The blame circle tall flange that contains big flange limit figuration method pre-test

Keywords: Figuration of flange of 　 of 　 Turn Edge of 　 Strain of Stress of Big Flange 　 is one of plasticity figuration fundamental pattern. Flange wide application produces a field at industry of etc of car, plane. But the blame circle tall flange of edge of big to containing flange (graph 1) , as a result of flange height of big, flange is tall, the structure is relatively complex, metallic flow influencing factor is much, its figuration has quite difficulty, cause extremely easily attenuate badly even craze. In the graph 1 is shown in producing a course, carry out through relapsing, overcame attenuate badly, flange craze, verticality is bad to wait for a problem, production gives eligible part. Graph the 1 blame that contains big flange limit is round Fig of tall flange spare parts.

Program of technology of 1 　 Non_Circular Part With Big Flange1 reachs figuration method surely really 1.

The determines this take shape key of 1 technology program depends on flange. Because flange height is tall, the height of the biggest flange that exceeded direct flange figuration to be able to be achieved, accordingly, cannot use take shape of direct flange law, and can pull the flange after delaying first only (pull to what what say by the side of big flange delay, be not common sense to go up pull delay. Be being told from some kind of meaning is a kind of local figuration, just use here " pull delay " one word) . Produce to facilitate, play delay time two common a wollens. Pull after delaying from the sliver intermediate, undertake flange next. To avoid corner of upend edge R and flange edge (face) the ply that the spherule face that contacts figuration is in attenuates badly, affecting a spare parts to become shape size and the premise that assemble use relation to fall finally, increase pull the spherical radius that delays place of face of spherule of spare parts of the figuration on the model, be in of semifinished product pull delay the gouge on underside " person " glyph craft chamfer. As a result of this chamfer dig make, reduced play delay time power gets on underside sectional, increased an unit to pull stress sectionally, benefit flows to sidewall at underside material, alleviated thereby of brim of flange straight wall attenuate badly. Technological process is: Wollens → draws contrast of school of → of flange of → of the sliver that delay → . 1.

2 pull delay height to decide the use requirement to satisfy a spare parts really, must assure the smallest ply after its figuration: δ Min= δ - K δ - ∣ of ∣ Δ T among them: δ -- material nominal ply, δ =2.

5mm; K -- flange attenuates rate, take 0.

25; ∣ of ∣ Δ T -- the absolute value of the deviation below material ply. Accordingly, the Min=2 of δ of the smallest ply after figuration.

5-0.

25 × 2. 5 - 0. 15 ＝ 1. 725(mm) , and existence concerns as follows between the ply of flange around material: In type: T ′ -- the ply of place of the brim after flange; T -- board makings ply, t= δ ; D0 -- prefab aperture; M -- flange coefficient; D -- the diameter after flange. Because haul the floor after delaying,material attenuates very small, can think ply is changeless, consider next error of material ply, have D0/D=0.

63466 ≈ 0.

635 　 so the Hmax=1/2D(1-m)+0 of height at ultimate load of flange.

57r=16.

In 4(mm) type: R -- part round part. Reason has pull delay high H=H-hmax+r+t=18.

0mm. In type: H -- spare parts height. In actual production, decide via experimenting to be taken actually pull delay height for 17.

3mm, adjacent be worth at theoretical calculation. 1.

3 moulds structure and pull the preform after delaying delay flange to be in same cover a mould aspirant travel, its mould structure sees a picture 2. Pull the wollens before delaying to see graph 3(a) , pull after delaying, show like graph 3(b) place. Pull the over all dimension after delaying (overall length, beam overall) did not change basically, "Person " glyph chamfer is pulled to move. Pull after delaying from the departure intermediate, take out surplus undertakes flange, after flange, verticality of office of corner of 1 ～ 4R is poorer, can use form of school of school form model. Graph Fig of plan of 2 moulds structure.

2 　 Die1.

Modular handle; 2.

Hit makings pole; 3.

Upper mould board; 4.

Bolster plate; 5.

Guide-post bushing; 6.

Sunken model; 7.

Discharge board; 8.

Control frontier group; 9.

Guide pillar; 10.

Punch; 11.

Ejector pin; 12.

Leave pattern plate; 13.

Fixed position is sold. (A) (B) graph 3 pull delay Fig of around preform graph.

Analysis of stress of 3 　 Plate Before And After Drawing Blank2, meet an emergency is pulled as a result of left, right both sides delay appearance likeness, characteristic of each bits of corresponding stress, meet an emergency is similar also, reason can take one of edges to undertake an analysis, regard it be circle of a 1/2 to pull delay and two 1/4 help the combination that delay rectangularly. 2.

Of bottom of circle of 1/2 of edge of 1 pair of big flange pull delay an analysis to part of big flange edge, in pull in extending a process, can divide for two areas: (1) pulls stress σ 1 influence area, put in σ in this area namely 1; (2) is not σ 1 influence area, see a picture 4. Graph of bottom of circle of 1/2 of edge of 4 pairs of big flange pull delay analytic Fig.

The small unit that in σ 1 influence area takes a distance to center O to be DRx for Rx, width undertakes 　 of 4 　 The Drawing Stress Of 1/2 Circular Base Of The Big Flange analysis, oversight is tall a D σ 1.

DRx, balance equation is σ 1.

Rx.

D φ .

T+ σ 1.

DRx.

D φ .

T+d σ 1.

Rx.

D φ .

T- σ 1.

Rx.

D φ .

T-2 σ 3.

DRx.

Sin(d φ / 2)=0 is random in D φ when little value, sin(d φ / 2)=d φ / 2, have R then.

When material of 3)dRx=0 of σ of 1- of σ of D σ 1+(produces plasticity to be out of shape, the basis bends family name criterion, σ having ∣ 1 - 3 ∣ of σ ＝ β .

In σ S type: σ S -- succumb the limit; σ 1, σ 3 -- be out of shape of the area pull delay with compress advocate stress; β -- stress condition coefficient, (μ : Lode parameter) ; =1.

1. Have. In type: C -- errant integral waits for calm constant mediumly. To big flange Bian Layan, dimension of the preform after because pull,be being delayed and pull the photograph before delaying to compare almost changeless, so Rt=R0. R1m -- the internal diameter average of the spare parts, r1m=r1+t/2; R0 -- the circle is pulled delay semifinished product radius; Rt -- mobile semifinished product external diameter; Rx -- those who allow to take is cricoid small internal diameter; T -- semifinished product ply (it is facilitating analysis, assume in whole pull the ply in extending a process changeless, namely T= δ ) . When Rx ≥ R0=Rt, 1 ＝ of σ 0; When Rx ＜ R0=Rt, 1 ＝ of σ 1.

1 σ Sln(Rt/Rx) , see graph 5(a) . (A) pulls stress to pursue (B) pressing stress pursues (Fig of curve of the stress that plan of plan of C) meet an emergency pulls delay time flange to go up by the side of 5 big flange, meet an emergency.

　 of 5 　 Curve Of The Stress And Strain While Drawing The Big Flange to big flange edge pull delay, part of the predestined relationship outside flange does not suffer basically play the effect that delays action, its are the accordingly biggest tangential press stress σ 3 be not appear in Rx=R0=Rt position, be in instead 3 ＝ of this position σ 0, see graph 5(b) . This is caused by the mutual embroil action of material oneself. As Rx reduce, σ 1 in increase, σ 3 by 0 turn into 3max of the biggest σ is reduced again for 0, so σ the formula of 3 turns into 3 ＝ of σ 1. 1-ln of ｛ of 1 σ S [(Rt-a)/Rx] ｝ (the) when Rt-a of ≤ of R1m ≤ Rx. In type: A -- 3 maximum position goes to σ the distance of the predestined relationship outside stress influence area. As a result of σ 1max ＝ 1. 1 σ S, below good position, take no account of round angle of attrition, sunken model to reach cold when making sclerosis, rt/r1m ＝ of ＝ of R0 ／ R1m 2. 72, have R0=Rt=2.

72r1m 　 is become namely Rx ≥ R0=Rt=2.

When 72r1m, do not suffer pull delay effect effect. Change by rule of stress, meet an emergency and model changeless condition has volume when ε 3 ＝ of 2 ＝ ε 0 when, namely Rx=0.

When 6Rt, see graph 5(c) , do not add thick also do not attenuate, have so arrive from Rx=Rt=R0 Rx=r1m, the ply change of material is to attenuate first, again thickening, decrease again next thin. Curve of the stress of the predestined relationship outside flange arriving from R1m position when big flange Bian Layan, meet an emergency is shown 5 times like the graph. Because aborning can get the influence of all sorts of elements, reason actually Rt (solid) with theory exist as follows to concern between Rt: Rt(is solid) in =KRt type: K -- all sorts of elements affect coefficient. R1m/Rt<K ≤ 1 (equality sign is taken below good position) the element such as round horn of the smooth pitch of the condition of 　 　 K and material oneself, strength approaching a limit that draws delay time, mould, sunken model is concerned. The liquidity of material is better (material is in anneal condition) , the force that approach a limit is smaller, attrition force is smaller, k value is greater, the specification suffers on flange face play the effect that delays action area is larger, to preventing material excessive attenuate, make sure spare parts figuration is more advantageous. 2.

2 pairs of 2 1/4 rectangle pull the corner of analytic 　 R that delay and flange surface contact to form the figuration of spherical place to be similar to the figuration that press a bag. Of the ply way that its get power control stress and the rest of two direction pull stress. The meet an emergency of ply direction is reduce strain, accordingly pushball side position attenuates serious, often because of this position attenuate badly and bring about discard as useless, see a picture 6. Graph Fig of the stress of 6 spherical place, meet an emergency.

　 of 6 　 Stress And Strain At The Sphere is 　 σ as a result of the meet an emergency of its ply direction 3 to lose a value, 3 ∣ of ∣ σ are bigger, ε 3 bigger; σ 1, σ 2 all be be worth, 1 ＋ of σ σ 2 bigger, ε 3 bigger. ε 3 to reduce strain, its jump over big specification to attenuate more serious. To reduce pushball side position attenuate badly, must reduce perpendicular at ply direction press stress σ 3 and other of two direction pull stress σ 1, σ 2. As a result of σ the size of 3 and spherical radius are concerned, spherical radius is smaller, σ 3 bigger, jump over conversely small. To reduce σ 3 affecting a spare parts to assemble use premise to fall, from the consideration of angle of figuration craft sex of the spare parts, use most means spherical replace diameter of original smaller part spherical, see a picture 7. (A)(b)(c) pursues 7 with most diameter spherical replace smaller part diameter spherical Fig.

The spherule face SR5 that 7(a) of graph of 　 of 7 　 Replacement Of The Little Radius Sphere By The Large Radius Sphere pulls the corner of straight wall R that delay and flange surface contact to form for 1/4 rectangle; Graph 7(b) is the section plane that supports through heart of spherule face ball, ball, join A of two point of tangency, b, f is AB midpoint, g is EF midpoint, the circle of two 4 Mm cuts AK respectively, BH two linear at A, b, what be 12 Mm through G dot radius is spherical cut with the circle of two 4 Mm at D, c at 2 o'clock, with SR12 big spherical replace face of former SR5 spherule, see graph 7(c) . Pull stress σ to reduce 1, σ 2, outside dividing the mould space that increases R corner point, still go up to go out in underside " person " glyph chamfer, flow at material with benefit. Verticality of area of the flange after flange is bad, want farther corrective verticality. Via carrying out a proof, dig craft chamfer to reach use big spherical pull delay ply of spherical to preventing place to enjoy some very good effect too. 3 last words to bringing up the blame circle tall flange of flange edge figuration, pull delay height to want to wait for an element to decide according to the requirement of the smallest ply after spare parts figuration and material status, coefficient of friction. Attenuate to prevent material effectively, use craft chamfer to reach using big spherical radius is cogent and significant craft step. CNC Milling CNC Machining