JP2001239382A - Scrape cutting method and apparatus by laser beam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a scrape cutting method and apparatus which can cut continuous scrapes growing while machining into short scrapes by low power laser beam. SOLUTION: A laser oscillator 13 is connected to a scrape cutting head 12 which can move integrally with a runner for a cutting device 23 of a machine tool 11. The swarf cutting head 12 includes a light-gathering means composed with a collimator-lens 34 and an objective lens 35, and a light-route changing means composed with a polygon-mirror 36 for example. Laser beams 41 emitted from a laser oscillator 13 converts to parallel beams by the collimator-lens 34, reflects to reflecting surface 43 of the polygon-mirror 36, and, passing through the objective lens, concentrates and irradiates to the continuous scrape 32 growing from a work 25. Laser beams 42 reflected from the reflecting surface 43, scanned by the rotation of the polygon-mirror 36 to follow continuous scrape' s movement, irradiates longer the same spot of the scrape, so that laser beams, even if small power, has an ability to cut the scrape.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for cutting continuous chips generated from a workpiece during cutting by a machine tool with a laser beam.

[0002]

2. Description of the Related Art Conventionally, when cutting metal with a machine tool such as a lathe, a chip breaker is provided near a cutting edge of a cutting tool to prevent continuous chips generated from a work from being entangled with the cutting tool. Was dropped, for example, as short as about 50 mm.

However, in cutting with a small cutting depth, even if the above-mentioned chip breaker is provided, the chips become continuous and long, sticking to the cutting tool, shortening the life of the cutting tool, and reducing the work life of the cutting tool. This could cause damage to the surface. Therefore, every time a certain amount of chips are entangled with the cutting tool, it is necessary to stop the machine and manually remove the chips each time, and the cutting operation cannot be automated.

[0004] In such cutting with a small cutting depth, continuous chips generated from the work are cut short.
For example, “Laser Research” Vol16, No. 9, P582
No. 591 proposes a chip cutting device using a laser beam.

[0005] This chip cutting device using laser light has a laser processing head connected to a YAG laser device via a condensing fiber cable. In this laser processing head, a collimator lens for collimating the laser light output from the laser device, a dichroic mirror for changing the optical path of the laser light in a right angle direction, and a continuous light source for generating the laser light from the work. An objective lens for irradiating the chips is arranged.

According to this chip cutting device, the laser processing head is mounted on a machine tool such as a lathe, and when continuous chips are generated by cutting the work, the YAG laser device is operated to emit laser light. This laser light is transmitted by a condensing fiber cable, a collimator lens,
The light passes through a dichroic mirror and an objective lens, and is condensed and irradiated on continuous chips generated from the work. As a result, the continuous swarf is cut into a predetermined length at each laser beam oscillation interval.

According to the above document, continuous oscillation (hereinafter referred to as CW)
) Type YAG laser with a pulse width of 0.1-0.
The chip was cut by oscillating the pulse in 6 sec or by oscillating the pulse of the CW type YAG laser by the Q switch, but when aiming at melting and fusing the chip,
It is described that a laser oscillating a W-type YAG laser is preferable to a laser oscillating a Q-switch because it can increase the average output of the laser oscillator.

Then, a CW type YAG laser having an average laser output of 200 W (optical fiber SI type, core diameter 0.5 mm, NA 0.3) is used for boring to obtain a cut depth of 0.04 to 0.15 mm and a feed rate. 0.06-0.25
(Mm / rev.), Peripheral speed 50 to 180 (m / mi)
It has been reported that continuous chips generated under cutting conditions in the range of n) could be cut.

[0009]

However, usually, the maximum value of the cutting condition range in which continuous chips are generated, including external cutting, is slightly different depending on the type of the chip breaker of the cutting tool and the material of the work. This is beyond the condition range of the cutting depth, feed speed and peripheral speed described in the prior art. For example, the maximum depth of cut is 0.3 mm,
The maximum value of the feed speed may reach 0.35 (mm / rev), and the maximum value of the peripheral speed may reach 450 (m / min). For example, when the peripheral speed is 450 (m / min), the generated chip speed may reach a maximum of 240 (m / min). At this chip speed, the chip length reaches 400 mm when the pulse width of the laser beam is 0.1 sec. That is, when the chip speed is high, there is a problem that it is difficult to cut chips in short with the CW type YAG laser.

In the above-mentioned CW type YAG laser,
In order to cut continuous chips generated in the above-mentioned normal cutting condition range, the average laser output needs to be 300 to 400 W or more. However, such a laser output oscillator causes an increase in maintenance cost due to an increase in the size of the device, an increase in the cost of the device, a decrease in the life of the excitation lamp, and the like. In that case, it has been difficult to automate and unmann the cutting operation for economic reasons.

Therefore, an object of the present invention is to provide a method for cutting continuous chips generated from a workpiece with a low-power laser beam in a short time even at a high chip speed in a normal cutting condition range.
An object of the present invention is to provide a method and an apparatus for cutting chips using a laser.

[0012]

In order to achieve the above object, a method for cutting chips by a laser according to the present invention is a method for cutting continuous chips generated from a workpiece by a laser beam when cutting with a machine tool. When irradiating the chips, the condensing irradiation point of the laser light is moved by following the movement of the chips.

According to the method for cutting chips by using the laser of the present invention, the point where the laser light is condensed and irradiated is moved in accordance with the movement of the chips, so that the time for irradiating the same portion of the chips with the laser light is increased. Can be. In other words, since the area irradiated with the laser beam can be reduced and the output per area can be increased, chips can be cut even with a relatively small output.

In the method for cutting chips using a laser according to the present invention, a polygon mirror that rotates in synchronization with the oscillation timing of the laser light is disposed in an optical path of the laser light, and each reflecting surface of the polygon mirror that rotates and moves. Preferably, the laser light is sequentially reflected to move the converging irradiation point of the laser light so as to follow the movement of the chips.

According to this aspect, the angle of incidence of the laser light on the reflecting surface changes continuously with the rotation of the polygon mirror, so that the position of the focal point of the laser light reflected by the reflecting surface is also continuous. Change. Therefore, by adjusting the rotation speed of the polygon mirror to the moving speed of the chips, the focal point of the laser beam can be moved to follow the chips.

Further, a galvanomirror oscillating in accordance with the oscillation timing of the laser light is arranged in the optical path of the laser light, and the laser light is reflected. Is preferably moved following the movement of the chips.

According to this aspect, the angle of incidence of the laser beam on the galvanomirror changes continuously by swinging the galvanomirror, so that the position of the focal point of the reflected laser beam also changes continuously. I do. Therefore, by adjusting the swing speed of the galvanomirror to the moving speed of the chips, it is possible to move the focal point of the laser beam following the chips.

Further, it is preferable that the chip is irradiated with the laser beam while blowing an assist gas along a moving path of the laser beam condensing irradiation point.

According to this aspect, the cutting fluid adhering to the continuous chips can be blown off during the wet cutting to facilitate the cutting, and the cut chips can be cut by a cutting tool or the like regardless of wet cutting or dry cutting. It can be prevented from adhering to a processing head or the like.

A laser chip cutting device according to the present invention is a device for cutting continuous chips generated from a workpiece by a laser beam during cutting by a machine tool, wherein the chip is moved together with the feed of a cutting tool of the machine tool. A chip processing head, the chip processing head comprising: a laser oscillator; a condensing means for condensing laser light oscillated from the laser oscillator; and an optical path of the laser light being changed so as to change the laser light. An optical path changing means for moving the focused irradiation point for a predetermined time following the movement of the chip is provided.

According to the laser chip cutting apparatus of the present invention, the chip processing head having the laser oscillator is provided so as to be able to move integrally with the feed of the cutting tool of the machine tool. Laser light can be applied to the generated continuous chips.

Also, the laser oscillated from the laser oscillator is focused by the focusing means, and the focused irradiation point of the laser beam is moved by the optical path changing means for a predetermined time following the movement of the chips. The light can illuminate the same part of the chip for a longer time. Therefore, chips can be cut even with laser light having a small output.

In the chip cutting device using a laser according to the present invention, it is preferable that the optical path changing means is constituted by a rotating polygon mirror arranged in the optical path of the laser light. Further, it is preferable that the optical path changing means is constituted by a galvanomirror that is swingably disposed in the optical path of the laser light. Further, it is preferable that an assist gas nozzle that blows an assist gas along a movement path of the laser beam converging irradiation point is attached to the chip processing head. The operation according to these aspects is the same as the content described in the chip cutting method.

[0024]

1 and 2 show an embodiment of a chip cutting apparatus using a laser beam according to the present invention. FIG.
2 is a schematic configuration diagram of a machine tool to which a chip cutting device using the present laser light is applied, and FIG. 2 is a schematic configuration diagram of an optical path changing unit and a condensing unit of laser light in the chip cutting device. In this embodiment, a case where a general-purpose NC lathe is used as a machine tool is described.

As shown in FIG. 1, the machine tool 11 includes a headstock 16 erected on one side of a base 15 and a slide way 17 horizontally arranged along the upper surface of the base 15. Have. The slide way 17 is provided with a feeding means 26 such as a ball screw and the like,
And a saddle 18 that reciprocates in the directions 1 and X2. The feeding means 26 is connected to a driving means (not shown) provided inside the headstock 16 so that power for reciprocating the saddle 18 is transmitted.

A tool post 19 is mounted on the upper surface of the saddle 18. The tool rest 19 is slidably mounted on the upper surface of the saddle 18 in a direction perpendicular to the reciprocating movement of the saddle 18 (directions of arrows Y1 and Y2). A tool holder 2 is provided at the upper end of the tool rest 19.
0 is slidably mounted in a vertical direction (directions of arrows Z1 and Z2). Further, from the tool holder 20, a tool attaching portion 21 and a machining head holder 22 for chips are provided.
Is extending.

The cutting tool 23 is detachably attached to the cutting tool attaching portion 21 by, for example, screwing. The cutting tool 23 is mounted on the cutting tool mounting portion 2 so that the cutting edge protrudes toward the headstock 16 in the X1 direction.
Attach to 1. Further, as the cutting tool 23, for example, a throw-away tip is used.

The chip processing head 12 is fixed to the chip processing head holder 22. A laser oscillator 13 is connected to the chip processing head 12 via an optical fiber cable 14, and laser light oscillated from the laser oscillator 13 enters the chip processing head 12 from the end of the optical fiber cable 14. It is designed to be emitted. In the chip processing head 12, there is provided a light condensing means for condensing the laser beam and irradiating the continuous chip 32 generated near the cutting edge of the cutting tool 23. The chip processing head holder 22 converts the laser beam into a continuous chip 32.
It is arranged with a predetermined positional relationship with respect to the bite attaching portion 21 so that the tool can be irradiated.

Since the cutting tool mounting portion 21 and the chip processing head holder 22 are fixed to the cutting tool holder 20, the cutting tool processing head 12 and the cutting tool mounting portion 21 are maintained in a predetermined positional relationship. 20 is linked. Further, in FIG. 1, the chip processing head 12 is disposed above the cutting tool 23, but in a range where the laser beam 42 can be applied to the continuous chips 32.
The position can be changed appropriately.

As shown in FIGS. 1 and 2, an emission end 33 provided at one end of the optical fiber cable 14 is inserted into the chip processing head 12.
The laser light transmitted through the chip 4 is emitted from the emission end 33 into the inside of the chip processing head 12. A collimator lens 34 is disposed in front of the emission end 33 so that the optical axis of the collimator lens 34 coincides with that of the emission end 33. The laser light 41 emitted from the emission end 33 while spreading at a predetermined angle passes through the collimator lens 34. It is designed to be parallel light.

Further, a polygon mirror 36 is provided in the optical path of the laser beam 41 passing through the collimator lens 34. The polygon mirror 36 has a polygonal prismatic body at both end surfaces, and each of a plurality of planes forming a peripheral surface is a reflecting mirror. Then, one of the plurality of reflecting mirrors is arranged in the optical path of the laser light 41 to form a reflecting surface 43. The polygon mirror 36 is rotated by a driving unit (not shown) via a rotation shaft 37 disposed at the axis of the polygon mirror 36. The angle of incidence of the laser light 41 on the reflection surface is gradually increased by this rotation. Change. Further, an objective lens 35 is arranged in the optical path of the laser beam 42 reflected by the reflection surface 43 of the polygon mirror 36, and the laser beam 4
Numeral 2 is emitted from the chip processing head 12 through the objective lens 35 and is focused on a predetermined position.

Incidentally, the collimator lens 34 and the objective lens 35 constitute the light condensing means of the present invention, and the polygon mirror 36 constitutes the light path changing means.

On the other hand, at a position at a predetermined height from the installation surface of the headstock 16, a collet chuck 24 which is rotated by driving means (not shown) installed in the headstock 16 is provided. A work 25 as a workpiece is attached to the collet chuck 24. The collet chuck 24 protrudes in parallel with the feeding means 26. When the saddle 18 reciprocates along the feeding means 26, the tool rest 19 and the tool holder 20 are located above the saddle 18.
The tool attaching portion 21 attached via the above-described method approaches the collet chuck 24 or moves away from the collet chuck 24.

Therefore, the work 25 is fixed to the collet chuck 24, the cutting tool 23 is attached to the cutting tool attaching portion 21, and the chip tool 23 is brought into contact with the work 25 while moving the saddle 18 along the feed means 26.
The work 25 can be cut.

Next, an embodiment of a laser chip cutting method according to the present invention using the machine tool 11 will be described.

First, the work 25 is moved to the collet chuck 24.
Fixed to. At this time, the work 25 is fixed so that the rotation center of the work 25 when the collet chuck 24 rotates is parallel to the feeding means 26. Next, the cutting tool 23 is mounted on the cutting tool mounting portion 21. Then, insert the tool holder 20 into Z1
Alternatively, the cutting tool 23 is slid in the Z2 direction so that the cutting tool 23 is positioned at the height of the work 25. Subsequently, the tool rest 19 is slid in the direction of Y1 or Y2, and when the cutting tool 23 is brought close to the work 25, the cutting tool 23 is adjusted to a position where the cutting edge of the cutting tool 23 contacts the outer peripheral portion of the tip of the work 25.

When the mounting of the cutting tool 23 is completed, the driving means (not shown) is driven to rotate the collet chuck 24 and the work 25 integrally. Then, the drive means (not shown) is operated to move the saddle 18 so that the cutting tool 23 is brought close to and in contact with the work 25 to start cutting. At this time, the work 25 is cut in the direction of the arrow Y1 from the outer peripheral surface toward the rotation axis, and continuous chips 32 are generated.

When the continuous chips 32 are generated, the laser oscillator 13 is operated, a laser beam is oscillated, and the polygon mirror 36 is rotated. The laser light oscillated by the laser oscillator 13 is transmitted via the optical fiber cable 14 and emitted from the emission end 33 toward the polygon mirror 36. The laser light 41 emitted from the emission end 33 is converted into parallel light by the collimator lens 34 and is reflected by the reflection surface 43 of the polygon mirror 36. Then, the laser light 42 reflected by the reflection surface 43 is emitted from the chip processing head 12 through the objective lens 35, is condensed and irradiated on the continuous chips 32, and the continuous chips 32 are cut.

Here, the laser oscillator 13 is not limited as long as it is a laser capable of cutting chips. For example, a pulse YAG laser oscillator, which is a pulse discharge type laser using a flash lamp, is used. be able to. This is because the output energy per pulse can be higher than that of a CW type YAG laser. Commercially available lasers of this type have a pulse width of 0.1
ms to 20 ms (pulse number 1 to 300 pps, maximum output energy 50 (J / p) level, average output 50 W
Up to 100W or up to 500W)
There is something.

It is preferable that the position where the laser beam 42 is condensed and irradiated on the continuous chips 32 be confirmed in advance using, for example, a He-Ne laser beam which is red light. That is, He is set so as to coincide with the optical axis of the laser light for cutting the continuous chips 32 oscillated from the laser oscillator 13.
If the Ne laser light is transmitted to the chip processing head 12 via the optical fiber cable 14, the chip processing head 12
The position where the laser beam 42 is condensed and irradiated by the He-Ne laser emitted from the laser beam can be confirmed. This He
Since the -Ne laser has a very small output, the danger is extremely low as compared with, for example, a YAG laser used for cutting the continuous chips 32 and is suitable for guide light.

The laser light oscillated by the laser oscillator 13 is transmitted through the optical fiber cable 14. If the laser light can be directly introduced into the chip processing head 12, the optical fiber cable 14 is used. It is not necessary.

As shown in FIG. 2, the laser light 42 is
Beam scanning (optical scanning) is performed by rotation of the polygon mirror 36. In other words, the reflection surface 43 gradually changes from the scan start state 43a where the incident angle of the laser beam 41 is large to the scan end state 43b where the incident angle is small due to the rotation of the polygon mirror 36 in the direction A. The reflected light 42 also changes from the scan start state 42a having a large reflection angle to the scan end state 42b having a small reflection angle.
Gradually changes to Therefore, the focused irradiation point 44 of the reflected light 42 is also scanned from the focused irradiation point 44a at the start of the scan to the focused irradiation point 44b at the end of the scan.
At this time, the focused irradiation point 44 is set in the moving direction X2 of the continuous chip 32.
Scan in the same direction as the polygon mirror 36
Adjust the rotation speed of the chip and set the scanning speed to
The laser beam follows the continuous chip 32 by making the moving speed equal to the moving speed. Therefore, since the laser light is relatively stationary with respect to the chips, it is possible to cut the continuous chips 32 even with extremely low output laser light.

After the continuous chips 32 are cut, when another adjacent reflecting mirror goes around the optical path, the reflecting surface 43 is again brought into the scanning start state 43a with a large incident angle. Then, the laser beam 42 also enters the scan start state 42a with a large reflection angle, and the converging irradiation point 44 also returns to the position of the converging irradiation point 44a at the start of scanning. Then, since the subsequent scanning is performed in the same manner, the cutting of the continuous chip 32 is continuously performed.

During the scanning, it is preferable that the timing of the rotation of the polygon mirror 36 and the pulse oscillation of the laser beam be adjusted and controlled by a computer.

The moving speed of the continuous chips 32 is substantially determined by cutting conditions (cutting depth, feed speed, peripheral speed, material, tool, etc.), and under the above-described ordinary cutting conditions, for example, the moving speed of the chips = Peripheral speed xa (a is 1/2 to 1/5
) Is empirically known. Therefore, the scanning speed of the laser beam can be easily set according to the cutting conditions.

Further, it is preferable that the scanning length of the laser beam is about the distance that the chips actually travel in the time of the predetermined pulse width of the laser beam. For example, in the case of a pulse width of 1 ms and a chip speed of 4 (m / s), the travel distance of the chip in the time of the pulse width is 4 mm, so that the scan length of the laser beam is 4
mm or 5 to 6 mm, which is slightly longer than that. Note that an f · θ lens is preferable as the objective lens 35, but if the scan length is 4 to 6 mm, L = f between the focal length f of the objective lens 35, the incident angle θ, and the scan length L. Since an approximation of θ = f · tan θ is established, a normal f · tan θ lens may be used.

Further, when a throw-away tip is used as the cutting tool 23, for example, the diameter of the focused irradiation point 44 is preferably about 1 mm in consideration of the position of the cutting point and the width of the chip. Although the converging irradiation point 44 has a generally circular cross section, the laser is shaped into an elliptical cross section in advance, and the converging irradiation point 44 becomes a linear spot (imaging) extending in the width direction of the continuous chip 32. Point). In this case, for example, even if the continuous chip 32 slightly shakes (or fluctuates) in the direction perpendicular to the moving direction, the laser light 4
Since 2 irradiates the continuous chips 32, the continuous chips 32 can be cut. However, since the required laser output energy also increases due to the increase in the area of the focused irradiation point 44, it is not preferable to increase the diameter of the focused irradiation point 44 unnecessarily.

Next, the operation and effect of the laser chip cutting method of the present invention using the machine tool 11 will be described.

The diameter of the focused irradiation point 44 emitted from the chip processing head 12 is φ1 mm, the chip speed is 1 (m / s),
Assuming that the pulse width of the laser beam is 1 ms, a comparison is made between the case where the laser beam follows the chip and the case where it does not follow (still state).

When the laser light follows the chips, the reflected light 4
2 irradiates the continuous chip 32 with a diameter of 0.1
cm (φ1 mm). Therefore, the area is 3.14 × (0.05) ² = 7.85 × 10 ⁻³ (c
m ² ).

When the laser light does not follow the chips, the focused irradiation point 44 relatively moves on the continuous chips 32 at the chip speed. At this time, the length that the laser beam moves is 100
(Cm / s) × 0.001 (s) = 0.1 cm.
Therefore, the portion where the laser light irradiates the chips has a shape in which a semicircle having a diameter of 0.1 cm is connected to both sides of a square having a length of 0.1 cm and a width of 7.85 × 10 ^-3 +
0.01 = 17.85 × 10 ⁻³ (cm ² ).

When these are compared, the area when the laser beam does not follow the chips is approximately 2.3 times the area when the chip follows. A similar calculation is performed with a chip speed of 4 (m / s).
When this is done, this area ratio becomes 6.1 times. Since the average power of the laser increases with the size of the irradiation area of the laser light, when the laser light follows the chips, for example, even if the chip can be cut at an average output of 60 W,
When the laser beam does not follow the chip, the chip speed is 1 (m
/ S), a chip speed of 4 (m /
In the case of s), an average output of about 366 W is required. In the case of a laser beam transmitter having an average output of 366 W, the maintenance cost is increased due to an increase in the size of the device, an increase in the cost of the device, and a decrease in the life of the excitation lamp, and the cutting work is performed for economic reasons. As described above, it will hinder automation and unmanned operation.

FIG. 3 shows another embodiment of the chip cutting apparatus using a laser beam according to the present invention. FIG. 3 is an operation explanatory view of the optical path changing means and the light condensing means of the chip processing head.

The chip machining head 27 is obtained by replacing the polygon mirror 36 as the optical path changing means of the chip machining head 12 shown in FIGS. That is, a galvanomirror 51 is swingably mounted in the optical path of the laser light 41 emitted from the emission end 33 and converted into parallel light through the collimator lens 34. The galvanomirror 51 has a rotating shaft (not shown) on the back surface thereof, and the rotating shaft is rotated by a driving means (not shown) so as to rotate alternately by a predetermined rotation angle in the B and C directions.

By rotating the galvanomirror 51 in the direction B,
Scan start state 51a with a large incident angle of laser light 41
From the scan end state 51b with a small reflection angle to the scan end state 4b with a small reflection angle.
2b. Therefore, the polygon mirror 3
As in the embodiment using No. 6, the focused irradiation point 44 can be scanned from the focused irradiation point 44a at the start of scanning to the focused irradiation point 44b at the end of scanning. And
When the continuous chips 32 are cut, the chips are quickly rotated in the C direction to set the scan start state 51a having a large reflection angle, and the condensing irradiation point 44 is returned to the condensing irradiation point 44a at the start of scanning. Thereafter, if scanning is performed in a similar manner, cutting of the continuous chips 32 can be performed continuously.

The laser beam may be oscillated, including the period in which the galvanomirror 51 is rotating in the direction C, to reciprocate the focused irradiation point 44. In this case, since it is not necessary to consider the timing at which the galvanomirror 51 returns, the control can be simplified.

In the above embodiment, two mirrors may be used. That is, in FIG. 3, by arranging the second galvanometer mirror in the optical path of the reflected light 42 between the galvanometer mirror 51 and the objective lens 35,
The laser beam can be made to follow the moving direction of the continuous chip 32 and can be scanned in a direction perpendicular to the moving direction of the chip.

Referring to FIG. 1, for example,
A first galvanomirror for reflecting the laser light in the Y2 direction is arranged in the optical path of the laser light 41 incident from the emission end 33 so as to be swingable with respect to the laser light 41, and further reflected by the first galvanomirror. A second galvanomirror for reflecting the laser light in the Z2 direction is arranged in the optical path of the laser light so as to be swingable with respect to the reflected light. Then, the objective lens 35 is arranged in the optical path of the reflected light 42 of the second galvanometer mirror.

According to this aspect, the condensing irradiation point 44 is scanned in the X1 and X2 directions by the first galvanomirror, and scanned in the Y1 and Y2 directions by the second galvanomirror. Therefore, since the position of the condensing irradiation point 44 can be set by combining the deflection angles of these two mirrors, in the operation of adjusting the position where the laser beam is condensed and irradiated on the continuous chip 32, the chip processing head 12 itself is adjusted. There is no need to change the direction to adjust. Moreover,
If the deflection angles of the two mirrors are controlled by a computer, the adjustment operation can be performed more easily.

Further, the laser beam is controlled so that the second galvanomirror is oscillated at a high speed and reciprocated at a high speed with a very small length in a direction orthogonal to the moving direction of the continuous chips 32. The diameter of the light irradiation point 44 can be reduced to a value close to the width of the continuous chip 32, and the variation in the width of the continuous chip 32 can be compensated for by making the condensing irradiation point 44 slightly reciprocate in the width direction. Therefore, the setting of the position of the focused irradiation point 44 can be slightly roughened. However, in this case, it is preferable that the pulse width is set slightly larger so that the pulse irradiation does not fall off.

FIG. 4 shows still another embodiment of the chip cutting apparatus using a laser beam according to the present invention. FIG. 4 (a)
Is a front sectional view of the tip of the processing head for chip, FIG. 4 (b)
FIG. 4 is a cross-sectional view taken along line DD ′ of FIG.
It is to be noted that the same parts as those in the above embodiment are denoted by the same reference numerals, and description thereof will be omitted.

The chip processing head 28 is obtained by forming a portion of the chip processing head 12 shown in FIGS.
The assist nozzle 61 includes a cylindrical portion 61a for holding the objective lens 35, and a nozzle portion 61b having a tapered narrow end on the light emission side of the cylindrical portion 61a. An elongated nozzle hole 62 extending along the moving direction of the chip 32 is formed. The objective lens 35 and the nozzle 6 are located inside the cylindrical portion 61a.
1b, a disc-shaped protective glass 63 is disposed, and foreign matter scattered from the cut portion causes the objective lens 3
5 is prevented from being soiled or damaged.
Further, the nozzle portion 61b is provided with a gas supply port 64 penetrating the side wall. A gas supply tube 65 is connected to the gas supply port 64, and a gas supply device (not shown) is connected to the other end of the gas supply tube 65.

According to this chip cutting device, a gas supply tube 65 and a gas supply port 6
4, the assist gas 66 is supplied under pressure into the nozzle portion 61b. Then, the assist gas 66 supplied under pressure is injected through the nozzle holes 62. At this time, since the nozzle hole 62 is provided along the path where the laser light is scanned, the assist gas 66 is provided at the focused irradiation point 44 regardless of the position of the scanned laser light.
Is in a state where the assist gas 66 is always sprayed.
Therefore, in the wet cutting using the cutting fluid 67, the cutting fluid 67 that constantly flows is used as the assist gas 66.
As a result, the continuous chips 32 can be cut.

Here, the gas pressure of the assist gas 66 is 1
(Kg / cm ² ) or more. In dry cutting in which cutting is performed without using the cutting fluid 67, the gas pressure of the assist gas 66 may be set to a level that can prevent foreign matter from adhering to the protective glass 63. However, regardless of wet cutting or dry cutting, by strongly blowing the assist gas 66 to the focused irradiation point 44, the cut continuous chips 32 are blown off, which has an effect of preventing adhesion and entrapment to the cutting tool 23. , Always 1 in any case
(Kg / cm ² ) or more. Dry air can be used as the assist gas 66, but there is no limitation as long as it is a dry gas, and N ₂ gas or an inert gas may be used.

The cutting fluid used in wet cutting includes a water-soluble type and a non-water-soluble type, but a non-flammable water-soluble type is preferred. When a non-flammable gas is used, O ₂ gas is used as the assist gas 66.
Gas can be used, which can improve chip cutting performance.

The beam scanning optical system is not limited to the above embodiment as long as the beam scanning speed can follow the speed of the continuous chips.

[0067]

As described above, according to the present invention,
Since the optical path changing means capable of scanning the laser beam is provided inside the processing head, the laser beam can follow the movement of the continuous chips generated from the workpiece at the time of cutting by the machine tool. Therefore, it is possible to reduce the output energy required for cutting by lengthening the time for irradiating the same portion with the laser light, thereby reducing the cost of the laser device, and reducing the installation space and maintenance cost. it can. Further, automation and unmanned processing machines, which have been hindered by the generation of continuous chips, can be realized, and the total cost of production can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a machine tool to which an embodiment of a chip cutting device using laser light according to the present invention is applied.

FIG. 2 is a schematic configuration diagram of an optical path changing unit and a condensing unit of laser light in the chip cutting device.

FIG. 3 is a schematic configuration diagram of an optical path changing unit and a condensing unit of a chip processing head showing another embodiment of a chip cutting device using a laser beam of the present invention.

4A and 4B show still another embodiment of a chip cutting device using laser light according to the present invention, wherein FIG. 4A is a front sectional view of a tip end portion of a chip processing head, and FIG. 4B is DD ′ of FIG. It is sectional drawing which followed the arrow line.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Machine tool 12 Chip processing head 13 Laser oscillator 14 Optical fiber cable 20 Bit holder 21 Byte mounting part 22 Chip processing head holder 23 Cutting tool 25 Work 32 Continuous chip 33 Emission end 34 Collimator lens 35 Objective lens 36 Polygon mirror 41 Laser Light 42 Reflected light

Claims (8)

[Claims] 1. A method for cutting continuous chips generated from a workpiece by a laser beam during cutting by a machine tool, wherein when irradiating the chip with the laser beam, a condensing irradiation point of the laser beam is set to A chip cutting method using a laser, wherein the chip is moved following the movement. 2. A method according to claim 1, wherein a polygon mirror that rotates in synchronization with an oscillation timing of the laser light is disposed in an optical path of the laser light, and the laser light is sequentially reflected by each reflection surface of the polygon mirror that rotates. The chip cutting method using a laser according to claim 1, wherein the laser beam condensing irradiation point is moved so as to follow the movement of the chip. 3. A laser beam is reflected by disposing a galvanomirror that oscillates in synchronization with an oscillation timing of the laser light in an optical path of the laser light, thereby reflecting the laser light.
The chip cutting method using a laser according to claim 1, wherein the converging irradiation point of the laser light is moved in accordance with the movement of the chip. 4. The chip cutting method using a laser according to claim 1, wherein the chip is irradiated with the laser light while blowing an assist gas along a movement path of a converging irradiation point of the laser light. . 5. An apparatus for cutting continuous chips generated from a workpiece by a laser beam during cutting by a machine tool, comprising: a chip processing head capable of moving integrally with a feed of a cutting tool of the machine tool; The processing head includes a laser oscillator, a condensing means for condensing the laser light oscillated from the laser oscillator, and changing the optical path of the laser light so that the converging irradiation point of the laser light moves the chip. And a light path changing means for moving the laser beam for a predetermined time following the laser beam. 6. The laser cutting device according to claim 5, wherein said optical path changing means comprises a rotating polygon mirror arranged in the optical path of said laser light. 7. The chip cutting device using a laser according to claim 5, wherein said optical path changing means is constituted by a galvanomirror which is swingably arranged in the optical path of said laser beam. 8. The laser according to claim 5, wherein an assist gas nozzle that blows an assist gas along a movement path of a converging irradiation point of the laser beam is attached to the chip processing head. By chip cutting equipment.