JP2003033967A - Method and device for working resin material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to effectively perform cutting and grooving work having high finish precision by increasing the speed of raising or lowering of a temperature of a heated blade body as well as avoiding a damage in a design face. SOLUTION: A skin material 1 made of resin is received and supported so as to make a work scheduled part flatter. Just before the work, the tip end part 5a of the heated blade body 5 which is pressed against the work scheduled part of the skin material made of resin 1 is raised up to the softening temperature or more than the melting temperature of the skin material by high frequency induction heating. Then, a V-grove 14 for expansion of an air bag is formed (worked) on the rear face of the skin material by pressing the work scheduled part by the heated blade 5. Immediately after the work, the high frequency inductor heating is stopped.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vinyl chloride (PV) forming an instrument panel for an automobile, for example.
C), polyolefin (TPO), polyurethane (TP)
U) A skin material made of thermoplastic resin such as a line of a predetermined depth to allow breakage at a portion corresponding to the airbag storage location when a destructive force exceeding a certain level is applied due to a collision or the like. TECHNICAL FIELD The present invention relates to a resin material processing method and a processing device applied when processing a groove or cutting a thermoplastic or thermosetting resin material into a predetermined shape.

[0002]

2. Description of the Related Art As a method of processing a resin material of this type, as disclosed in, for example, Japanese Patent Laid-Open No. 4-151345, a heating blade is attached to an electric heater provided with a heating wire such as a nichrome wire. The heating blade body is heated through the electric heater to a temperature higher than the melting point of the resin material to be processed and pressed at a planned processing location, thereby cutting or grooving the resin material. The method is known.

[0003]

However, in the conventional method of processing a resin material as described above, since heat is conducted to the blade from the power source via the heating wire and the electric heater, the blade is Not only is the speed of heating to a predetermined temperature, that is, the temperature above the melting point of the resin material, very low, but the speed of cooling the blade to prepare for the next processing is also very slow. In particular, when processing the above-mentioned thermoplastic resin materials such as TPO and TPU, it is necessary to raise the temperature of the blade to around 300 ° C, and in the case of thermosetting resin materials such as spray urethane, It is necessary to raise the temperature to a higher temperature of around 350 ° C. At this time, in order to prevent the heating wire from breaking, etc., there is a limit to the amount of electricity that must be applied, so the heating speed should be increased above a certain level. It is not possible to do this, and it takes a long time to heat up
Processing efficiency and productivity are very poor.

Further, in the case of an electric heater, when heating and cooling are repeated, troubles such as disconnection of the heating wire are likely to occur. Therefore, when a large number of resin materials are continuously processed, It is necessary to keep the blade body that has been heated to a predetermined temperature during processing of one resin material near that temperature even after processing one resin material, which causes a large heat loss and causes an increase in processing cost. Not only that, the durability of the electric heater and the blade itself may be significantly reduced due to the influence of high temperature heat.

Further, when grooving for deploying an air bag is performed on a skin material portion of an instrument panel for an automobile made of a thermoplastic resin, a groove having a predetermined depth and a predetermined width is pressed by a heating blade. When the blade is pulled up immediately after the is processed, not only does the so-called thread-drawing phenomenon occur, in which the molten resin adheres to the blade and is pulled up together, and the thread-drawn resin causes the side wall of the groove to move. A phenomenon of re-welding occurs on a portion or the like, and as a result, the finishing accuracy of the processed surface of the groove is very poor, and the design surface is greatly damaged. Especially when processing a groove for airbag deployment where it is strongly required to process so as to exhibit a constant reproducible destruction resistance because it is closely related to the safety of passengers of a car. If the above-mentioned stringing phenomenon or re-welding phenomenon occurs, it is not possible to process a groove having an accurate remaining thickness dimension and width dimension.

Therefore, in order to prevent the stringing phenomenon from occurring, the power source is turned off with the heating blade body left in the groove as it is after the groove having a predetermined depth is processed by pressing, and the temperature of the blade body is kept. The method is to lower the melting point of the resin material to below the melting point of the resin material and then pull up the blade after it has been cooled.
As already mentioned, the cooling speed is very slow, so it is necessary to leave the blade in the processed groove of the resin material for a long time after processing, which significantly deteriorates processing efficiency and productivity. However, there is a drawback that the processing cost will rise further.

The present invention has been made in view of the above circumstances, and in addition to being able to avoid damage on the design side, it is very efficient to perform machining with high finishing accuracy by accelerating the temperature rising and cooling rates of the heating blade. It is an object of the present invention to provide a resin material processing method and processing apparatus that can be performed, and are particularly suitable for processing an airbag deployment groove that can ensure accurate residual thickness dimension and width dimension.

[0008]

In order to achieve the above object, a method of processing a resin material according to the present invention is a method of cutting or grooving a resin material to be processed with a heating blade. In this method, the resin material is received and supported so that the planned processing part becomes flat, and immediately before the processing, the tip of the blade pressed against the planned processing part of the resin material is subjected to high-frequency induction heating. After the temperature is raised to above the softening point of the material, the temperature-increasing blade presses the planned processing location to cut or groove the resin material, and immediately after the processing, the high frequency induction heating is stopped. It is a thing.

The processing apparatus for resin material according to the present invention is
This is a resin material processing device that cuts or grooves the resin material to be machined with a heating blade, and a receiving jig that receives and supports the resin material so that the area to be machined is flat. A coil for high-frequency induction heating, which is separate from the blade body and is arranged close to the tip of the heating blade body,
A high-frequency oscillator that supplies high-frequency power to the high-frequency induction heating coil, and the output of this high-frequency oscillator, immediately before processing, the tip portion of the heating blade is heated and raised to a temperature above the softening point of the resin material by high-frequency induction heating, A control unit for controlling the high frequency induction heating to be stopped immediately after processing is provided.

According to the present invention having the above-mentioned constitutional requirements, the high frequency wave is applied immediately before the processing after the heating blade is pressed against the planned processing portion of the resin material which is received and supported so that the planned processing portion becomes flat. By supplying high-frequency power to the induction heating coil to perform high-frequency induction heating on the tip of the heating blade, eddy currents are concentrated on the tip of the heating blade to rapidly soften the tip of the blade. It is possible to heat up to a temperature above the melting point or above the melting point, and by pressing the planned processing point through the heating blade in this state, the resin material can be efficiently cut into a predetermined shape or grooved. It can be processed.

When carrying out the grooving process, the high-frequency induction heating coil is stopped immediately after the process to stop the high-frequency heating of the heating blade body, so that the tip portion of the heating blade body is rapidly moved. Since it is possible to lower the temperature to a temperature below the melting point of the resin material to cool it, even if the heating blade is pulled up after a very short time after processing, the stringing phenomenon and re-welding phenomenon as described above are completely eliminated. It is possible to avoid damage on the design surface without causing it, and to create an airbag deployment groove with an accurate residual thickness dimension and width dimension that exhibits a reproducible constant fracture resistance. It is possible to process with high accuracy and high efficiency.

Further, as described above, since it is possible to rapidly and uniformly heat and raise the temperature of the heating blade by high frequency induction heating and rapidly cool down and cool the blade, as in the case of the electric heater type, In order to stabilize the temperature and respond to continuous processing, it is not necessary to keep the blade at a temperature near the melting point of the resin material, and the output of the high frequency oscillator is turned on and off each time during continuous processing. It is possible to introduce a form, heat loss (power consumption) can be reduced accordingly, and the processing cost can be reduced, and also the deterioration of durability of the blade or the like due to high temperature heat influence can be suppressed.

In the method and apparatus for processing a resin material according to the present invention as described above, as described in claims 2 and 7, when high frequency induction heating is stopped immediately after processing,
By taking measures to rapidly cool the tip portion of the heating blade body, the cooling time can be shortened, the continuous machining cycle can be accelerated, and the productivity can be further improved.

The resin material to be processed according to the present invention may be a thermoplastic resin such as TPO or TPU, or a thermosetting resin such as spray urethane.

Further, as the heating blade in the resin material processing apparatus according to the present invention, as described in claim 6, only the tip portion is made of a material having large eddy current loss and hysteresis loss, for example, iron (Fe). It is preferable to use a material that is configured and whose other portion is smaller in eddy current loss and hysteresis loss than the tip portion, such as aluminum (Al) or copper (Cu). That is, in view of Gauss's law that the electromagnetic field decreases in inverse proportion to the square of the distance from the high-frequency heating coil, the entire heating blade is made of a material such as Fe, which has a large eddy current loss and hysteris loss. Then, a large amount of heat energy will escape to the area other than the tip. On the other hand, only the tip portion is Fe
It is possible to reduce the dissipation of heat energy and rapidly induction-heat only the tip of the blade required for machining with relatively little electric power by configuring it from materials such as it can.

Furthermore, in the apparatus for processing a resin material according to the present invention, as described in claim 8, the coil for high frequency induction heating is provided not on the side portion of the heating blade but on the rear surface of the planned processing portion of the resin material. By being arranged on the side and adapted to be applied to machining of a three-dimensional shape, the range of application of the machining apparatus can be expanded.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic view of an entire processing apparatus used for carrying out the method of processing a resin material according to the present invention, and FIG. 2 is a schematic plan view. This processing apparatus is roughly classified and a chloride for forming an instrument panel for an automobile is formed. Skin material 1 made of thermoplastic resin such as vinyl (PVC), polyolefin (TPO), polyurethane (TPU)
A surface plate 2 serving as a receiving jig for supporting and supporting the front surface side (an example of a resin material) so that the rear surface portion of the V groove processing planned portion corresponding to the airbag storage portion thereof is flat, and the surface plate 2. An elevating base frame 4 arranged directly above the board 2 and configured to be vertically movable through an elevating device 3 such as an air cylinder, and a heating blade body 5 attached to the lower part of the elevating base frame 4. And a plurality of suspenders 6 which are separate from the heating blade body 5 and which are arranged close to both sides of the heating blade body 5 on the lifting frame 4
A high-frequency induction heating coil 7 suspended and supported via the ..., a high-frequency oscillator 8 for supplying high-frequency power to the high-frequency induction heating coil 7, and a controller 9 for controlling the output of the high-frequency oscillator 8. There is.

The surface plate 2 adsorbs the resinous skin material 1 placed on the upper surface 2a thereof by depressurizing the air in the cavity by the suction force of a vacuum pump or the like (not shown) to absorb the resinous skin material 1 The high-frequency oscillator 8 is configured to hold the surface in a tightly fixed state, and the oscillation frequency of the high-frequency oscillator 8 is 2
The maximum output is set to about 20 KW at 0 to 60 KHz.

As shown in FIG. 3, the heating blade body 5 has a tip portion 5a made of Fe, which is a material having a large eddy current loss and hysteresis loss, in a V-shape, and the other portions. The portion 5b is made of a material having smaller eddy current loss and hysteresis loss than the tip portion 5a, for example, Al or Cu. A cooling water circulation path 10 for rapid cooling is formed in the wall thickness of a portion 5b of the heating blade body 5 made of Al or Cu other than the tip, and at a position in the vicinity of the heating blade body 5, machining is performed. A cooling air jetting device 11 for blowing compressed cooling air to the tip portion 5a immediately after is provided.

Further, a temperature sensor 12 is attached to the tip portion 5a of the heating blade 5, and the temperature detected by the temperature sensor 12 is a set temperature equal to or higher than the softening point or the melting point of the resinous skin material 1. When the temperature reaches, the temperature controller 13 is fed back to automatically control the output of the high frequency oscillator 8.

Next, by using the resin material processing apparatus having the above-described structure, a V for air bag deployment is provided at a predetermined portion of the resin skin material 1, that is, a back surface portion of the V groove processing planned portion corresponding to the air bag storage location. A method of processing the groove will be described. First, the planned processing portion of the resin skin material 1 is placed on the upper surface 2a of the surface plate 2 with the surface thereof facing down, and then the air in the cavity is sucked and depressurized by the suction force of a vacuum pump or the like. The skin material 1 is fixedly held on the surface plate 2 so that the surface of the skin material 1 is in close contact with the upper surface of the surface plate 2.

Next, the elevating underframe 4 is lowered through the elevating device 3 such as an air cylinder, and the heating blade 5 attached to the lower part of the elevating underframe 4 is attached to the skin material 1 as shown in FIG.
Press it on the planned processing area on the back side of. At this time, the high frequency induction heating coil 7 is located on both sides of the heating blade 5. Immediately before this processing, when the high frequency oscillator 8 is oscillated (ON) and the preset output power is supplied to the controller 9 to the high frequency induction heating coil 7, it is pressed against the back surface of the skin material 1. Tip 5 of heating blade 5
Eddy current is concentrated in the vicinity of a, and the tip portion 5a is rapidly heated and heated by induction heating. When the temperature detected by the temperature sensor 12 reaches a set temperature equal to or higher than the softening point or melting point of the skin material 1, the output of the high frequency oscillator 8 is controlled by a feedback signal through the temperature controller 13, and thereafter the heating blade is heated. The tip portion 5a of the body 5 is always automatically maintained at a temperature equal to or higher than the softening point or melting point of the skin material 1.

As described above, while the tip portion 5a of the heating blade body 5 is maintained at the set temperature or higher, the elevating underframe 4 is lowered by a set amount via the elevating device 3 such as an air cylinder or the like to heat the heating blade. By pressing the scheduled processing portion of the skin material 1 from the back side by the body 5, the resin in the scheduled processing portion of the skin material 1 is sequentially melted, and as shown in FIG. Shape, that is, it is deformed into a V shape, and a predetermined V groove 14 for airbag deployment is formed (processing).
To be done.

Immediately after the predetermined airbag deployment groove 14 is formed, the oscillating operation of the high frequency oscillator 8 is stopped (OFF).
Then, when the supply of the high frequency power to the high frequency induction heating coil 7 is stopped and the high frequency heating to the heating blade body 5 is stopped, the tip portion 5a of the heating blade body 5 is rapidly cooled to a temperature below the melting point of the skin material 1 and cooled. Will be done. At this time, the cooling water circulation passage 10 formed within the thickness of the portion 5b other than the tip end
Cooling water is circulated through the cooling air jetting device 11
By blowing compressed air for cooling to the tip portion 5a of the heating blade body 5, the heating blade body 5 can be lowered in temperature and cooled more quickly.

In this way, when the heating blade 5 is cooled to a temperature below the softening point or melting point of the skin material 1 and cooled,
By raising the elevating underframe 4 by a set amount through the elevating device 3 such as an air cylinder and pulling up the heating blade body 5 above the V groove 14, no stringing phenomenon or re-welding phenomenon occurs, and the design is improved. There is almost no damage on the surface,
As shown in FIG. 6, it is possible to process the V-groove 14 for deploying the airbag with a very high accuracy, which has an accurate remaining thickness t and a width w and exhibits a reproducible constant fracture resistance.

In the above embodiment, the object to be processed is the skin material 1 of the instrument panel for automobiles made of the thermoplastic resin, and the skin material 1 has the V groove 1 for deploying the airbag.
Although the case of processing No. 4 has been described, it is also applicable to cutting of a thermoplastic resin material, cutting of a thermosetting resin material such as spray urethane, or grooving processing. The tip portion 5a of the heating blade body 5 used for cutting is formed in a shape as shown in FIG.

Further, as shown in FIG. 8, the high frequency induction heating coil 7 may be arranged not on both sides of the heating blade 5 but on the back surface side of the resin material 1 to be processed. In this case, since the coil 7 is not present around the heating blade 5, it can be used for cutting or grooving the three-dimensional resin material 1, and the range of application can be expanded.

[0028]

As described above, according to the present invention, the heating blade that presses the planned processing portion of the resin material is heated and heated by the high frequency induction. Even if it has a high softening point and melting point such as a plastic resin or a thermosetting resin, the heating blade is rapidly heated to a temperature above the softening point or melting point without taking time,
Further, the temperature can be rapidly lowered and cooled. Therefore, in addition to being able to efficiently cut or groove the resin material into a predetermined shape, in particular,
In the grooving process, even if the heating blade is pulled up very shortly after the processing, it is possible to prevent the stringing phenomenon and the re-welding phenomenon caused by the molten resin adhering to the blade body, so that the design surface is not damaged. It is possible to avoid it, and it is possible to very accurately and efficiently process a groove or the like for deploying an airbag that has an accurate residual thickness dimension and a width dimension that exhibit a reproducible constant fracture resistance. .

In addition, even in the case of continuous processing, there is no need to keep the blade at a temperature near the softening point or melting point of the resin material, and the output of the high frequency oscillator is turned on and off at each processing.
It is possible to introduce a control form that reduces the heat loss (power consumption) to reduce the processing cost, and it is also possible to suppress the deterioration of the durability of the blade etc. due to the high temperature heat influence. Produce an effect.

In particular, by stopping the high frequency induction heating immediately after machining and also using another means for rapidly cooling the heating blade, the cooling time can be shortened, the continuous machining cycle can be accelerated, and the productivity can be further improved. Can be improved.

Further, as the heating blade body, only the tip portion is made of a material having large eddy current loss and hysteresis loss, and the other portion is made of a material having smaller eddy current loss and hysteresis loss than the tip portion. By using, it is possible to reduce the dissipation loss of thermal energy during high-frequency induction heating, and to rapidly induction-heat only the tip of the blade required for cutting or grooving with relatively little power, which reduces power consumption. It can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an entire processing apparatus used for carrying out a method for processing a resin material according to the present invention.

FIG. 2 is a schematic plan view of a main part of FIG.

FIG. 3 is an enlarged front view of a main part of the same processing apparatus.

FIG. 4 is an enlarged cross-sectional view of a main part showing a state immediately before processing.

FIG. 5 is an enlarged cross-sectional view of an essential part showing a state in which a heating blade body presses a planned processing portion.

FIG. 6 is an enlarged cross-sectional view of a main part showing a state of a processed V groove.

FIG. 7 is an enlarged front view of a main part showing the tip shape of a heating blade used when cutting a resin material.

FIG. 8 is an enlarged cross-sectional view of a main part for explaining another embodiment.

[Explanation of symbols]

1 Resin skin material (resin material) 2 Surface plate (receiving jig) 5 heating blade 5a V type tip 5b Other parts 7 High frequency induction heating coil 8 high frequency oscillator 9 Controller (control unit) 10 Cooling water circuit 11 Cooling air ejection device 14 V-groove for airbag deployment

Claims (8)

[Claims] 1. A method for processing a resin material, which comprises cutting or grooving a planned portion of the resin material with a heating blade, wherein the resin material is received and supported so that the planned portion is flat. Immediately before processing, the tip of the blade pressed against the planned processing point of the resin material is heated above the softening point of the resin material by high-frequency induction heating, and then the heating target blade presses the planned processing point. A method for processing a resin material, which comprises cutting or grooving the resin material with a groove and stopping high frequency induction heating immediately after the processing. 2. The method for processing a resin material according to claim 1, wherein the heating blade is rapidly cooled together with the stop of the high frequency induction heating immediately after the processing. 3. The method of processing a resin material according to claim 1, wherein the resin material to be processed is a thermoplastic resin material. 4. The method for processing a resin material according to claim 1, wherein the resin material to be processed is a thermosetting resin material. 5. A resin material processing device for cutting or grooving a planned portion of a resin material with a heating blade, which receives and supports the resin material so that the planned portion is flat. A jig and a high-frequency induction heating coil which are separate from the heating blade and are arranged close to the tip of the heating blade, and a high-frequency oscillator that supplies high-frequency power to the high-frequency induction heating coil. , The output of this high-frequency oscillator is controlled so that the tip portion of the heating blade is heated to a temperature above the softening point of the resin material by high-frequency induction heating immediately before processing, and the high-frequency induction heating is stopped immediately after processing. An apparatus for processing a resin material, comprising: a control unit. 6. The heating blade body is made of a material having large eddy current loss and hysteresis loss only at its tip portion,
The resin material processing apparatus according to claim 5, wherein the other portion is made of a material having smaller eddy current loss and hysteresis loss than the tip portion. 7. The heating blade body and / or a portion in the vicinity thereof is provided with a cooling means for rapidly cooling the heating blade body as well as stopping the high frequency induction heating immediately after processing.
Or the processing apparatus of the resin material as described in 6. 8. The high-frequency induction heating coil is arranged not on the side portion of the heating blade but on the back surface side of the scheduled processing portion of the resin material, and is applicable to three-dimensional processing. Item 8. An apparatus for processing a resin material according to any one of Items 5 to 7.