JPH0720423Y2 - Disc brake with parking brake mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field of the Invention The present invention relates to a disc brake having a parking brake mechanism.

2. Description of the Related Art Via a caliper having a cylinder bore that opens in one direction, and an adjust nut that is screwed into an adjust bolt that is fitted into the cylinder bore and axially reciprocates in association with the operation of a parking brake operating member. A piston to be pushed out, a peripheral wall into which the adjusting bolt is inserted, an inward flange formed at one end of the peripheral wall, and an outward flange formed at the other end of the peripheral wall, and the outward flange. At the inner peripheral surface of the cylinder bore or an inner peripheral surface separately provided on the inner peripheral side of the inner peripheral surface of the cylinder bore so as not to move in the direction toward the opening of the cylinder bore, and on the outer peripheral side of the adjustment bolt. It is provided between the inward flange of the spring receiver and the adjustment bolt,
There is known a disc brake including a parking brake mechanism of a type including a spring that biases the adjustment bolt in a direction opposite to the pushing direction of the piston. For example, the one described in Japanese Utility Model Application Laid-Open No. 1-25422, which was filed by the applicant earlier, is that, and in a disc brake equipped with this parking mechanism,
Normally, while compressing the spring arranged on the inner peripheral side of the spring receiver with the adjusting bolt, the spring receiver is inserted to a predetermined position in the cylinder bore to maintain this state, and a snap that has been reduced in diameter in advance. Insert the ring between the outer peripheral surface of the spring receiver and the inner peripheral surface of the cylinder bore to a predetermined position inside the cylinder bore, and then expand the diameter of the snap ring and fit it into the annular groove provided on the inner peripheral surface of the cylinder bore. As a result, the spring receiver is attached to the inner peripheral surface of the cylinder bore or the like.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in the work of mounting such a spring receiver on the inner peripheral surface of the cylinder bore, the operation of holding the spring receiver in a state where the spring is preloaded at a predetermined position in the cylinder bore and the snap ring are reduced in diameter. In this state, it is necessary to insert it into the cylinder bore and fit it into the annular groove at the same time, and when inserting the snap ring into the cylinder bore, the space between the outer peripheral surface of the spring receiver and the inner peripheral surface of the cylinder bore is Since it is usually relatively narrow, there is a problem that skillful or special jigs are required for the installation work of such a space receiver,
The diameter of the snap ring is usually reduced by bringing both ends of the snap ring closer to each other with a tool etc., and the posture of the snap ring when inserted into the cylinder bore is relatively unstable. At the time of insertion into the inside, there is a possibility that the snap ring may damage the inner peripheral surface of the cylinder bore, the seal member provided on the inner peripheral surface of the cylinder bore, or the like.

On the other hand, as disclosed in Japanese Utility Model Application Laid-Open No. 53-87372, for example, the peripheral wall of the spring holding cover (spring receiver) is configured to have a plurality of side wall portions located at regular intervals in the circumferential direction. In addition, an outward flange is provided at the tip of each side wall part, and with the side wall parts elastically deformed to the inner peripheral side, the spring holding cover is inserted from the flange side to a predetermined position in the cylinder bore and pushed against the rear side wall part. It is conceivable that each flange is configured to be fitted into a groove provided in the cylinder bore by releasing the pressure, and even in this case, the side wall portion of the peripheral wall when the spring holding cover is fitted into the groove is fitted. There is a problem in that a special jig is required to elastically deform the inward.

In addition, the applicant of the present application filed and published the actual Kaihei 1-27
As described in Japanese Patent No. 543, the end of the side wall (peripheral wall) of the spring receiver opposite to the bottom wall (inward flange) side is inclined with respect to the axis of the cylinder bore and is on the outer peripheral side. In addition, a plurality of engaging projections that project toward the opening side of the cylinder bore are provided, and when the spring receiver is pushed into the cylinder bore from the engaging projection side for a predetermined distance against the biasing force of the spring, the engaging projections become a snap action. It is considered that the above problem can be suitably solved by engaging with a hooking surface provided on the inner peripheral surface of the cylinder bore or the like.

However, even in this case, there is still a problem to be solved. That is, although a special jig is not required to mount the spring receiver in the cylinder bore, it is necessary to release the engagement between the engagement protrusion and the latching surface in order to remove the spring receiver mounted in the cylinder bore. In some cases, there is a problem that a special jig for deforming the side wall of the spring receiver toward the inner peripheral side is required.

The present invention has been made in view of the above circumstances, and its purpose is to prevent the snap ring from being attached to the inner surface of the cylinder bore when the spring receiver is mounted in the cylinder bore. Another object of the present invention is to provide a disc brake including a parking brake mechanism that does not require skill or a special jig for the work of attaching and removing the spring receiver.

Means for Solving the Problems In order to achieve such an object, the present invention provides a disc brake including a parking brake mechanism of the type described above, in which the inner peripheral surface of the cylinder bore or the inner peripheral surface of the inner peripheral surface of the cylinder bore. A plurality of first engaging projections projecting to the inner peripheral side are integrally provided on the inner peripheral surface separately provided on each side at predetermined intervals in the circumferential direction, and an outward flange of the spring receiver is provided at a predetermined circumferential direction. A state in which a plurality of second engaging protrusions protruding toward the outer peripheral side of the peripheral wall are provided at intervals, and the plurality of second engaging protrusions are located between the plurality of first engaging protrusions in the circumferential direction. The spring receiver is inserted into the cylinder bore until it passes through the first engaging protrusion, and then the spring receiver is rotated about the axis by a predetermined angle to form the first engaging protrusion and the second engaging protrusion. Can be engaged in a direction parallel to the axis of the cylinder bore, while the first engagement projection and the second engagement projection are engaged in the direction parallel to the axis of the cylinder bore according to the biasing force of the spring. At this time, at least one of the first engaging projection and the second engaging projection is provided with a rotation stopping means for preventing rotation of the spring receiver around the axis.

According to this structure, the plurality of first engaging protrusions protruding toward the inner peripheral side are integrally provided at the inner peripheral surface of the cylinder bore at predetermined intervals in the circumferential direction, and the outer peripheral surface of the spring receiver is prevented. The facing flange is configured to have a plurality of second engaging projections protruding toward the outer peripheral side of the peripheral wall at predetermined intervals in the circumferential direction, and the second engaging projections are located between the first engaging projections in the circumferential direction. In this state, the spring bearing is pushed into the cylinder bore against the biasing force of the spring until it passes through the first engaging projection, and then the spring bearing is rotated around the axis for a predetermined angle to release the pressing force on the spring bearing. By doing so, the first engagement protrusion and the second engagement protrusion are engaged in the direction parallel to the axis of the cylinder bore according to the biasing force of the spring, and at this time, the first engagement protrusion and the second engagement protrusion are engaged. The rotation stopping means provided on at least one of the engagement protrusion and the second engagement protrusion prevents rotation of the spring receiver around the axis, and thus disengages the engagement between the first engagement protrusion and the second engagement protrusion. To be prevented. As a result, since the snap ring is not required to attach the spring receiver to the inner peripheral surface of the cylinder bore, the snap ring may damage the inner peripheral surface of the cylinder bore or the seal member provided on the inner peripheral surface of the cylinder bore. On the other hand, when the spring receiver is attached to the inner peripheral surface of the cylinder bore, for example, a simple jig such as a pipe is used while pressing the inward flange against the biasing force of the spring. The spring receiver can be rotated about the axis by the predetermined angle only by rotating the first engaging projection and the first engaging protrusion and the first engaging projection according to the biasing force of the spring. 2Because the engagement protrusion and the engagement protrusion can be engaged with each other in a state where they cannot be disengaged, skill and a special jig are required to attach the spring receiver. In addition, when removing the spring receiver from the inner peripheral surface of the cylinder bore, etc., press the inward flange with a simple jig such as a pipe while pressing the inward flange with the jig as in the case of installation work. Since the engagement between the first engagement protrusion and the second engagement protrusion can be easily released only by rotating it around, skill or a special jig is not required even in the work of removing the spring receiver.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram showing a main part of a disc brake having a parking brake mechanism to which the present invention is applied. In the figure, a disc rotor rotatably provided with wheels.
A caliper 12 is laid across the outer peripheral portion of the 10, and the caliper 12 is a support member fixed to a non-rotating member (not shown).
14 through a slide pin or the like (not shown)
It is movably supported in a direction parallel to the axis of 10. The caliper 12 has a cylinder portion 20 having a cylinder bore 16 that opens in one direction, and a bifurcated claw that integrally extends from an opening side end of the cylinder portion 20 and faces the cylinder portion 20 with the disk rotor 10 in between. The cylinder portion 20 and the projection portion 22 integrally provided at the end portion on the opposite side to the opening side of the cylinder portion 20. The bottom side is located on the claw 24 side and is fitted so as to be able to project to the claw 24 side in a state in which relative rotation around the axis is impossible. Inside the caliper 12, that is, between the cylinder portion 20 and the claw portion 24, a pair of pads 26 and 28 are arranged with the disc rotor 10 sandwiched therebetween, and the pads 26 and 28 are the support members. It is supported by 14 so as to be movable in a direction parallel to the axis of the disc rotor 10.

Inside the protruding portion 22, a fitting hole 30 that is interlocked with the cylinder bore 16 and is substantially concentric is formed, and the fitting hole 30 has a male screw portion 32 and a head portion 34 having a larger diameter than that. The adjusting bolt 36 is fitted in the head 34 so as to be relatively movable in the axial direction and non-rotatably around the axial center in a state where the male screw portion 32 is located inside the piston 18. The adjusting bolt 36 is constantly urged in a direction away from the piston 18 by a compression coil spring 40 interposed between the head 34 and a spring receiver 38 integrally provided in the cylinder portion 20 on the outer peripheral side thereof. The adjust nut 42 is screwed onto the male screw portion 32 in a state having a certain amount of rattling in the axial direction. This adjust nut
A flange portion 44 projecting in the outer peripheral direction is provided at an end portion of the male screw portion 32 located on the tip side of the male screw portion 32. In this embodiment, the compression coil spring 40 constitutes a spring.

A substantially annular protrusion 46 protruding toward the inner peripheral side is integrally formed on the inner peripheral surface of the piston 18, and a thrust bearing 48 and a flat washer 50 are provided on the outer peripheral surface of the cylindrical portion of the adjust nut 42 as a flange portion. It is fitted so that it is adjacent to 44. A compression coil spring 52 is inserted between the flat washer 50 and the projection 46 of the piston 18 in a predetermined preload state, and the adjusting nut 42 is attached to the outer peripheral surface of the flange portion 44 according to the biasing force of the compression coil spring 52. The tapered inner surface of the piston 18 and the tapered inner surface of the piston 18 are pressed against each other in the protruding direction of the piston 18. As a result, during non-braking, the adjustment nut 42 is prevented from rotating in the direction opposite to the parking brake operation stroke adjusting direction, which will be described later, due to vehicle vibration or the like. The above compression coil spring
The biasing force of 52 is set smaller than the biasing force of the compression coil spring 40. Also, 54 seals the space between the piston 18 and the cylinder bore 16 in a liquid-tight manner, and
It is a piston seal that performs the return action of.

Inside the protruding portion 22, the cylinder bore 16 of the fitting hole 30
A mounting hole 56 extending in a direction perpendicular to the axis of the fitting hole 30 is provided on the opposite side to the fitting hole 30 so as to communicate with the fitting hole 30, and a cam shaft 58 is needle-shaped in the fitting hole 56. The roller bearing 60 is provided so as to be rotatable about its axis. Cam shaft
The crank lever to which the parking brake operating force is transmitted is located at one end of the 58 and outside the protrusion 22.
62 is attached so as not to rotate relative to each other, and an engaging recess 64 is formed in the longitudinal intermediate portion of the cam shaft 58. The engaging recess 64 and the tip surface of the head 34 of the adjusting bolt 36. A toggle 68 having a rod shape is interposed between the engagement recess 66 formed in the above and the needle roller bearing 60. In this embodiment, the crank lever 62 corresponds to the parking brake operating member, and
62 is always urged in the parking brake non-operating direction (clockwise direction in FIG. 1) by a return spring (not shown).

In the disc brake configured as described above,
When the camshaft 58 is rotated counterclockwise in FIG. 1 by the crank lever 62, a thrust is generated in the toggle 68, and the thrust is transmitted to the piston 18 via the adjustment bolt 36 and the adjustment nut 42, so that the piston 18 The pads 26 and 28 are narrowed by 18 and the claw portion 24 of the caliper 12, and braking by the parking brake is performed. On the other hand, when hydraulic pressure is supplied into the cylinder bore 16, the piston 18 is pushed out, and braking is performed in the same manner as in the above case. At this time, when the amount of wear of the pads 26, 28 becomes large and slippage occurs between the piston 18 and the piston seal 54 when the piston 18 projects, when the amount of movement of the piston 18 exceeds a predetermined fixed amount, Compression coil spring 52 and thrust bearing 48 as piston 18 advances.
The parking brake operation stroke is automatically adjusted on the basis of the adjustment nut 42 being rotated in one direction via the above. The above-mentioned brake operation and adjustment operation are not always necessary for understanding the present invention, and thus detailed description thereof will be omitted.

Here, in the present embodiment, the spring receiver 38
As shown in FIG. 1 and FIG. 3, a peripheral wall 70 through which the adjustment bolt 36 is inserted, an inward flange 72 formed at one end of the peripheral wall 70, and an other end of the peripheral wall 70 are formed. And an axial direction of the compression coil spring 40 located on the inner peripheral side of the peripheral wall 70 while being mounted in the cylinder portion 20 at the outward flange 74. One end is inward flange 72
Is abutted against. The outward flanges 74 are four engagement protrusions that protrude toward the outer peripheral side of the peripheral wall 70 at predetermined intervals in the peripheral direction.
It is configured to have 76, and each engaging projection 76 has a third portion in a middle position around the spring bearing 38 axis.
As shown in FIG. 5 to FIG. 5, a recess having a similar shape slightly larger than an engagement projection 80 described later and recessed toward the side opposite to the peripheral wall 70 side.
78 are formed. On the other hand, on the inner peripheral surface of the cylinder bore 16 located on the fitting hole 30 side, as shown in FIGS. 1 and 2, four engaging projections 80 protruding toward the inner peripheral side are provided.
Are integrally provided at predetermined intervals in the circumferential direction so that the engagement protrusions 76 of the spring receiver 38 can pass between the engagement protrusions 80 in a direction parallel to the axis of the cylinder bore 16. With
The engagement protrusion 80 is formed in the recess 78 of the engagement protrusion 76 of the spring receiver 38.
In the state where they are respectively fitted, the rotation of the spring receiver 38 around the axis is prevented due to the contact between the side wall of the recess 78 and the side end surface of the engaging projection 80, and the engaging projection 76 is engaged. Disengagement of the protrusion 80 in a direction parallel to the axis of the cylinder bore 16 is prevented. Therefore, in this embodiment, the engaging projection 80 constitutes the first engaging projection, the engaging projection 76 constitutes the second engaging projection, and the recess 78 constitutes the detent means.

When mounting the spring receiver 38 in the cylinder portion 20, first, for example, the engaging protrusion 76 of the spring receiver 38 is first.
The spring receiver 38 is attached with the compression coil spring 40 while pressing the inward flange 72 with a simple jig such as a pipe until it passes through the engagement protrusions 80 while being positioned in the circumferential direction between the engagement protrusions 80. Push it into the cylinder bore 16 against the force. Next, when the jig is rotated around the axis in this state, the spring receiver 38 is rotated around the axis along with the rotation of the jig based on the frictional resistance between the jig and the inward flange 72. Can be easily rotated and has a spring holder
After rotating 38 by a predetermined angle (about 45 ° in this embodiment), the pressing force of the jig on the spring receiver 38 is released, and the engaging protrusions 76 of the spring receiver 38 are pressed according to the biasing force of the compression coil spring 40. The engaging protrusions 80 are fitted in the recesses 78, respectively. With this, the engagement coil 76 and the engagement protrusion 80 are preferably prevented from being disengaged from each other, and the compression coil spring
According to the urging force of 40, they are engaged with each other in the direction parallel to the axis of the cylinder bore 16.

On the other hand, when removing the spring receiver 38 from the inside of the cylinder bore portion 20, while pressing the inward flange 72 with a simple jig such as a pipe as in the case of the mounting work, the spring holder 38 is rotated around the shaft center together with the jig. The engagement between the engaging projection 76 and the engaging projection 80 is released by rotating the engaging projection 76 and the engaging projection 80.

As described above, according to this embodiment, since the snap ring is not required to mount the spring receiver 38 in the cylinder portion 20, the snap ring is reduced in diameter in the cylinder bore 16 unlike the conventional case using the snap ring. Cylinder bore 16 due to its snap ring when inserting into
It is possible to avoid damaging the inner peripheral surface of the piston, the piston seal 54, and the like.

Further, according to the present embodiment, the spring receiver 38 is rotated around the axis together with the jig while pressing the spring receiver 38 against the biasing force of the compression coil spring 40 with a simple jig such as a pipe. Since the spring receiver 38 can be easily attached to and removed from the cylinder portion 20 only by such a simple operation,
No special skill or special jig is required for the installation and removal work of.

Further, according to the present embodiment, the engagement protrusion of the spring receiver 38 is
A recess 78 as a rotation stopping means is formed in 76, and since this recess 78 can be formed at the same time when the spring receiver 38 is formed by press working, a separate step is required to provide the rotation stopping means. There is an advantage not to.

In the embodiment described above, the engagement protrusion of the spring receiver 38
The four 76 and the engaging projections 80 projecting from the inner peripheral surface of the cylinder bore 16 are both provided, but it is not always necessary and both engaging projections may be provided two or more. However, it does not matter if both engaging protrusions are not equal in number to each other.

Further, in the above-described embodiment, the engaging protrusion of the spring receiver 38
A recess 78 as a rotation stopping means is formed in 76, but it is not always necessary. For example, it is located on the side opposite to the piston side of a plurality of engaging projections provided on the inner peripheral surface of the cylinder bore. It is also possible to provide a recess on the surface, and to insert the whole of the engagement protrusion of the spring receiver or the protrusion protruding so as to protrude toward the peripheral wall into the engagement protrusion in the recess. In the former case, the recess forms the rotation stopping means, and in the latter case, the recess and the projection form the rotation stopping means. In short, the detent means may be provided on at least one of the first engagement protrusion and the second engagement protrusion.

Further, in the above-described embodiment, the spring receiver 38 is configured to rotate about the axis according to the rotation of the jig based on the frictional resistance between the jig and the inward flange 72, but not necessarily. There is no need to do so. For example, a pair of through holes are provided at positions facing each other in the radial direction of the inward flange, and a pair of protrusions is provided on the tip surface of the jig. The spring receiver may be rotated around the axis along with the rotation of the jig.

Further, in the above-described embodiment, the engaging projection 80 is formed in the cylinder bore 16
The inner peripheral surface of the cylinder bore 16 is provided with a plurality of engaging projections protruding toward the inner peripheral surface separately provided on the inner peripheral surface of the cylinder bore 16. Can be configured.

In addition, the present invention can be variously modified without departing from the spirit thereof.

[Brief description of drawings]

FIG. 1 is a sectional view showing a main part of a disc brake having a parking brake mechanism according to an embodiment of the present invention. 2 is a sectional view taken along line II-II in FIG.
It is a figure which removes a spring receiver and the like. FIG. 3 is a view of the spring receiver in FIG. 1 viewed from the piston side. FIG. 4 is an enlarged view of a main part of a cross section taken along line IV-IV in FIG. FIG. 5 is an enlarged view of an essential part of a VV cross section in FIG. 12: Caliper 16: Cylinder bore 18: Piston 36: Adjust bolt 38: Spring holder 40: Compression coil spring (spring) 42: Adjust nut 62: Crank lever (parking brake operating member) 70: Circumferential wall 72: Inward flange 74: Outside Orientation flange 76: Engagement protrusion (second engagement protrusion) 78: Recess (rotation stop means) 80: Engagement protrusion (first engagement protrusion)

Claims (1)

[Scope of utility model registration request] 1. A caliper having a cylinder bore that opens in one direction, and an adjust nut screwed into an adjust bolt that is fitted in the cylinder bore and is axially reciprocally moved in association with the operation of a parking brake operating member. A piston to be pushed out, a peripheral wall into which the adjusting bolt is inserted, an inward flange formed at one end of the peripheral wall, and an outward flange formed at the other end of the peripheral wall, A spring receiver attached to the inner peripheral surface of the cylinder bore or an inner peripheral surface separately provided on the inner peripheral side from the inner peripheral surface so as not to move in the direction toward the opening of the cylinder bore in the facing flange, and the outer periphery of the adjust bolt. On the side between the inward flange of the spring receiver and the adjustment bolt, the adjustment bolt In a disc brake including a parking brake mechanism of a type including a spring biased in a direction opposite to the push-out direction of the piston, an inner peripheral surface of the cylinder bore or an inner peripheral surface provided separately from the inner peripheral surface is provided. A plurality of first engaging protrusions protruding toward the inner peripheral side are integrally provided on the peripheral surface at predetermined intervals in the circumferential direction, and outward flanges of the spring receiver are provided at outer peripheral sides of the peripheral wall at predetermined intervals in the circumferential direction. Multiple second sticking out to
The spring receiver is configured to have an engagement protrusion, and the plurality of second engagement protrusions are positioned between the plurality of first engagement protrusions in the circumferential direction until the spring receiver is passed through the first engagement protrusion. After inserting into the cylinder bore, the spring receiver is rotated around the axis by a predetermined angle to engage the first engaging protrusion and the second engaging protrusion in a direction parallel to the axis of the cylinder bore. On the other hand, when the first engagement protrusion and the second engagement protrusion are engaged with each other in a direction parallel to the axis of the cylinder bore according to the urging force of the spring, the rotation of the axis of the spring receiver is enabled. A disc brake having a parking brake mechanism, characterized in that detent means for preventing the rotation of the disk is provided on at least one of the first engaging projection and the second engaging projection.