JPS586732A - Method and device for electromagnetic formation of wind instrument - Google Patents

Abstract

PURPOSE:To form the morning-glory part of a wind instrument electromagnetically and smoothly in a simple process by equipping a morning-glory electrode with a material to be worked, and successively feeding and spreading the material in every power feeding operation. CONSTITUTION:A coil 1 and a deformed coil 2 are arranged inside of a morning-glory electrode, and molded in one body with a coupling material for a buffer material. This electrode is equipped with a material 13 to be worked which has its opening end spread in a corn shape, and consequently the electrode is adhered to the internal circumferential surface of the material 13 by the elasticity of the coupling material 3. When a large current is flowed through the coil 1 of the electrode, the material 13 is operated in the opposite direction to the electrode to be spread. Every time the electrode is fed with electricity, the material 13 is fed downward and the opening end 13a of the material 13 is bent roundly along the arc shape of the beltlike coil 2 having rigidity. This method facilitates the spreading work of the opening end of the material 13 for a wind instrument.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a ninth electromagnetic forming method and an electromagnetic forming apparatus for expanding and forming the morning glory portion of a wind instrument.

In the electromagnetic forming method, when electricity is applied to the electrode, a magnetic field generated by the current flowing through the electrode is applied to the current conducted through the metal workpiece, and at this time, the force acting on the workpiece due to the current flowing This method is used to deform the workpiece in layers, and is well known in principle.

Some of the electrodes used in conventional electromagnetic forming methods are simply coils wound around the workpiece, but if the workpiece is processed and deformed, the coil will break and become unusable after a single process. Therefore, the coil becomes a consumable item and cannot be avoided.

In addition, since the coil escapes from the workpiece during machining, the reaction force acting on the workpiece becomes smaller, reducing machining performance.

As a modification of this, a method has been proposed in which an electrode is formed into a coil so that it is rigid and does not deform. However, when using such electrodes, it is difficult to keep the electrodes in close contact with workpieces that have complex shapes, and the amount of deformation that cannot be sufficiently formed in one machining process is extremely high. When processing something, it is necessary to make electrodes in multiple shapes, which increases manufacturing costs.

When the electrode is not in close contact with the workpiece and a part of the coil is close to the workpiece, it is difficult to process the electrode because it is not possible to increase the voltage because the core part is prone to dielectric breakdown. The problem was that the ability had to be kept low.

This invention was made in view of the above points, and its purpose is to provide an electromagnetic forming method that can manufacture the morning glory part of a wind instrument with a simple process, and an economical method with excellent processing ability. An object of the present invention is to provide an electromagnetic forming device.

In order to achieve such an object, the present invention is such that a material to be processed is attached to a morning glory-shaped electrode, and each time electricity is applied, the material is sequentially fed into the electrode for expansion molding. Further, this electrode is constructed by molding a molded coil wound in a morning glory shape with a connecting material having heat resistance, insulation resistance, and flexibility.

Hereinafter, this invention will be explained in detail based on examples.

FIG. 4 is a longitudinal sectional view of one embodiment of the electrode used in the present invention. In the figure, IFi is a cylindrical I/c-wound coil that is sequentially expanded so that the winding diameter becomes larger, and 2 is a rigid band-shaped coil that is wound with an even larger winding diameter at the end of the part where the winding diameter is the largest. Coil 3 is a connecting member made of a cushioning material having excellent heat resistance, insulation resistance, and appropriate flexibility, which is integrally molded with a molded coil consisting of coil 1 and strip coil 2. This band-shaped fill 2 has a ring shape with an arcuate cross section and a cut at one point. Therefore, coil 1. The electrode consisting of the strip coil 2 and the connecting member 3 is formed in a morning glory shape with an opening opening outward. The lead [4] is drawn out from the end of the coil 1 with the smallest winding diameter, and the end of the coil 10 with the largest winding diameter is the lead II5.
It is connected to one cut end of the band-shaped coil 2 by. Further, a lead 416 is drawn out from the other cut end of the strip coil 2.

Now, turn on the switch T to turn on the DC high voltage power supply 8! ff
When the switch T is turned off after charging the capacitor 9 and then the switch 10 is turned on, the charge stored in the capacitor 9 is transferred to the lead wire 4. Coil 1. Lead aS, band coil 2. Lead! It is instantaneously discharged via I6. Due to this discharge, the coil 1'1? A large current flows through the strip coil 2. It goes without saying that at this time, current flows through the strip coil 2 in the same direction as the coil 1.

Next, a process of expanding and molding the morning glory part of a wind instrument using this electrode will be explained.

211(a) to 211(0) are longitudinal cross-sectional views of each step. In the figure, reference numeral 12 indicates a back-up body made of a cushioning material disposed inside the morning glory-shaped electrode, and reference numeral 13 indicates a workpiece material made of metal attached to the outer surface of the electrode.

The group of workpieces 13 has an open end shaped like a cone and is fitted onto the outer circumferential surface of the electrode and then pushed downward by a mold (not shown), so that the workpiece 13 strongly presses the outer circumferential surface of the electrode. . Here, since the electrode is configured to have elasticity due to the connecting member 3, the inner periphery rIi of the workpiece material 13
KpJ1 will come into close contact with the entire surface immediately.

In this state, when the companion switch 10 shown in FIG. 1 is turned on to discharge the capacitor 9, a large current flows through the coil of the electrode, and according to the principle of electromagnetic forming, the workpiece 13 is moved away from the electrode. Expands in response to acting force. At this time, the strip coil 20 is busy because the workpiece material 13 has not yet arrived, so the current R density in this coil section usually increases and it overheats, but the strip coil 2 has a larger cross-sectional area than the other coils 1. Because it is formed, the electric current is 1mm! 91 will not rise and will not cause dielectric breakdown. When the electrode is repeatedly energized, the expanded workpiece material 13 is sequentially fed into the electrode with a larger diameter (lower part in the figure) as shown in Figure 2 (
The state of b) is reached. By repeating this processing operation one more time, the skirt 5tsa at the open end of the workpiece material 13 is
The strip-like coil 20 having rigidity is bent into a round shape along the circular arc shape with strong force, and is smoothly expanded and formed as shown in FIG. 2(e).

As described above, according to this embodiment, since the electrode has elasticity, it is possible to easily bring the electrode into close contact with the workpiece material, which improves the processing efficiency, and also allows part of the coil to be brought close to the workpiece material. This eliminates the possibility of dielectric breakdown occurring. Further, by forming a rigid band-shaped coil at the end of the electrode with a larger diameter, the open end of the material to be processed can be easily widened to a large extent. Furthermore, since the strip coil has a large cross-sectional area, dielectric breakdown will not occur even if it is not bent by the material to be processed.

As described above, according to the present invention, the morning glory portion of a wind instrument can be smoothly widened through a simple process, and has excellent economical effects.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view of an embodiment of an electrode used for electromagnetic forming Ij & Ai according to the present invention, and Fig. 2 (a) to (e) show each step in carrying out the electromagnetic forming method according to the present invention. FIG. 1... Φ coil, 2... strip coil, 3000.
Connecting material, 12... Backup body, 13... Material to be processed. Patent applicant: Nippon Musical Instruments Manufacturing Co., Ltd. Agent: Masaki Yamakawa (1 person)

Claims (1)

[Scope of Claims] (The material to be processed is attached to the outer circumferential surface of a morning glory-shaped electrode in which a shape coil is inserted, and each time the forming coil is energized, the material to be processed is transferred to the side of the electrode with a larger diameter. An electromagnetic forming method for wind instruments, in which expansion molding is performed by sequentially feeding the material into molds. (2) A back-up body is disposed inside the electrode to mold the material to be processed. A method for electromagnetic forming of a wind instrument as described in Claim II Kei 1114. An electromagnetic forming device for a wind instrument, characterized in that the electrodes are formed by molding. (4) A patent characterized in that the forming coil is formed so that the end with a larger value has high rigidity. Billing 0
1EII Item 3 O Electromagnetic forming device for wind instruments. (5) The electromagnetic forming device for a wind instrument according to claim 4, wherein the forming coil has a larger diameter end portion having a larger cross-sectional area than the other portion.