JPS6163368A - Automatic setting method of welding condition for covered electrode - Google Patents

Abstract

PURPOSE:To execute a stable welding by a worker, and to improve the work efficiency by sending a diameter of a covered electrode clamped by a detecting means of an electrode holder, to a welding machine by an electric signal, and setting automatically the welding machine to a correct welding condition. CONSTITUTION:A potentiometer 12 of a spring 5 clamp type electrode holder 4 converts a diameter of the time when it holds a covered electrode 1, to a potential difference signal of the potentiometer 12 and sends it to a sequence circuit of a welding machine 3 by lead wires 12a-12c. The sequence circuit moves a movable iron core 6 by operating a motor 7, and selects automatically a welding current corresponding to the diameter of the electrode 1. It is unnecessary for a worker to go to the welding machine 3 in order to set a welding current, also a wrong selection is prevented, and a stable welding is executed with a high efficiency.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for automatically setting welding conditions for a covered arc welding rod, and in particular, when a covered arc welding rod is clamped with a welding holder, the welding power source This invention relates to a method of automatically setting appropriate conditions according to the diameter.

[Conventional technology]

Conventionally, when performing manual welding using this type of covered arc welding rod, first select a coated arc welding rod of the appropriate type and rod diameter depending on the plate thickness, groove conditions, and welding posture of the workpiece. Clamp to the rod holder. Next, the welding machine is adjusted to provide welding conditions suitable for the welding rod. For example, with a movable core type AC arc welding machine commonly used for manual welding, you must go to the welding machine's installation location, rotate the current adjustment handle to move the movable core, and set the conditions to the appropriate welding current value. . If equipped with a remote current adjustment device, operate a switch to increase or decrease the current, or if a wireless type rectifier (shunter) is used, operate the welding rod holder and the workpiece in the direction of increasing or decreasing the welding current. Touch a short circuit between objects to increase or decrease the current. Furthermore, the degree of this increase or decrease is generally determined by the operator's intuition by appropriately generating arcs.

Problems to be solved by invention C] In the above work, even though the welding current value actually set is specified in work standards, it may ultimately be set arbitrarily by the will of the worker. Almost. As a result, the welding current tends to become excessive, and defects such as bubbles (blowholes, pits, etc.) and undercuts are likely to occur in the weld. This is because the welding operator's will to increase the current to improve welding efficiency and the on-site situation that adjusting the welding current is troublesome. Therefore, when non-destructive inspection (X-ray inspection, etc.) of welds is performed, air bubbles are often found inside the weld, and it is necessary to remove the weld bead by causing etc. and re-weld, which affects not only welding quality but also welding efficiency. On the contrary, this will actually lead to a decline in this area. Although it is relatively rare compared to excessive welding current, cases of insufficient welding current are also seen, resulting in welding defects such as insufficient penetration and overlap.

The present invention was devised to solve the above problems, and eliminates the causes of bubbles and undercuts caused by excessive welding current, and insufficient penetration and overlap caused by too small welding current, thereby improving welding quality and welding efficiency. The purpose of the present invention is to provide a method for automatically setting welding conditions for covered arc welding, which improves the performance of shielded arc welding.

Means for Solving Problem C and Its Effect] In order to achieve the above object, the present invention sends an electric signal to a welding machine based on a change in the diameter of a covered arc welding rod when clamping it to a welding rod holder. A detecting means is provided in the welding rod holder, and the welding machine automatically sets appropriate welding conditions to perform high-quality welding work.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. 1st
The figure is a perspective view of a welding apparatus according to a first embodiment of the present invention, in which an AC arc welding machine is used as the welding machine. In the figure, 1 is a coated arc welding rod, 2 is a welding base material, and 3 is an AC arc welding machine.

4 is a spring clamp type welding rod holder for clamping the coated arc welding rod 1, and 5 is a spring for clamping the holder 4. The AC arc welding machine 3 includes a drive motor 7 for moving the movable core 6 of the AC arc welding machine and a movable core 6.
・Store the three sets of Mi, Tosui, and Chi. (In FIG. 1, only one set of limit switches 8a and 8b is shown, and the others are omitted.) In addition, 9 is a welding cable that supplies power from the AC arc welding machine 3 to the coated arc welding rod 1; 10 is a control cable of the welding cable 9, and 11 is a lead wire from the welding base material 2, both of which are connected to the secondary terminal 15 or welding terminal 16 of the AC arc welding machine 3.

FIG. 2 is a sectional view of a welding rod diameter change detection means attached to the spring clamp type welding rod holder 4. As shown in FIG. Both ends of the potentiometer 12 are hollow synthetic resin pipes 12M, 1
2N is fixed to one end of each pipe, and the other ends of these pipes are fixed to the grip portion 4a of the welding rod holder 4, respectively. A lead rod 12C3 connected to the variable contact of the potentiometer 12 is attached to a welding rod holder 4 to which one end 5a of the spring 5 is fixed via an insulator 12L so that the variable contact of the potentiometer 12 can slide freely on the resistance element of the potentiometer. It is fixed to the clamping portion 4b.

The above pipes 12M, 1 from both ends of the potentiometer 12
2N lead wires 12a are inserted through each lead wire 12a.

The lead cotton 12C connected to the lead rod 12b and the lead rod 12C is connected to the meter relay 13, as shown in FIG. The meter relay 13 has welding rods 1.2.
2.0. 2.6. 3.2. 4.0. 6.0°8
．． Since it says 0 dragon φ, for example, the diameter is 2.6 fin φ, 3.2 dragon φ, 4. (A voltage setting device corresponding to 1+uφ is provided, and these setting voltage signals and the detection voltage signal of the potentiometer 12 are respectively compared and calculated, and as a result, a predetermined signal corresponding to the welding rod of the selected diameter value is sequentially controlled. The output signal of the sequence control circuit 14 is applied to the drive motor 7 that moves the movable iron core 6 of the AC arc welding machine 3.The output signal of the sequence control circuit 14 is, on the other hand, 3.2 Dragonφ, 4.0
A limit switch 17a that stops the movement of the movable iron core 6 so that a welding current suitable for the φ welding rod can be selected.

Added to L7b and L7c.

With the above configuration, the diameter is 2.6 crane φ and 3.2+uφ.

Among the coated arc welding rods of 4.0 ++nφ, when the currently used welding rod 1 of 2.6 mmφ is replaced with a welding rod of 3.2 mmφ, the potentiometer 12 shown in FIG. .6 diameter 3.2f from the voltage value signal corresponding to φ
A voltage value signal corresponding to lφ is sent to the meter relay 13, and the meter relay 3 outputs 2.6 finφ, 3.2+uφ
, and the setting signal of the 4.0 mφ setting voltage generator, and outputs a voltage signal corresponding to the diameter of 3.2 mm to the sequence control circuit 14.
It is sent to the drive motor 7 via the . At the same time, the sequence control circuit 14 sends a signal to the limit switch 17b to stop the movable iron core 6, and the arc welder 3 outputs a welding current suitable for the welding rod 1 having a diameter of 3.2 mm.

Note that the mounting method of the potentiometer 12 is not limited to the above embodiment, and any method may be used as long as the variable terminal of the potentiometer 12 can slide on the resistor according to the elasticity of the spring 5.

Further, in this embodiment, the potentiometer 12 is used as a means for detecting a change in the diameter of the coated arc welding rod 1, but a differential transformer 22 may be used instead, as shown in FIG. . The differential transformer 22 has a secondary side wire 22c with an equal number of turns.

22d are connected in series in opposite directions, and the iron core 22
A is movably set so that the output of the secondary winding becomes zero when the primary winding 22b is excited by the AC power source. This iron core 22a may be attached to a spring clamp type welding rod holder in the same way as the potentiometer 12a.

Furthermore, although the spring clamp type welding rod holder 4 is used as a clamping means for the coated arc welding rod 1 in this embodiment, a screw type holder may be used instead. The screw-in type holder clamps the welding rod with a presser rod, and adjusts the degree of clamping by screwing in the holder. Therefore, by changing the stroke of the presser rod, welding rods of different diameter values can be clamped,
The variable terminal of the potentiometer can be moved in response to changes in the stroke of the presser bar.

Next, a second embodiment of the present invention will be described.

In the first embodiment, a large number of types of coated arc welding rods with different diameters may be used, but in the second embodiment, there are two types of coated arc welding rods with different diameters, for example, 3.2 φ and 4. This is a case limited to .0 silk φ. In the second embodiment, the arc welding machine is normally set to supply 120 amperes, which is optimal for a 3.2 mm diameter coated arc welding rod, to the welding rod. Only when a 4.0 dragon diameter coated arc welding rod is clamped to the welding rod holder, a contact provided in the spring of the welding rod boulder is activated, and a signal is sent to the movable core of the AC welding machine via a sequence circuit. In addition to the drive motor that moves the movable iron core, the output signal of the sequence circuit is applied to a limit switch to stop the movement of the movable iron core, and the arc welding machine operates as follows: 4. Q Outputs a welding current of 170 amperes, which is optimal for amφ coated arc welding rods.

Therefore, since the second embodiment is an on-off type, the structure is extremely simple.

Next, a third embodiment of the present invention will be described.

1st. The second embodiment uses an AC arc welder as the welding power source, while the third embodiment uses an engine-equipped welder, an electric power generation welder, a rectifier/Sirisk, a transistor type DC arc welder, and an inverter as the welding power source. Method: Use an arc welding machine. In the welding machine of the third embodiment, the output current or, in the case of a generator, the excitation circuit is adjusted by electronic control using an electronic circuit. This example is the first
As explained in the embodiment, the detection means attached to the welding rod boulder detects the change in the diameter of the clamped covered arc welding rod, and the detected electric signal is converted into a drive signal for the thyristor gate circuit of the welding machine. , and the conduction angle of the gate circuit is controlled.

〔Effect of the invention〕

From the above explanation, according to the present invention, appropriate welding conditions are automatically set just by the welding operator clamping the covered arc welding rod to the welding rod holder, so that the welding machine installed at a distance from the working position can There is no need to go all the way to adjust the setting conditions, and even when using a remote current adjustment device, there is no need for the operator to adjust the conditions based on his or her intuition. Further, it is possible to prevent the tendency of excessive current settings based on the operator's judgment, and the operator does not need to be extra careful.

In this way, by automatically setting appropriate welding conditions, welding defects such as undercuts and undercuts caused by excessive welding current, and insufficient penetration and overlap caused by insufficient welding current are eliminated, welding quality is improved, and welding is improved. It has effects such as improving efficiency.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a welding device according to a first embodiment of the present invention. FIG. 2 is a sectional view of a welding rod diameter change detection means attached to a spring clamp type welding rod holder, and FIG. 3 is a connection diagram showing a schematic configuration of the first embodiment of the present invention. FIG. 4 is a block diagram of a differential transformer used in the first embodiment of the present invention. 1...Coated arc welding rod 2...Welding base material 3...
・AC arc welding machine 4...Welding rod holder 5...
Spring 6...Movable iron core 7...Drive motor 8a, 8b...Limit switch 12...
Potentiometer 12M, 12N...Synthetic resin hollow pipe 13...
・Meter relay 14...Sequence circuit 14
...Sequence circuits 17a, 17b, 17c...Limit switch 2
2...Differential transformer

Claims (1)

[Claims] When a coated arc welding rod is clamped in a welding rod holder, a detection means provided on the welding rod holder extracts the change in the diameter of the welding rod as an electric signal and sends it to the welding machine, and appropriate welding conditions are automatically set. A method for automatically setting welding conditions for a coated arc welding rod.