JP4381336B2 - Disc brake device and method for forming cylinder hole in disc brake device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a disc brake device having simple construction with a fixed side cam plate, a driving side cam plate, a thrust transmission plate and a cam spring housed in a housing into a unit and the housing arranged in a cylinder hole in the state of being non-turnable for preventing the rotation of the thrust transmission plate in the state of being movable in the axial direction of a cylinder and the rotation of the fixed side cam plate, producing a good stroke feeling during the operation of a parking brake and holding a braking gap between a friction pad and a disc rotor always good with reliable operation of an adjuster. <P>SOLUTION: The housing 16 has a lock piece 16f to be locked to the fixed side cam plate 12 and an engaging hole 16d to be engaged with the thrust transmission plate 14b to prevent the rotation of the thrust transmission plate 14b in the state of being movable in the axial direction of the cylinder. The housing 16 has an engaging rib 16g on the outer peripheral face and the cylinder hole has an engaging groove 8f in the inner peripheral face. The engaging groove 8f and the engaging rib 16g engage each other to restrict the turning of the housing 16. <P>COPYRIGHT: (C)2007,JPO&amp;INPIT

Description

  The present invention relates to a disc brake device and a method of forming a cylinder hole in the disc brake device, and more particularly, a piston that presses a friction pad by hydraulic pressure, and an adjuster for automatically adjusting a gap between the friction pad and the disc rotor. And a disk brake device including a parking brake that presses a piston through the adjuster by a ball ramp type thrust conversion mechanism, and a method of forming a cylinder hole in the disc brake device.

  As a disc brake device used for a four-wheeled vehicle or the like, there is a disc brake device with a parking brake that includes a hydraulic operation mechanism using a brake pedal and a mechanical operation mechanism that is pulled by a hand lever or a foot pedal. This disc brake device with a parking brake is generally an adjuster in which a piston that constitutes a hydraulic operating mechanism is disposed on the end opening side of a cylinder hole provided in a caliper body, and an adjustment nut and an adjustment bolt are provided on the rear surface side of the piston. And a thrust conversion mechanism constituting a mechanical operating mechanism is disposed on the bottom side of the cylinder hole.

  Conventionally, a ball lamp type has been widely known as a thrust conversion mechanism. In this ball ramp type thrust converting mechanism, a fixed cam plate and a driving cam plate each having a ramp groove for accommodating a cam bearing are arranged opposite to each other, and the driving cam plate is rotated by a parking brake operation. The cam action of the ramp groove and the cam bearing generates a thrust that moves the piston toward the disk rotor, and this thrust pushes the piston toward the disk rotor via the adjuster and presses the friction pad against the disk rotor. To obtain braking force. The fixed cam plate, the drive cam plate, the thrust transmission plate, and a cam spring that biases the thrust transmission plate in the direction of the drive cam plate are disposed in a substantially cylindrical housing. It is housed and unitized to improve the assemblability (for example, see Patent Document 1).

Further, when forming the axial groove in the cylinder hole of the disc brake device, after processing the cylinder hole, an end mill cutter is inserted from the cylinder hole opening side to process the axial groove (for example, patent Reference 2).
Japanese Patent No. 2739879 JP 2004-353850 A

  In the ball ramp type thrust conversion mechanism as described above, the fixed cam plate, the drive cam plate, the thrust transmission plate, and the cam spring are housed in a substantially cylindrical housing and unitized. Therefore, when the thrust transmission plate is prevented from being rotated by the housing in a state in which the thrust transmission plate is movable in the cylinder axial direction, and the fixed-side cam plate is also prevented from rotating, it is necessary to restrict the rotation of the housing itself.

  Also, when forming an axial groove in the cylinder hole, an end mill cutter is inserted from the cylinder hole opening side, so the end mill cutter is thin, so the groove is machined by hitting the blade against the inner peripheral surface of the cylinder hole. At this time, it was difficult to apply the end mill cutter parallel to the inner peripheral surface of the cylinder hole, and the engagement groove could not be formed with high accuracy.

  Therefore, the present invention has a simple structure and houses the fixed cam plate, the drive cam plate, the thrust transmission plate, and the cam spring in a substantially cylindrical housing as a unit, and the housing cannot be rotated. In this state, the thrust transmission plate is prevented from rotating in a state where it can move in the cylinder axial direction, and the fixed cam plate is also prevented from rotating so that a good stroke fee can be obtained during parking brake operation. An object of the present invention is to provide a disc brake device that can obtain a ring, can operate the adjuster reliably, and can maintain a good braking gap between the friction pad and the disc rotor at all times. It aims at providing the formation method of the cylinder hole which can form a groove | channel accurately.

In order to achieve the above object, in the first configuration , the piston housed on the tip opening side of the cylinder hole formed in the caliper body, the thrust conversion mechanism disposed on the bottom side of the cylinder hole, and the thrust A disc brake device including a parking brake that includes an adjustment nut and an adjustment bolt provided between the conversion mechanism and the piston, and that pushes the piston from the thrust conversion mechanism via the adjuster; The thrust conversion mechanism includes a fixed cam plate attached to the bottom wall of the cylinder hole, and a cam that is rotatable with respect to the cylinder hole bottom wall and the fixed cam plate and movable in the cylinder axial direction. A shaft, a drive-side cam plate provided on the cylinder hole opening side of the camshaft, and opposed positions of the drive-side cam plate and the fixed-side cam plate A ramp groove formed in the lamp groove and a cam bearing accommodated in the ramp groove, and the adjuster thrusts on an end portion on the bottom side of the cylinder hole facing the driving cam plate of one of an adjustment nut and an adjustment bolt. A transmission plate, wherein the fixed cam plate, the drive cam plate, the thrust transmission plate, and a cam spring that biases the thrust transmission plate in the direction of the drive cam plate are substantially cylindrical. Housed in a housing, the housing is disposed on the bottom side of the cylinder hole, and the housing is mounted in the cylinder hole in a state in which movement in the cylinder axial direction is restricted by a retaining ring attached to the cylinder hole. in the disc brake device, the housing, interlocked with the locking groove provided in the cylinder bore bottom portion side end surface of the fixed side cam plate, detent the fixed side cam plate And locking piece of the cylinder hole bottom side end portion of the engaging hole for detent movably in the thrust transmitting plate engage in該推force transmission plate to the cylinder axis direction, the outer peripheral surface of the front Symbol housing And an engaging rib that engages with an engaging groove formed on the inner peripheral surface of the cylinder hole by projecting outward in the circumferential direction, and locking the locking piece of the housing in the locking groove of the fixed-side cam plate The fixed cam plate is non-rotatably attached to the housing, and the rotation of the housing is restricted by engaging the engagement rib of the housing with the engagement groove of the cylinder hole. Further, in the first configuration, the drive side cam plate has a cylindrical portion projecting from the center of the cylinder hole opening side end portion, and a projecting portion projecting from the outer peripheral side of the cylindrical portion, The thrust transmission plate is formed at the center of the cylinder hole bottom side end portion and the cylindrical portion. A projection hole is formed on the inner peripheral side of the accommodation hole, and the rotation amount of the driving cam plate is brought into contact with the projection so that the cam bearing does not fall out of the ramp groove. It is characterized in that a regulating part for regulating is projected .

In the second configuration, the piston housed on the tip opening side of the cylinder hole formed in the caliper body, the thrust conversion mechanism disposed on the bottom side of the cylinder hole, and between the thrust conversion mechanism and the piston An adjusting nut and an adjusting bolt provided with an adjusting bolt, and a disc brake device including a parking brake that pushes the piston through the adjuster from the thrust converting mechanism, wherein the thrust converting mechanism includes: A fixed cam plate attached to the bottom wall of the cylinder hole; a camshaft penetrating the cylinder hole bottom wall and the fixed cam plate so as to be rotatable and movable in the cylinder axial direction; and a cylinder of the camshaft Drive side cam plate provided on the hole opening side, and ramps formed respectively at positions facing the drive side cam plate and the fixed side cam plate And a cam bearing accommodated in the ramp groove, the adjuster includes a thrust transmission plate at a cylinder hole bottom side end facing the drive cam plate of either one of an adjustment nut and an adjustment bolt, A stationary cam plate, the drive side cam plate, the thrust transmission plate, and a cam spring that biases the thrust transmission plate in the direction of the drive side cam plate are accommodated in a substantially cylindrical housing. In the disc brake device in which the housing is disposed on the bottom side of the cylinder hole and the housing is mounted in the cylinder hole by a retaining ring attached to the cylinder hole, the housing is locked to the fixed cam plate. A locking piece that prevents the fixed cam plate from rotating, and an engagement hole that engages with the thrust transmission plate and prevents the thrust transmission plate from moving in the cylinder axial direction. In addition, an engagement rib is formed on one of the outer peripheral surface of the housing and the inner peripheral surface of the cylinder hole, and an engagement groove is formed on the other, and the engagement groove and the engagement rib are engaged with each other. Thus, the rotation of the housing is restricted, and the drive side cam plate has a cylindrical portion protruding at the center of the cylinder hole opening side end portion, and a protruding portion protrudes on the outer peripheral side of the cylindrical portion. The thrust transmission plate is formed with an accommodation hole for accommodating the cylindrical portion and the protrusion at the center of the cylinder hole bottom side end portion, and is in contact with the protrusion on the inner peripheral side of the accommodation hole. A restricting portion that restricts the amount of rotation of the driving cam plate within a range in which the cam bearing does not fall out of the ramp groove is projected, and the cylindrical portion and the protruding portion are accommodated in the accommodation hole, so that the thrust transmission plate Cylinder hole opening side of the drive cam plate is in contact with the cylinder bottom side And characterized in that it is further in the second configuration, the housing, the engaging rib which is formed by protruding the outer peripheral surface in the circumferential direction outwardly provided, in the cylinder bore, provided with the engaging groove It is characterized by that.

In the third configuration, a large-diameter portion that accommodates the piston on the opening side, a small-diameter portion that accommodates the thrust conversion mechanism of the parking brake mechanism on the bottom side, and the engagement groove on the inner peripheral surface of the small-diameter portion. The disc brake device according to the second configuration, wherein the first configuration or the housing is provided with the engagement rib formed by protruding an outer peripheral surface outward in the circumferential direction, and the engagement groove is provided in the cylinder hole. In the cylinder hole forming method in the above, after processing the cylindrical groove forming hole at the engagement groove forming position from the opening side, the small diameter portion is processed while leaving the groove forming hole partially, The engagement groove is formed on the inner peripheral surface of the small diameter portion, and then the large diameter portion is processed.

Ri by the be configured as described above, since the housings are arranged in a non-rotatable state in the cylinder bore, unrotatably fixed side cam plate contained within the housing by locking piece The thrust transmission plate is prevented from rotating in a state in which it can move in the cylinder axial direction by the engagement hole, and a simple structure can provide a good stroke feeling when the parking brake is operated. By operating reliably, the braking gap between the friction pad and the disk rotor can always be kept good. In addition, the housing is prevented from rotating with a simple structure, and accordingly, the fixed cam plate is securely prevented from rotating, and the thrust transmission plate is prevented from rotating in the cylinder axial direction, thereby reducing the number of parts. Can do.

Furthermore, the cylinder hole and the housing can be easily processed.

In addition, the axial engagement groove can be formed in the cylinder hole with high accuracy.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. 1 to 4 show an embodiment of the present invention. FIG. 1 is an enlarged sectional view of a main part of a disc brake device, FIG. 2 is a sectional view taken along line II-II in FIG. 1, and FIG. FIG. 4 is an exploded perspective view of the adjusting nut and the housing, and FIG. 4 is a sectional front view of the disc brake device.

  The disc brake device 1 includes a hydraulic operating mechanism 3 operated by a brake pedal (not shown) on the caliper body 2 and a mechanical operating mechanism 4 for a parking brake operated by a hand lever or a foot pedal (not shown). The caliper body 2 is a disc brake device with a parking brake provided side by side with a caliper bracket 6 fixed to the vehicle body on one side of the disc rotor 5 via a pair of sliding pins (not shown) in the disc axial direction. It is supported so as to be movable.

  The caliper body 2 includes an action part 2a and a reaction part 2b that are arranged to face both sides of the disk rotor 5, and a bridge part 2c that straddles the outside of the disk rotor 5 and connects them. A pair of friction pads 7 are disposed between the disk rotor 5 and the reaction portion 2b.

  A cylinder hole 8 that opens to the disk rotor side is formed in the action portion 2a. The cylinder hole 8 is formed with a large diameter portion 8a on the tip opening side and a small diameter portion 8b on the cylinder hole bottom side. The large diameter portion 8a has a seal groove 8c and a boot groove 8d on the cylinder hole opening side. Retaining ring mounting grooves 8e are respectively provided on the side, and three engagement grooves 8f are provided in the small diameter portion 8b at equal intervals in the circumferential direction of the small diameter portion 8b.

  A large diameter portion 8a of the cylinder hole 8 accommodates a bottomed cylindrical piston 9 constituting the hydraulic operation mechanism 3, and a ball ramp type thrust conversion constituting the mechanical operation mechanism 4 is accommodated in the small diameter portion 8b. The mechanism 10 is accommodated, and an adjuster 11 for automatically adjusting a braking gap between the disk rotor 5 and the friction pad 7 is disposed between the piston 9 and the thrust conversion mechanism 10. A fixed cam plate 12 is disposed on the cylinder hole bottom wall 8g.

  The adjuster 11 includes an adjusting bolt 13 and an adjusting nut 14, and a small-diameter piston 13 a and a clutch plate 13 b are provided on the head of the adjusting bolt 13. The adjustment nut 14 is internally formed with a multi-threaded screw 14a that is screwed with the adjustment bolt 13, and a thrust transmission plate 14b is provided at the end on the cylinder hole bottom side. A cylindrical housing 16 that houses the cam spring 15 and the thrust transmission plate 14b is disposed on the bottom side of the adjustment nut 14 in the cylinder hole 8 by a retaining ring 17 that is fitted in the retaining ring mounting groove 8e. It is arranged.

  The piston 9 is accommodated in the large-diameter portion 8a of the cylinder hole 8 with the bottom wall 9a facing the disk rotor side, and the adjusting nut 14 and the adjusting bolt 13 are provided on the inner central axis of the piston 9. ing. A fitting hole 9b is provided on the inner surface of the bottom wall of the piston 9, and the small-diameter piston 13a is fitted into the fitting hole 9b via a sealing material, and the clutch plate 13b is an opening portion of the fitting hole 9b. Is pressed against the conical surface 9c that expands by the action of the adjusting spring 18.

  The adjustment spring 18 is held at one end by the bearing receiver 19 and at the other end by a retaining ring 20 provided on the outer periphery of the adjustment nut 14, and the adjustment bolt 13 is connected to the bottom wall 9 a via the bearing receiver 19 and the bearing 21. It is energized in a state that it can pivot to the side.

  The thrust conversion mechanism 10 includes a camshaft 22 that is rotatable with respect to the cylinder hole bottom wall 8g and the fixed cam plate 12 and is movable in the cylinder axial direction, and a cylinder hole opening side end of the camshaft 22. A drive side cam plate 22a provided in the section, three ramp grooves 23 formed at opposite positions of the drive side cam plate 22a and the fixed side cam plate 12, and three cams accommodated in the ramp groove 23, respectively. And a bearing 24.

  The driving cam plate 22a has a cylindrical portion 22b projecting from the center of the cylinder hole opening side end, and two projecting portions 22c and 22c projecting from the outer peripheral side of the cylindrical portion 22b. The thrust transmission plate 14b comes into contact with the opening side surface of the cylinder hole via the thrust bearing 25.

  The thrust transmission plate 14b is formed with an accommodation hole 14c for accommodating the cylindrical portion 22b and the protrusions 22c, 22c at the center of the cylinder hole bottom side end, and the protrusion is formed on the inner peripheral side of the accommodation hole 14c. Restricting portions 14d and 14d projectingly come into contact with 22c and 22c and restrict the amount of rotation of the driving cam plate 22a within a range in which each cam bearing 24 does not fall off the ramp groove 23. In addition, three engaging protrusions 14e are provided at equal intervals on the outer periphery.

  The fixed-side cam plate 12 is formed in a disk shape, and an insertion hole 12a through which the cam shaft 22 is inserted is provided at the center. A cylinder hole bottom wall 8g is provided around the insertion hole 12a on the end surface on the cylinder hole bottom side. The rib 12b inserted into the rib receiving groove 8h provided in the projection protrudes, and three locking grooves 12c for locking the housing 16 are provided on the cylinder hole bottom side end surface.

  The housing 16 has a large diameter cylindrical portion 16a formed slightly smaller than the diameter of the small diameter portion 8b of the cylinder hole 8 and a small diameter formed larger than the outer diameter of the thrust transmission plate 14b formed on the adjustment nut 14. The cylindrical portion 16b is integrally provided, and on the bottom side of the cylinder hole of the small-diameter cylindrical portion 16b, a part of the peripheral wall is cut and raised to the outside to form a mounting piece 16c, and each of the thrust transmission plates 14b Three engagement holes 16d are formed in which the engagement protrusions 14e are engaged so as to be movable only in the axial direction. Further, a support piece 16e of the cam spring 15 protrudes on the inner peripheral side at the cylinder hole opening side end of the small diameter cylindrical portion 16b. Three locking pieces 16f that are respectively locked to the locking grooves 12c of the fixed cam plate 12 are formed on the cylinder hole bottom side end of the large-diameter cylindrical portion 16a. The three engaging ribs 16g bulged in are provided at equal intervals.

  Assembling the disc brake device 1 of the present embodiment formed in this way inserts the cam spring 15 from the opening on the bottom side of the cylinder hole of the housing 16 and abuts one end of the cam spring 15 on the support piece 16e. An adjustment nut 14 is inserted through the inner periphery. The other end of the cam spring 15 is brought into contact with the cylinder hole opening side end of the thrust transmission plate 14b provided on the adjustment nut 14, and the engagement protrusion 14e of the adjustment nut 14 is engaged with the engagement hole 16d of the housing 16. At the same time, the thrust transmission plate 14b is prevented from rotating while being movable in the cylinder axial direction. Next, the cylindrical portion 22b of the driving cam plate 22a and the protrusions 22c and 22c are received in the receiving hole 14c of the thrust transmission plate 14b, and the cylinder hole bottom side of the thrust transmission plate 14b and the cylinder of the driving cam plate 22a. The hole opening side end is brought into contact with the thrust bearing 25. The drive-side cam plate 22a is restricted from turning more than a predetermined amount by the protrusion 22c formed on the cylindrical portion 22b coming into contact with the restricting portion 14d formed in the accommodation hole 14c. Next, the camshaft 22 is passed through the insertion hole 12a of the fixed cam plate 12 so that the cam bearings 24 are accommodated in the ramp grooves 23, and the fixed cam plate 12 is disposed on the bottom side of the cylinder hole of the drive cam plate 22a. Then, the bent piece 16 f of the housing 16 is bent and locked in the locking groove 12 c of the fixed cam plate 12. As a result, the fixed cam plate 12 is attached to the bottom of the cylinder hole of the housing 16, and the thrust conversion mechanism 10, the thrust transmission plate 14b, and the cam spring 15 can be assembled into the housing 16 to form a unit.

  The unit assembled in this manner is inserted into the cylinder hole 8 with the fixed cam plate 12 facing the cylinder hole bottom wall 8g, and the engaging rib 16g of the housing 16 is connected to the small diameter portion 8b of the cylinder hole 8. The camshafts 22 respectively engaged with the formed engaging grooves 8f and projecting from the fixed cam plate 12 are projected outward from the insertion holes 8i of the cylinder hole bottom wall 8g, and the ribs 12b of the fixed cam plate 12 are formed. The rib housing groove 8h is engaged through a sealing material. Further, the unit is mounted in the cylinder hole 8 by fitting the retaining ring 17 into the retaining ring mounting groove 8 e of the cylinder hole 8 and bringing it into contact with the cylinder hole opening side surface of the mounting piece 16 c of the housing 16. Thus, by engaging the engagement rib 16g of the housing 16 with the engagement groove 8f of the cylinder hole 8, the rotation of the housing 16 can be restricted.

  On the other hand, inside the piston 9, an adjusting bolt 13, a bearing 21, a bearing receiver 19, an adjusting spring 18, and a retaining ring 20 are mounted in this order, which is also a unit. Next, the piston 9 is pushed into the cylinder hole 8 while the adjustment bolt 13 is screwed into the adjustment nut 14, and the operation lever 26 is attached to the protruding end of the camshaft 22. As a result, the hydraulic operating mechanism 3, the mechanical operating mechanism 4, and the adjuster 11 are assembled to the caliper body 2. Each sealing material is attached at an appropriate stage.

  In this disc brake device 1, in the brake operation using the hydraulic operation mechanism 3, the piston 9 is pushed in the direction of the disc rotor by the pressure of the hydraulic fluid introduced into the cylinder hole 8, and the friction pad 7 of the action portion 2 a is applied. Is pressed against one side of the disk rotor 5, and the reaction force causes the caliper body 2 to move in the direction of the action part 2a, so that the reaction part 2b presses the friction pad 7 on the reaction part 2b side against the other side of the disk rotor 5. A braking action is performed.

  At this time, when the braking gap between the friction pad 7 and the disk rotor 5 is within a predetermined range, the adjustment is performed only by the movement amount of the piston 9 moving the backlash between the adjustment bolt 13 and the adjustment nut 14. Absent. If the braking gap with the disk rotor 5 exceeds a predetermined value due to wear of the friction pad 7, the piston 9 greatly moves to the disk rotor side beyond the backlash, so that the clutch plate 13b and the conical surface 9c of the piston 9 It is in a separated state. In this state, the adjustment bolt 13 is fed out from the adjustment nut 14 by the urging force of the adjustment spring 18, and the clutch plate 13b and the conical surface 9c come into contact with each other. When the brake operation is released in this state, the piston 9 and the adjusting bolt 13 are moved backward by the backlash, so that the braking gap between the friction pad 7 and the disk rotor 5 is automatically adjusted to a predetermined range.

  In the parking brake operation by the mechanical operation mechanism 4, when the operation lever 26 is rotated by a hand lever or a foot pedal (not shown), the drive cam plate 22a is rotated together with the cam shaft 22, and the drive cam plate is driven. The phase of the ramp grooves 23a of 22a and the ramp grooves 23 of the fixed-side cam plate 12 in the non-rotating state shifts, so that the cam bearings 24 move to the shallow portions of the ramp grooves 23, respectively. The drive cam plate 22a is moved away from the disk rotor 12 so as to move away from the disk rotor. This axial movement of the driving cam plate 22a is transmitted from the adjusting nut 14 to the piston 9 via the adjusting bolt 13, and becomes a thrust force that pushes the piston 9 toward the disk rotor. The braking action is performed in the same manner as the braking action.

  As described above, when the parking brake operation is performed by the mechanical operation mechanism 4, the rotation of the housing 16 is restricted by the engagement rib 16 g engaging the engagement groove 8 f formed in the cylinder hole 8. At the same time, the cylinder hole opening side surface of the mounting piece 16c and the retaining ring 17 come into contact with each other, thereby restricting movement in the cylinder axial direction. Further, since the thrust transmission plate 14b is engaged with the engagement hole 16d of the housing 16, the thrust transmission plate 14b is prevented from rotating in a state of being movable in the axial direction, and the fixed cam plate 12 is locked in the locking groove 12c. The piece 16f is locked by being locked.

  As a result, the rotation of the housing 16 is restricted with a simple structure. Accordingly, the stationary cam plate 12 is restricted in a good state and the thrust transmission plate 14b can move in the cylinder axis direction. In this state, the rotation is restricted, and a good stroke feeling can be obtained when the parking brake is operated, and the adjuster 11 is reliably operated to keep the braking gap between the friction pad 7 and the disc rotor 5 always good. be able to. Moreover, the workability of assembling the disc brake device 1 can be improved. Further, the driving cam plate 22a is rotated by the protrusion 22c formed on the cylindrical portion 22b of the driving cam plate 22a coming into contact with the regulating portion 14d formed in the accommodation hole 14c of the thrust transmission plate 14b. Since the amount of movement is restricted to a range in which the cam bearing 24 does not fall out of the ramp groove 23 and is held in a rotatable state only within a predetermined angle range, the parking brake operation can be performed satisfactorily.

  In the above-described embodiment, the housing is provided with the engagement rib and the engagement groove is formed in the cylinder hole. However, the engagement rib is formed in the cylinder hole and the engagement groove is formed in the housing. But you can. Moreover, the thrust transmission plate is formed on the adjustment nut and the adjustment nut is accommodated in the housing, but the thrust transmission plate may be formed on the adjustment bolt and the adjustment bolt may be accommodated in the housing.

  Next, a method for forming the cylinder hole 8 shown in the above-described embodiment will be described with reference to FIG.

  First, as shown in FIG. 5 (a), three small-diameter cylindrical grooves are formed by drilling on three engagement groove forming portions from the cylinder hole large-diameter portion forming side of the caliper body 30 after casting. The hole 31 is processed. Next, as shown in FIG. 5B, the small-diameter hole 32 that becomes the small-diameter portion 8b is processed while leaving the groove-forming portion 31a that becomes the engaging groove 8f of each groove-forming hole 31. Next, as shown in FIG. 5C, the large-diameter hole 33 that becomes the large-diameter portion 8a and the conical surface 8f are processed. Finally, finish processing is performed in the cylinder hole 8 to process the seal groove 8c, the boot portion groove 8d, the retaining ring mounting groove 8e, the rib receiving groove 8h, and the insertion hole 8i.

  Thus, since the engaging groove 8f of the cylinder hole 8 is formed using the groove forming hole 31 processed in the cylinder axial direction, the engaging groove 8f can be accurately formed by a simple method. .

It is a principal part expanded sectional view of the disc brake apparatus which shows one example of this invention. It is II-II sectional drawing of FIG. It is a disassembled perspective view of a thrust conversion mechanism, an adjustment nut, and a housing similarly. It is a cross-sectional front view of the disc brake device. It is explanatory drawing which shows the formation method of the cylinder hole in the disc brake apparatus of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Disc brake device, 2 ... Caliper body, 2a ... Action part, 3 ... Hydraulic operation mechanism, 4 ... Mechanical operation mechanism, 5 ... Disc rotor, 6 ... Caliper bracket, 7 ... Friction pad, 8 ... Cylinder hole, 8a: Large diameter portion, 8b: Small diameter portion, 8e: Retaining ring mounting groove, 8f: Engaging groove, 8g: Cylinder hole bottom wall, 8h ... Rib receiving groove, 8i ... Insertion hole, 9 ... Piston, 10 ... Thrust conversion Mechanism: 11 ... Adjuster, 12 ... Fixed cam plate, 12a ... Insertion hole, 12b ... Rib, 12c ... Locking groove, 13 ... Adjust bolt, 13a ... Small-diameter piston, 13b ... Clutch plate, 14 ... Adjust nut, 14a ... Multi-thread screw, 14b ... Thrust transmission plate, 14c ... Accommodating hole, 14d ... Restriction part, 14e ... Projection for engagement, 15 ... Cam spring, 16 ... Housing, 16a ... Large diameter cylindrical part, 16b Small diameter cylindrical part ... 6c ... Installation piece, 16d ... Engagement hole, 16e ... Supporting piece, 16f ... Locking piece, 16g ... Engagement rib, 17 ... Retaining ring, 18 ... Adjusting spring, 19 ... Bearing receiver, 20 ... Retaining ring, 21 ... Bearing, 22 ... camshaft, 22a ... Drive side cam plate, 22b ... Cylindrical portion, 22c ... Projection, 23 ... Ramp groove, 24 ... Cam bearing, 25 ... Thrust bearing

Claims (5)

A piston housed on the tip opening side of the cylinder hole formed in the caliper body, a thrust conversion mechanism disposed on the bottom side of the cylinder hole, and an adjustment nut provided between the thrust conversion mechanism and the piston And a brake having a parking brake that pushes the piston from the thrust conversion mechanism via the adjuster, and the thrust conversion mechanism is formed on the bottom wall of the cylinder hole. A fixed cam plate to be mounted; a camshaft penetrating the cylinder hole bottom wall and the fixed cam plate so as to be rotatable and movable in the cylinder axial direction; and provided on the cylinder hole opening side of the camshaft. Drive-side cam plate, ramp grooves formed at opposite positions of the drive-side cam plate and the fixed-side cam plate, and the ramp grooves A cam bearing that is housed, and the adjuster includes a thrust transmission plate at a cylinder hole bottom side end facing the driving cam plate of any one of an adjusting nut and an adjusting bolt, and the fixed cam plate The drive-side cam plate, the thrust transmission plate, and a cam spring that biases the thrust transmission plate in the direction of the drive-side cam plate are accommodated in a substantially cylindrical housing, and the housing is stored in the cylinder. In a disc brake device installed in the cylinder hole in a state where the movement of the housing in the cylinder axial direction is restricted by a retaining ring attached to the cylinder hole and fixed to the housing. interlocked with the locking groove provided in the cylinder bore bottom portion side end surface of the side cam plate, the locking piece of the cylinder hole bottom side end portion for detent of the fixed side cam plate, wherein And engaging holes which detent the該推force transmitting plate is movable in the cylinder axial direction engaged with the force transmitting plate, said cylinder bore inner peripheral surface of the outer peripheral surface to protrude circumferentially outwardly before Symbol housing An engagement rib that engages with an engagement groove formed on the fixed side cam plate is provided, and the locking piece of the housing is locked to the locking groove of the fixed side cam plate so that the fixed side cam plate cannot be rotated relative to the housing. The disc brake device is characterized in that rotation of the housing is restricted by engaging the engaging rib of the housing with the engaging groove of the cylinder hole. The driving cam plate has a cylindrical portion projecting at the center of the cylinder hole opening side end portion, and a projecting portion projecting on the outer peripheral side of the cylindrical portion. The thrust transmission plate is disposed on the cylinder hole bottom side. An accommodation hole for accommodating the cylindrical portion and the protrusion is formed at the center of the end portion, and the cam bearing is configured to abut the protrusion on the inner peripheral side of the accommodation hole so that the rotation amount of the driving cam plate is increased. The disc brake device according to claim 1, wherein a restricting portion is provided so as to protrude within a range in which the lamp groove does not fall off . A piston housed on the tip opening side of the cylinder hole formed in the caliper body, a thrust conversion mechanism disposed on the bottom side of the cylinder hole, and an adjustment nut provided between the thrust conversion mechanism and the piston And a brake having a parking brake that pushes the piston from the thrust conversion mechanism via the adjuster, and the thrust conversion mechanism is formed on the bottom wall of the cylinder hole. A fixed cam plate to be mounted; a camshaft penetrating the cylinder hole bottom wall and the fixed cam plate so as to be rotatable and movable in the cylinder axial direction; and provided on the cylinder hole opening side of the camshaft. Drive-side cam plate, ramp grooves formed at opposite positions of the drive-side cam plate and the fixed-side cam plate, and the ramp grooves A cam bearing that is housed, and the adjuster includes a thrust transmission plate at a cylinder hole bottom side end facing the driving cam plate of any one of an adjusting nut and an adjusting bolt, and the fixed cam plate The drive-side cam plate, the thrust transmission plate, and a cam spring that biases the thrust transmission plate in the direction of the drive-side cam plate are accommodated in a substantially cylindrical housing, and the housing is stored in the cylinder. In the disc brake device that is disposed on the bottom side of the hole and in which the housing is mounted in the cylinder hole by a retaining ring attached to the cylinder hole, the housing is locked to the fixed cam plate, and the fixed side A locking piece for preventing the cam plate from rotating, and an engagement hole for engaging the thrust transmission plate to prevent the thrust transmission plate from rotating in the cylinder axial direction. An engagement rib is formed on one of the outer peripheral surface of the housing and the inner peripheral surface of the cylinder hole, and an engagement groove is formed on the other, and the engagement groove and the engagement rib are engaged with each other. The rotation of the housing is restricted, and the driving side cam plate has a cylindrical portion protruding at the center of the cylinder hole opening side end portion, and a protruding portion protruding from the outer peripheral side of the cylindrical portion, The thrust transmission plate is formed with an accommodation hole for accommodating the cylindrical portion and the protrusion at the center of the cylinder hole bottom side end portion, and is in contact with the protrusion on the inner peripheral side of the accommodation hole. A restricting portion for restricting the amount of rotation of the plate within a range in which the cam bearing does not fall out of the ramp groove is provided, and the cylindrical portion and the protruding portion are accommodated in the accommodation hole, so that the cylinder bottom side of the thrust transmission plate The cylinder side opening side of the drive side cam plate is in contact with Disc brake device characterized. 4. The disc brake device according to claim 3 , wherein the housing is provided with the engagement rib formed with an outer peripheral surface protruding outward in the circumferential direction, and the engagement groove is provided in the cylinder hole . 5. A large-diameter portion that accommodates a piston on the opening side, a small-diameter portion that accommodates a thrust conversion mechanism of a parking brake mechanism on the bottom side, and the engagement groove on the inner peripheral surface of the small-diameter portion. In the method for forming a cylinder hole in the disc brake device described above, after processing the cylindrical groove forming hole at the position where the engagement groove is formed from the opening side, the small diameter portion is left while partially leaving the groove forming hole. And forming the engagement groove on the inner peripheral surface of the small-diameter portion, and then machining the large-diameter portion .

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