The hot forming of high-duty steel part and edge-cutting integrated technique and mould
Technical field
The present invention relates to the hot press-formed and trimming technology and the mould of high strength steel, AHSS and unimach punching parts, belong to the forming technique field of high strength steel sheet-metal parts.
Background technology
Current, at automobile manufacturing field, people have become the important pushing factor of technological progress to the demand of high security, low deadweight and good fuel economy.Manufacturers are achieved consumer's hope by introducing measures such as new security concept and light-weighted body structure.Especially aspect body structure,, improved the collision performance of automobile and also realized light-weighted requirement simultaneously by use to high strength steel, AHSS and unimach.But raising along with steel strength, percentage elongation descends, the forming property of material also reduces greatly, also be easy to generate in the forming process break, wrinkling, size is difficult to problems such as control and shape defect, oneself can not satisfy the needs of technology and production development traditional cold punching forming process.
In recent years, Chinese scholars is developed a kind of new high strength, ultra-high strength steel hot stamping forming technology, this technology makes high strength steel and unimach plate be heated to austenitizing temperature (900~950 ℃) in heating furnace, and austenitic area maintenance 5 minutes, then plate is transferred to forcing press, in diel, carry out drawing and quenching simultaneously, make formation of parts obtain 100% martensitic structure.This technology can reduce the weight of automobile structure when improving collision performance and fatigue strength.
Chinese patent literature CN101288889 discloses a kind of " ultra-high strength steel hot stamping forming die ", this mould comprises upper bolster and is fixed on punch, the die shoe on the upper bolster and is fixed on die on the die shoe, be provided with cooling-water duct in the die, cooling-water duct is connected with a cooling water recirculation system.
Chinese patent literature CN1829813 discloses a kind of " method for hot forming and hot formed member ", for the steel plate of special component be heated to austenite point temperature (Ac3) above and keep after, carry out the shaping of end article shape, in the cooling of the forming temperature in shaping or after be shaped, the cooling velocity of the Ma Shi point temperature (Ms point) of arrival formed parts is more than critical cooling rate, and, be that Quenching Treatment is carried out in 25 ~ 150 ℃/s cooling with average cooling rate from Ms o'clock to 200 ℃.
There are through hole or hot forming part to have under the situation of binder flange on, the hot forming part higher, must carry out secondary operations the hot forming part for dimension precision requirement.In the cold stamping operation, generally be to utilize diel to carry out secondary operations such as punching, deburring, but in the drop stamping operation, utilize conventional mould structure to carry out very difficulty of secondary operations; The molded component that adopts cold punching die that the back intensity of quenching is improved is cut edge or punching processing needs very big processing load, metal pattern will be damaged or the lost of life, for the hot forming part of ultrahigh-strength steel plates even can't process with cold punching die.
In order to make hot formed high strength part meet corresponding dimensional accuracy and shape need, all adopt five laser cutting techniques to carry out deburring at present, but laser side cut efficient is low, article one, drop stamping generates line often needs number cover laser trim lines supporting with it, in addition, every cover laser trim lines all need corresponding anchor clamps to part position, clamping, thereby occupation area of equipment is big, equipment investment is many, production cost is high.In addition, after laser is cut edge, can have some motlten metals during the side cut of hot forming part and solidify the formed metallic particles in back, need follow-up polishing operation that scrap metal is removed, cause the production cycle of hot forming part long, limited applying of drop stamping technology.When using laser to cut edge, the deadline is subjected to part dimension and hole count quantitative limitation, and the simplest part is fixed to the side cut anchor clamps from part and finishes and need may need a few minutes for complex parts more than 30 seconds to cutting.
Chinese patent literature CN2617549 discloses a kind of " novel hot piercing, shaving die ", the hot piercing, the shaving die that are used for forging, the disclosed mould of this patent can only utilize the slide block movement of forcing press, finish single punching, side cut, and it is compound to be used for shaping, side cut or punching, and in addition, this mould structure is to be used for bloom to forge, belong to the bulk forming field, can not be used to belong to the punching or the side cut of the high strength plate in sheet forming field.
Summary of the invention
The problem that used secondary operations technology exists when the present invention is directed to present high strength or the hot forming of unimach drawing part and side cut, provide a kind of simple in structure, production efficiency is high, the hot forming of the measured high-duty steel part of matter and edge-cutting integrated technique, and a kind of integrated mould of realizing this technology is provided simultaneously.
The hot forming and the edge-cutting integrated technique of high-duty steel part of the present invention are:
The side cut instrument at first is set on the hot-forming die of high-duty steel part, before the high strength steel plate is hot press-formed, the high strength steel plate that is heated to after the complete austenitizing is positioned over punching press in the hot-forming die, after the hot-forming die closure, then utilize workpiece after the pressing operation of cutting edge that liquidates of side cut instrument on the hot-forming die, after finishing hot-forming die is cooled off, utilize with the contacted mold component of formation of parts formation of parts is quenched.
Realize the hot forming of high-duty steel part of above-mentioned integrated technique and edge-cutting integrated mould by the following technical solutions:
The hot forming of this high-duty steel part and edge-cutting integrated mould, comprise upper die and lower die, go up side cut instrument and following side cut instrument, in upper die and lower die, be provided with cooling-water duct, the bottom exterior contour of patrix is consistent with the inner profile profile of part, the die cavity profile of counterdie is consistent with the outer shape profile of part, the upper end of patrix is equipped with upper mould oil cylinder, the piston rod of upper mould oil cylinder is connected with last side cut instrument, the bottom of counterdie is equipped with lower mold oil cylinder, the piston rod of lower mold oil cylinder is connected with the lower end of a push rod, and the upper end of push rod is connected with following side cut instrument.
Last side cut instrument and following side cut instrument carry out piecemeal according to the outer shape of part, and the piecemeal quantity of last side cut instrument and following side cut instrument is identical.
The thickness of last side cut instrument and following side cut instrument is 1.5 ~ 4.0 times of institute's processing parts wall thickness.
The present invention is after hot press-formed, before formation of parts being carried out in the mould quenching, utilization is disobeyed the side cut instrument of the mould inside of depended on pressure function the hot forming part is cut edge, after side cut, again part is carried out quenching in the mould, this technology reduced hot formed equipment investment, reduced the floor space of equipment, reduced the hot forming part production cost, shortened production cycle of hot forming part, and the trimming quality height of hot forming part, the dimensional accuracy of part and form accuracy height.Use trimming technology of the present invention, the deadline is 1 ~ 2 second, and is not subjected to the restriction of part dimension and shape.
Description of drawings
Fig. 1 is the structural representation (closure state before cutting edge) of the edge-cutting integrated mould of hot forming of the present invention.
Fig. 2 is the view after hot forming shaving die side cut shown in Figure 1 finishes.
Fig. 3 is the vertical view of counterdie in the hot forming shaving die shown in Figure 1.
Fig. 4 is the left view of Fig. 1.
Fig. 5 is the left view of Fig. 2.
Wherein, 1, patrix, 2, counterdie, 3, go up the side cut instrument, 4, side cut instrument down, 5, the hot forming part of waiting to cut edge, 6, upper mould oil cylinder, 7, piston rod, 8, upper oil hole, 9, following oilhole, 10, push rod, 11, piston rod, 12, lower mold oil cylinder, 13, upper oil hole, 14, following oilhole, 15, the side cut waste material.
The specific embodiment
The hot forming edge-cutting integrated technique of high-duty steel part of the present invention, at first be on the patrix of the hot-forming die of high-duty steel part and counterdie, to be provided with corresponding side cut instrument, oil cylinder or cylinder are installed on mould, and the piston rod of oil cylinder or cylinder and side cut instrument are rigidly connected.The flow process of this technology be the plate that is heated to austenitic state be positioned on the counterdie of hot-forming die → under forcing press drives, mould closure up and down, oil cylinder or the cylinder finished in part hot forming → mould drive the side cut movement of tool, finishing side cut → in the cooling water channel of mould inside feeds cooling medium mould is cooled off, realize the quenching of high strength part, going up simultaneously side cut instrument and following side cut instrument resets under oil cylinder or cylinder drive, eject the formed waste material of cutting edge → under forcing press drives, upper and lower mould is opened, and takes out the hot forming part and the formed waste material of cutting edge.
Fig. 1, Fig. 3 and Fig. 4 have provided a kind of hot forming of part and the structure of edge-cutting integrated mould, and Fig. 2 and Fig. 5 have provided the state after this mould side cut.This mould comprises patrix 1 and counterdie 2, adopts the disclosed technology of CN101288889, is provided with cooling-water duct in patrix 1 and counterdie 2.The bottom exterior contour of patrix 1 is consistent with the profile of part, and the die cavity exterior contour of counterdie 2 is consistent with the exterior contour of patrix 1 bottom.The upper end of patrix 1 is equipped with upper mould oil cylinder 6, and the piston rod 7 of upper mould oil cylinder 6 is gone up side cut instrument 3 by being threaded; The bottom of counterdie 2 is equipped with lower mold oil cylinder 12, and the piston rod 11 of lower mold oil cylinder 12 links together by the lower end of screw thread and push rod 10, and the upper end of push rod 10 links together by screw thread and following side cut instrument 4.Patrix 1 is fixed on the cope match-plate pattern equally, and cope match-plate pattern is fixed on by bolt and pressing plate on the slide block of forcing press, and counterdie 2 is fixed on the lower bolster by screw and pin, and lower bolster is fixed on the workbench of forcing press by bolt and pressing plate.In the hot forming process, patrix 1 moves downward under press ram drives, the high-strength steel sheet that is heated to austenitic state that is positioned over counterdie 2 upper surfaces the most at last is pressed in the counterdie 2, makes high-strength plate at the mould internal shaping, forms the untrained hot forming part 5 of waiting to cut edge.
After the part forming, piston rod 7 drives of auxiliary supporting HYDRAULIC CONTROL SYSTEM upper mould oil cylinder 6 are gone up side cut instrument 3 and are moved downward, and the piston rod 11 of HYDRAULIC CONTROL SYSTEM lower mold oil cylinder 12 drives push rods 10 simultaneously, side cut instrument 4 moves downward down.Counterdie 2 upper surfaces, on side cut instrument 3, down under the acting in conjunction of side cut instrument 4, side cut waste material 15 separates from the hot forming part 5 of waiting to cut edge, thereby finishes mould inside hot trimming process, forms formation of parts.
After side cut is finished, in the cooling water channel of patrix 1 and counterdie 2, feed cooling medium, mould is cooled off, thereby formation of parts is quenched.When in mould, feeding cooling water, the piston rod 11 of auxiliary supporting HYDRAULIC CONTROL SYSTEM lower mold oil cylinder 12 drives push rod 10, side cut instrument 4 moves upward down, piston rod 7 drives of HYDRAULIC CONTROL SYSTEM upper mould oil cylinder 6 are simultaneously gone up side cut instrument 3 and are moved upward, and the side cut waste material 15 that forms ejects from counterdie with cutting edge.After formation of parts finished cooling, patrix 1 moved upward under press ram drives, and mould is opened, and side cut waste material 15 and formation of parts are taken out mould, entered next working cycles then.
The side cut operation needs and will all downcut around high strength steel wait the to cut edge waste material of hot forming part 5 peripheries, for the smooth implementation of the operation that guarantees to cut edge, simplifies the design of side cut instrument, to side cut instrument employing block form as shown in Figure 5.The peripheral profile of high-duty steel part may be an arbitrary curve, and the piecemeal quantity of following side cut instrument 4 is according to the complicated process decision of high-duty steel part, and last side cut instrument 3 is identical with the piecemeal quantity of following side cut instrument 4.Several boundary lines (dotted line among Fig. 3) that will exceed high-duty steel part are arranged in all piecemeals of side cut instrument, waste material can be divided into several after guaranteeing to cut edge, be convenient to the taking-up of waste material.The thickness of side cut instrument generally determines that according to the wall thickness of the high strength part that is shaped the thickness of side cut instrument is 1.5 ~ 4.0 times of part wall thickness, for the high strength part of sheet moulding, and capping, the high strength part for cut deal is shaped takes off limit.In the side cut process, last side cut instrument 3 by with patrix 1 in corresponding installing hole lead, following side cut instrument 4 by with counterdie 2 in corresponding installing hole lead.
The general length of side cut instrument of monolithic is bigger, if apply side cut power for the side cut instrument with an oil cylinder, will cause side cut power deficiency or side cut instrument in the side cut process because of unbalance stress causes deflection, accelerate the rate of wear of side cut instrument and mould.In order to address this is that, as shown in Figure 4 and Figure 5, size according to last side cut instrument 3 or following side cut instrument 4, adopt plural upper mould oil cylinder 6 or upper mould oil cylinder 12 to provide side cut power for the side cut instrument, and oil cylinder is uniform along the side cut instrument, guarantee to the side cut instrument provides enough big side cut power, and guarantee side cut instrument stress equalization, avoid deflection.Link together for last side cut instrument 3 provides the upper oil hole 8 of a plurality of upper mould oil cylinders 6 of power, following oilhole 9 links together, and guarantees that a plurality of oil cylinders of patrix can move simultaneously; For following side cut instrument 4 provides the upper oil hole 13 of a plurality of lower mold oil cylinder 12 of power to link together, following oilhole 14 links together, and guarantees that a plurality of lower mold oil cylinder 12 can move simultaneously.
When high-duty steel part is carried out hot trimming; because the part temperature height (about 850 ℃) after being shaped; side cut instrument and side cut instrument damage easily with the die surface position that combines; for the ease of mould is keeped in repair and maintains; adopt insert structure at the position that the side cut instrument is installed; after the side cut instrument or the damage of inserting, only need to change the parts that damage, and there is no need the whole surface of patrix or counterdie is repaired.