JPH0517411B2 - - Google Patents

Abstract

PURPOSE:To enable miniaturization to be attained of a reservoir tank for working fluid by providing an automatic clearance adjusting part adjusting a braking clearance between both friction pads and a brake disk and a stopper restricting a retracting position of the first friction pad. CONSTITUTION:When a brake is released, as a brake disk 6 rotates the first friction pad 91 is retracted, and its retracted position is restricted by bringing a back plate to be opposed to a stopper S1, so that a piston 13 places its retracting position in almost a fixed position, generating the volume of a pressure oil chamber 15 almost in a fixed value. While, when the first and second friction pads 91, 92 are worn exceeding a specified amount by controlling a parking brake, an adjusting bolt 24 is rotated in accordance with a wearing amount by actuating an automatic clearance adjusting part A advancing the second pad 92 toward the brake disk 6 ensuring a proper braking clearance. Since this adjustment is controlled in a side of a mechanically-operated mechanism M2, a hydraulically-operated mechanism M1 is given no influence, and the piston 13 is prevented from changing its retracting position.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Object of the Invention (1) Field of Industrial Application The present invention relates to a disc brake device used in vehicles and the like.

(2) Prior Art The present applicant has previously proposed a disc brake device disclosed in Japanese Utility Model Application Publication No. 62-68038.

(3) Problems to be Solved by the Invention However, in the above-mentioned device, within the hydraulic actuation mechanism that advances the friction pad toward the brake disk, between the hydraulic cylinder and the piston,
Equipped with an automatic distance adjustment section that adjusts the braking distance between both friction pads and the brake disc.
During this time, the retracted position of the piston is displaced in the direction closer to the brake disk in response to the adjustment action, and the volume of the hydraulic chamber defined between the hydraulic cylinder and the piston is gradually increased accordingly.

Therefore, since hydraulic oil must be supplied to the hydraulic chamber in accordance with the gradual increase in the amount of hydraulic oil in the hydraulic chamber, there is a problem that the hydraulic oil reserve tank becomes large.

An object of the present invention is to provide the disc brake device capable of solving the above problem.

B. Structure of the Invention (1) Means for Solving the Problems The present invention provides a system in which a brake disc is slidably provided on a rotating shaft, and a fixed brake caliper that straddles the brake disc is arranged on one side of the brake disc. a hydraulic actuation mechanism for advancing a first friction pad disposed on the other side of the brake disk toward the brake disk; and a mechanical actuation mechanism for advancing a second friction pad disposed on the other side of the brake disk toward the brake disk. wherein the hydraulic actuating mechanism includes a hydraulic cylinder and a piston slidably fitted thereto to define a hydraulic chamber between the hydraulic cylinder and the mechanical actuating mechanism, the mechanical actuating mechanism comprising both friction pads and a brake. Automatic adjustment to adjust the braking distance between the disc and the disc
It is characterized in that the brake caliper is provided with an adjustment section, and a stopper is provided on the brake caliper for regulating the retreating position of the first friction pad.

(2) Effect If the automatic distance adjustment section is provided in the mechanical operation mechanism as described above, even if the distance adjustment is performed, it will not affect the hydraulic operation mechanism in any way, and the first friction pad Since the retracted position of the piston is regulated by the stopper, the retracted position of the piston becomes a substantially normal position, and therefore the volume of the hydraulic chamber remains approximately constant.

(3) Embodiment In FIG. 1, a drive shaft 3 serving as a rotating shaft passing through a side wall 2 of a metal housing 1 constituting a part of a vehicle body is rotatably supported via a bearing 4. On one side of the side wall 2, a transmission chain sprocket 5 for driving a wheel is fixed to one end of a drive shaft 3, and on the other side of the side wall 2, the other end of the drive shaft 3 is connected to an engine (not shown). .

A brake disk 6 is slidably supported on the drive shaft 3 via a half-moon key 7 close to one side of the side wall 2.

A carrier body 8 is attached to one side of the end 2a of the side wall 2, and both sides of the brake disc 6 are sandwiched between the carrier body 8 and the side wall 2. Therefore, the side wall 2 and the caliper body 8 constitute a fixed brake caliper C that straddles the brake disc 6. brake disc 6
First and second friction pads ₉ 1 and 9 ₂ are arranged between one side and the side wall 2 and between the other side of the brake disk 6 and the carrier body 8, respectively. Both friction pads 9 ₁ and 9 ₂ are plate-shaped back plates 1
0 ₁ , 10 ₂ and linings 11 ₁ , 11 ₂ joined to the respective back plates 10 ₁ , 10 ₂ , and both the back plates 10 ₁ ,
10 ₂ is slidably fitted into both recesses 12 ₁ and 12 ₂ formed opposite to each other in the side wall 2 and the carrier body 8, respectively. The bottom surface of the recess ₁₂₁ of the side wall 2 functions as a stopper _s1 for regulating the retracted position of the first friction pad ₉₁ .

A service brake hydraulic actuation mechanism _M1 for advancing the first friction pad ₉₁ toward the brake disc 6 is provided on the side wall 2, and a hydraulic actuation mechanism M1 for moving the first friction pad 91 toward the brake disc 6 is provided.
A parking brake mechanical actuation mechanism M ₂ is provided for advancing the second friction pad 9 ₂ toward the brake disc 6 .

The hydraulic actuation mechanism M ₁ is constructed as follows.

That is, the piston 1 is placed on the other side of the end 2a of the side wall 2.
A hydraulic cylinder 14 having a cylinder 3 facing the side wall 2 is attached. A hydraulic chamber 15 defined by a hydraulic cylinder 14 and a piston 13 has a conduit 16 and a conduit 1.
It is connected to a master cylinder (not shown) via 7. The push shaft 18 is attached to the back plate 10 ₁ of the first friction pad 9 ₁ .
The push shaft 18 ₁ protrudes through the side wall 2 and is slidably supported by the side wall 2, and the tip of the push shaft 18 ₁ abuts against the end surface of the piston 13 _. do. Rubber seal member 1 on piston 13
9 is installed.

The mechanical actuation mechanism _M2 is constructed as follows.

That is, the brake lever body 8 has a brake lever housing chamber 20 adjacent to its recess 12 ₂ , and a hollow male screw member 22 with a relatively coarse lead that penetrates the outer wall 21 of the housing chamber 20 is attached to the inner wall of the housing chamber 20 . 23.

The push shaft 18 ₂ is attached to the back plate 10 ₂ of the second friction pad 9 ₂
is provided protrudingly, and its pushing shaft 18 ₂ is a male screw member 22
is slidably fitted within. Also, the male thread member 22
, adjust the adjustment bolt 24 so that it rotates together with it.
is screwed in, and the inner end of the adjustment bolt 24 abuts against the end surface of the push shaft ₁₈₂ .

The inner end of the brake lever 25 is squarely fitted to the outer circumferential surface of the male threaded member 22 within the housing chamber 20,
Further, the outer end of the brake lever 25 is connected to the operating wire 26 outside the accommodation chamber 20, as shown in FIG.
connected to.

The operating wire 26 is inserted through a hollow bolt 28 screwed into the support bracket 27 of the carrier body 8 and connected to a brake handle (not shown).
Further, a return spring 29 is compressed between the support bracket 27 and the brake lever 25.

A shaft-shaped stopper _s2 is installed between the outer walls 21 and 23 in the accommodation chamber 20, and the notch 30 of the brake lever 25 abuts against the stopper _s2 , thereby regulating the return position of the brake lever 25. Therefore, this stopper _s2 has the function of regulating the retracted position of the second friction pad ₉₂ .

The mechanical actuation mechanism M ₂ includes both friction pads 9 ₁ ,
A known automatic distance adjusting section A for adjusting the braking distance between the brake disc ₆ and the brake disc 6 is provided. This automatic distance adjustment section A rotates the adjustment bolt 24 according to the amount of wear when both friction pads 9 ₁ and 9 ₂ are worn beyond a specified amount, and the second friction pad 9
₂ toward the brake disc 6.

Next, the braking operation by the above device will be explained.

When operating the service brake while the vehicle is running, the hydraulic chamber 15 of the hydraulic actuation mechanism _M1
Hydraulic oil is pumped to. This causes the piston 13 to move forward and move the first friction pad ₉₁ forward toward the brake disc 6 via the push shaft 181, so the first friction pad ₉₁ moves forward toward the brake disc 6.
The brake disc 6 is pushed by the friction pad 9 ₁ and comes into contact with the second friction pad 9 ₂ . Due to this abutment, a thrust in the direction of advancing and retracting the second friction pad 9 ₂ acts on the male threaded member 22 via the second friction pad 9 ₂ , the push shaft 18 ₂ and the adjustment bolt 24, but the male thread member 22 acts as a brake. Since rotation is prevented by the stopper _s2 via the lever 25, the second friction pad ₉₂ is held in the retracted position,
As a result, the brake disc 6 is connected to both friction pads 9.
₁ and 9 _2, braking is applied to the drive shaft 3 and therefore the wheels.

With the braking, frictional heat is generated between the brake disc 6 and the first friction pad ₉₁ , but the hydraulic cylinder 14 and the piston 13 are spaced apart from the first friction pad ₉₁ , and the frictional heat is generated between the brake disc 6 and the first friction pad 91. Since the frictional heat is conducted to the housing 1 and dissipated via the back plate 10 ₁ and the push shaft 18 ₁ , the transfer of the frictional heat to the hydraulic cylinder 14 and the piston 13 is prevented. Thereby, the durability of the rubber seal member 19 attached to the piston 13 can be improved.

When the brake is released, the first friction pad ₉₁ retreats as the brake disc 6 rotates, and its retreated position is regulated by the back plate ₁₀₁ coming into contact with the stopper _s1 .

Since the retracted position of the first friction pad ₉₁ is regulated in this way, the retracted position of the piston 13 becomes a substantially normal position, and therefore the volume of the hydraulic chamber 15 becomes substantially constant. This makes it possible to reduce the amount of hydraulic oil supplied to the hydraulic chamber 15 to a small amount or to zero, thereby reducing the size of the hydraulic oil reserve tank.

When operating the parking brake after the vehicle has stopped running, operate the operating wire 2 of the mechanical actuator M ₂ .
6 and rotate the brake lever 25 counterclockwise in FIG. As a result _, the male threaded member 22 rotates and moves forward together with the adjustment bolt 24 to move the second friction pad ₉₂ forward toward the brake disc 6 via the push shaft 182.
₂ pushes the brake disc 6 into contact with the first friction pad ₉₁ . Since the first friction pad ₉₁ is restricted to the backward position by the stopper _s1 , the brake disc 6 is squeezed between the two friction pads ₉₁ and ₉₂ , and braking is applied to the drive shaft 3 and therefore the wheels. .

When the brake is released, the brake lever 25 rotates clockwise in FIG.
When it abuts against the stopper _s2 , the male threaded member 22 also stops. The second friction pad ₉₂ retreats as the brake disc 6 rotates, and the retreat is caused by the push shaft 18.
₂ abuts against the adjustment bolt 24, it stops. That is, the retracted position of the second friction pad ₉₂ is regulated by the stopper _s2 .

In the parking brake operation, the first,
When the second friction pads 9 ₁ , 9 ₂ are worn beyond a specified amount, the adjustment bolt 24 is rotated according to the amount of wear by the operation of the automatic adjustment part A, and the second friction pads 9 ₂ are braked. Since the motor is moved forward toward the disc 6, an appropriate braking period is ensured.

After this adjustment, since the amount of retraction of the second friction pad ₉₂ is kept constant by the stopper _s2 as described above, there is no fluctuation in the amount of adjustment of the second friction pad ₉₂ .

Since the adjustment operation is performed on the mechanical actuation mechanism M ₂ side, it does not affect the hydraulic actuation mechanism M ₁ in any way, and the above function can be obtained by the stopper s ₁ , so that the retracted position of the piston 13 can be adjusted. Fluctuations are prevented.

C. Effects of the Invention According to the present invention, the mechanical operating mechanism is equipped with an automatic interval adjustment section, and the brake caliper is provided with a stopper for regulating the retracted position of the first friction pad. By keeping the volume of the hydraulic chamber at a fixed position at all times, the amount of hydraulic oil supplied to the hydraulic chamber can be minimized or eliminated, thereby making it possible to downsize the hydraulic oil reserve tank.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a longitudinal sectional front view, and FIG. 2 is a view taken in the direction of the arrow in FIG. A...Automatic adjustment unit, C...Brake caliper, _M1 ...Hydraulic operating mechanism, _M2 ...Mechanical operating mechanism, _s1 ...Stopper, 3...Drive shaft (rotating shaft),
6...Brake disk, ₉₁ , ₉₂ ...First and second friction pads, 13...Piston, 14...Hydraulic cylinder, 15...Hydraulic chamber.

Claims (1)

[Claims] 1 A hydraulic type in which a brake disc is slidably provided on a rotating shaft, and a first friction pad disposed on one side of the brake disc is advanced toward the brake disc on a fixed brake caliper that straddles the brake disc. an actuation mechanism and a mechanical actuation mechanism for advancing a second friction pad disposed on the other side of the brake disk toward the brake disk, the hydraulic actuation mechanism having a hydraulic cylinder and a mechanical actuation mechanism slidably attached to the hydraulic cylinder; and a piston fitted to define a hydraulic chamber between the hydraulic cylinder and the mechanical actuating mechanism includes an automatic distance adjustment section for adjusting the braking distance between the friction pads and the brake disc. A disc brake device, characterized in that the brake caliper is provided with a stopper for regulating the retreating position of the first friction pad.