JP3291683B2 - Manufacturing method of hydraulic equipment parts - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing hydraulic equipment parts for automatic transmission parts for automobiles, particularly for automatic transmission pistons and the like used for automatic transmissions, particularly for automatic transmissions.

[0002]

2. Description of the Related Art Automatic transmission parts for automobiles, such as automatic transmission pistons, are operated and controlled by hydraulic pressure. In order to maintain confidentiality, a steel material is used as a constituent material, or functions are emphasized by weight reduction. In particular, those using an aluminum material are manufactured by die-casting using an aluminum die-cast alloy (JIS ADC-10) and then machining. A above
The material of DC-10 is most excellent in die-casting castability, but the ductility of the material is poor, so that plastic working is impossible, and all finishing processes such as oil seal grooves are performed by machining.

[0003]

Die-cast products formed by the above-mentioned conventional method of manufacturing hydraulic equipment parts such as automatic transmission parts for automobiles are liable to form a casting cavity, and therefore are machined to form oil seal grooves and the like. In such a case, there is a problem that the pressure leak defect due to the above-mentioned cavities frequently occurs in the machined portion such as the oil seal groove and the defect rate is high.

The present invention has been made in view of the above, and has been described in connection with an automatic transmission component for an automobile, particularly a function required for hydraulic equipment components such as an automatic transmission piston.
Provided is a method of manufacturing a hydraulic device component which is small, light in weight, imparts pressure resistance, can reduce a defective rate (pressure leakage defect), and can achieve a total cost reduction. The purpose is to do so.

[0005]

In order to achieve the above object, in the method for manufacturing a hydraulic device part according to the present invention, first, an aluminum alloy having special mechanical properties is selected as a base material. That is, although it is a die-cast intermediate product, the elongation is 10% or more, and the tensile strength is 15k.
An alloy having characteristics of g / mm ² or more is used.

[0006] In particular, the reason why the elongation property is required to be 10% or more is to secure the formability without underfill or crack in the plastic working step under an uneven load in the final step. Further, a tensile strength equal to or higher than a certain level (15 kg / mm ² ) is a strength necessary to secure a pressure resistance without deformation due to a pressure load of a hydraulic device part.

A material having such characteristics can be selected by optimally selecting and limiting chemical components. In the present invention, as an aluminum alloy having the above characteristics, Cu: 0.01 0.5%, Si: 0.01
0.5%, Mg: 0.2-0.8%, Zn: 0.01
~ 1.0%, Fe: 0.01 ~ 0.5%, Mn: 0.1
１．０1.0%, with a residual Al component ratio.

In the method for manufacturing a hydraulic device component according to the present invention, the chemical component is Cu: 0.01 to 0.5%,
i: 0.01 to 0.5%, Mg: 0.2 to 0.8%, Z
n: 0.01 to 1.0%, Fe: 0.01 to 0.5%,
Mn: 0.1-1.0%, aluminum alloy with remaining Al
To form a first intermediate product by die casting, and then cold-forge the first intermediate product with a forging die to form a second intermediate product having a circumferential surface .
Hydraulic equipment parts to complete the product by spinning the oil seal groove on the circumferential surface of the intermediate product by the roll spinning method
It is a manufacturing method of .

[0009]

Next, specific embodiments will be described. FIG. 1 shows an example of a hydraulic device to be manufactured by the method of the present invention, which is an automatic transmission piston 1 of an automatic transmission for an automobile. The piston part 3 has oil seal grooves 2a and 2b on the outer peripheral surface and the inner peripheral surface, and four partition parts 4 projecting in an arc shape on one side surface of the piston part 3.
And a pin 5 protruding between the partitions 4. A hydraulic valve (a check valve) is provided inside the partition portion 4 of the vehicle shifting piston 1, and each pin 5 is provided with a spring member for operating the hydraulic valve.

An automatic shifting piston 1 shown in FIG. 1 shows a finished product, and FIGS. 2 (a), 2 (b) and 2 (c) show cross-sectional shapes along respective axes in a molding process of the automatic shifting piston 1. The manufacturing method will be described with reference to FIG.

The chemical components are Cu: 0.08% (% by weight, the same applies hereinafter), Si: 0.16%, Mg: 0.4%, Zn:
0.10%, Fe: 0.25%, Mn: 0.5%, residual A
The first intermediate product 1a is formed as shown in FIG.
Get. The first intermediate product 1a is thicker (axial dimension) T than the finished product shown in FIG.
Is not molded. The partition part 4 is thick, and its height h (3 mm) is the height H (6 m) of this part of the molded product.
m). The height h of the partition 4 at this time is preferably １ ／ H to 〜H of the height H of the finished product.

Next, the first intermediate product 1a is cold forged by upper and lower forging dies (not shown) to obtain a second intermediate product 1b shown in FIG. 2 (b). In the second intermediate product 1b, each part excluding the oil seal grooves 2a and 2b, that is, the piston part 3, the partition part 4, and the pin 5 are formed into a finished product. The pressing pressure at this time was 300 tf.

As a final step, the oil seal grooves 2a and 2b are plastically worked on the outer peripheral surface and the inner peripheral surface of the piston portion 3 by roll spinning as shown in FIG. Let it be 1. The pressing force at this time was 7 tf, and the rotation speed was 600 to 700 rpm.

FIGS. 3 and 4 show the roll spinning process. In FIG. 3, upper and lower pressing dies 6a and 6b are shown.
The spinning roll 7 for the outer groove is pressed against the outer peripheral surface of the piston portion 3 of the second intermediate product 1b clamped by the above process to form the oil seal groove 2a on the outer peripheral surface.

FIG. 4 shows how the oil seal groove 2b on the inner peripheral surface is machined.
As in the case of machining a, the second intermediate product 1b is held between the upper and lower clamping dies 6a and 6b, and the spinning roll 8 for the inner groove is eccentric to form an oil seal groove on the inner peripheral surface of the piston portion 3. Process 2b.

The aluminum alloy used for molding the above product has a Si content (7.5 to 9.5) in ADC-10 conventionally used generally for die casting.
%), The content of Si is as extremely small as 0.01 to 0.5%.

Further, since the content of Si is small,
Since the elongation is large and the cold forgeability is excellent, plastic forming by cold forging to obtain the second intermediate product 1b is performed without generating cracks or cracks.

Since the second intermediate product 1b is formed by cold forging, even if the first intermediate product 1b is formed by die-casting and has a cavity unique to die-casting. The cavities are crushed and defects due to the cavities are improved.

The oil seal grooves 2a and 2b formed in the piston portion 3 are plastically deformed by roll spinning. As a result of inspecting the surfaces and the inside of the oil seal grooves 2a and 2b, no casting defects are found. there were.

In the above embodiment, an example of manufacturing a piston for an automatic transmission as an automatic transmission part for an automobile has been described. However, the present invention is not limited to these examples. Of course, it can be applied to equipment parts.

[0021]

According to the present invention, hydraulic equipment parts such as automatic transmission pistons can be reduced in size and weight by die-casting using an aluminum alloy, and at the time of die-casting by plastic working. The resulting casting defects such as cavities are improved to provide pressure resistance, and the defect rate due to cavities (pressure leakage defects) can be reduced. From this, it is possible to comprehensively reduce costs.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a hydraulic device component manufactured by a manufacturing method according to the present invention.

FIG. 2A is a sectional view showing a first intermediate product.
(B) is sectional drawing which shows a 2nd intermediate product. (C) is a sectional view showing a finished product.

FIG. 3 is a roll spinning process diagram for processing an oil seal groove on an outer peripheral surface.

FIG. 4 is a roll spinning process diagram for processing an oil seal groove on an inner peripheral surface.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Automatic transmission piston, 2a, 2b ... Oil seal groove, 3 ... Piston part, 4 ... Partition part, 5 ... Pin, 6a, 6
b: mold, 7, 8 ... spinning roll.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-53-56115 (JP, A) JP-A-61-227142 (JP, A) JP-A-54-35928 (JP, A) JP-A 8- 74747 (JP, A) JP-A-5-305358 (JP, A) JP-A-6-39468 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B21J 5/00 C22C 21 / 00-21/18

Claims (1)

(57) [Claims] The chemical component is Cu: 0.01 to 0.5.
%, Si: 0.01 to 0.5%, Mg: 0.2 to 0.8
%, Zn: 0.01 to 1.0%, Fe: 0.01 to 0.1%.
5%, Mn: 0.1 to 1.0%, aluminum remaining Al
The first intermediate product is formed by die casting using an alloy
And, then, as a second intermediate product having a circumferential surface and cold forging the first intermediate product at forging die, further, oil in roll spinning method the circumferential surface of the second intermediate product A method of manufacturing a hydraulic device part, comprising spinning a seal groove into a finished product.