JPS59147126A - Disc brake equipped with parking brake mechanism - Google Patents

Abstract

PURPOSE:To reduce the number of constitution parts by constituting the captioned apparatus of an adjusting nut whose closed edge is intruded into the bottom wall of a cylinder, adjusting bolt which is screwed in retreatale ways with the adjusting nut and has a ratchet at the head part, parking lever having a cam which makes contact with the head part top surface of the adjusting bolt, and a pole for swinging the parking lever. CONSTITUTION:An adjusting nut 36 is fitted sliding into the fitting hole 28e of a boss part 28d formed at the center of the bottom wall 28c of a cylinder 28b through a seal ring 37, and the closed edge 36a intrudes into the cylinder 28b and connected onto the top wall 30a of a piston 30, so as to be pulled-out and not to be revolved. An annular flange 38b is formed integrally with the head part 38a of an adjusting bolt 38, and a ratchet wheel 39 is integrally fixed. A pole 42 is installed onto the intermediate part of a parking lever 40 and engaged with the ratchet wheel 39 at the top edge. When the amount of swing in the counterclockwise direction is over a prescribed value, an intermittent revolution movement is provided for the adjusting bolt 38, which is projected from the adjusting nut 36.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a disc brake with a parking brake mechanism, and in particular, a cup-shaped piston is fitted into a cylinder formed in a caliper so as to be slidable in the axial direction via a seal ring. This invention relates to a parking brake mechanism in which a piston is pushed by a parking brake mechanism or a pressure fluid supplied into the cylinder to press a pad.

Conventionally, as this type of disc brake,
There is one disclosed in Japanese Patent No. 19556 and shown in FIG. In this disc brake, the parking brake mechanism includes an adjustment bolt 2 disposed coaxially within a cup-shaped piston 1 and fixed to the piston.
an adjusting nut 5 that engages with the bottom wall 4b of the cylinder 4a formed in the cylinder 4a; and a spring that urges the adjusting nut 5 to the right in the figure by locking its left end in the figure to a cylindrical retainer 6 fixed to the peripheral wall of the cylinder 4a. 7, this spring 7 and adjustment nut 5
a thrust bearing 8 interposed therebetween; a piston 9 that is slidably inserted in the axial direction into an inner hole 4C formed coaxially with the cylinder 4a and faces the adjustment nut 5 with a gap S;
A cam groove 10a is rotatably supported by the caliper 4 at the back of the piston 9 and faces the back recess 9a of the piston 9.
A camshaft 10 having a camshaft 10 and a screw 1-79.
It is constituted by a toggle 11 etc. that is interposed between the two and connects the two.

In this disc brake, when the piston 1 is pushed to the left by the pressure fluid supplied in the cylinder 4a, the adjustment nut 5 engages the spring 7 and thrust against the adjustment bolt 2, which moves together with the piston 1. It rotates due to the cooperative action of the bearing 8, and the so-called pad clearance is automatically adjusted.

Furthermore, when the piston 1 is pushed into the cylinder 4a when replacing the pad, the adjusting nut 5 rotates due to thrust and the action of the bearing 3, and the piston 1 and adjusting bolt 2 are returned to the illustrated state (initial state) without rotating. Therefore, not only is the workability good, but the seal ring 12 is not twisted by the piston 1.

However, in this disc brake, the parking brake mechanism is controlled by the adjustment bolt 2. Thrust bearing 3.
81i1 Section Natsu 5. Retainer 6, spring 7, thrust bearing 8. Piston 9. Camshaft 10 and toggle 11
Not only is it expensive because it is composed of many parts such as 2. Thrust bearing 3° adjustment nut 5. Many parts such as the retainer 6, spring 7, and thrust bearing 81 are attached to the cylinder 4a.
Since the cylinder 4a is housed within the cylinder 4a, a complicated air pocket is formed within the cylinder 4a, and the air removal performance is extremely poor.

The present invention was made in view of this problem, and its purpose is to reduce the number of parts of the parking brake mechanism to make the disc brake less expensive, and to reduce the number of parts of the parking brake mechanism accommodated in the cylinder. The purpose is to reduce the amount of air and improve air removal performance.

In order to achieve the above-mentioned object, the present invention includes a parking brake mechanism that is slidably inserted into a mounting hole provided in the bottom wall of the cylinder coaxially with the piston via a seal ring, and has a closed end. a bottomed cylindrical adjustment nut that is inserted into the cylinder and connected to the piston; and a head that is screwed into the adjustment nut so that it can move forward and backward, and that has a head that projects outside of the cylinder and that is connected to the piston. The parking lot includes an adjustment bolt having a ratchet, and a cam integrally supported by a support portion extending from the bottom wall of the cylinder of the caliper so as to be swingable and abutting the top surface of the head of the adjustment bolt. A lever is assembled to the parking lever and engages with the ratchet throat of the adjustment bolt, and when the amount of rocking of the parking lever exceeds a predetermined value, an interrupted rotational movement is applied to the adjustment bolt to cause the adjustment bolt to adjust. It has a structure that includes a pole that protrudes from the Nando.

According to the above configuration, the main components of the parking brake mechanism are the adjustment pad, adjustment bolt, parking lever,
and poles, etc., the number of component parts can be reduced, and the disc brake can be constructed at low cost. In addition, among the components of the parking brake mechanism, only the closed end of the paulownia knot is housed inside the cylinder, and the other parts are placed outside the cylinder, so no complicated air pockets are formed inside the cylinder. , air release performance is significantly improved.

Embodiments of the present invention will be described below based on the drawings. FIG. 2 shows a first embodiment of the present invention, and in the disc brake shown here, a part of the vehicle body (not shown) (
For example, the torque member 20 that is assembled to the knuckle arm) has vanes placed on both sides of the disc rotor 22.
24 and 26 are assembled so as to be slidable in the left and right directions in the figure. Further, a caliper 28 is attached to the torque member 20 by a known means so as to be slidable in the left and right directions shown in the figure. The caliper 28 is formed in a shape that straddles a part of the outer periphery of the disc rotor 22 and surrounds both pads 24 and 26. The caliper 28 is formed in a bifurcated shape at the right end in the drawing, and is attached to the back plate 248 of the pad 24 on the right side in the drawing. A push arm 28a is formed which comes into contact with the cylinder 28a, and a cylinder 28b is formed on the left side in the figure. The cylinder 28b is formed in the left-right direction in the figure, and a cup-shaped piston 30 is fitted into the cylinder 28b so as to be slidable in the left-right direction (axial direction) in the figure through a seal ring 32. is in contact with. This piston 30 is configured to be pushed by hydraulic pressure supplied into the cylinder 28b or by a parking brake mechanism, and a dust boot 34 is installed between its outer periphery and the outer end of the cylinder 28b. The piston 30 is rotated by a protrusion 26b provided on the back metal 262 of the band 26.

The parking brake mechanism is a bottomed cylindrical adjustment pad 36.
．． Adjustment bolt 38. It includes a parking lever 40, a ball 42, and the like. The adjustment nut 36 is connected to the cylinder 28
Attachment hole 2 of boss portion 28d formed in the center of bottom wall 28c of b.
The piston 8e is slidably fitted into the piston 8e via a seal ring 37, and its closed end 36a protrudes into the cylinder 28b and is connected to the top wall 30a of the piston 30 in a removable and non-rotatable manner. The connection between the piston 30 and the adjusting nut 36 is achieved by making the recess provided in the piston 30 and the right end of the adjusting nut 36 non-circular. Adjustment bolt 3
8 is screwed into the adjusting nut 36 with a large pitch screw so that it can move forward and backward, and its head 38a protrudes outside the cylinder 28b.

The head 38a of the adjustment bolt 38 has an annular flange 3.
8b is integrally formed, and a ratchet wheel 39 separate from the adjustment bolt 38 is integrally fixed. Further, the head 38a of the adjustment bolt 38 is connected to the caliper 2.
A thrust bearing 46 is interposed between the flange 38b of the adjustment pole [38] and the plug 44. The parking lever 40 is connected to the caliper 28
A pair of support arms 28g (
(One side is shown in the figure) is swingably supported via a support pin 41, and an adjustment bolt 3 is attached to the lower end of the support pin 41.
A cam 40a that comes into contact with the top surface of the head 38a of 8 is integrally formed. Also, the upper end 40 of the parking lever 40
b protrudes outside the boot 48, and is operable to swing ωJ.

The ball 42 is assembled in the middle part of the parking lever 40, and its tip engages with the ratchet wheel 39, and when the amount of rocking of the parking lever 40 in the counterclockwise direction shown in the figure exceeds a predetermined value. When the parking lever 40 swings in the clockwise direction shown in the drawing (returns), the radiator lift 39. Then, the adjusting bolt 38 is given an interrupted rotational movement to cause the adjusting bolt 38 to protrude from the adjusting nut 36.

In this embodiment configured as described above, the cylinder 2
When pressurized fluid is supplied into 8b, the piston 30 moves to the right and presses the pad 26 against the left side of the disc rotor 22, and at the same time the caliper 28 moves to the left and uses its pushing arm 28a to press the pad 26 against the left side of the disc rotor 22. Since the pad 24 is pressed against the right side surface of the disc rotor 22, a normal braking action can be obtained. At this time, in the parking brake mechanism, hydraulic pressure acts on the adjustment nut 36, and the acting force is transmitted to the plug 44 via the adjustment bolt 38 and the thrust bearing 46,
Accepted at 4. Also, at this time, the piston 30
Since the connection between the adjustment nut 36 and the adjustment nut 36 cannot be removed, the adjustment nut 36
is prevented from rotating by the piston 30, and the adjusting bolt 38 is prevented from rotating into the adjusting nut 36 by the ball 42, so that the adjusting nut 36 and the adjusting bolt 3.
The amount of screw engagement of No. 8 does not change.

Furthermore, when the hydraulic pressure in the cylinder 28b is released, the piston 30 is returned to the left by the restoring action of the seal ring 32, and the caliper 28 is returned to the right by the frictional vibration between the disc rotor 22 and the butt 26. , the braking action of the through hole is released. At this time, in the parking brake mechanism, the hydraulic pressure acting on the adjustment nut 36 simply disappears, and there is no operation at all.

On the other hand, when the parking lever 40 is swung in the counterclockwise direction in the figure, the cam 40a of the parking lever 40 causes the adjustment bolt 38. The joint nut 36 and piston 30 are pushed to the right, the pad 26 is pressed against the left side of the disc rotor 22, and the reaction force causes the caliper 28
is pushed to the left, and the pad 24 is pressed against the right side surface of the disc rotor 22 to obtain a parking brake effect.

Furthermore, when the parking lever 40 is returned to the illustrated state, the parking brake action is released.

Therefore, when the parking brake is operated as described above (including release operation), if the parking lever 40 is swung counterclockwise in the drawing by a predetermined amount or more due to wear of both pads 24 and 26, the ball 42 and the ratchet wheel 39 are The engagement position changes, and when the parking lever 40 swings in the clockwise direction in the drawing, the radiator rotary boiler 39 and the adjustment bolt 38 are interlocked in rotation by the ball 42.
An adjustment bolt 38 projects from the articulation nut 36. As a result, the clearance (pad clearance) between the disc rotor 22 and both pads 24 and 26 during non-braking is automatically adjusted. Note that if both bands 24 and 26 have little wear and the amount of rocking of the parking lever 40 in the direction of the counterclockwise hand is less than a predetermined value, the engagement position between the ball 42 and the ratchet wheel 39 does not change, and the above-mentioned pad Clearance is not provided for 8 laps.

By the way, in this embodiment, the main components of the parking brake mechanism are adjusted by using the 36° adjustment bolt 3.
8. Parking lever 40. and balls 42, etc., the number of component parts of the parking brake mechanism can be reduced compared to the conventional one, and the disc brake can be constructed at low cost. Further, among the components of the parking brake mechanism, only the closed end 36a of the adjusting Nand 36 is accommodated within the cylinder 28b, and the other components are disposed outside the cylinder 28b, so that no complicated air pocket is formed within the cylinder 28b. First, air removal performance is significantly improved. Furthermore, the sliding part of the joint nut 36 and the adjustment nano L 3
6 and the threaded part of the adjustment bolt 38 are provided in parallel (concentrically). The dimensions up to 3Qa can be shortened. Therefore, the heat insulating space R (piston 3
0, which communicates with the outside through a notch 30b provided at the right end of the hole L), thereby improving the heparonoke resistance. Further, in this embodiment, when replacing the band, if the ball 42 is removed from the ratchet wheel 39 and the piston 30 is pushed into the cylinder 28b, the adjustment bolt 38 will rotate due to the action of the thrust bearing 46.
Since the piston 30 enters the cylinder 28b without rotating, the seal ring 32 is not torn off by the screws 1 to 30.

FIG. 3 shows a second embodiment of the present invention, and the disc brake shown here has a parking brake of -14
0 is assembled to a support portion 128g having a rear wall 128h formed on the caliper 128, and in the illustrated state (parking brake released state), the parking lever 14
The cam 140a of 0 is the il1 part 138 of the joint bolt 138.
a-Abuts against the top surface and the parking lever 140
A stopper portion 140c integrally formed with the caliper 12
8 is in contact with the rear wall 128h. Therefore, in this embodiment, when pressure fluid is supplied into the cylinder 128b, the force acting on the adjustment nut 136 is applied to the joint bolt 13B.
and is received by the rear wall 128h via the parking lever 140. The other configurations are the same as those of the first embodiment, except that the plug 44 and the thrust bearing 46 are not used, so similar reference numerals in the 100 series will be given and explanations thereof will be omitted. Further, since the operation of this disc brake is substantially the same as that of the first embodiment, a description thereof will be omitted. In this embodiment, when replacing the band, the ball 142 is attached to the ratchet wheel 13.
9 and push the piston 130 into the cylinder 128b while rotating the adjustment bolt 138, the piston 1
30 enters the cylinder 128b without rotating, the seal ring 132 is not torn off by the piston 130.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a conventional disc brake with a parking brake mechanism, FIG. 2 is a sectional view showing a first embodiment of a disc brake with a parking brake mechanism according to the present invention, and FIG. 3 is a parking brake mechanism according to the present invention. FIG. 2 is a sectional view showing a second embodiment of the attached disc brake. Explanation of symbols 26...pad, 28...caliper, 28b...
・Cylinder, 28c...bottom wall, 28d...boss part,
28e...Mounting hole, 28g...Support arm, 30.
... Screw 1, 30a... Top wall, 32... Seal ring, 36... F17r1 joint nut, 36a... Closed end, 37... Seal ring, 38... Adjustment bolt,
38a...Head, 39...Rachesotoboile, 4
0... Parking lever, 40a... Cam, 42.
··ball. Applicant Aisin Seiki Co., Ltd. Representative Patent Attorney Teru Hase −

Claims (1)

[Claims] A cup-shaped piston is fitted into a cylinder formed in the caliper so as to be able to slide in the axial direction via a seal ring, and this piston is pushed by the parking brake mechanism or pressurized fluid supplied into the cylinder to close the pad. In the disc brake with a parking brake mechanism, the parking brake mechanism is provided on the bottom wall of the cylinder coaxially with the piston.
a bottomed cylindrical adjustment nut that is slidably inserted into the hole via a second seal ring and whose closed end protrudes into the cylinder and is connected to the piston; an adjustment bolt having a ratchet on the head, which is screwed into the adjustment bolt so that the head protrudes outside the cylinder; and a support part extending from the bottom wall of the cylinder of the caliper, which is swingable. a parking lever that is supported by and integrally includes a cam that abuts the top surface of the head of the adjustment bolt;
A ball that is assembled to the parking lever and engages the ratchet of the adjustment bolt, and when the amount of swing of the parking lever exceeds a predetermined value, imparts an interrupted rotational motion to the adjustment bolt, causing the adjustment bolt to protrude from the adjustment nand. A disc brake with a parking brake mechanism, characterized in that it has a configuration comprising: