JPS628272B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a laser spot welding machine that spot-welds a workpiece that has been polymerized by a laser beam from a laser device (laser generator) such as a carbon dioxide laser.

Generally, electric resistance welding means pressurizes two superposed objects to be welded using a pair of upper and lower electrode tips, and instantaneously supplies a large current to the objects to generate resistance heat. , the joints are melted and spot welded.

However, conventionally, this type of resistance welding means by spot welding has restrictions on the thickness of the objects to be welded that can be welded together due to limitations in power supply capacity.
If another spot weld is to be made very close to one welding point, the current from this spot welding will be diverted to the spot weld that has already been welded.
Effective spot welding may not be obtained, and the reliability of spot welding may be impaired.

On the other hand, the spot welding method described above requires the instantaneous flow of a large current;
A flexible thick conductor must be used,
Not only is there a problem with safety and electrode life, but also a large bonding force (pressure force) is required to bring the two objects to be welded into sufficient contact. The molten metal is often scattered in all directions, and the thickness of the weld point of the weld can be substantially reduced. Further, the double electrode chips used in the above-mentioned spot welding means must always be kept in a clean state in order to maintain electrical conductivity, cooling performance, and pressing force resistance.

In view of the above-mentioned points, the present invention includes a pair of horizontal arm rods arranged side by side on a machine frame equipped with a laser device, and a condenser that focuses the laser beam of the laser device on the end of one of the horizontal arm rods. A lower chip is provided on which the lens and the object to be welded are placed, and a reflector is attached within the lower chip to reflect the laser beam upward and focus it on the object to be welded. A blow pipe having a through hole through which the laser beam passes is provided in the lower chip near the object, a cylinder device is provided in the other horizontal arm located directly above the lower chip, and the output shaft of this cylinder device is The upper tip is installed so that it can press against the object to be welded so that it can be moved up and down, thereby preventing the metal mist and spatter generated during welding from staining the reflector and condensing lens. The present invention provides a laser spot welding machine for the purpose of reliably joining objects and improving reliability.

Hereinafter, the present invention will be described with reference to an illustrated embodiment.

In FIGS. 1 to 3, reference numeral 1 indicates a substrate 2.
It is a machine frame equipped with a laser device (laser generator) 3 using a carbon dioxide laser placed on the machine frame 1, and a pair of horizontal arm rods 4 and 5 are mounted on the machine frame 1.
are arranged horizontally in parallel, and at one end 4a of one of the horizontal arm rods 4, there is a condenser lens 6 for condensing the laser beam of the laser device 3, and a workpiece 7 to be welded.
A lower chip 8 is provided on which the chip is placed. or,
Inside the lower chip 8, a reflector 9, such as a reflector, is disposed diagonally so as to reflect the laser beam from the condenser lens 6 upward and focus it on the object to be welded 7. The lower chip 8, which is close to the workpiece 7, is provided with a blower pipe 11 having through holes 10 through which the laser beam from the reflector 9 passes, so as to be able to transfer a cooling fluid made of air. It is placed horizontally. Furthermore, each partition plate 12 is provided on the outside of the air pipe 11 where the through hole 10 is located, and these partition plates 12 connect the lower tip 8 to the reflector and the cabin 13 to be welded. It is provided so as to be divided into material cabinets 14.

On the other hand, a supply port 15 and a discharge port 16 for supplying an inert gas are provided in the lower chip 8 where the cabinet 14 next to the workpiece is located, and the inert gas flowing from the supply port 15 is , it is possible to prevent oxidation of the welded part that occurs during welding and to cool the lower chip 8. Also, the other horizontal arm rod 5 located directly above the lower tip 8
A cylinder device 17, such as a hydraulic cylinder device, is provided at one end 5a, and an output shaft 17a of this cylinder device 17 is configured such that an upper chip 18 can press the superposed workpiece 7. It is installed so that it can be raised and lowered freely. moreover,
This upper chip 18 and a part of the output shaft 17a are provided with an inlet 19 and an outlet 20 for supplying a cooling fluid such as cooling water, and the cooling fluid injected from the inlet 19 is The inner end surface 18a of the upper chip 18 can be cooled.

Therefore, when welding the two superposed objects 7 to be welded, the two objects 7 to be welded are placed on the lower chip 8, and the cooling fluid is transferred to the blast pipe 11. At the same time, inert gas is supplied from the supply port 15 to the cabinet 14 next to the work to be welded, and then,
This inert gas is discharged from the exhaust port 16 to prevent oxidation of the welded portion.

Next, the cylinder device 17 is driven to lower the upper tip 18 provided on the output shaft 17a of the cylinder device 17.
The object to be welded 7 is pressed and fixed, and cooling fluid is injected into the upper chip 18 from the inlet 19 to cool the inner end surface 18a of the upper chip 18, and then is caused to flow out of the machine from the outlet 20.

Therefore, when the laser device 3 is driven,
The laser beam of this laser device 3 passes through the condensing lens 6 and reflector 9 to form a focal point 0 on the object to be welded 7, and performs spot welding.

In this way, the object to be welded 7 is spot welded, and by moving the cylinder device 17 back, the object to be welded 7 can be removed from the lower chip 8.

Incidentally, the design of the reflector 9 in the above-described embodiment may be changed to, for example, a prism. Furthermore, although a specific example has been described in which air is used as the cooling fluid for the blower pipe 11, it goes without saying that an inert gas may be used to supply the cooling fluid into the cabin 14 around the object to be welded.

As described above, according to the present invention, a pair of horizontal arm rods 4 and 5 are arranged side by side on the machine frame 1 equipped with the laser device 3, and the laser device is attached to the end 4a of one of the horizontal arm rods 4. A condensing lens 6 for condensing the laser beam of No. 3 and a lower chip 8 on which the workpiece 7 to be welded is placed.
A reflector 9 is disposed diagonally within the lower chip so as to reflect the laser beam upward and focus it on the workpiece 7. 8 is provided with a blower pipe 11 having a through hole 10 through which laser light passes, and a cylinder device 17 is provided in the other horizontal arm rod 5 located directly above the lower tip 8.
Since the upper tip 18 is mounted on the output shaft 17a of the work piece 7 so as to be able to move up and down freely so as to be able to press the workpiece 7, spot welding can be reliably performed without oxidizing the spot welding. This has excellent effects such as eliminating the risk of metal mist generated during welding adhering to the reflector 9 and the condensing lens 6 and contaminating them.

[Brief explanation of the drawing]

FIG. 1 is a front view of a laser spot welding machine according to the present invention, FIG. 2 is an enlarged sectional view showing essential parts of the present invention, and FIG. 3 is an exploded perspective view of a lower tip section incorporated into the present invention. 1... Machine frame, 3... Laser device, 4, 5...
Horizontal arm rod, 6... Condensing lens, 7... Welding object,
8... Lower chip, 9... Reflector, 10... Through hole, 11... Air pipe, 15... Supply port, 16...
Discharge port, 17...Cylinder device, 18...Upper chip, 19...Inflow port, 20...Outflow port.

Claims (1)

[Scope of Claims] 1 A pair of horizontal arm rods are arranged side by side on a machine frame equipped with a laser device, and a condenser lens and a cover for condensing the laser beam of the laser device are provided at the end of one of the horizontal arm rods. A lower chip is provided on which the work to be welded is placed, and a reflector is disposed diagonally within the lower chip to reflect the laser beam upward and focus it on the workpiece. A blow pipe having a through hole through which the laser beam passes is provided in the adjacent lower chip, a cylinder device is provided in the other horizontal arm located directly above the lower chip, and the output shaft of this cylinder device is A laser spot welding machine characterized in that an upper tip is provided so as to be movable up and down so as to be able to press the object to be welded. 2. The laser spot welding machine according to claim 1, wherein the lower chip is provided with an inert gas supply port and an inert gas discharge port, and the upper chip is provided with a cooling fluid inlet and outlet port.