JPH0292447A - Method for casting multiple pot caliper for disk brake - Google Patents

Abstract

PURPOSE:To improve pressure proof strength of a pipe, to prevent the development of blow hole and to obtain multiple pot caliper having high quality by embedding strengthening pipe packing shell molding sand core into inner part of the pipe to form a communicating hole. CONSTITUTION:After packing the shell molding sand into the inner part of the pipe 1, this is heated and solidified to form the strengthening pipe 3. The foot parts 3a, 3b in the strengthening pipe 3 is inserted into holes 4a, 5a formed at upper part of the cores 4, 5 for forming a cylinder hole and the flat part 3c thereof is fitted into groove parts 4b, 5b and bridged between the cores 4, 5. Successively, by shifting a movable die 6 having the cores 4, 5, this is joined with a fixed die 7 to form a cavity 8, and filling the cavity with molten metal at high presence low speed and after solidifying, the movable die 6 is retreated to separate the caliper 9. The shell molding sand core 2 is removed and projecting parts of the strengthening pipe 3 into the cylinder holes 10, 11 are cut and the inner part of the remaining pipe 1 is made to the communicating hole 13.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a disk in which a plurality of cylinder holes are arranged in parallel, and a partition wall between adjacent cylinder holes has a communication hole that communicates the adjacent cylinder holes. The present invention relates to a method for casting a multi-bottom caliper for brakes.

[Conventional technology]

A plurality of cylinder hole pistons arranged in parallel in the caliper are inserted into the cylinder hole, and working pressure fluid is supplied into the cylinder hole to press the caliper and the piston in opposite directions, and friction pads are attached to the ends of both. In a multi-bot caliper for a disc brake that performs a braking action by pressing the caliper against both sides of a disc rotor that rotates together with the wheel, it is desirable that adjacent cylinder holes communicate with each other to allow hydraulic fluid to flow between them. Therefore, a communicating hole is provided in the partition wall between adjacent cylinder holes, and the method of forming this communicating hole is to embed a metal pipe at the position where the communicating hole is formed during casting and to make the inside thereof a communicating hole. , a method using a shell-type sand core, or a method of forming a communicating hole by drilling a through hole passing through the partition wall from the side wall of the caliper after casting, etc. are known. - Also, cast products such as disc brake calipers are required to be of high quality, and by pouring molten metal into the cavity at low speed, it prevents the occurrence of gas entrainment cavities during filling and shrinkage cavities due to solidification and shrinkage. For example, molding by a high-pressure, low-speed filling casting method called squeeze casting is desired.

[Problem to be solved by the invention]

However, it has been difficult to mold a multi-bot caliper having communicating holes in the partition wall between adjacent cylinder holes using a high-pressure, low-speed filling casting method. In other words, if a metal pipe made of aluminum alloy or the like, which is the same quality as the cast metal, is embedded, it will be crushed by the high-pressure molten metal, but if a steel pipe with high pressure resistance is used, pieces of the cutting tool will be broken during the cutting process after casting. It is undesirable that foreign materials and chips may be mixed in, and if a shell-type sand core is disposed and cast, the core may be damaged or crumbled due to impact during pouring of high-pressure molten metal. Furthermore, if the communicating holes are formed after casting, additional processing equipment is required, and the openings formed in the side walls must be closed.

The present invention was made to solve these problems, and it makes it possible to mold a multi-bot caliper with communicating holes using a high-pressure, low-speed filling casting method, thereby producing a high-quality multi-bot caliper for disc brakes. An object of the present invention is to provide a method for casting a multi-bottom caliper for a disc brake, which can be manufactured quickly and easily.

[Means to solve the problem]

In order to achieve the above-mentioned object, the present invention is a casting multi-bot caliper for a disc brake in which a plurality of cylinder holes are arranged in parallel, and a partition wall between adjacent cylinder holes has a communication hole that communicates the adjacent cylinder holes. In the method,
A reinforced pipe filled with a shell-shaped sand core inside the pipe is placed in the cavity at the position where the communication hole is formed, and then the cavity is filled with molten metal under high pressure and solidified, and then the caliper is released and then heat treated. This method is characterized in that a shell-shaped sand core inside the reinforcing pipe is removed to form a communicating hole.

[For production]

The shell-shaped sand core filled inside the pipe prevents the metal pipe from being crushed by high-pressure molten metal, and the shell-shaped sand core is covered with a metal pipe to prevent the core from being damaged or collapsing due to the impact when pouring the molten metal. To prevent.

〔Example〕

Next, the present invention will be explained based on embodiments shown in the drawings.

In this embodiment, the present invention is carried out using a vertical casting method to manufacture a two-bottom caliper.

First, as shown in Fig. 1, a pipe 1 made of aluminum alloy, which is the same material as the caliper, or copper, steel, etc., which is different from the caliper, is formed into a gate shape as a whole. A reinforcing vibe 3 is formed by densely filling the shell-shaped sand core 2 by filling the shell-shaped sand made by mixing fine powder of a connecting resin such as the like and heating and solidifying it at 300 to 350°C.

Next, as shown in Fig. 2, the legs 3a and 3b of the reinforcing vibrator 3 are inserted into the holes 4a and 5a formed in the upper part of the cylinder hole forming core 4. Grooves 4b and 5b' are formed so that the portion 3C is continuous with the holes 4a and 5a and have a depth that is approximately half the diameter of the reinforcing vibe 3.
Fit the core and install it between 4° and 5. At this time, since the reinforcing vibe 3 has a structure in which the shell core 2 is wrapped in the metal pipe 1, unlike the case where the shell type sand core itself is used as a casting, when installing it, it is necessary to tap it lightly with a wooden hammer before fitting. Since it can be inserted and installed, it can be brought into close contact with the core 4.5 without any gaps, so there is no fear of paris entering.

After installing the reinforcing vibrator 3 in this way, the movable mold 6 having a core 4°5 is moved and joined to the fixed mold 7 to form a cavity 8, and an aluminum alloy or the like is poured into the cavity 8 by squeeze casting. The mold is filled with molten metal at high pressure and low speed, and when it solidifies, the movable mold 6 is moved back to divide the mold, and the caliper 9 is released from the mold.

The reinforcing vibe 3 is attached to the leg portion 3 of the caliper 9 that has been released from the mold.
a, 3b protrude into the cylinder hole 10.11, and the horizontal part 3c penetrates the partition wall 12 between the cylinder holes 10.11. Since the child 2 collapses, it is removed, and then the portion of the reinforcing pipe 3 protruding into the cylinder hole 10.11 is cut along the cylinder hole 10.11.
The inside of the remaining pipe 1 is defined as a communication hole 13.

Note that vibration by bi-pressure may be used to remove the shell-shaped sand core 2, and cutting of the reinforcing pipe 3 is not necessarily required depending on the shape of the reinforcing pipe 3 and the like. .

In addition, when a pipe made of aluminum alloy or the like, which is the same material as the caliper, is used, there is no problem of foreign materials being mixed in with pieces of the cutting tool or chips.

〔Effect of the invention〕

As described above, the present invention is a casting method in which a communicating hole is formed by embedding a reinforcing pipe filled with a shell-shaped sand core inside the pipe. The compressive strength of aluminum alloy and copper is increased.

Even when high pressure is applied to pipes made of steel, they do not collapse. Therefore, it is possible to use casting methods such as squeeze casting, which fills molten metal at high pressure and low speed, which prevents the formation of cavities and produces high quality products. We can provide multi-bot calipers for disc brakes.

In addition, because the shell-shaped sand core is wrapped in a pipe, compared to the method of using the shell-shaped sand core itself as a casting, it is more convenient to use when installing the core for making cylinder holes, when injecting high-pressure molten metal, and during transportation. There is no problem of the core being damaged or collapsing due to impact, and since it can be installed reliably and precisely with a large amount of force when installing it on the core, there is no intrusion of particles or misalignment, and the inflow of molten metal. Also suitable for fast casting methods.

[Brief explanation of the drawing]

1 to 3 show embodiments of the present invention.
The figure is a sectional view of the reinforcing pipe, FIG. 2 is a sectional view when a cavity is formed, and FIG. 3 is a sectional view of a caliper.

Claims (1)

[Claims] 1. In a method for casting a multi-pot caliper for a disc brake in which a plurality of cylinder holes are arranged in parallel and a partition wall between adjacent cylinder holes has a communication hole that communicates the adjacent cylinder holes, shell-shaped sand is placed inside the pipe. A reinforcing pipe filled with a core is placed in the cavity at a position where the communication hole is formed, and then molten metal is filled into the cavity under high pressure and solidified.Then, after the caliper is released from the mold, heat treatment is performed to form a shell inside the reinforcing pipe. A method for casting multi-pot calipers for disc brakes, which involves removing mold sand cores and forming communicating holes.