JPS6219271B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a workpiece guiding device for a seam welding machine that is capable of guiding a complicated workpiece along its welding line at a constant speed.

Recently, the method of seam welding the outer periphery of objects to be welded, such as the outer periphery of automobile gasoline tanks, as shown in Figures 1a and b and Figure 2, using an induction device has become increasingly popular for reasons such as productivity, quality, and human resources. In response to demand, several types of mechanisms are in practical use.

However, conventional mechanisms have the disadvantage that they are complicated and difficult to operate.

Here, when seam welding objects to be welded having shapes as shown in FIGS. 1a and 2b and FIG. 2, the corner portions of the objects become a problem. In other words, due to the large inertia of the guiding device, especially at the corners, the rotational torque applied from the electrode disc to the workpiece is insufficient, the guiding device cannot rotate sufficiently, and the trajectory of the electrode disc moves away from the predetermined welding position. The electrode disc may become misaligned, the electrode disc may fall off the flange of the workpiece, making welding impossible, or the rotational speed, that is, the welding speed, may decrease due to insufficient rotational force and deviate from proper working conditions. There is.

Under such circumstances, two to three methods have been proposed so far in order to guide the corners of the workpiece without causing the above-mentioned problems.

For example, there is a method shown in FIG. The method shown in FIG. 3 is such that when the upper electrode disc 2 is inserted into the corner of the workpiece 1, a link-shaped arm 3 is pushed by a cylinder 4 to promote the rotational force of the guiding device. It is.

On the other hand, in addition to this method, a method has been proposed in which a fluid motor is attached to the center shaft of the copying cam and the fluid motor is driven at a corner portion to easily rotate the copying cam.

By the way, in the case of a device that pushes the arm 3 with a cylinder 4 as shown in FIG. Although it is easy to apply, it has the disadvantage that it is difficult to apply to the welded object 1 having a complicated shape as shown in FIG. In other words, when the workpiece 1 to be welded has a complicated shape, the center distance of each corner (second
In the figure, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ ), radius of curvature (r ₁ , r ₂ , r ₃ , r ₄ , r ₅ in Figure 2), forming angle (in Figure 2 ,
It is necessary to select a cylinder 4 with a stroke corresponding to θ ₁ , θ ₂ , θ ₃ , θ ₄ , θ ₅ ), install the cylinder 4 at an appropriate position, and control each cylinder accurately. Therefore, not only is the device complicated and expensive, but the operation is also very complicated.

In addition, in the case of a device equipped with a fluid motor on the central axis of the copying cam, even when applying rotational torque from the central axis, the distance between the centers of each corner of the workpiece 1,
A constant angular velocity is applied despite the difference in the radius of curvature and the forming angle, and as shown in Figure 4, when the distance between centers doubles, the velocity also doubles, and if used in this state, Quality problems may occur. In addition, in FIG. 4, the movement amount of the _P1 point and _P2 point is explained with the O point as the center of rotation. In the figure, W is the angular velocity of the motor. If you try to apply a rotational speed depending on the corner, you will need to prepare many pressure reducing valves and apply fluid pressure to the fluid motor using a solenoid valve for each corner, and this method also requires equipment. This becomes complicated and has poor operability.

It is an object of the present invention to solve such conventional drawbacks and to enable accurate seam welding with a simple structure.The following describes the welded object guiding device for a seam welding machine according to the present invention. This will be explained using the drawings of FIGS. 5 to 7.

In the figure, 10 is an object to be welded, 11 is an upper electrode disk, 11' is a lower electrode disk, 12 is a link-shaped arm, 13 is a copying cam, 14 is a holder for the object to be welded 10, and 15 is a clamp cylinder. , 16 is an arm, 17 is a bracket, 18 is an inner roller, 19
20 is the outer small diameter roller, 20 is the outer large diameter roller,
21 is a spring, 22 is a guide, 23 is a guide bar,
24 is an air motor.

Here, the object to be welded 10 is placed on the pedestal 14 in phase with a copying cam 13 machined into the same shape as the weld line of the object to be welded 1 . Also,
Since the copying cam 13 and the pedestal are fixed to the same shaft, the workpiece 10 and the copying cam 13 make the same movement. Also, on the inner circumferential side of the copying cam 13, there is an arm 16 connected to the rod of the clamp cylinder 15.
An inner roller 18 rotatably attached to the tip of the
is arranged so as to be in pressure contact with the inner circumferential surface of the copying cam 13. Since the arm 16 is pivotally supported by a bracket 17, it can swing, and the inner roller 18 can follow changes in the shape of the workpiece 10 to be welded. On the outer circumferential side of the copying cam 13, a plurality of small diameter rollers (four in the figure) are arranged with a slight interval between them so as to be in pressure contact with the outer circumferential surface of the copying cam 13 at the left and right positions of the inner roller 18. 19
is rotatably arranged. An upper electrode disc 11 is located at an intermediate position between the plurality of groups of small diameter rollers 19.
A large-diameter roller 20 is disposed on the same line as the center axis of the lower electrode disk 11' and faces the inner roller 18 via a copying cam 13. It is brought into pressure contact with the outer peripheral surface of the cam 13 and is movable in a direction perpendicular to the outer peripheral surface of the copying cam 13 while being guided by the guide 22 and the guide bar 23 . Further, the large diameter roller 20 is keyed to the shaft of an air motor 24 and rotated by the air motor 24.

Next, the function of the guiding device configured as described above will be explained. The pressure applied by the clamp cylinder 15 causes the inner roller 18 and the outer small-diameter roller 19 to clamp and guide the copying cam 13. At the corner portions of the workpiece 10, the rotational force of the air motor 24 is transmitted to the copying cam 13 via the outer large-diameter roller 20, supplementing the rotational force of the guiding device at the corner portions and causing smooth movement.

That is, when the guidance device of the present invention is used, even when the workpiece 10 has a complicated shape, the workpiece 10 can be moved at a relatively uniform speed regardless of the condition of the corner part.
This not only stabilizes the quality of seam welded products, but also improves operability.

As described above, according to the workpiece guiding device of the seam welding machine of the present invention, even workpieces with a simple structure and a complex shape can be welded regardless of the state of the corner part.
It is able to guide the workpiece at a relatively uniform speed, which makes it possible to stabilize the quality of seam welded products and improve operability during work. be.

[Brief explanation of the drawing]

Figures 1a and b are top and front views showing an example of the shape of the workpiece, Figure 2 is a top view showing another example of the shape of the workpiece, and Figure 3 is a conventional workpiece guidance device. FIG. 4 is an explanatory diagram showing changes in the rotational speed of the corner portion of the workpiece in another conventional workpiece guidance device; FIG. 5 is a seam according to an embodiment of the present invention. FIGS. 6 and 7 are plan views showing the overall configuration of a welding object guiding device of a welding machine, and FIGS. 6 and 7 are plan views showing the main structure of the device, respectively. 10... object to be welded, 11... upper electrode disk, 1
1'... Lower electrode disk, 12, 16... Arm,
13... copying cam, 14... cradle, 15... clamp cylinder, 18... inner roller, 19...
Small diameter roller, 20... Large diameter roller, 24... Air motor.

Claims (1)

[Claims] 1 A copying cam fixed to the same axis as the pedestal on which the workpiece is placed and having the same shape as the welding line of the workpiece, and a copying cam rotatably attached to the tip of a swingable arm connected to a cylinder. , and an inner roller that presses against the inner circumferential surface of the copying cam, and a plurality of small diameter rollers that are spaced apart from each other so as to press against the outer circumferential surface of the copying cam at the left and right positions of the inner roller. and a large-diameter roller disposed at an intermediate position between the plurality of small-diameter roller groups so as to be movable in a direction perpendicular to the releasing cam and to be in pressure contact with the outer peripheral surface of the copying cam, and this large-diameter roller. A welding object guiding device for a seam welding machine consisting of an air motor that drives the seam welding machine.