JP2000170474A - Laser boring method and device of ceramic structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser boring method and a device of a ceramic structure capable of minimizing vibration and noise and capable of efficiently boring a large and deep horizontal hole in the ceramic structure. SOLUTION: In a laser boring method and a device of a ceramic structure 2, a laser beam 29 is irradiated to a horizontal hole boring part 3a of the ceramic structure 2 to melt a ceramic substance of the boring part 3a to form molten dross 35, and a resolidified material 38 solidified by cooling the molten dross 35 is heated and remelted on the lower edge side of an opening part 36 of a hole 3a formed in the boring part 3a by spraying the beam 29 and a heating heat source fluid 53 oscillated in the B1 direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for drilling (perforating) using a laser beam.
The present invention relates to a method and an apparatus for laser drilling a ceramic structure.

[0002]

2. Description of the Related Art When there is a risk of rocks and rocks falling in an area adjacent to a road, a public structure, a private house, or the like, in order to safely remove the rocks and rocks in advance, a rock drill or the like is conventionally used. A mechanical construction method is used.

[0003]

However, mechanical methods involve impacts and the like, so that not only is it difficult to avoid noise, but also unknown cracks and the like in rocks increase due to vibrations caused by impacts such as impacts. Unintentional collapse or collapse may occur. Further, in the mechanical construction method, a large-scale device and a heavy object are indispensable for applying and supporting a load such as cutting and hitting, but it is difficult to transport the equipment to a high place such as a cliff. In the mechanical construction method, it is necessary to apply a mechanical load in contact with a rock, a rock, or the like, which is likely to fall, so that a person is forced to approach a place close to a dangerous place.

[0004] In order to avoid vibration and noise caused by a mechanical construction method, it has also been proposed to conduct high-power laser light to an excavation site with an optical fiber and perform excavation using thermal energy by the laser light (particularly). JP-A-9-242453).

However, this proposal is limited to the idea of using laser light from a high-power laser oscillator such as an iodine laser. That is, when the present inventors irradiate a high-power laser beam to the rock surface to drill a horizontal hole in the rock, the molten dross resulting from the melting of the rock in the drilled portion is deposited and solidified to form a glass dross. As a result, it has been found that it is not easy to efficiently irradiate a large and deep hole by hindering the irradiation of the laser beam into the hole.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and an object of the present invention is to provide a ceramic structure capable of efficiently forming a large and deep horizontal hole in a ceramic structure while minimizing vibration and noise. An object of the present invention is to provide a method and an apparatus for laser drilling a structure.

[0007]

In order to achieve the above object, a laser drilling method for a ceramic structure according to the present invention irradiates a laser beam to a laterally drilled portion of a ceramic structure to thereby form a ceramic material in the drilled portion. A molten dross forming step of melting the molten dross to form a molten dross, and a re-melting step of heating and re-melting the re-solidified material that has been cooled and solidified at the lower edge side of the opening of the hole being formed in the perforated portion Having.

In the laser drilling method for a ceramic structure according to the present invention, there is provided a re-melting step in which a molten dross is cooled at a lower edge side of an opening of a horizontal hole being formed by drilling and the re-solidified material is heated and re-melted. Because during normal drilling, the re-solidified material generated by re-solidification at the lower edge side of the opening located outside the laser beam irradiation area can be re-melted and flow down in the re-melting stage, The laser beam can be effectively applied to the innermost part of the hole by minimizing the irradiation of the laser beam to the inner part of the hole by the re-solidified material. Can be done.

[0009] In the perforation method of the present invention, the ceramic material is melted by heat using the energy of the laser beam.
Perforation is performed by flowing, evaporating and dispersing, so it is essentially non-contact, does not actually generate noise or vibration, and supports the mechanical processing load unlike the mechanical construction method There is no need for heavy objects.

In this specification, a "ceramic structure" is a part of a natural structure such as a rock on a mountain surface (or a rock) or a rock (or a rock) forming a rock wall. Includes both objects (rocks) and man-made concrete structures, such as concrete columns and piers, used in seismic retrofitting of buildings. Here, the “concrete structure” includes a composite material such as so-called reinforced concrete or a mixture of different materials. In this specification, “rock”, “rock” and “rock” are used almost synonymously in the sense that they include huge stones, but depending on the context,
“Rock” refers to something larger than “rock”, and “rock” refers to something larger than “rock”. When referred to collectively, it is mainly referred to as "rock."

In the case where the ceramic structure is made of rock constituting a natural structure, it is often difficult to accurately detect the existence and distribution of cracks inside the rock. Since no cracks are given, there is no risk of spreading the cracks, and there is little risk of accidental collapse. Further, since the thermal conductivity of the ceramic material constituting the rock is low, the heating of the perforated portion by the laser beam becomes local heating, and the perforated portion can be perforated without generating new thermal stress in a peripheral portion away from the perforated portion.

When the ceramic structure is a structure made of a composite material such as reinforced concrete, when piercing a portion such as a reinforcing bar, if desired, the beam diameter is reduced by melting, or the beam is irradiated while blowing oxygen gas. May be performed to oxidize and cut or melt.

The oscillator of the laser beam to be irradiated on the ceramic structure has a high output, for example, an output (or an average output).
Is preferably capable of generating a laser beam on the order of kilowatts (kW) or more, and includes, for example, a YAG laser device or a carbon dioxide gas laser device. Note that an iodine laser device may be used. As long as the (average) output is of the kW class, a type that generates a continuous wave or a type that generates a pulse may be used. Depending on the type of ceramic material, a beam diameter of 1
In the case of about 0 to 20 mm, the output is typically 2
３3 kW or more, preferably 4 kW or more, more preferably 5 kW or more. From the viewpoint of easiness in transmitting a beam to a high place, a YAG laser capable of transmitting a beam using a glass fiber or the like is more preferable than a long-wavelength laser such as a carbon dioxide laser.

[0014] Preferably, the beam is a parallel ray or a near parallel ray. In this specification, “parallel rays” or “quasi-parallel rays” are collectively referred to as “substantially” parallel rays. "Pseudo-parallel rays" are typically
It consists of a convergent beam focused by a long focus lens. The term “long focal length” means that the focal length is sufficiently long as compared with a hole to be formed by drilling (for example, 15 to 20 cm). For example, the focal length is 2-3 times the depth of the hole. It means that it is at least twice, preferably at least 5 to 10 times. One reason for using substantially parallel rays as the beam is that when the ceramic structure to be irradiated is a natural rock or the like, its surface has considerable irregularities. That is, temporarily
When trying to focus the beam to a very small spot diameter, the allowable range in the depth direction becomes short, and if there is unevenness on the surface, the spot-shaped focusing part may shift from the surface, making it difficult to control the beam diameter on the surface. There is. On the other hand, by using a long focal length lens, the depth of focus is increased, and the lens is less affected by surface irregularities. Therefore, it is preferred that the beam not be of an overly convergent (focused) type. In addition, the surface of the ceramic structure to be irradiated with the laser beam (the innermost portion of the hole being drilled) withdraws as the drilling proceeds, so that the laser structure is covered from a laser light emitting housing such as a laser torch. In order to eliminate the need for adjusting the distance to the irradiation surface, the beam is preferably a substantially parallel light beam.
In addition, since the laser beam has high directivity, the distance between the beam exit housing and the ceramic structure can be greatly increased by bringing the beam closer to a parallel beam, and work can be performed even when an unexpected collapse of rock or the like occurs during drilling. There is little risk that the user or equipment will be damaged.

Under conditions where the dross does not impede the irradiation of the beam, that is to say when the entire beam cross-section is substantially evenly illuminated at the deepest part of the hole being drilled, the holes formed in the ceramic structure Is typically about the same as the beam diameter, and the depth of the hole formed by drilling depends on the energy density of the beam (beam output / beam cross-sectional area) and the irradiation time. The beam output is the beam energy per unit time. Therefore, for example, when it is desired to pierce with a hole diameter of about 10 to 20 mm, the beam diameter is also set to be about 10 to 20 mm on the irradiated surface. In the case of a quasi-parallel beam, a long focal length lens is selected so that the beam diameter on the surface to be illuminated matches the desired hole diameter. The beam diameter may be selected according to the application (diameter of the hole or the material of the ceramic structure), and may be, for example, smaller than 10 mm or conversely larger than 20 mm.

In order to re-melt the re-solidified product, any means may be used as long as the re-solidified product can be heated to the melting temperature or higher. As a heating heat source, that is, a heat source for heating, a high-temperature source capable of re-melting as much of the re-solidified material as possible or a source having a large amount of heat input per unit time / unit area is preferable. What is necessary is just to be able to locally heat and re-melt a part. As a heating heat source, even when using the laser beam for perforation itself,
A heat source different from the laser beam may be used, or both may be used in combination.

When the drilling laser beam itself is used as a heat source, the laser beam is oscillated between a normal drilling position and a re-melting heating position where the lower edge of the beam hits the re-solidified material on the lower edge side of the opening. (Shaking). When the laser beam is oscillated to the remelting heating position, normally (i.e., during normal drilling), the lower edge of the beam is irradiated to the non-irradiated portion of the re-solidified material, whereby the leading edge portion of the re-solidified material is irradiated. That is, the portion facing the upstream side of the beam), more specifically, the upper portion of the leading edge is heated and re-melted. Therefore, the molten dross in the lateral hole partially blocked by the leading edge portion also quickly flows out of the hole. As a result, the laser beam is minimized from being obstructed or absorbed by the resolidified portion on the lower edge side of the opening of the horizontal hole or the molten dross layer at the bottom of the horizontal hole, and the beam is formed at the innermost portion of the hole. Since the portion to be perforated can be efficiently irradiated, the speed of forming holes can be increased. However, while irradiating the lower edge of the laser beam to the re-solidified portion not irradiated with the beam during normal drilling, unlike normal drilling,
Since there is a region on the upper edge of the hole that is not irradiated with the laser beam, the beam is oscillated in the opposite direction to return the beam to the normal drilling position so as to minimize resolidification of the molten dross in the region. For details on how to oscillate,
It is appropriately selected and controlled according to the beam output, energy density, hole diameter, hole depth, material of the ceramic material (usually the composition of each material constituting the mixture), environmental conditions (such as the outside air temperature), and the like. Further, the oscillation may be periodically and automatically performed according to the oscillation pattern, or may be manually performed while observing the state of the perforated portion. In order to oscillate the irradiation beam, even if the laser emission housing itself is moved up and down (oscillating), a mirror or the like is arranged obliquely in the optical path to shake the optical path of the laser beam emitted from the housing, and the mirror position is changed. It may be oscillated. Further, when the emission portion of the laser beam emission housing is relatively far away from the perforated portion, the vertical angle (elevation angle) of the emission housing is slightly oscillated so as to rotate the emission housing vertically. Is also good.

On the other hand, when re-melting and heating the re-solidified material on the lower edge side of the opening with a heat source different from the laser beam for drilling,
As a heating heat source, a combustion gas from a gas burner or a high-temperature plasma irradiation unit may be used. When another heating heat source such as these is used, it is also possible to locally apply heat from the heating heat source to a desired region of the resolidification unit. If desired, the oscillation of the laser beam for perforation and the heating by another heating heat source may be used in combination.

In view of the apparatus, the laser drilling apparatus for a ceramic structure according to the present invention has the following objects. To achieve the above object, (1) a high-power laser for melting a ceramic material in a lateral hole drilling portion of a ceramic structure; A beam exit housing for emitting a beam, and (2) i) a re-melting for irradiating the lower edge of the beam to the lower edge of the opening of the hole formed by the normal drilling position and the drilling for the ceramic structure. Beam oscillating means for oscillating the laser beam with the heating position, and ii) perforations provided at the lower edge of the openings of the holes formed by the perforations to heat the resolidified material which is resolidified. And at least one of the other heating heat sources.

In order to allow the molten dross to easily flow out, a laser beam is applied obliquely upward to the ceramic structure in the molten dross forming step of forming the horizontal hole. Preferably, a hole is formed. In this case, the hole formed in the ceramic structure by irradiating the ceramic structure with the laser beam obliquely upward is located closer to the opening, so that the ceramic material generated by the laser beam irradiation is positioned lower. The molten dross may flow under its own weight towards the opening. Therefore, the innermost portion (the deepest portion or the tip of the hole) of the hole to be subsequently drilled (drilled) is easily exposed to the laser beam over almost the entire diameter of the hole, so that the drilling can be reliably advanced. Therefore, a large-diameter hole that is difficult to ignore the dross flow can be drilled deeply.

The upward tilt or elevation of the beam is such that as long as the molten dross resulting from the melting of the ceramic material does not practically impede the further perforation, it can flow under gravity under its own weight to the opening side. The size can be any size (any number of times) in principle. The ease with which the molten dross flows out depends on the viscosity and density (specific gravity) of the molten dross and may depend on the type and temperature of the ceramic material (usually a mixture but may be a single material). Assuming that the elevation angle is taken numerically, it is typically 2 to 3 degrees or more, preferably about 5 degrees or more. For the flow of molten dross, a larger elevation angle is preferable, but the distance (depth) measured from the surface of the ceramic structure to the bottom of the hole in a direction perpendicular to the surface of the structure is sufficiently deep in a short time. In order to achieve this, it is preferable that the elevation angle is not so large, for example, about 45 degrees or less, and more preferably, for example, about 30 degrees.
It is less than degree.

In order to monitor the progress of the drilling, it is preferable that imaging means such as a CCD camera be provided as a monitoring means in the laser light emitting housing.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a preferred embodiment in which the laser drilling method and apparatus according to the present invention is applied to the removal of rocks, rocks or rocks that may collapse will be described with reference to a preferred embodiment shown in the accompanying drawings. It will be described based on the following.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, it is assumed that reference numeral 1 denotes a mountain, and the mountain 1 has a rock mass 2 which may collapse. In order to remove the rock mass 2 before the collapse accident occurs, holes 3 (for example, having a diameter of about 2 cm and a depth of 10 to 20 cm) are formed in the rock mass 2 at an appropriate interval.
The hole 3 is filled with a swelling agent which expands due to a chemical reaction, and the swelling force of the swelling agent cracks the rock part 2 around the hole 3 to break it into rocks or rocks 4 of an appropriate size. And drop it. In addition, in order to crack the rock part 2, instead of generating an expanding force chemically by an expanding agent, an expanding force may be physically generated by driving something like an arrow.

In the present invention, the hole 3 is opened by a laser beam. The laser beam oscillation equipment 10 has a vehicle 11 equipped with a laser-related device and a vehicle 12 equipped with a power supply device, which are arranged at a sufficient distance 6 from a collapse risk area 5 at the foot of the mountain 1. The vehicle 11 with a laser-related device is equipped with a laser oscillator 13 such as a YAG laser oscillator, a laser control panel 14 for controlling the laser oscillation of the oscillator 13, an air conditioner 15 around the oscillator 13, and the like. 12
A generator 16, a laser power supply 17 that receives electric energy from the generator 16 and supplies power to the oscillator 13,
Laser cooling water machine (chiller) that cools the oscillation section 3
18 etc. are mounted. The YAG laser oscillator 13
For example, it is composed of a continuous wave (CW) oscillator having an output of about 4 kW. The oscillator 13 includes a beam output monitor (not shown) that monitors the output of a beam emitted from the main body of the oscillator 13. A plurality of oscillators 13 and the like may be arranged in parallel.

At a high place 7 near the rock mass 2 at the middle of the mountain 1,
An aerial work platform 19 is provided. The work cart 19 is
The crane unit 20 includes a crane unit 20 that is hydraulically controlled.
An electric / hydraulic control type or an electric control type articulated small robot 21 is attached to the tip of the robot. The small robot 21 is an aerial work platform 19
(Altitude) 7 may be remote-controlled, but preferably, the beam-related control is performed at the laser-related device-equipped vehicle 11 (at the foot of the vehicle) so that the beam output can be controlled simultaneously or in parallel. (Safety area) 6. A laser torch 23 for shaping and emitting a laser beam sent from the laser oscillator 13 via the optical fiber 22 is provided on an arm 21 a (FIG. 2) at the tip of the small robot 21.
The CCD torch 23 is attached to the tip of the laser torch 23 to monitor the drilling operation by the laser beam from the laser torch 23. As will be described later with reference to FIG. 2, the branch arm 21d (FIG. 2) of the arm 21a at the distal end of the small robot 21 is further provided with a nozzle 51 for spraying a combustible gas or plasma serving as a heat source for heating. Installed.

Instead of arranging the high work cart 19 at the high place 7, a high place such as a work tower is assembled in the high place 7 or the safe area 6 at the foot of the vehicle, and the work is carried out along the stand. The small robot 21 having a high degree of freedom may be raised, and the robot 21 may support the laser torch 23 and the CCD camera 24 on the torch 23 to control the posture of the torch 23. When a substantially parallel beam is used as the laser beam, the beam diameter of the laser beam emitted from the laser torch 23 can be kept within a predetermined range even if the horizontal distance from the torch 23 to the perforated portion 3 is considerably large. However, in that case, the long branch arm 21d is extended.

An image of the perforated portion (perforated portion), that is, the hole 3 and its surroundings captured by the CCD camera 24 is displayed on a monitor display (not shown), and based on the display, the perforated portion (drills the hole). The position of the small robot 21, more specifically, the position and inclination of the laser torch 23 are controlled so that the beam is irradiated onto the beam 3 at a predetermined elevation angle. Adjustment is performed by the laser control panel 14 to perform a drilling operation to open the hole 3 having a predetermined diameter and a predetermined depth. If desired, the attitude of the small robot 21 may be directly controlled based on image data captured by the CCD camera 24.

The laser torch 23 includes, for example, as shown in FIG. 2, a collimator lens 26 having a short focal length for converting light from the emission end 25 of the optical fiber 22 into a parallel beam having a beam diameter corresponding to a desired hole diameter. Focal length is 1m, for example
An emission housing 28 having a focusing lens (condensing lens) 27 of about 10 m or more,
A laser beam 29 in the form of quasi-parallel light is emitted from the laser beam emission housing 28. In order to make the beam parallel, other optical components such as a compound lens may be used instead of a single convex lens. If desired, the beam is once made parallel by the lens 26 and then slightly turned by the lens 27. Instead of focusing, the beam may be converted to a quasi-parallel ray by a single lens or a compound lens. Further, instead of turning the beam into a quasi-parallel beam, the beam may be irradiated to the perforated portion of the bedrock 2 as it is. In order to adjust the beam diameter, for example, the focal length of the lens 26 may be changed, or another means such as an aperture means may be used.

In the above, one laser oscillator 13
Although the example using the laser beam from the above has been described, a plurality of laser oscillators 13 are provided.
The laser beams from the laser beams 3 are transmitted to the laser torch
The laser beam from the plurality of optical fibers 22, 22,... Is synthesized as shown by the imaginary line in FIG. 2 at the incidence part 30 of the laser torch 23, that is, the incidence part 30 of the laser emission housing 28, as a whole. A higher output laser beam 29 may be emitted and irradiated (the fiber 22
Is one, the input part 30 is the output end 25 of the fiber 22.
Matches). In this case, the housing 28 functions as a laser light combining housing. It should be noted that the beams are combined at the output portion of the optical fiber 22 (the input portion 3 of the laser torch 23)
Instead of performing the process at 0), the process may be performed at the entrance of the optical fiber 22. When a plurality of laser oscillators 13 are provided, the laser oscillators 13 may be oscillators having different characteristics or different types of lasers, if desired.

The irradiation beam 29 is inclined by the elevation angle α. When the irradiation beam 29 irradiates the rock part 2, the irradiation melts the rock material in the perforated part 3. Hole 3 of perforated part
Is small, the molten rock material, that is, the molten dross 35 flows out of the opening 36 of the hole 3 by its own weight, and is cooled and hardened near the opening 36. However, as schematically shown in FIG. 4A, when the irradiation beam is composed of a substantially horizontal beam 29a and the hole 3a formed by the irradiation beam 29a extends horizontally, the hole 3a becomes deeper. It takes time for the molten dross 35 to flow to the opening 36. Therefore, the molten dross 35 tends to stay in the hole 35 in a relatively large amount, and the ratio of energy of the laser beam 29 consumed for heating the staying molten dross increases, making it difficult for the beam energy to be efficiently used for drilling. The perforation speed tends to be low (a part of the beam 29 may be a dross surface such as a lower edge of the opening 36 (not shown)).
Is not reflected in the hole 3 and leads to loss of beam energy). Further, among the molten dross 35 at the back of the hole 3, those that can quickly flow out of the opening 36 are limited to those located at a position higher than the bottom wall on the side close to the opening. As schematically shown in FIG.
It gets thinner. As a result, there are surfaces on which it is difficult to form deep holes. On the other hand, as shown schematically in FIG. 4B, when the irradiation beam 29 irradiates the rock part 2 upward at the elevation angle α, the molten dross 35 generated by the irradiation The hole 3 can flow out of the opening 36 along the bottom 37 which is formed in accordance with the generation of the dross and is inclined to be higher at the back (lower toward the opening 36), so that the hole 3 has a beam diameter D. It is easy to be formed deep with a large diameter corresponding to the diameter. In this example, the case where the beam 29 is substantially a parallel ray is described. Therefore, although the inclination angle of the beam center axis is evaluated as the elevation angle α, the range in which the beam 29 can be regarded as a quasi-parallel ray is described. In the case of a beam having a certain degree of convergence, the lower edge of the beam defining the bottom of the hole 3 may be inclined with an elevation angle α. You can do it on the edge. In addition, the description here is mainly limited to the behavior of dross inside the hole 3 formed by drilling, and the cooling and re-solidification of the molten dross near the opening 36 of the hole 3 and the hole 3 The behavior of the molten dross will be described below.

By drilling the hole 3 obliquely upward,
Although the molten dross generated by the irradiation of the laser beam 29 easily flows down to the opening side, the flowability of the molten dross is not always high, so that the molten dross 35 reaches the opening 36 and attempts to flow down from the opening 36. When it comes out of the irradiation area of the beam 29, it is rapidly cooled by the outside air, becomes viscous, and starts to solidify. As a result, when the beam 29 is irradiated with a constant optical path and beam diameter, the resolidified deposit as shown by reference numeral 38 in FIG.
That is, the surface 2 of the portion of the rock 2 located below the opening 36
a. The re-solidification deposition section 38 cools the molten dross adjacent to the deposition section 38, and
Along the direction substantially parallel to the optical axis 29d (that is, along the area outside the irradiation area of the laser beam 29). The solidified deposit 38 grown in this manner is heated or partially re-melted by the energy of the laser beam 29, so that part of the beam energy that should be originally used for drilling is taken away, and The energy to be input to the inner perforated portion 3d decreases. Further, part of the energy of the laser beam 29 which is reflected by the molten dross surface (inner peripheral surface) in the hole 3 and enters the depth of the hole 3 is absorbed by the molten dross surface. As the depth increases, the energy to be injected into the perforated portion 3d at the back of the hole 3 decreases (a part of the beam 29 is reflected by the surface of the dross such as the edge of the opening 36 and enters the hole 3). Not doing so also leads to a loss of beam energy). As a result, as the hole 3 becomes deeper, the progress speed of perforation tends to decrease. Therefore, in order to increase the drilling speed of the holes 3 (perform drilling of the holes 3 efficiently), the generation and growth of the re-solidified portion 38 on the lower edge side of the opening 36 is suppressed, and thereby the molten dross layer 35 is formed. It is preferable to continuously flow out of the holes 3 while minimizing stagnation in the holes 3. In order to suppress the generation / growth of the resolidification unit 38, instead of cutting off the generation / growth process itself, it is necessary to balance cooling and heating so that the resolidification unit 38 being generated / grown is remelted. Good. In order to re-melt the re-solidification unit 38, the laser drilling device 60 is a small robot such as the devices 13, 14, 15, 16, 17, 18 and the like mounted on the vehicle 11 with the laser-related device and the vehicle 12 with the power supply device. 21, the optical fiber 22, the laser torch 23, and the like, and further include the following means.

That is, as shown in FIG. 2, the arm 21a at the tip of the small robot 21 holds the housing 28 of the laser torch 23 with the torch holding portion 21b, and the arm 21a is moved in the direction A via the joint 21c. The nozzle gripping portion 21e at the tip of the branch arm 21d, which is rotatable, holds a nozzle 51 for spraying a heating heat source made of a broadly defined fluid such as combustion gas or plasma. Torch gripper 2
1b is an outer grip 21f integral with the arm 21a,
It comprises an inner grip portion 21g that can be oscillated (vibrated) in the B1 and B2 directions with respect to the outer grip portion 21f and is integrated with the laser emission housing 28. The oscillation in the B1 and B2 directions of the inner gripping portion 21g with respect to the outer gripping portion 21f is performed by, for example, a driving means (not shown) at the arm 21a and a laser-equipped vehicle 11 to control the driving of the driving means. Control means (not shown) provided in the
Controlled.

The arm 21a of the small robot 21 is replaced with an oscillating mechanism in the torch grip 21b.
May be oscillated with respect to the main body or the base of the robot, a pair of mirrors are provided on the beam emitting portion of the housing 28 so as to face each other, and the downstream mirror is positioned close to the upstream mirror. You may make it oscillate so that it may separate. Although the oscillate is preferably in the form of a linear reciprocating translation,
In some cases (for example, when the turning radius is large), reciprocating turning within a small angle range may be used instead of translation.

The nozzle 51 is positioned so as not to hinder the irradiation of the laser beam 29 to the perforated portion 3 and to blow a fluid serving as a heating heat source such as a combustible gas or plasma onto the perforated portion 3. A fluid such as a combustible gas or a plasma source is supplied to the nozzle 51 from a supply source (not shown) via an electromagnetic valve 52. When the heating source fluid is made of a combustion gas, even if only the flammable gas that burns in combination with oxygen in the atmosphere is jetted from the nozzle 51, both the oxygen and the flammable gas are jetted. You may do so. In the latter case, like some burners, the nozzle 5
Even if oxygen in the atmosphere is sucked in at the base 51a of the nozzle 51 with the ejection of the combustible gas from the tip of the nozzle 1 and mixed with the combustible gas to be ejected, the oxygen is supplied to the nozzle 51 through a valve similar to the valve 52. Oxygen gas from an oxygen supply source may be supplied simultaneously. The combustible gas comprising the combustible gas and oxygen immediately burns and generates heat when exposed to the high temperature of the perforated portion 3. When the heating source is a plasma flow, for example, a plasma generator is provided at the base 51 a of the nozzle 51. Although the degree of freedom of the branch arm 21d with respect to the arm 21a is 1 in the illustrated example, the degree of freedom may be 0 or 2 or more.

In the laser drilling device 60, the laser beam emitting housing 28 can be oscillated up and down in the plane perpendicular to the optical axis 29d with respect to the arm 21a of the small robot 21 in directions B1 and B2. 2
9, the lower edge 29b can be moved up and down in the B1 and B2 directions between a normal perforation position C shown by a solid line in FIG. 3 and a remelting heating position D shown by an imaginary line. Therefore, when the drilling operation is performed at the normal drilling position C, C
After confirming that the re-solidification and deposition portion 38 has grown to a certain degree or more from an image around the perforated portion 3 captured by the CD camera 24 and displayed on a display (not shown), control means (not shown) To move the inner grip 21g in the direction B1 with respect to the outer grip 21f by remote control, and position the beam 29 so that the lower edge 21b thereof is located at the reheating melting position D. When the beam 29 is oscillated to the position D, the re-solidified deposition portion 38 is re-melted from the leading edge portion 38a of the re-solidified deposition portion 38 which directly receives the irradiation of the beam 29, and the leading edge portion is, for example, a dotted line in FIG. It retracts to the position indicated by 38b. Therefore,
Since the cooling and damming of the molten dross of the molten layer 35 by the re-solidification and deposition section 38 are eliminated, the molten dross 35 can quickly flow out of the hole 3 (the molten layer 35 can be smoothly separated from the inside of the hole 3). Stagnation of the dross 35 in the hole 3 can be minimized. As a result, it is possible to minimize the shielding of the beam and the absorption of the beam energy by the re-solidification deposition portion 38 and the molten dross 35 in the hole 3, so that the energy of the beam 29 is applied to the perforation of the innermost portion 3 d of the hole 3. It is used effectively and the perforation proceeds efficiently. After confirming the retreat of the re-solidification unit 38 on the display, the inner grip 21g is returned to the direction B2 again by remote control, and the beam 29 is returned to the normal perforation position C.

In the above description, an example has been described in which the oscillation of the laser housing 28 is manually controlled while monitoring the growth of the re-solidified portion 38. However, the inner grip portion 29g is usually replaced with the outer grip portion 29f without monitoring on a display. May be periodically oscillated in a predetermined movement pattern in the B1 and B2 directions.
In this case, the relationship between the position in the B1 and B2 directions and the moving speed of the inner gripping portion 29g with respect to the outer gripping portion 29f depends on the energy and energy density of the beam, the hole diameter and the hole depth of the hole,
Considering rock material, climatic conditions, etc., it is determined experimentally and a predetermined pattern is selected or set, and monitor information on the display may be used for manual adjustment only when necessary .

Along with or instead of the oscillation of the beam 29 as described above, the heating source fluid 53 is supplied from the nozzle 51 to the re-solidification deposition section 3 as shown in FIG.
By spraying on the beam 8, as in the case of the oscillation of the beam 29 in the B1 direction, the re-melting of the re-solidified deposition layer 38 and the outflow of the molten dross 35 from the holes 3 can be promoted. When the laser light 29 is a YAG laser or the like having a shorter wavelength than a carbon dioxide gas laser or the like, even if the oscillation of the beam 29 and the spraying of the heating source fluid 53 are used together,
There is no problem of absorption by the combustion gas or the plasma as the heating source fluid. The heating source fluid 53 is sprayed on the molten dross 3
5 is directly heated, and the degree of freedom in adjusting the spray position is high. Therefore, it is considered effective even if the absolute value of the input energy or the utilization efficiency of the energy is smaller than that in the case of the laser beam 29. Can be

When the irradiation of the laser beam 29 is stopped, the holes 3
The molten layer, that is, the molten dross layer 35 that has flowed along the bottom 37 is gradually deposited and solidified to finally become a solid glass dross layer 35, and the molten dross or the outflowing molten liquid flowing out from the opening 36. Layer 38 solidifies as it deposits, ultimately becoming outflow glass dross 38c. on the other hand,
A glass dross layer 35 similar to the glass dross layer 35 on the bottom side is formed on the inner wall portion on the upper side of the hole 3 although the thickness is small.
Remains. That is, the hole 3 whose inner wall is covered with the glass dross layers 35 and 38c is formed by the perforation by the laser beam 29.

Finally, the hole 3 formed in this way is filled with an expanding agent, and a portion of the bedrock 2 adjacent to the hole 3 is broken down and removed under control. In FIG. 1, 31 is
This is a vehicle for removing rocks 4 that have been broken down to a transportable size and dropped.

Although the present invention has been described above with respect to an example in which the present invention is applied to drilling for preventing rock collapse beforehand, the present invention is used for demolition of reinforced concrete piers and seismic reinforcement work of buildings. It can also be used for perforating composite materials based on ceramic materials, such as the removal of reinforced concrete columns. The iron part in the concrete is irradiated with a beam whose energy density is increased by narrowing the beam diameter as necessary, or as necessary, by blowing oxygen to promote oxidation. It may be melted or cut.

If desired, a relatively high-density rock such as granite is irradiated with a high-power laser beam to be heated and melted to form a hole. Cracks may be generated in the holes. In this case, the crushing of the dense rock can be controlled efficiently. Similarly, it is possible not only to perforate by melting / evaporation accompanying heating, but also to cause local thermal deterioration in the ceramic structure relatively deep (to the depth region of the hole) by local heating.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing an example in which a laser drilling method and apparatus according to a preferred embodiment of the present invention are applied to rock fall prevention.

FIG. 2 is an explanatory view schematically showing how a laser beam is irradiated by the laser torch of FIG. 1;

FIG. 3 is an explanatory diagram specifically showing a state of perforation by laser beam irradiation in FIG. 1;

4A and 4B are schematic explanatory diagrams for explaining the role of the elevation angle during the laser beam irradiation in FIG. 3; FIG. 4A is an example of horizontal (zero elevation angle) irradiation for comparison; Is an example of irradiation with an elevation angle.

[Explanation of symbols]

1 Mountain 2 Rock part 3 Hole (hole), Perforated part 3a Hole (hole) 3d Deepest part of hole 4 Rock (rock) 5 Collapse accident risk area at foot 6 Safe place away from collapse accident area (laser oscillation Equipment installation location) 7 Altitude 10 Laser beam oscillation equipment 11 Car with laser related equipment 12 Car with power supply unit 13 Laser oscillator 14 Laser control panel 15 Air conditioning equipment 16 Generator 17 Laser power supply 18 Laser water cooler (chiller) 19 High Work cart 20 Crane 21 Small robots 21a, 21d Arm 21b Laser torch grip 21c Joint 21f Outer grip 21g Inner grip 22 Optical fiber 23 Laser torch 24 CCD camera 25 Outgoing end (outgoing end) 26 Collimating lens 27 Focus lens (collection) Optical lens 28 Laser light emission housing (Laser light synthesis housing) 29 High-power laser beam 29b Lower edge of beam 30 Injection part 35 Dross molten (solid glass dross layer) 35a Solid glass dross 36 Opening 37 Bottom part 38 Re-solidified deposition layer 38b Retracted re-solidified deposition layer 38b Front edge 38c Glass dross 51 Heating heat source fluid spray nozzle 52 Valve 53 Heating heat source fluid 60 Laser drilling device A Rotating direction B1, B2 Oscillating direction C Normal drilling position of lower edge of beam D Re-melting heating position of lower edge of beam α Laser beam elevation angle

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroshi Mitamura 3-1-1-18, Hachiken 9-Johigashi, Nishi-ku, Sapporo, Hokkaido No. (72) Inventor Hisashi Konno 2-6-1, Nakanoshima, Toyohira-ku, Sapporo, Hokkaido, Japan (72) Inventor Kyo Sato, 2-3-6-7, Sumikawa, Minami-ku, Sapporo, Hokkaido, Japan Saiyu-so (72) Inventor, Mitsuru Yoshikawa 63-30 Yuyogaoka, Hiratsuka-shi, Kanagawa Prefecture, Sumitomo Heavy Industries Machinery Co., Ltd. Hiratsuka Works (72) Inventor Takashi Kurosawa 63-30 Yuyugaoka, Hiratsuka-shi, Kanagawa Prefecture Sumitomo Heavy Industries Machinery Co., Ltd. Hiratsuka Works F-term (reference) 4E068 AF01 CD06 CG00 CG01 DB12

Claims (5)

[Claims] 1. A step of forming a molten dross by irradiating a laser beam to a lateral hole perforated portion of a ceramic structure to melt a ceramic material in the perforated portion to form a molten dross, and an opening of a hole being formed in the perforated portion. A re-melting step of heating and re-melting the re-solidified material that has cooled and solidified the molten dross on the lower edge side of the ceramic dross. 2. The re-melting step comprises oscillating the laser beam between a normal drilling position and a re-melting heating position where the lower edge of the beam strikes the re-solidified material on the lower edge of the opening. 2. The laser perforation method according to 1. 3. The laser drilling method according to claim 1, wherein the re-melting step includes heating the re-solidified material on the lower edge side of the opening with a heat source different from the laser beam for drilling. 4. A beam emitting housing for emitting a high-power laser beam for melting a ceramic material in a lateral hole perforated portion of a ceramic structure, a normal perforation position for perforating the ceramic structure, and a hole formed by perforation. And a beam oscillating means for oscillating the laser beam between the lower melting portion and the re-melting heating position for irradiating the lower edge portion of the opening with the lower edge portion of the beam. 5. A beam emitting housing for emitting a high-power laser beam for melting a ceramic material in a lateral hole perforated portion of a ceramic structure; and a re-solidified resin at a lower edge of an opening of the hole formed by the perforated hole. A laser drilling device for a ceramic structure comprising a heating heat source different from a drilling laser beam provided to heat a solidified material.