JPS6229705Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE PRESENT EMBODIMENT This invention relates to a friction pad for a disk brake.

In a disc brake, friction pads consisting of a friction member and a back plate fixed to the friction member are arranged on both sides of the disc rotor, and when the brake is applied, the friction pads are pressed against the rotor by an actuator, causing the rotor to rotation is suppressed.

However, in conventional disc brakes,
Because there was a lack of a means to ensure that the pad returned to its original position when the pressure on the pad was released when the brake was released, the pad continued to contact the rotor even when the brake was not applied, so-called dragging. This has caused various problems such as residual braking force, increased pad wear, and poor fuel efficiency.

The applicant has filed a patent application for a disc brake that prevents such dragging (Japanese Patent Application No. 12234, 1982).
However, the present invention relates to an improvement of the pads used in this disc brake.
This pad consists of a friction member disposed facing the rotor, a back plate fixed behind the friction member, and a sliding member held behind the back plate and guided in the direction of pressing by a guide member. and a holding member that is slidably supported, and when the friction member is brought into contact with the rotor and a co-rotation torque of the rotor is applied to the friction member, the back plate and the holding member face each other. An inclined surface is formed that serves to substantially thicken the total thickness of the back plate and the holding member by pushing the plate toward the rotor while sliding it along the plate surface of the rotor;
In addition, a return spring acts in a direction substantially parallel to the plate surface of the rotor to restore the back plate and the holding member to their original positions when the pressure is released, and the back plate and the holding member are always kept in close contact with each other. An elastic holding member for elastic holding is provided.

In this pad, the back plate is moved toward and away from the rotor by sliding against the holding member supported by the guide member, so when the brake is released, the back plate can be returned without moving the holding member away from the rotor. By simply returning the pad to its original position on the retaining member using the spring and the elastic retaining member, pad clearance is reliably obtained between the friction member and the rotor and dragging is eliminated.

However, this pad lacks a means to prevent dust, muddy water, etc. from entering between such sloped surfaces, that is, the sliding surfaces of the back plate and the holding member, so the vehicle is driven through puddles, rough roads, etc. In such cases, these substances may enter the sliding surface and increase the sliding resistance of the backing plate or cause rust, making the operation of the pad unstable and failing to meet its initial purpose. Subsequent research has revealed that there is a problem in that it cannot be achieved.

The present invention was developed against this background, and its purpose is to prevent dust, muddy water, etc. from entering between the sloped surface of the back plate and the holding member, and to prevent the pad from entering. To provide a friction pad for a disc brake which can operate smoothly and thereby reliably generate an appropriate amount of pad clearance when the brake is not applied.

For this purpose, the present invention has the above-mentioned friction member, back plate,
In a friction pad for a disc brake equipped with a holding member, an inclined surface, a return spring, an elastic holding member, etc.,
The outer periphery of the inclined surface is sealed with a sealing member.

This prevents dust, muddy water, etc. from entering between the inclined surfaces of the back plate and the holding member, thereby improving the operational stability of the pad and further improving the reliability of the brake performance. Therefore, increases in pad wear, deterioration in fuel efficiency, etc. can be better avoided.

Hereinafter, embodiments of the present invention will be described in more detail based on the drawings.

In the figure, numeral 11 is a disc rotor that rotates together with wheels (not shown), and is provided with a pair of friction surfaces on both sides. A pair of friction pads 12 and 13 are disposed on both sides of the rotor 11 so as to face the rotor 11, and a caliper 14 is disposed so as to straddle these pads 12 and 13. Calipa 1
4 includes a cylinder portion 16 located at a position facing the inner pad 12 and a reaction portion 17 located at a position facing the outer pad 13,
The rotor 11 is supported movably in a direction parallel to the axis of the rotor 11 by a slide pin provided upright on a support member (not shown). A piston 118 is slidably fitted into the cylinder portion 16, and when brake fluid pressure is supplied into the cylinder portion 16 during braking, the piston 18 is pushed toward the rotor 11, and the inner pad 12 is moved toward the rotor 11. The reaction part 17 is pressed against the outer pad 1 due to the reaction force.
3 to the other surface of the rotor 11, rotation of the rotor 11 is suppressed.

The inner pad 12 includes a friction member 19 that is brought into sliding contact with the rotor 11, as shown in FIGS. 2 to 4.
It has a back plate 21 fixed to the friction member 19 and a holding member 22 that slidably holds the back plate 21. As the back plate 21 moves away from the axis of the rotor 11 (upward), the rotor 1
1, and a pair of press-fit holes 24 and 26 in the plate thickness direction are located at the center of action of the frictional force generated between the rotor 11 and the friction member 19 during braking (A in FIG. 2). It is located at a position equidistant from the position shown in ). The axes of the press-fit holes 24 and 26 are located on an inclined line C that passes through the center of action of the frictional force A and is inclined at an angle α with respect to the rotational direction of the rotor 11 (direction B in FIG. 2). The pins 2 are inserted into the press-fit holes 24 and 26.
7 and 28 are press-fitted so as to penetrate through the back plate 21 and cannot be removed.

Support holes 30 are formed in both shoulders of the holding member 22, into which support pins serving as guide members are inserted.
Therefore, the holding member 22 is slidable in the pressing direction. A stepped portion 42 shown in FIG. 3 is formed on the outer peripheral portion of the front side (rotor 11 side) of this holding member 22, and a supporting portion 29 is formed at the lower end portion of the stepped portion 42. is back plate 2
1 is supported. The holding member 22 has an inclined surface 31 that is inclined at the same angle as the inclined surface 23 of the back plate 21 on the front side in contact with the back plate 21, so that when the back plate 21 is pushed upward. , the friction member 19 is pushed forward (in the direction toward the rotor 11). A pair of guide grooves 32, 33 are formed on the front side of the holding member 22, and the pins 27, 28 are slidably fitted into the guide grooves 32, 33. The guide surfaces 34 and 36 of the guide grooves 32 and 33 are inclined surfaces that are inclined at the same angle as the above-mentioned inclined surface C. An elongated spring housing hole 37 is formed in the holding member 22 so as to be continuous with one of the guide grooves 33. A return spring 38 that engages with the pin 28 is installed in this housing hole 37, and the back plate 21 is biased towards the original position shown.

A heat shield plate 39 is disposed outside the outer peripheral portion of the back plate 21 so as to surround the back plate 21. The heat shield plate 39 is arranged so that its plate surface is substantially parallel to the plate surface of the rotor 11, and its inner edge is located on the outer peripheral front part of the back plate 21, and the heat shield plate 39 is arranged so that the plate surface is substantially parallel to the plate surface of the rotor 11. The holding member 22 is elastically engaged with the engaging portion 41 extending rearward. Therefore, this heat shield plate 39 allows the back plate 21 to be brought into close contact with the holding member 22 by the engaging portion 41.
Move with 1. That is, in this embodiment, this engaging portion 41 constitutes an elastic holding member. A heat insulating board 44 made of a heat insulating material such as asbestos or asbestos hardened with rubber or other bonding agent is fixed to the rear side of the heat shield plate 39, and this heat insulating board 44 and the stepped portion 42 of the holding member 22 are A dust cover 43 made of a material such as rubber is provided between the
is disposed to cover the gap between the heat shield plate 39 and the back plate 21. The dust cover 43 is attached by being adhesively fixed at one end to the heat insulating board 44 and fitted into the holding member 22 with the other end in contact with the stepped portion 42. In addition, board 4
4 and the dust cover 43 can be fixed by bonding them together with adhesive at the same time as the dust cover 43 is heated, or by separately preforming the board 44 and the dust cover 43 in the same mold. This is done by a method such as bonding while applying heat molding.

In addition, the outer pad 13 is the same as the inner pad 12.
It has a symmetrical shape.

Next, the operation of the friction pad constructed as described above will be explained together with the operation of the disc brake.

When braking fluid pressure is supplied to the fluid chamber 46 of the cylinder portion 16 and the piston 18 is pushed out, the inner pad 12 is pushed thereby and the friction member 19 is brought into sliding contact with the rotor 11. Then, since the co-rotating torque of the rotor 11 acts on the friction member 19 in the rotation direction, the friction member 19 and the back plate 21 move the pins 27 and 28 into the guide grooves 32 and 33 based on the frictional force generated between them. While sliding the back plate 21
is pushed upward along the inclined line C until the side end surface 47 of the holding member 22 hits the torque receiving surface 48 formed on the holding member 22. Then, along with this, the back plate 21
is pushed toward the rotor 11 by the action of the inclined surfaces 23 and 31, thereby suppressing rotation of the rotor 11. At this time, the back plate 21 of the pad 12 is connected to a pair of pins 27, 2.
8 and the guide grooves 32 and 33, the back plate 21 does not rotate relative to the holding member 22 when the back plate 21 is raised.

The outer pad 13 is pressed against the rotor 11 by the reaction portion 17 that receives this reaction force, but its action is similar to that of the ant pad 12, so a description thereof will be omitted.

Next, when the brake fluid pressure is removed and the piston 18 is returned to the non-operating position by the piston seal 49 as a retracting member built into the cylinder portion 16, the friction member 19 of the inner pad 12
Since it is freed from the entraining effect of 1, the back plate 21
is moved in a direction along the plate surface of the rotor 11 by the return spring 38 and in a direction away from the rotor 11 by the engaging portion 41, and returned to the original position. At this time, since the return force of the return spring 38 acts along the above-mentioned inclined line C, no harmful sliding resistance is generated between the guide surfaces 34, 36 and the pins 27, 28. Since the back plate 21 is returned to its original position in this manner, an appropriate amount of pad clearance is secured between the friction member 19 and the rotor 11, thereby eliminating pad dragging when the brake is not applied.

In this way, the back plate 21 of the pad 12 is smoothly and reliably raised by the action of the pins 27, 28 and the guide grooves 32, 33, and as a result, the inclined surface 23 of the back plate 21 is sliding on surface 31;
This is designed to ensure an appropriate amount of pad clearance when the brakes are not applied, which prevents dust, muddy water, etc. from entering these slopes when the vehicle is driving on rough roads or in puddles. This may increase sliding resistance on the inclined surface or cause rusting, which may impede smooth movement of the back plate 21. However, in the pad 12, the heat shield plate 39 and the dust cover 43 are arranged so as to surround the outer peripheries of the sloped surfaces 23, 31 of the back plate 21 and the holding member 22, and dust and dirt can be removed between them.
This prevents muddy water, etc. from entering, and at the same time, prevents the above-mentioned dust, etc. from entering the sliding parts of the pins 27, 28 and the guide grooves 32, 33, so that the back plate 21 is smooth. Movement can be ensured and the above-mentioned problems will not occur.

Further, radiant heat from the rotor 11 heated by frictional heat generated during braking to the dust cover 43 is blocked by the heat shield plate 39, and heat transferred from the friction member 19 is blocked by the heat insulating board 44. Since it is shut off, thermal deterioration of the dust cover 43 due to temperature rise is effectively suppressed. Therefore, the dust cover 43 can function satisfactorily even if it is made of a material with relatively low heat resistance, and the material cost can be reduced.

Next, other embodiments of the present invention are shown in FIGS. 5 and 6. In this embodiment, the outer peripheral portion of the heat shield plate 51 is bent rearward in order to more effectively shield the radiant heat from the rotor 11. Therefore, the radiant heat is also blocked by the bent portion 52, and thermal deterioration of the dust cover is more effectively suppressed.

In another embodiment shown in FIG. 7, a heat shield portion 53 is formed by extending the front side of the outer peripheral portion of the back plate 53 along the plate surface of the rotor 11.
One end of the dust cover 43 is adhesively fixed to this heat shielding part 53. The dust cover is fixed to the heat shield section 53 in accordance with the method for fixing it to the heat insulation board 44. Since the heat shield portion 53 can be formed at the same time as the back plate 21 is manufactured, there are advantages in that the number of parts can be reduced and productivity can be improved. The pad shown in this embodiment is suitable for use when the amount of radiant heat from the rotor 11 is relatively small.

Next, another embodiment of the present invention will be described based on FIGS. 8 and 9. In the figure, sloped surfaces 58 and 59 that approach the rotor 11 as the rotor 11 rotates in the direction of rotation are formed on opposing sides of the back plate 56 and the holding member 57, and the friction member 61 is When brought into contact with the rotor 11, the back plate 56 is moved together with the friction member 61 in the rotational direction of the rotor 11 and pushed toward the rotor 11. At this time, the side end surface 62 of the back plate 56 is brought into contact with the support member 63 and movement is prevented. Incidentally, the inclined surface 58 of the back plate 56 is chrome plated. A mounting fitting 64 is welded and fixed to the outer circumference of the holding member 57, and a rubber seal ring 67 is inserted into the annular groove of the accommodating portion 66 formed at the appropriate position of the fitting 64.
It is housed in close contact with 8. A space 68 surrounded by the seal ring 67, the holding member 57, the metal fitting 64, and the back plate 56 and the holding member 5
Grease as a lubricant is sealed in an oil groove 69 formed on the front side of the back plate 56, thereby ensuring smooth movement of the back plate 56. The type of grease is appropriately selected depending on the degree of temperature rise of the pads due to brake use. A spring 71 (see FIG. 9) serving as an elastic holding member is mounted between the holding member 57 and the back plate 56 in the upper portion thereof.
The spring 71 serves to bring the back plate 56 and the holding member 57 into close contact with each other and to return the back plate 56 to the non-operating direction when the brake is released.One end of the spring 71 penetrates the metal fitting 64 from the rear and engages with the front side. The other end is engaged with the front side of the back plate 56.

In this embodiment, the seal ring 67 is disposed on the back side of the back plate 56, that is, at a position farther from the rotor 11 than in the previous embodiment, and its radiant heat is also shielded by the back plate 56. This has the advantage of more effectively suppressing thermal deterioration.

[Brief explanation of the drawing]

Fig. 1 is a side sectional view of a disc brake including a friction pad that is an embodiment of the present invention, Fig. 2 is a front view (partially cut away) of the friction pad in Fig. Fig. 4 is a side sectional view of the main part of the pad, Fig. 5 is a side sectional view of a friction pad according to another embodiment of the present invention, and Fig. 6 is a side sectional view of the main part of the same pad. , FIG. 7 is a side sectional view of a main part of a friction pad which is still another embodiment of the present invention, and FIGS. 8 and 9 are sectional views and plan views of a friction pad which is still another embodiment of the present invention, respectively. It is a diagram. 11: Disc rotor, 12: Inner pad,
13: Outer pad, 19, 61: Friction member, 2
1, 56: back plate, 22, 57: holding member, 23,
31, 58, 59: Inclined surface, 39, 51: Heat shield plate, 43: Dust cover, 44: Heat insulation board, 5
2: Bent part, 67: Seal ring.

Claims (1)

[Claims for Utility Model Registration] A friction pad for a disc brake that is placed on both sides of a disc rotor and is pressed by the rotor that rotates when the brake is applied, the friction member being placed facing the rotor;
It has a back plate fixed behind the friction member, and a holding member that slidably holds the back plate further behind the friction member and is supported by a guide member so as to be slidable in the direction of the pressing. , when the friction member is brought into contact with the rotor and a co-rotation torque of the rotor is applied to the friction member, the back plate and the holding member face each other, so that the back plate is connected to the plate of the rotor. A state in which an inclined surface is formed that acts to substantially thicken the total thickness of the back plate and the holding member by pushing it out toward the rotor while sliding along the surface, and the pressing force is released. a return spring that acts in a direction substantially parallel to the plate surface of the rotor to restore the back plate and the holding member to their original positions, and a return spring that elastically keeps the back plate and the holding member in close contact at all times. Friction for a disc brake, characterized in that an elastic holding member is provided to hold the inclined surface, and the outer periphery of the inclined surface is sealed by a sealing member to prevent dust, muddy water, etc. from entering between the inclined surfaces. Patsudo.