JPS592949Y2 - Welding speed control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a welding speed control device in an automatic welding device for welding a circumferential welded portion such as a boundary between a cylindrical container and a lid.

For example, when automatically welding a disc-shaped lid to a cylindrical container, since the container is cylindrical, the welded part, that is, the weld line, which is the boundary between the container and the lid, is circumferential. In order to weld a circumferential weld line, as shown in FIG. Then, the container 2 and the lid 3 are rotated by the turntable 1, and the circumferential welding portion 4 is welded.

When the size of the container 2 changes and the diameter of the welding line that is the boundary between the container 2 and the lid 3 changes, the welding torch 5 is moved between the rack (not shown) provided on its support rod 6 and this rack. The welding torch 5 is driven in the diametrical direction of the groove 4 by the motor 7 via a pinion (not shown) that is meshed with the motor 7 and coaxially fixed to the rotating shaft 8 of the motor 7, so that the welding torch 5 corresponds to the welding part 4. move to position.

Conventionally, the motor 19 built into the above turntable 1
is controlled to a constant rotation speed set by a rotation speed setting device.

That is, as shown in FIG. 2, the rotational speed of the motor 19 detected by the tachogenerator 9 provided in the motor 19 and the rotational speed setting value set in the setting device 10 are input to the regulator 11. , are compared with each other, a calculation is performed on the deviation, and the motor 19 is controlled to a set rotational speed by an adjustment signal output from the regulator 11.

On the other hand, even if the diameter of the weld line changes, if the rotation speed of the turntable 1 is kept constant, the circumferential speed of the weld zone, that is, the welding speed, will change and a good weld zone will not be obtained. It disappears.

Therefore, in order to keep the welding speed constant, the operator had to calculate the rotational speed from the changed diameter so that the circumferential speed would be constant, and reset the rotational speed one by one.

Here, welding conditions, that is, circumferential speed F (cm/m1n
) and the diameter r (mm) of the weld line, the operator calculates and sets the rotation speed N.

Therefore, this setting work is required every time the diameter of the container changes, which requires manpower and has the problem of complicating the welding work.

The present invention was developed in view of the above circumstances, and its purpose is to change the diameter of the circumferential welding line, and when the welding torch is moved, the rotation speed is automatically adjusted, and the circumferential speed is always maintained. It is an object of the present invention to provide a welding speed control device which can eliminate the above-mentioned problems by controlling the welding speed to be constant, has a simple configuration, and is low in cost.

Hereinafter, an embodiment of the welding speed control device according to the present invention will be described based on the drawings.

As shown in FIG. 3, a peripheral speed setting device 12 is connected to a peripheral speed adjuster 13, and this peripheral speed adjuster 13 is connected to the motor 1g.

A tacho generator 14 that generates an AC output signal is attached to the rotating shaft 1B of the motor 19, and the tacho generator 14 is connected between the primary terminal 15a of the autotransformer 15 and the common terminal 15b.

The secondary terminal 15C of the autotransformer 15 is configured to slide on the winding of the transformer 15 by turning a setting knob (not shown) provided on the autotransformer 15. This allows the transformation ratio to be changed.

A rectifier 16 is connected between the common terminal 15b of the autotransformer 15 and a secondary terminal 15C sliding on the winding of the autotransformer 15, and the rectifier 16 is further connected to the circumferential speed regulator 13. Ru.

The rectifier 16 is also connected to a speedometer 17.

In the above circuit, the rotation speed of the motor 19 is detected by the tacho generator 14, and the output voltage v16 of the tacho generator 14 is applied to the primary terminal 1 of the autotransformer 15.
5a and the common terminal 15b.

In this case, the voltage vF between the common terminal 15b and the secondary terminal 15C of the autotransformer 15 becomes a voltage proportional to the circumferential speed, as will be described later.

This voltage VF is converted into direct current by a rectifier 16 and input to the circumferential speed regulator 13 , and the output of the rectifier 16 is input to a speed meter 17 .

In the circumferential speed adjuster 13, the circumferential speed set value set in the circumferential speed setting device 12 and the actual circumferential speed value output from the rectifier 16 are compared, and the deviation is calculated. A control signal is output, and the motor 19 is controlled so that the circumferential speed of the welded part is constant.

In the above circuit, since the output voltage 16 of the tachogenerator 14 is proportional to the rotational speed N of the motor 19, VTG=-N However, K is a constant.

If the transformation ratio of the autotransformer 15 is A, then the autotransformer 15
The secondary output voltage ■, is VF=A −VTG”A ”K’N Here, if the transformation ratio A of the autotransformer 15 is determined according to the diameter r of the welding wire, the autotransformer However, from the above equation (1), the peripheral speed F is as follows, so VF=K −F, and the secondary output voltage VF of the autotransformer 15 is as follows: It will be proportional to the speed F.

Therefore, if the welding conditions, that is, the circumferential speed F, are set in the circumferential speed setting device 12, if the diameter r of the weld wire changes, this radius r can be adjusted by sliding the secondary terminal 15C of the autotransformer 15. When the rotational speed of the motor 19 is set to satisfy the above-mentioned equation (2), the rotational speed of the motor 19 is automatically adjusted so that the circumferential speed is always constant.

When setting the diameter r of the welding wire in the autotransformer 15, if the diameter r of the welded object changes, the secondary side of the autotransformer 150 corresponds to the change in the position of the welding torch 5 in the diametrical direction. If the sliding motions of the terminals 15C are linked, the circumferential speed F can be controlled simply by setting the welding torch 5 to the welding part of the workpiece.

In the above embodiment, an autotransformer was used to convert the output voltage of the tachogenerator 14 into a voltage proportional to the circumferential speed, but this could be replaced with a transformer having primary and secondary windings. Therefore, a tap may be provided on the secondary side, or the secondary side terminal may be slid on the secondary winding.

As explained above, in the welding speed control device according to the present invention, when welding a circumferential weld line, when the diameter of the weld line changes, the transformer changes the transformer ratio in response to this change. By converting the motor rotational speed signal into a signal proportional to the circumferential speed of the groove and inputting it to the circumferential speed adjuster, welding can be performed by setting the welding conditions, that is, a constant circumferential speed. Even if the diameter of the welding wire changes, the rotational speed is automatically adjusted so that the circumferential speed remains constant; unlike conventional methods, when the diameter of the welding wire changes, the rotational speed has to be reset, which is a complicated task. can be eliminated, and
Since the above-described control device includes a tachogenerator that generates an AC output, a transformer, a rectifier, a speed setting device, and a circumferential speed regulator, it can be constructed at low cost.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an automatic welding device, FIG. 2 is a circuit diagram showing a conventional example, and FIG. 3 is a circuit diagram showing an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Turntable, 2... Container, 3... Lid, 4... Welding part, 5... Welding torch, 12... Peripheral speed setting device, 13... Peripheral speed adjuster , 14... Tacho generator, 15... Auto transformer, 16... Rectifier.

Claims (1)

[Claim for Utility Model Registration] A workpiece to be welded having a circumferential weld line is placed on a turntable, while a welding torch movable in the diametrical direction of the circumferential weld line is placed opposite the welding part. In a welding device that performs welding by rotating a turntable, there is a peripheral speed setting device that sets the peripheral speed of the welding part, and a peripheral speed setting device that is directly connected to the motor that drives the turntable and that is proportional to the rotational speed of the motor. A tacho generator generates AC output, and the AC output of this tacho generator is applied to the primary side, and the welding torch position changes in response to changes in the diameter of the circumferential weld line. A transformer that changes the transformation ratio, a rectifier to which the secondary output of the transformer is applied, and the output of the circumferential speed setting device and the output of the rectifier are differentially input to control the motor. A welding speed control device comprising: a circumferential speed regulator that outputs a signal.