JPH0244894Y2 - - Google Patents

Description

[Detailed explanation of the idea]

[Industrial Application Field] The present invention relates to a tool for ironing, and particularly to a tool suitable for ironing fin materials of heat exchangers. [Prior Art] Conventionally, ironing tools consist of a die die and a punch, and this tool stretches, or squeezes, a metal plate through the sliding gap between the die hole wall surface and the punch surface. It is. For example, it is used in the process of forming a fin material as shown in FIG. In this process, first, the plate material is subjected to punch burring processing (a), then ironing processing (b),
Step c is performed, and then reflare processing d is performed to form fins. Fig. 3 shows ironing tools used for fin processing, 1 is a die, 2 is a punch, and the punch 2 is used to insert a plate material 3 with punched holes into the formed hole 4 of the die. Press and process into fins. Conventionally, ironing tools used for fin processing are usually made of high-speed steel (SKH9), but recently tools made of carbide have also been used. [Problems to be solved by the invention] In the ironing process, as shown in Figure 3,
Since the plate material 3 has a new surface formed on the punch side, lubrication with the surface 5 of the punch 2 is important. Therefore, the punch surface 5 should be made as smooth as possible to reduce friction with the plate material 3. On the other hand, the forming hole wall surface 6 of the die 1 is such that the plate material 3 between that surface and the punch surface 5 is as much as possible on that surface 6.
The rougher the material 3, the more it will prevent slipping, that is, the greater the friction with the plate material 3, the more advantageous it will be in preventing the material 3 from "flipping off" (a state in which the fin is torn off at the center of the collar). In the figure, 7 indicates a fractured part due to head fly-off. However, the ironing tools used in conventional fin processing, such as dies and punches, are both said to have a good surface finish with a surface roughness of approximately 0.3 μm or less, and there is a lack of consideration for the above points. was. Therefore, the purpose of the present invention is to provide an ironing tool that can eliminate the collar skipping that occurs when ironing hard fin materials, or improve the ironing workability of fin materials and other work materials themselves. It is to provide. [Means for Solving the Problems] The ironing tool according to the present invention is configured as follows as a means for solving the above problems. That is, the present invention is a tool for ironing a plate material between the wall surface of a forming hole of a die and the surface of a punch inserted into the forming hole through a plate material, and The feature is that a titanium nitride layer with a maximum surface roughness of 1 μm or more is provided on the wall of the hole. FIG. 1 shows an example of the ironing tool of the present invention, showing the wall surface 6 of the forming hole 4 of the die 1.
is provided with a titanium nitride layer 8 having a maximum surface roughness of 1 μm or more. To provide such a titanium nitride layer on the surface 6, the wall surface is first sputtered with Ti to roughen the surface, and then nitrided to form a titanium nitride coating layer. In addition to the sputtering method, there are also ion plating methods and vacuum evaporation methods, but the sputtering method is most suitable for roughening the surface. Compared to titanium carbide, another typical hard material, titanium nitride has a coefficient of thermal expansion similar to that of high-speed tool steel, and also has an extremely low enthalpy of formation. Thermal distortion between the two is small, and the compound is also highly stable, making it difficult to seize. In addition, since the hardness is much higher than that of high-speed tool steel, the wear resistance of the tool is improved. This extends the life of the tool. Examples of metal plates that can be ironed using the tool of the present invention include aluminum plates, aluminum plates that have undergone various surface treatments, such as hydrophilic silicic acid film treatment containing SiO ₂ as the main component, Sn-coated steel plates, etc. . [Example] The material of each die was SKH9, the material of the punch was made of carbide (surface roughness 0.2μ), and five dice were used as samples in an angon atmosphere (450°C).
Ti was sputtered onto the wall surface of each hole except No. 1 at different times for each die to adjust the surface roughness of each hole. Then the Ti of each die
The sputtered surface was subjected to nitriding treatment for a constant treatment time to form a titanium nitride layer. Table 1 shows the sputtering time and surface roughness for each of the above dies.

[Table] * Roughness of die wall surface Using each of the sample dies and punches mentioned above, ironing tests were conducted under the following conditions. 1. Oil Idemitsu AF-8 2. Processing conditions 10 mm/min 3. Processed material A 1100-H26 (thickness 100 μm, surface roughness approximately 0.2 μm) The test results are as shown in Table 2.

[Table] * One-time rolling process As shown in Table 1, the surface roughness of the die increases as the sputtering time increases, but the processing cost also increases. Therefore, in the current ironing process for fins, the maximum ironing rate is 54%/time, so it can be seen from Table 2 that the sputtering time is only about 10 minutes. [Effects of the invention] The ironing tool according to the invention improves the material's limiting ironing rate by providing a titanium nitride layer with a maximum surface roughness of 1 μm or more on the wall surface of the formed hole. Can be done. By this,
It is possible to prevent the neck from flying off, which occurs when ironing fin materials. Furthermore, the properties of the titanium nitride layer provided make it possible to increase the service life of the tool.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view schematically showing an example of the ironing tool according to the present invention, Fig. 2 is a typical process diagram for forming the fin material, and Fig. 3 is a conventional ironing tool in the state of processing the fin material. FIG. 3 is a schematic cross-sectional view of a processing tool. 1...Dice, 2...Punch, 3...Plate material, 4
... Molded hole, 5... Punch surface, 6... Wall surface of formed hole, 7... Broken portion, 8... Titanium nitride layer.

Claims (1)

[Scope of utility model registration request] In a tool that irons a plate material between the wall surface of a forming hole of a die and the surface of a punch inserted into the forming hole through a plate material, the maximum surface roughness of the forming hole wall surface of the die is 1 μm or more. An ironing tool characterized by having a titanium nitride layer formed thereon.