JP2020051598A - Brake device - Google Patents

Abstract

To obtain a brake device having a novel constitution which has less malfunction in which, for example, the wear of an operation member hardly occurs.SOLUTION: A brake device comprises, for example: a motion conversion mechanism which has a rotating member which rotates in conjunction with a rotor of a motor and is provided with a penetration hole which an operation member penetrates, and a linear motion member which linearly moves according to the rotation of the rotating member to move the operation member between a brake position and a non-brake position and is different from the operation member; an abutment part for limiting the movement of the operation member from the brake position side to the non-brake position side in a linear motion direction of the linear motion member; and a control part for limiting the movement of the operation member to an intersection direction intersecting with the linear motion direction at the outside of the penetration hole in a state where the operation member is separated from the abutment part and the linear motion member. A first clearance in the intersection direction between a first region facing the control part of the operation member and the control part is smaller than a second clearance in the intersection direction between a second region passing through the penetration hole of the operation member and an inner face of the penetration hole.SELECTED DRAWING: Figure 2

Description

  The present disclosure relates to a brake device.

  Conventionally, a rotary member that rotates in conjunction with an output shaft of a motor, and a linear member that linearly moves in accordance with the rotation of the rotary member, provided with a rotary-to-linear conversion mechanism, and the linear member converts a cable. 2. Description of the Related Art A brake device that moves a brake shoe by pulling to apply a brake is known (for example, Patent Document 1).

Japanese Patent No. 6184873

  In this type of brake device, it is not preferable that the cable be worn due to interference with other parts.

  Therefore, one of the problems of the present disclosure is to obtain a brake device having a novel configuration with less inconvenience, for example, such that an operating member such as a cable is hardly worn.

  A brake device according to an embodiment of the present disclosure includes, for example, a motor, an operating member that moves the braking member between a braking position that places the braking member in a braking state, and a non-braking position that places the braking member in a non-braking state, A rotating member that rotates in conjunction with a rotor and has a through hole through which the operating member passes, and linearly moves according to the rotation of the rotating member to move the operating member between the braking position and the non-braking position. A motion conversion mechanism having a linear motion member separate from the operation member; and restricting movement of the operation member from the braking position side to the non-braking position side in a translation direction of the linear motion member. A restricting portion that restricts movement of the operating member in a direction crossing the linear movement direction outside the through hole in a state where the operating member is separated from the contact portion and the linear moving member. And the operating member A first gap in the intersecting direction between the first portion facing the restriction portion and the restriction portion is provided at the intersection between the second portion passing through the through hole of the operating member and the inner surface of the through hole. Smaller than the second gap in the direction.

  According to such a configuration, for example, since the first gap is smaller than the second gap, the operating member and the restricting portion come into contact before the operating member comes into contact with the inner surface of the through hole of the rotating member. Therefore, abrasion of the operating member due to contact between the operating member and the rotating member can be suppressed.

FIG. 1 is an exemplary schematic rear view of the brake device of the embodiment as viewed from the rear of the vehicle. FIG. 2 is an exemplary schematic cross-sectional view of a part of the brake device according to the embodiment, in a non-braking state. FIG. 3 is an exemplary schematic cross-sectional view of a part of a brake device according to a first modification of the embodiment. FIG. 4 is an exemplary schematic cross-sectional view of a part of a brake device according to a second modification of the embodiment.

  Hereinafter, exemplary embodiments and modifications of the present invention will be disclosed. The configurations of the embodiments and the modifications described below, and the operations and results (effects) provided by the configurations are examples. The present invention can be realized by configurations other than those disclosed in the following embodiments and modified examples. Further, according to the present invention, at least one of various effects (including derivative effects) obtained by the configuration can be obtained.

  The following embodiments and modified examples include similar components. Therefore, in the following, the same components are denoted by the same reference numerals, and redundant description may be omitted. Further, in the present specification, ordinal numbers are given for convenience in order to distinguish parts, parts, and the like, and do not indicate a priority order or an order.

  In each figure, the direction of the axis 150 of the rotation center Ax of the rotating member 141 and the direction in which the end 150a of the cable 150 approaches the braking member is indicated by an arrow D1, and the direction of the axis of the rotation center Ax is The direction in which the end 150a moves away from the braking member is indicated by an arrow D2. In the following description, unless otherwise specified, the axial direction of the rotation center Ax is simply referred to as the axial direction, the radial direction of the rotation center Ax is simply referred to as the radial direction, and the circumferential direction of the rotation center Ax is simply referred to as the circumferential direction. Is done. Arrow Y indicates the outside in the vehicle width direction, and arrow Z indicates the upper side of the vehicle.

[First Embodiment]
FIG. 1 is a rear view of the vehicle brake device 2 as viewed from the rear of the vehicle. As shown in FIG. 1, the brake device 2 is housed inside a peripheral wall 1 a of a cylindrical wheel 1. The brake device 2 is a so-called drum brake. The brake device 2 includes two brake shoes 3 that are separated from each other. The two brake shoes 3 extend in an arc along the inner peripheral surface of a cylindrical drum rotor (not shown). The drum rotor rotates integrally with the wheel 1 around a rotation center C along the vehicle width direction (direction Y). The brake device 2 moves the two brake shoes 3 so as to contact the inner peripheral surface of the cylindrical drum rotor. As a result, the drum rotor and thus the wheel 1 are braked by the friction between the brake shoe 3 and the drum rotor. The brake shoe 3 is an example of a braking member.

  The brake device 2 includes, as an actuator that moves the brake shoe 3, a wheel cylinder (not shown) that operates by hydraulic pressure, and a motor 120 that operates by energization. Each wheel cylinder and motor 120 can move two brake shoes 3. The wheel cylinder is used for braking during traveling, for example, and the motor 120 is used for braking during parking, for example. That is, the brake device 2 is an example of an electric parking brake. The motor 120 may be used for braking during traveling.

  The brake device 2 includes a disc-shaped backing plate 4. The backing plate 4 is provided so as to intersect with the rotation center C of the wheel 1. That is, the backing plate 4 extends substantially along the direction intersecting the rotation center C, specifically, substantially along the direction orthogonal to the rotation center C. The components of the brake device 2 are provided both outside and inside the backing plate 4 in the vehicle width direction. The backing plate 4 supports each component of the brake device 2 directly or indirectly. That is, the backing plate 4 is an example of a support member. Further, the backing plate 4 is connected to a connection member (not shown) with the vehicle body. The connection member is, for example, a part of a suspension (for example, an arm, a link, a mounting member, and the like). The brake device 2 can be used for both driving wheels and non-driving wheels.

  The electric actuator 100 is fixed to the backing plate 4 in a state of protruding from the inner surface 4a of the backing plate 4 in the vehicle width direction to the opposite side to the brake shoe 3. The electric actuator 100 includes a housing 110, a motor 120, a speed reduction mechanism 130, a motion conversion mechanism 140, a cable 150 (FIG. 2), and a control device (not shown).

  The housing 110 can be made of, for example, a metal material such as iron or an aluminum alloy, or a synthetic resin material such as plastic. The housing 110 is configured by integrating a plurality of components.

  The motor 120 has, for example, a stator, a rotor, a coil, a magnet, an output shaft, and the like (all not shown). The output shaft is part of the rotor. The motor 120 is controlled by the control device and rotates the rotor and the output shaft. The motor 120 can also be called an actuator.

  The reduction mechanism 130 includes a plurality of gears rotatably supported by the housing 110, and rotates in conjunction with the output shaft.

  FIG. 2 is a cross-sectional view of a part of the electric actuator 100 in a braking state. The electric actuator 100 pulls the brake shoe 3 via the cable 150 to bring the brake shoe 3 in a non-braking state into a braking state. The cable 150 passes through a through hole (not shown) provided in the backing plate 4. The cable 150 is an example of an operating member. As shown in FIG. 2, the cable 150 is provided movably between the non-braking position Pr and the braking position Pb. The non-braking position Pr may be referred to as a release position. The non-braking position Pr is separated from the braking position Pb in a direction D1 (downward in FIG. 2), and the braking position Pb is separated from the non-braking position Pr in a direction D2 (upper in FIG. 2). The directions D1 and D2 are moving directions of the cable 150 and the cable end 151.

  The motion conversion mechanism 140 has a rotating member 141, a linear moving member 142, and a rotation preventing member 143.

  The rotating member 141 has a peripheral wall 141a and a flange 141b. The shape of the peripheral wall 141a is cylindrical with the rotation center Ax as the center. Inside the peripheral wall 141a, a through hole 141c is provided along the axial direction.

  The shape of the flange 141b is annular and plate-shaped. The flange 141b projects radially outward from the peripheral wall 141a. A third gear 133 of the speed reduction mechanism 130 is provided on the outer periphery of the flange 141b. The rotation of the rotor and the output shaft of the motor 120 is transmitted to the rotating member 141 via the speed reduction mechanism 130. The rotating member 141 rotates in conjunction with the rotor of the motor 120. Note that the speed reduction mechanism 130 can also be referred to as a rotation transmission mechanism.

  The peripheral wall 141a has a first extension 141a1 extending in the direction D2 from the flange 141b, and a second extension 141a2 extending in the direction D1 from the flange 141b. The length of the first extension 141a1 is longer than the length of the second extension 141a2.

  A male screw 141d is provided on the outer periphery of the first extension 141a1. The center of the male screw 141d is the rotation center Ax. The rotation center Ax may be referred to as an axis.

  A radial bearing 161 such as a slide bush or a roller bearing is provided between the outer periphery of the second extending portion 141a2 and the inner periphery of the through hole 112a of the base 112. A thrust bearing 162 such as a roller bearing is provided between the end surface 141b1 of the flange 141b in the direction D1 and the end surface 112b of the base 112 in the direction D2. The rotating member 141 is supported by the base 112 via the radial bearing 161 and the thrust bearing 162 so as to be rotatable around the rotation center Ax. The rotating member 141 is driven to rotate by the second gear 132 by the engagement of the second gear 132 and the third gear 133 of the speed reduction mechanism 130.

  The third gear 133 is made of, for example, a synthetic resin material such as plastic, and the disk 141b2 of the peripheral wall 141a and the flange 141b except for the third gear 133 can be made of a metal material such as iron or an aluminum alloy. In the present embodiment, iron is used as an example. In this case, the rotating member 141 can be configured by, for example, insert molding. Note that the rotating member 141, including the third gear 133, may be integrally formed of a metal material.

  The translation member 142 has a side wall 142a and a flange 142b. The side wall 142a is disposed radially outward with respect to the rotating member 141, and extends in the axial direction. The side wall 142a surrounds the rotation center Ax and the rotation member 141, and the shape of the side wall 142a is cylindrical with the rotation center Ax as the center. The side wall 142a may be referred to as a peripheral wall. Inside the side wall 142a, a through hole 142c is provided along the axial direction. The rotating member 141 passes through the through hole 142c in the axial direction.

  The shape of the flange 142b is polygonal and plate-like. The flange 142b projects radially outward from the side wall 142a.

  The side wall 142a has a first extension 142a1 extending in the direction D2 from the flange 142b, and a second extension 142a2 extending in the direction D1 from the flange 142b. The length of the first extension 142a1 is longer than the length of the second extension 142a2.

  On the inner surface of the through hole 142c, a female screw 142d that meshes with the male screw 141d of the rotating member 141 is provided. The female screw 142d is provided adjacent to an end of the through hole 142c in the direction D1. The female screw 142d is provided in a section from an end of the through hole 142c in the direction D1 to a position radially aligned with the flange 142b, and is not provided at an end of the through hole 142c in the direction D2. Further, the flange 142b is surrounded by a detent member 143 extending in the axial direction.

  The detent member 143 has a side wall 143a. The side wall 143a is disposed radially outward with respect to the flange 142b, and extends in the axial direction. The side wall 143a surrounds the rotation center Ax and the periphery of the rotation member 141, and the shape of the side wall 143a is tubular. The side wall 143a may be referred to as a peripheral wall.

  The detent member 143 is fixed to the housing 110 such as the cover 111 and the base 112, for example. Therefore, it can be said that the detent member 143 is a part of the housing 110. A small gap is provided between the outer surface 142b1 of the flange 142b and the inner surface 143a1 of the side wall 143a in a state parallel to each other, and both the outer surface 142b1 and the inner surface 143a1 extend in a direction intersecting the circumferential direction. .

  Therefore, the rotation of the outer surface 142b1 around the rotation center Ax is restricted by the inner surface 143a1, whereby the rotation of the linear motion member 142 is restricted by the detent member 143. On the other hand, since both the outer surface 142b1 and the inner surface 143a1 extend in the axial direction, the inner surface 143a1 does not hinder the movement of the outer surface 142b1 in the axial direction. That is, the rotation preventing member 143 can guide the translation member 142 along the axial direction (the translation direction) while prohibiting the rotation of the translation member 142 around the rotation center Ax. The inner surface 143a1 may also be referred to as a guide.

  A bottom wall 143b protruding radially inward from the side wall 143a is provided at an end of the rotation preventing member 143 in the direction D2. The bottom wall 143b is provided with a through hole 143b1 penetrating in the axial direction. The bottom wall 143b has an annular and plate-like shape, and may be referred to as an inward flange. The inner edge of the through hole 143b1 is disposed radially outward of the side wall 142a of the linear member 142.

  The cable 150 passes through the through hole 141c of the rotating member 141 and extends in the axial direction. One end (not shown) in the axial direction is connected to a movable member that operates the brake shoe 3. A cable end 151 is coupled to an end 150a (the upper end in FIG. 2) as the other end in the axial direction. The cable end 151 has a cylindrical portion 151a and a flange 151b. The cable end 151 is fixed to the cable 150 by caulking the cylindrical portion 151a from the outside. The flange 151b projects radially outward from the side wall 142a of the linear motion member 142 and the bottom wall 143b of the rotation preventing member 143. The cable 150 and the cable end 151 can be made of, for example, a metal material. The cable end 151 is an example of an operating member together with the cable 150. The cable end 151 is an example of a fixing member.

  The cable end 151 and the translation member 142 are not integrated, and are configured to be separated in the axial direction. Here, the cable 150 is pulled by a return member (biasing member, elastic member) such as a spring (not shown) in a direction (direction D1, downward in FIG. 2) in which the braking member is in a braking state. The electric actuator 100 is configured such that the urging force of the return member always acts on the cable 150 in the movement range of the cable 150 (use range of the brake). However, due to the configuration of the brake device 2, the urging force of the return member decreases as the braking state approaches the non-braking state. In the braking state, tension is generated in the cable 150 in accordance with the rigidity of the drum brake. In such a configuration, a force is transmitted between the translation member 142 and the cable 150 via the cable end 151. Therefore, the cable end 151 can also be called a transmission member (first transmission member).

  The control device that controls the motor 120 is, for example, an electronic control unit (ECU). A part of the control device may be configured by hardware such as a central processing unit (CPU) that executes software or a controller, or the control device may be entirely configured by hardware. The control device may be referred to as a control unit.

  In such a configuration, the rotation of the output shaft of the motor 120 is transmitted to the rotation member 141 via the speed reduction mechanism 130, and when the rotation member 141 rotates, the male screw 141d of the rotation member 141 and the female screw 142d of the linear member 142 And the rotation of the outer surface 142b1 of the linear member 142 is restricted by the inner surface 143a1 of the rotation preventing member 143, so that the linear member 142 moves in the axial direction. Therefore, the cable 150 moves between the braking position Pb and the non-braking position Pr along the axial direction with the movement of the translation member 142.

  The rotation of the output shaft of the motor 120 in one direction (hereinafter, referred to as a braking rotation direction) controlled by the control device moves the cable 150 in the direction D2, and when the braking member is in the braking state, the tension of the cable 150 is reduced. This increases the rotational load of the motor 120 and, consequently, the drive current of the motor 120. Therefore, the control device detects that the cable 150 has reached the braking position Pb, for example, when the drive current of the motor 120 exceeds the threshold value, and stops supplying the drive current to the motor 120 at that time. As a result, the rotation of the output shaft is stopped, and the cable 150 is located at the braking position Pb.

  The rotation of the output shaft of the motor 120 in the other direction (hereinafter, referred to as a release rotation direction) controlled by the control device causes the cable 150 to move from the braking position Pb in the direction D1, and the cable end 151 to the rotation stop member 143. It moves to the non-braking position Pr that contacts the bottom wall 143b. In this state, the braking member is separated from the rotating member (not shown, for example, a brake drum), and the electric braking state by the electric actuator 100 is released. The bottom wall 143b restricts the cable end 151 from moving beyond the bottom wall 143b toward the opposite side of the braking position Pb from the non-braking position Pr, that is, in the direction D1. The detent member 143 is an example of a stopper. Further, the bottom wall 143b may be referred to as a positioning portion that positions the cable 150 at the non-braking position Pr, and the rotation preventing member 143 may be referred to as a movement restricting member.

  Further, as described above, in the present embodiment, the cable end 151 and the linear motion member 142 are not integrated, and can be separated in the axial direction. Therefore, when the output shaft of the motor 120 further rotates in the release rotation direction from the state where the cable 150 is arranged at the non-braking position Pr, the engagement between the male screw 141d and the female screw 142d and the rotation of the linear motion member 142 by the rotation preventing member 143 are performed. The stop moves the linear member 142 away from the cable end 151 in the direction D1. That is, in a state where the cable 150 is located at the non-braking position Pr and the operation of the motor 120 is stopped, a gap g is formed in the axial direction between the translation member 142 and the cable end 151.

  The control device measures the time (rotation time) during which the motor 120 is rotated from the state where the cable 150 is in the braking position Pb and the number of rotations of the output shaft, so that the linear motion member 142 moves in the direction D1 from the cable end 151. The operation of the motor 120 is stopped at the position where the motor 120 is separated. At this time, the rotation time and the number of rotations are set between the stopped linear member 142 and another member (for example, the second gear 132 or the flange 141b of the rotary member 141) separated from the linear member 142 in the direction D1. Is set so that a gap is reliably formed, in other words, it does not contact or interfere with other members.

  Further, as shown in FIG. 2, the electric actuator 100 includes a coil spring 171. The coil spring 171 is interposed between the bottom wall 111a (wall) of the cover 111 separated from the cable end 151 in the direction D2 and the flange 151b of the cable end 151, and its winding center is disposed along the rotation center Ax. Then, the cable end 151 is urged against the housing 110 in the direction D1. The coil spring 171 is a so-called compression spring that is assembled in an elastically compressed state and is used in a compressed state in its operation range. The coil spring 171 biases the cable end 151 against the cover 111 (housing 110) in the direction D1 in both the state where the cable 150 and the cable end 151 are at the non-braking position Pr and the state where the cable end 151 is at the braking position Pb. I have. The coil spring 171 may be a trapezoidal spring whose diameter gradually decreases in the direction D1 or a trapezoidal spring whose diameter gradually decreases in the direction D2. The coil spring 171 may be referred to as a first biasing member.

  Further, the electric actuator 100 has a guide member 113 adjacent to the rotating member 141 in the direction D1, and a ring 172 adjacent to the guide member 113 in the direction D1. The guide member 113 has an annular shape, and guides the cable 150 inside the through hole 112 a of the base 112. The guide member 113 is made of, for example, an elastomer or a synthetic resin material. The ring 172 is made of an elastic material such as an elastomer, is interposed in the axial direction between the guide member 113 and the step surface 112c of the base 112, and is assembled in a state of being elastically compressed in the axial direction. The guide member 113 and thus the rotating member 141 are urged against the base 112 (housing 110) in the direction D2, and the rotating member 141 is pressed against the translation member 142 or the rotation preventing member 143 (housing 110). Ring 172 may also be referred to as a second biasing member. Instead of the ring 172, for example, a second urging member different from the elastomer, such as a disc spring or a coil spring, may be provided.

  By the way, in the electric actuator 100, for example, the length of the cable 150 is considered in consideration of a dimensional tolerance or the like in order to more reliably bring the brake shoe 3 into the non-braking state in a state where the cable 150 is disposed at the non-braking position Pr. In some cases, such a margin is set, in other words, the length of the cable 150 is set longer. In this case, when the brake shoe 3 changes from the braking state to the non-braking state, the cable end 151 cannot reach the position where the cable end 151 is seated (contacted) on the bottom wall 143b due to the length of the cable 150 described above. It may be in a state separated from the bottom wall 143b. For example, the cable end 151 is located at a position indicated by a solid line in FIG. When the cable end 151 is separated from the linear member 142, the cable end 151 becomes unstable, and the cable end 151 and the cable 150 may be displaced from the linear member 142 in the radial direction of the rotation center Ax. In this case, when the cable 150 comes into contact with the inner peripheral surface 141c1 of the through hole 141c provided in the rotating member 141, the outer peripheral surface 150b of the cable 150 may be damaged or worn. In some cases, countermeasures may be required, such as forming the 150 with a member having higher strength or performing a surface treatment on the outer peripheral surface 150b. The radial direction of the rotation center Ax is an example of an intersecting direction of the directions D1 and D2 (moving direction). The bottom wall 143b is an example of a contact portion.

Therefore, in the present embodiment, as shown in FIG. 2, the cover 111 is provided with a bottomed cylindrical wall 111b centered on the rotation center Ax. The cylindrical wall 111b extends along the directions D1 and D2, is opened toward the direction D1, and houses the cable end 151. The inner peripheral surface 111b1 of the cylindrical wall 111b faces the cylindrical surface of the flange 151b of the cable end 151 or the torus-shaped outer edge 151c of the outer half, and the cable end 151 moves in the direction intersecting the directions D1 and D2. Is restricted. In such a configuration, the radial gap δ1 of the rotation center Ax between the inner peripheral surface 111b1 and the outer edge 151c is equal to the rotational center Ax between the cable 150 and the inner peripheral surface 141c1 of the through hole 141c of the rotating member 141. Is set smaller than the radial gap d2. That is, when the diameter of the inner peripheral surface 111b1 of the cylindrical wall 111b is d11, the diameter of the outer edge 151c is d12, the diameter of the inner peripheral surface 141c1 of the through hole 141c is d21, and the diameter of the outer peripheral surface 150b of the cable 150 is d22, The following equation (1) holds between the gap δ1 and the gap δ2.
δ1 <δ2 (1)
Here, δ1 = d11−d12 and δ2 = d21−d22. The gap δ1 is an example of a first gap, and the gap δ2 is an example of a second gap. The outer edge 151c of the cable end 151 is an example of a first portion, and the outer peripheral surface 150b of the cable 150 (a portion located in the through hole 141c of the rotating member 141) is an example of a second portion. The cylindrical wall 111b and its inner peripheral surface 111b1 are an example of the limiting portion 180, and the inner peripheral surface 141c1 of the through hole 141c of the rotating member 141 is an example of the inner surface. Further, the outer edge 151c may be referred to as an outer peripheral surface or an outer edge.

  As described above, in the present embodiment, since the gap δ1 (first gap) is smaller than the gap δ2 (second gap), the cable 150 (operating member) is connected to the inner peripheral surface 141c1 of the through hole 141c of the rotating member 141. Before the contact, the cable end 151 (operating member) and the inner peripheral surface 111b1 of the cylindrical wall 111b contact. According to such a configuration, abrasion of the cable 150 due to contact between the cable 150 and the rotating member 141 can be suppressed.

  In the present embodiment, the translation member 142 and the cable end 151 are configured to be able to be separated. According to such a configuration, for example, the non-braking position Pr of the cable end 151 and thus the cable 150 can be set regardless of the position of the translation member 142.

  In the present embodiment, the inner peripheral surface 111b1 of the cylindrical wall 111b serving as the restricting portion 180 is a part of the cover 111 (housing 110) that movably accommodates the cable end 151 (operating member). According to such a configuration, for example, the electric actuator 100 (brake device 2) can be configured to be smaller in size than a configuration in which a restriction portion is provided other than the housing 110, or the manufacturing of the electric actuator 100 can be reduced. Advantages such as reduced labor and cost can be obtained.

  In the present embodiment, the gap δ1 (first gap) is a gap between the cable end 151 (fixing member) and the inner peripheral surface 111b1 (restriction portion 180) of the cylindrical wall 111b. According to such a configuration, the gap δ1 (first gap) can be set more easily or more accurately according to specifications such as the shape of the cable end 151. In addition, the restriction part 180 may be provided other than the housing 110. Specifically, for example, the side wall 143a of the rotation preventing member 143 may be further extended in the direction D2 than the position of the bottom wall 143b, and the inner peripheral surface of the extended portion may be used as the limiting portion.

[First Modification]
FIG. 3 is a cross-sectional view of the electric actuator 100A (brake device 2) according to the first modification at the same position as FIG. 2 showing the cable 150, the cable end 151, and the housing 110. As shown in FIG. 3, in the present modification, a buffer member 181 that covers the outer edge 151c is provided on the flange 151b of the cable end 151, and the buffer member 181 is connected to the inner peripheral surface 111b1 of the cylindrical wall 111b. Facing The buffer member 181 is made of, for example, a synthetic resin material having relatively high wear resistance.

  According to the present modification, abrasion of at least one of the cable end 151 (operation member) and the inner peripheral surface 111b1 (restriction portion 180) is suppressed.

[Second Modification]
FIG. 4 is a cross-sectional view of the electric actuator 100 </ b> B (brake device 2) of the third modified example, showing the cable 150, the cable end 151, and the housing 110 at the same position as in FIG. 2. As shown in FIG. 4, in this modification, a buffer member 182 is provided on a portion of the inner peripheral surface 111b1 of the cylindrical wall 111b facing the outer edge 151c of the flange 151b of the cable end 151. The inner peripheral surface 182a of the buffer member 182 faces the outer edge 151c of the cable end 151. The buffer member 182 is made of, for example, a synthetic resin material having relatively high wear resistance. In the present modification, the inner peripheral surface 182a is an example of the restricting portion 180.

  According to this modification as well, abrasion of at least one of the cable end 151 (operation member) and the inner peripheral surface 111b1 and generation of abnormal noise due to collision between the two are suppressed.

  As mentioned above, although the embodiment and the modification of the present invention were illustrated, the above-mentioned embodiment and the modification are examples, and are not intended to limit the scope of the invention. The above embodiments and modifications can be implemented in other various forms, and various omissions, replacements, combinations, and changes can be made without departing from the spirit of the invention. In addition, the specifications (structure, type, direction, type, size, length, width, thickness, height, number, arrangement, position, material, etc.) of each configuration, shape, etc. may be changed as appropriate. Can be implemented.

  For example, the operating member is not limited to a tension member such as a cable, but may be a pressing member such as a rod. The specifications such as the shape of the cable end (operating member) and the housing can be appropriately changed. Further, the buffer member may be provided on both the operating member and the restricting portion.

  Reference numeral 2: brake device, 3: brake shoe (braking member), 111: cover (housing), 111b1: inner peripheral surface (restriction portion), 120: motor, 140: motion conversion mechanism, 141: rotating member, 141c: through hole .., 141c1... Inner circumferential surface (inner surface), 142... Linear motion member, 143b... Bottom wall (contact portion), 150... Cable (operating member), 150b. Member, fixing member), 151c: outer edge (first portion), 180: restricting portion, 181, 182: buffer member, Pb: braking position, Pr: non-braking position, δ1: gap (first gap), δ2: gap (Second gap).

Claims (4)

Motor and
An actuating member that moves the braking member between a braking position in which the braking member is in a braking state and a non-braking position in which the braking member is in a non-braking state;
A rotating member that is provided with a through-hole that rotates in conjunction with the rotor of the motor and through which the operating member passes, and that linearly moves according to the rotation of the rotating member to move the operating member between the braking position and the non-braking position. A motion converting mechanism having a direct-acting member that is separate from the operating member by moving between the
A contact portion that restricts movement of the operating member from the braking position side to the non-braking position side in the translation direction of the translation member;
A limiting unit that limits movement of the operating member in a direction crossing the linear direction outside the through hole in a state where the operating member is separated from the contact portion and the linear member;
With
A first gap in the intersecting direction between the first portion facing the restriction portion and the restriction portion of the operation member, the first gap between the second portion passing through the through hole of the operation member and the inner surface of the through hole. A brake device that is smaller than a second gap in the intersecting direction therebetween.   The brake device according to claim 1, wherein a buffer member facing at least one of the first portion and the restriction portion is provided.   The brake device according to claim 1, wherein the restriction portion is a part of a housing that movably houses the operation member. The operating member has a cable and a fixing member fixed to the cable,
The brake device according to any one of claims 1 to 3, wherein the first gap is a gap between the first portion of the fixing member and the restriction portion.

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