JPH075303Y2 - Needle roller bearings for disc brakes with parking brake mechanism - Google Patents

Description

TECHNICAL FIELD The present invention relates to a needle roller bearing used in a disc brake with a parking brake mechanism.

2. Description of the Related Art A piston is fitted so that it can project and a mounting hole is provided at the end opposite to the projecting direction of the piston in a direction perpendicular to the shaft center of the piston. A type of parking that includes a rotatably provided cam shaft, a toggle that is pushed toward the piston side as the cam shaft rotates, and a thrust transmission member that transmits the thrust generated in the toggle to the piston. Disc brakes with a brake mechanism are known. A kind of such disc brake with a parking brake mechanism is formed by arranging a plurality of needle rollers on the inner peripheral side of an outer ring, and is press-fitted into the mounting hole in the outer ring and on the inner peripheral side of the needle roller. There is one that includes a needle roller bearing that rotatably supports the cam shaft and that has an opening formed in a peripheral wall of an outer ring through which the toggle is inserted.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, when such a needle roller bearing is press-fitted into the mounting hole in the outer ring, it is difficult to obtain sufficient strength at the opening peripheral portion of the outer ring, and the outer ring is deformed at the opening peripheral portion. There was a case where the opening was deformed by being forced to do so.

The present invention has been made in view of the above circumstances, and its purpose is to prevent the opening from being deformed when the outer ring having the opening formed in the peripheral wall is press-fitted into the mounting hole. An object of the present invention is to provide a needle roller bearing for a disc brake with a parking brake mechanism that can be preferably prevented.

Means for Solving the Problems In order to achieve the above object, the present invention provides a disc brake with a parking brake mechanism of the type described above, in which a plurality of needle rollers are arranged on the inner peripheral side of an outer ring. And a needle roller bearing that has an opening through which the toggle is inserted in the peripheral wall of the outer ring, is press-fitted into the mounting hole in the outer ring, and rotatably supports the cam shaft on the inner peripheral side of the needle roller. It is characterized in that it includes a protruding portion formed by protruding a part of a peripheral wall of the outer ring toward an inner peripheral side and having a projecting end portion provided with the opening.

According to the needle roller bearing of the disc brake with the parking brake mechanism configured as described above, the protruding portion is formed on the peripheral wall of the outer ring by protruding a part thereof toward the inner peripheral side. Since the opening is provided at the protruding end portion of the protruding portion, the strength of the opening peripheral edge portion of the outer ring can be improved by the protruding portion, and when the needle roller bearing is press-fitted into the mounting hole in the outer ring, the strength can be improved. It is possible to preferably prevent the outer ring from being deformed at the peripheral edge portion of the opening and thus deforming the opening portion.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 2 is a view showing a main part of a disc brake with a parking brake mechanism equipped with a needle roller bearing to which the present invention is applied. In the figure, a caliper 12 is laid across the outer peripheral portion of a disk rotor 10 that is rotatably provided with wheels, and the caliper 12 is not shown in a support member 14 fixed to a non-rotating member (not shown). It is movably supported in a direction parallel to the axis of the disk rotor 10 via a slide pin or the like. The caliper 12 has a first cylinder bore 16, and a piston 18 having a bottomed cylindrical shape as a whole is fitted in the first cylinder bore 16 so as to be capable of projecting in one direction in a state where the piston 18 cannot relatively rotate about its axis. A cylinder portion 20, and a protrusion portion 22 integrally provided on the cylinder portion 20 at an end portion of the cylinder portion 20 opposite to the protrusion direction of the piston 18.
The cylinder portion (20) is provided with a bifurcated claw portion (24) that integrally extends from an end portion in the protruding direction of the piston (18) and faces the cylinder portion (20) with the disc rotor (10) in between. Inside the caliper 12, that is, between the piston 18 and the claw portion 24, a pair of pads 26 and 28 are arranged with the disc rotor 10 sandwiched therebetween, and the pads 26 and 28 are the supporting members 14 and 28. Are supported so as to be movable in a direction parallel to the axis of the disc rotor 10.

A second cylinder bore 30 is formed inside the protrusion 22 so as to be adjacent to and substantially concentric with the first cylinder bore 16, and the second cylinder bore 30 has a male screw portion 32 and a head portion 34 having a larger diameter than that. The adjusting bolt 36 having the above is fitted in the head 34 so that the male screw portion 32 is located inside the piston 18 so as to be relatively movable in the axial direction and not relatively rotatable around the axial center. The adjusting bolt 36 includes a washer 38 integrally provided on the head 34 and the inner peripheral surface of the first cylinder bore 16.
Is constantly urged in a direction away from the piston 18 by a spring 40 interposed between the adjusting nut 42 and the male screw portion 32 while being screwed in a state having a predetermined rattling in the axial direction. There is. A flange portion 44 protruding in the outer peripheral direction is provided at an end portion of the adjustment nut 42 located on the tip side of the male screw portion 32.

On the inner peripheral surface on the opening side of the piston 18, an annular member 46 having a plate shape is formed.
While being integrally fixed by caulking, a thrust bearing 48 and a flat washer 50 are provided adjacent to the flange portion 44 on the outer peripheral side of the cylindrical portion of the adjust nut 42. A spring 52 is inserted between the flat washer 50 and the annular member 46 in a predetermined preload state, and an adjusting nut 42 is formed on the outer peripheral surface of the flange portion 44 according to the urging force of the spring 52 to form a tapered surface. In the above, the tapered inner wall of the piston 18 is brought into contact with the piston 18 in the protruding direction of the piston 18. The biasing force of the spring 52 is set smaller than the biasing force of the spring 40. Also, 54 liquid-tightly seals between the piston 18 and the first cylinder bore 16 and
It is a piston seal that performs the return action of.

As shown in FIGS. 1 and 2, the protrusion 22 is further provided with a mounting hole on the side opposite to the first cylinder bore 16 side of the second cylinder bore 30 in a direction perpendicular to the axis of the second cylinder bore 30. 56 is provided so as to communicate with the second cylinder bore 30, and a cam shaft 58 is provided in the mounting hole 56 via a needle roller bearing 60 so as to be rotatable about its axis. As shown in FIGS. 1 to 3, the needle roller bearing 60 includes a cylindrical outer ring 62 and a large number of needle rollers provided on the inner peripheral side of the outer ring 62 and held by a cage 64. 66
The outer ring 62 is press-fitted into the inner peripheral surface of the mounting hole 56. A projecting portion 68 is formed on the peripheral wall of the outer ring 62 by protruding a part of the peripheral wall over a predetermined area toward the inner peripheral side at an intermediate portion in a direction parallel to the axis, and the projecting portion 68 is formed. An opening 70 is formed at the protruding end of the 68, and this opening 70 is formed in the second cylinder bore.
It is located in the position corresponding to 30.

A crank lever 72, to which the parking brake operating force is transmitted, is attached to one end of the cam shaft 58 and located outside the protruding portion 22 so that the crank lever 72 is relatively non-rotatable, and a longitudinal intermediate portion of the cam shaft 58. The engaging recess 74 is formed in the engaging recess 74 and the head of the adjusting bolt 36.
A toggle 78 in the form of a rod is interposed between the engaging recess 76 formed in the tip end surface of 34 and the opening 70 of the outer ring 62 of the needle roller bearing 60. In FIG. 1, 80 is a dust cover. The crank lever 72 is constantly urged in the parking brake non-operating direction (clockwise direction in FIG. 2) by a return spring (not shown).

When the parking brake of the disc brake configured as described above is operated, a thrust is generated in the toggle 78 as the cam shaft 58 is rotated counterclockwise in FIG. 2 by the crank lever 72, and the thrust is adjusted by the adjustment bolt. 36, by being transmitted to the piston 18 via the adjustment nut 42, the pads 18 and 28 are narrowed by the piston 18 and the claw portion 24 of the caliper 12 to perform braking. Therefore,
In this embodiment, the adjusting bolt 36 and the adjusting nut 42 constitute a thrust transmitting member. On the other hand, during braking by hydraulic pressure, the parking brake operation stroke is automatically adjusted based on the fact that the adjusting nut 42 is rotated in one direction via the thrust bearing 48 and the like by the annular member 46 that is advanced together with the piston 18. It is supposed to be done. The above-mentioned brake operation and adjustment operation are not always necessary for understanding the present invention, and thus detailed description thereof will be omitted.

Thus, according to this embodiment, the outer ring 62 of the needle roller bearing 60 is
Has a projecting portion 68 formed by projecting a part of its peripheral wall toward the inner circumferential side, and the projecting end portion of the projecting portion 68 is provided with an opening 70 through which a toggle 78 is inserted. The presence of the portion 68 effectively improves the strength of the peripheral portion of the opening 70 of the outer ring 62. This allows needle roller bearings 60
When a relatively large force is applied to the outer ring 62 in the axial direction when the outer ring 62 is press-fitted into the mounting hole 56 provided in the protrusion 22 of the caliper 12, the outer ring 62 is deformed at the peripheral edge of the opening 70. It is possible to preferably prevent the opening 70 from being deformed. Such an effect becomes more remarkable as the opening 70 is larger. By preventing the deformation of the opening 70 in this manner, for example, a toggle 78 is provided in the opening 70.
It is possible to surely insert the gear and to prevent the toggle 78 from interfering with the peripheral portion of the opening 70 when the parking brake is operated.

Further, conventionally, when the outer ring of the needle roller bearing is press-fitted into the mounting hole, the peripheral edge of the opening of the outer ring is slightly bulged toward the outer peripheral side, and the inner peripheral surface of the mounting hole is formed by the corners of the opening. The needle roller bearing may be chipped, which may increase the press-fit resistance of the needle roller bearing, or the cutting debris may enter the needle roller bearing and impair the function of the bearing. According to the example, the opening 70 is located on the inner peripheral side by a predetermined dimension with respect to the outer peripheral surface of the outer ring 62, so that the above problem can be preferably solved. In the conventional case, it is considered that the above problem can be solved by chamfering the periphery of the opening, but according to the present embodiment, when the protrusion 68 is formed by the protrusion process, usually, the Since R is formed between the outer peripheral surface of the protruding portion 68 on the base side and the outer peripheral surface of the outer ring 62 adjacent to the protruding portion 68, the press-fitting resistance is more suitable as compared with the case where the opening peripheral edge is chamfered. It can be reduced.

In the above-described embodiment, the needle roller bearing 60 is composed of the outer ring 62, the needle rollers 66, and the cage 64.However, the needle roller bearing consisting of the outer ring and the needle rollers, the outer ring, Needless to say, the present invention can be applied to a needle roller bearing, a needle roller bearing including an inner ring, and the like.

Further, in the above-described embodiment, the thrust transmission member is composed of the adjustment bolt 36 and the adjustment nut 42,
Although the adjusting mechanism is configured in cooperation with the annular member 46, the thrust bearing 48, the spring 52, etc., it is not always necessary.For example, such an adjusting mechanism is not provided and the thrust transmitting member is a single member. It is possible to use a rod-shaped member.

In addition, the present invention can be variously modified without departing from the spirit thereof.

[Brief description of drawings]

FIG. 1 is a view showing a main part of a cross section taken along line I-I in FIG. FIG. 2 is a cross-sectional view showing a main part of a disc brake with a parking brake mechanism equipped with a needle roller bearing according to an embodiment of the present invention. FIG. 3 is a perspective view of the needle roller bearing in FIG. 18: Piston 20: Cylinder part 36: Adjust bolt 42: Adjust nut 56: Mounting hole 58: Cam shaft 60: Needle roller bearing 62: Outer ring 66: Needle roller 68: Protruding part 70: Opening 78: Toggle

Claims (1)

[Scope of utility model registration request] 1. A cylinder part in which a piston is fitted so as to project, and a mounting hole is provided at an end portion on the side opposite to the projecting direction of the piston in a direction perpendicular to the axis of the piston, and the mounting hole. A cam shaft rotatably provided around the shaft, a toggle that is pushed toward the piston side as the cam shaft rotates, and a thrust transmission member that transmits the thrust generated in the toggle to the piston. In a disc brake with a parking brake mechanism of a type provided, a plurality of needle rollers are arranged on an inner peripheral side of an outer ring, and an opening through which the toggle is inserted is provided in a peripheral wall of the outer ring, A needle roller bearing that is press-fitted into a mounting hole and rotatably supports the cam shaft on the inner peripheral side of the needle roller, and is formed by protruding a part of a peripheral wall of the outer ring to an inner peripheral side, Protruding end A needle roller bearing for a disc brake with a parking brake mechanism, characterized in that it includes a protrusion provided with the opening.