Pad sets for disk brakes

This application claims priority to Japanese patent application serial number 2006-278396, the contents of which are incorporated herein by reference.

1. Field of the Invention

The present invention relates to a pad set for a disk brake which has a shim interposed between a pad and a pressing member for pressing the pad toward a disk rotor.

2. Description of the Related Art

In general, a shim is formed from a plate material of stainless steel, and is interposed between a pad and a pressing member (piston, etc.) for pressing the pad toward the disk rotor. When the pad is pressed against the disk rotor by the pressing member, the pad is slid on the shim interposed between the pad and the pressing member, and is moved to a stable position. Accordingly, the pad is stabilized by the shim, and a brake noise is restrained. However, the conventional shim has a structure in which a hook is arranged at an outer circumferential end and is engaged with an engaging groove at the outer circumferential end of the pad (e.g., JP-A-7-208516). Therefore, when the pad is greatly moved with respect to the shim, the hook hits against a wall face of the engaging groove and is deformed, and one portion of the hook and the shim is deformed in the direction away from the pad. Therefore, this results in problems such as brake noise being generated by the deformation of the shim, the pad not being uniformly pressed, the hook being damaged, etc., are caused.

Further, a shim having no hook and a pad corresponding to this shim are also conventionally known (e.g., JP-A-8-240234). A pair of concave portions are formed on a rear face of this pad, and projections engaged with the concave portions of the pad are formed in the shim. It is necessary that the projection and the concave portion are constructed so as to be tightly engaged, and to have a construction in which the shim does not separate from the pad. Because of this, the manufacturing accuracy must be high and it is therefore difficult to make this a commercial product. Further, since the projection is formed in the shim, a problem also exists in that the projection is easily deformed and durability is not good.

Therefore, an object of the present invention is to provide a pad set for a disk brake having a shim and a preventing deformation structure. The shim has a hook engaged with the outer circumferential end of the pad. The preventing deformation structure prevents deformation of the hook and is easily manufactured.

The present invention can include a disk brake having a pad with an engaging groove formed in the pad, the pad also includes a convex member projected from one portion of the pad, a shim is positioned between the pad and a pressing member for pressing the pad toward a disk rotor, the shim including an engaging member formed on a side of the shim, a hook that extends from the shim is engagable with the engaging groove, and the convex portion is able to contact the first engaging member to restrain movement of the pad.

Therefore, the convex portion of the pad restrains the movement of the pad with respect to the shim instead of the hook of the shim. Therefore, the convex portion can prevent deformation of the hook. Further, the convex portion and the shim are not need to be tightly engaged as in the conventional case. Therefore, the convex portion and the engaging portion are easily manufactured. Further, the shim and the convex portion have a construction in which the convex portion hit against the side end of the engaging portion of the shim. Therefore, the shim is less readily deformed and excellent in durability in comparison with a mode for applying force to a projection projected from the shim as in the conventional case.

FIG. 1 is a perspective view of a disk brake according to one configuration of the present invention;

FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1 ;

FIG. 3 is a perspective view of a pad set according to one configuration of the present invention;

FIG. 4 is a rear view of the pad set; and

FIG. 5 is a rear view of a pad set according to another configuration of the present invention.

Each of the additional features and teachings disclosed above and below may be utilized separately or in conjunction with other features and teachings to provide improved pad sets. Representative examples of the present invention, which examples utilize many of these additional features and teachings both separately and in conjunction with one another, will now be described in detail with reference to the attached drawings. This detailed description is merely intended to teach a person of skill in the art further details for practicing preferred aspects of the present teachings and is not intended to limit the scope of the invention. Only the claims define the scope of the claimed invention. Therefore, combinations of features and steps disclosed in the following detailed description may not be necessary to practice the invention in the broadest sense, and are instead taught merely to particularly describe representative examples of the invention. Moreover, various features of the representative examples and the dependent claims may be combined in ways that are not specifically enumerated in order to provide additional useful configurations of the present teachings.

A disk brake 10 in accordance with one embodiment of the present invention will be explained in accordance with FIGS. 1 to 4 . As shown in FIGS. 1 and 2 , the disk brake 10 has a mounting 11 mounted on a vehicle body side, a caliper 13 movably attached to the mounting 11 , and a pair of pad sets 1 . The pad set 1 has a pad 3 and a shim 2 suspended and engaged with a rear face of the pad 3 .

As shown in FIGS. 1 and 2 , the caliper 13 is attached to the mounting 11 by a pair of slide pins 14 so as to be movable in the rotor axis direction. The caliper 13 is extended from the vehicle body side so as to straddle both sides of the disk rotor R in the rotor axis direction. A cylinder portion 13 b is provided at a base end portion of the caliper 13 . A piston (pressing member) 12 is set in the cylinder portion 13 b . A pair of claw portions (pressing members) 13 a are arranged in a tip portion of the caliper 13 .

The piston (pressing member) 12 is advanced toward a disk rotor R by liquid pressure in the cylinder portion 13 b . And the piston 12 presses the pad 3 interposed between the piston 12 and the disk rotor R toward the disk rotor R. The reaction to this pressure moves the caliper 13 , and the claw portions 13 a of the caliper 13 presses the pad 3 interposed between the disk rotor R and the claw portions 13 a toward the disk rotor R. Accordingly, this one pair of pads 3 each is pressed against the disk rotor R, by the piston 12 and the claw portions 13 a acting as respective pressing members.

The pad 3 has a friction member 4 coming in slide contact with the disk rotor R and generating frictional force, integrated with a back plate member 5 for supporting the back of the friction member 4 . The back plate member 5 can be made from a metal or resin, and has guide portions 5 g , 5 h at both ends as shown in FIG. 3 . The guide portions 5 g , 5 h are projected from both the ends of the back plate member 5 , and are movably attached to the mounting 11 (see FIG. 1 ).

As shown in FIG. 3 , plural (e.g., four) engaging grooves 5 c to 5 f are formed at an outer circumferential end of the back plate member 5 . Two engaging grooves 5 c , 5 d are located in an outer circumferential portion further outward in the rotor radial direction. The other two engaging grooves 5 e , 5 f are located in an inner circumferential portion further inside in the rotor radial direction of the back plate member 5 .

As shown in FIGS. 3 and 4 , a pair of convex portions or members 5 a , 5 b has a columnar shape. And the convex portions 5 a , 5 b are formed on the back face of the back plate member 5 . One of convex portions 5 a , 5 b is located at one end portion in the disk rotor circumferential direction of the back plate member 5 , the other one is located at the other end portion of the back plate member 5 . The convex portions 5 a , 5 b are not covered with the shim 2 and projected from the back face of the back plate member 5 . These convex portions 5 a , 5 b , together with the pad 3 , are moved with respect to the shim 2 when braking, and abut on the shim 2 in a side direction. The convex portions 5 a , 5 b are arranged in positions in order to not obstruct the pressing member ( 12 , 13 a ).

The shim 2 can be made from stainless steel, and is interposed between the pressing member (piston 12 or claw portion 13 a ) and the pad 3 . As shown in FIGS. 3 and 4 , plural (e.g. four) hooks 2 c to 2 f are formed at an outer circumferential end of the shim 2 . The hooks 2 c to 2 f are extended from the outer circumferential end of the shim 2 toward the pad 3 . Two hooks 2 c , 2 d are formed extending outward in the rotor diametrical direction from the outer circumferential portion of the shim 2 , and are engaged with engaging grooves 5 c to 5 f . The other two hooks 2 e , 2 f are formed extending inward in the rotor diametrical direction from the inner circumferential portion of the shim 2 , and are engaged with engaging grooves 5 e , 5 f . Thus, the shim 2 is prevented from moving in the rotor radial direction with respect to the pad 3 .

As shown in FIGS. 3 and 4 , a pair of engaging portions or members 2 a , 2 b are formed in portions on both sides of the rotor circumferential direction of the shim 2 . The engaging portions 2 a , 2 b are located at corner portions on both sides of the shim 2 in the rotor circumferential direction and toward the center of the rotor in the rotor radial direction. The engaging portions 2 a , 2 b have through holes 2 a 1 , 2 b 1 in positions for receiving the convex portions 5 a , 5 b , and the convex portions 5 a , 5 b are projected into the through holes 2 a 1 , 2 b 1 . When the pad 3 is moved with respect to the shim 2 , the convex portions 5 a , 5 b hit against hole ends of the through holes 2 a 1 , 2 b 1 sideways.

As shown in FIG. 4 , clearances A, B are formed between the convex portions 5 a , 5 b and the engaging portions 2 a , 2 b . The clearances A, B have clearances A 1 , B 1 on an X-direction side of the convex portions 5 a , 5 b , and also have clearances A 2 , B 2 on a Y-direction side. Clearances C to F are formed between hooks 2 c to 2 f and engaging grooves 5 c to 5 f . The clearances C to F have clearances C 1 to F 1 on an X-direction side of hooks 2 c to 2 f , and also have clearances C 2 to F 2 on a Y-direction side.

As shown in FIG. 4 , when the pad 3 is pressed against the disk rotor R in case a vehicle is moving forward, the pad 3 receives force in a X-direction. The X-direction is a tangential direction of forward rotation of the disk rotor R. And the pad 3 moves in the X-direction with respect to the shim 2 . The convex portion 5 b of the pad 3 then hits against a hole end of the through hole 2 b 1 of the engaging portion 2 b , and the movement of the pad 3 in the X-direction is restrained. At this time, hooks 2 c to 2 f are not hitting against wall faces of engaging grooves 5 c to 5 f . In other words, hooks 2 c to 2 f have the relation of B 1 <A 1 , B 1 <C 1 . . . B 1 <F 1 . The engaging portion 2 b receives force toward the center of the shim 2 by the convex portion 5 b , and receives force in the compression direction.

As shown in FIG. 4 , when the pad 3 is pressed against the disk rotor R in case the vehicle is moving rearward, the pad 3 receives force in the rearward rotation tangential direction (Y-direction) of the disk rotor R and is moved in the Y-direction with respect to the shim 2 . The convex portion 5 a of the pad 3 then hits against a hole end of the through hole 2 a 1 of the engaging portion 2 a and the movement of the pad 3 in the Y-direction is restrained. At this time, hooks 2 c to 2 f are not hitting against the wall faces of engaging grooves 5 c to 5 f . In other words, hooks 2 c to 2 f have the relation of A 2 <B 2 . . . A 2 <F 2 . The engaging portion 2 a receives force toward the center of the shim 2 by the convex portion 5 a , and receives force in the compression direction.

The sum of clearances A 2 , B 1 of the convex portions 5 a , 5 b and the engaging portions 2 a , 2 b toward the center of the shim 2 is smaller than the sum of clearances A 1 , B 2 of the convex portions 5 a , 5 b and the engaging portions 2 a , 2 b of the shim 2 toward the outside of the shim 2 . In other words, the relation of A 2 + 21 A 1 +B 2 is formed. Therefore, the convex portions 5 a , 5 b have a construction which pushes the engaging portions 2 a , 2 b toward the center of the shim 2 , and which does not pull the engaging portions 2 a , 2 b away from the center of the shim 2 . Accordingly, damage to outside portions of the engaging portions 2 a , 2 b can be prevented.

As shown in FIG. 3 , the shim 2 has hooks 2 c to 2 f engaged with engaging grooves 5 c to 5 f of the outer circumferential end of the pad 3 . The pad 3 has the convex portions 5 a , 5 b projected from one portion of the back face where it is not covered with the shim 2 . When braking, the pad 3 is moved with respect to the shim 2 , and the convex portions 5 a , 5 b hit against the side end of the engaging portions 2 a , 2 b of the shim 2 so that the movement of the pad 3 is restrained.

Accordingly, the convex portions 5 a , 5 b of the pad 3 restrain the movement of the pad 3 with respect to the shim 2 instead of the hooks 2 c to 2 f of the shim 2 . Therefore, the convex portions 5 a , 5 b can prevent deformation of hooks 2 c to 2 f . Further, the convex portions 5 a , 5 b and the shim 2 are not need to be tightly engaged as in the conventional case. Therefore, the convex portions 5 a , 5 b and the engaging portions 2 a , 2 b are easily manufactured. Further, the shim 2 and the convex portions 5 a , 5 b have a construction in which the convex portions 5 a , 5 b hit against the side end of the engaging portions 2 a , 2 b of the shim 2 . Therefore, the shim 2 is less readily deformed and has excellent durability in comparison with a mode for applying force to a projection projected from the shim as in the conventional case.

Further, as shown in FIG. 4 , the engaging portions 2 a , 2 b of the shim 2 have the through holes 2 a 1 , 2 b 1 , and the convex portions 5 a , 5 b are projected into the through holes 2 a 1 , 2 b 1 . Since the convex portions 5 a , 5 b hit against the hole ends of the through holes 2 a 1 , 2 b 1 , the movement of the pad 3 with respect to the shim 2 is regulated. Accordingly, since the engaging portions 2 a , 2 b are not tightly engaged with the convex portions 5 a , 5 b , the engaging portions 2 a , 2 b have a form which can be easily manufactured.

Further, as shown in FIG. 4 , the pad 3 has convex portions 5 a , 5 b in the two side portions. When the pad 3 is moved from one side to the other side in a X-direction with respect to the shim 2 , the convex portion 5 b located at the one side hits against the engaging portion 2 b formed in the corresponding side portion of the shim 2 and pushes the engaging portion 2 b toward the center of the shim 2 . When the pad 3 is moved from the other side to the one side in the reverse direction (or Y-direction) with respect to the shim 2 , the convex portion 5 a located at the other side hits against the engaging portion 2 a formed in the other side of the shim 2 , and pushes the engaging portion 2 a toward the center of the shim 2 .

Accordingly, the pad 3 has one pair of convex portions 5 a , 5 b , and each of the convex portions 5 a , 5 b hits against one of the pair of engaging portions 2 a , 2 b formed in the shim 2 . Since the respective convex portions 5 a , 5 b push the respective engaging portions 2 a , 2 b toward the center of the shim 2 , the engaging portions 2 a , 2 b receive force in the compression direction. Therefore, it is possible to prevent the engaging portions 2 a , 2 b from being pulled from the center of the shim 2 , which can result in damage, etc. Thus, a construction able to restrain damage to the shim 2 is attained.

Further, the movement of the pad 3 in the rotor radial direction with respect to the shim 2 is regulated by the convex portions 5 a , 5 b and the engaging portions 2 a , 2 b instead of hooks 2 c to 2 f . Therefore, the widths of the hooks 2 c to 2 f can be reduced. Thus, frictional force of the pad 3 in the rotor radial direction with respect to the shim 2 can be reduced. With this configuration, the pad 3 can easily move with respect to the shim 2 , and brake noise can be effectively restrained.

Another configuration according to the present invention will be described in reference to FIG. 5 . This configuration is similar to the one shown in FIG. 4 . However, FIG. 5 includes engaging portions 2 g , 2 h instead of the engaging portions 2 a , 2 b . FIG. 5 will be described below, the description focusing on differences from FIG. 4 .

As shown in FIG. 5 , the shim 2 has plural hooks 2 c to 2 f and a pair of engaging portions 2 g , 2 h . The engaging portions 2 g , 2 h are formed at both sides of the shim 2 in the rotor circumferential direction. The engaging portions 2 g , 2 h are located at the corner portions on both sides of the shim 2 in the rotor circumferential direction and toward the center of the rotor in the rotor radial direction. The engaging portions 2 g , 2 h have concave portions 2 g 1 , 2 h 1 . The concave portions 2 g 1 , 2 h 1 are formed by concaving the outer circumferential end of the shim 2 in a central direction of the shim 2 . The concave portions 2 g 1 , 2 h 1 don't cover the convex portions 5 a , 5 b . And the convex portions 5 a , 5 b are inserted into the concave portions 2 g 1 , 2 h 1 .

Clearances G, H are formed between the convex portions 5 a , 5 b and the engaging portions 2 g , 2 h . Clearance G has clearance G 2 on the Y-direction side of the convex portion 5 a , and clearance H has clearance H 1 on the X-direction side of the convex portion 5 b . When the pad 3 is pressed against the disk rotor R when the vehicle is moving forward, the pad 3 is moved in the X-direction. The convex portion 5 b hits against an end of the concave portion 2 h 1 of the engaging portion 2 h , and the movement of the pad 3 in the X-direction is regulated. At this time, hooks 2 c to 2 f are not hitting against wall faces of engaging grooves 5 c to 5 f . In other words, hooks 2 c to 2 f have the relation of H 1 <C 1 . . . H 1 <F 1 . The engaging portion 2 h receives force toward the center of the shim 2 from the convex portion 5 b , and receives force in the compression direction.

When the pad 3 is pressed against the disk rotor R when the vehicle is moving rearward, the pad 3 receives force in the Y-direction and is moved in the Y-direction with respect to the shim 2 . The convex portion 5 a of the pad 3 then hits against an end of the concave portion 2 g 1 of the engaging portion 2 g , and the movement of the pad 3 in the Y-direction is restrained. At this time, hooks 2 c to 2 f are not hitting against the wall faces of engaging grooves 5 c to 5 f . In other words, hooks 2 c to 2 f have the relation of C 2 . . . G 2 <F 2 . The engaging portion 2 g receives force toward the center of the shim 2 from the convex portion 5 a , and receives force in the compression direction.

As shown in FIG. 5 , the engaging portions 2 g , 2 h of the shim 2 have the concave portions 2 g 1 , 2 h 1 . The concave portions 2 g 1 , 2 h 1 are formed by concaving the outer circumferential end of the shim 2 toward the center of the shim 2 . The movement of the pad 3 with respect to the shim 2 is regulated by the convex portions 5 a , 5 b hitting the concave portions 2 g 1 , 2 h 1 arranged nearby the concave portions 2 g 1 , 2 h 1 . Accordingly, since the engaging portions 2 g , 2 h are not tightly engaged with the convex portions 5 a , 5 b , the engaging portions 2 g , 2 h have a structure which can be simply formed.

While the invention has been described with reference to specific configurations, it will be apparent to those skilled in the art that many alternatives, modifications and variations may be made. Accordingly, the present invention is intended to embrace all such alternatives, modifications and variations that may fall within the spirit and scope of the appended claims. For example, the present invention should not be limited to the representative configurations, but may be modified as described below.

In FIGS. 4 and 5 , the shim 2 has the one pair of hooks 2 c , 2 d formed in its outer circumferential portion and the one pair of hooks 2 e , 2 f formed in its inner circumferential portion. However, it can be configured in a way that the shim has only one hook at the outer circumferential portion or the inner circumferential portion, or three or more hooks of the outer circumferential portion or the inner circumferential portion.

In FIGS. 4 and 5 , the pad set has one shim. However, it can be configured in a way that the pad set has plural shims and at least one of these shims has a form in accordance with one of above configurations, etc.

In FIGS. 4 and 5 , the pad set has one pair of convex portions 5 a , 5 b and has respective one pair of engaging portions 2 a , 2 b or 2 g , 2 h . However, it can be configured in a way that the pad set has one convex portion and one engaging portion, and the convex portion hits against one portion side end of the engaging portion when braking forward motion and when braking rearward motion, and the movement of the pad with respect to the shim is restrained.