JPH08270690A - Pad return structure for disc brake - Google Patents

Abstract

PURPOSE: To effectively prevent the occurrence of a drag against a rotor in such a way that an inner pad and an outer pad are both reliably returned and to provide a pad return mechanism which is effective to a fist type disc brake. CONSTITUTION: In a disc brake wherein a support 14 to hold an inner pad 22 movably in the axial direction of a rotor and a caliper to which an outer pad is attached are assembled together through a slide guide mechanism, a pad return spring mechanism 50 is formed at pad clip 46 disposed at a slide part between the inner pad 22 and the support 14, and the inner pad 22 is energized in a direction in which it is separated away from a rotor. A friction ring 60 effecting frictional engagement with a slide sleeve 40 on the support 14 side is mounted on a slide guide mechanism. A pad return spring 62 having a friction ring 60 serving as a reaction force fulcrum is arranged and a guide pin 16 on the caliper side is energized in a return direction, and the outer pad is separated away from the rotor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pad returning structure for a disc brake, and more particularly to an improvement for preventing pad dragging when releasing braking in a fist type disc brake.

[0002]

2. Description of the Related Art Conventionally, as a disc brake, there is known a disc brake having a structure in which a braking torque of an outer pad torque is supported on a vehicle body side through a caliper and an inner pad torque is supported by a support. (For example, Japanese Utility Model Laid-Open No. 5-14680). this is,
A caliper that straddles the rotor is made movable along the rotor axial direction via a pair of guide pins with respect to a support attached to the vehicle body, and an inner pad is pressed against the rotor by a hydraulic cylinder equipped on the inner side of the caliper. By the movement of the caliper due to the reaction force, the outer pad is pressed against the rotor by the outer side claw.

[0003]

By the way, in this type of disc brake, the piston is returned by the return function by the piston seal in the hydraulic cylinder mechanism equipped in the caliper. In order to prevent this, it is necessary to positively separate the pad from the rotor. In the conventional example described above, the V-shaped springs are arranged at the top end portions of the inner pad and the outer pad, and the pair of spring ends are inserted into the backing metal of the inner pad and the outer pad, and the pad is returned by the expanding action of the V-shaped spring. I am trying.

However, in the pad returning structure using the V-shaped spring, when the brake is not operated, only one pad having good slidability returns, and the other pad does not return due to sliding resistance but drags against the rotor. There is. Such a phenomenon causes uneven wear of the pad, and particularly in a fist type disc brake in which the outer pad is fixed to the caliper, one end of the V-shaped spring engages with the inner pad to move it back, At the other end, it is necessary to perform the returning movement action of the caliper together with the outer pad, the return of the outer pad is not performed smoothly, and the actual effective means for surely preventing the outer pad from being dragged is not taken.

In view of the above-mentioned conventional problems, the present invention provides a disc brake pad returning structure in which both the inner pad and the outer pad can be reliably returned and moved to effectively prevent drag on the rotor. The purpose is to provide.

[0006]

In order to achieve the above object, a pad return structure for a disc brake according to the present invention comprises a support for holding an inner pad movably in the axial direction of a rotor and a caliper to which an outer pad is attached. In a disc brake assembled via a slide guide mechanism, a pad return spring mechanism is formed on a pad clip disposed on a sliding portion between the inner pad and the support to urge the inner pad in a direction away from the rotor. A friction ring that frictionally engages the guide surface is attached to the slide guide mechanism, and a spring having the friction ring as a reaction force fulcrum is provided to urge the outer pad away from the rotor via a caliper. It is characterized by the following.

The clearance between the two return springs may be set so that the inner pad return stroke by the pad clip and the outer pad return stroke by the pad return spring provided on the slide guide substantially coincide with each other.

[0008]

According to the above construction, the inner pad is returned from the both sides of the pad clip by a fixed amount after braking, and the outer pad is returned together with the caliper by the return spring of the slide guide until the piston comes into contact with the inner pad.
As a result, both the inner pad and the outer pad are reliably separated from the rotor, and it is possible to prevent the pad from being dragged against the rotor.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A specific embodiment of a disc brake pad returning structure according to the present invention will be described below in detail with reference to the drawings.

FIG. 2 to FIG. 4 are a perspective view, a partial sectional plan view, and the like of a disc brake having a pad return structure according to the embodiment.
It is a front view. As shown in these figures, the disc brake of the embodiment has a pair of left and right parallel guide pins 16 and 18 with respect to a support 14 mounted on a vehicle body with a caliper 12 straddling a rotor 10 (see FIGS. 3 and 4). It is possible to move along the axial direction of the rotor. Caliper 1
A hydraulic cylinder 20 is provided on the inner side of 2, so that the inner pad 22 can be pressed against the rotor 10. Further, the caliper claw 24 on the outer side is moved by the movement of the caliper 12 due to the reaction force of pressing from the inner pad 22.
The outer pad 26 is pressed against the rotor 10.

The support 14 is disposed facing the inner surface of the rotor 10 and is supported by the guide pins 16 and 1.
At the position closer to the center of the rotor than the mounting position of 8, the mounting screw is inserted into the mounting hole 28 and fixed to the vehicle body side. Further, the mounting positions of the guide pins 16 and 18 are set outside the peripheral edge of the rotor 10. An inner pad 22 is attached to the support 14 so that the inner pad 22 can move in the rotor axial direction and can also support a rotational torque associated with braking. In this structure, the anchor projections 30 are formed on both side edges of the inner pad 22, and the concave groove 32 is formed in the corresponding portion of the support 14 along the rotor axial direction, and the concave-convex fitting portion is used as the braking anchor portion. is there. By operating the hydraulic cylinder 20 of the caliper 12, the inner pad 22 moves while being guided by the concave and convex fitting portion and is pressed against the rotor 10, and when the pad 22 tries to rotate following the rotor 10, The fitting portion functions as an anchor and receives the braking torque.

On the other hand, the caliper 12 is guided by the guide pins 16 and 18 and moves to the inner side along the rotor axial direction by the pressing reaction force of the inner pad 22,
The outer pad 26 is attached to the rotor 10 by the caliper claw 24.
Press on. The braking torque of the outer pad 26 is transmitted to the caliper 12. Therefore, an engaging projection 34 is formed on the back surface of the outer pad 26, and the engaging projection 34 is inserted into the caliper claw 24. Hole 36
Is provided. The caliper claw 24 is formed bifurcated, and the engagement projection 34 is engaged with each caliper claw 24, and the outer pad 26 is integrated with the caliper 12. Therefore, when the outer pad 26 is pressed against the rotor 10 and a braking torque is generated, this is transmitted to the caliper 12 via the engagement protrusion 34 and supported by the support 14 via the guide pin 16 on the rotor entry side. It

Here, in this embodiment, as described above,
The caliper 12 is guided to move by guide pins 16 and 18, which are attached to the caliper 12 as shown in FIG. On the inner side of the caliper 12, there is a caliper arm 38 extending leftward and rightward (in the direction along the rotor surface), and the guide pins 16 and 18 are erected on the caliper arm 38 and fixed by tightening. In this embodiment, the heads of the left and right guide pins 16 and 18 are fixed to the caliper arm 38,
The support 14 includes a slide sleeve 4 that straddles the rotor.
0, 42 are provided on the guide pin 16 that straddles the rotor,
18 is inserted. Thereby, the caliper 12 is guided to move along the axial direction of the rotor 10. The braking torque from the outer pad 26 is
Is transmitted to the rotor recirculation side guide pin 16 through
It is supported by a support through the sliding inner surface of the slide sleeve 40 into which the guide pin 16 is inserted. Note that rubber boots 44 are attached to the neck portions of the guide pins 16 and 18 exposed from the opening portions of the slide sleeves 40 and 42 to prevent dust.

In the disc brake constructed as described above, the pad returning structure for separating the inner pad 22 and the outer pad 26 from the rotor 10 at the time of non-braking is constructed as follows.

First, as shown in FIG. 1, the inner pad 22 has the anchor projections 30 formed on both side edges fitted in the concave grooves 32, 32 formed in the support 14. Pad clips 46, 46 are arranged. The details of the pad clip 46 are shown in FIG. As shown in the drawing, the pad clip 46 is formed in a U-shape so as to be inserted into the support concave grooves 32 and 32 and to hold the inner edge of the inner pad 22 so as to sandwich the periphery of the anchor projection 30 of the pad 22. have. That is, the clip body 48 is formed by bending an upper piece 48A, an anchor piece 48B, and a lower piece 48C into a U-shape. In particular, the upper piece 48A and the lower piece 48C have the tips thereof. Formed so as to be separated from the surface of the concave groove 32,
It is a spring piece that urges the inner pad 22, and frictionally holds the anchor projection 30 with a constant force. An outer edge (the hydraulic cylinder 20 side) of the anchor piece portion 48B of the clip body 48 is formed in such a manner that a strip is extended in a T-shape and is bent so as to be in contact with the outer surface of the support 14. A return spring mechanism 50 is formed.

The return spring mechanism 50 urges the inner pad 22 which has been advanced by the braking operation to return to the original position after the braking is released. The pad 22 is pulled back. Therefore, the return spring mechanism 5
No. 0 has an extension plate portion 50A extending in a T-shape from the anchor piece portion 48B, and forms a parallel surface portion 50B on the distal end side along the support 14 surface. A bent portion 50C is formed, and this is
0B and the support 14, the first bend 5
0Ca is brought into contact with the support 14. The final bent piece portion 50Cb of the S-shaped bent portion 50C is formed to be parallel to the extension plate portion 50A,
Notches 52 are formed on the upper and lower edges thereof, while claws 5 engaging with the notches 52 are formed on the upper and lower edges of the extension plate 50A.
4 are formed. The width of the notch 52 is set slightly (m) larger than the width of the engagement claw 54, and
4 is defined, and a return stroke of the clip body 48 that moves in the axial direction of the rotor 10 together with the inner pad 22 is set. When the inner pad 22 is worn, the pressing position of the anchor projection 30 of the inner pad 22 by the clip body 48 is shifted by the amount of wear, so that the return stroke of the inner pad 22 is reduced by the notch 52.
The fixed stroke is set by the gap between the finger and the claw 54.

Therefore, when shifting from the braking state to the non-braking state, since the inner pad 22 is frictionally held by the clip body 48, the return spring mechanism 50 is
4 and biases the inner pad 22 together with the clip body 48 in a direction away from the rotor 10.
The clip body 48 tends to return with the engagement claw 54 due to the spring action. However, depending on the width of the notch 52 formed on the side of the S-shaped bent portion 50C with which the engagement claw 54 is engaged. As a result, the engagement claw 54 comes into contact with the rear edge of the notch 52 and stops. Therefore, the width dimension (m) of the engaging claw 54 and the notch 52 becomes the return stroke of the inner pad 22.

FIG. 5B shows a modification of the pad clip. This is to form a cut-and-raised piece 54A that is bent toward the S-shaped bent portion 50C by making a U-shaped cut in the center of the extension plate portion 50A, while facing the S-shaped bent portion 54A. Final bent piece portion 50Cb of bent portion 50C
An opening window 52A is formed in the cutout and raised portion 54A. Return stroke is cut-and-raised piece 54A
Is regulated by the width dimension of the opening window 52A.
The clip body 48 can move by the difference between the width of A and the thickness of the cut-and-raised piece 54A. Thus, the return stroke of the inner pad 22 can be similarly regulated.

Next, the pad return structure on the outer pad 26 side will be described with reference to FIGS. As described above, the guide pins 16 and 18 protruding along the rotor axial direction are fixed to the caliper arm 38 of the caliper 12,
On the other hand, the slide sleeves 40 and 42 into which they are inserted are formed on the support 14 to form a slide guide mechanism.
There are 6 return structures. Explaining this on the rotor entry side, a small-diameter pin 56 is provided so as to project from the insertion tip of the guide pin 16, and a washer 58 is attached to the tip of the small-diameter pin 56 in a flange shape. A circular ring-shaped friction ring 60 is mounted on the outer circumference of the small-diameter pin 56. This friction ring 60 is loosely fitted to the small-diameter pin 56, while the ring outer surface is attached to the inner peripheral surface of the slide sleeve 40. Are brought into contact with each other, and are held at the contact position with the inner peripheral surface of the sleeve by the sliding resistance. A coil spring 6 is provided between the friction ring 60 and the washer 58.
2, the washer 58 is elastically biased by using the friction ring 60 as a spring seat to bias the guide pin 16 toward the pin insertion direction. As a result, the caliper 12 integrated with the guide pin 16 is urged, but the caliper moving direction by the coil spring 62 is the same as the direction in which the outer pad 26 is separated from the rotor 10. Further, a thin spacer sleeve 64 is mounted on the outer circumference of the small diameter pin 56 and located on the inner surface side of the coil spring 62. The spacer sleeve 64 includes the friction ring 6
The positioning is 0, and the guide pin 16 is pulled out from the slide sleeve 40 by the braking operation (see FIG.
To the left), but the outer pad 26
Is pressed and moved through the washer 58 to a position where the rotor 10 is pressed against the rotor 10 and abuts the friction ring 60 to move it against the sliding resistance. Therefore, the outer pad 2
When 6 wears, the position of the friction ring 60 is changed and adjusted according to the wear amount. The length of the spacer sleeve 64 is set to a length 1 shorter than the maximum separation length L of the friction ring 60 and the washer 58 on the outer circumference of the small diameter pin 56. Therefore, when the braking state is changed to the non-braking state, the gap (L-1) becomes the return stroke of the outer pad 26. Therefore, at the time of non-braking, the coil spring 62 presses the washer 58 with the friction ring 60 held at the braking-corresponding position as a base point, and the guide pin 16 and the caliper 1 are accompanied by this.
2 is moved to the braking release position. At this time, the spacer sleeve 6 is adjusted so that the return stroke of the outer pad 26 matches the return stroke of the inner pad 22.
4 may be adjusted. Spacer sleeve 6 for adjustment
The actual length of 4 may be changed, but it can also be done by mounting an adjusting ring (not shown). Since such a configuration is the same on the side where the rotor is fed out, the same components are designated by the same reference numerals and the description thereof will be omitted.

In the above example, the friction ring 60
Although an example of a simple circular ring is shown in FIG.
As shown in FIG. 5, a cup type friction ring 60A may be used. By doing this,
It is possible to prevent the coil spring 62 from interfering with the inner peripheral surface of the slide sleeve 40 (42) and prevent the sliding resistance from changing.

According to the pad returning structure having the above-described structure, the inner pad 22 is separated from the rotor 10 by the returning spring mechanism portion 50 formed in the pad clip 46 provided between the inner pad 22 and the support 14. On the other hand, the outer pad 26, which is moved and is integrated with the caliper 12, is returned and moved by the spring action of the coil spring 62 provided in the slide guide mechanism portion. The return movement resistance of the inner pad 22 and the return movement resistance of the outer pad 26 are, while the former is the mass and sliding resistance of the inner pad 22 itself,
Since the latter includes not only the outer pad 26 but also the mass of the caliper 12 and its sliding resistance, there is a considerable difference. In this embodiment, the returning forces corresponding to the sliding resistance on the inner pad 22 side and the sliding resistance on the outer pad 26 side can be independently applied. In particular, the outer pad 26 having a large sliding resistance can be easily dealt with by adjusting the spring constant of the coil spring 62. The return stroke can be easily adjusted to be the same by adjusting the gap between the notch 52 and the engaging claw 54 in the pad clip 46 on the inner pad 22 side and adjusting the length of the spacer sleeve 64 on the outer pad 26 side. is there.

The coil spring 62 can be replaced with a spacer sleeve 64 by using a wire having a square cross section. In this case, the return stroke can be adjusted by changing the spring length. In the above embodiment, the guide pins 16 and 18 are fixed to the caliper 12, but the guide pin is provided on the support 14 side.
It goes without saying that the structure can be applied to the structure in which the slide sleeve is provided on the.

[0023]

As described above, according to the present invention,
A pad return spring mechanism is formed on a pad clip provided on a sliding portion between the inner pad and the support to urge the inner pad in a direction away from the rotor, and the slide guide mechanism has a frictional engagement with a guide surface on the support side. Since the friction pad is attached to the friction ring and a pad return spring having the friction ring as a reaction fulcrum is provided to abut on the caliper side, the outer pad is biased in a direction away from the rotor. Even with the fist type disc brake fixed to the caliper, the inner pad and the outer pad can be reliably moved back even if there is a difference in sliding resistance, and the excellent effect that pad drag to the rotor can be effectively prevented is effectively achieved. can get.

[Brief description of drawings]

FIG. 1 is an explanatory perspective view of a pad returning structure according to an embodiment.

FIG. 2 is a perspective view of a disc brake including the pad returning structure of the embodiment.

FIG. 3 is a partial cross-sectional plan view of the disc brake and a main-part cross-sectional view of a modified example.

FIG. 4 is a front view of the disc brake as viewed from the outer side.

FIG. 5 is a perspective view of a pad clip.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Rotor 12 Caliper 14 Support 16 Rotor inflow side guide pin 18 Rotor outflow side guide pin 20 Hydraulic cylinder 22 Inner pad 24 Caliper claw 26 Outer pad 28 Mounting hole 30 Anchor projection 32 Recessed groove 34 Engagement projection 36 Engagement hole 38 Caliper arm 40 Slide sleeve 42 Slide sleeve 44 Rubber boot 46 Pad clip 48 Clip body 48A Upper piece 48B Anchor piece 48C Lower piece 50 Return spring mechanism 50A Extension plate 50B Parallel plane 50C S-shaped bent section 50Ca bent section 50Cb Final bent piece part 52 Notch 54 Engagement claw 52A Opening window 54A Cut and raised piece 56 Small diameter pin 58 Washer 60 Friction ring 62 Coil spring 64 Spacer sleeve 60A Cup type friction ring

Claims (2)

[Claims] 1. A disc brake comprising a support for holding an inner pad movably in a rotor axial direction and a caliper to which an outer pad is attached via a slide guide mechanism, and a sliding portion between the inner pad and the support. A pad return spring mechanism is formed on the pad clip arranged in the above to urge the inner pad in a direction away from the rotor, and a friction ring frictionally engaged with the guide surface is attached to the slide guide mechanism and the friction ring is attached. A disc brake pad returning structure characterized in that a spring serving as a reaction force fulcrum is provided to urge the outer pad in a direction away from the rotor via a caliper. 2. The pad return structure of a disc brake according to claim 1, wherein an inner pad return stroke by said pad clip and an outer pad return stroke by a pad return spring provided on said slide guide are substantially matched. .