JPH04245A - Welding method and device for armature lead wire - Google Patents

Abstract

PURPOSE:To improve welding quality by detecting the temperature of a welding rod and the contact resistance between the welding rod and the hook of commutator segment prior to welding and then selecting an optimal welding pattern based on thus detected data and controlling the welding current, in the resistance welding of a coil terminal and the hook of commutator segment. CONSTITUTION:In the resistance welding of a coil terminal and a hook 11a of commutator, a temperature sensor such as a radiation thermometer for detecting the temperature of a welding rod 1 and a sensor 4 for detecting the contact resistance between the welding rod 1 and a sub-welding rod 2 while bringing them into contact with the hook 11a and the commutator segment are provided. Outputs from the temperature sensor 3 and the contact resistance sensor 4 are fed, respectively through detecting circuits 3a, 4a, to a welding pattern memory 7. Output from the memory 7 is fed to a welding current control circuit 8 comprising a thyristor or the like in order to control the waveform of an AC current to be fed to the primary of a welding transformer 6 thus controlling the effective value of welding current.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an armature lead wire welding method and apparatus for welding a coil terminal wound around an armature core to a commutator hook.

[Conventional technology]

Generally, resistance welding is used to weld armature lead wires, and there are various methods for supplying current from a power source, such as a constant current method, a constant phase method, and a constant power method. Welding control methods include an initial setting method and a feedback method.

In the initial setting method, taking the constant current method as an example, you first decide on the number of current cycles and total amount of current required for one welding, then flow only that amount, and then check whether the specified amount has flowed or not. , check using a separate monitor.

Further, in the feedback method, taking the constant power method as an example, first, the current and voltage are initialized, and the current and voltage are changed to the values during one welding. That is, if the welding cycle is, for example, 10 cycles, the amount of current in the first cycle is checked, and if it does not reach the initial setting value, the amount of current is added to the current amount in the second cycle.

[Problem to be solved by the invention]

However, these conventional methods of welding armature lead wires only check the current and voltage on the circuit, but do not check the actual welding condition. For example, there is a problem in that the welding result changes significantly if the initial temperature of the electrode rod at the start of welding or the contact resistance between the electrode rod and the commutator hook changes.

In addition, the latter method requires a large amount of current to flow from time to time in order to make up for the current shortage, which poses the problem of being dangerous and difficult to handle.

In order to solve this problem, welding is completed by detecting the temperature of the commutator at a part slightly away from the electrode rod, and by detecting the amount of sinking of the electrode rod, and when the value reaches a predetermined value. Some devices indirectly control the temperature of the welding area in this way.

However, the temperature detection method described above cannot detect the temperature of the welding area itself because it is blocked by the electrode rod, so there is a problem that there is a large difference between the temperature of the actual welding area and the temperature depending on the quality of heat conduction. be.

Also, although the method of detecting the amount of submergence of the electrode rod may seem ideal at first glance, if you immediately stop welding and pull up the electrode rod as soon as the predetermined amount of subsidence is reached, the welding surface will be disturbed. After turning off the current, there is a hold time of, for example, 0.1 to 0.2 seconds, and then the electrode rod must be pulled up.
During this time, subduction progresses and there is a problem in that it is difficult to strictly control the amount of subsidence.

In either case, extremely sophisticated control technology is required.

This invention has been made in view of the above points, and an object of the present invention is to provide an armature lead wire welding method and device that is easy to control and can obtain good welding quality under all conditions. do.

[Means to solve the problem]

In order to achieve the above object, the present invention includes a welding method in which various welding patterns corresponding to changes in temperature of the electrode rod and changes in contact resistance between the electrode rod and the hook of the commutator are stored in advance in a memory. and the temperature of the electrode rod prior to welding,
The contact resistance between the electrode rod and the hook is detected, and based on the detected data, an optimal pattern is selected from the stored welding patterns for welding.

The welding device is a device for carrying out the above method, and stores various welding patterns in memory corresponding to changes in the temperature of the electrode rod and changes in contact resistance between the electrode rod and the hook of the commutator. A storage means for storing data, a temperature detection means for detecting the temperature of the electrode rod before welding, a resistance detection means for detecting the contact resistance between the electrode rod and the hook, and a welding pattern stored in the memory according to these detection results. A control means for selecting an optimum pattern and controlling the welding current is provided.

[For production]

If you do the above, the temperature of the electrode rod and
The contact resistance between the electrode rod and the hook of the commutator is detected, and according to the result, the closest one is selected from among various welding data stored in the memory in advance for welding.

According to this method, the current supply from the power source can be performed using an initial setting method that can be expected to have a stable effect, and the welding condition does not change when the machine is stopped, the electrode is replaced, or the temperature of the electrode changes due to factory temperature. There is no fear.

Further, since different welding patterns can be set depending on various types of commutators, wire diameters, types of wire coatings, etc., the present invention can be applied to all types of armatures.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. Prior to the description, a general method for welding armature lead wires will be briefly described with reference to FIG. 3.

A wire W whose outer peripheral surface is covered with an enamel coating connects its lead wire end to the first hook 11 of the commutator 11 of the armature 10.
After the lead wire is connected to a, the lead wire is wound between predetermined slots of the iron core 12 to form a first coil, and the lead wire at the end of the winding is connected to a second hook, and then the lead wire is wound between predetermined slots of the iron core 12. The lead wire at the end of the winding is wound to form a second coil, and the lead wire at the end of the winding is connected to the third hook, and the formation of the coil and the connection of the lead wire are repeated in the same manner to form the armature 1.
0 winding ends. When the winding is completed, the connection portion of each hook is welded using a resistance welding device.

This welding device consists of an electrode rod 1 made of high melting point tungsten, etc.
and a sub-electrode frame 2 made of copper with high conductivity.The electrode rod 1 presses the hook 11a of the commutator piece 11b with a predetermined pressure, and the sub-electrode frame 2 is brought into pressure contact with the commutator piece 11b. A predetermined voltage is applied between the electrode rod 1 and the sub-electrode frame 2.

As a result, current flows between the electrode rod 1 and the sub-electrode frame 2 via the commutator piece 11b, but the electrode rod 1 and the hook 1
Joule heat is generated in this part due to contact resistance with 1a. This heat melts or softens the lead wire coating, and at the same time, the electrode rod 1 presses the softened hook lla and mechanically presses it against the commutator piece 11b, thereby welding the wire W (see FIG. 4).

In the above-mentioned resistance welding, the welding temperature and pressure can be increased as the biggest factors that change the welding state. Of these, the pressurizing force can be easily controlled, so there is no risk of it fluctuating greatly.

The welding temperature varies greatly even when the same current is applied, depending on the temperature of the electrode rod 1 itself before welding and the contact resistance between the electrode rod 1 and the hook lla.

Therefore, in this embodiment, the engineering factor described above is detected as an initial condition before welding, and welding is performed using the closest pattern among various welding patterns predetermined based on the detected data.

That is, as shown in FIG. 1, a temperature detection sensor 3 such as a radiation thermometer that detects the temperature of the electrode rod 1 before welding from a remote point, and the electrode rod 1 and the sub-electrode frame 2 are connected to hooks.
and a contact resistance detection sensor 4 that detects the contact resistance between the electrode rod 1 and the sub-electrode frame 2 while in contact with the commutator piece 11b.
and

FIG. 2 is a block diagram including the control system of this embodiment.
A current necessary for welding is supplied between the electrode rod 1 and the sub-electrode frame 2 from an AC power source 5 via a welding transformer 6. Further, the output of the temperature detection sensor 3 is inputted via the temperature detection circuit 3a to a welding pattern memory 7 in which a large number of welding patterns are stored in advance, and the output of the contact resistance detection sensor 4 is inputted via the contact resistance detection circuit 4a. input into welding pattern memory 7,
The output is input to a known welding current control circuit 8 that performs phase control using a three-terminal thyristor (SCR), etc., and controls the waveform of the alternating current flowing to the primary side of the welding transformer 6 to determine the effective value of the welding current. Control.

The above-mentioned welding pattern memory 7 stores the optimum current values when the temperature of the electrode rod 1 before welding and the contact resistance between the electrode rod 1 and the hook 11a are respectively changed.

Welding patterns such as energization time and pressing force are stored in advance for each wire diameter.

In actual welding, first, before welding, the temperature detection sensor 3 detects the temperature of the electrode rod 1, and the contact resistance detection sensor 4 detects the contact resistance between the electrode rod 1 and the hook 9118.

Then, each detection data is stored in the welding pattern memory 7.
The welding current control circuit 8 controls the welding current by selecting the most similar welding pattern from a large number of pre-stored welding patterns.

By doing so, stable welding results can be obtained without performing troublesome feedback control during welding.

〔Effect of the invention〕

As described above, according to the present invention, various welding patterns corresponding to changes in the temperature of the electrode rod and changes in contact resistance between the electrode rod and the commutator hook are stored in advance in the memory, and the welding patterns are Since both of the above data are detected prior to welding, and the optimal pattern is selected from the welding patterns stored based on the detected data, welding current can be controlled using a simple initial setting method, resulting in stable can be increased.

In addition, it is possible to prevent changes in welding conditions due to welding equipment down time, factory temperature changes, electrode rod replacement, etc.
It can be widely adapted to various commutators, wire diameters, wire coatings, etc.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing an embodiment of the present invention. Figure 2 is a block diagram including the control system, Figure 3 is an explanatory diagram showing a general armature lead wire welding method, and Figure 4 is an explanatory diagram showing an enlarged view of the main parts of the welding completed state. . 1... Electrode rod 2... Sub-electrode frame 3... Temperature detection sensor 4... Contact resistance detection sensor 6...
Welding transformer 7...Welding pattern memory 8...
・Welding current control circuit 10... Armature 11... Commutator 12... Iron core

Claims (1)

[Claims] 1. In an armature lead wire welding method in which the end of a coil wound around an armature core is resistance welded to a hook of a commutator, temperature change of an electrode rod and contact resistance between the electrode rod and the hook are Various welding patterns corresponding to changes are stored in memory in advance, and the temperature of the electrode rod and the contact resistance between the electrode rod and the hook are detected prior to welding, and the stored welding pattern is created based on the detected data. An armature lead wire welding method that selects and welds the optimal pattern from among the following. 2. In an armature lead wire welding device that resistance welds the terminal end of a coil wound around an armature core to a hook of a commutator, it is possible to cope with changes in the temperature of the electrode rod and changes in the contact resistance between the electrode rod and the hook. storage means for storing in a memory various welding patterns to be welded; temperature detection means for measuring the temperature of the electrode rod before welding; resistance detection means for detecting contact resistance between the electrode rod and the hook; A welding device for armature lead wires, comprising a control means for selecting an optimal pattern from the welding patterns stored in the memory according to the result and controlling the welding current.