JP6450038B2 - Laser peening processing apparatus and laser peening processing method - Google Patents

Description

  Embodiments described herein relate generally to a laser peening apparatus and a laser peening method.

  Conventionally, laser peening has been known as a method of modifying a surface of a nuclear reactor structure by applying a residual stress (see, for example, Patent Document 1 and Patent Document 2). Laser peening is performed by condensing and irradiating a processing surface of a workpiece with a laser beam while being covered with a liquid. When the laser beam is focused and irradiated on the processing surface of the workpiece covered with the liquid, the plasma generated by the laser beam irradiation can be confined in the liquid. As a result, shock wave pressure is applied to the work surface. Thereby, the compressive stress generated inside the workpiece can be left as a residual stress.

  In laser peening, it is important to suppress the generation of bubbles in the liquid. This is because the energy of the laser beam reaching the processing surface is attenuated by the bubbles. Therefore, a technique has been proposed in which a valve for removing bubbles from a liquid is provided on a pipe for supplying a liquid for laser peening. In addition, a technique for suppressing the generation of bubbles due to cavitation by controlling the flow rate and flow rate of the liquid has been proposed.

JP 2008-238260 A JP 2006-137998 A

  However, when the laser beam is irradiated onto the processing surface of the workpiece, bubbles are generated at the irradiation point of the laser beam. That is, bubbles are generated at the construction point of the laser peening process. As a result, there is a problem that the optical path of the laser beam is blocked by the bubbles and the energy of the laser beam is attenuated. That is, there is a problem that laser peening cannot be performed with the energy of the set laser beam strictly because of bubbles generated at the irradiation point of the laser beam.

  Therefore, an object of the present invention is to reduce the attenuation of laser beam energy caused by bubbles in laser peening.

  A laser peening apparatus according to an embodiment of the present invention includes a laser oscillator that oscillates a laser beam, and a surface to be processed that is covered with a liquid with a jetting direction set vertically downward toward the work surface of the work piece. A nozzle for condensing the laser beam while ejecting a sufficient amount of liquid and irradiating the irradiation direction vertically downward, and holding the workpiece or a jig for attaching the workpiece, By inclining the workpiece so that the jetting direction and the normal direction of the processing surface are different, the liquid and the processing surface collide with each other and the laser light is irradiated on the processing surface. A tilting mechanism for causing bubbles generated by at least one of the impacts to flow in a direction corresponding to the tilting direction of the surface to be processed with respect to the liquid ejecting direction together with the liquid, the liquid ejecting direction A tilting mechanism capable of variably controlling the tilting angle of the workpiece surface, a moving mechanism for translating the nozzle relative to the workpiece, and a focal point of the laser beam on the workpiece surface. As described above, the controller for controlling the moving mechanism and the tilt mechanism so that the parallel movement of the nozzle by the moving mechanism and the tilt of the workpiece by the tilt mechanism are performed in conjunction with each other; A height adjusting mechanism for adjusting a height of the workpiece or a jig for mounting the workpiece so that a focal point is a processing position of the workpiece on the processing surface; The tilt mechanism is configured such that, based on the three-dimensional information representing the shape of the workpiece surface, the tilt angle of the workpiece surface with respect to the liquid ejection direction is constant or within a predetermined range during the parallel movement of the nozzle. Become The are intended to be configured to tilt the workpiece.

  Further, in the laser peening processing method according to the embodiment of the present invention, the step of oscillating the laser beam and the surface to be processed are covered with the liquid with the injection direction set vertically downward toward the surface to be processed. The laser beam is condensed while ejecting a sufficient amount of liquid to irradiate the irradiation direction vertically downward, and a nozzle for ejecting the liquid and irradiating the laser beam is applied to the workpiece. A step of producing a product or a semi-finished product by translating, and an inclination of the work surface with respect to a jet direction of the liquid by holding a jig for attaching the work piece or the work piece by an inclination mechanism By allowing the angle to be variably controlled and inclining the workpiece so that the liquid jet direction and the normal direction of the workpiece surface are different from each other, Bubbles generated by at least one of collision with a surface and impact caused by irradiation of the laser beam on the processing surface are caused to flow together with the liquid in a direction corresponding to an inclination direction of the processing surface with respect to the liquid jet direction. The nozzle is moved in parallel so that the parallel movement of the nozzle and the tilt of the workpiece by the tilt mechanism are interlocked so that the step and the focus of the laser beam are on the workpiece surface. And a step of controlling the tilt mechanism, and based on the three-dimensional information representing the shape of the work surface, the work surface is inclined with respect to the liquid ejection direction during the parallel movement of the nozzle. The workpiece is tilted by the tilt mechanism so that the angle is constant or within a predetermined range.

1 is a configuration diagram of a laser peening apparatus according to a first embodiment of the present invention. The figure which shows the conventional laser peening processing method. The block diagram of the laser peening processing apparatus which concerns on the 2nd Embodiment of this invention.

  A laser peening apparatus and a laser peening process according to embodiments of the present invention will be described with reference to the accompanying drawings.

(First embodiment)
(Configuration and function)
FIG. 1 is a configuration diagram of a laser peening apparatus according to a first embodiment of the present invention.

  The laser peening apparatus 1 is an apparatus that performs laser peening by irradiating a laser beam while injecting an arbitrary liquid L such as water onto a processing surface of a workpiece W such as metal. The laser peening process is a process in which a shock wave pressure is applied to the work surface of the work W by condensing and irradiating the laser beam with the liquid L attached to the work surface of the work W. When laser peening is performed, compressive residual stress can be applied as a reaction force to the work surface of the work W by the pressure of the shock wave. When compressive residual stress is applied to the work surface of the work W, the occurrence of cracks on the surface of the work surface can be suppressed by the formed compressive residual stress. Thereby, the fatigue characteristics of the workpiece W can be improved.

  The laser peening apparatus 1 can be constituted by a laser oscillator 2, a nozzle 3, a liquid supply system 4, a moving mechanism 5 and an inclination mechanism 6, as illustrated in FIG.

  The laser oscillator 2 is a device that oscillates laser light and irradiates the oscillated laser light toward the nozzle 3. A desired optical system such as a noise filter can be provided between the laser oscillator 2 and the nozzle 3.

  The nozzle 3 is configured to condense and irradiate the laser beam onto the processing surface while injecting the liquid L for laser peening processing toward the processing surface of the workpiece W. The nozzle 3 can be configured by using a condenser lens 7, an optical element 8, and a liquid tank 9.

  The condensing lens 7 is an optical element for entering and condensing the laser light emitted from the laser oscillator 2. For this reason, the condensing lens 7 is arrange | positioned so that it may become on the optical axis of a laser beam inside the cylindrical structure body for covering the laser beam radiate | emitted from the laser oscillator 2. FIG.

  In addition to the condenser lens 7, the nozzle 3 is provided with an optical element 8 for irradiating the processing surface of the workpiece W with the laser light by changing the traveling direction of the laser light transmitted through the condenser lens 7. it can. If the optical element 8 that changes the traveling direction of the laser beam is provided, the laser beam can be irradiated in a desired direction.

  In the illustrated example, a prism that bends the optical axis at a right angle is provided as the optical element 8. The prism is a polyhedron made of a transparent medium such as glass or quartz having a refractive index different from the refractive index on the incident side and the outgoing side of light. Of course, a mirror may be used instead of the prism. Or you may make it change the advancing direction of a laser beam with an optical fiber.

  The liquid tank 9 is a container for temporarily storing and ejecting the liquid L for laser peening processing of the workpiece W. The liquid tank 9 is provided with a supply port and an injection port for the liquid L, and the liquid L supplied from the supply port can be injected from the injection port toward the workpiece surface of the workpiece W.

  In addition, an incident window is provided in the liquid tank 9, and laser light transmitted through the incident window via the optical element 8 is emitted in the same direction as the liquid L ejection direction. That is, the liquid L injection port also serves as an exit of the laser beam, and the laser beam is irradiated from the liquid L injection port toward the workpiece surface of the workpiece W.

  Accordingly, the optical axis of the laser light and the liquid L ejection direction are substantially the same. That is, the nozzle 3 is configured to irradiate the laser beam while ejecting the liquid L with the ejection direction of the liquid L and the irradiation direction of the laser beam being the same direction. For this reason, the entrance window and the injection port of the liquid tank 9 are arranged on the optical axis of the laser beam.

  In addition, by providing the optical element 8 such as a prism, it is possible to eject the liquid L while ejecting the liquid L with the ejection direction of the liquid L and the irradiation direction of the laser light being vertically downward. In this case, it is possible to eject the liquid L using gravity in addition to the liquid pressure.

  The size of the liquid L ejection port is preferably larger than the beam diameter of the laser light. This is because the diameter of the flow of the liquid L becomes larger than the beam diameter of the laser light, and the laser light passes through the liquid L and is irradiated onto the processing surface of the workpiece W. That is, it is preferable that the laser light is transmitted through the liquid column formed by the flow of the liquid L.

  The liquid supply system 4 is a system that supplies the liquid L for laser peening processing to the liquid tank 9 of the nozzle 3. The liquid supply system 4 can be composed of a tank 11 that stores the liquid L for laser peening, a pump 12 and a pipe 13. The pipe 13 can be provided with an on-off valve 14 as necessary.

  The pipe 13 forms a flow path for the liquid L between the tank 11 and the liquid tank 9. The pump 12 and the on-off valve 14 are provided on the pipe 13. Therefore, when the pump 12 is operated, the liquid L in the tank 11 can be supplied to the liquid tank 9. Further, the hydraulic pressure can be adjusted by opening and closing the on-off valve 14. Therefore, the on-off valve 14 plays a role as a pressure control mechanism that controls the pressure of the liquid L sprayed toward the workpiece surface of the workpiece W.

  The moving mechanism 5 is a device that slides at least one of the nozzle 3 and the workpiece W with respect to the other. That is, the moving mechanism 5 has a function of moving the nozzle 3 relative to the workpiece W. The moving mechanism 5 can be configured by, for example, a three-axis slide mechanism that can translate the nozzle 3 in the three-axis directions of the X axis, the Y axis, and the Z axis that are orthogonal to each other. Of course, you may comprise the moving mechanism 5 using an inclination mechanism and a rotation mechanism. By driving the moving mechanism 5, laser peening can be continuously performed while changing the construction point.

  The tilt mechanism 6 is a device that tilts the workpiece W so that the jet direction of the liquid L for laser peening processing and the normal direction of the workpiece surface of the workpiece W are different. That is, the tilting mechanism 6 is configured to maintain a constant distance between the laser peening position and the nozzle 3 so that the focus of the laser beam is the laser peening position on the work surface of the work W. It is an apparatus for inclining the workpiece W so that L is not injected perpendicularly to the workpiece surface of the workpiece W.

  When laser peening is performed, bubbles are generated from the work surface irradiated with the laser light due to the collision between the liquid L and the work surface or the impact of the laser light being applied to the work surface of the work W. . If bubbles accumulate in the liquid L for laser peening, the optical path of the laser beam may be blocked, leading to scattering or attenuation of the laser beam. Therefore, it is important to remove bubbles from the liquid L for laser peening in order to apply a sufficient shock wave pressure to the surface to be processed in laser peening.

  As a result of observing the laser peening process, it was found that bubbles generated by laser light irradiation tend to accumulate in the stagnation where the flow of the liquid L is stagnant. For this reason, if the stagnation in the laser light irradiation area is reduced, it is possible to avoid the bubbles from staying locally in the laser light irradiation area.

  FIG. 2 is a diagram showing the stagnation produced by the conventional laser peening method.

  As shown in FIG. 2, when the liquid L for laser peening is injected perpendicularly to the surface to be processed of the workpiece W, stagnation of the liquid L is generated around the irradiation spot of the laser light on the surface to be processed. Accordingly, bubbles generated by laser light irradiation remain around the irradiation spot. As a result, the optical path of the laser light is blocked by the bubbles, leading to scattering or attenuation of the laser light.

  Therefore, by tilting the workpiece W by the tilt mechanism 6 as illustrated in FIG. 1, it is possible to avoid the stagnation generated in the liquid L from being concentrated in the vicinity of the laser light irradiation area. That is, when the workpiece W is tilted, the liquid L flows obliquely downward. That is, a flow of liquid L is formed. As a result, the amount of stagnation in the liquid L can be reduced. Even if stagnation occurs, stagnation flows along the flow of the liquid L obliquely downward from the laser light irradiation area. As a result, the bubbles generated by the collision between the liquid L and the surface to be processed and the impact caused by the laser light being applied to the surface to be processed W are allowed to flow obliquely downward together with the liquid L without remaining stagnation. it can.

  In the example shown in FIG. 1, the jet direction of the liquid L and the irradiation direction of the laser light are vertically downward, but depending on the structure of the workpiece W, the jet direction of the liquid L and the irradiation direction of the laser light are vertically downward. It is good also as a different direction. Even in such a case, if the workpiece W is tilted by the tilt mechanism 6 so that the jet direction of the liquid L and the normal direction of the workpiece surface of the workpiece W are different, the jet of the liquid L is performed. The liquid L can be made to flow in a specific direction according to the direction of inclination of the surface to be processed with respect to the direction. Accordingly, the bubbles generated by the laser peening process can flow along with the liquid L in a direction corresponding to the inclination direction of the surface to be processed with respect to the jet direction of the liquid L.

  For example, the tilt mechanism 6 variably controls the tilt angle of the workpiece surface of the workpiece W with respect to the jetting direction of the liquid L for laser peening while maintaining the focus of the laser beam on the workpiece surface of the workpiece W. The robot arm 6A can be configured and a control device 6B that controls the robot arm 6A. The robot arm 6A can be configured using a necessary number of rotation mechanisms and expansion / contraction mechanisms. The robot arm 6A may be configured using a plurality of rotation mechanisms so that the tilt angle in two directions can be adjusted. On the other hand, the control device 6B for controlling the robot arm 6A can be configured by an electronic circuit such as a computer.

  In the example shown in FIG. 1, the workpiece W is attached to the jig T, and the jig T is held by the robot arm 6A. Of course, the workpiece W may be directly held by the robot arm 6A. That is, the tilt mechanism 6 can be configured by the robot arm 6A that holds the workpiece W or the jig T for attaching the workpiece W.

  The tilt mechanism 6 may be configured not only by the robot arm 6A but also by a tilting mechanism having a rotation shaft capable of tilting the workpiece W or the jig T for mounting the workpiece W. . In this case, a control device for controlling the raising / lowering mechanism is provided.

  Further, the processing surface of the workpiece W is not necessarily a flat surface. For example, if the workpiece W is an aircraft part, there may be cases where the workpiece surface is uneven or the workpiece surface is a curved surface. Accordingly, when laser peening is performed while the relative position between the nozzle 3 and the workpiece W is changed by driving the moving mechanism 5, the angle formed between the jet direction of the liquid L and the normal direction of the workpiece surface changes. There is. Therefore, based on the three-dimensional information representing the shape of the workpiece surface, the inclination angle of the workpiece surface with respect to the liquid L injection direction is constant or within a predetermined range during the sliding of at least one of the nozzle 3 and the workpiece W. The workpiece W can be inclined so as to be.

  When performing laser peening while changing the tilt angle of the work surface of the work W, the focus of the laser light is focused on the work W as long as the rotation axis of the work W does not overlap the laser peening position. In addition to the rotational movement of the workpiece W, a parallel movement is required in order to maintain it on the workpiece surface. For example, as shown in FIG. 1, when the tilt angle of the workpiece W is changed by the robot arm 6A, the workpiece W needs to be translated in the vertical direction. Therefore, a plurality of rotating shafts can be provided on the robot arm 6A or a telescopic mechanism configured by a cylinder mechanism or the like can be provided so that the workpiece W can be translated.

  Further, the parallel movement of the nozzle 3 by the moving mechanism 5 may be performed in conjunction with the rotational movement of the workpiece W. In that case, the moving mechanism 5 can also be controlled by the control device 6B based on the three-dimensional information representing the shape of the surface to be processed. Therefore, it can be said that the moving mechanism 5 also functions as a part of the tilting mechanism 6.

  The three-dimensional information representing the shape of the surface to be processed can be stored in advance in a storage device provided in the control device 6B. Then, by controlling the robot arm 6A with reference to the three-dimensional information of the processing surface by the control device 6B, the inclination angle of the processing surface with respect to the jet direction of the liquid L can be maintained to be constant or within a predetermined range. it can. Further, by referring to the three-dimensional information of the processing surface, at least one of the robot arm 6A and the moving mechanism 5 can be controlled by the control device 6B so that the focal point of the laser beam is on the processing surface.

  The amount of stagnation of the liquid L caused by the collision between the liquid L and the surface to be processed also varies depending on the liquid pressure of the liquid L. Therefore, the pressure of the liquid L can be controlled so that stagnation is reduced by the on-off valve 14 as a pressure control mechanism for controlling the pressure of the liquid L. That is, the amount of stagnation can be reduced by adjusting the opening degree of the on-off valve 14. An appropriate opening degree of the on-off valve 14 for reducing stagnation can be obtained empirically by a test.

  If the liquid pressure of the liquid L can be controlled, a device other than the on-off valve 14 can be used as the pressure control mechanism. Even in this case, the pressure of the liquid L can be controlled by the pressure control mechanism so that the amount of stagnation is reduced.

  As described above, in the laser peening apparatus 1, by adjusting the liquid pressure of the liquid L and the tilt angle of the surface to be processed, it is possible to avoid stagnation of bubbles remaining in the vicinity of the laser light irradiation area. .

(Operation and action)
Next, a laser peening processing method using the laser peening processing apparatus 1 will be described.

  First, the workpiece W is fixed to the robot arm 6A via the jig T. Alternatively, the workpiece W is directly fixed to the robot arm 6A. Then, the workpiece W is positioned by driving the moving mechanism 5 so that the focal point of the laser light emitted from the nozzle 3 becomes the start position of the laser peening process on the workpiece surface of the workpiece W. Further, the robot arm 6A is driven by the control by the control device 6B, and the surface to be processed of the workpiece W with respect to the injection direction of the liquid L ejected from the nozzle 3 and the irradiation direction of the laser light emitted from the nozzle 3. The normal direction is tilted by a predetermined angle.

  Next, the laser oscillator 2 oscillates laser light. That is, laser light is emitted from the laser oscillator 2. The emitted laser light is incident on the condenser lens 7 in the nozzle 3 via an arbitrary optical system. The laser light incident on the condenser lens 7 passes through the condenser lens 7 while being condensed. The laser light that has passed through the condenser lens 7 enters the optical element 8. The traveling direction of the laser light incident on the optical element 8 is changed vertically downward in the optical element 8 and emitted.

  On the other hand, the pump 12 of the liquid supply system 4 is operated, and the laser peening liquid L in the tank 11 is supplied into the liquid tank 9 through the pipe 13. As a result, the liquid L is jetted from the opening formed below the liquid tank 9 toward the workpiece surface of the workpiece W. For this reason, the laser beam emitted from the optical element 8 passes through the inside of the liquid L and is condensed and irradiated toward the processing surface of the workpiece W. That is, the nozzle 3 collects and irradiates the laser beam while ejecting the liquid L toward the processing surface of the workpiece W.

  For this reason, plasma is generated on the processing surface of the workpiece W. Thereby, the pressure of the shock wave is applied to the workpiece surface of the workpiece W. If it does so, the intensity | strength of a to-be-processed surface can be increased with a residual stress.

  At this time, the workpiece W is inclined so that the direction in which the liquid L is jetted and the normal direction of the workpiece surface are different. For this reason, the liquid L injected to the processing surface flows along the processing surface in a direction in which the angle formed by the processing surface and the injection direction of the liquid L becomes the largest. As a result, the generation amount of stagnation points in the liquid L is reduced. Further, even if local stagnation occurs due to the collision between the surface to be processed and the liquid L, the stagnation is quickly caused to flow from the laser light irradiation area on the flow of the liquid L. For this reason, the bubbles generated by the collision between the liquid L and the surface to be processed and the impact by the laser light can also flow in the direction corresponding to the inclination direction of the surface to be processed with respect to the jet direction of the liquid L.

  Accordingly, the processing surface of the workpiece W is irradiated with the laser beam without being blocked by a large number of bubbles. In other words, a laser beam having a sufficient energy density is irradiated onto the workpiece surface of the workpiece W. As a result, the strength of the work surface can be reliably improved.

  When the work surface of the work W is wide, laser peening can be sequentially performed while the work W is relatively moved by driving the moving mechanism 5. And when the laser peening process with respect to all the to-be-processed surfaces is complete | finished, a processed product can be obtained. That is, a product or a semi-finished product that has been subjected to laser peening can be manufactured.

  If the workpiece W is not a flat surface, the inclination angle of the workpiece surface can be variably controlled following the movement of the workpiece W. In that case, based on the three-dimensional information representing the shape of the work surface by the control device 6B, the robot arm 6A is controlled so that the inclination angle of the work surface with respect to the jet direction of the liquid L is constant or within a predetermined range. Control. Thereby, the inclination angle of the surface to be processed with respect to the jet direction of the liquid L can be kept constant or within a predetermined range, and bubbles generated by the laser peening process can be prevented from remaining in the laser light irradiation area.

  Further, the pressure of the liquid L can be controlled so that stagnation that causes bubbles to remain is reduced. The pressure of the liquid L can be controlled by adjusting the opening degree of the on-off valve 14.

  That is, the laser peening processing apparatus 1 and the laser peening processing method as described above pay attention to the property that bubbles generated by laser peening processing accumulate in the stagnation of the liquid L for laser peening processing, and stagnation occurs in the vicinity of the laser peening processing position. The normal line direction of the workpiece surface of the workpiece W can be inclined with respect to the jet direction of the liquid L jetted from the nozzle 3 and the irradiation direction of the laser beam so that the amount is reduced. It is.

(effect)
For this reason, according to the laser peening processing apparatus 1 and the laser peening processing method, the amount of the stagnation point of the liquid L remaining in the vicinity of the laser peening processing point can be reduced. Thereby, the bubble which arises by laser peening process in the vicinity of the construction point of laser peening process can be removed. As a result, the attenuation of the energy of the laser beam due to the bubbles can be reduced. That is, laser peening can be performed under more suitable conditions.

(Second Embodiment)
FIG. 3 is a block diagram of a laser peening apparatus according to the second embodiment of the present invention.

  In the laser peening apparatus 1A in the second embodiment shown in FIG. 3, the first embodiment is that the inclination angle of the nozzle 3 with respect to the surface of the workpiece W can be variably controlled by the inclination mechanism 6A. It differs from the laser peening apparatus 1 in the form. Since other configurations and operations of the laser peening apparatus 1A in the second embodiment are not substantially different from those in the laser peening apparatus 1 in the first embodiment, the same or corresponding configurations are denoted by the same reference numerals. Therefore, the description is omitted.

  The tilting mechanism 6A of the laser peening apparatus 1A in the second embodiment is connected to the nozzle 3. For this reason, the inclination angle of the nozzle 3 with respect to the workpiece surface of the workpiece W can be variably controlled. For example, as shown in FIG. 3, the tilt mechanism 6 </ b> A can be configured using a rotating shaft 20 and a plurality of cylinder mechanisms 21 that expand and contract. That is, the inclination of the nozzle 3 is supported by supporting the lower end of one end of the table 22 that also serves as a part of the moving mechanism 5 by a plurality of cylinder mechanisms 21 and supporting the other end of the table 22 rotatably by the rotary shaft 20. The tilt mechanism 6A capable of variably controlling the angle can be configured. Therefore, the tilt mechanism 6 </ b> A may be a component of the moving mechanism 5.

  On the other hand, the height of the table 23 for installing the jig T of the workpiece W or the workpiece W is set so that the focal point of the laser beam becomes the laser peening processing position on the processing surface of the workpiece W. A height adjustment mechanism 24 for adjustment can be provided. The height adjusting mechanism 24 can be controlled by the control device 6B. Therefore, the height adjusting mechanism 24 also tilts the workpiece W so that the liquid L is not sprayed perpendicularly to the workpiece surface of the workpiece W while keeping the distance between the laser peening position and the nozzle 3 constant. It can be said that it constitutes a part of the tilting mechanism 6A. The height adjusting mechanism 24 can be configured using a cylinder mechanism, a ball screw, or the like. Of course, instead of adjusting the height of the table 23 for installing the jig T of the workpiece W, the height of the nozzle 3 may be adjusted by the moving mechanism 5. Further, the heights of both the table 23 and the nozzle 3 may be adjusted.

  In the laser peening apparatus 1A according to the second embodiment, the same effect as that of the laser peening apparatus 1 according to the first embodiment can be obtained. In particular, when the workpiece W is large or when the workpiece W is heavy, the workpiece W can be inclined, and thus a large-scale apparatus can be eliminated.

  On the contrary, when the workpiece W is small or the weight of the workpiece W is small, the injection direction of the liquid L is always changed by inclining the workpiece W side as in the first embodiment. It can be vertically downward. For this reason, it becomes possible to eject the liquid L using gravity. Further, by eliminating the inclination of the nozzle 3 and the moving mechanism 5, a large-scale device can be dispensed with.

(Other embodiments)
Although specific embodiments have been described above, the described embodiments are merely examples, and do not limit the scope of the invention. The novel methods and apparatus described herein can be implemented in a variety of other ways. Various omissions, substitutions, and changes can be made in the method and apparatus described herein without departing from the spirit of the invention. The appended claims and their equivalents include such various forms and modifications as are encompassed by the scope and spirit of the invention.

  For example, the first embodiment and the second embodiment may be combined. That is, the inclination angles of both the nozzle 3 and the workpiece W may be controlled. Therefore, the tilt mechanism can be configured to tilt at least one of the nozzle 3 and the workpiece W.

DESCRIPTION OF SYMBOLS 1, 1A Laser peening processing apparatus 2 Laser oscillator 3 Nozzle 4 Liquid supply system 5 Movement mechanism 6 Inclination mechanism 6A Robot arm 6B Control apparatus 7 Condensing lens 8 Optical element 9 Liquid tank 11 Tank 12 Pump 13 Piping 14 On-off valve 20 Rotating shaft 21 Cylinder mechanism 22 Table 23 Table 24 Height adjustment mechanism W Work piece L Liquid T Jig

Claims (7)

A laser oscillator that oscillates laser light;
The laser beam is condensed while jetting a sufficient amount of liquid so that the work surface is covered with liquid toward the work surface of the work piece with the jet direction set vertically downward, and the irradiation direction is set vertically downward. A nozzle that illuminates as
By holding the workpiece or a jig for attaching the workpiece, and tilting the workpiece so that the liquid jet direction and the normal direction of the workpiece surface are different from each other Bubbles generated by at least one of collision between the liquid and the surface to be processed and impact caused by irradiation of the laser beam on the surface to be processed are inclined with respect to the liquid jet direction along with the liquid. An inclination mechanism that flows in a direction corresponding to a direction, and an inclination mechanism capable of variably controlling an inclination angle of the surface to be processed with respect to a liquid ejection direction;
A moving mechanism that translates the nozzle relative to the workpiece;
The moving mechanism and the movement mechanism and the parallel movement of the nozzle by the movement mechanism and the inclination of the workpiece by the inclination mechanism are interlocked so that the focal point of the laser beam is on the processing surface. A control device for controlling the tilt mechanism;
Height adjustment for adjusting the height of the workpiece or a jig for mounting the workpiece so that the focal point of the laser beam is a machining position on the workpiece surface of the workpiece. Mechanism,
Have
The tilt mechanism is configured such that, based on the three-dimensional information representing the shape of the work surface, the tilt angle of the work surface with respect to the liquid ejection direction is constant or within a predetermined range during the parallel movement of the nozzle. A laser peening apparatus configured to incline the workpiece.   The laser peening apparatus according to claim 1, further comprising a prism that changes a traveling direction of the laser light oscillated from the laser oscillator vertically downward.   3. The laser peening apparatus according to claim 1, further comprising a pressure control mechanism that controls a pressure of the liquid so that stagnation of the liquid caused by a collision between the liquid and the surface to be processed is reduced.   The tilt mechanism is a robot arm that holds the workpiece or a jig for attaching the workpiece, and can variably control the tilt angle of the workpiece surface with respect to the liquid ejection direction. The laser peening apparatus according to any one of claims 1 to 3, wherein the laser peening apparatus is configured using a robot arm. Oscillating a laser beam;
The laser beam is condensed while jetting a sufficient amount of liquid so that the work surface is covered with liquid toward the work surface of the work piece with the jet direction set vertically downward, and the irradiation direction is set vertically downward. Producing a product or semi-finished product by translating a nozzle for performing ejection of the liquid and irradiation of the laser light with respect to the workpiece;
By holding the workpiece or a jig for attaching the workpiece by an inclination mechanism, an inclination angle of the processing surface with respect to the liquid injection direction can be variably controlled, and the liquid injection direction and the liquid By tilting the workpiece so that the normal direction of the workpiece surface is different, the collision between the liquid and the workpiece surface and the laser beam is irradiated to the workpiece surface. Flowing air bubbles generated by at least one of the impacts in a direction corresponding to an inclination direction of the surface to be processed with respect to a jet direction of the liquid together with the liquid;
A moving mechanism for moving the nozzle in parallel so that the parallel movement of the nozzle and the tilt of the workpiece by the tilting mechanism are interlocked so that the focal point of the laser beam is on the processing surface. And controlling the tilt mechanism;
Have
Based on the three-dimensional information representing the shape of the work surface, the tilt mechanism is configured so that the tilt angle of the work surface with respect to the liquid ejection direction is constant or within a predetermined range during the parallel movement of the nozzle. A laser peening method for inclining the workpiece.   6. The laser peening method according to claim 5, wherein the traveling direction of the oscillated laser beam is changed vertically downward by a prism.   The laser peening processing method according to claim 5, further comprising a step of controlling the pressure of the liquid so that stagnation of the liquid caused by the collision between the liquid and the surface to be processed is reduced.

Images