JP4381335B2 - 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 an axial groove precisely formed in a cylinder hole for restricting the turning of a fixed side cam plate and the turning of a thrust transmission plate in the state of being movable in the axial direction of a cylinder, 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 disc brake device comprises the fixed side cam plate 12 and the thrust transmission plate 14b having engaging ribs 12b, 14e formed on the outer peripheral face and on the outer peripheral face, respectively, and the cylinder hole 8 having an engaging groove 8f formed in the axial direction of the cylinder. The engaging groove 8f and the engaging ribs 12b, 14e engage each other to prevent the rotation of the fixed side cam plate 12 and the rotation of the thrust transmission plate 14b in the state of being movable in the axial direction of the cylinder. A grooved hole is machined in a range from a large diameter portion of the cylinder hole formed in a caliper body after casting to an engaging grooved portion. A small diameter portion 8b is formed while leaving the grooved portion as the engaging groove 8f, and then a large diameter portion 8a is formed. <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. Thus, a braking force is obtained (see, for example, Patent Document 1).

Also, when forming the axial groove in the cylinder hole of the disc brake device, after processing the cylinder hole, an end mill cutter was 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 rotation of the fixed cam plate must be restricted and the rotation of the thrust transmission plate must be restricted while being movable in the cylinder axis direction. Parts were necessary and the shape of each member was complicated.

  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 in parallel to the inner peripheral surface of the cylinder hole, and the axial groove could not be formed with high accuracy.

  Therefore, the present invention has a simple structure and the rotation of the fixed cam plate is restricted, and the thrust transmission plate is restricted in a state where it can move in the cylinder axial direction. An object of the present invention is to provide a disc brake device that can obtain a ring and that can operate the adjuster with certainty so that the braking gap between the friction pad and the disc rotor can always be kept good. It aims at providing the formation method of the cylinder hole which can form an axial direction groove | channel accurately.

In order to achieve the above object, a first invention includes a piston housed on the tip opening side of a cylinder hole formed in a caliper body, a 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 cam shaft, and a position opposite to the drive side cam plate and the fixed side cam plate. A ramp groove formed on each side, and a cam bearing accommodated in the ramp groove, and the adjuster has a cylinder hole bottom side end facing the drive cam plate of either one of an adjustment nut and an adjustment bolt. And a disc brake having a substantially cylindrical spring retainer disposed on the outer peripheral side of the adjuster and housing a cam spring for biasing the thrust transmitting plate toward the drive cam plate. In the device, an engagement rib is formed on one of the outer peripheral surface of the fixed cam plate, the outer peripheral surface of the thrust transmission plate, and the inner peripheral surface of the cylinder hole, and an engagement groove is formed on the other. By engaging the mating groove and the engagement rib, the fixed cam plate is prevented from rotating, and the thrust transmission plate is prevented from rotating in the state of moving in the cylinder axial direction. 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. A receiving hole for receiving the cylindrical portion and the protruding portion is formed in the center of the bottom side end portion, and the rotation amount of the driving cam plate is determined by contacting the protruding portion on the inner peripheral side of the receiving hole. A restricting portion for restricting the bearing so that it does not fall out of the ramp groove protrudes, the cylindrical portion and the protruding portion are accommodated in the accommodation hole, and the cylinder of the driving cam plate is located on the cylinder bottom side of the thrust transmission plate It is characterized in that the hole opening side is in contact .

  In the second invention, the engagement rib or engagement groove provided in the fixed cam plate and the engagement rib provided in the thrust transmission plate are formed in one engagement groove or engagement rib formed in the cylinder hole. Alternatively, both engaging grooves are engaged.

  In the third invention, a large-diameter portion that accommodates the piston on the opening side and a small-diameter portion that accommodates the thrust conversion mechanism of the parking brake mechanism and a part of the adjuster on the bottom side are provided on the inner peripheral surface of the small-diameter portion. An axial groove serving as the engagement groove is provided, and the engagement rib is provided on the outer peripheral surface of the fixed cam plate and the outer peripheral surface of the thrust transmission plate.

  In the fourth invention, 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 and a part of the adjuster on the bottom side, and an inner peripheral surface of the small-diameter portion In the method for forming a cylinder hole in a disc brake device having an axial groove serving as the engagement groove, a cylindrical groove forming hole is processed from the opening side to the axial groove forming position, and then the groove is formed. The small diameter portion is processed while leaving a 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.

  With the configuration as described above, in the first invention, the fixed cam plate can be prevented from rotating with a simple structure, and the thrust transmission plate can be prevented from rotating in a state of being movable in the cylinder axial direction. Can do. As a result, a good stroke feeling can be obtained when the parking brake is operated, and the adjuster can be operated reliably, so that the braking gap between the friction pad and the disc rotor can always be kept good. In addition, since the fixed cam plate and the thrust transmission plate can be prevented from rotating with a simple structure, the number of parts can be reduced.

  In the second invention, machining on the cylinder hole side can be suppressed to a small extent.

  In the third invention, the assembling property can be improved.

  In the fourth invention, the axial 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 6 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. -III sectional view, FIG. 4 is an exploded perspective view of a thrust conversion mechanism, an adjusting nut, and a spring retainer, and FIG. 5 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 has a large diameter portion 8a on the opening side of the tip, a small diameter portion 8b on the bottom side of the cylinder hole, a seal groove 8c and a boot groove 8d on the opening side of the large diameter portion 8a, and a retaining ring on the bottom side. Each of the mounting grooves 8e is provided circumferentially, 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. In addition, a conical surface 8g is formed between the retaining ring mounting groove 8e and the small diameter portion 8b. The conical surface 8g gradually decreases in diameter from the retaining ring mounting groove 8e toward 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 8h.

  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 substantially cylindrical spring retainer 16 for accommodating the cam spring 15 is disposed in the cylinder hole 8 by a retaining ring 17 fitted in the retaining ring mounting groove 8e on the bottom side of the adjusting nut 14 in the cylinder hole. The

  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 8h 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. Further, on the outer peripheral surface of the thrust transmission plate 14b, three engaging ribs 14e that engage with the engaging grooves 8f of the cylinder hole 8 are provided protruding at equal intervals in the circumferential direction.

  The fixed-side cam plate 12 is formed in a disc shape, and is provided with an insertion hole 12a through which the camshaft 22 is inserted in the center. A cylinder hole bottom wall 8h is formed around the insertion hole 12a on the end surface on the cylinder hole bottom side. Ribs 12b inserted into the rib receiving grooves 8i provided on the outer periphery of the cylinder holes 8 are projected, and three engagement ribs 12c that engage with the respective engagement grooves 8f of the cylinder hole 8 are equidistant in the circumferential direction. It is projecting at.

  The spring retainer 16 includes a cylindrical portion 16a formed to be slightly smaller in diameter than the inner diameter of the piston 9, a flange portion 16b formed on the cylinder hole bottom side of the cylindrical portion 16a, and a cylinder hole opening portion of the cylindrical portion 16a. And a support piece 16c protruding from the side to the inner peripheral side.

  In the assembly of the disc brake device 1 of this embodiment formed in this way, the engagement ribs 12c of the fixed cam plate 12 are engaged with the three engagement grooves 8f formed in the cylinder hole 8, respectively. The rib 12b of the cam plate 12 is inserted into a rib receiving groove 8i provided in the cylinder hole bottom wall 8h via a sealing material, and attached to the cylinder hole bottom wall 8h in a state in which the fixed cam plate 12 is prevented from rotating. The camshaft 22 is passed through the insertion hole 8j of the cylinder hole bottom wall 8h so that the three cam bearings 24 are accommodated in the ramp grooves 23, and the driving cam plate 22a is disposed on the cylinder hole opening side of the fixed cam plate 12. To do.

  Next, the respective engagement ribs 14e of the thrust transmission plate 14b provided on the adjusting nut 14 are engaged with the three engagement grooves 8f formed in the cylinder hole 8, so that the thrust transmission plate 14b can be moved in the cylinder axial direction. In this state, the rotation is stopped and held in the cylinder hole 8. The cylindrical portion 22b of the drive side cam plate 22a is received in the accommodation hole 14c of the thrust transmission plate 14b, and the cylinder hole opening side of the drive side cam plate 22a via the thrust bearing 25 on the cylinder hole bottom side of the thrust transmission plate 14b. Abut. A cam spring 15 is disposed on the outer peripheral side of the adjusting nut 14, one end of the cam spring 15 is brought into contact with the cylinder hole opening side end of the thrust transmission plate 14 b, and a spring retainer 16 is disposed on the outer peripheral side of the cam spring 15. Then, the other end of the cam spring 15 is brought into contact with the support piece 16 c of the spring retainer 16. The retaining ring 17 fitted in the retaining ring mounting groove 8e is brought into contact with the cylinder hole opening side of the flange portion 16b of the spring retainer 16 to fix the spring retainer 16 in the cylinder hole 8.

  On the other hand, the adjustment bolt 13, the bearing 21, the bearing receiver 19, the adjustment spring 18, and the retaining ring 20 are sequentially installed inside the piston 9 to form one unit. 9 is pushed into the cylinder hole 8, 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. Due to the axial movement of the driving cam plate 22a, the thrust transmission plate 14b is prevented from rotating, and moves in the cylinder axial direction. This movement is transmitted to the piston 9 via the adjusting bolt 13, and the piston 9 The thrust is pushed to the disk rotor side, and the braking action is performed in the same manner as the braking action by the hydraulic operating mechanism 3.

  As described above, when the parking brake operation is performed by the mechanical operation mechanism 4, the fixed cam plate 12 is engaged with the engagement grooves 8 f formed in the cylinder holes 8 by the respective engagement ribs 12 c. The thrust transmission plate 14b is parked with a simple structure by being prevented from rotating in a state in which the thrust transmission plate 14b can move in the cylinder axial direction by engaging the engagement ribs 14e with the engagement grooves 8f. A good stroke feeling can be obtained at the time of the brake operation, and the adjuster 11 can be operated reliably, so that the braking gap between the friction pad 7 and the disc rotor 5 can always be kept good.

  Furthermore, in this embodiment, the engagement rib 12c of the fixed cam plate 12 and the engagement rib 14e of the thrust transmission plate 14b are engaged with the same engagement groove 8f one by one to prevent rotation. The machining of the cylinder hole 8 can be simplified as much as possible. Further, the driving cam plate 22a is brought into contact with a protrusion 22c formed in the cylindrical portion 22b of the driving cam plate 22a and a 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 state where it can be rotated only within a predetermined angle range, the parking brake operation can be performed satisfactorily.

  In the above-described embodiment, engagement ribs are provided on the fixed cam plate and the thrust transmission plate, and an engagement groove is formed in the cylinder hole. However, the engagement rib is formed in the cylinder hole and fixed. An engagement groove may be formed in the side cam plate and the thrust transmission plate. Further, the thrust transmission plate may be formed on the adjustment bolt, not limited to the thrust transmission plate formed on the adjustment nut.

  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. 6A, 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. 6B, 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. 6C, the large-diameter hole 33 to be the large-diameter portion 8a is processed. Finally, the cylinder hole 8 is finished and a seal groove 8c, a boot portion groove 8d, and a retaining ring mounting groove 8e are formed in the large-diameter hole 33, respectively.

  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. FIG. 3 is a sectional view taken along line III-III in FIG. 1. It is a disassembled perspective view of a thrust conversion mechanism, an adjustment nut, and a housing. It is a section front view of a disc brake device which shows one example of the present invention. It is explanatory drawing which shows the shaping | molding method of the cylinder hole 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, 7 ... Friction pad, 8 ... Cylinder hole, 8a ... Large diameter part 8b: Small diameter portion, 8e: Retaining ring mounting groove, 8f: Engaging groove, 8g ... Conical surface, 8h ... Cylinder hole bottom wall, 8i ... Rib receiving groove, 8j ... Insertion hole, 9 ... Piston, 9a ... Bottom wall , 9b ... fitting hole, 9c ... conical surface, 10 ... thrust conversion mechanism, 11 ... adjuster, 12 ... fixed side cam plate, 12a ... insertion hole, 12b ... rib, 12c ... engagement rib, 13 ... adjustment bolt, 13a ... Small-diameter piston, 13b ... Clutch plate, 14 ... Adjust nut, 14a ... Multi-thread screw, 14b ... Thrust transmission plate, 14c ... Accommodating hole, 14d ... Regulator, 14e ... Engaging rib, 15 ... Cam spring, 16 ... Spring Retainer 16a ... cylindrical portion, 16b ... flange portion, 16c ... support piece, 17 ... retaining ring, 18 ... adjusting spring, 19 ... bearing receiver, 20 ... retaining ring, 21 ... bearing, 22 ... camshaft, 22a ... drive side cam Plate, 22b ... Cylindrical part, 22c ... Projection, 23 ... Ramp groove, 24 ... Cam bearing, 25 ... Thrust bearing, 26 ... Operating lever, 30 ... Caliper body, 31 ... Groove forming hole, 31a ... Groove forming part, 32 ... small-diameter holes, 33 ... large-diameter holes

Claims (4)

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 to be accommodated, and the adjuster includes a thrust transmission plate at a cylinder hole bottom side end facing the driving cam plate of either one of an adjustment nut and an adjustment bolt, and is provided on an outer peripheral side of the adjuster. In a disc brake device in which a substantially cylindrical spring retainer is disposed and a cam spring that urges a thrust transmission plate toward the drive cam plate is accommodated in the spring retainer, the outer peripheral surface of the fixed cam plate and the An engaging rib is formed on one of the outer peripheral surface of the thrust transmission plate and the inner peripheral surface of the cylinder hole, and an engaging groove is formed on the other, and the engaging groove and the engaging rib are engaged with each other. To prevent the fixed cam plate from rotating and the thrust transmission plate from rotating in a cylinder axial direction, and the driving cam plate has a cylinder hole opening. A cylindrical portion protrudes in the center of the end portion, and a protruding portion protrudes on the outer peripheral side of the cylindrical portion, and the thrust transmission plate has the cylindrical portion and the protruding portion in the center of the cylinder hole bottom side end portion. A regulation hole for regulating 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 by contacting the projection on the inner circumferential side of the accommodation hole. The cylindrical portion and the protruding portion are accommodated in the accommodating hole, and the cylinder hole opening side of the driving cam plate is brought into contact with the cylinder bottom side of the thrust transmission plate. Disc brake device. Both the engagement rib or the engagement groove provided in the fixed cam plate and the engagement rib or the engagement groove provided in the thrust transmission plate in one engagement groove or engagement rib formed in the cylinder hole The disc brake device according to claim 1, wherein the disc brake device is engaged. A large-diameter portion that accommodates the piston on the opening side, and a small-diameter portion that accommodates a thrust conversion mechanism of the parking brake mechanism and a part of the adjuster on the bottom side, and the engagement groove on the inner peripheral surface of the small-diameter portion 3. The disc brake device according to claim 1, further comprising an axial groove, wherein the engagement rib is provided on an outer peripheral surface of the fixed cam plate and an outer peripheral surface of the thrust transmission plate. 4. The method for forming a cylinder hole in a disc brake device according to claim 3, wherein after forming the cylindrical groove forming hole at the position where the axial groove is formed from the opening side, the groove forming hole remains partially. A method of forming a cylinder hole in a disc brake device, wherein the small diameter portion is processed, the engagement groove is formed on an inner peripheral surface of the small diameter portion, and then the large diameter portion is processed.

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