CN105414233A - Backward extrusion die with back pressure and processing technology adopting same - Google Patents

Backward extrusion die with back pressure and processing technology adopting same Download PDF

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Publication number
CN105414233A
CN105414233A CN201610003985.2A CN201610003985A CN105414233A CN 105414233 A CN105414233 A CN 105414233A CN 201610003985 A CN201610003985 A CN 201610003985A CN 105414233 A CN105414233 A CN 105414233A
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China
Prior art keywords
billet
punch
mould
cup
programme
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Granted
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CN201610003985.2A
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Chinese (zh)
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CN105414233B (en
Inventor
梅瑞斌
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Northeastern University China
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Northeastern University China
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    • BPERFORMING OPERATIONS; TRANSPORTING
    • B21MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21CMANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
    • B21C25/00Profiling tools for metal extruding
    • B21C25/02Dies
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B21MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21CMANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
    • B21C23/00Extruding metal; Impact extrusion
    • B21C23/02Making uncoated products
    • B21C23/20Making uncoated products by backward extrusion
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B23MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23PMETAL-WORKING NOT OTHERWISE PROVIDED FOR; COMBINED OPERATIONS; UNIVERSAL MACHINE TOOLS
    • B23P15/00Making specific metal objects by operations not covered by a single other subclass or a group in this subclass

Abstract

The invention discloses a backward extrusion die. The backward extrusion die comprises a top pressing die, a side-pressing male die and a bottom die, the top pressing die comprises a pressing table and a center male die, wherein the center male die is fixed on the lower portion of the pressing table, and the center male die and the pressing table form an integrated structure; the side-pressing male die is arranged on the outer side of the center male die, and the side-pressing male die and the pressing table are arranged together through a spring; the middle part of the bottom die is concaved to form a work space for containing the center male die, the side-pressing male die and a workpiece.

Description

A kind of with back pressure indirect-extrusion mould and the processing technology adopting this mould
Technical field
The present invention relates to cup/cylindrical member backward extrusion process technology apparatus field, especially relate to a kind of with back pressure indirect-extrusion mould and the processing technology adopting this mould.
Background technology
The advantages such as backward extrusion, has efficiently less without the metal forming technique of cutting as a kind of advanced person, high-quality, low consumption, crystal grain thinning, the cup/cylindrical member or the sleeve like members that are widely used in the non-ferrous alloys such as aluminium, magnesium, titanium and ferrous materials are shaped.Due to backward extrusion material experience large plastometric set process and the inhomogeneous deformation that causes of rubbing causes cup/cylindrical member phenomenon of " embracing mould " and wall portion to crack." embrace mould " phenomenon causes makes cup/cylindrical member cannot the demoulding, greatly reduces production efficiency and product quality; Wall portion crackle produces and causes percent defective to raise, and particularly low to plastic deformation abilities such as magnesium alloy, titanium alloy, high strength alumin ium alloys metal is difficult to cup/cylindrical member that backward extrusion obtains high-quality and performance.
Summary of the invention
Produce the shortcoming of embracing mould and inductile material and being difficult to backward extrusion for above-mentioned cup/cylindrical member backward extrusion process, the object of this invention is to provide a kind of structure simple, to make and maintenance cost is low, can overcome very well and embrace mould phenomenon and improve the band back pressure indirect-extrusion mould of inductile material cup/cylindrical member backward extrusion ability and adopt the processing technology of this mould.
Its technical scheme is, a kind of indirect-extrusion mould, comprises a top pressing mold, a flanging punch, a bed die, and top pressing mold comprises and presenting a theatrical performance as the last item on a programme, be fixed on present a theatrical performance as the last item on a programme bottom and with the central punch of presenting a theatrical performance as the last item on a programme in integrative-structure; Flanging punch to be located at outside central punch and by spring together with presenting a theatrical performance as the last item on a programme and being set to; Bed die medial recess forms the working space holding central punch, flanging punch and workpiece.
Described bottom and the flanging punch top of presenting a theatrical performance as the last item on a programme is respectively equipped with the groove coordinated with spring, and both ends of the spring is separately fixed in two grooves.
Described flanging punch bottom surface is horizontal by 2-5 ° of angle.
Adopt the technique that above-mentioned indirect-extrusion mould makes the cup/cylinder of alloy/metal, described technique comprises the following steps:
(1) billet is cast, cast metal/alloy cylinder billet;
(2) cut billet, base is machined away ingot epidermis and billet is cut to and meet mould requirement size;
(3) preheating billet, puts into billet in stove and is heated to 0.5-0.7Tm, and Tm is the melting temperature of this billet metal or alloy; In this step, general and according to stove instrument insulation 1-2 hour;
(4) lubricated dies, is participating in lubricant smeared by the central punch of squeeze job, bed die and flanging punch;
(5) setup parameter, sets the downstream rate of central punch, descending displacement and final mean annual increment movement in hydraulic press state modulator instrument board;
(6) preheated mold, is electrically heated to 150-200 DEG C by mould, mould is installed temperature measuring device and is connected with controller dial plate, realizing real-time testing and the control of mold temperature;
(7) squeeze job, hotter complete billet is put into mould, extrude according to the parameter of setting, central punch descending extruding billet center, flanging punch produces and metal flow direction opposite effect power and back pressure under the action of the spring, avoid wall portion metal embrace mould extruding billet periphery the most at last billet be processed into cup/cylindrical member, above-mentioned back pressure is calculated by following formula;
F 1 = k · d 2 D 2 - d 2 · S
In formula, F1 is real-time back pressure in extrusion process, and unit is N, k is the elastic coefficient, and unit is punch descending displacement centered by N/m, S, and unit is m, and test feedback by displacement transducer, d is cup shell internal diameter, and unit is m, D is cup shell external diameter, and unit is m.
(8) take out cup/cylindrical member, complete a sub-band back pressure backward extrusion.
In above-mentioned steps (4), lubricant is molybdenum bisuphide.
Mould provided by the invention and technique overcome " embracing mould ", and phenomena principles is: in backward extrusion process, central punch is descending, and flanging punch is simultaneously descending, and spring-compressed, flanging punch gives cup/cylindrical member wall portion downward pressure by spring-compressed.Because the contact surface on flanging punch and cup/cylindrical member wall portion top exists 2-5 ° of gradient, therefore the back pressure F1 (N) produced is perpendicular to this end surface, and becomes 2-5 ° of angle with central punch axial line, and F1 resolution of vectors is:
F → 1 = F → 2 + F → 3
for back pressure vector, for point force vector perpendicular to die inner surface, for point force vector perpendicular to female bottom.F1, F2, F3 unit is N.Under horizontally outward component F2 effect, the trend that cup/cylindrical member wall portion metal inwardly flows will be changed, thus avoid cup/cylindrical member wall portion to embrace central punch phenomenon.
The principle that the present invention improves the backward extrusion Plastic Forming limit and cup/cylindrical member depth dimensions is: perpendicular under the pressure F3 effect of female bottom, and cup/cylindrical member deformation zone stress state is:
σ 321<0
Mean stress value is:
&sigma; 0 = &sigma; 3 + &sigma; 2 + &sigma; 1 3 < 0
Wherein, σ 1(MPa) be first principal stress, σ 2(MPa) be second principal stress, σ 3(MPa) be third principal stress, σ 0(MPa) be mean stress.
Because three directions all produce compression, so backward extrusion process material inside produces stronger three-dimensional compressive stress under backpressure condition, the material that three-dimensional compressive stress state is not only conducive to plastic deformation difference realizes large plastometric set, improve its backward extrusion limit and cup/cylindrical member Forming depth, and three-dimensional compressive stress state is conducive to crack healing, thus avoid the next crackle generation of cup/cylindrical member backward extrusion process inhomogeneous deformation band.
Technique scheme tool has the following advantages: the present invention is according to cup/cylindrical member size die size different from design of material, the three-dimensional compressive stress produced under back pressure condition improves cup/cylindrical member forming limit, the component horizontally outward of the back pressure contact surface generation of constant slope can overcome metal material and inwardly flow, thus avoid " embracing mould " phenomenon, improve stock utilization and product quality.Compared with prior art, advantage of the present invention is:
1, adopt the flanging punch of constant slope, effectively can not only avoid the demoulding difficult problem that " embracing mould " phenomenon causes, and also serve positioning action to a certain extent;
2, band back pressure apparatus is adopted to be that backward extrusion process material inside produces stronger three-dimensional compressive stress state, and this three-dimensional compressive stress state greatly improves the backward extrusion limit and cup/cylindrical member Forming depth, be extremely conducive to the cup/cylindrical member backward extrusion of the advanced non-ferrous metals such as magnesium alloy, titanium alloy, high strength alumin ium alloy.
3, be with back pressure backward extruding die lamps structure simple, be easy to dismounting, and back pressure does not need too large, thus cost is low, easy care.
4, by different mold materials and size design, thus make the method can be used in the cup/cylindrical member backward extrusion of any shape and metal material, function is widened
Accompanying drawing explanation
Fig. 1 is the structural representation of one embodiment of the present invention;
Detailed description of the invention
Below in conjunction with specific embodiment, the present invention will be further described.
Composition graphs 1, a kind of indirect-extrusion mould, comprises top pressing mold 1, flanging punch 2, bed die 3, it is characterized in that, top pressing mold comprises and presents a theatrical performance as the last item on a programme 11, be fixed on present a theatrical performance as the last item on a programme bottom and with the central punch 12 of presenting a theatrical performance as the last item on a programme in integrative-structure; Flanging punch to be located at outside central punch and by spring 4 together with presenting a theatrical performance as the last item on a programme and being set to; Bed die medial recess forms the working space holding central punch, flanging punch and workpiece 5.In the present embodiment, described in present a theatrical performance as the last item on a programme bottom and flanging punch top be respectively equipped with the groove 21 coordinated with spring, both ends of the spring is separately fixed in two grooves.Described flanging punch bottom surface is horizontal by 2-5 ° of angle.
Adopt above-mentioned indirect-extrusion mould to make a technique for alloy/metal cup/bobbin, described technique comprises the following steps:
(1) billet is cast, cast metal/alloy cylinder billet;
(2) cut billet, base is machined away ingot epidermis and billet is cut to and meet mould requirement size;
(3) preheating billet, is heated to 0.5-0.7Tm by billet, and Tm is the melting temperature of this billet metal or alloy;
(4) lubricated dies, is participating in smearing lubricant on the central punch of squeeze job, bed die and flanging punch;
(5) setup parameter, sets the downstream rate of central punch, descending displacement and final mean annual increment movement;
(6) preheated mold, is electrically heated to 150-200 DEG C by mould;
(7) squeeze job, puts into mould by hotter complete billet, according to setting parameter extrude, central punch descending extruding billet center, flanging punch spring drive under extrude billet periphery the most at last billet be processed into hollow cup/bobbin;
(8) take out cup/bobbin, complete and once extrude.
In above-mentioned steps (4), lubricant is molybdenum bisuphide.
In above-described embodiment, put in stove by billet and be heated to 0.5-0.7Tm during preheating billet, Tm is the melting temperature of this billet metal or alloy, and according to stove instrument insulation 1-2 hour;
The downstream rate of central punch, descending displacement and final mean annual increment movement is set in hydraulic press state modulator instrument board.Downstream rate controls in actual downstream velocity feedback to instrument board according to velocity sensor.Descending displacement and final mean annual increment movement carry out controlling and feeding back according to displacement transducer;
During preheated mold, mould is electrically heated to 150-200 DEG C, mould is installed temperature measuring device and be connected with controller dial plate, realizing real-time testing and the control of mold temperature;
In squeeze job, hotter complete billet is put into mould, extrude according to the parameter of setting, central punch descending extruding billet center, flanging punch produces and metal flow direction opposite effect power and back pressure under the action of the spring, avoid wall portion metal embrace mould extruding billet periphery the most at last billet be processed into cup/cylindrical member, back pressure is calculated by following formula;
F 1 = k &CenterDot; d 2 D 2 - d 2 &CenterDot; S
In formula, F1 is real-time back pressure in extrusion process, and unit is N, k is the elastic coefficient, and unit is punch descending displacement centered by N/m, S, and unit is m, and test feedback by displacement transducer, d is cup shell internal diameter, and unit is m, D is cup shell external diameter, and unit is m.
Embodiment 2, the present embodiment with 7075 high strength alumin ium alloys for experiment material is described in further detail the specific embodiment of the present invention.Following examples for illustration of the present invention, but are not used for limiting the scope of the invention.
The first step: smelt 7075 aluminum alloy round bars, then carry out Homogenization Treatments;
Second step: peeling, and utilize Linear cut acquisition length to be 25mm, diameter is the pole blank of 80mm;
3rd step: be put in heating furnace, heating-up temperature is 450 DEG C (these alloy melting points about 700 degree), heats 2 hours;
4th step: setting central punch downlink working speed is 2.5mm/s, work down initial displacement 25mm, final descending displacement 20mm;
5th step: smear Molykote to punch-die;
6th step: mould utilizes heating mantle heats to 120 DEG C;
7th step: be put into by blank in die, punch starts downlink working, work shift 25mm, center material is depressed, and edge metal up flows and to contact with flanging punch; When punch downlink working, flanging punch is followed descending, and contacts with cup/cylindrical member wall portion end face gradually, produces reaction force, i.e. so-called back pressure.
8th step: punch continues descending, and spring is compressed, and back pressure progressively increases, and is finally increased to 300N;
9th step: the displacement of Back Extrusion Punches downlink working arrives 5mm, and punch is up;
Tenth step: flanging punch sets back under the action of the spring, knock-pin ejects backward extrusion part, and backward extrusion terminates.
After backward extrusion terminates, gained 7075 aluminium alloy cup/cylindrical member.
Measure this cup/cylindrical member degree of depth, perpendicularity and damage, aspect ratio is greater than 1.5, and forming limit significantly improves, wall portion and bottom vertical degree grade of errors higher, do not find crackle in wall portion, quality is better.
In sum, not whole intension of the present invention: after this, all to have within do by invention subject spirit any amendment, replacement until improve the projects such as upgrading, include within protection scope of the present invention.

Claims (5)

1. an indirect-extrusion mould, comprise a top pressing mold (1), a flanging punch (2), a bed die (3), it is characterized in that, top pressing mold comprise present a theatrical performance as the last item on a programme (11), be fixed on present a theatrical performance as the last item on a programme bottom and with the central punch of presenting a theatrical performance as the last item on a programme in integrative-structure (12); Flanging punch to be located at outside central punch and by spring (4) together with presenting a theatrical performance as the last item on a programme and being set to; Bed die medial recess forms the working space holding central punch, flanging punch and workpiece (5).
2. indirect-extrusion mould according to claim 1, is characterized in that, described in present a theatrical performance as the last item on a programme bottom and flanging punch top be respectively equipped with the groove (21) coordinated with spring, both ends of the spring is separately fixed in two grooves.
3. indirect-extrusion mould according to claim 1, is characterized in that, described flanging punch bottom surface is horizontal by 2-5 ° of angle.
4. adopt indirect-extrusion mould described in claim 3 to make a technique for the cup/cylinder of alloy/metal, it is characterized in that, described technique comprises the following steps:
(1) billet is cast, cast metal/alloy cylinder billet;
(2) cut billet, base is machined away ingot epidermis and billet is cut to and meet mould requirement size;
(3) preheating billet, is heated to 0.5-0.7Tm by billet, and Tm is the melting temperature of this billet metal or alloy;
(4) lubricated dies, is participating in smearing lubricant on the central punch of squeeze job, bed die and flanging punch;
(5) setup parameter, sets the downstream rate of central punch, descending displacement and final mean annual increment movement;
(6) preheated mold, is electrically heated to 150-200 DEG C by mould;
(7) squeeze job, puts into mould by hotter complete billet, according to setting parameter extrude, central punch descending extruding billet center, flanging punch spring drive under extrude billet periphery the most at last billet be processed into hollow cup/cylinder;
(8) take out cup/bobbin, complete and once extrude.
5. method according to claim 4, is characterized in that, in above-mentioned steps (4), lubricant is molybdenum bisuphide.
CN201610003985.2A 2015-03-10 2016-01-04 A kind of processing technology with back pressure indirect-extrusion mould and using the mould Expired - Fee Related CN105414233B (en)

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CN201510103618 2015-03-10
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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107598054A (en) * 2017-08-01 2018-01-19 江苏大学 A kind of disk-like accessory forging mold
CN107755446A (en) * 2017-09-25 2018-03-06 中北大学 A kind of processing technology of raising DT4C pure iron magnetic behaviors
CN108555054A (en) * 2018-04-20 2018-09-21 成都天智轻量化科技有限公司 A kind of preparation process for the mold external member and health-care cup preparing magnesium alloy health cup
CN110479787A (en) * 2019-07-09 2019-11-22 贵州安大航空锻造有限责任公司 The backward extrusion method of alpha+beta diphasic titanium alloy Shell Forging Parts
CN110479786A (en) * 2019-07-09 2019-11-22 贵州安大航空锻造有限责任公司 The backward extrusion method of alpha titanium alloy Shell Forging Parts

Citations (5)

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Publication number Priority date Publication date Assignee Title
JPS4843544A (en) * 1971-10-06 1973-06-23
CN2917849Y (en) * 2006-07-07 2007-07-04 唐建军 Oil drill pipe joint die
CN101020200A (en) * 2006-02-14 2007-08-22 江苏森威集团有限责任公司 Precise forging process with composite radial and back extrusion
CN101428303A (en) * 2008-11-27 2009-05-13 江苏飞船股份有限公司 Indirect-extrusion mould returned material plate assistant guide structure
CN202638924U (en) * 2012-05-10 2013-01-02 昆山永年先进制造技术有限公司 Backward extrusion die

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4843544A (en) * 1971-10-06 1973-06-23
CN101020200A (en) * 2006-02-14 2007-08-22 江苏森威集团有限责任公司 Precise forging process with composite radial and back extrusion
CN2917849Y (en) * 2006-07-07 2007-07-04 唐建军 Oil drill pipe joint die
CN101428303A (en) * 2008-11-27 2009-05-13 江苏飞船股份有限公司 Indirect-extrusion mould returned material plate assistant guide structure
CN202638924U (en) * 2012-05-10 2013-01-02 昆山永年先进制造技术有限公司 Backward extrusion die

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107598054A (en) * 2017-08-01 2018-01-19 江苏大学 A kind of disk-like accessory forging mold
CN107755446A (en) * 2017-09-25 2018-03-06 中北大学 A kind of processing technology of raising DT4C pure iron magnetic behaviors
CN108555054A (en) * 2018-04-20 2018-09-21 成都天智轻量化科技有限公司 A kind of preparation process for the mold external member and health-care cup preparing magnesium alloy health cup
CN110479787A (en) * 2019-07-09 2019-11-22 贵州安大航空锻造有限责任公司 The backward extrusion method of alpha+beta diphasic titanium alloy Shell Forging Parts
CN110479786A (en) * 2019-07-09 2019-11-22 贵州安大航空锻造有限责任公司 The backward extrusion method of alpha titanium alloy Shell Forging Parts

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