JPS6325014Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a hot wire type arc welding device that performs welding while supplying current to the wire and supplying the wire preheated by the resistance heat generation to the welding part. This relates to control of three conditions: feeding amount and wire heating power.

In this type of hot wire arc welding, welding current is required to melt the base metal, wire feed rate is required to obtain the desired amount of welding, and wire heating power is required to ensure that the wire melts into the weld zone in good condition. 3
One condition must be adjusted. Obtaining optimal welding conditions by adjusting the three conditions independently in this way is equivalent to finding a single point in a three-dimensional space, and is a very difficult task that requires a lot of experience and skill.

Therefore, recently, in order to simplify this adjustment work, a so-called unified method has been proposed in which the wire feed rate and wire heating power are automatically set to appropriate values by adjusting the welding current.

A conventional hot wire type arc welding apparatus of this type is shown in FIG. This device is
The electrode 12 and base metal 14 are connected to the output end of the welding power source 10 to generate an arc 16 between the electrode 12 and the base metal 14 to melt the base metal 14, and at the same time, one of the output ends of the wire heating power source 22 is connected to the base material 14, and the other is connected to the wire 18 via the power supply chip 20, and a current is supplied from the wire heating power source 22 through the path of the base material 14, the wire 18, and the power supply chip 20, and the resistance heat generated by this current is utilized. Thus, welding is performed while continuously supplying the wire 18 to the welding part in a high temperature state. In the welding power source 10, the command signal from the welding current setting device 24 is compared with the detection output of the current detector 26 by the comparator 28, and the comparison result is used to control the output regulator 30 to control the output from the electrode 12 to the base material. The welding current flowing to 14 is maintained at a predetermined value. The command signal of the welding current setting device 24 is also supplied to a function generator 32. The output of the function generator 32 is supplied as a control signal to the motor drive power supply 36, and as a result, the rotation speed of the wire feeding motor 38 is controlled in accordance with the command signal, and the motor 38 is directly connected to the motor 38. The wire 18 is fed to the welding part by a roller 42 at a predetermined speed. Further, the output of the function generator 32 is input to a function generator 42 in the wire heating power source 22, and the output of the function generator 42 and the output of the wire voltage detector 48 are compared in a comparator 44. Then, according to the comparison result, the output regulator 4
6 is controlled, and the wire heating voltage applied between the power supply chip 20 and the base material 14 is controlled to a predetermined value.

FIG. 2 is an example of the relationship between the wire heating voltage and the wire feed amount obtained through experiments. In FIG. 2, when the wire 18 is above the curve A, the wire 18 melts too much as shown in the figure and falls into a ball in the arc 16, whereas when the wire 18 is below the curve B, the unmelted part of the wire 18 is attached to the base material 14. This is an area where penetration may occur, causing molten metal to scatter or resulting in poor fusion. Therefore, the relationship between the heating voltage of the wire 18 and the feed rate that allows good welding is in the region between curves A and B. Figure 3 is an example of actually measuring the relationship between the wire feed rate and the welding current.The welding speed is constant, and the relationship between the wire feed rate and the wire applied voltage is expressed as the value in the area between curves A and B in Figure 2. There is. In Fig. 3, when the wire feed rate exceeds curve C, the base material 1
The amount of wire is too large compared to the amount of melting in No. 4, resulting in an extremely convex bead. Conversely, under conditions below curve D, the amount of wire is insufficient, and undercuts occur when welding is performed at a predetermined speed. Therefore, good welding can generally be performed in the area between curves C and D.

The input/output relationship of the function generator 32 described above is the third one.
This is the area between curves C and D in the figure, and the function generator 42
The input/output relationship lies in the area between curves A and B in FIG. That is, it is a combination of the good areas of FIGS. 2 and 3. In the conventional device described above, the three conditions of welding current, wire feed rate, and wire applied voltage can be adjusted simultaneously by adjusting one setting device 24, which greatly simplifies the adjustment operation. However, on the other hand, it has the following drawbacks. One of the major features of non-consumable electrode arc welding is that the welding current and wire feed rate can be adjusted freely and independently, and are used depending on the purpose of welding. The relationship between the welding current and the wire feed amount shown in FIG. 3 is an experimental value based on normal welding such as fillet, overlap, butt joints, etc. Therefore, if you want to make the welding amount especially large, such as in build-up welding, or if you want to make sure that the weld bead comes out even if you sacrifice the welding amount, you should use the general welding method described above. The set function relationship is inappropriate. In other words, the conventional apparatus shown in FIG. 1 could not be used for special welding applications such as those mentioned above.

This idea was created in view of the conventional problems mentioned above, and its purpose is to create a unified system that can handle a wide range of welding applications by allowing the relationship between welding current and wire feed amount to be used depending on the application. An object of the present invention is to provide an adjustable hot wire type arc welding device.

In order to achieve the above object, this invention is a function generator that inputs the output signal of the welding current setting device in a hot wire type arc welding device using a non-consumable electrode. The present invention is characterized by providing a switching means for enabling any one of the plurality of function generators.

Hereinafter, preferred embodiments of the present invention will be described based on the drawings.

FIG. 4 is a block diagram showing an embodiment of the hot wire type arc welding device according to this invention, and the same components as those of the conventional device shown in FIG. is omitted.

In the device of the present invention, the welding current setting device 24
Three function generators 32a, 32b, and 32c with different input/output characteristics are used as a first function generator that receives an output signal from and outputs a control signal for the motor drive power source 36 and an input signal for the second function generator 42. are provided, and these three function generators 32a, 32
b, 32c by the selector switch 5
0, and only the selected one function generator is made to function effectively. Here, the relationship between the welding current and wire feed amount by each of the function generators 32a, 32b, and 32c has three different characteristics as shown in FIG. For example, the characteristic of the function generator 32a is E, and the characteristic of the function generator 32b is
The characteristic of the function generator 32c is F, and the characteristic of the function generator 32c is G.

In the apparatus of the present invention configured as described above, the function generator 32a having characteristic E is selected by the changeover switch 50 in, for example, overlay welding which requires a particularly large amount of welding. Then, the function generator 32b with the characteristic F is selected by the changeover switch 50, and the function generator 32c with the characteristic G is selected by the changeover switch 50 for thin plate welding, uranami welding, etc., which require a particularly small amount of welding. In this way, the functional relationships among welding current, wire feed amount, and wire heating voltage can be set to be appropriate for each type of welding, and these conditions can be adjusted by adjusting one setting device 24. Predetermined functional relationships can also be adjusted simultaneously.

As explained in detail above, the hot wire arc welding device according to this invention maintains a unified adjustment method that is easy to operate even for beginners, in which three adjustment elements can be adjusted simultaneously with one setting device. Since it is possible to arbitrarily select a plurality of uniformly adjusted characteristic curves simply by switching a switch, it is possible to accommodate a wide range of welding applications.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing a conventional hot wire arc welding device, Fig. 2 is a graph showing the relationship between wire feed rate and wire applied voltage, and Fig. 3 shows the relationship between welding current and wire feed rate. Graph diagram, 4th
The figure is a block diagram showing a hot wire type arc welding apparatus according to an embodiment of the present invention, and FIG. 5 is a graph diagram showing the relationship between welding current and wire feed rate in the apparatus of this invention. In each figure, the same members are given the same symbols, 10 is a welding power source, 12 is an electrode, 14 is a base material, 16 is an arc, 18 is a wire, 20 is a power supply chip, 22 is a wire heating power source, 24 is a welding current Setting device, 32,3
2a, 32b, 32c are first function generators, 36
is a motor drive power supply, 42 is a second function generator, 5
0 is a changeover switch.

Claims (1)

[Scope of utility model registration request] a welding current control means for supplying a predetermined arc current between the non-consumable electrode and the base metal; a heating power control means for supplying a predetermined wire heating power between the wire and the base metal; a welding current setting device for giving a command signal for determining the welding current to the welding current control device; a first function generator that outputs an output having a predetermined functional relationship and supplies this to the wire feeding control means as a signal for determining the wire feeding speed; a second function generator that outputs an output having a predetermined functional relationship with respect to this output and supplies this to the heating power control means as a signal for determining the heating power; In a hot wire type arc welding device that simultaneously adjusts welding current, wire feed amount, and wire heating power while maintaining a predetermined functional relationship, a plurality of function generators with different input and output characteristics are provided as the first function generator, and , a hot wire type arc welding apparatus characterized in that a switching means is provided for enabling any one of the plurality of function generators.