JPS6272459A - Manufacture of brake rotor - Google Patents

Abstract

PURPOSE:To obtain a good brake rotor by preventing a forming failure caused by a sand drop, etc., by providing a core for forming a ventilating hole in a disk after forming, on a gap in a cavity and a ventilating hole forming position. CONSTITUTION:A core 9 is provided on the outside periphery of a cylindrical part 2b of a frame 2, and in the lower side of the core 9, the tip part of a flange part 2c is projecting into a cavity 8. As for the core 9, a ventilating port forming part 9b for forming each ventilating hole 3a is provided radially as one body with an annular gap forming part 9a for forming a gap S along the outside periphery of the cylindrical part 2b which faces the cavity 8. The frame 2 is placed in a prescribed position of a lower die 7, and thereafter, the core 9 is fitted and installed along the outside periphery of the frame 2 and also in a state that it is floating in the capacity 8. An upper die 6 and the lower die 7 are aligned, and thereafter, a molten metal is pressed into the cavity 8, a disk 3 in which a flange part 2c has become a pouring state is cast, and after releasing the mold, the core 9 is removed, and a brake rotor 1 is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Field of Application) The present invention relates to a method for manufacturing a brake rotor used for manufacturing a brake rotor equipped with a ventilated disk.

[Conventional technology]

5 and 6 are diagrams explaining a conventional brake rotor, and this brake rotor 100 includes, for example,
As shown in Japanese Utility Model Application Publication No. 58-82540, a frame has a mounting portion 101a for attaching to a wheel hub, a cylindrical portion 101b for accommodating the wheel hub, and a flange portion 101C projecting outward from the end of the cylindrical portion 101b. 10
1, and a disk 102 having radial ventilation holes 102a that are open in the radial direction. Note that the mounting portion 101a has an axle shaft insertion hole 101d and a hub bolt insertion hole 101e formed therein.

To manufacture the brake rotor 100 described below, a mold 103 shown in FIGS. 7 and 8 is used. Said mold 1
03 is the disc 1 with the second mold 104 and the lower mold 105.
A cavity 106 corresponding to the flange 101C is formed, and the fly 1.101 is sandwiched therein, so that the tip of the flange 101C protrudes into the cavity 106. Moreover, inside the cavity 106,
Cores 107 forming each ventilation hole 102a are provided at respective positions. Then, by injecting the eluate into the cavity 106, the disc 102 is formed with the flange portion 101c cast inside, and the core 107 is later removed to obtain the brake rotor 100.

Here, between the cylindrical portion 101b of the brake rotor 100 manufactured as described above and the inner peripheral surface of the disc 102, there is a
A gap S is formed. In other words, if the outer peripheral surface of the cylindrical portion 101b forms part of the inner wall of the cavity 106 to prevent the gap S from occurring, it is difficult to maintain the positional accuracy between the frame 101 and the cavity 106. Problems such as molten metal leaking from the sides are likely to occur. Therefore, as shown in FIG. 8, by providing a gap forming part 104a in the upper mold 104, the flange part 10
Only the part 1c is cast-encased to prevent M manufacturing defects due to leakage of molten metal to the cylindrical part 101b side. Note that the brake rotor described above uses a frame made of iron plate in order to solve the squeal during braking that tends to occur when the entire brake rotor is made of cast iron.

(Problems to be Solved by the Invention) However, in the conventional manufacturing method as described above, when the mold 103 is formed of green sand, sand is likely to fall especially in the gap forming portion 104a, so that the molding There is a problem that defects may occur, and in addition, there is another problem that the use of individual cores 107 forming each ventilation hole 102a makes the shape of the mold 103 more complicated and requires more effort. was there.

This invention was made with attention to these problems, and it is possible to obtain a good brake rotor by preventing molding defects due to sand drop etc., and to simplify the molding die and improve workability. It is an object of the present invention to provide a method for manufacturing a brake rotor that can achieve the desired results.

[Structure of the Invention] (Means for Solving the Problems) A method for manufacturing a brake rotor according to the present invention includes a mounting part to a wheel hub, a cylindrical part accommodating the wheel hub, and an end part of the cylindrical part to the outer circumferential side. When manufacturing a brake rotor consisting of a frame having an overhanging flange portion and an annular disk having a radially open ventilation hole and having an inner circumferential portion joined along the flange portion, the disk in the mold is A core that forms a gap with the molded disk along the outer periphery of the cylindrical part facing the molding cavity and forms a ventilation hole in the molded disk is placed in the gap in the cavity and at the ventilation hole formation position. At the same time, after arranging the frame with the tip of the flange portion facing into the cavity, an elution is made in the cavity to form a disk in which the flange portion is cast, and then,
The feature is that the brake rotor is obtained by removing the core. Therefore, in this invention, when using the core that forms the gap and the ventilation hole, if the amount of frame protrusion from the disk is the same as the conventional one due to constraints such as the axle size, the length of the cylindrical portion will be reduced as a result. It becomes something big. Further, the core may be one in which a portion forming a gap and a portion forming a ventilation hole are integrated in a radial manner.

(Example) The present invention will be explained below based on the drawings.

1 to 4 are diagrams for explaining one embodiment of the present invention.

That is, FIGS. 1 and 2 show an example of a brake rotor obtained by the manufacturing method of the present invention.
This brake rotor 1 consists of a frame 2 that is attached to a wheel hub (not shown), and a disc 3 that is provided on the outer periphery of the frame 2 and is sandwiched between a caliper (not shown). The frame 2 has an attachment part 2a for attaching to the wheel hub, a cylindrical part 2b for accommodating the wheel hub, and a flange part 2C extending outward from the end of the cylindrical part 2b. 2a has an axle insertion hole 2d and a plurality of hub bolt insertion holes 2e formed therein. The disc 3 is generally called a ventilation type, and has a large number of radial ventilation holes 3a that open between the inner peripheral surface and the outer peripheral surface, that is, in the radial direction.The brake rotor 1 shown in FIG. The flange portion 2C of 2 is fixed to the disk 3 above the ventilation hole 3a.

In addition, FIGS. 3 and 4 show the above-mentioned disc rotor 1.
FIG. 5 is a diagram illustrating a mold for manufacturing the mold 5.
The upper mold 6 and the lower mold 7 form an annular cavity 8 corresponding to the disk 3, and a mounting portion 2a is provided at the center of the mold.
The frame 2 is sandwiched with the frame 2 facing upward. Further, a core 9 is disposed on the outer periphery of the cylindrical portion 2b of the frame 2, and a flange portion 2 is provided below the core 9.
The tip portion of C projects into the cavity 8. The core 9 has ventilation openings 3a formed in an annular gap forming portion 9a forming a gap S (see FIGS. 1 and 2) along the outer periphery of the cylindrical portion 2b facing the cavity 8. In this embodiment, after placing the frame 2 at a predetermined position on the lower mold 7, the core 9 is placed along the outer periphery of the frame 2. It is fitted into the cavity 8 in a floating state.

After the upper mold 6 and the lower mold 7 are matched, molten metal is poured into the cavity 8 to form the flange portion 2C.
A brake rotor 1 is obtained by casting a disc 3 in a cast-in state, and removing a core 9 after releasing the mold.

The brake rotor 1 manufactured in this way has the same length of frame from the disc 3 as the conventional brake rotor (see Figs. 5 and 6) due to the axle dimensions, etc. ) The length of the cylindrical portion 2b is longer than that of the cylindrical portion 2b, and the opening on the inner circumferential side of the disk of the ventilation port 3a faces the outer circumferential surface of the cylindrical portion 2b. therefore,
The brake rotor 1 obtained by the manufacturing method is as follows.

The deformability of the cylindrical portion 2b is increased, and the vibration absorption performance during braking is improved. Furthermore, the heat dissipation area of the frame 2 is increased, and ventilation is also good, so cooling efficiency can be significantly improved. It has the advantage of Moreover, the cylindrical part 2b
A core 9 forms a gap S between the opposing portions of the disk 3 and the disk 3.
By using a core, the inner shape of the mold 3 can be made simple without the risk of sand falling out, and moreover, the mold 3 can have a simple internal shape without the risk of sand falling, and moreover, it is possible to make the inner shape of the mold 3 a simple one without worrying about the occurrence of sand drop. Therefore, the workability during installation is also good. In addition,
The shape of the 1 m portion of the gap forming portion 9a of the core 9 may be changed as appropriate depending on the mold side, such as providing a weir.

[Effects of the Invention] As described above, according to the method for manufacturing a brake rotor of the present invention, the attachment part to the wheel hub, the cylindrical part that accommodates the wheel hub, and the tension from the end of the cylindrical part to the outer circumferential side. When manufacturing a brake rotor consisting of a frame having a flange portion and an annular disk having a radially opened ventilation hole and having an inner circumferential portion joined along the flange portion, the disk is formed in a mold. A core that forms a gap with the molded disk along the outer periphery of the cylindrical portion facing the cavity and forms a ventilation hole in the molded disk is placed in the gap and at the ventilation hole formation position in the cavity. At the same time, the frame is placed with the tip of the flange portion facing into the cavity, and then molten metal is cast into the cavity to form a disk containing the flange portion, and then the core is removed. Since the brake rotor was made to be 111 by
Forming the part1. Because of this, it is possible to make the mold into a simple shape without sand drop etc., and it is possible to obtain a good brake rotor without molding defects, and it is possible to arrange the frame and core. This has the effect of improving workability during the process.

[Brief explanation of drawings]

Fig. 1 is a front view illustrating a brake rotor obtained by the manufacturing method of the present invention, Fig. 2 is a sectional view taken along line A-A of the brake rotor shown in Fig. 1, and Fig. 0'S3 shows a frame and core. 4 is an enlarged sectional view of the vicinity of the flange in FIG. 3; FIG. 5 is a front view of a conventional brake rotor; and FIG. 6 is a diagram showing the fifth factor. A cross-sectional view taken along the line B-B of the brake rotor, and Figure i7 is a cross-sectional view illustrating a mold for manufacturing a conventional brake rotor.
FIG. 8 is an enlarged sectional view of the vicinity of the flange in FIG. 7. 1... Brake rotor, 2... Frame, 2a...
・Mounting part, 2b...Cylindrical part, 2c...Flange part,
3... Disc, 3a... Ventilation port, 5... Molding die, 8... Cavity, 9... Core, S... Gap.

Claims (1)

[Claims] (1) A frame having an attachment part to a wheel hub, a cylindrical part that accommodates the wheel hub, and a flange part extending outward from an end of the cylindrical part, and having a ventilation hole opening in the radial direction, and When manufacturing a brake rotor consisting of an annular disk whose inner circumferential portion is joined along the outer periphery of the cylindrical portion facing the disk molding cavity in the mold, a gap is created between the molded disk and the outer periphery of the cylindrical portion facing the disk molding cavity in the mold. A core for forming a ventilation hole in the disk after molding is placed in the gap in the cavity and at a position where the ventilation hole is formed, and the frame is placed with the tip of the flange portion facing into the cavity. A method for manufacturing a brake rotor, comprising: subsequently casting molten metal into the cavity to form a disc with the flange portion cast in, and then removing a core to obtain a brake rotor.