JP2002096387A - Method and apparatus for forming linear groove on air bag of skin for automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable efficient forming of a linear groove having a reproducible predetermined breakage resistance with a predetermined thickness retained at a skin surface side by a small power consumption under a simple control while avoiding a damage of a design surface. SOLUTION: An apparatus for forming the linear groove on an air bag of a skin for an automobile comprises a heater 8 and an ultrasonic machining unit 4 aligned in parallel at a rear surface 3b side of the skin 3 made of a resin fixedly held, so that a front surface 3a is closely contacted with a flat surface 1a. An oscillation horn 4C of the unit 4 is regulated at its position so that a clearance between its distal end and the surface 1a coincides with the set residual thickness of the surface 3a side. The heater 8 and the unit 4 are moved along a line to be machined to preheat the machining part, softened and sequentially melted at the resin for the skin by ultraviolet oscillation immediately after the softening, the molten resin is removed to its side, and the groove 6 is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to vinyl chloride (PV) forming, for example, an instrument panel for a vehicle in order to ensure the safety of a passenger in the event of a vehicle collision.
C), polyolefin (TPO), polyurethane (TP
The present invention relates to a method and a processing apparatus for processing a linear groove for allowing breakage at a point where a destructive force exceeding a certain level is applied to an airbag portion of a resin skin such as U). is there.

[0002]

2. Description of the Related Art A linear groove to be formed on an airbag portion of a resin-made skin for automobiles is required to be formed not on the front side of the skin but on the back side of the skin from the viewpoint of design. Since the linear groove is closely related to the safety of the occupant, it is required to process the linear groove so as to exhibit a reproducible constant breaking resistance. In order to meet such demands and demands, in recent years, means for processing a linear groove from the back side of the skin so as to leave a predetermined thickness on the front side of the skin has been generally adopted.

Conventionally, as means for processing a linear groove from the back side of the skin, there are conventionally known means (a) for processing a linear groove by mechanically cutting a resin material using a knife-shaped cutter or the like. (B) As disclosed in, for example, JP-A-10-85966, there is known a means for processing a linear groove by radiating a laser beam to locally incinerate and remove a resin material.

[0004]

However, in the case of the mechanical processing means (a), even if the processing is performed from the back side of the skin, a linear processing mark is formed on the front side of the skin which is the design surface. It is technically difficult to excise it without exposing it, causing serious design damage. In this type of processed product, it is important to measure the remaining wall thickness on the skin surface side after processing the linear groove and record and save data for each processed product from the viewpoint of quality control. In the case of the processing means, since the groove width is narrow and both sides of the groove are in close contact with each other due to the elastic force of the resin material immediately after the cutting, it is difficult to accurately measure the remaining wall thickness. It is not preferable from the viewpoint.

On the other hand, in the case of the laser processing means (b), although a predetermined linear groove can be processed without damaging the design surface (skin surface), a large output power is required. In addition, the power consumption increases and the processing cost increases. In particular, to process wide grooves that are easy to accurately measure and record the remaining thickness, which is important for quality control, use a laser beam generator with enormous output power or compare It is necessary to trace a laser beam generator having a small output power a plurality of times along a planned processing line, and as a result, there is a problem that the processing cost is further increased.

In order to process a linear groove having a constant and reproducible breaking resistance by leaving a predetermined thickness on the surface of the skin by laser processing means, it is necessary to cope with variations in the thickness of the skin. It is necessary to delicately control the amount of incineration and removal of the resin material, that is, the processing depth of the groove, but there is no method other than controlling the output power of the laser beam generator. Requires skill.

In addition, in the case of laser processing, the resin material in the skin portion corresponding to the linear groove to be processed is incinerated and removed, so that a considerable amount of soot is generated and released during the processing, When the released soot enters the processed groove, it causes a variation in the measured value of the remaining wall thickness. In order to avoid this, it is necessary to use an inert gas together to suppress the generation of soot, and it is necessary to add a device that actively sucks and removes soot, so that the equipment cost of the entire processing apparatus is extremely high. Was a problem.

The present invention has been made in view of the above circumstances, and not only can avoid damage to the design surface, but also has a predetermined thickness remaining on the surface of the skin with low power consumption and simple control. A method and a method for processing a linear groove having a reproducible constant fracture resistance in an airbag portion of a skin for an automobile, which can efficiently process a linear groove having an advantageous condition for measuring the remaining wall thickness. It is intended to provide a device.

[0009]

In order to achieve the above object, a method for forming a linear groove in an airbag portion of an automobile skin according to the present invention comprises the steps of: A method in which a linear groove is machined from the back side of the skin while leaving a predetermined thickness on the back side, with the skin fixed and held so that the surface is in close contact with the flat surface, and arranged on the back side of the skin After adjusting the position of the vibration horn of the ultrasonic processing device so that the clearance between the tip and the flat surface matches a predetermined remaining thickness on the surface of the skin surface, the ultrasonic horn and the heating device and the flat surface for fixing the skin are used. The surface and the airbag portion of the skin are preheated and softened by the heating device by moving the surface relative to the direction of the linear groove to be processed, and the ultrasonic vibration is applied to the back side of the softened airbag portion through the vibration horn. By granting It is characterized in processing the skin resin by sequentially melting removing linear grooves.

Further, the apparatus for forming a linear groove in an airbag portion of an automobile skin according to the present invention comprises: A device that processes linear grooves from the side, a surface plate that fixes and holds the skin so that its surface is in close contact with a flat surface, and an ultrasonic vibration that is arranged on the back side of the skin and applies resin to the skin resin Ultrasonic processing device, a heating device provided on the upstream side in the moving direction of the ultrasonic processing device, and a heating device for preheating the airbag portion of the epidermis immediately before applying ultrasonic waves, an ultrasonic processing device, a heating device, and a surface plate. And a machining position moving mechanism for relatively moving the workpiece in the direction of the linear groove to be machined.

According to the present invention having the above constitutional requirements, the resin-made skin is fixed and held so that the surface thereof is in close contact with the flat surface, and the flat surface is used as a reference surface (zero) for the ultrasonic processing apparatus. The tip position of the vibrating horn is adjusted in the skin thickness direction so that the clearance between the tip of the horn and the flat surface matches the predetermined thickness to be left on the skin surface side. In this state, by relatively moving the ultrasonic processing device and the heating device and the flat surface for fixing the skin in the direction of the linear groove to be processed, first, the airbag portion to be processed of the skin was preheated and softened. Then, ultrasonic vibrations are sequentially applied to the back side of the airbag portion of the skin via the vibration horn of the ultrasonic processing device, and the resin for the skin at that location is melted and removed to process the linear grooves. In this way, the airbag portion is preheated and softened just before the ultrasonic vibration is applied, and the stress during ultrasonic processing is dispersed to avoid damage to the design surface on the skin surface side where the ultrasonic vibration is applied. It is possible to

In particular, as the vibration horns, various widths and shapes are already existing, and by selecting and using an appropriate width and shape from among them, the ultrasonic processing apparatus can be moved along the planned processing line by using the ultrasonic horn. In the case of mechanical processing, it is possible to process a wide groove with a predetermined depth only by tracing once, and only to melt the resin material for the skin and remove the molten resin to the side. Such a linear processing mark is not exposed on the surface side, and it is possible to eliminate damage to the design surface also on this surface. In addition, processing control for processing a linear groove having a constant and reproducible breaking resistance by leaving a predetermined thickness on the skin surface side also adjusts the position of the vibration horn according to the thickness fluctuation of the skin. It is possible to employ such a simple mechanical control as described above.

Further, the molten resin generated by the ultrasonic processing is removed only to the side of the groove and hardened, but does not enter the groove. Means for suppressing the generation of soot and means for sucking and removing the generated soot are not required at all, and it is possible to reduce the equipment cost of the entire device, and to perform the remaining thickness on the skin surface side after groove processing from the back side, It is possible to improve the measurement accuracy by eliminating the cause of the variation in the measured value, and to accurately perform the quality control of the processed product.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of an entire processing apparatus used for carrying out a method for processing a linear groove in an airbag portion of an automobile skin according to the present invention, and FIG. 2 is an enlarged side view of a main part thereof.

In FIG. 1 and FIG. 2, reference numeral 1 denotes a surface plate having a plurality of small holes 1b formed in a flat upper surface 1a thereof.
The air in the cavity 1c is sucked by a vacuum generator 2 such as a vacuum pump and decompressed, so that the airbag portion of the resin skin 3 mounted on the flat upper surface 1a is reduced to a small hole 1b.
And is fixed and held so that its surface 3a is in close contact with the flat upper surface 1a. Back 3b of skin 3
An ultrasonic processing device 4 for applying ultrasonic vibration to the skin resin is disposed above the surface plate 1 on the side. This ultrasonic processing device 4 is composed of an ultrasonic oscillator 4A having an oscillation frequency of 20 to 40 KHz, an ultrasonic vibrator 4B, and a vibration horn 4C which is integrally processed from an iron alloy and a titanium alloy and has a cut blade cut out. A plurality of types of vibration horns 4C having different widths and shapes are interchangeably attached to the ultrasonic vibrator 4B.

The ultrasonic vibrator 4B of the ultrasonic processing device 4
And the vibration horn 4C, the tip of the vibration horn 4C and the surface plate 1
The clearance t1 with the flat upper surface 1a of the
A processing position adjustment in which the tip position of the vibration horn 4C can be moved in the thickness direction of the skin 3 (arrows u-d direction) so as to match a predetermined thickness t (see FIG. 3) to be left on the a side. It is mounted on the mechanism 5. This machining position adjusting mechanism 5
With the input of the known or detected thickness T of the skin 3 during processing, the tip position of the vibration horn 4C is set based on the thickness T of the skin 3 based on the flat surface 1a of the surface plate as a reference plane (zero). Is a known mechanism that combines a telescopic device such as a cylinder and a control unit that calculates and outputs a required movement amount. Description and illustration are omitted.

The ultrasonic processing device 4 and the processing position adjusting mechanism 5 are provided with a linear groove 6 (see FIG. 3) to be processed on the back surface 3b side of the airbag portion of the skin 3 with respect to the surface plate 1. It is mounted on a processing position moving mechanism 7 which can be driven and moved in the direction (arrow X direction). As the processing position moving mechanism 7, for example, a well-known conveyor such as a belt conveyor or a chain conveyor can be used, and the description and illustration of the specific structure are omitted.

On the upper side of the processing position moving direction X of the ultrasonic processing device 4, as a heating device for preheating the processed portion of the skin 3 immediately before applying ultrasonic vibration, warm air is applied to the back surface 3 b of the skin 3. A hot air generator 8 with a temperature controller 8a to be sprayed is provided, and on the lower side of the processing position moving direction X of the ultrasonic processing device 4, on the back surface 3b of the skin 3 immediately after the ultrasonic processing. A cooling air ejection device 9 for blowing cooling air is provided, and a linear groove 6 formed on the back surface 3b of the skin 3 immediately after the cooling air ejection device 9.
For example, a laser displacement sensor and a CCD camera 10 are used to measure and record the remaining thickness t of the
Are arranged. As a heating device for preheating the processed portion of the skin 3, an electric heater or the like may be used in place of the hot air generator 8, and a laser displacement sensor and a CCD A transmission type photoelectric sensor may be used instead of the camera 10. Further, the hot air generator 8, the cooling air ejection device 9, the laser displacement sensor, and the CCD camera 10 are configured to move integrally with the ultrasonic processing device 4 in the processing position moving direction X via the processing position moving mechanism 7. Have been.

Next, a description will be given of a method of processing the linear groove 6 in the airbag portion of the automobile skin 3 using the processing apparatus having the above configuration. First, the processed portion (airbag portion) of the resin skin 3 is placed on the flat upper surface 1a of the platen 1 with its surface 3a facing down, and the air in the cavity 1c is sucked by the vacuum generator 2 And then reduce the pressure to make the resin skin 3
The workpiece 3 is adsorbed through the small holes 1b, and the skin 3 is fixed and held on the surface plate 1 such that the surface 3a is in close contact with the flat upper surface 1a.

Next, the ultrasonic vibrator 4B and the vibration horn 4 of the ultrasonic processing device 4 correspond to the thickness T of the skin 3 to be processed.
The surface plate C is adjusted so that the clearance t1 between the tip of the vibration horn 4C and the flat upper surface 1a of the surface plate 1 via the position adjusting mechanism 5 matches the predetermined thickness t to be left on the surface 3a side of the skin 3. By moving the flat upper surface 1a in the skin thickness direction (directions of arrows u and d) with the flat upper surface 1a as a reference plane (zero), the processing position by the ultrasonic processing apparatus 4 is initially adjusted.

Thereafter, the ultrasonic processing device 4 is integrally moved in the processing position moving direction X together with the hot air generator 8, the cooling air jetting device 9, the laser displacement sensor and the CCD camera 10 via the processing position moving mechanism 7. Then, the hot air generator 8
The hot air generated in the above is blown to the back surface 3b of the skin 3, and the processed portion of the skin 3 immediately before the ultrasonic processing is preheated and softened, and the softened portion is subjected to ultrasonic vibration via the vibration horn 4C. Thus, the linear groove 6 having the predetermined thickness t remaining on the surface 3a side is processed, and the stress at the time of this processing is dispersed, and damage to the design surface on the surface 3a side of the skin 3 is avoided. .

As shown in FIG. 3, the resin portions 3d which are sequentially melted by the ultrasonic processing by applying the ultrasonic vibration are removed on the back surface 3b on both sides of the processed linear groove 6. In this position, the molten resin portion 3d is immediately cured by the cooling air blown from the cooling air ejection device 9, so that the molten resin portion 3d does not enter the processed linear groove 6, and the wide groove 6 is formed. Processing can be performed reliably.

Immediately after the completion of the ultrasonic processing as described above,
The processed linear groove 6 is scanned from the back surface 3b side of the skin 3 by the laser displacement sensor and the CCD camera 10, and the remaining thickness t is measured and recorded by processing the photographed image. Effectively used as quality control data for

In the above embodiment, the case where the processing position by the ultrasonic processing device 4 is only initially adjusted in accordance with the thickness T of the skin 3 has been described. In the case where the skin 3 whose thickness t may fluctuate more than the allowable error with respect to the target value is to be processed, the position adjusting mechanism 5 is operated to feed back such that the remaining thickness t falls within the allowable error range. It is desirable to perform the adjustment of the system, and since the mechanical adjustment mechanism 5 is used, such adjustment of the feedback system can be easily realized.

[0025]

As described above, according to the present invention, as the linear groove processing means from the back side of the resin-made skin, the processing portion is softened by preheating immediately before the heating device, and the ultrasonic processing device is used. By using ultrasonic vibration, a wide groove can be processed only by tracing once along the planned processing line, and the molten resin generated by ultrasonic processing is removed to the side of the groove. It can be hardened to prevent foreign matter from entering the groove, so that linear processing marks such as in the case of mechanical processing are not exposed on the surface side, and the stress at the time of processing is dispersed Surface damage can be avoided. In addition, it is possible to adjust the processing position corresponding to the variation in the thickness of the skin by simple mechanical control, and efficiently create linear grooves with a predetermined thickness remaining on the surface of the skin and a reproducible constant breaking resistance. Can be processed. In addition, as in the case of laser processing, there is no need for any means for suppressing the generation of soot due to the groove processing and means for sucking and removing the generated soot, and processing is achieved by reducing equipment costs and power consumption of the entire apparatus. It is possible to easily and accurately measure the remaining thickness on the front surface side of the skin after groove processing from the back side while achieving significant cost savings, and it is possible to accurately control the quality of processed products. It works.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an entire processing apparatus used when performing a method of processing a linear groove in an airbag portion of an automobile skin according to the present invention.

FIG. 2 is an enlarged side view of a main part of FIG.

FIG. 3 is an enlarged longitudinal sectional view of a main part for explaining a processed linear groove and a peripheral state thereof.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Surface plate 1a Flat top surface 3 Resin skin for automobiles 3a Skin surface (design surface) 3b Skin back surface 4 Ultrasonic processing device 4C Vibration horn 5 Processing position adjustment mechanism 6 Linear groove 7 Processing position moving mechanism 8 Hot air generator ( Example of heating device) 10 Laser displacement sensor and CCD camera (Example of residual thickness measuring and recording device) t Clearance between flat upper surface and tip of vibrating horn t1 Remaining thickness

Claims (2)

[Claims] 1. A method of processing a linear groove from the back surface side of an airbag portion of an automobile resin skin while leaving a predetermined thickness on the surface side thereof, wherein the skin surface is flat. With the vibration horn of the ultrasonic processing device arranged on the back side of the skin in a state of being fixedly held so as to be in close contact with the surface, the clearance between the tip of the ultrasonic horn and the flat surface matches the predetermined remaining thickness on the skin surface side. After adjusting the position, the ultrasonic processing device and the heating device and the flat surface for fixing the skin are relatively moved in the direction of the linear groove to be processed, and the airbag portion of the skin is preheated and softened by the heating device. An airbag portion for an automotive skin, wherein a linear groove is formed by sequentially applying an ultrasonic vibration to the back side of the softened airbag portion through a vibration horn to melt and remove the resin for the skin. Linear groove to Processing method. 2. An apparatus for processing a linear groove from the back surface side of an automobile airbag portion while leaving a predetermined thickness on the surface side of the airbag portion, wherein the surface surface is flat. A surface plate fixed and held so as to be in close contact with the surface; an ultrasonic processing device arranged on the back side of the skin to apply ultrasonic vibration to the resin for the skin; and a vibration horn of the ultrasonic processing device having A processing position adjustment mechanism that adjusts the position so that the clearance with the flat surface of the surface plate matches the predetermined remaining thickness on the skin surface side, and is provided on the upper side in the moving direction of the ultrasonic processing device to apply ultrasonic waves. A heating device for preheating the airbag portion of the immediately preceding skin, and a processing position moving mechanism for relatively moving the ultrasonic processing device and the heating device and the platen in the direction of the linear groove to be processed. Characteristic automotive skin air Tsu linear grooves device to click portion.