JP2002321075A - Device and method for laser welding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To weld the end parts of three or more superposed plates firmly and efficiently by a simple process and composition. SOLUTION: A laser welding device 10 is provided with a holding mechanism 12 which positions and holds the welding parts of works W1, W2, W3, a laser irradiation mechanism 18 which can nearly simultaneously apply a first and a second laser beams L1, L2 to the interfaces 14, 16 of the works W1, W2, W3, a heat input control mechanism 20 which controls the heat input amount of the first and the second laser beam L1, L2, and an irradiating position control mechanism 22 which controls the irradiating positions of the first and the second laser beam L1, L2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for welding a laser beam at an end where three or more plates are overlapped.

[0002]

2. Description of the Related Art Generally, when joining ends of three or more plate materials by laser beam irradiation, a laser beam is irradiated from the overlapping direction to weld the overlapped ends. Work is taking place. However, in particular, when welding a thick plate-shaped plate, a large amount of heat input is required to melt the plate, and the thermal distortion also increases, which causes a problem that a desired laser welding operation is not performed. It is pointed out.

[0003] Therefore, for example, Japanese Patent Application Laid-Open No. 7-16775 (hereinafter referred to as prior art 1) and Japanese Patent Application Laid-Open No. 9-2069.
A welding method disclosed in Japanese Patent Application Publication No. 69 (hereinafter, referred to as Conventional Technique 2) is known.

In the above prior art 1, as shown in FIG. 7, of the flange portions 1, 2 and 3 to be welded in a superposed state, the flange to be positioned at one end in the direction of superimposition thereof. The high-density energy beam is irradiated to the portion 1 and the flange portion 2 adjacent to the other side from the overlapping direction. Thereby, the flange portions 1 and 2 are welded, and the beads 4 are formed extending in the overlapping direction.

[0005] Next, the flange portions 2 and 3 are welded by irradiating a beam to the overlapping portion of the flange portions 2 and 3 from a direction facing the end surfaces (interfaces) thereof (a direction orthogonal to the overlapping direction). For this reason, the flange portions 2, 3
In this case, the beads 5 are formed in a plane direction orthogonal to the overlapping direction.

Further, in the above-mentioned prior art 2, as shown in FIG. 8, three or more plate members including an outer panel 6a, an inner panel 6b, a rain hose 6c and the like are overlapped, and the end face is formed by a laser welding machine 7 as shown in FIG. Has a welding joint 8 to be welded. The laser welding machine 7
By irradiating a laser beam while moving the end face of the welded joint 8 in the zigzag direction, the end face of the welded joint 8 is heated to form a zigzag-shaped welded portion 9.

[0007]

However, in the above-mentioned prior art 1, when welding the flanges 1, 2, and 3, which are three plate members, a laser beam is irradiated in the overlapping direction to irradiate the flanges. While welding 1 and 2, a laser beam is irradiated in a plane direction orthogonal to the overlapping direction to weld the flange portions 2 and 3. For this reason, it has been pointed out that the three plate members must be irradiated with the laser beam twice from different directions, which increases the number of steps and lowers productivity.

In the above-mentioned prior art 2, the laser welding machine 7 must be moved in a zigzag manner, which complicates the entire system and, for example, reduces the interface between various plate materials having different plate thicknesses and materials. It may not be possible to perform an appropriate welding process.

SUMMARY OF THE INVENTION The present invention solves this kind of problem, and a laser capable of performing a quick and reliable welding process on an end portion where three or more plate materials are overlapped with a simple process and configuration. It is an object to provide a welding method and apparatus.

[0010]

In the laser welding method and apparatus according to the present invention, in a state where the plate material is positioned and held via a holding mechanism, two or more interfaces consisting of the contact surfaces of the plate materials are connected to the interface. By irradiating the same number of laser beams at substantially the same time, the plate members are welded to each other. Therefore, only one laser beam irradiation can melt two or more interface portions of each plate material contributing to strength at a time, and the welding work of the plate material can be efficiently performed with a simple process and configuration. In addition to being performed quickly and quickly, it is possible to reduce the occurrence of thermal distortion as much as possible.

Further, the heat input of two or more laser beams is
By being changed depending on the material and / or the thickness of the plate material, a desired penetration balance according to the plate thickness and the like can be obtained, and the plate materials can be reliably welded to each other.

Further, the irradiation position of the two or more laser beams is changed depending on the material and / or thickness of the plate material, so that it is possible to easily cope with a change in the plate thickness and the like, and to secure various different plate materials to each other. Can be welded.

[0013]

FIG. 1 is an explanatory side view showing a state in which a laser welding apparatus 10 for performing a laser welding method according to a first embodiment of the present invention is partially broken.

The laser welding apparatus 10 includes a holding mechanism 12 for positioning and holding a welding portion of a work W1, W2, and W3 such as a metal plate, and two interfaces 14, 16 comprising contact surfaces of the works W1, W2, and W3. The interface 14,
Sixteen first and second laser beams L1, L2
A laser irradiation mechanism 18 capable of irradiating substantially the same
And a heat input control mechanism 20 for controlling the heat input of the second laser beams L1, L2 by the material and / or plate thickness of the workpieces W1, W2, W3, and the first and second laser beams L1, L2 And an irradiation position control mechanism 22 for controlling the irradiation position of the work W1, W2, and W3 according to the material and / or plate thickness.

The laser welding device 10 includes a robot arm 2
4, a support bracket 28 constituting an equalizing mechanism 26 is fixed to the robot arm 24. The support bracket 28 is formed in a substantially L-shape.
A base 30 is provided, and guide rods 32 are fixed to both ends of the first base 30. Guide rod 32
Supports a cylindrical portion 36 constituting a movable frame 34, and springs 38 a and 38 b provided on the guide rod 32 are in contact with both ends of the cylindrical portion 36, so that the cylindrical portion 36 is Is held in place.

The holding mechanism 12 includes a fixed roller 40 supported by a movable frame 34, and a movable roller 42 that can advance and retreat in the direction of arrow A with respect to the movable frame 34.
The fixed roller 40 is provided rotatably with respect to a mounting member 44 formed by bending downward at the tip of the movable frame 34, and engages with, for example, a work W1 constituting an outer panel of a vehicle body.

The movable roller 42 is fixed to a rod 48 extending in the direction of arrow A from a first actuator 46 such as a cylinder via a mounting member 50. The first actuator 46 is mounted on the movable frame 34. ing. The movable roller 42 is provided rotatably with respect to the mounting member 50, and engages with the workpiece W3 facing the fixed roller 40.

A second base 52 is fixed to the movable frame 34, and a second actuator 54 such as a motor constituting the irradiation position control mechanism 22 is provided at one end of the second base 52. . A ball screw 56 is mounted on the drive shaft of the second actuator 54.
6 is screwed into the moving member 58. A casing 60 constituting the laser irradiation mechanism 18 is fixed to the moving member 58.

An optical fiber 64 for introducing a laser beam L from the laser oscillator 62 into the casing 60 is connected to an end of the casing 60. On the optical axis O of the laser beam L derived from the optical fiber 64,
A collimator lens 66, a bend mirror 68 and a condenser lens 70 are arranged, and a prism 72 is provided between the collimator lens 66 and the bend mirror 68.
Are arranged so as to be able to advance and retreat and turn via a heat input amount control mechanism 20 and an irradiation position control mechanism 22.

As shown in FIGS. 1 and 2, the heat input control mechanism 20 includes a third actuator 76 fixed to a rotating member 74, and the optical axis O is transmitted from the third actuator 76.
A prism 72 is fixed to the tip of a rod 78 protruding to the side. The rotating member 74 is rotatably supported by the casing 60 via a bearing 79. The prism 72 divides the laser beam L into first and second laser beams L1 and L2, and the heat input amount control mechanism 20 controls the first and second laser beams L1 and L2.
2 has a function of adjusting the output ratio.

The irradiation position control mechanism 22 includes a fourth motor such as a motor.
An actuator 80 is provided, and a drive gear 84 is axially mounted on a rotation shaft 82 of the fourth actuator 80. The rotating member 74 is provided with a ring-shaped driven gear 86 that meshes with the driving gear 84. Irradiation position control mechanism 22
Has a function of adjusting the relative positions (rotational positions) of the first and second laser beams L1 and L2 via the fourth actuator 80, and the work W via the second actuator 54.
1 has a function corresponding to the change of the plate thickness.

The drive of the laser welding apparatus 10 is controlled by a control mechanism 90 as shown in FIG. 1, and the control mechanism 90 includes an actuator control section 92 and a robot control section 94. Actuator control unit 92
Controls the driving of the first to fourth actuators 46, 54, 76 and 80, and controls the robot controller 94.
Performs drive control of a robot (not shown) including the robot arm 24. The control mechanism 90 controls the laser oscillator 6
2 is drive-controlled.

The laser welding apparatus 10 constructed as described above
Will be described below.

First, as shown in FIG.
2 and W3 are partially overlapped with each other,
It is held and positioned by the holding mechanism 12. Specifically, the robot arm 24 moves via the robot controller 94 constituting the control mechanism 90, and the fixed roller 40 constituting the holding mechanism 12 contacts the work W1.

In this state, when the first actuator 46 is driven and the rod 48 moves in the direction of arrow A1, the movable roller 42 moves in the direction of arrow A1 integrally with the mounting member 50 fixed to the rod 48. And work W
3 is engaged. Thus, the overlapped ends of the works W1, W2, and W3 are positioned and held via the fixed roller 40 and the movable roller 42.

Here, the laser oscillator 62 is driven via the control mechanism 90, and the laser beam L derived from the laser oscillator 62 is sent to the laser irradiation mechanism 18 via the optical fiber 64. In the laser irradiation mechanism 18, when the laser beam L reaches the bend mirror 68 via the collimator lens 66, the laser beam L is split by the prism 72 into first and second laser beams L1 and L2.

First and second laser beams L1, L2
After being reflected by the bend mirror 68 and bent downward by approximately 90 °, the workpieces W 1,
Irradiation is performed on the polymerization sites of W2 and W3. At that time, the first
Laser beam L1 constitutes an axial beam, and is applied to the interface 14 of the workpieces W1 and W2 to weld the interface 14, while the second laser beam L2 constitutes a rotating beam and the workpiece W2 , W3 are radiated to weld the interface 16.

Next, the robot arm 24 moves the work W
By moving along the welding direction of 1, W2 and W3, the fixed roller 40 and the movable roller 42 position and hold the overlapped ends of the works W1, W2 and W3 through the laser irradiation mechanism 18, The interfaces 14 and 16 are irradiated with the first and second laser beams L1 and L2, and the work of welding the interfaces 14 and 16 is performed.

In this case, in the first embodiment, two interfaces 14, 16 are present at the overlapped end where the three works W1, W2, and W3 are superimposed.
First and second laser beams L1, L of the same number as 4, 16
2 are irradiated on the interfaces 14 and 16 substantially simultaneously, and the works W1, W2 and W3 are welded to each other.

For this reason, the laser beam L is split into the first and second laser beams L1 and L2 only by irradiating the laser beam L once from the laser oscillator 62.
Interface 1 of each work W1, W2 and W3 that contributes to strength
4, 16 can be melted at a time. Therefore, for each interface 14, 16, the first and second laser beams L
1, compared with the conventional welding method of individually irradiating L2, it is possible to obtain an effect that the welding work of the works W1, W2 and W3 is performed efficiently and quickly with a simple process and configuration.

Moreover, the laser beam is not irradiated from the direction in which the workpieces W1, W2 and W3 are superposed,
The first and second laser beams L1 and L2 are emitted toward the interfaces 14 and 16. This makes it possible to prevent the occurrence of thermal distortion as much as possible without requiring a large amount of heat input, such as when welding a sheet material having a large thickness.

Further, the laser irradiation mechanism 18 is supported by the robot arm 24 via an equalizing mechanism 26, and the fixed roller 40 moves in the welding direction following the position of the work W1 under the action of the equalizing mechanism 26. are doing. For this reason, the position of the fixed roller 40 and the interface 14 is
The first laser beam L1, which is held constant and is an axial beam, is always and accurately irradiated onto the interface 14, so that the welding operation is reliably performed.

Incidentally, in the first embodiment, the work W
1. When the thickness or material of W2 and W3 is changed,
Heat input control mechanism 20 and / or irradiation position control mechanism 2
2 can be easily handled. Hereinafter, a case where the thickness is changed will be described in detail. It should be noted that the case where the material is changed can be dealt with by adjusting the output ratio of the first and second laser beams L1 and L2, and a detailed description thereof will be omitted.

For example, as shown in FIG. 3, when the thicknesses of the works W2 and W3 are larger than the thickness of the work W1, the beam ratio of the second laser beam L2 on the thick plate side is set to It is necessary to increase the first laser beam L1 on the thin plate side.

Then, the third actuator 76 constituting the heat input control mechanism 20 is driven, and the position of the prism 72 is adjusted in the direction of arrow B in FIG. As a result, the output ratio of the first and second laser beams L1 and L2 split from the laser beam L is changed, and bonding suitable for the required strength can be easily and reliably performed on the workpieces W1, W2 and W3. The effect is obtained.

On the other hand, as shown in FIG.
In the case where the thickness of the first and second laser beams L1 and L2 is considerably small, it is conceivable to reduce the distance between the first and second laser beams L1 and L2.
, There is a possibility that the desired penetration cannot be obtained.

Then, under the driving action of the fourth actuator 80 constituting the irradiation position control mechanism 22, the driving gear 84
Is rotated. A driven gear 86 meshes with the driving gear 84, and the angular position of the prism 72 is adjusted via a rotating member 74 provided with the driven gear 86 (see FIG. 2).

For this reason, as shown in FIG. 4, the second laser beam L2 rotates in the direction of the arrow with the first laser beam L1 as an axis, and is reliably irradiated on the interface 16. Therefore, since the second laser beam L2 rotates while the distance between the first and second laser beams L1 and L2 is kept constant, the molten pool is independently formed at the interfaces 14 and 16 to a desired depth. Penetration is obtained. Thereby, the interface 14,
16 can be firmly welded.

Further, when the thickness of the outer work W1 is changed, the second position of the irradiation position control mechanism 22 is changed.
The actuator 54 is driven, and the moving member 58 moves in the direction of arrow A under the rotation of the ball screw 56. For this reason, the distance between the fixed roller 40 and the optical axis O is adjusted, and the first laser beam L1 is applied to the interface 1 between the works W1 and W2.
4 is accurately and reliably irradiated.

In the laser irradiation mechanism 18, a single laser beam L can be irradiated to an interface (not shown) between two works by separating the prism 72 from the optical axis O. Therefore, when welding two workpieces,
A single-beam laser beam L is applied to the interface of the workpiece.
Irradiation makes it possible to perform a welding operation smoothly.

In the first embodiment, the second actuator 54 is used to adjust the positions of the first and second laser beams L1 and L2 in the direction of arrow A. The bend mirror 68 itself may be configured to be adjustable in angle without using it.

FIG. 5 is a partial side view of a laser welding apparatus 100 according to a second embodiment of the present invention. Note that the same components as those of the laser welding apparatus 10 according to the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

The laser welding apparatus 100 includes three workpieces W1, W2, W3, and W4, each of which has a contact surface.
Interface 102, 104 and 106
A laser irradiation mechanism 108 capable of irradiating the same number of first to third laser beams L1, L2, and L3 as 2, 104, and 106 substantially simultaneously is provided.

A collimator lens 66 and a condenser lens 7 are provided in a casing 110 constituting the laser irradiation mechanism 108.
0, the prisms 72a, 72b are disposed so as to be able to advance and retreat via the heat input amount control mechanisms 20a, 20b, and the prisms 72a, 72b are pivotable via the irradiation position control mechanism 22. is there.

The heat input amount control mechanisms 20a and 20b include third actuators 76a and 76b, and prisms 72a and 72b are fixed to rods 78a and 78b of the third actuators 76a and 76b. The bend mirror 68 is not provided in the casing 110, and the laser irradiation mechanism 108 is configured as a straight head type.

The laser irradiation mechanism 10 configured as described above
8, when the laser beam L reaches the condenser lens 70 via the collimator lens 66, the first to third laser beams L1, L2 and L
It is divided into three. Then, the first laser beam L1, which is an axial core beam, is applied to the interface 104 between the workpieces W2, W3, and the second and third laser beams L2, L3, which are rotating beams, are applied to the workpieces W1, W2. Interface 10
2 and the interface 106 between the workpieces W3 and W4.

As a result, the three interfaces 102, 104 and 106 have three laser beams, ie, the first to third laser beams.
Laser beams L1, L2, and L3 can be irradiated almost simultaneously, and the work of welding the workpieces W1 to W4 can be efficiently and quickly performed with a simple process and configuration.
The same effects as in the first embodiment can be obtained.

In the second embodiment, the straight head type laser irradiation mechanism 108 is used. However, similarly to the laser irradiation mechanism 18 according to the first embodiment, a bend head type laser having a bend mirror 68 is used. Can be configured. On the other hand, the laser irradiation mechanism 1 according to the first embodiment
8 may be configured as a straight head type without using the bend mirror 68.

FIG. 6 is an explanatory side view showing a state where a part of a laser welding apparatus 120 according to a third embodiment of the present invention is broken. Note that the same components as those of the laser welding apparatus 10 according to the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

The laser welding apparatus 120 includes first and second laser beam heads (laser irradiation mechanisms) 122 and 124 for individually irradiating the first and second laser beams L1 and L2, respectively. First and second
Laser beam heads 122 and 124 are integrally fixed to the moving member 58.

First and second laser beam heads 12
Although not shown, a collimator lens and a condenser lens are held therein, respectively, and focus the first and second laser beams L1 and L2 sent through the optical fibers 126 and 128 at a predetermined focus. It is configured to collect light at a distance and irradiate the interfaces 14, 16 of the works W1, W2, and W3.

In the third embodiment configured as described above, the first and second laser welding operations can be performed easily and quickly, and the productivity can be effectively improved. The same effect as that of the embodiment can be obtained.

[0053]

In the laser welding method and apparatus according to the present invention, the same number of laser beams as the number of interfaces are applied to two or more interfaces formed of the contact surfaces of the sheet materials at substantially the same time. By performing only once, two or more interface portions between the respective plate members that contribute to the strength can be melted at a time. Therefore, with a simple process and configuration, the welding operation of the plate material can be performed efficiently and quickly, and the thermal distortion can be reduced as much as possible.

The amount of heat input of two or more laser beams is
By being changed depending on the material and / or the thickness of the plate material, a desired penetration balance according to the plate thickness and the like can be obtained, and the plate materials can be reliably welded to each other.

Further, by changing the irradiation position of two or more laser beams depending on the material and / or thickness of the plate material, it is possible to easily cope with changes in the plate thickness and the like, and to secure various different plate materials to each other. Can be welded.

[Brief description of the drawings]

FIG. 1 is an explanatory side view showing a state in which a part of a laser welding apparatus for performing a laser welding method according to a first embodiment of the present invention is partially broken.

FIG. 2 is an explanatory perspective view of an advancing / retreating means and a rotating means constituting the laser welding apparatus.

FIG. 3 is an explanatory diagram when a beam ratio is changed by the laser welding apparatus.

FIG. 4 is an explanatory diagram when a laser beam is rotated by the laser welding apparatus.

FIG. 5 is a partial side view of a laser welding apparatus according to a second embodiment of the present invention.

FIG. 6 is an explanatory side view showing a state in which a part of a laser welding apparatus according to a third embodiment of the present invention is broken.

FIG. 7 is an explanatory diagram of a welding method according to Prior Art 1.

FIG. 8 is an explanatory diagram of a welding method according to Prior Art 2.

[Explanation of symbols]

10, 100, 120 laser welding device 12 holding mechanism 14, 16, 102, 104, 106 interface 18, 108 laser irradiation mechanism 20, 20a, 20
b: Heat input control mechanism 22: Irradiation position control mechanism 24: Robot arm 26: Equalize mechanism 34: Movable frame 40: Fixed roller 42: Movable roller 46, 54, 76, 76a, 76b, 80: Actuator 56: Ball screw 58 ... Moving member 60. Casing 62. Laser oscillator 64. Optical fiber 66. Collimator lens 68. Bend mirror 70. Condensing lens 72, 72a, 72b. Prism 90. Control mechanism 92. Actuator controller 94. Robot controller 110. Casing 122,124 ... Laser beam head 126,128 ... Optical fiber L, L1, L2, L
3: Laser beam W1, W2, W3, W4: Work

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Jun Kitagawa 1-10-1 Shinsayama, Sayama City, Saitama Prefecture Honda Engineering Co., Ltd. (72) Junya Tanabe 1-10-1 Shinsayama, Sayama City, Saitama Prefecture Honda Engineering Co., Ltd. (72) Inventor Keiji Otsuka 1-10-1 Shinsayama, Sayama City, Saitama Prefecture Honda Engineering Co., Ltd. F-term (reference) 4E068 BD02 CA01 CA14 CD04 CD09 DA14 DB01

Claims (6)

[Claims] 1. A laser welding method for welding an overlapped portion of three or more plate members by irradiating a laser beam, wherein the plate member is positioned and held via a holding mechanism.
A laser welding method, comprising: irradiating the same number of laser beams to the two or more interfaces formed of the contact surfaces between the plate members at substantially the same time as the interfaces to weld the plate members. 2. The laser welding method according to claim 1, wherein
A laser welding method, wherein the heat input amounts of the two or more laser beams are changed depending on the material and / or thickness of the plate material. 3. The laser welding method according to claim 1, wherein
A laser welding method, wherein irradiation positions of two or more laser beams are changed depending on a material and / or a thickness of the plate material. 4. A laser welding apparatus for welding an end obtained by superposing three or more plate members by irradiating a laser beam, wherein a holding mechanism for positioning and holding an overlapped end portion of the plate members; A laser irradiation mechanism capable of irradiating the same number of laser beams to the two or more interfaces consisting of contact surfaces of the two at substantially the same time; and a heat input amount of the two or more laser beams by the material and / or thickness of the plate material. And a heat input amount control mechanism controlled by the laser welding apparatus. 5. A laser welding apparatus for welding an end obtained by superposing three or more plate members by irradiating a laser beam, wherein a holding mechanism for positioning and holding an overlapped end portion of the plate members; A laser irradiation mechanism capable of irradiating the same number of laser beams to the two or more interfaces composed of the contact surfaces thereof at substantially the same time; and irradiating the two or more laser beams with the material and / or thickness of the plate material And a radiation position control mechanism controlled by the laser welding apparatus. 6. A laser welding apparatus for welding an overlapped portion of three or more plate members by irradiating a laser beam thereto, wherein a holding mechanism for positioning and holding an overlapped end portion of the plate members; A laser irradiation mechanism capable of irradiating the same number of laser beams to the two or more interfaces consisting of contact surfaces of the two at substantially the same time; and a heat input amount of the two or more laser beams by the material and / or thickness of the plate material. A laser welding apparatus, comprising: a heat input amount control mechanism that controls the irradiation positions of two or more laser beams according to a material and / or a plate thickness of the plate material.