JP7095535B2 - Brake device - Google Patents

Description

The present disclosure relates to a braking device.

Conventionally, it is provided with a rotary linear motion conversion mechanism having a rotary member that rotates in conjunction with the output shaft of the motor and a linear motion member that rotates linearly in response to the rotation of the rotary member, and the cable is connected by the linear motion member. A braking device that moves and brakes a brake shoe by pulling is known (for example, Patent Document 1).

Japanese Patent No. 6184873

In this type of braking device, it is not desirable for the cable to wear due to interference with other components.

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

The braking device of the present disclosure includes, for example, a motor, an operating member that moves the braking member between a braking position that puts the braking member in a braking state, and a non-braking position that puts the braking member in a non-braking state, and the motor. A rotating member that rotates in conjunction with the rotor and is provided with a through hole through which the operating member passes, and a rotating member that directly moves in response 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 that is separate from the actuating member, and restriction of movement of the actuating member from the braking position side to the non-braking position side in the linear motion direction of the linear motion member. A limiting portion that restricts the movement of the operating member in a direction intersecting the linear motion direction outside the through hole with the contact portion and the actuating member separated from the contact portion and the linear motion member. And, the first gap in the crossing direction between the first portion of the actuating member facing the restricting portion and the limiting portion passes through the through hole of the actuating member and the penetrating portion. It is smaller than the second gap in the above crossing direction with the inner surface of the hole.

According to such a configuration, for example, since the first gap is smaller than the second gap, the working member and the limiting portion come into contact with each other before the working member comes into contact with the inner surface of the through hole of the rotating member. Therefore, it is possible to suppress the wear of the operating member due to the contact between the operating member and the rotating member.

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

Hereinafter, exemplary embodiments and variations of the present invention will be disclosed. The configurations of the embodiments and modifications shown below, as well as the actions and results (effects) brought about by the configurations, are examples. The present invention can also be realized by configurations other than those disclosed in the following embodiments and modifications. Further, according to the present invention, it is possible to obtain at least one of various effects (including derivative effects) obtained by the configuration.

The following embodiments and modifications include similar components. Therefore, in the following, similar components may be given a common reference numeral and duplicate explanations may be omitted. Further, in the present specification, the ordinal numbers are given for convenience in order to distinguish parts, parts, etc., and do not indicate the priority order or the order.

Further, in each drawing, the direction in which the end portion 150a of the cable 150 approaches the braking member in the axial direction of the rotation center Ax of the rotation member 141 is indicated by the arrow D1, and is the axial direction of the rotation center Ax of the cable 150. The direction in which the end portion 150a is separated from the braking member is indicated by the arrow D2. Further, in the following, 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. Will be done. Further, the arrow Y indicates the outside in the vehicle width direction, and the arrow Z indicates the upper side of the vehicle.

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

The brake device 2 includes a wheel cylinder (not shown) operated by hydraulic pressure and a motor 120 operated by energization as an actuator for moving the brake shoe 3. The wheel cylinder and the motor 120 can each move two brake shoes 3. The wheel cylinder is used, for example, for braking during traveling, and the motor 120 is used, for example, for braking during parking. 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 in a posture intersecting the rotation center C of the wheel 1. That is, the backing plate 4 spreads 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 on both the outside and the inside of the backing plate 4 in the vehicle width direction. The backing plate 4 directly or indirectly supports each component of the braking device 2. That is, the backing plate 4 is an example of a support member. Further, the backing plate 4 is connected to a connecting member (not shown) with the vehicle body. The connecting member is, for example, a part of the suspension (for example, an arm, a link, a mounting member, etc.). 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 side opposite to the brake shoe 3. The electric actuator 100 includes a housing 110, a motor 120, a deceleration 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 aluminum alloy, or a synthetic resin material such as plastic. The housing 110 is configured by integrating a plurality of parts.

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 a control device to rotate the rotor and the output shaft. The motor 120 may also be referred to as 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 put the brake shoe 3 in the non-braking state into the braking state. The cable 150 penetrates 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 so as to be movable between the non-braking position Pr and the braking position Pb. The non-braking position Pr may also be referred to as the release position. The non-braking position Pr is separated from the braking position Pb in the direction D1 (lower part in FIG. 2), and the braking position Pb is separated from the non-braking position Pr in the direction D2 (upper part in FIG. 2). The directions D1 and D2 are the moving directions of the cable 150 and the cable end 151.

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

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

The shape of the flange 141b is an annular shape and a plate shape. The flange 141b projects radially outward from the peripheral wall 141a. A third gear 133 of the 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 reduction mechanism 130. The rotating member 141 rotates in conjunction with the rotor of the motor 120. The deceleration mechanism 130 may also be referred to as a rotation transmission mechanism.

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

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

A radial bearing 161 such as a slide bush or a roller bearing is provided between the outer circumference of the second extension portion 141a2 and the inner circumference of the through hole 112a of the base 112. Further, a thrust bearing 162 such as a roller bearing is provided between the end surface 141b1 in the direction D1 of the flange 141b and the end surface 112b in the direction D2 of the base 112. The rotating member 141 is rotatably supported by the base 112 around the center of rotation Ax via these radial bearings 161 and thrust bearings 162. The rotating member 141 is rotationally driven by the second gear 132 by meshing the second gear 132 of the reduction mechanism 130 with the third gear 133.

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

The linear motion member 142 has a side wall 142a and a flange 142b. The side wall 142a is arranged radially outward with respect to the rotating member 141 and extends axially. The side wall 142a surrounds the rotation center Ax and the rotation member 141, and the shape of the side wall 142a is a cylinder centered on the rotation center Ax. The side wall 142a may also be referred to as a peripheral wall. Inside the side wall 142a, a through hole 142c along the axial direction is provided. The rotating member 141 penetrates 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 from the flange 142b in the direction D2 and a second extension 142a2 extending from the flange 142b in the direction D1. 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 the end of the through hole 142c in the direction D1. The female screw 142d is provided in the section from the end of the through hole 142c in the direction D1 to the position where the through hole 142c is radially aligned with the flange 142b, and is not provided at the 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 arranged radially outward with respect to the flange 142b and extends axially. The side wall 143a surrounds the rotation center Ax and the rotation member 141, and the shape of the side wall 143a is tubular. The side wall 143a may also be referred to as a peripheral wall.

The detent member 143 is fixed to a housing 110 such as a cover 111 or a base 112. Therefore, it can be said that the detent member 143 is a part of the housing 110. Further, a minute 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 axial movement of the outer surface 142b1. That is, the detent member 143 can guide the linear motion member 142 along the axial direction (linear motion direction) while prohibiting the rotation of the linear motion member 142 around the rotation center Ax. The inner surface 143a1 may also be referred to as a guide portion.

At the end of the detent member 143 in the direction D2, a bottom wall 143b protruding inward in the radial direction from the side wall 143a is provided. The bottom wall 143b is provided with a through hole 143b1 that penetrates in the axial direction. The bottom wall 143b has an annular and plate-like shape, and may also be referred to as an inward flange. The inner edge of the through hole 143b1 is arranged radially outward from the side wall 142a of the linear motion member 142.

The cable 150 penetrates the through hole 141c of the rotating member 141 and extends in the axial direction. One end in the axial direction (not shown) is coupled to a movable member that operates the brake shoe 3. Further, the cable end 151 is coupled to the end portion 150a (upper end in FIG. 2) as the other end in the axial direction. The cable end 151 has a tubular portion 151a and a flange 151b. The cable end 151 is fixed to the cable 150 by crimping the tubular 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 detent member 143. The cable 150 and the cable end 151 can be made of, for example, a metallic material. The cable end 151, along with the cable 150, is an example of an actuating member. Further, the cable end 151 is an example of a fixing member.

The cable end 151 and the linear motion member 142 are not integrated and are configured to be axially separable. Here, the cable 150 is pulled in the direction in which the braking member is in the braking state (direction D1, downward in FIG. 2) by a return member (a urging member, an elastic member) such as a spring (not shown). The electric actuator 100 is configured so that the urging force of the return member always acts on the cable 150 within the movement range of the cable 150 (the range in which the brake is used). However, due to the configuration of the brake device 2, the urging force of the return member becomes smaller as the braking state approaches the non-braking state. Further, in the braking state, tension is generated in the cable 150 according to the rigidity of the drum brake. In such a configuration, a force is transmitted between the linear motion member 142 and the cable 150 via the cable end 151. Therefore, the cable end 151 can also be referred to as a transmission member (first transmission member).

The control device that controls the motor 120 is, for example, an ECU (electronic control unit). A part of the control device may be configured by hardware such as a central processing unit (CPU) or a controller that executes software, or the control device may be configured by hardware as a whole. The control device may also 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 rotating member 141 via the deceleration mechanism 130, and when the rotating member 141 rotates, the male screw 141d of the rotating member 141 and the female screw 142d of the linear motion member 142 The linear motion member 142 moves in the axial direction due to the meshing of the members and the limitation of the rotation of the outer surface 142b1 of the linear motion member 142 by the inner surface 143a1 of the detent member 143. 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 linear motion member 142.

The rotation of the output shaft of the motor 120 controlled by the control device in one direction (hereinafter referred to as braking rotation direction) causes the cable 150 to move in the direction D2, and when the braking member is in the braking state, the tension of the cable 150 is increased. This increases the rotational load of the motor 120, which in turn increases the drive current of the motor 120. Therefore, for example, the control device detects that the cable 150 has reached the braking position Pb because 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 controlled by the control device in the other direction (hereinafter referred to as the release rotation direction) causes the cable 150 to move from the braking position Pb to the direction D1, and the cable end 151 of the detent member 143. It moves to the non-braking position Pr in contact with the bottom wall 143b. In this state, the braking member is separated from the rotating member (not shown, for example, the 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 to the opposite side of the non-braking position Pr to the braking position Pb, i.e., in the direction D1. The detent member 143 is an example of a stopper. Further, the bottom wall 143b may also be referred to as a positioning portion for positioning the cable 150 at the non-braking position Pr, and the detent member 143 may also be referred to as a movement limiting 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 male screw 141d and the female screw 142d are engaged with each other and the rotation of the linear motion member 142 by the detent member 143. By stopping, the linear motion member 142 is separated from the cable end 151 in the direction D1. That is, in a state where the cable 150 is arranged 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 linear motion member 142 and the cable end 151.

The control device measures the time (rotation time) for rotating the motor 120 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 from the cable end 151 to the direction D1. The operation of the motor 120 is stopped at a position where the motor 120 is separated. At this time, the rotation time and the number of rotations are set between the stopped linear motion member 142 and another member (for example, the second gear 132, the flange 141b of the rotary member 141, etc.) separated from the linear motion member 142 in the direction D1. In other words, it is set so that it does not come into contact with 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 the winding center thereof is arranged along the rotation center Ax. The cable end 151 is urged in the direction D1 with respect to the housing 110. The coil spring 171 is a so-called compression spring that is incorporated in an elastically compressed state and is used in a compressed state in the operating range thereof. The coil spring 171 urges the cable end 151 in the direction D1 with respect to the cover 111 (housing 110) in both the non-braking position Pr and the braking position Pb when the cable 150 and the cable end 151 are in the non-braking position Pr. There is. The coil spring 171 may be a trapezoidal spring whose diameter gradually decreases toward the direction D1 or a trapezoidal spring whose diameter gradually decreases toward the direction D2. The coil spring 171 may also be referred to as a first urging member.

Further, the electric actuator 100 has a rotating member 141, a guide member 113 adjacent to the direction D1, and a ring 172 adjacent to the guide member 113 and the direction D1. The guide member 113 has an annular shape and guides the cable 150 inside the through hole 112a of the base 112. The guide member 113 is made of, for example, an elastomer or a synthetic resin material. Further, 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 stepped surface 112c of the base 112, and is incorporated 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 linear motion member 142 or the detent member 143 (housing 110). The ring 172 may also be referred to as a second urging member. In addition, instead of the ring 172, a second urging member having a form different from that of the elastomer, such as a disc spring or a coil spring, may be provided.

By the way, in the electric actuator 100, for the purpose of more reliably setting the brake shoe 3 in the non-braking state when the cable 150 is arranged at the non-braking position Pr, for example, dimensional tolerances and the like are taken into consideration in the length of the cable 150. The margin may be set, in other words, the length of the cable 150 may be 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 it sits (contacts) with the bottom wall 143b due to the above-mentioned margin of length of the cable 150. It may be separated from the bottom wall 143b. For example, the cable end 151 is located at the position shown by the solid line in FIG. The cable end 151 becomes unstable when it is separated from the linear motion member 142, and the cable end 151 and the cable 150 may be displaced from the linear motion member 142 in the radial direction of the rotation center Ax. In this case, if the cable 150 comes into contact with the inner peripheral surface 141c1 of the through hole 141c provided in the rotating member 141, there is a concern that the outer peripheral surface 150b of the cable 150 may be damaged or worn. Therefore, for example, the cable It may be necessary to take measures such as configuring the 150 with a member having higher strength or applying a surface treatment to the outer peripheral surface 150b. The radial direction of the rotation center Ax is an example of the crossing direction of the directions D1 and D2 (moving direction). The bottom wall 143b is an example of the contact portion.

Therefore, in the present embodiment, as shown in FIG. 2, the cover 111 is provided with a bottomed cylindrical cylindrical wall 111b centered on the rotation center Ax. The tubular wall 111b extends along directions D1 and D2 and is open toward direction D1 to accommodate the cable end 151. The inner peripheral surface 111b1 of the tubular wall 111b faces the cylindrical surface-shaped or torus-shaped outer edge 151c of the outer half of the flange 151b of the cable end 151, 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 the rotation center Ax between the cable 150 and the inner peripheral surface 141c1 of the through hole 141c of the rotating member 141. It is set to be smaller than the radial gap d2 of. That is, when the diameter of the inner peripheral surface 111b1 of the tubular 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 the first gap, and the gap δ2 is an example of the second gap. Further, the outer edge 151c of the cable end 151 is an example of the first portion, and the outer peripheral surface 150b of the cable 150 (of which the portion located in the through hole 141c of the rotating member 141) is an example of the second portion. The tubular wall 111b and its inner peripheral surface 111b1 are examples 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 also 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 (acting member) is aligned with the inner peripheral surface 141c1 of the through hole 141c of the rotating member 141. Before contacting, the cable end 151 (actuating member) and the inner peripheral surface 111b1 of the tubular wall 111b come into contact with each other. According to such a configuration, wear of the cable 150 due to contact between the cable 150 and the rotating member 141 can be suppressed.

Further, in the present embodiment, the linear motion member 142 and the cable end 151 are configured to be separable. 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 linear motion member 142.

Further, in the present embodiment, the inner peripheral surface 111b1 of the tubular wall 111b as the limiting portion 180 is a part of the cover 111 (housing 110) that movably accommodates the cable end 151 (actuating member). According to such a configuration, for example, the electric actuator 100 (brake device 2) can be configured to be smaller than the configuration in which the limiting portion is provided other than the housing 110, or the electric actuator 100 can be manufactured. There are merits such as labor and cost can be further reduced.

Further, 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 (restricted portion 180) of the tubular wall 111b. According to such a configuration, the gap δ1 (first gap) can be set more easily or more accurately depending on the specifications such as the shape of the cable end 151. The limiting portion 180 may be provided in addition to the housing 110. Specifically, for example, the side wall 143a of the detent member 143 may be extended further toward the direction D2 from 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) of 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 this modification, the flange 151b of the cable end 151 is provided with a cushioning member 181 that covers the outer edge 151c, and the cushioning member 181 is the inner peripheral surface 111b1 of the tubular wall 111b. Facing. The cushioning member 181 is made of, for example, a synthetic resin material having relatively high wear resistance.

According to this modification, wear of at least one of the cable end 151 (actuating 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 100B (brake device 2) of the third modification at the same position as FIG. 2, showing the cable 150, the cable end 151, and the housing 110. As shown in FIG. 4, in this modification, the cushioning member 182 is provided on the inner peripheral surface 111b1 of the tubular wall 111b at a portion facing the outer edge 151c of the flange 151b of the cable end 151. The inner peripheral surface 182a of the cushioning member 182 faces the outer edge 151c of the cable end 151. The cushioning member 182 is made of, for example, a synthetic resin material having relatively high wear resistance. In this modification, the inner peripheral surface 182a is an example of the limiting portion 180.

Also in this modification, the wear of at least one of the cable end 151 (actuating member) and the inner peripheral surface 111b1 and the generation of abnormal noise due to the collision between the two are suppressed.

Although the embodiments and modifications of the present invention have been exemplified above, the above-described embodiments and modifications are merely examples, and the scope of the invention is not intended to be limited. The above embodiments and modifications can be implemented in various other embodiments, and various omissions, replacements, combinations, and modifications can be made without departing from the gist of the invention. In addition, specifications such as each configuration and shape (structure, type, direction, type, size, length, width, thickness, height, number, arrangement, position, material, etc.) are changed as appropriate. Can be carried out.

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. In addition, specifications such as the cable end (actuating member) and the shape of the housing can be changed as appropriate. Further, the cushioning member may be provided on both the operating member and the limiting portion.

2 ... Brake device, 3 ... Brake shoe (braking member), 111 ... Cover (housing), 111b1 ... Inner peripheral surface (restricted part), 120 ... Motor, 140 ... Motion conversion mechanism, 141 ... Rotating member, 141c ... Through hole , 141c1 ... Inner peripheral surface (inner surface), 142 ... Linear member, 143b ... Bottom wall (contact portion), 150 ... Cable (acting member), 150b ... Outer peripheral surface (second part), 151 ... Cable end (operation) Member, fixing member), 151c ... outer edge (first part), 180 ... limiting part, 181,182 ... cushioning member, Pb ... braking position, Pr ... non-braking position, δ1 ... gap (first gap), δ2 ... gap (Second gap).

Claims (4)

With the motor
An actuating member that moves the braking member between a braking position that puts the braking member in the braking state and a non-braking position that puts the braking member in the non-braking state.
A rotating member that rotates in conjunction with the rotor of the motor and is provided with a through hole through which the operating member passes, and a rotating member that directly moves in response to the rotation of the rotating member to move the operating member into the braking position and the non-braking position. A motion conversion mechanism having a linear motion member that is moved between and separate from the actuating member, and
A contact portion that limits the movement of the actuating member from the braking position side to the non-braking position side in the linear motion direction of the linear motion member, and
A limiting portion that restricts the movement of the operating member in a direction intersecting the linear motion direction outside the through hole while the actuating member is separated from the contact portion and the linear motion member.
Equipped with
The first gap in the crossing direction between the first portion of the actuating member facing the limiting portion and the limiting portion is the second portion of the actuating member passing through the through hole and the inner surface of the through hole. A braking device that is smaller than the second gap in the crossing direction between them. The brake device according to claim 1, wherein a cushioning member facing the other is provided on at least one of the first portion and the limiting portion. The brake device according to claim 1 or 2, wherein the limiting portion is a part of a housing that movably accommodates the operating member. The actuating member includes 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 limiting portion.

Images