inner circumferential surface of the large-diameter gear 51 and the outer circumferential surface of the sun gear 52. An annular stopper portion 59 is formed on the other end face of the annular wall portion 58 near the outer periphery, protruding toward the other end. The annular stopper portion 59 abuts against an annular wall portion 68 of an internal gear 63, which will be described later. An annular stopper portion 60 is formed on one end surface of the annular wall portion 58, protruding toward one end near the inner periphery thereof. This annular stopper portion 60 abuts against the periphery of a cylindrical shaft portion 79 of a one-end plate member 74, which will be described later.

[0022] 1 and 2, the planetary gear reduction mechanism 38 is housed in the motor housing 18. The planetary gear reduction mechanism 38 includes a sun gear 52 of the third reduction gear 43, a plurality of (five in this embodiment) planetary gears 62, 62, and an internal gear 63. Each planetary gear 62 and internal gear 63 is made of, for example, a metal member obtained by sintering or forging, or a resin-molded member. Each planetary gear 62 has a gear 65 that meshes with internal teeth 67 of the sun gear 52 and internal gear 63. Each planetary gear 70 is inserted into a pin (not shown) that extends from a carrier (not shown), which will be described later, so as to be rotatable relative to the sun gear 52. The planetary gears 62 are arranged at equal intervals around the sun gear 52 in the circumferential direction. More specifically, the planetary gears 62 are arranged at equal intervals along the circumferential direction inside the internal teeth 67 of the internal gear 63 (described later) in the annular space 56 between the inner circumferential surface of the large diameter gear 51 of the third reduction gear 43 and the outer circumferential surface of the sun gear 52. The gears 65 of each planetary gear 62 mesh with the internal teeth 67 of the sun gear 52 and the internal gear 63.

[0023] 1 and 2, the internal gear 63 includes internal teeth 67 that mesh with the gears 65 of each planetary gear 62, an annular wall portion 68 that extends continuously from one end of the internal teeth 67 toward the radial center and restricts axial movement of each planetary gear 62, and a cylindrical wall portion 69 that extends from the internal teeth 67 toward the other end. The internal teeth 67 of the internal gear 63 are disposed between the inner circumferential surface of the large diameter gear 51 of the third reduction gear 43 and each planetary gear 62. The annular wall portion 68 of the internal gear 63 is disposed between each planetary gear 62 and the annular wall portion 58 of the third reduction gear 43. Referring to FIGS. 8 and 9, a plurality of anti-rotation projections 71 are formed at intervals along the circumferential direction on the outer circumferential surface of the other end of the internal gear 63.

[0024] 3 and 4, in the reduction mechanism 26, the second reduction gear 42 and the planetary gear reduction mechanism 38 are sandwiched between a one-end plate member 74 and an other-end plate member 75. The one-end plate member 74 corresponds to the first plate. Meanwhile, the other-end plate member 75 corresponds to the second plate. With reference to FIGS. 1 to 3 and 5, the one-end plate member 74 has an opening 77 that is generally rectangular in plan view and in which the rotation angle detection means 31 (magnet member 32) is disposed at a position on the electric motor 25 side. A cylindrical shaft portion 79 that is concentric with the radial center of a spindle 113 (described later) protrudes from the one-end plate member 74 toward the other end. The portion of the one-end plate member 74 where the cylindrical shaft portion 79 is formed is penetrated. The cylindrical shaft portion 79 of the one-end plate member 74 is inserted into the insertion hole 54 of the third reduction gear 43. As a result, the third reduction gear 43 is supported by the cylindrical shaft portion 79 extending from the one end side plate member 74 so as to be relatively rotatable.

[0025] Furthermore, a support shaft 81 is erected on the one-end plate member 74 at a position close to the opening 77, facing the other end. The support shaft 81 is inserted into the support hole 45 of the second reduction gear 42 so as to be relatively rotatable. As a result, the second reduction gear 42 is supported on the support shaft 81 from the one-end plate member 74 so as to be relatively rotatable. Referring to FIG. 9 , an L-shaped plate portion 84 is protruded from one end surface of the one-end plate member 74, at a position on the cylinder portion 9 side. A positioning protrusion 85 that is generally rectangular in plan view is protruded from one end surface of the L-shaped plate portion 84. This positioning protrusion 85 is airtightly fitted into a positioning opening 22 formed in the cover member 20.

[0026] 5 and 9, a plurality of bosses 86 for fixing the electronic control unit 35 (control board) are protrudingly provided at predetermined positions on one end surface of the one-end plate member 74. Referring to FIG. 4, the electronic control unit 35 is fixed to one end surface of the one-end plate member 74 by fastening members 87 via the bosses 86 so as to cover the opening 77 in an area excluding the positioning protrusion 85. Referring to FIGS. 1 to 4 and 6, the other-end plate member 75 has a large-diameter opening 89 concentric with the radial center of a spindle 113 (described later) and a small-diameter opening 90 concentric with the radial center of a rotating shaft 29 of the electric motor 25. A plurality of (three in this embodiment) support posts 92 are provided on the outer periphery of the other-end plate member 75 at intervals toward one end. In FIG. 6, each fastening member 105 is screwed into each support post 92. 7 to 9, a holding member 95 is fixed by a plurality of fastening members 97, 97 around the large diameter opening 89 on one end surface of the other end side plate member 75.

[0027] The retaining member 95 is a plate member extending in a substantially semicircular ring shape. An engagement groove 100 extends circumferentially on the outer periphery of one end surface of the retaining member 95. A plurality of anti-rotation recesses 102 are formed around the engagement groove 100 at intervals in the circumferential direction. Referring to FIG. 2, the cylindrical wall portion 69 of the internal gear 63 engages with the engagement groove 100 of the retaining member 95, and the annular wall portion 68 of the internal gear 63 abuts against the annular stopper portion 59 provided on the annular wall portion 58 of the third reduction gear 43, thereby restricting radial and axial movement of the internal gear 63. Referring to FIGS. 8 and 9, the anti-rotation protrusions 71 of the internal gear 63 fit into the anti-rotation recesses 102 of the retaining member 95, thereby restricting relative rotation.

[0028] 3 and 4, in the disc brake 1 according to this embodiment, the second reduction gear 42, the third reduction gear 43, and the planetary gear reduction mechanism 38 of the reduction mechanism 26 are disposed between a one-end plate member 74 and an other-end plate member 75, the one-end plate member 74 and the other-end plate member 75 are fixed to each other by fastening members 105 via support portions 92, and an electronic control unit 35 (control board) is fixed to one end face of the one-end plate member 74 by fastening members 87 via boss portions 86 so as to cover the opening 77 except for the positioning protrusion 85, thereby forming an integrated reduction mechanism / control unit unit 107. The reduction mechanism / control unit unit 107 is housed in a motor housing 18, and the other-end plate member 75 of the reduction mechanism / control unit 107 and the motor housing 18 are fixed to each other by a plurality of fastening members 110.

[0029] 1 and 2, the brake mechanism 27 is a rotary-linear motion conversion mechanism that converts the rotational motion from the electric motor 25 and the speed reduction mechanism 26 (the multi-stage gear reduction mechanism 37 and the planetary gear reduction mechanism 38), i.e., the rotational motion transmitted from each planetary gear 62 of the planetary gear reduction mechanism 38 to the spindle 113 via the carrier, into linear motion relative to the linearly moving member 115, and applies thrust to the piston 14 by the movement of the linearly moving member 115, thereby propelling the piston 14 (moving it toward the other end). The spindle 113 is rotatably supported by the cylinder portion 9, and a portion of the other end side is disposed within the cylinder bore 11.

[0030] One end of the spindle 113 passes through the large-diameter opening 89 (see FIG. 6 ) of the other-end plate member 75 and is supported within the cylindrical shaft portion 79 of the one-end plate member 74 so as to be relatively rotatable. The spindle 113 is engaged with a disk-shaped carrier so as not to be rotatable relative to the carrier. This enables transmission of rotational torque between the spindle 113 and the carrier, and rotation from each planetary gear 62 of the planetary gear reduction mechanism 38 is transmitted to the spindle 113 via the carrier. When the spindle 113 rotates in conjunction with the rotation of the rotary shaft 29 of the electric motor 25, the brake mechanism 27 (rotation-to-linear motion conversion mechanism) acts to move the linear motion member 115 forward toward the other end, thereby moving the piston 14 forward. The piston 14 presses the inner brake pad 2 against the disc rotor D, thereby generating a braking force for the vehicle.

[0031] Next, a method for assembling the disc brake 1 in this embodiment will be described, particularly a method for assembling the electric motor 25, the reduction mechanism 26, and the cover member 20, i.e., the so-called MGU (Motor Gear Unit). The MGU can be assembled through the first to fourth assembly steps described below. In this assembly method, the first and second assembly steps can be performed in parallel. In the first assembly step, the reduction mechanism / control unit unit 107 shown in FIG. 3 is assembled. First, the second reduction gear 42, the third reduction gear 43, and the planetary gear reduction mechanism 38 of the reduction mechanism 26 are sandwiched between the one-end plate member 74 and the other-end plate member 75. That is, referring to FIG. 8, a retaining member 95 is fixed around the large-diameter opening 89 on one end surface of the other-end plate member 75 by a plurality of fastening members 97.

[0032] 2, the third reduction gear 43 is arranged so as to concentrically cover the entire internal gear 63 from one end side, and each planetary gear 62 is arranged so as to mesh with the sun gear 52 of the third reduction gear 43 and the internal teeth 67 of the internal gear 63 at intervals along the circumferential direction between them, thereby assembling the planetary gear reduction mechanism 38 including the third reduction gear 43. Next, the cylindrical wall portion 69 of the internal gear 63 of the planetary gear reduction mechanism 38 is engaged with the engagement groove portion 100 of the holding member 95, and, referring to FIGS. 8 and 9, each anti-rotation protrusion 71 of the internal gear 63 is fitted into each anti-rotation recess 102 of the holding member 95.

[0033] 2 and 3, the support shaft portion 81 provided on the other-end plate member 75 is inserted into the support hole 45 of the second reduction gear 42 so as to be relatively rotatable. Next, the small-diameter shaft gear 48 of the second reduction gear 42 on the other-end plate member 75 meshes with the large-diameter gear 51 of the third reduction gear 43, and the cylindrical shaft portion 79 of the one-end plate member 74 is inserted into the insertion hole 54 of the third reduction gear 43 so as to be relatively rotatable, thereby sandwiching the second reduction gear 42, the third reduction gear 43, and the planetary gear reduction mechanism 38 of the reduction mechanism 26 between the one-end plate member 74 and the other-end plate member 75. Next, the one-end plate member 74 and the other-end plate member 75 are fixed together by fastening members 105, 105 via the support portions 92, 92. Next, the electronic control unit 35 (control board) is fixed to one end surface of the one-end plate member 74 with the fastening members 87, 87 via the bosses 86, 86 so as to cover the opening 77 in an area excluding the positioning protrusion 85. This completes the assembly of the reduction gear mechanism / control unit unit 107. Meanwhile, in a second assembly process, the electric motor 25 is attached to the motor housing 18 with the multiple fastening members 28, 28.

[0034] Next, a third assembly step is carried out. That is, referring to Fig. 4, in the third assembly step, the reduction gear / control unit 107 is housed inside the motor housing 18. Next, the other end side plate member 75 of the reduction gear / control unit 107 is fixed inside the motor housing 18 with the fastening members 110, 110. At this time, referring to Fig. 1, the reduction gear / control unit 107 is press-fitted onto the rotating shaft 29 of the electric motor 25 so that the fixed first reduction gear 41 and the large diameter gear 47 of the second reduction gear 42 mesh with each other. Next, wiring to the electronic control unit 35 (control board) is carried out.

[0035] 1, 2, and 4, in the fourth assembly step, the cover member 20 is positioned relative to the motor housing 18 so that the positioning protrusion 85 of the one-end plate member 74 of the speed reduction mechanism / control unit unit 107 fits into the positioning opening 22 provided in the cover member 20, and is fixed with a plurality of fastening members 23, 23 so as to close the open portion on one end of the motor housing 18. This completes the assembly of the MGU.

[0036] Next, the braking and braking release actions of the disc brake 1 according to this embodiment, particularly during normal driving, will be described. During braking during normal driving, such as when the driver depresses the brake pedal (not shown), the electric motor 25 is rotated in the forward direction, i.e., the apply direction, in response to a command from the electronic control unit 35, and the rotation is transmitted in the reduction mechanism 26 to the sun gear 52 of the planetary gear reduction mechanism 38 via the multi-stage gear reduction mechanism 37. The rotation of the sun gear 52 causes each planetary gear 62 to rotate about its own axis while revolving around the axis of the sun gear 52, thereby rotating the carrier. The rotation from the carrier is then transmitted to the spindle 113. When the spindle 113 rotates in accordance with the operation of the planetary gear reduction mechanism 38, the linearly acting member 115 thereof advances due to the action of the braking mechanism 27, thereby advancing the piston 14.

[0037] As the piston 14 advances, it presses the inner brake pad 2 against the disc rotor D. Then, due to a reaction force against the pressing force of the piston 14 on the inner brake pad 2, the caliper body 8 moves inward (to the right in FIGS. 1 and 2) relative to the carrier 5, and the claws 10, 10 press the outer brake pad 3 against the disc rotor D. As a result, the disc rotor D is sandwiched between the pair of inner and outer brake pads 2, 3, generating a frictional force, which in turn generates a braking force for the vehicle.

[0038] On the other hand, when the brake is released, for example when the driver releases the brake pedal, the electric motor 25 rotates in the reverse direction, i.e., the release direction, in response to a command from the electronic control unit 35, and the rotation in the reverse direction is transmitted to the spindle 113 via the multi-stage gear reduction mechanism 37 and the planetary gear reduction mechanism 38 of the speed reduction mechanism 26. Then, as the spindle 113 rotates in the reverse direction, the linearly moving member 115 moves backward and returns to its initial state due to the action of the braking mechanism 27, and the braking force applied to the disc rotor D by the pair of inner and outer brake pads 2, 3 is released. Note that the disc brake 1 according to this embodiment also functions basically in the same way as a parking brake, which is an example of an action for maintaining the vehicle in a stopped state.

[0039] As described above, in this embodiment, the motor housing 18 in which the electric motor 25 is disposed includes the reduction mechanism / control unit 107, which integrates the second reduction gear 42, the third reduction gear 43, and the planetary gear reduction mechanism 38 of the reduction mechanism 26 with the electronic control unit 35 (control board). This eliminates the need for thermal countermeasures and enables efficient assembly. That is, the first assembly process for assembling the reduction mechanism / control unit 107 and the second assembly process for attaching the electric motor 25 to the motor housing 18 with the multiple fastening members 28 can be performed in parallel, thereby shortening assembly time compared to conventional methods, improving productivity, and ultimately proposing an efficient assembly method. Furthermore, because there is no longer a restriction on integrating the electronic control unit 35 and the electric motor 25 as in conventional methods, separating them eliminates the need for thermal countermeasures and allows for free placement, eliminating layout constraints.

[0040] Furthermore, the reduction mechanism / control unit unit 107 provided in the disc brake 1 according to this embodiment has a one-end plate member 74 and an other-end plate member 75 that sandwich the second reduction gear 42, the third reduction gear 43, and the planetary gear reduction mechanism 38 of the reduction mechanism 26, and the electronic control unit 35 is fixed to the one-end plate member 74, while the other-end plate member 75 is fixed to the interior of the motor housing 18 via a plurality of fastening members 110, 110. As a result, vibrations generated by meshing of the reduction mechanism 26 are transmitted from the one-end plate member 74 and the other-end plate member 75 to the motor housing 18, which is an effective measure against noise and vibration.

[0041] Furthermore, the assembly method for the disc brake 1 according to this embodiment particularly includes a first assembly process for assembling the reduction mechanism / control unit 107 and a second assembly process for assembling the electric motor 25 to the motor housing 18 with a plurality of fastening members 28, 28, and these first and second assembly processes can be carried out in parallel, thereby shortening the assembly time for the disc brake 1, more specifically, the MGU, and improving productivity.

[0042] Although this embodiment has been applied to a disc brake 1 in which both the service brake and the parking brake are driven by an electric motor 25, it may also be applied to a disc brake in which, for example, the service brake is hydraulically operated and the parking brake, etc., is driven by an electric motor 25. [Explanation of symbols]

[0043] 1 disc brake (corresponding to electric brake), 2 inner brake pad (corresponding to braking member), 3 outer brake pad (corresponding to braking member), 18 motor housing, 20 cover member, 25 electric motor, 26 reduction mechanism, 27 braking mechanism, 35 electronic control unit (corresponding to control unit), 74 one end side plate member (corresponding to first plate), 75 other end side plate member (corresponding to second plate), 107 reduction mechanism / control unit unit, 110 fastening member, D disc rotor (corresponding to braked member)

Claims

1. An electric motor; a reduction mechanism to which rotation from the electric motor is transmitted; a braking mechanism that generates a braking force by pressing a braking member against a member to be braked using rotation from the reduction mechanism; a control unit that controls the driving of the electric motor; An electric brake comprising: An electric brake characterized in that a reduction mechanism / control unit in which the reduction mechanism and the control unit are integrated is provided within a motor housing in which the electric motor is disposed.

2. 2. The electric brake according to claim 1, the speed reduction mechanism / control unit has a first plate and a second plate that sandwich the speed reduction mechanism, the control unit is disposed on the first plate or the second plate, and the first plate or the second plate is fastened to the inside of the motor housing via a fastening member; The electric brake is characterized in that the motor housing accommodates the reduction mechanism / control unit and is covered with a cover member.

3. An electric motor; a reduction mechanism to which rotation from the electric motor is transmitted; a braking mechanism that generates a braking force by pressing a braking member against a member to be braked using rotation from the reduction mechanism; a control unit that controls the driving of the electric motor; A method for assembling an electric brake comprising: a first assembly step of assembling the speed reduction mechanism and the control unit into a speed reduction mechanism / control unit unit; a second assembly step of assembling the electric motor into a motor housing; a third assembly step of assembling the speed reduction mechanism / control unit to the motor housing; 1. A method for assembling an electric brake, comprising:

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