JPH04294830A - Spinning die - Google Patents

Abstract

PURPOSE:To obtain a die for spinning excellent in wear resistance by coating a surface whereon a spinning die and a work come in contact with each other with a TiC layer. CONSTITUTION:The surface with which the spinning die 10 comes in contact is coated with a hard ceramic TiC layer 12 less in frictional resistance in a forming time. Consequently, since the frictional coefficient between the die 10 in the forming time and the work 2 is decreased, flaws generated on the surface of the work 2 are not only prevented but the wear resistance of the die 10 itself is improved.

Description

[Detailed description of the invention]

[Purpose of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spinning mold used for spinning.

0002

[Prior Art] Generally, spinning is widely used to manufacture various drawn parts from workpieces.
The manufactured parts are formed into any axially symmetrical shape by forming rolls. Therefore, since only a male mold is required as a mold, the mold manufacturing cost is low and can be manufactured quickly, so a wide variety of small quantities of drawn parts can be manufactured in a short period of time and at low cost.

Furthermore, especially in spinning processing, when spinning a structure with both ends closed, such as a kettle, a fixed eccentric type is used to facilitate the removal of the mold inside the workpiece after processing. It uses a mold.

0004

[Problems to be Solved by the Invention] In conventional fixed eccentric spinning molds, the mold and workpiece are rubbed against each other during processing, resulting in scratches on the contact surface between the mold and the workpiece. , and the mold wears out. Particularly, when it is necessary to give gloss to the surface of a workpiece in the final finishing step, the mold and workpiece are strongly pressed together during processing, resulting in increased wear of the mold.

[0005] Conventionally, therefore, countermeasures have been taken to solve the above problem by attaching felt coated with oil to the side surface of the mold, or by applying chrome plating to the surface that comes into contact with the workpiece.

However, the lubrication effect disappears due to lack of oil, and the hardness of chrome plating is also insufficient.The above two measures are effective in preventing scratches on the inner surface of the workpiece that comes into contact with the mold during spinning processing, and in improving the mold. Not effective in reducing wear.

[0007] Another countermeasure is to use cemented carbide as the mold material, which is effective in reducing wear on the mold, but is expensive and is not effective in preventing scratches on the inner surface of the workpiece. Not. [Structure of the invention]

[0008]

[Means for Solving the Problems] In order to achieve the above objects, the present invention provides a method for forming a workpiece using a fixed eccentric mold used in spinning processing in which a workpiece is formed into a desired shape using forming rolls. The surface that contacts the workpiece is coated with a TiC layer.

[0009]

[Operation] As described above, in the spinning mold of the present invention, the surface where the workpiece and the fixed eccentric mold come into contact during forming is coated with a TiC layer, which is a hard ceramic with a small coefficient of friction. In other words, the coefficient of friction between the mold and the workpiece during molding is reduced, which not only prevents scratches on the surface of the workpiece, but also increases the wear resistance of the mold itself.

0010

Embodiments An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of a spinning processing apparatus to which the present invention is applied. The spinning processing device has a rotary drive shaft 1
A mandrel 3 that is attached to the rotary drive shaft 1 and holds the workpiece 2 from the outside, and a holding plate 4 that holds the workpiece 2 from the inside.
A flange 6 is connected via bearings 7 and 8 to a body 5 that tightens and presses the holding plate 4 against the workpiece 2, and a flange 6 is fixed to the body 5 with bolts 9 to form the desired shape of the workpiece 2. It consists of a fixed eccentric mold 10 whose surface is coated with a TiC layer, and a forming roll 11 that presses a workpiece 2 against the fixed eccentric mold 10 to form a desired product. Here, reference is made to an enlarged cross-sectional view of the surface of the stationary eccentric mold 10 shown in FIG. The surface of the fixed eccentric mold 10 of the present invention is coated with a TiC layer 12 by a physical vapor deposition method (PVD method), a chemical vapor deposition method (CVD method), or the like. Next, the spinning operation will be explained.

First, when the rotary drive shaft 1 rotates, the workpiece 2 held between the mandrel 3 and the holding plate 4 rotates together with the rotary drive shaft 1 due to the tightening of the flange 6. The workpiece 2 includes a mandrel 2 and a holding plate 4.
The forming roll 11 is held between the forming rolls 11 and
Then, it is narrowed down to a desired shape using a fixed eccentric mold 10 that has a desired shape.

As described above, since the surface of the spinning mold is coated with a TiC layer with a low coefficient of friction during spinning, the workpiece is not scratched and the wear of the mold itself is reduced. Furthermore, the cost can be lower than using cemented carbide as the mold material.

[0014]

As explained above, according to the present invention, the surface of the fixed eccentric mold, which is one of the spinning molds, is coated with a TiC layer having a small coefficient of friction, so that the workpiece can be easily A spinning mold with excellent wear resistance can be obtained without causing scratches.

[Brief explanation of the drawing]

[Fig. 1] Cross-sectional view of a spinning processing device to which the present invention is applied

[Figure 2] Enlarged cross-sectional view of the surface of the fixed eccentric mold of the present invention

[Explanation of symbols]

1...Rotation drive shaft, 2...Workpiece,
3...Mandrel, 4...Press plate, 5...Body,
6...flange, 7,8...bearing, 9...bolt,
10... Fixed eccentric mold, 11... Forming roll, 12... TiC layer.

Claims (1)

[Claims] 1. In a spinning mold used for spinning processing in which a workpiece is formed into a desired shape by a forming roll, a TiC layer is coated on the surface that comes into contact with the workpiece during spinning. A mold for spinning processing that is characterized by: