JPH0616733U - Disc brake - Google Patents

Abstract

(57) [Summary] [Purpose] To enhance the effect of suppressing squeal during reverse braking, which is a problem with a disc brake that distributes a large amount of pad pressing force to the disc squeeze side during forward movement. [Structure] Center O of cylinder 2 is center C of friction pad 4
In the brake that is offset in the forward rotation direction of the disc D or in the disc brake that presses one pad with a plurality of pistons with large diameters on the disc feeding side, the corner angle of the friction surface (lining 4a) on the feeding side of the forward disc Cut out the part. As a result, the surface pressure on the entry side during forward travel is increased, and low-frequency squeaking during reverse braking is suppressed.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a disc brake having an enhanced effect of suppressing abnormal noise (so-called squeal) generated during braking.

[0002]

[Prior art]

 It is known that when a disc brake is braked, a rotational moment is generated on the friction pad, which increases the pad surface pressure on the disc entry side, which causes uneven wear of the pad.

Therefore, as a countermeasure against this, the brake cylinder is offset from the center of the pad in the forward rotation direction of the disc, or one wear pad is pushed by a plurality of pistons having a large diameter on the disc feeding side to push the piston. It is considered that the surface pressure distribution is corrected by allocating a larger amount to the delivery side than to the disc entry side during forward movement.

On the other hand, a shim for damping vibration is inserted between the piston and the friction pipe in order to stop the squeal during braking.

In order to enhance the effect of the shim, an elastic coating layer is provided on the surface or a lubricant is applied.

A part of the front surface of the piston is prevented from hitting the shim by cutting out a part of the shim.

A part of the front surface of the piston is cut out so that a part of the front surface does not hit the shim or pad.

The method described above is adopted.

[0009]

[Problems to be solved by the device]

 With a disc brake of the type that prevents uneven wear of the pad by adjusting the distribution of the piston pressing force, squeaking is likely to occur during reverse braking even if the above-mentioned squeal prevention measures are taken. Particularly, in the case of a piston-opposed disc brake, squeal at a relatively low frequency (usually 1.5 to 5 kHz) is likely to occur.

Therefore, an object of the present invention is to provide a disc brake that is also effective in preventing the low-frequency squeal during reverse travel.

[0011]

[Means for Solving the Problems]

 In order to solve the above problems, the present invention allocates a large amount of piston pressing force to the disc squeezing side during forward movement by offsetting the brake cylinder or pressing one pad with multiple pistons with different diameters. In the disc brake configured as described above, at least one of the pair of friction pads facing each other is cut out at the corner portion of the friction surface of the friction-advancing side at the time of forward movement.

Note that the notch may be provided in the corner portion on the disc feed-out side, but in this case, the width of the notch on the disc feed-in side in the disc rotation direction is smaller than that of the feed-out side notch. Also make loud.

[0013]

[Action]

 It has been empirically known that the above-mentioned relatively low frequency squeal is related to the surface pressure distribution of the pad in the disc rotation direction, and that when squeaking occurs, the disc entry side pressure at that time is larger than the disc ejection side pressure. Has been.

During reverse braking, a rotational moment reverse to that during forward braking is generated on the pad, and the pad surface pressure on the disc turn-in side (forward side forward side) at this time increases. In the disc brake to be improved by the present invention, a large amount of piston pressing force is distributed to the disc squeeze side at the time of forward movement, so that the surface pressure increases remarkably, and therefore squeal easily occurs during reverse braking. There is. However, as mentioned above, if the corners of the disk entry side (advance side when moving backward) of the friction surface during forward movement are cut out with an appropriate width, the surface pressure on this side increases due to the reduction of the area of the friction surface. The non-uniformity of the surface pressure distribution is corrected, and the squeal during reverse braking can be suppressed.

[0015]

【Example】

 1 to 3 show an embodiment of the present invention. In the disc brake of FIG. 1, the center O of the cylinder 2 provided in the caliper 1 is offset from the center C of the friction pad 4 in the forward rotation direction of the disc D, and the pressing of the pad 4 by the piston 3 is performed on the forward side disc extension side. As shown in the drawing, the corners of the pad lining 4a are notched by a predetermined width in the disc rotation direction on the forward advancing side (advancing side when advancing backward) of the disc D as shown in the figure. Reference numeral 5 in the figure indicates the cutout portion.

In the disc brake shown in FIG. 2, one pad 4 is pushed by two pistons 3a and 3b having a large diameter on the forward side and a small diameter on the forward side when the pad 4 is moved forward so that the pressing force of the pistons is the same as that of the brake of FIG. A large amount is distributed to the advancing side of the advancing disc, and in this case as well, the corner portion on the advancing advancing side of the lining 4a is cut out with a predetermined width.

In the illustrated brake, both of the pads 4 and 4 are provided with the notches 5, but it is also effective to provide the notches 5 on only one of the pads.

Further, as shown in FIG. 3, notches 5 may be provided at the corners on both the disk entry side and the disk exit side. At this time, the effect of the present invention can be obtained by making the width B 1 in the disc rotation direction of the notch on the inflow side during forward movement larger than the width A in the same direction of the notch on the inflow side.

Thus, fine adjustment can be performed by changing the surface pressure distribution by notching the lining. The offset amount and diameter difference of the piston are decided at the design stage and cannot be changed after manufacturing. However, disc brakes may or may not squeal strongly due to slight differences in conditions. Since the notch width of the lining can be adjusted freely in the brake of the present invention, there is a high degree of freedom in responding to changes in conditions, and fine adjustment of the surface pressure distribution does not significantly worsen the uneven wear prevention effect of the pad during reverse travel. A squeal suppressing effect can be produced.

[0020]

[Effect of device]

 As described above, according to the present invention, the problem of squealing during reverse braking, which is a problem in a brake that distributes a large amount of pad pressing force to the disc squeeze side during forward travel, has been addressed. This can be solved by a simple process called notch, and the reliability of this type of disc brake can be improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional plan view showing a main part of a disc brake of the present invention.

FIG. 2 is a cross-sectional plan view of another embodiment.

FIG. 3 is a plan view of a pad having notches on both sides.

[Explanation of symbols]

 1 Caliper 2 Cylinder 3, 3a, 3b Piston 4 Friction Pad 4a Lining 5 Notch D Disk

Claims (2)

[Scope of utility model registration request] 1. A brake cylinder is offset from the center of the pad in the forward rotation direction of the disc, or one friction pad is pressed by a plurality of pistons having a large diameter on the disc feeding side so that the piston pushing force pushes the disc into the disc during forward movement. In the disc brake adapted to be distributed more to the squeeze side than to the squeeze side, at least one of the pair of friction pads facing each other has a notch at a disc turn-in side corner portion at the time of forward movement of the friction surface of the pad. Disc brake. 2. A notch at both corners of the friction surface of the pad in the disc rotation direction, the notch width of the disc rotation direction on the disc advancing side during forward movement being made larger than the notch width on the disc ejection side. The disc brake according to claim 1.