RU2060084C1 - Method of making adaptors with outer cylindrical land - Google Patents

Abstract

FIELD: metal pressure forming, namely deformation of cylindrical tubular blanks. SUBSTANCE: method comprises steps of making a cylindrical tubular blank by cutting it from a tube or by bending and welding a strip; deforming the blank by combining operations of reduction and expansion in one transition. Upon the last operation in order to provide high accuracy and therefore lowering of metal consumption for working, one of the above mentioned operations (reduction or expansion) may be restricted. Then the semifinished product is being fed to a second transition for making a cylindrical land on it. A pattern of its stressed condition corresponds to a pattern of stressed condition of the drawing operation. EFFECT: increased degree deformation due to performing the above mentioned operations. 3 cl, 5 dwg

Description

 The invention relates to the processing of metals by pressure, in particular to the deformation of cylindrical tubular blanks.

 A known method of producing adapters with an outer cylindrical girdle, including obtaining a cylindrical tube billet and deformation of a part of its crimp.

 The disadvantage of this method is the limited formation.

 The technical result of the invention is to provide the possibility of increasing the degree of deformation.

 This technical result is achieved due to the fact that in the method of producing adapters with an outer cylindrical girdle, which includes obtaining a cylindrical tube billet and deforming a part of it by crimping, simultaneously distributing the remaining part of the billet to obtain an intermediate conical semi-finished product, and then extracting it from the larger side the diameter of the semi-finished product, obtaining an outer cylindrical girdle, while the height of the initial billet N is determined from the ratio.

(1-1/K_o)(K_o)

+

(1)
где K_р

коэффициент раздачи; (2)
К_о D_o/d коэффициент обжима;
b μ^.ctgα
μ (0,1-0,2) коэффициент трения;
D_o диаметр исходной заготовки;
α угол конусности;
h высота цилиндрического пояска,
D и d наибольший и наименьший диаметры детали соответственно.H =

(1-1 / K _o ) (K _o )

+

(one)
where K _p

distribution ratio; (2)
K _o D _o / d crimp ratio;
b μ ^. ctgα
μ (0.1-0.2) coefficient of friction;
D _{o the} diameter of the original workpiece;
α taper angle;
h the height of the cylindrical girdle,
D and d are the largest and smallest part diameters, respectively.

 The distribution or crimping of the workpiece can be performed with restriction.

 In FIG. 1 shows the finished part; in FIG. 2 a scheme for producing an intermediate conical semi-finished product from a cylindrical tubular billet by combining crimping and distributing operations; in FIG. 3 intermediate conical semi-finished product; in FIG. 4 deformation with a possible restriction of the operations of distribution (left) or crimping (right) using persistent collars; in FIG. 5 is a diagram for obtaining an outer cylindrical belt using an extraction operation.

 The method is as follows. A cylindrical tube billet, which is obtained by cutting from a pipe or bending and welding a strip, is deformed, combining the crimping and distribution operations in one transition. Moreover, to increase the accuracy and, consequently, reduce the metal consumption for machining, one of the operations (crimping or distribution) can be limited. After that, the resulting semi-finished product goes to the second transition and it turns a cylindrical belt. In this case, the stress state diagram corresponds to the stress state diagram of the drawing operation.

 With a small size of the cylindrical girdle, the difference in diameters D and d obtained in this method will be greater than in the known method.

(3)
d ε_ρ + d ε_θ + d ε_z 0 (4) где δ_ρ и δ_θ меридиональные и тангенциальные напряжения;
d ε_θ d ρ / ρ d ε_ρdl/l dε_z приращения деформаций,
ρ d_ρ текущий радиус элемента и приращение текущего радиуса,
l, dl длина и приращение длины элемента. Отсюда будем иметь:

(5)
Напряжения, возникающие в коническом очаге деформации при обжиме, согласно [1] можно представить в виде
σ_ρ σ_s (1+b)(1-r/ρ ) (6)
σ_θ σ_s где r d/2; ρ радиус торца заготовки и текущий радиус;
σ_s напряжение текучести. После подстановки (6) в (5) получим

(7)
Проинтегрировав это уравнение и подставив соответствующие пределы, после упрощения будем иметь:
ln

LnR_o/r

(8) где h^o часть длины образующей исходной заготовки, которая пошла на обжим;
L^o длина образующей конуса в зоне обжима. Откуда после потенциирования и замены R_o/r на К_о(r=d/2, R=D_o/2) получим:

(K_o)

(9)
Из (9) получим:
h^o=L^o(K_o)

(10)
Проведем аналогичные выкладки для операции раздачи. В этом случае выражения для напряжения σ_ρ и σ_θ возникающих в коническом очаге деформирования, можно представить в виде [2]
σ_ρ σ_s(1+b)LnR/ρ
σ_θ σ_s[1-(1+b)LnR/ρ (11) где R и ρ наружный радиус фланца и текущий радиус элемента.Formula (1) is obtained from the following considerations. When the crimping and distributing operations are carried out jointly, at the first stamping transition, two distinct deformation zones are observed. In the crimping zone, the length of the generatrix increases, while in the distribution zone it decreases. The simultaneous occurrence of these two processes leads to a change in the initial length of the generatrix. To determine this change, we use the equation of the relationship between stresses and strains and the condition of constant volume, which, taking into account the planar diagram of the stress state, will take the form:

(3)
d ε _ρ + d ε _θ + d ε _z 0 (4) where δ _ρ and δ _{θ are} meridional and tangential stresses;
d ε _θ d ρ / ρ d ε _ρ dl / l dε _z the strain increment,
ρ d _ρ current element radius and increment of the current radius,
l, dl length and increment of the length of the element. From here we will have:

(5)
Stresses arising in the conical deformation zone during crimping, according to [1], can be represented as
σ _ρ σ _s (1 + b) (1-r / ρ) (6)
σ _θ σ _s where rd / 2; ρ radius of the end face of the workpiece and the current radius;
σ _s yield stress. After substituting (6) into (5), we obtain

(7)
Integrating this equation and substituting the corresponding limits, after simplification we will have:
ln

LnR _o / r

(8) where h ^{o is the} part of the length of the generatrix of the initial billet, which went to crimp;
L ^{o the} length of the generatrix of the cone in the crimp zone. Where, after potentiation and replacement of R _o / r with K _o (r = d / 2, R = D _o / 2), we get:

(K _o )

(9)
From (9) we get:
h ^o = L ^o (K _o )

(ten)
We will carry out similar calculations for the distribution operation. In this case, the expressions for the stress σ _ρ and σ _θ arising in the conical deformation zone can be represented in the form [2]
σ _ρ σ _s (1 + b) LnR / ρ
σ _θ σ _s [1- (1 + b) LnR / ρ (11) where R and ρ are the outer radius of the flange and the current radius of the element.

LnR/R_o-

ln

1

LnR/R

(12) где R D^'/2, R_o D_o/2;
L^p длина образующей конуса в зоне раздачи;
h^p часть длины образующей исходной заготовки, которая пошла на раздачу. Заменяя R/R_o на К_p и проведя потенциирование, будем иметь:
L^p/h^p=K

1

Ln K

(13) откуда
h^p

(14)
Суммарная высота исходной заготовки Н равна сумме h^o и h^p, т.е.Substituting (11) into (5) and integrating within the appropriate limits, we obtain:
ln

LnR / R _o -

ln

1

LnR / R

(12) where RD ^' / 2, R _o D _o / 2;
L ^{p the} length of the generatrix of the cone in the distribution zone;
h ^{p the} part of the length of the generatrix of the original billet, which went to the distribution. Replacing R / R _o by K _p and conducting potentiation, we will have:
L ^p / h ^p = K

1

Ln k

(13) where
h ^p

(14)
The total height of the original workpiece H is equal to the sum of h ^o and h ^p , i.e.

+

(15)
Длины образующей конуса в зоне L^p раздачи и обжима L^o найдем из геометрических соотношений
L^p=

(K_p-1)
L^o=

(1-1/K_o) (16)
После подстановки (16) в (15) получим формулу (1).H h ^o + h ^p = L ^o (K _o )

+

(fifteen)
The lengths of the generatrix of the cone in the zone L ^p distribution and crimping L ^o find from the geometric relations
L ^p =

(K _p -1)
L ^o =

(1-1 / K _o ) (16)
After substituting (16) in (15), we obtain formula (1).

 The value of the diameter D 'will be found from the condition of equality of the area of the side surface of the section of the cone, which went to the formation of a cylindrical section of height h, and the area of the side surface of the resulting cylindrical section of height h.

l_o= pDh (17) где l_o длина образующей участка усеченного конуса, идущая на образование цилиндрического участка.From this condition we will have:

l _o = pDh (17) where l _{o is the} length of the generatrix of the section of the truncated cone, going to the formation of a cylindrical section.

Dh (19)
Откуда находим l_o:
l_o=

+

(20)
Подставляя выражение для l_o из (20) в (18), получим:
D′

(21)
С учетом (21) K_p= D′/D_o=

D_o, т.е. получаем формулу (2).On the other hand
D 'D + 2l _o sinα (18)
Substituting (18) in (17) we get:

Dh (19)
Where do we find l _o :
l _o =

+

(20)
Substituting the expression for l _o from (20) in (18), we obtain:
D ′

(21)
In view of (21), K _p = D ′ / D _o =

D _o , i.e. we obtain the formula (2).

PRI me R. Received an adapter with the following dimensions D 100 mm; d 55 mm; α 45 ^about ; S 3 mm; h 4 mm from steel 12X18H10T. For this part, the total shape factor is greater than the allowable crimp ratio, so the proposed method was used. First, we determined the dimensions of the cone obtained at the first transition before the drawing operation, i.e. diameters D and d. By the formula (21) we obtain D '105.5 mm, d we take equal to 55 mm. Taking the diameter of the initial preform equal to 80 mm according to the formula (1), determined the height of the initial preform H 37.1 mm. After two stamping transitions, we got the desired product.

Claims (3)

A method of producing adapters with an outer cylindrical girdle, including obtaining a cylindrical tube billet and deforming a portion of it by crimping, characterized in that at the same time as crimping, the remaining part of the billet is distributed to obtain an intermediate conical semi-finished product, and then the hood is drawn from the side of the larger diameter of the semi-finished product, obtaining an external cylindrical belt, while the height H of the initial workpiece is determined from the ratio

Where

distribution ratio;
K _o = D _o / d crimp ratio;
b = μ • ctg α;
μ = 0.1-0.2 coefficient of friction;
D _{about the} diameter of the original workpiece;
α taper angle;
D and d are the largest and smallest diameters of the part;
h the height of the cylindrical girdle.  2. The method according to p. 1, characterized in that the distribution of the workpiece is carried out with restriction.  3. The method according to p. 1, characterized in that the crimping of the workpiece is carried out with restriction.

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