JP2011231892A - Disc brake - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a disc brake that suppresses the generation of a brake squeak.SOLUTION: In an annular or polygonal contact surface 54A which can abut on a brake pad 33 of an insulator 51, an inside dimension is made larger than an inside-diameter dimension of an opposing portion 37A between the brake pad 33 of a piston 6 and the contact surface, an outside dimension is made larger than an outside-diameter dimension of the opposing portion 37A between the brake pad 33 of the piston 6 and the contact surface, and an area which can abut on the brake pad 33 is made smaller than an area of the opposing portion 37A between the brake pad 33 of the piston 6 and the contact surface.

Description

  The present invention relates to a disc brake for braking a vehicle such as a motorcycle or an automobile.

  There is a disc brake in which an insulator having heat insulation is housed in a piston (for example, see Patent Document 1).

JP-A-9-203425

  In the above-described disc brake, since the insulator is smaller than the outer diameter of the piston, the behavior of the brake pad may become unstable, which may cause a brake squeal.

  Therefore, an object of the present invention is to provide a disc brake that can suppress the occurrence of brake squeal.

  In order to achieve the above object, according to the present invention, an annular or polygonal contact surface portion capable of abutting on a brake pad of an insulator has an inner dimension larger than an inner diameter dimension of a portion of the piston facing the brake pad, and an outer dimension. The dimension is larger than the outer diameter dimension of the portion of the piston facing the brake pad, and the area capable of contacting the brake pad is smaller than the area of the portion of the piston facing the brake pad.

  According to the invention concerning Claim 1, generation | occurrence | production of a brake squeal can be suppressed.

It is a front view showing a disc brake of one embodiment concerning the present invention. 1 is a plan view showing a disc brake according to an embodiment of the present invention. It is XX sectional drawing of FIG. 2 which shows the disc brake of one Embodiment which concerns on this invention. It is a front view showing an insulator of a disc brake of one embodiment concerning the present invention. FIG. 5 is a YY cross-sectional view of FIG. 4 showing an insulator and a piston of a disc brake according to an embodiment of the present invention. It is a front view which shows the modification of the insulator of the disc brake of one Embodiment which concerns on this invention. It is a front view which shows the modification of the insulator of the disc brake of one Embodiment which concerns on this invention. It is a front view which shows the modification of the insulator of the disc brake of one Embodiment which concerns on this invention. It is sectional drawing which shows the modification of the insulator of the disc brake of one Embodiment which concerns on this invention, and a piston. It is sectional drawing which shows the modification of the insulator of the disc brake of one Embodiment which concerns on this invention, and a piston.

  A disc brake according to an embodiment of the present invention will be described with reference to the drawings.

  The disc brake 1 of the present embodiment shown in FIGS. 1 to 3 is a disc brake for braking the front wheel of a motorcycle. Of course, the present invention is not limited to this, and can be applied to a disc brake for braking a rear wheel of a motorcycle or a brake of a four-wheeled vehicle.

  The disc brake 1 includes a disc 2 that rotates with a wheel to be braked, and a caliper 3 that imparts frictional resistance to the disc 2.

  The caliper 3 has a caliper body 5 that is attached to a non-rotating portion of the vehicle in a state of straddling the disk 2. As shown in FIG. 3, the caliper 3 has pistons 6 arranged on the caliper main body 5 so as to face the disc 2 at predetermined intervals in the circumferential direction of the disc 2 on both sides in the axial direction of the disc 2. A plurality, specifically two, are provided (one by one because of the cross section in FIG. 3). Therefore, the caliper 3 is an opposed piston type four-pot caliper. In the following, description will be given with the state of attachment to the vehicle, the radial direction of the disc 2 in this attachment state will be referred to as the disc radial direction, the axial direction of the disc 2 will be referred to as the disc axial direction, and the circumferential direction of the disc 2 ( (Rotation direction) is called the disk circumferential direction.

  The caliper body 5 has a long shape along the circumferential direction of the disk and a cylinder portion 10 disposed on the outer side of the disk 2 (opposite side to the wheel), and a long shape along the circumferential direction of the disk and the disk 2. The cylinder part 11 disposed on the inner side (wheel side) of the cylinder 2 and the cylinder part 10 and the cylinder part 11 extend from the outer side in the disk radial direction of the cylinder part 10 and the cylinder part 11 to the outer peripheral side of the disk 2. The bridge portion 12 is formed integrally with the outer side in the radial direction.

  Here, as shown in FIG. 2, the bridge unit 12 includes a pair of bridge components 15 disposed on both sides in the disk circumferential direction and a bridge component 16 disposed between these in the disk circumferential direction. ing. As a result, the bridge portion 12 includes a bridge configuration portion 15 and a bridge configuration portion 16 on one side in the disk circumferential direction, and a bridge configuration portion 15 and a bridge configuration portion 16 on the opposite side in the disk circumferential direction. Each has an opening 18 penetrating in the disk radial direction.

  On the outer side in the disk radial direction of one of the bridge components 15 arranged on the upper side when the vehicle is mounted, a substantially cylindrical passage convex portion 21 projecting outward in the circumferential direction of the disk, on the outer side, and outward in the radial direction of the disk. Is formed on the inner side of the passage convex portion 21 so as to protrude partly in the circumferential direction of the disc, toward the inner side, and outward in the radial direction of the disc. Has been.

  A communication passage (not shown) is formed in the passage convex portion 21 in the direction of the cylinder portion 11, and a bleeder plug 23 for air bleeding is attached to the outer portion thereof. A communication passage (not shown) is formed in the passage convex portion 22 in the direction of the cylinder portion 10, and a spherical plug 24 for sealing the communication passage is attached to the outer portion of the passage. These communication passages intersect each other in the caliper main body 5 and communicate the inside of the cylinder portion 10 and the inside of the cylinder portion 11.

  The outer cylinder portion 10 has a pair of mounting holes 26 extending along the disk radial direction in parallel to a line passing through the center of the disk 2 and the center of the caliper body 5 in the circumferential direction on both sides of the disk. Is formed. The caliper 3 is a so-called radial mount type that is fixed to the vehicle body side of the vehicle with mounting bolts (not shown) inserted through the mount holes 26.

  Further, a communication passage 27 is formed in the outer cylinder portion 10 at a central position in the circumferential direction of the disk in parallel with the mount hole 26. A brake hose (not shown) for supplying and discharging brake fluid into and from the cylinder portion 10 is connected to the communication path 27.

  The caliper body 5 is provided with a plurality of, specifically two, pad pins 30 that are bridged between the cylinder portion 10 and the cylinder portion 11 along the disc axial direction and are spaced apart in the disc circumferential direction. Each pad pin 30 is provided at the position of each opening 18.

  A pair of brake pads 33 are supported in each opening 18 of the caliper body 5 so as to be movable in the disk axial direction by pad pins 30, and are arranged on both surfaces in the axial direction of the disk 2.

  As shown in FIG. 3, the bores 35 and 36 facing the disk 2 are formed in the cylinder part 10 and the cylinder part 11 of the caliper main body 5 at two locations spaced apart in the circumferential direction of the disk (in FIG. 3, (It is shown one by one because of the cross-sectional relationship). Each bore 35, 36 is formed at the position of each opening 18 shown in FIG. As shown in FIG. 3, the bores 35 and 36 have substantially the same shape, and the piston 6 having the same shape is slidably fitted into each of the bores 35 and 36.

  The piston 6 has a bottomed cylindrical shape having a cylindrical portion 37 and a bottom portion 38 that closes one end side of the cylindrical portion 37, that is, a cup shape, and an opening 39 is formed on the opposite side of the cylindrical portion 37 from the bottom portion 38. Yes. The piston 6 is inserted into the bores 35 and 36 with the opening 39 facing the disc 2 side.

  Here, the pistons 6 respectively provided in the bores 35 and 36 of the caliper body 5 slide in the bores 35 and 36 by the hydraulic pressure introduced into the bores 35 and 36 and move in the direction of the disk 2. Thereby, the brake pads 33 provided between the piston 6 and the disk 2 are respectively pressed by the piston 6 and pressed against the disk 2 to generate a braking force on the vehicle. As shown in FIG. 2, a pad spring 40 that presses the brake pads 33 is provided outside the brake pads 33 in the radial direction of the disk.

  As shown in FIG. 3, each bore 35, 36 has a fitting inner diameter portion 35 a, 36 a for slidably fitting the piston 6, and a fitting inner diameter portion located on the back side of the fitting inner diameter portions 35 a, 36 a. Large diameter inner diameter portions 35b and 36b having a larger diameter than the portions 35a and 36a. Further, at substantially intermediate positions in the axial direction of the fitting inner diameter portions 35a, 36a, piston seal grooves 35c, 36c having a larger diameter than the fitting inner diameter portions 35a, 36a and holding the piston seal 42, and the fitting inner diameter portion 35a. , 36a and piston seal grooves 35d, 36d for holding the piston seal 43 on the disk 2 side of the piston seal grooves 35c, 36c are formed.

  The piston 6 provided in the bore 35 of the cylinder portion 10 on the outer side is slidably supported by the fitting inner diameter portion 35a and the piston seals 42 and 43 held in the piston seal grooves 35c and 35d. Similarly, the piston 6 provided in the bore 36 of the inner cylinder portion 11 is slidably supported by the fitting inner diameter portion 36a and the piston seals 42 and 43 held in the piston seal grooves 36c and 36d. The That is, the cup-shaped piston 6 that presses the brake pad 33 against the disk 2 is housed in the caliper body 5 so as to be slidable via the piston seals 42 and 43.

  The caliper body 5 has an opening 45 communicating with the bore 36 in a part of the inner cylinder 11 opposite to the disk 2, and is formed from an integrally formed material made of, for example, an aluminum alloy casting. The fitting inner diameter portions 35a and 36a, the large diameter inner diameter portions 35b and 36b, the piston seal grooves 35c and 36c, and the piston seal grooves 35d and 36d on the inner peripheral surface of the bores 35 and 36 are processed through the portion 45. Thereafter, the opening 45 is formed by closing and closing the separate lid member 46 by friction stir welding.

  And in this embodiment, the insulator 51 whose heat conductivity is lower than the piston 6 is provided between each opposing brake pad 33 and the piston 6. Specifically, in this embodiment, the piston 6 is made of an aluminum alloy, and the insulator 51 is made of a synthetic resin having a lower thermal conductivity than that of an aluminum alloy.

  The insulator 51 is a single member integrally formed from the above-described synthetic resin material. As shown in FIGS. 4 and 5, the cylindrical inner cylindrical portion 52 and one axial end of the inner cylindrical portion 52 are arranged. An annular flat plate portion 53 that extends in the radial direction, and a cylindrical outer cylindrical portion 54 that extends from the outer diameter side of the flat plate portion 53 in the axial direction to the opposite side of the inner cylindrical portion 52. ing. Therefore, the outer cylindrical portion 54 has a larger diameter than the inner cylindrical portion 52. The outer cylindrical portion 54 and the inner cylindrical portion 52 are arranged concentrically with the center axes aligned.

  As shown in FIG. 5, the inner cylindrical portion 52 of the insulator 51 is fitted into the opening 39 of the cylindrical portion 37 of the piston 6, and the flat plate portion 53 is the opening of the cylindrical portion 37 of the piston 6. It contacts the entire surface of the end surface 37A on the 39 side. In this state, the insulator 51 comes into contact with the brake pad 33 as shown in FIG. 3 at the annular contact surface portion 54 </ b> A opposite to the inner cylindrical portion 52 of the outer cylindrical portion 54.

  Here, the contact surface portion 54 </ b> A on the surface facing the brake pad 33 of the insulator 51 and capable of contacting the brake pad 33 has an inner dimension, that is, an inner diameter, at a portion facing the brake pad 33 of the piston 6. The inner diameter dimension of the end surface 37 </ b> A on the opening 39 side of a certain cylindrical portion 37 is larger, and the outer dimension, that is, the outer diameter dimension, is larger than the outer diameter dimension of the end surface 37 </ b> A on the opening 39 side of the piston 6. Further, the inner diameter dimension of the contact surface portion 54A is equal to the outer diameter dimension of the end surface 37A on the opening 39 side of the piston 6. The contact surface portion 54A of the insulator 51 is in contact with the brake pad 33 over the entire surface. The area of the contact surface portion 54A that can contact the brake pad 33 is the area of the end surface 37A on the opening 39 side of the piston 6. Is smaller than

  According to the present embodiment described above, the contact surface portion 54A of the insulator 51, which is provided between the brake pad 33 and the piston 6 and has a lower thermal conductivity than the piston 6, has an inside dimension of the opening of the piston 6. Since the outside dimension of the end surface 37A on the side of the portion 39 is larger than the outside diameter of the end surface 37A on the opening 39 side of the piston 6, the brake pad 33 is pressed when the brake pad 33 is pressed by the piston 6. A range larger than the end surface 37A on the opening 39 side of the piston 6 33 can be pressed, and the behavior of the brake pad 33 during braking is stabilized. Therefore, occurrence of brake squeal can be suppressed. At the same time, since uneven wear of the brake pad 33 can be suppressed, drag torque can be reduced and lever touch can be improved.

  Further, the contact surface portion 54A of the insulator 51 has a smaller area that can contact the brake pad 33 than the area of the end surface 37A on the opening 39 side of the piston 6, so that the braking heat from the brake pad 33 to the piston 6 is increased. Transmission can be suppressed, vapor lock can be suppressed, and lever feeling can be improved.

  Further, the insulator 51 is fitted into the opening 39 of the piston 6 in the inner cylindrical portion 52, and the entire end surface 37A on the opening 39 side, which is the portion facing the brake pad 33 of the piston 6 in the flat plate portion 53, is applied. Therefore, the contact area between the insulator 51 and the piston 6 can be ensured. Therefore, the stress at the opening 39 side portion of the cylindrical portion 37 of the piston 6 can be reduced, and the buckling of the opening 39 side portion of the cylindrical portion 37 caused by fatigue or the like can be suppressed.

  Further, since the shape of contact of the insulator 51 with the brake pad 33 can be fixed regardless of the outer diameter of the piston 6, the wear pattern of the brake pad 33 can be made constant.

  The insulator 51 can be changed as follows.

  As shown in FIG. 6, a cutout portion 60 that is cut out by including a part of the contact surface portion 54 </ b> A in a portion smaller than half in the circumferential direction of the outer cylindrical portion 54 of the insulator 51, specifically in a range of 90 degrees. The remaining contact surface portion 54A in the range of 270 degrees is brought into contact with the brake pad 33.

  As shown in FIG. 7, the flat plate portion 53 has a polygonal plate shape that spreads radially from one axial end of the inner cylindrical portion 52, specifically, an octagonal plate shape. The cylindrical portion 54 has a polygonal cylindrical shape, specifically, an octagonal cylindrical shape. Then, the inner dimension in the longitudinal direction of the contact surface portion 54A is made larger than the outer diameter dimension of the end surface 37A on the opening 39 side which is a portion facing the brake pad 33 of the piston 6. If comprised in this way, the larger range of the brake pad 33 can be pressed when the brake pad 33 is pressed by the piston 6, and the behavior of the brake pad 33 during braking is further stabilized.

  As shown in FIG. 8, a plurality of specifically, the outer cylindrical portions 54 of the two insulators 51 are connected to each other by two connecting plate portions 65 arranged on the same plane as the flat plate portion 53. A one-part insulator 51 is provided. Also in this case, the notch 60 can be formed in a part smaller than half of the outer cylindrical portions 54 of the two insulators 51, and in this case, the notch 60 can be formed at a mirror-symmetrical position.

  Instead of the inner cylindrical portion 52, an elastically deformable locking claw portion 70 that is locked to the inner peripheral surface of the cylindrical portion 37 of the piston 6 may be provided as shown in FIG. In this case, an annular locking groove 71 for locking the locking claw 70 is preferably formed on the inner peripheral surface of the cylindrical portion 37 of the piston 6.

  Instead of the inner cylindrical portion 52, a solid flat plate portion 75 may be fitted into the opening 39 of the piston 6 as shown in FIG. That is, it is good also as the insulator 51 by which the inner side was obstruct | occluded instead of an annular shape.

1 Disc brake 2 Disc 5 Caliper body 6 Piston 33 Brake pad 37A End face (opposite part with brake pad)
42, 43 Piston seal 51 Insulator 54A Contact surface

Claims (3)

A disc having a cup-shaped piston that presses the brake pad against the disc is slidably mounted on the caliper body via a piston seal, and includes an insulator having a lower thermal conductivity than the piston between the brake pad and the piston. Brake,
An annular or polygonal contact surface portion capable of contacting the brake pad is formed on the surface of the insulator facing the brake pad.
The contact surface portion has an inner dimension larger than an inner diameter dimension of a portion of the piston facing the brake pad, an outer dimension larger than an outer diameter dimension of a portion of the piston facing the brake pad, and the brake pad. The disc brake is characterized in that an area capable of contacting the piston is smaller than an area of a portion of the piston facing the brake pad.   2. The disc brake according to claim 1, wherein the insulator is formed such that the inner dimension is larger than an outer diameter dimension of a portion of the piston facing the brake pad.   3. The disc brake according to claim 1, wherein the insulator is formed to be fitted into an opening of the piston and to be in contact with an entire surface of a portion of the piston facing the brake pad. .

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