JP2015140921A - Brake caliper and brake device with brake caliper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brake caliper capable of improving a water discharging characteristic of a piston and provide a brake device including the brake caliper.SOLUTION: This invention relates to a disc brake comprising a disc rotor 2 assembled to a rotor and integrally rotated with the rotor; a caliper striding over a partial outer circumference of the disc rotor 2; a pair of brake pads 6 including a frictional member and a rear plate 9 bonded and fixed to the frictional member, and arranged to enable the disc rotor 2 to be held; pistons 4, 5 assembled to the caliper and pressing the brake pad 6 toward the disc rotor 2; and shim plates 10. The abutted surfaces in the pistons 4, 5 with the shim plates 10 are formed with recesses acting as a communication passage between the inside and outside of each of the pistons under the abutted state among the pistons 4, 5 and the shim plates 10.

Description

  The present invention relates to a brake caliper for a vehicle and a brake device including the same.

  As a brake device used in a vehicle, there is known a disc brake device that has a caliper that supports a brake pad across the outer peripheral side of a disc rotor and applies a braking force to the vehicle, as shown in Patent Document 1. This disc brake has a brake pad including a friction material, a back plate bonded and fixed to the friction material, and a shim plate slidably disposed on the back plate. At the time of braking, the piston presses the shim plate so that the disc rotor is held between the brake pads and the rotation of the disc rotor is restricted.

In the above configuration, for example, when the vehicle travels, moisture that has entered the inside of the piston (recessed portion) can accumulate without being drained outside the piston. The water accumulated inside the piston becomes a factor that forms rust between the shim plate and the piston, and there is a concern that they stick to each other. Due to this fixing, the piston and the brake pad are integrated, and the mass of the brake pad is increased as compared with the case where the piston and the brake pad are not fixed. This causes a frictional force to increase on the sliding surface between the brake pad and the caliper, and restricts the brake pad from being separated from the disk rotor in the axial direction when braking is released. As a result, separation of the brake pad from the disc rotor is hindered, and there is a concern that the brake pad may be dragged during non-braking, causing an abnormal noise.
On the other hand, in the disc brake in Patent Document 1, the shim plate has a notch formed on the contact surface between the shim plate and the piston. As a result, in the state where the piston and the shim plate are in contact with each other, moisture accumulated inside the piston can be drained to the outside of the piston by the notch that communicates the inside and outside of the piston. Occurrence is prevented.

Shoko 54-30556

  However, in the brake device of Patent Document 1, the passage width (axial width) of the notch portion in the shim plate is limited to be equal to or less than the thickness of the shim plate. difficult. In addition, a film is formed by the surface tension of moisture, and the notch, which is a communication path through which moisture passes between the inside and outside of the piston, is sealed. There is concern about the occurrence of abnormal noise.

  In view of the above problems, an object of the present invention is to provide a brake caliper that can improve the drainage performance of the piston and a brake device including the brake caliper.

  In order to solve the above-mentioned problem, the invention according to claim 1 includes a disk rotor that is assembled to a rotating body and rotates integrally with the rotating body, a caliper that straddles a part of the outer periphery of the disk rotor, and friction. A pair of brake pads arranged to be able to sandwich the disc rotor, a piston that is assembled to the caliper and presses the brake pad toward the disc rotor, In a disc brake having a shim plate interposed between the plate and the piston, the abutting surface of the piston with the shim plate is in contact with the inside and outside of the piston when the piston and the shim plate are in contact with each other. A notch portion is formed as the communication path.

  According to the first aspect of the present invention, for example, when a notch portion is formed in the shim plate, only the notch portion smaller than the thickness of the shim plate can be formed. In contrast, in the present invention, by forming the notch in the piston, the passage width of the notch can be ensured to be larger. As a result, compared with the case where the notch is formed in the shim plate, the passage width of the notch that communicates the inside of the piston with the outside can be secured in a contact state between the piston and the shim plate. The water collected in the piston can be efficiently drained outside the piston. Therefore, the drainage of the piston can be improved, the piston and the shim plate can be prevented from sticking due to the moisture in the piston, and the above-mentioned abnormal noise can be suppressed.

  By the way, at the time of braking, the piston presses the shim plate and the friction material comes into contact with the disk rotor, so that the brake pad is rotated in the rotational direction of the disk rotor. The accompanying rotation of the brake pad rotates the piston in contact with the brake pad around the axis.

  In that respect, in the invention of claim 2, the caliper has a piston that can rotate about its axis, and at least one of the back plate and the shim plate protrudes from a facing surface facing the notch portion of the piston, A latching portion that is inserted into the notch portion toward the far end and restricts the rotation of the piston is formed.

  According to the present invention, when rotation about the axis of the piston occurs, the latching portion that protrudes from the back plate side and is inserted into the notch portion of the piston toward the inner end of the piston contacts the inner peripheral side surface of the notch portion. Contact and regulate the rotation around the piston axis. For this reason, it can prevent that the notch part of a piston rotates from arbitrary positions (initial position). Therefore, the notch can be held at an arbitrary position (initial position) as compared with the case where the latching part is not formed. Therefore, in order to drain the water accumulated in the piston, the notch is cut at a more effective position. The part can be located. Thereby, generation | occurrence | production of the above-mentioned unusual sound can further be suppressed.

  The invention according to claim 3 is characterized in that the notch portion in the piston is formed such that a passage diameter of the notch portion is larger than a passage length.

  According to the present invention, the passage diameter of the notch can be secured sufficiently to drain water, so that, for example, when water enters the piston due to running of the vehicle, the piston and shim plate In the state where the contact is made, it is possible to prevent the notch portion, which is a communication path between the inside and outside of the piston, from being sealed by the surface tension of moisture. As a result, it is possible to prevent the piston and the shim plate from adhering to each other due to moisture accumulated inside the piston, and thus it is possible to further suppress the occurrence of the above-described abnormal noise.

The perspective view of the brake device in 1st Embodiment which concerns on this invention (A) Sectional view similarly seen from the axial direction of the brake device (b) Diagram showing only the piston seen from the axial direction Side view of the inner brake pad in the same brake system Front view of shim plate in the second embodiment according to the present invention Also side of shim board

  Hereinafter, the present invention will be described in detail by way of embodiments, but the present invention is not limited by the following embodiments unless it exceeds the gist of the present invention.

  Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings. 1 to 3 show a first embodiment of the opposed disc brake of the present invention. The opposed disk brake 1 of this embodiment includes a disk rotor 2 (see a broken line in FIG. 2) that is assembled to an axle hub (not shown) and rotates integrally with a wheel (not shown), and the disk. A total of four pistons (a figure corresponding to the inside of the piston of the present invention) having two calipers 3 arranged on one side of the caliper 3 arranged so as to straddle a part of the outer peripheral portion of the rotor 2 (see FIG. 2 and 4), a vehicle body side inner brake pad 6 assembled to the caliper 3, and an outer side brake pad 7 on the opposite side of the disc rotor 2 therebetween. Further, a pair of pad support pins 8 assembled to the caliper 3 and the brake pads 6 and 7 are provided.

  The inner brake pad 6 includes a back plate 9, a shim plate 10 interposed between the back plate and the pistons 4 and 5, and a friction material 11 bonded and fixed to the back plate 9. The outer brake pad 7 is formed in the same shape. For this reason, the structure of the inner side brake pad 6 is explained in full detail below, and description of the structure similar to the outer side brake pad 7 is abbreviate | omitted. Moreover, the same code | symbol is used about the same structure.

The disc rotor 2 has an annular brake surface that can be clamped by the friction material 11 of the inner brake pad 6 and the outer brake pad 7. The pistons 4 and 5 on the inner side and the outer side are assembled to each cylinder (not shown) so as to be fluid-tight and slidable in the rotor axial direction. The inner and outer pistons 4 and 5 are pushed by the hydraulic oil supplied from the brake master cylinder to the oil chamber formed between the cylinders when the disk rotor 2 is braked, The side brake pad 6 and the outer brake pad 7 can be pressed toward the disc rotor 2 in the rotor axial direction.
As a result, in a state where the disc rotor 2 is rotating (when the vehicle is running), during braking, the pistons 4 and 5 press the inner brake pad 6 and the outer brake pad 7 toward the disc rotor 2, and the inner The side brake pad 6 and the outer side brake pad 7 sandwich the disc rotor 2. At this time, a pressing force is applied to the shim plate 10 by the pistons 4 and 5 to apply a braking torque corresponding to a frictional force generated between the friction material 11 and the rotating disk rotor 2, thereby restricting the rotation.

  Further, at the time of braking described above, the friction material 11 comes into contact with the disk rotor 2, thereby causing the inner brake pad 6 to move in the rotational direction of the disk rotor 2. The accompanying rotation of the brake pad 6 causes the rotation of the pistons 4 and 5 that press the inner brake pad 9 and the outer brake pad 7 through the shim plate 10 around the axis.

The caliper 3 includes an inner housing portion 12 and an outer housing portion 13 that face each other so as to straddle a part of the outer periphery of the disk rotor 2, and a pair of end bridge portions 14 that connect these at the rotor circumferential end. , 15 and a single intermediate bridge portion 16 connected at the center in the circumferential direction of the rotor.

Further, in this embodiment, the notches 17 are formed on the end surfaces of the pistons 4 and 5 that contact the shim plate 10. The notch 17 is formed on an imaginary line 22 that is parallel to the vertical direction 23 and passes through the centers of the pistons 4 and 5. Furthermore, the notch 17 is located below the center of the piston (on the left side of the page). Further, a latching portion 19 projects from the piston contact surface 18 of the shim plate 10 facing the notch portion 17. The latching portion 19 is inserted into the cutout portion 17 through the hole (not shown) of the shim plate 10 toward the back end.
In FIG. 2, the imaginary line 22 passing through the centers of the pistons 4 and 5 shows a case where the imaginary line 22 is parallel to the vertical direction 23, but the imaginary line 22 is not perpendicular and parallel to the vertical direction 23 (for example, It is also included that is attached to the vehicle at an angle.

  With the above configuration, for example, when moisture enters the pistons 4 and 5, even when braking, the inner side brake pad 6 and the outer side brake pad 7 and the pistons 4 and 5 are in contact with each other. The notch part 17 formed in the end surface of the pistons 4 and 5 can hold | maintain the state which connected the piston inside and the exterior. Thereby, the notch part 17 becomes a communicating path through the inside and outside of the piston, and can be drained to the outside of the piston. Therefore, generation | occurrence | production of the noise by the above-mentioned piston 4 and the shim board 10 adhering can be suppressed.

  Moreover, since the latching | locking part 19 inserted toward the back end is formed in the notch part 17 of the pistons 4 and 5 from the backplate 9, even if rotation around the axis | shaft of the pistons 4 and 5 mentioned above arises, When the latching portion 19 abuts against the inner peripheral side surface of the notch portion 17, the rotation of the pistons 4 and 5 is restricted. Therefore, the notch 17 can be held at an arbitrary position. Thereby, for example, it can be avoided that the pistons 4 and 5 rotate around the axis and the notch 17 is positioned above the center of the piston, so that it is possible to prevent the drainage of the pistons 4 and 5 from being deteriorated. .

  Next, a second embodiment of the present invention will be described with reference to FIGS. The description of the same configuration as that of the first embodiment is omitted. In the present embodiment, unlike the first embodiment, as shown in FIG. 4, a part of the shim plate 10 is cut and raised to form a latching portion 19. This latching part 19 is inserted into the notch part of piston 4,5 toward the back end. Further, the concave portion 20 formed by forming the latching portion 19 communicates the inside and outside of the piston in a state where the shim plate 10 and the pistons 4 and 5 are in contact with each other.

  According to the above configuration, in the state where the shim plate 10 and the piston 4 are in contact with each other, in addition to the notch 17 of the pistons 4 and 5 that communicates the inside and outside of the piston as compared with the first embodiment, The passage width (axial width) of the recess 20 in the shim plate 10 can also be secured as a communication passage. As a result, the amount of drainage from the inside of the piston to the outside can be increased, and further, the sealing of the notch 17 with the film generated by the surface tension of moisture can be suppressed, so that the piston 4 can be compared with the first embodiment. , 5 can be further improved, and abnormal noise due to the fixing of the shim plate 10 and the pistons 4, 5 can be prevented.

Of the above-described configurations, the point that the center line of the passage length of the notch portion 17 and the imaginary line 22 shown in the first embodiment are formed substantially coaxially is not an essential configuration. Furthermore, although the embodiment with one notch has been shown, a plurality of notches may be formed.
Moreover, the recessed part 20 which arises by forming the latching | locking part 19 of the shim board 10 among the structures mentioned above does not need to fulfill | perform a function as a communicating path which connects the pistons 4 and 5 inside and the exterior. For example, the length in the radial direction of the recess 20 may be shorter than the passage length of the notch 17.

  In the first and second embodiments described above, the embodiment of the opposed disc brake has been described. However, for example, the same applies to a so-called floating disc brake disclosed in Japanese Patent Application Laid-Open No. 2012-067888. It is possible.

DESCRIPTION OF SYMBOLS 1 ... Opposite type disc brake 2 ... Disc rotor 3 ... Caliper 4 ... Piston 5 ... Piston 6 ... Inner side brake pad 7 ... Outer side brake pad 8 ... Pad Support pin 9 ... back plate 10 ... shim plate 11 ... friction material 12 ... inner housing 13 ... outer housing 14 ... end bridge 15 ... end bridge 16 ... Intermediate bridge 17 ... Notch 18 ... Piston contact surface 19 ... Hook 20 ... Recess 21 ... Vertical direction 22 ... Virtual line 23 ... Vertical direction

Claims (3)

A disc rotor that is assembled to the rotating body and rotates integrally with the rotating body;
A caliper straddling the outer periphery of a part of the disk rotor;
A pair of brake pads, which are composed of a friction material and a back plate bonded and fixed to the friction material, and are arranged so as to sandwich the disk rotor;
A piston that is assembled to the caliper and presses the brake pad toward the disc rotor;
A shim plate interposed between the back plate and the piston;
In a disc brake having
A disc brake characterized in that a notch portion is formed in a contact surface of the piston with the shim plate as a communication path between the piston inside and the outside when the piston and the shim plate are in contact with each other. .   The piston is rotatable about an axis, and protrudes from at least one of the back plate and the shim plate from an opposing surface facing the notch portion of the piston and is inserted into the notch portion toward the inner end thereof. The disc brake according to claim 1, wherein a latching portion for restricting rotation of the piston is formed. The disc brake according to claim 1 or 2, wherein the notch portion in the piston is formed such that a passage diameter of the communication passage of the notch portion is larger than a passage length.