JP2019100351A - Disc brake - Google Patents

Abstract

To provide a disc brake for improving responsiveness while securing a brake force.SOLUTION: A rotation linear conversion mechanism 32 of a disc brake 1a comprises: an input rod 35 to which rotation from an electric motor 30 is transmitted; a cylindrical output member 36 arranged outside the input rod 35 in a radial direction, movably in an axial direction and relatively non-rotatably supported with respect to a caliper main body 6, and imparting thrust to a piston 15; a plurality of planetary rods 37 which are arranged between the input rod 35 and the cylindrical output member 36 at an interval along a peripheral direction, and engaged with the input rod 35 and the cylindrical output member 36; and a coil spring 39 arranged between the planetary rod groups 37 ... and the cylindrical output member 36, and imparting an energization force to the relative rotation of the cylindrical output member 36 and the planetary rod groups 37 .... This constitution can improve responsiveness while securing a brake force.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a disc brake used for braking a vehicle.

  As a prior art of the disk brake mentioned above, Patent Document 1 has a motor and a rotation-linear motion conversion device for converting rotational motion of the motor into linear motion, and the brake pad is formed by the rotation-linear motion conversion device. A braking device for a vehicle that generates a braking force by pressing against a brake disc, wherein the rotation-linear motion conversion device includes a screw shaft, and a plurality of planets disposed around the screw shaft and screwing with the screw shaft. It is described that it is a planetary differential screw type rotation-linear motion conversion device having a screw roller and a roller nut surrounding a screw shaft and a planetary screw roller and engaged with the planetary screw roller.

Unexamined-Japanese-Patent No. 2005-133863

  However, in the vehicle braking device according to Patent Document 1, the input torque to the rotation-linear motion conversion device is the same when the lead of a screw such as a screw shaft is enlarged in order to improve the response of the braking device. In this case, there is a possibility that the problem that the maximum thrust is reduced may occur.

  An object of the present invention is to provide a disc brake which improves responsiveness while securing a braking force.

As means for solving the above problems, a first disk brake according to the present invention comprises an electric motor and one pad of a pair of pads disposed on both sides of the rotor in the axial direction of the rotor. A pressing member for pressing in the axial direction, a caliper main body for supporting the pressing member so as to be movable toward the rotor, and a rotational motion from the electric motor are converted into a linear motion to move the pressing member toward the rotor A disk drive provided with a rotary linear motion conversion mechanism for moving the
The rotary-to-linear motion conversion mechanism is an input rod to which rotation from the electric motor is transmitted, and is disposed radially outward of the input rod, axially movable with respect to the caliper main body, and relatively rotating And a plurality of cylindrical output members supported incompliance with each other to apply a thrust to the pressing member, and spaced apart along the circumferential direction between the input rod and the cylindrical output member; A planetary rod engaged with each of the cylindrical output members, and a planetary rod group including the plurality of planetary rods and the cylindrical output member, and the cylindrical output member and the planetary rod group An elastic member for applying a biasing force to the relative rotation of
Until the cylindrical output member receives a reaction force from the rotor via the pad, the cylindrical output member and the planetary rod group do not rotate relative to each other by the biasing force of the elastic member, and the cylindrical When the output member receives a reaction force from the rotor via the pad, the cylindrical output member and the planetary rod group relatively rotate against the biasing force of the elastic member. It is.

According to a second disc brake of the present invention, an electric motor and a pressing member for pressing one pad of a pair of pads disposed on both sides in the axial direction of the rotor sandwiching the rotor in the axial direction of the rotor A caliper main body supporting the pressing member so as to be movable toward the rotor; and a linear-to-linear motion converting mechanism converting the rotational motion from the electric motor into a linear motion to move the pressing member toward the rotor And a disc brake provided with
The rotary-to-linear motion conversion mechanism is an input rod to which rotation from the electric motor is transmitted, and is disposed radially outward of the input rod, axially movable with respect to the caliper main body, and relatively rotating And a plurality of cylindrical output members supported incompliance with each other to apply a thrust to the pressing member, and spaced apart along the circumferential direction between the input rod and the cylindrical output member; The relative rotation between the planetary rod group and the input rod is disposed between a planetary rod group engaged with each of the cylindrical output members, a planetary rod group including the plurality of planetary rods, and the input rod. An elastic member for applying a biasing force to the
Until the cylindrical output member receives a reaction force from the rotor via the pad, the planetary rod group and the input rod do not rotate relative to each other by the urging force of the elastic member, and the cylindrical output member However, when the reaction force from the rotor is received through the pad, the planetary rod group and the input rod rotate relative to the biasing force of the elastic member.

  According to the disc brake according to the present invention, the responsiveness can be improved while securing the braking force.

1 is a partial cross-sectional view of a disc brake according to a first embodiment. The expanded sectional view of the rotation direct-acting conversion mechanism adopted as the disk brake concerning a 1st embodiment. FIG. 3 is an exploded perspective view of a rotary-to-linear motion conversion mechanism adopted for the disc brake according to the first embodiment. The figure which shows transition of a thrust, a position, efficiency, and a lead at the time of the input rod of a rotation linear-motion conversion mechanism rotating. (A) Front view of rotational-to-linear motion conversion mechanism adopted for disc brake according to the second embodiment, (b) A sectional view taken along the line A-A of (a). The disassembled perspective view of the rotation linear motion conversion mechanism employ | adopted as the disc brake which concerns on 2nd Embodiment.

The present embodiment will be described in detail based on FIGS. 1 to 6.
The disk brakes 1a and 1b according to the first and second embodiments will be respectively described below.
First, the disc brake 1a according to the first embodiment will be described based on FIGS. In the disc brake 1a according to the first embodiment, as shown in FIG. 1, a pair of inner brake pads 2 and outer brake pads disposed on both sides in the axial direction across the disc rotor D attached to the rotating portion of the vehicle. 3 and a caliper 4 are provided. The present disk brake 1a is configured as a caliper floating type. The pair of inner brake pads 2 and outer brake pads 3 and the caliper 4 are supported movably in the axial direction of the disk rotor D by a bracket (not shown) fixed to a non-rotating part such as a knuckle of the vehicle. . Hereinafter, for convenience of explanation, the right side of FIGS. 1 and 2 will be appropriately described as one end side and the left side as the other end side.

  As shown in FIG. 1, the caliper main body 6 which is the main body of the caliper 4 faces the cylinder portion 7 disposed on the base end side facing the inner brake pad 2 inside the vehicle and the outer brake pad 3 outside the vehicle. And a claw portion 8 disposed on the distal end side. A cylinder bore 10 is formed in the cylinder portion 7 along the axial direction of the disk rotor D. The piston 15 is formed in a bottomed cup shape including a bottom portion 16 and a cylindrical portion 17. The piston 15 is housed in the cylinder bore 10 such that its bottom 16 faces the inner brake pad 2. A small diameter opening 19 located on the bottom 16 side and a large diameter opening having a diameter larger than the small diameter opening 19 continuously from the small diameter opening 19 in the cylindrical portion 17 of the piston 15 And 20 are formed. An annular receiving surface 21 is formed between the small diameter opening 19 and the large diameter opening 20.

  A recess 25 is provided on the outer peripheral side of the other end surface of the bottom portion 16 of the piston 15 facing the inner brake pad 2. The concave portion 25 is engaged with the convex portion 26 formed on the back surface of the inner brake pad 2, and the engagement is supported relative to the cylinder portion 7 and hence the caliper main body 6 by this engagement. Ru. A seal member 27 is disposed on the other inner peripheral surface of the cylinder bore 10 on the other end side. A piston 15 is disposed in the cylinder bore 10 of the cylinder portion 7 so as to be axially movable in contact with the seal member 27. A dust boot 28 is interposed between the outer wall surface on the bottom 16 side of the piston 15 and the inner wall surface of the cylinder bore 10. The seal member 27 and the dust boot 28 suppress the entry of foreign matter into the cylinder bore 10. The piston 15 corresponds to a pressing member.

  As shown in FIGS. 1 and 2, the caliper body 6 converts the rotational motion from the electric motor 30, the reduction mechanism 31 for increasing the rotational torque from the electric motor 30, and the rotational motion from the reduction mechanism 31 into linear movement. And a linear motion conversion mechanism 32 for propelling the piston 15. As described above, the rotational torque from the electric motor 30 is increased by the reduction mechanism 31 and transmitted to the linear translation conversion mechanism 32. The rotary / linear motion conversion mechanism 32 is disposed outward of the input rod 35 to which the rotational torque from the reduction gear mechanism 31 is transmitted, and the input rod 35, is axially movable relative to the cylinder portion 7, and is relative A plurality of cylindrical output members 36 supported in a non-rotatable manner, and a plurality of input rods 35 and cylindrical output members 36 are spaced apart along the circumferential direction, and each of the input rod 35 and the cylindrical output member 36 Between the cage 38 and the cylindrical output member 36 supporting the respective planetary rods 37 such that the distance between the planetary rods 37 engaged with each other and the adjacent planetary rods 37 and 37 is constant. The coil spring 39 is disposed, and applies a biasing force to the relative rotation of the cage 38 and the cylindrical output member 36.

  Referring also to FIG. 3, the input rod 35 is supported so as to be rotatable relative to the cylinder 7 and to be relatively immovable in the axial direction. The input rod 35 is disposed such that the other end thereof is close to the bottom 16 of the piston 15 in the cylinder bore 10. The input rod 35 includes an engagement rod portion 41 formed substantially in the axial direction from the substantially central portion to the other end portion, and a transmission rod portion 42 continuously provided from the engagement rod portion 41 to one end side. Configured A threaded portion 44 is formed on the outer peripheral surface of the engagement rod portion 41. The outer peripheral surface of the transmission rod portion 42 is formed into a polygonal surface 46. The transmission rod portion 42 of the input rod 35 is engaged with the reduction gear mechanism 31, and the rotation from the reduction gear mechanism 31 is transmitted to the input rod 35. A plurality of planet rods 37 are arranged at intervals along the circumferential direction around the input rod 35. A plurality of annular grooves 49 are provided in a row along the axial direction on the outer peripheral surface of each of the planetary rods 37 near the approximate center of the axial direction. Each annular groove 49 (each annular projection) of each planetary rod 37 is engaged with a threaded portion 44 provided on the outer peripheral surface of the engagement rod portion 41 of the input rod 35. Small diameter engaging portions 50 are formed at both axial ends of each of the planetary rods 37.

  The cage 38 supports each planet rod 37 such that the distance between the adjacent planet rods 37 and 37 is substantially constant. The cage 38 includes an end support plate 53 for supporting one axial end of each of the planet rods 37 and an other end support 54 for supporting the other axial end of each of the planet rods 37. The one end side support plate 53 is formed in an annular shape. A plurality of support holes 56 are formed in the one end side support plate 53 at intervals in the circumferential direction. The small diameter engaging portions 50 at one end of each of the planet rods 37 are rotatably supported by the support holes 56, respectively. On the other hand, the other end side support 54 includes an annular plate portion 57 extending in an annular shape, and a cylindrical portion 58 integrally extending from the annular plate portion 57 toward the other end side. Configured A plurality of first support holes 60 are formed in the annular plate portion 57 at intervals in the circumferential direction. In the annular plate portion 57, one second support hole 61 is appropriately formed at one place. The small diameter engaging portions 50 at the other end of each of the planetary rods 37 are rotatably supported by the first support holes 60, respectively. Further, one end 39 A of a coil spring 39 described later is inserted into and supported by the second support hole 61. The input rod 35 is inserted into the cylindrical portion 58.

  A cylindrical output member 36 is disposed around each planet rod 37. The cylindrical output member 36 is formed in a cylindrical shape. A plurality of annular grooves 63 are continuously provided along the axial direction on the inner peripheral surface of the cylindrical output member 36. The annular groove 63 is formed in a range excluding both axial ends of the cylindrical output member 36. The annular grooves 63 in the inner circumferential surface of the cylindrical output member 36 and the annular grooves 49 (annular projections) in the outer circumferential surface of the planetary rods 37 are engaged. The cylindrical output member 36 is supported so as to be relatively movable in the axial direction relative to the caliper main body 6, specifically, the piston 15, and to be relatively non-rotatable. The other end side of the cylindrical output member 36 is disposed inside the piston 15. The outer peripheral surface of the cylindrical output member 36 is the cylindrical portion 17 of the piston 15 and is in contact with the inner peripheral surface of the large diameter opening 20. The other end surface of the cylindrical output member 36 is in contact with the annular receiving surface 21 in the cylindrical portion 17 of the piston 15. Thereby, when the cylindrical output member 36 advances, the piston 15 advances. On the inner peripheral surface of the other end of the cylindrical output member 36, a restricting projection 65 is protruded inward.

  A coil spring 39 is disposed around the cylindrical portion 58 of the other end support 54 of the cage 38. The coil spring 39 corresponds to an elastic member. The one end 39 A of the coil spring 39 is inserted into and supported by the second support hole 60 of the annular plate portion 57 in the other end side support 54 of the cage 38. On the other hand, the other end 39 </ b> B of the coil spring 39 abuts on any one surface facing the circumferential direction in the restriction projection 65 provided on the cylindrical output member 36. The coil spring 39 applies an urging force to the relative rotation between the cage 38, that is, the planetary rod group 37 consisting of a plurality of planetary rods 37 and the cylindrical output member 36.

Next, the operation of the disc brake 1a according to the first embodiment will be described.
At the time of braking in normal traveling, the electric motor 30 is driven by a command from a controller (not shown), and the rotation thereof is transmitted to the input rod 35 of the rotary-linear motion conversion mechanism 32 via the reduction mechanism 31. Subsequently, when the input rod 35 starts to rotate, the cylindrical output member 36 can not rotate relative to the piston 15, and the cage 38, that is, the planetary rod group 37 ... and the cylindrical output member 36 are coiled. The relative rotation is restricted by the biasing force of the spring 39, that is, the relative rotational torque between the planetary rod group 37 ... and the cylindrical output member 36 is smaller than the set rotational torque of the coil spring 39, so The engagement of the threaded portion 44 of the rod 35 with the annular groove 49 of each of the planetary rods 37... And the engagement of the annular groove 49 of the planetary rods 37 ... with the annular groove 63 of the cylindrical output member 36 The cage 38 (each planetary rod group 37...) Does not rotate, but moves linearly toward the piston 15 and the cylindrical output member 36 moves linearly to move the piston 15 forward. As shown in FIG. 4, in this section A, that is, in the section A in which the thrust is lower than the predetermined value R, the piston 15 is a large lead of the screw portion 44 of the input rod 35 and is advanced with low efficiency and high response. It will be.

  Subsequently, the input rod 35 is rotated, and the piston 15 is advanced to press the inner brake pad 2 against the disc rotor D by the piston 15. The caliper main body 30 is moved to the right in FIG. 1 with respect to the bracket (not shown) by the reaction force against the pressing force to the inner brake pad 2 by the piston 15, and the outer brake pad attached to the claw portion 35 Press 3 onto the disc rotor D. As a result, the disc rotor D is pinched by the pair of inner and outer brake pads 2, 3 to generate a frictional force, which in turn generates a braking force of the vehicle.

  Subsequently, when the disc rotor D is pinched by the pair of inner and outer brake pads 2 and 3 and the braking force starts to be generated, the reaction force is the piston 15, the cylindrical output member 36, each planetary rod 37 and the input rod It is transmitted to 35. Due to the reaction force, the relative rotational torque between the planetary rod groups 37 and the cylindrical output member 36 is increased by the set rotational torque of the coil spring 39. Then, while the cage 38, ie, the planetary rod group 37, rotates relative to the cylindrical output member 36 against the biasing force of the coil spring 39, the cylindrical output member 36 linearly moves and the piston 15 Advances. As shown in FIG. 4, in this section B, that is, in the section B in which the thrust is greater than the predetermined value R, the piston 15 has a lead shorter than the lead of the threaded portion 44 of the input rod 35 and has high efficiency and high thrust type You will come to Finally, the controller controls the drive of the electric motor 30 to establish the braking state.

  As described above, the rotary / linear motion conversion mechanism 32 in the disk brake 1a according to the first embodiment is disposed on the input rod 35 to which the rotation from the electric motor 30 is transmitted, and radially outward of the input rod 35. Between the input rod 35 and the cylindrical output member 36, which is axially movable and relatively non-rotatably supported with respect to the caliper main body 6, and applies a thrust to the piston 15. And a plurality of planetary rods 37, which are arranged at intervals along the circumferential direction and are engaged with the input rod 35 and the cylindrical output member 36, respectively, the planetary rod group 37 ... and the cylindrical output member 36 And a coil spring 39 that applies a biasing force to relative rotation between the cylindrical output member 36 and the planetary rod group 37. In addition, a threaded portion 44 is formed on the outer peripheral surface of the input rod 35. A plurality of annular grooves 49 are provided in a row along the axial direction on the outer peripheral surface of the planetary rod 37. A plurality of annular grooves 63 are continuously provided along the axial direction on the inner peripheral surface of the cylindrical output member 36.

  Then, until the cylindrical output member 36 receives a reaction force from the disk rotor D via the inner and outer brake pads 2 and 3, the cylindrical output member 36 and the planetary rod group 37 ... are coil springs. Since it does not rotate relative to each other due to the biasing force of 39, the piston 15 is advanced with low efficiency and high response type by the large lead of the threaded portion 44 of the input rod 35 until it receives a reaction force. On the other hand, when the cylindrical output member 36 receives a reaction force from the disk rotor D via the inner and outer brake pads 2 and 3, the cylindrical output member 36 and the planetary rod group 37. Since it rotates relative to the biasing force, after receiving the reaction force, the piston 15 has a lead shorter than the lead of the threaded portion 44 of the input rod 35, and is advanced with high efficiency and high thrust type. . Thereby, in the disc brake 1a according to the first embodiment, the responsiveness can be improved while securing the braking force.

Next, a disc brake 1b according to a second embodiment will be described in detail based on FIGS. 5 and 6. FIG. When the disc brake 1b according to the second embodiment is described, only differences from the disc brake 1a according to the first embodiment will be described.
In the disc brake 1b according to the second embodiment, as shown in FIGS. 5 and 6, the input rod 35 is continuously engaged with an engagement rod portion 70 provided on the other end side and one end side from the engagement rod portion 70. The support rod portion 71 is provided, and the transmission rod portion 72 continuously provided from the support rod portion 71 to one end side. A plurality of annular grooves 74 are provided in a row along the axial direction on the outer peripheral surface of the engagement rod portion 70. A plurality of planet rods 37 are spaced around the engagement rod portion 70. Each of the planetary rods 37 has a length substantially equal to the length in the axial direction of the engagement rod portion 70 of the input rod 35, and a plurality of annular grooves 49 are continuously provided along the axial direction on the outer peripheral surface thereof There is. Then, the annular grooves 74 of the engagement rod portion 70 and the annular grooves 49 (annular projections) of the planetary rods 37 are engaged.

  The support rod portion 71 of the input rod 35 supports one end 39 A of the coil spring 39. A rotation restricting groove 77 is formed on the outer peripheral surface of the support rod portion 71 along the axial direction from one end surface thereof. A cylindrical support 79 is provided in contact with the outer peripheral surface of the support rod portion 71 so as to cover the end surface of the support rod portion 71. On the inner peripheral surface of the cylindrical support 79, a rotation restricting engagement portion 80 is protruded inward. The rotation restricting engagement portion 80 extends in the axial direction. A stopper portion 82 is provided on the outer peripheral surface of one end of the cylindrical support 79 so as to protrude radially outward. Then, the rotation restricting engaging portion 80 of the cylindrical support 79 is engaged with the rotation restricting groove portion 77 of the support rod portion 71, and the cylindrical support 79 is connected relatively nonrotatably around the support rod portion 71. Do. The outer peripheral surface of the transmission rod portion 72 is formed into a polygonal surface 46. On the inner peripheral surface of the cylindrical output member 36, a screw portion 85 is formed substantially in the entire axial direction. Then, the screw portion 85 of the cylindrical output member 36 and the annular grooves 49 (annular projections) of the planetary rods 37 are engaged.

  The cage 38 includes the other end support plate 88 for supporting the other axial end of each of the planet rods 37 and the one end support 89 for supporting one axial end of each of the planet rods 37. The other end support plate 88 is formed in an annular shape. A plurality of support holes 90 are formed in the other end side support plate 88 at intervals in the circumferential direction. The small diameter engaging portions 50 at the other end of each of the planetary rods 37 are rotatably supported by the support holes 90, respectively. On the other hand, the one end side support body 89 is configured of an annular plate portion 92 extending in an annular shape and a cylindrical portion 93 integrally extending concentrically from the annular plate portion 92 toward one end. . A plurality of first support holes 95 are formed in the annular plate portion 92 at intervals in the circumferential direction. In the annular plate portion 92, one second support hole 96 is appropriately formed at one place. The small diameter engaging portions 50 at one end of each of the planetary rods 37 are rotatably supported by the first support holes 95, respectively. Further, the other end 39 B of a coil spring 39 described later is inserted into and supported by the second support hole 96. The input rod 35 is inserted into the cylindrical portion 93.

  A coil spring 39 is disposed around the cylindrical portion 93 of the one end side support 89 of the cage 38. The other end 39 B of the coil spring 39 is inserted into and supported by the second support hole 96 of the annular plate 92 of the one end support 89 of the cage 38. On the other hand, one end 39A of the coil spring 39 is abutted against any one surface facing the circumferential direction of the stopper portion 82 of the cylindrical support 79 connected non-rotatably around the support rod portion 71 of the input rod 35 Ru. Thus, the coil spring 39 is disposed between the cage 38 and the input rod 35. The coil spring 39 applies an urging force to the cage 38, that is, relative rotation between the planetary rod group 37 and the input rod 35.

Next, the operation of the disc brake 1b according to the second embodiment will be described.
At the time of braking in normal traveling, the electric motor 30 is driven by a command from the controller, and its rotation is transmitted to the input rod 35 of the rotary-linear motion conversion mechanism 32 via the reduction mechanism 31. Subsequently, when the input rod 35 starts to rotate, relative rotation of the cage 38, that is, the planetary rod group 37 ... and the input rod 35 is restricted by the biasing force of the coil spring 39, ie, the planetary rod group 37. And the input rod 35, the engagement between the annular groove 74 of the input rod 35 and the annular groove 49 of each planetary rod 37, since the relative rotational torque between the input rod 35 and the set rotational torque of the coil spring 39 is smaller, Due to the engagement between the annular groove 49 of the planetary rod 37 and the screw portion 85 of the cylindrical output member 36, the cage 38, that is, the planetary rod group 37 is cylindrical while rotating with the input rod 35 by the biasing force of the coil spring 39 The output member 36 linearly moves to move the piston 15 forward. As shown in FIG. 4, in this section A, that is, in the section A in which the thrust is lower than the predetermined value R, the piston 15 is a large lead of the screw portion 85 of the cylindrical output member 36 and the efficiency is low. You will move forward.

  Subsequently, the input rod 35 is rotated, and the piston 15 is advanced to press the inner brake pad 2 against the disc rotor D by the piston 15. Then, the caliper main body 30 moves to the right in FIG. 1 with respect to the bracket by the reaction force against the pressing force to the inner brake pad 2 by the piston 15, and the outer brake pad 3 attached to the claw portion 35 Press on D As a result, the disc rotor D is pinched by the pair of inner and outer brake pads 2, 3 to generate a frictional force, which in turn generates a braking force of the vehicle.

  Subsequently, when the disc rotor D is pinched by the pair of inner and outer brake pads 2 and 3 and the braking force starts to be generated, the reaction force is the piston 15, the cylindrical output member 36, each planetary rod 37 and the input rod It is transmitted to 35. When the relative rotational torque between the cage 38, that is, the planetary rod group 37... And the input rod 35 is increased by the set rotational torque of the coil spring 39 by the reaction force, the cage 38, ie, the planetary rod group 37. The tubular output member 36 is linearly moved to move the piston 15 forward while rotating relative to the input rod 35 so as to oppose the biasing force of the coil spring 39. As shown in FIG. 4, in this section B, that is, in the section B in which the thrust is greater than the predetermined value R, the piston 15 has a lead shorter than the lead of the threaded portion 85 of the cylindrical output member 36 and has high efficiency and high thrust Will move forward with Finally, the controller controls the drive of the electric motor 30 to establish the braking state.

  As described above, the rotary / linear motion conversion mechanism 32 in the disk brake 1b according to the second embodiment is disposed on the input rod 35 to which the rotation from the electric motor 30 is transmitted, and radially outward of the input rod 35. Between the input rod 35 and the cylindrical output member 36, which is axially movable and relatively non-rotatably supported with respect to the caliper main body 6, and applies a thrust to the piston 15. Between the planetary rods 37 and the input rods 35, which are arranged at intervals along the circumferential direction, and are engaged with the input rod 35 and the cylindrical output member 36 respectively. The coil spring 39 is disposed, and applies a biasing force to the relative rotation of the input rod 35 and the planetary rod group 37. Further, a plurality of annular grooves 74 are provided in a row along the axial direction on the outer peripheral surface of the input rod 35. A plurality of annular grooves 49 are provided in a row along the axial direction on the outer peripheral surface of the planetary rod 37. A threaded portion 85 is formed on the inner peripheral surface of the cylindrical output member 36.

  Then, until the cylindrical output member 36 receives a reaction force from the disk rotor D via the inner and outer brake pads 2 and 3, the input rod 35 and the planetary rod group 37. Since the relative rotation is not caused by the biasing force, the piston 15 is advanced with high efficiency and low response by the large lead of the screw portion 85 of the cylindrical output member 36 until the reaction force is received. On the other hand, when the cylindrical output member 36 receives a reaction force from the disk rotor D through the inner and outer brake pads 2 and 3, the input rod 35 and the planetary rod group 37 are biased by the coil spring 39. The piston 15 is advanced with high efficiency and high thrust type with a lead shorter than the lead of the threaded portion 85 of the cylindrical output member 36 after receiving the reaction force. . Thereby, also in the disc brake 1b according to the second embodiment, the responsiveness can be improved while securing the braking force as in the disc brake 1a according to the first embodiment.

  DESCRIPTION OF SYMBOLS 1a, 1b Disc brake, 2 inner brake pad, 3 outer brake pad, 4 caliper, 6 caliper main body, 18 piston (pressing member), 30 electric motor, 32 rotation linear motion conversion mechanism, 35 input rod, 36 cylindrical output member , 37 planetary rod, 38 cage, 39 coil spring (elastic member), 44 screw portion (input rod), 49 annular groove (planet rod), 63 annular groove (cylindrical output member), 74 annular groove (input rod), 85 Threaded part (cylindrical output member), D disc rotor

Claims (6)

Electric motor,
A pressing member for pressing one of the pair of pads disposed on both sides of the rotor in the axial direction of the rotor in the axial direction of the rotor;
A caliper body movably supporting the pressing member toward the rotor;
A rotary-to-linear motion conversion mechanism that converts rotational movement from the electric motor into linear movement and moves the pressing member toward the rotor;
A disc brake equipped with
The rotational linear motion conversion mechanism
An input rod to which rotation from the electric motor is transmitted;
A cylindrical output member which is disposed radially outward of the input rod, is axially movable with respect to the caliper main body, is supported so as not to be able to relatively rotate, and applies a thrust to the pressing member;
A plurality of planetary rods which are arranged at intervals along the circumferential direction between the input rod and the cylindrical output member, and which are engaged with the input rod and the cylindrical output member, respectively;
An elastic member disposed between a planetary rod group including the plurality of planetary rods and the cylindrical output member, for applying a biasing force to relative rotation between the cylindrical output member and the planetary rod group; Equipped
Until the cylindrical output member receives a reaction force from the rotor via the pad, the cylindrical output member and the planetary rod group do not rotate relative to each other by the biasing force of the elastic member.
When the cylindrical output member receives a reaction force from the rotor via the pad, the cylindrical output member and the planetary rod group relatively rotate against the biasing force of the elastic member. Disc brake with. A threaded portion is formed on the outer peripheral surface of the input rod;
A plurality of annular grooves are provided in a row along the axial direction on the outer peripheral surface of each of the planetary rods,
The disk brake according to claim 1, wherein a plurality of annular grooves are provided in a row along the axial direction on the inner peripheral surface of the cylindrical output member. Electric motor,
A pressing member for pressing one of the pair of pads disposed on both sides of the rotor in the axial direction of the rotor in the axial direction of the rotor;
A caliper body movably supporting the pressing member toward the rotor;
A rotary-to-linear motion conversion mechanism that converts rotational movement from the electric motor into linear movement and moves the pressing member toward the rotor;
A disc brake equipped with
The rotational linear motion conversion mechanism
An input rod to which rotation from the electric motor is transmitted;
A cylindrical output member which is disposed radially outward of the input rod, is axially movable with respect to the caliper main body, is supported so as not to be able to relatively rotate, and applies a thrust to the pressing member;
A plurality of planetary rods which are arranged at intervals along the circumferential direction between the input rod and the cylindrical output member, and which are engaged with the input rod and the cylindrical output member, respectively;
And an elastic member disposed between the planetary rod group including the plurality of planetary rods and the input rod and applying an urging force to relative rotation between the planetary rod group and the input rod.
The planetary rod group and the input rod do not rotate relative to each other due to the biasing force of the elastic member until the tubular output member receives a reaction force from the rotor via the pad.
When the cylindrical output member receives a reaction force from the rotor via the pad, the planetary rod group and the input rod rotate relative to the biasing force of the elastic member. Disc brakes. A plurality of annular grooves are provided in a row along the axial direction on the outer peripheral surface of the input rod,
A plurality of annular grooves are provided in a row along the axial direction on the outer peripheral surface of the planetary rod,
The disc brake according to claim 3, wherein a screw portion is formed on an inner peripheral surface of the cylindrical output member.   The disc brake according to any one of claims 1 to 4, further comprising a cage for supporting each of the planetary rods such that the distance between the adjacent planetary rods is substantially constant.   The disk brake according to any one of claims 1 to 5, wherein the elastic member is provided between the cage and the cylindrical output member or between the cage and the input rod. .

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