JPS61149626A - Caliper piston - Google Patents

Abstract

PURPOSE:To obtain better slidability and heat insulation performance by constituting a main part with ceramic material and covering its outer peripheral face with metal cylinder. CONSTITUTION:A caliper piston 6 is made up by a cylindrical piston body 12 made of ceramic material which is excellent in heat insulating performance such as alumina as a main part. And the piston body 12 is covered with a metal cylinder 13 of better slidability and of relative thinness.

Description

[Detailed Description of the Invention] &jLl, History 1 The present invention is applied to a caliper piston of a disc brake caliper provided in a disc brake device of a vehicle such as a motorcycle or an automobile.

The i-Sue Wataru disc brake device has #+1 on both sides of the brake disc that rotates with the heavy wheels! A braking force is generated by pressing the friction pad, and the pad is supported by a lever and is pressed against the brake disc by a caliper cylinder and a caliper piston provided in the caliper.

In such a disc brake caliper, t? between the brake disc and pad during braking. The heat generated by the tal is transferred to the hydraulic oil in the caliper cylinder via the caliper piston, raising the temperature of the hydraulic oil. Insulation material is placed on the inside.

For example, as shown in FIG. 1, this heat insulating material is fixedly arranged on the surface of the pad back metal on the 4tF ribapiston side. In FIG. 1, reference numeral 01 denotes a pad back metal, which supports a pad 02 made of, for example, a sintered metal.

A heat insulating material 03 made of asbestos material or the like is attached to the surface of the pad metal 01 opposite to the pad 02, and the heat insulating material 03 is connected to the surface of the pad 01 through a stainless steel plate 04 and a washer 06. ) It is fixed to the pad back metal 01 with studs 05.

In addition, for example, Japanese Utility Model Application Publication No. 55-43138P3 also discloses a heat insulating material assembly mechanism for a disc brake in which a heat insulating material is disposed between a pad and a piston.

70 - Conventional devices such as those described above require ms to attach the insulation material to the pad, which increases the number of component parts and increases the cost.

Furthermore, since a heat insulating material is interposed between the pad and the caliper piston, the shape of the 4I7 liper becomes larger accordingly.

Therefore, the present invention aims to eliminate the need for intervening a heat insulating material between the caliper piston and the pad by providing heat insulating properties to the caliper piston itself.

. Therefore, in the present invention, the 4 Yariba piston has a cylindrical piston body made of ceramic, and the outer peripheral surface of the piston body is covered with a relatively thin metal cylinder.

Ceramic materials generally have a low thermal conductivity, so the 4 Yariba piston of the present invention, whose main parts are made of such ceramic materials, has a great heat insulating effect, and the frictional heat generated in the pads is transferred through the caliper piston. This prevents the oil from being transmitted to the hydraulic fluid inside the caliper cylinder.

Therefore, in the disc brake caliper equipped with the caliper piston according to the present invention, there is no need to interpose a heat insulating material between the pad and the caliper piston.

However, when the ceramics constituting the piston is brought into direct sliding contact with the inner surface of a caliper cylinder made of metal such as aluminum alloy, the inner surface of the cylinder is likely to wear out.

Therefore, as mentioned above, in the Luriba piston according to the present invention, the outer circumferential surface of the main body made of ceramics is covered with a relatively thin metal cylinder. The problem is solved, and a caliper piston with good heat insulation properties and good sliding properties on the inner surface of the cylinder can be obtained.

Tributary stream 1 The present invention will be described below with reference to the embodiments shown in FIGS.

FIG. 2 shows a disc brake caliper equipped with a caliper piston 6 according to the present invention! In the side view II, the caliper body 1 is divided into a main body part 2 and an opposing part 3, and both parts 2 and 3 are fixed to each other by tightening bolts 4. Chiralon, the main body part 2 and the opposing part 3 are all tat! It can also be used as a lipobody.

The caliper body 1 is mounted so as to be able to move horizontally in parallel at 113 in the figure, and the brake disc 7 extends within a spiral space formed between the main body portion 2 and the inner portion 3. ing. The brake disc 7 is attached to a middle wheel (not shown) and rotates together with the wheel. , V:t? 4 in the main body part 2 of the lipabody 1
A caliper cylinder 5 is provided, and a caliper piston 6 according to the present invention is fitted into the caliper cylinder 5 so as to be freely movable. Hydraulic pressure is supplied to the caliper cylinder 5 from a brake control device (not shown), and the caliper piston 6 is pushed to the left inside the caliper cylinder 5 by the hydraulic pressure, and the caliper body 1 is moved to the right by this reaction.

The bolt 4 also serves as a pad hanger pin, and two pad back metals 8 and 9, which are disposed opposite to each other on each side of the brake disc 7, are suspended from the bolt 4 so as to be freely movable. There are pads 10. on the surface of these pad backings 8.9 facing the brake disc 7, respectively. A pad 11 is provided, and as mentioned above, when the hydraulic pressure inside the caliper cylinder 5 is applied to the hydraulic pressure inside the caliper cylinder 5, the pad piston 6 is moved to the left and the yariba body 1 is moved to the right. , the pad backings 9 are each pushed toward the brake disc 7 by the opposing portion 3, and the pad 10. The pads 11 sandwich the brake disc 7 from both sides and S
The brake disc 7 is braked by friction. At this time, even if the opposing portion 3 is slightly deformed, the pad 11 always remains parallel to the brake disc 7 and is evenly pressed against the surface of the brake disc 7 to prevent uneven contact. The abutment surface facing the pad back metal 9 is formed into a curved surface convex toward the pad back metal 9 side, so as to be in substantially line contact or line contact with the pad back metal 9.

The caliper piston 6 is mainly composed of a cylindrical screw body 12 made of a ceramic material such as alumina, and the piston body 12 is surrounded by a relatively thin metal cylinder 13. It's a reversal. The metal cylinder 13 is formed by molding a steel plate, for example, and has a 117-point shape extending from the circumferential part 13a to the bottom wall part 13b, and has a mesh 4- cut on the surface. Then, the piston main body 12 is press-fitted into the metal cylinder 13 to form the following structure: 1-Yaripapis 1hen 6.

As shown in the figure, the end face of the key 11 which protrudes from the metal cylinder 13 of the piston body 12 is in contact with the pad back metal 8, and is fitted into the caliper cylinder 5. The bottom wall portion 13b of the metal stand R13 receives the pressure of the hydraulic oil introduced into the caliper cylinder 5, and presses the pad 10 against the brake disc 7 via the pad back metal 8. At this time, frictional heat is generated due to the friction between the pad back metal 8 and the brake disc 7.
The piston body 12 is composed of a lamic material, which has good heat insulating properties due to its inherent properties, so the 12m heat is blocked by the piston body 12, and the caliper cylinder 5
Very little is transmitted to the hydraulic fluid inside.

The piston body 12 has a cylindrical shape, and the caliper piston 6 touches the pad back metal 8 and 18 only in a limited area around the circumference, so the Buddha heat surface is small, and the metal cylinder 13
Since C1 has a thin wall thickness, the amount of heat transferred through this part is also extremely small. Therefore, there is no need to interpose a heat insulating material between the caliper piston 6 and the pad back metal 8 as in the conventional case, and the number of parts can be reduced and the caliper can be made smaller.

Furthermore, the outer peripheral surface of the screw 1-n wooden body 12 is made of metal.
Since the caliper piston 6 comes into sliding contact with the inner surface of the caliper cylinder 5 through the plated surface of the metal cylinder 13, good sliding performance can be obtained.

FIG. 3 shows another embodiment of the invention. This embodiment is different from the caliper screw 1 shown in FIG. 2 in that the piston body 12 is formed into a cylindrical shape with an eave and a bottom portion 12a, but the functions, effects, etc. are the same.

As described above, the caliper piston of the present invention has good heat insulation properties because the outer peripheral surface of the cylindrical piston body made of ceramic is covered with a relatively thin metal cylinder. Therefore, a disc brake caliper equipped with this 4ty liper piston does not require a heat insulating material to be interposed between the caliper piston and the pad, so the number of parts can be reduced and the caliper can be made smaller.

Furthermore, although the caliper cylinder of the present invention is mainly made of ceramics, the F
! lJJ Tetsu is good.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing a conventional pad back plate provided with a heat insulating material, Fig. 2 is a cross-sectional view of a disc brake caliper showing one embodiment of the present invention, and Fig. 3 is a cross-sectional view showing another embodiment of the present invention. FIG. 3 is a cross-sectional view of a caliper piston. 1... Caliper body, 2... Main body part, 3...
Opposed part, 4...Pol 1-95...Caliper cylinder, 6...Caliper screw 1 hen, 7...Play 4.
Disc, 8...pad backing metal, 9...pad backing metal,
10... Pad, 11... Pa-rad, 12... Screw 1 to body, 13... Gold FJJ cylinder. Attorney: Nozomi Ehara (2 persons) Figure 1, Figure 2

Claims (1)

[Claims] A caliper piston is made by covering the outer peripheral surface of a cylindrical piston body made of ceramic with a relatively thin metal cylinder.