JP2020022978A - Laser irradiation device, fluid supply device, and laser processing method - Google Patents

Abstract

To provide a laser irradiation device which improves processing quality by atmosphere control at an irradiation location, and so on.SOLUTION: A laser irradiation device comprises: an optical system including a condensing optical system 10 for condensing a laser beam R generated by a laser oscillator at a prescribed focus position BS, and a deflection optical system 20 for deflecting the laser beam to scan a focus position along a surface of an irradiation object O in a prescribed scanning pattern; and fluid supply parts 90, 100 which supply fluids PG, SG each containing an inert gas as a main component, to an area including the scanning pattern at the focus position, thereby making at least the focus position have an atmosphere filled with the fluids.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a laser irradiation apparatus that performs laser processing such as cleaning by irradiating a processing target with laser light, a fluid supply apparatus used for such laser processing, and a laser processing method.

  As a conventional technique related to surface treatment using laser light, for example, Patent Document 1 discloses that an irradiation head that irradiates an object to be irradiated with laser light is provided with a wedge prism that deflects laser light by a predetermined angle. By irradiating the laser beam while rotating the prism, the irradiation location scans while rotating the surface of the irradiation target, and removes (cleans) old coatings and foreign substances adhered to the surface of the irradiation target. Is described.

  Patent Document 2 discloses that an optical element is driven by rotating a wedge prism by an air motor that converts gas pressure into a rotational motion and introducing exhaust air of the air motor into a duct from which laser light is emitted. It is described that foreign matter is prevented from adhering to a motor or an air motor.

Patent No. 5574354 International Publication WO2016 / 009978

Cleaning using a laser beam as described in Patent Document 1, for example, removes an old paint film adhering to the surface of a metal structure such as steel and removes foreign matters such as rust generated near the surface. It is effective to remove.
However, when the surface of the irradiation target is locally heated by laser light irradiation, oxygen in the air contacts the base material to promote oxidation, and for example, when the base material is an iron-based metal, In some cases, an oxide film of iron oxide (Fe ₂ O ₃ , Fe ₃ O _4, etc.) was formed.
Since the generation of such an oxide or the like may not be preferable depending on the purpose of use of the irradiation target, it is desired that the quality of the laser processing be further improved by appropriately controlling the atmosphere of the irradiation place. I have.
In view of the above-described problems, an object of the present invention is to provide a laser irradiation device, a fluid supply device, and a laser processing method in which the processing quality is improved by controlling the atmosphere of an irradiation location.

The present invention solves the above-mentioned problems by the following means.
The invention according to claim 1 is a condensing optical system that condenses laser light generated by a laser oscillator at a predetermined focal position, and deflects the laser light to set the focal position along a surface of an irradiation target. An optical system including a deflection optical system for scanning with the scanning pattern, and a fluid containing an inert gas as a main component is supplied to a region including the scanning pattern at the focal position so that at least the focal position is filled with the fluid. A laser irradiation apparatus comprising: a fluid supply unit for setting an atmosphere.
According to this, by filling the focal position with a fluid containing an inert gas as a main component, it is possible to prevent the irradiation target from coming into contact with oxygen when the temperature becomes high due to the incidence of laser light, and to form an oxide coating. Can be prevented from being formed.
In the present specification and claims, a fluid containing an inert gas as a main component refers to a fluid in which all but an unavoidable impurity is an inert gas (generally, pure nitrogen, pure argon, etc.). Available as a).
Further, by scanning the focal position in a predetermined scanning pattern, it is possible to prevent the same spot on the surface of the irradiation target from being continuously irradiated for a long time even when the CW laser is used. For this reason, it is possible to prevent a part of the irradiation target from locally receiving excessive heat input to cause a thermal effect.
In addition, laser processing can be rapidly performed on a relatively wide range of the irradiation target.
Here, as a scanning pattern on the surface of the irradiation target, for example, a circle, an ellipse, a polygon, or any other shape can be used.

The invention according to claim 2 is characterized in that the fluid supply unit is configured such that the fluid is provided in a space that is in contact with a surface on the focal position side of an optical element that is arranged closest to the focal position among optical elements constituting the optical system. 2. The laser irradiation apparatus according to claim 1, wherein the fluid is supplied and the fluid is caused to flow out of the space toward the focal position.
According to this, foreign matter such as dust and spatter scattered from the irradiation target due to the irradiation of the laser beam is prevented from flowing into the optical element side, and contamination of the optical element and foreign matter adhering to the surface of the optical element are prevented. It is possible to prevent burning of the optical element due to the high temperature caused by heating by light.

The invention according to claim 3 is characterized in that it has a suction port disposed adjacent to the focal position, and further includes a dust collection unit that sucks dust generated by irradiating the irradiation target with the laser light. A laser irradiation device according to claim 1 or claim 2.
According to this, it is possible to prevent dust generated by the irradiation of the laser beam from re-adhering to the irradiation target and impairing the quality of laser processing.
In addition, it is possible to prevent dust from scattering to the surroundings and to improve the environment of the construction site.
Further, by sucking the dust together with a fluid containing an inert gas as a main component, the ignition of the collected dust can be prevented.

The invention according to claim 4 includes an inner cylinder through which the laser light emitted from the optical system passes, and an outer cylinder provided on an outer diameter side of the inner cylinder, wherein the fluid supply unit includes: The fluid is supplied from the inner diameter side of the inner cylinder to the irradiation object side, and the dust collection unit suctions the dust from a gap between the outer peripheral surface of the inner cylinder and the inner peripheral surface of the outer cylinder. The laser irradiation device according to claim 3, wherein
According to this, a fluid composed of an inert gas or the like can be reliably supplied to the focal position by a compact configuration, and dust can be sucked from the surroundings.

The invention according to claim 5 is directed to an optical system including a condensing optical system for condensing laser light generated by a laser oscillator at a predetermined focal position, and an optical element constituting the optical system closest to the focal position side. A first fluid supply unit configured to supply a first fluid to a space in contact with the surface portion on the focal position side of the disposed optical element and to cause the first fluid to flow out of the space to the focal position side; A second fluid having a composition different from that of the first fluid is provided to a region including the focus position, the second fluid being provided closer to the focus position than the first fluid supply unit, and at least the focus position is set to the second position. A second fluid supply unit configured to provide an atmosphere filled with a second fluid.
According to this, it is possible to set the irradiation location to an atmosphere filled with the second fluid, and to set a desired laser processing condition such as, for example, using an inert gas as the second fluid and blocking oxygen by its shielding effect. Can be obtained.
On the other hand, the first fluid that functions as a purge gas for preventing contamination of the optical system or the like can be a relatively low-cost and easy-to-use gas such as air.

The invention according to claim 6 is characterized in that the optical system has a deflection optical system that deflects the laser beam and scans the focal position along a surface of the irradiation target in a predetermined scanning pattern. Item 6. A laser irradiation apparatus according to Item 5.
According to this, even when the CW laser is used, it is possible to prevent the same spot on the surface of the irradiation target from being continuously irradiated for a long time. For this reason, it is possible to prevent a part of the irradiation target from locally receiving excessive heat input to cause a thermal effect.
In addition, laser processing can be rapidly performed on a relatively wide range of the irradiation target.
Here, as a scanning pattern on the surface of the irradiation target, for example, a circle, an ellipse, a polygon, or any other shape can be used.

8. The wedge prism according to claim 7, wherein the deflection optical system deflects the laser light by a predetermined deflection angle and is driven to rotate around an optical axis of the laser light emitted from the light collection optical system. The laser irradiation apparatus according to claim 6, comprising:
According to this, the above-described effects can be obtained with a simple, small, and lightweight device configuration.

The invention according to claim 8 is characterized in that the first fluid has air as a main component, and the second fluid has an inert gas as a main component. 2. A laser irradiation apparatus according to item 1.
According to this, by using an inert gas as a main component of the second fluid, it is possible to prevent the surface of the irradiation target from being oxidized at the irradiation location and forming an oxide film or the like.
In addition, by using air that can be collected from the surrounding atmosphere as the main component of the first fluid, the amount of the second fluid, which is relatively expensive, is reduced and the construction cost is reduced. The device configuration such as a gas supply source can be simplified.
In the present specification and claims, the fluid containing air as a main component includes a fluid that is substantially entirely air.

The invention according to claim 9 is characterized in that the second fluid supply unit has an ejection hole formed inside in a circumferential direction of a ring through which the laser light passes, and the second fluid supply unit irradiates an object to be irradiated with the second fluid. The laser irradiation apparatus according to any one of claims 5 to 8, further comprising a nozzle unit for injecting a laser beam.
According to this, the region including the irradiated portion can be appropriately set as the atmosphere filled with the second fluid with a simple configuration.

The invention according to claim 10 is such that the ejection hole of the nozzle portion is arranged such that the ejection hole of the nozzle portion is arranged with respect to an optical axis of the laser beam so that the second fluid is ejected from the outer diameter side to the inner diameter side of the ring. The laser irradiation device according to claim 9, wherein the laser irradiation device is provided to be inclined toward the inner diameter side of the ring.
According to this, the area including the irradiation location can be more reliably set as the atmosphere filled with the second fluid.

The invention according to claim 11, wherein the nozzle portion is supported by a column extending from the first fluid supply portion or the vicinity thereof to the irradiation object side, and the column is provided with the second fluid by the nozzle portion. The laser irradiation device according to claim 9 or 10, further comprising a flow path for supplying the laser beam.
According to this, it is possible to support the nozzle portion and supply the second fluid to the nozzle portion with a simple configuration.
Further, the first fluid can be discharged from the gap between the columns, and it is possible to prevent the first fluid from flowing into the vicinity of the irradiation location and impairing the atmosphere filled with the second fluid.

The invention according to claim 12 is characterized in that it has a suction port arranged adjacent to the focal position, and further includes a dust collection unit that sucks dust generated by irradiating the irradiation target with the laser light. A laser irradiation apparatus according to any one of claims 5 to 11.
According to this, it is possible to prevent dust generated by the irradiation of the laser beam from re-adhering to the irradiation target and impairing the quality of laser processing.
In addition, it is possible to prevent dust from scattering to the surroundings and to improve the environment of the construction site.

The invention according to claim 13 is characterized in that the suction port of the dust collecting section extends in a circumferential direction around a location where the second fluid supply section ejects the second fluid toward the irradiation target. 13. The laser irradiation apparatus according to claim 12, wherein the laser irradiation apparatus is provided as:
According to this, it is possible to reliably supply the second fluid to the focal position with a compact configuration, and to suck dust from around the second fluid.

The invention according to claim 14 has a fluid deflecting unit that deflects the traveling direction of the first fluid supplied from the first fluid supply unit from the irradiation direction of the laser light. A laser irradiation apparatus according to any one of claims 5 to 13.
According to this, it is possible to prevent the first fluid from flowing into the vicinity of the irradiation location, and to more reliably fill the area including the irradiation location with the second fluid.

The invention according to claim 15 is characterized in that the fluid deflecting unit is provided in at least a part of a circumferential direction of an optical axis of the light collecting optical system in a traveling direction of the first fluid, and The laser irradiation apparatus according to claim 14, further comprising a deflecting member that deflects a traveling direction of the first fluid by interfering with a part of the fluid.
According to this, the above-described effects can be obtained with a simple configuration that does not require power or the like.

The invention according to claim 16 is characterized in that a surface portion of the deflecting member that interferes with the first fluid is arranged to be inclined with respect to the outflow direction of the first fluid. Laser irradiation device.
According to this, the deflection direction of the first fluid can be appropriately controlled by the tilt direction and the tilt angle of the deflection member.

The invention according to claim 17 is characterized in that the deflecting member has a surface portion facing the upstream side of the first fluid and having a central portion formed with an opening through which the laser light passes. A laser irradiation apparatus according to claim 15 or claim 16.
According to this, by arranging the surface portion of the deflecting member that interferes with the first fluid over the entire circumference of the opening through which the laser light passes, the laser light reflected by the irradiation target or the spatters scattered from the irradiation target, etc. Foreign matter can be appropriately blocked.

The invention according to claim 18, wherein the fluid deflecting portion is injected so as to intersect with the fluid flow composed of the first fluid and generates another fluid flow that deflects the fluid flow composed of the first fluid. The laser irradiation apparatus according to claim 14, further comprising a generation unit.
According to this, the degree of freedom in controlling the deflection of the fluid flow composed of the first fluid can be increased by setting the flow velocity, flow rate, direction, collision location, and the like of another fluid flow injected into the fluid flow composed of the first fluid. Can be enhanced.
In the present specification and claims, the term “injected so as to intersect” means that a fluid flow having a main flow component that is inclined or orthogonal to the main flow direction of the fluid flow composed of the first fluid is applied to each fluid flow. Interfere with each other and generate the main flow direction of the fluid flow composed of the first fluid in a deflectable positional relationship.

The invention according to claim 19 is the laser irradiation apparatus according to claim 14, wherein the fluid deflecting unit has suction means for sucking a fluid flow composed of the first fluid.
According to this, the degree of freedom in controlling the deflection of the fluid flow composed of the first fluid can be increased by setting the suction strength, suction direction, position, and the like of the suction unit.

The invention according to claim 20 is a fluid supply device attached around an irradiation point where a laser beam irradiated by a laser irradiation device is incident on an irradiation target, wherein the irradiation is performed in a state surrounding the irradiation point. A cover portion that is detachably attached to the target and has an opening through which the laser light passes, and a fluid containing an inert gas as a main component is supplied to the inside of the cover portion so that at least the irradiating portion is exposed to the fluid. And a fluid supply unit that fills the atmosphere.
According to this, in a state where the fluid supply device is attached to the irradiation target and the fluid is supplied, by irradiating the laser beam from the opening of the cover, a general-purpose irradiation head having no fluid supply function is used. Even if it does, laser processing can be performed in an atmosphere filled with an inert gas, and generation of oxides can be prevented.

The invention according to Claim 21 is characterized in that it has a suction port disposed inside the cover portion, and further includes a dust collection portion that sucks dust generated by the irradiation of the laser beam. Fluid supply device.
According to this, it is possible to prevent dust generated by the irradiation of the laser beam from re-adhering to the irradiation target and impairing the quality of laser processing.
In addition, it is possible to prevent dust from scattering to the surroundings and to improve the environment of the construction site.

The invention according to claim 22 is a focusing optical system that focuses laser light generated by a laser oscillator at a predetermined focal position, and deflects the laser light to set the focal position along a surface of an irradiation target. A laser beam emitted from an optical system including a deflecting optical system that scans with a scanning pattern, and a laser beam emitted from an optical system that scans the surface of the irradiation target. A laser processing method characterized by supplying a shielding gas containing, as a main component, at least the focal position to an atmosphere filled with the shielding gas.
A laser processing method for scanning the surface of an irradiation target with laser light emitted from an optical system including a condensing optical system for condensing laser light generated by a laser oscillator at a predetermined focal position, according to an embodiment of the present invention. And supplying a first fluid to a space in which an optical element constituting the optical system is arranged at a position closest to the focus position, and supplying the first fluid from the space to the focus position. And supplying a second fluid having a composition different from that of the first fluid to a region including the focal position, so that at least the focal position is set to an atmosphere filled with the second fluid. This is a laser processing method.
According to each of these aspects, it is possible to obtain the same effects as those of the above-described aspect of the laser irradiation apparatus.

  As described above, according to the present invention, it is possible to provide a laser irradiation device, a fluid supply device, and a laser processing method in which the processing quality is improved by controlling the atmosphere of an irradiation position.

It is a sectional view of an irradiation head in a 1st embodiment of a laser irradiation device to which the present invention is applied. It is a sectional view of an irradiation head in a 2nd embodiment of a laser irradiation device to which the present invention is applied. It is an external appearance perspective view of the output side end part of the laser irradiation head of 2nd Embodiment. FIG. 7 is an enlarged cross-sectional view around a nozzle in a laser irradiation head according to a second embodiment. It is a sectional view of an irradiation head in a 3rd embodiment of a laser irradiation device to which the present invention is applied. FIG. 6 is a sectional view taken along the line VI-VI in FIG. 3. FIG. 11 is a cross-sectional view of an emission-side end of an irradiation head in a fourth embodiment of a laser irradiation head to which the present invention has been applied. It is an external appearance perspective view of the output side end part of the laser irradiation head of 4th Embodiment. It is sectional drawing of the irradiation head in the 5th Embodiment of the laser irradiation head to which this invention is applied. It is a two side view showing appearance of an embodiment of a fluid supply device to which the present invention is applied. It is sectional drawing which shows the state at the time of use of the fluid supply device of embodiment.

<First embodiment>
Hereinafter, a first embodiment of a laser irradiation apparatus and a laser processing method to which the present invention is applied will be described.
The laser irradiation apparatus of the first embodiment irradiates a laser beam supplied from a laser oscillator via a fiber to an irradiation target O, and the irradiation position (beam spot BS) scans the surface of the irradiation target O on an arc. An irradiation head 1 is provided which performs various cleaning processes such as peeling of an old coating film and removal of attached foreign matter by scanning along a pattern.
The irradiation target O is, for example, a metal structure such as general steel, stainless steel, or an aluminum alloy, concrete, or the like.
In the cleaning process, the irradiation spot (beam spot BS) on the surface of the irradiation target O is swirled and scanned along a relatively large arc of, for example, about 10 mm in diameter or more, and the surface of the irradiation target O is scanned. Laser processing (surface treatment) for cleaning old films (films to be peeled off), various films such as oxide films, dust, rust, soot, etc.
FIG. 1 is a sectional view of an irradiation head in the laser irradiation apparatus of the first embodiment.

The irradiation head 1 irradiates an irradiation target O with CW laser light R transmitted from a laser oscillator (not shown) via a fiber (not shown).
As the laser oscillator, for example, a CW laser having an average output of about 1 kW can be used.
The irradiation head 1 is, for example, a handy type that can be carried by a worker by hand, but it is also possible to use the irradiation head 1 by attaching it to a robot that can move the irradiation head 1 along a predetermined path. is there.

  The irradiation head 1 includes a focus lens 10, a wedge prism 20, a protective glass 30, a rotating cylinder 40, a motor 50, a motor holder 60, a protective glass holder 70, a housing 80, a duct 90, and the like.

The focus lens 10 is an optical element into which the laser light R transmitted from the laser oscillator to the irradiation head 1 via the fiber passes through a collimator lens (not shown).
The collimating lens is an optical element that collimates (collimates) the laser light emitted from the end of the fiber.
The focus lens 10 is an optical element that focuses (focuses) the laser beam R emitted from the collimator lens at a predetermined focal position.
As the focus lens 10, for example, a convex lens having a positive power can be used.
Note that the beam spot BS, which is an irradiation position on the surface of the irradiation target O by the laser light R, is arranged so as to coincide with the focus position (focus state) or close to the focus position (defocus state).

The wedge prism 20 is an optical element that deflects the laser light R emitted from the focus lens 10 by a predetermined declination θ (see FIG. 1), and makes the optical axis angles of the incident side and the emission side different.
The wedge prism 20 is formed in a plate shape whose thickness changes continuously so that one thickness in a direction orthogonal to the optical axis direction on the incident side becomes larger than the other thickness.
The protective glass 30 is an optical element made of flat glass or the like disposed adjacent to the focus position side (the irradiation target O side / beam spot BS side) along the optical axis direction with respect to the wedge prism 20.
The protective glass 30 is a protective member that prevents foreign matter such as spatter and dust scattered from the irradiation object O side from adhering to other optical elements such as the wedge prism 20.
The protective glass 30 is an optical element arranged at the most focal position side along the optical axis direction in the optical system of the irradiation head 1, and irradiates an object to be irradiated through a space S or a duct 90 described later. It will be exposed on the object O side.
The focus lens 10, the wedge prism 20, and the protective glass 30 are configured by applying a coating for the purpose of anti-reflection, surface protection, and the like to the surface of a transparent material such as optical glass.

The rotating cylinder 40 is a cylindrical member that holds the focus lens 10 and the wedge prism 20 on the inner diameter side.
The rotary cylinder 40 is formed concentrically with the optical axis of the focus lens 10 and the optical axis of the laser light R incident on the focus lens 10 (the optical axis of the collimator lens).
The rotary cylinder 40 is instructed by a bearing (not shown) so as to be rotatable around a rotation center axis coincident with the optical axis of the focus lens 10 with respect to the housing 80.
The rotary cylinder 40 is formed of, for example, a metal such as an aluminum-based alloy or an engineering plastic.

The motor 50 is an electric actuator that drives the rotary cylinder 40 to rotate about the rotation center axis with respect to the housing 80.
The motor 50 is configured, for example, concentrically with the rotary cylinder 40 and is configured as an annular motor provided on the outer diameter side of the rotary cylinder 40.
The stator (not shown) of the motor 50 is fixed to the housing 80 via the motor holder 60.
The rotor (not shown) of the motor 50 is fixed to the rotary cylinder 40.
The motor 50 is controlled by a control device (not shown) such that the rotation speed of the rotary cylinder 40 substantially matches a desired target rotation speed.
The target rotation speed of the rotary cylinder 40 is, for example, about 15,000 to 20,000 rpm.

The motor 50 rotates the wedge prism 20 together with the rotary cylinder 40 so that the rotation center axis of the rotary cylinder 40 is orthogonal to the surface near the irradiation position of the irradiation target O, and the motor 50 rotates the wedge prism 20. Scans in a circular arc around the rotation center axis of the rotary cylinder 40 along the surface of the irradiation object O.
When the irradiation head 1 is translated along the surface of the irradiation target O in this state, the beam spot BS scans the surface of the irradiation target O while turning in an arc shape.
Thus, when focusing on an arbitrary point on the irradiation target O, the laser light R is pulsed only for a short time of, for example, about several msec, and rapid heating and rapid cooling are sequentially performed in a short time. Will be
At this time, an object to be cleaned such as an old coating film, rust, a film, or the like formed on the surface of the object O to be irradiated, or an attached foreign substance is crushed and scattered.

The motor holder 60 is a support member that holds the stator of the motor 50 at a predetermined position inside the housing 80.
The main body of the motor holder 60 is formed in a cylindrical shape, and is fixed to the housing 80 while being inserted into the inner diameter side of the housing 80.
The inner peripheral surface of the motor holder 60 is disposed so as to face the outer peripheral surface of the motor 50, and is fixed to a stator of the motor 50.

A purge gas passage 61 through which a purge gas PG flows is formed at a part of the interval between the outer peripheral surface and the inner peripheral surface of the motor holder 60.
When the irradiation head 1 is used (at the time of irradiation), the purge gas PG is moved from the space S where the surface of the protective glass 30 on the side of the irradiation target O in the inside of the inner cylinder 91 of the duct 90 described later contacts the irradiation target O side. It is a gas that is blown out to The surface portion of the protection glass 30 on the irradiation object O side is arranged to be exposed inside the space S.
The purge gas PG prevents dust such as old paint film, rust, and film fragments scattered from the irradiation object O side, and foreign matter such as spatter from coming into the housing 80 and adhering to the protective glass 30. Has functions.
The purge gas passage 61 is an opening formed so as to penetrate a part of the motor holder 60 in the axial direction of the motor 50.
The purge gas PG that has flowed out of the purge gas flow channel 61 is introduced to the inner diameter side of the inner cylinder 91 of the duct 90 via a flow channel provided in the housing 80.
For example, a fluid supply source such as a cylinder or a gas generator and each flow path in the irradiation head 1 cooperate to function as a fluid supply unit according to the present invention.

The protective glass holder 70 is a member fixed to the inner diameter side of the housing 80 while holding the protective glass 30.
The protective glass holder 70 is formed, for example, in a disk shape having a circular opening in the center.
The laser beam R passes from the wedge prism 20 side to the irradiation object O side through the opening.
A concave portion into which the protective glass 30 is fitted is formed on the surface of the protective glass holder 70 on the irradiation object O side.
The protective glass 30 is held inside the housing 80 in a state of being fitted into the concave portion.
The protection glass 30 is detachably attached to the protection glass holder 70 so that it can be replaced when contamination or burning occurs.
The surface of the protective glass holder 70 on the side opposite to the irradiation object O side is disposed facing the end face of the motor holder 60 on the irradiation object O side with a space.
This interval constitutes a part of the flow path (part of the fluid supply part) for introducing the purge gas PG introduced from the purge gas flow path 61 of the motor holder 60 into the space S on the irradiation target O side of the protective glass 30. I do.

The housing 80 is a cylindrical member that forms a housing of the main body of the irradiation head 1.
Inside the housing 80, in addition to the focus lens 10, the wedge prism 20, the protective glass 30, the rotary cylinder 40, the motor 50, the motor holder 60, the protective glass holder 70, and the like, an end of a fiber (not shown) on the irradiation head 1 side is provided. And a collimating lens.

The duct 90 is a double cylindrical member provided to protrude from the end of the housing 80 on the irradiation object O side.
The duct 90 has an inner cylinder 91, an outer cylinder 92, a dust collector connection cylinder 93, and the like.
The motor holder 60, the protective glass holder 70, and the housing 80 described above are formed of, for example, a metal such as an aluminum alloy, engineering plastic, or the like.

The inner cylinder 91 is formed in a cylindrical shape.
The laser light R passes through the inner diameter side of the inner cylinder 91 and is emitted to the irradiation object O side.
At the end of the inner cylinder 91 on the housing 80 side, there is formed a small-diameter portion 91a formed in a stepwise smaller diameter than other portions.
A purge gas PG is introduced into the space S inside the small diameter portion 91a from inside the housing 80.

At the end of the inner cylinder 91 on the irradiation object O side, a tapered portion 91b tapered so that the irradiation object O side has a small diameter is formed.
The tapered portion 91b has a function of increasing the flow velocity by restricting the air flow of the purge gas PG while permitting the passage of the laser light R.

The outer cylinder 92 is a cylindrical member arranged concentrically with the inner cylinder 91, and is provided on the outer diameter side of the inner cylinder 91.
A continuous gap is formed between the inner peripheral surface of the outer cylinder 92 and the outer peripheral surface of the outer cylinder 91 over the entire circumference.
At the end of the outer cylinder 92 on the housing 80 side, there is formed a small-diameter portion 92a that is formed in a stepwise smaller diameter than other portions.
The small-diameter portion 92a is fixed in a state of being fitted to an end of the housing 80 on the irradiation object O side.
The edge of the end portion 92b on the irradiation object O side of the outer cylinder 92 is rotated so that the upper part in normal use when irradiating with the rotation center axis of the rotary cylinder 40 being horizontal is closer to the housing 80 than the lower part. It is formed to be inclined with respect to the rotation center axis of the cylinder 40.
The space between the end 92b of the outer cylinder 92 and the inner cylinder 91 functions as a suction port of the dust suction portion according to the present invention.

The dust collector connection cylinder 93 is a cylindrical cylinder that protrudes from the outer cylinder 92 to the outer diameter side and is connected in a state of communicating with the inner diameter side of the outer cylinder 92.
The dust collector connection cylinder 93 is provided below the outer cylinder 92 during normal use described above.
The dust collector connection cylinder 93 is arranged obliquely with respect to the outer cylinder 92 so as to approach from the irradiation object O side to the housing 80 side and to be separated from the outer cylinder 92.
One end of the dust collector connection cylinder 93 is connected to the outer cylinder 92 near the irradiation object O side end of the outer cylinder 92 so as to communicate with the inside of the outer cylinder 92.
The other end of the dust collector connection tube 93 is connected to a dust collector (not shown), and is vacuum-evacuated so that the inside thereof has a negative pressure.

In the first embodiment, by rotating the rotary cylinder 40 and the wedge prism 20 while emitting the laser light R, the beam spot BS turns on an arc of a predetermined radius along the surface of the irradiation target O. .
In this state, by performing translational movement of the irradiation head 1 along the surface of the irradiation target O, it is possible to perform a cleaning process in which the beam spot BS scans the surface of the irradiation target O.

In the first embodiment, an inert gas such as a nitrogen gas, which also functions as a shielding gas, is used as the purge gas PG.
This inert gas is used to make the region including the beam spot BS and its turning radius (in the scanning pattern) into an atmosphere filled with nitrogen and to be shielded from oxygen.

According to the first embodiment described above, the following effects can be obtained.
(1) By filling the beam spot BS with a purge gas PG such as nitrogen gas, the irradiation target O is prevented from coming into contact with oxygen when the temperature becomes high due to the incidence of the laser beam R, and the oxide film is formed. Can be prevented from being formed.
Further, by turning the beam spot BS in an arc-shaped scanning pattern, it is possible to prevent the same spot on the surface of the irradiation target O from being continuously irradiated for a long time even when the CW laser is used.
For this reason, it is possible to prevent a part of the irradiation target O from locally receiving excessive heat input to cause an undesirable heat influence. Further, a relatively wide range of the irradiation target O can be rapidly laser-processed.
(2) Since the purge gas PG is supplied to the irradiation target O through the space S in which the protective glass 30 is disposed, dust scattered from the irradiation target O by the irradiation of the laser beam R. This prevents foreign matter such as dust and spatter from flowing into the protective glass 30, thereby preventing contamination of the protective glass 30 and burning of the protective glass 30 due to the foreign matter attached to the surface of the protective glass 30 being heated by the laser beam R. Can be prevented.
(3) By sucking the dust from the suction port arranged adjacent to the beam spot BS, the dust generated by the irradiation of the laser beam R is reattached to the irradiation target O, thereby impairing the quality of laser processing. Can be prevented.
In addition, it is possible to prevent dust from scattering to the surroundings and to improve the environment of the construction site.
(4) The gap between the inner cylinder 91 that supplies the purge gas PG made of nitrogen gas to the irradiation object O and the outer cylinder 92 arranged on the outer diameter side of the inner cylinder 91 is used as the suction port, so that the focal position is compactly configured. In addition to reliably supplying nitrogen gas, dust can be sucked from the surroundings.

<Second embodiment>
Next, a laser irradiation apparatus and a laser processing method according to a second embodiment of the present invention will be described.
In each of the embodiments described below, the same portions as those in the previous embodiment are denoted by the same reference numerals, and description thereof will be omitted, and different points will be mainly described.

FIG. 2 is a sectional view of the laser irradiation head according to the second embodiment.
FIG. 3 is an external perspective view of an emission-side end of the laser irradiation head according to the second embodiment.
The irradiation head 1 according to the second embodiment cuts off the irradiation spot (beam spot BS) by the laser beam R on the surface of the irradiation target and the area in the vicinity thereof, from the outside air, instead of the duct 90 in the first embodiment. The nozzle 100, the nozzle cap 110, the support 120, the support base 130, the shield gas introducing cylinder 140, and the like are provided to make the shield gas SG filled (shield gas atmosphere).
The shielding gas SG is the second fluid according to the present invention.
Further, in the second embodiment, for example, air is used as the purge gas PG.
The purge gas PG is the first fluid according to the present invention.

FIG. 4 is an enlarged cross-sectional view of the vicinity of the nozzle in the laser irradiation head according to the first embodiment, showing a state in which the shielding gas is ejected.
As the shielding gas SG, for example, an inert gas such as a nitrogen gas or an argon gas can be used.

The nozzle 100 cooperates with the nozzle cap 110 to eject the shielding gas SG supplied from the inside of the column 120 toward the irradiation object O side.
The nozzle 100 functions as the second fluid supply unit according to the present invention in cooperation with the nozzle cap 110, the support 120, and the like.
The nozzle 100 is disposed so as to protrude toward the irradiation target O with respect to the housing 80.
The nozzle 100 is formed by integrally forming a cylindrical portion 101, a flange portion 102, a tapered portion 103, and the like with a metal material such as an aluminum alloy.
The cylindrical portion 101 is formed in a cylindrical shape, and is arranged concentrically with the rotation center axis of the rotary cylinder 40.
The laser light R passes through the inner diameter side of the cylindrical portion 101 and is emitted toward the irradiation target O side.

The flange portion 102 is a surface portion formed so as to protrude from an end of the cylindrical portion 101 on the housing 80 side toward the outer diameter side in a brim shape.
The flange portion 102 is formed in a disk shape having a circular opening through which the laser beam R passes at the center.
The end of the support column 120 on the irradiation object O side is fixed to the flange portion 102.

  The tapered portion 103 is formed by tapering the outer peripheral surface near the end of the cylindrical portion 101 on the irradiation object O side (the side opposite to the flange portion 102 side) so that the outer diameter of the irradiation object O side is reduced. It is formed in a shape.

The nozzle cap 110 is a cylindrical member provided on the outer diameter side of the tapered portion 103 of the nozzle 100.
The nozzle cap 110 is formed in a tapered cylindrical shape having the same taper angle as the tapered portion 103.
As shown in FIG. 4, a gap G that functions as a discharge hole for the shield gas SG is provided between the inner peripheral surface of the nozzle cap 110 and the surface of the tapered portion 103 (the outer peripheral surface of the nozzle 100). It is provided over the entire circumference.

The shield gas SG such as nitrogen gas supplied from the support 120 to the nozzle 100 is supplied into the gap G.
The shield gas SG supplied to the gap G is ejected from the entire circumference of the nozzle 100 to the irradiation object O side.
At this time, the shielding gas SG is jetted in a cylindrical curtain shape surrounding the area including the beams 1 pot BS.
A part of the shield gas SG that has collided with the irradiation target O reverses the traveling direction, and forms an airflow A traveling from the outer diameter side to the inner diameter side of the nozzle 100 and further toward the housing 80 side.
Such an inverted air flow A has a function of preventing a purge gas PG such as air from flowing into the vicinity of the irradiation location.
Another part of the shielding gas SG that has collided with the irradiation object O is an air current that travels along the surface of the irradiation object O from the collision point with the irradiation object O toward the outer diameter side of the nozzle 100. Form B.

The support 120 is a member that extends from the housing 80 to the irradiation target O side and is a member that supports the nozzle 100 and the like.
The support column 120 is formed, for example, in a cylindrical shape extending along a direction parallel to the rotation center axis of the rotary cylinder 40.
The end of the support 120 on the irradiation object O side is fixed to the flange 102 of the nozzle 100.
An end of the support 120 on the housing 80 side is fixed to a surface of the support base 130 on the nozzle 100 side.
The shielding gas SG introduced from the shielding gas introduction cylinder 140 is supplied to the nozzle 100 after passing through the inside of the support 120, and is ejected from a gap between the tapered portion 103 and the nozzle cap 110.
A plurality of columns 120 are provided at equal intervals in the circumferential direction of the nozzle 100 (for example, four columns are provided in the case of the first embodiment).

The support base 130 is an annular member attached to the housing 80 via the shield gas introduction tube 140.
The support base 130 is a base to which the end of the support 120 on the housing 80 side is fixed.
The support base 130 is formed with a flow path for introducing the shield gas SG introduced from the shield gas introduction cylinder 140 to the inner diameter side of the support 120.

The shield gas introduction cylinder 140 is a cylindrical member formed to protrude from the end of the housing 80 on the irradiation object O side.
A column base 130 is attached to the protruding end (the end on the nozzle 100 side) of the shielding gas introduction cylinder 140.
A connection portion 141 is formed on the outer peripheral surface of the shield gas introducing cylinder 140 to which a conduit for supplying the shield gas SG from a shield gas supply source (not shown) is connected.
The shield gas SG introduced from the connection part 141 is introduced into the flow path of the support base 130.

The surface portion of the protective glass 30 on the irradiation object O side is arranged so as to be exposed in the space portion S on the inner diameter side of the shield gas introducing cylinder 140 (a state in contact with the space portion S).
The purge gas PG introduced into the housing 80 via the purge gas flow channel 61 of the motor holder 60 is introduced into the space S on the inner diameter side of the shield gas introduction cylinder 140, and is irradiated from the inner diameter side of the support base 130 to the irradiation target. It flows out to the object O side.

The flow rate, flow rate, and the like of the purge gas PG are set in consideration of preventing dust (dust), spatter, and the like scattered from the irradiation target O from reaching the protective glass 30 and attaching thereto.
The shield gas introduction cylinder 140 functions as a first fluid supply unit according to the present invention in cooperation with the support base 130, the housing 80, the purge gas flow channel 61 of the motor holder 60, and the like.

The irradiation head 1 further has a purge gas deflection nozzle 150.
The purge gas deflection nozzle 150 is injected into the gas flow of the purge gas PG flowing out from the support base 130 to the irradiation target O side so as to intersect from the radial outside of the support base 130 to generate a collision air flow.
The purge gas deflection nozzle 150 is provided, for example, above the irradiation head 1 during normal use.
As a result, the purge gas PG is deflected to the opposite side (in this case, downward) to the side where the purge gas deflection nozzle 150 is provided, and is prevented from flowing into the irradiation location.
The purge gas deflecting nozzle 150 is a fluid deflecting unit and a fluid flow generating means according to the present invention.

According to the second embodiment described above, the following effects can be obtained.
(1) The beam spot BS and its peripheral portion can be set to an atmosphere filled with a shielding gas SG made of an inert gas, nitrogen gas. Oxygen is blocked by the shielding effect, and irradiation is performed at the beam spot BS. It is possible to prevent the surface of the object O from being oxidized to form an oxide film or the like.
On the other hand, by using relatively low-cost and easy-to-use air as the purge gas PG for preventing contamination of the optical system and the like, the use amount of the shield gas SG is suppressed, and the running cost (construction cost) of the apparatus is reduced. At the same time, it is possible to simplify the device configuration such as a gas supply source (for example, an inert gas cylinder or a generator).
(2) When the CW laser is used by rotating the wedge prism 20 around the optical axis of the condensing optical system 10 and scanning the beam spot BS while turning the surface of the irradiation target O along an arc. Even in this case, it is possible to prevent the same location on the surface of the irradiation target O from being continuously irradiated for a long time. For this reason, it is possible to prevent a part of the irradiation target O from locally receiving excessive heat input to cause a thermal effect.
Further, a relatively wide range of the irradiation target O can be rapidly laser-processed.
(3) By forming the nozzle 100 into an annular shape on the inner diameter side through which the laser beam R passes, a region including the beam spot BS near the surface of the irradiation target O is appropriately filled with the shielding gas SG with a simple configuration. Atmosphere can be.
(4) The gap G between the tapered portion 103, which is the ejection hole of the nozzle 100, and the nozzle cap 110 is inclined with respect to the optical axis of the laser light R so as to be directed toward the inner diameter side of the annular nozzle 100. The area including the beam spot BS can be more reliably set as the atmosphere filled with the shielding gas SG.
(5) The nozzle 100 is supported by the support base 120 from the support base 130 provided at the distal end of the housing 80, and the support 120 has a flow path for the shield gas SG therein. And the supply of the shield gas SG from the main body side (housing 80 side) of the irradiation head 1 to the nozzle 100 side.
Further, the purge gas PG flowing out of the space S can be discharged from a gap provided between the plurality of columns 120, and the atmosphere in which the purge gas PG flows near the beam spot BS and is filled with the shield gas SG is provided. Damage can be prevented.
(6) The air flow jetted from the purge gas deflection nozzle 150 is jetted into the air flow of the purge gas PG so as to intersect with the air flow, thereby deflecting the main flow direction of the purge gas PG and causing the purge gas PG to flow into the vicinity of the beam spot BS. This prevents the region including the beam spot BS from being more reliably filled with the shielding gas SG.
Further, by setting the flow velocity, flow rate, direction, collision location, and the like of the air flow ejected from the purge gas deflection nozzle 150, the degree of freedom in controlling the deflection of the air flow composed of the purge gas PG can be increased.

<Third embodiment>
Next, a third embodiment of a laser irradiation apparatus and a laser processing method to which the present invention is applied will be described.
The same parts as those in the above-described second embodiment are denoted by the same reference numerals, and description thereof will be omitted, and different points will be mainly described.
FIG. 5 is a cross-sectional view of an irradiation head in the laser irradiation apparatus according to the third embodiment.
FIG. 6 is a view taken along the line VI-VI in FIG.
The irradiation head 1 according to the third embodiment includes a purge gas deflection plate 160 described below that functions as a deflector instead of the purge gas deflection nozzle 150 according to the second embodiment.
The purge gas deflecting plate 160 is the fluid deflecting unit and the deflecting member according to the present invention.

The purge gas deflecting plate 160 is provided at an intermediate portion in the longitudinal direction of the support column 120, closes a part of a region through which the purge gas PG passes, interferes with a part of the air flow of the purge gas PG, and prevents the passage thereof. It has a function of deflecting the main flow direction in the traveling direction of the purge gas PG in a direction away from the purge gas deflecting plate 160 (downward during normal use in the case of the third embodiment).
In the third embodiment, as shown in FIG. 6 and the like, the purge gas deflecting plate 160 is formed in a crescent shape in which the plane through which the laser beam R passes is concave when viewed from the rotation center axis direction of the rotary cylinder 40. Have been.
The purge gas deflecting plate 160 is provided in an upper region during normal use of the irradiation head 1, and the main flow of the purge gas PG is generated by a pressure difference between a region where a part of the purge gas PG collides with the purge gas deflecting plate 160 and another region. Is a deflector that deflects downward as shown in FIG.
The purge gas deflection plate 160 functions as a deflection member according to the present invention.

  According to the third embodiment described above, in addition to the effect similar to the effect of the second embodiment described above, the purge gas PG such as air flows into the vicinity of the irradiation location by a simple configuration that does not require power or the like. And the area around the beam spot BS can be more reliably filled with a shielding gas such as nitrogen.

<Fourth embodiment>
Hereinafter, a laser irradiation apparatus and a laser processing method according to a fourth embodiment of the present invention will be described.
FIG. 7 is a cross-sectional view of the irradiation side end of the irradiation head according to the fourth embodiment.
FIG. 8 is an external perspective view of the irradiation side end of the irradiation head according to the fourth embodiment.
The irradiation head of the fourth embodiment has a purge gas deflection plate 170 described below instead of the purge gas deflection plate 160 of the third embodiment, and a dust suction duct 180 described below is provided around the nozzle 100. is there.
The purge gas deflection plate 170 is a deflection member (deflector) provided over the entire circumference of the region through which the laser light R passes, as shown in FIGS.
The purge gas deflecting plate 170 is formed in a flat disk shape, and has a circular opening at the center where the laser beam R passes.
The purge gas deflecting plate 170 is fixed to the outer peripheral surface of the support column 120 in a concave portion formed by denting the outer peripheral edge toward the inner diameter side.
As shown in FIG. 7, the purge gas deflection plate 170 has one end (upper end in normal use) in the diameter direction closer to the nozzle 100 than the other end (lower end in normal use). In addition, it is arranged to be inclined with respect to the rotation center axis of the rotary cylinder 40.
The normal direction of the purge gas deflection plate 170 is inclined by θp shown in FIG. 7 with respect to the optical axis of the light collecting optical system 10 (substantially parallel to the direction in which the main flow of the purge gas PG proceeds).

The dust suction duct 180 is a cylindrical member provided around the periphery of the periphery of the nozzle 100.
The dust suction duct 180 is formed in a cylindrical shape concentric with the rotation center axis of the rotary cylinder 40.
The inner peripheral surface of the dust suction tact 180 is disposed facing the outer peripheral surface of the nozzle cap 110 and the inner cylinder 183 with a space therebetween.

The end 181 of the dust suction duct 180 on the irradiation object O side is formed along a plane orthogonal to the central axis of the dust suction duct 180.
The ends of the nozzle 100 and the nozzle cap 110 on the irradiation target O side are arranged to protrude from the end of the dust suction duct 180 toward the irradiation target O side.
A flange 182 projecting toward the inner diameter side is formed at an end of the dust suction duct 180 on the side of the support base 130.
The inner peripheral edge of the flange 182 is in contact with the surface of the column 120 or is arranged with a small gap.

The inner cylinder 183 is a cylindrical member that is concentrically arranged on the inner diameter side of the dust suction duct 180 in a region closer to the support base 130 than the nozzle 100.
The inner peripheral surface of the inner cylinder 183 is in contact with the surface of the column 120 or is opposed with a small gap.
A gap is formed between the outer peripheral surface of the inner cylinder 183 and the inner peripheral surface of the dust suction duct 180, through which the sucked dust and the like can pass.

A dust collector connection tube 190 is connected to the dust suction duct 180.
The dust collector connection cylinder 190 is a cylindrical cylinder that protrudes from the dust suction duct 180 to the outer diameter side and is connected in a state of communicating with the inner diameter side of the dust suction duct 180.
The dust collector connection cylinder 190 is provided below the dust suction duct 180 during normal use.
The dust collector connection cylinder 190 is inclined with respect to the dust suction duct 180 so as to approach the column base 130 side from the irradiation object O side and separate from the dust suction duct 180.
One end of the dust collector connection tube 190 is connected to the dust suction duct 180 on the peripheral surface of the dust suction duct 180 so as to communicate with the inside of the dust suction duct 180.
The other end of the dust collector connection tube 190 is connected to a dust collector (not shown), and is vacuum-evacuated so that the inside thereof has a negative pressure.

  According to the fourth embodiment described above, the amount of use of the shielding gas SG is reduced as in the second and third embodiments, and the dust collection function similar to that in the first embodiment is added to reduce the amount of the irradiation object O. The surface can be prevented from being contaminated, and the construction environment can be improved.

<Fifth embodiment>
Next, a fifth embodiment of a laser irradiation apparatus and a laser processing method to which the present invention is applied will be described.
FIG. 9 is a cross-sectional view of an irradiation head in the laser irradiation apparatus according to the fifth embodiment.
The irradiation head 1 according to the fifth embodiment is different from the purge gas deflection nozzle 150 according to the second embodiment in that a shield 120 is provided inside a part of the columns 120 (for example, one or two columns when four columns 120 are present). In addition to introducing the purge gas PG instead of the gas SG, the purge gas PG (for example, air) is ejected from the injection hole 121 formed in the support 120 toward the main flow direction of the purge gas PG flowing out of the space S.
The support 120 into which the purge gas PG is introduced is closed before the nozzle 100 so that the purge gas PG does not flow into the nozzle 100 and mix with the shield gas SG.
According to the fifth embodiment described above, the same effect as that of the second embodiment can be obtained with a simple configuration in which the number of components is reduced.

<Sixth embodiment>
Next, a sixth embodiment of a laser processing method according to the present invention, which is an embodiment of a fluid supply device to which the present invention is applied, will be described.
In the sixth embodiment, a fluid supply device 500 described below is attached to an irradiation target O, and the surroundings of the irradiation location are set to an atmosphere filled with a shield gas SG. Irradiate with R and scan.

FIG. 10 is an external view of the fluid supply device according to the embodiment.
FIG. 10A is a diagram of the fluid supply device as viewed from the irradiation head side (the normal direction of the irradiation target surface).
FIG. 10B is a view taken along a line bb in FIG. 10A.
FIG. 11 is a cross-sectional view illustrating a state when the fluid supply device of the embodiment is used.

The fluid supply device 500 includes a cover 510, a shield gas supply tube 520, a dust collector connection tube 530, and the like.
The cover unit 510 is a container-like member attached to the irradiation target O so as to cover the irradiation location.
The cover portion 510 has a side surface portion 511, a top surface portion 512, an opening 513, a flange 514, and the like.

The side surface portion 511 is a wall portion formed so as to rise vertically from the surface of the irradiation object O.
The side surface portion 511 is formed so that, for example, the shape viewed from the irradiation head side (the normal direction of the surface of the irradiation target O) is rectangular.
The top surface portion 512 is a surface portion provided at an end of the cover portion 510 on the irradiation head side (the side opposite to the irradiation target O side).
The top surface portion 512 is formed in a rectangular flat plate shape.
The peripheral portion of the top surface portion 512 is connected to the end of the side surface portion 511 on the side opposite to the irradiation object O side over the entire circumference.
The opening 513 is a through hole formed at the center of the top surface 512.
The opening 513 is formed in such a size and shape that the laser beam R is irradiated from the irradiation head and the laser beam R is not blocked when the beam spot BS scans the surface of the irradiation target O.
The flange 514 is formed at the periphery of the opening 513 so as to rise from the top surface 512 to the irradiation head side.

The shield gas supply cylinder 520 is a fluid supply unit to which a shield gas SG mainly containing an inert gas is supplied from a shield gas supply device (not shown).
The shield gas supply cylinder 520 protrudes outside the cover 510 from a region of the one side wall 511 close to the irradiation target O, and is formed to communicate with the inside of the cover 510.

The dust collector connection tube 530 is a dust collector to which a dust collector (not shown) is connected and which sucks dust generated inside the cover unit 510.
The dust collector connection cylinder 530 protrudes from the center of the side wall 511 opposite to the shield gas supply cylinder 520 to the outside of the cover 510, and is formed to communicate with the inside of the cover 510.

According to the embodiment of the fluid supply device described above and the laser processing method of the sixth embodiment, the following effects can be obtained.
(1) A general-purpose irradiation head having no fluid supply function by irradiating the laser beam R from the opening 513 of the cover 510 in a state where the fluid supply device 500 is attached to the irradiation target O and the shield gas SG is supplied. Even when is used, laser processing can be performed in an atmosphere filled with an inert gas, and generation of oxides can be prevented.
(2) Since the fluid supply device 500 is provided with the dust suction device connecting tube 530 connected to the dust suction device, the dust generated by the irradiation of the laser beam R adheres again to the irradiation target O to improve the quality of the laser processing. Damage can be prevented.
In addition, it is possible to prevent dust from scattering to the surroundings and to improve the environment of the construction site.

(Modification)
The present invention is not limited to the embodiments described above, and various modifications and changes are possible, and these are also within the technical scope of the present invention.
(1) The configurations of the laser irradiation device, the irradiation head, the fluid supply device, and the laser processing method are not limited to the above-described embodiments, and can be appropriately changed.
(2) In each embodiment, the deflection optical system is, for example, a single rotating wedge prism, but a plurality of such wedge prisms may be used in combination. Such a plurality of wedge prisms may be configured to rotate integrally, or may be configured to rotate independently.
Further, instead of the wedge prism or together with the wedge prism, another kind of deflection optical system such as a galvanometer mirror may be used.
(3) In the second to fifth embodiments, the first fluid is air as an example, but another kind of gas, liquid, gas-liquid mixture, or the like may be used.
In addition, the second fluid is not limited to nitrogen gas, and other inert gases, other gases, liquids, gas-liquid mixtures, and the like can be used.
When it is desired to form a coating of a predetermined component on the surface of the irradiation target, a gas containing the raw material may be used.
For example, when an oxide film is intentionally formed on the surface of the irradiation object, a gas containing oxygen can be used.
(4) In the second embodiment, the airflow is deflected by colliding another airflow with the airflow of the purge gas PG, but instead or together with this, the airflow of the purge gas PG is sucked. A suction means may be provided.
(5) The laser processing in each embodiment is a cleaning process as an example, but the present invention is not limited to this and can be used for other purposes.
For example, it can be used for adjustment of a base before painting, formation of a coating for rust prevention and the like.
For example, by using a gas containing a high concentration of oxygen instead of the shield gas made of an inert gas as the second fluid, it is possible to form a corrosion-resistant oxide film on the metal surface.

DESCRIPTION OF SYMBOLS 1 Irradiation head 10 Focus lens 20 Wedge prism 30 Protective glass 40 Rotating cylinder 50 Motor 60 Motor holder 61 Purge gas flow path 70 Protective glass holder 80 Housing 90 Duct 91 Inner cylinder 91a Small diameter section 91b Tapered section 92 Outer cylinder 92a Small diameter section 92b End section 93 Dust collector connection cylinder 100 Nozzle 101 Cylindrical part 102 Flange part 103 Taper part 110 Nozzle cap 120 Column 121 Injection hole 130 Column base 140 Shield gas introduction cylinder 141 Connection part 150 Purge gas deflection nozzle 160 Purge gas deflection plate 170 Purge gas deflection plate 180 Dust suction duct 181 End part 182 Flange 183 Inner cylinder 190 Dust suction unit connection cylinder 500 Fluid supply device 510 Cover part 511 Side part 512 Top surface part 513 Opening 514 Flange 52 Shielding gas supply cylinder 530 dust collector connecting tube O irradiation target R laser beam BS beam spot PG purge SG shield gas S space

Claims (23)

A focusing optical system that focuses laser light generated by a laser oscillator at a predetermined focal position,
An optical system including a deflection optical system that deflects the laser light and scans the focal position along a surface of the irradiation target in a predetermined scanning pattern;
A laser supply unit for supplying a fluid containing an inert gas as a main component to a region including the scanning pattern at the focal position to make at least the focal position an atmosphere filled with the fluid. apparatus. The fluid supply unit supplies the fluid to a space in contact with a surface portion on the focal position side of an optical element arranged closest to the focal position side of the optical elements constituting the optical system, and supplies the fluid to the space unit. The laser irradiation device according to claim 1, wherein the laser light is caused to flow out of a space to the focal position side. 3. A dust collecting unit having a suction port arranged adjacent to the focal position and sucking dust generated by irradiating the irradiation target with the laser light. 4. A laser irradiation apparatus according to claim 1. An inner cylinder through which the laser light emitted from the optical system passes,
An outer cylinder provided on the outer diameter side of the inner cylinder,
The fluid supply unit supplies the fluid from the inner diameter side of the inner cylinder to the irradiation object side,
The laser irradiation device according to claim 3, wherein the dust collection unit sucks the dust from a gap between an outer peripheral surface of the inner cylinder and an inner peripheral surface of the outer cylinder. An optical system including a focusing optical system that focuses laser light generated by a laser oscillator at a predetermined focal position,
The first fluid is supplied to a space in contact with the surface on the focal position side of the optical element arranged closest to the focal position among the optical elements constituting the optical system, and the first fluid is supplied to the space. A first fluid supply unit that flows from the unit to the focal position side;
A second fluid having a composition different from that of the first fluid is supplied to a region including the focus position, the second fluid being provided closer to the focus position than the first fluid supply unit, and at least the focus position is set to the second position. And a second fluid supply unit configured to provide an atmosphere filled with the fluid. The laser irradiation apparatus according to claim 5, wherein the optical system includes a deflection optical system that deflects the laser light to scan the focal position along a surface of the irradiation target in a predetermined scanning pattern. . The deflection optical system includes a wedge prism that deflects the laser light by a predetermined deflection angle and that is driven to rotate around the optical axis of the laser light emitted from the focusing optical system. Item 7. A laser irradiation device according to Item 6. The laser irradiation apparatus according to any one of claims 5 to 7, wherein the first fluid has air as a main component, and the second fluid has an inert gas as a main component. . The second fluid supply unit includes a nozzle portion that has an ejection hole formed inside in a circumferential direction of a ring through which the laser light passes and that ejects the second fluid to an irradiation target. The laser irradiation apparatus according to any one of claims 5 to 8, wherein: The ejection hole of the nozzle portion is inclined toward the inside diameter of the ring with respect to the optical axis of the laser beam so that the second fluid is ejected from the outside diameter side to the inside diameter side of the ring. The laser irradiation apparatus according to claim 9, wherein the laser irradiation apparatus is provided. The nozzle unit is supported by a support extending from the first fluid supply unit or the vicinity thereof to the irradiation target side,
The said support | pillar has a flow path which supplies the said 2nd fluid to the said nozzle part. The laser irradiation apparatus of Claim 9 or Claim 10 characterized by the above-mentioned. The apparatus according to claim 5, further comprising: a dust collecting unit having a suction port arranged adjacent to the focal position and sucking dust generated by irradiating the irradiation target with the laser light. 13. The laser irradiation apparatus according to any one of the above items. The suction port of the dust collection unit is provided so as to extend in a circumferential direction around a location where the second fluid supply unit ejects the second fluid toward the irradiation target. The laser irradiation device according to claim 12, wherein 14. A fluid deflecting unit for deflecting a traveling direction of the first fluid supplied from the first fluid supply unit from an irradiation direction of the laser beam. The laser irradiation apparatus according to claim 1. The fluid deflecting unit is provided in at least a part of a peripheral direction of an optical axis of the light collecting optical system in a traveling direction of the first fluid, and interferes with a part of the first fluid. The laser irradiation device according to claim 14, further comprising: a deflecting member that deflects a traveling direction of the first fluid. The laser irradiation device according to claim 15, wherein a surface portion of the deflection member that interferes with the first fluid is arranged to be inclined with respect to an outflow direction of the first fluid. The said deflecting member has the surface part which was arrange | positioned facing the upstream of the said 1st fluid and which formed the opening through which the said laser beam passes in the center part. The Claim 15 or Claim 16 characterized by the above-mentioned. Laser irradiation equipment. The fluid deflecting unit includes a fluid flow generating unit that is injected so as to intersect with the fluid flow of the first fluid and generates another fluid flow that deflects the fluid flow of the first fluid. The laser irradiation apparatus according to claim 14, wherein The laser irradiation device according to claim 14, wherein the fluid deflecting unit includes a suction unit that sucks a fluid flow composed of the first fluid. A fluid supply device attached around an irradiation point where laser light irradiated by a laser irradiation device is incident on an irradiation target,
A cover portion having an opening through which the laser light passes, while being detachably attached to the irradiation target in a state surrounding the irradiation location,
A fluid supply unit that supplies a fluid containing an inert gas as a main component to the inside of the cover unit and makes at least the irradiation location an atmosphere filled with the fluid. 21. The fluid supply device according to claim 20, further comprising: a dust collection unit that has a suction port disposed inside the cover unit and suctions dust generated by the irradiation of the laser beam. A focusing optical system that focuses the laser light generated by the laser oscillator at a predetermined focal position,
A deflection optical system that deflects the laser light and scans the focal position along the surface of the irradiation object in a predetermined scanning pattern; and a laser that scans the surface of the irradiation object with laser light emitted from an optical system. Processing method,
A laser processing method, characterized in that a shielding gas containing an inert gas as a main component is supplied to a region including the scanning pattern at the focal position to set at least the focal position to an atmosphere filled with the shielding gas. A laser processing method for scanning the surface of an irradiation target with laser light emitted from an optical system including a focusing optical system that focuses laser light generated by a laser oscillator at a predetermined focal position,
The first fluid is supplied to the space where the one at the focal position side among the optical elements constituting the optical system is arranged, and the first fluid flows out of the space to the focal position side,
A laser processing method, characterized in that a second fluid having a composition different from that of the first fluid is supplied to a region including the focal position so that at least the focal position is set to an atmosphere filled with the second fluid.

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