JPH06296050A - Cooling device for laser oscillator - Google Patents

Abstract

PURPOSE:To obtain a cooling device having excellent cooling efficiently without lowering laser output due to the mixed foam in the device. CONSTITUTION:The foam in this cooling device is removed and the cubical expansion of cooling water is prevented by providing a bellows cap 19, having cooling water injection hole 12, on the upper part of a cooling water tank 8. Besides, the heat of the cooling water can be conveyed efficiently by attaching a heat pipe on the cooling water tank 8. As a result, a cooling device, having excellent cooling power, can be obtained without lowering the laser output by the mixture of foam.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device for a laser oscillator provided with a cooling liquid circulator for transporting heat from a heat generating portion and a radiator for discharging the heat to the outside.

[0002]

2. Description of the Related Art FIGS. 8 and 9 are views showing a conventional cooling device for a laser oscillator, FIG. 8 is an overall configuration diagram of the conventional device, and FIG. 9A is a cooling diagram when the posture of the conventional device is changed by 90.degree. FIG. 9 (b) is a diagram showing the state of cooling water in the water tank, and FIG. 9 (b) is a diagram showing the state of cooling water in the cooling water tank when the posture of the conventional apparatus changes by 45 °. 2 is a flash lamp connected through 2, 3 is a YAG rod arranged in parallel with the flash lamp 1 in close proximity, 4 is a cavity for assembling the flash lamp 1, the YAG rod 3, and the reflection tube 4 therein. Yes, laser oscillator 6
Is composed of the above. 7 is the laser oscillator 6
A pump 8 for feeding cooling water to the above is connected to the laser oscillator 6 and the pump 7 by a cooling pipe 9, and a tank cooling water outlet 10 is provided at a lower portion thereof and a tank cooling water inlet 11 is provided at an upper portion thereof.
Is a cylindrical cooling water tank, 12 is a cooling water inlet arranged in the upper surface cover 13 of the cooling water tank 8, and 14 is a radiation fin attached around the cylindrical surface of the cooling water tank 8. In order to increase the surface area, for example, corrugated fins are stacked in two or three layers.
15 is a cooling fan disposed on the bottom surface of the cooling water tank 8 for sending cooling air to the radiation fins 14, 16 is an air duct surrounding the cooling fan 15 and the radiation fins, and 17 is a tank filled in the entire cooling system. Cooling water having a water level in the middle of the cooling water inlet 11 and the top cover 13, and 18 is an air layer in the cooling water tank 8.

The conventional cooling device for a laser oscillator is constructed as described above. First, the flash lamp 1 connected to a high voltage circuit emits light and is focused on the YAG rod 3 via the reflecting cylinder 4. It When the energy collected by the YAG rod 3 reaches a certain state,
Laser light is oscillated in a pulse form from the end surface of the YAG rod. The above is the basic operation of laser oscillation, and when laser oscillation is repeated, a large amount of heat is intensively generated inside the cavity 5, and it is necessary to form a heat dissipation system by direct liquid cooling from the heat generation density. In this structure, heat from the flash lamp 1, the YAG rod 3, and the reflector is carried out from the laser oscillator 6 by the cooling water 17 circulated by the pump 7, and passes through the pump 7 and the tank cooling water inlet 11. And reaches the inside of the cooling water tank 8. The arrow in the figure indicates the flow direction of the cooling water. Radiating fins 14 having a large radiating area are arranged around the cylindrical surface of the cooling water tank 8, and the heat from the cooling water 17 passes through the wall surface of the cooling water tank 8 and the radiating fins 1
4 is radiated to the outside by the cooling air from the cooling fan 15. The arrow in the figure indicates the direction of the cooling air. The cooling water 17 whose temperature has been lowered due to heat dissipation is sent from the tank cooling water outlet 10 through the cooling pipe 9 into the cavity 5 to form a cooling system. Further, it is necessary to absorb the liquid expansion of the cooling water 17 in the present apparatus, and for this reason, the cooling water tank 8 has a structure in which a certain amount of air layer 18 is secured. By the way, as one of the causes of the decrease in the laser output efficiency of the laser oscillator, bubbles remain in the cavity 5. This is especially the flash lamp 1, YA
When bubbles adhere to the periphery of the G rod 3 and the reflecting cylinder 4, the transmittance of the laser light decreases, the light energy collected in the YAG rod 3 decreases, and the bubbles adhere to the YAG rod 3 itself. The cooling efficiency is lowered and the temperature rises, and the laser output is lowered from the above two points. For this reason, it is important that the cooling system of the laser oscillator has a structure that prevents bubbles from entering the cavity and that the heat exchange efficiency is good.
As shown in (a) and (b), even when the entire posture of the laser distance measuring device changes and the angle of the cooling water tank changes, the air layer 18 is formed in the tank cooling water inlet 11 and the tank cooling water outlet 10. It is located above the tip portion, and has a structure in which bubbles do not return to the inside of the cavity 5 even if the posture is changed. An upper cover 13 is provided above the cooling water tank 8 and has a structure for injecting cooling water 17 from a cooling water inlet 12 provided therein.

[0004]

Since the conventional cooling device for the laser oscillator is constructed as described above, it is possible to prevent air bubbles from being mixed into the laser distance measuring device even if the posture of the entire laser distance measuring device is gradually changed, but it is possible to prevent sudden changes. When the posture is changed or the vehicle is mounted on a vehicle and an external vibration force is applied, a state in which the air layer is mixed in the cooling water occurs. Therefore, the cooling water containing the bubbles is sent into the cavity, and the bubbles adhere to the YAG rod or the like, resulting in a problem that the laser output is reduced. Further, the heat radiation fins mounted around the cooling water tank are, for example, two stages of corrugated fins,
Since it has a structure in which it is stacked in three stages, it has extremely high ventilation resistance. Furthermore, as the outer corrugated fins are provided, the heat transfer resistance increases and the fin efficiency decreases. Therefore, there is a problem that the cooling capacity of the cooling water tank is low as a whole.

The present invention has been made to solve the above problems, and proposes a cooling device for a laser oscillator, which does not cause a reduction in laser output due to inclusion of bubbles and has an excellent cooling capacity.

[0006]

In a first embodiment of a cooling device for a laser oscillator according to the present invention, a bellows cap having a cooling water inlet at an upper portion of a cooling water tank, and a bellows for extending the bellows cap. A holder and a bellows stopper are attached, and a heat pipe is attached around the cooling water tank.

In the second embodiment of the laser oscillator cooling apparatus according to the present invention, a pressure abnormality detection switch is attached to a position on the lower surface of the upper portion of the bellows holder which is in contact with the bellows holder.

In the third embodiment of the laser oscillator cooling device according to the present invention, a conical bellows cap is attached to the upper portion of the cooling water tank.

Further, in the fourth embodiment of the cooling device for the laser oscillator according to the present invention, the cooling water tank is opened at the upper part and the lower part respectively, and the cooling water inlet is provided at the upper part, and the cooling water tank has a conical shape. A bellows cap having the same is attached, and a bellows cap having a conical shape and having a cooling water discharge port at its lower part is attached.

In the fifth embodiment of the cooling device for the laser oscillator according to the present invention, the cooling water tank is provided with the liquid expansion and absorption tank.

[0011]

The first aspect of the laser oscillator cooling device according to the present invention
In the embodiment of, when injecting cooling water into the cooling device,
After the bubbles remaining in the cooling system are sequentially collected in the bellows, the expansion and contraction of the bellows are used to remove the bubbles from the cooling water inlet. Further, the volume expansion of the cooling water is absorbed by the bellows. Further, a heat pipe attached to the cooling water tank efficiently transfers heat from the cooling water to the outside of the cooling water tank.

Further, in the second embodiment of the laser oscillator cooling device according to the present invention, when the pressure in the cooling system becomes abnormally high, the bellows cap extends and the pressure abnormality detection attached to the lower surface of the bellows holder is detected. By contacting the switch, the abnormal pressure in the cooling system is notified.

Further, in the third embodiment of the cooling device for the laser oscillator according to the present invention, the bellows cap having a conical shape attached to the cooling water tank has a large amount of cooling water on the side where the cooling water is fixed. Since the cooling water amount is small as the tip end side of the bellows is approached, the lateral wobbling amount of the bellows part when a vibration external force or the like is applied in the horizontal direction is small.

Further, in the fourth and fifth embodiments of the cooling device for the laser oscillator according to the present invention, the bellows caps are attached to the upper and lower parts of the cooling water tank, and the liquid in the cooling water tank. Since the expansion absorption tank is provided, the volume expansion absorption amount of the liquid is increased.

[0015]

【Example】

Example 1. 1, 2, and 3 show a first embodiment of a cooling device for a laser oscillator according to the present invention.
1 is an overall configuration diagram of the device, FIG. 2 is a diagram showing when the bellows cap is extended, and FIG. 3 is a top view of the bellows holder.
Reference numerals 14 to 18 are exactly the same as those of the conventional device. 1
Reference numeral 9 is a bellows cap attached to the upper portion of the cooling water tank 8, and 20 is a bellows having a shaft hole 22 that engages with the central shaft 21 of the bellows cap 19 and a height dimension that limits the amount of expansion and contraction of the bellows cap 19. A holder, 24 is a heat pipe attached to the cylindrical surface of the cooling water tank so as to have an evaporation portion inside the cooling water tank 8 and a condensation portion outside, and 25 is the bellows cap 1
9 is a bellows stopper inserted between the bellows holder 20 and the bellows holder 20, and is fixed on the bellows holder 20. The cooling water inlet 12 provided in the upper cover in the conventional device is provided in the central shaft 21 at the upper end of the bellows cap 19. In addition, the radiation fins 14 attached to the periphery of the cooling water tank 8 in the conventional device are attached to the periphery of the condensing portion of the heat pipe 24.

In the cooling device for the laser oscillator configured as described above, first, as shown in FIGS. 2 and 3, the bellows holder 20 is pulled in a state where the tip of the central shaft 21 of the bellows cap 19 is pulled up. The bellows stopper 25 is inserted between and. At this time, the internal volume is increased by the extension of the bellows of the bellows cap 19. Then, the cooling water inlet 12
After injecting the cooling water 17 into the apparatus from above, the pump 7 is operated with the cap of the cooling water inlet 12 closed. Then, inside the cavity 5 and the pump 7
Bubbles remaining in the cooling pipe 9 and the like enter the cooling water tank 8 through the tank cooling water inlet 11 and gradually fill the cooling water in the upper portion of the bellows cap 19 as shown in FIG. An air layer is collected near the entrance 12. At the time when air bubbles have been removed from various places in the device and have finished gathering in the upper part of the bellows cap 19, the pump 7
To stop. When the inserted state of the bellows stopper 25 is released after removing the cap of the cooling water inlet 12, the bellows cap 19 returns to the free height dimension. As a result, the internal volume of the device is reduced by the amount of contraction of the bellows, and the air layer gathered near the cooling water inlet 12 is discharged to the outside from the cooling water inlet 12 and the air inside the device is discharged. The layer will be completely removed. Further, the liquid volume expansion of the cooling water in the device is absorbed by the expansion of the bellows cap 22. The evaporating portion of the heat pipe 24 attached to the cooling water tank 8 receives heat from the cooling water 17, efficiently transports the heat to the condensing portion on the outer periphery of the cooling water tank 8, and finally radiates heat. The cooling air is discharged from the fins 14 to the external space.

Example 2. FIG. 4 shows a second embodiment which is a further improvement of the first embodiment, and a pressure abnormality detection switch 26 is attached to a position on the lower surface of the upper portion of the bellows holder 20 which is in contact with the upper surface of the bellows cap. According to such an embodiment, when the pressure inside the device becomes abnormally high, the bellows cap 19 expands,
The pressure abnormality detection switch 26 is contacted. This makes it possible to know the pressure abnormality in the device.

Example 3. FIG. 5 shows a third embodiment which is a further improvement of the first embodiment, in which a bellows cap 19 having a conical shape is attached to the upper part of the cooling water tank 8 having a cooling water inlet 12. There is. According to such an embodiment, since the bellows has a conical shape, the amount of cooling water is large on the side where the cooling water tank 8 is fixed, and the amount of cooling water is smaller toward the tip of the bellows. The lateral wobbling amount of the bellows cap 19 when a vibration external force or the like is applied is small. Therefore, the vibration resistance of the bellows cap 19 containing the cooling water in the horizontal direction is improved.

Example 4. FIG. 6 shows a fourth embodiment which is a further improvement of the first embodiment, and has the cooling water inlet 12 or the cooling water outlet 27 at both ends of the opening of the cooling water tank 8, and A bellows cap 19 having a conical shape is attached. According to such an embodiment, a large volume expansion absorption amount of the liquid can be secured.

Example 5. FIG. 7 shows a fifth embodiment which is a further improvement of the first embodiment, and a liquid expansion / absorption tank 28 is provided inside the cooling water tank 8. The liquid expansion / absorption tank 28 is, for example, one in which a gas such as air is sealed inside a thin film skin, and according to such an embodiment, a large volume expansion absorption amount of the liquid can be secured as in the case of the fourth embodiment. You can

[0021]

Since the present invention is constructed as described above, it has the following effects.

In the first embodiment, the bellows cap having the cooling water inlet is attached to the upper part of the cooling water tank, whereby the expansion and contraction of the bellows can be used to remove air bubbles inside the cooling system and the bellows can be cooled. By absorbing the liquid volume expansion of water, a device without an air layer can be obtained. Therefore, it is possible to obtain a cooling device that does not cause a reduction in laser output due to inclusion of bubbles. Further, since the heat pipe attached to the cooling water tank efficiently transfers heat from the cooling water, it is possible to obtain a cooling device having an excellent cooling capacity.

Further, in the second embodiment, since the pressure abnormality detection switch attached to the lower surface of the bellows holder informs the pressure abnormality inside the apparatus, the pressure inside the apparatus becomes too high due to dust clogging, for example. It is possible to prevent problems such as leakage of cooling water.

In addition, in the third embodiment, by mounting a bellows cap having a conical shape, it is possible to obtain a device with improved horizontal vibration resistance of the bellows cap.

Further, in the fourth embodiment, a conical bellows cap having a cooling water inlet is attached to the upper portion of the cooling water tank, while a cone having a cooling water outlet is attached to the lower portion of the cooling water tank. By attaching the bellows cap having a shape, it is possible to easily exchange the cooling water and to secure a large volume expansion absorption amount of the liquid.

Further, in the fifth embodiment, by providing the liquid expansion / absorption tank in the cooling water tank, it is possible to secure a device having a large volume expansion / absorption amount of liquid, as in the above case.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a laser oscillator cooling device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing the bellows cap extension of the cooling device for the laser oscillator according to the first embodiment of the present invention.

FIG. 3 is a top view of the bellows holder of the cooling device for the laser oscillator according to the first embodiment of the present invention.

FIG. 4 is a diagram showing a cooling device for a laser oscillator according to a second embodiment of the present invention.

FIG. 5 is a diagram showing a cooling device for a laser oscillator according to a third embodiment of the present invention.

FIG. 6 is a diagram showing a cooling device for a laser oscillator according to a fourth embodiment of the present invention.

FIG. 7 is a diagram showing a cooling device for a laser oscillator according to a fifth embodiment of the present invention.

FIG. 8 is an overall configuration diagram of a conventional laser oscillator cooling device.

FIG. 9 is a diagram showing a state of cooling water when a posture of a cooling device in a conventional laser oscillator is changed.

[Explanation of symbols]

 1 Flash Lamp 2 Electrode 3 YAG Rod 4 Reflector 5 Cavity 6 Laser Oscillator 7 Pump 8 Cooling Water Tank 9 Cooling Piping 10 Tank Cooling Water Outlet 11 Tank Cooling Water Inlet 12 Cooling Water Inlet 13 Top Cover 14 Radiating Fin 15 Cooling Fan 16 Air duct 17 Cooling water 18 Air layer 19 Bellows cap 20 Bellows holder 21 Central shaft 22 Shaft hole 24 Heat pipe 25 Bellows stopper 26 Pressure abnormality detection switch 27 Cooling water discharge port 28 Liquid expansion absorption tank

Claims (5)

[Claims] 1. A flash lamp connected to a high voltage circuit through an electrode, a YAG rod arranged in parallel with and in proximity to the flash lamp, and arranged so as to wrap around the flash lamp and the YAG rod. A reflecting tube, a cavity in which the flash lamp, the YAG rod, and the reflecting tube are incorporated, a laser oscillator including the flash lamp, the YAG rod, a reflecting tube, and a cavity, and the laser oscillator and cooling pipe. A connected cooling water tank, a heat pipe attached to the cooling water tank, a radiation fin attached to the heat pipe, a bellows cap attached to the upper portion of the cooling water tank, and a top end of the bellows cap. Cooling water inlet provided on the central shaft and the center of the bellows cap A bellows holder having a hole that engages with the shaft and a height dimension that limits the expansion amount of the bellows cap, a bellows stopper that is inserted between the bellows cap and the bellows holder, and a cooling unit that is attached to the lower portion of the cooling water tank. A fan, an air duct surrounding the radiation fin and the cooling fan, a pump connected to the laser oscillator and the cooling water tank by a cooling pipe, and pumping the cooling water to the laser oscillator via the cooling water tank. Cooling device for laser oscillator. 2. A cooling device for a laser oscillator according to claim 1, wherein a pressure abnormality detection switch is attached to a position on the lower surface of the upper portion of the bellows holder that comes into contact with the bellows cap. 3. A cooling device for a laser oscillator according to claim 1, further comprising a bellows cap having a conical shape. 4. A conical bellows cap having a cooling water injection port on the upper end side of a cooling water tank with both ends opened and a conical bellows cap on the opposite lower end side. A cooling device for a laser oscillator according to claim 1, further comprising a bellows cap having a. 5. A cooling device for a laser oscillator according to claim 1, further comprising a liquid expansion / absorption tank inside the cooling water tank.