THREE-DIMENSIONAL LASER PROCESSING MACHINE

A three-dimensional laser processing machine performs high-precision laser processing on a workpiece (W) by setting the focal position of laser light to be condensed by a condensing lens at a predetermined distance from a portion to be processed of the workpiece (W), is provided with a three-dimensional shape measuring instrument (50) for measuring the three-dimensional shape of the workpiece (W), and sets the focal position of the laser light at the predetermined distance from the portion to be processed on the basis of three-dimensional shape data relating to the workpiece (W) measured by the three-dimensional shape measuring instrument (50).

TECHNICAL FIELD

The present invention relates to a three-dimensional laser processing machine.

BACKGROUND ART

In recent years, adoption of high tensile strength steels (high tensile materials) is increasing and the high tensile materials are used in various fields. For example, in the automotive industry, there are demands for reducing weight of body parts to improve fuel efficiency of automobiles and at the same time maintaining or improving the safety of the body parts which are reduced in weight. High tensile materials are adopted as materials for achieving light weight and high strength of body parts.

The body parts and the like using the high tensile materials have far higher stiffness than conventional parts using soft iron, and processing of cutting and boring such body parts is difficult to perform by a conventional pressing method. Accordingly, the parts using the high tensile materials are sometimes cut and bored by a method using laser light instead of the pressing method.

Processing using the laser light is performed by a three-dimensional laser processing machine <see, for example, Patent Literature 1 and Patent Literature 2>. The laser processing is processing in which a workpiece being a processing object is cut and bored by irradiating a processing portion of the workpiece with the laser light to melt the material of the processing portion and blowing away the melted material with gas or the like.

The three-dimensional laser processing machine includes a condenser lens to improve processing accuracy and the like of the laser processing and emits the laser light through the condenser lens. The laser light is condensed on the processing portion of the workpiece or near the processing portion by the condenser lens, and this can reduce an irradiation area to be irradiated with the laser light in the processing portion. A portion melted by the laser light is thus small, and cutting and boring of fine shapes and small regions can be performed. Hence, highly-accurate processing can be performed.

In other words, the irradiation area of the laser light in the processing portion affects the processing accuracy of the laser processing. Factors determining the irradiation area of the laser light include a distance between the processing portion of the workpiece and a focal position where the laser light is condensed. Accordingly, it is important to grasp this distance and set the processing portion and the focal position at a predetermined distance from each other in the laser processing.

In view of this, the conventional three-dimensional laser processing machine includes a distance detector (gap sensor) such as a capacitive sensor or a laser displacement meter near the laser light emitting portion. The gap sensor measures the distance (gap) to the processing portion of the workpiece, and the three-dimensional laser processing machine calculates the distance between the focal position of the emitted laser light and the processing portion of the workpiece from the gap measurement value and checks whether the calculation result is within a tolerance of a processing setting value in the laser processing.

When the calculation result of the gap sensor is within the tolerance of the processing setting value, the laser light is emitted from a laser light emitting portion and processing of cutting or boring is performed. When the calculation result of the gap sensor is outside the tolerance of the processing setting value, a laser head including the laser light emitting portion is moved. Then, the gap measurement by the gap sensor, the calculation of the distance between the focal position of the laser light and the processing portion of the workpiece, and the checking of the calculation result is performed again. After the laser head is set such that the calculation result of the gap sensor is within the tolerance of the processing setting value, the laser processing is performed on the processing portion of the workpiece.

A series of operations from the gap measurement to the laser processing as described above is performed for one processing portion. In laser processing of a workpiece having multiple processing portions, the aforementioned series of operations is performed for each of the processing portions in the workpiece.

CITATION LIST

Patent Literatures

SUMMARY OF INVENTION

1. Technical Problem

However, the conventional three-dimensional laser processing machine does not perform the processing of cutting and boring with the laser light while performing the gap measurement with the gap sensor, the calculation of the distance between the focal position of the laser light and the processing portion of the workpiece, and the checking of the calculation result. This prevents an improvement of the processing efficiency of the three-dimensional laser processing machine.

As a matter of course, if the laser processing is performed without measuring the distance between the focal position of the laser light and the processing portion of the workpiece to improve the processing efficiency of the three-dimensional laser processing machine, the distance cannot be set to the predetermined processing setting value and the processing accuracy of the laser processing decreases.

The present invention has been made in view of the problem described above, and an object thereof is to improve processing efficiency of laser processing in a three-dimensional laser processing machine.

2. Solution to Problem

A three-dimensional laser processing machine according to a first aspect of the present invention for solving the aforementioned problem provides a three-dimensional laser processing machine which performs highly-accurate laser processing on a processing portion of a processing object by setting a focal position of laser light condensed by a condenser lens at a predetermined distance from the processing portion, the three-dimensional laser processing machine comprising a three-dimensional shape measurement device configured to measure a three-dimensional shape of the processing object, wherein

the focal position of the laser light is set at the predetermined distance from the processing portion, on the basis of three-dimensional shape data of the processing object measured by the three-dimensional shape measurement device.

A three-dimensional laser processing machine according to a second aspect of the present invention for solving the aforementioned problem provides the three-dimensional laser processing machine according to the first aspect, wherein the three-dimensional shape measurement device is installed in a setup space for the processing object, and

the three-dimensional shape of the processing object setup in the setup space is measured before the processing object is subjected to the laser processing.

A three-dimensional laser processing machine according to a third aspect of the present invention for solving the aforementioned problem provides the three-dimensional laser processing machine according to the first or the second aspect, wherein the three-dimensional shape of the processing object subjected to the laser processing is measured by the three-dimensional shape measurement device, and

processing accuracy of the laser processing is checked by using the three-dimensional shape data of the processing object subjected to the laser processing.

3. Advantageous Effects of Invention

The three-dimensional laser processing machine of the first aspect of the present invention comprises the three-dimensional shape measurement device configured to measure the three-dimensional shape of the processing object, and can thereby accurately grasp the shape of the processing object and the position of the processing portion. Accordingly, there is no need to detect a gap for each of the processing portions by using a gap sensor or the like or to perform similar operations. Hence, it is possible to eliminate gap detection time by the gap sensor and the like and improve the processing efficiency of the laser processing by the three-dimensional laser processing machine. Moreover, since the distance between the focal position of the laser light and the processing portion is set based on the three-dimensional shape data of the processing object measured by the three-dimensional shape measurement device, the laser processing can be performed with the actual irradiation area of the laser light in the processing portion being the same as the set irradiation area, and the processing accuracy of the laser processing does not decrease.

In the three-dimensional laser processing machine of the second aspect of the present invention, the three-dimensional shape measurement device is installed in the setup space for the processing object, and there is thus no need to secure an additional space for the three-dimensional shape measurement. Moreover, the three-dimensional shape of the processing object setup in the setup space is measured before the processing object is subjected to the laser processing. Due to this, the three-dimensional shape of the processing object can be measured while another processing object is subjected to the laser processing.

The three-dimensional laser processing machine of the third aspect of the present invention can check whether the laser processing is performed on the processing object as set, i.e. check the processing accuracy of the laser processing by the three-dimensional laser processing machine by measuring the three-dimensional shape of the processing object with the three-dimensional shape measurement device after the laser processing. The three-dimensional laser processing machine can thereby detect a processing error and the like which occur in the laser processing, and incorporate data of the detected processing error and the like into processing data of the next processing object to perform the laser processing with the processing error and the like corrected for each of the processing objects.

DESCRIPTION OF EMBODIMENT

An embodiment of a three-dimensional laser processing machine of the present invention is described below in detail with reference to the attached drawings. As a matter of course, the present invention is not limited by the following embodiment and various changes can be made within a scope not departing from the spirit of the present invention.

First, a structure of the three-dimensional laser processing machine in Embodiment 1 of the present invention is described with reference toFIGS. 1 to 6.

As illustrated inFIG. 1, the three-dimensional laser processing machine of the embodiment includes a bed1horizontally installed on a floor surface, a gate-shaped column2installed to straddle the bed1, a cross rail3supported on a front surface of the column2and configured to be movable in Z-axis directions (vertical directions) relative to the column2, a saddle4supported on the cross rail3and configured to be movable in Y-axis directions (horizontal directions) along the cross rail3, and a ram5held by the saddle4and configured to be movable in the Z-axis directions relative to the saddle4.

The ram5is provided with a laser head10configured to be movable in the Z-axis directions and turnable in C-axis directions (directions of rotation about an axis parallel to the Z-axis) relative to the ram5. The laser head10includes a laser light emitting portion11configured to be turnable in B-axis directions (directions of rotation about an axis parallel to the Y-axis) relative to the laser head10.

Laser light emitted from the laser light emitting portion11is condensed on a not-illustrated processing portion in a workpiece W which is a processing object or near the processing portion by a not-illustrated condenser lens incorporated in the laser head10. Accurate processing of cutting and boring of the workpiece W is performed as follows. The not-illustrated processing portion of the workpiece W is heated by being irradiated with the condensed laser light and is locally melted, and the melted material of the processing portion is blown away by gas jetted from a not-illustrated gas jetting portion included in the laser head10.

Note that the three-dimensional laser processing machine includes a safety cover6for securing safety of a worker and the like and an area where the laser processing is performed is defined by the safety cover6. InFIG. 1, the safety cover6is illustrated by two-dot chain lines for clarity of the drawing.

The bed1includes a processing table20for processing of the workpiece W, a setup plate30for setup of the workpiece W, and a workpiece changing device40(seeFIGS. 3 to 6). InFIG. 1, illustration of the workpiece changing device40is omitted.

The processing table20is installed on the bed1to be movable between a processing position (a solid line portion inFIG. 1) and a setup position (a two-dot chain line portion inFIG. 1). The setup plate30is installed on one end side of the bed1to be adjacent to the processing table20at the setup position, and the workpiece changing device40is installed between the processing table20at the setup position and the setup plate30(seeFIGS. 3 to 6).

As illustrated inFIGS. 3 to 6, the workpiece changing device40has a main body portion41and workpiece holding portions42and also includes a not-illustrated lifting-lowering mechanism configured to lift and lower the main body portion41and the workpiece holding portions42in W-axis directions (axial directions parallel to the Z-axis) and a not-illustrated rotating mechanism configured to rotate the main body portion41and the workpiece holding portions42in D-axis directions (directions of rotation about an axis parallel to the W-axis).

The workpiece changing device40can perform work of changing a processed workpiece W1on the processing table20which has been subjected to the laser processing and moved to the setup position, for a to-be-processed workpiece W2on the setup plate30which is newly loaded onto the three-dimensional laser processing machine to be subjected to the laser processing. The work of changing the processed workpiece W1for the to-be-processed workpiece W2which is performed by the workpiece changing device40will be described later.

In the embodiment, as illustrated inFIG. 1, the bed1in the three-dimensional laser processing machine includes a scanning device50which is a three-dimensional shape measurement device for measuring the three-dimensional shape of the workpiece W before and after the processing. The scanning device50is installed in a set-up space for the workpiece W at the one end side of the bed1and, as illustrated inFIG. 2, includes a base portion51configured to be slidable in V-axis directions (axial directions parallel to the Y-axis) relative to the bed1, a body portion52supported on the base portion51and configured to be slidable in U-axis directions (axial directions parallel to the X-axis) relative to the base portion51, an arm portion53supported on the body portion52and configured to be slidable in the W-axis directions relative to the body portion52, and a neck portion54supported on one end side of the arm portion53and configured to be slidable in the U-axis directions and turnable in E-axis directions (directions of rotation about an axis parallel to the V-axis).

The neck portion54has two cameras55for measuring the three-dimensional shape of the workpiece W. Note that the setup plate30is provided with a not-illustrated rotating mechanism which can rotate the workpiece W placed on the setup plate30in F-axis directions (directions of rotation about an axis parallel to the Z-axis and the W-axis) so that the shape of the entire workpiece W can be measured by the scanning device50before and after the processing.

In other words, the three-dimensional shapes of workpieces W of various sizes and shapes can be measured by the sliding of the base portion51in the V-axis directions, the sliding of the body portion52in the U-axis directions, the sliding of the arm portion53in the W-axis directions, the sliding of the neck portion54in the U-axis directions, and the turning of the neck portion54in the E-axis directions in the scanning device50as well as the rotating operation of the workpiece W on the setup plate30in the F-axis directions.

Note that loading and unloading of the workpiece W in the three-dimensional laser processing machine is performed in the setup plate30. Moreover, the workpiece W is placed on the setup plate30with a workpiece placing jig60therebetween, rotated on the setup plate30together with the workpiece placing jig60, and changed for another workpiece W together with the workpiece placing jig60by the workpiece changing device40(seeFIGS. 3 to 6).

Next, a flow of laser processing by the three-dimensional laser processing machine in Embodiment 1 of the present invention is described with reference toFIGS. 1 to 6.

First, while the workpiece W1is being subjected to the laser processing on the processing table20at the processing position, the workpiece W2to be processed is placed on the setup plate30in the three-dimensional laser processing machine with the workpiece placing jig60therebetween, by a not-illustrated crane or manual work of a worker, and the scanning device50performs the three-dimensional shape measurement of the workpiece W2to be processed (seeFIGS. 1 and 2).

An image capturing position and an image capturing direction of the cameras55are adjusted by sliding and turning the base portion51, the body portion52, the arm portion53, and the neck portion54of the scanning device50installed near the setup plate30, and the scanning device50is thereby setup to be suitable for the three-dimensional shape measurement of the workpiece W2to be processed which is placed on the setup plate30.

On the setup plate30, the workpiece placing jig60and the workpiece W2to be processed are rotated in the F-axis direction by the not-illustrated rotating mechanism and the three-dimensional shape measurement of the workpiece W2to be processed is performed by the scanning device50. Three-dimensional shape data d2of the workpiece W2to be processed which is measured by the scanning device50is transmitted to a not-illustrated data processing portion and is used for later-described laser processing of the workpiece W2to be processed.

Note that, in the embodiment, the workpiece W2to be processed is loaded onto the three-dimensional laser processing machine and is subjected to the three-dimensional shape measurement by the scanning device50while the workpiece W1already loaded onto the three-dimensional laser processing machine is subjected to the laser processing, and the laser processing of the workpiece W1and the three-dimensional shape measurement of the workpiece W2to be processed is thereby performed in parallel. Accordingly, processing efficiency of the laser processing by the three-dimensional laser processing machine can be improved.

Next, the workpiece changing device40performs work of changing the processed workpiece W1for the workpiece W2to be processed (seeFIG. 1andFIGS. 3 to 6).

The processed workpiece W1placed on the processing table20is moved to the setup position after being subjected to the laser processing at the processing position (seeFIG. 1).

Then, as illustrated inFIG. 3, one holding portion42(one on the right side inFIG. 3) of the workpiece changing device40holds the workpiece placing jig60to which the processed workpiece W1is fixed, on the processing table20having moved to the setup position, while another holding portion42(one on the left side inFIG. 3) holds the workpiece placing jig60to which the workpiece W2to be processed is fixed, on the setup plate30.

Next, as illustrated inFIG. 4, the main body portion41is lifted in the W-axis direction by the not-illustrated lifting-lowering mechanism in the workpiece changing device40, and the holding portions42, the workpiece placing jigs60which are held by the holding portions42, and the processed workpiece W1and the workpiece W2to be processed which are fixed onto the workpiece placing jigs60are also lifted.

Then, as illustrated inFIG. 5, the main body portion41is rotated in the D-axis direction by the not-illustrated rotating mechanism in the workpiece changing device40, and the holding portions42, the workpiece placing jigs60which are held by the holding portions42, and the processed workpiece W1and the workpiece W2to be processed which are fixed onto the workpiece placing jigs60are also rotated. The processed workpiece W1is thereby disposed above the setup plate30and the workpiece W2to be processed is disposed above the processing table20.

Next, as illustrated inFIG. 6, the main body portion41is lowered in the W-axis direction by the not-illustrated lifting-lowering mechanism in the workpiece changing device40, and the holding portions42, the workpiece placing jigs60which are held by the holding portions42, and the processed workpiece W1and the workpiece W2to be processed which are fixed onto the workpiece placing jigs60are also lowered.

The not-illustrated lifting-lowering mechanism lowering the main body portion41in the W-axis direction causes the workpiece placing jig60and the processed workpiece W1which is fixed onto the workpiece placing jig60to be placed on the setup plate30and causes the workpiece placing jig60and the workpiece W2to be processed which is fixed onto the workpiece placing jig60to be placed on the processing table20. The work of changing the processed workpiece W1for the workpiece W2to be processed is thereby completed.

Next, the scanning device50performs the three-dimensional shape measurement of the processed workpiece W1, and the workpiece W2to be processed is subjected to the laser processing (seeFIGS. 1 and 2).

As in the aforementioned three-dimensional shape measurement of the workpiece W2to be processed, the image capturing position and the image capturing direction of the cameras55are adjusted, and the scanning device50performs the three-dimensional shape measurement of the processed workpiece W1placed on the setup plate30(seeFIG. 2). Three-dimensional shape data d1of the processed workpiece W1which is measured by the scanning device50is transmitted to the not-illustrated data processing portion and is used for the later-described laser processing of the workpiece W2to be processed, together with the three-dimensional shape data d2of the workpiece W2to be processed.

Note that since the three-dimensional laser processing machine in the embodiment performs only boring on the workpiece W, there is no great difference between the shape of the processed workpiece W1and the shape of the workpiece W2to be processed. Accordingly, the adjustment of the image capturing position and the image capturing direction of the cameras55are omitted. As a matter of course, in cases such as where the three-dimensional laser processing machine performs laser processing such as cutting on the workpiece W and the there is great difference between the shape of the workpiece W2to be processed and the shape of the processed workpiece W1, the image capturing position and the image capturing direction of the cameras55can be readjusted.

The processed workpiece W1which has been subjected to the three-dimensional shape measurement by the scanning device50is removed from the setup plate30by the not-illustrated crane or the manual work of the worker, and a new workpiece W3(not illustrated) is placed on the setup plate30with the workpiece placing jig60therebetween, by the not-illustrated crane or the manual work of the worker.

Meanwhile, the workpiece placing jig60and the workpiece W2to be processed which are placed on the processing table20are disposed at the processing position by moving the processing table20from the setup position to the processing position (seeFIG. 1) . The workpiece W2to be processed which is placed on the processing table20with the workpiece placing jig60therebetween is subjected to laser processing at the processing position.

In this case, processing data D2used for the laser processing of the workpiece W2to be processed is data incorporating the aforementioned three-dimensional shape data d2of the workpiece W2to be processed and the three-dimensional shape data d1of the processed workpiece W1.

Specifically, on the basis of the three-dimensional shape data d2of the workpiece W2to be processed, the three-dimensional laser processing machine reflects slight difference in shape among the workpieces W and the position of the workpiece W2relative to the workpiece placing jig60, and corrects the position and the laser light emitting direction of the laser light emitting portion11for the laser processing of the not-illustrated processing portion of the workpiece W2. The three-dimensional laser processing machine can thereby accurately grasp the distance between the focal position of the emitted laser light and the processing portion of the workpiece W2, and set the focal position and the processing portion at a predetermined distance from each other.

Moreover, the three-dimensional laser processing machine compares the aforementioned three-dimensional shape data d1of the processed workpiece W1and the processing data D1of the laser processing performed on the workpiece W1, and checks whether the laser processing is performed on the workpiece W1as indicated in the processing data D1, i.e. checks the processing accuracy of the laser processing by the three-dimensional laser processing machine. The three-dimensional laser processing machine can thereby detect a processing error and the like occurring in the laser processing and perform laser processing in which the processing error and the like is corrected on the workpiece W2by incorporating the data of the processing error and the like into the processing data D2of the workpiece W2.

Accordingly, there is no need to measure the distance between the processing portion and the laser light irradiation portion for each of processing portions by using a gap sensor or the like as in the conventional three-dimensional laser processing machine, and the time for gap detection by the gap sensor can be eliminated. The processing efficiency of laser processing by the three-dimensional laser processing machine can be thereby improved.

As a matter of course, timings of performing the three-dimensional shape measurement of the workpiece W1and the laser processing of the workpiece W2and a timing of incorporating the three-dimensional shape data d1of the processed workpiece W1into the processing data in the present invention are not limited to those in the embodiment. For example, the timings may be as follows. The three-dimensional shape of the processed workpiece W1is measured while the workpiece W2is being subjected to the laser processing, and the three-dimensional shape data d1of the processed workpiece W1is incorporated into processing data D3of the next workpiece W3(not illustrated).

Moreover, in the embodiment, the setup and the three-dimensional shape measurement of the workpiece W is performed on the setup plate30separate from the processing table20, and the workpiece W is placed on the processing table20and the setup plate30with the workpiece placing jig60therebetween. However, the present invention is not limited to this configuration. For example, the configuration may be as follows. The workpiece W is setup directly on the processing table20at the setup position, the scanning device50is provided near the processing table20at the setup position, and the three-dimensional shape measurement of the workpiece W before and after the processing thereof is performed with the workpiece W being placed directly on the processing table20.

Moreover, although the scanning device50is used as the three-dimensional shape measurement device in the embodiment, the three-dimensional shape measurement device is not limited to this in the present invention. For example, a non-contact three-dimensional shape measurement device (point laser, line laser, or optical measurement device) or a contact three-dimensional shape measurement device (probe) may be used as the three-dimensional shape measurement device.

Note that the present invention can be applied also to “cutting”, “boring”, “welding”, “cladding”, “surface modification”, and “surface roughness improvement” in laser processing.

REFERENCE SIGNS LIST

11LASER LIGHT EMITTING PORTION

40WORKPIECE CHANGING DEVICE

41MAIN BODY PORTION OF WORKPIECE CHANGING DEVICE

42HOLDING PORTION OF WORKPIECE CHANGING DEVICE

51BASE PORTION OF SCANNING DEVICE

52BODY PORTION OF SCANNING DEVICE

53ARM PORTION OF SCANNING DEVICE

54NECK PORTION OF SCANNING DEVICE

55CAMERA OF SCANNING DEVICE