CN100448561C

CN100448561C - Drawing method and drawing mould

Info

Publication number: CN100448561C
Application number: CNB2005101239400A
Authority: CN
Inventors: 杨秋莲
Original assignee: BYD Co Ltd
Current assignee: BYD Co Ltd
Priority date: 2005-11-24
Filing date: 2005-11-24
Publication date: 2009-01-07
Anticipated expiration: 2025-11-24
Also published as: CN1970188A

Abstract

The stretch method extends the plate material into two parts with the surrounding area of the stretched part being held by ridge pining ring. It also provides a stretch mold for the above said extension method. Based on this invention, it can prevent wrinkling of the parts being stretched. Meanwhile, it can reduce edge pining force while stretching, with surrounding material flowing to the stretched parts to prevent breach in the process of stretching.

Description

Drawing Method And Drawing Dies

Technical field

The present invention relates to a kind of Drawing Method And Drawing Dies in the Sheet Metal Forming Technology.

Background technology

Drawing (being called pull and stretch or calendering again) is to utilize drawing die under the pressure effect of forcing press, will be cut into the plate blank of definite shape in advance, is drawn into the processing method of stereo hollow spare.Drawing used mould mainly is made up of punch, die and blank holder three parts.When drawing, the plate blank is subjected to the power effect that punch, die and blank holder produce, and plate is drawn into reservation shape (product draw part).Blank holder is pushed down the marginal portion (below be referred to as " blank holder part ") that product draws part, prevents that plate punch part in drawing process from promptly forming so-called " wrinkling " because the effect of circumferential stress can lose to stablize arches upward.

In drawing work, break with wrinkling be two principal modes that draw inefficacy.Breaking mainly is the punch-nose angle place (this area is referred to as " critical section ") that occurs in product, because product is subjected to radially due to the tension in the drawing process.Wrinkling then mainly is because the material of punch part is subjected to the effect of hoop pressure stress, makes material lose stable when the material attenuate and the generation gauffer.The influence factor of breaking is more, comprise drawing coefficient (drawn component diameter d/plate diameter D, deformation extent in the expression drawing process), plate mechanical performance, die profile radius, punch ratius, coefficient of friction, pressure-pad-force or the like, wherein, protruding, die profile radius and coefficient of friction are main influence factors.Wrinkling influence factor mainly contains the relative thickness (thickness t/plate diameter D) and the drawing coefficient of plate.

It is wrinkling to adopt blank holder effectively to prevent, promptly when drawing beginning, the blank holder of plate part or binder part are just pushed down by blank holder, in whole drawing process, are constrained between blank holder and die two planes always, have limited plate and have flowed.But the pressure of blank holder has also increased product material flowing friction resistance simultaneously, and promptly in drawing process, owing to be subjected to the effect of pressure-pad-force, the product material is not easy to flow, thereby has strengthened the danger that the product critical section is pulled open.

For the drawing work of complicated shape spare, automobile parcel shelf gripper shoe for example, the problem of existence is more concentrated.For example, Fig. 1 is a kind of schematic diagram of automobile parcel shelf gripper shoe.As can be seen from Figure 1, this product belongs to complex-shaped, draws the part A except having main first, also have a plurality of second and draw part B, and first and second draws close together between part A and the B.Product is represented with numeral 10.

For drawing work, this type of product to draw difference in height very big, and undulations close proximity, so material flows extremely inhomogeneous in die.So, utilize traditional drawing work, be difficult to overcome some problems that product often occurs in drawing process, as the high-end material (material that drawing depth is bigger, being first to draw the two ends convex closure part of part A among Fig. 1) the excessive generation of distortion breaks, and the low side edge of materials partly produces wrinkle Zhe.

In the prior art, can take specific measure at above-mentioned specific problem, for example, when the product material draws distortion excessive and when having break dangerous in die, should increase the inflow of exterior material, generally take to reduce pressure-pad-force or adjustment and reduce the bead height or increase methods such as die entrance to reduce the resistance that material flows into, increase the purpose that exterior material flows into to reach.But the inflow that increases exterior material can make the gauffer of lower portion generation again.Therefore, press for a kind of method and can solve the problem that occurs in the above-mentioned complicated shape spare drawing work simultaneously.

Summary of the invention

Therefore, an object of the present invention is to provide a kind of drawing method, can address the above problem by this method, as draw part and be out of shape excessive generation and break, it is inhomogeneous and make the local problem such as wrinkle Zhe that produces of product to draw the part edge distortion.

Another object of the present invention provides a kind of drawing die that is exclusively used in said method.

This drawing method comprise with board-like material draw become to comprise at least two draw the part products, it is characterized in that, in drawing process, described draw the part the peripheral region pushed down always, promptly pushed down by the blank holder in the mould always.

This drawing die comprises punch, die and blank holder, and the shape of wherein said punch and die consistent (cooperatively interacting) is characterized in that described punch and die comprise at least two finishing dies, blank holder be positioned at finishing die around.

Utilize above-mentioned drawing method, because in drawing process, the described peripheral region that draws part is pushed down by blank holder always, so can prevent to draw the peripheral region generation wrinkling of part.Simultaneously, because in drawing process, drawing part zone on every side on the product is the flanging part, promptly pushed down and can be not wrinkling by the blank holder in the mould, therefore can when drawing, suitably reduce pressure-pad-force, material around when drawing can flow to smoothly and draw in the part, breaks in drawing process thereby can effectively prevent to draw part.

Drawing die of the present invention belongs to the particular manufacturing craft of drawing method of the present invention.Use this drawing die can realize above-mentioned drawing method.

Description of drawings

Fig. 1 is the schematic diagram of an example of automobile parcel shelf gripper shoe in the prior art.

Fig. 2 is the schematic diagram of drawing method of the present invention and drawing die.

Fig. 3 to Fig. 6 is the schematic diagram of other embodiments of the invention.

The specific embodiment

Describe principle of the present invention with reference to the accompanying drawings in detail.

Fig. 2 is the schematic diagram of a kind of embodiment of drawing method of the present invention.As shown in Figure 2, by product 10 that drawing method of the present invention drew out as an example, comprise that one first draws part A and two second and draws part B.In the drawing process, the part of being pushed down by the blank holder of mould on the product 10 (below be referred to as the flanging portion C, shown in hatching) is positioned at first and draws part A and second and draw zone around the part B.

Therefore, in drawing process, because the flanging portion C surrounds first and draws part A and second and draw part B, therefore, to draw drawing of part B highly higher even first draws part A and/or second, violent extension distortion takes place and flow to this and draw part in its material around, but since this material around (flanging portion C) in drawing process or draw the later stage and be subjected to the pressure effect of mould blank holder, so wrinkling can not take place.

In addition, because the flanging portion C is surrounded first and is drawn that part A and second is drawn part B and can be not wrinkling in drawing process, so when drawing, can suitably reduce the pressure of blank holder to product, increase the flowability of material in drawing process, thus can effectively prevent to draw part A and B in drawing process because material replenishes deficiency breaks.

First draws part A and second draws size, the shape of part B, draws highly and can differ from one another, and the present invention is also unrestricted to this.

As shown in Figure 3, in drawing process, draw the zone that part and second draws between the part adjacent first and pushed down, can further prevent to draw regional wrinkling around the part by the blank holder in the mould.

As shown in Figure 4, in drawing process, all pushed down, therefore can prevent better that product is wrinkling by blank holder in the every other zone except drawing part on the product 10.

In addition, return Fig. 2, the binder portion C be formed at draw part A and B around, the shape of binder part is not particularly limited, can be circular (as shown), also can be square or other shapes.The size of binder portion C also is not particularly limited, and promptly mainly is can push down to draw the zone around the part and make it wrinkle resistant and get final product.Particularly, the geometric center that for example will draw part A or B is orientated an O as, drawing the point that part edge intersects from the outward extending line of an O and this is E, the point that the extended line of line OE and binder portion C edge intersect is F, the length of line OF 1.5 times to 3 times of length of line OE preferably then, can certainly be higher than 3 times and less than 1.5 times greater than 1 times.

In addition, wrinkling in order to prevent product as shown in Figure 5 and Figure 6 at periphery, can also draw out one or more bead D in the appropriate location of the periphery of flanging portion C.

Fig. 2 also can represent the schematic diagram of drawing die of the present invention, and wherein A and B represent first and second finishing dies in the mould respectively, and C then represents blank holder.Blank holder C can comprise the part that is positioned at around the finishing die, perhaps can comprise the part between adjacent finishing die.In addition, blank holder C can also have at least one bead in its fringe region.

When utilizing this drawing die that product is drawn, draw out on the product corresponding first by the first and second finishing die A and B and draw part and second and draw part.In drawing process, blank holder C pushes down on the product first and draws part and second and draw part zone on every side, prevents that the product part is wrinkling.

Claims

1, a kind of drawing method, this method comprise with board-like material draw become to comprise at least two draw the part products, it is characterized in that, in drawing process, the described peripheral region that draws part is pushed down always, and described adjacent zone of drawing between the part is pushed down always.

2, drawing method as claimed in claim 1, wherein in drawing process, the every other part on the described product except drawing part is all pushed down always.

3, drawing method as claimed in claim 1 wherein in drawing process, draws out a bead at the product fringe region at least.

4, a kind of drawing die, this mould comprises punch, die and blank holder, wherein said punch and die cooperate, it is characterized in that, described punch and die comprise at least two finishing dies, blank holder comprises the part that is positioned at around the finishing die, and described blank holder also comprises the part between adjacent finishing die.

5, drawing die as claimed in claim 4, wherein said blank holder comprise the every other part except finishing die.

6, drawing die as claimed in claim 4 wherein has at least one bead in the fringe region of described blank holder.