JPS6348825Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is designed to be attached to the open end of a bottomed cylindrical piston to reduce the conduction of heat from the pad, and to improve the heat dissipation effect of the piston by allowing air to circulate inside the piston. This invention relates to a heat shield plate for a piston in a disc brake.

The piston in a disc brake is inserted into a cylinder formed in the caliper, and its bottom outer end surface serves as the pressure receiving surface from the pressurized hydraulic oil during braking, and its open end surface serves as the pressure surface that directly contacts the pad back plate. It is formed. Therefore, the inside of the piston, which has a cylindrical shape with a bottom, becomes an air pocket, and since the trapped air is in contact with the high-temperature backing plate of the pad, simply providing a heat shield at the open end of the piston will cause the temperature of the piston to rise. This is not sufficient to prevent temperature rise, and unless this accumulated air is constantly replaced with outside air, a sufficient temperature rise prevention effect cannot be obtained. However, in the conventional example, there is no heat shield plate formed to replace the air trapped inside the piston. This idea provides a heat shield plate for a new disc brake that is configured to provide a heat insulator on the piston opening end surface that is in direct contact with the pad back plate, and to displace the accumulated air inside the bottomed cylindrical piston. The purpose is to

This invention will be explained in detail based on illustrated embodiments.

FIG. 1 is an explanatory cross-sectional view of a conventional disc brake. In the figure, 1 is the caliper, 2 is the cylinder provided in the caliper 1, 3 is the piston inserted into the cylinder 2, 4 is the pad back plate, 5
is the pad, and 6 is the rotor. During braking of the disc brake, pressurized hydraulic oil is introduced into the cylinder 2 to push out the piston 3, and the open end of the piston 3 pushes the pad back plate 4.
Press the pad 4 that is paired with the rotor 6 against the side surface of the rotor 6. On the other hand, the caliper 1 moves due to the reaction of this pressing force, pushes the other pad back plate 7 with its protruding wall part 9, and pushes the pad 8 that is paired with the other pad back plate 7 to the other side of the rotor 6. The rotor 6 is clamped between the pad 5 and the other pad 8 to perform braking. This movement of the piston 3 is performed while elastically deforming the seal 10 that seals the liquid between the outer circumferential surface of the piston 3 and the inner circumferential surface of the cylinder 2. Simultaneously with the release of the brake, the inside of the cylinder 2 is depressurized, and the piston 3 is moved under the seal. It is pulled back by a deformation of 10 to maintain an appropriate distance between the rotor 6, the pad 5, and the other pad 8.

As shown in FIGS. 2 and 3, the heat shield plate 11 according to this invention has a heat shield body 12 formed in a cylindrical shape with a flange, so that the outer end surface 13 has a maximum diameter at the flange side opening edge. At the same time, the outer periphery of the disc-shaped shielding portion 15 is attached to the heat shield body 1.
A sloped part 16 is formed to have the same slope angle as the sloped surface 14 of No. 2 and a certain distance from the sloped surface 14, and a part of the sloped part 16 is further cut into widths. A shielding plate 18 is formed by providing a locking part 17 formed by bending in the opposite direction to the inclined part 16, and is locked to the inner circumferential surface of the heat shield main body 12. Here, a heat insulating body 20 formed in the shape of a thin plate ring is attached to the back surface 19 of the flange of the heat shield body 12, that is, the surface that comes into contact with the opening end surface of the piston 3, or the back surface 19 of the flange is provided with a ring shape. A shallow groove 21 with a bottom is formed and a heat insulator 20 is fitted thereinto. Further, it is preferable that the outer circumferential diameter of the cylindrical part of the heat shield body 12 is formed so as to have a slight interference with the inner circumferential surface of the piston 3, and that a relief part 22 is provided to facilitate insertion. .

Further, as shown in FIGS. 4 and 5, the shielding plate 18 has a plurality of locking portions 17 formed in pairs on the diameter line, and the outer surface of the locking portions 17 is connected to the heat shield body 12.
The inner peripheral surface of the cylindrical part is brought into contact with the inner peripheral surface of the cylindrical part with mutual pressure. In this case, it is preferable that the constant gap formed between the inclined portion 16 and the inclined surface 14 be formed between 1 mm and 4 mm, depending on the size of the piston 3. Further, it is desirable that the angle of inclination of the inclined surface 14 of the heat shield main body 12, that is, the opening diameter of the outer end surface, be formed as large as possible. However, the heat shield plate 11 provided with the shield plate 18 as a lever is inserted into the piston 3 from its cylindrical part and locked, and while the vehicle is running, the air flow flowing in the direction perpendicular to the plane of the paper in FIG. 1 is prevented. The air is introduced from the gap on one side and flows out from the gap on the other side, and at the same time, the band flow air, which has been heated up inside the piston 3 due to the temperature rise immediately after stopping the running, is discharged from the gap in the upper part, and the air is discharged from the gap in the bottom part. It is formed so that external air can be introduced from the gap. Also, during braking, the outer end surface 13 of the flange of the heat shield plate body 12 is removed from the pad back plate 4.
The heat transferred to the piston 3 is transferred directly to the piston 3 by the heat insulator 20.
Formed so that it does not propagate to the opening end surface.

Since this device is constructed as claimed in the utility model registration based on the above-mentioned embodiment, it is possible to prevent the conduction of heat from the pad back plate, which becomes hot during braking, and to prevent the piston from opening when braking is released. A slight drop that occurs between the end face and the padded back plate
It is possible to introduce the airflow flowing in from the gap into the piston from the inner peripheral surface on one side to make the accumulated air flow, and at the same time discharge it from the gap on the other side to enhance the heat dissipation effect of the piston. In addition, even when the temperature rises immediately after stopping running, the accumulated air inside the piston, which has risen in temperature, can be drawn out from the upper space, and external air can be introduced from the bottom space, making it a practical piston shield that is highly effective in preventing temperature rise. It becomes possible to provide hot plates.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of a conventional disc brake, Fig. 2 is a cross-sectional view of a piston provided with a heat shield according to this invention, Fig. 3 is a cross-sectional view of a heat shield with a part removed, and Fig. Figure 4 is a front view of the shielding plate, and Figure 5 is its sectional view taken on the line AA. Explanation of symbols, 3... Piston, 4... Pad back plate, 11... Heat shield plate, 12... Heat shield body, 13
... Outer end surface, 14 ... Inclined surface, 15 ... Shielding part, 16 ... Inclined part, 17 ... Locking part, 18 ...
Shielding plate, 19...Back side of flange, 20...Insulator.

Claims (1)

[Scope of utility model registration request] In a disc brake incorporating a bottomed cylindrical piston, a thin plate is formed into a cylindrical shape with a flange, the cylindrical part is inserted into and locked with the piston 3, and the flange back surface 19 abuts the open end surface of the piston 3. A heat shield main body 12 is provided with a ring-shaped heat insulating body 20 and at the same time has an inclined surface 14 formed on the brim-side opening edge so as to have a maximum diameter at the outer end surface 13, and a disc-shaped shielding portion 15. The outer periphery of the shielding portion 15 is formed into an inclined portion 16 having the same inclination angle as the inclined surface 14 of the heat shield body 12, and a part of the inclined portion 16 is formed into a plurality of diametrically opposed pairs. At the same time, the locking part 17 is inserted into the cylindrical part of the heat shield body 12 so that the inclined part 16 has a certain distance from the slope 14 of the heat shield body 12. A heat shield plate for a piston, characterized in that it has a closing plate 18 that is locked in such a manner.