JPH0751870A - Laser beam machine - Google Patents

Abstract

PURPOSE:To provide a device capable of surely making check, maintenance, display and control at the time of a failure of optical parts such as condenser lens of a processing head an resonator mirrors of a laser oscillator. CONSTITUTION:An electric conductivity is detected at all times through an electric conductivity detector 15 from a conductive material 14 stuck to the condenser lens 4 held in an insulating holder 25 and the PR mirror 11 and TR mirror 12 of the resonator of the laser oscillator 1 and, therefore, the electric conductivity degrades and the fault of the condenser lens 4 is detected in case of the deterioration and failure of the condenser lens 4. Since the electric conductivity detector 15 and a controller 6 are wired, the irradiation with lens light 2 is stopped when the detected signal is processed by the controller 6 and then, the fault is detected from the condenser lens 4. As a result, the failure of the optical parts, such as condenser lens 4 of the processing head and resonator mirrors of the laser oscillator, is monitored at all times and there is an effect of safely executing the processing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to countermeasures against damage to optical components such as a condenser lens of a processing head of a laser processing apparatus and a resonator mirror of a laser oscillator.

[0002]

2. Description of the Related Art FIG. 10 shows, for example, JP-A-60-66226.
FIG. 1 is a configuration diagram of a conventional laser processing apparatus disclosed in Japanese Patent Publication No. 2 (1994), 2 is laser light, 4 is a condenser lens, 20 is dirt detection laser light, 21 is dirt detection laser light 20 oscillator, and 2 is
Reference numeral 2 is a light amount detecting device for detecting the reflected light of the dirt detecting laser light 20 by the condenser lens 4, 23 is a power source of the dirt detecting laser light 20, and 24 is a light quantity comparing circuit of the dirt detecting laser light 20.

Next, the operation will be described. The dirt detection laser beam 20 is applied to the condenser lens 4, and the light that hits the surface of the condenser lens 4 and is reflected is detected by the photodetector. The dirt on the lens surface is detected by comparing the detected reflected light. Although the reflection component of the detection laser light 20 is detected here, a method of detecting the reflection component of the processing laser light is also valid.

[0004]

Since the conventional laser processing apparatus is constructed as described above, various changes (atmosphere temperature or assist gas) in the detection space (processing head) are caused because the detection means is light. The reflected light cannot be accurately detected because the light is refracted and diverged in response to pressure changes, changes in the flow of assist gas such as turbulence, and vortices. Further, an extra space for disposing the detection device (light source, light receiving element) is required in the processing head, and the processing head itself becomes large. Further, an arithmetic circuit for performing an arithmetic operation with the detected value and instructing the control device is required, which increases the cost of the detection device and the control arithmetic circuit. In addition, there are problems that the light source is cut off, spatter, dust and the like adhere to the light source, and the function as the light source is impaired.

The present invention has been made in order to solve the above-mentioned problems, and it is possible to perform confirmation, maintenance, control and the like when an optical component such as a condenser lens of a processing head or a resonator mirror of a laser oscillator is damaged. The purpose is to obtain a laser processing device that can perform.

[0006]

A laser processing apparatus according to the present invention is a laser processing apparatus for converging a laser beam output from a laser oscillator and irradiating the object to be processed to perform desired processing. The laser processing device has a resonator mirror as an optical member for oscillating laser light,
It has a condensing lens as an optical member for condensing laser light at a high energy density, and is configured to include a conductive material for applying a conductive material to the optical member and detecting the conductivity of the conductive material. It is provided with a conductivity detecting means.

A laser processing apparatus for converging laser light output from a laser oscillator and irradiating the object to be processed to perform desired processing, wherein the laser light forming the laser processing apparatus has a high energy density. The temperature detecting means is provided between the condensing lens for condensing the light and the workpiece, and the operation is stopped when the temperature detected by the temperature detecting means reaches a predetermined temperature.

Further, when there is no abnormality in the condenser lens, the temperature range detected by the temperature detecting means is stored, and the stored temperature is compared with the detected temperature to calculate the laser. A control means for controlling the output of the oscillator is provided.

Further, the laser processing apparatus is a laser processing apparatus for converging a laser beam output from a laser oscillator and irradiating the object to be processed to perform desired processing, wherein the laser beam constituting the laser processing apparatus has a high energy density. A plurality of temperature detecting means are symmetrically arranged around the condensing lens between the condensing lens for condensing the light and the object to be processed, and the heat distribution state of the condensing lens is detected.

[0010]

In the laser processing apparatus according to the present invention, the condensing lens is deteriorated, damaged, or cracked by attaching a conductive material to the outer periphery of the condensing lens and providing a processing head capable of detecting the conductivity of the conductor. In this case, the abnormality of the condenser lens can be detected by the degree of conductivity. Similarly, when a conductor is attached to the resonator mirror of the laser oscillator, and the conductivity is constantly detected by the conductivity detector, if the conductor is deteriorated or damaged, the conductivity is lowered and an abnormality can be sensed.

Further, when a processing head equipped with a temperature sensor is provided between the condensing lens for laser light and the workpiece, the condensing lens interferes with its operation and the laser light is not condensed. The temperature sensor detects the laser light, rises above the normal detection value, operates when reaching a predetermined temperature, and can detect an abnormality of the condenser lens. Also,
When the laser light is not normally incident on the processing head and hits a part of the processing head, heat is conducted by the laser light and the temperature rises, so that the sensor can detect an abnormality in the same manner as described above.

Further, in the laser processing apparatus, even if the condenser lens is not damaged, the heat absorption rate of the condenser lens itself increases and the temperature rises due to changes in the environment inside the machining head. Even if the temperature is too high, the temperature range of the condenser lens that can be processed normally is stored in the control device in advance and the processing is continued by comparing it with the current detected temperature. By providing a function of stopping or controlling the output of the laser light, it is possible to perform control according to the state of the condenser lens.

Further, by mounting a plurality of temperature sensors symmetrically around the condenser lens, each temperature sensor detects the temperature at each point, and the temperatures are compared and calculated to calculate the temperature of the condenser lens. The temperature distribution can be detected.

[0014]

【Example】

Example 1. The first embodiment of the present invention will be described below. FIG. 1 is a block diagram of a laser processing apparatus. 1 is a laser oscillator, 2 is laser light, 3 is a processing head, 4 is a condenser lens, 5 is a processing table, 6 is a controller, 7 is a reflecting mirror, and 8 is a reflecting mirror.
Is a workpiece, 9 is a nozzle at the tip of the processing head 3, 10 is a processing assist gas, 11 is a PR mirror which is provided in the laser oscillator 1 and is in contact with the outside and serves as an extraction part of the laser beam 2, and 12 is a reflection of the PR mirror 11. The TR mirror serving as the mirror 7 and the remaining symbols will be described later with reference to the drawings. FIG. 2 shows a mirror configuration diagram inside the laser oscillator 1, 13 is a resonator of the oscillator 1 for generating the laser beam 2, 14 is a condenser lens 4, and PR mirror 1
1, a conductive material such as a metal particle coated on the outer circumference of an optical member such as the TR mirror 12 or a conductive material such as a conductive resin material coated on the outer circumference, and 15 a conductivity detecting device. FIG. 3 is a view seen from the optical axis direction of the laser light of the optical component 16 such as the condenser lens 4, the PR mirror 11, and the TR mirror 12. FIG. 4 shows a sectional view of the processing head 3. 25 is a processing head 3 that holds the condenser lens 4 and is a metal body.
It is an insulating holder for insulating from
It holds the R mirror 11 and the TR mirror 12.
FIG. 7 is a schematic circuit diagram of this embodiment, in which an output unit 26 serves as a current source for measuring the resistance of the conductive material 14,
Reference numeral 27 is a current detector that detects the current value after the conductive material 14 is loaded, 28 is a comparator that compares the power supply current (set current) with the current value after the conductive material 14 is loaded, and 30 is an abnormality after the comparison. It is a circuit breaker that stops the laser processing device.

Condensing lens 4 held by insulating holder 25
As shown in FIG. 3, the conductivity is constantly detected from the conductive material 14 attached as shown in FIG. 3, so that when the condenser lens 4 is deteriorated and damaged, the conductivity is reduced and The abnormality of the optical lens 4 is detected. Similarly, for the resonator 13 of the laser oscillator 1, the conductivity is constantly detected by the circuit of FIG. 7 from the conductive material 14 attached as shown in FIG. Mirror 11
When the TR mirror 12 is deteriorated and damaged, the conductivity decreases,
The abnormality of the PR mirror 11 and the TR mirror 12 is detected.

Further, when a detection signal detected by the conductivity detecting device 15 is input to the control device 6 and the detection signal is processed by the control device 6 and an abnormality is sensed by the condenser lens 4, the laser beam 2 is detected. Stop irradiation.

Reference numeral 18 in FIG. 1 denotes another device. By sending the detection signal to another device 18 such as a peripheral device (supporting device) of the laser processing apparatus, that is, a work unloading / carrying-in device via the control device 6, it is possible to activate a safety measure against a processing abnormality. Further, not only the peripheral equipment but also the apparatus systematized with the laser processing apparatus can stop the entire system.

Reference numeral 17 in FIG. 1 denotes a display screen of the control device 6. Since the conductivity detecting device 15 and the control device 6 are wired, the detection signal can be processed by the control device 6 and the abnormality of the condenser lens 4 can be displayed on the display screen 17 of the control device 6.

Example 2. A second embodiment of the present invention will be described. FIG. 5 shows a state when the condenser lens 4 is broken. 1
9 is a temperature sensor installed between the condenser lens 4 and the nozzle 9.

When the condenser lens 4 is used for laser processing and is deteriorated and damaged after a lapse of a certain processing time, the laser beam 2 is not condensed, and the processing head 3 has the same size as it is incident on the processing head 3. As a result, heat reaches the nozzle 9 at the tip of the nozzle, and heat is transmitted to and sensed by the temperature sensor 19 installed between the condenser lens 4 and the nozzle 9, as shown in FIG. When the laser light 2 is not normally incident on the processing head 3 and hits a part of the processing head 3, the heat of the laser light 2 is conducted, the temperature rises, and the temperature sensor 19 operates. In any case, the temperature sensor 19 operates when the set temperature is reached and the conduction is turned off. This signal causes the controller to display an error.
introduce.

Example 3. A third embodiment of the present invention will be described. FIG. 8 is a schematic circuit diagram of the third embodiment. 26 is an output unit that serves as a current source for measuring the resistance of the conductive material 14, 27 is a current detector that detects a current value after the conductive material 14 is loaded, and 28 is a power supply current (set current) and the conductive material 14 A comparator for comparing the current value after loading, and 32 is an oscillator control device for controlling the output value of the oscillator by the numerical value from the comparator.

In the laser processing apparatus, even if the condenser lens 4 is not damaged, the heat absorption rate of the condenser lens 4 itself is increased due to a change in the environment inside the processing head 3 and the temperature is increased. Even in such a case, the temperature region in the condenser lens 4 which can be normally processed by the circuit of FIG. 8 is stored in the control device 6 in advance, and the processing is continued by comparing it with the current detected temperature, or the temperature region is changed. When the laser beam 2 deviates from the above, the laser beam 2 is stopped, or a control device 6 for controlling the output of the laser beam 2 performs more appropriate control according to the state of the condenser lens 4.

Example 4. A fourth embodiment of the present invention will be described. FIG. 6 shows the processing head 3 in which the temperature sensor 19 is combined with the laser processing apparatus in the first embodiment. Figure 9
9 is a circuit schematic diagram of Embodiment 4. FIG. 26 is an output unit which serves as a current source for measuring the resistance of the conductive material 14, 27 is a current detector for detecting the current value after the conductive material 14 is loaded, 2
8 is a comparator for comparing the power supply current (set current) with the current value after the conductive material 14 is loaded, 29 is a calculator for calculating the high temperature point by calculating the numerical value from the comparator, 31 is data from the calculator Is a screen control system for controlling the screen for displaying.

A plurality of temperature sensors 1 are arranged around the condenser lens 4.
By mounting 9 in a symmetrical manner, each temperature sensor 19
Detects the temperature at each point by a circuit as shown in FIG. 9 and compares / calculates the temperatures to calculate the highest temperature point, thereby obtaining the temperature state and heat distribution state of the condenser lens 4. To observe. Further, since it is also close to the conductive material 14, it is possible to set an abnormal temperature (within the normal conduction operation range of the conductive material) in the temperature sensor 19 and also detect the dangerous temperature of the conductive material 14.

[0025]

As described above, according to the present invention, since the element for detecting the conductivity is in close contact with the optical member such as the condenser lens of the processing head and the resonator mirror of the laser oscillator, the medium such as gas. There is an effect that the converging performance of the laser light of the optical member can be clearly monitored without being affected by the above, and that the processing head itself does not need to have an excessive device.

Further, by providing a temperature sensor between the laser light condenser lens and the workpiece, the condenser lens can be
If there is a problem, the temperature sensor responds immediately and the temperature sensor detects the abnormality, which has the effect of enabling safe processing.

Further, the output of the oscillator is controlled in accordance with the temperature of the condenser lens as well as the processing conditions, so that an excellent laser processing can be performed.

Further, by disposing a plurality of temperature sensors symmetrically around the condenser lens, there is an effect of detecting the heat distribution state of the condenser lens.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a laser processing apparatus according to an embodiment of the present invention.

FIG. 2 is a mirror configuration diagram of the laser oscillator according to the first embodiment of the present invention.

FIG. 3 is a detailed view of an optical member according to Embodiment 1 of the present invention.

FIG. 4 is a sectional view of a processing head of the laser processing apparatus according to the first embodiment of the present invention.

FIG. 5 is a configuration diagram of a processing head according to a second embodiment of the present invention.

FIG. 6 is a configuration diagram of a processing head according to a fourth embodiment of the present invention.

FIG. 7 is a schematic diagram of a circuit according to the first embodiment of the present invention.

FIG. 8 is a circuit schematic diagram according to a third embodiment of the present invention.

FIG. 9 is a circuit schematic diagram according to a fourth embodiment of the present invention.

FIG. 10 is a configuration diagram of a conventional laser processing apparatus.

[Explanation of symbols]

 1 Laser Oscillator 2 Laser Light 3 Processing Head 4 Condensing Lens 5 Processing Table 6 Controller 7 Reflector 8 Workpiece 9 Nozzle 10 Processing Assist Gas 11 PR Mirror 12 TR Mirror 13 Resonator 14 Conductive Material 15 Conductivity Detector Reference Signs List 16 optical member 17 display screen 18 other device 19 temperature sensor 20 contamination detection laser light 21 contamination detection laser light oscillator 22 light intensity detection device 23 contamination detection laser light power supply 24 light intensity comparison circuit 25 insulation holder 26 output unit 27 Current detector 28 Comparator 29 Computing device 30 Circuit breaker 31 Screen control system 32 Oscillator control device

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location H01S 3/08

Claims (4)

[Claims] 1. A laser processing apparatus for condensing laser light output from a laser oscillator and irradiating a workpiece to perform desired processing, wherein the laser processing apparatus is an optical member for oscillating laser light. And a condenser lens as an optical member for condensing laser light at a high energy density, and a conductive material is applied to the optical member to detect the conductivity of the conductive material. A laser processing apparatus comprising: a conductivity detecting unit configured to include a conductive material. 2. A laser processing apparatus for converging laser light output from a laser oscillator and irradiating a workpiece to perform desired processing, wherein the laser light constituting the laser processing apparatus has high energy density. A laser processing apparatus, characterized in that temperature detecting means is provided between a condensing lens for condensing light onto a workpiece and a workpiece, and the operation is stopped when the temperature detected by the temperature detecting means reaches a predetermined temperature. 3. When the condenser lens has no abnormality, the temperature range detected by the temperature detecting means is stored, and the stored temperature and the detected temperature are compared and calculated to obtain a laser beam. The laser processing apparatus according to claim 2, further comprising control means for controlling the output of the oscillator. 4. A laser processing apparatus for converging laser light output from a laser oscillator and irradiating a workpiece to perform desired processing, wherein the laser light constituting the laser processing apparatus has high energy density. Laser processing characterized in that a plurality of temperature detecting means are symmetrically arranged around the condensing lens between the condensing lens for condensing the light onto the workpiece and the workpiece, and the heat distribution state of the condensing lens is detected. apparatus.