JPH08170660A - Disc brake device pad - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a pad of a disc brake device capable of reducing brake squeal substantially resulting from a friction coefficient of a friction material of the pad. [Structure] A disk rotor (1 that rotates together with wheels)
The pad (10) of the disc brake device having the friction material (14) pressed against the (2) means for supplying the lubricant to the contact surface of the friction material (14) with the disc rotor (2).
4) is provided. This means (24) comprises a plurality of holes (26, 27, 28) for containing a lubricant, which appear on the contact surface of the friction material (14) with the disc rotor when it wears.
And a lubricant (30) housed in each hole. The plurality of holes are arranged so that the lubricant appears substantially continuously in the contact surface in the thickness direction of the friction material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc brake device pad, and more particularly to a pad suitable for a vehicle disc brake device.

[0002]

2. Description of the Related Art A disk rotor that rotates together with wheels and pads arranged on each side of the disk rotor,
In the disc brake device including the caliper that supports the pad, the pad is pressed against the disc rotor by using the hydraulic cylinder provided in the caliper to obtain the braking force.
Brake squeal may occur during this braking, which may give an occupant a discomfort.

The squeal of the brake is considered to be caused not only by the shape of the friction material of the pad but also by the coefficient of friction of the friction material. The squeal of the brake caused by the shape of the friction material makes contact with the disc rotor of the friction material. It is known that chamfering is applied to reduce the surface (Japanese Utility Model Publication No. 62-18439).

[0004]

Since the chamfering of the friction material of the pad is eliminated by the abrasion of the friction material, the effect of reducing the brake squeal gradually decreases. In addition, even if chamfering is performed on the friction material, the effect of reducing brake squeal due to the friction coefficient of the friction material cannot be substantially obtained.

An object of the present invention is to provide a pad for a disc brake device, which can reduce brake squeal substantially due to a friction coefficient of a friction material of the pad.

[0006]

SUMMARY OF THE INVENTION The present invention is a pad of a disc brake device having a friction material which is pressed against a disc rotor which rotates with the moving part of the object to be braked, said disc of said friction material. A lubricant supply means is provided for supplying a lubricant to the contact surface with the rotor.

The lubricant supplying means includes a plurality of holes for containing a lubricant, which appear on a contact surface of the friction material with the disk rotor when the friction material is worn, and a lubricant contained in each hole. Is preferably provided. In this case, the plurality of holes are arranged so that the lubricant substantially continuously appears on the contact surface in the thickness direction of the friction material.

The invention also includes a disk having a friction material which is pressed against a disk rotor which rotates with the moving parts of the object to be braked, and a backing which supports the friction material and which receives a pressing force via the shims. A pad of a brake device, comprising: a first lubricant supplying means for supplying a lubricant to a contact surface of the friction material with the disc rotor; and a lubricant for supplying a contact surface of the backing plate with the shim. 2 lubricant supply means.

[0009]

[Operation and effect] As a result of supplying the lubricant to the contact surface of the friction material of the pad with the disk rotor, the friction coefficient of the friction material decreases. According to the experimentally confirmed fact, the brake squeal does not occur until the friction coefficient reaches a certain value,
After reaching said value, the brake squeal increases sharply with increasing coefficient of friction. On the other hand, when the friction coefficient of the friction material decreases, the braking force decreases. Therefore, the lubricant is supplied so that the friction coefficient is large enough to secure the required braking force.

The friction coefficient of the friction material of the pad is reduced by the lubricant, which reduces brake squeal.

When the friction material wears, the lubricant supply means appears on the contact surface of the friction material with the disk rotor,
A plurality of holes for containing a lubricant and a lubricant contained in each hole are provided, and the plurality of holes are such that the lubricant appears substantially continuously in the contact surface in the thickness direction of the friction material. When the friction material is worn, the lubricant appears and is applied to the contact surface so that the lubricant oozes out from the hole to reduce the friction coefficient of the friction material.

Even if the friction material of the pad wears, the holes containing the lubricant appear on the contact surface substantially continuously,
Brake squeal can be effectively reduced until the thickness of the friction material reaches its service limit.

If the pad has a friction material that is pressed against the disk rotor that rotates with the moving part of the object to be braked, and a backing that supports this friction material and that receives a pressing force through the shims, the friction material When the brake squeal is reduced by supplying a lubricant to the contact surface with the disc rotor of, the vibration generated at the time of braking is transmitted to the pressing force adding means, for example, the caliper through the back metal, and between the back metal and the shim. The lubricant supplied is attenuated, and brake squeal caused by vibration can be reduced. In this way, the effect of reducing the brake squeal becomes higher.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A pad 10, as shown in FIG. 1 which is a partially cutaway front view, has a friction material 14 which is pressed against a disk rotor 12 which rotates together with a movable part of an object to be braked, and a friction material. And a back metal 16 that supports 14. Two
A caliper 1 including two pads 10 of the same shape and the same size so as to sandwich the disc rotor 12 and including a hydraulic cylinder.
The pad 10 is supported by 8 to form a disc brake device 20. The caliper 18 includes a pair of pins 22.
It has a structure known per se that can be moved in a direction perpendicular to the plane of the drawing. The object to be braked is a vehicle or other transportation machine or industrial machine that needs to brake a movable part such as a wheel, and is used in an environment in which the squeal of the brake affects people around it. .

The pad 10 is a lubricant supply means 2 for supplying a lubricant to the contact surface of the friction material 14 with the disk rotor 12.
4 is provided. In the illustrated embodiment, the lubricant supply means 24
Includes a plurality of holes 26, 27, 28 for containing a lubricant, which appear on the contact surface of the friction material 14 with the disk rotor 12 when the friction material 14 is worn, and a lubricant 30 contained in each hole. . As shown in FIG. 2, the plurality of holes 26, 27, 28 are arranged so that the lubricant appears substantially continuously in the direction of the thickness T of the friction material 14 on the contact surface.

Although three holes 26, 27 and 28 are provided here for the sake of explanation, a larger number can be provided. In the illustrated embodiment, when one hole disappears, The holes are arranged so that the next holes appear, and the above conditions are satisfied. As shown in FIGS. 1 and 2, the friction material 14
Each of the holes formed in the above extends from above the contact surface between the friction material 14 and the backing metal 16 with a downward inclination (see FIG. 2 (b)). Due to the wear of the friction material 14, the bottom of one hole 26 first appears, and the lubricant 30 that appears to leak or ooze out from the hole 26 is applied in the circumferential direction of the friction material 14 by the rotation of the disk rotor 12. . Lubricant 30
Since it has a high viscosity as will be described later, it does not flow out all at once, and as the friction material 14 wears, the lubricant 30 located corresponding to the worn hole 26 oozes out. Therefore, the top of the filling material 30 housed in the hole 26
When the wear progresses to A _1, the bottom A ₂ of the next hole 27 appears.

In the embodiment shown in FIG. 3, holes 36, 37, 3 are provided.
Numeral 8 extends downward from the contact surface of the friction material 34 with the disk rotor 12 toward the back metal 16. Friction material 3
Due to the wear of No. 4, the upper end of the hole 36 appears, the portion of the hole 36 that appears gradually moves downward, and the lubricant 30 eventually oozes out. In this case, when wear progresses to the bottom B ₁ of the hole 36, the top B ₂ of the lubricant 30 in the next hole 37 appears. Due to the downward slope, such as holes 36, 37, 38, the viscosity of the lubricant 30 is less than that of the lubricant 30 contained in the holes 26, 27, 28 of the friction material 14 shown in FIGS. Can be made smaller.

The plurality of holes 26, 27, 28 are arranged at different positions in the direction of the thickness T of the friction material 14, so that if one hole is dealt with, the wear of the friction material 14 will be reduced. This is because the position where the lubricant appears to ooze out as it progresses becomes substantially different in the radial direction of the disk rotor 12, and the lubricant 30 cannot be applied at a predetermined position of the friction material 14.

However, the lubricant 30 is applied to the friction material 14 in the lateral direction R which is substantially the radial direction of the disk rotor 12.
Is preferably applied over substantially the entire surface of.
To this end, as shown in FIGS. 1 and 2, a hole 26A is provided outside the short side direction R of the hole 26, and a hole 26B is provided outside the hole 26A, and the bottom portions of the holes 26, 26A, 26B are Arrange them to appear together. Similarly for the holes 27, 28, another hole 27A, 27B, 28 is provided outside in the lateral direction R.
A and 28B are provided.

In the embodiment shown in FIG. 4, the hole 4 of the friction material 44 is
6, 47, and 48 are formed in a form elongated in the lateral direction R from the back metal 50 in a slanting downward inclination, and accommodate the lubricant 30 over the entire length of the hole. These holes 46, 47,
According to 48, the lubricant 30 substantially continuously appears in the contact surface in the direction of the thickness T, and the lubricant is applied over substantially the entire surface of the friction material 44 in the lateral direction R.

In the embodiment shown in FIGS. 2 and 4, chamfers 15 are applied to the friction materials 14, 44 and the holes are positioned so that they will appear when the chamfers disappear. in this way,
When a relatively large chamfer 15 is provided, the contact area of the friction material 44 is small, and thus the brake squeal caused by the friction coefficient is small. Therefore, the friction coefficient may be reduced when the chamfer 15 disappears.

The lubricant 30 is, for example, copper 14%, zinc 2%, aluminum 2%, graphite 20% or more (all are weight%), and the others are mineral oil type lubricants and thickeners such as lithium soap. Highly viscous grease can be obtained by mixing.

In the disc brake device 20, the pad 1
When arranging 0, as shown in FIG. 2B, the shim 54 is inserted between the back metal 16 and the hydraulic cylinder 56 of the caliper, and the pressing force of the hydraulic cylinder 56 is received by the back metal 16 via the shim 54. There is. In this case, the pad 10 is
A means for supplying a lubricant to the contact surface of the back metal 16 with the shim 54, that is, a plurality of holes formed in the back metal 16 and extending downward from above the contact surface of the friction material 14 and the back metal 16 toward the shim 54 side. 58 and a lubricant 30 housed in each hole 58
And can be provided.

Even if the shim has a lubricant retaining groove and the lubricant retained in this retaining groove flows out little by little over time, according to the embodiment shown in FIG. Since the lubricant is supplied to the shim, it is possible to suppress the squeal of the brake due to the vibration generated during braking for a long period of time.

In the embodiment shown in FIG. 5, the pad 60 comprises a friction material 62 and a back metal 64, and the friction material 62 is the friction material 6
A hole 66 formed obliquely downward with respect to the friction surface 2;
A plurality of capsules 6 containing a lubricant and arranged in the holes 66
8 and. The friction material 62 wears and the holes 66 make contact surfaces 6
3, the capsule 68 is melted by frictional heat, and the lubricant appears on the contact surface 63. The capsule 68 is made of, for example, a resin such as polyimide. This resin is about 400
It is resistant to temperatures up to ° C, but melts at higher temperatures.

In the case of the embodiment of FIG. 5, as the friction material wears, the capsule closest to the friction surface among the plurality of capsules is melted by frictional heat, and the contained lubricant is transferred to the contact surface with the disk rotor. Flow out. Since the capsule is larger than the hole for containing the lubricant and can be expected to gradually melt as the friction material wears, one capsule can supply the lubricant over a wide range of the friction surface. Therefore, compared to the one that contains the lubricant in the hole,
The number of holes can be reduced, and the rigidity of the friction material can be prevented from decreasing.

As shown in FIG. 6, when the friction coefficient μ is substantially constant C, the brake squeal occurrence rate D ₁ is low until the wear amount of the pad reaches a predetermined value X ₀ , but the wear amount of the pad is small. When the value exceeds a predetermined value X ₀ , the brake squeal occurrence rate D ₂ was rapidly increased. However, the wear amount of the pad is a predetermined value X _0.
When the friction coefficient μ is set to a low value C ₁ , the brake squeal occurrence rate D ₃ becomes substantially the same as D ₁ .

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of a pad of a disc brake device according to the present invention, showing a state cut along a plane orthogonal to a rotation axis of a disc rotor.

FIG. 2 shows the pad shown in FIG. 1, where a is a bottom view and b is a side view.

FIG. 3 is a side view of another embodiment of the pad of the disc brake device according to the present invention.

FIG. 4 shows still another embodiment of the pad of the disc brake device according to the present invention, in which a is a front view and b is a bottom view.

FIG. 5 is a sectional view schematically showing still another embodiment of the pad of the disc brake device according to the present invention.

FIG. 6 is a graph showing a wear amount of a pad, a friction coefficient, and a brake squeal occurrence rate.

[Explanation of symbols]

10, 60 Pad 12 Disc rotor 14, 34, 44, 62 Friction material 16, 50, 64 Back metal 18 Caliper 20 Disc brake device 24 Lubricant supply means 26, 27, 28, 36, 37, 38, 46, 47, 4
8, 58 holes 26A, 26B, 27A, 27B, 28A, 28B holes 30 lubricant 54 shims

Claims (3)

[Claims] 1. A pad of a disk brake device having a friction material pressed against a disk rotor rotating together with a movable part of an object to be braked, wherein a lubricant is provided on a contact surface of the friction material with the disk rotor. A pad of a disc brake device, comprising a lubricant supply means for supplying the. 2. The lubricant supply means has a plurality of holes for containing a lubricant, which appear on a contact surface of the friction material with the disk rotor when the friction material is worn, and a lubrication housed in each hole. The pad of the disc brake device according to claim 1, wherein the plurality of holes are arranged so that the lubricant substantially continuously appears on the contact surface in a thickness direction of the friction material. 3. A disc brake device comprising: a friction material which is pressed against a disk rotor rotating together with a movable part of an object to be braked; and a backing metal which supports the friction material and receives a pressing force through a shim. A pad, a first lubricant supplying means for supplying a lubricant to a contact surface of the friction material with the disk rotor, and a second lubricant for supplying a lubricant to a contact surface of the backing metal with the shim. A pad of a disc brake device, which comprises an agent supply means.