JPS63224882A - Lap resistance seam welding equipment - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a lap resistance seam welding device, particularly a lap resistance seam welding device that can automatically adjust welding conditions according to the thickness of a plate to be welded. It is related to the device.

[Conventional technology]

Conventionally, for example, in a seam welding device for electric resistance welded pipes, a plate thickness gauge is installed upstream of the pressure roll in the direction of movement of the raw pipe, and the plate thickness measurement result by the plate thickness gauge is measured as the plate thickness. a delay circuit for transmitting the signal to a control circuit to be described later with a delay corresponding to the distance between the meter and the pressure roll; and d) a control circuit for controlling the welding conditions according to the measurement result of the plate thickness. A device having the following is disclosed in Japanese Unexamined Patent Publication No. 52-69842.

[Problem that the invention seeks to solve]

In the case of whether the above-mentioned seam welding device for electric resistance welded pipes can be applied to a lap resistance seam welding device for welding multiple overlapping plates to be welded, the following problem arises: . That is, in heavy resistance seam welding, as shown in FIG. .1' from the welding power source 3 to resistance weld the stacked plates 2 to be welded, but since it is necessary to provide a delay circuit, the structure of the welding device becomes complicated. is,
Rotating electrode 1. Since it is necessary to install the plate thickness gauge in a place different from the workpiece, it is necessary to secure a place for installing the plate thickness gauge around the plate 2 to be welded. Furthermore, at the start of welding, welding conditions cannot be controlled with respect to variations in the thickness of the plate 2 to be welded between the rotating electrodes 1, 1' and the plate thickness gauge.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a lap resistance seam welding apparatus that does not require a delay circuit and can eliminate any uncontrollable welding conditions at the start of welding.

[Means for solving problems]

As a result of intensive research to solve the above-mentioned problems, the inventors of the present application have found that all the above-mentioned problems can be solved by providing a plate thickness measuring means at the same position as the rotating electrode. Ta.

The present invention has been made based on the above-mentioned knowledge, and includes a pair of rotating electrodes for sandwiching a plurality of stacked plates to be welded and applying a welding current thereto, and A lap resistance seam Km device having a welding power supply for supplying a welding current to a welding current, a load cell attached to the electrode with 10 rotations per force via a force 1 pressure spring, and a load signal based on the load signal from the load cell. and a controller for controlling welding conditions based on a plate thickness signal from the plate thickness calculator. It is something that you have.

Next, one embodiment of the lap resistance seam welding apparatus of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the lap resistance seam welding apparatus of the present invention.

In FIG. 1, a pair of rotating electrodes 1 and 1' are rotated by a motor 4 while sandwiching a plurality of overlapping sheets 2 (in this example, two sheets) to be welded. A welding current from a power source is applied to the plate 2 to be welded. As shown in FIG. 2, one of the fixed rotating electrodes 1 of the pair of 41 rotating electrodes l, 1' is fixed to the frame 5, and the other movable rotating electrode 1' is
It is attached to the frame 5 via a pressure spring 6, an adjustment screw 7, and a load meter to be described later, so as to be movable in the thickness direction of the plate 2 to be welded. The adjustment screw 7 is screwed into the frame 5 and adjusts the pressure force applied by the movable rotating electrode 1' to the plate 2 to be welded. A cylinder or the like may be used instead of the adjustment screw.

The load cell 8 consists of a load cell, is provided between the pressure spring 6 and the adjustment screw 7, and detects the pressure applied by the movable rotating electrode 1' to the plate 2 to be welded.

The welding power source 9 is a transformer 10. It consists of an AC power supply 11 and a thyristor 12 connected to the primary side of the transformer 1O, and an SCR ignition circuit 13 for controlling the thyristor 12, and a pair of rotating electrodes 1,
1' is connected.

The plate thickness calculator 14 calculates that the distance between the fixed rotating electrode l and the load cell 8 is constant, and that the change in the pressing force of the movable rotating electrode 1' on the plate 2 to be welded depends on the Since there is a one-to-one correspondence with the plate thickness, the plate thickness (1) of the plate to be welded 2 is calculated based on the load signal from the load meter 8 according to the following formula.

However, Fo: Pressure force on the plate 2 to be welded before the plate thickness changes; F: Pressure force on plate 2 to be welded after plate thickness variation, K: Spring constant of the pressure spring 6.

The controller 15 controls the motor 4 and the OCR ignition circuit 13 based on the plate thickness signal from the plate thickness calculator 14 . That is, the relationship between the thickness (1) of the plate to be welded 2 and the optimum welding conditions is stored in advance in the controller 15, and for example, when the thickness of the plate to be welded 2 becomes thicker than the initial value. In this case, SCR
A welding current increase command is sent to the ignition circuit 13, and if the plate thickness becomes thicker than that, a speed reduction command is sent to the motor 4.

[Effect]

According to the lap resistance seam welding apparatus of the present invention described above, even if the thickness of the plate 2 to be welded changes, the plate 2 to be welded is always welded under appropriate welding conditions in the following manner. That is, as shown in FIG. 3, while the pair of rotating electrodes 1 and 1' are performing welding while rotating on the surface of the two surfaces of the plates to be welded, as shown in FIG.
When another plate 2' is inserted between the plates 2 to be welded and the plate thickness of the plate 2 to be welded becomes thicker, the movable rotating electrode 1' is moved by the force of the pressure spring 6. move against it. As a result,
The pressurizing force on the plate 2 to be welded increases, and the pressurizing force at this time is detected by the load meter 8. When the pressurizing force is detected in this way, the plate thickness (1) of the plate to be welded 2 is calculated by the plate thickness calculator ] 4
is calculated according to equation (1) above. When the plate thickness is calculated, a command to increase the contact current of the SCR ignition circuit 3 is sent from the controller 5 based on the result. Welded plate 2
If the plate thickness becomes even thicker, a speed reduction command is also sent to the motor 4 to reduce the welding speed. Thereby, even if the thickness of the plate 2 to be welded changes, welding is always performed according to appropriate welding conditions.

〔Effect of the invention〕

As explained above, according to the present invention, the plate thickness gauge is not provided at a separate position from the rotating electrode as in the conventional case, but is located physically with the rotating electrode, that is, at the same position as the rotating electrode. Since a plate thickness gauge is provided, there is no need to provide a delay circuit.

Therefore, the structure of the welding equipment is simplified, there is no need to secure a place to install a plate thickness gauge, and welding conditions can be controlled according to changes in the thickness of the plate to be welded at the same time as welding starts. , various very useful effects are brought about.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the lap resistance seam welding device of the present invention, FIG. 2 is a front view of the rotating electrode portion of the same device, and FIG. 3 is a FIG. 4 is an explanatory diagram of a conventional lap resistance seam welding device. In the drawings, 1, 1'... Rotating electrode, 2, 2'... Welding plate, 3... Welding power source, 4... Motor, 5
1. Frame body, 6...Pressure spring, 7...Adjustment screw, meter/load cell, 9...Welding power source,
]0...Transformer, 11...AC power supply,
12... Thyristor, 13... SCR ignition circuit,
14... Plate thickness calculator, 15... Controller.

Claims (1)

[Scope of Claims] A pair of rotating electrodes for sandwiching a plurality of stacked plates to be welded and applying welding current thereto, and a welding power source for supplying welding current to the pair of rotating electrodes. A lap resistance seam welding device comprising: a load meter attached to the pair of rotating electrodes via a pressure spring; and calculating the thickness of the plate to be welded based on a load signal from the load meter. A lap resistance seam welding device comprising: a plate thickness calculator for controlling the welding conditions; and a controller for controlling welding conditions based on a plate thickness signal from the plate thickness calculator.