JPH0530555B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to butt welding of metal plates, metal wires, or members formed from these.

[Conventional technology]

When butt welding metal plates, metal wires, or parts formed from these, especially when the metal plates or wires are relatively thin or thin,
Butt resistance welding methods such as upset butt welding and flash butt welding, or high energy beam welding methods such as laser and electron beam welding are often used.

In the upset butt welding method, two members to be welded together are clamped to a fixed table and a movable table, respectively, and the movable table is moved forward toward the fixed table.
After abutting the butt end surfaces of the objects to be welded, while applying a predetermined pressure, a current is passed between the members to heat the members to be welded by resistance heat generation due to the inherent resistance of the objects to be welded and the contact resistance at the abutting surfaces. , and join the members by causing plastic deformation.

Further, the flash butt welding method is performed using the same member arrangement and steps as the above-mentioned upset butt welding, but flash is generated between the members during the welding process to generate heat more efficiently.

These resistance welding methods have great economic advantages, such as not requiring any welding materials, high efficiency because welding can be performed in a short time, and not requiring very high precision in processing the edges of the parts to be joined. .

Another feature is that the entire cross section is joined at the same time, and compared to welding by arc welding or beam welding, in which the weld line is welded sequentially from the end, the problem of distortion caused by temperature gradients in the weld is smaller. There is.

Comparing flat butt welding and upset butt welding, we find that flat butt welding has the advantage that the edge processing before welding can be carried out even if it is rougher, while upset butt welding does not involve the occurrence of flashing during the welding process, making it easier to work in the working environment. Each has its own characteristics, such as being suitable for automating lines that require clean, precise control equipment.

Regarding the butt welding method, for example, JP-A-61-
It is described in Publication No. 38787, Japanese Unexamined Patent Application Publication No. 61-38788, etc.

High-energy beam welding is a method of melting and welding by irradiating the weld with a laser beam or high-energy electron beam, and because it uses a concentrated heat source with high energy density, the heating and melting range is narrow, making it difficult to weld. The range in which the material or geometrical shape of the object changes is narrowed, and it is highly efficient, so it has great economic advantages and is widely used.

For example, in the production of welded pipes, a metal plate is bent into a pipe shape, the ends are wedge-shaped, and the apex of the wedge is heated by passing a high-frequency current through it, and then a laser beam is irradiated thereon. (Tokuko Showa 61-
Publication No. 29830). In addition, in butt welding of plates, the groove gap is pre-welded, and this welded part is irradiated with a laser beam to perform the main welding (Japanese Patent Laid-Open No. 57-1999-1).
Publication No. 160582). There is also a proposal to perform both preheating and main welding by laser irradiation (Japanese Unexamined Patent Publication No. 121093/1983).

[Problem to be solved by the invention]

Although the butt welding method enjoys the above advantages, it also has the following drawbacks.

Large electrical power for heat generation and large mechanical power for pressurization are required.

Since a large excess buildup is created at the joint interface, it is necessary to remove it after welding, which not only increases the number of steps but also causes a lot of material loss, resulting in poor yields.

Defects such as oxides and cold welding tend to remain at the joint interface, especially at the welded edges, and there is no appropriate non-destructive testing method for these defects, so destructive testing by sampling is used to ensure stable quality. Therefore, it is a major factor in increasing costs in terms of quality assurance for components that require high reliability.

On the other hand, high-energy beam welding methods have the following drawbacks.

Since it is a concentrated heat source, butting accuracy is required, and the pre-processing process is time-consuming. As a countermeasure to this problem, Japanese Patent Application Laid-open No. 160582/1983 discloses a method of welding by irradiating energy beams after preliminary welding.

Because the object to be welded is rapidly heated and cooled, excessive hardening occurs, resulting in undesirable material changes.

Shrinkage of the end of the welded object at the welding end point, undercuts and dents in the cross section of the welded part, etc. due to insufficient molten metal, which cannot be repaired after welding is completed, and which have a negative impact on the mechanical strength of the processed item. Bead shape defects are likely to occur.

Incidentally, an electric welding method in which electrical contact is made in advance by laser irradiation and then electricity is applied to generate resistance heat is disclosed in Japanese Patent Application Laid-Open No. 57-202985.
This is to efficiently join two objects to be welded that have significantly different heat capacities.

The present invention compensates for the drawbacks of the two welding methods,
Or by compensating for the weaknesses of one with the strengths of the other,
The purpose of this invention is to provide a device that does not simply combine two welding methods, but also realizes a completely new welding method.

[Means to try to solve the problem]

In order to improve the above-mentioned conventional problems, the inventor of the present invention formed a gap-free weld line for high-energy beam welding by butt welding metal materials, and then reduced the input due to resistance heat generation during the butt welding. A method of welding by irradiating a high-energy beam with an output determined based on the amount of heat and pressurizing force along the welding line, and as necessary, one or two steps of pre-irradiation, post-irradiation, etc. In the above steps, the metal material is heated by being energized. A high-energy beam welding method using butt welding was provided (Patent Application No. 1983-221562). The present invention provides an apparatus for implementing such a welding method with high reliability.

First, to explain the welding method, as a specific example,
Here, an explanation will be given with reference to FIG. 1 showing an embodiment of the present invention. A wheel material 100 that is formed into a ring shape and has an open butt end and requires welding is butt welded to form a complete ring shape. The basic structure for making wheel material is shown. 8 is a hydraulic cylinder for pressurizing the open ends of the wheel material 100; 6;
and 7 are hydraulic cylinders for clamping opposite ends of the wheel material 100. Also, 23 is
It is a laser torch for irradiating a carbon dioxide laser beam, and can inject a gas such as argon gas or helium gas during processing.

The energization to the welding object by butt welding is as follows:
The object to be welded can be heated and softened by the resistance heat generated at the abutting portion. By pressing the heated welded parts together, pressurization imparts plastic deformation to the joint interface, which can improve fitting and form a small excess buildup. This provides the gap-free abutting edges required for high-energy beam irradiation, and the small excess serves as a replacement for welding material during high-energy beam irradiation. At this time, the thickness of the plate to be melted by irradiating the high-energy beam is the original thickness of the object to be welded plus the height of the excess buildup created by preliminary butt welding. The overfill formation is determined by the welding current value and the strength of the pressing force during butt welding, and therefore the output of the high-energy beam is determined based on the amount of heat input due to resistance heat generation and the pressing force during the preliminary butt welding. There must be. The high-energy beam irradiation can melt and weld the incomplete joint interface obtained by the preliminary butt welding.

After the butt welding and before high energy beam irradiation,
During irradiation and after irradiation, energization in one or more of the steps causes rapid heating of the welding object by the high-energy beam and rapid ease cooling,
Excessive hardening of the welded part can be prevented.

Furthermore, when a laser beam is used as the high-energy beam, argon gas or other processing gas that facilitates melting of the metal material can be sprayed. When argon gas is used, the melting width due to laser beam irradiation becomes wider, and when helium gas is used, the melting width becomes narrower than in the case of argon gas. Which gas to use as the processing gas, a mixture of these gases, or other gases must be determined by taking into account the metallurgical properties of the welding object, the shape of the excess material, and the plate thickness. There is.

In such a combination of butt welding and high-energy beam welding, a weld line is formed by butt welding, but in detail, this weld line bends in the direction perpendicular to the weld line in the length direction, and the high-energy beam, for example, laser Since the irradiation diameter of the beam is extremely small, there are places where the irradiation point of the laser beam is shifted from the center of the welding line.

In order to carry out the welding method as described above, and in order to direct the laser beam irradiation after butt welding to the center of the butt weld line, the butt welding device of the present invention extends in the y direction and attaches to the material to be welded. a first member 10 ₁₁ for supporting; a second member 10 12 extending in the y direction and facing the first member in the z direction substantially orthogonal to the y direction; a first member 10 ₁₁ and a second member 10 _{12 ;} a first drive means 6 for driving at least one toward the other; a third drive means 6 extending in the y direction and facing the first member 10 ₁₁ in the x direction substantially perpendicular to the y and z directions;
Member 10 ₂₁ ; Extends in the y direction, and extends in the z direction with the third member 1
4th member 10 ₂₂ facing 0 ₂₁ ; third member 10 ₂₁
and the fourth member 10 ₂₂ , the second driving means 7 for driving at least one of them toward the other; the third member 10 ₂₁ , the fourth member 10 22 ;
x moving support means 4 that supports the members 10 ₂₂ and the second driving means 7 movably in the x direction; third driving means 8 that drives the x moving supporting means 4 in the x direction; the first members 10 ₁₁ and the second member At least one of 10 ₁₂ 10 ₁₁
and a power supply device 40 _, 41 that energizes the welding target material 100 between at least one of the third member 10 ₂₁ and the fourth member 10 ₂₂ ; the first member 10 ₁₁ and the third member 1;
Laser beam irradiation means 22 1 to 22 _{8 , 42 , each having a laser torch 23 directed toward a space between 0 21 and} 22 ₈ , 42 ,
43; y-scan driving means My for driving the laser torch 23 in the y direction; x driving means Mx for driving the laser torch 23 in the x direction; x direction of the butt weld line between the first member 10 ₁₁ and the third member 10 ₂₁ position detection means 24, 49 for detecting the position; and a first
The driving means 6 and the second driving means 7 are energized, and the third
energizing the drive means 8 and said power supply device 40;
41, the y-scanning drive means My is energized, and the x-drive means Mx is energized in accordance with the position detected by the position detection means 24, 49, so that the laser torch 23 is energized.
Welding control means 44, 39 are provided for causing the welding to follow the butt welding line and for energizing the laser beam irradiation means 22 ₁ to 22 ₈ , 42, 43.

[Effect]

According to this butt welding device, following the above-mentioned butt welding, laser beam welding in which the irradiation point follows the center of the butt weld line is automatically realized. Therefore, high-energy beam welding using the above-mentioned butt welding in combination is automatically realized, and the quality of laser beam welding is improved. It is also possible to perform heating using the power supply for butt welding before, during, and after laser beam welding.

Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.

〔Example〕

FIG. 1 shows the external appearance of a mechanical part of an embodiment of the present invention. For ease of understanding, FIG. 1 shows the y-drive mechanism for driving the laser torch 23 along the welding line disassembled, and the laser torch support 13 removed from the machine frame 9 and lifted upward. Indicates the condition.

A fixed support 2 and a support 5 are fixed upright to a base 1 of a butt welding device. Guide beams 3 ₁ and 3 ₂ extend vertically between the tables 2 and 5 and are fixed to the tables 2 and 5. An electrode support block 4 is attached to the guide beams 3 ₁ and 3 ₂ so as to be movable in the x direction.

One end of a first electrode material 10 ₁₁ extending in the y direction is fixed to the fixed support base 2 . An electrode support block (not shown) is attached to the fixed support base 2 so as to be movable in the vertical direction z, and a second electrode material 10 ₁₂ extending in the y direction is fixed to this electrode support block. A hydraulic cylinder 6 is inserted between the electrode support block and the fixed support base 2.
By connecting the upper and lower chambers of the hydraulic cylinder 6, which are separated by the piston rod, to the high pressure line and the low pressure line, respectively, the piston moves downward, the piston rod extends from the cylinder, and the second
The electrode material 10 ₁₂ moves upward and hits the first electrode material 10 ₁₁ . At this time, if the wheel material 100 to be butt welded is between these electrodes, the material 100 is compressed by the electrode materials 10 ₁₁ and 10 ₁₂ .

A third electrode material ₁₀₂₁ extending in the y direction is fixed to the electrode support block 4 via an insulating material.
An electrode support block 52 is attached to the electrode support block 4 so as to be movable in the vertical direction z, and a fourth electrode material ₁₀₂₂ extending in the y direction is fixed to the electrode support block 52 via an insulating material. A hydraulic cylinder 7 is inserted between the electrode support block 52 and the electrode support block 4, and the cylinder is fixed to the block 52 and the piston rod is fixed to the block 4. By connecting the upper and lower chambers of the hydraulic cylinder 7, which are separated by the piston rod, to a high pressure line and a low pressure line, respectively, the piston moves downward, the piston rod extends from the cylinder, and the fourth electrode material ₁₀₂₂ moves upward. This corresponds to the third electrode material ₁₀₂₁ . At this time, if the wheel material 100 to be butt welded is between those electrodes, the wheel material 100 is the electrode material 10 ₂₁ and 10
₂₂ .

A hydraulic cylinder 8 is inserted between the electrode support block 4 and the support base 5, and the cylinder is fixed to the block 4, and the piston rod is fixed to the support base 5. By connecting the left and right chambers of the hydraulic cylinder 8, which are separated by the piston rod, to the high pressure line and the low pressure line, respectively, the piston moves to the right, the piston rod extends from the cylinder, and the electrode support block 4 moves to the left. Then, the third electrode material 10 ₂₁ and the fourth electrode material 10 ₂₂ are moved to the left, and one end of the wheel material 100 is pinched between the first and second electrode materials 10 ₁₁ and 10 ₁₂ as described above. The other end is the third and fourth electrode material 10 ₂₁ , 10 ₂₂
When the two ends are pressed together, the one end and the other end abut and collide, and a pressurizing force is applied between the end faces (butt faces).
By applying a butt welding voltage to the first and third electrode materials 10 ₁₁ and 10 ₂₁ while applying pressure in this manner, the abutting end surfaces are crimped by resistance welding. At this time, due to the softening of the end faces, both end portions are respectively raised in the shape of a mountain with the abutting surface in the center. That is, the cross section of the weld line becomes M-shaped.

A U-shaped machine frame 9 is fixed to the fixed support base 2 and extends in the y direction. In this machine frame 9, y
A threaded rod 12 ₁ extending in the direction is rotatably supported, and a guide bar 12 ₁ is fixed in parallel thereto. Another guide bar 12 ₁ is fixed between the fixed support base 2 and the machine frame 9 in parallel with the threaded rod 12 ₁ . One end of the threaded rod 12 ₁ passes through the machine frame 9 and is connected to the output shaft of the reducer 53 . An electric motor is connected to the input shaft of the reducer 53.
My rotation axis is connected and rotary encoder
RE1 is connected. This rotary encoder RE1 generates one electric pulse per rotation of the input shaft of the reducer 53 by a predetermined angle.

Although shown separately in FIG. 1, the threaded rod 11 actually passes through a threaded hole in a nut (female thread) 14 fixed to the laser torch support 13 and is threaded therein. The laser torch support base 13 has guide seats 15 ₁ and 15 ₂ each having a concave cross section.
are fixed to the guide bars 12 ₁ and 12 ₂ and are supported by the guide bars. Therefore, when the motor My rotates in the normal direction, the threaded rod 11 rotates in the normal direction and the laser torch support base 1
3 moves forward (from the front to the back of the page in Figure 1), and when the motor My rotates in the opposite direction, the threaded rod 11 rotates in the opposite direction and the laser torch support 13 moves backward (from the back to the front in the page in Figure 1). direction). The laser torch stand 13 has one limit switch S1.
is equipped, and when the above-mentioned backward movement approaches the limit position, the actuator of this limit switch S1 hits the machine frame 9, the limit switch S1 changes from closed to open, and the reverse rotation (return movement) of motor My is energized. Stop.

The laser torch stand 13 includes the aforementioned threaded rod 11,
A threaded rod 17 and guide bars 18 ₁ , 18 ₂ (18 2 not shown in the drawing ₎ similar to guide bars 12 ₁ , 12 ₂ are installed along the x direction.

The threaded rod 17 is attached to another laser torch stand 19
It is screwed into a nut (not shown in the drawing) that is fixed to the. Guide seats 21 ₁ and _{21 2} (not shown in the drawing) having concave cross sections are fixed to the laser torch stand 19, and these are engaged with the guide bars 18 ₁ and 18 ₂ . and is supported by the guide bar. An output shaft of a reducer 54 is connected to one end of the threaded rod 17, and a motor Mx and a rotary encoder RE2 are connected to the input shaft of the reducer 54. Therefore, when the motor Mx rotates forward, the threaded rod 17 rotates forward and the support base 19 moves forward (to the left) relative to the laser torch support base 13. When the motor Mx rotates in the reverse direction, the threaded rod 17 rotates in the opposite direction and the support base 19 moves relative to the laser torch support base 13. Move backwards (to the right). The laser torch stand 19 is also equipped with one limit switch S2, and when the above-mentioned return movement approaches the limit position, the actuator of this limit switch S2 hits the threaded rod support of the laser torch stand 13, causing the limit switch S2 to close. open, motor Mx
The reverse (backward movement) bias of stops.

The laser torch 2 is mounted on the laser torch support stand 19.
It is equipped with a mirror box ₂₂₈ in which 3 are combined. A beam duct 22 6 enters the beam duct 22 ₇ fixed to the mirror box 22 ₈ , and this beam duct _{22 6 is} fixed to the mirror box 22 ₄ . mirror box 2
2 ₄ is the laser torch support 1 via the support 22 ₅
It is fixed at 3. Mirror box 22 ₄ has
Another beam duct 22 ₃ is fixed.
A laser emitting device 22 ₁ is connected to this beam duct 22 ₃ .
beam duct 22 ₂ is entering. Duct 2
2 ₇ can move forward and backward in the x direction with respect to 22 ₆ . The duct 22 ₃ can move forward and backward in the y direction with respect to the duct 22 ₂ . The laser emitting device 22 ₁ is separate from the above-mentioned movable part and is fixed on a support stand (not shown) on the floor.

On the other hand, a television camera 2 is mounted on the laser support stand 13.
4 and an illumination light 25 are attached. Therefore, in this embodiment, the laser torch support 13 moves only in the y direction with respect to the machine frame 9, and therefore the television camera 24 and illumination light 25 also move only in the y direction, whereas the laser torch Support stand 19
moves in both the y-direction and the x-direction with respect to the machine frame 9, and therefore the laser torch 23 moves in the y-direction and the x-direction. The television camera 24 and illumination lamp 25 are located at positions slightly shifted to the right in the x direction from the right side surfaces of the first electrode material 10 ₁₁ and the second electrode material 10 ₁₂ , that is, the weld line is formed by the planned flash butt welding. It is located directly above the position , and moves in the y direction from that position in the x direction by the rotation of the motor My. Along with this movement, the laser torch 23
similarly moves in the y direction, but when motor Mx rotates, it also moves in the x direction. This driving in the x direction is performed in response to the positional shift of the welding line in the x direction so that the laser irradiation is always aligned with the center of the line width of the welding line during movement in the y direction.

FIG. 2 shows the configuration of electrical elements that drive the various mechanical elements described above and a control system that controls the energization of these electrical elements.

Electromagnetic switching valves 26 - 28 are inserted between each of the hydraulic cylinders 6 - 8 and the high pressure hydraulic line and the low pressure hydraulic line, and when these electromagnetic switching valves are energized, the hydraulic cylinders are switched. , supplies hydraulic pressure to push out the piston rod, and when not energized, supplies hydraulic pressure to retract the piston rod. These electromagnetic switching valves 26 to 28
, the solenoid drivers 29 to 31 are energized in response to instructions from a microprocessor (hereinafter referred to as CPU) 45.

The illumination lamp 25 receives constant current from the lamp driver 32 . The lamp driver 32 is connected to the CPU 45
A constant current is applied to the lighting lamp 25 when the controller instructs the lighting lamp 25 to be energized. By this energization, the illumination lamp 25 illuminates the field of view of the television camera 24.

The motor My is energized in forward and reverse directions by the motor driver 33. Motor driver 33 is CPU 45
In response to the forward and reverse drive instructions, the motor My is energized in the forward and reverse directions. Note that the limit switch S1 is inserted in the energizing line for reverse biasing, so when the limit switch S1 is changed from closed to open during reverse biasing (when the torch support base 13 reaches the backward movement limit position), , the energization of the electric motor My will automatically stop.

When the electric motor My is rotating, the rotary encoder RE1 generates an electric pulse, and the amplification and waveform shaping circuit 34 amplifies this and shapes the waveform into a rectangular wave, and divides the frequency at a predetermined frequency division ratio. The frequency-divided pulse (hereinafter referred to as y drive synchronization pulse) is
Interrupt port of CPU 45 and image processing unit 49
(to the CPU's interrupt port).

While the switch S1 is closed, the CPU 45 maintains the contents of the y position register at 0 (clear), and while the electric motor My is energized for forward rotation, every time one y drive synchronization pulse arrives, the CPU 45 Increment (count up) the contents of the y position register by 1. While the motor My is reversely energized, the contents of the y position register are decremented (counted down) by 1 every time one y drive synchronization pulse arrives. As a result, the contents of the y-position register indicate the y-position of the laser torch support 13, that is, the y-position of the laser torch 23.

Motor Mx is energized in forward and reverse directions by a motor driver 36. The motor driver 36 energizes the motor in the forward and reverse polarities in response to forward and reverse drive instructions from the positioning controller (mainly CPU) 39.
Go to Mx. Note that the limit switch S2 is inserted in the energizing line for reverse biasing, so when the limit switch S2 is changed from closed to open during reverse biasing (when the torch support base 19 reaches the backward movement limit position), , the electric motor Mx is automatically de-energized.

When the electric motor Mx is rotating, the rotary encoder RE2 generates an electric pulse, and the amplification and waveform shaping circuit 37 amplifies this and shapes the waveform into a rectangular wave, and divides the frequency at a predetermined frequency division ratio. The frequency-divided pulse (hereinafter referred to as x drive synchronization pulse) is sent to the positioning controller 39 (CPU interrupt port)
give to

The positioning controller 39 sets the contents of the x position register to 0 (clears) while the switch S2 is closed.
While the electric motor Mx is maintained in the normal rotation direction and the electric motor Mx is energized for normal rotation, the contents of the x position register are incremented (counted up) by 1 every time one x drive synchronization pulse arrives. While motor Mx is energized in reverse, the contents of the x position register are decremented (counted down) by 1 every time one x drive synchronization pulse arrives. As a result, the contents of the x-position register indicate the x-position of the laser torch support 19, that is, the x-position of the laser torch 23.

The ground output end of the butt welding power source 40 is connected to the first electrode material 10 ₁₁ , and the positive output end is connected to the third electrode material 10 ₂₁ . The butt welding power source 40 is capable of controlling the butt welding current, and is also capable of outputting and controlling heating current for purposes other than welding. The butt welding current, heating energization current, and energization start/stop of the welding power source 40 are specified and instructed by the welding controller 41. The CPU 45 provides the welding controller 41 with butt welding current specification data, energization time data, and a start signal, and also provides heating energization current specification data, energization time data, and a start signal. The welding controller 41 includes butt welding current specification data,
Upon receiving the energization time data and start signal,
The welding power source 40 is set to the output current indicated by the current designation data, the power source 40 is energized to output, and then the output is turned off after the time indicated by the energization time data. In addition, upon receiving the heating current specification data, the current application time data, and the start signal, the welding power source 40
is set to the output current indicated by the current designation data to turn on the output of the current 40, and then turn off the output after the time indicated by the energization time data.

The laser power source 42 of the laser emitting device 22 ₁ is capable of controlling the laser welding energy, which is set by the laser controller ₄₃ and turns the laser on (emission: shutter open)/off ( Stop: shutter closed) and power supply 42
A controller 43 controls on/off of the. The CPU 45 provides data specifying laser irradiation energy and a start (on)/stop (off) signal to the laser controller 43.
In response to this, the laser power supply 42 is set to the specified laser irradiation energy, the output device 22 ₁ is instructed to turn on (shutter open), and in response to the stop signal, the output device 22 ₁ is turned off (shutter opened). closed)
instruct.

When image reading is commanded by the CPU 45, the image processing unit 49 performs the required image reading, detects the welding line, and generates data indicating the position of each part of the welding line.
Send to CPU 45.

Operation board & display 51 is CPU45
Input the various data described below into the CPU 45.
The operation board has various input keys and a start instruction key. When the start instruction key is operated, a start signal is transmitted to the CPU 45. On the other hand, the butt welding equipment shown in Fig. 1 is located in an automatic wheel manufacturing line.
A separate automatic machine (robot) performs mounting of the wheel material 100 thereon and removal of the wheel material 100 after butt welding. This robot is the wheel material 1
00 is properly installed in the butt welding device (Fig. 1), a start signal (in the case of a robot, an installation end signal) is generated. This start signal is sent to the CPU 4 through the signal cable connected to the operation board 51.
given to 5. That is, a start signal is given to the CPU 45 when the start instruction key on the operation board 51 is operated or when the aforementioned robot issues a start signal.

FIG. 3 shows the operation timing of each electrical element during one cycle of butt welding operation brought about by the control of the CPU 45, and FIG.
Figure b shows the control operation of the CPU 45. The control operation of the CPU 45 will be described below with reference to these drawings.

The power is turned on (Step 1 in Figure 4a; hereinafter, the word "step" will be omitted in the box).
Then, the CPU 45 sets the output port to the standby (non-energized) signal level, and sets the internal registers, counters, timers, etc. to the standby contents2. Then, input reading 3 on the operation board 51 is performed, and a display corresponding to the input is displayed.

Here, the minimum data necessary for butt welding control, which will be described later, is D ₀₁ to D ₈ shown in FIG. 3. The details of these will be described later. When these data are input from the operation board 51, the CPU 45 writes them into the required registers3.

Note that data ₀₁ indicates the position in the y direction of the scheduled welding start end of the wheel material 100 (the amount of movement dy of the laser torch support base 13 during one period of the y drive synchronization pulse is taken as 1 unit), Data D ₀₂
indicates the x-direction position of the scheduled welding start end of the wheel material 100 (assuming the movement amount dx of the laser torch support 13 during one cycle of the x drive synchronization pulse is 1 unit), and these are input. and CPU4
5 writes them to the register and performs the initial positioning of the laser torch 23.

In this initial positioning, the CPU 45 first drives the motor My in the reverse direction, and when the switch S1 changes from closed to open (this turns off the reverse bias line of the motor My), the CPU 45 stops energizing the motor My. Clear the position register (write origin position 0). At this time, the center of the field of view of the television camera 24 is located at a distance indicated by the data D ₀₁ from the expected starting end of the properly mounted wheel material 100 . Next, the CPU 45 urges the motor My to rotate in the normal direction. This normal rotation bias causes the y position register to count up. And the contents of the y position register are
When the position becomes equal to the position indicated by D ₀₁ , the energization of the motor My is stopped. As a result, the center of the field of view of the television camera 24 is located directly above (the y position of) the scheduled starting end of the properly mounted wheel material 100.

Next, the CPU 45 controls the positioning controller 39
instructs the driver to drive backwards. In response, the positioning controller 39 drives the motor Mx in the reverse direction, and when the switch S2 changes from closed to open (this turns off the reverse bias line of the motor Mx), it stops energizing the motor Mx. Then, 0 is written (cleared) in the x position register, and then the CPU 45 outputs D ₀₂ to the controller 39. In response to this, the controller 39 urges the motor Mx to rotate normally. This normal rotation bias causes the x position register to count up. When the contents of the x position register become equal to the position indicated by D ₀₂ , the energization of the motor Mx is stopped. Thereby, the irradiation position of the laser torch 23 is located on the x position of the planned welding start end of the properly mounted wheel material 100.

With the initial positioning described above, the center of the field of view of the television camera 24 is located at the y position of the planned welding start end, and the laser irradiation point of the laser torch 23 is located at the x position of the planned welding start end.

When a start signal arrives from the operation board 51 or the computer of the processing line, the CPU 45
It is checked whether reading of data D ₀₁ to _{D 8} has been completed or not (step 5), and if it has not been completed, the process returns to input reading step 3.

When the start signal arrives while the reading of data D ₀₁ to D ₈ is completed, the CPU 45 holds (squeezes) the hydraulic cylinders 6 and 7 and starts the timer t ₁ . _t1 is a time limit value and is represented by data _D1 . this t ₁
After the electromagnetic switching valves 26 and 27 are energized, the hydraulic cylinders 6 and 7 apply a predetermined squeezing force between the first and second electrode materials 10 ₁₁ and 10 ₁₂ and between the third and fourth electrode materials 10 . ₂₁ , 10 and ₂₂ . The CPU 45 waits for the timer t ₁ to time out (8), and when the time expires, holds and energizes the hydraulic cylinder 8 (9) and starts the timer t ₂ (10).
_t2 is a time limit value and is represented by data _D2 . This t ₂ is the time when the hydraulic cylinder 8 applies a predetermined butt pressure to the wheel material 100 sandwiched between the first and second electrode materials 10 ₁₁ and 10 ₁₂ after the electromagnetic switching valve 28 starts to be energized. This is the time required between the end face of one end and the end face of the other end of the wheel material 100 sandwiched between the third and fourth electrode materials 10 ₂₁ and 10 ₂₂ .

The CPU 45 waits for the timer _t2 to time out11.
When the time is over, the welding controller 41
Give data D ₃ and D ₆ and give a start signal 12 to start timer t ₃ 13. D ₃ indicates the current application time t ₃ for butt welding, and D ₆ indicates the butt welding current value. Welding controller 41
In response, the _D6- compatible welding current output is set to the welding power source 40, the output is turned on, and the timer is turned on.
Start _t3 and turn off the welding current output when timer _t3 times out. This means that butt welding has been performed (end of butt welding).

The CPU 45 waits for the timer _t3 set by itself to time out (14), and when it times out, it lights up the illumination light 25 (15) and instructs the image processing unit 49 to detect the welding line starting position (16).

When the CPU 45 instructs the image processing unit 49 to detect the position of the welding line, the image processing unit 49 reads the photographed image of the television camera 24, calculates the starting position x ₀ and y ₀ of the welding line, and transmits this to the CPU 45 .

When the image processing unit 49 finishes detecting the starting end positions x ₀ and y ₀ of the welding line (receiving the data thereof), the CPU 45 outputs the x coordinate x ₀ of the starting end to the positioning controller 39 17 . Positioning controller 3
9 is the content of the x position register at this time as HPx
The data is written in the register, and based on this data (x ₀ ) and the contents of the x position register, the motor Mx is energized forward/reversely so that the laser torch 23 is placed directly above the x position of the starting end of the welding line.

The CPU 45 writes the contents of the y position register at this time to the HPy register, energizes the motor My to constant speed forward rotation (forward drive), and then
The center of the field of view in step 4 is located at the start of the welding line due to the forward drive.
When y reaches ₀ , it stops energizing motor My18.

As a result, the center of view of the television camera 24 is positioned at the y position of the welding start of the weld line formed by the butt welding described above, and the laser torch 23 is positioned at the x position of the welding start.

Next, the CPU 45 starts constant-speed forward driving of the motor My19, sets _D4 in the counter, starts the y-drive synchronization pulse countdown of this counter20, and sends the image processing unit 49 to the y-drive synchronization pulse response. It instructs welding line position detection 21 and permits an interrupt to receive data transmission from the image processing unit 49 22. D ₄ is TV camera 2 in the y direction
This data indicates the distance from the center of the visual field of No. 4 to the laser irradiation point of the laser torch 23 (in units of movement amount dy of the support base 13 during one period of the y drive synchronization pulse).

When the image processing unit 49 is instructed to detect the welding line position in response to the y-drive synchronization pulse, it reads the captured image of the television camera 24 every time the y-drive synchronization pulse arrives, and detects the welding line position at the center of the field of view in the y-direction. The x-coordinate value of the center position of the line is calculated and sent to the CPU 45. The CPU 45 accumulates and writes this data to the reception register. Image processing unit 49
When detecting the rear end of the welding line (there is no welding line at the y-coordinate position of the center of the field of view), it sends data indicating "end" to the CPU 45, and detects the x-coordinate value of the welding line in response to the y-drive synchronization pulse. Terminates the operation (interrupt processing) (disables interrupts). The CPU 45 also accumulates and writes data indicating this "end" to the reception register.

The CPU 45 checks the counter value 23 set in step 20, and when it becomes 0, that is, when the laser torch 23 reaches the starting position of the butt welding line, it outputs data D ₇ to the laser controller 43 and then starts. output signal
twenty four. Data _D7 specifies laser irradiation energy. The laser controller 43 sets the laser power source 42 to the energy output of _D7 and turns on the output. This starts laser irradiation, that is, laser welding, and the laser is first irradiated to the center of the weld line width at the starting end of the butt weld line.

Thereafter, the CPU 45 reads the next data from the reception register (the x position advanced by dy in the y forward movement direction) and outputs it to the positioning controller 39 every time the y drive synchronization pulse arrives25. The positioning controller 39 refers to the x-position data given in this way and the contents of the x-position register, and controls the electric motor Mx so that the torch 23 is located directly above the center of the welding line indicated by the x-position data.
energizes forward/reverse. As a result, the laser irradiation moves along the weld line in the y direction and advances along the width center (x position) of the weld line.

Each time the CPU 45 reads data from the reception register, it checks whether or not this data indicates an "end" 26, and if it does not indicate an "end", it outputs this to the positioning controller 39 27. It indicates the "end",
Give a stop signal to the laser controller 43
28. This stops laser irradiation (end of laser welding irradiation).

Next, the CPU 45 starts driving the motor My back and sets the y position register to a subtraction count.
The data of the HPx register is output to the positioning controller 3929. As a result, the laser torch support stand 13 is driven back, and the support stand 19 is positioned at the planned welding start end (x position: HPx).

The CPU 45 outputs data _D5 and _D8 to the welding controller 41, then outputs a start signal 30, and starts a timer _t5 . The welding controller 41 sets the output of the welding power source 40 to the current indicated by the data _D8 and turns on the power source 40, and also sets the time limit value _t5 indicated by the data _D5 to the timer to start. As a result, the butt weld line portion that has been irradiated with laser welding is heated and energized.

Thereafter, the CPU 45 determines that the data in the y position register is HPy (HPy
32, 33B, ₃₄ , and the contents of the y position register become HPy, the motor My starts to rotate in reverse. When switch S1 is opened (at this time, the reverse rotation bias line of motor My is turned off), the reverse rotation bias of motor My is stopped.
33A. When the timer _t5 times out, a stop signal is output to the welding controller 41, the hold on the hydraulic cylinders 6 to 8 is released, and the operation board 51
35, 36 to output the end signal. In response, the welding controller 41 turns off the welding power source 40, and the second and fourth electrode materials 10 ₁₂ and 10 ₂₂
Then, the support block 4 moves away from the third electrode materials 10 ₁₁ and 10 ₂₁ and retreats to the right. The end of butt welding is displayed on the operation board 51, and when a processing line computer is connected, an end signal is sent to it.

After outputting the end signal, the CPU 45 returns to input reading 3 and waits for the next start signal to arrive. In this waiting state, the center of field of view of the television camera 24 is at position HPy (contents of the HPy register), and the laser irradiation position of the laser torch 23 is at position
It's on HPx. When a new input is received again in input reading 3, it is written to the corresponding register. That is, the data that has already been written is updated with the newly input data. If this update is D ₀₁ and/or D ₀₂ , the initial positioning described with respect to step 20 is performed again.

In the laser beam welding irradiation, argon gas or other processing gas that facilitates melting of the metal material is blown onto the weld line. When argon gas is used, the melting width due to laser beam irradiation becomes wider, and when helium gas is used, the melting width becomes narrower than in the case of argon gas. Which gas to use as the processing gas, a mixed gas of these gases, or which other gas to use is determined by taking into consideration the metallurgical properties of the welding object, the shape of the excess buildup, and the plate thickness.

In the above embodiment, the current heating for annealing is performed for a predetermined time _t5 at the same time as the laser welding irradiation ends, but this current heating is performed either before the laser welding irradiation or at the same time as the laser welding irradiation starts. You may start it. For example step 15
Alternatively, it may start at step 19, or it may start at step 24.

In any case, in the above embodiment, the butt welding current value _D6 and the energization time are transmitted from the operation board 51.
D ₃ , laser welding irradiation energy D ₇ , heating current value D ₈ and energization time D ₅ are input (set) to the CPU 45 before butt welding, so these are set to optimal values based on actual results. Can be set to .

〔Effect of the invention〕

When the butt welding apparatus of the present invention described above applies electricity to the object to be welded 100 by the above-mentioned butt welding, the object to be welded is heated and heated by resistance heat generation at the butt portion, and is softened. Pressurization applies plastic deformation to the joint interface by pressing the heated welds together, improving fitting and forming a small excess buildup. This provides the gap-free butt edges required for the laser beam welding irradiation described above, and the small excess serves as a substitute for welding material during the laser beam irradiation. At this time, the plate thickness irradiated with laser welding includes the original thickness of the welding object 100 and the height of the excess buildup caused by butt welding. The overfill shape is determined by the welding current value and the strength of the pressing force during butt welding, and the output of the laser beam is therefore determined based on the amount of heat input due to resistance heat generation during butt welding and the pressing force. I can do it. Then, the welding irradiation of the laser beam melts and welds the incomplete joint interface obtained by butt welding.

After butt welding, it is possible to conduct electricity in one or more of the following steps: before, during, and after laser beam irradiation, and this reduces resistance heat generation in the joint interface and the metal material at the interface. Therefore, rapid heating and rapid cooling of the object to be welded by the laser beam is alleviated, and excessive hardening of the welded portion is prevented.

In such a combination of butt welding and high-energy beam welding, a weld line is formed by butt welding, but in detail, this weld line bends in the direction perpendicular to the weld line in the length direction, and the high-energy beam, for example, laser Since the irradiation diameter of the beam is extremely small, the irradiation point of the laser beam may deviate from the center of the weld line, but in the butt welding device of the present invention, the laser beam is aligned with the center of the line width of the butt weld line. As a result, high-quality butt welding can be achieved over the entire length of the weld line.

[Brief explanation of the drawing]

FIG. 1 is a perspective view mainly showing the appearance of a mechanical part of an embodiment of the present invention. FIG. 2 is a block diagram showing the configuration of the electrical control system of this embodiment. FIG. 3 is a time chart showing the operation timing of the electrical elements of this embodiment. 4a and 4b show the microprocessor CPU 45 shown in FIG.
3 is a flowchart showing the control operation of FIG. 1... base, 2... fixed support stand, 3 ₁ , 3 ₂ ...
Guide beam, 4... Electrode support block, 5... Support stand, 6... Hydraulic cylinder (first driving means), 7...
... Hydraulic cylinder (second drive means), 8 ... Hydraulic cylinder (third drive means), 9 ... Machine frame, 10 ₁₁ ...
...First electrode material (first member), 10 ₁₂ ... Second electrode material (second member), 10 ₂₁ ... Third electrode material (third member), 10 ₂₂ ... Fourth electrode material (fourth parts), 11...
...Threaded rod, 12 ₁ , 12 ₂ ... Guide bar, 13...
...Laser torch support stand, My...Electric motor (y
scanning drive means), RE1...rotary encoder,
53...Reducer, 14...Nut, 15 ₁ , 15 ₂
... Guide seat, 16 ₁ , 16 ₂ ... Abutment, S1...
...Limit switch, 17...Threaded rod, 18 ₁ ...
...Guide bar, 19...Laser torch support stand,
Mx...Electric motor (x drive means), RE2...Rotary encoder, 54...Reduction gear, 21 ₁ ...
Guide bar, S2...Limit switch, 22 ₁
...Laser emission device, 22 ₂ , 22 ₃ , 22 ₆ , 2
2 ₇ ... Beam duct, 22 ₄ , 22 ₈ ... Mirror box, 25 ₅ ... Abutment, 22 ₁ to 22 ₈ ... Laser beam irradiation means, 23 ... Laser torch (laser torch), 24 ... Television camera ( position detection means), 25... lighting lamp, 45... microprocessor (welding control means), 100... wheel material (welding target material).

Claims (1)

[Claims] 1. A first member extending in the y direction and supporting the material to be welded; A second member extending in the y direction and opposing the first member in the z direction substantially orthogonal to the y direction; a first driving means for driving at least one of the first member and the second member toward the other; a third member extending in the y direction and facing the first member in the x direction substantially orthogonal to the y direction and the z direction; a fourth member extending in the y direction and facing the third member in the z direction; a second driving means for driving at least one of the third member and the fourth member toward the other; a third member, a fourth member, and a fourth member; x-movement support means for movably supporting the second drive means in the x-direction; third drive means for driving the x-movement support means in the x-direction; at least one of the first member and the second member, the third member and the third member; A power supply device that energizes the material to be welded between at least one of the four members; A laser beam irradiation unit having a laser torch directed toward the space between the first member and the third member; Y scanning that scans and drives the laser torch in the y direction Driving means; energizing the third drive means, and after energizing the power supply device, energizing the y-scan drive means and energizing the x drive means in response to the position detected by the position detection means; a welding control means for causing a laser torch to follow a butt welding line and energizing a laser beam irradiation means;