Laser deposit removal apparatus equipped with a cylindrical concave lens and laser deposit removal method using the same

Abstract

To provide a laser deposit removal device and a laser deposit removal method which can improve efficiency in removing deposit on an inner surface of a pipe, by scanning a linear laser beam on the inner surface of the pipe.SOLUTION: A laser deposit removal device 1 comprises: a main body 2 that can be inserted into a pipe P form which deposit should be removed, and moved in a direction of an axis line of the pipe; an optic system 3 that guides a laser beam emitted from a laser oscillator to the main body 2 in the direction of the axis line of the pipe; a prism 5 which is mounted on the main body 2 to be turnable around the axis line of the pipe and refracts a laser beam emitted from the optic system 3 and directs the beam toward the inner surface of the pipe P; a hollow motor 7 mounted on the main body to rotationally drive the prism 5; and a cylindrical concave lens 6 which is mounted on the main body 2 to rotate together with the prism 5, converges a laser beam L transmitted through the prism 5 on a linear laser beam L1 in the direction of the axis line of the pipe, and emits it to the inner surface of the pipe P.SELECTED DRAWING: Figure 3

Description

Technical Field

[0004] , ,

[0001] The present invention relates to an apparatus for removing deposits such as rust generated on the inner surface of a pipe by laser light irradiation and a deposit removal method using the same.

Background Art

[0002] Conventionally, a laser decontamination apparatus has been described in Patent Document 1, which includes a mobile body capable of self-running inside a pipe to be decontaminated, an optical fiber for guiding laser light emitted from a laser oscillator to the mobile body, a mirror attached to the mobile body so as to be able to rotate around the pipe axis and irradiate the inner surface of the pipe with the laser light emitted from the optical fiber, a dust removal means capable of communicating with the inside of the pipe, and an intake means for sucking air inside the pipe through the dust removal means. In addition, a laser irradiation apparatus including a laser oscillator, a fiber for transmitting laser light output from the laser oscillator, and a portable laser head for focusing the laser light transmitted through the fiber and irradiating the surface of a structure has been described in Patent Document 2. This laser head includes an optical system for irradiating laser light and a shielding member for protecting the optical system from removed substances generated from the irradiation point of the laser light. The optical system removes a coating film or the like attached to the surface by scanning the irradiation point of the laser light so as to draw a locus of a circle with a radius centered on the optical axis on a surface substantially perpendicular to the optical axis of the laser light.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] The conventional devices described above all have the problem that the spot diameter of the laser beam irradiation point is small, resulting in inefficient removal of attached materials. Therefore, the object of the present invention is to provide a deposit removal device that improves the efficiency of removing deposits from the inner surface of a pipe by scanning the inner surface of the pipe with a linear laser beam, and a deposit removal method using the same. [Means for solving the problem]

[0005] The following description refers to reference numerals in the attached drawings, but the present invention is not limited thereto. To solve the above problems, the laser deposit removal device 1 of the present invention comprises a main body 2 that can be inserted into the inside of a tube P from which deposits are to be removed and is movable in the direction of the tube axis, an optical system 3 that guides the laser light emitted from the laser oscillator to the main body 2 in the direction of the tube axis, a focusing lens 4 that focuses the laser light L, a prism 5 that is attached to the main body 2 so as to be able to rotate around the tube axis and refracts the laser light emitted from the optical system 3 and directs it toward the inner surface of the tube P, and a hollow motor 7 that is attached to the main body to rotate the prism 5 and the cylindrical concave lens 6. Therefore, the prism 5 and the cylindrical concave lens 6 rotate together. The cylindrical concave lens 6 focuses and diffuses the laser light L that has passed through the prism 5 into a long linear laser beam L1 in the direction of the tube axis and irradiates the inner surface of the tube P. [Effects of the Invention]

[0006] According to the laser deposit removal device of the present invention, the efficiency of deposit removal on the inner surface of a pipe can be improved by scanning a linear laser beam in the direction of the pipe axis across the inner surface of the pipe. [Brief explanation of the drawing]

[0007] [Figure 1] This is a front view of the laser-based deposit removal device of the present invention. [Figure 2] Figure 1 is a side view of the laser deposit removal device. [Figure 3] Figure 2 is a cross-sectional view of the laser deposit removal device taken along line III-III. [Figure 4] Figure 2 is a cross-sectional view taken along line IV-IV of the laser deposit removal device. [Figure 5] This is a front view of a laser deposit removal device according to another embodiment of the present invention. [Figure 6] Figure 5 is a side view of the laser deposit removal device. [Figure 7] Figure 5 is an enlarged view of the roller legs in the laser deposit removal device. [Modes for carrying out the invention]

[0008] The laser deposit removal device 1 is a device that removes deposits such as rust from the inner surface of a pipe P by ablation, while moving in the direction of the pipe axis inside the pipe P where deposits such as rust are present on the inner surface of the pipe, and irradiating the inner surface of the pipe with laser light.

[0009] The laser deposit removal device 1 comprises a generally cylindrical body 2, an optical system 3 that guides the laser beam emitted from the laser oscillator into the body 2 in the axial direction of the tube P, a focusing lens 4 that focuses the laser beam within the body 2, a prism 5 that refracts the focused laser beam, and a hollow motor 7 that rotates the prism 5 and the cylindrical concave lens 6.

[0010] The main body 2 is inserted into the inside of the pipe P and is movable in the direction of the pipe axis, and is equipped with a centering spring 8 on its outer circumference. As the main body 2 moves inside the pipe P, the centering spring 8 slides against the inner circumference of the pipe P and guides the axis of the main body 2 to align with the axis of the pipe P.

[0011] In other embodiments shown in Figures 5, 6, and 7, a centering roller mechanism 13 is provided instead of the centering spring 8. The centering roller mechanism 13 comprises a bracket 14 fixed to the outer circumference of the main body 2, a roller leg 15 whose base end is pivotally supported by the bracket 14 and which is biased by a spring 16 to open radially outward from the main body 2, and a roller 17 pivotally supported at the tip of the roller leg. The centering mechanism 13 guides the axis of the main body 2 to coincide with the axis of the pipe P by pressing and rolling the roller 17 against the inner circumference of the pipe P as the main body 2 moves inside the pipe P.

[0012] The hollow motor 7 is attached to the tip side inside the main body 2 and supports the prism 5 and the cylindrical concave lens 6 so that they can rotate about the axis (tube axis) of the main body 2.

[0013] The prism 5 refracts the laser beam L converged along the axis of the main body 2 by the condenser lens 4 in the orthogonal direction.

[0014] The cylindrical concave lens 6 condenses the laser beam L from the prism 5 into a linear laser beam L1 extending in the direction of the axis (tube axis) of the main body 2 and irradiates the inner peripheral surface of the tube P.

[0015] The prism 5 and the cylindrical concave lens 6 are attached to the tip of the main body 2 and are arranged in a protective cylinder 9 made of transparent glass whose tip side is closed by a protective cover 10, and are protected so that dust etc. peeled off from the inner periphery of the tube P do not enter the inside of the main body 2. A reflecting mirror portion 10a for reflecting the laser beam L3 from the laser sensor 11 described later at a right angle is provided on the outer peripheral edge of the protective cover 10.

[0016] Two laser sensors 11, 12 for detecting that two predetermined positions in the front and rear in the moving direction of the main body 2 sandwiching the transmission portion of the laser beam L1 in the protective cylinder 9 are located inside the tube P are provided at the tip of the main body 2. As shown in FIG. 3, the laser sensors 11, 12 detect whether they are inside the tube P respectively by the reflected light of the laser beams L2, L3 projected toward the inner surface of the tube P. The position information of the laser sensors 11, 12 is sent to a control device (not shown), and the laser oscillator is controlled so that the laser beam L is irradiated only when the transmission portions of the laser beams L2, L3 are inside the tube P.

[0017] For the rust removal work of the tube P, the laser attachment removal device 1 is inserted into the inside of the tube P, and in a state where both the laser sensors 11, 12 detect that they are inside the tube P, the laser transmitter and the hollow motor 7 are started and moved manually in the tube axis direction. Thereby, on the inner surface of the tube P, a linear laser beam in the tube axis direction is scanned, and the deposits on the inner surface of the tube P can be efficiently removed.

Explanation of Signs

[0018] 1 Laser附着物Removal Device 2 Main Body 3 Optical System 4 Condensing Lens 5 Prism 6 Cylindrical Concave Lens 7 Hollow Motor 8 Guide Spring 9 Protection Cylinder 10 Protection Cover 10a Reflector Part 11 Laser Sensor 12 Laser Sensor 13 Centering Roller Mechanism 14 Bracket 15 Roller Leg 16 Spring 17 Roller

Claims

1. A laser-based deposit removal device comprising: a main body that can be inserted into the inside of a tube from which deposits are to be removed and is movable in the direction of the tube axis; an optical system that guides laser light emitted from a laser oscillator to the main body in the direction of the tube axis; a focusing lens that focuses the laser light; a prism that is attached to the main body so as to be able to rotate about the tube axis and refracts the laser light emitted from the optical system and directs it toward the inner surface of the tube; a hollow motor that is attached to the main body to rotate the prism; and a cylindrical concave lens that is attached to the main body so as to rotate together with the prism and focuses the laser light that has passed through the prism into a long linear laser beam in the direction of the tube axis and irradiates it toward the inner surface of the tube, wherein Sensors are provided on either side of the laser beam projection unit onto the inner surface of the tube, in front of and behind the main body in the direction of movement, to detect that the laser beam projection unit is located inside the tube. A laser-based object removal device characterized by comprising a control device that controls the laser oscillator so that the laser light is irradiated only inside the tube based on positional information from the sensor.

2. The laser deposit removal device according to claim 1, further comprising a protective member attached to the leading edge of the main body in the direction of movement so as to transmit the laser light from the cylindrical concave lens and cover the prism and the cylindrical concave lens.

3. A laser deposit removal method characterized by inserting the laser deposit removal device described in claim 1 into the inside of a pipe and moving it in the direction of the pipe axis, while irradiating the inner surface of the pipe with a linear laser beam in the direction of the pipe axis only when the light-emitting unit is inside the pipe, thereby removing deposits from the inner surface of the pipe.

Images