JPH0616734U - Disc brake - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a disc brake that has a simple and inexpensive structure and can effectively suppress squeal during braking. [Structure] A pair of friction pads for holding the disc D,
The thickness of the lining 1b of at least one of the pads 1 is changed as shown in the figure. If this change in thickness is made to be large on the disk feed-out side when the disk D rotates in the direction in which low-frequency squeal occurs, a piston with a notch shim or front notch that requires rotation prevention is provided. Even without using, the pad surface pressure on the disc feeding side increases, and squeaking hardly occurs.

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]

 The following are the general methods that have been adopted to suppress the squeal of disc brakes.

A vibration damping shim is sandwiched between the piston and the friction pad.

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

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

[0007]

[Problems to be solved by the device]

 It is difficult to completely stop the squealing only with the above method. In particular, it is not very effective for squealing at relatively low frequencies (usually 1.5 to 5 kHz) in piston-opposed disc brakes.

The method (1) is effective for low-frequency squeal, but the method (2) does not achieve the purpose without the notch shim, and the method (2) requires the piston rotation stop. , This detent involves technical difficulties.

Therefore, an object of the present invention is to obtain a squealing effect equivalent to that of the above method by eliminating the need for a notch shim or a rotation stopper of a piston.

[0010]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, in the present invention, when the lining thickness of at least one of the pair of rubbing pads for sandwiching the disc is such that the disc rotation direction tends to cause low-frequency squeaking. That is, the taper gradient that gradually increases in thickness from the disk entry side to the disk entry side is adopted in advance.

[0011]

[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.

In the disc brake of the present invention, since the lining thickness is increased on the disc feeding side, the surface pressure on the disc feeding side is increased similarly to the method described above, so that the above-mentioned squeaking is effectively suppressed. To be done.

Further, since the surface pressure distribution is changed by making a difference in the lining thickness, the surface pressure distribution can be adjusted even if there is no shim or the piston rotates in the cylinder. The shortcomings of are also removed.

Since low-frequency squeal occurs when the disc rotates in the normal direction or when the disc rotates in the reverse direction depending on the type of brake, the lining thickness does not have an adverse effect by emphasizing the direction in which the squeal easily occurs. Need to be careful to decide.

[0015]

Embodiment FIG. 1 shows an embodiment of the present invention. The disc brake is of a piston-opposed type in which a pair of opposed friction pads 1 and 1 are separately pressed by pistons 2 and 2 and slidably contact a disc D.

The friction pad 1 is composed of a back plate 1a and a lining 1b attached to the front surface thereof. Here, both the inner pad and the outer pad have a smaller thickness of the lining 1b on the disc entry side. , It is changed with a constant gradient so that it becomes large on the disc feeding side.

In this brake, when hydraulic pressure is introduced into the cylinder 3 to move the piston 2 forward, the brake is pushed by this piston and the pad 1 is pressed against the disc D. At this time, the condition that θ> α is satisfied, where α is the allowable tilt angle of the piston 2 in the cylinder 3 (this is due to clearance and is extremely small), and θ is the tilt angle of the friction surface with respect to the disk end surface. If so, the pad 1 does not incline by more than α °, so that the surface pressure on the side of the disc that has a large lining thickness is surely increased. The result is the same if the piston 2 does not rotate in the cylinder 3 and therefore effectively suppresses low frequency squeaking without notch shims and without piston locking. be able to.

If low-frequency squeal occurs when the rotation direction of the disk D is opposite to the arrow in the figure, the inclination of the friction surface is reversed.

[0019]

[Effect of device]

 As described above, according to the present invention, since the pad lining thickness is changed in the disc axial direction so that the surface pressure distribution in the same direction is desired, it is more advantageous than before to suppress low-frequency squeaking. realizable.

[Brief description of drawings]

FIG. 1 is a cross-sectional view in plan view showing an example of a disc brake of the present invention.

[Explanation of symbols]

 1 Friction pad 1a Back plate 1b Lining 2 Piston 3 Cylinder D disk

Claims (1)

[Scope of utility model registration request] 1. A disc inflow-out side to a inflow-out side when the rotational direction of the disc is a direction in which a low-frequency squeal is likely to occur in the lining thickness of at least one of the pair of friction pads for sandwiching the disc. A disc brake having a taper gradient that gradually becomes thicker toward the front.