WO2017017952A1

WO2017017952A1 - Cooling device for laser shutter apparatus

Info

Publication number: WO2017017952A1
Application number: PCT/JP2016/003464
Authority: WO
Inventors: 皓平舩井; 西村　哲二
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2015-07-28
Filing date: 2016-07-27
Publication date: 2017-02-02

Abstract

A cooling device for a laser shutter apparatus according to the present disclosure includes a reflection mirror, a mirror block, a driving unit, and an absorber. The reflection mirror reflects laser light. The reflection mirror is provided on the mirror block and disposed so as to be rotatable. The driving unit rotationally drives the mirror block. The absorber receives laser light reflected by the reflection mirror and converts the laser light into heat. The absorber has an inner cylinder having a cone shape and an outer cylinder that fits on the cone shape of the inner cylinder. A spiral rib is provided on the outer side of the cone shape of the inner cylinder, and a predetermined space is provided between the leading end of the rib and a recessed section of the outer cylinder. Cooling water flows through the space.

Description

Cooling device for laser shutter device

The present disclosure relates to a laser shutter device of a laser oscillator of a kilowatt class, and particularly relates to a cooling device for the laser shutter device.

The laser shutter device is disposed inside or outside the laser oscillation device. The laser shutter device is a protection device that absorbs the laser light oscillated by the laser oscillation device without irradiating the laser beam to the outside except when a heat source such as laser processing or laser welding is necessary.

In recent years, there has been a demand for a laser processing machine capable of cutting a thick metal material, and the demand for a high-power laser oscillator is increasing. Accordingly, there is a need for a laser shutter device that can receive (absorb) more laser energy.

A schematic configuration of a conventional laser shutter device will be described with reference to FIGS. 6A and 6B. FIG. 6A is a component arrangement diagram showing the configuration of a conventional laser shutter device, and is a view seen from the side with respect to the optical axis of the laser beam. FIG. 6B is a component arrangement diagram showing a configuration of a conventional laser shutter device, and is a front view seen from the optical axis direction of laser light. The mirror block 42 is equipped with a reflecting mirror 41 that reflects laser light. The drive device 43 drives the mirror block 42 in the rotational direction to open and close the laser light passage hole. FIG. 6A shows a state in which the laser light passage hole is closed. FIG. 6B shows both the closed state and the opened state of the laser light passage hole. In FIG. 6B, when the mirror block 42 is located in the downward direction, the laser light passage hole is closed, and when the mirror block 42 is located in the lower right direction, the laser light passage hole is opened. . The laser light is incident from the right in FIG. 6A and is incident from the front of the paper in FIG. 6B.

6A and 6B, the laser light absorbing means 44 absorbs the laser light reflected by the reflecting mirror 41. As shown in FIG. 6A, the laser light absorbing means 44 is composed of an absorber inner cylinder 45 and an absorber outer cylinder 46. The cooling water passage 47 is piped so as to cool both the mirror block 42 and the laser light absorbing means 44.

As shown in FIG. 6B, the laser shutter device is provided with a limit switch 48 and a limit switch 49 for detecting opening / closing of the mirror block 42. The movement of the mirror block 42 is detected via the sensor dog 50. The sensor dog 50 rotates together with the mirror block 42 and shields the photoelectric part of the limit switch 49 to detect that the laser shutter is in the “open” position. The sensor dog 50 returns to the original position, and the photoelectric part of the limit switch 48 is shielded to detect that the laser shutter is in the “closed” position.

As shown in FIGS. 6A and 6B, the base 51 is provided with each component device, and a cover 52 covers them. The above is the configuration of the conventional laser shutter device (see, for example, FIG. 6 of Patent Document 1).

JP 2010-212563 A

However, in the cooling mechanism of the conventional laser shutter device, since the cooling water contact area of the absorber inner cylinder 45 is small, the water cooling effect is low and high power laser light cannot be absorbed. The conventional laser shutter device has a large thermal gradient between the reflecting mirror 41 that receives high-power laser light and the bottom surface of the reflecting mirror 41 that is water-cooled. Therefore, the reflecting mirror 41 is distorted by heat, the laser beam to the laser beam absorbing means 44 is shifted, and a sufficient cooling effect cannot be exhibited.

When the laser beam is misaligned, the position of the reflecting mirror 41 needs to be adjusted, or the laser beam is reflected in multiple stages without being absorbed in the absorber inner cylinder 45 to heat the case or the protective cover. is there. Further, although cooling water is constantly circulated through the laser light absorbing means 44 and the mirror block 42, there is no means for adjusting the amount of water, and the cooling efficiency is not improved.

Therefore, the present disclosure solves the above problems and provides a cooling device for a laser shutter device that can block high-power laser light and has high cooling efficiency.

In order to solve the above-described problem, a cooling device for a laser shutter device according to the present disclosure includes a reflecting mirror, a mirror block, a driving unit, and an absorber. The reflecting mirror reflects the laser light. The mirror block is provided with a reflecting mirror and is rotatably installed. The drive unit rotationally drives the mirror block. The absorber receives the laser beam reflected by the reflecting mirror and converts it into heat. Further, the absorber has a conical inner cylinder and an outer cylinder that fits into the conical shape of the inner cylinder. Furthermore, a spiral rib is formed outside the conical shape of the inner cylinder, and a predetermined space is provided between the tip of the rib and the recess of the outer cylinder. And cooling water flows through the space.

Further, another cooling device for a laser shutter device according to the present disclosure includes a reflecting mirror, a driving unit, and an absorber. The reflecting mirror reflects the laser light. The drive unit is provided with a reflecting mirror and rotationally drives the mirror block. The absorber receives the laser beam reflected by the reflecting mirror and converts it into heat. Further, the mirror block has a reflecting mirror holding portion and an arm portion for fixing the driving portion at a predetermined position from the reflecting mirror, and the arm portion is provided with a flow path through which cooling water passes.

Furthermore, the cooling device for the laser shutter device according to the present disclosure includes a reflecting mirror, a mirror block, a drive unit, and an absorber. The reflecting mirror reflects the laser light. The mirror block is provided with a reflecting mirror, has a cooling water channel in an arm portion, and is rotatably installed. The drive unit rotationally drives the mirror block. The absorber has a space constituted by the inside of the inner cylinder and the inside of the outer cylinder, receives the laser beam reflected by the reflecting mirror, and converts it into heat. Further, the laser shutter device has a first flow path through which cooling water is discharged from the supply port of the absorber through the space to the outside. Further, the laser shutter device has a second flow path in which cooling water branches from between the flow paths connecting the supply port of the absorber and the supply port of the space, passes through the arm portion of the mirror block, and is discharged to the outside. .

With the above configuration, in the cooling device for the laser shutter device according to the present disclosure, the cooling water is spirally flowed by the conical helical rib outside the absorber inner cylinder. In addition, cooling water flows through the gap between the tip of the helical rib outside the conical shape of the inner cylinder of the absorber and the recess of the outer cylinder of the absorber. Can be made.

Also, with the above-described configuration, in the cooling device for the laser shutter device according to the present disclosure, the reflecting mirror that receives the laser light is water-cooled by the cooling water flowing in the mirror block arm portion that is spaced from the reflecting mirror. Therefore, the temperature gradient from the reflecting mirror surface to the mirror block arm portion becomes smooth, and the distortion of the reflecting mirror due to a rapid temperature change can be suppressed to prevent the laser irradiation position shift to the absorber.

Further, with the above-described configuration, the cooling device for the laser shutter device according to the present disclosure is configured to branch the cooling water to the absorber inside the absorber and to send the cooling water to the arm portion of the mirror block. Therefore, only by adjusting the amount of cooling water to the absorber supply port, the amount of cooling water inside both the absorber and the mirror block arm can be adjusted, and the cooling efficiency can be improved.

As described above, thermal problems can be prevented with high cooling efficiency even if high-power laser light is cut off.

FIG. 1A is a diagram illustrating a schematic configuration of a cooling device of a laser shutter device according to an embodiment, and is a diagram viewed from a side with respect to an optical axis of laser light. FIG. 1B is a diagram illustrating a schematic configuration of the cooling device of the laser shutter device according to the embodiment, and is a front view seen from the optical axis direction of the laser light. FIG. 2 is a diagram illustrating a schematic configuration of a cooling water flow path of the cooling device of the laser shutter device according to the embodiment. FIG. 3 is an exploded perspective view showing an outline of the absorber inner cylinder and the absorber outer cylinder according to the embodiment. FIG. 4A is a cross-sectional view showing the space in the absorber according to the embodiment. FIG. 4B is a partially enlarged view of a cross-sectional view showing the absorber inner space of FIG. 4A. FIG. 5A is a partial cross-sectional view showing a cooling water flow path in the mirror block arm portion according to the embodiment, and is a view seen from the side with respect to the rotation axis. FIG. 5B is a partial cross-sectional view showing the cooling water flow path in the mirror block arm portion according to the embodiment, and is a front view seen from the direction of the rotation axis. FIG. 6A is a component arrangement diagram showing the configuration of a conventional laser shutter device, and is a view seen from the side with respect to the optical axis of the laser beam. FIG. 6B is a component arrangement diagram showing a configuration of a conventional laser shutter device, and is a front view seen from the optical axis direction of laser light.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the following drawings, the same components are denoted by the same reference numerals, and the description thereof may be omitted.

(Embodiment 1)
<Main configuration of cooling device for laser shutter device>
1A and 1B are diagrams illustrating a schematic configuration of a cooling device for a laser shutter device according to an embodiment of the present disclosure. FIG. 1A is a side view of the optical axis of laser light. FIG. 1B is a front view seen from the optical axis direction of the laser light.

As shown in FIGS. 1A and 1B, a reflecting mirror 102 that reflects the laser beam 101 is attached to a mirror block 103. The reflecting mirror 102 is made of copper with good heat transfer, and the surface is gold-plated so that the surface is almost totally reflected. Since the mirror block 103 is also heated by the laser beam 101 via the reflecting mirror 102, a copper material having good heat transfer is used in order to increase the cooling efficiency.

The drive unit 104 attached to the mirror block 103 receives a command from the control unit 105 and rotates the mirror block 103. The drive unit 104 uses a rotary solenoid, a motor, or the like. The mirror block 103 functions as a shutter for the laser beam 101. When the mirror block 103 is at the position depicted by the broken line in FIG. 1B, the laser light 101 is emitted to the outside of the shutter device without being blocked by the mirror block 103. When the mirror block 103 is at the position depicted by the solid line in FIG. 1B, this corresponds to a state where the shutter is closed, and the laser light 101 is reflected by the reflecting mirror 102 attached to the mirror block 103. Thereby, the laser beam 101 is not output to the outside but is blocked.

The laser beam 101 reflected by the reflecting mirror 102 is guided into the conical shape of the absorber inner cylinder 106. The surface of the reflecting mirror 102 is processed into a spherical surface, and the received laser light 101 is appropriately diffused to reduce the energy density of the reflected light.

This prevents a serious accident such as burnout without locally concentrating the laser beam inside the conical shape of the absorber inner cylinder 106. A superabsorbent such as dotite is applied to the inside of the conical shape of the absorber inner cylinder 106, and heat generated by the irradiation of the laser beam 101 is efficiently transmitted to the absorber inner cylinder 106.

The absorber outer cylinder 107 is fitted and fixed to the absorber inner cylinder 106 with a certain gap. The cooling water is supplied to the absorber outer cylinder 107 via the cooling water tube 111a and the joint 110a. As one flow, the cooling water passes through a gap between the fitting portions of the absorber inner cylinder 106 and the absorber outer cylinder 107, and is discharged through the cooling water tube 111b connected to the joint 110b.

The cooling water supplied to the absorber outer cylinder 46 is branched inside as the other flow, passes through the cooling water tube 111c from the joint 110c, passes through the inside of the mirror block 103 to which the joint 110d is fixed, and is connected to the joint 110e. The discharged cooling water tube 111d is discharged.

The cooling water tube 111 c and the cooling water tube 111 d are fixed with a margin so as to draw a circle in front of the absorber outer cylinder 107 so as not to hinder the rotation of the mirror block 103. The center of the circle drawn by the cooling water tube 111c and the cooling water tube 111d is set away from the rotation center of the drive unit 104 in the direction in which the cooling water tube 111c and the cooling water tube 111d become longer. Thereby, rotational load can be reduced.

In order to further reduce the rotational load, the cooling water tube is made of highly flexible polyurethane. The cooling water tube should have a diameter as small as possible, and is preferably about φ6 mm.

Next, the operation of the cooling device of the laser shutter device of the present disclosure will be described.

The laser beam 101 oscillated from the laser oscillation device is reflected by the reflecting mirror 102 attached to the mirror block 103 and reaches the conical portion inside the absorber inner cylinder 106. The laser beam 101 that has reached the conical portion inside the absorber inner cylinder 106 is absorbed by repeating multi-stage reflection.

From this state, when irradiating laser light outside the laser shutter for laser processing or laser welding, power is supplied to the drive unit 104 and the mirror block 103 rotates. On the other hand, when the external laser beam is stopped and returned to its original state, the power supply to the drive unit 104 is stopped. As a result, the mirror block 103 causes the reflecting mirror 102 to spontaneously fall under its own weight and return to its original state. Return. By supplying power to the drive unit 104 when the laser oscillation is stopped, the laser beam 101 is prevented from being irradiated to the outside while the mirror block 103 is being driven.

Further, cooling water constantly circulates in the gap formed by the absorber inner cylinder 106 and the absorber outer cylinder 107 and the mirror block 103 to prevent parts from being burned out.

Next, the flow of cooling water will be schematically described with reference to FIG. FIG. 2 is a diagram illustrating a schematic configuration of a cooling water flow path of the cooling device of the laser shutter device according to the embodiment of the present disclosure.

As shown in FIG. 2, the cooling water 108 a passes from the cooling water supply unit 109 through the water amount adjustment unit 112 toward the supply port 113 of the absorber outer cylinder 107. The cooling water 108 a that has entered the absorber outer cylinder 107 is divided into a cooling water 108 b that is directed toward the tip of the absorber inner cylinder 106 and a cooling water 108 c that is directed toward the mirror block 103 at the internal branching portion 114.

The cooling water 108b toward the tip of the absorber inner cylinder 106 returns to the cooling water supply unit 109 after passing through a gap formed by the absorber inner cylinder 106 and the absorber outer cylinder 107. Further, the cooling water 108 c to the mirror block 103 side returns to the cooling water supply unit 109 after passing through the inside of the mirror block 103. The water amount adjustment unit 112 may be configured using a valve, an orifice, or the like.

When the flow path passing through the gap formed by the absorber inner cylinder 106 and the absorber outer cylinder 107 and the flow path passing through the mirror block 103 are determined, the water flow rate adjustment unit 112 at one location controls the cooling water flow rates of the two flow paths. be able to. Thereby, installation space and member cost can be reduced compared with the case where the flow path passing through the absorber inner cylinder 106 and the absorber outer cylinder 107 and the flow path passing through the mirror block 103 are two independent flow paths.

Further, the amount of heat generated in the absorber inner cylinder 106 is larger than the amount of heat of the mirror block 103. Therefore, in order to make the pressure loss of the flow path appropriate, the inner diameter of the cooling water tube 111b through which the cooling water 108b flows is set to about 2 to 4 times the inner diameter of the cooling water tube 111c through which the cooling water 108c flows and the cooling water tube 111d. It is desirable. In the embodiment of the present disclosure, as an example, when the inner diameters of the cooling water tube 111c and the cooling water tube 111d are “1”, the inner diameter of the cooling water tube 111b is “2.25”, and the inner diameter of the cooling water tube 111a is Is set to “3.2”.

Further, when the cooling water 108b that has passed through the absorber inner cylinder 106 and the absorber outer cylinder 107 and the cooling water 108c that has passed through the mirror block 103 are merged, the pressure loss of the entire cooling device 100 of the laser shutter device increases. If it does in this way, since the cooling efficiency of the cooling device 100 of a laser shutter apparatus will fall, it is returned to the cooling water supply part 109, with the cooling water 108b and the cooling water 108c separated.

<Detailed configuration of the absorber>
FIG. 3 is an exploded perspective view showing the general shape of the absorber inner cylinder 106 and the absorber outer cylinder 107 according to the embodiment of the present disclosure. FIG. 4A is a cross-sectional view showing the space in the absorber according to the embodiment of the present disclosure. 4B is a partial enlarged view of a cross-sectional view showing the absorber inner space of FIG. 4A (enlarged view of a portion surrounded by A in FIG. 4A). The detailed configuration and efficient cooling action of the absorber will be described with reference to these drawings.

In FIG. 3, the absorber outer cylinder 107 is a cast of bronze or stainless steel, has a conical recess for fitting the absorber inner cylinder 106, and has a supply port 113 for cooling water 108a at the bottom. Further, a branch portion 114 of the cooling water 108 a is provided inside the absorber outer cylinder 107, and a discharge port 115 a for the cooling water 108 b is provided above the absorber outer cylinder 107.

The cooling water 108c is supplied from the branch part 114 to the mirror block 103 through the discharge port 115b. The branch portion 114 is disposed in front of the absorber inner cylinder 106 as viewed from the supply port 113. This is because the flow passage cross-sectional area of the cooling water 108b is reduced due to the fitting of the absorber inner cylinder 106 and the absorber outer cylinder 107, and the cooling water 108c is maintained by holding a sufficient water pressure on the mirror block 103 before the pressure loss increases. This is to supply.

◎ Appropriate meat stealing (meat removal) is given to the outside of the absorber outer cylinder 107 in order to increase the surface area. The portion that fits into the absorber inner cylinder 106 is thinned by stealing meat from the outside of the absorber outer cylinder 107, and not only water cooling by the cooling water 108b but also air cooling by the atmosphere is performed to improve the cooling efficiency. .

The material of the absorber inner cylinder 106 is a cast of bronze material with good heat transfer, and has a helical rib 116 outside the conical shape. Thereby, the cooling water becomes a spiral flow, the cooling water contact area of the absorber inner cylinder 106 is increased, and the cooling efficiency is improved.

The rib height is set so that when the absorber inner cylinder 106 is fitted with the absorber outer cylinder 107, a predetermined gap 117 is formed between the outside of the absorber inner cylinder 106 and the recess of the absorber outer cylinder 107. Therefore, the tip of the spiral rib 116 is processed into a flat surface. This is because a gap having a width y shown in FIG. 4A is formed between the tip of the spiral rib 116 and the absorber outer cylinder 107. Thereby, the flow 122 passing through the gap of the width y is generated, the amount of cooling water inside the absorber is increased, and the cooling capacity is further enhanced.

Further, when the absorber inner cylinder 106 is fitted to the absorber outer cylinder 107, the O-ring 120 is attached to prevent the water leakage when the cooling water 108b is flowed inside after fitting.

Further, doughite, which is a high absorption material, is applied to the inside of the conical shape of the absorber inner cylinder 106 to suppress the reflection of the irradiated laser beam 101 and absorb it.

4A and 4B indicate the flow of cooling water inside the absorber. The supplied cooling water 108 b is guided to the tip of the absorber inner cylinder 106. Thereby, cooling efficiency can be improved compared with the case where cooling water is supplied to the absorber inner cylinder 106 from the side surface.

As shown in FIG. 4B, the cooling water 108b is divided into a flow 121 along the spiral rib and a flow 122 passing through the gap of the width y, and as shown in FIG. , Carried outside the absorber.

By doing in this way, the cooling water flowing through the gap of width y generates a spiral flow, so that the flow rate per unit time flowing while contacting the surface that requires heat dissipation can be increased. In addition, since the load of the cooling water flowing through the gap with the width y is smaller than simply providing the spiral water channel, the amount of water itself is also increased. As a result, cooling can be performed more efficiently by setting a predetermined space between the tip of the rib and the recess of the outer cylinder and flowing cooling water.

The ratio of the space y in the gap inside the absorber outer cylinder 107 to the rib height x of the spiral rib 116 is as follows:
y / x = 0.15 to 0.3
The cooling water flows with the least load while maintaining the spiral flow.

<Configuration inside mirror block>
5A and 5B are partial cross-sectional views showing cooling water flow paths in the mirror block arm portion according to the embodiment of the present invention. 5A is a view seen from the side with respect to the rotation axis, and FIG. 5B is a front view seen from the direction of the rotation axis. The configuration and operation of the cooling water channel inside the mirror block will be described with reference to FIGS. 5A and 5B.

The mirror block 103 is divided into an arm portion 118 through which the cooling water 108c passes and a holding portion 119 to which the reflecting mirror 102 is attached. The arm portion 118 is provided with a first cooling water passage 123 and a second cooling water passage 124 in the longitudinal direction, and a third cooling water passage 125 that connects the first cooling water passage 123 and the second cooling water passage 124 is provided. It has been.

A one-way flow path is formed in the arm portion 118 by closing the opening of the third cooling water passage 125 with the plug 126. The mirror block 103 whose temperature rises is cooled by the cooling water 108c through the reflecting mirror 102 that receives the laser beam 101 and generates heat.

By cooling only the arm portion 118, the temperature gradient from the surface to the bottom of the reflecting mirror 102, which is an accurate component attached to the holding portion 119, becomes gentle. The time difference of the deformation amount of the part 119 is suppressed, and the trajectory of the laser light 101 to the absorber inner cylinder 106 is stabilized.

This eliminates the need for position adjustment such as centering due to laser beam misalignment. Further, the laser beam is reflected in a multistage manner in the absorber inner cylinder 106 without being absorbed, and the problem of heating the laser shutter device does not occur.

As described above, according to the cooling device 100 of the laser shutter device of the present embodiment, the cooling water 108 b is spirally flowed by the spiral rib 116 outside the conical shape of the absorber inner cylinder 106, and further the spiral rib 116. The cooling water also flows from the gap between the tip of the absorber and the concave portion of the absorber outer cylinder 107. Thereby, a sufficient amount of cooling water flows evenly outside the absorber inner cylinder 106, and the cooling efficiency can be improved.

Further, the reflecting mirror 102 that receives the laser beam 101 is water-cooled by the cooling water 108c flowing in the arm portion 118 of the mirror block at a distance. Therefore, the temperature gradient in the reflecting mirror 102 becomes gentle, the thermal distortion of the reflecting mirror 102 is suppressed, and the laser irradiation position shift to the absorber inner cylinder 106 can be prevented.

Further, the cooling water 108a is branched inside the absorber outer cylinder 107, and the cooling water 108c is also sent to the arm portion 118 of the mirror block. Therefore, the amount of cooling water inside both the absorber and the arm portion 118 of the mirror block can be appropriately adjusted by one water amount adjusting unit 112, and the cooling efficiency of the entire cooling device 100 of the laser shutter device can be increased.

As described above, according to the cooling device of the laser shutter device of the present embodiment, it is possible to prevent thermal problems with high cooling efficiency even if high-power laser light is cut off.

A cooling device for a laser shutter device according to the present disclosure can prevent a thermal problem with high cooling efficiency even when high-power laser light is cut off. Useful in.

DESCRIPTION OF SYMBOLS 100 Cooling apparatus of laser shutter apparatus 101 Laser beam 102 Reflecting mirror 103 Mirror block 104 Drive part 105 Control part 106 Absorber inner cylinder 107 Absorber

outer cylinder

108a, 108b, 108c Cooling water 109 Cooling

water supply part

110a, 110b, 110c, 110d,

110e Joint

111a, 111b, 111c, 111d Cooling water tube 112 Water quantity adjustment part 113 Supply port 114

Branch part

115a, 115b Discharge port 116 Spiral rib 117 Gap 118 Arm part 119 Holding part 120 O-ring 121 Along the spiral rib Flow 122 Flow through gap 123 First cooling water channel 124 Second cooling water channel 125 Third cooling water channel 126 Plug 41 Reflecting mirror 42 Mirror block 43 Drive device 44 Laser light absorption means 45 In the absorber Cylinder 46 Absorber outer cylinder 47 Cooling water flow path 48 Limit switch 49 Limit switch 50 Sensor dog 51 Base 52 Cover

Claims

A reflecting mirror that reflects the laser light;
A mirror block provided with the reflecting mirror and rotatably installed;
A drive unit for rotationally driving the mirror block;
An absorber that receives the laser light reflected by the reflecting mirror and converts it into heat;
The absorber includes a conical inner cylinder and an outer cylinder that fits into the conical shape of the inner cylinder,
A spiral rib is formed outside the conical shape of the inner cylinder,
A predetermined space is set at the tip of the rib and the recess of the outer cylinder;
A cooling device of a laser shutter device for flowing cooling water into the space.
The cooling device for a laser shutter device according to claim 1, wherein the cooling water is supplied from the tip of the conical shape.
The laser shutter device cooling device according to claim 1 or 2, wherein a ratio of a distance of a space from a tip of the rib to the outer cylinder with respect to a height of the rib is 0.15 or more and 0.3 or less.
4. The cooling device for a laser shutter device according to claim 1, wherein the outer cylinder is formed by casting, is provided with a predetermined thickness from a conical inner surface, and is provided with a meat steal so as to be in contact with the outside air.
A reflecting mirror that reflects the laser light;
A driving unit provided with the reflecting mirror and rotating the mirror block;
An absorber that receives the laser beam reflected by the reflecting mirror and converts it into heat,
The mirror block includes the reflector holding unit,
An arm for fixing the drive unit at a predetermined position from the reflecting mirror;
A cooling device for a laser shutter device, wherein the arm portion is provided with a flow path through which cooling water passes.
The flow path includes a first cooling water channel and a second cooling water channel in the longitudinal direction of the arm portion,
6. The cooling device for a laser shutter device according to claim 5, further comprising a third cooling water channel that passes through the first and second cooling water channels.
A reflecting mirror that reflects the laser light;
A mirror block provided with the reflecting mirror, having a cooling water channel in an arm portion, and rotatably installed;
A drive unit for rotationally driving the mirror block;
It has a space constituted by an inner cylinder exterior and an outer cylinder interior, and comprises an absorber that receives the laser beam reflected by the reflecting mirror and converts it into heat,
A first flow path through which cooling water is discharged from the supply port of the absorber through the space and to the outside;
A laser shutter device comprising a second flow path in which cooling water branches from between the flow path connecting the supply port of the absorber and the supply port of the space, passes through the arm portion of the mirror block, and is discharged to the outside Cooling system.
A cooling water supply unit that supplies cooling water to the first channel and the second channel is provided, and a cooling water amount adjusting unit is provided between the cooling water supply unit and the channel to the absorber supply port. The cooling device of the laser shutter apparatus according to claim 7 provided.