JP6929208B2 - Disc brake - Google Patents

Description

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

As a prior art of the above-mentioned disc brake, Patent Document 1 includes an electric motor and a rotation-linear motion conversion device that converts the rotational motion of the electric motor into linear motion, and the brake pad is provided by the rotary-linear motion conversion device. A braking device for vehicles that generates braking force by pressing against a brake disc, and a rotation-linear motion conversion device is a screw shaft and a plurality of planets arranged around the screw shaft and screwed with the screw shaft. It is described that it is a planetary differential screw type rotary-linear motion conversion device having a screw roller and a roller nut that surrounds a screw shaft and a planetary screw roller and is screwed with the planetary screw roller.

Japanese Unexamined Patent Publication No. 2005-133863

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

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

As a means for solving the above problems, the first disc brake of the present invention uses an electric motor and one of a pair of pads arranged on both sides of the rotor in the axial direction with the rotor sandwiched between the electric motor and the rotor. A pressing member that presses in the axial direction, a caliper body that movably supports the pressing member toward the rotor, and a rotational motion from the electric motor are converted into a linear motion to direct the pressing member toward the rotor. It is a disc brake equipped with a rotary linear motion conversion mechanism that moves the brakes.
The rotation linear motion conversion mechanism is arranged outside the radial direction of the input rod to which the rotation from the electric motor is transmitted and the input rod, and is movable in the axial direction and relative to the caliper main body. A plurality of tubular output members that are impossibly supported and apply thrust to the pressing member and the input rod and the tubular output member are arranged at intervals along the circumferential direction, and the input rod and the tubular output member are arranged. A planetary rod engaged with each of the tubular output members, a planetary rod group composed of the plurality of planetary rods, and the tubular output member are arranged between the tubular output member and the planetary rod group. With an elastic member that imparts urging force to the relative rotation of
Until the tubular output member receives a reaction force from the rotor via the pad, the tubular output member and the planetary rod group do not rotate relative to each other due to the urging force of the elastic member, and the tubular output member and the planetary rod group do not rotate relative to each other. When the output member receives a reaction force from the rotor via the pad, the tubular output member and the planetary rod group rotate relative to each other against the urging force of the elastic member. Is.

Further, the second disc brake of the present invention includes an electric motor and a pressing member that presses one of a pair of pads arranged on both sides of the rotor in the axial direction with the rotor in the axial direction. A caliper body that movably supports the pressing member toward the rotor, and a rotary linear motion conversion mechanism that converts rotational motion from the electric motor into linear motion and moves the pressing member toward the rotor. It is a disc brake equipped with
The rotation linear motion conversion mechanism is arranged outside the radial direction of the input rod to which the rotation from the electric motor is transmitted and the input rod, and is movable in the axial direction and relative to the caliper main body. A plurality of tubular output members that are impossibly supported and apply thrust to the pressing member and the input rod and the tubular output member are arranged at intervals along the circumferential direction, and the input rod and the tubular output member are arranged. A planetary rod engaged with each of the tubular output members is arranged between the planetary rod group composed of the plurality of planetary rods and the input rod, and the relative rotation of the planetary rod group and the input rod is provided. It is equipped with an elastic member that gives an urging force to the rod.
Until the tubular 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 due to the urging force of the elastic member, and the tubular output member does not rotate. However, when a reaction force from the rotor is received via the pad, the planetary rod group and the input rod rotate relative to each other against the urging force of the elastic member.

According to the disc brake according to the present invention, it is possible to improve the responsiveness while ensuring the braking force.

A partial cross-sectional view of the disc brake according to the first embodiment. The enlarged sectional view of the rotary linear motion conversion mechanism adopted for the disc brake which concerns on 1st Embodiment. The exploded perspective view of the rotary linear motion conversion mechanism adopted for the disc brake which concerns on 1st Embodiment. The figure which shows the transition of a thrust, a position, an efficiency and a lead when the input rod of a rotary linear motion conversion mechanism rotates. (A) A front view of the rotation linear motion conversion mechanism adopted for the disc brake according to the second embodiment, and a cross-sectional view taken along the line AA of (b) and (a). The exploded perspective view of the rotary linear motion conversion mechanism adopted for the disc brake which concerns on 2nd Embodiment.

This embodiment will be described in detail with reference to FIGS. 1 to 6.
The disc brakes 1a and 1b according to the first and second embodiments will be described below.
First, the disc brake 1a according to the first embodiment will be described with reference to FIGS. 1 to 4. As shown in FIG. 1, the disc brake 1a according to the first embodiment includes a pair of inner brake pads 2 and outer brake pads arranged on both sides in the axial direction with the disc rotor D attached to the rotating portion of the vehicle interposed therebetween. 3 and a caliper 4 are provided. The disc brake 1a is configured as a floating caliper type. The pair of inner brake pads 2, the outer brake pads 3, and the caliper 4 are supported by a bracket (not shown) fixed to a non-rotating portion such as a knuckle of a vehicle so as to be movable in the axial direction of the disc rotor D. .. Hereinafter, for convenience of explanation, the right side of FIGS. 1 and 2 will be referred to as one end side, and the left side will be referred to 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 arranged on the base end side facing the inner brake pad 2 inside the vehicle and the outer brake pad 3 on the outside of the vehicle. It has a claw portion 8 arranged on the tip side. A cylinder bore 10 is formed in the cylinder portion 7 along the axial direction of the disc 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 so that its bottom 16 faces the inner brake pad 2. In the cylindrical portion 17 of the piston 15, a small-diameter opening 19 located on the bottom 16 side and a large-diameter opening 19 that is continuously located on the open side from the small-diameter opening 19 and has a larger diameter than the small-diameter opening 19. 20 and 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 16 of the piston 15 facing the inner brake pad 2. A convex portion 26 formed on the back surface of the inner brake pad 2 is engaged with the concave portion 25, and the piston 15 is supported by the engagement with respect to the cylinder portion 7 and the caliper main body 6 so as not to rotate relative to each other. NS. A seal member 27 is arranged on the inner peripheral surface on the other end side of the cylinder bore 10. A piston 15 is arranged in the cylinder bore 10 of the cylinder portion 7 so as to be movable in the axial direction in a state of being in contact with the seal member 27. A dust boot 28 is interposed between the outer wall surface of the piston 15 on the bottom 16 side and the inner wall surface of the cylinder bore 10. The seal member 27 and the dust boot 28 prevent foreign matter from entering the cylinder bore 10. The piston 15 corresponds to the pressing member.

As shown in FIGS. 1 and 2, the caliper main body 6 includes an electric motor 30, a deceleration mechanism 31 for increasing the rotational torque from the electric motor 30, and a linear motion for converting the rotational motion from the deceleration mechanism 31. A rotary linear motion conversion mechanism 32 that propels the piston 15 is provided. In this way, the rotational torque from the electric motor 30 is increased by the reduction mechanism 31 and transmitted to the rotational linear motion conversion mechanism 32. The rotary linear motion conversion mechanism 32 is arranged outside the input rod 35 to which the rotational torque from the deceleration mechanism 31 is transmitted and the input rod 35, and is movable in the axial direction and relative to the cylinder portion 7. A plurality of tubular output members 36 that are non-rotatably supported and the input rod 35 and the tubular output member 36 are arranged at intervals along the circumferential direction, and the input rod 35 and the tubular output member 36 are respectively arranged. Between the cage 38 that supports each planetary rod 37 and the cage 38 and the tubular output member 36 so that the distance between the planetary rod 37 that is engaged with the rod 37 and the adjacent planetary rods 37, 37 is constant. It is provided with a coil spring 39 that is arranged and imparts an urging force to the relative rotation of the cage 38 and the tubular output member 36.

With reference to FIG. 3, the input rod 35 is supported so as to be relatively rotatable with respect to the cylinder portion 7 and so as not to be relatively movable in the axial direction. The input rod 35 is arranged so that the other end is close to the bottom 16 of the piston 15 in the cylinder bore 10. The input rod 35 is composed of an engaging rod portion 41 formed from a substantially central portion in the axial direction to the other end portion, and a transmitted rod portion 42 serially provided on one end side from the engaging rod portion 41. It is composed. A threaded portion 44 is formed on the outer peripheral surface of the engaging rod portion 41. The outer peripheral surface of the rod portion 42 to be transmitted is formed on the polygonal surface 46. The transmitted rod portion 42 of the input rod 35 is engaged with the speed reduction mechanism 31, and the rotation from the speed reduction mechanism 31 is transmitted to the input rod 35. A plurality of planetary rods 37 are arranged around the input rod 35 at intervals along the circumferential direction. A plurality of annular grooves 49 are continuously provided along the axial direction on the outer peripheral surface of each planet rod 37 near the substantially center in the axial direction. Each annular groove 49 (each annular protrusion) of each planet rod 37 is engaged with a screw portion 44 provided on the outer peripheral surface of the engagement rod portion 41 of the input rod 35. Small diameter engaging portions 50 and 50 are formed at both ends in the axial direction of each planet rod 37, respectively.

The cage 38 supports each of the planetary rods 37 so that the distance between the adjacent planetary rods 37, 37 is substantially constant. The cage 38 is composed of an end-side support plate 53 that supports one end in the axial direction of each planet rod 37, and a support 54 on the other end that supports the other end in the axial direction of each planet rod 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. A small-diameter engaging portion 50 at one end of each planetary rod 37 is rotatably supported in these support holes 56. On the other hand, the other end side support 54 is composed of an annular plate-shaped portion 57 extending in an annular shape and a cylindrical portion 58 integrally extending concentrically from the annular plate-shaped portion 57 toward the other end side. It is composed. A plurality of first support holes 60 are formed in the annular plate-shaped portion 57 at intervals in the circumferential direction. A second support hole 61 is formed at an appropriate position in the annulus plate-shaped portion 57. The small-diameter engaging portion 50 at the other end of each planetary rod 37 is rotatably supported by these first support holes 60. Further, one end 39A of the coil spring 39, which will be described later, is inserted into the second support hole 61 to support the coil spring 39. The input rod 35 is inserted into the cylindrical portion 58.

A tubular output member 36 is arranged around each planet rod 37. The tubular 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 tubular output member 36. The annular groove 63 is formed in a range excluding both ends in the axial direction of the tubular output member 36. Each annular groove 63 on the inner peripheral surface of the tubular output member 36 and each annular groove 49 (each annular protrusion) on the outer peripheral surface of each planetary rod 37 are engaged. The tubular output member 36 is supported so as to be relatively movable and non-rotatably relative to the caliper main body 6, specifically, the piston 15 along the axial direction. The other end of the tubular output member 36 is arranged inside the piston 15. The outer peripheral surface of the tubular output member 36 is a cylindrical portion 17 of the piston 15 and is in contact with the inner peripheral surface of the large-diameter opening 20 thereof. The other end surface of the tubular output member 36 is in contact with the annular receiving surface 21 in the cylindrical portion 17 of the piston 15. As a result, the tubular output member 36 moves forward, so that the piston 15 moves forward. A regulation protrusion 65 is projected inward on the inner peripheral surface of the other end of the tubular output member 36.

A coil spring 39 is arranged around the cylindrical portion 58 of the other end side support 54 of the cage 38. The coil spring 39 corresponds to an elastic member. One end 39A of the coil spring 39 is inserted into and supported by the second support hole 60 of the annular plate-like portion 57 in the other end support 54 of the cage 38. On the other hand, the other end 39B of the coil spring 39 is in contact with any one surface of the regulation protrusion 65 provided on the tubular output member 36 facing in the circumferential direction. Then, the coil spring 39 applies an urging force to the relative rotation between the cage 38, that is, the planet rod group 37 ... Consisting of the plurality of planet rods 37, and the tubular 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 its rotation is transmitted to the input rod 35 of the rotation linear motion conversion mechanism 32 via the reduction mechanism 31. Subsequently, when the input rod 35 starts to rotate, the cylindrical output member 36 cannot 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 regulated by the urging force of the spring 39, that is, the relative rotation torque between the planetary rod group 37 ... And the cylindrical output member 36 is smaller than the set rotation torque of the coil spring 39, so that the input is made. By engaging the threaded portion 44 of the rod 35 with the annular groove 49 of each planet rod 37 ..., And engaging the annular groove 49 of the planet rod 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 advance the piston 15. As shown in FIG. 4, in this section A, that is, in the section A where the thrust is lower than the predetermined value R, the piston 15 is a large lead of the threaded portion 44 of the input rod 35, has low efficiency, and advances in a highly responsive manner. Will be.

Subsequently, the input rod 35 rotates, the piston 15 advances, and the inner brake pad 2 is pressed 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 (not shown) due to the reaction force against the pressing force on the inner brake pad 2 by the piston 15, and the outer brake pad attached to the claw portion 35. 3 is pressed against the disc rotor D. As a result, the disc rotor D is sandwiched between the pair of inner brake pads and the outer brake pads 2 and 3, and a frictional force is generated, which in turn generates a braking force of the vehicle.

Subsequently, when the disc rotor D is sandwiched between the pair of inner brake pads and the outer brake pads 2 and 3 and a braking force begins to be generated, the reaction force is generated by the piston 15, the tubular output member 36, each planet rod 37, and the input rod. It is transmitted to 35. Due to the reaction force, the relative rotational torque between the planetary rod group 37 ... And the tubular output member 36 becomes larger due to the set rotational torque of the coil spring 39. Then, while the cage 38, that is, the planetary rod group 37 ... Rotates relative to the tubular output member 36 against the urging force of the coil spring 39, the tubular output member 36 moves linearly and the piston 15 Moves forward. As shown in FIG. 4, in this section B, that is, in the section B where the thrust is larger 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, is highly efficient, and advances with a high thrust type. Will come to do. Finally, the controller controls the drive of the electric motor 30 to establish the braking state.

As described above, the rotation linear motion conversion mechanism 32 in the disc brake 1a according to the first embodiment is arranged on the input rod 35 to which the rotation from the electric motor 30 is transmitted and on the radial outer side of the input rod 35. Between the tubular output member 36, which is supported by the caliper body 6 so as to be movable in the axial direction and cannot rotate relative to each other, and which applies thrust to the piston 15, and between the input rod 35 and the tubular output member 36. A plurality of planetary rods 37 are arranged at intervals along the circumferential direction and are engaged with each of the input rod 35 and the tubular output member 36, and the planetary rod group 37 ... And the tubular output member 36. A coil spring 39, which is arranged between the tubular output members 36 and applies an urging force to the relative rotation of the tubular output member 36 and the planetary rod group 37 ... Further, a screw portion 44 is formed on the outer peripheral surface of the input rod 35. A plurality of annular grooves 49 are continuously provided 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 tubular output member 36.

Then, until the tubular output member 36 receives a reaction force from the disc rotor D via the inner and outer brake pads 2 and 3, the tubular output member 36 and the planetary rod group 37 ... are coil springs. Since the piston 15 does not rotate relative to each other due to the urging force of 39, the piston 15 moves forward with a large lead of the threaded portion 44 of the input rod 35 in a low efficiency and high response type until the reaction force is received. On the other hand, when the tubular output member 36 receives a reaction force from the disc rotor D via the inner and outer brake pads 2 and 3, the tubular output member 36 and the planetary rod group 37 ... Since it rotates relative to the urging 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, is highly efficient, and moves forward with a high thrust type. .. As a result, in the disc brake 1a according to the first embodiment, the responsiveness can be improved while ensuring the braking force.

Next, the disc brake 1b according to the second embodiment will be described in detail with reference to FIGS. 5 and 6. When the disc brake 1b according to the second embodiment is described, only the 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 connected to the engaging rod portion 70 provided on the other end side and one end side from the engaging rod portion 70. It is composed of a support rod portion 71 to be provided and a transmission rod portion 72 connected to one end side of the support rod portion 71. A plurality of annular grooves 74 are continuously provided along the axial direction on the outer peripheral surface of the engaging rod portion 70. A plurality of planetary rods 37 are arranged at intervals around the engaging rod portion 70. Each planet rod 37 has a length substantially equal to the length in the axial direction of the engaging 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, each annular groove 74 of the engaging rod portion 70 and each annular groove 49 (each annular protrusion portion) of each planetary rod 37 are engaged.

One end 39A of the coil spring 39 is supported by the support rod 71 of the input rod 35. On the outer peripheral surface of the support rod portion 71, a rotation restricting groove portion 77 is formed along the axial direction from one end surface thereof. A cylindrical support 79 that comes into contact with the outer peripheral surface of the support rod portion 71 is provided so as to cover the support rod portion 71 from one end surface. A rotation restricting engaging portion 80 is projected inward on the inner peripheral surface of the cylindrical support 79. The rotation regulation engaging portion 80 extends in the axial direction. A stopper portion 82 is provided so as to project outward in the radial direction on the outer peripheral surface of one end of the cylindrical support 79. Then, the rotation-regulating engaging portion 80 of the cylindrical support 79 is engaged with the rotation-regulating groove portion 77 of the support rod portion 71, and the cylindrical support 79 is connected around the support rod portion 71 so as to be relatively non-rotatable. do. The outer peripheral surface of the rod portion 72 to be transmitted is formed on the polygonal surface 46. On the inner peripheral surface of the tubular output member 36, a threaded portion 85 is formed over substantially the entire axial direction thereof. Then, the threaded portion 85 of the tubular output member 36 and each annular groove 49 (each annular protrusion) of each planetary rod 37 are engaged with each other.

The cage 38 is composed of an other end side support plate 88 that supports the axially other end of each planet rod 37, and one end side support 89 that supports the axial end of each planet rod 37. The other end side 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 portion 50 at the other end of each planetary rod 37 is rotatably supported in these support holes 90. On the other hand, the one-end side support 89 is composed of an annular plate-shaped portion 92 extending in an annular shape and a cylindrical portion 93 integrally extending concentrically toward one end side from the annular plate-shaped portion 92. .. A plurality of first support holes 95 are formed in the annular plate-shaped portion 92 at intervals in the circumferential direction. A second support hole 96 is formed at an appropriate location in the annulus plate-shaped portion 92. A small-diameter engaging portion 50 at one end of each planet rod 37 ... Is rotatably supported in these first support holes 95. Further, the other end 39B of the coil spring 39, which will be described later, is inserted into the second support hole 96 to support the coil spring 39. The input rod 35 is inserted into the cylindrical portion 93.

A coil spring 39 is arranged around the cylindrical portion 93 of the one-end support 89 of the cage 38. The other end 39B of the coil spring 39 is inserted into and supported by the second support hole 96 of the annular plate-shaped portion 92 of the one-end side support 89 of the cage 38. On the other hand, one end 39A of the coil spring 39 is in contact with any one surface of the stopper portion 82 of the cylindrical support 79 connected so as not to rotate relative to the support rod portion 71 of the input rod 35 facing in the circumferential direction. NS. In this way, the coil spring 39 is arranged between the cage 38 and the input rod 35. Then, the coil spring 39 applies an urging force to the relative rotation between the cage 38, that is, the planet 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 rotation linear motion conversion mechanism 32 via the reduction mechanism 31. Subsequently, when the input rod 35 starts to rotate, the relative rotation of the cage 38, that is, the planetary rod group 37 ... And the input rod 35 is regulated by the urging force of the coil spring 39, that is, the planetary rod group 37. Since the relative rotational torque between ... And the input rod 35 is smaller than the set rotational torque of the coil spring 39, the engagement between the annular groove 74 of the input rod 35 and the annular groove 49 of each planetary rod 37, and By engaging the annular groove 49 of the planetary rod 37 with the threaded portion 85 of the tubular output member 36, the cage 38, that is, the planetary rod group 37 is rotated together with the input rod 35 by the urging force of the coil spring 39, and has a tubular shape. The output member 36 moves linearly and the piston 15 moves forward. As shown in FIG. 4, in this section A, that is, in the section A where the thrust is lower than the predetermined value R, the piston 15 is a large lead of the threaded portion 85 of the tubular output member 36, has low efficiency, and is highly responsive. You will move forward.

Subsequently, the input rod 35 rotates, the piston 15 advances, and the inner brake pad 2 is pressed 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 due to the reaction force against the pressing force on the inner brake pad 2 by the piston 15, and the outer brake pad 3 attached to the claw portion 35 is moved to the disc rotor. Press against D. As a result, the disc rotor D is sandwiched between the pair of inner brake pads and the outer brake pads 2 and 3, and a frictional force is generated, which in turn generates a braking force of the vehicle.

Subsequently, when the disc rotor D is sandwiched between the pair of inner brake pads and the outer brake pads 2 and 3 and a braking force begins to be generated, the reaction force is generated by the piston 15, the tubular output member 36, each planet rod 37, and the input rod. It is transmitted to 35. Due to the reaction force, when the relative rotational torque between the cage 38, that is, the planetary rod group 37 ... And the input rod 35 becomes larger due to the set rotational torque of the coil spring 39, the cage 38, that is, the planetary rod group 37 ... The tubular output member 36 moves linearly and the piston 15 advances while rotating relative to the input rod 35 so as to oppose the urging force of the coil spring 39. As shown in FIG. 4, in this section B, that is, in the section B where the thrust is larger than the predetermined value R, the piston 15 has a lead shorter than the lead of the threaded portion 85 of the tubular output member 36, and is highly efficient and has a high thrust type. Will move forward. Finally, the controller controls the drive of the electric motor 30 to establish the braking state.

As described above, the rotation linear motion conversion mechanism 32 in the disc brake 1b according to the second embodiment is arranged on the input rod 35 to which the rotation from the electric motor 30 is transmitted and on the radial side of the input rod 35. Between the tubular output member 36, which is supported by the caliper body 6 so as to be movable in the axial direction and cannot rotate relative to each other, and which applies thrust to the piston 15, and between the input rod 35 and the tubular output member 36. A plurality of planetary rods 37 are arranged at intervals along the circumferential direction and are engaged with each of the input rod 35 and the tubular output member 36, and between the planetary rod group 37 ... And the input rod 35. It is provided with a coil spring 39 that is arranged and imparts an urging force to the relative rotation of the input rod 35 and the planetary rod group 37 .... Further, a plurality of annular grooves 74 are continuously provided along the axial direction on the outer peripheral surface of the input rod 35. A plurality of annular grooves 49 are continuously provided along the axial direction on the outer peripheral surface of the planetary rod 37. A screw portion 85 is formed on the inner peripheral surface of the tubular output member 36.

Then, until the tubular output member 36 receives the reaction force from the disc rotor D via the inner and outer brake pads 2 and 3, the input rod 35 and the planetary rod group 37 ... Since the piston 15 does not rotate relative to each other due to the urging force, the piston 15 moves forward with a low efficiency and a high response type due to the large lead of the threaded portion 85 of the tubular output member 36 until the reaction force is received. On the other hand, when the tubular output member 36 receives a reaction force from the disc rotor D via the inner and outer brake pads 2 and 3, the input rod 35 and the planetary rod group 37 ... are urging forces of the coil spring 39. After receiving the reaction force, the piston 15 has a lead shorter than the lead of the threaded portion 85 of the tubular output member 36, is highly efficient, and moves forward with a high thrust type. .. As a result, the disc brake 1b according to the second embodiment can also improve the responsiveness while ensuring the braking force as in the disc brake 1a according to the first embodiment.

1a, 1b Disc brake, 2 Inner brake pad, 3 Outer brake pad, 4 Caliper, 6 Caliper body, 18 Piston (pressing member), 30 Electric motor, 32 Rotational linear motion conversion mechanism, 35 Input rod, 36 Cylindrical output member , 37 Planetary rod, 38 cage, 39 coil spring (elastic member), 44 threaded part (input rod), 49 annular groove (planetary rod), 63 annular groove (cylindrical output member), 74 annular groove (input rod), 85 Threaded part (cylindrical output member), D disc rotor

Claims (6)

With an electric motor
A pressing member that presses one of the pair of pads arranged on both sides of the rotor in the axial direction with the rotor in the axial direction.
A caliper body that movably supports the pressing member toward the rotor, and
A rotary linear motion conversion mechanism that converts a rotary motion from the electric motor into a linear motion and moves the pressing member toward the rotor.
It is a disc brake equipped with
The rotary linear motion conversion mechanism
The input rod to which the rotation from the electric motor is transmitted and
A tubular output member arranged outside the radial direction of the input rod, supported by the caliper body so as to be movable in the axial direction and non-rotatably relative to the caliper body, and to apply thrust to the pressing member.
A plurality of planetary rods are arranged between the input rod and the tubular output member at intervals along the circumferential direction, and are engaged with each of the input rod and the tubular output member.
An elastic member that is arranged between the planetary rod group composed of the plurality of planetary rods and the tubular output member and imparts an urging force to the relative rotation of the tubular output member and the planetary rod group. Prepare,
Until the tubular output member receives a reaction force from the rotor via the pad, the tubular output member and the planetary rod group do not rotate relative to each other due to the urging force of the elastic member.
When the tubular output member receives a reaction force from the rotor via the pad, the tubular output member and the planetary rod group rotate relative to each other against the urging force of the elastic member. Disc brake. A threaded portion is formed on the outer peripheral surface of the input rod.
A plurality of annular grooves are continuously provided along the axial direction on the outer peripheral surface of each planetary rod.
The disc brake according to claim 1, wherein a plurality of annular grooves are continuously provided on the inner peripheral surface of the tubular output member along the axial direction. With an electric motor
A pressing member that presses one of the pair of pads arranged on both sides of the rotor in the axial direction with the rotor in the axial direction.
A caliper body that movably supports the pressing member toward the rotor, and
A rotary linear motion conversion mechanism that converts a rotary motion from the electric motor into a linear motion and moves the pressing member toward the rotor.
It is a disc brake equipped with
The rotary linear motion conversion mechanism
The input rod to which the rotation from the electric motor is transmitted and
A tubular output member arranged outside the radial direction of the input rod, supported by the caliper body so as to be movable in the axial direction and non-rotatably relative to the caliper body, and to apply thrust to the pressing member.
A plurality of planetary rods are arranged between the input rod and the tubular output member at intervals along the circumferential direction, and are engaged with each of the input rod and the tubular output member.
An elastic member arranged between the planetary rod group composed of the plurality of planetary rods and the input rod and applying an urging force to the relative rotation of the planetary rod group and the input rod is provided.
Until the tubular 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 due to the urging force of the elastic member.
When the tubular output member receives a reaction force from the rotor via the pad, the planetary rod group and the input rod rotate relative to each other against the urging force of the elastic member. Disc brake. A plurality of annular grooves are continuously provided along the axial direction on the outer peripheral surface of the input rod.
A plurality of annular grooves are continuously provided along the axial direction on the outer peripheral surface of the planetary rod.
The disc brake according to claim 3, wherein a threaded portion is formed on the inner peripheral surface of the tubular output member. The disc brake according to any one of claims 1 to 4, wherein a cage for supporting each planetary rod is provided so that the distance between the adjacent planetary rods is substantially constant. The disc brake according to claim 5 , wherein the elastic member is provided between the cage and the tubular output member, or between the cage and the input rod.

Images