JP2014190413A - Mechanical disc brake - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mechanical disc brake having a simple constitution as a whole, and capable of improving assemblability without unnecessarily increasing the number of components.SOLUTION: A mechanical disc brake includes a piston 7 disposed at an action portion 3 side of a caliper body 1, and friction pads 35 and 40 disposed at the action portion 3 side and a reaction portion 4 side, and slidably kept into contact with a disc rotor 2 by movement of the piston 7, and further includes a thrust converting mechanism 12 disposed at a bottom portion 8 side of a cylinder hole 6 and capable of pressing the piston 7 to the disc rotor 2 side. The thrust converting mechanism 12 includes a fixed-side cam plate 17 disposed in the cylinder hole 6, a cam shaft 11 disposed so as to be rotatable to the fixed-side cam plate 17 and movable in the cylinder axial direction, a driving-side cam plate 13 fixed to the cam shaft 11, ramp grooves 21 formed on opposed positions of the driving-side cam plate 13 and the fixed-side cam plate 17, and cam bearings 22 accommodated in the ramp grooves 21, and the piston 7 is integrally mounted on the cam shaft 11.

Description

  The present invention relates to a mechanical disc brake that operates by rotating a lever.

JP 2002-206576 A No. 1-330662

  As a mechanical disc brake including a piston and an adjustment shaft, for example, there is a mechanical vehicle disc brake described in Patent Document 1. In this disc brake, a piston and an adjusting shaft are formed separately, and the piston and the adjusting shaft are individually operated when braking and releasing the braking. Further, as a ball ramp type mechanical disc brake, for example, there is a disc brake described in Patent Document 2. This disc brake is provided with a piston, an automatic adjustment mechanism, and a ball ramp mechanism.

  However, in the invention described in Patent Document 1, since the piston and the adjustment shaft are formed separately, the number of parts increases and the assembly becomes complicated. In the invention described in Patent Document 2, since the ball ramp mechanism is arranged between the piston and the automatic adjustment mechanism, the overall configuration is further complicated and the size is increased.

  Therefore, the present invention is intended to solve the above-described problems, and has a simple structure as a whole, and can improve the assemblability without increasing the number of parts more than necessary. Is trying to get a disc brake.

  In order to solve the above-mentioned problems, the present invention provides a piston assembled on the working part side of the caliper body, and a working part side and a reaction that enable the piston to slide on both sides of the disk rotor by moving the piston to the disk rotor side. This is based on a mechanical disc brake having a friction pad on the part side.

  A thrust conversion mechanism is provided on the bottom side of the cylinder hole provided in the action portion of the caliper body, so that the piston can be pushed toward the disk rotor, and the thrust conversion mechanism is fixedly disposed at the bottom of the cylinder hole. A fixed cam plate, a camshaft provided through the fixed cam plate so as to be rotatable with respect to the fixed cam plate and movable in the cylinder axial direction, and fixed to the piston side of the camshaft. A drive-side cam plate, a ramp groove formed at each opposed position of the drive-side cam plate and the fixed-side cam plate, and a cam bearing accommodated in the ramp groove, wherein the piston is attached to the camshaft. Are integrally provided.

  The piston may have a shaft extending to the bottom side of the cylinder hole, and the shaft may pass through the center of the camshaft and be fixed to the camshaft. By configuring as described above, the piston extending the shaft and the drive side cam plate fixed to the camshaft can be easily integrated, so that the work efficiency at the time of assembly can be improved. It becomes possible.

  In addition, the shaft and the camshaft are screwed together, and a nut is screwed to the opposite side of the shaft from the piston side via a rotating lever, whereby the rotating lever is fixed to the shaft. There may be. By configuring as described above, the rotating lever can be assembled by screw machining, so that the number of machining steps does not increase more than necessary, and the work efficiency can be improved.

  Since the present invention is configured as described above, by integrally forming the piston and the camshaft to which the drive side cam plate is fixed, the entire configuration can be simplified and the assemblability can be improved. it can. In addition, since the piston and the driving cam plate are integrally operated, it is not necessary to increase the number of parts more than necessary, and the overall configuration is complicated and is not likely to increase in size.

1 is a cross-sectional view of a mechanical disc brake showing a first embodiment of the present invention. The partial expanded sectional view of FIG. In Example 1, the conceptual diagram which shows the positional relationship of a cam bearing and a ramp groove.

  Embodiment 1 of the present invention will be described with reference to FIGS. 1 to 3. (1) is a caliper body of a mechanical disc brake, and this caliper body (1) is formed on both sides of a disc rotor (2) as shown in FIG. The action part (3) and the reaction part (4) arranged on the bridge, and the bridge part (5) connecting the action part (3) and the reaction part (4) via the disk rotor (2). Is. A cylinder hole (6) is formed in the disk rotor (2) on the working part (3) side.

  A piston (7) is disposed on the disk rotor (2) side of the cylinder hole (6), and a shaft (10) is disposed on the cylinder hole (6) bottom (8) side of the piston (7). Is provided as an integral extension. The piston (7) is integrally provided with a camshaft (11). That is, the camshaft (11) is formed in a cylindrical shape, and the thrust conversion mechanism (12) of this embodiment is configured on the outer periphery of one end of the camshaft (11) on the piston (7) side. A disk-shaped drive side cam plate (13) is fixedly arranged integrally. Further, an inner peripheral thread groove (14) is formed on the inner peripheral surface of the camshaft (11), and an outer peripheral thread groove (15) that can be screwed into the inner peripheral thread groove (14) is provided on the shaft ( It is formed on the outer peripheral surface of 10).

  Then, the camshaft (11) is arranged to penetrate the camshaft (11) while the outer thread (15) of the shaft (10) is screwed into the inner thread (14) of the camshaft (11). The shaft (10) is integrally fixed to the camshaft (11) so that the (11) and the shaft (10) can rotate and slide integrally. As described above, the camshaft (11) and the shaft (10) are screwed together and assembled, whereby the piston (7) extending the shaft (10) and the drive cam fixed to the camshaft (11) Since the plate (13) can be easily integrated, it is possible to improve the working efficiency during assembly. Further, as shown in FIG. 2, the drive side cam plate (13) is located between the piston (7) and the bottom (8) of the cylinder hole (6) and the tip (16) of the shaft (10). Projecting outward from the camshaft (11).

  As described above, since the piston (7) and the camshaft (11) to which the drive side cam plate (13) is fixed are integrated, the overall configuration is simplified and the assemblability is improved. Can do. Further, since the piston (7) and the drive side cam plate (13) are integrally operated, it is not necessary to increase the number of parts more than necessary, and the situation in which the entire configuration is complicated and large is less likely to occur.

  Further, on the bottom (8) of the cylinder hole (6), a fixed cam plate (17) that constitutes a thrust conversion mechanism (12) together with the drive cam plate (13) is provided on the end surface of the caliper body (1). (20) is fixedly arranged. That is, a through hole (18) is provided in the central portion of the fixed cam plate (17), and the cam shaft (11) with the shaft (10) assembled therein is passed through the through hole (18) in this state. The fixed cam plate (17) is fixedly disposed on the end surface (20) of the caliper body (1) located on the bottom (8) side of the cylinder hole (6).

  Further, the fixed cam plate (17) and the drive cam plate (13) arranged as described above have ramp grooves (21) on the inner surfaces facing each other as shown in FIG. (Only one location is shown in FIG. 2), and each ramp groove (21) has a shape P at each facing position between the fixed cam plate (17) and the drive cam plate (13). ing. Further, the ramp groove (21) is formed in a substantially elliptical shape elongated in the circumferential direction, and is formed so that the central portion is deepest as shown in FIG.

  Further, a cam bearing (22) is accommodated in the ramp groove (21) formed in the fixed cam plate (17) and the drive cam plate (13) as described above. The drive-side cam plate (13) is urged so that the cam bearing (22) does not fall out of the ramp groove (21). That is, an engagement protrusion (25) that allows engagement of one end of the spring (23) is provided on the inner wall (24) of the cylinder hole (6) on the piston (7) arrangement side, and this engagement protrusion One end of the spring (23) is placed in contact with (25), and the other end of the spring (23) is placed on the back surface (26) opposite to the ramp groove (21) formation surface of the drive cam plate (13). The driving cam plate (13) is urged toward the fixed cam plate (17) by being disposed in contact therewith.

  Then, by urging the drive cam plate (13) toward the fixed cam plate (17) as described above, the cam bearing (22) is connected to the ramp groove (21) of the drive cam plate (13) and the fixed cam plate (13). Since it can hold | maintain between the ramp grooves (21) of a cam board (17), it can prevent that a cam bearing (22) falls out from each ramp groove (21). When the brake is not operated, the cam bearing (22) is positioned at the deepest portion of each ramp groove (21) as shown in FIG. The thrust conversion mechanism (12) of the present embodiment configured as described above is a so-called ball ramp type.

  An engagement step portion (27) is formed at the tip of the camshaft (11), and an engagement hole (30) provided at one end of the rotation lever (28) is inserted into the engagement step portion (27). It is arranged. Then, in this state, a nut (31) that can be screwed into the outer peripheral thread groove (15) of the shaft (10) is screwed from the tip side of the shaft (10), and the nut (31) is arranged as described above. Tighten until the rotating lever (28) comes into pressure contact. As a result, the rotating lever (28) can be integrally fixed to the camshaft (11) and the shaft (10) by the nut (31). Since the rotation lever (28) can be assembled by screw machining as described above, it becomes possible to improve work efficiency without increasing the number of processing steps more than necessary, and the rotation lever (28) 11) and the shaft (10) rotate together.

  Also, one end of a brake wire (not shown) is connected to the tip of the rotating lever (28), and the other end of the brake wire is connected to a brake operation such as a brake pedal or a brake lever operated by the driver. It is connected to a child (not shown). Further, as shown in FIGS. 1 and 2, a fitting recess (34) having a circular shape and a U-shaped cross section is formed at the center of the tip surface (33) of the piston (7). Then, on the back plate of the friction pad (35) connected to the tip surface (33) of the piston (7), a fitting protrusion (36) that can be fitted into the fitting recess (34) is formed, The fitting protrusion (36) is fitted into the fitting recess (34) via the C clip (37).

  As a result, the piston (7) and the friction pad (35) are connected to each other so as to be rotatable independently of each other in a state in which separation is difficult. Then, the reaction pad (4) of the caliper body (1) is also provided with a friction pad (40) formed in the same manner as the friction pad (35) on the action part (3) side, and a friction pad on the action part (3) side. It is fixedly arranged facing the pad (35). As a result, as shown in FIG. 1, the disk rotor (2) is positioned between the friction pad (40) on the reaction part (4) side and the friction pad (35) on the action part (3) side.

  A case where the mechanical disc brake is braked in the above-described configuration will be described below. First, the lever (28) is rotated in one direction by pulling the brake wire against a biasing force of a return spring (not shown) with a brake operator (not shown). As the rotating lever (28) rotates, the camshaft (11) and the drive cam plate (13) formed integrally with the camshaft (11) are aligned in the same direction as the rotating lever (28). Rotate.

  As described above, the drive side cam plate (13) rotates together with the cam shaft (11), but the fixed side cam plate (17) facing the drive side cam plate (13) is the end face of the caliper body (1). Since it is fixed to (20), it does not rotate. In addition, the shaft (10) integrally assembled with the camshaft (11) and the piston (7) formed integrally with the shaft (10) by the rotation of the rotation lever (28) are also provided with the rotation lever. It rotates in the same direction as (28).

  Further, as described above, the drive side cam plate (13) rotates with respect to the fixed side cam plate (17), so that the cam groove of the fixed side cam plate (17) that was at the opposite position before the start of braking is changed. The phase with the cam groove of the drive side cam plate (13) is shifted. Therefore, each cam bearing (22) located at the deepest position of the ramp groove (21) moves to a shallow position of the ramp groove (21), and the fixed cam plate (17) and the drive side cam plate (13) The interval will be increased. At this time, since the fixed cam plate (17) is fixed to the end surface (20) of the caliper body (1) as described above, the drive cam plate (13) is disc-shaped relative to the fixed cam plate (17). It will slide to the rotor (2) side.

  And since the camshaft (11), the shaft (10) and the piston (7) all slide toward the disk rotor (2) side by sliding of the drive side cam plate (13), it is assembled to the piston (7). The friction pad (35) slides toward the disk rotor (2) and comes into pressure contact with the surface of the disk rotor (2). The caliper body (1) moves in a direction opposite to the moving direction of the piston (7) due to the reaction force accompanying the movement of the friction pad (35) on the side of the action part (3), and the caliper body (1 ) Moves the friction pad (40) on the reaction part (4) side to the disk rotor (2) side and comes into pressure contact with the side surface on the reaction part (4) side of the disk rotor (2). As a result, the pair of friction pads (35) and (40) respectively provided on the action part (3) side and the reaction part (4) side are pressed against both surfaces of the disk rotor (2) as shown in FIG. Braking with a disc brake is performed.

  Next, the release of braking will be described below. First, by releasing the traction of the brake wire by operating a brake operator (not shown), the rotating lever (28) is moved before the braking is started by the urging force of the return spring. Restore to the original position. As a result, the piston (7), the shaft (10), the drive side cam plate (13), and the camshaft (11) simultaneously rotate in the opposite direction to that during braking and return to the position before the start of braking, The ramp groove (21) of the plate (13) and each ramp groove (21) of the fixed cam plate (17) are restored to the opposing positions, which are the positions when not braked, and the cam bearing (22) is restored to each ramp groove (21 ) Is returned to the deepest position.

  With the return of the cam bearing (22), the drive cam plate (13) slides in the direction of the fixed cam plate (17) by the urging force of the spring (23). While restoring the original position in the separation direction, the camshaft (11), the shaft (10), and the piston (7) also slide in the separation direction from the disk rotor (2). Therefore, the friction pad (35) connected to the piston (7) is forced to slide in the direction away from the disk rotor (2). Further, the caliper body (1) is moved by the reaction force accompanying the movement of the friction pad (35) on the action part (3) side as described above, and the friction pad (40) on the reaction part (4) side is moved to the anti-disk rotor. (2) Slide to the side. As described above, since the friction pads (35) and (40) on the action part (3) side and the reaction part (4) side move to the anti-disk rotor (2) side, both friction pads (35) and (40) and the disk rotor ( There is a gap between 2) and the mechanical disc brake is released.

DESCRIPTION OF SYMBOLS 1 Caliper body 2 Disc rotor 3 Action part 4 Reaction part 5 Cylinder hole 6 Piston 7 Bottom part 10 Shaft 11 Cam shaft 12 Thrust conversion mechanism 13 Drive side cam board 17 Fixed side cam board 21 Lamp groove 22 Cam bearing 28 Rotating lever 31 Nut 35, 40 Friction pad

Claims (3)

A mechanical disk comprising a piston assembled on the working part side of the caliper body, and friction pads on the working part side and the reaction part side that can slide on both sides of the disk rotor by moving the piston toward the disk rotor side Brake,
On the bottom side of the cylinder hole provided in the action part of the caliper body, a thrust conversion mechanism that enables the piston to be pushed toward the disk rotor side,
The thrust conversion mechanism includes a fixed cam plate fixedly disposed at the bottom of the cylinder hole, and a fixed cam plate that is rotatable with respect to the fixed cam plate and movable in the cylinder axial direction. A camshaft provided, a driving cam plate fixedly disposed on the piston side of the camshaft, a ramp groove formed at each opposed position of the driving cam plate and the fixed cam plate, and accommodated in the ramp groove A mechanical disc brake, wherein the piston is integrally provided on the camshaft.   2. The mechanical disc brake according to claim 1, wherein a shaft is extended to the bottom side of the cylinder hole of the piston, and the shaft is fixed to the camshaft through the center of the camshaft. The shaft and the camshaft are screwed together, and a rotation lever is fixed to the shaft by screwing a nut on the opposite side of the shaft from the piston side via a rotation lever. The mechanical disc brake according to claim 1 or 2.