CN102935578A

CN102935578A - Method for manufacturing local boss nut plate by high-intensity biphase steel plate

Info

Publication number: CN102935578A
Application number: CN2012103985504A
Authority: CN
Inventors: 王雷刚; 黄瑶; 贺佳阳; 王楚翘
Original assignee: Jiangsu University
Current assignee: Jiangsu University
Priority date: 2012-10-18
Filing date: 2012-10-18
Publication date: 2013-02-20

Abstract

The invention discloses a multistep composite forming method for manufacturing a local high-boss nut plate by a high-intensity biphase steel plate. A high-intensity biphase steel plate blank is taken as a blank; and the blank is subjected to multiple composite formation procedures of debossing, cold impact forging, cold extrusion, cold punching and annealing by a stepped convex die, conical convex dies with different heights, a flattop convex die and a back-pressure convex die. The plate blank is taken as the blank and is subjected to multistep composite forming. By the method, biphase particles are separated out in a plastic processing process and are used for processing the plate blank with remarkable hardening to form a local high boss. The loads of the dies are small by virtue of the multistep composite forming method, and the material utilization rate is high by virtue of the plastic processing, so that a large quantity of materials are saved, the structure performance is good, and the method is particularly suitable for production of components for high load connection.

Description

The be shaped manufacture method of local boss nutplate of high strength dual phase steel plate

Technical field

The present invention relates to the local high boss nutplate of high strength dual phase steel plate multistep combined shaping method, the method is specifically related to the manufacture method of cold forging pressure, cold extrusion, the local high boss nutplate of cold stamping combined shaping on such plate.

Background technology

High strength high boss nutplate is that automobile manufacture industry realizes the vital part be fixedly connected with between all parts, and most of kinds of processes methods such as welding, machining, plastic working that adopt are produced at present.Because plastic working production efficiency is high, save material, and the nutplate comprehensive mechanical property of processing is good, therefore, the batch production of most of high boss nutplate all adopts the process of plastic working.By contrast, adopt the methods such as welding, machining to produce the high boss nutplate, operation is more, and production efficiency is low, and stock utilization is low.

Due to the difference of boss height and the manufactured materials thereof of high boss nutplate, its plastic processing method is not identical yet, generally can adopt the techniques such as cold forging pressure, cold extrusion, cold stamping.High strength dual phase steel high boss nutplate is compared with other nutplate, and adopt the difficult point of plastic processing method production to be: (1) boss is higher, and the metal flow momentum is large; (2) the two-phase particle that the high strength dual phase steel plate is separated out in forming process hinders dislocation motion, makes this kind of material hardening exponent high.Therefore the high boss nutplate shaping difficulty of this kind of material is large, needs multi-step forming and annealing in process.

Summary of the invention

Technical problem to be solved by this invention is: a kind of combined shaping method that is applicable to high strength dual phase steel high boss nutplate will be provided.

Combined shaping high strength dual phase steel high boss nutplate manufacture method of the present invention, concrete forming process is characterised in that and comprises the steps:

1) blank presses preform first: the blank plate is placed on die and with holding pad and pushes down, use the step drift to be pressed preform to the motherboard upper surface.Detailed process is: the step drift is inserted in the through hole of holding pad, and drift be positioned at concave die cavity directly over, back pressure push rod one end is positioned at concave die cavity.The back pressure push rod compresses plate under certain back pressure effect, and the step drift moves downward together with the back pressure push rod under impact forging pressure, and the material of the plate of step drift below is flowed in concave die cavity; When the step drift goes downwards to certain position, now the induration due to material is increased sharply the step punch load, need to stop the descending of step drift;

2) the first forging extrusion molding of dull and stereotyped step drift to plate: preformed boss plate is positioned on die.Now, the dull and stereotyped step drift (now without holding pad) that makes to be positioned at directly over plate is descending, to the plate forging and stamping, the tack back pressure push rod in concave die cavity hole is applied to certain back pressure effect simultaneously, and plate is pushed.When dull and stereotyped step punch stroke reaches preset value, stop dull and stereotyped step drift descending;

3) annealing in process of preform boss plate;

4) again press preform on motherboard: motherboard is placed on die and with holding pad and pushes down, use tapered punch to press for the second time preform to motherboard.Detailed process is identical with step 1);

5) dull and stereotyped tapered punch is forged extrusion molding again to plate: preformed boss plate is positioned on die, the dull and stereotyped tapered punch that now makes to be positioned at directly over plate is descending, plate is forged and pressed, the step back pressure push rod in concave die cavity hole need to apply certain back pressure simultaneously, plate is pushed, while reaching the default stroke of dull and stereotyped tapered punch, stop descending;

6) punching of preform boss plate: the piercing punch that is positioned at preform boss below moves upward, and the gross weight of boss bottom is washed out, and obtains bright and clean through hole, the plate of the boss that is shaped.

Beneficial effect of the present invention is: effectively in conjunction with plate cold forging pressure, cold extrusion cold stamping, three processes, the metal flow characteristics have been given full play to, this combined shaping method is comprehensively brought into play cold forging pressure, cold extrusion, cold stamping advantage separately, the high boss part of high-strength high hardenability value material is conducive to be shaped, make the part structure property good, stock utilization is high.

The accompanying drawing explanation

Below in conjunction with accompanying drawing and example, the present invention is further described.

Fig. 1 is plate blank schematic cross-section of the present invention.

Fig. 2 is high boss nutplate part schematic diagram of the present invention.

Fig. 3 component shaping operation of the present invention schematic diagram.

Fig. 4 step drift of the present invention presses the shaping schematic diagram first.

Fig. 5 dull and stereotyped step drift of the present invention is forged the extrusion molding schematic diagram first.

Fig. 6 tapered punch of the present invention presses the shaping schematic diagram again.

Fig. 7 dull and stereotyped tapered punch of the present invention is forged the extrusion molding schematic diagram again.

1-step drift, 2-motherboard to be processed (plate, blank), 3-holding pad, 4-die, 5-tack back-pressure bar, the dull and stereotyped step drift of 6-, 7-tapered punch, the dull and stereotyped tapered punch of 8-, 9-step back-pressure bar.

The specific embodiment

In order better to understand this method, below in conjunction with concrete data, describe, should understand specific embodiment and not form the restriction to institute of the present invention protection domain.

A concrete high boss nutplate manufacture example is as follows:

A. according to the dimensional requirement of part, adopt the stamping-out mode to strike out Single Size Rectangular Blanks as shown in Figure 1 (size: the length * wide 42.5 * 38mm of being, thickness is 6mm) to raw material, material is B340/590 DP cold-rolled biphase steel plate.

B. as Fig. 4, after blank 2 is put into die 4 and had good positioning, holding pad 3 first contacts plate blank 2 and compresses, and next step drift 1 is at 1000KN forcing press active force (F _Punching) move down and contact with blank 2, make blank 2 flow in die 4 die cavities and contact with dull and stereotyped back pressure push rod 5, when step drift 1 stroke reaches 1,2,5 positions on right side, 6mm(Fig. 4 axis [chain-dotted line]) time, step drift 1 stops moving downward, and the preformed section of blank 2 is as Fig. 3 (a).

C. as Fig. 5, after b is walked to preformed blank 2 and puts into die 4 and have good positioning, dull and stereotyped step drift 6 is at 1000KN forcing press active force (F _Punching) lower motion, to plate 2 forging and stamping, tack back-pressure bar 5 is at active force (F simultaneously _Press) lower motion, to plate 2 extruding.

Reach

2,5,6 positions on right side, 1mm(Fig. 5 axis [chain-dotted line] to down stroke when dull and stereotyped step drift 6) time, dull and stereotyped step drift 6 stops moving downward, the blank that obtains being shaped, and cross-section structure is as Fig. 3 (b).

D. the blank 2 c step has been shaped, carry out annealing in process.(concrete technology: workpiece is heated to 2 ~ 3 hours laggard line spaces of 640 ℃ ~ 720 ℃ insulations cold)

E. as Fig. 6, after by the d step annealing, good blank 2 is put into die 4 and had good positioning, holding pad 3 first contacts plate blank 2 and compresses, and next tapered punch 7 is at 1000KN forcing press active force (F _Punching) move down and contact with blank 2, make blank 2 flow in die 4 die cavities and contact with dull and stereotyped back pressure push rod 5, when tapered punch 7 strokes reach 2,5,7 positions on right side, 5mm(Fig. 6 axis [chain-dotted line]) time, tapered punch 7 stops moving downward, and the stock section shape obtained is as Fig. 3 (c).

G. as Fig. 7, after the blank 2 that the e step has been shaped is put into die 4 and is had good positioning, dull and stereotyped tapered punch 8 in the effect of 1000KN forcing press to (F _Punching) lower motion, to plate 2 forging and stamping, step back-pressure bar 9 is at active force (F simultaneously _Press) lower motion, to plate 2 extruding.Reach 2,8,9 positions on right side, 1mm(Fig. 7 axis [chain-dotted line] to down stroke when dull and stereotyped tapered punch 8) time, dull and stereotyped tapered punch 9 stops moving downward, and the stock section shape obtained is as Fig. 3 (d).

H. blank g step pressed carries out punching, and processes screw thread and obtain local high boss nutplate, and shape is as shown in Fig. 3 (e) and Fig. 2.

Sheet material blank of the present invention is by the method for multistep combined shaping high strength dual phase steel high boss nutplate, can make to have that the two-phase particle is separated out, the significant material forming of work hardening in plastic processing, the compound die load that makes of multistep is little, and stock utilization is high, has saved a large amount of materials.Structure property is good, is particularly suitable for the production of top load part.

Claims

1. the method for the local high boss nutplate of a rectangular plate blank multistep combined shaping high strength dual phase steel plate, it is characterized in that: adopting the high strength dual phase steel plate blank material is blank, by taper punch, the tack punch of step punch, differing heights, the back pressure punch is pressed, the operation multistep combined shaping of cold punching forging, cold extrusion, cold stamping, annealing.

2. method according to claim 1 is characterized in that comprising the following steps:

1) blank presses preform first: the blank plate is placed on die and with holding pad and pushes down, use the step drift to be pressed preform to the motherboard upper surface;

2) the first forging extrusion molding of dull and stereotyped step drift to plate: preformed boss plate is positioned on die, the dull and stereotyped step drift that makes to be positioned at directly over plate is descending, to the plate forging and stamping, the tack back pressure push rod in concave die cavity hole applied to certain back pressure effect simultaneously, plate is pushed; When dull and stereotyped step punch stroke reaches preset value, stop dull and stereotyped step drift descending;

3) annealing in process of preform boss plate;

4) again press preform on motherboard: the motherboard of step 3) annealing in process is placed on die and with holding pad and pushes down, use tapered punch to press for the second time preform to motherboard, detailed process is identical with step 1);