KR100969007B1 - A laser brazing head - Google Patents

Abstract

The present invention relates to a laser head for brazing bonding, and more particularly, to a laser brazing head for outputting lasers of different densities from one laser source to improve the wettability of the base material and the filler wire.

To this end, the present invention is a laser brazing head for brazing and bonding the filler wire to the junction of the panel parts using a laser beam passing through a collimator installed inside the head body mounted on the arm tip of the working robot,

A pair of linear guides mounted on the front end portion from the lower side of the collimator across the inside of the head body in a left-right direction, and the irradiation direction and the amount of light collection of the laser beam mounted on the linear guides and passing through the collimator Variable draw to preheat the base material,

It is mounted to the inner wall of the rear end of the head body provides a laser brazing head comprising a fixed draw for melting the filler wire.

Brazing, laser brazing, brazing head, bonding, lens

Description

LASER BRAZING HEAD {A LASER BRAZING HEAD}

The present invention relates to a laser head for brazing bonding, and more particularly, to a laser brazing head for outputting lasers of different densities from one laser source to improve the wettability of the base material and the filler wire.

In general, laser brazing is a process of brazing a panel part, which is a base material (for example, a vehicle roof and a side assembly) by melting an insertion metal (that is, filler wire) using a laser as a heat source. Joined by entering between parts.

At this time, the ends of the panel to be brazed and the focal point of the laser and the end of the filler wire to be supplied are coincident to obtain a good brazing joint.

FIG. 1 is a diagram illustrating a conventional laser brazing bonding system, and FIG. 2 is a schematic view showing panel components bonded using a conventional laser brazing bonding system, and FIG. 3 is a schematic diagram showing a conventional laser brazing head.

The configuration of the conventional system for such a laser brazing bonding, as shown in FIG. 1, oscillates the laser beam B from the laser oscillator 3 controlled by the controller 1 and is joined by the working robot 5. The laser beam B is irradiated to the two panel parts 10 through the laser head 7 moving along (S) to melt the filler wire and to braze the bonding.

In general, the laser brazing bonding determines the affinity with the base material according to the degree of wettability of the melted filler wire when the filler wire 13 is melted by a laser to determine whether the bonding is good or not.

The wettability refers to a phenomenon in which a liquid spreads by an interaction between a solid and a liquid atom when a liquid is attached to a surface of a solid, or a liquid is adsorbed on a surface of a solid. The attraction between the two decreases and the surface tension decreases, thereby increasing the wettability of the liquid.

That is, the higher the temperature of the base material and the molten filler wire, the better the wettability, the more effectively the brazing bonding is made.

Such a laser brazing joint has a smoother appearance than conventional spot welding, which improves design freedom and merchandise and reduces cost by eliminating molding and sealer, and improves body strength according to stress distribution at the joint.

However, the conventional laser brazing bonding has a problem that the wettability of the cold base material and the melted filler wire is lowered by melting only the filler wire without considering the state of the base material, in particular, the temperature, and thus the bonding property is lowered. Since the brazing is performed only at a predetermined teaching speed and direction, it is impossible to adjust the output or focusing of the laser according to the material characteristics of the panel parts, and as shown in FIG. 2, there is a problem in that the wettability is not uniform.

Accordingly, in order to increase the wettability of the base material and the filler wire, an expensive equipment such as a twin head generating a laser for preheating the base material is required, and the number of working steps increases because the base material is preheated and then brazed. The problem is that the efficiency of the work decreases.

In addition, in the case of a roof or side panel of a galvanized vehicle, a copper filler wire is used for brazing bonding, due to a difference between a boiling point of zinc (907 ° C) and a melting point of copper wire (1027 ° C). The zinc is vaporized and bubbles are formed at the junction between the roof and the side panel, thereby degrading the commerciality.

The present invention has been invented to solve the above problems, it is possible to calculate two different outputs from one laser source supplied to the laser head consisting of a variable draw for preheating the base material and a fixed draw for melting the filler wire However, it is an object of the present invention to provide a laser brazing head configured to adjust the moving direction and the output amount of the laser that the variable draw is irradiated to the base material.

In order to achieve the above object, the present invention uses a laser beam passing through a collimator installed inside a head body mounted on an arm tip of a working robot, and a laser brazing head for melting and brazing a filler wire to a joint of panel parts. To

A pair of linear guides mounted on the front end portion from the lower side of the collimator across the inside of the head body in a left-right direction, and the irradiation direction and the amount of light collection of the laser beam mounted on the linear guides and passing through the collimator Variable draw to preheat the base material,

It is mounted to the inner wall of the rear end of the head body provides a laser brazing head comprising a fixed draw for melting the filler wire.

Preferably, the variable draw is a pair of linear moving tools to move in the left and right direction along the linear guide, a screw shaft frame installed in the linear movement tool, and the servo motor is mounted on the bottom of the screw shaft frame And a variable draw lens installed between the pair of screw shafts rotated by and a pair of lens connection gears coupled to the screw shafts.

In addition, the linear moving tool is characterized in that the upper roller mounted between the linear guide and a roller servo motor for driving the upper roller,

In addition, the linear moving tool is further characterized in that the lower roller is freely rotated between the linear guide.

More preferably, the lower end of the head body is characterized in that the locking jaw is formed is supported by the variable draw is stacked,

In addition, the fixed draw is located between the collimator and the variable draw, it characterized in that it comprises a fixed lens fixed to the lens fixing portion mounted to the inner wall surface of the head body and the lens fixing portion.

More preferably, the roller servo motor is characterized in that the rotary encoder for detecting the position of the laser spot irradiated by sensing the number of revolutions of the upper roller.

Laser brazing head according to the present invention by melting the filler wire and at the same time preheating the base material to increase the wettability can improve the bonding between the fill material and the base material to obtain the effect of improving the quality of the vehicle body and the brazing operation speed, the laser irradiation on the base material By adjusting the output of the beam to the characteristics of the base material, brazing bonding can be effectively performed.

In addition, by adjusting the preheating degree and the melted area according to the material of the base material, there is no need for a pressurizing device to secure a gap between panels, thereby reducing the installation cost.

In addition, the variable draw for preheating the base material is configured in front of the laser head to move first to vaporize the zinc plated layer of the body panel to remove pore phenomena generated during melting of the filler wire to secure the body joint quality.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present disclosure, and the singular forms “a”, “an” and “the” include plural forms unless the context clearly indicates otherwise.

There may be a plurality of embodiments of the present invention, and overlapping descriptions of the same parts as in the prior art may be omitted.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the present invention.

The laser brazing head preferably implemented according to the present invention can properly adjust the density of the laser irradiated with the base material and the filler wire by separating the laser beam supplied by oscillation from the laser oscillator for preheating the base material and melting the filler wire after vertical change. It is configured to be.

FIG. 4 is a schematic side view showing an embodiment of a laser brazing head preferably implemented according to the present invention, and FIG. 5 is a front view thereof.

4 and 5, the variable draw 130 for preheating the base material and the fixed draw 120 for melting the filler wire are installed in the head body 110 to which the laser beam is incident. do.

The laser beam incident through the laser beam cable 111 installed at the upper end of the head body 110 is diverged through the collimator 113 installed inside the upper end of the head body 110, and the emitted laser is It is incident to the variable draw 130 and the fixed draw (120).

The fixed draw 120 includes a lens fixing part 123 fixed to an inner wall surface of the head body 110 and a fixed draw lens 121 connected to the lens fixing part 123. It is mounted below the collimator 113.

The variable draw 130 is a linear moving tool 135 mounted to the linear guide 119 installed on both side walls across the head body 110 in the left and right direction, as shown in Figure 5, and the linear moving tool 135 The screw shaft frame 134 is mounted on the side of the screw shaft 134 is configured to include a screw shaft 133 is configured in the interior. The screw shaft 133 is installed so that the servo motor 139 is mounted to rotate at the bottom, the lens connecting portion 132 is connected to the gear coupling on the top.

The linear moving tool 135 and the screw shaft frame 134, the screw shaft 133, the servomotor 139, and the lens connecting portion 132 constituting the variable draw 130 are all preferably formed in one pair. The variable draw lens 131 for preheating the base material is configured between the lens connecting portions 132.

In addition, the linear moving tool 135 includes an upper roller 136 and a lower roller 138 between the linear guide 119 and the upper roller 136 is provided inside the linear moving tool 135. It is driven by the roller servo motor 137 thus horizontally moving the linear moving tool 135 in the left and right directions. The lower roller 138 rotates freely during left and right movement by the operation of the roller servomotor 137 mounted on the upper roller 136 to reduce surface friction between the linear guide 119 and the linear moving tool 135.

When the linear movement tool 135 is moved in the left and right direction, the entire variable draw 130 is moved left and right so that the position of the laser spot for preheating the base material is changed, and the rotary encoder provided in the roller servo motor 137 When the linear movement tool 135 moves, the rotation speed of the upper roller 136 is sensed to recognize the position of the laser spot.

On the other hand, the lower end of the head body 110 is formed convexly bent inwardly so that the locking jaw 117 is formed so that the screw shaft 134 close to the inner wall surface of the head body 110 is formed to the variable draw 130 To support it. In addition, a protective glass 115 made of a material that transmits a laser is installed at a lower end of the head body 110.

7 is an operation diagram showing an operating state of the variable draw according to the present invention.

Wherein the lens connecting portion 132 is connected to the screw shaft and gear coupling, the screw shaft frame 134 is configured as a non-engaged structure as shown in Figure 4 when the servo motor 139 is driven, as shown in Figure 7, The screw shaft 133 rotates and the lens connecting portion 132 is pushed up to raise the variable draw lens 131, and the linear moving tool 135 connected to the screw shaft frame 134 does not rotate.

As the variable draw lens 131 moves up and down as described above, the focusing amount of the laser irradiated to the base material changes, so that the focusing amount increases when the variable draw lens 131 rises and the focusing amount decreases when the variable draw lens 131 rises. do.

8 is a view schematically showing a change in the irradiation direction and focusing amount of the laser according to the movement of the variable draw according to the present invention, Figure 9 is a schematic diagram showing a brazing process between the roof of the vehicle body and the side panel.

As shown in FIG. 8, the variable draw 130 moves in the horizontal direction (X axis) and the vertical direction (Z axis) while preheating the joint of the base material (two panel parts), thereby providing uniform wettability of the filler wire. The melted filler wire is evenly spread and introduced into the joints of the two panel parts as it becomes, and the appropriate area is melted according to the joint area between the two panel parts.

In addition, in the present invention, the preheating of the base material and the melting of the filler wire proceed simultaneously, but as shown in FIG. 4, the variable draw 130 is located in front of the laser head 100 and the fixed draw 120 is located in the rear. Accordingly, the relatively variable draw 130 first approaches the base material, so that bubbles do not occur when the molten filler wire is introduced.

That is, as shown in Figure 9, when the melting point of the filler wire is higher than the boiling point of the metal panel forming the base material, the metal component of the base material is vaporized by the laser irradiated from the fixed draw to generate bubbles in the filler wire to be melt-coated However, in the present invention, since the variable draw 130 moves first, the preheating of the base material causes vaporization to occur before performing brazing bonding, thereby preventing bubbles from being introduced into the filler wire.

Hereinafter, the operating state of one embodiment according to the present invention configured as described above is as follows.

6 is an operation diagram illustrating a variable draw according to the present invention to move in the X-axis direction to adjust the irradiation direction of the laser, and FIG. 10 is a flowchart illustrating a laser brazing bonding process according to the present invention.

When the laser beam is incident through the laser beam cable 111 installed on the top of the head body 110 and the laser emitted through the collimator 113 is incident on the variable draw 130 and the fixed draw 120, The fixed draw 120 irradiates the filler wire with a laser of a predetermined direction and focusing amount, and the variable draw 130 moves the linear movement tool 135 to the left and right according to the characteristics of the base material and the screw shaft 133. The variable draw lens 131 is raised and lowered by rotation of the variable draw lens 131 to vary the position and the laser focusing amount of the variable draw lens 131 to irradiate a laser having an appropriate density.

The laser head operating as described above moves in the moving direction for laser brazing bonding according to the arm movement of the working robot and performs brazing bonding.

The present invention is applied to a fixed draw 120 for melting a filler wire with a high power (intensity) of a relatively high density in a relatively small area, the laser output with a small focusing amount in a large area is a variable to preheat the base material Is applied to the draw 130.

In addition, the spot position of the laser beam collected when the variable draw 130 moves in the X-axis direction is changed, and the amount of laser focusing changes when the variable draw 130 is moved in the Z-axis direction.

Therefore, the present invention can obtain two different outputs from one laser source without using twin heads for the base material and the filler wire, thereby enabling efficient brazing bonding.

While the invention has been shown and described with respect to certain preferred embodiments, the invention is not limited to these embodiments, and those of ordinary skill in the art claim the invention as claimed in the appended claims. It includes all embodiments of the various forms that can be carried out without departing from the spirit.

1 shows a conventional laser brazing bonding system,

Figure 2 is a schematic diagram showing the panel parts bonded using a conventional laser brazing bonding system,

3 is a schematic view showing a conventional laser brazing head,

Figure 4 is a schematic side view showing an embodiment of a laser brazing head preferably implemented according to the present invention,

5 is a schematic front view showing one embodiment of a laser brazing head according to the present invention;

6 is an operation diagram showing that the variable draw according to the present invention moves in the X-axis direction to adjust the irradiation direction of the laser,

7 is an operation diagram showing an operating state of the variable draw according to the present invention,

8 is a view schematically showing a change in the irradiation direction and focusing amount of the laser according to the movement of the variable draw according to the present invention,

9 is a schematic diagram showing a brazing process between a roof of a vehicle body and a side panel;

10 is a flowchart illustrating a laser brazing bonding process according to the present invention.

<Description of the symbols for the main parts of the drawings>

100: laser head 110: head body

111: laser beam cable 113: collimator

115: protective glass 117: locking jaw

119 linear guide

120: fixed draw 121: fixed draw lens

123: Lens Fixing

130: variable draw 131: variable draw lens

132: lens connection 133: screw shaft

134: screw shaft 135: linear moving tool

136: upper roller 137: roller servo motor

138: lower roller 139: servo motor

Claims (7)

In the laser brazing head for melting and brazing the filler wire to the joining of the panel parts using a laser beam passing through a collimator installed inside the head body mounted on the arm tip of the working robot, A pair of linear guides mounted on the front end portion from the lower side of the collimator across the inside of the head body in a left-right direction, and the irradiation direction and the amount of light collection of the laser beam mounted on the linear guides and passing through the collimator Variable draw to preheat the base material, And a fixed draw mounted on an inner wall of the rear end of the head body to melt the filler wire. The method according to claim 1, The variable draw is rotated by a pair of linear moving tools moving in the horizontal direction along the linear guide, a screw shaft frame installed in the linear movement tool, and a servo motor mounted inside the screw shaft frame and mounted on the lower end. And a variable draw lens installed between a pair of screw shafts and a pair of lens connecting gears coupled to the screw shafts. The method according to claim 2, The linear moving tool is a laser brazing head, characterized in that the upper roller is mounted between the linear guide and a roller servo motor for driving the upper roller. The method according to claim 2 or 3, The linear moving tool is a laser brazing head, characterized in that the lower roller is further mounted freely rotated between the linear guide. The method according to claim 1, Laser brazing head, characterized in that the locking jaw is formed in the lower end of the head body is supported by the variable draw is stacked. The method according to claim 1, The fixed draw is positioned between the collimator and the variable draw, laser brazing characterized in that it comprises a fixed lens fixed to the lens fixed to the inner wall surface of the head body connected to the lens fixing head. The method according to claim 3, The roller servo motor is a laser brazing head, characterized in that the rotary encoder for detecting the position of the irradiated laser spot by sensing the rotational speed of the upper roller.

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