WO2006074840A1

WO2006074840A1 - Device and method for machining an interior panel component of a motor vehicle

Info

Publication number: WO2006074840A1
Application number: PCT/EP2005/056271
Authority: WO
Inventors: Volker Kantz; Andreas Steiner
Original assignee: Faurecia Innenraum Systeme Gmbh
Priority date: 2005-01-12
Filing date: 2005-11-28
Publication date: 2006-07-20
Also published as: DE102005001608B4; DE102005001608A1

Abstract

The invention relates to a method for machining an interior panel component (100) of a motor vehicle using a laser beam. Said method comprises the following steps: the surface profile (108) of a surface to be machined of the interior panel component is scanned at various measuring points; a predefined displacement course (130) of the interior panel component is corrected with reference to laser optics (116) using the measured values that have been obtained by the scanning process; the surface is treated with the laser beam during the corrected displacement course.

Description

Device and method for processing a motor vehicle

Interior trim part

Description

The invention relates to a device and a method for processing a motor vehicle interior trim part and a computer program product.

From the prior art, the processing of a motor vehicle interior trim part, in particular an instrument panel, with a laser beam for producing an airbag flap opening is known. In particular, DE 196 36 429 C1, WO 02/26 534 A1, EP 0 711 627 B1, US Pat. No. 5,883,356, EP 1 118 421 A2, GB 2 276 354 A and JP 2-99324 show corresponding methods and devices for laser attenuation. From the prior art also already known the production of invisible predetermined breaking lines by laser attenuation for the realization of an airbag outlet opening. Usually, the already removed or the remaining layer thickness is measured during the loading of the motor vehicle interior trim part with the laser beam. For this purpose, either an ultrasonic sensor is used or it is measured by the laser beam through the wall of the motor vehicle interior trim part transmitted proportion. When the motor vehicle interior trim part is exposed to the laser beam, it is focused onto the respective processing point by means of laser optics.

The invention is based on the object to provide an improved method and an improved device and a computer program product for processing a motor vehicle interior trim part with a laser.

The objects underlying the invention are each achieved with the features of the independent claims. Preferred embodiments of the invention are indicated in the dependent claims.

The invention provides a method for processing a motor vehicle interior trim part with a laser beam. First, a surface profile of a surface to be machined of the motor vehicle interior trim part is scanned at several measuring points. The scanning is done by a sensor, such as an optical sensor or a probe.

With the aid of the measured values obtained by the scanning, a predetermined course of movement of the motor vehicle interior trim part is corrected with reference to a laser optics. The processing of the surface of the motor vehicle interior trim part is then carried out by applying the laser beam during the corrected course of motion. The invention makes it possible to detect component tolerances of the motor vehicle interior trim part to be machined by scanning the surface profile. The component tolerances detected by the scanning are used to correct a predetermined course of motion, which relates, for example, to an ideal surface profile profile. As a result, the predetermined course of motion is adapted to the vehicle interior trim part, which is afflicted with the component tolerances. Accordingly, an improved machining result can be achieved because the movement pattern during the exposure of the surface to the laser beam is corrected in accordance with the component tolerances detected by the scanning.

This correction is particularly advantageous when the laser optics is stationary and has a stationary focal point. In this case, in order to obtain an optimal machining result, it is necessary for the stationary focal point to be located as precisely as possible on the machining point on the surface of the motor vehicle interior trim part. This can be achieved according to the invention in that the predetermined course of motion is corrected such that the processing points on the surface of the motor vehicle interior trim part have a substantially constant distance from the laser optics, taking into account the component tolerances, when they respectively pass the laser beam.

This is particularly advantageous for the laser processing of automotive interior trim parts made by a long fiber thermoplastic direct process (LFT-D) and in-line compounding (ILC). In a so-called LFT-D / ILC process, the plastic is incorporated directly into the system (so-called in-line compounding) and mixed with the component-dependent additives. In a plant, the reinforcing fibers are incorporated directly into the plastic melt and molded into the component. Significant cost savings and weight savings are possible with this process, with component tolerances slightly larger than conventional methods. The present invention also allows for automotive interior trim parts made in a long fiber thermoplastic (LFT) which, accordingly, have relatively large component tolerances to machine accurately with a laser beam, such as an invisible one Set breaking line for the realization of the outlet opening of an airbag manufacture. By means of the invention, therefore, a component subject to tolerances can also be processed in such a way that an invisible predetermined breaking line is realized and the predetermined opening forces are maintained.

According to one embodiment of the invention, the sampling takes place before the start of the course of the movement. For example, the motor vehicle interior trim part is first fixed in a robot gripper. The surface profile of the motor vehicle interior trim part located in the robot gripper is then scanned at the intended measuring points. Only after the scanning has taken place at all measuring points, the course of motion is started to apply the laser beam to the surface. This has the advantage that it is not necessary to scan the surface simultaneously with laser processing. This makes it possible in particular to use a relatively inexpensive sensor principle for the scanning of the surface, such as a probe for the mechanical scanning of the surface profile.

According to one embodiment of the invention, the probe is stationary. The motor vehicle interior trim part located in the robot gripper is moved by the robot along the probe, so that it can scan the surface profile. Thereafter, the correction of the predetermined course of motion with the measured values thus obtained and the application of the laser beam to the surface during the corrected course of motion takes place.

The scanning of the surface profile after the motor vehicle interior trim part has been fixed in the robot gripper has, in particular, the advantage that the motor vehicle interior trim part is already in its processing position for later exposure to the laser beam. In particular, due to the clamping in the robot gripper conditional elastic deformations of the motor vehicle interior trim part are detected in the scan, so that they can go into the correction of the predetermined course of movement with. Since the exposure of the surface with the laser beam in the same position of the motor vehicle interior trim part with With respect to the robot gripper as the scanning is done, this results in a particularly high precision machining.

According to one embodiment of the invention, the laser optics and the laser focal point are stationary. The given course of motion refers to an ideal surface profile that is not subject to tolerances. The predetermined course of motion is chosen such that a substantially constant distance between the processing points provided for the processing on the surface and the laser optics is maintained, i. the distance between a machining point and the laser optics is the same for all machining points when the machining point passes the laser beam. In particular, this distance is chosen so that the focus is as congruent with the processing points.

The correction of the predetermined course of motion then takes place in such a way that the essentially constant distance is maintained even in the case of the real surface profile of the motor vehicle interior trim part, which is subject to component tolerances. Thus, for example, if there is a real processing point with respect to the ideal surface profile in a trough, then the predetermined course of motion is adapted such that the robot gripper moves the motor vehicle interior lining part somewhat closer to the laser optics.

According to a further embodiment of the invention, a correction value for the entire course of the movement can be stored. As a result, fluctuations in the material composition of different batches of motor vehicle interior trim parts can be taken into account. Such a correction value can be added as a global offset to the given course of motion, so that the distance between the processing points and the laser optics changes accordingly. Alternatively or additionally, specific correction values can also be entered for one or more of the processing points.

The addition or subtraction of a uniform offset is also advantageous for the correction of tolerances of the laser optics. The laser optics has a focal lens that needs to be replaced from time to time, with the focal lenses relative to their Focal length tolerances have. According to the invention, the focal length of the focal lens, to which the predetermined course of motion relates, is stored. The focal length of the replacement focal lens is measured and compared with the focal length of the first focal lens. The difference of the focal lengths gives the global offset, which is added to or subtracted from the given course of motion. This has the particular advantage that the teaching of the movement or sequences does not have to be repeated.

According to one embodiment of the invention, a desired break line is generated by the laser processing. This may be groove-shaped and / or as a perforation.

In a further aspect, the invention relates to a computer program product, in particular a digital storage medium, for controlling a robot to set a motor vehicle interior trim part in a course of movement, while a surface to be machined of the motor vehicle interior trim part is subjected to a laser beam. The computer program product can drive the robot and / or a suitable measuring sensor for scanning a surface profile of the surface to be processed and calculate a correction of the predetermined course of the movement with the measured values obtained by the scanning.

In further preferred embodiments of the invention will be explained in more detail with reference to the drawings. Show it:

FIG. 1 shows a block diagram of an embodiment of a device according to the invention for the laser processing of a motor vehicle interior trim part,

FIG. 2 shows a flow chart of an embodiment of a method according to the invention.

FIG. 1 schematically shows a motor vehicle interior trim part 100, such as an instrument panel. The motor vehicle interior trim part 100 has a surface 102, which is visible in the installed position of the motor vehicle interior trim part 100 from a motor vehicle interior. Furthermore, the motor vehicle interior trim part 100 has a surface 102 opposite surface 104, which is not visible in the installed state of the motor vehicle interior trim part. For example, the surface 102 is the skin of an instrument panel and the surface 104 is the underside of the instrument panel, which is generally formed by the support layer of the instrument panel.

FIG. 1 schematically shows an ideal surface profile 106 of the surface 104 as well as a real surface profile 108 of the surface 104, which is subject to component tolerances.

The motor vehicle interior trim part 100 is clamped in a gripper 110 of a robot 112. The robot 112 with its gripper 110 is arranged so that it can move the motor vehicle interior trim part 100 in the area of a sensor 114 and a laser optics 116.

The sensor 114 is used to scan the real surface profile 108. Preferably, the sensor is stationary. The sensor 114 has an interface 118 for outputting the measurements obtained by the scan to a controller 120 having a corresponding interface 122. The sensor 114 is, for example, a probe with a mechanical probe for scanning the surface profile 108. For example, the position of a potentiometer of the probe is changed by the probe, so that the course of the surface profile is converted into an electrical signal.

The processing of the motor vehicle interior trim part 100 takes place with a laser 124. The laser 124 supplies a laser beam, which can pass from the laser optics 116 to the surface to be processed. The laser optics 116 has a fixed focal length 126. Preferably, both the laser optics 116 and the laser 124 are stationary. In particular, it is advantageous if both the sensor 114 and the laser optics 116 are stationary; in this case, only the moves Robot gripper 110 with the motor vehicle interior trim part 100 during the scanning or the laser processing operation ..

The controller 120 has a memory 128 with a memory area 130 for storing a predetermined course of motion. The predetermined course of motion describes the relative movement of the motor vehicle interior trim part 100 with respect to the laser optics 116. This predetermined course of motion relates to the ideal surface profile 106 and is preferably selected so that each treatment point on the ideal surface profile 106 is at a distance from the laser optics 116. the focal length corresponds to 126 when the processing point is applied to the laser beam. In addition, a movement pattern for the movement of the robot gripper with the motor vehicle interior trim part 100 along the sensor 114 can be stored in the memory area 130 for the purposes of the scanning.

The determination of the motion profiles can be done by calculation or simulation on the basis of CAD data of the motor vehicle interior trim part 100. Alternatively, the movement patterns are determined by so-called teaching of the robot. For this purpose, the robot gripper is manually brought to so-called teaching points, which are then stored. The teaching points are preferably substantially congruent with the sample points and the processing points.

The memory 128 further has a memory area 132 for storing the measurements provided by the sensor 114.

The controller 120 has a processor 134 for executing a control program 136 for the robot 112. The control program 136 has a program module 138 for interpolating the sensor measured values 132 and a program module 140 for calculating a corrected course of motion taking into account the measured or interpolated sensor measured values. For processing the motor vehicle interior trim part 100, this is first clamped in the gripper 110. The robot 112 is controlled by the controller 120 or the control program 136 such that the sensor 114 can scan the real surface profile 108 at a plurality of, for example six measuring points. For example, these measuring points are at the same time machining points which are to be loaded later with the laser beam.

The measured values acquired by the sensor 114 are output via its interface 118 and input via the interface 122 into the controller 120, where they are stored in the memory area 132. For this purpose, the interfaces 118 and 122 can be connected directly or indirectly via a network. For example, a fieldbus, an Ethernet or a so-called. Realtime Ethernet can be used for this purpose. TCP / IP can be used as the transmission protocol. Alternatively, the measured values of the sensor are first detected by the controller of the laser attenuation system which controls the laser 124. From there, the measured values are read out and in a separate computer in a format that is compatible with the controller 120 of the robot 122.

Optionally, the sensor readings stored in the memory area 132 are interpolated by the program module 138.

Thereafter, a correction of the movement history stored in the storage area 130 is calculated by the program module 140 on the basis of the optionally interpolated sensor measured values. If, for example, the scanning of the surface profile 108 indicates that a processing point is located in a trough, then the predetermined course of motion is correspondingly corrected, that is to say the gripper 110 must be moved closer to the depth of the trough closer to the laser optical system 116 if the relevant processing point coincides with the laser beam is applied. Accordingly, the distance of the gripper 110 from the laser optics is to be increased when a processing point is above the ideal surface profile 106. The correction of the predetermined course of motion ensures that each of the processing points is at a distance when exposed to the laser beam from the laser optics 116, which corresponds to the focal length 126 as closely as possible.

After calculating the correction of the predetermined course of the movement, the control program 136 controls the robot 112 such that it places the gripper 110 with the motor vehicle interior trim part 100 in the corrected course of movement while the laser 124 is switched on. The laser beam removes material from the surface 104 at the processing points, so that, for example, a desired break line is formed.

FIG. 2 shows a corresponding flow chart. In step 200, the motor vehicle interior trim part to be processed is received by the robot gripper. The motor vehicle interior trim part located in the robot gripper is then measured by being scanned at a plurality of measuring points. In step 204, with the aid of the measured values thus obtained, a predetermined course of motion, which relates to an ideal surface profile which does not involve tolerance, is corrected in order to take account of the component tolerances actually present. Thereafter, the motor vehicle interior trim part is placed in the corrected course of motion, while at the same time an exposure to the laser beam takes place (step 206).

Compound list

100 motor vehicle interior trim part

102 surface

104 surface

106 ideal surface profile

108 real surface profile

110 grippers

10 112 robots

114 sensor

116 laser optics

118 interface

120 control

15 122 interface

124 lasers

126 focal length

128 memory

130 memory area

20 132 memory area

134 processor

136 Control program

138 program module

140 program module

25

Claims

Patent claims

A method of machining a motor vehicle interior trim part (100) with a laser beam, comprising the steps of:

Scanning a surface profile (108) of a machined surface of the motor vehicle interior trim part at a plurality of measuring points, wherein the motor vehicle interior trim part by a robot gripper (110) for scanning the surface profile along a

Sensor (114) is moved,

Correction of a predetermined course of movement (130) of the motor vehicle inner lining part with respect to a laser optics (116) with the measured values obtained by the scanning,

Applying the laser beam to the surface during the corrected course of the movement, wherein the motor vehicle interior trim part is put into the course of movement by the robot gripper.

2. The method of claim 1, wherein the scanning is completed before the start of the movement history.

3. The method of claim 1 or 2, wherein the sampling is performed with a probe (114).

4. The method according to claim 3, wherein the motor vehicle interior trim part is fixed in a robot gripper (110) before the scanning takes place.

5. The method according to any one of the preceding claims, wherein the laser optics is stationary.

6. The method of claim 5, wherein the same robot gripper is used for the scanning and for the course of the movement.

7. The method according to any one of the preceding claims, wherein the correction of the predetermined course of movement by interpolation by the

Sampling obtained measured values takes place.

8. The method according to any one of the preceding claims, wherein the predetermined movement pattern refers to an ideal surface profile (106) and a substantially constant distance from ideal

Indicates processing points to the laser optics, and wherein the predetermined course of motion is corrected with the measured values obtained by the scan so that the substantially constant distance is maintained when the surface is exposed to the laser beam.

9. The method of claim 8, wherein a uniform correction value for the predetermined course of motion can be input to change the distance.

10. The method according to any one of the preceding claims, wherein one or more correction values for one or more processing points can be entered.

11. The method according to any one of the preceding claims, wherein by applying the surface with the laser beam a desired breaking line in the

Surface is introduced.

12. The method of claim 11, wherein the desired breaking line is groove-shaped.

13. The method of claim 11 or 12, wherein the laser beam is pulsed to produce a perforation.

14. The method of claim 11, 12 or 13, wherein the desired breaking line is used to release an outlet opening of an airbag after the deployment of the airbag.

15. The method according to any one of the preceding claims 11 to 14, wherein the action of the surface with the laser beam takes place such that the predetermined breaking line is not visible in an installed position of the motor vehicle interior trim part from the motor vehicle interior.

A computer program product, in particular a digital storage medium with computer-executable instructions for performing the following steps:

Scanning a surface profile (108) of a surface of the motor vehicle interior trim part to be machined at a plurality of measuring points,

Impingement of the surface with the laser beam during the corrected course of the movement,

wherein the computer-executable instructions are adapted to drive a robot (115) such that a robotic gripper (110) is moved along a sensing sensor (114) with the automotive interior trim panel fixed in the robotic gripper, and then the robotic Gripper offset the motor vehicle interior trim part in the course of movement.

The computer program product of claim 16, wherein the scan is completed prior to starting the motion history.

18. Computer program product according to claim 16 or 17, wherein the correction of the predetermined course of motion takes place by interpolation of the measured values obtained by the scanning.

The computer program product of any one of the preceding claims 16 to 18, wherein the predetermined course of motion relates to an ideal surface profile (106) and indicates a substantially constant distance from ideal processing points to the laser optic, and wherein the predetermined motion profile matches that obtained by the scan Measured values are corrected so that the substantially constant distance is maintained when the surface is exposed to the laser beam.

20. An apparatus for processing a motor vehicle interior trim part (100) with a laser beam with:

a robot gripper (110) for receiving the motor vehicle interior trim part,

Means (115, 102, 114) for scanning a surface profile of a surface of the motor vehicle interior trim part to be machined at a plurality of measuring points, wherein the means for scanning the surface profile are designed such that the scanning takes place after the motor vehicle interior trim part in the robot Gripper has been fixed,

Means (140) for correcting a predetermined course of movement (130) of the motor vehicle interior trim part with respect to a laser optics (116) with the measured values obtained by the scanning,

- Means (115, 102, 116, 124) for acting on the surface with the

Laser beam during the corrected course of movement, wherein the robot gripper belongs to a robot (112), which can put the motor vehicle interior trim part in the corrected course of movement, while the application of the laser beam.

21. The apparatus of claim 20, comprising means for inputting an offset for the predetermined course of motion.

22. Apparatus according to claim 20 or 21, comprising a memory for storing a first focal length of a first focal lens of the laser optics, to which the predetermined course of motion relates, and for storing a second focal length of a second focal lens of the laser optics, and means for storing an offset, which corresponds to the difference between the first and second focal lengths.