JP7012621B2 - Disc brake - Google Patents

Description

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

As conventional disc brakes, Patent Document 1 describes a planetary gear deceleration mechanism for transmitting rotation from an electric motor, a rotary linear motion conversion mechanism for converting rotation from the planetary gear deceleration mechanism into linear motion, and the rotation. A disc brake having a piston propelled by a linear motion conversion mechanism, wherein the sun gear of the planetary gear reduction mechanism is press-fitted and fixed to a support plate provided close to a cover member of a gear housing accommodating the planetary gear reduction mechanism. It is disclosed that the shaft is rotatably supported by the shaft.

Japanese Unexamined Patent Publication No. 2016-125544

As described above, in the disc brake according to Patent Document 1, the sun gear of the planetary gear reduction mechanism is rotatably supported by a shaft extending from the support plate. Therefore, in this disc brake, the axial size of the shaft is large. There is a risk that the size will increase and the weight will also increase. Moreover, since this disc brake is equipped with a support plate, the number of parts is large, which leads to an increase in cost.

An object of the present invention is to provide a disc brake that reduces the number of parts, enables miniaturization, and improves mountability in a vehicle.

As a means for solving the above-mentioned problems, the present invention has a transmission mechanism for transmitting rotation from an electric motor, a rotation / linear motion conversion mechanism for converting rotation from the transmission mechanism into thrust, and the rotation / linear motion conversion. In a disc brake having a piston propelled by a mechanism, the transmission mechanism has a sun gear, a planetary gear, and a carrier, and rotation from the electric motor is from the sun gear to the carrier via the planetary gear. The rotation linear motion conversion mechanism includes a rotation shaft member to which rotation from the carrier is transmitted, and the sun gear is rotatably supported by the rotation shaft member. The rotary shaft member includes a supported portion that is rotatably supported by the cylinder portion in which the piston is housed, and a support that extends integrally from the supported portion and rotatably supports the sun gear. The engaging portion comprises a portion, an engaging portion provided between the supported portion and the supporting portion, engaged with the carrier, and mutually transmitting rotational torque between the carriers. , The supported portion has a smaller diameter than the supported portion, and the supported portion has a smaller diameter than the engaging portion .

According to the disc brake of the present invention, the number of parts can be reduced, the disc brake can be miniaturized, and the mountability on a vehicle can be improved.

The perspective view of the disc brake which concerns on this embodiment. The perspective view of the disc brake which concerns on this embodiment. The front view from the outer side in the disc brake which concerns on this embodiment. Sectional drawing of the disc brake which concerns on this embodiment. The enlarged sectional view around the motor gear assembly of the disc brake which concerns on this embodiment. The enlarged sectional view in the cylinder part of the disc brake which concerns on this embodiment.

Hereinafter, the present embodiment will be described in detail with reference to FIGS. 1 to 6.
The disc brake 1 according to the present embodiment is an electric brake device that generates a braking force by driving an electric motor 32 during normal driving. In the following description, the inside of the vehicle is referred to as the inner side, and the outside of the vehicle is referred to as the outer side. As shown in FIGS. 1 to 3, the disc brake 1 has a pair of inner brake pads 2 (see FIG. 4) arranged on both sides in the axial direction with the disc rotor D (see FIG. 4) attached to the rotating portion of the vehicle interposed therebetween. (See FIG. 2), an outer brake pad 3 (see FIG. 3), and a caliper 4. The disc brake 1 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 5 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.

As shown in FIGS. 1 to 3, the bracket 5 is integrally connected to a pair of pin insertion portions 12 and 12 through which slide pins 10 and 10 are inserted, and a pair of pin insertion portions 12 and 12, respectively. , Inner side and outer side support portions 14 and 15 that independently support the inner and outer brake pads 2 and 3, respectively. The pair of pin insertion portions 12, 12 are arranged at intervals along the rotation direction of the disc rotor D, and both extend along the axial direction of the disc rotor D. Each pin insertion portion 12 is formed in a bottomed cylindrical shape. The slide pin 10 is inserted inside each pin insertion portion 12. The opening side of each pin insertion portion 12 faces the inner side, and the bottom side thereof faces the outer side. A cylindrical pin hole boss portion 16 is formed at the inner side end portion of each pin insertion portion 12. The inner side support portion 14 is integrally connected to the inner side of each pin insertion portion 12. The outer side support portion 15 of each pin insertion portion 12 is connected from the inner side support portion 14 to the outer side at intervals along the axial direction of the disc rotor D.

The inner side support portion 14 connects a pair of inner side arm portions 20 and 20 extending in directions substantially orthogonal to each pin insertion portion 12 and 12 and an end portion of the pair of inner side arm portions 20 and 20. It is composed of an inner beam portion 21 and an inner beam portion 21. The inner brake pad 2 is movably supported inside the pair of inner arm portions 20, 20 along the axial direction of the disc rotor D. Through holes 23 and 23 penetrating along the axial direction of the disc rotor D are formed at both ends of the disc rotor D of the inner beam portion 21 in the rotational direction, respectively. The bracket 5 is attached to the non-rotating portion of the vehicle via the through holes 23 and 23 provided in the inner side support portion 14 (inner side beam portion 21). The outer side support portion 15 is an outer that connects a pair of outer side arm portions 25, 25 extending in a direction substantially orthogonal to each pin insertion portion 12, 12 and an end portion of the pair of outer side arm portions 25, 25. It is composed of a side beam portion 26 and a side beam portion 26. The outer brake pad 3 is movably supported inside the pair of outer arm portions 25, 25 along the axial direction of the disc rotor D.

The caliper 4 includes a caliper main body 30, which is the main body of the caliper 4, and a drive mechanism 31 that applies thrust to the piston 53 in the cylinder portion 34 of the caliper main body 30. The caliper main body 30 is arranged on the base end side facing the inner brake pad 2, and has a cylindrical cylinder portion 34 that opens facing the inner brake pad 2 and an outer side straddling the disc rotor D from the cylinder portion 34. A pair of claw portions 35, 35 extending to the outer side of the brake pad 3 facing the outer end side, and a pair of caliper arm portions 36, 36 extending outward from the cylinder portion 34 are provided. Slide pins 10 and 10 are fixed to the caliper arms 36 and 36 by mounting bolts 38, respectively. Then, the slide pins 10 and 10 are slidably inserted into the pin insertion portions 12 and 12, so that the caliper main body 30 is slidably supported with respect to the bracket 5 along the axial direction. is doing. A rubber pin boot 40 having a stretchable bellows portion covering the slide pins 10 and 10 between the caliper arm portions 36, 36 of the caliper main body 30 and the pin insertion portions 12, 12 of the bracket 5. 40 is provided.

In the following description, for convenience of explanation, the inner side (cover member 78 side) is appropriately described as one end side, and the outer side (disc rotor D side) is appropriately described as the other end side.
As shown in FIGS. 4 and 6, the cylinder portion 34 of the caliper main body 30 has a large-diameter opening 43 through which the inner brake pad 2 side is opened, and the opposite side is closed by a bottom wall 46 having an insertion hole 47. The bottomed cylinder bore 50 is formed. On the bottom wall 46 side in the cylinder bore 50, a small diameter opening 44 which is connected to the large diameter opening 43 and has a smaller diameter than the large diameter opening 43 is formed. The piston 53 is housed in the cylinder bore 50 (large diameter opening 43) of the cylinder portion 34 so as to be non-rotatable relative to the cylinder portion 34 and movable in the axial direction.

The piston 53 presses the inner brake pad 2, and is formed in a bottomed cup shape including a bottom portion 54 and a cylindrical portion 55. The piston 53 is housed in the cylinder bore 50 of the cylinder portion 34 so that the bottom portion 54 thereof faces the inner brake pad 2. A plurality of recesses 58 are provided on the outer peripheral side of the other end surface of the bottom portion 54 of the piston 53 facing the inner brake pad 2. A convex portion (not shown) formed on the back surface of the inner brake pad 2 is engaged with these concave portions 58. This engagement makes the piston 53 non-rotatable relative to the cylinder bore 50 and thus the caliper body 30. The cylinder bore 50 is provided with a seal member 57 on the inner peripheral surface on the other end side of the large-diameter opening 43. The piston 53 is housed in the large-diameter opening 43 of the cylinder bore 50 so as to be movable in the axial direction in a state of being in contact with the seal member 57. A dust boot 56 is interposed between the outer peripheral surface of the piston 53 on the bottom 54 side and the inner peripheral surface of the large diameter opening 43 of the cylinder bore 50 on the other end side. These sealing members 57 and dust boots 56 prevent foreign matter from entering the cylinder bore 50.

As shown in FIGS. 4 and 5, a gear housing 60 is arranged on the bottom wall 46 side of the cylinder portion 34 of the caliper main body 30. The motor gear assembly 63 and the control board 64 are housed inside the gear housing 60. A support recess 67 is formed on the other end surface of the bottom wall portion of the gear housing 60 to support the bottom wall 46 of the cylinder portion 34 (cylinder bore 50). The bottom wall 46 of the cylinder portion 34 (cylinder bore 50) is airtightly supported by the gear housing 60 support recess 67 by the seal member 68. A first opening 71 through which the small-diameter cylindrical portion 153 of the carrier 117 including the spindle 150 described later is inserted is formed in the bottom wall of the support recess 67. Further, a second opening 72 through which the main body of the electric motor 32 is inserted and fixed is formed in the bottom wall of the gear housing 60.

A cylindrical restraint portion 74 is projected from the bottom wall portion of the gear housing 60 toward one end side from substantially the same position as the support recess 67. The cylindrical restraint portion 74 has a discontinuous portion along the circumferential direction. The connectors 76, 76 electrically connected to the control board 64 are supported on the side wall portion of the gear housing 60 close to the electric motor 32. The opening on one end side of the gear housing 60 is closed by the cover member 78, and the cover member 78 is airtightly attached to the gear housing 60 via the seal member 79. A through hole 82 is formed in the cover member 78 at a position facing one end of the spindle 150, which will be described later. The through hole 82 is airtightly closed by the cap 83 via the seal member 84. As shown in FIG. 1, the gear housing 60 including the cover member 78 is connected to the cylinder portion 34 of the caliper main body 30 by a plurality of mounting bolts 86.

As shown in FIGS. 4 and 5, the drive mechanism 31 includes an electric motor 32, a spur tooth multi-stage reduction mechanism 88 as a motor gear assembly 63, and a planetary gear, which is a transmission mechanism for increasing the rotational torque from the electric motor 32. A speed reduction mechanism 89, a spur tooth multi-stage speed reduction mechanism 88, and a screw mechanism 90 as a rotation linear motion conversion mechanism for transmitting a rotation from the planetary gear speed reduction mechanism 89 to apply a thrust to the piston 53 are provided. The electric motor 32 is arranged substantially parallel to the cylinder portion 34. The main body of the electric motor 32 is inserted and fixed to the second opening 72 of the gear housing 60. The rotary shaft 33 of the electric motor 32 extends into the gear housing 60.

With reference to FIG. 5, the spur tooth multi-stage reduction mechanism 88 has a pinion gear 92, a first reduction gear 93, and a second reduction gear 94. The first reduction gear 93 and the second reduction gear 94 are made of metal or a resin such as a fiber reinforced resin. The pinion gear 92 has a hole 98 formed in a cylindrical shape and into which the rotating shaft 33 of the electric motor 32 is press-fitted and fixed, and a gear 99 formed on the outer periphery thereof. The first reduction gear 93 includes a large-diameter large gear 101 that meshes with the gear 99 of the pinion gear 92, and a small-diameter small gear 102 that extends concentrically from the large gear 101 toward one end side in the axial direction. .. The first reduction gear 93 is rotatably supported by the gear housing 60.

The small gear 102 of the first reduction gear 93 meshes with the second reduction gear 94. The second reduction gear 94 includes a large-diameter large gear 105 that meshes with the small gear 102 of the first reduction gear 93, and a small-diameter sun gear 106 that concentrically extends from the large gear 105 toward the other end side in the axial direction. It is equipped with. The sun gear 106 is configured as a part of the planetary gear reduction mechanism 89 described later. A hole 110 is formed in the radial center of the second reduction gear 94. A support rod portion 155 of the spindle 150, which will be described later, is inserted into the hole portion 110. As a result, the second reduction gear 94 is rotatably supported by the support rod portion 155 of the spindle 150 with respect to the gear housing 60. In the large gear 105 of the second reduction gear 94, the annular stopper portion 112 protruding toward the planetary gear reduction mechanism 89 is formed on the annular wall portion 108 located on one end side.

The planetary gear reduction mechanism 89 has a sun gear 106 of the second reduction gear 94, a plurality of (four in this embodiment) planetary gears 115, an internal gear 116, and a carrier 117. Each planetary gear 115 has a gear 120 that meshes with the sun gear 106 of the second reduction gear 94, and a hole 121 through which a pin 148 erected from the carrier 117 is rotatably inserted. The planetary gears 115 are arranged around the sun gear 106 at equal intervals along the circumferential direction.

The carrier 117 is formed so that the polygonal hole portion 124 penetrates in the axial direction substantially at the center thereof in the radial direction. The inner peripheral surface of the polygonal hole portion 124 is formed, for example, in a hexagonal shape. The carrier 117 is composed of a large-diameter annular plate-shaped portion 125 and a small-diameter cylindrical portion 126 concentrically projecting from the large-diameter annular plate-shaped portion 125 to the other end side. The small-diameter cylindrical portion 126 of the carrier 117 is inserted through the first opening 71 of the gear housing 60. On the outer peripheral side of the large-diameter annular plate-shaped portion 125 of the carrier 117, a plurality of pin hole portions 127 are formed so as to correspond to each planetary gear 115 at intervals along the circumferential direction. Pins 129 are press-fitted and fixed to each pin hole 127 of the carrier 117. Each pin 129 is rotatably inserted into a hole 121 of each planetary gear 115.

Then, by fitting the polygonal hole portion 124 of the carrier 117 and the polygonal rod portion 154 of the spindle 150 of the screw mechanism 90 described later, the rotational torque can be transmitted to each other between the carrier 117 and the spindle 150. It has become. Further, the wave washer 131 and the washer 132 are inserted through the small-diameter cylindrical portion 126 of the carrier 117. The washer 132 is in contact with one end surface of the bottom wall 46 of the cylinder portion 34. The urging force of the wave washer 131 urges the cylinder portion 34 and the carrier 117 in a direction in which they are separated from each other.

The internal gear 116 is arranged inside the large gear 105 of the second reduction gear 94. The internal gear 116 is an annular wall portion that extends radially from one end of the internal teeth 135 with which the gears 120 of each planetary gear 115 mesh with each other and restricts the axial movement of each planetary gear 115. It includes 136 and a cylindrical wall portion 137 extending from the internal teeth 135 toward the other end side. The inner peripheral surface of the cylindrical wall portion 137 of the internal gear 116 is in contact with the outer peripheral surface of the cylindrical restraint portion 74 provided in the gear housing 60, and the movement of the internal gear 116 along the radial direction is restricted. .. The internal gear 116 is provided on the annular wall portion 108 of the second reduction gear 94 on one end surface of the annular wall portion 136 in which the other end of the cylindrical wall portion 137 is in contact with the inner surface of the gear housing 60. Since the annular stopper portion 112 is in contact with the gear housing 60, it is supported by the gear housing 60 so as to be restricted from moving in the axial direction. Further, the internal gear 116 is supported so as not to rotate relative to the gear housing 60.

An annular plate 139 is arranged between the other end surface of each planetary gear 115 and one end surface of the carrier 117 (large diameter annular plate-shaped portion 125). The annular plate 139 is sandwiched between the end surface of the internal teeth 135 of the internal gear 116 and one end surface of the cylindrical restraint portion 74 of the gear housing 60, whereby the planetary gear 115 moves in the axial direction. Is regulated. A plurality of pins 129 are inserted inside the annular plate 139. In the present embodiment, in order to obtain the rotational force for propelling the piston 53, a spur tooth multi-stage deceleration mechanism 88 and a planetary gear deceleration mechanism 89 are adopted as a deceleration mechanism for enhancing the driving force by the electric motor 32, but the planetary gears are used. It may be composed only of a gear reduction mechanism 89. Further, a speed reducer according to another known technique such as a cycloid speed reduction mechanism or a wave speed reducer may be combined with the planetary gear speed reduction mechanism 89.

The rotary shaft 33 of the electric motor 32 projects to one end side from the pinion gear 92. A ratchet gear 142 is press-fitted and fixed to one end of the rotating shaft 33 of the electric motor 32. By engaging the lever member (not shown) with the ratchet gear 142, the thrust of the piston 53 to the inner brake pad 2 is maintained. The rotation angle detecting means 145 is arranged on one end side of the ratchet gear 142. The rotation angle detecting means 145 detects the rotation angle of the rotation shaft 33 of the electric motor 32, and includes a magnet member 147 and a magnetic detection IC chip 148. The support rod 146 is press-fitted and fixed in the hole provided in the ratchet gear 142. A ring-shaped magnet member 147 arranged in the cup-shaped support member 149 is supported by the support rod 146. The magnetic detection IC chip 148 is arranged so as to face one end side of the magnet member 147. The magnetic detection IC chip 148 detects a change in the magnetic field generated from the magnet member 147. The magnetic detection IC chip 148 is attached to the other end surface of the control board 64. Then, by detecting the change in the magnetic flux from the rotating magnet member 147 by the magnetic detection IC chip 148, the rotation angle of the rotation shaft 33 of the electric motor 32 is calculated and detected by the control board 64.

With reference to FIG. 6, the screw mechanism 90 converts the rotary motion from the spur tooth multi-stage speed reduction mechanism 88 and the planetary gear speed reduction mechanism 89, that is, the rotary motion of the electric motor 32 into a linear motion (hereinafter, referred to as a linear motion for convenience). , A thrust is applied to the piston 53. The screw mechanism 90 is a spindle 150 which is a rotary shaft member to which rotational motion from the spur tooth multi-stage deceleration mechanism 88 and the planetary gear deceleration mechanism 89 is transmitted, and a nut member which is screw-engaged with a male screw portion 156 of the spindle 150. It is composed of 151 and.

As shown in FIGS. 1 and 6, the spindle 150 has a main rod portion 153 which is a supported portion and is rotatably supported by an insertion hole 47 provided in the bottom wall 46 of the cylinder portion 34, and the main rod portion. The polygonal rod portion 154, which is an engaging portion, and the polygonal rod, which extend integrally from one end of the 153 toward the one end side and engage with the polygonal hole portion 124 provided at substantially the center of the carrier 117 in the radial direction. A support rod portion 155, which is a support portion, and a main rod portion, which extend integrally from one end of the portion 154 toward one end side and are inserted into the hole portion 110 of the second speed reduction mechanism 126 to rotatably support the sun gear 106. It is integrally provided on the other end side from 153, and has a male screw portion 156 that is screw-engaged with the nut member 151.

Between the main rod portion 153 and the male thread portion 156 of the spindle 150, an annular end-side ball bearing portion 162, which is a configuration of the thrust bearing 160, is integrally projected outward in the radial direction. Will be done. A ball groove 162A extending in the circumferential direction is formed on one end surface of the other end side ball receiving portion 162. As the thrust bearing 160, an annular end-side ball receiving portion 161 is arranged at a distance from the other-end side ball receiving portion 162 to one end side. A ball groove 161A extending in the circumferential direction is formed on the other end surface of the one-end side ball receiving portion 161. As the thrust bearing 160, a plurality of balls 163 are interposed between the ball groove 161A of the ball receiving portion 161 on the one end side and the ball groove 162A of the ball receiving portion 162 on the other end side. Further, a thrust sensor 165 is arranged between the bottom wall 46 of the cylinder portion 34 and the thrust bearing 160 in the cylinder bore 50.

The outer peripheral surface on one end side of the thrust sensor 165 is in contact with the inner peripheral surface of the small diameter opening 44 of the cylinder bore 50. The thrust sensor 165 is composed of a cylindrical load cell. The thrust sensor 165 detects the reaction force against the thrust from the piston 53 to the inner and outer brake pads 2 and 3. The main rod portion 153 of the spindle 150 is inserted in the thrust sensor 165.

The polygonal rod portion 154 is formed to have a smaller diameter than the main rod portion 153. The support rod portion 155 is formed to have a smaller diameter than the polygonal rod portion 154. The male screw portion 156 is formed to have a smaller diameter than the main rod portion 153. The other end of the male threaded portion 156 of the spindle 150 is close to the bottom wall 54 of the piston 53. The nut member 151 is screw-engaged with the male threaded portion 156 of the spindle 150. The nut member 151 is formed in a T-shaped cross section. The nut member 151 has a cylindrical shape whose outer peripheral surface is integrally extending from the radial center of the annular plate-shaped portion 168 to the other end side with the annular plate-shaped portion 168 whose outer peripheral surface is close to the inner wall surface of the cylinder bore 50 of the cylinder portion 34. It is provided with a unit 169. The other end surface of the outer peripheral portion of the annular plate-shaped portion 168 of the nut member 151 can come into contact with one end surface of the piston 53. The nut member 151 is supported in the cylinder bore 50 of the cylinder portion 34 so as to be movable in the axial direction with respect to the cylinder portion 34 and to be non-rotatably relative to the cylinder portion 34.

Then, when the spindle 150 rotates with the rotation of the carrier 117 of the planetary gear reduction mechanism 89, the nut member 151 is directed to the other end side by the screw engaging portion between the male screw portion 156 of the spindle 150 and the nut member 151. By moving forward, the piston 53 moves forward, and the inner brake pad 2 can be pressed against the disc rotor D by the piston 53.

The drive of the electric motor 32 is controlled by a command from the control board 64 shown in FIG. The control board 64 is arranged in the gear housing 60. The control board 64 is electrically connected to the magnetic detection IC chip 148 of the rotation angle detecting means 145. The control board 64 is electrically connected to the thrust sensor 165. Further, on the control board 64, a detection sensor for detecting the driver's request such as a stroke sensor for detecting the stroke of the brake pedal (not shown) and various situations in which the brake is required are detected without the driver's request. Various detection sensors are electrically connected. Then, at the time of braking in normal driving, the control board 64 provides a detection signal from a detection sensor corresponding to the driver's request, various detection sensors for detecting various situations requiring braking, and a rotation angle detecting means 145. The drive of the electric motor 32 is controlled based on the detection signal from the magnetic detection IC chip 148 and the detection signal from the thrust sensor 165.

Next, in the disc brake 1 according to the present embodiment, the actions of braking and releasing braking in normal driving will be described.
During braking in normal driving, the electric motor 32 is driven by a command from the control board 64, and the rotation in the positive direction, that is, in the braking direction is the sun gear 106 of the planetary gear reduction mechanism 89 via the spur tooth multi-stage reduction mechanism 88. Is transmitted to. Due to the rotation of the sun gear 106 of the planetary gear reduction mechanism 89, each planetary gear 115 revolves around the rotation axis of the sun gear 106 while rotating around its own rotation axis, thereby rotating the carrier 117. That is, the rotation from the electric motor 32 is decelerated and increased at a predetermined reduction ratio by passing through the spur tooth multi-stage deceleration mechanism 88 and the planetary gear deceleration mechanism 89, and is transmitted to the carrier 117. Then, the rotation from the carrier 117 is transmitted to the spindle 150 of the screw mechanism 90.

Subsequently, when the spindle 150 rotates with the rotation of the carrier 117, the nut member 151 is supported so as not to rotate relative to the cylinder portion 34, so that the male screw portion 156 of the spindle 150 and the nut member 151 are supported. The screw engaging portion advances the nut member 151 to advance the piston 53. As the piston 53 moves forward, the inner brake pad 2 is pressed against the disc rotor D. Then, the caliper main body 30 moves toward the inner side with respect to the bracket 5 due to the reaction force against the pressing force on the inner brake pad 2 by the piston 53, and the outer brake pad 3 is transferred to the disc rotor D by the claws 35 and 35, respectively. Press. The reaction force against the pressing force of the piston 53 on the inner brake pad 2 is detected by the thrust sensor 165. As a result, the disc rotor D is sandwiched between the pair of inners and the outer brake pads 2 and 3, and a frictional force is generated, which in turn generates a braking force of the vehicle.

On the other hand, when the braking is released, the rotation shaft 33 of the electric motor 32 rotates in the opposite direction, that is, in the braking release direction, and the rotation in the opposite direction is the spur tooth multi-stage deceleration mechanism 88 and the planetary gear deceleration. It is transmitted to the spindle 150 via the mechanism 89. As a result, the rotation of the spindle 150 in the opposite direction causes the nut member 151 to retract and return to the initial state, and the braking force of the pair of inners and outer brake pads 2 and 3 on the disc rotor D is released.

As described above, in the disc brake 1 according to the present embodiment, the screw mechanism 90 includes a spindle 150 having a polygonal rod portion 154 that engages with the polygonal hole portion 124 of the carrier 117 of the planetary gear reduction mechanism 89. The support rod portion 155 of the spindle 150 is inserted into the hole portion 110 of the sun gear 106 of the second reduction gear 94, and the sun gear 106 is rotatably supported by the support rod 155 of the spindle 150. As a result, the support plate to which the shaft that rotatably supports the sun gear 106, which has been conventionally required, is not required, so that the number of parts of the disc brake 1 can be reduced and the cost increase can be suppressed. Moreover, in the disc brake 1, the size of the spindle 150 in the axial direction can be reduced, the weight thereof can be reduced, and the mountability on a vehicle can be improved.

Further, in the disc brake 1 according to the present embodiment, the spindle 150 has a main rod portion (supported portion) 153 rotatably supported by an insertion hole 47 provided in the bottom wall 46 of the cylinder portion 34, and the main rod. A polygonal rod portion (engagement portion) 154 extending integrally from one end of the portion 153 toward one end side and engaging with the polygonal hole portion 124 provided substantially in the radial center of the carrier 117, and the polygonal rod. A support rod portion (support portion) 155 that extends integrally from one end of the portion 154 toward one end side and is inserted into the hole portion 110 of the second speed reduction mechanism 126 (sun gear 106) to rotatably support the sun gear 106. It is integrally provided on the other end side from the main rod portion 153, and has a male screw portion 156 that is screw-engaged with the nut member 151. As a result, since the spindle 150 is configured as a multifunctional component, the number of components can be reduced, and the size of the disc brake 1 can be reduced, and the weight thereof can be reduced. can.

Therefore, in the present embodiment, during braking in normal running, the piston 53 is advanced by the brake hydraulic pressure supplied in the cylinder bore 50 of the caliper main body 31, and the disc rotor D is moved to the pair of inner and outer brake pads 2. A braking force is generated by sandwiching the brake with 3, and during parking braking such as when parking, the driving force from the drive mechanism 31, that is, the electric motor 32 is passed through the spur tooth multi-stage reduction mechanism 88, the planetary gear reduction mechanism 89, and the screw mechanism 90. The piston 53 may be advanced by transmitting to the piston 53, and the disc rotor D may be sandwiched between a pair of inner brake pads 2 and 3 to generate a braking force, which may be adopted as a disc brake.

1 disc brake, 2 inner brake pad, 3 outer brake pad, 4 caliper, 30 caliper body, 31 drive mechanism, 32 electric motor, 34 cylinder part, 53 piston, 88 spur tooth multi-stage deceleration mechanism (transmission mechanism), 89 planetary gear Deceleration mechanism (transmission mechanism), 90 screw mechanism (rotational linear motion conversion mechanism), 94 second deceleration mechanism, 106 sun gear (sun gear), 110 holes, 115 planetary gear (planetary gear), 116 internal gear (internal gear) , 117 carrier, 150 spindle (rotary shaft member), 153 main rod part (supported part), 154 polygonal rod part (engagement part), 155 support rod part (support part), 156 male screw part, D disc rotor

Claims (2)

A transmission mechanism that transmits the rotation from the electric motor,
A rotational linear motion conversion mechanism that converts rotation from the transmission mechanism into thrust, and
The piston propelled by the rotary linear motion conversion mechanism and
In disc brakes with
The transmission mechanism includes a sun gear, a planetary gear, and a carrier, and includes a planetary gear reduction mechanism in which rotation from the electric motor is transmitted from the sun gear to the carrier via the planet gear.
The rotary linear motion conversion mechanism has a rotary shaft member to which rotation from the carrier is transmitted.
The sun gear is rotatably supported by the rotating shaft member, and is supported by the rotating shaft member .
The rotary shaft member is
A supported portion that is rotatably supported by the cylinder portion in which the piston is housed, and a supported portion.
A support portion that extends integrally from the supported portion and rotatably supports the sun gear, and a support portion.
An engaging portion provided between the supported portion and the supporting portion, which is engaged with the carrier and transmits rotational torque to and from the carrier.
Equipped with
A disc brake characterized in that the engaging portion has a smaller diameter than the supported portion, and the supporting portion has a smaller diameter than the engaging portion . The electric motor is arranged so as to overlap the cylinder portion with respect to the radial direction of the piston.
The disc brake according to claim 1 , wherein the rotating shaft of the electric motor extends in a direction opposite to the propulsion direction of the piston .

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