JPH0451500Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates to an optical axis adjustment device for adjusting the mounting angle position of a resonant mirror of a gas laser oscillator.

Prior Art A pair of resonant mirrors provided at both ends of a cylindrical frame of a gas laser oscillator must support its posture with high precision. Among these, the optical axis adjustment device of the mirror, which is frequently adjusted, uses a motor to extend and retract the adjustment shaft to adjust the tilt angle.
The shaped mirror holder maintains its mounting position by pressing the mirror holder against the mounting ring using compression springs provided near adjustment shafts provided at both ends and a pivot shaft provided at the center.

Problems that the invention aims to solve In order to maintain high precision of the mirror holder, it is necessary to increase the spring pressure, but if the spring pressure is increased, the torque of the motor of the optical axis adjustment device will be insufficient. There is a limit to the spring pressure, and it is not possible to make the spring pressure too large. As a result, the mounting position of the mirror holder is displaced due to vibrations, shocks, etc., which disrupts the uniformity of reflection of the resonating laser beam and makes the mode of the output laser beam unstable.

Means for Solving the Problem An L-shaped mirror holder H is provided with a mirror M that is attached to a mounting ring 2 that is fixed to the side surface of a cylindrical container of a laser oscillator, with its central portion as a fulcrum, and is provided so as to be able to adjust its inclination angle. adjustment screws 2 whose tips abut against the mounting ring 2 at both ends of the L-shape;
A motor 21 is provided on the mirror holder H to rotate the adjusting screw 22 in order to change the distance between the end of the mirror holder H and the ring 2. Support shaft 11B that is pulled to the side via a spring
is implanted in the mounting ring 2, and is made of a shape memory alloy whose inner diameter is slightly smaller than the outer diameter of the support shaft at room temperature and has a tightening margin, and which is gripped in a winding manner and released by enlarging the inner diameter at a predetermined temperature. A clamper 24 is fixed on the side of the mirror holder H, and a heater 25 is attached concentrically to the support shaft 11B to maintain the temperature of the grip part 24b of the shape memory alloy clamper 24 at a predetermined temperature. The grip portion 24b of the clamper 24 is heated by the heater 25 during shaft adjustment.
After heating and unclamping and adjustment, the clamped state is achieved by heat radiation cooling.

Embodiments Hereinafter, embodiments of the present invention will be described based on the drawings. The cylindrical container of the gas laser oscillator is provided with flanges at both ends, and contains parts related to laser oscillation. A mounting ring 2 is attached to the side of the left flange of the cylindrical container. An L-shaped mirror holder H having a mirror M is attached to the outer surface of the attachment ring 2 via attachment members 3 and 4.

As shown in FIG. 3, the mounting member 3 is screwed into the center of the L-shape of the mirror holder H, and its spherical end 10a is attached to the mounting ring 2 side at a slightly distant position from the stud bolt 10 fitted into the recess 2a of the mounting ring 2. A support shaft 11A that is screwed and freely passes through a hole provided in the mirror holder H, and a spring holder that is screwed onto the threaded end of the support shaft 11A and presses the mirror holder H via a washer 12A and a compression spring 13A. The recess 2a and stud bolt end 10a function as a pivot bearing. The compression spring 13A or the mirror holder H is always pressed against the attachment ring 2 side with a predetermined force. The mirror holder H is rotatable around the X-axis or the Y-axis around the recess 2a.

As shown in FIG. 1, the attachment member 4 is attached to both ends of the L-shape of the mirror holder H, and similarly to the attachment member 3, it has a recess 2a, a support shaft 11B, a washer 12B, a spring 13B, and a nut 14B. Support shaft 11B
A square block-shaped bracket 18 having a hole 18a parallel to the mirror holder H and a female thread 18b coaxially connects the female thread 18b to the bolt 19 on the ring 2 side with the hole 17 drilled at both ends of the mirror holder H coaxially with the hole 18a. Therefore, it is fixed to the mirror holder H, and a cylindrical motor case 20 is fitted into the hole 18a of this bracket. The motor case 20 has a hole with a large diameter in the center, and a play hole 20 at the tip.
A small hole 20c for an electric wire is provided at the rear end of a large diameter hole 20a in the center of which the motor 21 is inserted. Furthermore, a long hole 2 that penetrates in the radial direction and is long in the axial direction is formed in a part of the outer circumference.
0d are provided at two locations symmetrically with respect to the axis.

The motor 21 installed in the large diameter hole 20a of the motor case 20 is equipped with a speed reducer, and an adjustment screw 22 is carved into the output shaft of the motor 21, and a spherical surface 22 is formed at the tip of the adjustment screw 22.
a is formed. Further, a collar 21a is provided on the output shaft side of the frame of the motor 21, and the collar 21a has two square peaks 21b that protrude laterally symmetrically with respect to the axis.
is cut out, and this rectangular peak 21b is engaged with the elongated hole 20d of the motor case 20. motor 21
adjustment screw 22 and female thread 18b of bracket 18
are screwed together, and the adjustment screw 2 is rotated by the rotation of the motor 21.
2 rotates and moves in the axial direction, and the motor itself is moved only in the axial direction within the large diameter hole 20a of the motor case. It is pressed.

A clamper 24 made of a shape memory alloy is provided on the side surface of the bracket 18 on the support shaft 11B side. As shown in FIG. 8, the clamper 24 has an L-shaped mounting seat 24a, and the tip has a gripping part 24b rolled up into a cylindrical shape.
It is inserted into. The inner diameter of the gripping portion 24b is made slightly smaller than the outer diameter of the support shaft 11B at room temperature, with a tightening allowance, and the diameter increases when heated. Further, a cylindrical heater 25 is fitted to the base of the support shaft 11B and connected to a power source (not shown).

Function Now, glow discharge occurs in the electrode space provided in the cylindrical container, and a part of the laser beam resonated by reflection from a pair of resonant mirrors passes through the output mirror and becomes the output laser beam. It is then taken out and guided to a laser processing machine where laser processing is performed. As the output of the output laser beam decreases, it becomes necessary to adjust the optical axis of the resonant mirror, and the mounting angle of the mirror M is adjusted. First, the cylindrical heaters 25 of the attachment members 4 at both ends of the mirror holder H including the mirror M are energized to heat the support shaft 11B. The gripping portion 24b of the clamper 24, which is fixed to the bracket 18 and grips the outer periphery of the support shaft 11B, is heated above the transformation point and deformed, and the inner diameter becomes larger as shown in FIG. 4B, and the clamp is released. Subsequently, when the motors 21 at both ends are energized and rotated simultaneously or separately, the adjustment screw 2
2 is rotated, and the length of the threaded portion protruding from the female thread 18b of the bracket 18 is changed by the rotation of the adjustment screw 22. Therefore, both ends of the mirror holder H are moved simultaneously or separately without any gap by the pressing force of the compression spring 13B. On the other hand, the mounting member 3 provided at the center of the mirror holder H is a pivot bearing in which the tip spherical surface 10a of the stud bolt 10 is pressed against the recess 2a of the mounting ring 2 by the compression spring 13A. springs 13A and 13B due to the movement of the mounting members 4 at both ends.
The mirror M is rotated in the Y-axis direction and the X-axis direction using the pivot bearing as a fulcrum by overcoming the pressing force of , and the inclination angle of the mirror M is adjusted. When the optical axis adjustment is completed, the motor 21 is stopped, the cylindrical heater 25 is de-energized, and the support shaft 11B is returned to room temperature by radiation cooling, and the gripping portion 24b of the clamper 24 becomes below the transformation point and the clamper gripping portion 24b becomes the original inner diameter with a tightening allowance and becomes the state shown in FIG. 4A, gripping the support shaft 11B and clamping the mirror holder H. The mounting position of the mirror holder H is maintained with high precision by the clamper 24 in addition to the pressing force of the compression springs 13A and 13B. In this way, the optical axis is adjusted, the laser output is restored, and the uniformity of three-dimensional reflection of the laser beam is ensured.

Effects As detailed above, the present invention has a shape memory alloy clamper that is fixed to the mirror holder via a bracket, and a spindle that is fixed to the mounting ring so that the inner diameter is slightly smaller than the outer diameter of the spindle at room temperature. It has a clamping margin and is gripped in a wrap-around style, and the spindle is heated by a heater.When adjusting the optical axis, the heater heats the gripping part of the clamper above the transformation point and clamps the spindle. As the inner diameter becomes larger, it is unclamped, and after adjustment, the temperature drops below the transformation point through heat radiation cooling, ensuring that it returns to its original clamped state, so a force is applied to displace the mirror holder relative to the spindle axis. Even if the mirror holder is clamped and unclamped frequently without doing so, there is no risk of the mirror axis being displaced. In addition, the additional mechanism is simple, there is no failure, there is no deviation after optical axis adjustment due to vibration or external shock, the uniformity of reflection of the laser beam during resonance is ensured, and the output and mode of the output laser beam are stabilized. have an effect.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of the present invention, Fig. 2 is a front view of the mirror holder H, Fig. 3 is an explanatory diagram showing the attachment members of the mirror holder, and Fig. 4 A and B are A in Fig. 1.
It is an explanatory diagram of the operation of the clamper shown in a sectional view taken along the line -A. 2... Mounting ring, 11A, 11B... Support shaft, 13A, 13B... Compression spring, 18... Bracket, 21... Motor, 22... Adjusting screw, 2
4... Clamper (shape memory alloy), 25... Cylindrical heater, H... Mirror holder, M... Mirror.

Claims (1)

[Scope of utility model registration request] The mounting ring is fixed to the side surface of the cylindrical container of the laser oscillator, and the mounting ring is attached at both ends of the L-shape of the L-shaped mirror holder, which is equipped with a mirror whose central part is attached as a fulcrum and whose inclination angle can be adjusted. A motor is provided on the mirror holder to rotate the adjusting screws in order to change the distance between the end of the mirror holder and the mounting ring, and the end of the screw is attached to the mounting ring. A spindle that is pulled through a spring is embedded in the mounting ring, and the inner diameter is slightly smaller than the outer diameter of the spindle at normal temperature, with a tightening margin, and the inner diameter is increased at a predetermined temperature. A clamper made of a shape memory alloy that releases the grip is fixed on the side of the mirror holder, and a heater that maintains the temperature of the gripping part of the clamper made of the shape memory alloy at a predetermined temperature is attached concentrically to the spindle, and the light of the mirror is A clamping mechanism for an optical axis adjustment part of a laser oscillator, characterized in that during axis adjustment, the gripping part of the clamper is heated by a heater to unclamp and unclamp it, and after adjustment, it is brought into a clamped state by heat radiation cooling.