JP2983148B2 - Laser processing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION This invention is a process gas with focused laser light is supplied to the laser beam irradiation portion on the workpiece cutting of the workpiece, the line sold over the laser processing such as welding The present invention relates to a processing apparatus.

[0002]

2. Description of the Related Art FIG. 12 shows, for example, JP-A-63-52792.
FIG. 13 is a side view showing a nozzle of the laser processing apparatus shown in FIG. 12, and FIG. 14 is a cross-sectional view showing the vicinity of a laser processing head of the laser processing apparatus shown in FIG. It is. In the figure, reference numeral 1 denotes a laser oscillator for emitting a laser beam 2, and 3 denotes a laser beam for guiding the laser beam 2 emitted from the laser oscillator 1 to a processing section.
A reflecting mirror for changing the direction of the laser beam; 4 a condenser lens for condensing the laser beam 2; 5 a condenser head for holding the condenser lens 4 and a processing gas inlet 6 provided downstream of the condenser lens 4 A main body 7 is a nozzle detachably mounted on the distal end side of the processing head main body 5, and a workpiece 8 is set near the focal point of the condenser lens 4. Reference numeral 9 denotes an O-ring provided on the outer peripheral portion of the upper side of the condenser lens 4, reference numeral 10 denotes a holding ring for holding the O-ring 9, and reference numeral 11 denotes a holding screw for pressing the holding ring 10 toward the condenser lens 4 via the O-ring 9. is there. Here, the nozzle 7 is made of a high melting point material, and the laser beam 2 is passed through the tip thereof, and the processing gas introduced into the processing head body 5 from the processing gas inlet 6 is coaxial with the laser beam 2. A nozzle hole 7a is provided at the rear end side, and a male screw portion 7b is formed at the rear end side so as to be screwed to the front end side of the processing head body 5.

Next, the operation of the above conventional laser processing apparatus will be described. The laser beam 2 emitted from the laser oscillator 1 is changed in direction by the reflection mirror 3 and guided to the condenser lens 4. Then, the laser light 2 is condensed by the condenser lens 4, and irradiates the workpiece 8 through the nozzle hole 7 a of the nozzle 7. At the same time, a processing gas is introduced from a gas supply device (not shown) into the processing head body 5 via the processing gas inlet 6 at a predetermined pressure. At this time, the condensing lens 4 is pressed by the press ring 10 via the O-ring 9 and is fixed to the processing head main body 5, so that the processing gas introduced into the processing head main body 5 is above the condensing lens 4. Intrusion is prevented. Then, the processing gas is injected coaxially with the laser beam 2 from the nozzle hole 7 a and supplied to the laser irradiation part on the workpiece 8. Then, a processing gas is supplied to the processing portion of the processing portion 8 together with the laser beam 2, and the processing object 8 is processed.
Laser processing such as cutting, welding and the like is performed.

In this laser processing, the spatter generated from the workpiece 8 adheres to the tip of the nozzle 7 or the reflected laser light from the workpiece 8 irradiates the tip of the nozzle 7 so that the tip of the nozzle 7 Accompanied by a rise in the temperature of the part. However, since the nozzle 7 is made of a high melting point material, melting of the tip of the nozzle 7 is suppressed. Also, the tip of the nozzle 7 melts or spatter adheres to the nozzle hole 7a.
Is closed, the nozzle 7 is replaced with a new nozzle 7.

However, in this type of laser processing apparatus, since it is a small apparatus, it is difficult to employ a cooling mechanism at the tip of the nozzle 7, and the temperature rise of the nozzle 7 cannot be suppressed efficiently. However, the heat resistance is insufficient. Therefore, as in the above-described conventional laser processing apparatus, a method has been devised in which the nozzle 7 is made of a high melting point material to increase the heat resistance of the nozzle 7.

On the other hand, in an arc welding apparatus which is a large apparatus, as described in, for example, Japanese Utility Model Application Laid-Open No. 56-131980, a high-temperature plasma formed so as to surround an electrode at a nozzle tip and a focused beam is used. In some cases, a water-cooled shield nozzle is provided on the outer periphery of the nozzle tip so as to inject the cooled shield gas. This water-cooled shield nozzle cools the electrode at the tip of the nozzle with the cooled shield gas to extend the life of the electrode, and pinches high-temperature plasma near the processing point by the pinch effect.
It is intended to improve the processing quality and is not configured to be easily detachable.

[0007]

As described above, in the conventional laser processing apparatus, the nozzle 7 is made of a material having a high melting point. However, since there is no cooling mechanism at the tip of the nozzle 7, a particularly high-power laser beam is used. In the case where welding, surface modification, etc. are performed by using No. 2, spatter generated during the processing increases, and the sputter adheres to the tip of the nozzle 7 to block the nozzle hole 7a, and the laser When the light 2 interferes, or when the workpiece 8 is a high-reflectance material such as an aluminum material, the laser beam reflected from the workpiece is applied to the tip of the nozzle 7 so that the The temperature at the tip of the nozzle 7 rises sharply, and the temperature at the tip of the nozzle 7 exceeds the melting point.
There was a problem that the tip would melt. In addition, there is a problem that the nozzle hole 7a is deformed due to melting of the tip of the nozzle 7 and the nozzle 7 needs to be replaced, which increases the running cost.

[0008] The present invention has been made to solve the above problems, remembering cooling mechanism Roh nozzle tip, and constitutes a nozzle tip a detachable nozzle tip to the nozzle body In addition, a laser processing apparatus capable of improving the heat resistance of the nozzle tip to prolong the life thereof, furthermore, coping with the deformation of the nozzle hole due to the melting of the nozzle tip by replacing only the nozzle tip, and reducing the running cost. The purpose is to:

[0009]

A laser processing apparatus according to the present invention applies a laser beam emitted from a laser oscillator.
Holds a condenser lens that collects light on the workpiece and collects light.
A processing gas inlet for introducing a processing gas downstream of the lens
A provided processing head body and a tip of the processing head body
And a nozzle detachably mounted on the side.
Nozzle processing gas with laser light focused by
Jets coaxially with the laser beam from the tip of the
A laser beam is supplied to the laser beam irradiator to process the workpiece.
In the construction equipment, one end of the nozzle is connected to the cooling water inlet
A first cooling water flow path, the other end of which is open to the tip, and
One end is connected to the cooling water outlet, and the other end opens to the tip.
Nozzle body provided with a second cooling water flow path,
First cooling water detachably attached to the tip of the main body
A third cooling water flow path that communicates the flow path with the second cooling water flow path
And a nozzle tip provided with
Cooling water supply means for supplying cooling water through a water inlet;
Purge gas via cooling water inlet when replacing nozzle tip
To supply cooling remaining in the first to third cooling water passages.
Purge gas supply means for discharging water from a cooling water discharge port;
It is provided with .

[0010]

[0011]

[0012]

[0013] In addition, the laser processing apparatus according to the inventions is,
Collects the laser light emitted from the laser oscillator on the workpiece
Hold the condenser lens that emits light, and
A processing gas inlet for introducing a processing gas is provided on the flow side
Detachable to the processing head body and the tip side of the processing head body
Nozzle attached to the Noh
Processing gas with focused laser light from nozzle tip
Laser light irradiation on the workpiece by ejecting coaxially with the laser light
Laser processing equipment that supplies the laser beam to the
The nozzle has one end connected to the cooling water inlet and the other end
The first cooling water passage opening at the tip and one end cooling
A second cooling device connected to the water outlet and having the other end opened at the tip end.
Nozzle body with recirculating water flow path and tip of nozzle body
The first cooling water flow path and the second cooling water flow path
A third cooling water flow path communicating with the cooling water flow path of
And a cooling water inlet.
A cooling water supply means for supplying cooling water via the cooling water supply means , a flow rate detection means arranged in a path of the cooling water supplied from the cooling water supply means to detect a flow rate of the cooling water, and It is provided with a notifying means for notifying, and a control means for monitoring the flow rate of the cooling water from the detection signal of the flow rate detecting means and activating the notifying means when the flow rate of the cooling water becomes equal to or less than a predetermined flow rate.

[0014] In addition, the laser processing apparatus according to the inventions is,
Collects the laser light emitted from the laser oscillator on the workpiece
Hold the condenser lens that emits light, and
A processing gas inlet for introducing a processing gas is provided on the flow side
Detachable to the processing head body and the tip side of the processing head body
Nozzle attached to the Noh
Processing gas with focused laser light from nozzle tip
Laser light irradiation on the workpiece by ejecting coaxially with the laser light
Laser processing equipment that supplies the laser beam to the
The nozzle has one end connected to the cooling water inlet and the other end
The first cooling water passage opening at the tip and one end cooling
A second cooling device connected to the water outlet and having the other end opened at the tip end.
Nozzle body with recirculating water flow path and tip of nozzle body
The first cooling water flow path and the second cooling water flow path
A third cooling water flow path communicating with the cooling water flow path of
And a cooling water inlet.
Cooling water supply means for supplying cooling water via the cooling water supply means , flow rate detection means arranged in a path of the cooling water supplied from the cooling water supply means for detecting a flow rate of the cooling water, and a detection signal of the flow rate detection means And a controller for stopping the laser oscillator when the flow rate of the cooling water falls below a predetermined flow rate.

[0015] In addition, the laser processing apparatus according to the inventions is,
Collects the laser light emitted from the laser oscillator on the workpiece
Hold the condenser lens that emits light, and
A processing gas inlet for introducing a processing gas is provided on the flow side
Detachable to the processing head body and the tip side of the processing head body
Nozzle attached to the Noh
Processing gas with focused laser light from nozzle tip
Laser light irradiation on the workpiece by ejecting coaxially with the laser light
Laser processing equipment that supplies the laser beam to the
The nozzle has one end connected to the cooling water inlet and the other end
The first cooling water passage opening at the tip and one end cooling
A second cooling device connected to the water outlet and having the other end opened at the tip end.
Nozzle body with recirculating water flow path and tip of nozzle body
The first cooling water flow path and the second cooling water flow path
A third cooling water flow path communicating with the cooling water flow path of
And a cooling water inlet.
A cooling water supply means for supplying cooling water through the cooling water supply means , a temperature detection means disposed in a path of the cooling water supplied from the cooling water supply means to detect a temperature of the cooling water, and an abnormality in the temperature of the cooling water. It is provided with an informing means for informing, and a control means for monitoring the temperature of the cooling water from the detection signal of the temperature detecting means and activating the informing means when the temperature of the cooling water becomes equal to or higher than a predetermined temperature.

[0016] In addition, the laser processing apparatus according to the inventions is,
Collects the laser light emitted from the laser oscillator on the workpiece
Hold the condenser lens that emits light, and
A processing gas inlet for introducing a processing gas is provided on the flow side
Detachable to the processing head body and the tip side of the processing head body
Nozzle attached to the Noh
Processing gas with focused laser light from nozzle tip
Laser light irradiation on the workpiece by ejecting coaxially with the laser light
Laser processing equipment that supplies the laser beam to the
The nozzle has one end connected to the cooling water inlet and the other end
The first cooling water passage opening at the tip and one end cooling
A second cooling device connected to the water outlet and having the other end opened at the tip end.
Nozzle body with recirculating water flow path and tip of nozzle body
The first cooling water flow path and the second cooling water flow path
A third cooling water flow path communicating with the cooling water flow path of
And a cooling water inlet.
Cooling water supply means for supplying cooling water via the cooling water supply means , temperature detection means arranged in a path of the cooling water supplied from the cooling water supply means for detecting the temperature of the cooling water, and a detection signal of the temperature detection means And a control means for monitoring the temperature of the cooling water from the apparatus and stopping the laser oscillator when the temperature of the cooling water becomes equal to or higher than a predetermined temperature.

[0017]

[Action] Oite this inventions, the nozzle is composed of the nozzle tip which is removably attached to the tip of the nozzle body and the nozzle body. Therefore, when the nozzle tip, that is, the nozzle tip is melted due to the temperature rise due to the attachment of spatter from the workpiece or the irradiation of reflected laser light during laser processing and the nozzle hole is deformed, or the attached spatter is When the nozzle hole is closed, only the nozzle tip can be replaced to cope with the problem. Also, a first cooling water flow passage having one end connected to the cooling water inlet and the other end opened to the tip of the nozzle body, one end connected to the cooling water outlet, and the other end connected to the nozzle body. A second cooling water flow path that opens at the tip of the nozzle, and a third cooling water flow path that connects the first and second cooling water flow paths when the nozzle tip is attached to the tip of the nozzle body. Is provided, the cooling water can flow from the cooling water inlet to the first cooling water flow path, the third cooling water flow path, and the second cooling water flow path. Therefore, it is possible to suppress the temperature rise of the nozzle tip due to the attachment of spatter from the workpiece and the irradiation of the reflected laser light during the laser processing.

[0018]

[0019] In addition, after stopping the supply of cooling water at the time of Roh Zuruchippu exchange, can supply a purge gas through the cooling water inlet from the purge gas supply means. And the first to third
The cooling water remaining during the cooling water circulation is discharged from the cooling water discharge port by the purge gas supplied from the cooling water inlet. Therefore, there is no scattering of cooling water at the time of replacing the nozzle tip, and the nozzle tip is replaced while suppressing surrounding contamination.

[0020] Also, the flow rate of the coolant flowing through the cooling water circulation of the first to third is monitored by the control means via the flow rate detection means. Then, when it is determined that the flow rate of the cooling water is equal to or less than the predetermined flow rate, the control means activates the notification means to notify the worker that the flow rate of the cooling water has decreased. Therefore,
The operator can adjust the flow rate of the cooling water or stop the laser oscillator to stop the laser processing. As a result, a rise in the temperature of the nozzle tip caused by a decrease in the cooling performance of the nozzle tip due to a decrease in the flow rate of the cooling water is prevented, and melting of the nozzle tip is avoided.

[0021] Also, the flow rate of the coolant flowing through the cooling water circulation of the first to third is monitored by the control means via the flow rate detection means. Then, when the flow rate of the cooling water is determined to be equal to or less than the predetermined flow rate, the control means stops the laser oscillator and stops the laser processing. As a result, a rise in the temperature of the nozzle tip caused by a decrease in the cooling performance of the nozzle tip due to a decrease in the flow rate of the cooling water is prevented, and melting of the nozzle tip is avoided.

[0022] Also, the temperature of the cooling water flowing through the cooling water circulation of the first to third is monitored by the control unit via the temperature detection means. Then, when it is determined that the temperature of the cooling water is equal to or higher than the predetermined temperature, the control means activates the notifying means to notify the worker that the temperature of the cooling water has increased. Therefore,
The operator can adjust the flow rate of the cooling water or stop the laser oscillator to stop the laser processing. As a result, a rise in the temperature of the nozzle tip caused by a decrease in the cooling performance of the nozzle tip due to a rise in the temperature of the cooling water is prevented, and melting of the nozzle tip is avoided.

[0023] Also, the temperature of the cooling water flowing through the cooling water circulation of the first to third is monitored by the control unit via the temperature detection means. Then, when it is determined that the temperature of the cooling water is equal to or higher than the predetermined temperature, the control means stops the laser oscillator and stops the laser processing. As a result, a rise in the temperature of the nozzle tip caused by a decrease in the cooling performance of the nozzle tip due to a rise in the temperature of the cooling water is prevented, and melting of the nozzle tip is avoided.

[0024]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. Reference example 1 . Figure 1 is a sectional view showing around a laser machining head of a laser machining apparatus according to Embodiment 1 of the present invention, FIG. 1
The same or corresponding parts as those of the conventional laser processing apparatus shown in FIGS. 2 to 14 are denoted by the same reference numerals, and description thereof will be omitted.
In the drawing, reference numeral 20 denotes a nozzle mounted on the distal end side of the processing head main body 5, and this nozzle 20 is a nozzle main body 21 detachably mounted on the distal end side of the processing head main body 5.
And a nozzle tip 22 detachably attached to the tip of the nozzle body 21. 23a,
23b is the nozzle body 2 when the nozzle tip 22 is mounted.
An O-ring interposed between the nozzle tip 1 and the nozzle tip 22. The nozzle body 21 has a truncated conical cylindrical body, and has a male screw portion 21a formed on the outer peripheral portion at the rear end thereof, and a female screw portion 21b formed on the inner peripheral portion at the distal end. A pair of through-holes penetrating from the rear end surface to the front end surface are formed in the peripheral wall of the nozzle body 21 symmetrically with respect to the axis, and a blind plug 24 is mounted on one side of each through-hole. First and second cooling water passages 25 and 26 are formed at the front end face of the cooling water passage 21. Further, the first and second cooling water flow paths 2
A cooling water inlet 27 and a cooling water outlet 28 are provided so as to face 5 and 26. On the other hand, the nozzle tip 22 has a truncated conical cylindrical body, and the nozzle body 2
A male screw portion 22a screwed with the first female screw portion 21b is formed, and a nozzle hole 22b having a hole axis coinciding with the optical axis of the laser beam 2 is formed at the tip. Then, the nozzle tip 22
A third cooling water passage 29 is formed by annularly hollowing the inside of the peripheral wall from the rear end face.

The nozzle 20 is formed by screwing the male screw portion 22a of the nozzle tip 22 into the female screw portion 21b of the nozzle body 21, and the nozzle tip 22
Are detachably attached and assembled. And
The nozzle 20 is screwed onto the processing head body 5 to form a laser processing head. At this time, the first and second cooling water passages 25 and 26 are opened at the front end face of the nozzle body 21, and the third cooling water passage 29 is opened at the rear end face of the nozzle chip 22 in an annular shape. By attaching the nozzle tip 22 to the main body 21, the first and second cooling water flow paths 25 and 26 are communicated by the third cooling water flow path 29, and the cooling water from the cooling water inlet 27 to the cooling water outlet 28 is cooled. A water flow path is configured. Also, plug 24, O-ring 2
Leakage of cooling water flowing through the cooling water flow path is prevented by 3a and 23b. The other configuration is the same as that of the conventional laser processing apparatus shown in FIG.

Next, the operation of the first embodiment will be described. The first cooling water flow path 2 is provided from a cooling water supply device (not shown) as cooling water supply means through a cooling water inlet 27.
Cooling water is supplied into the inside 5 at a predetermined pressure. The cooling water flows from the first cooling water flow path 25 to the second cooling water flow path 26 via the third cooling water flow path 29, and is discharged from the cooling water discharge port 28. The cooling water flows through the nozzle body 2
1 and the nozzle tip 22 are cooled. On the other hand, the direction of the laser light 2 emitted from the laser oscillator 1 is changed by the reflection mirror 3 and guided to the condenser lens 4. And
The laser beam 2 is condensed by the condensing lens 4, and irradiates the workpiece 8 through the nozzle hole 22 b of the nozzle 20. A processing gas is introduced from the gas supply device (not shown) into the processing head main body 5 through the processing gas inlet 6 at a predetermined pressure. Then, the processing gas is injected coaxially with the laser light 2 from the nozzle hole 22 a and supplied to a laser light irradiation unit on the workpiece 8. Therefore, a processing gas is supplied to the processing portion of the processing portion 8 together with the laser beam 2, and laser processing such as cutting and welding of the processing object 8 is performed.

In this laser processing, the spatter generated from the workpiece 8 adheres to the tip of the nozzle tip 22 or the reflected laser light from the workpiece 8
Irradiation is performed on the tip of the nozzle tip 2 to heat the tip of the nozzle tip 22. However, when the cooling water flows through the third cooling water flow 29 in the nozzle tip 22, the heat applied to the nozzle tip 22 is absorbed by the cooling water, and the temperature rise of the nozzle tip 22 is suppressed. Therefore, melting of the tip of the nozzle tip 22 is suppressed. When the tip of the nozzle tip 22 is melted and the diameter of the nozzle hole 22b is deformed, or when spatter adheres and the nozzle hole 22b is closed, only the nozzle tip 22 is replaced with a new nozzle tip 22. Will do.

As described above, according to the first embodiment , the nozzle 20 attached to the front end of the processing head body 5 is composed of the nozzle body 21 and the nozzle tip 22 screwed to the nozzle body 21. , Nozzle body 2
1 is provided with first and second cooling water passages 25 and 26, and the nozzle tip 22 is provided with first and second cooling water passages 2.
Since the third cooling water passage 29 communicating the nozzles 5 and 26 is provided, the heat resistance of the nozzle tip 22 is improved, the diameter of the nozzle hole 22b is hardly deformed, and the life of the head is extended. In addition, there is an effect that a laser processing head capable of reproducing the nozzle 20 can be obtained by replacing only the nozzle tip 22 even when the life of the nozzle 20 has expired.

Further, according to the first embodiment , since the nozzle 20 is attached to the front end side of the processing head body 5, the temperature rise of the nozzle tip 22 is suppressed and the nozzle hole 22b is formed.
Is less likely to occur, the life of the head is extended, and even if the life of the nozzle 20 has expired, the nozzle 20 can be regenerated by replacing only the nozzle tip 22 and the running cost can be reduced. A laser processing device that can be obtained.

In the first embodiment , the material of the nozzle tip 22 may be made of a heat-resistant, high-melting-point, high-thermal-conductivity material such as copper, copper alloy, stainless steel, or tungsten alloy. The heat resistance of the tip 22 is improved, and the effect of reducing the rate of occurrence of defects of the nozzle tip 22 due to the deformation of the diameter of the nozzle hole 22b due to melting is obtained.

In the first embodiment , if the thickness of the tip of the nozzle tip 22, that is, the portion facing the workpiece 8 is reduced, the heat applied to the tip of the nozzle tip 22 is rapidly reduced. The heat is transmitted to the cooling water flowing through the cooling water flow path 29 of No. 3 and is absorbed, so that the temperature rise at the tip of the nozzle tip 22 is further suppressed. Therefore, the thickness of the tip of the copper alloy nozzle tip 22 is changed to change the nozzle hole 2.
When the number of times of processing to reach the nozzle life caused by the diameter deformation of 2b was measured, as shown in FIG.
It was found that the thickness of the front end portion was preferably 3 mm or less, and more preferably 1 to 3 mm in consideration of the strength and the production cost.

Reference Example 2 In the first embodiment , the tip of the nozzle tip 22 is manufactured to be flat, but in the second embodiment , FIG.
As shown in (1), the same effect can be obtained by manufacturing the nozzle tip 22 with a rounded tip.

Embodiment 1 FIG. 4 is a configuration diagram showing a main part of the laser processing apparatus according to the first embodiment of the present invention. In FIG. 4, reference numeral 30 denotes a cooling water supply device as cooling water supply means, and reference numerals 31a and 31b denote cooling on the outward path and the return path. A coupler disposed in the water pipe path, a purge gas supply device 32 as purge gas supply means, a ball valve 33a disposed in a purge gas pipe path from the purge gas supply device 32 to the cooling water pipe on the outward path, Reference numeral 33b denotes a ball valve disposed in a purge gas pipe path branched from the return water pipe. The other configuration is the same as that of the first embodiment .

Next, the operation of the first embodiment will be described. At the time of laser processing, the couplers 31a and 31b are jointed, and cooling water is supplied from the cooling water supply device 30 to the cooling water inlet 27 via the cooling water pipe on the outward path side. Then, the cooling water passes through the first cooling water passage 25, the third cooling water passage 29, and the second cooling water passage 26, and the cooling water outlet 2
8 and the nozzle 20, especially the nozzle tip 22, is cooled. Further, the cooling water is discharged through the cooling water pipe on the return side. Here, when the life of the nozzle 20 expires, that is, when the diameter of the nozzle hole 22a of the nozzle tip 22 is deformed, the laser processing is stopped. Then, the cooling water supply device 30 is stopped, and the joints of the couplers 31a and 31b are opened. Then, the ball valves 33a, 3
3b is opened to operate the purge gas supply device 32 to supply air as a purge gas to the cooling water inlet 27. This air is supplied to the first cooling water passage 25 and the third cooling water passage 2
9. The cooling water passes through the second cooling water flow path 26 and reaches the cooling water discharge port 28. Further, the air is discharged outside through the ball valve 33b. At this time, the first to third cooling water passages 25, 2
The cooling water remaining in 6, 29 is expelled to the outside together with the air. Next, the ball valves 33a and 33b are closed, and the purge gas supply device 32 is stopped. Thereafter, the nozzle tip 22 is detached from the nozzle body 21, a new nozzle tip 22 is screwed to the nozzle body 21, and the replacement operation of the nozzle tip 22 is completed.

According to the first embodiment , the cooling water inlet 27
Is provided with a purge gas supply device 32 for supplying a purge gas to the first to third cooling water passages 25, 26, 29 through the first cooling water passages 25, 26, 29. , 29 can be expelled. Therefore, it is possible to prevent the cooling water from scattering around and contaminating the nozzle tip 22 when the nozzle tip 22 is replaced.

Embodiment 2 FIG. In the first embodiment , the couplers 31a and 31b for flowing or stopping the cooling water and the purge gas and the ball valves 33a and 33b are disposed in the piping path. In the second embodiment , as shown in FIG. The three-way valves 34a and 34b are provided in the piping path, and the same effect is obtained. In this case, the couplers 31a and 31b become unnecessary, and the cost can be reduced accordingly.

Embodiment 3 FIG. FIG. 6 is a configuration diagram showing a main part of a laser processing apparatus according to Embodiment 3 of the present invention. In FIG. 6, reference numeral 35 denotes cooling water that is disposed in a return-side cooling water pipe path and flows through the cooling water pipe. A flow meter as flow rate detecting means for detecting the flow rate of the water, 36 is an alarm device as a notifying means, 37 is a flow rate of the cooling water flowing through the cooling water pipe based on a detection signal of the flow meter 35 becomes equal to or less than a predetermined flow rate. It is a control device as a control means for activating the alarm device 36 when it is determined whether or not the cooling water flow rate is equal to or less than a predetermined flow rate. The other configuration is the same as that of the first embodiment .

Next, the operation of the third embodiment will be described. During laser processing, cooling water is supplied from the cooling water supply device 30 to the cooling water inlet 27 via the cooling water pipe on the outward path side. Then, the cooling water passes through the first cooling water flow path 25, the third cooling water flow path 29, and the second cooling water flow path 26, reaches the cooling water discharge port 28, and cools the nozzle 20, especially the nozzle tip 22. . Further, the cooling water is discharged through the cooling water pipe on the return side. Here, the flow rate of the cooling water is detected by a flow meter 35 disposed in the cooling water pipe path on the return side. Then, the detection signal of the flow meter 35 is
7 is output. Therefore, the flow rate of the cooling water is monitored by the control device 37. When the control device 37 determines from the detection signal of the flow meter 35 that the flow rate is equal to or less than the predetermined flow rate, the control device 37 activates the alarm device 36 to notify the operator of the occurrence of the abnormality.

According to the third embodiment , the flow meter 35 for detecting the flow rate of the cooling water is provided in the cooling water pipe on the return path, and the flow rate of the cooling water is monitored based on the detection signal of the flow meter 35. When the flow rate of the cooling water falls below a predetermined flow rate, an alarm device 36 is provided.
The control device 37 is provided to notify the operator of the abnormality by operating the controller, so that the operator can be notified of the decrease in the flow rate of the cooling water. Therefore, the temperature of the nozzle tip 22 rises due to the decrease in the flow rate of the cooling water, and the nozzle hole 22 of the nozzle tip 22
The occurrence of a defect in which the diameter of b is deformed can be suppressed, and the life of the nozzle tip 22 can be extended.

Embodiment 4 FIG. FIG. 7 is a configuration diagram showing a main part of a laser processing apparatus according to a fourth embodiment of the present invention. In FIG. 7, reference numeral 38 denotes a flow rate detecting means and a control means provided in a return water cooling water pipe. It is a flow meter with contacts. In the fourth embodiment , the flow rate of the cooling water is monitored by the flow meter 38 with contacts. Then, when the flow rate of the cooling water becomes equal to or less than the predetermined flow rate, the contact point of the flow meter with contact point 38 is closed, and the alarm device 36 is operated. Therefore, in this embodiment 4, the embodiment
The same effect as that of No. 3 can be obtained. In addition, the flow meter 38 with contacts
Also functions as a control means for operating an alarm device 36 for notifying a decrease in the flow rate of the cooling water, so that the control device 37 is not necessary, and the configuration is simplified accordingly.

Embodiment 5 FIG. FIG. 8 is a block diagram showing a main part of a laser processing apparatus according to Embodiment 5 of the present invention. In FIG. 8, reference numeral 39 denotes a temperature detecting means for detecting the temperature of the cooling water flowing through the return-side cooling water pipe. A thermometer, 40 is an alarm device as a notification means, 4
1 judges whether the temperature of the cooling water flowing through the cooling water pipe is higher than a predetermined temperature based on the detection signal of the thermometer 39, and issues an alarm when the temperature of the cooling water is higher than the predetermined temperature. This is a control device as control means for operating the device 40. The other configuration is the same as that of the first embodiment .

Next, the operation of the fifth embodiment will be described. During laser processing, cooling water is supplied from the cooling water supply device 30 to the cooling water inlet 27 via the cooling water pipe on the outward path side. Then, the cooling water passes through the first cooling water flow path 25, the third cooling water flow path 29, and the second cooling water flow path 26, reaches the cooling water discharge port 28, and cools the nozzle 20, especially the nozzle tip 22. . Further, the cooling water is discharged through the cooling water pipe on the return side. Here, the temperature of the cooling water flowing in the cooling water pipe on the return side is detected by the thermometer 39.
The detection signal of the thermometer 39 is output to the control device 41. Therefore, the temperature of the cooling water is monitored by the control device 41. When the control device 41 determines from the detection signal of the thermometer 39 that the temperature has become equal to or higher than the predetermined temperature, the control device 41 operates the alarm device 40 to notify the operator of the occurrence of the abnormality.

According to the fifth embodiment , the thermometer 39 for detecting the temperature of the cooling water is provided, and the temperature of the cooling water is monitored based on the detection signal of the thermometer 39. Since the control device 41 that activates the alarm device 40 to notify the abnormality in the case described above is provided, it is possible to notify the worker of the temperature rise of the cooling water. Therefore, the temperature of the nozzle tip 22 rises due to the rise in the temperature of the cooling water, and the occurrence of a defect in which the diameter of the nozzle hole 22b of the nozzle tip 22 is deformed can be suppressed, and the life of the nozzle tip 22 can be extended.

Embodiment 6 FIG. FIG. 9 is a block diagram showing a main part of a laser processing apparatus according to Embodiment 6 of the present invention. In FIG. 9, reference numeral 42 denotes a flow rate detecting means for detecting the temperature of the cooling water flowing in the cooling water pipe on the return path and control. It is a thermometer with a contact as a means. This implementation
In Example 6 , the temperature of the cooling water is monitored by the thermometer 42 with contacts. When the temperature of the cooling water becomes equal to or higher than the predetermined temperature, the contact of the thermometer with contact 42 is closed, and the alarm device 3
9 is activated. Therefore, also in the sixth embodiment , the same effect as in the fifth embodiment can be obtained. In addition, the thermometer 42 with a contact also functions as a control means for operating the alarm device 39 for notifying the rise in the temperature of the cooling water.
1 becomes unnecessary, and the configuration is simplified accordingly.

Embodiment 7 FIG. FIG. 10 is a configuration diagram showing a main part of a laser processing apparatus according to Embodiment 7 of the present invention. In FIG. 10, reference numeral 43 denotes a detection signal of a flow meter 35 disposed in a return-side cooling water pipe path. A control unit that monitors the flow rate of the cooling water based on the detection signal and stops the operation of the laser oscillator 1 when the flow rate of the cooling water becomes equal to or less than a predetermined flow rate. The other configuration is the same as that of the first embodiment .

Next, the operation of the seventh embodiment will be described. During laser processing, cooling water is supplied from the cooling water supply device 30 to the cooling water inlet 27 via the cooling water pipe on the outward path side. Then, the cooling water passes through the first cooling water flow path 25, the third cooling water flow path 29, and the second cooling water flow path 26, reaches the cooling water discharge port 28, and cools the nozzle 20, especially the nozzle tip 22. . Further, the cooling water is discharged through the cooling water pipe on the return side. Here, the flow rate of the cooling water is detected by a flow meter 35 disposed in the cooling water pipe path on the return side. Then, the detection signal of the flow meter 35 is transmitted to the control device 4.
3 is output. Therefore, the flow rate of the cooling water is monitored by the control device 43. When the control device 43 determines from the detection signal of the flow meter 35 that the flow rate has become equal to or less than the predetermined flow rate, it stops the operation of the laser oscillator 1.

According to the seventh embodiment , the flow meter 35 for detecting the flow rate of the cooling water is provided in the cooling water pipe on the return path, and the flow rate of the cooling water is monitored based on the detection signal of the flow meter 35. Since the control device 43 for stopping the operation of the laser oscillator 1 when the flow rate of the cooling water becomes equal to or less than the predetermined flow rate is provided,
When the flow rate of the cooling water becomes equal to or less than the predetermined flow rate, the operation of the laser oscillator 1 is automatically stopped. Therefore, the temperature of the nozzle tip 22 rises due to the decrease in the flow rate of the cooling water, and the occurrence of a defect in which the diameter of the nozzle hole 22b of the nozzle tip 22 is deformed can be suppressed, and the life of the nozzle tip 22 can be extended. it can.

Embodiment 8 FIG. FIG. 11 is a configuration diagram showing a main part of a laser processing apparatus according to Embodiment 8 of the present invention. In FIG. 11, reference numeral 44 denotes a thermometer 39 for measuring the temperature of cooling water flowing in a return-side cooling water pipe.
The control device as a control means for monitoring the temperature of the cooling water based on the detection signal and stopping the operation of the laser oscillator 1 when the temperature of the cooling water becomes equal to or higher than a predetermined temperature. is there. The other configuration is the same as that of the first embodiment .

Next, the operation of the eighth embodiment will be described. During laser processing, cooling water is supplied from the cooling water supply device 30 to the cooling water inlet 27 via the cooling water pipe on the outward path side. Then, the cooling water passes through the first cooling water flow path 25, the third cooling water flow path 29, and the second cooling water flow path 26, reaches the cooling water discharge port 28, and cools the nozzle 20, especially the nozzle tip 22. . Further, the cooling water is discharged through the cooling water pipe on the return side. Here, the temperature of the cooling water flowing in the cooling water pipe on the return side is detected by the thermometer 39.
The detection signal of the thermometer 39 is output to the control device 44. Therefore, the temperature of the cooling water is monitored by the control device 44. Then, when the control device 44 determines from the detection signal of the thermometer 39 that the temperature has become equal to or higher than the predetermined temperature, the operation of the laser oscillator 1 is stopped.

According to the eighth embodiment , the thermometer 39 for detecting the temperature of the cooling water flowing through the return-side cooling water pipe is provided, and the temperature of the cooling water is detected based on the detection signal of the flow thermometer 39. And a controller 44 for stopping the operation of the laser oscillator 1 when the temperature of the cooling water becomes equal to or higher than a predetermined temperature. 1 is automatically stopped. Therefore, the temperature of the nozzle tip 22 rises due to the rise in the temperature of the cooling water, and the occurrence of a defect that the diameter of the nozzle hole 22b of the nozzle tip 22 is deformed can be suppressed.
2 can be extended.

[0051]

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

[0052]

[0053]

[0054] Also, according to this inventions, holds the condenser lens for condensing the laser beam emitted from the laser oscillator on the workpiece, the processing for introducing a process gas to the downstream side of the condenser lens A processing head main body provided with a gas inlet; and a nozzle detachably attached to the distal end side of the processing head main body. To the laser beam irradiation section on the workpiece,
In a laser processing apparatus for processing a workpiece, one end of a nozzle is connected to a cooling water inlet, the other end is connected to a first cooling water flow path opening at a tip end, and one end is connected to a cooling water outlet, and the other. A nozzle body provided with a second cooling water flow path having an end opening at the tip, and a nozzle body detachably attached to the tip of the nozzle body to communicate the first cooling water flow path and the second cooling water flow path. the third is composed of a cooling water channel nozzle tip which is provided, and a cooling water supply means for supplying a cooling water through the cooling water inlet, cold at the nozzle tip replacement
A purge gas is supplied through the recirculating water inlet to perform the first to third purging.
The cooling water remaining in the cooling water flow path of the
And a purge gas supply means for discharging the nozzle tip, so that the nozzle tip can be cooled, the temperature rise of the nozzle tip is suppressed, the heat resistance of the nozzle tip is improved, and the life of the nozzle tip is prolonged. be modified occurs due to melting of the tip can be addressed by replacing the nozzle tip only can reduce the running cost, and further
When the nozzle tip is replaced, it remains in the first to third cooling water passages.
The existing cooling water can be expelled, and the surrounding area can be
It can be the contamination obtain a laser machining apparatus that can prevent.

[0055]

[0056] In addition, according to the inventions, the laser oscillator
Focusing lens that focuses the emitted laser light on the workpiece
And keep processing gas downstream of the condenser lens.
Processing head body with processing gas inlet for introducing
And detachably attached to the tip side of the processing head body.
With a converging nozzle
The processing gas is coaxial with the laser beam from the nozzle tip with the light
To the laser beam irradiation part on the workpiece,
In a laser processing device that processes a workpiece, a nozzle
Has one end connected to the cooling water inlet and the other end open at the tip.
The first cooling water flow path and one end connected to the cooling water discharge port
A second cooling water flow path is provided, the other end of which is open at the tip.
Can be attached to and detached from the nozzle body and the tip of the nozzle body
A first cooling water flow path and a second cooling water flow path
Nozzle nozzle provided with a third cooling water flow path
And cooling water through a cooling water inlet.
Means for supplying cooling water , flow rate detecting means disposed in a path of the cooling water supplied from the cooling water supply means for detecting the flow rate of the cooling water, and reporting means for reporting an abnormality in the flow rate of the cooling water when monitors the flow rate of the cooling water from a detection signal of the flow amount detecting means, the flow rate of the cooling water and a control means for actuating the alarm means if it becomes less than a predetermined flow rate, Bruno
The nozzle tip temperature rises by allowing the tip to cool
The heat resistance of the nozzle tip is improved,
Extending the life of the tip and the nozzle tip
Even if deformation due to melting of the end occurs, only the nozzle tip
Can be replaced to reduce running costs.
In addition, a rise in the temperature of the nozzle tip due to a decrease in the flow rate of the cooling water can be prevented beforehand, and the occurrence of defective nozzle tips due to melting can be suppressed.

[0057] In addition, according to the inventions, the laser oscillator
Focusing lens that focuses the emitted laser light on the workpiece
And keep processing gas downstream of the condenser lens.
Processing head body with processing gas inlet for introducing
And detachably attached to the tip side of the processing head body.
With a converging nozzle
The processing gas is coaxial with the laser beam from the nozzle tip with the light
To the laser beam irradiation part on the workpiece,
In a laser processing device that processes a workpiece, a nozzle
Has one end connected to the cooling water inlet and the other end open at the tip.
The first cooling water flow path and one end connected to the cooling water discharge port
A second cooling water flow path is provided, the other end of which is open at the tip.
Can be attached to and detached from the nozzle body and the tip of the nozzle body
A first cooling water flow path and a second cooling water flow path
Nozzle nozzle provided with a third cooling water flow path
And cooling water through a cooling water inlet.
A cooling water supply means for supplying the cooling water, a flow rate detection means arranged in a path of the cooling water supplied from the cooling water supply means to detect a flow rate of the cooling water, and a cooling water the flow rate was monitored, the flow rate of the cooling water and a control means for stopping the laser oscillator when it becomes less than a predetermined flow rate, Nozuruchi as possible the cooling of the nozzle tip
The temperature rise of the tip is suppressed, improving the heat resistance of the nozzle tip.
To extend the life of the nozzle tip,
Nozzles even if the tip of the nozzle tip deforms due to melting
Can be replaced by replacing only the tip
When the flow rate of the cooling water decreases, the laser oscillator is automatically stopped, and the temperature of the nozzle tip does not increase due to the decrease in the flow rate of the cooling water, so that the life of the nozzle tip can be extended.

[0058] In addition, according to the inventions, the laser oscillator
Focusing lens that focuses the emitted laser light on the workpiece
And keep processing gas downstream of the condenser lens.
Processing head body with processing gas inlet for introducing
And detachably attached to the tip side of the processing head body.
With a converging nozzle
The processing gas is coaxial with the laser beam from the nozzle tip with the light
To the laser beam irradiation part on the workpiece,
In a laser processing device that processes a workpiece, a nozzle
Has one end connected to the cooling water inlet and the other end open at the tip.
The first cooling water flow path and one end connected to the cooling water discharge port
A second cooling water flow path is provided, the other end of which is open at the tip.
Can be attached to and detached from the nozzle body and the tip of the nozzle body
A first cooling water flow path and a second cooling water flow path
Nozzle nozzle provided with a third cooling water flow path
And cooling water through a cooling water inlet.
Means for supplying cooling water, temperature detecting means disposed in the path of the cooling water supplied from the cooling water supply means for detecting the temperature of the cooling water, and reporting means for reporting an abnormality in the temperature of the cooling water If, monitor the temperature of the cooling water from a detection signal of the temperature detecting means, the temperature of the cooling water and a control means for actuating the alarm means when it becomes equal to or higher than a predetermined temperature, Bruno
The nozzle tip temperature rises by allowing the tip to cool
The heat resistance of the nozzle tip is improved,
Extending the life of the tip and the nozzle tip
Even if deformation due to melting of the end occurs, only the nozzle tip
Can be replaced to reduce running costs.
In addition, a rise in the temperature of the nozzle tip due to an increase in the temperature of the cooling water can be prevented beforehand, and the occurrence of defective nozzle chips due to melting can be suppressed.

[0059] In addition, according to the inventions, the laser oscillator
Focusing lens that focuses the emitted laser light on the workpiece
And keep processing gas downstream of the condenser lens.
Processing head body with processing gas inlet for introducing
And detachably attached to the tip side of the processing head body.
With a converging nozzle
The processing gas is coaxial with the laser beam from the nozzle tip with the light
To the laser beam irradiation part on the workpiece,
In a laser processing device that processes a workpiece, a nozzle
Has one end connected to the cooling water inlet and the other end open at the tip.
The first cooling water flow path and one end connected to the cooling water discharge port
A second cooling water flow path is provided, the other end of which is open at the tip.
Can be attached to and detached from the nozzle body and the tip of the nozzle body
A first cooling water flow path and a second cooling water flow path
Nozzle nozzle provided with a third cooling water flow path
And cooling water through a cooling water inlet.
A cooling water supply means for supplying the cooling water, a temperature detection means arranged in a path of the cooling water supplied from the cooling water supply means to detect a temperature of the cooling water, and a cooling water from a detection signal of the temperature detection means. the temperature was monitored, the temperature of the cooling water and a control means for stopping the laser oscillator when it becomes equal to or higher than the predetermined temperature, Nozuruchi as possible the cooling of the nozzle tip
The temperature rise of the tip is suppressed, improving the heat resistance of the nozzle tip.
To extend the life of the nozzle tip,
Nozzles even if the tip of the nozzle tip deforms due to melting
Can be replaced by replacing only the tip
When the temperature of the cooling water rises above a predetermined temperature, the laser oscillator is automatically stopped, so that the temperature of the nozzle chip does not rise due to the temperature rise of the cooling water, and the life of the nozzle chip can be extended. .

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing the periphery of a laser processing head of a laser processing apparatus according to Embodiment 1 of the present invention.

FIG. 2 is a graph showing a relationship between a thickness of a tip portion of a nozzle tip and a nozzle life in a laser processing apparatus according to a first embodiment of the present invention.

FIG. 3 is a sectional view showing a main part of a laser processing apparatus according to Embodiment 2 of the present invention.

FIG. 4 is a configuration diagram illustrating a main part of the laser processing apparatus according to the first embodiment of the present invention.

FIG. 5 is a configuration diagram illustrating a main part of a laser processing apparatus according to a second embodiment of the present invention.

FIG. 6 is a configuration diagram illustrating a main part of a laser processing apparatus according to a third embodiment of the present invention.

FIG. 7 is a configuration diagram illustrating a main part of a laser processing apparatus according to a fourth embodiment of the present invention.

FIG. 8 is a configuration diagram illustrating a main part of a laser processing apparatus according to a fifth embodiment of the present invention.

FIG. 9 is a configuration diagram illustrating a main part of a laser processing apparatus according to a sixth embodiment of the present invention.

FIG. 10 is a configuration diagram illustrating a main part of a laser processing apparatus according to a seventh embodiment of the present invention.

FIG. 11 is a configuration diagram illustrating a main part of a laser processing apparatus according to an eighth embodiment of the present invention.

FIG. 12 is a configuration diagram showing a conventional laser processing apparatus.

FIG. 13 is a side view showing a nozzle of a conventional laser processing apparatus.

FIG. 14 is a cross-sectional view showing the periphery of a laser processing head of a conventional laser processing apparatus.

[Explanation of symbols]

1 laser oscillator, 2 laser light, 4 condenser lens, 5
Processing head body, 6 processing gas inlets, 8 workpieces,
Reference Signs 20 nozzle, 21 nozzle body, 22 nozzle tip, 25 first cooling water flow path, 26 second cooling water flow path, 27 cooling water inlet, 28 cooling water outlet, 29
Third cooling water flow path, 30 cooling water supply device (cooling water supply means), 32 purge gas supply device (purge gas supply means), 35 flow meter (flow rate detection means), 36 alarm device (notification means), 37 control device ( Control means), 38 flow meter with contacts (flow detection means, control means), 39 thermometer (temperature detection means), 40 alarm device (notification means), 41
Control device (control means), 42 thermometer with contacts (temperature detection means, control means), 43 control device (control means), 4
4 Control device (control means).

──────────────────────────────────────────────────続 き Continuing on the front page (72) Yoshiaki Kato 5-1-1, Yadaminami, Higashi-ku, Nagoya-shi Nagoya Works, Mitsubishi Electric Co., Ltd. (72) Naoto Sugiyama 5-1-1, Yadaminami, Higashi-ku, Nagoya No. Ryo Technica Co., Ltd. (56) References JP-A-8-1118058 (JP, A) JP-A-63-52792 (JP, A) JP-A-53-30099 (JP, A) 33984 (JP, U) Japanese Utility Model 1-84890 (JP, U) Japanese Utility Model 63-34591 (JP, U) Japanese Utility Model Utility Model 61-59366 (JP, U) (58) Field surveyed (Int. ⁶ , DB name) B23K 26/00-26/18

Claims (5)

(57) [Claims] A condenser lens for condensing a laser beam emitted from a laser oscillator on a workpiece;
A processing head main body provided with a processing gas inlet for introducing a processing gas downstream of the condenser lens; and a nozzle detachably attached to the tip side of the processing head main body. In a laser processing apparatus for processing a processing object by supplying a processing gas together with the laser light emitted from the tip of the nozzle in a coaxial direction with the laser light and supplying the processing gas to a laser light irradiation unit on the processing object, the nozzle has one end. A first cooling water flow path connected to the cooling water inlet, the other end of which is open to the distal end, and a second cooling water flow path, one end of which is connected to the cooling water outlet, and the other end opened to the distal end, are provided. A nozzle body provided with a third cooling water flow path detachably attached to a tip end portion of the nozzle body and communicating the first cooling water flow path and the second cooling water flow path; Consisting of and A cooling water supply means for supplying cooling water through the cooling water inlet; and a purge gas being supplied through the cooling water inlet when the nozzle tip is replaced, to remain in the first to third cooling water passages. And a purge gas supply means for discharging cooling water from the cooling water discharge port. 2. A condensing lens for converging laser light emitted from a laser oscillator on a workpiece,
A processing head main body provided with a processing gas inlet for introducing a processing gas downstream of the condenser lens; and a nozzle detachably attached to the tip side of the processing head main body. In a laser processing apparatus for processing a processing object by supplying a processing gas together with the laser light emitted from the tip of the nozzle in a coaxial direction with the laser light and supplying the processing gas to a laser light irradiation unit on the processing object, the nozzle has one end. A first cooling water flow path connected to the cooling water inlet, the other end of which is open to the distal end, and a second cooling water flow path, one end of which is connected to the cooling water outlet, and the other end opened to the distal end, are provided. A nozzle body provided with a third cooling water flow path detachably attached to a tip end portion of the nozzle body and communicating the first cooling water flow path and the second cooling water flow path; Consisting of and Cooling water supply means for supplying cooling water through the cooling water introduction port, flow rate detection means disposed in a path of the cooling water supplied from the cooling water supply means and detecting a flow rate of the cooling water, An informing means for informing the abnormality of the flow rate of the cooling water, and a flow rate of the cooling water is monitored from a detection signal of the flow rate detecting means. A laser processing apparatus comprising: a control unit for operating the laser processing apparatus. 3. A condensing lens for condensing a laser beam emitted from a laser oscillator on a workpiece,
A processing head main body provided with a processing gas inlet for introducing a processing gas downstream of the condenser lens; and a nozzle detachably attached to the tip side of the processing head main body. In a laser processing apparatus for processing a processing object by supplying a processing gas together with the laser light emitted from the tip of the nozzle in a coaxial direction with the laser light and supplying the processing gas to a laser light irradiation unit on the processing object, the nozzle has one end. A first cooling water flow path connected to the cooling water inlet, the other end of which is open to the distal end, and a second cooling water flow path, one end of which is connected to the cooling water outlet, and the other end opened to the distal end, are provided. A nozzle body provided with a third cooling water flow path detachably attached to a tip end portion of the nozzle body and communicating the first cooling water flow path and the second cooling water flow path; Consisting of and Cooling water supply means for supplying cooling water through the cooling water introduction port, flow rate detection means disposed in a path of the cooling water supplied from the cooling water supply means and detecting a flow rate of the cooling water, A laser processing means for monitoring a flow rate of the cooling water from a detection signal of the flow rate detecting means and stopping a laser oscillator when the flow rate of the cooling water becomes equal to or less than a predetermined flow rate. apparatus. 4. A holding lens for collecting a laser beam emitted from a laser oscillator on a workpiece,
A processing head main body provided with a processing gas inlet for introducing a processing gas downstream of the condenser lens; and a nozzle detachably attached to the tip side of the processing head main body. In a laser processing apparatus for processing a processing object by supplying a processing gas together with the laser light emitted from the tip of the nozzle in a coaxial direction with the laser light and supplying the processing gas to a laser light irradiation unit on the processing object, the nozzle has one end. A first cooling water flow path connected to the cooling water inlet, the other end of which is open to the distal end, and a second cooling water flow path, one end of which is connected to the cooling water outlet, and the other end opened to the distal end, are provided. A nozzle body provided with a third cooling water flow path detachably attached to a tip end portion of the nozzle body and communicating the first cooling water flow path and the second cooling water flow path; Consisting of and Cooling water supply means for supplying cooling water through the cooling water introduction port; and temperature detection means for detecting the temperature of the cooling water disposed in a path of the cooling water supplied from the cooling water supply means. An informing unit that informs of an abnormality in the temperature of the cooling water; anda monitoring unit that monitors the temperature of the cooling water from a detection signal of the temperature detecting unit. A laser processing apparatus comprising: a control unit for operating the laser processing apparatus. 5. A condensing lens for condensing a laser beam emitted from a laser oscillator on a workpiece,
A processing head main body provided with a processing gas inlet for introducing a processing gas downstream of the condenser lens; and a nozzle detachably attached to the tip side of the processing head main body. In a laser processing apparatus for processing a processing object by supplying a processing gas together with the laser light emitted from the tip of the nozzle in a coaxial direction with the laser light and supplying the processing gas to a laser light irradiation unit on the processing object, the nozzle has one end. A first cooling water flow path connected to the cooling water inlet, the other end of which is open to the distal end, and a second cooling water flow path, one end of which is connected to the cooling water outlet, and the other end opened to the distal end, are provided. A nozzle body provided with a third cooling water flow path detachably attached to a tip end portion of the nozzle body and communicating the first cooling water flow path and the second cooling water flow path; Consisting of and Cooling water supply means for supplying cooling water through the cooling water introduction port; and temperature detection means for detecting the temperature of the cooling water disposed in a path of the cooling water supplied from the cooling water supply means. A laser processing means for monitoring a temperature of the cooling water from a detection signal of the temperature detecting means, and stopping a laser oscillator when the temperature of the cooling water becomes equal to or higher than a predetermined temperature. apparatus.