KR20150053884A - Method for creating work path of work piece using laser cladding system - Google Patents

Abstract

The present invention relates to a method to create a work path of a workpiece to remodel or repair in a z-axis direction using a laser cladding system. The laser cladding system comprises: a laser beam illumination unit having a laser generation device to illuminate a laser beam to form a molten pool on a surface of the workpiece; a beam transport unit, and a beam condenser unit; a cladding material supply device to supply a cladding material to the molten pool formed on the surface of the workpiece; a displacement sensor disposed adjacent to the beam condenser unit to form an inclination angle with a vertical line, and measure a distance from an object; a transport system to transport the workpiece or the laser beam to perform laser cladding; a CAD/CAM apparatus to generate a work path from a three dimensional CAD data, and transmit the work path to a control unit; and the control unit to control parts and receive the work path from the CAD/CAM apparatus to perform laser cladding. The displacement sensor moves along the surface of the workpiece and measures the distance between the displacement sensor and the workpiece. The control unit calculates the distance from the surface of the workpiece to an end portion of the beam condenser unit based on a measurement of the displacement sensor, and generates the work path in the z-axis direction. Accordingly, work can precisely be proceeded without getting affected by a plasma or the like which can be created during work.

Description

TECHNICAL FIELD [0001] The present invention relates to a laser cladding system,

The present invention relates to a method for creating a work path in the z-axis direction for remodeling or repairing a workpiece using a laser cladding system.

Laser-aided direct metal manufacturing is a process that uses precision materials such as metals, alloys, ceramics, etc., The laser cladding technique can be used to produce the tools necessary for producing a three-dimensional product or a product in a very short time.

The three-dimensional shape information includes three-dimensional CAD data, medical CT (Computer Tomography) and MRI (Magnetic Resonance Imaging) data, and digital data measured by a 3D object digitizing system It says. A tool is a mass-production mold necessary for producing a die or a mold.

These technologies can be used to produce metal prototypes, mass production molds, complex final products and tools in a short period of time comparable to conventional machining methods such as cutting and casting using CNC (Computerized Numerical Control) And can also be applied to restoration, remodeling and repairing of a mold using reverse engineering.

The basic concept of implementing the physical shape from CAD data is similar to a general printer. Just as a printer produces a document with two-dimensional paper on its exact location on a plane using document data files stored on a computer, the direct metal molding technology uses three-dimensional CAD data to determine the exact location of the three- Dimensional physical shape by forming an amount of the functional material in an amount required. These technologies are being developed as 3D printers and have recently been commercialized in different directions depending on the characteristics of materials such as plastics, ceramics, paper, and metals.

In a laser direct metal forming technology, a two-dimensional plane is implemented physically using laser cladding technology.

1 is a view for explaining a general laser cladding process.

The laser cladding is formed by locally forming a melt pool 40 by irradiating the specimen surface 11 with a laser beam 20 and simultaneously forming a powder cladding material (metal, alloy, ceramic, paper, etc.) 30 is supplied to form a new cladding layer 45 on the surface 11 of the specimen.

In the laser direct metal forming technology, two-dimensional cross-sectional information is calculated from three-dimensional CAD data, and a cladding layer having a shape, thickness and / or height corresponding to each two-dimensional cross-sectional information is sequentially formed, Build products or tools quickly.

In the laser direct metal forming technique, the substrate 10 (or the specimen) is transferred in the x- and y-axes around a fixed laser beam, or the laser beam is moved around the fixed specimen 10 to form a cladding layer. The laser beam and metal specimen can be transported together. In order to increase the degree of freedom of machining, it is also possible to use a robot with three or more axes.

The shape of the cladding layer corresponding to the two-dimensional cross-sectional information in the molding process depends mainly on the accuracy of the tool path and the transfer system calculated from the cross-sectional information, and the physical implementation is relatively easy. However, the height of the laser cladding layer depends on the output of the laser, the mode of the laser beam, the size of the laser beam, the feed rate of the specimen, the characteristics of the cladding powder, the powder feed rate, the falling rate of the powder, The type and the flow rate of the gas. External factors such as the temperature of the specimen surface caused by heat accumulation during the cladding process, the surface of the specimen and the state of the laser oscillator also affect the height of the cladding layer formed.

Therefore, in order to obtain the height of the cladding layer corresponding to the two-dimensional cross-sectional information, the position of the melting pool for determining the height of the cladding layer is monitored in real time, There is a difficulty.

In the conventional laser cladding process, it is difficult to determine the height of the available pool due to the plasma generated during the operation, and it is difficult to utilize the laser cladding system in the preliminary work such as the correction of the work origin, .

Korean Patent No. 10-0341489

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a laser welding apparatus capable of being used for a preliminary work such as correction of a work origin before laser cladding, And an object of the present invention is to provide a method of generating a work path of a workpiece using the free laser cladding system.

According to an aspect of the present invention, there is provided a method of generating a work path in the z-axis direction for remodeling or repairing a workpiece using a laser cladding system, A laser beam irradiating unit including a laser generator, a beam conveying unit, and a beam collecting unit for producing a molten pool on the surface of the workpiece by beam irradiation; A cladding material supply device for supplying a cladding material to the molten pool formed on the surface of the workpiece; A displacement sensor that is inclined by a predetermined angle from a vertical line and is disposed adjacent to the beam condensing unit and measures a distance to an object; A transfer system for transferring the workpiece or laser beam to perform laser cladding; CAD / CAM equipment for generating a work path from three-dimensional CAD data and delivering it to a control unit; A controller for controlling components and performing laser cladding by receiving a work path from the CAD / CAM equipment; Wherein the displacement sensor measures a distance between the displacement sensor and the workpiece while moving along the surface of the workpiece, and the control unit calculates the distance from the surface of the workpiece to the workpiece based on the measured value of the displacement sensor And calculates the distance to the end of the beam concentrator to generate a work path in the z-axis direction.

According to another aspect of the present invention, there is provided a method of automatically setting a working height of a laser beam irradiating unit using a laser cladding system, the laser cladding system comprising: A laser beam irradiating unit including a laser generator, a beam conveying unit, and a beam collecting unit for producing a molten pool on the surface of the wafer; A cladding material supply device for supplying a cladding material to the molten pool formed on the surface of the workpiece; A displacement sensor that is inclined by a predetermined angle from a vertical line and is disposed adjacent to the beam condensing unit and measures a distance to an object; A transfer system for transferring the workpiece or laser beam to perform laser cladding; CAD / CAM equipment for generating a work path from three-dimensional CAD data and delivering it to a control unit; A controller for controlling components and performing laser cladding by receiving a work path from the CAD / CAM equipment; Measuring a distance between the displacement sensor and the workpiece using the displacement sensor; Calculating an actual height from a surface of the workpiece to an end of the beam collector based on the measured value of the displacement sensor; If the calculated actual height is different from a desired working height, vertically transferring the beam concentrator to correct the actual height to match the working height; .

According to another aspect of the present invention, there is provided a method of controlling a laser cladding for laminating a cladding layer on a work using a laser cladding system, the laser cladding system comprising: A laser beam irradiating unit including a laser generator, a beam conveying unit, and a beam collecting unit for producing a molten pool on a surface of the workpiece; A cladding material supply device for supplying a cladding material to the molten pool formed on the surface of the workpiece; A displacement sensor that is inclined by a predetermined angle from a vertical line and is disposed adjacent to the beam condensing unit and measures a distance to an object; A transfer system for transferring the workpiece or laser beam to perform laser cladding; CAD / CAM equipment for generating a work path from three-dimensional CAD data and delivering it to a control unit; A controller for controlling components and performing laser cladding by receiving a work path from the CAD / CAM equipment; Stacking one or more cladding layers on the workpiece; Measuring the distance between the displacement sensor and the surface of the workpiece while moving along the surface of the workpiece having the cladding layer stacked using the displacement sensor; Calculating a distance from a surface of the workpiece to an end of the beam condensing unit based on the measurement value of the displacement sensor to generate a work path in the z axis direction; Further comprising laminating a cladding layer on the workpiece while controlling process variables such as a laser output, a powder feed amount, and a gas amount based on the work path in the z-axis direction; .

According to the present invention, it is possible to use a laser cladding system which can be used for a preliminary work such as correction of a work origin before a laser cladding operation and is free from movement of a mold with a curved portion, Can be provided.

1 is a view for explaining a general laser cladding process.
2 is a configuration diagram of a laser cladding system according to an embodiment of the present invention.
3 is a view showing in detail the configuration of main parts of the laser cladding system of the present invention.
4 is a view for explaining a method of measuring the height of the molten pool in the laser cladding system of the present invention.
FIG. 5 is a view for explaining a method of generating a work path in the z-axis direction for remodeling or repairing a workpiece using the laser cladding system of the present invention.
6A and 6B are views for explaining a method of setting a correct position of a workpiece using the laser cladding system of the present invention.
7 is a view for explaining a method of automatically setting a working height of a laser beam irradiating unit using the laser cladding system of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, like reference numerals refer to like elements throughout. The same reference numerals in the drawings denote like elements throughout the drawings.

2 is a configuration diagram of a laser cladding system according to an embodiment of the present invention. 3 is a view showing in detail the configuration of main parts of the laser cladding system of the present invention. 4 is a view for explaining a method of measuring the height of the molten pool in the laser cladding system of the present invention.

The laser cladding system 100 of the present invention includes laser beam irradiators 110, 120 and 130, a cladding material supplier 135, a displacement sensor 140, a transfer system 150, a CAD / CAM equipment 160, (Not shown).

The laser cladding is formed by locally forming a melt pool 40 by irradiating a laser beam onto a specimen (or a workpiece) 10 and at the same time forming a powder cladding material (metal, alloy, ceramic, Is supplied to form a new cladding layer on the surface of the test piece 10, and a new cladding layer can be further stacked to form a three-dimensional shape. The laser cladding system 100 is a device implementing this technique.

Laser cladding technology is superior to conventional plasma spraying, arc welding, etc., and it has excellent bonding between base metal and cladding layer, minimizes melting of base metal, can precisely place cladding layer at desired position, There are many other excellent advantages.

In addition, such laser cladding techniques are widely used for surface modification of molds, repair and regeneration of molds, fabrication of special materials and hard workable materials, and bonding of two or more kinds of metals. These technologies are also being applied to 3D printers.

The laser beam irradiation units 110, 120, and 130 are devices for making the molten pool 40 by irradiating a laser beam onto a specimen (or a workpiece) 10. The laser beam irradiation units 110, 120, and 130 may include a laser generator 110, a beam transfer unit 120, and a beam condenser 130.

The laser generating apparatus 110 can use a laser of any wavelength capable of forming the molten pool 40 on the surface of the specimen 10 due to irradiation of the laser beam.

The laser beam emitted from the laser generator 110 is transmitted to the beam condensing unit 130 through the beam transfer unit 120. The beam transfer unit 120 can transfer the laser beam in a desired direction using a flexible material.

The beam condensing unit 130 combines optical components such as a lens or a mirror to perform a function of condensing the laser beam so as to be suitable for laser cladding. The condensed laser beam in the beam condensing unit 130 may be irradiated on the specimen 10 to form the molten pool 40. [ A new cladding layer having a small thickness (for example, 250 탆) is formed on the specimen 10 when the specimen 10 is transferred while the cladding material is continuously supplied to the molten pool 40 along with the irradiation of the laser beam. The cladding layer is first formed on a two-dimensional plane, and when all of the cladding layer is formed on a two-dimensional plane, a cladding layer is laminated on the cladding layer to form a three-dimensional shape.

The cladding material supply unit 135 is disposed adjacent to the beam condensing unit 130 and can supply the cladding material to the vicinity of the end of the beam condensing unit 130 through the transfer hose 136. [ The cladding material supply device 135 may be disposed far from the beam condensing part 130 and may supply the cladding material to the vicinity of the end of the beam condensing part 130 through the transfer hose 136.

The cladding material is preferably in powder form, but it can also be used in the form of a wire or the like.

The displacement sensor 140 is disposed adjacent to the beam condensing unit 130 connected to the laser generator 110 to measure the distance between the object separated from the displacement sensor 140 and the displacement sensor 140. The displacement sensor 140 is arranged to be inclined at a certain angle with respect to the vertical line, and two of the displacement sensors 140 can be disposed on both sides of the beam condensing unit 130 for the accuracy of measurement. As the displacement sensor 140, a laser displacement sensor can be used. The displacement sensor 140 may have a measurement accuracy in the order of micrometers.

Since the displacement sensor 140 is spaced apart from the end of the beam condensing unit 130, when the existing workpiece 10 having a curved portion or a groove is to be repaired, There is no problem that the work is limited due to interference with the part.

The transfer system 150 is provided with a beam condensing unit 130 on the z axis to keep the focal distance of the laser beam constant during the shaping process, fix the specimen 10 on the xy axis table, Thereby transferring the test piece 10 freely so that laser cladding can be performed. The conveying system 150 may be installed in the beam collecting unit 130 to allow the laser beam to be freely transferred along the work path in a state where the test piece 10 is fixed. Alternatively, a transfer system capable of simultaneously transferring the laser beam and the specimen 10 may be applied.

The CAD / CAM equipment 160 generates a work path from the three-dimensional CAD data and transmits the work path to the control unit 170.

The control unit 170 includes a PC or an NC (personal computer, numerical control system) and various input / output devices, and includes a function of controlling all devices constituting the laser cladding system and monitoring the status of each device in real time .

The control unit 170 receives a work path from the CAD / CAM apparatus 409, performs a laser cladding operation, calculates the height of the molten pool from the measured value of the displacement sensor 140, The process variable is controlled such that the height reaches the target value. In addition, the controller 170 may also perform various functions for controlling various gases used for laser cladding.

Reference numeral 101 denotes a cooling device, which can be connected to the laser generator 110 to perform cooling.

Hereinafter, a method of measuring the height of the molten pool 40 formed on the specimen 10 using the displacement sensor 140 of the present invention will be described with reference to FIG.

When the laser beam is irradiated from the beam condensing unit 130 connected to the laser generating apparatus 110 onto the test piece 10, a molten pool 40 is formed on the test piece 10 by melting the base material and the cladding powder. When the specimen 10 moves while keeping the height of the molten pool 40 constant, a cladding layer of a uniform height is formed along the working path. If the cladding layers are further stacked in succession according to the three-dimensional CAD data stored in the computer, the workpiece has a desired three-dimensional shape.

In the laser cladding control method of the present invention, first, the height of the molten pool 40 generated on the specimen 10 is measured by the displacement sensor 140, and the controller 170 measures the height of the molten pool 40 The laser power, the powder supply amount, the gas supply amount, the size and the mode of the laser beam, and the like.

The height of the molten pool 40 is controlled to be, for example, 250 μm. If the measured height of the molten pool 40 is low, the laser power is increased, the amount of the powder is increased, If the measured height of the molten pool 40 is high, the molten pool 40 may be controlled by a method such as reducing the laser output, reducing the amount of the powder, or strengthening the gas, Is controlled to be low. For this reason, in the laser cladding process, it is most important to accurately measure the height of the molten pool 40 in real time.

In the present invention, the displacement sensor 140 is used to measure the height of the molten pool 40. The displacement sensor 140 measures the distance between the object separated from the displacement sensor 140 and the displacement sensor 140. Therefore, not only the height of the molten pool 40 by the displacement sensor 140, but also the distance between the displacement sensor 140 and the specimen 10 can be measured.

The greatest advantage of the displacement sensor 140 is that it can be measured even when the cladding operation is not performed by the laser beam. Further, the displacement sensor 140 is not affected by the measurement accuracy at all due to the plasma or flame generated during the laser cladding operation. Since the displacement sensor 140 is spaced apart from the end portion of the beam condensing unit 130, the displacement of the specimen 10 in the course of the movement of the specimen 10 in the case of the specimen 10 having a curved surface or a groove- There is no fear that the displacement sensor 140 will interfere with the portion on the specimen 10. [

Referring to Fig. 4, the height h of the molten pool 40 is calculated by equation (1).

h = cos? (D-d) Equation (1)

Here,? Is an angle at which the displacement sensor 140 is inclined with respect to the vertical line, that is, the optical axis (a) of the laser beam. It is best that θ is kept close to 0 °, and it should be maintained within at least 20 °. is a known value in advance when the laser cladding system 100 is installed.

D is the distance between the displacement sensor 140 and the center point s of the molten pool 40. The center point s of the melting pool 40 refers to the point s at which the optical axis a of the laser beam meets on the specimen 10 with the directional line of the displacement sensor 140. D is a value that is known in advance when the laser cladding system 100 is installed.

d is the distance between the displacement sensor 140 and the end of the molten pool 40 and is measured in real time by the displacement sensor 140.

There is some error between the computed h and actual h, but if θ is small, this error is negligible. Two displacement sensors 140 are disposed on both sides of the beam condensing unit 130 to improve the measurement accuracy by correcting the errors. Three or more displacement sensors 140 may be disposed.

When it is desired to know the distance H between the surface of the specimen 10 and the end of the beam condensing part 130 before the laser cladding operation, H is calculated by the following equation (2).

H = cos? * D - L Equation (2)

Where D is the distance between the displacement sensor 140 and the center point s of the molten pool 40. In this case, the angle? Is the angle at which the displacement sensor 140 is inclined with respect to the vertical line. L is a distance between the end of the displacement sensor 140 and the end of the beam condensing unit 130, which is a known value.

This H is used to create a work path in the z-axis direction of the specimen 10 before the laser cladding operation.

The laser cladding system 100 of the present invention measures the distance d between the displacement sensor 140 and the end of the molten pool 40 in real time by the displacement sensor 140, Calculate the height. Depending on the height of the measured molten pool 40, the controller 170 controls the process variables. Since the displacement sensor 140 is not affected at all by the measurement accuracy due to the plasma or flame generated during the laser cladding operation, the laser cladding system 100 with higher precision can be provided.

The displacement sensor 140 measures the distance between the end of the beam condensing unit 130 and the workpiece 10 before the laser cladding operation is performed as described later, It can also be applied to measuring the coordinates in the axial direction.

Since the displacement sensor 140 is spaced apart from the end portion of the beam condensing unit 130, the displacement of the specimen 10 in the course of the movement of the specimen 10 in the case of the specimen 10 having a curved surface or a groove- There is no fear that the displacement sensor 140 will interfere with the portion on the specimen 10 and there is no restriction on the workpiece 10 that can work with the laser cladding system 100 of the present invention.

Hereinafter, a method of generating a work path in the z-axis direction for remodeling or repairing a workpiece using a laser cladding system will be described with reference to FIG.

The laser cladding system includes all the major components of the laser cladding system 100 shown in FIG. That is, the laser cladding system includes a laser generating device 110, a beam conveying part 120, a laser beam irradiating part including a beam condensing part 130, a cladding material supplying device 135, a displacement sensor 140, A CAD system 150 for generating a work path from the three-dimensional CAD data and transmitting the work path to the control unit, a CAD / CAM apparatus 160 for controlling the apparatuses, 160 for performing laser cladding on the work path.

Remodeling or repair of the workpiece (e.g., a mold) 10 is performed when a small portion is changed or when the mold is damaged due to carelessness or long-term use. In this case, the method of welding to the mold was different from person to material and poor in physical properties, so that it was difficult to use for a long time and could not be repaired precisely. However, if the CAD data is automatically obtained as in the present invention, Quality can be obtained.

In the case of repairing the workpiece 10, since the shape of the workpiece 10 is changed due to abrasion or the like, the workpiece 10 is greatly different from the 3D CAD data of the first manufactured state. Therefore, in this case, there arises a problem that 3D CAD data of the workpiece 10 must be generated by actual measurement.

In the present invention, in order to repair the workpiece 10, the workpiece 10 to be repaired is placed on the transfer system and the workpiece 10 is moved in the x and y axes to obtain the x-y axis coordinates. If the workpiece 10 is a rectangle, four vertexes are input, and if the workpiece 10 is hexagonal, six vertexes are input. Then you can get all the x, y coordinates information that move the face in zigzag. The task of obtaining the x and y coordinate value information can be similarly applied to the conventional laser cladding system. However, in order to generate the work path in the z-axis direction for remodeling or repairing the workpiece 10, In the system, it was difficult.

The laser cladding system 100 of the present invention is capable of generating a work path in the z-axis direction of the workpiece 10 by the displacement sensor 140 while moving along the surface of the workpiece 10. [

To this end, the displacement sensor 140 measures the distance between the displacement sensor 140 and the workpiece 10 while moving along the surface 12 of the workpiece 10. The movement of the displacement sensor 140 along the surface 12 of the workpiece 10 is controlled by the displacement sensor 140 being fixed and the workpiece 10 being moved or the workpiece 10 being fixed and the displacement sensor 140 ).

Referring to FIG. 4, the distance between the displacement sensor 140 and the workpiece 10 is denoted by D, and this distance D can be measured by the displacement sensor 140.

Next, the control unit 170 calculates the distance H from the surface of the workpiece 10 to the end of the beam condensing unit 130 based on the measurement value of the displacement sensor 140. H can be calculated from the equation (2) of H = cos? * D - L as described above.

5, since the surface 12 of the workpiece 10 has a curvature, the height in the z-axis direction is different, and accordingly, the work path in the z-axis direction when the laser cladding operation is performed must be different do.

Thus, the displacement sensor 140 can obtain continuous coordinate information in the z-axis direction while moving along the surface 12 of the workpiece 10 in accordance with the obtained x, y coordinate value information.

When the coordinate information in the x-, y-, and z-axis directions is obtained in this way, a three-dimensional work path can be generated. Information about the work path is stored in the CAD / CAM apparatus 160, Thereby performing the laser cladding operation.

Since the controller 170 knows the three-dimensional information in advance and controls the cladding operation, the cladding layer can be always stacked at a constant height during the cladding operation.

Hereinafter, a method of controlling laser cladding for laminating a cladding layer on a workpiece using a laser cladding system will be described.

The laser cladding system includes all the major components of the laser cladding system 100 shown in FIG. That is, the laser cladding system includes a laser generating device 110, a beam conveying part 120, a laser beam irradiating part including a beam condensing part 130, a cladding material supplying device 135, a displacement sensor 140, A CAD system 150 for generating a work path from the three-dimensional CAD data and transmitting the work path to the control unit, a CAD / CAM apparatus 160 for controlling the apparatuses, 160 for performing laser cladding on the work path.

First, one or more cladding layers are stacked on a workpiece using the laser cladding system 100. Generally, the height of one cladding layer can be laminated to, for example, 250 mu m. However, it is best if the cladding layer is always stacked on the workpiece at a constant height. However, due to various variables, the height at which the cladding layer is actually stacked on the workpiece has a slight variation along the surface of the workpiece. The variation in the height at which the cladding layers are stacked on the workpiece becomes larger as the cladding layers are stacked. In order to prevent such deviation, the height of the molten pool on the workpiece during the cladding operation is measured in real time, and the cladding layer is laminated while controlling the process parameters such as the laser output, the powder supply amount, and the gas amount. Sometimes it can be difficult to control variables while controlling them.

Accordingly, in the present embodiment, after one or more cladding layers are stacked on the workpiece, the height deviation of the stacked cladding layers is measured as a whole to obtain a work path in the z-axis direction, and thereby the laser output, the powder supply amount, A cladding layer is further laminated on the workpiece while controlling the process parameters of the workpiece.

To this end, the displacement sensor 140 is used to measure the distance between the displacement sensor 140 and the surface of the workpiece while moving along the surface of the workpiece having the cladding layer stacked thereon.

Next, the control unit 170 calculates the distance from the surface of the workpiece to the end of the beam condensing unit 130 based on the measurement value of the displacement sensor 140, thereby generating a work path in the z-axis direction. The working path in the z-axis direction is the height information of the cladding layer already laminated on the workpiece. The method of generating the work path in the z-axis direction is as described with reference to Fig.

Next, based on the generated work path in the z-axis direction, while controlling the process parameters such as the laser output, the powder supply amount, and the gas amount so that the height of the cladding layer is low and the height of the cladding layer is low, A cladding layer is laminated on the substrate. Thus, since the cladding layers are stacked by changing the process conditions during the movement of the laser beam by knowing the height information of the cladding layers already stacked, the height control of the cladding layer can be performed without measuring the height of the melting pool in real time during the cladding operation .

The above process can be repeated several times during the laser cladding operation.

According to this method, when the cladding layer is formed on the workpiece, the difficulty of measuring the height of the molten pool in real time and controlling the process parameters accordingly is eliminated, and the control method of the laser cladding is simplified, The quality of the cladding layer to be laminated can be maintained at a certain level or more.

Hereinafter, a method of setting the correct position of the workpiece using the laser cladding system will be described with reference to FIGS. 6A and 6B.

The laser cladding system includes all the major components of the laser cladding system 100 shown in FIG. That is, the laser cladding system includes a laser generating device 110, a beam conveying part 120, a laser beam irradiating part including a beam condensing part 130, a cladding material supplying device 135, a displacement sensor 140, A CAD system 150 for generating a work path from the three-dimensional CAD data and transmitting the work path to the control unit, a CAD / CAM apparatus 160 for controlling the apparatuses, 160 for performing laser cladding on the work path.

In order to perform the laser cladding operation, first, the work origin at which the work is started is set. This is an operation in which the position where the workpiece 10 is placed exactly coincides with the position on the CAD data. The workpiece 10 must be accurately positioned at the work origin so that the work can be performed while the laser beam moves according to previously known CAD data. Conventionally, an operation for positioning the workpiece 10 at the work origin, that is, an operation for setting the correct position of the workpiece 10, has been performed by the operator using a naked eye or using a separate measuring instrument. When the operator performs the visual inspection, many errors occur, and when using the separate measuring equipment, the working time is increased.

In order to solve such a problem, in the present invention, a correct position of a workpiece is automatically set by using a laser cladding system.

For this purpose, it is necessary to check whether the workpiece 10 is correctly positioned at the work origin and correct the position of the workpiece 10 when the workpiece 10 is not accurately positioned at the work origin.

6A, the displacement sensor 140 measures the distance between the displacement sensor 140 and the workpiece 10 while moving along the surface of the workpiece 10 in the x-axis direction. A sudden change occurs between the measurement values of the displacement sensor 140 before and after the x-axis direction boundary point M of the workpiece 10. [ Accordingly, the coordinates of the x-axis direction boundary point M of the workpiece 10 can be obtained on the basis of the point at which the measurement value of the displacement sensor 140 is abruptly changed. For example, the coordinate of the measured x-axis directional boundary point M is (101, 50).

Next, it is confirmed whether or not the coordinates of the obtained x-axis directional boundary point coincides with the coordinates of the workpiece 10 provided by the CAD / CAM apparatus 160. If the coordinate of the x-axis direction boundary point M provided by the CAD / CAM apparatus 160 is (100, 50), it does not coincide with the coordinate of the measured x-axis direction boundary point M.

If the coordinate of the x-axis directional boundary point M does not coincide with the coordinate of the workpiece 10 provided by the CAD / CAM apparatus 160, the position of the workpiece 10 is corrected. Such a work can be performed by a transfer system by a table on which the workpiece 10 is placed or by an operator manually.

Next, the displacement sensor 140 measures the distance between the displacement sensor 140 and the workpiece 10 while moving along the surface of the workpiece 10 in the y-axis direction. A sudden change occurs between measured values of the displacement sensor 140 before and after the y-axis direction boundary point of the workpiece 10. [ Accordingly, the coordinates of the y-axis direction boundary point N of the workpiece 10 can be obtained on the basis of the point at which the measurement value of the displacement sensor 140 is abruptly changed. For example, the coordinate of the measured y-axis direction boundary point N is (50, 101).

Next, it is confirmed whether the coordinates of the obtained y-axis direction boundary point N coincide with the corresponding coordinates of the workpiece 10 provided by the CAD / CAM apparatus 160. If the coordinate of the y-axis direction boundary point N provided by the CAD / CAM apparatus 160 is (50, 100), it does not coincide with the coordinate of the measured y-axis direction boundary point N. [

If the coordinate of the y-axis direction boundary point N does not coincide with the coordinate of the workpiece 10 provided by the CAD / CAM apparatus 160, the position of the workpiece 10 is corrected.

When the workpiece 10 has a polygonal shape, the displacement sensor 140 moves in the x-axis direction on the basis of the vertex of the workpiece 10, And the displacement sensor 140 moves in the y-axis direction to find two boundary points in the y-axis direction, thereby forming another straight line. It is also possible to check whether the coordinates of the vertexes coincide with the coordinates of the vertexes on the CAD data, and correct them if they do not match.

Hereinafter, a method of automatically setting the working height of the laser beam irradiating unit using the laser cladding system will be described with reference to FIG.

The laser cladding system includes all the major components of the laser cladding system 100 shown in FIG. That is, the laser cladding system includes a laser generating device 110, a beam conveying part 120, a laser beam irradiating part including a beam condensing part 130, a cladding material supplying device 135, a displacement sensor 140, A CAD system 150 for generating a work path from the three-dimensional CAD data and transmitting the work path to the control unit, a CAD / CAM apparatus 160 for controlling the apparatuses, 160 for performing laser cladding on the work path.

When laser cladding is performed, the working height of the laser beam irradiation part is a very important process variable. This is because the focusing position of the laser beam varies depending on the working height of the laser beam irradiating portion, that is, the distance between the workpiece 10 and the end portion of the beam condensing portion 130. Therefore, when performing the laser cladding operation, the laser beam (or the end of the beam condenser 130) must start working at an accurate height so that a cladding layer of the same quality can be formed.

Conventionally, an operator has moved the beam concentrator finely in the z-axis direction to align the beam concentrator with a measuring tool, resulting in a lot of errors depending on the operator. In order to solve such a problem, in the present invention, a work height of a laser beam irradiation part is automatically set by using a laser cladding system.

To this end, first, the distance between the displacement sensor 140 and the workpiece 10 is measured using the displacement sensor 140.

Next, based on the measured value of the displacement sensor 140, the actual height H from the surface of the workpiece 10 to the end of the beam condensing section 130 is calculated. H can be calculated from the equation (2) of H = cos? * D - L as described above.

Next, when the calculated actual height H is different from the desired working height, the beam condensing unit 130 is transferred in the vertical direction to correct the actual height H to match the desired working height. Generally, the laser cladding system is configured to automatically transport the beam condensing unit 130 in the vertical direction.

In the present invention, since the working height of the laser beam irradiating unit is automatically set, the accuracy and speed of the cladding operation can be improved as compared with manual setting by the operator.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention will be.

10: Specimen, Workpiece
100: Laser cladding system
101: Cooling unit
110: laser generating device
120:
130: beam concentrator
135: Cladding material feeder
140: displacement sensor
150: Transfer system
160: CAD / CAM equipment
170:

Claims (3)

A method for generating a work path in the z-axis direction for remodeling or repairing a workpiece using a laser cladding system,
The laser cladding system includes a laser beam irradiating unit including a laser generator, a beam conveying unit, and a beam collecting unit to produce a molten pool on a surface of the workpiece by a predetermined laser beam irradiation. A cladding material supply device for supplying a cladding material to the molten pool formed on the surface of the workpiece; A displacement sensor that is inclined by a predetermined angle from a vertical line and is disposed adjacent to the beam condensing unit and measures a distance to an object; A transfer system for transferring the workpiece or laser beam to perform laser cladding; CAD / CAM equipment for generating a work path from three-dimensional CAD data and delivering it to a control unit; A controller for controlling components and performing laser cladding by receiving a work path from the CAD / CAM equipment; Lt; / RTI >
Wherein the displacement sensor measures the distance between the displacement sensor and the workpiece while moving along the surface of the workpiece,
Wherein the control unit calculates a distance from a surface of the workpiece to an end of the beam condensing unit based on a measurement value of the displacement sensor to generate a work path in the z axis direction A method for creating a z-axis work path for remodeling or repairing an object. A method for automatically setting a working height of a laser beam irradiating unit using a laser cladding system,
The laser cladding system includes a laser beam irradiating unit including a laser generator, a beam conveying unit, and a beam collecting unit to produce a molten pool on a surface of the workpiece by a predetermined laser beam irradiation. A cladding material supply device for supplying a cladding material to the molten pool formed on the surface of the workpiece; A displacement sensor that is inclined by a predetermined angle from a vertical line and is disposed adjacent to the beam condensing unit and measures a distance to an object; A transfer system for transferring the workpiece or laser beam to perform laser cladding; CAD / CAM equipment for generating a work path from three-dimensional CAD data and delivering it to a control unit; A controller for controlling components and performing laser cladding by receiving a work path from the CAD / CAM equipment; Lt; / RTI >
Measuring a distance between the displacement sensor and the workpiece using the displacement sensor;
Calculating an actual height from a surface of the workpiece to an end of the beam collector based on the measured value of the displacement sensor;
If the calculated actual height is different from a desired working height, vertically transferring the beam concentrator to correct the actual height to match the working height;
And automatically setting a working height of the laser beam irradiating unit using the laser cladding system. A laser cladding control method for laminating a cladding layer on a workpiece using a laser cladding system,
The laser cladding system includes a laser beam irradiating unit including a laser generator, a beam conveying unit, and a beam collecting unit to produce a molten pool on a surface of the workpiece by a predetermined laser beam irradiation. A cladding material supply device for supplying a cladding material to the molten pool formed on the surface of the workpiece; A displacement sensor that is inclined by a predetermined angle from a vertical line and is disposed adjacent to the beam condensing unit and measures a distance to an object; A transfer system for transferring the workpiece or laser beam to perform laser cladding; CAD / CAM equipment for generating a work path from three-dimensional CAD data and delivering it to a control unit; A controller for controlling components and performing laser cladding by receiving a work path from the CAD / CAM equipment; Lt; / RTI >
Stacking one or more cladding layers on the workpiece;
Measuring the distance between the displacement sensor and the surface of the workpiece while moving along the surface of the workpiece having the cladding layer stacked using the displacement sensor;
Calculating a distance from a surface of the workpiece to an end of the beam condensing unit based on the measurement value of the displacement sensor to generate a work path in the z axis direction;
Further comprising laminating a cladding layer on the workpiece while controlling process variables such as a laser output, a powder supply amount, and a gas amount based on the work path in the z-axis direction;
Wherein the cladding layer is formed on the workpiece by using the laser cladding system.

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