JPH05245685A - Dust guard for laser head - Google Patents

Abstract

PURPOSE:To provide a dust guard, for the laser head of a laser beam machine, which is compact, free from damage due to hot spatters, and capable of surely preventing dirt such as spatters, floating gas and dust from entering into the laser head. CONSTITUTION:In the laser head 30 which is provided with a movable head part 62 movably fitted forwards and backwards with respect to a fixed head part 42, a high pressure air chamber 42 is formed in the outer periphery from the tip of the fixed head part 42 to the movable head part 62; a dust protective fluid is injected from the air chamber 42 along the peripheral wall of the movable head part 62 via a gap-like opening 55, blowing out the spatters, gas, dust, etc.; and thereby the fear for dirt damaging the laser head 30 and entering inside the head are preventively eliminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser light emitting laser head in a laser processing apparatus such as a laser robot, and more particularly to an optical mechanism for focusing laser light for laser processing on a fixed head having a built-in laser optical path. With a built-in laser head equipped with a movable head that can be focused to adjust the distance of the laser light irradiation port to the work according to the distance measurement signal from the distance sensor, spatter, gas, etc. The present invention relates to a dustproof device capable of preventing the intrusion of fine dust and the like to prevent the laser beam path and the optical mechanism from being contaminated, and thus maintaining the performance of the laser head.

[0002]

2. Description of the Related Art Laser processing devices such as laser robots are
A laser head included in a laser processing apparatus of this type has been practically used, and generally, a distance between a nozzle portion having a laser beam irradiation opening at its tip and a workpiece is always maintained at a predetermined constant distance. Is important from the standpoint of maintaining a constant laser processing quality. Therefore, a nozzle with a built-in focusing optical mechanism such as a condenser lens is provided as a movable head that can move directly with respect to the fixed head. The distance measuring sensor is provided on the movable head to measure the distance of the laser light irradiation port to the work, and the movable head moves directly according to the distance measurement signal to keep the distance at a predetermined distance at all times. Conventionally, the structure to do is provided.

In a laser head including a fixed head and a movable head of this type, the laser head itself has a drive source and a transmission mechanism for linearly displacing the movable head in response to a distance measurement signal from a distance measurement sensor. The structure in which the movable head portion is telescopically arranged with respect to the fixed head portion and relatively linearly displaced is often used.

However, if a structure in which the movable head portion is provided in a relative displacement with respect to the fixed head portion is used, spatter generated during laser processing, that is, laser welding, gas, dust during laser cutting, or air in the processing site. The fine dust floating on the inside of the laser beam passes through the unavoidable gap in the relative displacement part between the fixed head part and the movable head part into the laser beam path, and the surface of the laser beam reflection mirror inside the laser processing device and the condenser lens There is a concern that the surface, the wall surface of the laser beam path, the drive mechanism of the movable head portion, etc. may be polluted to directly or jointly deteriorate the laser processing performance.

For this reason, conventionally, a structure in which an oil seal is attached to a dust-proof portion of a fixed head portion and a movable head of a laser head by attaching an oil seal, and relative sliding between the fixed head and the movable head is performed. A structure in which an antifriction material made of a synthetic resin material is arranged in a portion to allow smooth and sliding displacement, and a bellows cover is provided around the movable head portion that is displaced relative to the fixed head portion. A structure is provided to prevent dust by surrounding the laser optical path and the displacement driving mechanism with the same bellows.

[0006]

However, in the structure provided with the above-mentioned oil seal, there is a danger that the oil seal will be damaged when high-temperature spatter that does not completely cool during laser processing comes in, and that the movable head part has Even if similar spatter adheres to the relative displacement portion, there is a risk that the oil seal may be damaged due to the friction between the oil seal and the adhered spatter.

On the other hand, in the structure in which the movable head portion can be smoothly and slidably displaced with respect to the fixed head portion by disposing the above-described antifriction material, when high-temperature spatter comes in again, The antifriction material may be damaged, and similarly, when spatter adheres to the relative displacement part of the movable head part, there is also a risk of damage due to rubbing. Moreover, when the anti-friction material is gradually worn away and a gap is generated in the relative portion, the dustproof effect is deteriorated, and as a result, the highly accurate linear displacement guide mechanism used in the relative displacement portion, that is, the well-known LM. Since the operating performance of the guides and the linear bushes, that is, the linear displacement accuracy of the movable head portion decreases, the laser processing accuracy is likely to deteriorate. Further, in order to prevent such deterioration, the processing accuracy in the manufacturing process of the fixed head part and the movable head part and the assembling accuracy of both of them result in demanding strict accuracy, which makes assembling difficult and The motor, which is a drive source for linear displacement of the movable head portion due to increased cost and increased friction, needs to have a large output torque, and thus it is inevitable to increase the size of the motor. There is a disadvantage.

Further, the structure using the bellows cover described above has a drawback that the life of the bellows is relatively short, and like the above-described two structures, the bellows cover is generated when spatter generated during laser processing comes flying. I cannot avoid the danger of damage. Further, in the structure using the bellows cover, the space volume surrounded by the cover fluctuates according to the forward / backward movement of the bellows, and particularly when the space volume increases and the internal pressure becomes lower than the atmospheric pressure outside the bellows cover. In addition, fine dust and processing gas are likely to enter the inside from the gaps of various parts of the head, and therefore the dustproof function is deteriorated. In addition, since the head volume around the laser irradiation port increases by the volume of the bellows, the operability during laser processing, for example, when the laser head is inserted from the opening of the work into the inside and laser processing is performed. There is also a fear of decline.

Therefore, the present invention is to provide a dustproof device having a novel structure capable of eliminating the disadvantages and drawbacks associated with the conventional dustproof device in the laser head of the laser processing apparatus as described above.

[0010]

In view of the above-mentioned object, the present invention provides a laser head having a movable head part which is telescopically engaged with the fixed head part so as to be movable back and forth. In a predetermined outer peripheral area extending from the tip end area toward the movable head portion, an air chamber having a tapered shape is formed toward the laser light irradiation port of the movable head portion, and the pressure in the air chamber is usually higher than atmospheric pressure. A dust-proof fluid consisting of pressurized air is supplied, and the dust-proof fluid is ejected from the opening of the air chamber along the peripheral wall of the movable head section, so that spatter, gas, and dust from the engagement area of both head sections into the laser head. The air chamber is kept at a pressure higher than the atmospheric pressure, so that floating dust such as dust or gas is not sucked into the laser head. ..

That is, according to the present invention, a fixed head portion having a built-in laser beam path and an optical mechanism for focusing and emitting the laser light passing through the fixed head portion toward a work are built in, and the fixed head portion is provided. In a dustproof device for a laser head for laser light irradiation having a movable head that can be moved back and forth with respect to, a relative displacement in the axial direction of the movable head portion fixed to the end portion of the fixed head portion. And a cone-shaped wall that surrounds the movable head part and forms an air chamber having a gap-like opening around the movable head part, and a dust-removing fluid supply means for supplying a dust-removing fluid consisting of pressurized air to the air chamber part from the outside. And a dust-proof device for a laser head, characterized in that the dust-removing fluid is jetted from a narrow opening of the air chamber to prevent dust. Since the above-mentioned conical wall forms a tapered nozzle structure toward the tip side of the movable head, it is possible to enhance the dustproof effect of the jet flow of the dust removal fluid from the air chamber, and at the same time, the tip shape of the laser head. Can be made compact.

[0012]

The dust removing fluid having a pressure higher than the atmospheric pressure is supplied to the air chamber to maintain the air chamber at a high pressure, and the dust removing fluid is ejected from the gap-shaped opening of the air chamber. Fixing dust generated such as spatter and gas or dust floating in the atmosphere surrounded by a high pressure air chamber,
It is possible to reliably prevent the invasion into the laser beam path inside the laser head from the engaging region of the movable head. Moreover, since the conical wall forming the air chamber has a tapered nozzle shape, the dust removal fluid can be jetted out and the laser head tip can be made compact. Hereinafter, the present invention will be described in more detail based on the embodiments shown in the accompanying drawings.

[0013]

1 is an enlarged sectional view showing the structure of a dustproof device for a laser head according to the present invention, and FIG. 2 is a laser as an example of a laser processing device to which the dustproof device for a laser head according to the present invention is applicable. It is a perspective view showing the appearance of a robot.

First, referring to FIG. 2, a machine body 10 of a laser robot as a laser processing apparatus has a base portion 12 on which the robot machine body is installed, and a robot body 14 is vertically mounted on the base portion 12. A robot arm 16 is erected so as to be rotatable about its axis, and a robot arm 16 is provided on the upper side surface of the robot body 14 so as to be vertically swingable. The front part of the robot arm 16 is further provided with respect to the rear part so as to be able to move back and forth in the arm axial direction as indicated by arrow L. The laser processing head 20 is provided so as to be rotatable about orthogonal axes and is capable of directing the laser beam irradiation direction of the laser processing head 20 mounted on the tip of the robot wrist 18 to a desired direction.

The laser beam is transmitted from an external facility such as a laser oscillator through a laser beam line (not shown) to the robot body 1.
0 is introduced into the robot body 10 from there, for example, through a laser light inlet provided below the base 12 or above the robot body 14, and is introduced to an indirect portion inside the robot body 10. The laser processing head 2 moves while changing the course by the provided laser light reflecting mirror.
Induced to 0. The laser processing head 20 focuses the laser light and focuses the laser light on the irradiation point of the work to be irradiated so that the laser light is irradiated as appropriate converged light, and irradiates the target work from the irradiation port 20a at the tip. It will be configured to be. Further, the laser processing head 20 is supplied with a processing assist gas through the robot arm 16 through a pipe line, and the assist gas is also ejected from the irradiation port 20a toward the outside. Further, the laser mirror provided in each indirect part of the robot body 10 for changing the course of the laser light is also provided with a configuration in which cooling water is circulated to cool the laser mirror.

In the laser machining process, the machine body 10 of the laser robot directs the laser beam irradiation port 20a at the tip of the laser processing head 20 to the irradiation point of the work according to the teaching program, and also makes a predetermined focus with the work irradiation surface. A laser beam is emitted at a distance to perform various desired laser processing such as welding, cutting, and deburring of a work.

Next, referring to FIG. 2, there is shown an enlarged view of a laser head which is applicable to a laser processing apparatus such as the above-described laser robot and at the same time is provided with a novel dustproof device. The laser head 30 is formed so as to be replaceable with and attachable to the laser head 20 of the laser robot body 10 of FIG. 1, and a laser processing device, for example, a screw at the tip of the robot wrist 18 of the robot body 10 described above. A fixed head portion 42 mounted by using an appropriate fixing means such as
And a movable head portion 62 provided so as to be movable back and forth in a predetermined axial direction C with respect to the fixed head portion 42.

The fixed head portion 42 has a tubular structure having an outer cylinder 44, and a flange 45 for attaching to the wrist 18 is provided at the rear end thereof, while the movable head portion 62 drives the forward / backward movement. Drive motor 4 constituting a drive device for
6, a gear box 47 incorporating a gear mechanism for transmitting the rotation output from the output shaft of the drive motor 46, a ball screw shaft 48 coupled to the output gear of the transmission gear in the gear box 47, the ball screw shaft 48 A pair of rotary bearings 49, 49 that are rotatably supported are attached. The inside of the cylindrical body of the fixed head portion 42 is formed as an optical path of laser light, and is formed so that the laser light guided from the wrist 18 of the robot body 10 advances toward the irradiation opening 30 a at the tip of the laser head 30. .. Therefore, a structure that does not allow spatter, gas, other dust, etc. generated during laser processing to enter the laser beam path inside the fixed head portion 42 is required. That is, when the dust enters, the wall surface of the cylindrical body or the surface of the laser reflection mirror provided indirectly on the wrist in the preceding stage is contaminated, the energy of the laser light is reduced, and the desired laser processing cannot be performed. Further, in this structure, since the ball screw shaft and the guide rail are exposed in the optical path, it is necessary to prevent damage due to dust adhesion. The arrow in FIG. 1 indicates laser light.

The movable head portion 62, which is telescopically engaged with the fixed head portion 42, also has a tubular structure.
A lens holder 64, which supports a condenser lens 63 for receiving and condensing the laser light traveling through the fixed head 42, is held on the path of the laser light. The tubular rear end portion 65 of the movable head 62 is telescopically inserted into the fixed head 42 as described above, and is provided at a predetermined position on the outer periphery of the rear end portion 65 inside the tubular body of the fixed head portion 42. A guide 66 slidably engaged with the provided linear guide 50 is attached, and has a structure that smoothly guides the forward / backward movement of the movable head portion 62. A ball screw nut 67 screw-engaged with the ball screw shaft 48 of the drive device for driving the forward / backward movement of the movable head portion 62 is also provided on the outer periphery of the rear end region 65, and is transmitted in response to the drive of the drive motor 46. gear,
The movable head portion 62 can advance and retreat in the direction of the coaxial line with the laser beam path via the ball screw mechanism. The front portion of the front end region 68 of the movable head portion 62 has a nozzle shape, and the irradiation opening 30a is provided at the tip thereof. A distance measuring sensor 70 for measuring the distance and distance between the irradiation opening 30a and the workpiece to be irradiated is attached to the outer peripheral portion of the front end region 68. This distance measuring sensor 7
0 itself is a well-known device, and a distance measuring sensor using laser light, an electric capacitance type distance measuring sensor, an eddy current type distance measuring sensor, etc. are widely used. A distance measurement signal indicating the distance data from the irradiation opening 30a to the work surface measured by the distance measurement sensor 70 is sent to the sensor amplifier 73 via the signal line 72, and after the signal is amplified, an appropriate controller 74 is provided.
Then, the drive motor 46 formed by the servo motor is operated to move the movable head portion 62 forward and backward with respect to the fixed head portion 42 via the transmission mechanism such as the ball screw mechanism described above. It is composed. That is, the movable head portion 62 is replaced with the fixed head portion 42.
By moving and adjusting the laser beam in the direction of the laser beam, the laser beam irradiation port 30a can be always held at a predetermined set distance position with respect to the laser beam irradiation position of the workpiece, and the optimum light condensing degree can be obtained. The formed laser beam can be applied to the work surface.

Here, in the region below the outer cylinder 44 of the fixed head section 42, a cylindrical rear end section 65 of the movable head section 62 and a cylindrical fitting section 52 fitted in a telescopic manner are formed, and
An outer jacket portion 53 having a conical or funnel-like tapered shape is provided so as to surround the outer periphery of the fitting portion 52, and an air chamber 54 is formed by the outer jacket portion 53. The air chamber 54 has an open end 55 on the lower end side that forms a minute annular gap with the outer periphery of the movable head portion 62, and has an external pressure air source (for example, an air compressor and a filter, a pipe line). The pressurized air having a pressure higher than the atmospheric pressure, which is sent from the pressure air supply source (1), is supplied through the fluid coupling 56 and is provided as an air pressure chamber higher than the atmospheric pressure.
The compressed air supplied to the air chamber 54 is subjected to the nozzle effect of the tapered curved surface shape of the outer cover portion 53 in the air chamber 54 itself, and along the outer periphery of the movable head portion 62 from the outlet formed by the opening end 55. Is ejected as a pressurized air stream. In the illustrated example, the pressure air is supplied to the air chamber 54 through the plurality of fluid couplings 56, so that the pressure air flow is evenly ejected from the entire area of the opening end 55 forming the annular gap. It is devised.

With the above-described structure, the conical air chamber 54 is provided, pressurized air is supplied to the air chamber 54, and the pressurized air flow from the open end 55 is maintained while maintaining the room pressure higher than the atmospheric pressure. Since it is configured to eject, the laser head 30
Performs a dustproof function as described below during the laser processing process. That is, since the inside of the air chamber 54 is always maintained at a high pressure state with respect to the atmospheric pressure, spatter generated from the laser processing area of the workpiece in the laser processing process of the laser head 30 is generated from the area below the movable head portion 62. When flying upward, it is blown off by the high-speed jet of pressurized air ejected from the air chamber 54. For this reason, even if the spatter comes in while maintaining the momentum due to the scattering, there is no fear that such spatter will directly approach the outer peripheral surface of the laser head 30, and, of course, the fixed head portion 42. There is no danger that spatter will enter the inside of the laser head 30 through the annular gap formed in the fitting region between the tubular fitting portion 52 at the lower end of the tubular body 44 and the tubular rear end portion 65 of the movable head portion 62. The dustproof effect is achieved. In particular, since the air chamber 54 has a nozzle shape and exerts an effect of letting out the high-speed air flow ejected from the opening end 55 along the outer peripheral surface of the movable head portion 62, the floating dust and the like in the surroundings are annular gaps. Therefore, the suction action of sucking the shaped open end 55 into the air chamber does not occur.

Similarly, the processing gas generated during laser processing is also pushed back by the pressure air jet flow jetted from the air chamber 54, and the inside of the air chamber 54 is maintained at a high pressure state. Laser head 3 as well as the inside
The danger of entering the 0 interior space is completely resolved. Further, dust generated in the laser processing process or suspended in the atmosphere cannot enter the air chamber 54 maintained at a high pressure, so that the fixed head portion 42 and the movable head portion 62 are, of course, fitted to each other. The inside of the laser head 30 does not penetrate through the annular gap formed in the joint area. Moreover, since the annular gap is formed in the fitting portion between the fixed head portion 42 and the movable head portion 62 in this way to avoid complete contact between the two, the movable head portion 62 is displaced by adjusting the distance to the work. Both heads 42, 62
Since there is no sliding action, dust generation due to abrasion can be prevented, and there is no risk of hard sputter particles or the like adhering to this region, so there is no risk of damage to the fitting part.

In FIG. 2, a fluid coupling 75 mounted on the lower portion of the movable head portion 62 is provided for supplying an assist gas at the time of laser processing to an area below the condenser lens 63 from an external pipeline. It is what has been.
Further, in the above description, the case of the most usual embodiment using pressurized air as the pressurized fluid for dust prevention has been described, but of course, when other pressurized gas bodies are used as the dust removal gas as necessary. It goes without saying that is also applicable.

[0024]

As is apparent from the above description, according to the present invention, it is possible to reliably prevent the spatter, the processing gas, the dust, etc. generated by the laser processing from entering the inside of the laser head of the laser processing apparatus. Because the dustproof effect to prevent is obtained,
It is possible to reliably prevent contamination of the laser optical path inside the laser head, the condensing lens, the reflection mirror, and other optical mechanisms with dust
As a result, the effect of preventing the reduction of the propagation efficiency of the laser light is exerted. In addition, since the cover forming the air chamber can be formed of a metal body, it is possible to avoid the risk of damage even if high-temperature spatter comes in. Furthermore, spatter and dust are fixed and movable head. Since it does not adhere to the fitting area with the parts, it is possible to avoid the fear of mechanical damage due to rubbing of both the fixed and movable head parts according to the operation of the movable head part 62.

Further, according to the present invention, since the cylindrical outer jacket portion 53 forming the air chamber has the tapered curved surface shape, a compact dustproof device capable of preventing the expansion of the lower region of the laser head is formed. Therefore, in laser processing, it is relatively easy to insert the laser head into a narrow space such as the inside of the work and perform the laser processing.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view showing the structure of a dustproof device for a laser head according to the present invention.

FIG. 2 is a perspective view showing an external appearance of a laser robot as an example of a laser processing apparatus to which a dustproof device for a laser head according to the present invention can be applied.

[Explanation of symbols]

 10 ... Machine body of laser robot 20 ... Laser head 20a ... Laser light irradiation port 30 ... Laser head 30a ... Laser light irradiation port 42 ... Fixed head part 44 ... Outer cylinder 52 ... Cylindrical fitting part 53 ... Outer part 54 ... Air chamber 55 ... Opening end 56 ... Fluid coupling 62 ... Movable head portion 65 ... Cylindrical rear end portion

Claims (1)

[Claims] 1. A built-in fixed head part having a built-in laser beam path and an optical mechanism for focusing and emitting a laser beam that has passed through the fixed head part toward a work, and can be moved back and forth with respect to the fixed head part. In a dustproof device of a laser head for laser light irradiation having a movable head portion, fixed to an end portion of the fixed head portion, surrounding the axial relative displacement portion of the movable head portion with respect to the fixed head portion, And a cone-shaped wall forming an air chamber having a gap-like opening around the movable head part, and a dust removal fluid supply means for externally supplying a dust removal fluid consisting of pressurized air to the inside of the air chamber. A dust-proof device for a laser head, characterized in that the dust-removing fluid is ejected from a narrow opening of the air chamber to prevent dust.