JP3780570B2 - Disc brake with sliding cylinder - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The invention of this application relates to a disc brake provided with a sliding cylinder used as a vehicle wheel brake.
[0002]
[Prior art]
Today, a disc brake used as a vehicle wheel brake includes a disc rotor that rotates integrally with a vehicle wheel, an inner pad and an outer pad that face the inner and outer surfaces of the disc rotor, respectively, A mounting that is fixed to the non-rotating part of the vehicle on the inside and receives brake torque applied to the inner and outer pads, and supported by the mounting so as to be slidable in the axial direction of the disk rotor. A configuration with a sliding cylinder that presses toward the disk and a cylindrical piston that is slidably fitted in the cylinder bore of the sliding cylinder and that presses the inner pad toward the disk rotor from behind Has been.
[0003]
In the disc brake provided with this sliding cylinder, the pressing force transmission portion between the inner pad and the piston is disposed along a circle centered on the axial center of the piston. The pressure transmission part between the outer pad and the piston is arranged irrespective of the pressure transmission part between the inner pad and the piston. This is largely different from the pressing force transmission part between the piston and the piston.
[0004]
[Problems to be solved by the invention]
However, the above-described disc brake has a problem that the brake torque drop with the passage of time is larger than that of the opposed fixed cylinder type disc brake at the time of braking operation under a constant brake hydraulic pressure.
[0005]
An object of the present invention is to provide a disc brake having a sliding cylinder that solves the above-described problems.
[0006]
[Means for Solving the Problems]
According to the above-described object, a disc brake including the sliding cylinder of the invention of this application includes a disc rotor that rotates integrally with a vehicle wheel, an inner side surface and an outer side surface of the disc rotor, respectively. Opposing inner pads and outer pads, a mounting that is fixed to a non-rotating portion of the vehicle inside the disk rotor and receives brake torque applied to the inner pads and the outer pad, and that slides in the axial direction of the disk rotor. A sliding cylinder that is movably supported and presses the outer pad from behind to the disk rotor, and is slidably fitted in a cylinder bore of the sliding cylinder, and the inner pad is inserted into the disk A cylindrical piston that presses against the rotor, the inner pad In which pushing force transmitting part between the pressing force transmission section and the outer pad and the slide cylinder between said piston is formed in the same arc shape centered on the axial center of the piston.
[0007]
In the disc brake having such a configuration, when the brake is applied, the surface pressure distribution of the outer pad approximates the surface pressure distribution of the inner pad, and the brake torque decreases with the passage of time. Less than brakes.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a disc brake according to the invention of this application will be described with reference to the drawings.
[0009]
1 to 4 show a first embodiment. In FIG. 1, a disc brake 10 is disposed on a disc rotor 11 that rotates integrally with a wheel (not shown), and on the inner side (right side in FIG. 1) and the outer side (left side in FIG. 1). The inner pad 12 and the outer pad 13 are fixed to the non-rotating portion (not shown) of the vehicle inside the disk rotor 11 with bolts, and both pads 12 and 13 are guided so as to be movable along the axis of the disk rotor. A mounting 14 that directly receives the brake torque applied to the motors 12 and 13, and a sliding cylinder that is supported by the mounting 14 so as to be slidable in the axial direction of the disk rotor and presses the outer pad 13 against the outer surface of the disk rotor 11 from behind 15 and the inner pad 1 slidably fitted in the cylinder bore 16 of the sliding cylinder 15. And a cylindrical piston 17 for pressing the inner surface of the disc rotor 11 from behind.
[0010]
The end surface of the piston 17 facing the back surface of the inner pad 12 has a ring shape, and the pressing force transmitting portion 18 between the inner pad 12 and the piston 17 is shown in FIG. It has an arc shape along a circle centered on the axis center 19. In FIG. 2, the piston 17 is indicated by a two-dot chain line, and reference numerals 20 and 21 denote shim plates interposed between the inner pad 12 and the piston 17. As shown in FIG. 3, the sliding cylinder 15 has an arcuate protrusion 22 that protrudes toward the back surface of the outer pad 13 and extends along a circle centered on the axial center 19 of the piston 17. The pressing force transmitting portion 23 between the outer pad 13 and the sliding cylinder 15 is also disposed along a circle centered on the axial center 19 of the piston 17 as shown by hatching in FIG. And has the same shape as the pressing force transmitting portion 18. In FIG. 4, reference numerals 24 and 25 denote shim plates interposed between the inner pad 12 and the piston 17.
[0011]
The arrows shown in FIGS. 2 and 4 indicate the direction of rotation of the disc rotor 11 when the vehicle moves forward.
[0012]
In the disc brake 10 having the configuration described above, the brake fluid pressure is applied to the brake fluid pressure chamber 26 formed by the slide cylinder 15 and the piston 17 so that the slide cylinder 15 and the piston 17 are connected to the outer pad 13 and the brake fluid pressure chamber 26. At the time of a brake action that presses the inner pad 12 against the disc rotor 11, the surface pressure distribution of the inner pad 12 and the surface pressure distribution of the outer pad 13 are caused by the pressing force transmitting portion 18 and the pressing force transmitting portion 23 having the same shape. Approximate. As a result, a decrease in brake torque with the passage of time is less than that of a disc brake having a conventional sliding cylinder.
[0014]
FIG. 5 shows a main part of the second embodiment. In the first embodiment , the protruding portion 22 is formed on the sliding cylinder 15 to form the pressing force transmitting portion 23. However, in this second embodiment, the surface of the sliding cylinder 15 facing the back surface of the outer pad 13 is made flat. The shim plate 27 interposed between the outer pad 13 and the sliding cylinder 15 is formed to have the same outer diameter as the outer diameter of the protruding portion 22 in FIG. 1 (or the outer diameter of the protruding portion 22 in FIG. 2). The pressing force transmission part 23 is formed.
[0015]
【The invention's effect】
In the disc brake provided with the sliding cylinder according to the invention of this application, the surface pressure distribution of the outer pad approximates the surface pressure distribution of the inner pad when the brake is applied, and the brake torque decreases with the passage of time. The effect is less than that of a disc brake having a sliding cylinder.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a first embodiment of the invention of this application.
FIG. 2 is a view showing a shape of a pressing force transmission part between an inner pad and a piston.
FIG. 3 is a view showing a protruding portion of a sliding cylinder.
FIG. 4 is a diagram illustrating a shape of a pressing force transmission portion between an outer pad and a sliding cylinder.
FIG. 5 is a view showing a shape of a pressing force transmission portion between an outer pad and a sliding cylinder according to a second embodiment.

Claims (1)

A disc rotor that rotates integrally with a wheel of the vehicle, an inner pad and an outer pad that face the inner and outer surfaces of the disc rotor, respectively, and is fixed to a non-rotating portion of the vehicle inside the disc rotor, A mounting for receiving a braking torque applied to the inner pad and the outer pad, and a sliding cylinder that is supported by the mounting so as to be slidable in the axial direction of the disk rotor and presses the outer pad toward the disk rotor from behind. A cylindrical piston that is slidably fitted in a cylinder bore of the sliding cylinder and presses the inner pad toward the disk rotor is provided, and a pressing force is transmitted between the inner pad and the piston. And the pressing force transmission part between the outer pad and the sliding cylinder Disc brake having a sliding cylinder, characterized in that the axial center of the piston is formed in the same arc shape as each other as a center.

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