JP2020003047A - Brake device - Google Patents

Abstract

To obtain, for example, a brake device having a further improved and novel constitution which can further enhance the responsiveness of an electric brake.SOLUTION: A brake device has, for example, a first rotation transmission changeover mechanism for switching a rotation transmission state for transmitting rotation by friction in a state that a first transmission part and a second transmission part are pressed to each other in an axial direction and a block state, a rotation part rotating in conjunction with the second transmission part, and a linear motion part for obtaining a brake state by pressing an operation member for bringing a brake member into the brake state to a first direction by linearly moving to the first direction according to the rotation of the rotation part to a first rotation direction. The rotation part comprises a rotation linear motion conversion mechanism for pressing the second transmission part which is pressed to a side opposite to the first direction from the linear motion part to a side opposite to the first direction, and a second rotation transmission changeover mechanism which is constituted so as to transmittable in rotation to the first rotation direction to the second transmission part from the first transmission part, and non-transmittable in rotation to a rotation direction opposite to the first rotation direction to the second transmission part from the first transmission part.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a brake device.

  2. Description of the Related Art Conventionally, there has been known an electric brake that converts rotation of a rotating member driven by a motor into linear motion of a linear member, and presses a pad against a disk via a piston by the linear member (Patent Document 1).

Japanese Patent No. 4275310

  With this type of technology, it would be beneficial to have a more responsive electric brake.

  Therefore, one of the objects of the present invention is to obtain a brake device having a novel and improved configuration that enables, for example, a higher response in an electric brake.

  The brake device according to an embodiment of the present disclosure includes, for example, a first transmission unit that is rotated around a central axis extending in a first direction by a motor, and is adjacent to the first transmission unit so as to be separated from the first direction and around the central axis. A second transmission portion rotatable to the first transmission portion and the second transmission portion in a state where the first transmission portion and the second transmission portion are pressed against each other in the axial direction of the central axis. A first rotation transmission switching mechanism for switching between a rotation transmission state in which rotation is transmitted by friction between the first transmission section and a cutoff state in which rotation is not transmitted between the first transmission section and the second transmission section; and the second transmission section. A rotating part that rotates about the central axis in conjunction with the part, and an actuating member that brings the braking member into a braking state by directly moving in the first direction in accordance with the rotation of the rotating part in the first rotational direction. A linearly moving portion for pressing in the first direction to obtain a braking state; The portion is pressed in the direction opposite to the first direction from the translation portion moving in the first direction and presses the second transmission portion in the direction opposite to the first direction, a rotation / linear motion conversion mechanism, Rotation in the first rotation direction can be transmitted from one transmission unit to the second transmission unit, and rotation in the rotation direction opposite to the first rotation direction from the first transmission unit to the second transmission unit. And a second rotation transmission switching mechanism configured to be unable to transmit the rotation.

  In the above-described brake device, in a state where the first transmission unit and the second transmission unit are rotating in the rotation direction opposite to the first rotation direction at the time of braking release, the linear motion that occurs within a short time from the start of braking release When the pressing force in the axial direction is reduced between the first transmitting portion and the second transmitting portion with the release of the pressing by the portion, the first rotation transmission switching mechanism is in a cutoff state, whereby the rotation of the second transmitting portion is reduced. The linear motion part stops, and the linear motion in the direction opposite to the first direction of the linear motion part also stops. According to such a configuration, for example, the amount of movement of the direct acting portion in the direction opposite to the first direction at the time of braking release can be further reduced, so that the direct acting portion moves in the first direction at the next braking time. Can be further reduced, and a more responsive electric brake can be obtained.

  In the brake device, for example, the first rotation transmission switching mechanism and the second rotation transmission switching mechanism are arranged so as to be shifted in a radial direction of the central axis. According to such a configuration, for example, the first rotation transmission switching mechanism and the second rotation transmission switching mechanism can be more compactly arranged, and the brake device can be configured smaller.

  In the brake device, for example, the first rotation transmission switching mechanism is located radially outside the second rotation transmission switching mechanism. According to such a configuration, for example, since the moment arm of the torque transmission portion in the first rotation transmission switching mechanism can be made longer, the transmittable torque of the first rotation transmission switching mechanism can be further increased. .

  In the brake device, for example, the first transmission unit has a first contact surface, the second transmission unit has a second contact surface that contacts the first contact surface, and the first rotation transmission The switching mechanism transmits rotation by friction between the first contact surface and the second contact surface, and the first contact surface and the second contact surface have a partial conical surface shape. Have. According to such a configuration, for example, axial displacement (radial displacement) between the first transmission unit and the second transmission unit can be suppressed.

FIG. 1 is a schematic and exemplary cross-sectional view of the brake device of the first embodiment, showing a braking state. FIG. 2 is a schematic and exemplary cross-sectional view of the brake device according to the first embodiment, illustrating a non-braking state. FIG. 3 is a schematic and illustrative cross-sectional view of the brake device according to the first embodiment, illustrating a non-braking state when the lining is worn down more than in FIG. 1. FIG. 4 is a schematic and exemplary cross-sectional view of a brake device according to a modified example of the first embodiment, showing a braking state. FIG. 5 is a schematic and exemplary cross-sectional view of the brake device according to the second embodiment, illustrating a braking state. FIG. 6 is a schematic and exemplary cross-sectional view of the brake device according to the third embodiment, illustrating a braking state.

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

  A plurality of embodiments described below include similar components. Therefore, in the following, the same reference numerals are given to the same components, and the duplicate description will be omitted. In the embodiments, similar actions and effects based on similar components are obtained.

  In each figure, the first direction in which the piston 43 presses the pad 45 is the direction indicated by the arrow X, and is also referred to as the X direction. The second direction is a direction opposite to the direction indicated by the arrow X, and is referred to as a direction opposite to the X direction. Hereinafter, the axial direction of the central axis Ax of the rotation of the rotating member 51 is simply referred to as the axial direction, the radial direction of the central axis Ax is simply referred to as the radial direction, and the circumferential direction of the central axis Ax is simply referred to as the circumferential direction. Called.

[First Embodiment]
FIG. 1 is a cross-sectional view of the brake device 10 of the present embodiment in a braking state, FIG. 2 is a cross-sectional view of the brake device 10 in a non-braking state (retracted state), and FIG. FIG. 4 is a cross-sectional view of the brake device 10 in a non-braking state in which the lining 45b is worn.

  The brake device 10 illustrated in FIGS. 1 and 2 is a vehicular brake, and includes an ECU 11 (electronic control unit), a motor 20, a rotation transmission mechanism 30, and a caliper 40 including a rotation / linear motion conversion mechanism 50. , Is provided. The brake device 10 can operate not only as a hydraulic brake but also as an electric brake. The caliper 40 is a component of a hydraulic brake, and the ECU 11, the motor 20, the rotation transmission mechanism 30, the rotation / linear motion conversion mechanism 50, and the caliper 40 are components of an electric brake. The electric brake is a so-called electric parking brake. That is, the brake device 10 is configured such that the braking state by the electric brake function is maintained during parking. However, the electric brake may be operated at the time of running or at the time of temporary stop. The ECU 11 is an example of a control device.

  The operation of the motor 20 is controlled by the ECU 11. The rotation of the shaft 21 of the motor 20 is transmitted to the rotation member 51 of the rotation / linear motion conversion mechanism 50 via the rotation transmission mechanism 30 having a plurality of rotation elements such as gears 31 and 32. The rotation transmission mechanism 30 can also be called a speed reduction mechanism.

  The caliper 40 has a body (not shown), a cylinder 42, and a piston 43. The cylinder 42 is provided on the body. The cylinder 42 has a bottomed cylindrical shape opened in the X direction. The inner peripheral surface 42a of the cylinder 42 has a cylindrical inner surface shape centered on the central axis Ax.

  The piston 43 is accommodated in the cylinder 42 so as to be able to reciprocate along the central axis Ax. A liquid chamber R is provided in the cylinder 42. As the liquid pressure in the liquid chamber R increases, the piston 43 pushes the back plate 45a of the pad 45 in the X direction, and presses the lining 45b against a disk (not shown). As a result, a braking state by the hydraulic brake is obtained in which the wheels (not shown) of the vehicle that rotate integrally with the disk are braked. Specifically, the piston 43 has a cylindrical outer peripheral surface 43a and an end surface 43b opposite to the liquid chamber R (X direction). A minute gap (clearance) is set between the outer peripheral surface 43a of the piston 43 and the inner peripheral surface 42a of the cylinder 42, and the outer peripheral surface 43a is formed in a lubricated state where the working fluid exists in the clearance. It slides on the surface 42a. The seal 70 is interposed between the outer peripheral surface 43a and the inner peripheral surface 42a, and suppresses leakage of hydraulic fluid from the liquid chamber R via a gap. The pad 45 is an example of a braking member.

  Further, the seal 70 exerts an elastic force on the piston 43 in a direction of being drawn into the cylinder 42 (a direction opposite to the X direction) as the liquid pressure in the liquid chamber R decreases, and as shown in FIG. Is separated from the pad 45. This function is called a retract function. When the pressure of the piston 43 against the back plate 45a is released with a decrease in the liquid pressure of the liquid chamber R, the pressing of the lining 45b against the disk by the piston 43 is released, and the braking release state by the hydraulic brake is released. can get. Thus, the caliper 40 can operate as a hydraulic brake. The pad 45 is an example of a braking member.

  A rotation / linear motion conversion mechanism 50 is provided in the caliper 40, in this embodiment, in the cylinder 42. The rotation / linear motion conversion mechanism 50 has a rotation member 51 and a linear motion member 52. In the rotation / linear motion conversion mechanism 50, the male screw 51 a provided on the rotary member 51 and the female screw 52 a provided on the linear member 52 are engaged with each other, and the rotation of the linear member 52 is restricted. The linear motion of the linear motion member 52 according to the rotation of. In the example of FIG. 1, when the rotating member 51 rotates in the counterclockwise direction as viewed in the X direction, the linear motion member 52 moves in the X direction, and when the rotating member 51 rotates in the clockwise direction as viewed in the X direction. The translation member 52 moves in the direction opposite to the X direction. The rotation direction of the rotation member 51 corresponding to the movement of the translation member 52 in the X direction, that is, the counterclockwise direction when viewed in the X direction in the example of FIG. 1 is referred to as a first rotation direction. The rotating member 51 (a second member 512 thereof) is an example of a rotating portion, and the translation member 52 is an example of a translation portion.

  The translation member 52 has a cylindrical portion 52b and a projection 52c. The shape of the cylindrical portion 52b is a cylindrical shape centered on the central axis Ax. The female screw 52a is provided on the inner surface of the cylindrical portion 52b, and the protrusion 52c projects radially outward from the cylindrical portion 52b with respect to the central axis Ax.

  The rotation / linear motion conversion mechanism 50 is housed in a concave portion 43 c provided in the piston 43. The concave portion 43c is open in a direction opposite to the X direction. The concave portion 43c is a part of the liquid chamber R. The translation member 52 is provided so as to be movable in the axial direction of the central axis Ax in the concave portion 43c. The recess 43c is provided with a groove 43d extending in the axial direction of the central axis Ax. The groove 43d accommodates the projection 52c of the translation member 52 movably along the groove 43d. That is, the side surface of the groove 43d and the projection 52c of the translation member 52 constitute a rotation preventing mechanism for the translation member 52. In the present embodiment, the rotation of the piston 43 around the central axis Ax is restricted by the friction between the piston 43 and the seal 70 or the pad 45. As described above, the male screw 51a of the rotating member 51 meshes with the female screw 52a of the linear member 52, and the rotation of the projection 52c of the linear member 52 is restricted by the groove 43d of the piston 43. The linear motion member 52 can linearly move in the axial direction of the central axis Ax according to the rotation.

  When the rotation member 51 rotates in the first direction, the linear motion member 52 moves in the X direction, and when the piston 43 presses the back plate 45a in the X direction, the piston 43 pushes the lining 45b of the pad 45 against a disk (not shown). Press in the X direction. As a result, a braking state by the electric braking function in which the vehicle wheel (not shown) rotating integrally with the disk is braked is obtained. On the other hand, by the rotation of the rotating member 51 in the reverse direction, the linear motion member 52 moves in the opposite direction to the X direction, and when the pressing of the piston 43 against the back plate 45a is released, the lining 45b of the piston 43 against the disk is released. The pressing is released, whereby a release state (non-braking state) of the braking by the electric brake function is obtained. The piston 43 is an example of an operating member.

  However, in the present embodiment, the rotating member 51 has a first member 511 and a second member 512. The second member 512 is adjacent to the first member 511 in the X direction. The male screw 51a is provided on the second member 512. A friction clutch 61 and a one-way clutch 62 are provided between the first member 511 and the second member 512. The first member 511 is an example of a first transmission unit, and the second member 512 is an example of a second transmission unit.

  In the friction clutch 61, when the contact surface 511a of the first member 511 and the contact surface 512a of the second member 512 are pressing each other with a required pressing force in the axial direction, the first member 511 and the second member 512 can rotate integrally about the central axis Ax. This state may be referred to as a connection state. On the other hand, as in the state where the contact surface 511a and the contact surface 512a are separated from each other in the axial direction, the pressing force in the axial direction of the contact surface 511a and the contact surface 512a is smaller than the required pressing force. In a low state, rotation (torque) is not transmitted between the first member 511 and the second member 512. This state can be referred to as a shut-off state. The friction clutch 61 is an example of a first rotation transmission switching mechanism. The contact surface 511a is an example of a first contact surface, and the contact surface 512a is an example of a second contact surface.

  Although the one-way clutch 62 can transmit the rotation of the first member 511 in the first rotation direction to the second member 512, the one-way clutch 62 rotates the first member 511 in the second rotation direction opposite to the first rotation direction. Are not transmitted to the second member 512. One-way clutch 62 is an example of a one-way rotation transmission mechanism. In the present embodiment, the first member 511 and the second member 512 are configured to be slightly movable in the axial direction, but the one-way clutch 62 is configured so that the first member 511 and the second member 512 In the range of relative movement in the direction, the rotation of the first member 511 in the first rotation direction is transmitted to the second member 512 regardless of their relative positions, and the rotation of the first member 511 in the second rotation direction is performed. It is configured not to transmit to the second member 512. The one-way clutch 62 is an example of a second rotation transmission switching mechanism.

  As described above, in the present embodiment, since the first member 511 and the second member 512 constituting the rotating member 51 are connected via the friction clutch 61 and the one-way clutch 62, the brake device 10 is configured as follows. To work.

  During braking by the electric brake, the motor 20 rotates the first member 511 in the first rotation direction. Here, the one-way clutch 62 transmits the rotation in the first rotation direction to the second member 512 irrespective of the axial position of the first member 511 and the second member 512. Therefore, the second member 512 rotates in the first rotation direction, and the male screw 51a provided on the second member 512 rotates in the first rotation direction. Due to the engagement between the male screw 51a and the female screw 52a, the second member 512 receives a reaction force from the female screw 52a in a direction opposite to the X direction. Accordingly, the pressing force in the axial direction between the first member 511 and the second member 512 increases, and the friction clutch 61 is in a state where rotation (torque) can be transmitted, that is, a connected state. The second member 512 continues to rotate in the first rotation direction integrally with the first member 511, and accordingly, the translation member 52 linearly moves in the X direction. The linear motion member 52 moving in the X direction presses the pad 45 in the X direction via the piston 43 to press the pad 45 against the disk. Since the drive current of the motor 20 increases in accordance with the increase in the drive load of the motor 20, the ECU 11 stops the operation of the motor 20 when the drive current is equal to or exceeds the threshold value corresponding to the braking state by the electric brake. I do. Thereby, the braking state by the electric brake as shown in FIG. 1 is obtained. At this time, the translation member 52 is located at the braking position Pb.

  When the braking state by the electric brake is released, the motor 20 rotates the first member 511 in the second rotation direction. At the beginning of the rotation, the axial pressing force between the first member 511 and the second member 512 is relatively large, and the friction clutch 61 is in the connected state. It can rotate in the second rotation direction in conjunction therewith. The one-way clutch 62 does not transmit the rotation of the first member 511 in the second rotation direction to the second member 512.

  When the second member 512 rotates in the second rotation direction, the translation member 52 moves in the direction opposite to the X direction. As the translation member 52 moves in the direction opposite to the X direction, the pressing force of the translation member 52 on the piston 43 decreases. Accordingly, the pressing force in the axial direction between the first member 511 and the second member 512 decreases, and the friction clutch 61 changes from the connected state to the disconnected state. As a result, a retracted state (non-braking state, braking released state) as shown in FIG. 2 is obtained. At this time, the translation member 52 is located at the retract position Pr (standby position). In this embodiment, when the pressing force in the axial direction between the first member 511 and the second member 512, that is, the reaction force received from the pad 45 and the retracting force due to the seal 70 have almost disappeared, the linear motion member 52 Since it is located at the retract position Pr, the stroke δ from the braking position Pb to the retract position Pr has a magnitude including the amount of retraction due to the thermal expansion of the pad 45 and the elastic deformation of the seal 70. In the conventional structure, for example, the return stroke of the linear motion member 52 is not changed in accordance with the change in the retract amount, but the retract is assumed in consideration of the use conditions such as the variation in the specifications of the parts and the temperature. The number of rotations and the rotation time of the motor 20 are set so as to return the distance equal to or more than the maximum value of the amount. Therefore, the linear motion member 52 is returned from the braking position Pb by a distance longer than the originally required retracting amount, so that not only the movement from the braking position Pb to the retracting position Pr but also the movement relating to the braking, that is, from the retracting position Pr. Extra time was required to move to the braking position Pb. In this regard, according to this embodiment, the linear motion member 52 is returned from the braking position Pb to the retracted position Pr separated from the braking position Pb by the distance corresponding to the retracted amount at that time in the opposite direction of the X direction. And the retracting position Pr can be shorter than before. Further, as shown in FIGS. 2 and 3, regardless of the wear amount of the lining 45b of the pad 45, the linear motion member 52 moves between the braking position Pb and the retract position Pr with a stroke δ according to the retract amount. You can move. Thus, for example, even when the brake function due to the hydraulic pressure is reduced or impaired for some reason, the braking state can be more quickly obtained by the electric brake.

  In the present embodiment, the friction clutch 61 is located closer to the inner peripheral surface 42a of the cylinder 42 than the center axis Ax. Specifically, the first member 511 has a shaft 511b extending along the central axis Ax, and a flange 511c projecting radially outward from an end of the shaft 511b in the X direction. The second member 512 has a shaft 512b extending along the central axis Ax, and a flange 512c projecting radially outward from an end of the shaft 512b in the direction opposite to the X direction. The contact surface 511a, which is a component of the friction clutch 61, is provided at a radially outer end of the flange 511c, and the contact surface 512a, which is a component of the friction clutch 61, is radially outward of the flange 512c. It is provided at the end. The contact surfaces 511a and 512a are located closer to the inner peripheral surface 42a than the center axis Ax. Further, the contact surfaces 511a and 512a are located radially outside the male screw 51a and the female screw 52a. According to such a configuration, as the moment arm of the friction clutch 61 increases, the torque that can be transmitted by the friction clutch 61 can be set larger. Further, thereby, for example, the transmission torque by the friction clutch 61 becomes smaller than the friction torque between the male screw 51a and the female screw 52a, and it is possible to more reliably avoid a situation in which the friction clutch 61 idles. .

  The contact surface 511a is an outer surface of a cone centered on the center axis Ax, and the abutment surface 512a is an inner surface of a cone centered on the center axis Ax. The diameters of the contact surfaces 511a and 512a are smaller in the X direction. According to such a configuration, axial displacement (radial displacement) between the first member 511 and the second member 512 can be suppressed.

  In the present embodiment, the one-way clutch 62 has a known configuration such as a cam-type clutch or a sprag-type clutch, for example, and includes an outer ring that rotates integrally with one of the first member 511 and the second member 512. And an inner ring that rotates integrally with the other, and a connecting member that switches a connection state between the outer ring and the inner ring according to the rotation direction. In the present embodiment, the one-way clutch 62 has a cylindrical shape, and is located radially inward of the friction clutch 61 as shown in FIG. By arranging the friction clutch 61 and the one-way clutch 62 in the radial direction as described above, the friction clutch 61 and the one-way clutch 62 can be more efficiently arranged in the cylinder 42, and the cylinder 42 and the brake device 10 Can be prevented from increasing in size.

[Modification of First Embodiment]
FIG. 4 is a cross-sectional view of the brake device 10 of the present modified example in a braking state. In the present modification, the one-way clutch 62 is located radially outside the friction clutch 61. Also in this modification, the friction clutch 61 and the one-way clutch 62 can be arranged more efficiently in the cylinder 42 by disposing the friction clutch 61 and the one-way clutch 62 in the radial direction. 10 can be prevented from becoming large.

  As described above, in the present embodiment, the rotation member 51 has the first member 511 (first transmission unit) and the second member 512 (second transmission unit), and the rotation / linear motion conversion mechanism 50. Converts the rotation of the first member 511 (rotating part) of the rotating member 51 into the direct movement of the linear member 52 (linear part), and the friction clutch 61 connects between the first member 511 and the second member 512. The rotation / linear motion conversion mechanism 50 switches between a rotation transmission state in which the rotation is transmitted and a cut-off state in which the rotation is not transmitted between the first member 511 and the second member 512, and the rotation / linear motion conversion mechanism 50 switches the second member 512 ( The one-way clutch 62 converts the rotation of the second transmission portion) into the linear motion of the linear motion member 52, and transmits the rotation in the rotation direction (first rotation direction) during braking from the first member 511 to the second member 512. Possible and from the first member 511 to the second member 512 The rolling direction is impossible transmit the rotation in the opposite second rotational direction. In such a brake device 10, in a state where the first member 511 and the second member 512 are rotating in the second rotation direction at the time of release of braking, the linear motion member 52 that is generated within a short time from the start of release of braking is used. When the pressing force in the axial direction between the first member 511 and the second member 512 decreases with the release of the pressing, the friction clutch 61 is disconnected, whereby the rotation of the second member 512 stops and the linear motion The linear movement of the member 52 in the direction opposite to the X direction also stops. According to such a configuration, for example, the amount of movement of the translation member 52 in the direction opposite to the X direction at the time of braking release can be further reduced, so that the translation member 52 moves in the X direction at the next braking. Can be further reduced, and a more responsive electric brake can be obtained.

  In the present embodiment, for example, the friction clutch 61 and the one-way clutch 62 are arranged to be shifted in the radial direction. According to such a configuration, for example, the friction clutch 61 and the one-way clutch 62 can be arranged more compactly, and the brake device 10 can be configured smaller.

  In the present embodiment, for example, the friction clutch 61 is located radially outward of the one-way clutch 62. According to such a configuration, for example, the moment arm of the contact surfaces 511a, 512a (torque transmitting portion) of the friction clutch 61 can be made longer, so that the transmittable torque of the friction clutch 61 can be made larger. Can be.

  In the present embodiment, for example, the first member 511 has a contact surface 511a (first contact surface), and the second member 512 has a contact surface 512a (second contact surface) that contacts the contact surface 511a. ), The friction clutch 61 transmits rotation by friction between the contact surface 511a and the contact surface 512a, and the contact surface 511a and the contact surface 512a have a partially conical shape. According to such a configuration, for example, axial deviation (radial deviation) between the first member 511 and the second member 512 can be suppressed.

[Second embodiment]
FIG. 5 is a partial cross-sectional view of the brake device 10A according to the second embodiment. The first embodiment is an example of application to a disc brake, but the present embodiment is an example of application to a drum brake. The brake device 10A is fixed inside a backing plate (not shown) in the vehicle width direction. In the present embodiment, the linear motion member 52A of the rotation / linear motion conversion mechanism 50A moves (pulls) the cable 80 as the operating member in the X direction, so that a shoe (not shown) as a braking member enters a braking state. . In addition, when the translation member 52A moves (releases) the cable 80 in the direction opposite to the X direction, the shoe enters the non-braking state.

  The rotating member 51A has a first member 511A and a second member 512A. However, in the present embodiment, similarly to the first embodiment, the second member 512A is provided with the male screw 51a, and the cylindrical member of the linear motion member 52A is provided with the female screw 52a that meshes with the male screw 51a. I have. The linear motion member 52A is restricted by the case 12 from rotating around the central axis Ax, and is supported by the case 12 so as to be movable in the axial direction. A friction clutch 61A and a one-way clutch 62A are interposed between the first member 511A and the second member 512A in parallel. The operations of the friction clutch 61A and the one-way clutch 62A are the same as in the first embodiment. Note that the cable 80 passes through both the rotating member 51A and the linear moving member 52A in the axial direction.

  With the rotation of the first member 511A and the second member 512A in the first rotation direction, the translation member 52A moves in the X direction, and the end 52d in the X direction of the translation member 52A is fixed to the cable 80. The fixing member 81 is pressed in the X direction. As the cable 80 moves in the X direction together with the fixing member 81, the shoe is pressed against a drum (not shown), and the shoe enters a braking state. On the other hand, with the rotation of the first member 511A and the second member 512A in the second rotation direction, the translation member 52A, the fixed member 81, and the cable 80 move in the direction opposite to the X direction, and the shoe presses the drum. Is canceled, and the vehicle enters the non-braking state. However, also in the present embodiment, in the friction clutch 61A, when the required pressing force and thus the frictional force cannot be obtained between the contact surface 511a of the first member 511A and the contact surface 512a of the second member 512A, The rotation of the second member 512A stops, and the movement of the translation member 52A, the fixing member 81, and the cable 80 in the direction opposite to the X direction stops. Therefore, according to the present embodiment as well, the amount of movement of the translation member 52A in the direction opposite to the X direction at the time of braking release can be further shortened, and the translation member 52A moves in the X direction at the next braking. The amount can be shorter, and a more responsive electric brake can be obtained. The contact surfaces 511a and 512a intersect (are orthogonal to) the axial direction.

[Third embodiment]
FIG. 6 is a partial cross-sectional view of a brake device 10B according to the third embodiment. This embodiment is also an example of application to a drum brake as in the second embodiment. The brake device 10B is fixed inside a backing plate (not shown) in the vehicle width direction. In this embodiment, a shoe (not shown) as a braking member is brought into a braking state by the linear motion member 52B of the rotation / linear motion conversion mechanism 50B moving (pulling) the cable 80 as an operating member in the X direction. . In addition, the shoe is put into the non-braking state by the linear motion member 52B moving (releasing) the cable 80 in the direction opposite to the X direction.

  The rotating member 51B has a first member 511B and a second member 512B. In the present embodiment, unlike the first embodiment, a female screw 512d is provided in the second member 512B, and a male screw 52e that meshes with the female screw 512d is provided in the translation member 52B. The translation member 52B is restricted by the case 12 from rotating around the central axis Ax, and is supported by the case 12 so as to be movable in the axial direction. Further, between the first member 511B and the second member 512B, a friction clutch 61B and a one-way clutch 62B are interposed in parallel. The operations of the friction clutch 61B and the one-way clutch 62B are the same as in the first embodiment.

  With the rotation of the first member 511B and the second member 512B in the first rotation direction, the translation member 52B moves in the X direction, and moves the cable 80 in the X direction. When the cable 80 moves in the X direction, the shoe is pressed against a drum (not shown), and the shoe enters a braking state. On the other hand, with the rotation of the first member 511B and the second member 512B in the second rotation direction, the translation member 52B and the cable 80 move in the opposite direction to the X direction, the pressing state of the drum by the shoe is eliminated, and It becomes a braking state. However, also in the present embodiment, in the friction clutch 61B, when the required pressing force and thus the frictional force cannot be obtained between the contact surface 511a of the first member 511B and the contact surface 512a of the second member 512B, The rotation of the second member 512B stops, and the movement of the translation member 52B and the cable 80 in the direction opposite to the X direction stops. Therefore, according to the present embodiment as well, the amount of movement of the translation member 52B in the direction opposite to the X direction at the time of release can be further reduced, and thus the amount of movement of the translation member 52B in the X direction at the next braking. Can be made shorter, and a more responsive electric brake can be obtained.

  As described above, the embodiments of the present invention have been exemplified, but the above embodiments are merely examples, and are not intended to limit the scope of the invention. The above embodiment can be implemented in other various forms, and various omissions, replacements, combinations, and changes can be made without departing from the spirit of the invention. In addition, the specifications (structure, type, direction, shape, size, length, width, thickness, height, number, arrangement, position, material, etc.) of each configuration, shape, etc. may be changed as appropriate. Can be implemented. For example, the rotation / linear motion conversion mechanism and the rotation preventing mechanism can be realized as various configurations.

  For example, the second rotation transmission switching mechanism may include a latch that allows the first transmission unit and the second transmission unit to interlock only in one rotation direction, or an engagement member such as a mainspring. In addition, the rotating unit and the second transmitting unit only need to be linked, and may be separate members.

  10, 10A, 10B: brake device, 20: motor, 43: piston (operating member), 45: pad (braking member), 50, 50A, 50B: rotation / linear motion conversion mechanism, 52, 52A, 52B: linear member (Linear motion parts), 61, 61A, 61B ... friction clutch (first rotation transmission switching mechanism), 62, 62A, 62B ... one-way clutch (second rotation transmission switching mechanism), 511, 511A, 511B ... first member ( The first transmitting portion) 511a: contact surface (first contact surface), 512a: contact surface (second contact surface), 512, 512A, 512B ... second member (second transmitting portion, rotating portion), Ax: central axis, X: arrow (direction, first direction).

Claims (4)

A first transmission unit that is rotated around a central axis extended in a first direction by a motor, and a second transmission unit that is adjacent to the first transmission unit so as to be separated in the first direction and rotatable around the central axis. The first transmission unit and the second transmission unit transmit rotation by friction between the first transmission unit and the second transmission unit in a state where they are pressed against each other in the axial direction of the central axis. A first rotation transmission switching mechanism that switches between a rotation transmission state to be performed and a cutoff state in which rotation is not transmitted between the first transmission unit and the second transmission unit,
A rotating unit that rotates about the central axis in conjunction with the second transmitting unit, and the braking member is brought into a braking state by moving directly in the first direction in accordance with rotation of the rotating unit in the first rotational direction. A linearly moving portion that presses the operating member in the first direction to obtain a braking state, wherein the rotating portion presses the linearly moving portion that moves in the first direction in a direction opposite to the first direction. And presses the second transmission unit in the opposite direction of the first direction, a rotation / linear motion conversion mechanism,
Rotation in the first rotation direction can be transmitted from the first transmission portion to the second transmission portion, and the rotation direction is opposite to the first rotation direction from the first transmission portion to the second transmission portion. A second rotation transmission switching mechanism configured to be unable to transmit the rotation of
A braking device with   2. The brake device according to claim 1, wherein the first rotation transmission switching mechanism and the second rotation transmission switching mechanism are arranged to be shifted in a radial direction of the center axis.   The brake device according to claim 2, wherein the first rotation transmission switching mechanism is located radially outside of the second rotation transmission switching mechanism. The first transmission unit has a first contact surface,
The second transmission unit has a second contact surface that contacts the first contact surface,
The first rotation transmission switching mechanism transmits rotation by friction between the first contact surface and the second contact surface,
The brake device according to claim 1, wherein the first contact surface and the second contact surface have a partially conical shape.

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