RU2072271C1 - Cylindrical part deep drawing stamp - Google Patents

Abstract

FIELD: production of cylindrical parts by sheet stamping. SUBSTANCE: stamp has axially aligned punch 2, pressure member 1 and die 3, and unit for blocking critical section of part in the process of drawing. Drawing die is composed of die 3 and restricting ring 7 attached to die 3. Blocking unit disposed between restricting ring 7 and die 3 is formed as sleeve composed of a set of centered rings 4,5,6 . . , made from antifriction material and seated one onto the other. EFFECT: increased efficiency, increased depth of drawn products, improved quality without usage of special presses, reduced cost of stamping jigs. 2 cl, 4 dwg

Description

 The invention relates to sheet stamping and can be used in the manufacture of hollow cylindrical products.

Closest to the proposed invention in technical essence and the achieved effect is a stamp for deep drawing of cylindrical parts from sheet metal, containing a coaxially mounted punch, clamp and die, as well as a unit for blocking a dangerous section of the drawn product [1]
The disadvantage of this technical solution is that its implementation requires special energy-intensive press equipment, and the stamping process itself with pouring liquid into the die cavity and removing it from the part is laborious.

 The technical result achieved using the proposed stamp is that along with an increase in the depth of the drawn products, their high quality and cylindricality of the inner surface of the stamped product are ensured, as well as the fact that the use of this stamp does not require the use of special presses for hydromechanical drawing and provides high productivity stamping parts.

 This is facilitated by the fact that the exhaust matrix is made up of the matrix itself and a restrictive ring attached to it, between which there is a unit for blocking a dangerous section of the extruded product, made in the form of a sleeve consisting of a set of rings of antifriction material centered and mounted on each other, with the inner bushing diameter is given taking into account the elastic tension of the sleeve to the diameter of the matrix Dm by 0.2 0.25 from the one-sided gap between the die and the punch, and the rings of which the sleeve of the block of the block of the dangerous section of the workpiece of the drawn product is made are made of beryllium bronze Br, B2.5 .

 In FIG. 1 shows a longitudinal section of the stamp in the initial position and in the position before the start of the hood; in FIG. 2 the same at the intermediate moment of drawing and at the end of the drawing of the hollow cylindrical product.

The stamp contains the following main parts and components:
clip 1 mounted on the outer slider of the press (not shown conditionally);
a punch 2 mounted on the inner slider of the press (not shown conditionally);
matrix 3 with a node for blocking a dangerous section of the product being drawn, made in the form of a sleeve of rings 4, 5, 6 centered and mounted on each other and fixed under the exhaust edge of the matrix 3 using a restrictive ring and bolts 8.

 An exhaust matrix with a unit for blocking a dangerous section of the extruded product is mounted on the press table 9, the workpiece 10 with a diameter of Do and thickness So is mounted on the working surface of the matrix 3 and centered using the adjusting ring 11. Position the semi-finished product at the intermediate moment of the hood and position 12 stamped on the stamped cylindrical product 13.

 Deep drawing sheet parts using the proposed stamp is as follows.

 When the working stroke of the press is turned on, clamp 1 and punch 2 from the initial position (Fig. 1) are lowered, as a result of which, after touching them with the workpiece 10, the workpiece 10 is first pressed against the matrix 3 by the clamping forces 1, which prevents folding of the stamped material in the flange part of the workpiece and then (after the contact of the punch with the workpiece 10 according to Fig. 2), the semi-finished product 12 is shaped at the intermediate drawing moment (Fig. 3), followed by its drawing into the cylindrical product 13 (Fig. 4).

 As the punch 2 with the deformable workpiece 12 is lowered into the exhaust cavity of the matrix 3, the wall of the semi-finished product 12 sequentially distributes the rings 4, 5, 6. of the blocking sleeve of the dangerous section of the drawn product, which ensures that the wall of the latter is pressed against the punch 1.

 After the product 13 has been drawn to a predetermined depth, the rings 4, 5, 6. the blocking sleeves of the dangerous section of the product being drawn are restored to their original shape, as a result of the backward movement of the punch 2 upwards, the stamped part 13 is removed from the punch 2 and removed from the press working area, since the inner diameter of the sleeve Dv is less than the diameter of the product Dm by the value of Dm Dv (0.2 0.25) (Dm Dp).

Due to the fact that the coefficient of friction μ _{p of the} stamped material with the punch (in the absence of lubrication between them) is μ _p 0.2, and the coefficient of friction μ _{m of the} stamped material with rings 4, 5, 6. of the blocking block of the dangerous section of the product being drawn ( if there is lubricant between them and these rings are made of antifriction material, for example, from beryllium bronze Br, B2, 5) is μ _m 0.1, as a result, the total coefficient μΣ between the stamped material and the working surfaces of the punch and die is provided mS = μ _p -μ _m 0.2 0.1 0.1 that with cash If there is a well-defined pressure q from the side of rings 4, 5, 6. the blocking sleeves of the dangerous section create useful friction forces when these rings are deformed by 0.2 - 0.25 from the one-sided gap between the die 3 and the punch 2, i.e., the value of Dm Dv (0.2 0.25) (Dv Dp). It should be noted that the value of (Dm Dv) / (Dv Dp) 0.2 0.25 is selected from the condition of ensuring that the wall of the product being drawn is pressed against the punch, which can get thinning at the punch edge of the punch to 0.2 0.25 of the original thickness So (Dm Dp) / 2 blanks 10.

коэффициент вытяжки Ко До/Дп в зависимости от показателя пластичности n штампуемого материала увеличивается от Ко 0,2 (при n 0) до Ко 2,6 (при n 0,5).Deep drawing with blocking the dangerous section of the product being drawn out by the liquid under controlled pressure according to the prototype was considered in the Works of NIAT N 276, which established the technological capabilities of this method and determined the pressure q required to block the dangerous section of the product being drawn. In particular in these Proceedings shown that the losses on friction at a draw preform στ of the clamp 1 and the matrix 3 and the bending straightening drained material with _g s within 30% of the ultimate strength of the material drained _into σ, t. E. During

the coefficient of drawing Ko To / Dp, depending on the ductility index n of the material being pressed, increases from Ko 0.2 (at n 0) to Ko 2.6 (at n 0.5).

где s_в предел прочности штампуемого материала;
n показатель пластичности вытягиваемого материала.Considering that the mechanism of blocking the dangerous section of the workpiece during the hood in the proposed stamp is practically the same as that with the hydromechanical hood according to the prototype, the pressure q can be set either by the nomogram in FIG. 16 [3] either by the formula

where s _{is the} tensile strength of the stamped material;
n is an indicator of the ductility of the material being drawn.

и, во-вторых, из условий равновесия, записываемого в виде:

что, с учетом значения q по формуле (1), приводит к следующей зависимости

где Е модуль упругости колец 4, 5, 6. втулки блокирования опасного сечения заготовки.The thickness value in the rings 4, 5, 6. The blocking bushings are established by jointly solving equations that determine the stresses σ _in the circumferential direction, firstly, according to Hooke's law

and, secondly, from the equilibrium conditions, written in the form:

which, taking into account the value of q by formula (1), leads to the following dependence

where E is the elastic modulus of the rings 4, 5, 6. the blocking sleeve of the dangerous section of the workpiece.

We establish the thickness of the rings 4, 5, 6. of the hazardous section blocking unit using the example of deep drawing of a cylindrical glass made of stainless steel Х18Н9Т (σ _в ) 54 kgf / mm ² ; n 0.5) with a thickness of So Rm Rп 2 mm with a workpiece diameter of up to 260 mm into a matrix 3 with a diameter of Dm 100 mm, rings 4, 5, 6. Blocking bushings, which are made of beryllium bronze Br, B2, 5 (E 12000 kgf / mm ^2. σ _in W 130 kgf / mm ² ).

 According to the formula (3), the value of the width of the rings is 4, 5, 6.

Длину Lвт втулки блокирования опасного сечения следует принимать не более 1/3 максимальной глубины штампуемой детали (Lвт < Hmax/3).

The length Lw of the blocking sleeve of the dangerous section should be taken no more than 1/3 of the maximum depth of the stamped part (Lw <Hmax / 3).

Применение предложенного штампа с металлическим упруго-деформируемым узлом блокирования опасного сечения заготовки, размещенным под вытяжной кромкой матрицы наряду с расширением технологических возможностей глубокой вытяжки обеспечивает высокое качество изготавливаемых изделий без использования специальных прессов для гидромеханической вытяжки при значительном снижении затрат на изготовление штамповой оснастки.The use of the values Lw <Hmax / 3 is impractical, because, firstly, when the drawing depth H> Hmax / 3, there is a sharp decrease in the stamping force Pm, which allows the hood to be drawn at this stage without blocking the dangerous section of the drawn product and, secondly , with a length Lw <Hmax / 3, there is an unnecessary complication of manufacturing an exhaust matrix with a block for blocking a dangerous section of the workpiece, and hence an increase in the metal consumption of the stamp. Hence

The use of the proposed stamp with a metal elastically deformable unit for blocking the dangerous section of the workpiece located under the drawing edge of the matrix, along with expanding the technological capabilities of deep drawing, ensures high quality of manufactured products without the use of special presses for hydromechanical drawing with a significant reduction in the cost of manufacturing die tools.

Claims (2)

1. A stamp for deep drawing of cylindrical parts, containing a coaxially mounted punch, clamp and die, as well as a dangerous section blocking unit, characterized in that the exhaust matrix is made up of a matrix itself and a restrictive ring attached to it, and a dangerous section blocking unit for the stretched product placed between them and made in the form of a sleeve, consisting of a set of centered and mounted on each other rings of antifriction material, and the inner diameter of the sleeve D _{in n is} given with y even elastic stretching of the sleeve to the diameter of the inner hole of the matrix D _m by 0.2 0.25 from the one-sided gap between the matrix and the punch and is D _{in n} D _m (0.2 0.25) (D _m D _p ), where D _{n is the} diameter of the punch.  2. The stamp according to claim 1, characterized in that the rings of which the sleeve is composed are made of beryllium bronze Br B 2.5.

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