JP2005249006A - Disk brake - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively restrain uneven abrasion of a brake pad as well as brake noise. <P>SOLUTION: In this disk brake 10, projecting parts 52 formed on both ends of the back plate of the brake pad 50 are supported on a recessed part 22 of a mounting 20. The top face of the projecting part 52 opposite to the bottom 23 of the recessed part 22 includes a curved surface having a predetermined curvature, and the abutting positions of the projecting parts 52 to the recessed part 22 are on the curved surface, and rather closer to a disk rotor than the center of board thickness of the back plate 54 in the direction vertical to the rotating surface of the disk rotor 14. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a disc brake in which convex portions formed at both ends of a back pad of a brake pad are supported by concave portions of a mounting.

2. Description of the Related Art Conventionally, a disc brake in which convex portions formed on both ends of a back metal of a brake pad are supported in a groove portion (concave portion) of a mounting (caliper) via a pad spring (pad clip) is widely known. In this type of disc brake, the contact part (the side surface, not the top surface of the convex part) of the convex part of the brake pad is formed in a substantially arc shape (elliptical shape), so that the brake pad support part can rotate freely. There is known a technique for increasing the degree and reducing drag due to surface runout of the disk rotor (see, for example, Patent Document 1).
JP-A-8-93807 (FIG. 5 etc.)

  By the way, if the contact part (particularly the upper surface of the convex part) with the groove part of the convex part of the brake pad is formed in an arc shape, the stability of the contact between the arc-shaped convex part and the mounting groove part is increased. It becomes effective against. However, as is apparent from Patent Document 1 described above, conventionally, attention has not been paid to the action of the arc shape on the upper surface of the convex portion of the brake pad, and special consideration is given to the apex position of the arc-shaped convex portion. Has not been made.

  Therefore, the present invention focuses on the fact that the configuration of the protrusions of the brake pad further affects the uneven wear of the brake pad, and the disc brake of the disc brake that can effectively suppress the uneven wear of the brake pad together with the brake squeal. For the purpose of provision.

In order to solve the above problems, according to one aspect of the present invention, in the disc brake in which the convex portions formed at both ends of the back metal of the brake pad are supported by the concave portions of the mounting,
The upper surface of the convex portion facing the bottom of the concave portion includes a curved surface having a predetermined curvature,
The contact position of the convex portion with the concave portion is on the curved surface when viewed in the direction perpendicular to the rotational surface of the disc rotor, and is on the disc rotor side with respect to the thickness center of the back metal. Disc brakes are provided.

  According to the present invention, it is possible to obtain a disc brake that can effectively suppress uneven wear of a brake pad as well as brake noise.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a plan view showing a disc brake 10 according to an embodiment of the present invention (a plan view seen in a direction perpendicular to the disc surface), and FIG. 2 is a cross-sectional view taken along line AA in FIG. It is. The disc brake 10 of the present embodiment includes a mounting bracket 20 (hereinafter simply referred to as “mounting 20”) fixed to the vehicle body. A brake pad 50 (an inner pad and an outer pad) is supported on the mounting 20 by a pad clip 40. The inner pad and the outer pad are arranged so as to sandwich the disk rotor 14 that rotates together with the wheels from the inside and outside of the vehicle.

  The disc brake 10 includes a cylinder (caliper) (not shown). The cylinder is attached to the mounting 20 via a slide pin or the like (not shown). Typically, a master cylinder (not shown) communicates with the cylinder via a hydraulic passage. When a high-pressure fluid is supplied to the cylinder, the inner pad and the outer pad are pressure-bonded to both sliding surfaces of the disk rotor 14 by the operation of the piston and the claw portion that sandwich the brake pad 50 (inner pad and outer pad) from the inside and outside of the vehicle. Brake operation is realized. The disc brake 10 may be disposed at any angular position in the circumferential direction of the wheel.

  As shown in FIG. 2, the brake pad 50 includes a friction material 56 that contacts the sliding surface of the disk rotor 14, and the friction material 56 wears substantially parallel to the sliding surface of the disk rotor 14 without wear. Has a surface. A back metal (back plate) 54 is attached to the back side of the friction material 56 (back side toward the disk rotor 14). On the back side of the back metal 54 of the brake pad 50, a piston or claw portion of a cylinder is brought into contact with and pressed through a shim (not shown). The shim is attached to the back metal 54 of the brake pad 50 with a hook or the like, and has a function of suppressing brake noise.

  As shown in FIG. 2, the back metal 54 of the brake pad 50 has a predetermined thickness (for example, 5 or 6 mm), and includes convex portions 52 at both ends. The convex portion 52 of the back metal 54 is supported by a concave portion (groove portion) 22 formed in the mounting 20 via a pad clip 40 to constitute a torque receiving portion. The pad clip 40 may be configured to support the convex portion 52 of the brake pad 50 in a floating state in the concave portion 22 of the mounting 20. In the example of FIG. The rotor 14 is supported in a displaceable state on the inner peripheral side of the rotor 14.

  FIG. 3 is an enlarged detailed view of the vicinity of the contact portion of the back metal 54 (convex portion 52) with the pad clip 40 in FIG. A contact portion of the convex portion 52 of the brake pad 50 with the pad clip 40 is processed into a smooth arc shape. The curvature 1 / R of the arc of the convex portion 52 is set to an appropriate value so that the convex portion 52 of the brake pad 50 can stably come into contact with the concave portion 22 (pad clip 40) of the mounting 20 as will be described later. Is set. Note that the arc shape of the contact portion of the convex portion 52 may be formed by machining a wave section constituting the contact portion after the brake pad 50 is punched.

  The arc-shaped curvature center O of the convex portion 52 is set in the plate thickness region of the back plate 54 and on the friction material 56 side with respect to the plate thickness center line of the back plate 54 (indicated by a dotted line in the drawing). That is, the distance d between the arc-shaped curvature center O of the convex portion 52 and the back surface of the friction material 56 is set to be smaller than half the plate thickness t of the back metal 54 (d <t / 2). In this case, the convex portion 52 contacts the pad clip 40 at a point B corresponding to the top of the arc shape of the convex portion 52, that is, at a point B closer to the friction material 56 than the plate thickness center line of the back metal 54. It will be.

  As described above, according to the present embodiment, the convex portion 52 of the brake pad 50 stably contacts and abuts on the concave portion 22 (pad clip 40) of the mounting 20 at the fixed point B, so that the concave portion 22 of the mounting 20 Compared to a configuration that can abut at a plurality of sites (for example, a configuration in which the abutment portion of the convex portion 52 is not subjected to special processing and has a rough surface by punching), the type of squeal frequency is limited Thus, it is possible to effectively suppress the brake squeal phenomenon when the brake is operated. In addition, the convex part 52 of the brake pad 50 may be a shape extruded substantially in the same cross section shown in FIG. 2, and in this case, the concave part 22 of the mounting 20 is formed by a set of arcuate vertices B (that is, lines). Abutment with the bottom 23 is realized.

  Incidentally, as schematically shown in FIG. 4, when the brake is operated (that is, when the friction material 56 is pressed against the rotating disk rotor 14), the reaction force F <b> 1 that the friction material 56 receives from the disk rotor 14, A moment M (= F1 × l) acts on the brake pad 50 in a counterclockwise direction in FIG. 4 due to a reaction force received from the mounting 20 by the convex portion 52 (contact point B) of the brake pad 50. Therefore, as schematically shown in FIG. 4B, the surface pressure acting on the brake pad 50 is higher on the inlet side in the rotational direction of the disk rotor 14 than on the outlet side, and thus the friction material 56 Cause uneven wear.

  In contrast, in this embodiment, as described above, the contact point B of the convex portion 52 of the brake pad 50 with the pad clip 40 is set on the friction material 56 side of the plate thickness center line of the back metal 54. . Therefore, according to the present embodiment, l is smaller than the configuration in which the contact point B is set on the plate thickness center line of the back metal 54 or on the back side of the plate thickness center line, and the moment M acting on the brake pad 50 is small. Therefore, uneven wear of the friction material 56 can be effectively suppressed.

  In the above description, the configuration of the convex portion 52 on the outlet side in the rotational direction of the disc rotor 14 among the two convex portions 52 on both sides of the brake pad 50 has been described with reference to FIG. The same may be said of the structure of the convex part 52 of the entrance side of the rotation direction.

  An alternative embodiment of the disc brake 10 according to the present invention will now be described with reference to FIG. FIG. 5 is an enlarged view of the vicinity of the contact portion of the convex portion 52 of the brake pad 50 with the pad clip 40. 6 is a perspective view of the protrusion 52 of the brake pad 50 shown in FIG.

  In this alternative embodiment, a circular arc shape is not formed on the convex portion 52 of the brake pad 50 by molding as in the above-described embodiment, but a cylindrical pin member 55 is provided on the convex portion 52 of the brake pad 50. It is formed by. The cylindrical pin member 55 of this alternative embodiment is fixed by welding to a semicircular concave portion provided in the upper surface of the convex portion 52 of the brake pad 50. The pin member 55 may be formed of a material different from the back metal 54 of the brake pad 50, for example, a material having high hardness advantageous for wear and deformation. Also in this alternative embodiment, the contact point B of the outer peripheral surface of the pin member 55 is set closer to the friction material 56 than the plate thickness center line of the back metal 54 from the above viewpoint of suppressing uneven wear of the friction material 56. It's okay.

  Therefore, also in this alternative embodiment, the brake squealing phenomenon at the time of brake operation can be effectively suppressed, and uneven wear of the brake pad 50 can be effectively suppressed, as in the above-described embodiment.

  Next, another alternative embodiment of the disc brake 10 according to the present invention will be described with reference to FIG. FIG. 8 is a plan view showing a mounting portion of the brake pad 50 according to this alternative embodiment when viewed from the same direction as FIG.

  In this alternative embodiment, as shown in FIG. 8, the cross section of the bottom 23 (contact surface) of the recess 22 of the mounting 20 is formed in an arc shape. That is, the bottom 23 of the recess 22 of the mounting 20 is formed with a curve of curvature such that the convex 52 side of the brake pad 50 is convex. In this alternative embodiment, the convex portion 52 of the brake pad 50 is not a line (a line of a set of vertices B as in the above-described embodiment) with respect to the bottom 23 of the concave portion 22 of the mounting 20 (ie, the vertex B). ), The posture of the brake pad 50 is further stabilized, and the brake squeal phenomenon at the time of brake operation can be effectively suppressed.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the present invention. Can be added.

  For example, in the above-described embodiment, the arc shape of the convex portion 52 of the brake pad 50 that defines the contact point B with the concave portion 22 (pad clip 40) needs to be defined by an arc over the entire thickness of the back metal 54. As long as the contact point B is on the friction material 56 side with respect to the plate thickness center line of the back metal 54, there is no need to define the entire surface of the convex portion 52 facing the concave portion 22 with a curved surface. As shown in FIG. 7 (corresponding to the AA cross section of FIG. 1), for example, the contact surface of the convex portion 52 has an appropriate angle at the apex B ′ on the friction material 56 side. It may be formed by setting an appropriate roundness (R) in the two formed planes.

[Appendix]
According to another aspect of the present invention, a back metal provided opposite to the rotating surface of the disk rotor and having a predetermined plate thickness in a direction perpendicular to the rotating surface, and between the back metal and the rotating surface of the disk rotor. A brake pad including a friction material provided on the
The brake pad is supported by convex portions formed at both ends of the back metal in concave portions formed in the mounting,
In a cross-section taken along a plane perpendicular to the rotation surface and including a straight line passing through both convex portions of the back metal, the cross-sectional line of the surface facing the concave portion of the convex portion of the back metal is not on the concave side The disc brake is characterized in that an arc of a predetermined curvature having a center of curvature is included, and a point closest to the concave portion on the arc is on the friction material side with respect to a plate thickness center of the back metal. Provided.

1 is a plan view showing an embodiment of a disc brake 10 according to the present invention. It is a figure which shows the AA cross section of FIG. FIG. 3 is an enlarged detailed view of the vicinity of a contact portion of a convex portion 52 of FIG. 2 with a pad clip 40. It is explanatory drawing which shows the partial wear reduction principle of the disc brake 10 by a present Example. FIG. 3 shows an alternative embodiment of a disc brake 10 according to the present invention. It is a perspective view of the convex part 52 of the brake pad 50 of FIG. It is a figure which shows the modification of the circular arc shape of the contact part with the pad clip 40 of the convex part 52. FIG. FIG. 3 shows an alternative embodiment of a disc brake 10 according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Disc brake 14 Disc rotor 20 Mounting 22 Concave part 40 Pad clip 50 Brake pad 52 Convex part 54 Back metal 56 Friction material

Claims (2)

In the disc brake in which the convex portions formed at both ends of the back metal of the brake pad are supported by the concave portion of the mounting,
The upper surface of the convex portion facing the bottom of the concave portion includes a curved surface having a predetermined curvature,
The disc brake characterized in that the contact position of the convex portion with the concave portion is on the curved surface and in the direction perpendicular to the rotational surface of the disc rotor and on the disc rotor side with respect to the thickness center of the back metal.   The disc brake according to claim 1, wherein a bottom portion of the concave portion of the mounting is formed in an arc shape in which the convex portion side swells when viewed in a direction perpendicular to a rotation surface of the disc rotor.

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