JPS60191686A - Laser working device - Google Patents

Abstract

PURPOSE:To eliminate damage on a material to be worked which contacts with a nozzle member by delineating a pressure chamber to a nozzle member at the top end of a freely liftably provided focusing head, and introducing an assist gas into said chamber to energize upward a nozzle member. CONSTITUTION:A focusing head 1 is constituted of a lifting member 10 driven by a lifting mechanism 5 and a nozzle member 12. An assist gas is introduced into a pressure chamber 17 formed between cylindrical members 13, 14 and flange parts 15, 16 to keep the member 12 free from pressure fluctuation. The member 12 is lightly energized to the material 4 to be worked by a spring 20. The focal position of laser light L is then set in the position adequate for working of the material 4 while the member 12 is in contact with the material 4. The mechanism 5 is controlled via a control device 31 by a detector 27 and laser working is executed by using the assist gas. Laser working is thus made possible without damaging the work.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a laser processing apparatus, and more particularly to a laser processing apparatus suitable for maintaining an optimum distance between a condensing lens for condensing a laser beam and a workpiece.

Conventionally, various types of focus adjustment devices have been proposed that adjust the distance between the condenser lens and the workpiece to obtain the optimal focal length of the laser beam. The gap between the fixed focus head and the workpiece is detected with a non-contact detector or a contact detector, and the focus head is moved up and down so that the detected value remains constant, thereby forming a condenser lens. The distance from the workpiece is kept constant.

By the way, in order to obtain an accurate focal length, it is desirable to measure the above-mentioned gap at the irradiation position of the laser beam, but since plasma is generated by the laser beam at that position, measurement is difficult and errors are likely to occur. Generally, measurements are made at a position slightly distant from the irradiation position. However, if the irradiation position of the laser beam and the measurement position are different, for example, if the processing surface of the workpiece is sloped or uneven, the focus head will be controlled to an inaccurate position. There were drawbacks.

In order to improve such drawbacks, the focus head is constructed of an elevating member that is raised and lowered by an elevating mechanism, and a nozzle member that is provided on the elevating member so that it can be raised and lowered and that irradiates a laser beam. By using itself as a detector that moves up and down along the processing surface of the workpiece while in contact with it, the laser beam irradiation position and measurement position are virtually the same, ensuring the optimum focal length at all times. However, in such a configuration, the assist gas supplied to the focus head acts on the nozzle member and urges it downward, so the nozzle member is pressed against the workpiece with a strong force due to the pressure of the assist gas, and there is a possibility that the workpiece may be damaged.

In view of such circumstances, the present invention enables the nozzle member to be used as the above-mentioned detector, and at the same time provides a pressure chamber that urges the nozzle member upward by the pressure of the introduced assist gas. The laser beam irradiation position and the measurement position can be set to substantially the same position, and the influence of assist gas on the nozzle member can be reduced or eliminated, thereby reducing the amount of damage caused by the nozzle member. An object of the present invention is to provide a laser processing device that can prevent damage to a workpiece and perform smooth laser processing.

The present invention will be described below with reference to an illustrated embodiment. In FIG. 1, a focus head 1 that irradiates a laser beam is shown.
The workpiece 4 is moved along the guide rod 3 provided on the support frame 2.
It is possible to go up and down towards. 2. The support frame 2 is provided with an elevating mechanism 5 for elevating and lowering the focus head l, and in the illustrated embodiment, the elevating mechanism 5 includes a motor 6,
It is provided with a vertical screw shaft 7 which is reversely reversed by the motor 6, and the screw shaft 7 is screwed onto the focus head 1 to enable the focus head 1 to be raised and lowered.

A support frame 2 that supports the focus head l so as to be able to rise and fall freely.
is capable of moving forward and backward along a guide member 9 provided horizontally on the machine frame 8 so as to be perpendicular to the screw shaft 7, and is moved in that direction by a drive mechanism (not shown) similar to the lifting mechanism 5 shown in L. It is now possible to do so. The workpiece 4 is placed on a table (not shown), and is movable fIf in a direction perpendicular to the screw shaft 7 and the guide member 9, respectively.

However, the focus head 1 mentioned above has the above-mentioned guide rod 3.
It is composed of an elevating member lO that engages with the screw shaft 7, and a nozzle member 12 provided in a cylindrical portion 11 formed at the lower part of the elevating member lO so as to be able to rise and fall freely. A first cylindrical member 13 is engaged with the inner circumferential surface of the lower part of the cylindrical portion 11 so as to be movable up and down, and a first cylindrical member 13 is engaged with the outer circumferential surface of the cylindrical portion 11 so as to be movable up and down, and integrated into the first cylindrical member 13. The second cylindrical member 14 is connected to the second cylindrical member 14.

]-, a flange portion 15 facing radially inward is provided at the upper end of the second cylindrical member 14, and a flange 1 facing radially outward is provided at the lower end of the cylindrical portion 11.
6, the inner circumferential surface of the second cylindrical member 14, the outer circumferential surface of the cylindrical portion 11, and the pair of flange portions 15
．． A pressure chamber 17 is partitioned by 1B, and this pressure chamber 1
7 formed in the cylindrical part 11 and the hole 18 and the cylindrical part 11
It is communicated with an assist gas supply source (not shown) via a conduit 18 connected to.

Therefore, the pressure of the assist gas supplied into the cylindrical part 11 acts on the first cylindrical member 13 and urges it in the opposite direction, but at the same time, the pressure of the assist gas supplied into the cylindrical part 11 flows through the hole 18 into the pressure chamber 17.
The pressure of the assist gas introduced into the nozzle member 12 acts on the flange portion 15 of the second cylindrical member 14 forming the pressure chamber 17 and forces it in the −F direction. Upward and downward forces come into play at the same time. In this embodiment, even if the pressure receiving area of the flange portion 15 and the pressure receiving area of the first cylindrical member 13 are set to be the same, the pressure of the assist gas may vary. The influence is prevented from reaching the slide member 12.

Further, the nozzle member 12 is always urged downward by the elastic force of the spring 20, and the nozzle member 12 is applied to the workpiece 4 with a predetermined light urging force by the elastic force of the spring 20 and its own weight. This allows for pressure contact.

Next, a condensing lens 25 for condensing the laser beam is attached to the upper end of the elevating member IO, and the outer circumferential surface of the lower end of the first cylindrical member 13 is formed into a conical shape, with the tip of the condensing lens 25 condensing the laser beam. A hole 26 is formed in the shaft portion of the object 4 to allow the laser beam tIaL to pass therethrough. Then, the focus position of the laser beam by the condensing lens 25 is set so that the nozzle member 12 is positioned at a reference height position with respect to the elevating member IO, and at the same time, the workpiece is placed on the first cylindrical member 13 at the reference height position. 4 are in contact with each other, the workpiece 4 is set at a position suitable for laser processing. The focal point position in this state varies somewhat depending on the material and thickness of the workpiece 4, but generally it is approximately at the opening edge of the hole 26 to the outside.

Further, a main body 28 of a detector 27 for detecting the vertical position of the nozzle member 12 with respect to the lifting member 10 is attached to the lifting member 10, and the detector 29 of the detector 27 is connected to the nozzle member 12 via the connecting member 30. It is connected. This detector 27 is capable of detecting the position of the detector 28 with respect to the main body 27, and therefore the vertical position of the nozzle member 12 with respect to the vertical movement member IO as described above, and the signal from the detector 27 is The information is input to a control device 31 such as a computer. This control device 31 controls the elevating mechanism 5 in response to a signal from the detector 27, and can maintain the elevating position of the nozzle member 12 with respect to the elevating member 10 at a predetermined elevating position. .

In the above configuration, in the non-operating state, the focus head 1 is located at the L end, and the nozzle member 12 is located at the lower end position with respect to the elevating member 10 due to its own weight and the elastic force of the spring 20. Therefore, the nozzle member 12
The detector 29 of the detector 27, which is interlocked via the connecting member 30, is also located at the lower end position.

When an operation start command is given to the control device 31 from this state, the control device 31 controls the lifting mechanism 5 to lower the focus head 1, thereby lowering the lower end of the nozzle member 12, that is, the first cylindrical member 13. When the lower end comes into contact with the workpiece 4, the nozzle member 12 stops descending, but the elevating member 10 continues to descend.

As a result, the nozzle member 1 is moved relative to the elevating member 10.
2 is raised and the raised position of the nozzle member 12 with respect to the elevating member IO reaches the reference height position described above, the control device 31 detects this via the detector 27. When the control device 31 detects that the nozzle member 12 has reached a predetermined height position, the control device 31
The lowering of the elevating member 10 by the elevating mechanism 5 is stopped, and then the laser beam is directed toward the workpiece 4 to start laser processing. In this state, the focus of the laser beam is of course maintained at the normal position.

Next, during the above-described laser processing, if the workpiece 4 is tilted or has unevenness, and the nozzle member 12 is raised one step relative to the elevating member lO, the nozzle member 1
2 will be displaced above the normal position with respect to the elevating member lO, the control device 31 detects this by detecting the detector 2.
7 and controls the elevating mechanism 5 to raise the elevating member lO by −L.

As a result, the position of the nozzle member 12 with respect to the elevating member 10 is always at the above-mentioned reference height position, so that the condenser lens 25 provided on the elevating member IO and the hole 2 of the nozzle member 12
The focal distance from the opening edge of 6 is maintained constant to allow smooth laser processing. At this time, since the first cylindrical member 13 of the nozzle member 12 that irradiates the laser beam is integrated with the detector 22 of the detector 18 and also has the function,
The irradiation position of the laser beam and the measurement position substantially match, and as described above, accurate detection is possible even if the machined surface of the object 4 is sloped or uneven. and control.

When the amount of elevation of the nozzle member 12 relative to the elevation member 10 becomes large and exceeds the allowable range, the control device 31 detects this via the detector 27 and controls the elevation mechanism 5. Then, the elevating member 10 is lowered by y1, and the position of the nozzle member 12 relative to the elevating member 10 is always maintained within a predetermined range.

Also, during this time, as described above, since the pressure receiving area of the flange portion 15 and the pressure receiving area of the first cylindrical member 13 are set to be the same, even if the pressure of the assist gas fluctuates, the nozzle member 12 is affected. never reach.

FIG. 2 shows another embodiment of the present invention. In this embodiment, a nozzle member 12 is provided via a bearing 40 on an elevating member lO so as to be freely lowered by y1, and a laser beam is emitted onto the upper end of the nozzle member 12. In addition, the outer peripheral surface of the lower end of the nozzle member 12 is formed into a conical shape so that its tip can come into contact with the workpiece 4, and the lower end shaft part Hole 2G that allows the passage of the above laser beam
is formed. In this embodiment as well, the workpiece 4 is laser-processed while the focal position of the laser beam by the condenser lens 25 is adjusted so that the nozzle member 12 of the nozzle member 12 is in contact with the workpiece 4. It is set in a position suitable for

The condensing lens 25 divides the interior of the nozzle member 12 into a pressure chamber 17, and the pressure chamber 17 is communicated with an assist gas supply source (not shown) via a conduit 19 connected to the nozzle member 12. At this time, the pressure receiving area on the condensing lens 25 side is larger than the pressure receiving area on the lower hole 26 side.
However, the upward and downward biasing forces of the assist gas acting on the nozzle member (12) are almost balanced, and even if the pressure of the assist gas fluctuates, the nozzle member (12)
2 has almost no effect.

In this embodiment, the nozzle member 12 is urged downward by the elastic force of the springs 20 and 41, and the nozzle member 12
The nozzle member 12 can be brought into pressure contact with the workpiece 4 with a predetermined light biasing force by its own weight and the elastic force of the spring 20.41.

The rest of the structure is similar to that of the above-described embodiment, and the same or corresponding parts are denoted by the same reference numerals.

It is clear that the same effects as described above can be obtained in this embodiment as well.

In particular, in this embodiment, the nozzle member 1 is
3 is moved up and down with respect to the elevating member 1O, since the condenser lens 25 is integrally provided with the nozzle member 13, the focal position of the condenser lens 25 is moved up and down by the elevation of the nozzle member 13 to the hole 2B. There is no displacement from the edge of the opening, and smooth laser processing can be continued.

Further, in this embodiment, it is not always necessary to control the vertical position of the nozzle member 13 with respect to the lifting member 10 by the control device 2G, and the nozzle member 1 with respect to the lifting member 1o
The lifting mechanism 5 may be controlled by the control device 2B only when the lifting amount of the lifting mechanism 3 becomes large and exceeds a permissible range.

In the embodiment described in 1, the biasing direction of the spring 20.41 is downward, but this may be omitted if necessary, and the biasing direction is upward to counteract the weight of the nozzle member 12. It's okay. Of course, the pressure-receiving area that receives an upward biasing force from the assist gas and the pressure-receiving area that receives a downward biasing force can be set to appropriate values as necessary. Furthermore, although the present invention is explained based on the upward and downward direction for convenience, it is needless to say that the present invention is not limited to this.

As described above, according to the present invention, the influence of the assist gas on the nozzle member can be reduced to zero, thereby preventing damage to objects caused by the nozzle member and facilitating smooth laser processing. You can get the effect of being able to do it.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing one embodiment of the present invention, and FIG. 2 is a sectional view showing another embodiment. l... Focus head 4... Workpiece 5...
Lifting 41! , Lateral 10... Lifting member 12... Nozzle member 17... Pressure chamber 19... Conduit 25... Condensing lens L... Laser beam patent applicant Shibuya Kogyo Co., Ltd.

Claims (1)

[Claims] A condenser lens is provided on a focus head that is raised and lowered by an elevating mechanism, an assist gas is supplied to the focus head, and a laser beam focused by the condenser lens is irradiated from the focus head to a workpiece together with the assist gas. In the laser processing apparatus, the focus head is made up of an elevating member that is moved up and down by an elevating mechanism, and a nozzle member that is provided on the elevating member so as to be able to rise and fall and that contacts the workpiece and irradiates the laser beam. A laser processing apparatus characterized in that a pressure chamber is provided in which an assist gas is roughly introduced to urge the L nozzle member upward.