JP2003120725A - Disc brake device - Google Patents

Abstract

(57) Abstract: Provided is a disk brake device capable of reliably preventing pad dragging of a disk rotor while reducing manufacturing costs by reducing the number of parts. A reduced-diameter cylindrical portion on the other end side of a boot is arranged on an inner periphery of an entrance of a slide hole, and is restricted from moving in an axial direction. The reduced-diameter cylindrical portion includes an annular holding portion 30 that holds the outer periphery of the slide pin 10 while sliding the outer periphery thereof on the inner peripheral surface.
b, and an annular lip portion 30c provided at a position axially separated from the annular holding portion and elastically deformed when the slide pin moves in the slide hole during braking. An annular cut 30d is provided between the annular holding portion and the annular lip.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a floating caliper type disc brake device.

[0002]

2. Description of the Related Art A slide pin is slidably inserted into a guide hole provided in a torque member, and a slide pin slides a caliper body containing a piston for pressing a pad against the disc in a direction orthogonal to the disc. In the floating type disc brake device, when the brake is released, the pad arranged on the caliper body is dragged unless the pad is separated from the disc.

Techniques for preventing the dragging of the pad include, for example, a caliper tract mechanism (hereinafter referred to as a first prior art) for a disc brake disclosed in Japanese Patent Laid-Open No. 08-4806 and Japanese Patent Laid-Open No. 11-63034. A disc brake device (hereinafter referred to as a second related art) is known.
In the first conventional technique, liquid seals are provided at two positions, that is, the outer periphery of the tip of the slide pin and the inlet of the guide hole into which the slide pin is inserted, and grease is filled in the gap between the liquid seals on the outer periphery of the slide pin. It has a structure. According to this technology, when the slide pin slides due to the movement of the caliper body during braking, the grease between the liquid seals is compressed and internal pressure is generated in the grease filled part, and this internal pressure causes the liquid seal at the inlet side of the slide hole to Elastically deforms. When the brake is released, the slide pin is pulled back by utilizing the elastic restoring force of the liquid seal on the inlet side, whereby the pad is pulled away from the disc to restore the caliper body.

In the second prior art, a slide piston slidably inserted in a guide hole is fitted into a circular through hole of a pin fixing portion provided on a caliper body via an elastic bush made of rubber or the like. It is fixed. According to this technology,
Since the slide pin is supported via the elastic bush, the machining intersection can be absorbed by the deformation of the elastic bush.
By setting the clearance between the slide pin and the guide hole to be small, it is possible to prevent the slide pin from returning defectively due to the influence of machining intersection at the time of releasing the brake, and to prevent the pad from being dragged against the disc.

[0005]

By the way, in the first prior art, a liquid seal is provided at two locations, that is, at the outer periphery of the tip of the slide pin and at the inlet of the guide hole, and between the liquid seal on the outer periphery of the slide pin. Since the structure in which the gap is filled with grease is adopted, the structure for preventing the drag of the pad is complicated and the number of parts is also increasing. For this reason,
There is a problem in terms of manufacturing cost.

Also in the second prior art, the slide piston for preventing the dragging of the pad is fitted and fixed in the through hole of the pin fixing portion provided in the caliper body through the elastic bush made of rubber or the like. However, there is a problem in terms of manufacturing cost. Therefore, the present invention has been made in view of the above circumstances, and provides a disc brake device capable of reliably preventing dragging of a pad with respect to a disc rotor while reducing manufacturing cost by reducing the number of parts. The purpose is to do.

[0007]

In order to solve the above-mentioned problems, a disk brake device according to claim 1 of the present invention comprises a torque member fixed to a vehicle body and a piston for pressing a friction pad against a disk rotor. A caliper body connected to the torque member so as to slide in a direction orthogonal to the plane of the disc rotor, and fixed to either the torque member or the caliper body to guide the slide of the caliper body. In a disc brake device including a slide pin, a slide hole that guides the slide pin to the other of the torque member or the caliper body, and a boot that protects an outer periphery of the slide pin, the boot includes the slide pin. And the outer side of the radial gap of the slide hole is the front An engagement portion that is engaged with the slide hole side, and a sliding contact portion that is in sliding contact with the outer periphery of the slide pin on the inner peripheral surface of the engagement portion in the axial direction are provided. A holding portion that holds the slide pin slidably in the axial direction, and a lip portion that elastically deforms when the slide pin slides at a position axially separated from the holding portion are provided.

According to a second aspect of the present invention, in the disc brake device according to the first aspect, the inner peripheral surface of the holding portion has a serration shape in which grooves extending in the axial direction are continuous in the circumferential direction. There is. Further, the invention according to claim 3 is the disc brake device according to claim 1 or 2, wherein an annular cut is provided in the radial direction between the holding portion and the lip portion.

[0009]

According to the invention described in claim 1, the boot is provided with a lip portion which is elastically deformed when the slide pin slides during braking, and when the brake is released, the slide pin is elastically restored by the elastic restoring force of the lip portion. Since the action of pulling back the friction pad works, it is possible to reliably prevent the friction pad from dragging with respect to the disc rotor. Further, according to the present invention, drag of the friction pad can be prevented only by improving the boot, so that the number of parts does not increase and the manufacturing cost can be reduced.

Further, according to the second aspect of the present invention, the inner peripheral surface of the holding portion has a serration shape in which the grooves extending in the axial direction are continuous in the circumferential direction. The contact area becomes smaller, the sliding resistance when the slide pin slides becomes smaller, and the defective return of the slide pin at the time of braking release can be more reliably prevented. Further, according to the invention of claim 3, since the annular notch is provided in the radial direction between the holding portion and the lip portion, the lip portion is largely elastically deformed at the time of braking, and the braking is released. The elastic return force of the lip portion at the time can be increased to increase the force for pulling back the slide pin.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a disc brake device according to the present invention will be described below with reference to the drawings. First, as shown in FIG. 1, the disc brake device 2 of the present embodiment includes a torque member 4 fixed to a vehicle body (for example, a knuckle of a suspension), and a torque member 4.
The caliper body 6 supported by the caliper body 6 is inserted into the slide hole 12 formed in the torque member 4 by inserting the slide pin 10 fixed to the pin fixing portion of the caliper body 6 with the bolt 8. Is connected to the torque member 4 slidably in a direction orthogonal to the disc rotor 14.

The caliper body 6, as shown in FIG.
A pair of friction pads 16 and 18 facing each other with the disc rotor 14 interposed therebetween are provided. The outer side and inner side friction pads 16 and 18 are held by the caliper body 6.
The piston indicated by the reference numeral 20 is housed in the cylinder chamber 22 of the caliper body 6 so as to be slidable along the pressing direction of the friction pad 18. A piston seal 24 is arranged on the inner periphery of the cylinder chamber 22, and the inner peripheral portion of the piston seal 24 is in close contact with the outer periphery of the piston 20 to seal the gap between the piston 20 and the cylinder chamber 22. Then, by introducing hydraulic pressure into the cylinder chamber 22, the piston 20 moves to press the friction pad 18 against the disc rotor 2.

Thus, during braking, when the piston 20 is driven in the direction of arrow (a) and the inner friction pad 18 is pressed against the disc rotor 14, the reaction force causes the caliper body 6 to move in the direction of arrow (b). The outer side friction pad 16 is pressed against the disc rotor 6 by sliding to generate a braking force. 3 and 4 specifically show the slide pin 10 inserted into the slide hole 12, and the boot 26 of the first embodiment is attached to the outer periphery of the slide pin 10 near the entrance of the slide hole 12. The boots 26 prevent dust and the like from entering the slide hole 12 from the outside.

The boot 26 is a tubular member formed of an elastic member such as rubber. One end tubular portion 28 is locked to the outer periphery of the slide pin 10 on the pin fixing portion 7 side, and the other end tubular portion 30 slides. The slide pin 10 is slidably held so as to move coaxially with the axis of the slide hole 12, and the bellows portion 32 is provided between the one end 28 and the other end 30. Has been formed. As shown in FIG. 4, an annular groove 34 is formed on the inner circumference of the torque member 4 near the entrance of the slide hole 12. Further, the other end tubular portion 30 described above
Is an annular convex portion 30a as a locking portion that fits in the annular groove portion 34, and a holding portion that is provided on the inner peripheral side of the annular convex portion 30a and holds the outer periphery of the slide pin 10 while sliding. 30b and an annular lip portion 30c that is formed separately from the holding portion 30b by providing a notch 30d on the one end cylinder portion 28 side of the holding portion 30b.

Here, as shown in FIG. 5, the inner periphery of the holding portion 30b has a serration shape in which grooves extending in the axial direction are continuously formed in the circumferential direction. When the boot 26 is attached to the outer periphery of the slide pin 10 near the entrance of the slide hole 12, when the slide pin 10 moves in the arrow (a) direction with respect to the torque member 10 during braking, as shown in FIG. The friction pad 16 and the inner friction pad 18 are pressed against the disc rotor 14 to generate a braking force.

At this time, in the other end tubular portion 30 of the boot 26, the movement of the holding portion 30b is restricted by fitting the annular convex portion 30a into the annular groove portion 34 of the torque member 4, and the holding portion 30b is The outer periphery of the slide pin 10 is held while sliding. The serration-shaped inner periphery of the holding portion 30b has a small contact area with the slide pin 10, and thus has a small sliding resistance. In addition, one end of the tubular portion 28 from the holding portion 30b
The annular lip portion 30c provided on the side moves in the direction of the arrow (c) together with the slide pin 10, and is in a state of being largely elastically deformed so that the space of the cut 30d becomes small as shown in FIG.

When the brake is released, the slide pin 10 is pulled back by utilizing the elastic restoring force of the annular lip portion 30c, whereby the friction pads 16 and 18 are pulled away from the disc rotor 14 and the caliper body 6 returns.
According to the above configuration, the serration-shaped inner circumference of the holding portion 30b has a small contact area with the slide pin 10 and a small sliding resistance, so that it is possible to prevent a return failure of the slide pin 10 when releasing the braking. At this time, since the annular lip portion 30c does not slide but only elastically is released, it does not become a resistance when the slide pin 10 returns. When the brake is released, the annular lip portion 30 has the slide pin 10 which is elastically restored by the elastic restoring force of the annular lip portion 30c.
Since the action of pulling back the disk works, the disk rotor 1
It is possible to prevent the friction pads 16 and 18 from dragging with respect to the gear 4.

Further, in this embodiment, the friction pads 16,
Since only the boot 26 is improved in order to prevent the dragging of 18, the number of parts does not increase and the manufacturing cost can be reduced. Next, as shown in FIG.
It shows the boot 40 of the second embodiment according to the present invention. The same components as those of the boot 26 of the first embodiment shown in FIGS. 3 to 6 are designated by the same reference numerals, and the description thereof will be omitted.

Also in this embodiment, an annular groove portion 34 is formed on the inner periphery of the slide hole 12 near the inlet, and the other end tubular portion 42 of the boot 40 arranged in the annular groove portion 34.
Is an annular convex portion 42a serving as a locking portion that fits in the annular groove portion 34, an annular lip portion 42c provided on the inner peripheral side of the annular convex portion 42a, and the annular lip portion 42c. A holding portion 42b, which is formed separately from the annular lip portion 42c by providing the notch 42d on the side closer to the tubular portion 28 and holds the sliding pin 10 while sliding the outer periphery thereof, is provided.

Here, the inner circumference of the holding portion 42b of the present embodiment is also serrated, in which grooves extending in the axial direction are continuously formed in the circumferential direction. When the boot 40 having the above-described configuration is used, the serration-shaped inner periphery of the holding portion 42b has a small contact area with the slide pin 10 and a small sliding resistance. As well as
Since the elastic return force of the annular lip portion 42c acts to pull back the slide pin 10, it is possible to reliably prevent the friction pads 16 and 18 from being dragged with respect to the disc rotor 14.

Further, similarly to the first embodiment, since the boot 40 is only improved in order to prevent the friction pads 16 and 18 from being dragged, the number of parts is not increased and the manufacturing cost is reduced. You can Furthermore, what is shown in FIG. 8 shows the boot 50 of the third embodiment according to the present invention. The other end tubular portion 52 of the boot 50 of the present embodiment is
An annular convex portion 52a as a locking portion that fits in the annular groove portion 34, and a holding portion 52b that holds while sliding the outer periphery of the slide pin 10 provided on the inner peripheral side of the annular convex portion 42a. And an annular lip portion 52c provided on the one end tubular portion 28 side of the holding portion. The inner periphery of the holding portion 52b of the present embodiment also has a serration shape in which grooves extending in the axial direction are continuously formed in the circumferential direction.

When the boot 50 having the above-described structure is used, the serration-shaped inner periphery of the holding portion 52b has a small contact area with the slide pin 10 and a small sliding resistance, so that the slide pin 10 returns when the brake is released. The defect can be prevented and the annular lip portion 52c
Since the elastic restoring force acts to pull back the slide pin 10, it is possible to reliably prevent the friction pads 16 and 18 from being dragged with respect to the disc rotor 14.

Further, as in each of the above-described embodiments, the boot 50 is merely improved in order to prevent the friction pads 16 and 18 from being dragged, so that the number of parts is not increased and the manufacturing cost is reduced. You can In addition, in each of the embodiments, the annular holding portion and the annular lip portion are used, but the annular shape may not be a perfect annular shape. For example, the shape may be such that the circumference is partially cut away.

[Brief description of drawings]

FIG. 1 is a perspective view showing a disc brake device.

FIG. 2 is a diagram showing an internal structure of a caliper body of the disc brake device.

FIG. 3 is a sectional view of relevant parts showing a state in which a slide pin fixed to a caliper body is inserted into a slide hole formed in a torque member according to the present invention.

FIG. 4 is a cross-sectional view of essential parts showing a state when braking of the boot of the first embodiment according to the present invention is released.

5 is a view taken along the line VV of FIG.

FIG. 6 is a cross-sectional view of essential parts showing a boot state of the boot according to the first embodiment of the present invention.

FIG. 7 is a cross-sectional view of essential parts showing a state when braking is released of the boot according to the second embodiment of the present invention.

FIG. 8 is a cross-sectional view of essential parts showing a state when braking is released of the boot of the second embodiment according to the present invention.

[Explanation of symbols]

2 Disc brake device 4 Torque member 6 caliper body 10 slide pins 12 slide holes 14 disk rotor 16,18 Friction pad 26,40,50 boots 28 One end cylinder part (one end side reduced diameter cylinder part) 30, 42, 52 Other end cylinder part (reduced diameter cylinder part on the other end side) 30a, 42a, 52a Annular convex part (locking part) 30b, 42b, 52b annular holding portion 30c, 42c, 52c annular lip 30d, 42d annular notch 32 bellows 34 annular groove

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 3J058 AA48 AA53 AA63 AA77 AA87                       BA16 CC84 CC94 DC02 DC18                       FA01

Claims (3)

[Claims] 1. A torque member fixed to a vehicle body, and a caliper body including a piston for pressing a friction pad against a disk rotor and connected to the torque member so as to slide in a direction orthogonal to a plane of the disk rotor. A slide pin fixed to either one of the torque member or the caliper body for guiding the slide of the caliper body, and a slide hole for guiding the slide pin to the other of the torque member or the caliper body, In a disc brake device comprising: a boot that protects the outer circumference of a slide pin, the boot has a lock in which an outer peripheral side of a radial gap between the slide pin and the slide hole is locked to the slide hole side. And the slide pin on the inner peripheral surface in the vicinity of the locking portion in the axial direction. A slide contact portion that is in sliding contact with the outer periphery of the slide contact portion, the slide contact portion includes a holding portion that holds the slide pin slidably in the axial direction, and a position that is separated from the holding portion in the axial direction. A disc rake device comprising: a lip portion that elastically deforms when the slide pin slides. 2. The disc brake device according to claim 1, wherein the inner peripheral surface of the holding portion has a serration shape in which grooves extending in the axial direction are continuous in the circumferential direction. 3. The disc brake device according to claim 1, wherein an annular cut is provided in the radial direction between the holding portion and the lip portion.