JPS6340664Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a brake disc for a disc brake device for a vehicle.

Conventionally, general brake discs have been made of cast iron, but while cast iron has excellent mechanical properties, its surface is easily oxidized, resulting in the problem of rust forming on the sliding surface with the brake pads.

The present invention was proposed in view of the above, and is a brake disc that has a simple structure and can effectively form a rust-preventing film over a long period of time on the sliding surface of the brake disc and the brake pad. The object of the present invention is to provide a brake disc having a sliding part on which a pair of brake pads can slide on both sides, the sliding part having a plurality of openings at both ends on both sides of the sliding part. A pair of locking hole portions having a diameter larger than the inner diameter of the hole are formed at both ends of each through hole, and the metal is harder than the metal constituting the sliding portion. A columnar metal body having a low ionization rate and a large ionization tendency is fitted into each of the through holes, and both ends of the metal body are exposed on both sides of the sliding part, and the pair of metal bodies are attached to the outer periphery of both ends of the metal body. A pair of annular locking protrusions that respectively engage with the locking holes are integrally formed.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. Reference numeral 1 denotes a cast iron brake disc of a disc brake device, which includes a boss part 2 located on the inside and attached to the wheel hub, and an annular sliding part located on the outside. 3 and more. A pair of brake pads 4, which are held by brake calipers (not shown), are disposed facing each other on both side surfaces 3a, 3a of the sliding portion 3, respectively.

In the sliding portion 3, metal bodies 5, which have a lower hardness than the base metal of cast iron and have a greater tendency to ionize, are dispersed and buried. This kind of metal body 5 corresponds to bad lead, aluminum, etc.

As for this metal body embedding method, first, in the sliding part 3,
A plurality of through holes 6 which pass through the sliding portion 3 and open at both ends on both side surfaces 3a, 3a are drilled in a distributed manner, and the edges of both openings of the through holes 6 are chamfered. Large-diameter locking holes 6a are formed at both ends, and then a columnar metal body 5 processed into a rivet shape is fitted into each through-hole 6, and then the metal bodies 5 are pressed from both ends with a dedicated crimping machine. and press it onto the sliding part 3. By this crimping, annular locking protrusions 5a that engage with the respective locking holes 6a are integrally formed on the outer periphery of both ends of the metal body 5, and both end surfaces of each metal body 5 are formed on both side surfaces 3a of the sliding portion 3. , 3a, that is, exposed on the sliding surface with the brake pad 4.

When embedding the metal bodies 5 in the sliding part 3, each metal body 5 is buried in the sliding part 3 as shown in FIG.
are arranged at equal intervals in the circumferential direction (for example, central angle θ = 40° of the brake disk), and as the brake disk 1 rotates, the entire sliding surface 4a of the brake pad 4 is rubbed by the end surface of the all-metal body 5. The metal bodies 5 are arranged on a plurality of concentric circles, respectively.

When a disc brake device is assembled using the brake disc 1 having the above configuration and a test run of a vehicle is performed,
During braking, the metal body 5, which has a lower hardness than the base material of cast iron, is ground by sliding friction with the brake pad 4, and the ground metal powder is transferred to the brake pad 4 on both sides 3a of the sliding part of the brake disc 1. , 3a, and the metal powder forms a rust-preventing film.

If this anti-rust film is observed microscopically focusing on the metal powder, it will form a local battery in the presence of an electrolyte solution; When observed from a macroscopic perspective with a focus on this, in the presence of an electrolyte solution it forms a sacrificial electrode, which is the anode of a galvanic cell, and can serve as a protective film on the surface of the base material, which is the cathode. This is clear from FIG. 4, and B and C are metal bodies 5 in which zinc and aluminum are used.
It has been confirmed that the rust occurrence rate is extremely low compared to the product A that does not use the product, and that this rust prevention effect is maintained over a long period of time.

The metal body 5 may be made of zinc, aluminum or an alloy thereof, or may be a base body with zinc or the like bonded to both ends thereof.

As described above, according to the present invention, in a brake disk having a sliding part on which a pair of brake pads can slide on both sides, the sliding part has a plurality of parts each having openings at both ends on both sides of the sliding part. The through-holes are dispersedly drilled, and a pair of locking hole portions having a diameter larger than the inner diameter of the hole are formed at both ends of each through-hole, and the metal is harder than the metal constituting the sliding portion. A columnar metal body having a low ionization tendency and a large ionization tendency is fitted into each of the through holes, and both ends of the metal body are exposed on both sides of the sliding part, and the pair of engagement members are attached to the outer periphery of both ends of the metal body. Since a pair of annular locking protrusions that respectively engage with the stopper holes are integrally formed, the brake pads slide into both sides of the sliding portion of the brake disc in the braking portion, and at the same time, both end surfaces of the metal body are brought into contact with the pads. The ground metal powder can form a strong anti-rust film on both sides of the brake disc, which effectively prevents rust from forming on both sides of the sliding part even if the brake disc is made of cast iron. Can be prevented.

In particular, since the metal body is fitted into through-holes that are dispersedly drilled in the relatively wide sliding part of the brake disc, even if a large number of through-holes are formed, the sliding part itself is There is no risk of a significant decrease in strength, and since both ends of the metal body are simultaneously compressed by both brake pads during braking, and only one end is not subjected to a sliding action, the locking protrusions and locking holes are Coupled with the retaining effect caused by the engagement, this is extremely effective in preventing the metal body from falling out of the through hole. Furthermore, since it is possible to use a thick metal body with the same thickness as the sliding part of the brake disc, there is no risk that the metal body will disappear prematurely due to wear on both sides of the disc sliding part. The ground metal powder can be continuously generated from the exposed surface of the metal body over a long period of time, and the rust-preventing effect of the ground metal powder on both sides of the disk sliding portion can be maintained for a long period of time.

[Brief explanation of the drawing]

1 to 3 show an embodiment of the present invention, in which Fig. 1 is a front view with the main part broken away, Fig. 2 is a side view, Fig. 3 is a partially enlarged view, and Fig. 4 is a graph comparing the rust occurrence rate of the brake disc of the present invention with that of a conventional one. 1 ... brake disc, 3 ... sliding part, 3a
...side surface, 4...brake pad, 5...metal body, 5a...engagement projection, 6...through hole, 6a...
Locking hole portion.

Claims (1)

[Scope of utility model registration request] In a brake disc having a sliding part 3 in which a pair of brake pads 4 can slide on both side surfaces 3a, 3a, the sliding part 3 has a plurality of parts whose ends are open on both sides 3a, 3a of the sliding part 3. Through-holes 6 are drilled in a distributed manner, and a pair of locking hole portions 6a having a diameter larger than the inner diameter of the hole 6 are formed at both ends of each through-hole 6 to form the sliding portion 3. A columnar metal body 5 having lower hardness and greater ionization tendency than metal is fitted into each of the through holes 6, and the metal body 5 is
Both ends of the metal body 5 are exposed on both side surfaces 3a, 3a of the sliding portion 3, and a pair of annular locking protrusions 5a are provided on the outer periphery of both ends of the metal body 5 to engage with the pair of locking holes 6a, respectively. Formed in one piece,
brake disc.