JPH0323093A - Head of laser beam machine - Google Patents

Abstract

PURPOSE:To obtain a working head whose focal position does not move irrespective of change of the irradiating direction by providing the working head having two optical joints at the lower end of an arm of a moving mechanism and connecting the rear end of the working head to the lower end of a link moving vertically along the arm through parallel holding mechanisms. CONSTITUTION:At the lower end of an arm 2 of an axis Z hung and rotated by a moving mechanism having three freedoms X, Y, Z are provided a 1st and a 2nd optical joints 14, 22 composed of a pair of mirrors 11A, B and 19A, B having 45 deg. to a laser optical axis L transmitted in the arm 2 horizontally and in parallel and in series through a manifold 18. Then, there is provided a driving part 17 to drive the 1st optical joint 14 on the 1st optical joint 14, the lower end of a link 31 connected to a moving part 33 whose upper end moves vertically along the arm 2 and the rear end of a condensing part set to the 2nd optical joint 22 are connected and a mechanism holding the link 31 and the manifold 18 in parallel is provided between the lower end of the link 31 and the 2nd optical joint 22, consequently, the head of the laser beam machine obtained can keep a fixed focal position irrespective of change of an irradiation direction and is easy of instruction.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a head for a laser processing machine.

(Prior art) Some laser processing machines that perform three-dimensional machining include rotation α, swing β, etc. at the tip of the arm 2 of the moving mechanism that has three degrees of freedom: Some laser beams are equipped with a head 3 with a degree of freedom of 30 degrees, and the position and direction of the laser beam relative to the workpiece 4 are changed to perform welding, cutting, etc.

(Problem to be Solved by the Invention) However, in a laser processing machine having such a structure, when changing only the irradiation direction with respect to the irradiation point P of the workpiece, as shown in FIG. , B, and C, the operating speed of each axis is restricted, it is difficult to make sudden posture changes at protruding corners, etc., and the weight of the transfer mechanism 1 not only requires a large amount of power. , the system vibrates.

Therefore, in order to change only the direction of the sword without moving the arm, there is a head like the one shown in Figure 7.

This consists of an α axis that rotates the first optical system 5 that bends the laser beam L at right angles at the lower end of an arm 2 provided in a moving mechanism (not shown), and a second axis that bends the laser beam L diagonally at its tip.
optical system 6, and a third optical system that bends this laser beam L at a right angle.
A T-axis for rotating the optical system 7 and this third optical system 7 around the previous laser optical axis, a fourth optical system 8 for obliquely bending the laser optical axis at its tip, and a fourth optical system 8 provided at its tip. It consists of a condensing system 9 and the like, and the direction of illumination is changed by changing the orientation of the head 3 by movement of the α-axis and T-axis.

However, this head 3 has a posture angle operating range with respect to the vertical that is limited to about 90 degrees, and has a T-axis drive system 10 that once bends the laser beam at a right angle at the lower end of the arm, and third and fourth optical systems 7. , 8. Not only is the movable space of the condensing system 9 large,
Since the attitude angle with respect to the vertical is determined by the rotation of the α-axis and the T-axis, it is not possible to intuitively determine whether there is interference between the head 3 and the workpiece, and teaching and programming are difficult.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a head for a laser processing machine that is small in size and easy to teach, with little change in head position due to changes in the direction of laser beam irradiation.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a mechanism for transmitting a signal to the lower end of a Z-axis arm that is suspended from a movement mechanism with three degrees of freedom (X, Y, and Z) and rotates. First and second optical joints each consisting of a pair of mirrors at an angle of 45 degrees to the laser optical axis are provided horizontally and in parallel in series through a connecting tube, and the first optical joint is connected to the first optical joint. 1) The lower end of the link is connected to the rear end of the condensing part attached to the second optical joint, and the lower end of the link is connected to the moving part that moves up and down along the arm. This head of a laser processing machine is provided with a mechanism for holding the link and the connecting pipe in parallel between the link and the second optical joint or the third optical joint and the link.

(Function) As a result, when the first optical joint at the lower end of the arm is driven by the drive unit, the output side of the first optical joint and the link are always oscillated in parallel by the parallel holding mechanism. At this time, the ratio from the focal point P of the condensing section to the axis of the second optical joint, as well as the ratio from the focal point P to the link fulcrum at the rear end of the condensing section, and the ratio between the axes of the first optical joint and the second optical joint. By setting the ratio between the length of the link and the length of the link to be equal, a triangle surrounded by three points, the focal point P, the axis of the first optical joint, and the axis of the second optical joint, and the focal point P
The triangles surrounded by the three points of the connecting axes at both ends of the link are similar, and since the upper end of the link and the axis of the first optical joint are on the arm axis, the focal point P is always on the arm axis. It is on the extension, and when the first optical joint is rocked by the drive part,
The vertical position of the focal point P and the irradiation angle of the laser beam with respect to the vertical change.

(Example) Hereinafter, an example of the head of a laser cutter machine of the present invention will be described with reference to the drawings.

FIG. 1 is a longitudinal cross-sectional view showing a main part of a head of a laser processing machine according to the present invention, and FIG. 2 is a right side view of FIG. 1.

In FIGS. 1 and 2, X, Y. The lower end of the hollow arm 2, which is suspended from a moving mechanism (not shown) with three degrees of freedom in Z and rotates about an axis by a driving means (not shown), has laser optical axes L and 4.
A pair of mirrors 11A, 11B facing each other at 5 degrees, bearing 1
2. A first optical joint 14 consisting of a housing 13 and the like is provided, and a spur gear 15 fixed to the arm 2 is provided on the bearing 12.
A spur gear 16 meshing with the output shaft 16 is fixed to the output shaft 16, and a driving section 17 is provided, which is constituted by a motor, a speed reducer, and the like. Furthermore, the E end of a transmission pipe 18 is fixed to the output side of the first optical joint 14, and the second optical joint 18, which also includes mirrors 19A, 19B, a bearing 20, a housing 21, etc., is fixed to the lower end of the transmission pipe 18. A joint 22 is provided, and the outer periphery of the base of a hollow shaft 23 fixed to the housing 21 forms a hammer wheel 23a.

Next, the condensing system housing 2 at the tip of the second optical joint 22
A lens mount 26 and a nozzle 27 are provided at the tip of the link 3 , and a link 3 is provided on the protrusion 25 a at the rear end to which a spur gear 30 having the same number of teeth as the spur gear 24 is fixed by a shaft 28 and a bearing 29 .
The lower end of the link 31 is connected in a swingable manner, and the upper end of the link 31 is
A bearing 34 is mounted on a movable table 33 supported by a guide bearing 32a that can be moved up and down on a track 32 provided on the surface of the arm 2.
, are connected to each other so as to be able to swing freely by a shaft 35 (note: the saw-cut shape is a dust-proof bellows). Further, at the rear end of the condensing system housing 25, a shaft 37, to which idler gears 36A and 36B are attached on both sides, is rotatably supported by a bearing 38.

Next, the operation of the head of the laser 710 machine tool of the present invention will be explained first.
This will be explained in Figure 3.

First, when the first optical joint 14 is swung by the drive unit 17,
The link 31 is made up of the gear 23a of the second optical joint 22, idler gears 36A and 36B, and a spur gear 30, and is connected to the output side of the first optical joint 14 (i.e., the transmission pipe 18) with a shaft 35 as a fulcrum.
).

At this time, the ratio of the distance l2 from the focal point P to the axis Q of the second optical joint 22 and the distance PR from the focal point P to the axis R of the connecting shaft 28, and the ratio of the distance l2 from the focal point P to the axis Q of the second optical joint 22, joint 22
If the length of the link 31 is set so that the ratio of the distance l1 between the axes and the length l of the link 31 is equal, and the axis of the shaft 35 is set to S, then the triangle OPQ and the triangle SPR are similar. , the focal point P is always on the extension of the axis of the arm 2.

Furthermore, at this time, the included angle ψ formed by the axis of the laser beam illumination direction arm 2 is as follows, where θ is the operating angle of the first optical joint 14.

At this time, the displacement jZ of the focal point P in the Z direction when the transmission tube 18 and the second optical joint 22 are fully extended (that is, θ-0° state) is Ilz-(1-cosθ)! ! 1+(1- cos
(Sin-1 '2i Si'θ)}.

Therefore, by measuring this Z-direction displacement jz and sequentially correcting it using the Z-axis drive system to control the angle θ, it is possible to change the irradiation direction of the laser beam without changing the position of the focal point P.

Generally, the Z axis is relatively light in the configuration shown in FIG. 6, so the power required for this correction is also small.

Furthermore, unlike the X and Y axes, the movement is in the axial direction, so there is no vibration.

Furthermore, the first and second optical joints 14. When the head 22 is not bent, the first and second optical joints 14.
It only occupies a space with a width of 22 mm, and there is no part that protrudes in the direction of illumination even when bent, so it is difficult to use the conventional rotation α and bending β
With the same degree of freedom as , you can intuitively see if there is interference with the workpiece.

In this embodiment, the means for interlocking the second optical joint 22 with the first optical joint 14 is provided by the spur gear 3 of the link 31.
0 and the spur gear 2 with the same number of teeth on the output side of the first optical joint 14
3a, but as shown in FIG. 4(a), an arm 21A extending from the upper end of the transmission pipe 18 and this arm 41
A link 4113 is provided between the shafts 35 and parallel to the QR, or the output shaft 1 is connected parallel to the QR as shown in FIG. 4(b).
A parallelogram link may be used by providing a link 41C that connects the axis O of No. 6 and the link 31.

[Effects of the Invention] As described above, according to the present invention, X, Y. At the lower end of the Z-axis arm that rotates and is suspended from a Z-3 degree of freedom movement mechanism, there are first and second optics consisting of a pair of mirrors at an angle of 45 degrees to the optical axis of the laser beam transmitted within the arm. The lower end of the link is attached to a movable part whose upper end moves up and down along the arm. and the second optical joint (connecting the rear end of the cut light condensing part, and a parallel holding mechanism for the link and the connecting pipe between the lower end of the link and the second optical joint or between the first optical joint and the link. As a result, it is possible to obtain a head for a laser processing machine that can be easily taught without changing the focal position even if the illumination direction is changed.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of the head of the laser processing machine of the present invention, FIG. 2 is a side view of FIG. 1, and FIG. 3 is an explanation showing the operation of the head of the laser processing machine of the present invention. Figure, Figure 4 (
aL(b) is a mechanism explanatory diagram showing another embodiment of the head of the laser processing machine of the present invention, FIG. 5 is a perspective view showing an example of a conventional laser processing machine, and FIG. 6 shows the function of FIG. 5. Figure shown, 7th
The figure is a front view showing the head of a conventional laser processing machine. 2... Arm 14... First optical joint 17... Drive section 18... Transmission pipe 22... Second optical joint 25... Condensing system housing 27... Nozzle 28, 35. 37...Axis 31...Link 33...Moving table (8733) Agent Patent attorney Yoshiaki Inomata (Idiot)
1 person〉 Figure 5 Kaya Z Figure Broom 7 A

Claims (1)

[Claims] In the head of a laser processing machine, in which a light condensing section is provided at the lower end of a rotating Z-axis arm that is attached to a moving mechanism with three degrees of freedom (X, Y, and Z), a beam transmitted into the arm is attached to the lower end of the arm. First and second optical joints each consisting of a pair of mirrors that bend a laser beam at 45 degrees are provided in parallel via a connecting tube, a drive section for the first optical joint is provided in the first optical joint, and the upper end connects the lower end of the link connected to the movable part that moves up and down along the arm and the rear end of the light condensing part attached to the second optical joint, and the lower end of the link and the second optical joint are connected to each other. A head of a laser processing machine, characterized in that a parallel holding mechanism for the link and the connecting pipe is provided between the joints or between the first optical joint and the link.