JPH10314968A - Laser beam machining device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To carry out observation of a material to be machined at a narrow place and attachment of a distance sensor and the like to the tip of a nozzle and to facilitate nozzle replacement in accordance with the use by making the conical nozzle at the tip of a laser torch freely attachable to and detachable from the torch cylindrical body and burying an illuminating device in the nozzle. SOLUTION: A conical nozzle 112 is made freely attachable to and detachable from the cylindrical body 111 of a laser torch 100. An illuminating device 90 is constituted of plural miniature lamps arranged radially with equally angled spaces apart against the optical axis CA of a CCD camera 120, with the lamps buried on the surface of the conical nozzle 112 and with the illuminating light emitted towards the tip end of the nozzle 112. By this structure, illuminating light can be cast in the direction nearly vertical to a machining line regardlessly of the machining direction, so that in observing the machining line with the CCD camera or in detecting the machining line with an image processor, a stable image can be obtained regardlessly of heat rays of a work.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser beam processing apparatus, and more particularly to an illumination device for illuminating a workpiece when the workpiece is observed by an imaging device.

[0002]

2. Description of the Related Art As is well known, a laser beam processing apparatus performs laser beam processing by condensing a laser beam on the surface of an object to be processed (object work) using an optical system. Laser beam processing includes laser cutting, laser welding, and the like.

[0003] As such a laser beam processing apparatus,
A three-dimensional laser beam machine shown in FIG. 2 is known. This three-dimensional laser processing machine has a laser irradiation unit 100 for irradiating a target workpiece 51 with laser light. The laser irradiation unit 100 is connected to one end of the robot arm 52. One end of a movable frame 53 is connected to the other end of the robot arm 52. Laser irradiation unit 100
, Laser light is incident from a light source 55 via a flexible optical fiber 56. As the light source 55, a YAG laser device that emits a YAG laser beam as a laser beam,
Excimer, excimer which emits CO ₂ laser beam, a CO ₂ laser device is used as a laser beam.

[0004] The three-dimensional laser beam machine further has a three-axis stage 60. The three-axis stage 60 includes the target workpiece 51
The X-axis bellows mechanism 61 and the Y-axis bellows mechanism 62 for driving the movable frame 53 in the x-axis direction (left-right direction) and the y-axis direction (front-back direction), respectively, and the movable frame 53 And a Z-axis bellows mechanism 63 that moves in the axial direction (vertical direction).

As will be described later in detail with reference to FIGS. 3 and 4, the laser irradiation unit 100 includes a CCD camera (to be described later) as an image pickup device, and the target work 51 picked up by the CCD camera is captured. The pixels on the front surface are displayed on the camera monitor 71 of the controller 70. Controller 7
Numeral 0 is for controlling the driving of the three-axis stage 60 and the robot arm 52. The operator inputs an operation command to the controller 70 from the teaching box 73 carried while monitoring the camera monitor 71 and the target work 51, and remotely controls the three-dimensional laser processing machine.

Next, the laser irradiation unit 100 will be described with reference to FIGS. Laser irradiation unit 100
Has a laser torch 110 and a CCD camera 120. The laser torch 110 includes a cylindrical body 111 and a conical body 112 extending continuously from one end of the cylindrical body 111. A hole 112a is formed in the top of the cone 112. The laser torch 110 is used for the irradiation lens 11.
3, the irradiation half mirror 114, and the imaging lens 11
5 and built-in. The laser light guided through the optical fiber 56 is reflected by the irradiation half mirror 114, then condensed by the irradiation lens 113, and emitted from the hole 112a. Thus, the target workpiece 51 provided opposite to the top of the cone 112 can be subjected to laser beam processing.

FIG. 4 shows a case of laser welding, in which the target work 51 has a welding line 51a. In the case of general laser beam processing, the welding line 51a is called a processing line.

The CCD camera 120 is a laser torch 110
Is provided on the other end side of the cylindrical body 111. The CCD camera 120 is connected to the surface of the target workpiece 51 through the hole 112a,
In particular, the welding line (processing line) 51a is imaged. This CCD
In order to better observe the welding line 51a with the camera 120, it is necessary to uniformly and stably illuminate the surface of the target workpiece 51. This is because it is easy to process the image captured by the CCD camera 120.

Hereinafter, a conventional illumination device used in a laser beam processing apparatus will be described with reference to FIGS.

The illumination device shown in FIG. 5 includes a light source 81 for emitting illumination light, a flexible tube 82 for guiding illumination light emitted from the light source 81, and a light guided from the flexible tube 82 to a laser torch 110. And a light guide 83 that emits light toward the illumination half mirror 116 housed in the camera. Half mirror for lighting 1
Illumination light reflected by the target workpiece 51 is transmitted through the hole 112a along the camera axis CA of the CCD camera 120.
It is emitted as incident light on the surface of FIG. Therefore, the incident light enters the surface of the target work 51 almost perpendicularly. This illuminator is called a coaxial epi-illuminator because the illumination light falls along the camera axis CA.

The lighting device shown in FIG.
5 except that a spot-type (line-type) light guide 84 is used instead. However, unlike the case of FIG. 5, since the illumination light is emitted from the outside of the laser torch 110, the illumination half mirror 116 as shown in FIG. 5 is unnecessary. The spot-shaped light guide 84 irradiates the illumination light in a spot form from the irradiating section 84a. In such an illuminating device, it is necessary to irradiate the illumination light to the welding line (processing line) 51a of the target work 51 (FIG. 4) from a predetermined direction. This lighting device is called a spot-type lighting device.

The illumination device shown in FIG. 7 has the same configuration as that shown in FIG. 6 except that a ring type light guide 85 is used instead of the spot type light guide 84. The ring-shaped light guide 85 has an annular irradiation section 85a.
The illumination unit 85a emits illumination light having a circular cross section. The ring type light guide 85 is a laser torch 11
0 (FIG. 4). In order to detect the welding line 51a of the target work 51 (FIG. 5), it is necessary to make the illumination light enter the surface of the target work 51 at an angle within a predetermined range. Therefore, the ring-type light guide 85 must be attached to the laser torch 110 at a position where the angle in the predetermined range can be realized. This lighting device is called a ring type lighting device.

The above-described conventional lighting devices have the following disadvantages. In the coaxial epi-illumination device shown in FIG. 5, since the surface of the target work 51 and the illumination light (incident light) are almost perpendicular, the welding line (processing line) 51a
Has the disadvantage that it is difficult to see. The spot-type lighting device shown in FIG. 6 has a drawback that an adjustment operation is required because it is necessary to apply illumination light to the welding line (processing line) 51a from a predetermined direction. The ring-type lighting device shown in FIG. 7 has a drawback in that when the ring-shaped light guide 85 is attached to the laser torch 110 at a position where an angle in a predetermined range can be realized, it hinders work.

In order to solve the above-mentioned drawbacks of the conventional illumination device, the applicant of the present application has developed a laser beam provided with an illumination device capable of accurately observing a processing line of an object to be processed by an imaging device. A processing device has already been filed (hereinafter, referred to as an earlier application) (Japanese Patent Application Laid-Open No. H8-19727)
No. 3).

Referring to FIG. 8, there is shown a laser irradiation section provided with the illumination device according to the earlier application. The laser irradiation section itself has the configuration shown in FIG. The illumination device according to the present invention is attached to the laser irradiation unit.

The illumination device according to the earlier application is obtained by adding a cap-type light guide 86 to the ring-type illumination device shown in FIG. Ring type light guide 85
Is attached to the outer wall of the cylindrical body 111 of the laser torch 110 along the outer periphery thereof. The ring-shaped light guide 85 emits illumination light from the annular irradiation section 85a along the outer wall of the cylindrical body 111 toward the surface of the target work 51 (FIG. 4).

The cap-type light guide 86 is attached to the outer wall of the laser torch 110, and is optically coupled to the ring-shaped light guide 85 of the ring-shaped light guide 85. The cap-type light guide 86 has a cylindrical portion 86-1 and a truncated conical portion 86-corresponding to the outer shapes of the cylindrical body 111 and the conical body (nozzle) 112 of the laser torch 110, respectively.
2 has a cap shape. The cap-type light guide 86 irradiates the illumination light emitted from the annular irradiation part 85a via the cylindrical part 86-1 and the truncated cone part 86-2 to the cylindrical body 111 and the conical body 11 of the laser torch 110.
Guide along the outer wall of No. 2. Cap-type light guide 86
Emits the guided light from the tip of the truncated cone portion 86-2 toward the surface of the target work 51 immediately below the top of the cone 112 at a predetermined angle with respect to the surface of the target work 51 (FIG. 4). .

Since the cap-type light guide 86 conforms to the outer shape of the laser torch 110, it can illuminate the surface of the target work 51 (FIG. 4) from an oblique direction. The material of the cap-type light guide 86 is preferably a transparent plastic material or a glass material.

Next, with reference to FIG. 9A, conditions of the illumination direction in the illumination device shown in FIG. 8 suitable for detecting the welding line 51a of the target workpiece 51 will be described. The angle θ ₁ between the illumination light (incident light) and the surface of the target work 51 is 20
It is preferable that it is in the range of ° ≦ θ ₁ ≦ 45 °. This is because if the angle is out of this range, an image in which the irregularities, scratches, and roughness of the welding target are emphasized can be obtained as an image captured by the CCD camera 120. It is generally difficult to digitally process such images. here,
Digital processing refers to differentiation processing, binarization processing, and the like.

The cap-type light guide 8 according to the earlier application
6 has an outer shape that matches the outer shape of the laser torch 110, so that the above-mentioned optimum angle condition (illumination condition) can be satisfied only by attaching it to the laser torch 110. In addition, since the cap-type light guide 86 has an outer shape that matches the outer shape of the laser torch 110, even if the cap-type light guide 86 is attached to the laser torch 110, there is no obstacle to work.

The cap-type light guide 86 is detachable. Therefore, adhesion, breakage, and the like of dirt due to laser processing can be prevented. That is, the operator attaches the cap-type light guide 86 to the laser torch 110 only when detecting the welding line 51a of the target work 51. Then, after the operation is completed, the cap-type light guide 86 is removed from the laser torch 110.

By simply performing such an operation, when illumination is required, it is possible to easily perform illumination that satisfies the optimum angle condition as shown in FIG. Further, since the cap type light guide 86 has a ring shape, regardless of the direction of the welding line 51a, as shown in FIG.
The illumination light can be applied from a direction in which the angle θ ₂ is perpendicular to the direction of the welding line 51a.

As described above, when the operator wants to observe the welding line 51a of the target work 51 with the CCD camera 120, a stable image can be obtained regardless of the skill level of the operator. Therefore, it is possible to easily digitally process the pixels captured by the CCD camera 120.

[0024]

However, in the lighting device according to the earlier application, the cap-type light guide 86 is mounted on the outer wall of the laser torch 110 (the outer wall of the cylindrical body 111 and the outer wall of the conical body (nozzle) 112). There is a disadvantage that the outer shape of the nozzle 112 becomes larger by that amount and the observable area is limited. The nozzle 11
There is also a disadvantage that a sensor such as a distance sensor cannot be attached to the tip of the second.

Therefore, an object of the present invention is to provide a laser beam processing apparatus provided with an illuminating device which enables observation in a narrow place.

Another object of the present invention is to provide a laser beam processing apparatus provided with an illumination device capable of attaching a sensor such as a distance sensor to the tip of a nozzle.

[0027]

According to the present invention, there is provided a laser beam processing apparatus comprising: a cylindrical body having a central axis; and a conical body extending coaxially with the central axis and extending continuously from one end of the cylindrical body. And a laser torch that emits laser light along the center line from a hole opened at the top of the cone to process a workpiece provided to face the top of the cone. An imaging device provided on the other end side of the cylindrical body of the laser torch and imaging the surface of the workpiece through the hole; and an illumination device for illuminating the surface of the workpiece. In the laser beam processing apparatus, the cone is detachable from the cylinder, and the illumination device is embedded in the cone.

[0028]

The illumination device is embedded in the cone (nozzle), so that the outer shape of the nozzle can be reduced.
Observation in a narrow place becomes possible. It is also possible to attach a sensor such as a distance sensor to the tip of the nozzle. Furthermore, since the nozzle is detachable from the cylinder,
The nozzle can be changed according to the application.

[0029]

Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a laser irradiation unit provided with an illumination device according to one embodiment of the present invention. The laser irradiation section itself has the configuration shown in FIG. The illumination device according to the present invention is attached to the laser irradiation unit. 1A is a schematic sectional view, and FIG. 1B is a schematic plan view of a cone (nozzle) 112 viewed from above.

In the laser irradiation section shown in FIG. 1, a cone (nozzle) 112 is detachable from a cylinder 111. The lighting device 90 according to the present invention is embedded in a cone (nozzle) 112. As shown in FIG. 1B, a plurality of illuminating devices 90 (six in the illustrated example) are arranged at equal angular intervals symmetrically (radially) with respect to the camera optical axis (center axis) CA. A) light source 91). The illustrated light source 91 is formed of a small light bulb, and the illumination light from each small light bulb 91 is emitted toward the tip of the nozzle 112 as shown by an arrow A in FIG. In the illustrated example, the nozzle 112 is a nozzle for observation (teaching).

Next, the operation of the laser irradiating section provided with the illuminating device having such a configuration will be described. Operations performed by the laser beam processing apparatus are divided into teaching (observation) operations and processing operations. The laser irradiation unit according to the present invention is used for teaching (observation) work.

First, an illumination device 9 as shown in FIG.
Assume that nozzle 112 with zero has already been assembled. In the teaching (observation) work, the processing line 5
1a (FIG. 9) is observed by the CCD camera 120 and detected by image processing. When observing and detecting the processing line 51a, the operator moves the nozzle 112 shown in FIG.
As shown in (a), the cylindrical portion 11 of the laser torch 110
Attach to 1. Then, wiring of the small light bulb 91 is performed.

Thus, the illumination conditions as described with reference to FIG. 9 can be easily realized. Further, since a plurality of the light sources 91 are radially arranged at equal angular intervals inside the nozzle 112, it is possible to irradiate the illumination light in a direction substantially perpendicular to the line direction regardless of the direction of the processing line 51a. it can.

Therefore, the operator operates the CCD camera 1
When the processing line 51a is observed at 20 or when the processing line 51a is detected in the subsequent image processing, a stable image can be obtained regardless of the skill level of the operator by using the illumination device 90 according to the present invention. Can be.

After the teaching operation as described above is completed, the observation nozzle 112 is replaced with a processing nozzle. still,
If a material that can withstand the heat generated at the time of processing is used for the nozzle 112 and a small light bulb 91 that can withstand the heat is used, the observation nozzle 112 can be used as it is as a processing nozzle.

The illumination device having such a configuration has the following operation and effects. Since the plurality of small light bulbs 91 are arranged at equal angular intervals symmetrically with respect to the central axis CA, illumination light can be uniformly applied to the target work 51 immediately below the laser torch 110. In addition, the nozzle 112 for observation (teaching) is detachable from the cylindrical body 111, so that a nozzle having a different shape depending on the application such as cutting or welding can be easily replaced according to the application. it can. Since the light source (small bulb) 91 is embedded in the nozzle 112 for observation (teaching), the nozzle 112
Can be reduced, whereby the illumination device can be mounted on the outer wall and the nozzle 112 can be moved to a narrow place which cannot be observed in the case of the conventional nozzle having a large external shape (FIG. 8).
It is possible to observe the narrow place. Further, since nothing is mounted on the outer wall of the nozzle 112, the nozzle 1
It is possible to attach a distance sensor such as a capacitance sensor to the tip of the twelve. When the nozzle 112 is made of a heat-resistant material and the light source (small bulb) 91 is also made of a heat-resistant material, the nozzle 112 can be used for processing.

Although the present invention has been described with reference to preferred embodiments, the present invention is not limited thereto, and various modifications and changes can be made without departing from the spirit of the present invention.

[0039]

As described above, according to the present invention, the illumination device is embedded in the conical body (nozzle), so that the outer shape of the nozzle can be reduced and observation in a narrow place becomes possible. . It is also possible to attach a sensor such as a distance sensor to the top (tip) of the nozzle. Further, since the nozzle is detachable from the cylindrical body, the nozzle can be replaced according to the application.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a laser irradiation unit of a laser beam processing apparatus including an illumination device according to an embodiment of the present invention;
(A) is a schematic sectional view, (b) is a schematic plan view of a cone (nozzle) viewed from above.

FIG. 2 is a perspective view illustrating a schematic configuration of a conventional laser beam processing apparatus (three-dimensional laser processing machine).

FIG. 3 is a perspective view showing a configuration of a laser irradiation unit shown in FIG. 2 in detail.

FIG. 4 is a cross-sectional view showing an internal configuration of a laser irradiation unit shown in FIG.

FIG. 5 is a schematic front view showing a first example of a conventional lighting device.

FIG. 6 is a schematic front view showing a second example of a conventional lighting device.

FIG. 7 is a diagram showing a third example of a conventional lighting device, and FIG.
Is a bottom view and (b) is a front view.

FIG. 8 is a cross-sectional view showing a laser irradiation unit of a laser beam processing apparatus provided with the illumination device according to the earlier application (Japanese Patent Application Laid-Open No. 8-197273).

9A and 9B are views for explaining conditions of an illumination direction in the illumination device shown in FIG. 8, where FIG. 9A is a cross-sectional view and FIG. 9B is a plan view.

[Explanation of symbols]

 90 Illumination device 91 Light source (small bulb) 110 Laser torch 111 Cylindrical body 112 Conical body (nozzle)

Claims (3)

[Claims] 1. A laser torch comprising a cylindrical body having a central axis and a cone coaxial with the central axis extending continuously from one end of the cylindrical body, the laser torch being provided at the top of the cone. A laser torch for emitting a laser beam from the hole along the center line and processing an object to be processed provided to face the top of the cone; provided on the other end side of the cylindrical body of the laser torch; A laser beam processing apparatus comprising: an imaging device configured to capture an image of the surface of the object to be processed through the hole; and an illumination device that illuminates the surface of the object to be processed. A laser beam processing apparatus, which is detachable with respect to the laser beam, and wherein the illumination device is embedded in the cone. 2. The laser beam processing apparatus according to claim 1, wherein the illumination device includes a plurality of light sources arranged at equal angular intervals symmetrically with respect to the central axis. 3. The laser beam processing apparatus according to claim 1, wherein a distance sensor is mounted on a top of the cone.