JPS58181488A - Method for controlling resistance welding current - Google Patents

Abstract

PURPOSE:To stabilize the quality of welding, by dividing the control in one current conduction period to 3 periods, assuring the route for the current conduction meeting the electrode consumption after the start of melting and supplying adequate current density. CONSTITUTION:The welding current control in one current conduction period of resistance welding is divided to three control periods. In the 1st period, constant current control is accomplished for a prescribed time, and the degree of electrode consumption is estimated from the max. value of the resistance value between tips obtained at that time, then the next target value is determined. In the 2nd period, the resistance value is subjected to feedback control until the resistance value between the tips attains the target value or below and the route for the current conduction meeting the degree of the electrode consumption is assured. In the 3rd period, the voltage value is subjected to feedback control so that the voltage between the tips follows up the curve of the targe voltage value and adequate current density is supplied. The quality of welding is thus stabilized.

Description

DETAILED DESCRIPTION OF THE INVENTION In the Fi resistance welding according to the present invention, nugget generation is carried out in one step, and AA is provided with a function of 1 mm.

Conventionally, non-conformist services (for example, spot bath services) have been performed for 70 days.
[-Tanijisa Monitoring Tei 1, Tei 4tIL-GoA-, etc. have been used in the bird of protection. But these devices are only 4
Even if there are 6 machines that control the flow rate at a certain level, it is possible to improve product quality more positively. Nakatsu 90 On the other hand, return acoustic eifushi 1 + 1, infrared mff 1 degree 11! No., Hot horse mackerel, Tsu, I gave up the Okio system Misaki Shinto using the chip l11114 pressure and chip 1vJ resistance etc. as feedback No. 91, which is a rattan material!
Xfi4t&place has been developed. However, when attempting to actually apply 1 gL to the main layer, the usage limit was ≈4 cups, which was not practical.

For example, acoustic music 3) traffic lights, infrared lights,
The V& position that uses the FIT number and Waki 4 ◆ as a feedback signal will not be fully put into practical use in terms of noise countermeasures, difficulty in Ishiminato, and high cost.

Although a device using t7t, chip pressure, and interchip resistance as feedback signals is relatively simple to implement, it has the following drawbacks.

First, a method of setting the chip viewing pressure to feedback+II@ will be described. Write down the chip pressure car 1 corresponding to the nugget that seems to be good, and follow this curve #! This is a method of controlling four-way flow. However, as the power consumption progresses, stable 44 values may not be obtained, and even if the same curve can be followed, there may be variations in nugget generation. The method using 11 (density) as a feedback signal is a four-way method in which the density is measured, and one reason for the variation in nugget generation in this method will be described below.

In the above explanation, following the same car 1 means different chips [! 1iF8
1, chips waiting for ri (1) (1) and 41 t! If l is sandwiched between the same 41 pins + st 1 lil 1 and the resistance layer is layered, then the chip capacitor 4 pressure V in these two cases is:
V2 becomes Ma, Abuse 2 at a time, and 1□-
11/ml-LBIsI/am (Is specific resistance) is established.

Nagetsu) If you consider that I after starting $1 is almost equal, ' l
/ #4 fossa/ , becomes. From this, it can be seen that even if the flow path 1 changes by 2, the current sliding degree is controlled equally.

Therefore, in order to obtain a proper nugget number, it is necessary to have 4 rows and 4 routes above a certain level. However, with the above method of using the tip pressure as a feedback signal, even if the 4-way (4-way) is equal to 1 curve, the 4-4-way (44-way) cannot be controlled accurately. In this case, the pressurizing force by 4mu (3) 131 naturally decreases once, stabilizes, and only a small amount of Kusaku 4ro can be obtained. was not obtained, and 4- was performed with the chip l &&! voltage feedback + No. 11 on the 44 path smaller than this/'L.
Even if 51EIf can be marketed as l4+ILa, a proper nugget will not be generated.

In other words, if a stable conduction path 4 corresponding to the tip tip 4 is not established at the beginning of the process, the nugget formation using the 4-voltage direct feedback will not be successful.

Next, a method of tossing the inter-chip resistance with a feedback signal will be explained. This causes the chip resistance 1st line to follow the 41st line curve. However, this method only makes the 14th diameter the same as the 41st diameter. Since the wax flow If that refers to the 41st diameter is not the same, the nugget generation is not stable. do not have.

Resistance dfi like this! The response @ Umugi is also JXJ
and put it into practical use. 4VC, as mentioned above, must satisfy two essential conditions.

That is, the seventh 518! As a note, it is 1#1411 with an appropriate IIE flow degree as a note on 4 roads and 44 maintenance of the can after the start of planting, and 4 on Shimako.

Therefore, the present invention improves this, achieves the above two conditions, and provides a resistance method (flow control force method).

In other words, Book 9 @ Akira is 4 of /1 can period Kannai at the resistance m junction.
- 4 waves 1
The ninth Xi to estimate mt4)! 4-flow control, its - 914 that matches the 914 only, the poor resistance 1-direction feedback control, and the proper 4-flow, the B rounded 4 that is suitable for
Pressure foot °batsuta, ff11m J no Ichi U4 M
, No. 15.

Absolutely, regarding these J 4M- rules, the 1st/1st one in the same column is 1111IA. In the dark, the constant flow is 4
Go back and perform regular vomiting. In this case, the inter-chip resistance 1 line 1L (4mm 14 resistance 1 line) is 4 layers 1 Teraseki C (swickle)
K changes as shown in Figure 5. In the same figure, the characteristic of H) is 4 go, which is slightly smaller than 4, and the 4 note of (B) is 4 go, which is slightly larger than 4. r, that is, the breakdown of the chip 1''15 resistance a is lowered according to the consumption of 1 direct point-1.Here, the 4-dog feedback d Liu is
4 This is to receive the same − other than 4 and −1 during the initial low order between the chips.
- Diameter) can be estimated, and the electric diameter is slightly commensurate with the diameter of the
(Substitute included) is determined as the next 111i Goiimame 41 shift.

In addition, in the 24th 1vIll# period, the resistance value feedback III# is performed until the degging resistance correction is determined in the /#th -# period and becomes less than 9 times Rin 1 correction. As a result, the communication flow is controlled in accordance with the m-res of Merindan and Sadao 1st shift, and the necessary 14-way L4t-4, which is the condition of #i/ above, can be maintained.

Further, in the J#th Fi control period, a 4-pressure 1-direction feed butter A is performed so that the chip can pressure follows a preset 14-pressure curve. As a result, the appropriate number of 111 encounters, which is a condition of the above-mentioned bribe, can be endured.

It has been a long time since we used the method of the present invention to resistance weld mild steel plates (spot 4).
(contact) a-contact flow 11, ijl, 4 in a controlled concrete example
The change in resistance between electrodes R1 and U*4 when 41 pressure vy > 41) with respect to 5C is 4@C4 where 4mm1 is small (fJy diagram (&)) and 4mm diameter is consumed and becomes large. Figure '1 (b)
). In the diagram (a), the maximum one shift (ryo) of the electrical resistance value (6) at 74th control + lJ period tI) is 45, and in the case of diagram (b), the maximum one shift (ryo) is工')K
Large compared to others! <4m indicates that it is small. As a result, depending on these pupil diameters (r) (ryo')K, the resistance 1st shift (r2)<r;>K, which is the second control period ■, is determined respectively by f & feed batter
will be carried out. Then, when the bath contact 4a (il) (i,) rises and becomes 1 in the eye 4 low resistance straightness (r2) (ra'), the 4th pressure 1st straightness feedback which is between the third III control #A
Umugi has set it up in advance! And the ninth IJ! 1 issue pressure 1 straight curve (v)
K1m is performed accordingly.

As explained above, according to the present invention, the resistance welding can 1 and 2 are connected between the conductive lIA and the 41-hole persimmon of the mortar and the starting iron.
VC worth it 44 only 4 stones and proper 4 [,'l! The supply of A becomes widespread, nuggets are reliably generated, and a practical resistance 4-fluroscopic control force method can be achieved. In addition, by the method of the present invention, the ignition of the chip 1 resistor 1 at F'i 4 o'clock is determined by the direct ignition of the chip 1 resistor 444. It also eliminates the instability of the stability. For example, even if the fit between plates is 7'4 due to variations in the contact angle of a press-formed product, etc., the method of the present invention will produce a bonded product. 4 fiber instability is removed〇

[Brief explanation of the drawing]

The figure shows a simulated front view of resistance welding when the tip size is small, and Shimako A vaguely shows the 4th way of resistance welding with a large tip size. front view, J
The lij diagram shows typical 4 resistance welding resistances; 4 resistance-m
Figure y ta) and (1)), which shows the entertainment opening curve, show the resistance, 400,000,000, 4f, and a, 4υt when the resistance method of the present invention is applied. Fig. 2 is a characteristic diagram showing a representative sequence of changes with respect to welding time, where Fig. y (&) shows the case where the chip is slightly small, and Fig. 1 (1) shows the case when the chip is slightly large. Ill Ill... Chip, +31 a @ 4 contacts 4m
, (kl) am chitu 7'11 Jtt anti, j[(4m:j
Jlmffllll), (vyo) (Y2)-14, m,
64 pressure, (il) (12) I @ d, #4 flow, (r
2) (r2')・11th turn (4th resistance 1st turn), (Ma)
・Eye 14 pressure: Direct, (■)・E74 eye control 4th period, Tsukasa (
Definite 4th control moan), face...Kth F! I control period (resistance 1
Direct feedback 1f14 control), (2)... J4th +u control multiplicity field ('4 pressure 1 direct feedback l!1I
II (Il). '''('-1L'4 convex #! 4 figure (Q) Saifurun

Claims (1)

[Claims] 11) At the resistance fII contact i, / 4th period Kannai I
constant current control, resistance value feedback d#,
(In the J dtllll1 period of the pressure 1 direct tweed putter control, constant current control is performed for a predetermined time in the /#th control period, and the chip resistance value is broken 11I [due to the following l!Il# Determine the inter-item directivity of the period, perform resistance value ride patsuta control in the co-th control period until the inter-chip resistance value becomes less than or equal to the inter-chip resistance value tllll11 determined in the subsequent control period, Between +utl, alj, and m of the no.
4th style of resistance that considers the fact that @ is done → If
lIJ-force method・