Automobile body is light quantify in making solder technology

8% , CO2 discharge capacity decreases 4.

5% . Accordingly, reducing car oneself weight is the most significant step that drops fuel to use up. Of automobile body light the one big main trend that quantifying a technology is development of contemporary car technology. Occupy recently the project considers to make clear, use material of light qualitative excel in to be able to decrease automobile body heavy 25% . Current, the use of excel in steel occupies automobile body to always be measured with steel about 30% the left and right sides, and this scale still will expand further. Normally for, it is cent of high strenth armor plate steel of common excel in (HSS) with steel of super excel in (AHSS) . Exceed the research of light steel car according to be opposite on international, succumb intensity calls high strenth steel in the armor plate inside limits of 210 ～ 550MPa, succumb the armor plate that intensity is more than 550MPa calls steel of extra high strength. Among them, steel basically includes common high strenth steel of unoccupied place atom of high strenth very close to each other (IF) , aluminous composed steel (roast and AKDQ) , sclerotic steel (BH) with high strenth low-alloy steel (HSLA) ; Steel basically includes super high strenth Shuang Xianggang (DP) , change cause plasticity steel (TRIP) , martensite steel (MS) etc. Steel of excel in of the BH in excel in steel, IF basically uses as cover of door, engine, dashboard and suspender; DP and TRIP use as inside board, motherboard and wheel; Martensite steel (MS) use as bridge of bumper, door. Graph 1 be steel of all sorts of advanced excel in extend gender and intensity character to contrast, this shows, shuang Xianggang has higher intensity and better outspread rate, a perspective is the widest kind of new-style data uses in becoming automobile body to make. Graph intensity of all sorts of 1 steel of advanced excel in and extend a gender comparative Shuang Xianggang applies extensively in reduce while the car is heavy, also assemble to automobile body join raised new requirement. Resistance welding is made as automobile body in one of the vitallest join technology, spot welding quality of Shuang Xianggang is controlled and detect also become more and more important. The electrode pressure of traditional pneumatic welding torch by air cylinder drive, cannot get be controlled accurately and assuring, hand in vintagely change voltaic welder solders electric current is not smooth, and suffer a net to control fluctuant impact bigger, cannot have gotten used to new material gradually solder. In recent years, new-style servo welding torch uses electrode of drive of servo electric machinery, can control electrode pressure accurately. Dc of intermediate frequency inversion (MFDC) welder is controlled with the electric current with its fast speed, smooth response, get more and more extensive attention, be new material solder quality control offerred good solution. Shuang Xianggang solders because special phase is used to change when preparation,craft improves Shuang Xianggang aggrandizement handles technology, look from phasor, its martensite becomes critical the curve slants left, when undertaking resistor spot welding, the high temperature austenite after fusing is being protected in controlling a process, cooling process curve can pass through its martensite becomes critical area, different content and the martensite that distributing are formed in nucleus of the frit after causing solder, cause frit nucleus division more fragile, tensile strength of solder dot cross and function of low week exhaustion not beautiful. When the pneumatic welding torch that uses convention and communication welder undertake soldering, because uncontrollable electrode pressure reachs voltaic wave motion, solder to assure quality, use normally bigger solder electric current, can cause the generation when soldering very big splatter. New-style servo welding torch and dc of intermediate frequency inversion solder of voltaic controller introduce, make solder the electrode pressure in the process and voltaic control become a possibility. The servo welding torch of Shanghai global scene has C model, X with P model, it is with C gun exemple, its structure is shown 2 times like the graph. Compare with photograph of traditional pneumatic welding torch, motor of use servo of servo welding torch will drive ball guide screw (Ball Screw) or lever guide screw (Roller Screw) rotate, with drive electrode lever linear fluctuation moves, realize pressurization and soldering whole process. Because the digitlization of servo motor is controlled, compare with photograph of traditional pneumatic welding torch, servo welding torch is like next character: Graph structure of 2 servo welding torch pursues 1.

Electrode movement position and speed can accuse accurately, can realize the soft contact with workpiece on one hand, reduce concussion noise, prolong electrode life; On the other hand, make electrode opens extent to be able to accuse, the robot runs orbit to be able to realize optimization, reduce needless travel. 2.

Whole solder the electrode pressure in the process can accuse, its pressure adjusts speed can amount to 200kgf/cycle(10kgf/ms) , can avoid well and restrain splatter, assure effectively and rise solder quality; When undertaking tube plate solders, the character with electrode adjustable pressure can reduce a canal solder be out of shape, prevent crackle generation. 3.

Those who use electric energy of servo welding torch spend cost under compress airy to spend cost, can achieve energy-saving result. 4.

The information of dynamic electrode displacement that feedbacks through coder of servo electric machinery can mirror solder to nod quality secondhand, quality of the drop that it is solder is online monitor offerred a possibility. Welder of dc of intermediate frequency inversion (MFDC) is labour frequency (50Hz) communication commutation is intermediate frequency (output of 1 000Hz) dc, time resolution rises than labour frequency, control precision also rises, and output electric current does not suffer effect of change of sub output return, thermal efficiency is taller also, output power is very great also, solder quality is better also. With tradition communication welder photograph is compared, be like next character: 1.

Solder quality: The adjustment that is versed in frequency communicates welder is periodic and longer, to the electrified wire netting of 50Hz, resolution of weld time adjustment is 20ms. Time of machine of inversion dc spot welding adjusts resolution can amount to 1ms (frequency of 1 000Hz inversion) , control precision is tall. Pilot of inversion welder feedback answers speed to be accelerated apparently, output stability is good. Because electric current crosses the influence of 0,labour frequency communicates welder, thermal efficiency is low, canal of the brake that use any crystalline substance adjusts electric current, slant when voltaic per cent hour, cross zero time to grow, the impact is bigger; Machine of inversion dc spot welding outputs electric current to be pulsatile dc, successive dc is to output below the action of loop inductance, thermal efficiency is tall, solder hot input is stable. 2.

Solder speed: Because electric current crosses the influence of 0,labour frequency communicates welder, heat time is relatively longer. Machine of inversion resistor spot welding is dc to output, heat concentration, weld time shortens. 3.

Energy-saving effect: Work of engine of spot welding of labour frequency communication is in 50Hz, transformer loss is big, welder power factor is low, loop loss is big. Job of inversion welder transformer is in taller frequency, loss is very small, dc output improves power element, energy-saving effect is apparent. 4.

Equipment bulk and weight: The transformer core that is versed in frequency communicates welder is bigger, the equipment below same power condition is heavier. Inversion dc resistor nods welder transformer to be reduced greatly, equipment is defter. Dc of inversion of intermediate frequency of ＋ of use servo welding torch solders controller and communication of ＋ of traditional pneumatic welding torch solder controller, soldering 0.

8mm ＋ 0.

When DP600 of 8mm Shuang Xianggang, choose solder likewise parameter (304kfg, 240ms, below the circumstance of 9 ～ 12kA) , solder quality contrast is shown like graph 3a place, the dimension of nucleus of solder dot frit of new facility wants than conventional device big 0.

2mm left and right sides, and solder dot is pulled cut force to want big 300kN left and right sides, raised solder effectively to nod quality. In solderability respect, if graph 3b place is shown, the solderability of new facility wants than conventional device tall 0.

4kA, improved Shuang Xianggang's solderability effectively. Graph quality of drop of solder of communication of ＋ of welding torch of pneumatic of Vs of dc of intermediate frequency of ＋ of 3 servo welding torch detects because the solder aspect that craft improves excel in steel contains more martensite, certain brittleness is shown in the meeting on function. When the authentic check law of use tradition undertakes solder nods quality to detect, the case that can appear to nod an interface to tear off from solder (if pursue 4) , this undertakes repairing to solder dot with respect to need, on certain level, increased to solder cost. Accordingly, detect to quality of spot welding of excel in steel and character, suit to use nondestructive to detect law. Graph 4 Shuang Xianggang's solder nod an interface to tear off solder of excel in steel to nod nondestructive to detect the method is collected besides online real time solder process signal will undertake judging besides, the nondestructive leaving a line after still having solder detects method. Among them, the most commonly used is method of ultrasonic nondestructive flaw detection (if pursue 5) , it is to use ultrasonic to nod the degree of sound wave attenuation when interfacial reflex or nucleus of frit of penetrable spot welding and echo interval to judge solder to nod the stand or fall of quality in solder. Handlers holds probe, cooperate couplant, probe is clingy solder nods the surface, as perpendicular as workpiece surface, the change such as the breadth of ultrasonic curve weaveform that indicates according to monitor and extent, will judge solder to nod quality stand or fall. Graph nondestructive of ultrasonic of quality of 5 solder drop detects law 1.

Eligible solder nods: The amplitude of echo alignment decreases successively quickly accordingly. This is the grain because of solder nucleus metal relatively mother capable person is bulky, when sound wave is crossed, energy attenuation is big also. The interval of echo mirrors the ply that solder nods. 2.

Solder nucleus frit is deep insufficient: Display long echo series right now. The reason is sound wave crosses less solder nucleus section, sound energy attenuation decreases accordingly. 3.

Solder nucleus diameter is too small: Intermediate wave can appear among the echo signal with be in normal right now, it is the reflection wave that causes by interface of mother capable person, pass it to be able to differentiate solder nucleus diameter to whether be less than beam diameter, why must this consider the reason of solder nucleus diameter when choice probe diameter namely. 4.

Empty solder: The second half of echo signal alignment with be in normal paragraph, show intermediate blemish wave, echo alignment is longer at the same time. 5.

Leakage solder: Sound wave fails to enter the 2nd layer board, echo alignment shows signal of rife bottom wave. 6.

Burn too: Echo alignment shows have a few echo only. Solder nucleus area is too right now large, sound energy attenuation is very serious. The ultrasonic spot welding of Shanghai global company detects equipment is used 4.

5mm diameter is high frequency (20MHz) probe, undertake to the authentic check blind area of motherboard of excel in steel ultrasonic detects, cooperate a few the tradition is ruinous detect, the 3 form that make rigor examine a system. According to crop and sampling observation batch, draw-out car undertakes ultrasonic flaw detection, after discovering flaw, to blemish solder the dot undertakes ruinous detect come test and verify checks a result. The solder that its explore nods the 50% above that hold sum total, accuracy rate amounts to 95% above, favorable result was obtained in be used actually. The place on put together is narrated, automobile body is light the organization of excel in steel that in quantifying a trend, uses follows common mild steel endless and identical, solder traditionally equipment and detect the method also cannot satisfy excel in steel gradually solder requirement. It is with Shuang Xianggang exemple, use new-style servo welding torch and controller of dc of intermediate frequency inversion to be able to be stabilized very well solder process, rise solder quality. In solder drop quality detects methodological respect, real time the electrode pressure method that monitor and law of sampling ultrasonic flaw detection can solve the problem in Shuang Xianggang qualitative check well, for farther promotion of Shuang Xianggang application laid a foundation. CNC Milling