JPS5839640B2 - Hikinzokuzairiyounopresskakohouhoutsonosouchi - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention includes processing such as punching out flat plate materials such as wood or synthetic resin products to produce various shapes, or punching out a part of a molded product to make holes. The present invention relates to a method and apparatus for press working, including cutting, forming, drawing, coining, and other forming processes.

More specifically, non-metallic materials (hereinafter sometimes simply referred to as non-metallic materials) selected from thermoplastic materials, heat-degradable materials, and composite materials containing these materials that tend to cause defects such as cracking, fuzzing, and buckling during press working.

) The present invention provides a novel press working method and an apparatus therefor, which enable the above press working to be carried out without problems and efficiently.

Conventional press processing is carried out using a press machine equipped with a punch and a die that receives the punch, but the materials to be processed include hard materials with low impact strength, materials containing fibrous substances, materials with large molecular orientation, and foamed materials. When pressing a low-density material such as a body, problems such as cracking, fuzzing, and buckling are likely to occur (this method is extremely difficult to implement).

In particular, when the thickness is several millimeters or more, press working is impossible in many cases, and the materials that can be practically applied are limited to soft materials and thin parts.

Conventional techniques for preventing cracking, which is the biggest problem in press working of these non-metallic materials, include raising the temperature of the workpiece material using a heating means such as a hot air oven or infrared irradiation. to a temperature substantially above the glass transition point,
In the case of drawing, bending, etc., there is a method of press working at a temperature above the heat distortion temperature, but the heating means and process are complicated, the heat loss is large, and the effect of thermal expansion of the workpiece material There are many problems in implementation, such as a decrease in dimensional accuracy and the tendency for appearance irregularities to occur on the surface of the processed product due to differences in thermal history caused by the heating process.

On the other hand, those skilled in the art have also attempted a method of heating the required portions of the punch or die with a nichrome wire heater, but there are unavoidable problems in implementing this method industrially.

For example, the finished surface may be rough due to welding due to thermal forces, dimensional accuracy may be poor, the temperature of the cutting edge decreases when it comes into contact with the workpiece, resulting in poor "cutting", and the transmission of electricity to the equipment body. These include heat loss due to heat and its insulation measures.

Although part of the problem of welding due to heat can be solved by cooling the heating section and then removing the product, this heating method is not a rational method in terms of heat loss, cooling time, etc.

It is an object of the present invention to have a punch in which only the processing part that comes into contact with the workpiece can be rapidly heated and cooled with a small amount of energy, and is thereby made of a thermoplastic material that is easily cracked or prone to fuzzing on the surface. It is an object of the present invention to provide a press working device capable of press working a workpiece without generating cracks or fuzz.

The press processing apparatus of the present invention achieves this objective.

It is characterized by consisting of a punch whose tip part that comes into contact with the workpiece is made of a magnetic material, and a die for placing the workpiece, which is equipped with a high-frequency induction heating inductor at the upper position for induction heating the magnetic material. That is.

According to the device of the present invention, based on the characteristics of high-frequency induction heating, Joule heat and hysteresis loss heat due to eddy currents generated in the magnetic material due to electromagnetic induction by the high-frequency electromagnetic field are generated concentrated in the surface layer of the magnetic material. However, since the surface layer can be heated locally and in an extremely short time of a few seconds,
In addition to being able to limit the amount of magnetic material, only the surface layer is heated, resulting in extremely high thermal efficiency.

Therefore, it is possible to easily perform press processing such as fusing, burning, coining, etc. of non-metallic materials with extremely high thermal efficiency.

The punch in the present invention is provided with a magnetic material in the portion of its tip that contacts the workpiece, but the material of the other portions is not particularly limited.

As the magnetic material, common materials such as iron, nickel, cobalt, or alloys containing these as one component can be used.

The surface of the magnetic material attached to the punch can also be coated with a heat-resistant resin to improve mold release properties.

Various shapes of punches can be used depending on the purpose and are not different from conventional punches, but in the case of punching large areas, punches of a type where only the contour part for punching comes into contact with the workpiece material are recommended. Punch is suitable.

It is preferable to provide a through hole inside the punch for cooling, since the press working time can be shortened.

An inductor connected to a high frequency power source to heat the magnetic material portion of the punch is preferably provided near the position where the punch contacts the workpiece material in order to increase the heating effect.

In other words, if it is installed inside the die below the die surface on which the workpiece material is placed, the magnetic flux density will gradually increase as the distance between the punch tip and the die surface approaches, resulting in a rapid increase in heat generation and a decrease in efficiency. High press processing is easily possible.

Especially when cutting, "cutting" becomes better.

The inductor may be of a mechanism that removes copper loss heat generated by passing cooling water through a coil made of copper pipe.If multiple independent shapes are to be stamped at the same time, each coil may be connected in series. It can also be implemented.

The material of the dice is preferably a non-magnetic material with good electrical insulation properties and high structural strength; for example, synthetic resin materials, wood materials, inorganic materials, etc. can be used.

The shape of the die is determined by the shape of the intended product and the shape of the punch, but it is convenient to adjust the magnetic flux density distribution if the inductor can be moved and adjusted inside the die.

The punch or die is generally preferably driven pneumatically or hydraulically.

In particular, for fragile materials with low impact resistance, it is more preferable to use a two-stage pressing mechanism that applies a predetermined pressing pressure after bringing the tip of the punch into soft contact so as not to apply a strong impact to the workpiece material.

It is efficient to excite the inductor intermittently in conjunction with the movement position of the punch.

Materials that can be pressed using the method and apparatus of the present invention are non-metallic materials such as thermoplastic materials, heat-degradable materials, or composite materials containing these materials.

The frequencies of the high frequency power source used in the present invention are 50Hz, 6
Although it is sufficient to use a commercial frequency of 0 Hz or higher, the higher the heating power density, the higher the heating power density, so a high frequency is preferable when heating more rapidly or when heating a punch with a smaller shape.

An industrially effective frequency is 102 Hz or more, and a particularly effective frequency is 103 to 106 Hz.

The present invention will be explained below with reference to the drawings.

FIG. 1 is a longitudinal cross-sectional view showing important parts of an example of a press working apparatus of the present invention, and a shows a state before working.

The punch 1 is provided with a magnetic material 2 at its tip, and further has a through hole 3.
is installed to allow cooling water to pass through.

An inductor 5 is provided inside the die 4 for exciting a high frequency electromagnetic field.

The inductor 5 is a coil made of copper pipe, and is designed to remove copper loss heat generated by passing cooling water into the pipe.

The workpiece material 6 is placed on the die 4 and pressed.

b shows the state after punching, and a relay circuit is set up so that the inductor 5 is not energized at this time.

FIG. 2 shows a vertical cross-sectional view of a punch 1 and die 4 of the punch type, and the magnetic material 2 at the tip of the punch 1 is provided only at the punching contour.

The upper surface of the die 4 is simply flat, and an inductor 5 is provided as a double-wound coil made of copper pulp inside the surface under which the workpiece is placed.

FIG. 3 shows a longitudinal cross-sectional view of a coining device for imparting an uneven pattern to the surface of a workpiece. All the reference numerals in the drawing are the same as in FIGS. 1 and 2.

Next, examples will be shown.

Example 1 Punch 1 and die 4 shown in FIG. 1 were used (not shown) to punch a 15 square hole in a glass fiber-reinforced styrene-acrylonitrile copolymer resin plate with a wall thickness of 5 mm. The test was carried out by attaching it to a pressure-type press machine.

The punch 1 of the apparatus is an epoxy resin cast product with a steel attached to the tip 2, and the die 4 is a cast product with a copper pipe inductor 5 sealed in epoxy resin at the position shown in the figure.

Although the inductor 5 is not shown, it is connected to a power source with a high frequency output of 3 KW and an oscillation frequency of 400 KHz.

A relay circuit is constructed so that excitation from the inductor 5 starts when the punch 1 starts descending and ends when punching is completed.

The test was carried out while cooling water was constantly passed through the cooling hole 3 of the punch and the copper pipe of the inductor 5.

When the plate material 6 was punched using the above-mentioned apparatus at a press pressure of 30 kg/i, no cracks were generated in the punched portion, and holes could be formed without any fuzzing of the glass fibers.

Example 2 The punch and die shown in FIG.
A star-shaped punching process (tip end diameter 70 mm) was performed on a 5-inch board.

The punch 1 is a skin-removal type punch made of polyester resin and has a tip 2 equipped with a star-shaped blade made of stainless steel.

The die 4 was made of wood, and an inductor 5 made of a copper pipe was fixed at the position shown in the figure.

Although not shown, the inductor 5 is connected to a power source with a high frequency output of 3 KW and an oscillation frequency of 450 KHz.

The timing of excitation from the inductor 5 was the same as in the first embodiment.

This was carried out while constantly passing cooling water through the cooling hole 3 of the punch and the copper pipe of the inductor 5.

As a result of punching the plate material 6 using this machine at a pressure of 10 kg/crt, the cut surface had no cracks or buckling, and an unexpectedly smooth skin was formed on the cut surface.

Example 3 In order to punch a hole in the same shape as Example 2 in a flat plate of lauan material with a wall thickness of 5 mm, a new punch was used with a wall thickness of 0.8 mm and a band width of 50 mm.
A piece produced by bending a steel strip of mm was attached to a phenol plate, and combined with a die in which only the upper layer of the die 4 shown in Fig. 2 was replaced with an asbestos plate, Setefless processing was carried out.

As a result, a product with no cracks or fluffing of the fibers was obtained, although there was some discoloration due to burns along the area in contact with the punch.

Example 4 For the purpose of forming an uneven pattern by coining on the surface of a 300 times expanded styrene resin plate, die 1 and punch 2 shown in FIG. 3 were used.

The punch 1 has a magnetic material portion 2 manufactured by iron electroforming on the surface that contacts the workpiece material, and is lined with resin-containing plaster.

The die 4 is made of resin-containing plaster by fixing an inductor 5 made of a copper pipe at the position shown in the figure.

A relay circuit is constructed so that the excitation from the inductor 5 is applied from the time when the punch 1 starts descending until the punch 1 reaches a predetermined depth.

The inductor 5 was connected to a power supply device with a power output of 6 KW and a frequency of IKHz.

As a result of coining by applying a pressure of 1.5 kg/i while constantly passing cooling water through the cooling hole 3 and inductor 5 of the punch 1, no cracks were generated and a smooth skin layer was formed on the coined surface.
Moreover, extremely good mold reproducibility accuracy was obtained.

The present invention has the configuration described above, and the effects of the invention can be summarized as follows.

First of all, it is now possible to press the materials mentioned above, which were impossible to press with conventional techniques, or which are prone to problems such as cracking, fuzzing, buckling, etc. This makes it possible to cut not only straight lines but also curved lines without producing chips.

Other advantages include that the press pressure is low, so the strength level of the equipment is lower than that of conventional press machines, and that the heated part is concentrated at the tip of the punch, and rapid heating can be performed intermittently, so the The loss is very small compared to other heating means, and the characteristic effect of the present invention is that the punch can be rapidly heated and cooled repeatedly, making the pressing process easier than when using other heating means. This is a revolutionary improvement in speed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view showing an example of the apparatus of the present invention for hole drilling, where a shows the state before processing and b shows the state after processing. FIG. 2 is a cross-sectional view showing an example of the apparatus of the present invention using a skin removal type punch, and FIG. 3 is a cross-sectional view showing an example of the apparatus of the present invention for coining. 1... Punch, 2... Magnetic material part of punch, 3... Punch cooling hole, 4...
・Dice, 5... Inductor, 6...
Material to be processed.

Claims (1)

[Claims] 1 In a press processing device for non-metallic materials selected from thermoplastic materials, thermally degradable materials, and composite materials containing these materials, a punch whose tip portion that contacts the workpiece is made of a magnetic material, and the magnetic material is heated by induction heating. 1. A press working device for non-metallic materials, comprising a die for placing a workpiece, and a die for placing a workpiece, which is provided with an inductor for high-frequency induction heating at an upper position.