JPS61281848A - Mechanical parts made of casting, method for casting said mechanical parts and casting mold therefor - Google Patents

Abstract

PURPOSE:To provide mechanical parts made of castings which can satisfy the respective characteristics required for respective constituting parts by forming the surface skin part and inside of the 1st constituting part where wear resistance, etc. are demanded of flake graphite cast iron structure and forming the surface skin part and inside of the 2nd constituting part which is provided successively and integrally with the 1st constituting part and where high strength is demanded of spheroidal graphite cast iron structure. CONSTITUTION:The 1st constituting part of, for example, a brake disk 1 of a disk brake for a vehicle as the above-mentioned mechanical parts made of castings is an annular sliding part 1a with a friction pad. A cup-shaped hub part 1b which is provided successively and integrally with the sliding part 1a and is fixed to the hub part of a wheel is constituted as the 2nd constituting part. The surface skin part and inside of the sliding part 1a are formed of the flake graphite cast iron structure so that the excellent wear resistance, attenuating power, machineability, etc., are provided thereto. The surface skin part and inside of the hub part are formed of the spheroidal graphite cast iron structure so that the high strength is provided thereto. The spheroidal graphite cast iron structure and the flake graphite cast iron structure contact therewith each other in both constituting parts, by which both structures are thoroughly welded.

Description

Detailed Description of the Invention A8 Objective of the Invention (1) Industrial Application Field The present invention provides a first component that requires wear resistance, damping ability, machinability, etc. The present invention relates to a cast machine part including a second component that is integrally connected and requires high strength, a method for casting the cast machine part, and a mold for the cast machine part.

(2) Prior art Examples of the above-mentioned cast machine parts include brake discs used in vehicle disc brakes, particularly those in which the sliding part with the friction pad and the hub part fixed to the wheel are integrally cast. be able to. In this case, the sliding part is required to have wear resistance, damping ability, machinability, etc., and the hub part is required to have high strength.

(3) Problems to be Solved by the Invention If a brake disc that requires such mechanical properties is made of, for example, flake graphite cast iron, the required properties can be met in the sliding part, but the Due to the low strength of graphite cast iron, the above required characteristics cannot be met in the hub portion. On the other hand, the brake disc
For example, if the hub is made of spheroidal graphite cast iron, the required characteristics can be met in the hub part, but
There is a problem in that the sliding portion cannot satisfy the above-mentioned required characteristics.

In view of the above, an object of the present invention is to provide a cast machine part having two component parts having different required characteristics, each of which is configured so that each component can satisfy the required characteristics. .

Another object of the present invention is to provide the casting method that allows the mechanical parts to be obtained easily and reliably.

A further object of the present invention is to provide a mold with a simple structure that allows the mechanical parts to be obtained easily and reliably.

B1 Structure of the Invention (1) Means for Solving Problems The cast machine part according to the present invention includes a first component that is required to have wear resistance, damping ability, machinability, etc., and the first component. The second component is integrally connected to the second component and requires high strength. It is characterized by its skin and interior being formed into a spheroidal graphite cast iron structure.

Further, the method for casting machine parts made of cast iron according to the present invention includes a first component that requires wear resistance, damping ability, machinability, etc., and a component that is integrally connected to the first component and has high strength. The first component has a skin part and an interior formed of a flaky graphite cast iron structure, and the second component has a skin part and an interior made of a spheroidal graphite cast iron structure. In casting the machine parts to be formed, a molten metal adjusted to have a flaky graphite cast iron structure is poured into a first cavity of a mold for forming the first component, and the molten metal is subjected to a graphite nodularization treatment. After the molten metal is applied, the molten metal is injected into a second cavity of the mold for molding the second component.

Further, the mold for a cast machine part according to the present invention includes a first component that is required to have wear resistance, damping ability, machinability, etc.;
The second component is integrally connected to the component and is required to have high strength. is a mold for casting a machine part made of cast metal whose skin and interior are formed into a spheroidal graphite cast iron structure, using molten metal adjusted to a flaky graphite cast iron structure, the mold having a sprue; and the first component. a first cavity for molding; a second cavity communicating with the first cavity and molding the second component; a first runner communicating between the sprue and the first cavity;
A second runner that communicates between the sprue and the second cavity; and a reaction chamber that is provided at an intermediate portion of the second runner and that subjects the molten metal to graphite spheroidization treatment. .

(2) Effect As mentioned above, since the first component is a flaky graphite cast iron structure, it has excellent wear resistance, damping ability, machinability, etc., and the second component is a spheroidal graphite cast iron structure. High strength. Therefore, the mechanical component can meet the required performance characteristics.

Further, according to the casting method, the first component has a flake graphite cast iron structure using one type of molten metal adjusted to have a flake graphite cast iron structure, and the second component has a spheroidal graphite cast iron structure. Parts can be obtained easily and reliably.

Furthermore, the mold has a simple structure because it is composed of a pair of cavities, a pair of runners, a sprue, and a reaction chamber. In addition, the molten metal adjusted to have a flaky graphite cast iron structure and passing through the second runner is changed into a spheroidal graphite cast iron structure by the graphite spheroidization treatment in the reaction chamber, and the molten metal with the spheroidal graphite cast iron structure and the flake graphite cast iron structure are Since the molten metal flows through a completely independent runner and is injected into the second and first cavities separately, the two molten metals do not mix, and therefore the first component has a pure flake graphite cast iron structure. Further, it is possible to obtain a mechanical component in which the second component has a pure spheroidal graphite cast iron structure.

(3) Embodiment FIG. 1 shows a brake disc 1 of a disc brake for a vehicle, which is a cast iron mechanical part. The second component is a cup-shaped hub portion 1b that is integrally connected to the sliding portion 1a and fixed to the hub portion of the wheel.

As shown in the micrograph (100x magnification) of FIG. 2, the sliding part 1a has a flaky graphite cast iron structure in its skin and inside, so it has excellent wear resistance, damping ability, machinability, etc. The hub portion 1b has high strength because its skin and interior are formed of spheroidal graphite cast iron m-weave as shown in the micrograph (100x magnification) of FIG. At the connecting portion C of the hub portion 1b to the sliding portion 1a, the micrograph (100
As shown in Figure 2), the spheroidal graphite cast iron structure and the flaky graphite cast iron structure are in contact with each other, and both m weaves are completely fused.

The basic chemical components of the flaky graphite cast iron of the sliding part 1a and the spheroidal graphite cast iron of the hub part 1b are shown in Table (2).

The unit % is weight % (the same applies hereinafter).

Table I As is clear from Table ■, the Si content of the sliding part 1a is 1
．． Since it is set to 7 to 2.5%, the base structure of the sliding portion 1a is made of pearlite and has high hardness. In adjusting the base structure of the sliding part 1a and the hub part 1b, 0.3 to 1.0% of Cu and 0.3% of Cu are added to the basic chemical components.
~1.0% Cr, 0.2-1.0% Ni, 0.01
~0.04% of Sn etc. is added alone or in combination.

5 to 7 show a sand mold 2 as a mold used to cast the brake disc 1 from a molten metal adjusted to have a flaky graphite cast iron structure, and the sand mold 2 is made up of an upper mold 3 and a lower mold opposite thereto. It consists of type 4. The upper mold 3 is provided with one sprue 5, and communicates with the first cavity C8 for molding the sliding part 1a on the mating surface of the upper mold 3 and the lower mold 4, and the cavity CI to mold the hub part 1b. A second cavity C2 is formed. Furthermore, a first runner 7 is provided on the mating surface of both molds 3 and 4, which communicates between the sprue 5 and the first cavity C5 via a weir 6. is formed, and furthermore, a series of second runners 7□ are formed in the mating surfaces of both molds 3, 4 and in the upper mold 3, which communicate between the sprue 5 and the second cavity C2 via a pair of weirs 8. .

2nd hot water path7. A reaction chamber 9 is provided in the middle of the molten metal, and the reaction chamber 9 allows the passage of molten metal adjusted to have a flaky graphite cast iron structure, and the molten metal is filled into the 0 reaction chamber 9, where the molten metal is subjected to graphite nodularization treatment. The graphite nodularized alloy A is 46% Si, 6%
The alloy consists of Mg and the balance is Fe containing trace impurities, and the amount of the alloy is adjusted so that the Mg content is equivalent to 0.04% with respect to the molten metal tapped from the melting furnace. In the figure, 10
is the core.

During casting work, first, C3o47% is removed from the melting furnace.
, Si2.1%, Mn0.56%, Po, 02%, Cu
A molten metal adjusted to a flaky graphite cast iron structure having a chemical composition of 0.6% and 30.042% was tapped, and 0.04% was added to the molten metal.
Inoculate with 15% ferrosilicon (Fe-3t).

The molten metal is introduced into the sprue 5 at a temperature of 1430°C, and the molten metal is passed through the first sprue. 2nd runner 7I, 7g and weir 6, 8
Through the 1st. Inject into the second cavities C1 and C8.

Since the molten metal is directly injected into the first cavity CI, a sliding portion 1a having a structure of flaky graphite cast iron is formed. In this case, the amount of hot water for the first cavity C1 is regulated by the cross-sectional area of the weir 6.

Since a reaction chamber 9 is provided in the middle of the second runner 78, when passing through the reaction chamber 9, the molten metal having a flaky graphite cast iron structure is subjected to graphite spheroidization treatment by the alloy A, and becomes spherical. It is changed into a graphite cast iron structure, and then injected into the second cavity Ct, thereby forming the hub portion 1b of the spheroidal graphite cast iron structure. In this case, the amount of hot water for the second cavity C2 is regulated by the sum of the cross-sectional areas of the art platform 8.

In the casting operation, the molten metal having a flaky graphite cast iron structure and the molten metal having a spheroidal graphite cast iron structure are completely separated from each other in first and second runners 7.
1. Flowing through 7□, the first. Second cavity C,,C! Since the two molten metals are injected separately, the two molten metals do not mix together (,
Therefore, both the structures of the sliding portion 1a and the hub portion 1b are pure.

By demolding after casting, a brake disc 1 having the structure shown in FIG. 1 was obtained, and its chemical composition is as shown in Table (2).

Table ■ Effects of the C0 invention In the cast machine parts according to the present invention, the first component, which is required to have wear resistance, damping ability, machinability, etc., is a flaky graphite cast iron structure, so the required characteristics are satisfied. Moreover, since the second component, which is required to have high strength, has a spheroidal graphite cast iron structure, the required characteristics can be met. Therefore, the mechanical component has the required mechanical properties.

Further, according to the method for casting machine parts made of cast iron according to the present invention,
Using one type of molten metal adjusted to have a flaky graphite cast iron structure, the machine part in which the first component is formed to have a flake graphite cast iron structure and the second component is formed to be a spheroidal graphite cast iron structure can be easily and You can definitely get it.

Furthermore, the mold for a cast machine part according to the present invention has a simple structure because it is composed of a pair of cavities, a pair of runners, a sprue, and a reaction chamber. Further, according to the mold, it is possible to easily and reliably obtain a mechanical part in which the first component is formed of a pure flaky graphite cast iron structure and the second component is formed of a pure spheroidal graphite cast iron structure. can.

[Brief explanation of the drawing]

Fig. 1 is a vertical sectional front view of the brake disc, Fig. 2, Fig.
Figure 4 is a microscopic photograph showing the metal structure of the sliding part of the brake disc, the hub part, and the part where the hub part is connected to the sliding part, Figure 5 is a plan view of the mold, and Figure 6 is Figure 5. VI
FIG. 7 is an enlarged sectional view taken along line -VI in FIG. 5. A... graphite spheroidized alloy, C,, C,... 1st. Second
Cavity, 1...Brake disc as a mechanical part, 1a...
- Sliding part as a first component, 1b... A hub part as a second component, 2... Sand mold as a mold, 5... Sprue, 71.7□... First. 2nd runner, 9... during reaction chamber Applicant Honda Motor Co., Ltd. Figure 3
Liao 2 = (] - [Figure 14

Claims (6)

[Claims] (1) A casting consisting of a first component that requires wear resistance, damping ability, machinability, etc., and a second component that is integrally connected to the first component and requires high strength. A manufactured machine part,
The first component has a skin part and an interior formed of a flaky graphite cast iron structure, and the second component has a skin part and an interior thereof a spheroidal graphite cast iron structure. (2) The cast metal mechanical part is a brake disc of a disc brake for a vehicle, and the first component corresponds to a sliding part with a friction pad, and the second component corresponds to a hub part fixed to a wheel. A casting machine part according to claim (1). (3) Consisting of a first component that requires wear resistance, damping ability, machinability, etc., and a second component that is integrally connected to the first component and requires high strength, The first constituent part has a skin part and an interior formed with a flaky graphite cast iron structure, and the second constituent part has a skin part and an interior thereof a spheroidal graphite cast iron structure. At this time, a molten metal adjusted to have a flaky graphite cast iron structure is injected into a first cavity of a mold for forming the first component, and after the molten metal is subjected to graphite spheroidization treatment, the molten metal is poured into the second component. A method for casting a machine part made of a cast metal, the method comprising: injecting into a second cavity of the mold for molding. (4) The cast metal mechanical part is a brake disc of a disc brake for a vehicle, and the first component corresponds to a sliding part with a friction pad, and the second component corresponds to a hub part fixed to a wheel. A method for casting machine parts made of cast metal according to claim (3). (5) Consisting of a first component that requires wear resistance, damping ability, machinability, etc., and a second component that is integrally connected to the first component and requires high strength, The first component has a flaky graphite cast iron structure in its skin and inside, and the second component has a flaky graphite cast iron structure in its skin and inside. A mold for casting using a molten metal adjusted to have a graphite cast iron structure, the mold comprising: a sprue; a first cavity for molding the first component;
a second cavity that communicates with the cavity and molds the second component; a first runner that communicates between the sprue and the first cavity; a second runner that communicates between the sprue and the second cavity. A mold for a cast machine part, comprising; and a reaction chamber provided at an intermediate portion of the second runner, for subjecting the molten metal to a graphite spheroidization treatment. (6) The cast metal mechanical component is a brake disc of a disc brake for a vehicle, and the first component corresponds to a sliding part with a friction pad, and the second component corresponds to a hub part fixed to a wheel. A mold for a cast machine part according to claim (5).