JPH0763861B2 - Panel parts welding equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a welding device for sequentially welding a plurality of welded portions of a panel component including, for example, an outer panel and an inner panel.

BACKGROUND ART Panel components such as doors, hoods, and trunk lids of automobiles are generally composed of an outer panel and an inner panel that are hemmed to each other. However, in order to improve the bonding strength of both panels, the hemming is performed. In some cases, spot welding may be performed on the hemming joint portion after the joint. In this case, in normal spot welding, the electrode tip bites into the panel member and a welding mark is generated, so a back bar is sandwiched between the outer panel and the electrode tip, which is the outer surface, so that the electrode tip does not directly contact the outer panel. The law has been adopted.

Problems to be Solved by the Invention As described above, when the back bar is applied to the outer surface of the panel component to perform spot welding, it is necessary to bring the back bar into close contact with the outer surface of the panel component. Must be processed according to the external curved surface shape.

Therefore, it is necessary to prepare a back bar for each panel component, and it is necessary to replace the back bar each time the panel component to be manufactured changes. These things
In today's demand for high-mix low-volume production, there is a problem that the man-hour required for replacing the back bar leads to an increase in manufacturing cost.

Further, there is a back bar supported on the tip of the electrode chip by a spherical bearing so that the metal plate can be easily brought into close contact with the panel member.However, since a large current flows, the spherical bearing portion is electrolytically corroded in a short period of time. Another problem is that the life is very short.

Therefore, the present invention is to provide a welding device which has a long life and is versatile enough to handle panel parts of any shape without damaging the outer panel.

Means for Solving the Problems The present invention relates to a welding device for sequentially welding a plurality of welded portions of a panel component, and a laser welding head attached to the tip of a robot arm for irradiating the welded portion with a laser beam. , Is placed opposite to the laser welding head across the panel component, and has a metal plate attached at its tip so that it can be in close contact with the panel metal component. Based on the temperature of the laser welding head, which is provided on the backing plate, a pressure sensor that press-contacts the back surface of the welding part, and a temperature sensor that detects the temperature of the welding part. By controlling the welding feed rate, a penetration amount adjusting means for adjusting the penetration amount of the welded portion is provided.

Effect According to the present invention, the metal plate is moved to the welded portion at a predetermined position of the panel component to be welded, and is pressed against the back surface of the welded portion. Then, while welding is performed by irradiating a laser beam from a facing position sandwiching the panel component, the temperature of the welded portion is detected by a temperature sensor of a metal plate which is in close contact with the welded portion irradiated with the laser beam. Then, based on the detected temperature, the welding feed speed of the laser welding head at the welding portion during the welding is controlled. By this welding feed rate control, the amount of penetration at the welded portion is adjusted.

By repeating the above operation for each welded part, the same joint strength as when spot welding is applied to each welded part of the panel part, and moreover, it is possible to perform welding that does not scratch the outer surface of the panel part. it can.

Embodiment First, the configuration of an embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is an overall perspective view showing an embodiment of the present invention, and FIG. 2 is an explanatory view showing the configuration of the main part thereof.

Reference numeral 1 denotes a so-called polar coordinate system robot, which has an axis for rotating the robot base 2 as indicated by arrow A, an axis for swinging the robot arm 3 as indicated by arrow B, and a robot arm 3 as indicated by arrow C. It is composed of an axis for expanding and contracting, an axis for rotating the tip 3a of the robot arm 3 as indicated by an arrow D, and the position of the tip 3a of the robot arm 3 can be freely moved.

A laser welding head 4 is provided at the tip 3a of the robot arm 3 so that the irradiation position of the laser beam can be freely changed by the operation of each axis of the robot 1. This laser welding head 4 is oscillated by a laser oscillator (not shown),
Irradiating the laser beam 8 guided to the internal optical path of the robot arm 3 through the optical path 5, the reflection mirror 6 and the optical path 7 provided in the robot 1 to the hemming joint portion 9a of the panel part 9 which is the member to be welded. To do. The panel component 9 is supported by a holder (not shown).

Reference numeral 10 is a caulking device, a caulking plate 11, a pneumatic cylinder 12 for supporting the caulking metal 11 from below and vertically moving it, and a pneumatic cylinder.
Y-axis bed 13 that moves 12 horizontally and linearly, and Y-axis bed 13
Is composed of an X-axis bed 14 for linearly moving.
Servo motors for Y-axis bed 13 and X-axis bed 14, respectively
It is equipped with 15,16, ball screws 17,18, etc.
11 horizontal positioning is possible. Further, the pneumatic cylinder 12 is controlled by the pneumatic control device 19, and the pad 11 can be pressed against the panel component 9 at a predetermined pressure.

The structure around the pad 11 will be described in detail with reference to FIG. 2. The pad 11 has a temperature sensor 20 composed of a thermocouple or the like in the upper recess, and is arranged at the rod tip of the pneumatic cylinder 12. Supported by a spherical bearing 11a. By being supported by the spherical bearing 11a, the temperature sensor 20 can be pneumatically operated as long as the upper surface of the pad 11 is formed in a horizontal plane or a protruding portion even if it is not along the outer surface 9b of the hemming joint 9a of the panel component 9. Cylinder 12 pressurizes the outer surface
Close to 9b. In addition, the close contact of the reliance 11
At the time of welding, there is also a cooling effect that prevents the outer surface 9b from melting.

Each motor of the robot 1 and the contact pressure welding device 10 described above
15, 16 and the pneumatic cylinder 12 are controlled by the welding control device 21. The welding control device 21 issues an instruction to move the laser welding head 4 to a plurality of welding portions of the hemming joint portion 9a of the panel component 9 set in advance and a welding feed instruction of the laser solution head 4 in the welding portion of the robot 1. It is given to the laser welding head position control unit 1a. Therefore, the welding control device 21 has a function as a penetration amount adjusting means for adjusting the penetration amount in the welded portion as described later. In addition, the welding control device 21 includes the contact metal pressure welding device 10
While comparing the position given by the position sensor of the motors 15 and 16 with the preset moving position of the pad 11 to move the pad 11 to the horizontal plane setting position, the pneumatic control device 19
An on / off instruction of the pneumatic cylinder 12 is given to and the pad 11 is moved up and down. Further, although not shown, the welding control device 21 also instructs the laser oscillator to irradiate the laser beam 8 and to stop the irradiation.

Next, the operation of this embodiment will be described with reference to the flowchart of FIG. 3 and the welding feed pattern of FIG.

First, in step 1, the pad 11 and the laser welding head 4 are moved to the first welding portion 30 shown in FIG. The pad 11 is horizontally moved by the motors 15 and 16 and then raised by the pneumatic cylinder 12, and the temperature sensor 20 disposed on the upper surface of the pad 11 has an outer surface 9b of the hemming joint 9a of the first welded portion 30.
Is pressed against. Further, the laser welding head 4 is the robot 1
Is moved to a position above the first welded portion 30 by the operation of each axis.

In step 2, the laser is oscillated so that the laser beam 8 is emitted from the laser welding head 4 to the welding feed start point of the welded portion 30.

In step 3, it is judged whether or not the temperature detected by the temperature sensor 20 is a predetermined allowable minimum temperature. This allowable minimum temperature is a temperature at which the panel member of the irradiation portion begins to melt by the laser beam 8. When the detected temperature exceeds the allowable minimum temperature, the process proceeds to the next step 4.

In step 4, the laser welding head 4 is moved in a pattern such that the irradiation position of the laser beam 8 draws a circle as shown in FIG. 4, and welding feed is started at a predetermined speed.

In step 5, it is determined whether the temperature detected by the temperature sensor 20 is within the allowable welding temperature range. The permissible welding temperature range is a temperature range that indicates that the panel component 9 as the base material has an adequate amount of penetration when welding is performed at the above-described predetermined speed and that the welding is performed well. If the detected temperature is outside the allowable welding temperature range, the process proceeds to step 6, and if it is within the allowable welding temperature range, the process proceeds to step 9.

In step 6, it is determined whether the detected temperature is above the upper limit or below the lower limit of the allowable welding temperature range. If it is equal to or more than the upper limit, it is determined that the amount of melting of the panel component 9 is too large.
Proceeding to the next step 7, the welding feed speed is increased by a predetermined amount. When the welding feed speed is increased, the penetration amount of the panel component 9 is reduced. If it is below the lower limit, it is determined that the amount of penetration of the panel component 9 is insufficient, so the routine proceeds to step 8, where the welding feed speed is reduced by a predetermined amount,
Increase the amount of melt. When steps 7 and 8 are completed, the process returns to step 5. That is, the amount of heat input per unit length is increased or decreased depending on the welding feed rate.

In step 9, it is determined whether or not the welding feed of the first welded portion 30 is completed. That is, it is determined whether or not the irradiation position of the laser beam 8 has returned to the welding feed start point, and if it has not returned to the start point, the process returns to step 5 to continue welding feed, and if it has returned to the start point, welding feed Step at the end
Go to 10.

In step 10, it is determined whether or not it moves to the next weld portion, and in step 1 so that the welding operation of the second weld portion 31 which is a predetermined distance from the first weld portion 30 is performed in the next weld portion. Return.
In this way, steps 1 to 10 are repeated, and when the welding operation of the second welded portion 31 is completed, the welding operation of the third welded portion 32 is performed, and each predetermined welding of the hemming joint portion 9a is performed. The parts 30, 31, 32 are sequentially welded. The operation ends when the predetermined welds 30, 31, 32 are welded.

As described above, in this embodiment, the plurality of welds 30, 31, 32 in the hemming joint 9a of the panel component 9 are sequentially welded in spots in the same manner as spot welding is performed, and the hemming joint 9a is welded. Bonding strength similar to that obtained by spot welding can be obtained without scratching the outer surface 9b. When performing spot welding, it was necessary to prepare one pad 11 for each panel component 9 so that the entire contact surface of the back bar closely contacts the outer surface 9b of the hemming joint 9a. In the embodiment, since it is only necessary to press the temperature sensor 20 against the outer surface 9b, it is only necessary to prepare one pad 11 for a plurality of panel parts 9. Therefore, the manufacturing cost of the pad 11 is significantly reduced, and even if the type of the panel component 9 to be manufactured is changed, the need for replacing the pad 11 is eliminated, and a welding device with high adaptability can be provided.
Furthermore, since there is no current flowing through the pad 11,
As in the case of spot welding, the spherical bearing 11a is not electrolytically corroded, so that the life of the pad 11 is extremely extended.

In the above-described embodiment, the welding feed is performed by drawing a circle, but the welding feed pattern is not limited to a circle.
Other patterns may be used as long as the bonding strength similar to spot welding such as spiral shape can be obtained.

EFFECTS OF THE INVENTION As is apparent from the above description, according to the panel component welding apparatus of the present invention, the metal plate is pressed against a predetermined weld portion of the panel component, and the laser beam is applied from the facing position sandwiching the panel component. While welding is performed by irradiating with, the temperature of the corresponding position is detected by the temperature sensor that is brought into close contact with the welded part by the metal plate, and the laser welding feed rate at the welded part is controlled based on the detected temperature. Since the amount of penetration of the panel parts is adjusted by adjusting the amount of penetration of the panel parts, it is not necessary to prepare a metal plate for each panel part like the back bar required for spot welding. It can be used in common for panel parts, the processing cost of the metal plate can be greatly reduced, the man-hours for replacing the metal are not required, and a highly adaptable welding device can be provided. Welding can be done so that the surface is not scratched. Further, unlike spot welding, there is no portion to be electrolytically corroded, so that the life is extended.

[Brief description of drawings]

FIG. 1 is an overall perspective view showing an embodiment of the present invention, FIG. 2 is an explanatory view showing the configuration of the main part thereof, FIG. 3 is a flow chart showing the operation of the embodiment of the present invention, and FIG. 4 is welding. It is explanatory drawing which shows a sending pattern. 1 ... Robot, 3 ... Robot arm, 4 ... Laser welding head, 8 ... Laser beam, 9 ... Panel parts,
9a …… Hemming joint, 10 …… Bracket pressure welding device, 11 ……
Metal plate, 20 ... Temperature sensor, 21 ... Welding control device (penetration amount adjusting means), 30 ... First welded part, 31 ... Second welded part, 32 ... Third welded part.

Claims (1)

[Claims] 1. A welding device for sequentially welding a plurality of welded parts of a panel part, wherein a panel welding part is installed between a laser welding head attached to the tip of a robot arm for irradiating the welded part with a laser beam. And has a metal plate attached to the laser welding head so as to be in close contact with the panel component so that the metal plate can be brought into close contact with the panel component. A pressure-applying means for pressure-contacting, a temperature sensor provided on the metal-cover for detecting the temperature of the welded portion, and a welding feed speed of the laser welding head is controlled based on the temperature detected by the temperature sensor. Accordingly, the welding apparatus for panel parts, comprising: a penetration amount adjusting means for adjusting the penetration amount of the welded portion.