JP2016087620A - Manufacturing method for automobile component having oil passage and automobile component manufactured by the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method for an automobile component having an oil passage which has high sealability and no possibility of oil leakage even when the long oil passage having a small inner diameter is formed, and the automobile component obtained by the method.SOLUTION: A manufacturing method for an automobile component having an oil passage includes: a step for disposing an insert member made of solid aluminium or aluminum alloy which has an internal defect in a metallic mold; a step for injection-casing molten metal of the aluminum alloy into the metallic mold at a high pressure and a high speed; and a step for forming an oil passage in the cast insert member by machining.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method of manufacturing an automobile part having an oil passage, and particularly relates to a method of manufacturing by aluminum die casting.

Various cases are used to incorporate drive transmission parts such as torque converters, clutches, and gears, speed change parts, and the like in automobile drive system parts.
For example, a transmission case, a transfer case, a transaxle case and the like can be given as examples.
These cases are manufactured by die casting of an aluminum alloy for the purpose of weight reduction.
In recent years, for example, 6-speed automatic transmission, 8-speed automatic transmission, etc., the number of parts has been increasing, so the weight and size of cases have been required. Have been receiving more.
In general aluminum die-casting, if the wall thickness of the oil passage wall is not secured to 15 mm or more, there is a risk of oil leakage due to a cast hole or the like due to machining of the oil passage, and an oil passage with a cast surface is formed. It is possible.
However, when the oil passage becomes longer, a portion of the oil passage diameter increases due to an increase in the amount of draft gradient at the time of casting.
Therefore, when the oil passage diameter is reduced over the entire length, it is difficult to adopt the casting method.
Although it is conceivable to press-fit the pipe material after machining the oil passage, the sealing performance becomes a problem.

Patent Document 1 discloses a method of casting a hollow member. However, when casting is performed by an aluminum die casting method, there is a problem that the hollow member is deformed because a molten aluminum alloy is injected into the mold in a high pressure state. .
Patent Document 2 discloses a method of casting a solid insert member made of an iron-based metal member with molten aluminum and then forming an oil passage by machining.
However, there is a large difference in the coefficient of thermal expansion between the combination of an iron-based metal member and aluminum, and in the case of a product with a temperature difference during use, such as automobile parts, the boundary between iron and aluminum is likely to be crisp and sealability There is also a problem that cannot be secured.

JP 2004-344955 A Japanese Patent No. 4742129

  An object of the present invention is to provide a method of manufacturing an automobile part having an oil path that has a high sealing performance and does not cause oil leakage even when an oil path having a small inner diameter is formed, and an automobile part obtained thereby.

The method of manufacturing an automobile part according to the present invention includes a step of placing an insert member made of solid aluminum or aluminum alloy having no internal defects in a mold, and a molten aluminum alloy in the mold at high pressure and high speed. It has a step of performing injection casting and a step of forming an oil passage by machining in the cast insert member.
Here, the insert member made of solid aluminum or aluminum alloy having no internal defect means an aluminum member having no internal defect that causes oil leakage when an oil passage is formed by machining.
For example, a solid aluminum member produced by wrought material produced by extruding, drawing or the like, or having an internal defect produced by forging or the like is very small.
For the purpose of forming an elongated oil passage, an insert member having a rod-like shape is preferable, and the outer diameter is not limited to a circular shape, and may be an irregular cross-sectional shape.
Further, the outer shape may be different over the entire length.

There are no particular limitations on the automobile parts that are the subject of the present invention as long as they use parts such as lubricating oil and hydraulic oil.
Among them, particularly effective are mission cases that require a long and narrow oil passage and require high sealing performance and light weight by thinning.
Examples of mission cases include a transmission case, a transaxle case, and a transfer case.

In the present invention, an insert member made of a solid aluminum material having no internal defect is cast by die casting of an aluminum alloy, and then an oil passage is formed in the insert member by machining. There is no fear, and the aluminum material is casted with aluminum material, so the interface has excellent adhesion, and the difference in thermal expansion is very small, so there is very little risk of cracking due to temperature differences during use.
The degree of freedom in the shape of the oil passage is high as long as machining is possible.
This makes it possible to reduce the thickness and weight of mission cases, and also enables a compact design.

The state where the aluminum insert member is cast by the aluminum die casting method is shown. An example in which an oil passage is formed by machining along an aluminum insert member is shown.

  Although the manufacturing method example which concerns on this invention is demonstrated based on drawing below, this invention is not limited to this.

Although not shown in the drawings, the aluminum insert member 12 is arranged in the die for aluminum die casting, and for example, a molten aluminum alloy for aluminum die casting such as JIS ADC12 is injected into the die at high pressure and high speed. An automobile part (coarse material) in which an insert member 12 is cast in a case main body 11 as shown in FIG. 1 is obtained.
Here, the insert member 12 is machined on the outer peripheral portion of a rod-like extruded material using an aluminum alloy to form a flange portion 12a that matches the outer shape of the case body 11 and a flange portion 12b that matches the inner shape. It is an example.
Next, as shown in FIG. 2, an oil passage 13 is formed along the insert member 12 by machining.
As long as machining is possible, it is possible to provide a stepped shape or a bent portion in the oil passage.

10 Automotive parts 11 Case body 12 Aluminum insert member 13 Oil passage

Claims (3)

Placing an insert member made of solid aluminum or aluminum alloy without internal defects in the mold;
Injection casting the molten aluminum alloy into the mold at high pressure and high speed;
The manufacturing method of the motor vehicle part which has an oil path characterized by having the step of forming an oil path by machining in the cast insert member.   2. The method of manufacturing an automobile part having an oil passage according to claim 1, wherein the automobile part is a mission case.   A transmission case manufactured by the manufacturing method according to claim 1.

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