CN111230246A - Double-focus center wire feeding laser processing head and processing method thereof - Google Patents

Abstract

A dual focus center wire feeding laser processing head and a processing method thereof, the wire feeding system comprises a wire feeding tube (9), a wire feeding wheel (10) and a wire feeding nozzle (11), wherein the wire feeding tube (9) is embedded in the wire feeding tube (9) On the inner wall of the center of the processing head, the wire feeding nozzle (11) is located below the wire feeding tube (9), and the wire feeding wheel (10) is arranged between the wire feeding tube (9) and the wire feeding nozzle (11). 9) It is concentric with the wire feed nozzle (11) and has a welding wire channel inside; it realizes the laser processing method of double focus center wire feeding. It ensures the consistency of the laser processing head in different orientations and attitudes, improves the quality of laser processing, and avoids the interference problem when processing complex parts. The protection effect is better, avoiding the adjustment and interference problems of the side shaft air supply. The pressure of the wire feeding wheel (10) on the welding wire improves the straightness of the welding wire (8) and ensures the quality of processing and forming. The adjustment of the filament spacing is accomplished by changing the beam reflection angle.

Description

A dual focus center wire feeding laser processing head and processing method thereof

technical field

The invention is a dual focus center wire feeding laser processing head and a processing method thereof, which can be widely used in laser dual focus self-fusion welding, laser wire filling welding, laser cladding and laser 3D printing industries, and belongs to the field of laser processing.

Background technique

In the field of laser processing, laser welding is widely used in aerospace, transportation, chemical industry and other fields due to the advantages of high beam quality, small metallographic variation in the heat-affected zone, high welding quality, and high forming efficiency. Compared with other welding methods, laser wire filling welding has higher welding adaptability and more advantages in welding quality, but its equipment is more complicated, and a wire feeding system needs to be added on the basis of laser self-fusion welding equipment. To the intersection of the optical axis and the base metal, a collimating wire device is required. The straightness of the welding wire is difficult to ensure, resulting in poor welding stability. Generally, the laser wire filling processing head adopts lateral wire feeding in actual welding production, that is, the laser processing head and the welding gun are assembled by flanges, so they are easily affected by interference when welding complex workpieces, so the laser wire filling welding method is abandoned. In addition, the protective gas nozzle also adopts lateral protection. During the welding process, the laser spot needs to be in the center of the protective gas nozzle, and the height is between 5-10mm. Therefore, it is complicated to adjust the relative position of the protective gas nozzle, and the protective effect is not good.

In the field of laser processing rapid prototyping, laser beam energy melts welding wire or powder and deposits it on a substrate to form a three-dimensional solid. Compared with the traditional process, the advantages are as follows: 1. Rapidity: the processing cycle is shorter than that of the traditional casting process, and the sensitivity is low, and the shape problem is hardly considered when forming, thus saving a lot of time. 2. Suitable for forming complex parts: The forming parts are decomposed into two-dimensional data for forming and manufacturing by computer, and there is no simple or complex point, so it is more suitable for parts that are difficult or even impossible to manufacture by traditional methods. 3. High flexibility: parts with certain precision and certain functions can be rapidly formed on one piece of equipment. Modifications to parts can be accomplished simply by changing their software model. 4. Highly integrated: After the laser rapid prototyping technology converts the software data into STL format, rapid processing can be started.

At present, laser coaxial powder feeding or lateral wire feeding has become the mainstream rapid prototyping method at home and abroad. The problems existing in the multi-channel coaxial powder feeding method are as follows: 1. The adjustment and alignment accuracy of the powder feeding tube during the processing is difficult to control and is time-consuming. 2. The powder utilization rate during processing is low, and the unmelted powder adheres to the processing surface, which is prone to defects such as uneven processing and poor surface quality. The advantages of the lateral wire feeding method are that the material utilization rate and forming efficiency are high, the wire cost is low, and the wire feeding accuracy is easier to control, but there are also the following problems: 1. The relative movement of the welding torch and the laser processing head during the forming process. It is easy to be interfered and restricted, and it is difficult to realize path planning when forming complex structural parts. 2. The quality of the formed surface is rough and difficult to guarantee. 3. The wire feeding angle is difficult to adjust and the repeatability is poor. 4. The gas protection is uneven, and the machined surface is easy to oxidize.

SUMMARY OF THE INVENTION

Purpose of invention:

The present invention provides a dual focus center wire feeding laser processing head and a processing method thereof, which aim to solve the problems existing in the past.

Technical solutions:

A double focus center wire feeding laser processing head, the processing head includes a wire feeding system and an optical system;

The wire feeding system comprises a wire feeding tube (9), a wire feeding wheel (10) and a wire feeding nozzle (11), wherein the wire feeding tube (9) is embedded in the inner wall of the center of the processing head, and the wire feeding nozzle (11) is located in the wire feeding tube Below (9), the wire feeding wheel (10) is arranged between the wire feeding tube (9) and the wire feeding nozzle (11). wire channel;

The optical system includes a collimating mirror module (3), a prismatic beam splitting mirror module (4) and a reflecting focusing mirror module (5), wherein the collimating mirror module (3) and the prismatic beam splitting mirror module (4) are located in one group, The straight mirror module (3) and the prismatic beam splitter module (4) are located on the path of the light in sequence, the two reflection focusing mirror modules (5) are located on both sides of the welding wire (8), and the reflection focusing mirror module (5) is located in the The position where the light split by the prismatic beam splitter module (4) can be received.

The reflecting focusing mirror module (5) is symmetrically arranged with the wire feeding system as the center.

The upper end of the wire feed nozzle (11) is provided with a plurality of protective gas through holes (12).

The optical module includes a fixed collimating mirror module (3), a prismatic beam splitter module (4) and an adjustable reflecting focusing mirror module (5), wherein the adjustable reflecting focusing mirror module (5) is capable of transforming dual Reflective focusing mirror with focal spacing.

The single laser beam passes through the prismatic beam splitter module (4) to form a cross-type double parallel laser beam and surrounds the wire feeding system, enters the reflection focusing mirror module (5) and focuses on a point on the processing plane.

The wire feeding wheel (10) is controlled synchronously with the external wire feeding machine, and wire feeding and wire drawing are adjusted by the wire feeding wheel.

A double focus center wire feeding laser processing method, which is characterized in that: the double laser beams formed after the laser beam transmitted by the optical fiber passes through the optical module is focused on the surface of the workpiece to form a molten pool, and the wire is passed through the coaxial protective gas wire feeding system. The laser beams are vertically fed into the molten pool to realize the laser processing process of single beam double focus center wire feeding.

Advantage effect:

The problem to be solved by the present invention is to provide a laser processing head and a processing method for realizing double-focus center wire feeding with a single beam, aiming at the deficiencies of the general laser welding and laser rapid prototyping methods, which ensures that the laser beam and the wire (powder) are the same The consistency of axis degree and processing quality improves processing efficiency, material utilization rate and surface processing quality, and avoids interference problems during the movement of the laser processing head.

The wire feeding system in the dual focus center wire feeding laser processing head of the present invention comprises a wire feeding tube (9), a wire feeding wheel (10), and a wire feeding nozzle (11), wherein the wire feeding tube (9) is embedded in the inner wall of the processing head center , the bottom end of the wire feeding tube (9) and the wire feeding nozzle (11) are connected by a wire feeding wheel (10). Welding wire channel; the optical system comprises a collimating mirror module (3), a prismatic beam splitter module (4), and a reflecting focusing mirror module (5), wherein the collimating mirror module (3) and the prismatic focusing mirror module (4) are located in a The wire feeding system and the reflection focusing mirror module (5) are located in one group, and the two groups are combined into the laser processing whole, and the reflection focusing mirror module (5) is symmetrically arranged with the wire feeding system as the center; The wire feeding tube (9), the wire feeding wheel (10) and the wire feeding nozzle (11) are sent to a point on the surface of the workpiece, and the laser beam transmitted laterally to the optical fiber is focused on both sides of the point through the optical system.

Wherein, the upper end of the wire feeding nozzle (11) has a plurality of protective gas through holes to form a gas channel, and is connected with an external protective gas source, and is fully wrapped around the molten pool formed by the melting of the wire material. The wire feeding wheel (10) is controlled synchronously with the external wire feeding machine, and wire feeding and wire drawing can be adjusted by the wire feeding wheel. The optical module includes a fixed collimating mirror module (3), a prismatic beam splitter module (4) and an adjustable reflecting focusing mirror module (5), and the adjustable reflecting focusing mirror module (5) is rotated by a side screw Manually change the bifocal spacing.

The laser processing method for laser processing of the present invention is as follows: the laser beam transmitted by the optical fiber passes through the optical module to make the single laser beam symmetrical to form a double parallel laser beam, which is laterally transmitted around the wire feeding head (7), and is focused on the processing plane to form a molten pool . The formed double laser beams are symmetrically distributed on both sides of the wire feeding mechanism, so as to realize the center wire feeding laser processing method of single beam and double focus.

Compared with other laser processing heads, the method of the present invention has the following advantages:

1. A single laser beam can be focused on the processing surface into double laser beams surrounding the wire on both sides of the wire through the optical module, realizing the laser processing method of double focus center wire feeding. It ensures the consistency of the laser processing head along different orientations and attitudes, improves the quality of laser processing, and avoids the interference problem when processing complex parts.

2. The protective gas is blown vertically and uniformly to the molten pool by the wire feed nozzle (11) of the laser processing head, and the protective effect is good, avoiding the adjustment and interference of the side shaft gas supply. The pressure of the wire feeding wheel (10) on the welding wire improves the straightness of the welding wire (8) and ensures the processing and forming quality.

3. The adjustable reflective focusing mirror module (5) controls its angle by rotating the manual screw up and down, and changes the beam reflection angle to complete the adjustment of the optical fiber spacing.

4. It can realize a multi-functional laser processing head that combines double-focus central wire feeding and powder feeding.

Description of drawings

FIG. 1 is a schematic cross-sectional view of the structure of the dual focus center wire feeding laser welding processing head of the present invention.

FIG. 2 is a schematic cross-sectional view of the wire feeder in the dual focus center wire feed laser welding processing head of the present invention.

In Figure 1: 1-fiber, 2-laser beam, 3-collimating mirror module, 4-prism beam splitter module, 5-reflection focusing mirror module, 6-reflection focusing mirror knob, 7-wire feeder, 8- welding wire.

In Figure 2: 9- wire feeding tube, 10- wire feeding wheel, 11- wire feeding nozzle, 12- protective gas channel.

Detailed ways

A double focus center wire feeding laser processing head, the processing head includes a wire feeding system and an optical system;

The wire feeding system comprises a wire feeding tube (9), a wire feeding wheel (10) and a wire feeding nozzle (11), wherein the wire feeding tube (9) is embedded in the inner wall of the center of the processing head, and the wire feeding nozzle (11) is located in the wire feeding tube Below (9), the wire feeding wheel (10) is arranged between the wire feeding tube (9) and the wire feeding nozzle (11), and a wire feeding wheel is used between the bottom end of the wire feeding tube (9) and the wire feeding nozzle (11). (10) Connection, the wire feeding tube (9) and the wire feeding nozzle (11) are arranged concentrically and are provided with wire channels of different diameters (the diameter of the welding wire is thick and thin, so the welding wire channel also scores the thickness);

The optical system includes a collimating mirror module (3), a prismatic beam splitting mirror module (4) and a reflecting focusing mirror module (5), wherein the collimating mirror module (3) and the prismatic beam splitting mirror module (4) are located in one group, The straight mirror module (3) and the prismatic beam splitter module (4) are located on the path of the light in sequence, the two reflecting focusing mirror modules (5) are located on both sides of the welding wire (8), and the reflecting focusing mirror module (5) is located on both sides of the welding wire (8). The position where the light split by the prismatic beam splitter module (4) can be received. The wire feeding system and the reflecting focusing mirror module (5) are located in one group, and the two groups are combined to form the laser processing whole.

The reflecting focusing mirror module (5) is symmetrically arranged with the wire feeding system as the center (the center of the welding wire (8)); the welding wire (8) passes through the wire feeding tube (9), the wire feeding wheel (10) and the wire feeding nozzle (11) It is sent to a point on the surface of the workpiece, and the laser beam transmitted by the lateral fiber is focused on this point from both sides through the optical system.

The upper end of the wire feeding nozzle (11) has a plurality of protective gas through holes (12) (the gas from this through hole is sent from top to bottom in the hollow interior of the wire feeding system, and 12 is connected to the outer wall, and its structure is similar to that of the outer wall. The shape of the drill hole around the wafer is arranged around the center of the wire feed nozzle (11) to form a gas channel, which is connected to the external protective gas source, and is fully wrapped around the molten pool formed by the melting of the wire to avoid oxidation of the processing surface and other defects. Set the interference and asynchrony of the protective gas nozzle.

The optical module includes a fixed collimating mirror module (3), a prismatic beam splitter module (4) and an adjustable reflecting focusing mirror module (5), wherein the adjustable reflecting focusing mirror module (5) is capable of transforming dual Reflective focusing mirror with focal spacing. For example, the bifocal distance can be manually changed by rotating the side screw. Of course, its structural principle can adopt the same structure as the adjustment structure of the car's exterior rearview mirror, which can be manual or electric.

The single laser beam passes through the prismatic beam splitter module (4) to form a cross-type double parallel laser beam and surrounds the wire feeding system, enters the reflection focusing mirror module (5) and focuses on a point on the processing plane.

The adjustable reflective focusing mirror can control the angle by rotating the manual screw up and down to change the reflection angle of the laser beam to complete the control of the optical fiber spacing. As mentioned above, its structural principle can adopt the same structure as the adjustment structure of the car's exterior rearview mirror, which can be manual or electric.

After the single laser beam transmitted by the optical fiber passes through the optical system, the double laser beam focused on the surface of the workpiece can coincide with the point from the wire to the surface of the workpiece.

The wire feeding wheel (10) is controlled synchronously with the external wire feeding machine, and wire feeding and wire drawing are adjusted by the wire feeding wheel.

A dual-focus center wire-feeding laser processing method. The laser beam transmitted by the optical fiber passes through the optical module, and the dual laser beams formed are focused on the surface of the workpiece to form a molten pool, and the wire is passed through the coaxial protective gas wire feeding system. It is sent into the molten pool to realize the laser processing process of single-beam double-focus center wire feeding. The laser processing heads can be installed on welding robots and multi-axis linkage machine tools.

The wire feeding system can be disassembled and installed with a powder feeding system, so as to realize the laser processing method of double-beam central powder feeding, and can be used for laser rapid prototyping processes such as laser cladding and laser 3D printing. (Pull off the welding wire, insert the powder feeding tube, and the powder feeding tube is connected to the external powder feeder)

A wire feeding system in a dual focus center wire feeding laser processing head of the present invention comprises a wire feeding tube (9), a wire feeding wheel (10), and a wire feeding nozzle (11), wherein the wire feeding tube (9) is embedded in the processing On the inner wall of the center of the head, the bottom end of the wire feeding tube (9) and the wire feeding nozzle (11) are connected by a wire feeding wheel (10). There are welding wire channels of different diameters, and the wire feed nozzle (11) has a plurality of shielding gas through holes to form gas channels, which are connected to the external shielding gas source, and are fully wrapped around the molten pool formed by the melting of the wire. 10) Synchronous control with the external wire feeder, wire feeding and wire drawing can be adjusted through the wire feeding wheel; the optical system includes a fixed collimating mirror module (3), a prismatic beam splitter module (4) and an adjustable reflective focusing mirror module (5), wherein the adjustable reflective focusing mirror module (5) controls the angle by rotating the manual screw up and down to change the reflection angle of the laser beam to complete the control of the optical fiber spacing. The collimating mirror module (3) and the prismatic beam splitter module (4) are located in one group, the wire feeding system and the reflecting focusing mirror module (5) are located in one group, and the two groups are combined into the laser processing whole, and the reflecting focusing mirror module (5) Symmetrically arranged with the wire feeding system as the center; the welding wire (8) is sent to a point on the surface of the workpiece through the wire feeding tube (9), the wire feeding wheel (10), and the wire feeding nozzle (11), and the laser beam transmitted laterally to the optical fiber Focus on both sides of the point through the optical system. The laser beam transmitted by the optical fiber passes through the optical module, and the double laser beam formed is focused on the surface of the workpiece to form a molten pool, and the wire is vertically fed into the molten pool between the two laser beams through the wire feeding system of the coaxial protective gas, realizing single light speed double Laser machining process for wire feeding at the center of focus.

The processing method of a dual-focus center wire feeding laser processing head of the present invention is as follows:

The laser processing head can be installed on a welding robot or a multi-axis linkage machine tool. The workpiece to be processed is fixed in a workable position with a fixture. By adjusting the clamping force of the wire feeding wheel in the wire feeding system, the fed wire can be sent vertically to the workpiece surface. And to ensure its straightness, after determining the focus position, the distance between the laser beam and the wire is determined by adjusting the knob (6) on the side of the reflective focusing mirror module. The laser processing process can be completed by determining the processing path and processing speed through the programming of the welding robot or multi-axis linkage machine tool, and adjusting the output power of the laser. Among them, the wire feeding system in the laser processing head is removed and the powder feeding system is installed, and the laser rapid prototyping process can be completed by setting the feeding amount of the powder feeder.

Claims (7)

1. The utility model provides a double focus center send a laser beam machining head which characterized in that: the processing head comprises a wire feeding system and an optical system;

the wire feeding system comprises a wire feeding pipe (9), a wire feeding wheel (10) and a wire feeding nozzle (11), wherein the wire feeding pipe (9) is embedded in the inner wall of the center of the machining head, the wire feeding nozzle (11) is positioned below the wire feeding pipe (9), the wire feeding wheel (10) is arranged between the wire feeding pipe (9) and the wire feeding nozzle (11), the wire feeding pipe (9) and the wire feeding nozzle (11) are arranged concentrically, and a welding wire channel is arranged inside the wire feeding pipe and the wire feeding nozzle;

the optical system comprises a collimating mirror module (3), a prismatic spectroscope module (4) and a reflecting focusing mirror module (5), wherein the collimating mirror module (3) and the prismatic spectroscope module (4) are located in a group, the collimating mirror module (3) and the prismatic spectroscope module (4) are sequentially located on a path through which light passes, the two reflecting focusing mirror modules (5) are located on two sides of a welding wire (8), and the reflecting focusing mirror module (5) is located at a position where light split by the prismatic spectroscope module (4) can be received.

2. A bifocal center wire feed laser machining head according to claim 1, characterized in that: the reflecting focusing mirror modules (5) are symmetrically arranged by taking the wire feeding system as a center.

3. A bifocal center wire feed laser machining head according to claim 1, characterized in that: the upper end of the wire feeding nozzle (11) is provided with a plurality of protective gas through holes (12).

4. A bifocal center wire feed laser machining head according to claim 1, characterized in that: the optical module comprises a fixed collimating mirror module (3), a prismatic spectroscope module (4) and an adjustable reflecting focusing mirror module (5), wherein the adjustable reflecting focusing mirror module (5) is a reflecting focusing mirror capable of changing the distance between double focuses.

5. A bifocal center wire feed laser machining head according to claim 1, characterized in that: the single laser beam forms a crossed double-parallel laser beam after passing through the prismatic spectroscope module (4) to surround the wire feeding system, enter the reflecting focusing mirror module (5) and be focused on one point of a processing plane.

6. A bifocal center wire feed laser machining head according to claim 1, characterized in that: the wire feeding wheel (10) is synchronously controlled with an external wire feeder, and wire feeding and wire drawing are regulated through the wire feeding wheel.

7. A double-focus center wire feeding laser processing method is characterized in that: the laser beam transmitted by the optical fiber is focused on the surface of a workpiece to form a molten pool after passing through the optical module to form double laser beams, and the wire is vertically fed into the molten pool between the double laser beams through a wire feeding system of coaxial protective gas, so that the laser processing process of single-beam double-focus central wire feeding is realized.

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