JPS6015001Y2 - disc brake - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a retainer for preventing vibration of a yoke in a disc brake.

An overview of conventional disc brakes will be described below with reference to drawings.

A housing fixed type disc brake has a cylinder formed in a housing fixed to a non-rotating member of a wheel, such as a wheel support member, and two pistons are slidably fitted into the cylinder, and when the brake is applied, a cylinder is formed in the housing. The two pistons are actuated in opposite directions so that one piston acts directly on one of the friction pads located between the piston and the disk, while the other piston acts through a flat yoke that straddles the disk. , on the other friction pad, thereby forcing both friction pads into pressure contact with the respective discs.

Further, a guide groove is provided in the longitudinal direction of the curved wall portion of the cylinder, and a part of the yoke is engaged and supported within the guide groove.

However, in conventional retainers, as shown in Fig. 2, the inner distance B of the upwardly protruding portion of the yoke 7 is larger than the distance A between the bottoms of the fitting grooves of the pistons. There was a drawback that 15 pieces fell off.

The present invention provides a floating caliper type disc brake with a fitting groove 13 provided on the circumferential surface of the other piston 3, and a pair of contact portions 14a that abut against the yoke 7 between the other piston 3 and the yoke 7. , a pair of first circular arc parts 14b extending and bent in a direction away from the contact part 14a; Fitting groove 13 of the other piston 3
and a second circular arc portion 14c that fits into the retainer 14, and the distance B between the inner sides of the pair of first circular arc portions is equal to the bottom of the fitting groove of the other piston 3. The distance A is set smaller than the distance A, and the second arc portion 14
The curvature of c is smaller than the curvature of the bottom of the fitting groove of the piston 3, and when the piston 3 and the retainer 14 are engaged, the second circular arc portion 14
C is characterized by forming a gap between the fitting groove 13 of the piston 3 and the fitting groove 13 of the piston 3 in the vicinity of the connecting portion with the first circular arc portion 14b. When attached, the vicinity of the connecting portion between the first circular arc portion 14b and the second circular arc portion 14e of the retainer 14 is connected to the fitting groove 1 of the other piston 3.
3, the retainer 14 can be prevented from falling off, and after the retainer 14 is installed, the radius R2 of the second circular arc portion 14c is aligned with the bottom of the fitting groove of the piston 3. Since the radius is larger than R1, the retainer 14
The stress applied to the yoke 7 and the piston 14 can be reduced, and the springiness prevents the yoke 7 and the piston 14 from shaking.

An embodiment of the present invention will be described below with reference to the drawings.

Reference numeral 1 denotes a cylinder with both ends open, and two pistons 3.4 forming a hydraulic pressure chamber 2 inside are slidably fitted into the cylinder 1, respectively.

Guide grooves 5 extending in the sliding direction of the pistons 3 and 4 are formed on both sides of the cylinder 1. A yoke 7 that straddles a disk 6 is slidably fitted into the guide grooves 5 and supported.

The yoke 7 engages with the one piston 3 and slides within the guide groove 5 following the movement of the piston 3.

A friction pad 8 is attached to the other piston 4 side facing the disk 6.

Correspondingly, a friction pad 9 is attached to the yoke 7.

10 is a guide rod that guides the friction pads 8 and 9.

Reference numeral 11 denotes a yoke spring, whose protruding pieces engage and are locked in two symmetrical holes 12 provided in the yoke 7, respectively.

Furthermore, a fitting groove 13 is formed in the circumferential direction of the outer periphery of the portion of the piston 3 protruding from the cylinder 1, and this fitting groove 1
3, the retainer 14 is fitted along the outer peripheral surface of the piston 3 from below to above.

As shown in FIG. 3, the retainer 14 has a pair of abutting portions 1 that abut the yoke 7 near the end and press the yoke 7.
4a, a pair of first circular arc parts 14b bent from this contact part 14a, and a second circular arc provided continuously with this first circular arc part and fitted into the fitting groove 13 of the other piston 3. 14c.

Furthermore, the radius R2 of the second arc portion 14c of the retainer 14 is
The radius R1 of the fitting groove bottom of the piston 3 is made larger, and the inner distance B of the upper part of the retainer 14 is smaller than the distance diameter A (=water □) between the fitting groove bottoms of the piston 3.

As a result, when the piston 3 and the retainer 14 are engaged,
A gap is formed between the second circular arc portion 14c and the fitting groove 13 of the piston 3 at a portion near the connection with the first circular arc portion 14b.

With the above configuration, when pressure fluid is introduced into the hydraulic pressure chamber 2 from the master cylinder (not shown), the piston 4
moves downward in FIG. 1 to press the friction pad 8 against the disk 6.

Then, due to the reaction force of the pressing force, the piston 3 moves upward in FIG. 1, and the yoke 7 also moves accordingly, and the friction pad 9 is pressed against the disk 6, thereby performing a braking action.

At this time, the yoke 7 is prevented from swinging in the vertical direction by the yoke spring 11 interposed in the guide groove 5, and the swinging in the longitudinal direction is also removed by the retainer 14.

Although the present invention has been described as being applied to a type of disc brake in which pistons are placed opposite each other in a cylinder, as shown in Fig. It can also be applied to disc brakes.

According to the present invention as described above, the inner distance B of the upper part of the retainer 14 is made smaller than the distance A between the bottoms of the fitting grooves of the piston, so there is no fear of the piston falling off when assembling it, and there is no need to hold it down by hand.

Further, since the radius R2 of the second circular arc portion 14c of the retainer 14 is made larger than the radius R□ of the bottom of the fitting groove of the piston 3, the stress applied to the retainer can be reduced.

[Brief explanation of the drawing]

Fig. 1 is a plan view of a half section of the disc brake according to the present invention, Fig. 2 is a schematic diagram of a conventional retainer assembled;
Figure 3 is a schematic diagram of the assembled retainer according to the present invention;
The figure is a side view of FIG. 3. 1...Cylinder, 3,4...Zeston,
7...: L-ri, 11... Yoke spring, 13... Fitting groove, 14, 15...
...Retainer, 14a... Contact part, 14b...
....First circular arc portion, 14c...Second circular arc portion.

Claims (1)

[Claim for Utility Model Registration] A yoke that straddles a disk is slidably fitted into a guide groove formed on the side of a cylinder having two pistons, and one piston directly presses a friction pad against one surface of the disk. , in a disc brake in which the other piston presses another friction pad against the other surface of the disk via the yoke, a fitting groove is provided in the curved surface of the other piston, and between the other piston and the yoke, a pair of abutting portions that abut the yoke; a pair of first arcuate portions extending and bent in a direction away from the abutment portions; and a first arcuate portion that is continuous with the first arcuate portions and
and a second circular arc portion that is provided to draw an arc in the opposite direction to the circular arc portion and that fits into the fitting groove of the other piston. The distance between the inner sides of the first circular arc portion is set smaller than the distance between the bottoms of the fitting groove of the other piston, and the curvature of the second circular arc portion is smaller than the curvature of the bottom of the fitting groove of the piston, and the piston and a disc brake characterized in that when the retainer is engaged, a gap is formed between the second circular arc part and the fitting groove of the piston at a portion near the connection part with the first circular arc part.