TW458832B - Resistance welder - Google Patents

Abstract

The present invention provides a resistance welder to steadily supply a prescribed welding current to each weld point, so as to uniformly weld each weld point, moreover to reduce the defective ratio of products and to lessen the volume of a transformer for welding. The structure includes a transformer 13 for welding which converts an AC from a welding power source part 11 into electric power of low voltage and large current, and a resistance welder which welds with multipoints an object A to be welded by rectifying a current induced in the secondary side of the transformer 13 for welding with a rectifier circuit 14 and feeding it to a welding electrode. The present invention has the feature that the welding electrode is composed of a lower electrode 15 in which the object A to be welded is set up and plural upper electrodes 16-1 to 16-N which are pressurized to the lower electrode 15 via the object A to be welded and are abutted on plural weld places of the object A to be welded, switching elements 17-1 to 17-N are respectively connected in series to each current feeding line connecting the part between the output terminal of the rectifier circuit 14 and respective upper electrodes 16-1 to 16-N, and the respective switching elements 17-1 to 17-N are ON/OFF controlled at a specified time interval in sequence by the control signal S1 from a controller 12.

Description

458832 丨 V. Description of the invention (π I ί

The present invention relates to a resistance welding machine capable of multi-point welding to an object to be welded by an electric welding machine. In detail, the present invention relates to a resistance welding machine capable of sequentially flowing welding current to each welding point to perform multi-point i 丨 welding on the object to be welded. 'I | For example' When welding the filaments of the fluorescent display tube and their wires through a resistance method, a plurality of filaments are arranged at a certain interval 丨! On the lower electrode of the welding fixture, and then One end of a plurality of wires is arranged and stacked on each filament, and a strip-shaped material is stacked on one end of each wire along the filament arrangement direction, and the corresponding plurality of filaments are arranged on the welding fixture. A plurality of upper electrodes are stacked and crimped on top of the strip-shaped material, and in this state of crimping, a current is passed between the lower electrode and the upper electrode to connect each filament and wire And strip welding. When the welding is completed, it is separated by cutting the strip between each two adjacent filaments to form a filament member for a fluorescent display tube. According to the conventional multi-point resistance resistance welding machine, in addition to having the above i-lower β electrode and a plurality of upper electrodes, it has a primary side connection | 丨 phase control is applied to a commercial power supply to control the current The so-called AC type welding power source is a welding transformer, and the above lower electrode is connected to the square output terminal on the m side of the i welding transformer, and the above upper parts are connected here in parallel. Weld the other output terminals of the transformer.丨 丨 When multi-point welding is performed on the object to be welded, the object to be welded is clamped and held between | = a plurality of upper electrodes. In this state, since the welding I flows to the lower electrode and the upper electrode, each The upper electrode is welded to each welding part of the object to be welded.

Page 5 4δ 883 2: V. Description of the invention (2) However,: Extreme processing error! 丨 each of the welding objects between the welding points; the same causes the flow through I 丨 welding transformer to flow through the welding and: The product of the total welding current on the welding side resists the voltage of the welding machine itself. Furthermore, the mode has the disadvantage of half the power supply. Also, the customary resistance of | will make a difference | so these electricity i cannot divide each; the rate is for the resistance welding machine of the present invention, due to its welding fixture or electrical + error and other factors, making it Each state of the object to be welded is slightly different, so that the resistance values including the electrodes and j are different from each other, and the current values of the uneven contacts of this resistance value are different. As a result, the secondary side The total welding current is controlled to a certain value, nor is it: The current value of the contacts remains uniform. 1; t connection current flows into several welding points at the same time, even if the current value of ^ is not large, but the secondary current flowing into the welding transformer is equal to the number of flowing welding points N times the welding point θ, which is also quite large. The total welding current is therefore known that electric welding transformers must have a large current capacity, which causes the welding variable volume to become large, which is its disadvantage. ^ The welding power supply system adopts the phase control feedback control of commercial power supply in the slowest speed (in the fastest case, also lags behind the cycle). 'Because the current has an interruption time, there is thermal efficiency f. The method of welding the upper electrode at the same time is that the welding machine 'because the current value flowing through each welding point is as described above. The Joule heating of the welding point is proportional to the square of the current. The difference of ^ has a great influence on the welding quality of each welding point. The homogeneous welding of the welding points also increases the disadvantages of the product. The purpose is to solve the above-mentioned shortcomings and provide a stable 458832. V. Description of the invention (3) The supply of a suitable homogeneous small capacity is the output of the resistance welding section; At each welding, quantification is achieved on the pick-up machine, and the AC will be welded, or borrowed by applying features to rectify the electrode electrode on the part to rectify it back to the series connection point. Therefore, the resistance is reduced. Point at: The 'and the return to the lower road are connected to a certain product that needs to be opened. 'The present invention: a welding structure is a low-voltage primary circuit to be welded. Several welding electrodes are abutted on the electrodes, and the terminal spot is closed, and the welding current' 俾 but the welding point yield rate 'can make the welding transformer reach the application. Dedicated power supply section: First, the electric current of the electric power flowing in a large range after induction rectification is supplied to the creator by a large power station: It is provided by an upper electrode of the upper electrode for the object to be welded. According to the item 1, the welding transformer of the power source for welding is directly supplied to the welding electrode, and the welding object is placed at its welding position; the power supply lines in the chain are applied to each switching element at a set time interval. Control means by on / off control. i The resistance welding machine according to item 2 of the scope of patent application of the present invention, wherein the welding power supply unit has a converter (c ο nverter) that converts commercial AC to DC, and outputs the converter The direct current conversion to high frequency alternating current | inverter (inverter) constitutes a structure that can supply the high frequency alternating current converted by this reverse converter to the primary side of the above welding transformer. i According to the resistance welding machine described in item 3 of the scope of patent application of the present invention, wherein the control section has a sequence that can be set in advance to set the above-mentioned switching elements to the ON state, and the above-mentioned switches can be arbitrarily set. Device for setting the on-time of a piece of equipment, and sequentially according to the information set by the above setting device

Page 7 458832: V. Description of the invention (4) '"] I, select each of the above-mentioned switching elements, and only make the above on within the predetermined time | 丨 switch element selection, driving circuit for conducting the closing element . I According to the resistance welding machine described in item 4 of the scope of patent application of the present invention, it is provided between the above lower electrode and the upper electrode that can be supplied to the above: as described above, the welding current value of the upper electrode and The power-on time is arbitrarily set, and the control unit that controls the above-mentioned reverse converter to obtain the current value and the power-on time of the above-mentioned setting device.丨 ^ According to the resistance welding machine described in item 5 of the scope of patent application of the present invention, there is a sensing I ^ that can sense the welding current of each welding part during welding, and by sensing the above-mentioned sensor, The sensed value is fed back to the inverter control unit to control the welding current to a set current value. According to the embodiment of the present invention described above, the switching element provided by each upper electrode is sequentially subjected to conduction control i by the control unit at a set time interval, and during this conduction time, each time By applying an electrode to the welding i 丨 part of the object to be welded corresponding to the upper electrode connected to the switching element in the conducting state I, it is possible to stably supply a certain welding current suitable for each welding point. Furthermore, the welding point can be homogeneously welded, the defect rate of product I can be reduced, and the welding transformer can be reduced in capacity. I Furthermore, the welding power supply unit according to the present invention has a reverse converter that converts commercial AC: electricity to DC output by a converter and converts it to high-frequency AC. Fine welding current for multi-point welding. According to the present invention, the conducting order and the conducting time of each switching element can be arbitrarily set by the setting device.

Page 8 458832: V. Description of the invention (5) i 1 According to the present invention, the setting of Pei; welding current value and still, press to feed to the reverse current value. | Refer to it below. The first diagram is the intention; the second diagram; the block diagram; the third diagram; the fourth diagram. In the figure, the welding rectifier circuit 14 of this 10; .15 and a plurality of 丨 丨 1 6-1 ~ 16-N are selected. I The present invention is shown, for example, by a wire, and one of the ends 31 of the electrode 15 has these components, so that it can be energized by the device of the present invention. Invent a connection to a three-phase AC power source and a welding transformer 13;-The current value of the welding current which can be set by the related parts 1 7- 1 ~ 1 7-N and the current sensor 18, etc. Time at the junction of the object to be welded. It can return the sensing value sensed by the edge detector to control the welding current of each joint. For the detailed description of the embodiment of the resistance welding machine of the present invention, the overall structure of the embodiment of the resistance welding machine is shown: Figure t The internal structure of the power supply unit for welding is shown in the first figure of the internal structure of the control unit. The current waveforms to the welding points of the invention. The resistance welding machine is composed of the source unit 11: a control unit 1 2-applicable The lower electrode part electrode 1 6-1 ~ 16-N is welded at the multiple points of the object 4 to be welded. A number of objects A to be welded corresponding to the upper electrode resistance welding machine are as shown in the first picture. The object A can be fluorescent. The filament used for the display tube and its guide will be multi-point welded. It looks like the lower part of the welding fixture is arranged with a plurality of filaments 30 at a certain interval, each wire is arranged on the filament 30, and one is arranged along the filament 0 883 2 V. Description of the invention (6)! The shape M is stacked on one end of these wires 31. A plurality of upper electrodes 16-1 to 16-N provided on the welding jig corresponding to the arrangement of the filaments 30 are crimped from above and pressurized on the strip 32, and under this crimped cancer, the The welding current flows between the lower electrode 15 and each of the upper electrodes 16-1 to 16-N, and the filaments 30, the wires 3, and the strip 32 can be welded into one body. The above-mentioned welding power supply unit 11 can convert three-phase AC power supply 10 into high-frequency AC (4KHz) 'required for multi-point welding and generate AC waveforms suitable for multiple points ¥ connected to the object to be welded. -Constructor of DC-AC conversion. ! The welding power supply unit 11 that can achieve this is shown in the second figure, which is composed of: a converter for converting three-phase AC to DC 丨 11; DC generated by converter 1 1 1 A capacitor 1 1 2 whose output is smoothed, and a reverse converter 1 1 3. Which converts the smoothed DC to an AC of a certain frequency. The AC output terminal of the above-mentioned reverse converter 1 1 3 is shown in the first figure: it is connected to the welding transformer! The primary coil 131 of 3 and the two ends of the secondary coil 132 of the welding transformer 13 are connected to a rectifying circuit 14 for full-wave rectification of the high-frequency alternating current I induced by the secondary coil 132. Loop 1 4 is mainly composed of semiconductors D1 and D2. i The positive (+) output terminal of the above rectifying circuit 14 is as shown in the first figure. | It is connected to the lower electrode 15 through the power supply line LA. Furthermore, the negative (a) output terminal of the rectifying circuit 14 is a medium. The power supply lines L-B LN are connected in parallel to each of the upper electrodes 16-1 to 16-N. Moreover, the negative (a) output terminal of the rectifying circuit 14 is connected in series with each upper electrode 16-1 to 16-N, which is useful for individual pairing.

Page 10 V. Description of the invention (7) i. The switching of each upper electrode 16-1 ~ 16-N is controlled by switching elements such as SCR or metal oxide semiconductor (MOSFET). 17- 卜 Π-N ° : The control unit 1 2 is mainly used to sequentially control the power on and off at each switching element 1 7- 1 ~ 1 7-N at a certain time and interval, and control the directional converter 11 3 to generate a preset As shown in the figure, the welding current value of the current value and the energizing time is as shown in the figure, and it has cpp 1 1 2 which controls the entire control section 12 and a connection to this CPU 121 via a bus 122. M 123 and RAM 124. In addition, the CPU 121 is connected to a setting input interface 125, a display output interface 126, a command output interface 127, a current sensing input interface 1 2 8 and a switching element control input interface via a bus 122. 1 2 9. The above ROM123 is stored with:-a program that can process the input data required for setting the multi-point welding: current value and the time it is energized, one that can set the control or switching element 丨 7_ 1 ~ 1 7-N A program for processing input data at the time of the conduction sequence and a time interval for conducting the same, a program for displaying and processing the input setting data, and a program for setting the welding current value and the current sensor 18 The current value is compared with the data such as the program. i The above-mentioned RAMI 24 stores the calculation results and input settings of cp [J i 21 | welding current value and its conduction time data, or the conduction sequence of switching elements, and conduction time interval data, etc.丨 The above-mentioned setting input interface 125 is an interface that is connected to the input section 19 composed of a keyboard or the like. 'Operating this input section 丨 9 can input data of welding current value and time for conducting multi-point welding or Or the conduction sequence and conduction time interval of switching elements.

Page 11 ^ 〇8832 V. Description of the invention (8) The above-mentioned display output interface 126 is used as an interface between the display and the display 20 composed of the LCD and the like, and the display 20 is configured so that the input 1 9 Those who enter various setting data for display. The above-mentioned instruction output interface 127 is connected to the D-A conversion section 21, and the 1 D-A conversion section 2 1 is a set current value obtained by executing a comparison processing program with the CPU 1 2 1 and the current sensor 1 8 The comparison calculation result between the sensed current values changes: the analog signal is output, and the converter instruction output by the DA conversion unit 21 causes the signal to be input to the pulse width modulation circuit 22. Moreover, the pulse signal output from the pulse width: modulation circuit 22 is supplied to the reverse converter 11 3 via the driving circuit 23 to control the converter 11 3 to generate a welding current corresponding to the set value. . The above-mentioned sensing current input interface 128 is connected to an AD conversion unit 24 which converts the welding current sensed by the current sensor Y 18 into a digital signal, and thereby the AD conversion unit 24 converts the welding current into a digital quantity. Then it passes: Input interface 1 28 for sensing current enters CPU 1 2 1 and compares calculation with the set current value. The above-mentioned switching element control output interface 1 2 9 is connected to the switching element I: selection, driving circuit 25. This switching element selection and driving circuit 2 5 is based on the switching element control signal S1 outputted from the control unit 12 through the switching element control output interface 129 during the welding process i 丨 and will be used to sequentially select the switching elements 17 -7-N and make it output the gate signal with the set time to turn on i !; And the output terminal of this switching element selection and driving circuit 25 is connected to each 丨

I Gates of switching elements 17-1 ~ 17-N. : The above-mentioned switching element control signal S1 is generated by the CPU 121 and based on 45 883 2 i. V. Invention Description (9) | RAM 124 The conduction order and conduction time interval of the switching elements are stored. The output interface 29 outputs to the switch element ii component selection and drive circuit 25. ί Furthermore, the above-mentioned input section 19, CPU 121, and ROM; l23 constitute a predetermined setting means for setting the conduction sequence and conduction time of the switching elements described in the patent application, and the welding current. The setting means for setting the current value and its on time, and the control section 1 2, the pulse width modulation circuit 22 and the driving circuit 23 constitute the control section of the converter 113 described in the scope of the patent application. Secondly, the operation of the embodiment of the resistance coupler with the above structure 丨 i will be described in detail. i Firstly, the welding current value necessary for the multi-point welding of the object to be welded A: the setting of its conduction time, and the conduction sequence of switching elements 17-1 to 17-N I 丨 and its conduction time interval Explain it. j In this case, the control unit 12 is set to the data setting mode by using the keys set by the operation input unit 19, and the welding current value of the object to be welded A and its conduction time are selected as the setting mode. And in this state, the operation input unit 19 '俾 will input the welding current value and conduction time suitable for each welding part of the object to be welded a, for example, a welding current value of 4 〇 A and i 10 Power-on time is entered ° The welding current value that has been entered and the data between I and I when the power is turned on are entered into the CPU 1 2 1 by the input interface for setting 1 25, which is executed in accordance with the processing program spilled from the ROM 123. After processing, it is stored in the RAM 124r as i setting data. jLL ndt, the setting data of the welding current value and energizing time that have been input are

45 883 2 '' — ._ · " ". —— ~~~~~~-.. ..__________- 5. The invention description (10) is displayed on the display section 20. Therefore, by viewing the values displayed on the display section 20, it is possible to confirm whether the input welding current value and the energization time are suitable for multi-point welding. r Furthermore, when setting the conduction sequence of the switching elements 1 7-1 to 1 7-N and the conduction time interval thereof, the control unit 12 is set to the conduction sequence and conduction time interval setting mode. In this state, when the input unit 19 is operated, the conduction sequence and the conduction time interval are inputted. For example, the switching elements 1 7-17 1-N are set to conduct the conduction action in this order, and the switching element is set. The on-time of 17-1 ~ 17-N is set to 40ms. The turn-on turn-on sequence and its turn-on time data are entered into the CPU 121 through the input interface 125 for setting, and the processing I set by the processing program read from ROM 1 23 is executed as setting data. It is stored in the RAM 124. | At this time, the inputted conduction sequence and the setting data of the conduction time interval are displayed on the display section 20. Therefore, by looking at the value displayed on the display section 20, it can be confirmed whether the entered conduction sequence and the conduction time interval are: values suitable for multi-point welding. Secondly, the field of the resistance welding machine is controlled based on the above setting data.

丨 To explain. I!; In this case, first, the predetermined key of the input section 19 is operated, and the |; control section 12 is set to the welding mode, and then the predetermined key of the input section 19 is operated. Welding material A multi-point welding setting information. At the same time, by means of an insertion device (not shown) such as a robot controlled by a program, as shown in the first figure, the filament 30, the lead 31 and the strip 32 are arranged in a certain arrangement and stacked on it. For the lower electrode 15 above the welding jig

458832 V. Description of the invention (11) The i-plane, and then the upper electrodes 16-1 to 16-N corresponding to the arrangement of the filaments 30, are pressed against each other and held on the strip-shaped material 32. I After holding down, and inputting the start signal from the programmer to the input section 19, first, the switching elements 1 7- 1 to 1 7-N are stored by the CPU 1 2 1 based on the RAM 1 24. The conduction sequence and conduction time interval data generate a switching element control signal S1. The switching element control signal S1 is output through the switching element control input interface 129 and then output to the switching element selection and driving circuit 25. This switching element selection and driving circuit 2 5 can select switching element 17-1 'and can supply the gate signal to the gate, so that the switching element 17_ 丨 丨 reaches the on state for a set time, such as the on state of 40 ms . On the other hand, while the switching element 17-1 remains on, the set current value data selected from the RAM 124 is output to the DA conversion section 21 through the command output interface 127 |, and then converted to the analog by the DA conversion section 21. The signal 'i' is input to the pulse width modulation circuit 22 as a converter command signal. The pulse width modulation circuit 2 2 is a pulse signal after the pulse width modulation | is supplied to the inverter 113 via the driving circuit 25, and also drives the inverter i 113 to convert the current The DC output from the converter 1U is converted by a smoothing capacitor 112 into an AC with a certain frequency. The high-frequency AC is converted into low-voltage and high-current power by welding the transformer 13. The power is converted to DC by the rectifier circuit 14 and then supplied to the lower electrode 15 and the upper electrode 16-1 Between the welded parts, and welding is applied to this welded part 丨 the energization time at this time is about 10 ms. I. Furthermore, when the welding current flows between the lower electrode 15 and the upper electrode 16_1 I, the welding current is sensed by the current sensor 18. This sensing

45 8Θ3 2; V. Description of the invention (12) The welding current is converted into a digital quantity by the A-D conversion unit 24, that is, it flows into the CPU 121 through the input interface 128 for sensing current measurement, and does the same as the set current value. Compare calculations. I Also, the comparison result is input to the pulse width modulation circuit 22 through the command output interface 127 and the DA conversion unit 21, and in order to make the comparison result; the deviation is equal to zero, and the change is output by the pulse width modulation circuit 22 The pulse signal width is used to control the converter 1 1 3 so that the welding current supplied to the welding portion between the lower electrode 5 and the upper electrode 16-1 reaches a set value. Therefore, after the on-time of the above-mentioned switching element 1 7 -1 has elapsed (this on-time i is controlled by the timer (omitted in the figure) and [pu 1 2 1 j controlled by the control unit 12]), the switching element controls The signal S1 is updated to select the switching element 1 7 _ 2. The updated switching element control signal S1 is output to the switching element selection and driving AC power through the switching element control output interface 129; 2 5. Therefore, the switching element selection and driving circuit 2 5 select the switching elements 1 7-2 and supply the gate signal to the gate, so that the switching element 丨 7 _ 2 is achieved. The ON state of the set time is, for example, 40 ms. On state. Secondly, as in the case of the above-mentioned switching element 17-1, a set welding current is supplied to the switching element 17-2 for a set time to connect the welding portion between the upper electrode 16-2 and the lower electrode 15 ' Welding is performed on this welding portion. In the following, the same as the above-mentioned case, 'the switching element control signal S 1 is updated by connecting a welding part every time, and the switching elements 1 7-3 ~ i and N are switched and turned on in this order' During the on-time of 17-3 ~ 17-N 'will be supplied to these switching elements 1 7-3 ~ 17-N

45 883 2 V. Description of the invention (13) —:

I | Welding current of each welding part between the poles 16-3 ~ 16-N and the lower electrode 15, 丨 _ | is controlled to a set value by the reverse converter 1 1 3, so that the welded parts can be sequentially welded.丨: Welding is performed on each welding part of the object A. The fourth diagram is to sequentially turn on the switching elements 17-1 ~ 17-N to make Tan. 丨

i The waveform of the welding current when the current flows through each welding part between the upper electrode 16-3-16-N and the lower electrode 15 D According to the embodiment of the present invention described above, the reason is that the control unit 12 and the switching element | Components, drive circuit 25, and the switching elements 17_1 to 171 provided to each upper electrode i 1 6-bu 1 6-N are sequentially controlled at a set time interval, and during this conduction period, every When a switching element in a conducting state is connected to the upper electrode corresponding to the welding part A of the welding object A and welding i is applied, then a certain welding current suitable for each welding point can be stably supplied, and Homogeneous welding of welding points, which can reduce the defect rate of the product, can also use only one transformer to achieve the welding work and reduce the transformer capacity. Moreover, according to the above-mentioned welding current waveform of the present invention, it is not limited to the simple waveform not shown in Fig. 4; the welding current waveform of the present invention can also be set to | Waveform. The resistance welding machine according to the present invention is not limited to those shown in the above embodiment I where the filaments and wires of the fluorescent display tube are subjected to multi-point welding, but also applicable to other multi-point welding of objects to be welded A But it goes without saying. : — The above-mentioned embodiment is to add β to the semiconductor on the secondary side of the welding transformer and rectify the i-line, and this switching element composed of sc R 1 7 _ 1 ~ 1 7-Ν to I to be welded The case where the current A is controlled by on / off control will be described; however, the present invention is not limited to those described in the above embodiments.

V. Description of the invention (14) | For example, 17-1 ~ 17-N, the switching element current for the 丨 system is directly connected to the transformer for AC control 1 3, and the borrowing and connection are also based on the above: time interval pair丨 system, and here: the lower switch element 丨 is applied with welding current yield of welding, and it can be converted from 1 I current to i current converter. According to the conducting sequence of this issue I, the switching element composed of SCR shown in the first figure of this issue can be replaced by an AC control such as a three-terminal triac switching element, and the inductance induced by the secondary side of the welding transformer It is also feasible that Jiaotao supplies to the welding electrodes and the current of each electrode is controlled by the switching element. In this case, the rectifying element can be omitted on the secondary side of the welding. Furthermore, in this field, the special welding effect which makes the welding result different due to the polarity of the current. In the embodiment of the present invention, since the switching element provided by each of the upper electrodes is set to sequentially perform the conduction control conduction period by the control unit, one electrode pair is in a conducting state at a time | the upper electrode connected to the element Corresponding welding of the welding object. It can then stably supply a certain amount of I suitable for each welding point, and perform homogeneous welding on the welding points to reduce the inferiority of the product and achieve a small capacity of the welding transformer. The welding power supply unit according to the present invention is provided with a method for converting the direct current output from a commercial AC-DC rectifier into high-frequency alternating current: a detailed welding electrode system capable of generating a detailed welding bead suitable for multi-point welding can be set by Device, and arbitrarily set each switching element and its on time. It is clear that because it has a current value that can set the welding current and the time when it is energized, it can arbitrarily set the connection position and its energization time suitable for the welding part.丨 Setting equipment i Welding current value j

Page 18 45883 ^ Five 'invention description (15) Moreover, according to the present invention, the sensed value sensed by the sensor can be fed back to the converter, so that the welding current of each welding part can be controlled to a set value . Brief description of the drawings: i The first drawing is a schematic diagram of the overall structure of the embodiment of the resistance welding machine of the present invention. The second diagram is a block diagram showing the internal structure of the welding power supply unit in the first diagram. The third figure is a block diagram showing the internal structure of the control section in the first figure. The fourth figure is a diagram of current waveforms leading to each welding point according to the embodiment of the present invention.丨 In the picture: A… to-be-welded, 1 0… AC power supply, 11… welding power supply section, 丨 1Π… converter, 112… smoothing capacitor, 113 reverse converter, 12… 丨 control section, 121… CPU, 123 ... ROM, 124 ... RAM, 13 ... welding transformer | voltage transformer, 1 4 ... rectifier circuit, 1 5 ... lower electrode, 1 6 -1 to 16-N ... upper electrode, 17-1 to 17-N ... Switching element, 18 ... current sensor, 19 ... input section, 20 ... display section, 2 1 ... DA conversion section, 22 ... pulse width modulation circuit 2 2, 23 ... drive circuit, 24 _... A-0 conversion 25, switching elements, selection, driving circuit. i

Page 19

Claims (1)

45 883 2 丨 VI. Scope of patent application 1 -----------! 1 'resistance welding machine, which has a welding power supply unit and a conversion of AC power output from the welding power supply unit to low voltage, High-current power i: Connect to 5 voltage transformers; and supply the current induced by the secondary side of the welding transformer to 'to the welding electrode' or rectify the secondary side of the welding transformer; the induced current is rectified It is then supplied to the welding electrode to form a multi-point resistance welding machine for the object to be welded; characterized in that the welding electrode is provided by an object to be welded; the upper electrode, the lower electrode, and a plurality of A plurality of welded parts abutting the welded object press the welded object on the upper electrode of the lower electrode! Composition: The power supply lines are connected to the output terminals connected to the rectifier circuit and the upper electrodes. On the road, switching elements are respectively connected in series, and a control unit is provided to sequentially control each switching element at a set time interval. : 2. The resistance welding machine according to item 1 of the scope of the patent application, wherein the welding | power supply unit has a converter that converts commercial AC power to DC, and i converts the DC output from the side converter to high The inverter with a high frequency AC, i, is a structure that can supply the high frequency AC transformed by the inverter to the primary side of the welding transformer. 3. According to the resistance welding machine described in the first item of the scope of the patent application, wherein the control | section has a sequence that can be set in advance to set the above-mentioned switching elements to 丨 on, and the on-time of each of the above-mentioned switching elements can be set arbitrarily The setting device, and the switching elements selected sequentially according to the information set by the setting device, and the switching element selection and driving circuit that turns on the switching elements only during the setting time. i Page 20 45 883 2 — — _____ — 6. Application for patent scope; 4. The resistance welding machine according to item 1 or 2 of the scope of patent application, in which the lower electrode and the upper electrode are provided with A setting device for arbitrarily setting the welding current value and the energization time supplied to each of the above upper electrodes; and a control section that controls the reverse current converter so as to obtain the current value and the energization time set by the setting device. ： I 5. The resistance welding machine described in item 4 of the scope of the patent application is equipped with a sensor that can sense the welding current of each welding part during welding, and borrow!: I The above sensor The sensed value is fed back to the inverter control unit to control the welding current to a set current value. Page 21