JPS6219954B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a continuous flange portion formed at the periphery of a sealed container such as a radiator or a gasoline tank, consisting of a straight line portion and a corner portion, between a pair of upper and lower seam electrodes. This invention relates to an automatic seam weld line tracing device that applies pressure and current to the seam weld line and guides the seam weld line between the electrodes using the electrode driving force.

Conventional devices of this type include, for example, a rotary plate provided in the link mechanism so as to be able to rotate.
The object to be welded is fixed above the rotary plate, and a plate cam with a welding line traced below the rotary plate is passed through the gap between the guide roller and the guide plate, which are fixed at a position directly below the seam electrode. A so-called plate cam guide method is generally known in which a regular welding line is guided between upper and lower seam electrodes.

Recently, instead of the above-mentioned plate cam guide system, for example, Japanese Patent Publication No. 52-22746 and Japanese Patent Publication No. 54-3012
A pin guide system has been proposed. In this pin guide method, a half-moon cam is installed at the center of the bend of each corner corresponding to the weld line of the workpiece, and the movement of the straight part of the weld line is controlled by fixing the cam below the seam electrode. The rotation of the corner of the weld line is achieved by engaging and rotating a half-moon cam with a cam stopper provided at a position intersecting the electrode rotation axis of the guide rail. What makes it special is what it does.

However, in the case of the former plate cam guide method, knocking is likely to occur due to mechanical inertia, and moreover, overswing occurs when going around corners, and the weld line often shifts from the electrode position. be.

On the other hand, in the case of the latter pin guide method, although it does not cause serious accidents like the former, it is necessary to align multiple half-moon cams with the center position of each corner of the weld line. For example, as shown in Japanese Patent Publication No. 54-3012, when a polygonal workpiece including corners with different radii is to be welded, the mounting position of the half-moon cam is different depending on the radius, so multiple In addition to requiring multiple cam stops that correspond to the cams, it is quite difficult to adjust the height of the half-moon cam and the positioning of the cam stop, and the structure is complicated, with small corner angles and short straight sections, and If the object is a polygonal shape consisting of a weld line in which the difference in radius between adjacent corners is smaller than the diameter, it is impossible to provide cam stoppers in multiple rows depending on the position of the half-moon cam, so it is impossible to implement in principle. It was possible.

The present invention effectively incorporates a pin guide system into the conventional plate cam guide system, thereby preventing the previous problems and further improving the radius of the corner of the weld line, the length of the straight part, and the corner guide system. We have developed an automatic seam weld line tracing device that can be called a versatile device that can handle any shape of weld line, regardless of the size of the angle.

Embodiments of the present invention will be described in detail below with reference to the drawings.

In Figures 1 to 3, 1 is a welding machine main body 2, 3 is an upper and lower seam electrode, 4 is a rotary plate, and this is connected to a seam by a link device that rotatably connects a plurality of arms 5. It is attached to a bearing 6 at the tip of the arm so that it can freely rotate in a horizontal plane in front of the electrode. In this example, the object to be welded is a gasoline tank.

The flange portion formed around the body of this tank has corner portions a with the same radius but different center angles Θ.
It is continuous from ~i and straight portions I~i having different lengths. 8 is a plate cam, which is a projection of the flange of the tank.

This plate cam is fixed to the lower side of the rotary plate 4 mentioned above.

9 is a guide pin. This pin is connected to rotating plate 4
installed on. As shown in FIG.
The starting point a′ and the bending center point P ₂ of the corner a
excluding the fan-shaped portion 10 drawn outside the straight line A-A passing through and inside the inner radius line r, r of the plate cam that constitutes the center angle Θ of the corner a. Each is fixed at an arbitrary setting position. That is, the mounting position of the guide pin in this embodiment is at a right angle to the straight line BB connecting the bending center points P ₁ and P ₂ of adjacent corners of the cam plate 8, for example, a and i, and outside of P ₂ . Take _an arbitrary value y for , _and also take an arbitrary value ~9
i is fixed in position.

Arbitrary distances in x and y are selected to be constant at each corner.

Reference numeral 11 denotes a guide rail into which a guide pin enters when the rotation of corner welding is completed, and provides parallel guidance during straight welding. This guide rail consists of a front rail plate 11a and a rear rail plate 11b, and is formed with a guide groove 12 having a width that allows only the guide pin 9 to pass, and this groove is long in the direction perpendicular to the electrode rotation axis C--C. It's growing.

Reference numeral 13 denotes a guide device that guides the plate cam near the electrode rotation axis so as to sandwich the plate cam from both sides. This guide device includes a rotating roller 13a that contacts the inside of the plate cam with the same rounded surface as the corner portion of the plate cam.
and a small-diameter rotating roller 13b in contact with the outer surface of the plate cam, and these two rollers are mounted on the support plate 14 facing each other with a gap large enough to allow the plate cam to pass through. . Reference numeral 15 denotes a ratinite device that moves the opening/closing plate 16 in a freely rising and falling manner, and this device is provided at a location where the guide pin 9 of the front rail plate 11a enters. When the guide pin enters the guide rail, the guide pin pushes down the opening/closing plate and jumps over it, and then the opening/closing plate returns to close the entry point.

17 is a stopper device, and this device
When each guide pin pushes open this stopper and passes through it one after another, the stopper serves as a return to the original position to align the welding start point with the electrode pressurization point after welding is completed. .

18 is a drive cylinder. This is a driving source for swinging the entire guide rail toward the front surface of the electrode around the support shaft 19 on one side, and is attached to the welding machine main body. This was devised to facilitate the loading and unloading of objects to be welded.

The operation of the present invention will be explained below with reference to FIGS. 1 and 4.

First, the workpiece 7 to be welded is set above the rotating plate so that it does not move. Then, the welding line of the object to be welded is sandwiched between the upper and lower seam electrodes from a predetermined position, and the electrodes are rotated while applying a constant pressure and current to start seam welding along the welding line. The arrow → indicates the direction of welding progress.

Now, when welding is to be started from the planned position of the welding straight part A, the starting position of the welding line is set by returning the guide pin 9a to the stopper device 17 of the guide groove 12 of the guide rail 11 and stopping it at the original position. be done. When welding is started in this way, the plate cam 8 of the rotating plate is moved by the guide device 13 by the rotational driving force of the electrode.
At the same time, the guide pin 9a moves in the direction of the arrow in parallel with the welding straight line along the guide groove. When the starting point of the welding corner reaches the electrode pressurizing point, the corner a of the plate cam begins to rotate while being guided by the guide device. At this start, the guide pin 9a in the guide rail comes out from the end of the rail by going around the outside of the guide device as shown by arrow A.

In this way, the welding curve corresponding to the previous corner a is guided to the electrode pressurizing point. Then, after going around the corner part a, the next guide pin 9b
passes over the ratchet device 15 provided at a predetermined position on the guide rail and enters the guide groove 12, and thereafter, while the straight portion B of the plate cam guides and passes through the guide device,
Move along the guide groove.

The welding work is completed by repeating the same operation once.

Therefore, according to the present invention, the following effects can be obtained.

(1) Since the rotational guidance of the weld line corner is performed by a plate cam and a rotational guide device, there is no need to add any mechanism even if each radius of the same workpiece is different, and it is different from the conventional guide pin method. A more stable rotational motion can be obtained.

(2) Since there is no need for guide rails on the exit side, design maintenance is very advantageous.

(3) It eliminates the need to change the height of the half-moon cam, provide a step on the exit side of the guide rail, and perform difficult positioning adjustments of the cam stopper as in the conventional pin guide system.

(4) In the conventional pin guide method, the range of application was limited by the bending center angle Θ and radius r of the corner part of the workpiece, or the distance of the straight part, but with the method of the present invention, the corner angle Since the x and y values can be arbitrarily determined regardless of the distance between the straight and radial sections, all reaction forces can be eliminated by the lever principle, resulting in stable and accurate operation, making it suitable for high-speed welding. .

(5) Another great feature is that the plate cam system currently in operation can be easily improved to the system of the present invention by simply adding guide pins and guide rails according to the present invention to the conventional plate cam system.

(6) Compared to the conventional roller cam system, there is no need for shape processing or the use of multiple cam stoppers to change the thickness of the half-moon cam.

As explained above, the present invention enables welding tracks of any shape to be guided and driven accurately to the electrode pressurizing point at a stable speed, has a simple structure, is cost-effective, and is easy to operate. We provide a new type of automatic seam weld line tracing device that has significant effects in terms of shortening takt times, stabilizing welding quality, safety, and reducing manufacturing man-hours and maintenance.

[Brief explanation of the drawing]

Fig. 1 is a schematic plan view showing an embodiment of the profiling device according to the present invention, Fig. 2 is a schematic front view, Fig. 3 is a schematic side view, and Fig. 4 shows the positional relationship between the guide pin and the plate cam. FIG. 3 is a schematic plan view for explaining the operation of the apparatus of the present invention. [Explanation of symbols], 1... Seam welding machine, 2, 3...
Seam electrode, 4... rotating plate, 8... plate cam, 9... guide pin, 11... guide rail, 13... guide device.

Claims (1)

[Claims] 1 A seam weld line consisting of a corner part and a straight part continuously formed around the workpiece is pinched and energized between a pair of upper and lower seam electrodes, and this is While rotating in the horizontal plane,
A welding device that continuously performs seam welding by guiding a target seam weld line between the electrodes, which comprises: a rotating plate that rotates together with the workpiece; and the welding line fixed to the underside of the rotating plate. Similar plate cams and
A guide device that guides both sides of the plate cam on the rotation axis of the electrode, a series of guide pins fixed in position near the plate cam of the rotary plate, and a guide pin that enters from a predetermined position and It consists of a guide rail that is configured to guide parallel to the straight section and move away from a predetermined position, and each guide pin is substantially connected to the starting point of the plate cam from the straight section to the corner section and the bending center of the corner section. Any setting position that is outside the straight line A-A passing through the point and excluding the fan-shaped range drawn inside the inner radius line of the plate cam that constitutes the center angle Θ of the corner bend. An automatic seam weld line tracing device characterized in that each position is fixed at each position.