JP7347086B2 - brake device - Google Patents

Description

The present disclosure relates to a brake device.

Conventionally, a brake shoe is equipped with a rotating member that rotates in conjunction with the output shaft of a motor, and a linearly moving member that moves linearly in accordance with the rotation of the rotating member, and the brake shoe is moved by pulling a cable with the linearly moving member. A brake device that performs braking is known (for example, Patent Document 1).

In Patent Document 1, a disc spring is compressed between a linearly moving member and a rotating member, so that a load is applied to the motor when the linearly moving member returns from a braking position to a non-braking position (rotating member side). It is now possible to As a result, for example, mutual interference between the linearly moving member and the rotating member during the return operation is suppressed, and the screw mechanisms of the linearly moving member and the rotating member are prevented from becoming tightly connected and becoming difficult to return. can do.

JP2019-006223A

However, in the above conventional technology, when the disc spring is axially misaligned in the radial direction and comes into contact with the inner peripheral surface of the recess that accommodates the disc spring (the inner peripheral surface of the peripheral wall of the rotating member), this causes the disc spring to There was a risk that the posture of the compressor would not be stable, making it difficult to obtain the desired compression reaction force.

Therefore, one of the problems of the present disclosure is to obtain a brake device with a novel configuration that is less inconvenient and can suppress the occurrence of a fastened state of the screw mechanism, for example.

The brake device of the present disclosure includes, for example, an actuating member that moves the braking member between a braking position in which the braking member is in a braking state and a non-braking position in which the braking member is in a non-braking state, and a male thread and a female thread that engage with each other. The shaft has a shaft on which one of the threads is provided, a flange projecting outward in the radial direction from the shaft, and a peripheral wall projecting from the peripheral edge of the flange in a first direction along the axial direction of the shaft, and the above-mentioned A bottomed recess surrounded by the flange and the peripheral wall and opening in the first direction is provided, and a rotating member that rotates in conjunction with the rotor of the motor, and the other of the male and female threads are provided, and the rotating member The operating member moves linearly in the first direction in response to normal rotation of the rotating member, and moves linearly in a second direction opposite to the first direction in response to the reversal of the rotating member to move the operating member between the braking position and the braking position. and a non-braking position spaced apart in the second direction; and an outer peripheral portion that extends along the circumferential direction, faces the inner peripheral surface of the peripheral wall, and is spaced apart from the inner peripheral surface in a state of maximum axis deviation in the radial direction with respect to the male thread. an elastic member configured in an annular shape and capable of being sandwiched between the flange and the translational member as the translational member moves in the second direction.

According to the above-mentioned brake device, for example, changes in the posture of the elastic member due to contact between the outer circumferential portion of the elastic member and the inner circumferential surface of the peripheral wall are suppressed, and as a result, variations in compression reaction force due to changes in the posture of the elastic member, etc. is unlikely to occur. Therefore, with such a configuration, for example, the desired compression reaction force of the elastic member can be easily obtained, and the fastened state in which one screw of the rotating member and the other screw of the linearly moving member are firmly connected can be achieved. This can be more reliably suppressed.

FIG. 1 is an exemplary and schematic rear view of the brake device according to the embodiment as seen from the rear of the vehicle. FIG. 2 is an exemplary and schematic cross-sectional view of the electric actuator of the brake device according to the embodiment, in a non-braking state. FIG. 3 is an enlarged view of the rotation-to-linear motion conversion mechanism of FIG. 2. FIG. 4 is an enlarged view of the rotation-to-linear motion conversion mechanism of FIG. 2, showing a state in which the translation member is in contact with the elastic member.

Exemplary embodiments of the invention are disclosed below. The configuration of the embodiment shown below and the effects and effects brought about by the configuration are merely examples. The present invention can be realized by configurations other than those disclosed in the following embodiments. Further, according to the present invention, it is possible to obtain at least one of various effects (including derivative effects) obtained by the configuration.

Note that in this specification, ordinal numbers are used only to distinguish parts, members, regions, positions, directions, etc., and do not indicate order or priority. Furthermore, all drawings are schematic and illustrative.

[Embodiment]
FIG. 1 is a rear view of a vehicle brake device 2 from the rear of the vehicle. Note that in FIG. 1, arrow Y indicates the outward direction in the vehicle width direction, and arrow Z indicates the upward direction of the vehicle.

As shown in FIG. 1, the brake device 2 is housed inside the peripheral wall 1a of the cylindrical wheel 1. The brake device 2 is a so-called drum brake. The brake device 2 includes two brake shoes 3 spaced apart from each other in the front and rear. The two brake shoes 3 extend in an arc shape along the inner peripheral surface of a cylindrical drum rotor (not shown).

The drum rotor rotates together with the wheel 1 around a rotation center C along the vehicle width direction (direction Y). The brake device 2 moves two brake shoes 3 so as to come into contact with the inner peripheral surface of a cylindrical drum rotor. As a result, the drum rotor and eventually the wheel 1 are braked by the friction between the brake shoes 3 and the drum rotor. The brake shoe 3 is an example of a braking member.

The brake device 2 includes, as an actuator for moving the brake shoes 3, a wheel cylinder (not shown) operated by hydraulic pressure, and a motor 120 operated by electricity. The wheel cylinder and motor 120 can each move two brake shoes 3. The wheel cylinder is used, for example, for braking while the vehicle is running, and the motor 120 is used, for example, for braking when parking. That is, the brake device 2 is an example of an electric parking brake. Note that the motor 120 may be used for braking while the vehicle is running.

The brake device 2 includes a disk-shaped backing plate 4. The backing plate 4 is provided in a posture intersecting the rotation center C of the wheel 1. That is, the backing plate 4 extends substantially along a direction intersecting the rotation center C, specifically, substantially along a direction perpendicular to the rotation center C.

The components of the brake device 2 are provided on both the outside and inside of the backing plate 4 in the vehicle width direction. The backing plate 4 supports each component of the brake device 2 directly or indirectly. Further, the backing plate 4 is connected to a connection member (not shown) with the vehicle body. The connection member is, for example, a part of the suspension (for example, an arm, a link, a mounting member, etc.). Note that the brake device 2 can be used for both driving wheels and non-driving wheels.

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

FIG. 2 is a cross-sectional view of the electric actuator 100 in a non-braking state. In each of the following figures, the direction in which the end 150a of the cable 150 approaches the brake shoe 3 in the axial direction of the rotation center Ax1 of the rotating member 141 is indicated by an arrow D1, and the direction in which the end 150a of the cable 150 approaches the brake shoe 3 is indicated by an arrow D1, and The direction in which the end 150a of the cable 150 moves away from the brake shoe 3 is indicated by an arrow D2.

Direction D2 is an example of a first direction, and direction D1 is an example of a second direction. In addition, in the following description, unless otherwise stated, the axial direction of the rotation center Ax1 is simply referred to as the axial direction, the radial direction of the rotation center Ax1 is simply referred to as the radial direction, and the circumferential direction of the rotation center Ax1 is simply referred to as the circumferential direction. It is called.

The electric actuator 100 pulls the brake shoe 3 in the direction D2 via the cable 150 to bring the brake shoe 3, which is in a non-braking state, into a braking state. The cable 150 passes through a through hole (not shown) provided in the backing plate 4. Cable 150 is an example of an actuation member.

As shown in FIG. 2, the cable 150 is provided movably between a non-braking position Pr and a braking position Pb. The non-braking position Pr may also be referred to as a release position. The non-braking position Pr is spaced apart from the braking position Pb in the direction D1 (downward in FIG. 2), and the braking position Pb is spaced apart from the non-braking position Pr in the direction D2 (upward in FIG. 2). Directions D1 and D2 are directions in which the cable 150, cable end 151, and linear motion member 142 move.

The housing 110 accommodates a motor 120, a deceleration mechanism 130, a rotation-to-linear conversion mechanism 140, an elastic member 170, which will be described later, and the like. The housing 110 is configured by integrating a plurality of parts, such as a cover 111 and a base 112, for example. The housing 110 may be made of a metal material such as iron or aluminum alloy, or a synthetic resin material such as plastic.

The motor 120 includes a case 121 and housing components housed within the case 121. The housing components include, for example, in addition to the output shaft 122, a stator, a rotor, a coil, a magnet, etc. (all not shown). Output shaft 122 is part of the rotor and protrudes from case 121 in direction D1. Motor 120 is controlled by a controller and rotates a rotor and output shaft 122. The motor 120 may also be referred to as an actuator or a rotation source.

Reduction mechanism 130 includes a plurality of gears rotatably supported by housing 110. The plurality of gears are, for example, first gear 131, second gear 132, and third gear 133. First gear 131, second gear 132, and third gear 133 rotate in conjunction with output shaft 122. The speed reduction mechanism 130 may also be referred to as a rotation transmission mechanism or the like.

The first gear 131 rotates around the rotation center Ax3 together with the output shaft 122 of the motor 120. The rotation center Ax3 is parallel to the rotation center Ax1. First gear 131 may be referred to as a drive gear. The first gear 131, the second gear 132, and the third gear 133 may be made of, for example, a metal material such as iron or an aluminum alloy, or a synthetic resin material such as plastic. Note that each gear 131 to 133 may include a portion made of metal material and a portion made of synthetic resin material.

The second gear 132 rotates around a rotation center Ax2 that is parallel to the rotation centers Ax1 and Ax3. Second gear 132 includes an input gear 132a and an output gear 132b. Input gear 132a meshes with first gear 131. The number of teeth of input gear 132a is greater than the number of teeth of first gear 131. Therefore, the second gear 132 is decelerated to a lower rotational speed than the first gear 131. Output gear 132b is positioned offset in direction D1 with respect to input gear 132a. Second gear 132 may be referred to as an idler gear.

The third gear 133 meshes with the output gear 132b of the second gear 132 and rotates around the rotation center Ax1. The number of teeth of the third gear 133 is greater than the number of teeth of the output gear 132b. Therefore, the third gear 133 is decelerated to a lower rotational speed than the second gear 132. Third gear 133 may be referred to as a driven gear. Note that the configuration of the speed reduction mechanism 130 is not limited to this example. The speed reduction mechanism 130 may be a rotation transmission mechanism other than a gear mechanism, such as a rotation transmission mechanism using a belt, a pulley, or the like.

FIG. 3 is an enlarged view of the rotation-to-linear motion conversion mechanism 140 of FIG. 2. As shown in FIGS. 2 and 3, the rotation-linear motion conversion mechanism 140 includes a rotating member 141, a linear motion member 142, and a rotation prevention member 143.

The rotating member 141 includes, for example, a shaft 141a, a flange 141b, and a peripheral wall 141e. The shaft 141a has a cylindrical shape centered on the rotation center Ax1. A through hole 141c along the axial direction is provided inside the shaft 141a. The rotation center Ax1 is an example of a central axis.

The shape of the flange 141b is annular and plate-like. The flange 141b projects radially outward from the shaft 141a. A peripheral wall 141e is provided at the peripheral edge of the flange 141b.

The peripheral wall 141e has a cylindrical shape centered on the rotation center Ax1. The peripheral wall 141e protrudes from the flange 141b in the direction D2. The above-mentioned third gear 133 is provided on the outer peripheral surface 141e1 of the peripheral wall 141e. The rotation of the rotor of the motor 120 and the output shaft 122 is transmitted to the rotating member 141 via the speed reduction mechanism 130. The rotating member 141 rotates in conjunction with the rotor of the motor 120.

Further, the rotating member 141 is provided with a bottomed recess 141f that is surrounded by the flange 141b and the peripheral wall 141e and is open in the direction D2. An end surface 141b2 of the flange 141b in the direction D2 has a circular and planar shape, and forms the bottom surface of the bottomed recess 141f. The inner circumferential surface 141e2 of the peripheral wall 141e has a cylindrical shape and constitutes the inner circumferential surface of the bottomed recess 141f. An elastic member 170, which will be described later, is housed in the bottomed recess 141f.

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

A male thread 141d is provided on the outer peripheral surface 141a3 of the first extending portion 141a1. The center of the male screw 141d is the rotation center Ax1. The rotation center Ax1 may also be referred to as an axis.

A radial bearing 161, such as a slide bush or a roller bearing, is provided between the outer periphery of the second extending portion 141a2 and the inner periphery of the through hole 112a of the base 112 shown in FIG. 2, for example. Further, a thrust bearing 162 such as a roller bearing is provided between the end surface 141b1 of the flange 141b in the direction D1 and the end surface 112b of the base 112 in the direction D2.

The rotating member 141 is rotatably supported by the base 112 via the radial bearing 161 and the thrust bearing 162 around the rotation center Ax1. The rotating member 141 is rotationally driven by the second gear 132 due to engagement between the second gear 132 and the third gear 133 of the reduction mechanism 130 .

The third gear 133 is made integrally with the rotating member 141 from a metal material such as iron or aluminum alloy, for example. Note that the third gear 133 is not limited to this example, and may be made of a synthetic resin material such as plastic, for example. In this case, the third gear 133 may be integrated with the rotating member 141 made of a metal material by insert molding or the like.

As shown in FIG. 3, the translation member 142 includes, for example, a side wall 142a and a flange 142b. The side wall 142a is arranged radially outward with respect to the rotating member 141 and extends in the axial direction. The side wall 142a surrounds the rotation center Ax1 and the rotating member 141.

The side wall 142a has a cylindrical shape centered on the rotation center Ax1. The side wall 142a may also be referred to as a peripheral wall. A through hole 142c along the axial direction is provided inside the side wall 142a. The rotating member 141 passes through the through hole 142c in the axial direction.

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

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

A female thread 142d that engages with a male thread 141d of the rotating member 141 is provided on the inner surface of the through hole 142c. The female thread 142d is provided adjacent to the end of the through hole 142c in the direction D1. The female thread 142d is provided in a section from the end of the through hole 142c in the direction D1 to a position radially aligned with the flange 142b, and is not provided in the end of the through hole 142c in the direction D2. Further, the flange 142b is surrounded by a rotation preventing member 143 shown in FIG.

The rotation prevention member 143 has a side wall 143a. The side wall 143a is arranged radially outward with respect to the above-mentioned flange 142b and extends in the axial direction. The side wall 143a surrounds the rotation center Ax1 and the linear motion member 142, and the side wall 143a has a tubular shape. The side wall 143a may also be called a peripheral wall.

The rotation prevention member 143 is fixed to the housing 110. Specifically, the detent member 143 has a flange 143c provided with an opening (not shown). The flange 143c is connected to the base 112 by a bolt passing through the opening being fixed to the base 112 while in contact with an end surface (not shown) of the base 112.

Further, a minute gap is provided between the inner surface 143a1 of the side wall 143a and the outer surface 142b1 of the flange 142b in a mutually parallel state, and both the outer surface 142b1 and the inner surface 143a1 extend in a direction intersecting the circumferential direction. .

Therefore, the rotation of the outer surface 142b1 around the rotation center Ax1 is restricted by the inner surface 143a1, and thereby the rotation of the linear motion member 142 is restricted by the rotation stopper 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 become an obstacle to the movement of the outer surface 142b1 in the axial direction. That is, the anti-rotation member 143 can guide the translation member 142 along the axial direction (linear motion direction) while prohibiting rotation of the translation member 142 about the rotation center Ax1. The inner surface 143a1 may also be referred to as a guide portion.

A bottom wall 143b that protrudes radially inward from the side wall 143a is provided at the end of the rotation prevention member 143 in the direction D2. A through hole 143b1 passing through in the axial direction is provided in the bottom wall 143b. The bottom wall 143b has an annular and plate-like shape, and may also be referred to as an inward flange. The inner edge of the through hole 143b1 is arranged radially outward from the side wall 142a of the translation member 142.

The cable 150 passes through the through hole 141c of the rotating member 141 and extends in the axial direction. One axial end (not shown) is coupled to a movable member that operates the brake shoe 3. Further, a cable end 151 is coupled to an end 150a (upper end in FIG. 2) serving as the other end in the axial direction. Cable 150 and cable end 151 may be made of metal material, for example.

The cable end 151 has a cylindrical portion 151a and a flange 151b. The cable end 151 is fixed to the cable 150 by crimping the cylindrical portion 151a from the outside. The flange 151b projects outward in the radial direction from the side wall 142a of the translational member 142 and the through hole 143b1 of the rotation prevention member 143. Cable end 151, together with cable 150, is an example of an actuating member. Further, the cable end 151 is an example of a fixing member.

The cable end 151 and the linear motion member 142 are not integrated, but are configured to be able to be separated from each other in the axial direction. Here, the cable 150 is pulled in the direction D1 (downward in FIG. 2) in which the brake shoe 3 is in a non-braking state by a return member (biasing member, elastic member) such as a spring (not shown). The electric actuator 100 is configured such that the biasing force of the return member always acts on the cable 150 within the range of movement of the cable 150 (range where the brake is used).

However, due to the structure of the brake device 2, the biasing force exerted by the return member becomes smaller as the braking state approaches the non-braking state. Furthermore, in the braking state, tension is generated in the cable 150 in accordance with the rigidity of the drum brake. In such a configuration, force is transmitted between the linear motion member 142 and the cable 150 via the cable end 151. Therefore, the cable end 151 may also be referred to as a transmission member.

A control device that controls the motor 120 is, for example, an ECU (electronic control unit). A part of the control device may be configured by hardware such as a central processing unit (CPU) or a controller that executes software, or the control device may be configured entirely by hardware. The control device may also be referred to as 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 thread 141d of the rotating member 141 and the female thread 142d of the linear motion member 142 are rotated. The translational member 142 moves in the axial direction due to the engagement with the rotation stopper member 143 and the restriction of rotation of the outer surface 142b1 of the translational member 142 by the inner surface 143a1 of the detent member 143. Therefore, as the linear motion member 142 moves, the cable 150 moves between the braking position Pb and the non-braking position Pr along the axial direction.

Due to the rotation of the output shaft 122 of the motor 120 in one direction (hereinafter referred to as the braking rotation direction) controlled by the control device, the cable 150 moves in the direction D2, and when the brake shoe 3 enters the braking state, the cable 150 moves in the direction D2. The tension increases, which increases the rotational load on the motor 120 and, in turn, increases the drive current of the motor 120.

Therefore, the control device detects that the cable 150 has reached the braking position Pb, for example, when the drive current of the motor 120 exceeds a threshold value, and stops supplying the drive current to the motor 120 at that point. As a result, the rotation of the output shaft 122 is stopped, and the cable 150 is located at the braking position Pb.

Due to the rotation of the output shaft 122 of the motor 120 in the other direction (hereinafter referred to as the release rotation direction) controlled by the control device, the cable 150 moves from the braking position Pb to the direction D1, and the cable end 151 moves toward the rotation prevention member 143. It moves to the non-braking position Pr where it comes into contact with the bottom wall 143b of the brake. In this state, the brake shoe 3 is separated from the drum rotor, and the electrical braking state by the electric actuator 100 is released.

The bottom wall 143b restricts the cable end 151 from moving beyond the bottom wall 143b to the side opposite to the braking position Pb from the non-braking position Pr, that is, in the direction D1. That is, the rotation preventing member 143 is an example of a stopper. The bottom wall 143b may also be referred to as a positioning portion that positions the cable 150 at the non-braking position Pr, and the rotation prevention member 143 may also be referred to as a movement restriction member.

Further, as described above, in this embodiment, the cable end 151 and the linear motion member 142 are not integrated, but can be separated from each other 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 disposed at the non-braking position Pr, the male thread 141d and the female thread 142d engage with each other, and the locking member 143 causes the linear motion member 142 to rotate. Due to the rotation stop, the translation member 142 is separated from the cable end 151 in the direction D1. That is, when the cable 150 is placed in the non-braking position Pr and the operation of the motor 120 is stopped, a gap is created between the linear motion member 142 and the cable end 151 in the axial direction.

The control device measures the time (rotation time) for rotating the motor 120 from the state where the cable 150 is in the braking position Pb and the number of rotations of the output shaft 122, so that the linear motion member 142 moves from the cable end 151 in the direction D1. The operation of the motor 120 is stopped at the position where the motor 120 is separated from the motor 120. At this time, the rotation time and the number of rotations are determined so as to ensure that there is a gap between the stopped translational member 142 and the flange 141b of the rotational member 141 that is distant from the translational member 142 in the direction D1. It is set so that there is no contact or interference.

Further, the electric actuator 100 includes a rotating member 141 and a guide member 113 adjacent to the rotating member 141 in the direction D1. The guide member 113 has an annular shape and guides the cable 150 inside the through hole 112a of the base 112. The guide member 113 is made of, for example, elastomer or synthetic resin material.

As described above, the rotation-to-linear motion conversion mechanism 140 has a screw mechanism including a male screw 141d and a female screw 142d. In the rotation-to-linear motion conversion mechanism 140 having a screw mechanism, for example, if the linear motion of the linear motion member 142 is restricted for some reason, there is a possibility that the male thread 141d and the female thread 142d may be in a fastened state. For example, if the linear member 142 moves in the direction D1 beyond the normal movable range in FIGS. 2 and 3 due to a malfunction of the control device or the like and comes into contact with the flange 141b of the rotating member 141, the fastened state occurs.

In this case, the engaged state can be canceled by rotating the rotor of the motor 120 in a rotation direction opposite to the rotation direction before the engaged state. However, the more tightly it is tightened, the more the torque of the motor 120 needs to increase, and the power consumption of the motor 120 increases accordingly. Moreover, the size of the motor 120 is likely to increase on the premise of releasing such a fastened state, which in turn becomes a factor in increasing the size of the brake device 2.

Therefore, in this embodiment, a fail-safe structure is provided in which an elastic member 170 is arranged between the flange 141b of the rotating member 141 and the end portion 142f of the linearly moving member 142 in the direction D1. When the linear motion member 142 is returned too far in the direction D1, the elastic member 170 is sandwiched between the end portion 142f and the flange 141b, thereby reducing the fastening torque between the male thread 141d and the female thread 142d. . The end portion 142f is an example of a first end portion. A failsafe structure may also be referred to as a buffer structure.

FIG. 4 is an enlarged view of the rotation-to-linear motion conversion mechanism 140 of FIG. 2, with the translation member 142 in contact with the elastic member 170. As shown in FIGS. 3 and 4, the elastic member 170 has, for example, an annular and plate-like shape centered on the rotation center Ax1. The elastic member 170 is made of a thermoplastic elastomer such as polyester elastomer, and has a flat plate shape in its free state.

Note that the elastic member 170 is not limited to this example, and may have a C-shape when viewed in the axial direction, for example. Further, it may be in the shape of a plate that is not flat in the free state, or it may not be in the shape of a plate. Further, for example, the cross-sectional shape on the virtual plane extending in the axial direction is not limited to a rectangle as in the above embodiment in the free state, but may be a square, a polygon other than a quadrilateral, a circle, an ellipse, etc. It's okay.

The elastic member 170 has an inner peripheral part 170a, an outer peripheral part 170b, and two end surfaces 170c and 170d. The inner peripheral part 170a and the outer peripheral part 170b have a cylindrical shape, and the end surfaces 170c and 170d have an annular and planar shape. The end surface 170c extends between the ends of the inner circumference 170a and the outer circumference 170b in the direction D2, and the end surface 170d extends between the ends of the inner circumference 170a and the outer circumference 170b in the direction D1.

The elastic member 170 is accommodated in the bottomed recess 141f of the rotating member 141. The outer peripheral part 170b faces the inner peripheral surface 141e2 of the peripheral wall 141e, and the inner peripheral part 170a faces the outer peripheral surface 141a3 of the male thread 141d. In this embodiment, the diameter d1 of the outer circumference 170b is set smaller than the diameter d3 of the inner circumference 141e2, and the diameter d2 of the inner circumference 170a is set larger than the diameter d4 of the male screw 141d (shaft 141a). There is.

Specifically, the outer peripheral portion 170b has two states: a state P1 in which the elastic member 170 is arranged concentrically with respect to the male thread 141d (see FIG. 4), and a state P1 in which the elastic member 170 is axially misaligned in the radial direction with respect to the male thread 141d. The dimensions are set such that the inner peripheral portion 170a does not contact the inner peripheral surface 141e2 in a range between a state P2 in which the inner peripheral portion 170a contacts the male screw 141d.

In this embodiment, such a configuration suppresses a change in the posture (tilt) and wear of the elastic member 170 due to contact between the outer circumferential portion 170b and the inner circumferential surface 142e. Variations in the compression reaction force due to this are less likely to occur. State P1 is an example of a minimum axis deviation state, and state P2 is an example of a maximum axis deviation state. Further, a state between state P1 and state P2 is an example of an intermediate axis misalignment state.

Further, the shaft 141a is provided with an incompletely threaded portion 141ac facing the inner peripheral portion 170a. The incompletely threaded portion 141ac is provided at an enlarged diameter portion located at the end of the male thread 141d in the direction D1, and is connected to the root portion 141ab of the shaft 141a adjacent to the flange 141b in the direction D2 and the complete thread of the male thread 141d. It is located between the

The incompletely threaded portion 141ac is inclined so as to expand radially outward from the root portion 141ab toward the male thread 141d. That is, the diameter d4 of the male thread 141d is larger than the diameter of the root portion 141ab. The shaft 141a is provided with a recess 141ad adjacent to the flange 141b in the direction D2 by the root portion 141ab and the incompletely threaded portion 141ac.

Further, in the present embodiment, the axial length of the recess 141ad formed by the root portion 141ab and the incompletely threaded portion 141ac is set to be larger than the axial thickness W1 of the elastic member 170 (see FIG. 3). has been done. Therefore, when the elastic member 170 attempts to move in the direction D2 in a state in which the inner circumferential portion 170a is inside the recessed portion 141ad (for example, the above-mentioned state P2), the elastic member 170 is caught by the incompletely threaded portion 141ac. Thereby, movement of the elastic member 170 in the direction D2 with respect to the bottomed recess 141f is suppressed. The incompletely threaded portion 141ac is an example of a hook portion.

In this embodiment, the axial thickness W1 of the elastic member 170 is set to be larger than one pitch of the male thread 141d. This prevents the elastic member 170 from entering the spiral groove of the male thread 141d and being held in an inclined position. The incompletely threaded portion 141ac is also referred to as the end of the fully threaded portion of the male thread 141d, and the root portion 141ab is also referred to as a constricted portion or the like.

Further, the end portion 142f of the translational member 142 is provided with an end surface 142f1 and an inclined surface 142f2. The end surface 142f1 has a planar and annular shape perpendicular to the axial direction, and faces the end surface 170c of the elastic member 170.

In the present embodiment, the entire surface of the end surface 142f1 is in contact with the end surface 170c of the elastic member 170 in all states of the above-described state P1, state P2, and states between state P1 and state P2. configured to be possible. This suppresses variations in the compression reaction force in the axial direction due to the generation of regions in the elastic member 170 that do not come into contact with the end surface 142f1.

The inclined surface 142f2 is configured, for example, by chamfering a corner of the end surface 142f1. The inclined surface 142f2 is inclined so as to expand radially outward in the direction D2. In this embodiment, wear of the end surface 170c of the elastic member 170 is suppressed by eliminating the corners of the end surface 142f1 by the inclined surface 142f2. The inclined surface 142f2 is also referred to as a C-plane, a tapered surface, or the like.

Further, in this embodiment, the area (width) of the end surface 142f1 is made relatively small by the above-mentioned inclined surface 142f2. As a result, the opposing area (contact area) between the end surface 142f1 and the end surface 170c of the elastic member 170 is reduced, which in turn suppresses the linear motion member 142 from leaving in the direction D2 while in contact with (sticking to) the end surface 170c. It can be done. Note that the end surface 170c and the end surface 170d of the elastic member 170 may be subjected to surface treatment.

As described above, in this embodiment, the brake device 2 is accommodated in the bottomed recess 141f of the rotating member 141, extends along the circumferential direction of the shaft 141a (male thread 141d), and faces the outer peripheral surface 141a3 of the male thread 141d. an inner peripheral part 170a, and an outer peripheral part 170b that extends along the circumferential direction of the shaft 141a, faces the inner peripheral surface 141e2 of the peripheral wall 141e, and is spaced from the inner peripheral surface 141e2 in state P2 (maximum axis misalignment state) with respect to the male thread 141d. , and includes an elastic member 170 that can be sandwiched between the flange 141b and the translation member 142 as the translation member 142 moves in the direction D1 (second direction).

According to the brake device 2, for example, a change in the posture (inclination) of the elastic member 170 due to contact between the outer circumferential portion 170b and the inner circumferential surface 142e of the elastic member 170 is suppressed, and thus a change in the posture of the elastic member 170 is suppressed. Therefore, variations in the compression reaction force based on the compression reaction force are less likely to occur. Therefore, according to such a configuration, for example, the desired compression reaction force of the elastic member 170 can be easily obtained, and the male thread 141d of the rotating member 141 and the female thread 142d of the linear member 142 are firmly connected. can be more reliably suppressed.

Furthermore, in this embodiment, the elastic member 170 is made of thermoplastic elastomer. According to such a configuration, durability and moldability are improved compared to, for example, a case where the elastic member 170 is made of cross-linked rubber, vulcanized rubber, etc., and the fastening between the male thread 141d and the female thread 142d is improved. The occurrence of this condition can be further suppressed.

Further, in this embodiment, the elastic member 170 has a flat plate shape in a free state. According to such a configuration, compared to, for example, a case where the elastic member 170 is constituted by a disc spring, it is easier to achieve smaller size in the axial direction, lighter weight, noise suppression effect, etc. Further, by using the elastic member 170 that is not coiled as in this embodiment, it becomes easy to reduce the space in which the elastic member 170 is placed in a free state in the axial direction, for example.

Further, in this embodiment, the thickness W1 of the elastic member 170 along the axial direction is larger than one pitch of the male thread 141d. According to such a configuration, for example, the elastic member 170 is prevented from entering the spiral groove of the male thread 141d and being held in an inclined position, and the compression reaction force due to the change in the position of the elastic member 170 is suppressed. Variations, etc. are more likely to be suppressed.

Further, in this embodiment, the rotating member 141 includes a third gear 133 (gear) provided on the outer circumferential surface 141e1 of the peripheral wall 141e, and to which driving force is transmitted from the rotor of the motor 120. According to such a configuration, for example, compared to the case where the peripheral wall 141e is provided separately from the peripheral wall 141e constituting the third gear 133, the labor and cost of manufacturing can be further reduced, and the rotating member 141 can be It can be configured more compactly.

In this embodiment, the linear motion member 142 has an end surface 142f1 facing the elastic member 170 and perpendicular to the axial direction, and has a state P1 (minimum axis misalignment state), a state P2, and a state P2 with respect to the male thread 141d of the elastic member 170. In a state between state P2 and state P1 (intermediate axis deviation state), the entire surface of end face 142f1 is configured to be able to come into contact with elastic member 170. According to such a configuration, for example, a region in the elastic member 170 that does not come into contact with the end surface 142f1 is suppressed, and variations in the compression reaction force in the axial direction are suppressed, and as a result, the fastened state of the male thread 141d and the female thread 142d is improved. It is possible to further suppress this occurrence.

In the present embodiment, the shaft 141a has a root portion 141ab adjacent to the flange 141b in the direction D2 (first direction), and an elastic member protruding radially outward on the opposite side of the root portion 141ab from the flange 141b. 170 has an incompletely threaded portion 141ac (hanging portion) that suppresses movement in the direction D2 with respect to the bottomed recess 141f. According to such a configuration, for example, the elastic member 170 tends to remain in the bottomed recess 141f due to the incompletely threaded portion 141ac.

Although the embodiments of the present invention have been illustrated above, the above embodiments are merely examples and are not intended to limit the scope of the invention. The embodiments described above can be implemented in various other forms, and various omissions, substitutions, 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, shape, size, length, width, thickness, height, number, arrangement, position, material, etc.) may be changed as appropriate. It can be implemented by

For example, the rotating member may be provided with a female thread, and the linear member may be provided with a male thread. Further, for example, a plurality of elastic members may be stacked in the bottomed recess. Further, for example, a bottomed recess may be provided in the linear motion member.

2... Brake device, 3... Brake shoe (braking member), 120... Motor, 133... Third gear (gear), 141... Rotating member, 141a... Shaft, 141a3... Outer peripheral surface, 141ab... Root, 141ac... Incomplete Threaded portion (hanging portion), 141b...flange, 141d...male thread, 141e...peripheral wall, 141e1...outer circumferential surface, 141e2...inner circumferential surface, 141f...bottomed recess, 142...linear motion member, 142d...female thread, 142f...end portion (first end), 142f1...end face, 150...cable (operating member), 170...elastic member, 170a...inner circumference, 170b...outer circumference, Pb...braking position, Pr...non-braking position, P1...state ( (minimum axis misalignment state), P2... state (maximum axis misalignment state), D1... direction (second direction), D2... direction (first direction).

Claims (7)

an actuating member that moves the braking member between a braking position in which the braking member is in a braking state and a non-braking position in which the braking member is in a non-braking state;
a shaft provided with one of a male thread and a female thread that engage with each other; a flange projecting radially outward from the shaft; and a peripheral wall projecting from a peripheral edge of the flange in a first direction along the axial direction of the shaft; a rotating member having a bottomed recess surrounded by the flange and the peripheral wall and opening in the first direction, and rotating in conjunction with a rotor of a motor;
The other of the male thread and the female thread is provided, and moves linearly in the first direction in response to normal rotation of the rotating member, and in a second direction opposite to the first direction in response to reversal of the rotating member. a linearly moving member capable of moving the actuating member between the braking position and a non-braking position spaced from the braking position in the second direction;
The entire body is housed in the bottomed recess, and includes an inner peripheral part that extends along the circumferential direction of the male thread and faces the outer peripheral surface of the male thread, and an inner peripheral part that extends along the circumferential direction and faces the inner peripheral surface of the peripheral wall. and an outer circumferential portion that is spaced apart from the inner circumferential surface in the state of maximum axis deviation in the radial direction with respect to the male thread, and as the linear motion member moves in the second direction, the flange and an elastic member that can be sandwiched between the linear motion member and the linear motion member;
Brake device with. an actuating member that moves the braking member between a braking position in which the braking member is in a braking state and a non-braking position in which the braking member is in a non-braking state;
a shaft provided with one of a male thread and a female thread that engage with each other; a flange projecting radially outward from the shaft; and a peripheral wall projecting from a peripheral edge of the flange in a first direction along the axial direction of the shaft; a rotating member having a bottomed recess surrounded by the flange and the peripheral wall and opening in the first direction, and rotating in conjunction with a rotor of a motor;
The other of the male thread and the female thread is provided, and moves linearly in the first direction in response to normal rotation of the rotating member, and in a second direction opposite to the first direction in response to reversal of the rotating member. a linearly moving member capable of moving the actuating member between the braking position and a non-braking position spaced from the braking position in the second direction;
an inner peripheral part accommodated in the bottomed recess, extending along the circumferential direction of the male thread and facing the outer peripheral surface of the male thread; and an inner peripheral part extending along the circumferential direction and facing the inner peripheral surface of the peripheral wall. and an outer circumferential portion that is spaced apart from the inner circumferential surface in the state of maximum axis deviation in the radial direction with respect to the male screw, and as the linear motion member moves in the second direction, the flange and the an elastic member that can be sandwiched between the linear motion member;
Equipped with
In the brake device, the elastic member has a flat plate shape in a free state. an actuating member that moves the braking member between a braking position in which the braking member is in a braking state and a non-braking position in which the braking member is in a non-braking state;
a shaft provided with one of a male thread and a female thread that engage with each other; a flange projecting radially outward from the shaft; and a peripheral wall projecting from a peripheral edge of the flange in a first direction along the axial direction of the shaft; a rotating member having a bottomed recess surrounded by the flange and the peripheral wall and opening in the first direction, and rotating in conjunction with a rotor of a motor;
The other of the male thread and the female thread is provided, and moves linearly in the first direction in response to normal rotation of the rotating member, and in a second direction opposite to the first direction in response to reversal of the rotating member. a linearly moving member capable of moving the actuating member between the braking position and a non-braking position spaced from the braking position in the second direction;
an inner peripheral part accommodated in the bottomed recess, extending along the circumferential direction of the male thread and facing the outer peripheral surface of the male thread; and an inner peripheral part extending along the circumferential direction and facing the inner peripheral surface of the peripheral wall. and an outer circumferential portion that is spaced apart from the inner circumferential surface in the state of maximum axis deviation in the radial direction with respect to the male screw, and as the linear motion member moves in the second direction, the flange and the an elastic member that can be sandwiched between the linear motion member;
Equipped with
The translational member has an end face facing the elastic member and perpendicular to the axial direction,
In the minimum axis deviation state, the maximum axis deviation state, and the intermediate axis deviation state between the maximum axis deviation state and the minimum axis deviation state in the radial direction of the elastic member with respect to the male thread, the entire surface of the end face is A brake device configured to be able to come into contact with the elastic member. an actuating member that moves the braking member between a braking position in which the braking member is in a braking state and a non-braking position in which the braking member is in a non-braking state;
a shaft provided with one of a male thread and a female thread that engage with each other; a flange projecting radially outward from the shaft; and a peripheral wall projecting from a peripheral edge of the flange in a first direction along the axial direction of the shaft; a rotating member having a bottomed recess surrounded by the flange and the peripheral wall and opening in the first direction, and rotating in conjunction with a rotor of a motor;
The other of the male thread and the female thread is provided, and moves linearly in the first direction in response to normal rotation of the rotating member, and in a second direction opposite to the first direction in response to reversal of the rotating member. a linearly moving member that is movable between the braking position and a non-braking position spaced from the braking position in the second direction;
an inner peripheral part accommodated in the bottomed recess, extending along the circumferential direction of the male thread and facing the outer peripheral surface of the male thread; and an inner peripheral part extending along the circumferential direction and facing the inner peripheral surface of the peripheral wall. and an outer circumferential portion that is spaced apart from the inner circumferential surface in the state of maximum axis deviation in the radial direction with respect to the male screw, and as the linear motion member moves in the second direction, the flange and the an elastic member that can be sandwiched between the linear motion member;
Equipped with
The shaft of the rotating member is provided with the male thread, and the shaft has a root portion adjacent to the flange in the first direction, and a root portion on the opposite side of the flange to the outside in the radial direction. A brake device comprising: a protruding hook portion that suppresses movement of the elastic member in the first direction with respect to the bottomed recess. The brake device according to any one of claims 1 to 4, wherein the elastic member is made of thermoplastic elastomer. The brake device according to any one of claims 1 to 5, wherein the thickness of the elastic member along the axial direction is greater than one pitch of the one screw. The brake device according to any one of claims 1 to 6, wherein the rotating member has a gear provided on the outer peripheral surface of the peripheral wall and to which driving force is transmitted from the rotor.

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