JP6984406B2 - Brake device - Google Patents

Description

The present invention relates to a braking device.

Conventionally, it is provided with a motion conversion mechanism having a rotating member that rotates in conjunction with the output shaft of the motor and a linear moving member that moves linearly in response to the rotation of the rotating member, and the cable is pulled by the linear moving member. A brake device for moving and braking a brake shoe is known (for example, Patent Document 1 and Patent Document 2). In Patent Document 1, a linearly moving member having a male screw is linearly moving in response to rotation of a rotating member having a female screw. In Patent Document 2, a member that transmits the rotation of the output shaft of the motor is connected to the shaft end surface on the side far from the brake shoe of the rotating member.

Japanese Patent Publication No. 2014-504711 Germany DE102007002907A1 Gazette

In a brake device such as Patent Document 1, in which a linearly moving member having a male screw moves linearly in response to the rotation of a rotating member having a female screw, the diameter of the bearing supporting the rotating member tends to be large, whereby the brake is used. The device may become large.

Further, in a brake device such as Patent Document 2, in which the output shaft of the motor or a member that rotates in conjunction with the output shaft is connected to the axial end face of the rotating member of the motion conversion mechanism, the brake device is axially connected. In some cases, it became large.

Therefore, one of the problems of the present invention is to obtain a brake device having a novel configuration with less inconvenience, such as being able to be made smaller.

The brake device of the present invention is provided on, for example, a braking member that brakes the drum rotor by being pressed by a drum rotor that rotates integrally with the wheel, a backing plate that supports the braking member, and the backing plate. A braking device including an electric actuator for operating a braking member, wherein the electric actuator has a motor having a rotating output shaft and a male screw, and is interlocked with the output shaft to rotate around the axis of the male screw. A motion conversion mechanism including a rotating member that rotates and a linear moving member that has a female screw that meshes with the male screw and that moves linearly with the rotation of the rotating member, and a force that activates the braking member from the linear motion member. The electric actuator is attached to the backing plate with the motion conversion mechanism protruding from the surface of the backing plate opposite to the braking member, and the rotating member is attached to the backing plate. It is rotationally driven via a ring gear provided on the outer periphery of the rotating member and rotating in conjunction with the output shaft, and the male screw and the female screw mesh with each other on the opposite side of the ring gear from the braking member to operate the ring gear. One end of the member receives a force for operating the braking member from the linear motion member, and the other end of the operating member is configured to operate the braking member. The rotating member has a through hole along the axial center. Is provided, the actuating member penetrates the through hole, and one end thereof is located on the opposite side of the through hole from the braking member.

According to such a configuration, for example, a bearing that supports a rotating member is compared with a mode in which a linearly moving member having a male screw rotates linearly in response to rotation of the rotating member having a female screw as in Patent Document 1. Since the diameter of the electric actuator tends to be smaller, the electric actuator can be made smaller in the radial direction, and the smaller diameter of the bearing makes the sliding speed of the bearing at the same rotation speed lower, so that it is wear resistant. There is an advantage that durability such as sex is easily improved. Further, according to the above configuration, for example, as compared with the embodiment of Patent Document 2, in which the output shaft of the motor or a member that rotates in conjunction with the output shaft is connected to the axial end face of the rotating member of the motion conversion mechanism. Therefore, there is an advantage that the total length of the electric actuator tends to be shorter. Therefore, according to the above configuration, for example, in a brake device attached to the backing plate in a state where the electric actuator protrudes from the surface of the backing plate opposite to the braking member, the electric actuator is mounted on the vehicle due to the miniaturization of the electric actuator as described above. The advantage that it is easy to secure space and the advantage that durability can be improved can be obtained.

Further , according to such a configuration, for example, as compared with the mode in which the male screw and the female screw mesh with each other on the braking member side of the ring gear, the transmission position of the force between the operating member and the linear motion member is linearly moved. The member can be further away from the braking member. Therefore, for example, since it is not necessary to provide a relatively large body or case on the side close to the braking member of the brake device, the brake device can be configured to be smaller, and the vibration energy when the brake device vibrates can be increased. You can get the advantage of making it smaller.

Further , according to such a configuration, the operating member extends linearly closer to the axis of the rotating member, as compared with, for example, an embodiment in which the operating member is arranged so as to bypass the radial outer side of the ring gear. Since it can be arranged in a vertical state, it is possible to suppress the reaction force applied to the operation of the braking member from acting in the direction intersecting the axis. Therefore, for example, it is possible to suppress a force for tilting the rotating member, which contributes to miniaturization and improvement of durability of the support structure of the rotating member. Further, for example, it is possible to suppress the electric actuator from becoming larger in the radial direction as compared with the embodiment in which the operating member is arranged so as to bypass the radial outer side of the ring gear.

The brake device of the present invention is provided on, for example, a braking member that brakes the drum rotor by being pressed by a drum rotor that rotates integrally with the wheel, a backing plate that supports the braking member, and the backing plate. A brake device including an electric actuator for operating a braking member, which is provided with a transmission member, wherein the electric actuator has a motor having a rotating output shaft and a male screw in conjunction with the output shaft. A motion conversion mechanism including a rotating member that rotates around the axis of the male screw and a linear motion member that has a female screw that meshes with the male screw and that moves linearly with the rotation of the rotary member, and braking from the linear motion member. The electric actuator has an operating member that receives a force for operating the member, and the electric actuator is attached to the backing plate in a state where the motion conversion mechanism protrudes from the surface of the backing plate opposite to the braking member. The rotating member is rotationally driven via a ring gear provided on the outer periphery of the rotating member and rotating in conjunction with the output shaft, and the transmission member is fixed to the operating member and is different from the linear motion member. A force that is configured to be separable in the axial direction of the center and that operates the braking member from the linear motion member is transmitted to the operating member. According to such a configuration, for example, the linear motion member can be moved independently of the actuating member. In a more specific example, the overrun of the linear motion member can be tolerated without moving the actuating member and thus the braking member. Therefore, the control accuracy when controlling the movement amount of the linear motion member can be relaxed.

Further, the brake device includes, for example, a movement limiting member that limits the movement of the transmission member in the release direction in which braking by the braking member is released. According to such a configuration, it is possible to suppress the rotation of the rotating member from being transmitted to the transmitting member due to the contact of the transmitting member with the rotating member. Therefore, for example, the rotating member and the transmitting member slide with each other. It is possible to suppress the occurrence of an inconvenient situation such as wear.

Further, the brake device includes, for example, a control unit that controls the motor, and the control unit operates the motor so that the operating member moves in the release direction from the braking position in the braking state. The motor is controlled so that the rotation is stopped after the movement of the transmission member in the direction is restricted by the movement limiting member. According to such a configuration, for example, the operating member reaches the release position more reliably based on the driving time and the amount of rotation (rotation speed, rotation angle) of the motor required to move the operating member from the braking position to the release position. It is possible to operate or stop the motor in the activated state. Therefore, for example, there is an advantage that it is not necessary to particularly provide a sensor or the like for detecting the position of the operating member or the linear motion member when stopping the operation of the motor.

Further, in the brake device, for example, the movement limiting member has a guide portion that guides the linear moving member in the axial direction of the axial center while limiting the rotation of the linear moving member. According to such a configuration, for example, the brake device can be realized as a simpler configuration as compared with a configuration in which the detent member and the movement restricting member are separately provided.

FIG. 1 is an exemplary and schematic rear view of the brake device of the embodiment from the rear of the vehicle. FIG. 2 is an exemplary and schematic side view of the brake device of the embodiment from the outside in the vehicle width direction. FIG. 3 is an exemplary and schematic side view of the operation of the braking member by the moving mechanism of the braking device of the embodiment, and is a view in a non-braking state. FIG. 4 is an exemplary and schematic side view of the operation of the braking member by the moving mechanism of the braking device of the embodiment, and is a view in a braking state. FIG. 5 is an exemplary and schematic cross-sectional view of the electric actuator of the embodiment, and is a view in a non-braking state. FIG. 6 is an exemplary and schematic cross-sectional view of a part of the electric actuator of the embodiment, and is a view in a state where the operating member is in the braking position. FIG. 7 is an exemplary and schematic cross-sectional view of a part of the electric actuator of the embodiment, showing a state when the operating member reaches the release position from the braking position. FIG. 8 is an exemplary and schematic cross-sectional view of a part of the electric actuator of the embodiment, in a state where the operating member reaches the release position and the rotation of the motor is stopped. FIG. 9 is an exemplary and schematic perspective view of the movement limiting member included in the electric actuator of the embodiment. FIG. 10 is an exemplary and schematic perspective view of a linear motion member included in the electric actuator of the embodiment. FIG. 11 is an exemplary and schematic perspective view of a part of the motion conversion mechanism included in the electric actuator of the embodiment. FIG. 12 is an exemplary and schematic cross-sectional view of a part of the electric actuator of the first modification, and is a view in a non-braking state. FIG. 13 is an exemplary and schematic cross-sectional view of a part of the electric actuator of the second modification, and is a view in a non-braking state. FIG. 14 is an exemplary and schematic perspective view of a movement limiting member included in the electric actuator of the third modification.

Hereinafter, exemplary embodiments 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 (one end) of the cable 150 is separated from the braking member in the axial direction of the third rotation center Ax3 is indicated by the arrow D1 and is the axial direction of the third rotation center Ax3. The direction in which the end portion 150a approaches the braking member is indicated by the arrow D2. Further, in the following, unless otherwise specified, the axial direction of the third rotation center Ax3 is simply referred to as the axial direction, the radial direction of the third rotation center Ax3 is simply referred to as the radial direction, and the circumferential direction of the third rotation center Ax3. Is simply called the circumferential direction.

[Embodiment]
[Brake device configuration]
FIG. 1 is a rear view of the brake device 2 for a vehicle from the rear of the vehicle. FIG. 2 is a side view of the brake device 2 from the outside in the vehicle width direction. FIG. 3 is a side view showing the operation of the brake shoe 3 (braking member) by the moving mechanism 8 of the braking device 2, and is a view in a non-braking state. FIG. 4 is a side view showing the operation of the brake shoe 3 by the moving mechanism 8 of the brake device 2, and is a view in a braking state.

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. As shown in FIG. 2, the brake device 2 includes two brake shoes 3 which are separated from each other in the front-rear direction. As shown in FIGS. 3 and 4, the two brake shoes 3 extend in an arc shape along the inner peripheral surface 4a of the cylindrical drum rotor 4. The drum rotor 4 rotates integrally with the wheel 1 around the rotation center C along the vehicle width direction (Y direction). The brake device 2 moves the two brake shoes 3 so as to come into contact with the inner peripheral surface 4a of the cylindrical drum rotor 4. As a result, the friction between the brake shoe 3 and the drum rotor 4 brakes the drum rotor 4 and thus the wheel 1. The brake shoe 3 is an example of a braking member.

The brake device 2 includes a wheel cylinder 51 (see FIG. 2) operated by hydraulic pressure and a motor 120 operated by energization as an actuator for moving the brake shoe 3. The wheel cylinder 51 and the motor 120 can each move two brake shoes 3. The wheel cylinder 51 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.

As shown in FIGS. 1 and 2, the brake device 2 includes a disk-shaped backing plate 6. The backing plate 6 is provided in a posture intersecting the rotation center C. That is, the backing plate 6 spreads substantially along the direction intersecting the rotation center C, specifically, substantially along the direction orthogonal to the rotation center C. As shown in FIG. 1, the components of the brake device 2 are provided on both the outside and the inside of the backing plate 6 in the vehicle width direction. The backing plate 6 directly or indirectly supports each component of the braking device 2. That is, the backing plate 6 is an example of a support member. Further, the backing plate 6 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 opening 6b provided in the backing plate 6 shown in FIG. 2 is used for coupling with a connecting member. The brake device 2 can be used for both driving wheels and non-driving wheels. When the brake device 2 is used for the drive wheels, an axle (not shown) penetrates the opening 6c provided in the backing plate 6 shown in FIG.

[Brake shoe operation by wheel cylinder]
The wheel cylinder 51, the brake shoe 3, and the like shown in FIG. 2 are arranged outside the backing plate 6 in the vehicle width direction. The brake shoe 3 is movably supported by the backing plate 6. Specifically, as shown in FIG. 3, the lower end portion 3a of the brake shoe 3 is supported by the backing plate 6 (see FIG. 2) so as to be rotatable around the rotation center C11. The rotation center C11 is substantially parallel to the rotation center C of the wheel 1. Further, as shown in FIG. 2, the wheel cylinder 51 is supported by the upper end portion of the backing plate 6. The wheel cylinder 51 has two movable parts (pistons) (not shown) that can project in the vehicle front-rear direction (left-right direction in FIG. 2). The wheel cylinder 51 projects two movable parts in response to pressurization. The two protruding movable parts each push the upper end portion 3b of the brake shoe 3. Due to the protrusion of the two movable portions, the two brake shoes 3 rotate around the rotation center C11 (see FIGS. 3 and 4), and the upper end portions 3b move so as to be separated from each other in the vehicle front-rear direction. As a result, the two brake shoes 3 move radially outward of the rotation center C of the wheel 1. A strip-shaped lining 31 along the cylindrical surface is provided on the outer peripheral portion of each brake shoe 3. Therefore, as the two brake shoes 3 move outward in the radial direction of the rotation center C, the lining 31 and the inner peripheral surface 4a of the drum rotor 4 come into contact with each other, as shown in FIG. The friction between the lining 31 and the inner peripheral surface 4a brakes the drum rotor 4 and thus the wheel 1 (see FIG. 1). Further, as shown in FIG. 2, the brake device 2 includes a return member 32. The return member 32 is at a position where the two brake shoes 3 come into contact with the inner peripheral surface 4a of the drum rotor 4 when the operation of pushing the brake shoes 3 by the wheel cylinder 51 is released (braking position Psb, see FIG. 4). To a position where the drum rotor 4 does not come into contact with the inner peripheral surface 4a (non-braking position Psn, initial position, see FIG. 3). The return member 32 is, for example, an elastic member such as a coil spring, and exerts a force on each brake shoe 3 in a direction toward the other brake shoe 3, that is, a force in a direction away from the inner peripheral surface 4a of the drum rotor 4. give.

[Structure of moving mechanism and operation of brake shoe by moving mechanism]
Further, the brake device 2 includes the moving mechanism 8 shown in FIGS. 3 and 4. The moving mechanism 8 moves the two brake shoes 3 from the non-braking position Psn (FIG. 3) to the braking position Psb (FIG. 4) based on the operation of the electric actuator 100 (see FIG. 5) including the motor 120. The moving mechanism 8 is provided outside the backing plate 6 in the vehicle width direction. The moving mechanism 8 has a lever 81, a cable 150, and a strut 83. The lever 81 is located between the brake shoe 3L on the left side and the backing plate 6 in one of the two brake shoes 3, for example, in FIGS. It is provided so as to overlap in the axial direction. Further, the lever 81 is rotatably supported by the brake shoe 3L around the rotation center C12. The rotation center C12 is located at the end of the brake shoe 3L on the side away from the rotation center C11 (upper side in FIGS. 3 and 4), and is substantially parallel to the rotation center C11. The cable 150 moves the lower end portion 81a of the lever 81 on the side far from the rotation center C12, on the other hand, for example, in the direction approaching the brake shoe 3R on the right side in FIGS. 3 and 4. The cable 150 moves substantially along the backing plate 6. Further, the strut 83 is interposed between the lever 81 and a brake shoe 3R different from the brake shoe 3L on which the lever 81 is supported, and is stretched between the lever 81 and the other brake shoe 3R. Further, the connection position P1 between the lever 81 and the strut 83 is set between the rotation center C12 and the connection position P2 between the end portion 150b (the other end) of the cable 150 and the lever 81. The cable 150 is an example of an operating member that moves the brake shoe 3.

In such a moving mechanism 8, when the cable 150 is pulled and moves to the right in FIG. 4, the lever 81 moves in a direction approaching the brake shoe 3R (arrow a), the lever 81 moves via the strut 83. Press the brake shoe 3R (arrow b). As a result, the brake shoe 3R rotates from the non-braking position Psn (FIG. 3) around the rotation center C11 (arrow c in FIG. 4), and comes into contact with the inner peripheral surface 4a of the drum rotor 4 at the braking position Psb (FIG. 4). Move to. In this state, the connection position P2 between the cable 150 and the lever 81 corresponds to the power point, the rotation center C12 corresponds to the fulcrum, and the connection position P1 between the lever 81 and the strut 83 corresponds to the action point. Further, when the lever 81 moves to the right of FIG. 4, that is, in the direction in which the strut 83 pushes the brake shoe 3R while the brake shoe 3R is in contact with the inner peripheral surface 4a (arrow b), the strut 83 is stretched. As a result, the lever 81 rotates in the direction opposite to the direction in which the lever 81 moves, that is, counterclockwise in FIGS. 3 and 4, with the connection position P1 with the strut 83 as a fulcrum (arrow d). As a result, the brake shoe 3L rotates from the non-braking position Psn (FIG. 3) around the rotation center C11 and moves to the braking position Psb (FIG. 4) in contact with the inner peripheral surface 4a of the drum rotor 4. In this way, by the operation of the moving mechanism 8, the brake shoes 3L and 3R both move from the non-braking position Psn (FIG. 3) to the braking position Psb (FIG. 4). In the state after the brake shoe 3R comes into contact with the inner peripheral surface 4a of the drum rotor 4, the connection position P1 between the lever 81 and the strut 83 becomes a fulcrum. The amount of movement of the brake shoes 3L and 3R is very small, for example, 1 mm or less.

[Electric actuator]
As shown in FIG. 1, the electric actuator 100 is fixed to the backing plate 6 in a state of protruding from the inner surface 6a of the backing plate 6 in the vehicle width direction to the side opposite to the brake shoe 3.

FIG. 5 is a cross-sectional view of the electric actuator 100 in a non-braking state. The electric actuator 100 pulls the brake shoe 3 (braking member) via the cable 150 and moves the brake shoe 3 from the non-braking position to the braking position. The cable 150 penetrates the through hole 6d provided in the backing plate 6. The cable 150 is an example of an operating member.

As shown in FIG. 5, the electric actuator 100 includes a housing 110, a motor 120, a deceleration mechanism 130, a motion conversion mechanism 140, a cable 150, and a control device 200.

The housing 110 supports a motor 120, a deceleration mechanism 130, and a motion conversion mechanism 140. The housing 110 includes a body 112 (base), a lower case 113, an inner cover 114, and an upper case 115. These are integrated by, for example, a binder (not shown) such as a screw, insert molding, or the like. A storage chamber R surrounded by a wall portion 111 of the housing 110 is provided in the housing 110. The motor 120, the deceleration mechanism 130, and the motion conversion mechanism 140 are each housed in the storage chamber R and covered with the wall portion 111. The housing 110 may be referred to as a base, a support member, a casing, or the like. The configuration of the housing 110 is not limited to that exemplified here.

The body 112 may be made of a metal material such as, for example, an aluminum alloy. In this case, the body 112 can be manufactured, for example, by die casting. The lower case 113, the inner cover 114, and the upper case 115 may be made of, for example, a synthetic resin material.

The motor 120 is an example of an actuator and has a case 121 and a housing component housed in the case 121. The accommodating parts include, for example, an output shaft 122, a stator, a rotor, a coil, a magnet (not shown), and the like. The output shaft 122 projects from the case 121 in the direction D2 (to the right in FIG. 5) along the first rotation center Ax1 of the motor 120. The motor 120 is controlled by a control device such as an ECU (electronic control unit) to rotate the output shaft 122.

The reduction mechanism 130 includes a plurality of gears rotatably supported by the housing 110. The plurality of gears are, for example, the first gear 131, the second gear 132, and the third gear 133. The deceleration mechanism 130 may be referred to as a rotation transmission mechanism.

The first gear 131 rotates integrally with the output shaft 122 of the motor 120. The first gear 131 may be referred to as a drive gear.

The second gear 132 rotates around the second rotation center Ax2 parallel to the first rotation center Ax1. The second gear 132 includes an input gear 132a and an output gear 132b. The input gear 132a meshes with the first gear 131. The number of teeth of the input gear 132a is larger than the number of teeth of the first gear 131. Therefore, the second gear 132 is decelerated to a lower rotation speed than the first gear 131. The output gear 132b is located behind the direction D1 (to the left in FIG. 5) with respect to the input gear 132a. The second gear 132 may be referred to as an idler gear.

The third gear 133 rotates around the third rotation center Ax3 parallel to the first rotation center Ax1. The third gear 133 meshes with the output gear 132b of the second gear 132. The number of teeth of the third gear 133 is larger than the number of teeth of the output gear 132b. Therefore, the third gear 133 is decelerated to a lower rotation speed than the second gear 132. The third gear 133 may be referred to as a driven gear. The third gear 133 is an example of a ring gear. Here, the ring gear is an annular gear, and in this case, an external tooth. The configuration of the deceleration mechanism 130 is not limited to that exemplified here. The speed reduction mechanism 130 may be a rotation transmission mechanism other than the gear mechanism, such as a rotation transmission mechanism using a belt, a pulley, or the like.

The motion conversion mechanism 140 has a rotating member 141 and a linear motion member 142. FIG. 6 is an enlarged cross-sectional view of the motion conversion mechanism 140. The position of the cable 150 is different between FIGS. 5 and 6.

As shown in FIG. 6, 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 third rotation center Ax3. 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 is provided on the outer periphery of the flange 141b. That is, the rotating member 141 and the flange 141b may also be referred to as a driven portion or a third gear.

The peripheral wall 141a has a first extension portion 141a1 extending from the flange 141b in the direction D1 and a second extension portion 141a2 extending from the flange 141b in the direction D2. 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 third rotation center Ax3. The third rotation center Ax3 is an example of the axis.

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 body 112. Further, a thrust bearing 162 such as a roller bearing is provided between the end surface 141b1 in the direction D2 of the flange 141b and the end surface 112b in the direction D1 of the body 112. The rotating member 141 is rotatably supported by the body 112 around the third rotation center Ax3 via these radial bearings 161 and thrust bearings 162. The rotating member 141 is rotationally driven by the second gear 132 by meshing with the second gear 132 and the third gear 133.

The third gear 133 may be made of, for example, a synthetic resin material, and the disc 141b2 of the peripheral wall 141a and the flange 141b excluding the third gear 133 may 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 located radially outward with respect to the rotating member 141 and extends axially. The side wall 142a surrounds the third rotation center Ax3 and the rotating member 141, and the shape of the side wall 142a is a cylinder centered on the third rotation center Ax3. 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 D1 and a second extension 142a2 extending from the flange 142b in the direction D2. 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 D2. The female screw 142d is provided in the section from the end of the through hole 142c in the direction D2 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 D1. 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 located radially outward with respect to the flange 142b and extends axially. The side wall 143a surrounds the third rotation center Ax3 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 body 112 or an upper case 115. 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 third rotation center Ax3 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 while prohibiting the rotation of the linear motion member 142 around the third rotation center Ax3. The inner surface 143a1 is an example of a guide portion.

At the end of the direction D1 of the detent member 143, a plurality of protrusions 143b protruding inward in the radial direction from the side wall 143a are provided. The inner end of the protrusion 143b is located radially outward of the side wall 142a of the linear motion member 142. In addition, instead of the plurality of protrusions 143b, one annular protrusion (inward flange) along the circumferential direction may be provided.

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 (right end in FIG. 6) is coupled to a movable member that operates the brake shoe 3. Further, a cable end 144 is coupled to an end portion 150a (left end in FIG. 6) as the other end in the axial direction. The cable end 144 has a tubular portion 144a and a flange 144b. The cable 150 and the cable end 144 are coupled by crimping the tubular portion 144a from the outside. The flange 144b projects radially outward from the inner end of the side wall 142a of the linear motion member 142 and the protrusion 143b of the detent member 143.

The cable end 144 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 (direction D2) in which the braking member is in the braking state by an elastic member (urging member) such as a spring (not shown). Therefore, the cable end 144 is pressed against the linear motion member 142 in the direction D2. The electric actuator 100 is configured so that the urging force of the elastic member always acts on the cable 150 within the moving range of the cable 150 (the range in which the brake is used). Further, in the braking state, tension is generated in the cable 150 according to the rigidity of the braking device. In such a configuration, a force is transmitted between the linear motion member 142 and the cable 150 via the cable end 144. The cable end 144 is an example of a transmission member.

The control device 200 controls the motor 120. A part of the control device 200 may be configured by hardware such as a central processing unit (CPU) or a controller that executes software, or the control device 200 may be configured by hardware as a whole. .. The control device 200 is an example of a control unit.

In such a configuration, the rotation of the output shaft 122 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 142d. The linear motion member 142 moves in the axial direction due to the engagement with the engine 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 release position Pr along the axial direction with the movement of the linear motion member 142.

FIG. 6 is a cross-sectional view of the motion conversion mechanism 140 in a state where the cable 150 is in the braking position Pb, and FIG. 7 is a cross-sectional view of the motion conversion mechanism 140 when the cable 150 reaches the release position Pr from the braking position Pb. FIG. 8 is a cross-sectional view of the motion conversion mechanism 140 in a state where the cable 150 reaches the release position Pr and the rotation of the motor 120 is stopped.

The rotation of the output shaft 122 of the motor 120 controlled by the control device 200 in one direction (hereinafter referred to as braking rotation direction) causes the cable 150 to move in the direction D1, and when the braking member is in the braking state, the cable 150 The tension increases, which 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 200 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 122 is stopped, and the cable 150 is located at the braking position Pb (FIG. 6).

The rotation of the output shaft 122 of the motor 120 controlled by the control device 200 in the other direction (hereinafter referred to as the release rotation direction) causes the cable 150 to move from the braking position Pb (FIG. 6) to the direction D2, and the cable end 144. Moves to the release position Pr in contact with the protrusion 143b of the detent member 143 (FIG. 7). 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 protrusion 143b limits the movement of the cable end 144 in the direction D2 beyond the position of contact with the protrusion 143b. That is, the protrusion 143b is an example of a positioning portion for positioning the cable 150 at the release position Pr, and the detent member 143 is an example of a movement limiting member.

In the state where the cable 150 is located at the release position Pr, a gap g is provided in the axial direction between the rotating member 141 and the cable end 144. It should be noted that positioning of the cable 150 at the release position Pr by contact between the protrusion 143b and the cable end 144 is not essential. For example, the release position Pr may be determined by contact between the lever 81 and another member, and in this case, the protrusion 143b and the cable end 144 may not be in contact with each other.

As described above, in the present embodiment, the cable end 144 and the linear motion member 142 are not integrated and can be separated in the axial direction. Therefore, when the output shaft 122 of the motor 120 further rotates in the release rotation direction from the state where the cable 150 is positioned at the release 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 144 in the direction D2 (FIG. 8).

The control device 200 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 122, so that the linear motion member 142 is directed from the cable end 144. The operation of the motor 120 is stopped at the position shown in FIG. 8 separated from D2. 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 D2. In other words, it is set so that it does not come into contact with or interfere with other members.

9 is a perspective view of the detent member 143, FIG. 10 is a perspective view of the linear motion member 142, and FIG. 11 is a perspective view of the cable 150, the cable end 144, the detent member 143, and the linear motion member 142. , Is a perspective view in a state where the cable 150 is positioned at the release position Pr.

As shown in FIG. 9, the detent member 143 can be configured by press-molding or bending-molding a plate material of a metal material such as an iron-based material. The side wall 143a is formed in the shape of a hexagonal cylinder. The six inner surfaces 143a1 of the side wall 143a each have a planar shape orthogonal to the radial direction and extending in the axial direction. The end face 143b1 of the direction D1 of the protrusion 143b is substantially orthogonal to the axial direction.

Further, the protrusion 143b is formed by bending the protrusions protruding in the axial direction from the end portion of the side wall 143a in the direction D1 in the radial direction. Although the detent member 143 has three protrusions 143b, it may have two protrusions 143b or four or more protrusions 143b.

As shown in FIG. 10, the shape of the flange 142b provided on the linear motion member 142 is a hexagonal plate shape. Each of the six outer surfaces 142b1 of the flange 142b has a planar shape orthogonal to the radial direction and extending in the axial direction. Since the six inner surfaces 143a1 of the detent member 143 and the six outer surfaces 142b1 of the flange 142b face each other, the linear motion member 142 moves in the axial direction while the rotation around the third rotation center Ax3 is restricted. The linear motion member 142 may be constructed by forging a metal material such as, for example, an aluminum alloy.

As shown in FIGS. 9 and 7, the cable 150 is positioned at the release position Pr by abutting the cable end 144 flange 144b on the end surface 143b1 of the three protrusions 143b. The cable end 144 can be supported more stably by the three protrusions 143b.

As described above, in the present embodiment, the motion conversion mechanism 140 has the male screw 141d and is interlocked with the output shaft 122 to rotate around the third rotation center Ax3 (the axis of the male screw 141d). Includes a linear motion member 142 having a female thread 142d that meshes with a male thread 141d and that moves linearly with the rotation of the rotating member 141. Further, the electric actuator 100 is attached to the backing plate 6 in a state where the motion conversion mechanism 140 protrudes from the surface 6a on the backing plate 6 opposite to the brake shoe 3 (braking member), and the rotating member 141 is the rotating member. It is rotationally driven via a third gear 133 (ring gear) that is provided on the outer periphery of 141 and rotates in conjunction with the output shaft 122.

According to such a configuration, for example, the rotating member 141 is supported as compared with the mode in which the linear motion member having a male screw linearly moves in response to the rotation of the rotating member having a female thread as in Patent Document 1. Since the diameters of the radial bearing 161 and the thrust bearing 162 tend to be smaller, the support structure of the rotating member 141 can be made smaller, and the diameters of the radial bearing 161 and the thrust bearing 162 become smaller, so that the same rotation can be achieved. Since the sliding speed of the radial bearing 161 and the thrust bearing 162 in terms of speed is lower, there is an advantage that durability such as wear resistance can be easily improved. Further, according to the above configuration, for example, as compared with the embodiment of Patent Document 2, in which the output shaft of the motor or a member that rotates in conjunction with the output shaft is connected to the axial end face of the rotating member of the motion conversion mechanism. Therefore, there is an advantage that the total length of the electric actuator 100 tends to be shorter. Therefore, according to the above configuration, for example, in the brake device 2 attached to the backing plate 6 with the electric actuator 100 protruding from the surface 6a on the backing plate 6 opposite to the brake shoe 3, the electric motor as described above. The miniaturization of the actuator 100 has the advantage that it is easy to secure an in-vehicle space and the advantage that the durability can be improved.

Further, in the present embodiment, the male screw 141d and the female screw 142d mesh with each other on the opposite side of the brake shoe 3 of the third gear 133, and the end portion 150a (one end) of the cable 150 (actuating member) is from the linear motion member 142. The other end of the cable 150 is configured to operate the brake shoe 3 by receiving a force for operating the brake shoe 3. According to such a configuration, for example, the connection portion of the linear motion member 142 with the cable 150 can be further separated from the braking member as compared with the embodiment in which the male screw and the female screw mesh with each other on the braking member side of the ring gear. Therefore, the body 112 can be configured to be shorter in the axial direction than in the case where the connection portion of the linear motion member 142 with the cable 150 is provided at a position closer to the braking member. Since the body 112 is a portion that receives tension acting from the cable 150 in the braking state, the rigidity is set to be relatively high. Therefore, the longer the axial length of the body 112, the heavier the housing 110 and thus the electric actuator 100 tend to be. Further, since the body 112 serves as a mounting portion for the electric actuator 100, the longer the axial length of the body 112 is, the more the center of gravity of the electric actuator 100 is separated from the mounted member (for example, the backing plate). The vibration energy when the motor vibrates tends to be larger. In this regard, according to the above configuration, since the body 112 can be configured shorter, for example, the electric actuator 100 can be configured to be smaller or lighter, or vibration when the electric actuator 100 vibrates. Benefits such as lower energy can be obtained.

Further, in the present embodiment, for example, the cable 150 penetrates the through hole 142c provided in the linear motion member 142, and the end portion 150a (one end) opposite to the brake shoe 3 with respect to the through hole 142c. , Receives a force for operating the brake shoe 3 from the linear motion member 142. According to such a configuration, for example, the cable 150 is located at the third rotation center Ax3 (axis center of the rotation member 141) as compared with the embodiment in which the actuating member is arranged so as to bypass the radial outer side of the ring gear. Since it can be arranged in a linearly extended state in the vicinity, it is possible to suppress the reaction force applied to the operation of the brake shoe 3 from acting in the direction intersecting the third rotation center Ax3. Therefore, for example, the force for tilting the rotating member 141 can be suppressed, which contributes to miniaturization and improvement of durability of the support structure of the rotating member 141. Further, for example, it is possible to suppress the electric actuator 100 from becoming larger in the radial direction as compared with the embodiment in which the operating member is arranged so as to bypass the radial outer side of the ring gear.

Further, in the present embodiment, the cable end 144 (transmission member) fixed to the cable 150 is configured to be axially separable from the linear motion member 142. According to such a configuration, the linear motion member 142 can be moved independently of the cable 150. In a more specific example, the overrun of the linear motion member 142 can be tolerated without moving the cable 150 and thus the brake shoe 3. Therefore, the control accuracy when controlling the movement amount of the linear motion member 142 can be relaxed.

Further, in the present embodiment, the protrusion 143b of the detent member 143 (movement restricting member) restricts the movement of the cable end 144 in the direction D2. According to such a configuration, for example, the cable end 144 can be used not only for the transmission of force between the cable 150 and the linear motion member 142, but also for limiting the movement of the cable 150. Therefore, for example, it is possible to suppress the rotation of the rotating member 141 from being transmitted to the cable end 144 by the cable end 144 coming into contact with the rotating member 141. Therefore, for example, the rotating member 141 and the cable end 144 slide against each other. It is possible to suppress the occurrence of inconvenient situations such as movement and wear.

Further, in the present embodiment, the control device 200 controls the motor 120 so that the movement of the cable end 144 in the direction D2 (release direction) is restricted by the detent member 143 (movement limiting member) and then the rotation is stopped. do. According to such a configuration, for example, the cable 150 is released more reliably based on the drive time and the amount of rotation (rotation speed, rotation angle) of the motor 120 required to move the cable 150 from the braking position Pb to the release position Pr. It is possible to operate or stop the motor 120 while reaching the position Pr. Therefore, for example, there is an advantage that it is not necessary to particularly provide a sensor or the like for detecting the position of the cable 150 or the linear motion member 142 when stopping the operation of the motor 120.

Further, in the present embodiment, the detent member 143 has an inner surface 143a1 (guide portion) that guides the linear motion member 142 in the axial direction while limiting the rotation of the linear motion member 142. According to such a configuration, for example, the electric actuator 100 can be realized as a simpler configuration as compared with a configuration in which the detent member 143 and the movement limiting member are separately provided.

Further, in the present embodiment, the rotating member 141 is provided with a male screw 141d, and the linear motion member 142 is provided with a female screw 142d. According to such a configuration, as an example, the motion conversion mechanism 140 and thus the electric actuator 100 are realized by a relatively simple configuration by the rotating member 141 having the male screw 141d and the linear motion member 142 having the female screw 142d. be able to.

Further, in the present embodiment, a gap is provided in the axial direction between the rotating member 141 and the cable end 144 in a state where the cable 150 is located at the release position Pr. According to such a configuration, for example, the rotation of the rotating member 141 is suppressed from being transmitted to the cable 150 via the cable end 144. The same effect can be obtained even when a detent structure is provided between the cable end 144 and the detent member 143 to limit the relative rotation in the circumferential direction by being caught by unevenness or the like.

Further, in the present embodiment, the detent member 143 may be formed by press molding or bending molding of a metal material. According to such a configuration, for example, the detent member 143 can be configured relatively easily or at a lower cost.

[First modification]
FIG. 12 is a cross-sectional view of a part of the electric actuator 100A of this modified example. The configuration shown in FIG. 12 can be replaced with the corresponding portion of the electric actuator 100 of the above embodiment. In the motion conversion mechanism 140A of this modification, the center of the cable end 144A and thus the cable 150 is the third rotation center between the cable end 144A and the detent member 143A, and between the cable end 144A and the linear motion member 142A. A guide mechanism 145 that positions in the radial direction so as to be located at Ax3 is provided. The guide mechanism 145 includes an outer surface 144c1 of a protrusion 144c protruding from the flange 144b of the cable end 144A in the direction D2, an inner surface 143b2 (recess, an opening) of the protrusion 143b of the detent member 143A, and the direction D1 side of the linear motion member 142A. It is composed of an inner surface 142c1 provided at the tip of the above. The outer surface 144c1 is a conical outer surface whose diameter decreases toward the direction D2, and the inner surface 143b2 and the inner surface 142c1 are conical inner surfaces whose diameter decreases toward the direction D2. The outer surface 144c1 and the inner surface 143b2 are configured so that a minute gap is formed between the outer surface 144c1 and the inner surface 143b2 in a state where the flange 144b is in contact with the end surface 143b1 of the protrusion 143b. Further, the outer surface 144c1 and the inner surface 142c1 are configured so that a minute gap is formed between the outer surface 144c1 and the inner surface 142c1 in a state where the flange 144b is in contact with the tip of the linear motion member 142A on the direction D1 side. According to such a configuration, for example, it is possible to suppress the tension of the cable 150 from acting unbalancedly on the detent member 143A and the linear motion member 142A due to the inclination or bias of the cable 150. The protrusion (outer surface) may be provided on the detent member or the linear motion member, and the recess (opening, inner surface) may be provided on the transmission member. Further, as described above, the guide mechanism 145 does not have to include both the detent member 143A and the linear motion member 142A, and may include, for example, one of the detent member 143A and the linear motion member 142A.

[Second modification]
FIG. 13 is a cross-sectional view of a part of the electric actuator 100B of this modified example. The configuration shown in FIG. 13 can be replaced with the corresponding portion of the electric actuator 100 of the above embodiment. In this modification, the motion conversion mechanism 140B has a linear motion member 142B in which the cable end 144B is integrated. A disc spring 146 is provided between the flange 144b of the cable end 144B and the detent member 143 as a compression spring that generates a repulsive force in the axial direction. In this case, as the cable 150 approaches the release position Pr, the reaction force in the axial direction due to the disc spring 146 increases, and the torque of the motor 120 increases accordingly. Therefore, for example, the control device 200 detects that the cable 150 has reached the release position Pr 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. be able to.

[Third modification example]
FIG. 14 is a perspective view of a part of the electric actuator 100C of this modified example. The configuration shown in FIG. 14 can be replaced with the corresponding portion of the electric actuator 100 of the above embodiment. In this modification, the protrusion 143b of the detent member 143C functions as a leaf spring (compression spring) that generates a repulsive force in the axial direction. In this case, the protrusion 143b is elastically deformed so that the bending of the protrusion 143b becomes larger as the cable 150 approaches the release position Pr, whereby the reaction force in the axial direction by the protrusion 143b increases and the torque of the motor 120 increases. Therefore, even in this modification, the control device 200 detects that the cable 150 has reached the release position Pr because, for example, the drive current of the motor 120 exceeds the threshold value, and at that time, the drive current reaches the motor 120. Supply can be stopped. The repulsive force (elastic force, urging force) and the spring constant can be adjusted by the specifications (number, shape, size, thickness, number, etc.) of the protrusion 143b. In the example of FIG. 14, as an example, the thickness of the tip portion of the protrusion 143b is configured to be thinner than the thickness of the root portion.

The compression spring (urging member, elastic member) that generates a repulsive force in the axial direction with the movement of the cable 150 is not limited to a disc spring or a leaf spring, and may be, for example, a coil spring, an elastoma, or the like. .. Further, the compression spring may intervene in various places such as between the flange 142b of the linear motion member 142 and the flange 141b of the rotary member 141, or between the flange 142b of the linear motion member 142 and the body 112. Further, the various compression springs exemplified in the present specification may be provided in the electric actuator 100 in which the cable end 144 and the linear motion member 142 can be separated in the axial direction, as in the above embodiment. In this case, the compression spring can suppress the sticking of the male screw 141d and the female screw 142d due to biting, for example.

Although the embodiments of the present invention have been exemplified above, the above-described embodiment is an example and is not intended to limit the scope of the invention. The above embodiment can be implemented in various other embodiments, and various omissions, replacements, combinations, and changes 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.

Further, for example, the operating member does not have to penetrate the through hole of the rotating member. In this case, the actuating member may bypass the ring gear radially outward. The rotating member may not be provided with a through hole. Further, the male screw and the female screw may mesh with each other on the braking member side of the ring gear.

1 ... Wheel, 2 ... Brake device, 3 ... Brake shoe (braking member), 4 ... Drum rotor, 6 ... Backing plate, 6a ... Surface, 100, 100A, 100B, 100C ... Electric actuator, 120 ... Motor, 122 ... Output Shaft 133 ... Third gear (ring gear), 140, 140B ... Motion conversion mechanism, 141 ... Rotating member, 141c ... Through hole, 141d ... Male screw, 142, 142B ... Linear member, 142d ... Female screw, 143, 143A, 143C ... Anti-rotation member (movement limiting member), 143a1 ... Inner surface (guide portion), 144, 144A ... Cable end (transmission member), 150 ... Cable (actuator member), 150a ... End (one end), 150b ... End (end) The other end), 200 ... Control device (control unit), Ax3 ... Third rotation center (axis center), D2 ... Direction (release direction), Pb ... Braking position, Pr ... Release position.

Claims (7)

A braking member that brakes the drum rotor by being pressed by a drum rotor that rotates integrally with the wheel, a backing plate that supports the braking member, and an electric actuator that is provided on the backing plate and operates the braking member. It is a brake device equipped with
The electric actuator is
A motor with a rotating output shaft and
It includes a rotating member having a male screw and rotating around the axis of the male screw in conjunction with the output shaft, and a linear moving member having a female screw meshing with the male screw and rotating linearly with the rotation of the rotating member. Motion conversion mechanism and
An actuating member that receives a force for actuating the braking member from the linear motion member, and
Have,
The electric actuator is attached to the backing plate with the motion conversion mechanism protruding from the surface of the backing plate opposite to the braking member.
The rotating member is rotationally driven via a ring gear provided on the outer periphery of the rotating member and rotating in conjunction with the output shaft .
The male screw and the female screw mesh with each other on the opposite side of the ring gear from the braking member.
One end of the actuating member receives a force for actuating the braking member from the linear motion member, and the other end of the actuating member is configured to actuate the braking member.
The rotating member is provided with a through hole along the axis.
The actuating member penetrates the through hole and
One end of the through hole was located on the opposite side of the braking member.
Brake device. A braking member that brakes the drum rotor by being pressed by a drum rotor that rotates integrally with the wheel, a backing plate that supports the braking member, and an electric actuator that is provided on the backing plate and operates the braking member. It is a brake device equipped with
Equipped with a transmission member
The electric actuator is
A motor with a rotating output shaft and
It includes a rotating member having a male screw and rotating around the axis of the male screw in conjunction with the output shaft, and a linear moving member having a female screw meshing with the male screw and rotating linearly with the rotation of the rotating member. Motion conversion mechanism and
An actuating member that receives a force for actuating the braking member from the linear motion member, and
Have,
The electric actuator is attached to the backing plate with the motion conversion mechanism protruding from the surface of the backing plate opposite to the braking member.
The rotating member is rotationally driven via a ring gear provided on the outer periphery of the rotating member and rotating in conjunction with the output shaft.
The transmission member is fixed to the actuating member and is configured to be separable from the linear motion member in the axial direction of the axis, and transmits a force for actuating the braking member from the linear motion member to the actuating member.
Brake device. The male screw and the female screw mesh with each other on the opposite side of the ring gear from the braking member.
The brake device according to claim 2 , wherein one end of the actuating member receives a force for actuating the braking member from the linear motion member, and the other end of the actuating member actuates the braking member. A claim provided with a transmission member fixed to the actuating member, configured to be separable from the linear motion member in the axial direction of the axis, and transmitting a force for actuating the braking member from the linear motion member to the actuating member. Item 1. The brake device according to item 1. The brake device according to claim 2 or 4, further comprising a movement limiting member that restricts the movement of the transmitting member in the release direction in which braking by the braking member is released. A control unit for controlling the motor is provided.
When the motor is operated so that the operating member moves in the release direction from the braking position in the braking state, the control unit rotates after the movement of the transmission member in the release direction is restricted by the movement limiting member. The brake device according to claim 5, wherein the motor is controlled so that the motor is stopped. The brake device according to claim 5 or 6, wherein the movement limiting member has a guide portion for guiding the linear moving member in the axial direction of the axial center while limiting the rotation of the linear moving member.

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