CN100512994C

CN100512994C - Enclosed extruding precision punching forming method

Info

Publication number: CN100512994C
Application number: CNB2007100932256A
Authority: CN
Inventors: 邓明; 吕琳; 李庆; 李艳霞
Original assignee: Chongqing Institute of Technology
Current assignee: Chongqing University of Technology
Priority date: 2007-12-27
Filing date: 2007-12-27
Publication date: 2009-07-15
Anticipated expiration: 2027-12-27
Also published as: CN101214509A

Abstract

The invention belongs to the plastic forming field and relates to a closed type fine blanking squeezing forming method. The dies used by the invention mainly includes a convex die, a main concave die, a vice concave die and a reverse top plate, etc. The main concave die is fixed on a lower die seat through a concave die fixing plate. The reverse top plate is arranged in the main concave die. The convex die is mounted on an upper die seat through a convex liner plate. The vice die is mounted outside the convex die. The end surfaces of the main concave and the vice concave die are provided with corresponding material blocking lug bosses at the location close to the edge position of a concave cavity. When the fine blanking begins, the main concave die and the vice concave die carry out compound squeezing on a stock and when the main concave die and the vice concave die are squeezed to contact, the convex die carries out fine blanking squeezing on a part. The method can be used for processing thick plates or low plastic curve profile parts (like gear, cam) and acquire a section with the advantages of good quality and high manufacture efficiency.

Description

A kind of enclosed extruding precision punching forming method

Technical field

The invention belongs to plastic forming technology, relate to a kind of method of fine-punching formation.

Background technology

Existing fine-punching formation technology has powerful flanging fine blanking technology, subtend die fine blanking technology etc., and they each have its pluses and minuses and accommodation:

1. powerful flanging fine blanking technology is a separation circuit from see in form, but in fact workpiece with remain before billot in the end separates as a whole.Essence is broken through the process that journey is a plastic deformation, and the part of processing has that dimensional uniformity is good, and the shear surface roughness can reach Ra3.6～0.2, and collapse angle and burr are all than advantages such as common stamping part are little.Its shortcoming is to process cut deal inductile part.

2. smart the dashing of subtend die grows up on the basis in powerful flanging essence, towards unmanageable part, can adopt subtend die essence to dash for the powerful flanging essence of the thicker employing of the relatively poor thickness of material plasticity.Its shortcoming is because on protruding die and the die size or installation or kinematic error, essence towards the time as easy as rolling off a logly on section, leave a trace, cause cross section quality poor.

The applicant applied for once that a kind of compound essence was washed into the patent of invention of type method, adopted this method not only can the processing low-plasticity slab, and can obtain the good part of section uniformity.But still come with some shortcomings.At first, this method is to provide radial pressure by the V-type circle on the pressing plate, when moving downward and make the V-type circle, pressing plate is pressed in the blank, the V-type circle is exerted pressure to blank, this pressure can be vertically and radially is decomposed into axial compressive force and radial pressure, therefore the V-type circle need directly be pressed into sheet material when three-dimensional compressive stress is provided, and its stress state can not reach the stress state when being similar to extruding, still has certain deficiency for the stamping-out of slab and inductile material.In addition, in this method, blank is not closed in die cavity, and blank just is subjected to the restriction of V-type circle and V-type groove diametrically, and the waste material that is produced is many comparatively speaking.

Summary of the invention

The objective of the invention is to deficiency at the prior art existence, on the technical foundation of composite extruding fine-punching formation method, the enclosed extruding precision punching forming method of a kind of Processing Curve profile part of developing, directly fine-punching formation slab or inductile material can obtain accurate curved profile part efficiently.

Technical scheme of the present invention is as follows:

The present invention proposes a kind of enclosed extruding precision punching forming method of Processing Curve profile part, the employed mould of this method includes punch, main die, secondary die, upper bolster, die shoe, guide pin bushing guide pillar etc., also is provided with anti-top board, die block, convex mould pad in addition.Wherein, the marginal position near matrix cavity on the end face of major and minor die is provided with corresponding resistance material boss, and resistance material boss height is decided with sotck thinkness.

The implementation process of this method is as follows:

The first step: lock secondary die is relative with punch, lock the formed indent degree of depth, promptly shallow die cavity is the angle thickness that collapses of workpiece.Integral body moves downward then, causes blank to be subjected to squeeze radially and outwards flows, simultaneously, material also upward the secondary die and the main matrix cavity of below flows, when mobile, be subjected to stopping of main die, secondary die and last resistance material boss, produce lateral pressure, make the deformed area form the triaxial pressure state.

Second step: extruding action is proceeded, and the waste part of blank fully is extruded, and material is a large amount of simultaneously flows in the main concave die cavity, and anti-top board is forced to back off, and when secondary die moves to when contacting with main die, secondary die stops descending.

The 3rd step: keep secondary die pressure, invariant position, allow punch move downward, make blank enter main die fully under forward extrusion, anti-top board applies counter-pressure to the blank middle part, finishes the essence of profile and dashes.

The 4th step: the mould die sinking, with anti-top board part is released, promptly obtain product.

The employed mould of this method must be used on triaxial pressure machine or the ordinary press that three dynamic pressure can be provided through repacking.

The principle of this method is that main die and secondary die have carried out Compound Extrusion to waste material in the composite extruding fine-punching process, impel waste material to produce plasticity depletion, to around waste material almost can't redeformation, at this moment, when punch moves downward again just as forward extrusion workpiece in rigid cylinder, thereby the essence of high-carbon steel part 3mm that has substantially exceeded fine blanking technology processing is towards the limit, and can obtain high surperficial matter.

Advantage of the present invention shows following several aspect:

1. provide radial pressure by boss (E) in the enclosed extruding precision punching method, boss during work (E) is exerted pressure to blank, and its active force can be decomposed into radial pressure and axial compressive force; Provide the boss (E) of three-dimensional compressive stress directly not to be pressed into plate in this method, but by forming the die cavity of a temporary transient sealing, the stress state when making plate be subjected to such an extent that be similar to extruding;

2. in the enclosed extruding precision punching method, blank is limited in producing plastic deformation in the die cavity of lower convex platform (E), punch (5) and anti-top board (4) composition in this die cavity all the time, and the waste material that is produced is less, and stock utilization is higher.

3. the good product quality of Huo Deing: dimensional tolerance is IT8～7 grade, and the shear surface roughness can reach 0.8um～0.4um, and the curved profile part of being produced (as gear, cam) can be directly used in the assembling of machinery, saves subsequent handling.｀

4. this method can be processed inductile, the slab curved profile part that existing fine blanking technology is difficult to processing.In the composite extruding fine-punching process, plastic deformation does not occur over just the place that separates of part and waste material, and bigger plastic deformation has also taken place in the waste material zone.Break through in the journey in essence waste material has been carried out Compound Extrusion because one of main feature of this composite extruding fine-punching is exactly its pressing plate, impel waste material to produce plasticity depletion, to around waste material almost can't redeformation, at this moment, when punch moves downward again just as forward extrusion workpiece in rigid cylinder, thereby the essence of high-carbon steel part 3mm that has substantially exceeded fine blanking technology processing is towards the limit, and can obtain high surface quality.

5. workpiece section uniformity is fine, can not produce burr.Because in composite extruding fine-punching technology, secondary die indent (the being shallow die cavity) degree of depth is the angle thickness that collapses of workpiece, and the two-sided angle of collapsing has appearred in the extruding at two, has removed the chamfer machining of two part end faces from, has saved man-hour.

6. compare with gear ring type composite extruding fine punch die, closed type resistance material better effects if, die life is longer.

7. can enhance productivity, save production equipment.Dash can only working plastic material because existing gear ring pressing plate is smart, thickness can not be too big (domestic can only arrive 12mm), China adopts mechanical processing technique mostly for inductile slab gear at present, and this composite extruding fine punching method and mould are used on the production spur gear, production efficiency is improved greatly, and, therefore can save equipment such as milling machine, grinding machine because part just has Grinding Machining Quality after essence has been dashed.

Description of drawings

Fig. 1 a, Fig. 1 b, Fig. 1 c and Fig. 1 d are respectively the four step working state schematic representations of this die device

The specific embodiment

Below referring to the implementation process of figure process in detail:

The first step: with secondary die 1 and punch 5 relative lockings, the indent degree of depth that forms, the angle thickness that collapses for workpiece makes their integral body move downward then, causes blank to be subjected to squeeze radially and outwards flows, simultaneously, material also upward the secondary die 1 and main die 3 chambeies of below flows, and is subjected to the stopping of resistance material boss E on main die 3 and the secondary die 1 when flowing, and produces lateral pressure, make the deformed area form the triaxial pressure state, see the state of Fig. 1 a.

Second step: extruding action is proceeded, and the waste part of blank fully is extruded, and material is a large amount of simultaneously flows in main die 3 die cavities, and anti-top board 4 is forced to back off, and when secondary die 1 moves to when contacting with main die 3, secondary die 1 stops descending, sees the state of Fig. 1 b.

The 3rd step: keep secondary die 1 pressure, invariant position, allow punch 5 move downward, make blank enter main die 3 fully under forward extrusion, 4 pairs of blank middle parts of anti-top board apply counter-pressure simultaneously, finish the essence of profile and dash, and see the state of Fig. 1 c.

The 4th step: the mould die sinking, with anti-top board 4 part is released, promptly obtain product, see Fig. 1 d.

Claims

1, the enclosed extruding precision punching forming method of a kind of processing low-plasticity, slab curved profile part, the employed mould critical component of this method includes punch, main die, secondary die; Described main die is fixed on the die shoe by die block, and punch is installed on the upper bolster by convex mould pad, and secondary die is installed in outside the punch, and anti-top board puts in main die inside; The end face of described major and minor die is provided with corresponding resistance material boss near the marginal position of matrix cavity, and resistance material boss height is decided with sotck thinkness; Manufacturing process comprises four steps:

The first step: lock and move downward secondary die is relative with punch, causing blank to be subjected to squeeze radially outwards flows, simultaneously, material also upward the secondary die and the main matrix cavity of below flows, when mobile, be subjected to stopping of main die, secondary die and last resistance material boss, produce lateral pressure, make the deformed area form the triaxial pressure state;

Second step: extruding action is proceeded, and the waste part of blank fully is extruded, and material is a large amount of simultaneously flows in the main concave die cavity, and anti-top board is forced to back off, and when secondary die moves to when contacting with main die, secondary die stops descending;

The 3rd step: keep secondary die pressure, invariant position, punch is moved downward matrix cavity is become owner of in the blank extruding, anti-top board applies counter-pressure to the blank middle part, blank is limited in the die cavity that main die, secondary die, punch and anti-top board surround, punch continues to move downward, part is separated with blank, finish the essence of parts profile and dash;

The 4th step: the mould die sinking, with anti-top board part is released.

2, enclosed extruding precision punching forming method according to claim 1 is characterized in that: in the first step that essence is dashed, and the formed indent degree of depth of the relative locking of secondary die with punch, promptly shallow die cavity is the angle thickness that collapses of workpiece.