JP2008183676A - Method and device for forming breaking line on instrument panel skin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce fraction defective by stabilizing machining quality, to suppress machining dispersion due to wear of a cutter blade, and to reduce the replacing frequency of the blade. <P>SOLUTION: In a method for forming a breaking line of half-cut on an instrument panel skin 24 by using the cutter blade by an industrial robot 22, a pressure detecting mechanism 26 is provided on a back surface of the cutter blade 23 to always detect pressure during processing. So as to always fix the pressure, a speed command signal is decided as needed by taking an error due to environment and temperature changes into consideration, and fed back to a robot controller 21, thereby controlling the speed of the industrial robot 22. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an instrument processing method for performing cutter processing on the back surface of an instrument panel in order to ensure that an airbag door opens when an airbag for an auxiliary seat is deployed. In particular, the cutter blade is operated by an industrial robot. The present invention relates to a method and an apparatus for processing an instrument panel.

  In recent vehicles, an airbag device for a passenger seat is also mounted. The airbag device for the passenger seat is disposed inside the instrument panel in front of the passenger seat. The instrument panel is provided with an airbag door. When an airbag that is inflated by an inflator when the airbag is deployed presses the airbag door to the indoor side to open the airbag door, the airbag is opened from the opening. Expand to the front of the passenger in the passenger seat.

  On the back surface of the instrument panel, invisible streaks, dotted lines, or intermittent half-cut cuts are made from the seat side to ensure that the airbag door opens when the airbag is deployed. Hereinafter, this type of cut line is collectively referred to as a breaking line. This invisible breaking line is formed as an H-shaped or U-shaped fragile portion so as to be easily cleaved by the inflation pressure of the airbag.

  For soft instrument panels consisting of a base material, intermediate layer (polyurethane foam) and skin, a half-cut invisible break line is applied to the skin along the airbag door opening line formed on the base material. Has been.

  In the conventional method of forming an invisible fracture line, the cutter blade held by the robot hand based on the speed command signal input from the robot controller by the industrial robot is pushed to the instrument panel skin as shown in FIG. Thus, the invisible fracture line L is formed by moving and incising at a constant speed. In FIG. 3, reference numeral 11 denotes a robot hand, reference numeral 12 denotes a cutter, and reference numeral 13 denotes an instrument panel skin.

Patent Document 1 proposes forming an invisible fracture line that is intermittently connected to the back surface layer by laser processing. Patent Document 2 proposes forming an invisible fracture line that is intermittently connected to the surface layer by laser processing. Patent Document 3 proposes forming an invisible fracture line in the core material and the surface material. Patent Document 4 proposes forming a breaking groove along an opening line of an airbag door formed on an instrument panel base material with respect to an instrument panel skin.
Japanese Patent Laid-Open No. 11-43003 JP 2003-191815 A JP 2004-359019 A JP 2002-326241 A

  However, in the method of forming the breaking line L shown in FIG. 3, the cutting amount r (incision depth) varies. FIG. 4 is a graph showing the relationship between the processing speed of the cutter and the pressure in the method of forming the breaking line L shown in FIG. FIG. 4 shows that when the pressure is different from Ph, P, and PL, the cutting amount r (incision depth) is different and the remaining thickness of the epidermis is different. That is, even if the processing speed is constant, if the pressure applied by the cutter to the instrument panel skin is different, the remaining skin thickness will be different and variations will occur.

Further, the cutting amount r (incision depth) and the thrust force of the cutter blade have the following relationship. FIG. 5 shows an enlarged view for explaining the size and shape of the triangular cut formed when the cutter blade 12 is pushed against the instrument panel skin 13. Assuming that the Young's modulus of the instrument panel skin 13 is indicated by E, the thickness of the cutter blade 12 is indicated by h, and the cutter approach angle determined by the tip shape of the cutter blade 12 is indicated by α and β, the cutter blade 12 When the force FD is thrust perpendicularly to the instrument panel skin 13, the cutting amount r (incision depth) and the thrust force FD have the relationship of the following formula 1.

  However, the cutting amount r (incision depth) cannot be expressed by a complete relational expression related to the thrusting force of the cutter blade, and the processing speed, pre-processing skin temperature, cutter blade wear, humidity, room temperature, instrument It has been found that the thickness varies depending on the thickness and hardness of the intermediate layer of the ment panel and other environmental conditions. If the cutting amount r is too small, it affects the development performance. If the cutting amount r is too large, the design surface quality is marked, so it is important how to stabilize the cutting amount to an appropriate amount. In addition, if the pressure of the cutter blade changes greatly, the wear speed of the cutter blade will increase, and the wear of the cutter blade will greatly affect the processing variation. Therefore, it is necessary to increase the frequency of blade replacement, and the operating rate This leads to a reduction in For this reason, the non-defective condition width in which the cutting amount r (incision depth) is appropriate is very narrow, and after the line formation (after each incision formation), the remaining thickness of the instrument panel epidermis is measured by the laser sensor from the incision side. Measured and confirmed to be within the allowable range. In addition, if the remaining thickness is not within the allowable range, there is an uneconomical waste product as a defective product.

  The present invention is capable of forming a break line on the instrument panel skin, which can stably reduce the defect rate, can reduce the processing variation due to the wear of the cutter blade, and can reduce the frequency of blade replacement. It is an object to provide a method and an apparatus thereof.

  In order to achieve the above object, the present invention provides a method for forming a half-cut breaking line on an instrument panel skin using a cutter blade by an industrial robot, and providing a pressure detection mechanism on the back surface of the cutter blade. It is characterized by detecting the pressure of the hour, determining the speed command signal taking into account errors due to environmental and temperature changes and feeding back to the robot controller to control the speed of the industrial robot. The breaking line in the present invention includes a half-cut cut of streaks, dotted lines or intermittent.

  In order to achieve the above object, the breaking line forming apparatus of the present invention includes an industrial robot holding a cutter blade, a robot controller for sending a speed command signal to the industrial robot, and the cutter blade being added to the instrument panel. A pressure detection mechanism that detects pressure, and a control device that detects pressure from the pressure detection mechanism, determines a speed command signal in consideration of errors due to environmental and temperature changes, and feeds back to the robot controller. The speed of the cutter blade is controlled.

  According to this invention, the processing pressure of the cutter blade is kept constant in consideration of the processing speed, the skin temperature before processing, the wear of the cutter blade, humidity, room temperature, the thickness and hardness of the intermediate layer of the instrument panel, and other environmental conditions. Therefore, the cutting amount (incision depth) can be managed to an appropriate value, and the defect rate can be reduced. Moreover, when the processing pressure of the cutter blade becomes constant, the wear of the cutter blade is reduced, the replacement frequency of the cutter blade can be reduced, and the operating rate of the breaking line forming apparatus can be increased. Therefore, the processing quality is stable, the defect rate can be reduced, the processing variation due to wear of the cutter blade can be suppressed, and the replacement frequency of the blade can be reduced.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
A method for forming a breaking line on an instrument panel skin according to an embodiment of the present invention uses an industrial robot to guarantee the deployment performance of an airbag of an auxiliary seat airbag portion of an instrument panel of an automobile. This is a method of forming a half-cut breaking line having a certain depth on the instrument panel skin (hereinafter simply referred to as the skin) using a cutter blade. The instrument panel in this embodiment is configured as a soft instrument panel, and is made of an instrument panel base material (hereinafter simply referred to as a base material), a polyurethane foam as an intermediate layer, and a synthetic resin such as a polypropylene sheet. It is a three-layer structure consisting of an instrument panel skin.

  As shown in FIG. 1, in the breaking line forming method, the cutter blade 23 held by the robot hand 22 based on the speed command signal input from the robot controller 21 by the industrial robot is placed on the skin 24 of the instrument panel at a predetermined depth. In this way, a half-cut invisible rupture line is formed in the skin 24 by keeping the pressure constant by thrusting at the required pressure, and moving and incising while controlling the speed variation in this way. .

  As shown in FIG. 1, in this breaking line forming method, the robot controller 21 outputs a speed command signal S1 to the industrial robot, incises the cutter blade 23 with respect to the epidermis 24, and the controller 25 presses the pressure. And the speed is fed back so that the pressure is kept constant.

  That is, a pressure detection mechanism 26 is provided on the back surface of the cutter blade 23 to constantly detect the pressure S2 during processing, and the pressure is monitored by the control device 25, so that this pressure is always constant. In this configuration, a speed command signal is determined at any time in consideration of an error, and is fed back to the robot controller 21 to control the speed of the industrial robot.

次に、制御装置２５によるモニタリング時間が経過したときには、環境・温度変化による誤差をα（Ｔ）が加わるので、速度と圧力は以下の関係式（３）で表すことができる。

そこで、この式（３）について、制御装置２５は、Ｐ₍₁₎＝Ｐ₀となるように、α（Ｔ）が加わった分、Ｖ（１）を補正して速度指令信号をロボットコントローラ２１へフィードバックする。
以上のようにして、制御装置２５はモニタリング時間が経過する毎に、以下の一般式（４）から、Ｐ₍₂₎〜Ｐ_(n)まで演算を実施してＰ_(i)＝Ｐ₀となるように(ここで、iは２〜ｎ)、Ｖ₍₂₎〜Ｖ_(n)を補正して速度指令信号をロボットコントローラ２１へフィードバックする。

As a specific example, the control device 25 performs the following calculation.
When the initial speed V _{0 of} the cutter blade 23, the set (reference) pressure (initial pressure) applied to the tip of the cutter blade 23 is represented by P ₀ , and the correction coefficient is represented by k, it can be expressed by the following relational expression (2).

Next, when the monitoring time by the control device 25 elapses, an error due to environmental / temperature changes is added by α (T), so that the speed and pressure can be expressed by the following relational expression (3).

Therefore, with respect to this equation (3), the control device 25 corrects V (1) and adds a speed command signal to the robot controller 21 so that P ₍₁₎ = P ₀ is added. Feedback to
As described above, every time the monitoring time elapses, the control device 25 performs the calculation from the following general formula (4) to P _{(2) to} P _(n), and P _(i) = P ₀ . (Where i is _{2 to n)} , V _{(2) to} V _(n) are corrected, and the speed command signal is fed back to the robot controller 21.

FIG. 2 shows that a speed command signal is output to the industrial robot from the robot controller 21 that receives a feedback of the speed command signal of V _{(1) to} V _(n) so that P _{(1) to} P _(n) becomes equal to P _0. Then, when the break line is formed, the fluctuation of the speed V of the cutter blade 23 and the state of the pressure P are shown. The breaking line is formed at a substantially constant depth.

  Thus, according to the method for forming a break line on the instrument panel skin according to the present embodiment, the processing speed, the skin temperature before processing, the wear of the cutter blade, the humidity, the room temperature, the thickness of the intermediate layer of the instrument panel Since the processing pressure of the cutter blade can be made constant taking into account the hardness, hardness and other environmental conditions, the cutting amount (incision depth) can be managed to an appropriate value, and the defect rate can be reduced. . Moreover, when the processing pressure of the cutter blade becomes constant, the wear of the cutter blade is reduced, the replacement frequency of the cutter blade can be reduced, and the operating rate of the breaking line forming apparatus can be increased.

It is a conceptual diagram of the line formation method for fracture | rupture which concerns on embodiment of this invention. It is a correlation graph which shows the fluctuation | variation of the speed of a cutter blade, and the state of a pressure when the line formation method for a fracture | rupture of FIG. 1 is implemented. It is principal part explanatory drawing of the conventional line formation method for fracture | rupture. It is a correlation graph which shows the fluctuation | variation of the speed of a cutter blade, and the state of a pressure when the conventional line formation method for a fracture | rupture is implemented. It is an enlarged view for demonstrating the dimension and shape of a triangular incision formed when a cutter blade is thrust on the instrument panel skin.

Explanation of symbols

21 Robot controller 22 Robot hand (industrial robot)
23 Cutter blade 24 Skin (soft instrument panel skin)
25 Control Device 26 Pressure Detection Mechanism

Claims (2)

In a method of forming a half-cut breaking line on the instrument panel skin using a cutter blade by an industrial robot,
A pressure detection mechanism is provided on the back of the cutter blade to detect the pressure during processing, and a speed command signal is determined by taking into account errors due to changes in the environment and temperature, and fed back to the robot controller to control the speed of the industrial robot. A method for forming a break line on an instrument panel skin, characterized in that: An industrial robot holding a cutter blade;
A robot controller that sends a speed command signal to the industrial robot;
A pressure detection mechanism for detecting the pressure applied by the cutter blade to the instrument panel;
A control device that detects a pressure from the pressure detection mechanism, determines a speed command signal in consideration of an error due to a change in environment and temperature, and feeds back to the robot controller, and the speed of the cutter blade is A breaking line forming device controlled.

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