JPH10286774A - Coating processing method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smoothly perform treatment such as peeling and cleaning of paint film and surface oxide even in the case of performing blast treatment using dry ice of low hardness. SOLUTION: Laser beam is pulse-radiated to a subject surface to be treated to form a number of fine holes 31a in only a coating layer such as a paint film on the surface, and dry ice grain is jetted to hole formed parts at high speed after or simultaneously as the fine holes 31a are formed. By wedge effect when the dry ice grain jetted at high speed to advance along a boundary surface between the subject surface and the paint film, and by volume expansion effect of it when it is gasified, coating 31 such as a paint film layer and surface oxide layer can be peeled or cleaned.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for treating a coating applied to peeling or cleaning of various coatings such as coatings and surface oxides applied to steel structures and the like. The present invention relates to a coating method for performing high-speed spraying to remove or wash a coating such as a coating or a surface oxide.

[0002]

2. Description of the Related Art Conventionally, shot blasting with a sand has generally been used as a method for peeling off and cleaning a coating film or a film on the surface of a steel structure. However, this method only deteriorates the working environment. In addition, there is a problem that the worker may be injured by the rebounded media (sand), and furthermore, it takes much time and cost to recover the media.

[0003]

As an alternative method, a processing method has recently been proposed in which dry ice particles are sprayed at high speed onto a target surface through compressed air to wash and peel off a coating film. ing. In the ice blasting process using such dry ice particles, since the dry ice particles as the spray material sublime after use, compared to the sand blasting process, the ice blasting process does not scatter around and degrade the environment. However, there is a merit that the processing ability is not required, but on the other hand, there is a disadvantage that the processing ability is remarkably low as compared with the sand blasting method because the hardness of the dry ice particles is low.

[0004] In view of the above technical problems, the present invention provides a coating treatment capable of smoothly performing a treatment such as peeling / cleaning of a coating film or a surface oxide even when blasting is performed using dry ice having low hardness. It is to provide a method and a device.

[0005]

According to the first aspect of the present invention,
After applying a pulse of laser light to the surface to be processed and forming a large number of micro-perforations only on various coating layers such as the coating film on the surface, or simultaneously with the formation of the micro-perforations, it is necessary to inject high-speed dry ice particles into the perforation forming part. Due to this, the dry ice particles sprayed at a high speed cause a wedge effect when developing along the boundary surface between the target surface and the coating film in the perforation and a volume expansion effect when gasifying, so that the coating film layer and the surface The coating such as an oxide layer is peeled off or washed. As the laser light used in the present invention, besides a YAG laser light capable of pulse oscillation, an excimer laser light or a harmonic laser light which is itself a pulsed laser can be used.

A second aspect of the present invention relates to an apparatus for achieving such a method smoothly, in which a beam scanning means for scanning a pulsed laser beam at a predetermined irradiation angle is used to jet dry ice particles at high speed. It is characterized by being integrally connected to the injection gun and configured to be movable with the injection gun. The high-speed injection of the dry ice particles is generally preferably performed at high speed through compressed air, but is not limited thereto.

According to the present invention, since a large number of microperforations can be formed only in the coating layer by forming an image of the pulsed laser beam on the coating surface, It is preferable to provide a focal length adjusting unit configured to be capable of adjusting the focal length of the laser beam scanned by the beam in accordance with the effective projection distance of the dry ice particles by the spray gun,
Further, by performing the optical scanning of the laser beam through the polygon mirror, the irradiation scanning angle can be set accurately and wide.

Further, in the present invention, since the dry ice particles are jetted to the perforation forming portion formed by the laser beam, the particle jet pattern shape from the jet gun nozzle as described in claim 4 is defined as follows. It is preferable to form the fan into a flat shape corresponding to the irradiation angle of the laser beam. Further, according to the present invention, a cable or a hose is provided by housing an optical fiber cable for transmitting the pulsed laser light in a supply hose for supplying dry ice particles or compressed air to the injection gun. There is no need to uselessly.

Further, according to a sixth aspect of the present invention, the ejection gun and the beam scanning means are integrally connected to each other, and the laser beam is emitted and the dry ice particles are ejected to the movable processing apparatus main body. An operation switch and a distance sensor for detecting a distance between a nozzle tip of the injection gun and a target surface are provided, and the switch can be operated only when a detection value of the sensor indicates a work allowable value. It is characterized by. According to a seventh aspect of the present invention, an operation switch for emitting laser light and injecting dry ice particles is provided on the processing apparatus main body, and a distance between a nozzle tip of the injection gun and a target surface is kept constant. A guide unit and a contact sensor for detecting that the guide unit has contacted the target surface are provided, and the switch is operable only when a contact detection signal from the contact sensor is obtained. In this case, it is preferable to provide a lamp for displaying the transmission of the YAG laser light in accordance with the above configuration.

According to this invention, when the processing apparatus body in which the beam scanning means and the injection gun are integrally formed is brought closer to the target surface, the distance between the nozzle of the target surface and the nozzle of the injection gun is detected by the distance sensor every moment. When the detected value reaches a workable allowable value, or when a contact sensor provided in a guide unit for keeping the distance between the injection gun nozzle tip and the target surface constant outputs a detection signal, The switch is automatically turned “ON”, or the switch becomes operable and turned on by manual operation, and the target surface is irradiated with laser light from the beam scanning means in a pulsed manner to paint the target surface. A number of microperforations are machined in the membrane layer. With a slight delay from this, or at the same time, dry ice particles are sprayed at high speed from the spray gun through the compressed air into the perforated portion, and the dry ice particles are applied to the target surface within the fine perforations in the coating film. It develops along the boundary surface between the surface and the coating film, and is rapidly expanded by gasification, and the coating film layer is sequentially peeled off from the surface of the target surface by the wedge effect and the volume expansion effect generated at this time.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be illustratively described in detail below with reference to the drawings. However, unless otherwise specified, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention thereto, but are merely illustrative examples. It's just FIG. 1 is an overall schematic view showing the principle of peeling a coating film (film) according to the embodiment of the present invention and the basic configuration of the apparatus, and is applied as a shot blast apparatus using dry ice particles. Reference numeral 1 denotes a coating film peeling gun, which sprays dry ice particles at high speed through compressed air.
And a beam scanner (optical scanning means) 3 for scanning (optical scanning) the pulse-transmitted YAG laser light 1 in an irradiation angle range. The spray gun 2 and the beam scanning means 3 And are configured to be able to operate simultaneously.

A YAG laser oscillator 6 is connected to the beam scanner 3 via an optical fiber 9.
As shown in (1), the YAG laser beam 1 transmitted from the oscillator 6 via the optical fiber 9 is optically scanned at a predetermined irradiation (scanning) angle while irradiating the coating film 31 on the processing target surface 30 in a pulsed manner. A compressor 4 for supplying compressed air via a high-pressure air hose 7 and a dry ice particle supply device 5 for purifying and supplying dry ice particles i via a supply hose 8 are connected to the injection gun 2. The apparatus 5 is further connected with an air dryer 5 ′ for producing dry air necessary for supplying dry ice particles,
To the coating film 31 via compressed air supplied from a high-pressure air hose 7 ′.

According to this configuration, the YAG laser beam 1 is radiated in a pulsed manner onto the surface 30 to be processed while being optically scanned at a predetermined irradiation angle to form a large number of minute perforations 31a in the coating film 31, and then the perforations are formed. The spray gun 2 injects dry ice particles i through the compressed air to the forming portion, and the dry ice particles i propagate along the boundary surface between the target surface 30 and the coating film 31 in the perforations 31a, Further, the coating film 31 can be peeled off from the surface of the target surface 30 by a wedge effect and a volume expansion effect that occur when the gas is rapidly expanded by gasification.

Next, the respective elements will be described in detail with reference to the drawings. First, the beam scanner 3 is generally constituted by a polygon mirror, for example, as shown in FIG.
The beam scanner 3 is installed in a case 23, and is a set of a lens group 24 that can arbitrarily adjust the focal length of the transmitted YAG laser 1 and a polygonal body (octagon in the figure) that rotates about an axis 25a. And a polygon mirror 25 having a reflection surface formed on the outer periphery of the lens group 24. The focal length of the YAG laser light 1 transmitted in a pulse form (intermittently) from the YAG laser By moving in the axial direction, it is possible to make appropriate adjustments according to the effective projection distance of the dry ice particles from the injection gun 2 to make the incident light incident on the polygon mirror 25, and a plurality of reflections of the polygon mirror 25 rotating at a predetermined speed. Optical scanning is performed while being sequentially deflected and reflected by the surface, and the target surface 3 is irradiated from the irradiation port 23a.
The beam is irradiated at a predetermined irradiation angle to 0, and as a result, a large number of minute perforations 31a are formed in the coating film 31 within the optical scanning width W.

FIG. 5 shows the construction of the spray gun 2 and the dry ice particle supply device 5. As shown in FIG. 5, a dry ice particle supply device 5 includes a fixed shaft 16a and a circular table 16 slidably supported by the fixed shaft 16a in a frame 14.
dry ice chunk I supported on a support member 16 made of b
Is pushed out along the receiving table 14a by the urging force of the spring 17 interposed on the back side of the circular table 16b, and is pressed against the cutting blade 19 attached to the tip of the shaft 18a of the motor 18 provided at the opposing position. The motor 18 is driven to cut the dry ice chunks I with the cutting blade 19 to purify the dry ice particles i, and has an opening 142 with a reduced diameter at the bottom provided below the pedestal 14a. It is accumulated on the hopper 141. Further, a dry air intake 14b is provided on the upper side of the hopper 141, and while the dry ice particles i are falling, the dry air supplied from the air dryer 5 'is blown to dry the dry ice particles i. After the hopper 141
To accumulate. Then, the dry ice particles i accumulated in the hopper 141 are transported using the conveying force of the dry air.
The supply hose 8 is configured to be supplied to the supply hose 8 from the outlet 15 connected to the hopper bottom opening 142.

On the other hand, the spray gun 2 has a nozzle 10 for spraying dry ice particles on a front wall of a frame 11, a nozzle 12 for compressed air intake connected to a high pressure air hose 7 on a rear wall, and a supply hose on a side wall. A dry ice particle i supplied from the side of the dry ice particle supply device 5 through the supply port 13 into the frame 11 through the nozzle 12 through the high pressure air hose 7. The compressed air blown into the frame 11 is used to eject the compressed air from the nozzle 10 to the target surface 30 together with the compressed air.

Here, the nozzle 10 for spraying dry ice particles
5A is formed in a flat fan shape as shown in FIG. 5A, and the light scanning width W of the YAG laser light
The outlet 10a having an outlet width W corresponding to
Further, as shown in FIG. 5 (B), it is formed flat so as to increase the injection efficiency.

2 and 3 show the configuration of the coating film peeling gun 1. FIG. 2A is a front view, and FIG. 2B is a cross-sectional view of the high-pressure air hose 7 (cross-sectional view taken along line AA). FIG. 3 is a plan view, in which the ejection gun 2 and the beam scanner 3 are arranged adjacent to each other so that the position of the ejection nozzle 10 and the position of the beam irradiation port 23a substantially coincide with each other, and both are integrally formed. , So that they can be simultaneously moved via the handle 20. The cross section of the high-pressure air hose 7 is shown in FIG.
As shown in (B), the optical fiber 9 is housed in the hose 7, so that the YAG laser light 1 and the compressed air can be transmitted and supplied by one hose.

Further, the coating film peeling gun 1 is provided with a lamp 26 for displaying the irradiation of the YAG laser light 1 and a distance sensor for detecting the distance between the nozzle 10a of the spray gun 2 and the target surface. 22 are installed. Further, the injection nozzle 10, the beam irradiation port 23a, and the distance sensor 2
They are arranged so that the distance to each of the two target surfaces is substantially horizontal. The detection signal of the distance sensor 22 is taken into the control circuit 29, and the operation permission control of the switch 21 provided on the handle 20 is performed. That is, when the distance detection value calculated by the control circuit 29 based on the detection signal of the distance sensor 22 is larger than the operable distance (allowable work value), the coating film peeling gun 1 does not operate even if the switch 21 is turned on. When the detected value reaches the work allowable value, the switch 21 is automatically turned “ON” or the switch 21 becomes operable and the YAG is manually operated by the beam scanner 3.
Irradiation of the laser beam 1 and ejection of the dry ice particles i from the ejection gun 2 are performed.

Next, the operation of the blast device will be described.
First, the position of the lens group 24 of the beam scanner 3 shown in FIG. 6 is properly set, and the focal length of the YAG laser beam 1 is measured as the effective projection distance of the dry ice particles of the injection gun 2 (previously measured).
To approximately match. When the work is started and the coating film peeling gun 1 picked up via the handle 20 shown in FIG. 2 is brought close to the target surface 30, the distance between the ejection gun 2 and the target surface 30 is detected every moment by the distance sensor 22, It is sent to the control circuit 29 of the gun 1. When the detected value reaches the allowable work value, the switch 21 is turned on to operate the gun 1, and the YAG laser light 1 is first pulsed from the beam scanner 3 to the target surface 30 and the polygon mirror 25 Is irradiated while optically scanning the range of the width W, whereby a large number of minute perforations 31a are formed in the coating film (or coating) 31 applied to the target surface 30. (Note that the pulse transmission control of the laser beam based on the detected value of the distance sensor is a step for improving work safety, and can be omitted if necessary.) Simultaneously or with a slight delay in timing The dry ice particles i are sprayed together with the compressed air from the spray gun 2 onto the perforated surface.

As a result, the dry ice particles i blown into the fine perforations 31a of the coating film 31 propagate along the boundary between the surface of the target surface 30 and the coating film 31 in the perforations 31a, and gasify and rapidly The coating layer 31 is sequentially peeled off from the surface of the target surface 30 by the wedge effect and the volume expansion effect generated at this time. Thus, by moving the coating film peeling gun 1 laterally (manually or automatically) at a predetermined speed via the handle 20, the work of peeling the coating film (film) 31 can be efficiently executed in units of the optical scanning width W. it can.

Further, as shown in FIG. 4, the same injection control can be performed by the guide wheel 33 and the contact sensor 34 built in the guide wheel 33. That is, in this embodiment, in order to keep the distance between the tip 10 of the nozzle 10 of the spray gun 2 and the target surface 30 constant,
The guide rod 32 is extended toward the target surface by a predetermined length, and a guide wheel 33 and a contact sensor 34 for detecting that the guide wheel 33 has contacted the target surface 30 are provided at the tip thereof. The switch 21 is configured to be operable only when a contact detection signal is obtained from the switch 34. In this embodiment, the same operation as the above embodiment can be obtained.

[0023]

As described above, according to the present invention, a laser beam is radiated to a surface to be processed in a pulse shape to form a large number of minute perforations in the coating film on the surface. The dry ice particles are irradiated through compressed air, and the coating film can be peeled off from the target surface by a wedge effect and a volume expansion effect generated when the dry ice particles blown into the perforations develop and expand. At this time, the focal length of the laser beam can be adjusted according to the projection distance of the dry ice particles, and the inside of the laser beam can be optically scanned to a predetermined width. Because it is formed in a fan shape and flat shape according to the scanning width, a large number of micro perforations are appropriately processed in the coating film in the optical scanning width range,
In addition, since the stripping process of the optical scanning width can be performed at a time, the working efficiency is greatly improved.

Further, since the projectile is dry ice particles,
The working environment does not deteriorate, and post-processing is not required.
Further, the switch circuit is controlled by monitoring the allowable working distance by the distance sensor, and furthermore, the irradiation of the YAG laser light can be indicated by a lamp, so that there is an effect that a safe work is ensured.

[Brief description of the drawings]

FIG. 1 is an overall schematic diagram showing the principle of peeling a coating film (film) and the basic configuration of the apparatus according to an embodiment of the present invention, and is applied as a shot blast apparatus using dry ice particles.

FIG. 2 shows a coating film peeling gun applied to FIG. 1 (A).
Is a front view, and (B) is a sectional view of the high-pressure air hose 7 (A-
FIG.

FIG. 3 is a plan view of the coating film peeling gun of FIG. 2;

FIG. 4 is a view showing a coating film peeling gun according to another embodiment applied to FIG. 1 and corresponding to FIG. 3;

FIG. 5A is an overall view showing an overall configuration of an injection gun 2 and a dry ice particle supply device 5, and FIG. 5B is a view taken along the line BB showing an opening of a particle injection nozzle.

FIG. 6 is a schematic configuration diagram of a beam scanner applied to FIG. 1;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 coating film peeling gun 2 injection gun 3 beam scanning means 4 compressor 5 dry ice particle supply device 5 ′ air dryer 6 YAG laser oscillator 7, 7 ′ high pressure air hose 8 supply hose 9 optical fiber 10 nozzle 20 handle 21 switch 21 Reference Signs List 22 distance sensor 24 lens group 25 polygon mirror 26 lamp 30 target surface 31 coating film (coating) 31a micro perforation 33 guide wheel 34 contact detection sensor

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Ichiro Masuda 4-6-22 Kannonshinmachi, Nishi-ku, Hiroshima-shi Hiroshima Works, Mitsubishi Heavy Industries, Ltd.

Claims (7)

[Claims] 1. A coating method in which dry ice particles are sprayed at a high speed to peel or wash a coating such as a coating film or a surface oxide. A coating treatment method comprising: spraying dry ice particles at a high speed onto a perforated portion after forming a large number of micro perforations only in the coating layer or simultaneously with the formation of the micro perforations. 2. A coating processing apparatus comprising a spray gun for spraying dry ice at a high speed for removing or cleaning a coating such as a coating film or a surface oxide. A film processing apparatus, wherein a beam scanning unit to be operated is integrally connected to the spray gun, and is configured to be movable together with the spray gun. 3. A focal length adjusting means configured to adjust a focal length of the laser beam to be beam-scanned in correspondence with an effective projection distance of dry ice particles by the spray gun, and a light scanning of the laser beam. 3. The film processing apparatus according to claim 2, wherein the step is performed via a polygon mirror. 4. The coating according to claim 2, wherein the shape of the particle ejection pattern from the nozzle of the ejection gun is formed in a fan-like and flat shape corresponding to the irradiation angle of the laser beam by the beam scanning means. Processing equipment. 5. An apparatus according to claim 2, wherein an optical fiber cable for transmitting said pulsed laser light is accommodated in a supply hose for supplying dry ice particles or compressed air to said injection gun. 6. An operation switch which integrally connects the injection gun and the beam scanning means and is configured to be movable, the operation switch for emitting laser light and injecting dry ice particles to the main body. And a distance sensor for detecting the distance between the nozzle tip of the injection gun and the target surface, wherein the switch is operable only when the detection value of the sensor indicates an allowable work value. The film processing apparatus according to claim 2, wherein 7. An operation switch which integrally connects the injection gun and the beam scanning means and is movable so as to emit laser light and eject dry ice particles to the main body. A guide portion for keeping a constant distance between the nozzle tip of the spray gun and the target surface, and a contact sensor for detecting that the guide portion has contacted the target surface, 3. The apparatus according to claim 2, wherein said switch is operable only when a detection signal is obtained.