Showing papers on "Spot welding published in 1982"

Resistance spot welder adaptive control

Abstract: The adaptive controller for a resistance spot welder is implemented with a microcomputer and peripherals to handle the monitoring of several process variable inputs and control the welding machine in real time. Before welding power is applied, electrode load, workpiece thickness and dynamic resistance are measured and must fall within predefined limits in order to continue. The workpiece, if necessary, is conditioned to correct fit-up and surface contamination problems by applying power pulses to lower its resistance. The welding power in each half cycle is dynamically adjusted as a function of workpiece thermal expansion and its first derivative to control formation of the weld nugget, and to control the cooling rate and temper the workpiece. During welding the power limits are adjusted in real time to compensate for electrode flattening and shunt effects. The quality of each weld is diagnosed and machine diagnostics are performed.

Method and apparatus for controlling resistance welding

Abstract: Method of controlling resistance welding to obtain high quality welds in which the pressure between the electrodes (2a, 2b) holding the materials (1a, 1b) to be welded is controlled so that the resistance value between the two electrodes (2a, 2b) is a predetermined value, and the welding current is regulated so that the voltage between the electrodes is a predetermined value, and the time during which the welding current flows is controlled to a fixed period.

Manufacture of spiral battery

Abstract: PURPOSE:To prevent any generation of defective welding and internal short circuits by facilitating spot welding of a battery case and a lead member by using a spot-welding electrode as a core for the formation of a spiral electrode. CONSTITUTION:A negative plate 1a prepared by pressing and fixing lithium to a stainless steel perforated metal, and a positive plate 1b prepared by packing a positive mixture containing manganese dioxide as an active material into a welding metallic net before this is wrapped in a separator 1c are superposed on each other. Next, the thus prepared body is rolled around a copper bar (A) which is used as an electrode in spot welding thereby making a spiral electrode 1. After the electrode 1 including the copper bar (A) is inserted into a battery case 2 on the bottom of which an insulating ring 3 is placed, a lead member 4 attached to the end of a negative plate is spot-welded to the bottom of the case 2. Next, an insulating ring 5 is placed on the spiral electrode 1 before electrolyte is poured, then a positive-side lead member 8 is connected to a metallic washer 7, attached to a sealing plate 6, by spot welding or similar method. After that, the sealing plate 6 is placed on a stage part 2a so as to seal the opening end of the case 2 thereby constituting a spiral battery.

Connecting method of sheet

Abstract: PURPOSE:To reduce the cost for cutting thin sheets and to improve the efficiency in connecting and welding the sheets in a connecting method of the sheets, by overlapping the sheets with each other and tack welding the sheets by arc spot welding then welding the connecting parts of the sheets over the entire circumference. CONSTITUTION:A base material 1 is disposed on the bases of the side A or B, and a base material 1' is disposed in overlap on the material 1. The lap part 2 of the materials 1, 1' are tack welded by arc spot welding 3. Thereafter, the part shown by 4 or 5 or if necessary both parts 4 and 5 are subjected to fillet welding over the entire circumference. The above-mentioned operation is accomplished with several sheets of the base materials until the sheet of a desired size is obtd.

Spot welding method for aluminum alloy

Abstract: PURPOSE:To perform spot welding of Al alloys with a general spot welding machine of single phase AC by interposing straps of a metallic material of lower heat conductivity and electric conductivity than tnose of materials to be welded and a higher m.p. temp. between electrodes and the materials to be welded. CONSTITUTION:When materials 2a, 2b to be welded which are Al alloy plates are grasped by an upper electrode 1a and a lower electrode 1b via straps 4a, 4b under pressure and are electrically conducted under the same conditions as spot welding conditions for mild steel, a molten part (nugget) 5 of an hourglass shape is formed. A metallic material of heat conductivity and electric conductivity lower than those of the materials 2a, 2b, and a higher m.p. temp., for example, a mild steel plate, an alloy steel plate such as stainless steel plate, a high carbon steel plate or the like is used for the straps 4a, 4b. Thereby, the spot welding of Al alloys is easily accomplished under the welding conditions (low electric current) similar to those in the case of spot welding of mild steel plates, by using an ordinary portable spot welding machine.

Magnetic head comprising two spot welded metal plates

Abstract: A magnetic recording head may be assembled from laminar plates of ferromagnetic material which are welded together by spot welds to form a core stack. The core stack is welded by spot welds (E, F, G) to a base plate (16). The ferromagnetic material is typically an alloy of Si, Al and Fe and tends to produce stress cracks around the areas of the welds. In order to overcome this problem, the edges of the plates, at least around the areas of the welds, and provided with a layer of ductile metal such as Ni, Fe or Mo. The layer is between 5 and 500 μm thick. The depth of the welds is arranged to lie substantially within the ductile metal layer.

Portable spot welding device

Abstract: PURPOSE:To provide a titled device which can weld the work without leaving any trace of spots on the outside surface thereof by connecting a cylinder side electrode tip of a portable welding gun to be brought into contact with the welding place of the work and an electrode plate placed on the nonwelding part of the work electrically. CONSTITUTION:A door 5 of an automobile before welding is placed in the prescribed position on the wooden post 32 of a working table 34. An electrode plate 38 hoisted above the table 34 by means of a spring balancer 42, a wire rope 43 and a cable 40 is lowered down to the prescribed position of an inner panel 3 of the door and a spring 3 is sandwiched by pressure with clamps 39. As a result, electric current is flowed from the other secondary terminal 20 of a welding transformer 11 to a cable 21, a cylinder 27, a piston rod 26, an electrode tip 29, the side seamed part of an outer panel 4 of the door, the panel 3, the plate 38, the cable 40 and the terminal 20, whereby the side seamed part of the panel 4 and the panel 3 are indirectly welded. This welding work is executed with a required number of welding places 30 by rotating the rotatable table 34.

Joining two metal strips coated with insulating material - where heated spot welding electrodes are used to melt coatings before making spot welds in lap joint

Abstract: The tail end of one strip is placed over the front end of another strip so the ends overlap. Heated spot welding electrodes are first used to melt the insulation present on at least one side of each strip, and are then employed to make spot welds, so the lap joint will withstand tensile and bending stresses. The insulating coatings may be made of a polymer. The adjacent ends of the two strips are pref. first cut obliquely, esp. at 30 deg., and then the overlapping ends are stuck together by heat before being further heated by the spot welding electrodes. Each electrode is pref. provided with an electric resistance heating coil, and the electrodes may consist of rollers producing seam welds. Process is used esp. where the strip is to be wound round a cable, where continuous strip is required, and where the joints must be strong and will conduct electricity.

Manufacture of battery with coiled electrode body

Abstract: PURPOSE:To increase the current collecting part of a battery by placing disclike current collecting bodies, each being made of a plain metal plate and integrated with a lead piece, on upper and lower protruding edges of a coiled electrode body, and welding each current collecting body and the coiled body at several spots. CONSTITUTION:A positive and a negative electrode 1 and 2 for a cylindrical battery are vertically moved from one another, before a separator 3 is interposed between the electrodes 1 and 2 and these three are rolled into a coiled body. Disclike current collecting bodies 4 and 7 made of a nickel plated plain steel plate are placed at the top of and the bottom of the coiled body, before each of the bodies 4 and 7 is fused to a plural number of protruding edges of each of the electrodes 1 and 2 by arc spot welding. In the former arc spot welding, an arc spot welder 9 having pressing parts 10, a welding electrode 11 and inert gas supply holes 12 is used. By the means mentioned above, part of the bodies 4 and 7 can be molten with relatively small pressure, and welding of satisfactory intensity can be performed by fusing several spots. Consequently, the strong discharge characteristic of a battery can be enhanced by increasing the current collecting part of the battery.

Compact tool for automatic MAG spot welding

Abstract: In a compact tool for automatic MAG spot welding, all of the elements are located close to the welding zone and a single set of props both support the articles to be welded and provide a negative electrical current contact A welding head is slidably supported upon a base which is connected to a robot arm by quick release couplings The base further supports a welding wire reel and brake while the head supports the torch and a welding wire drive device Props on either side of the welding zone press the article to be welded and provide negative electrical current contact

Control appts. for multiple programmable welding stations - esp. for computer controlled spot welding of motor car bodies, where read-write memory can alter welding parameters

Abstract: Each welding station has its own independent, programmable electronic control unit (ICU). Between all the ICUs and a central computer is a control appts. for adjusting and displaying the welding program parameters (WPP). The control appts. is connected to a memory store (I) contg. the working programs for each ICU, and to a read/write memory (II) for the WPP. Memory (II) has storage stations for each WPP; for the numbers of each welding program and each ICU; and for each type of welding. All these stations can be directly addressed by a switchboard actuated by a digital keyboard. Used e.g. with a multiple spot welding appts. for mfg. motor car bodies. All the WPP can be displayed for each ICU and easily altered with min. loss of prodn. time.

Method and apparatus for observing welding strength in spot welding

Abstract: PURPOSE:To detect strength of spot welding at high accuracy by taking out only true component of voltage between electrodes that acts as an effective component in spot welding. CONSTITUTION:Voltage generated by a zinc plating layer is detected from voltage between electrodes impressed between two poles of an electrode of a welding gun. Induction noise component and welding gun electrode resistance component are removed from the voltage and detected voltage, and remaining component is integrated. The integrated value of effective component is obtained by subtracting a value obtained by integrating minimum voltage during conducting time from this value. This is compared with a preset reference voltage value, and welding strength is observed by the result of comparison.

Spot welding device

Abstract: PURPOSE:To facilitate carrying of objects to be welded by connecting a secondary side terminal of a welding transformer to the first plate and another one to the second plate and forming a circuit that connects the first and second plates when the place to be welded is held by the two electrode chips connected electrically CONSTITUTION:A receiving face 36 that supports an object 5 to be welded, for instance the door of an automobile, having welding position 27 superposed each other, the first plate 38 fitted to the receiving face 36 in insulated state and the second plate 45 which is near the part other than welding part of the object 5 to be welded and can be connected to the above are installed One of secondary side terminals 41 of a fixed welding transformer 31 is connected to the first plate 38, and another secondary side terminal 47 is conncted to the second plate 45 Two electrode chips 59, 60 of a welding gun 62 that presses the position 27 to be welded are connected electrically The position 27 to be welded is pressed by these electrode chips 59, 60 to form a circuit that connects the first plate 38 and the second plate 45

Projection for aluminium sheet projection welding - with specified base diameter and height for conical dimple

Abstract: A projection welding system for parts made of aluminium sheeting uses projections in the shape of a cone with an outside dia. at the base of the convex cone of two to three- times the sheet metal thickness. The height of this cone is not less than the thickness and not more than twice its value. A projection with the suggested geometry is capable of absorbing the prepress force of the electrode which is required for the welding operation and concentrates the electrode force and welding current at the predetermined spot in the optimum fashion.

Measuring device for welding current

Abstract: PURPOSE:To eliminate the variance in the output voltage of a coil and know an accurate current value by interposing and fixing a rectangular conducting piece wound with the coil on the outside circumference in close contact therewith to part of the secondary circuit of a welding machine. CONSTITUTION:When a coil for measuring welding current is used for a multispot welding machine, a rectangular conducting piece 6 wound with a coil 5 in close contact therewith is connected to one of the output terminals T1, T2 of a welding transformer T, and cables 7, 8 are connected to this piece 6 and the other output terminal T2 and are respectively connected to the holders 9, 10 of welding guns G1, G2. This case is series spot welding, wherein it turns out that spot welding of two points is accomplished with one welding circuit by using a back bar. The above eliminates the variance in the output voltage of the coil, and facilitates setting of welding conditions. Since the device is fixed to the secondary side of the welding machine, there is no moving in the and of a toroidal coil as on the prior art, and the failure of the coil itself is prevented.

Spot welding equipment

Abstract: PURPOSE:To make shifting of electrode at high speed in pressurizing and releasing of a large-sized welding gun by making pressurizing and releasing action of electrode with a direction change valve through each pressurizing cylinder. CONSTITUTION:When pressurizing an electrode, air from an air source 12 is led into head side acting chambers C, C of pressurizing cylinder 2, 3 by a direction change valve 9 through a flow control valve 10 and a conduit 7 to move pistons 4, 4. Electrodes 6, 6' collide against both sides of a plate 13 to be welded and come to a stop. When air is sent further in succession, pressure in the conduit rises to actuate an opening and closing valve 11. Then, a large quantity of air flows into chambers C, C to raise electrode pressurizing force. Welding is performed by flowing current through electrodes 6, 6'. In releasing, when a valve 9 is changed, air enters into rod side acting chambers D, D of each cylinder 2, 3 through a conduit 8 to puch back pistons 4, 4. Thus, electrodes 6, 6 are released from pressurized state at a stroke.

Manufacturing the peripheral wall of a tank for an oil-immersed electric apparatus

Abstract: A method of manufacturing the peripheral wall of a tank for an oil-immersed electric apparatus which comprises manufacturing a panel unit through the steps of: fabricating a panel by pressing a thin steel sheet to form an upward extending flange along both edges of the panel and provide a plurality of reinforcement depressions concaved toward the backside of the flat portion of said panel; folding the panel into two parts with the surface of the panel kept outside along the central line extending between both edges of the panel to fabricate a hollow fin; joining both sides of the folded fin by spot welding the reinforcement depressions; and welding together the closely facing edges of both sides of the fin, and constructing the peripheral wall of the tank by joining together a plurality of panel units fabricated through the above-mentioned steps by welding the flanges of said panel units.

Spot welding method

Abstract: PURPOSE:To form stable weld zones in the stage of spot-welding metallic members having a large difference in melting temp. by providing a hole in one of the metallic members and press contacting a specific base piece in said hole then pressing the another metallic member thereto and spot welding the member. CONSTITUTION:In the stage of spot-welding a heating wire 6 consisting of a nichrome wire in a thermal overload relay to a connecting plate 8 made of brass, there is a large difference in melting temp. between both metallic members; therefore, the formation of spot-weld zones of good quality is difficult. In such a case, a through-hole 81 of a circular or square shape is pierced in the plate 8, and a base piece 10 of phosphor bronze or Fe-Ni ''Imvar '' which can be welded to both of nichrome wires and brass is inserted therein, and is pressurized from both sides E to expand the parts extruded to the outside from the hole 81. The wire 6 as heating metal is pressed to this part, whereby the wire is spot- welded. The stable weld zones of both metallic members are formed with the piece 10.

Laser welding method

Abstract: PURPOSE:To execute spot welding extremely easily by opening an under hole to a material to be welded by the first irradiation of laser and welding the materials to be welded by the second irradiation CONSTITUTION:The 1st irradiation generates energy by a laser 5 and works an under hole 6 The diameter of the under hole is 60-70% the spot welding diameter and arrives slightly at a material 2 to be welded A part of a material 1 to be welded and the material 2 are melted simultaneously by the 2nd irradiation of the laser 5, whereby a sound molten metal 3 is obtained and the material 1 is thoroughly welded to the material 2 Since the laser 5 is irradiated to the metal 3 at the same center as that of the hole 6, a sufficient joined area is obtained without deviation to one side

Detection of melt-sticking of electrode tip for spot welding

Abstract: PURPOSE:To make constitution simple and detect the melt sticking defect owing to the melt-sticking of electrode tips surely by detecting the melt-sticking of the tips with an electric current and voltage detecting means and announcing this with a signal generating means. CONSTITUTION:When electrode tips 1, 1' are normally opened from objects 5 to be welded during open time without causing melt-sticking, no electric current and voltage are detected by an electric current and voltage detecting means 3 despite the supply of test current from a current supply means 2, hence a signal generating means 4 emits no signals. Next, in case the tips 1, 1' are stuck by melting, a welding circuit is conducted via the conductive objects 5 upon supplying of the test current from the means 2, and the current is detected with the mens 3. This is transmitted to the mans 4, which in turn generates a prescribed signal, thereby announcing the occurrence of the welding defect owing to the melt-sticking of the tips. Hence, the required detection is accomplished without providing any melt sticking detecting circuit separately to the secondary circuits.

Method and device for monitoring of weld strength in spot welding

Abstract: PURPOSE:To detect weld strength with extremely good accuracy by comparing the integratd value of the voltage drop after the max. value of the effective voltage removed of non-effective components from welding voltage with a reference set value. CONSTITUTION:Out of the voltage V between welding gun electrodes 2 and 3 derected with a detection circuit 8, a component VN is removed with a removing circuit 9 for the induction noise component VN. Following to this, the voltage Vr corresponding to the loss components produced with the electrodes 2, 3 is removed with a removing circuit 10 for the welding gun electrode resistance component Vr, thereby leaving an effective component VR. This is removed of the component VN as the detection current of a coil 15 is processed with a detection circuit 16 and the voltage is detected when dI/ dT=0. This signal goes through circuits 17, 19 and is subtracted by the addition of a circuit 14. The circuit 24 of a processing circuit 11 stores the max. value out of the resultant component VR, and a circuit 25 outputs the difference between this and the value lowered below this, and the decision of goodness is displayed via circuits 26, 28. Here, the integrated value by the circuit 26 has a sufficient correlation with the effective diameter of nugget, and the decision of weld strength is made possible.

Projection welding method

Abstract: PURPOSE:To stabilize the resistance between welding materials and to form weld zones of high quality in the stage of spot welding of thin steel sheets by forming insulation layers beforehand on the welding materials and eliminating the irregular contact in the welding. CONSTITUTION:In the stage of resistance welding of a material 1 to be welded which is a thin steel sheet to a decorative base material 4 by means of plural projections 2, 3, the projection 2 for focusing of electric current is formed on the material 1, after which an insulator 6 of soft PVC or the like is coated thinly. This is set to the material 4, and is pressurized to the material 4 by a welding electrode 7 to break the layer 6 of the part 2 locally, after which a voltage is applied from the electrode 7 to an electrode 8 in contact with the material 4 to flow electric current to the electrode 8 through the electrode 7, the sheet 1 and the material 4, whereby both material are spot welded with the resistance heat of the part 2. There is no generation of stray current on account of the contact with parts other than the projection, and the high quality of the weld zones is obtained stably.

Spot welding method by tig welding

Abstract: PURPOSE:To prevent the generation of blowholes surely and to perform titled spot welding by preheating objects to be welded by the arc for a prescribed time then melting the same by the arc of heat input larger than that during preheating. CONSTITUTION:Materials 8 to be welded are superposed in 2-3 sheets, and insulators 9 are placed therebetween. The upper parts thereof are spot welded by a 2-electrode Tig welding method while a welding torch is moved in a right direction. At this time, a preceding electrode 10 generates an arc 12 on the objects 8 and the insulators 9 to preheat these and to degrease and degas the surfaces of the objects 8. At the same time, the gas produced from the insulators 9 is escaped. Next, weld metal 2 is formed by a succeeding electrode 11. In this case, the DC current supplied from a DC electric power source 13 is controlled of peak current with a peak current control circuit 14, and is supplied to the electrodes 10 and 11. The peak current is changed over by switching circuits 15 and 16 for the preceding and succeeding electrodes. The controlling of these is accomplished by a pulse control circuit 17. The base current is supplied to the electrodes 10 and 11 by a base current supply circuit 18.

Electrode for intermittent welding, esp. spot welding of aluminium - is made of material such as silver so that unsightly marks are not left on workpieces

Abstract: The electrode is used for the welding of material which is a good conductor of electricity, e.g. Al. The material of which the electrode is made forms reaction prods. with the workpiece; and the reaction prods. are easily removed by light mechanical action, e.g. wiping or rinsing, after pickling. The electrode is made e.g. of silver, which is dispersion hardened; reinforced by fibres; or hardened by finely dispersed powder consisting of Al2O3, BeO, SiO2, SnO2, or similar powder. Useful as a replacement of copper electrodes which form black marks on the workpieces being welded. Such black marks are very difficult to remove.

Panel of elevator cage

Abstract: PURPOSE:To increase joining strength and eliminate the formation of dents and strain by concentrating laser spot welding by >=2 points to one joining area in joining a reinforcing material to the rear side of a panel used for an elevator cage. CONSTITUTION:A reinforcing material 5 is welded to the rear side of a panel 1 used for an elevator cage by means of laser welding. At this time, laser spot welding of >=2 points, for example, points C1, C2, C3 is applied to one joining part. Then, the welding strength is assured and the material 5 is mounted without dents and strain which are the characteristics of laser welding.

Welding method of pipe and welding fitting used therefor

Abstract: PURPOSE:To prevent welding defects such as mis alignment and to improve the efficiency of welding, by inserting a fitting pipe between two pipes and by arc welding its two parts as a filler metal with nonconsumable electrode. CONSTITUTION:A pipe fitting 8 is inserted between two pipes 1, 1', and both the ring-shaped projection 9, 9' is fitted to the both end of the pipes 1, 1' and is fixed by clamps 11, 11'. Next, the position of electrode is set by a positioning clamp 12 fitted to a center projected part 10. Then, two position are welded by electrodes 13, 13' utilizing the projected parts 9, 9' as fillers. Before this, water-soluble gas dams 16, 16' has been inserted in the inside of the tubes 1, 1' and protective gas is applied to the inside through a tube 17 by a hole 15 or through a notch at the projected line part of the pipe fitting 8. After the completion of these joint welding, the tube 17 is removed from the hole or the notch, and the hole is closed by spot welding or the like.

Parts fixing device for color cathode ray tube

Abstract: PURPOSE:To perform the accurate positioning by making holes in a mask frame and an inner magnetic shield then fitting the projection on the first and second jigs in said holes and welding them with the welding electrode of the second jig. CONSTITUTION:The left side hole 42 made in a mask frame 41 is matched with the left side hole 42 made in a magnetic frame 43, then the projection 46 of the first jig 45 is inserted into said holes. Thereafter the right side holes 47 are matched and the projection 49 of the second jig 48 is inserted, then the lever of a hand welder 50 is pressed and the spot welding is perfomed by a welding electrode 35 provided on the second zig 48. Thereafter same spot welding is performed at proper positions to fix the magnetic shield to the frame. Consequently the positioning can be performed easily and accurately.