JPH0739955A - Method for molding pure titanium or titanium alloy sheeet parts by detonation pressure - Google Patents

Abstract

PURPOSE:To produce cup-shaped parts of titanium without causing cracking and distortion by converting the high pressure obtd. by converting the detonation waves by firing of a combustible gaseous mixture to a pressure by liquid or rubber-like material and executing die molding. CONSTITUTION:A titanium sheet P is set on a metal mold 16. A specific vacuum degree is maintained in a firing chamber 4, a dispersion chamber 4, an induction path 2, a combustion chamber 1 and a molding device 13 by a vacuum pump device 17. A pressure medium is thereafter packed into a pressure chamber 12 and combustible gases of almost theoretical mixing ratios re supplied and packed from a fuel supplying source 9 and an oxidizing material supplying source 10 into the induction path 2 and the combustion chamber 1. An ignition plug 5 is operated by a firing device 6 after completion of setting. The detonation by firing is induced in the firing chamber 4 and the fires thereof are propagated through the dispersion chamber 3 and the induction path 2 into the top end 1A of the combustion chamber 1. Since the cross area of the combustion chamber 1 decreases successively, an extremely high pressure is generated at the bottom end 1B. This pressure propagates from the aperture to the pressure medium in the pressure chamber 12 and presses the sheet material P to the metal mold 16 under the equal pressure, thereby molding the material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of molding a pure titanium or titanium alloy thin plate as a raw material into a cup-shaped component such as a container, a pot or a helmet by a mold.

[0002]

BACKGROUND OF THE INVENTION Mild steel, stainless steel or aluminum,
As a forming method for forming a thin plate made of copper or the like into a cup-shaped part by drawing, hitherto, press forming is generally widely used. On the other hand, cold forming methods for titanium materials include press forming, spinning method, and spatula drawing method, but the flange part is deformed unevenly due to the strong plastic anisotropy peculiar to titanium, which is called the so-called ear. The edges are wavy. Therefore, the yield is reduced and the number of processes is increased. In addition, the modulus of elasticity is lower than that of steel, and because of the strong elastic and plastic anisotropy peculiar to titanium, when the molded product is removed from the mold after molding, the molded product deforms and the shape is distorted. There is. In order to solve this problem, Japanese Patent Laid-Open No. 4-3
Japanese Unexamined Patent Publication No. 0817 discloses a method of punching with a hammer while rotating a blank material using a swivel punching machine.

[0003]

However, the technique disclosed in Japanese Patent Application Laid-Open No. 4-30817 has a problem that it takes a long time to process. The present invention solves such a problem, and when molding a cup-shaped component from a pure titanium or titanium alloy thin plate, a method for molding the molded component with high dimensional accuracy and good yield in one step in a short time is provided. It is intended to be provided.

[0004]

The method of forming a pure titanium or titanium alloy thin plate component by detonation pressure according to the present invention comprises:
When molding a cup-shaped part from a pure titanium or titanium alloy thin plate using a mold, the detonation wave generated by igniting a combustible mixture is converged as it progresses, and the high pressure obtained at the converging part is converted into liquid or It is transmitted to a pressure medium made of a rubber-like substance and converted into a hydraulic pressure or an elastic pressure, and the hydraulic pressure or the elastic pressure is applied to a member to be molded on a mold via the medium or directly to perform molding.

[0005]

In the present invention, the pure titanium or titanium alloy thin plate is formed in the following manner. First, a pure titanium or titanium alloy thin plate is placed on a mold and the peripheral portion is fixed.
Then, the combustible chamber, the guide passage, and the ignition chamber, which can communicate with each other, are filled with a combustible mixed gas having an almost ideal mixing ratio. Next, ignition is performed in the ignition chamber. When ignited, the flame advances in the combustion chamber through the taxiway due to the detonation. At this time, since the respective guide passages have the same path length, the respective guide passage flames simultaneously reach one end of the combustion chamber.

In the combustion chamber, the flame propagates toward the other end, but since the cross-sectional area of the combustion chamber decreases toward the other end, the flame pressure rises and reaches the maximum value at the other end. Become. Since the pressure medium chamber is connected to the opening at the other end and the pressure medium faces the opening, the pressure is transmitted to the pressure medium in the pressure medium chamber. The pressure of the pressure medium in the pressure medium chamber further presses the pure titanium or titanium alloy thin plate which is the member to be molded on the die through the medium or directly to mold the cup-shaped component.

[0007]

EXAMPLE In this example, pure titanium (JIS standard 1 to 3 types) was used as the titanium material to be molded, but a titanium alloy having cold forming ability, for example, Ti-3% Al-2.5% V alloy. Alternatively, β-type titanium alloy may be used. The thickness of thin plates made of these titanium materials is in the range of about 0.5 mm to 3 mm, but in the case of materials with high cold workability, it is possible to form plates with a thickness of 3 mm or more. The titanium material in this range is mainly a cold-rolled plate, but a hot-rolled thin plate can be used when the plate thickness is around 3 mm.

In the case of the first embodiment in which a cup-shaped component is molded from the above-mentioned titanium thin plate, the apparatus as shown in FIG. 1 is used. In the figure, reference numeral 1 denotes a combustion chamber, which has a conical shape facing downward and has a maximum cross-sectional area at the upper end 1A and a minimum at the lower end 1B to form a converging portion. The inner wall of the upper end portion 1A of the combustion chamber 1 is curved slightly upward, and a plurality of hole-shaped guide passages 2 communicate therewith. The plurality of guide paths 2 are converged at the upper side into a disk-shaped dispersion chamber 3. The dispersion chamber 3 is connected to an ignition chamber 4 extending upward. An ignition plug 5 that is operated by an ignition device 6 is provided above the ignition chamber 4, and a fuel supply source 9 and an oxidant supply source 10 are connected via flowmeters 7 and 8, respectively. . In addition, 11 is a pressure gauge for confirming the pressure in the ignition chamber 4.

The upper end portion 1B of the combustion chamber 1 is opened, and the pressure chamber 12 is connected thereto. The pressure chamber 12
An elastic body or a liquid is contained therein as a pressure medium. In the case shown, an example of a liquid is shown. A molding device 13 is provided immediately below it. The pressure chamber 12
In the figure, a liquid such as water as a pressure medium is converged in the case shown in the figure. However, even if the liquid surface directly faces the lower end portion 1B of the combustion chamber 1 as shown in the figure, it is strong and easily deformable. The intermediate surface may be formed by a film body. A pipe 14 for venting air is connected to the pressure chamber 12 via a valve, and a liquid supply device 15 such as water for hydraulic pressure is connected via a valve.

The molding apparatus 13 accommodates a cylindrical mold 16 for molding in a replaceable manner. If the curvature of the shoulder portion of the cylindrical die is set appropriately, it can be punched simultaneously with molding. . The molding device 13 is
Between the pressure chamber 12 and the flange, for example, the peripheral edge of the titanium thin plate P to be subjected to molding can be held. A vacuum pump device 17 is connected to the molding device 13 so as to penetrate the mold and communicate with the upper space thereof to create a vacuum in the space. The vacuum pump device 17
Is also connected to the ignition chamber 4 described above.

High pressure hydraulic pressure or elastic pressure is generated by this device, and molding using this is performed as follows. First, a titanium thin plate is set on the mold 16 as a plate material P to be molded. Next, the vacuum pump device 17 brings the ignition chamber 4, the dispersion chamber 3, the guide passage 2, and the combustion chamber 1 to a predetermined vacuum degree. At the same time, the inside of the molding device 13 is also sucked so as to have a predetermined degree of vacuum. The suction time is several tens.
It only takes a few seconds to a few minutes.

After that, when the pressure medium is a liquid, for example, water is filled in the pressure chamber 12, and the ignition chamber 4, the dispersion chamber 3,
The induction passage 2 and the combustion chamber 1 are filled with a fuel supply source 9 and an oxidant supply source 10 with a combustible gas having a substantially theoretical mixing ratio. After such setting is completed, the ignition device 6 operates the spark plug 5. Detonation occurs due to ignition in the ignition chamber 4, and the flame is propagated to the upper end 1A of the combustion chamber 1 via the dispersion chamber 3 and the guide passage 2. At this time, since the path lengths of the plurality of guideways 2 are set to be equal to each other, the flames of the plurality of guideways 2 simultaneously reach the upper end portion 1A.

In the combustion chamber 1, the flame progresses from the upper end portion 1A to the lower end portion 1B, but since the cross-sectional area of the combustion chamber 1 gradually decreases downward, its pressure rises and at the lower end portion 1B. It becomes extremely high pressure. At the opening of the lower end 1B of the combustion chamber 1, the pressure chamber 1
Since the liquid surface of the liquid in 2 or the end surface of the elastic body faces, the above-mentioned high pressure is propagated from the liquid surface or the end surface into the liquid or the elastic body, and the plate material P is made equal pressure to the mold 16. Press forming is performed. After that, the plate material as a molded product is taken out and the above steps 1 to 3 are repeated, so that molding can be performed one after another.

Next, a second embodiment of the present invention will be described.
In the case of this embodiment, the device shown in FIG. 2 is used. Since this device has some parts in common with the device used in the first embodiment, the common parts in FIG. 2 are assigned the same reference numerals as in FIG. 1 and their explanations are omitted.

In the present embodiment, the combustion chamber 1'is formed in a horizontal shape that expands in the radial direction. The combustion chamber 1'has a shape in which its cross-sectional area decreases toward the center due to the upper wall surface of a part of a substantially spherical surface which bulges downward. On the upper wall,
An appropriate number of grooves 1'C directed toward the center are radially formed, and the combustion chamber 1'communicates with the pressure chamber 12 at the central portion.

This device is convenient when used in places where the height of the device cannot be increased. The operation is similar to that of the first embodiment, and after the flame reaches the peripheral portion 1′A which is one end portion of the combustion chamber 1 ′ from the guide passage 2, the central portion 1 ′ which is the other end portion. Proceed toward B. At that time, the pressure becomes extremely high as the cross-sectional area decreases. And
The high pressure is propagated to the pressure medium in the pressure chamber 12, and the plate material P is pressed against the molding die 16 by the molding device 13 to mold the cup-shaped component.

Next, specific examples of the present invention carried out by using the apparatus shown in FIGS. 1 and 2 will be shown numerically. As shown in Table 1, the chemical composition of the pure titanium thin plate (cold rolled, annealed material) used in the trial production is JIS Class 1 and Class 2 grades.

[0018]

[Table 1]

Table 2 shows examples of the present invention and comparative examples by the press and swivel embossing methods. With the press of the comparative example, cracks and distortions occur and it is impossible to form into a predetermined shape. Moreover, although the swirl-type embossing method enables molding, it takes 60 minutes or more for molding. On the other hand, in the detonation pressure method according to the present invention, defects such as cracking and distortion do not occur, and molding can be performed in a short time (1 to 3 minutes or less per cycle).

[0020]

[Table 2]

[0021]

According to the present invention, it becomes possible to manufacture titanium cup-shaped parts, such as containers, pots, helmets and golf club heads, which have been difficult to form in the past, with a high yield and in a short time.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an apparatus used for carrying out a first embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view of an apparatus used when performing the second embodiment of the present invention.

[Explanation of symbols]

 1 Combustion chamber 1'Combustion chamber 1A One end (upper end) 1'A One end (surrounding part) 1B Other end (lower end) 1'B Other end (center) 2 Taxiway 4 Ignition chamber 5 Spark plug 12 Pressure Chamber 13 Molding Chamber (Molding Device) 16 Mold for Molding P Molded Member

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshio Murayama 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Steel Pipe Co., Ltd.

Claims (1)

[Claims] 1. When forming a cup-shaped part from a pure titanium or titanium alloy thin plate using a mold, a detonation wave generated by igniting a flammable mixture is converged as it progresses and obtained at the converging portion. The high pressure is transmitted to a pressure medium composed of a liquid or a rubber-like substance to be converted into a liquid pressure or an elastic pressure, and the liquid pressure or the elastic pressure is applied to the member to be molded on the mold through the medium or directly to perform molding. A method for forming pure titanium or titanium alloy thin plate parts by detonation pressure.