UA134328U - METHOD OF ELECTRO-HYDRAULIC STAMPING OF EXTENDED BOX SHAPE DETAILS - Google Patents

Abstract

Method for electro-hydraulic stamping of elongated box-shaped parts, which includes primary deformation of the sheet billet and its final formation by the action of fluid pressure impulses on the workpiece, sandwiched between the die and the discharge chamber, which carry out the primary deformation of the workpiece in the previous molding, when removing the rubber liner from the matrix, according to the utility model, a rubber liner of saddle shape is used, and the Young's modulus of rubber is not less than 5 MPa, and its size is determined in advance from the ratios: L-2,2 (B (l (L-1,8 (B, l1 = L-2,5 (B, 0,8 (H (max, H, 0.6 (H (hmin (0.8 (H, b = B, where L is the length of the matrix cavity; L (2.5 (B, B is the width of the matrix cavity; H is the depth of the matrix cavity; l is the maximum length of saddle-shaped rubber liner; l1 - minimum length of saddle-shaped rubber liner; hmax - maximum height of saddle-shaped rubber liner; hmin - minimum height of saddle-shaped rubber liner in the plane of its maximum symmetry; b is the maximum width of the saddle-shaped rubber liner.

Description

The useful model belongs to the field of processing materials by pressure, in particular, using the energy of an electric discharge in water, namely to the technologies of impulse electro-hydraulic (EG) stamping of materials under the action of impulse pressure.

As an analogue, the method of electro-hydraulic stamping is adopted, which is implemented in a device for electro-hydraulic stamping (V.N. Chachyn Zlektrogidroimpulsnoe formoobrazovanie s uzikastaniem zasztschikh cameras / V.N. Chachyn, V.L. Shaduya, A.Yu.

Zhuravsky. - Minsk: Science and Technology, 1985. - 200 p., fig. 4.68, c). The method includes deformation of the workpiece, clamped between the matrix and the discharge chamber, by the action of liquid pressure pulses on the workpiece during the implementation of high-voltage impulse discharges with a given energy when a rubber insert is previously placed in the matrix.

The features that coincide with the features of the claimed useful model are as follows: deformation of the sheet blank by the action of liquid pressure pulses on the blank sandwiched between the matrix and the discharge chamber when the rubber insert is previously placed in the matrix.

The reason that prevents obtaining the expected technical result is as follows: the method does not allow to ensure high-quality electrohydraulic stamping of the elongated box-shaped part.

As the closest analogue, the method of stamping box-shaped parts was chosen, which is implemented by a device for stamping box-shaped parts with pulsed energy sources (patent of Ukraine Mo 115602, IPC 8210 26/12, publ. 04/25/2017. Bull. Mo 8). The device includes matrices placed symmetrically in such a way that they form a common cavity in which the transmission medium and the pulse load source are located. Between the matrices there are pressure rings with an annular gasket between them, the matrices are connected to each other with screws with washers and nuts. In the bottom parts of the symmetrically located matrices, spacers made of rubber material are installed, the workpieces are mixed on them, attached masses of plates of solid material are placed from their outer part, with the help of which, during deformation at the first transition of the workpiece, the necessary field of deformations is obtained, and the plates are connected between elastic elements themselves.

After the impulse load source is initiated, the shock wave through the attached masses acts on the workpieces and deforms them. At the same time, the deformation of the rubber material gasket,

The attached masses and elastic elements ensure a uniform field of deformations in the central parts of the workpieces and deformation of the workpieces in the opposite direction in the corner zones at the first transition. In the second step, rubber gaskets, attached masses, elastic elements are removed from the device and the blanks are finally stamped. At the end of the deformation process, the finished workpieces are removed from the matrices.

The features that coincide with the essential features of the claimed useful model are as follows: primary deformation of the sheet blank and its final shaping by the action of liquid pressure pulses on the blank sandwiched between the matrix and the discharge chamber, which carry out the primary deformation of the blank when previously placed in the matrix of rubber liner, and the final molding - when removing the rubber liner from the matrix.

The reason that prevents obtaining the expected technical result is as follows: the method does not provide high-quality electrohydraulic stamping of a part of an elongated box shape.

The basis of the useful model is the task of improving the method of electrohydraulic stamping of elongated box-shaped parts by changing the shape of the rubber insert, which will allow to ensure a more uniform distribution of the pressure pulse on the workpiece and prevent reversible deflection of the workpiece during deformation and its destruction during final molding, and due to this, improve the quality electrohydraulic stamping.

The essence of the claimed useful model is that in the method of electrohydraulic stamping of elongated box-shaped parts, which includes the primary deformation of the sheet blank and its final shaping by the action of fluid pressure pulses on the blank sandwiched between the matrix and the discharge chamber, which carry out the primary deformation blanks when the rubber insert is previously placed in the matrix, and the final shaping - when the rubber insert is removed from the matrix, according to the useful model, a saddle-shaped rubber insert is used, and the Young's modulus of the rubber is not less than 5 MPa, and its dimensions are determined in advance from the ratios:

I-2,2-Be11I-1,8.8,

I-I-2,5.8, 0.8-NePtakh-H, 0.6-NePtips0.8-H, r-v, because where Г is the length of the matrix cavity; at the same time GI 2 2.58,

B - the width of the cavity of the matrix;

H - the depth of the cavity of the matrix; - the maximum length of the saddle-shaped rubber insert; ""- the minimum length of the saddle-shaped rubber insert;

Bird - the maximum height of the saddle-shaped rubber insert;

Ntip - the minimum height of a saddle-shaped rubber insert in the plane of its symmetry, which passes through its maximum height;

Jur - the maximum width of the saddle-shaped rubber insert. Revealing the cause-and-effect relationship between the essential features of the claimed useful model and the expected technical result, it is necessary to note the following.

The sign "uses a saddle-shaped rubber insert, and the Young's modulus of the rubber is not less than 5 MPa, and its dimensions are determined in advance from the ratios:

I-2,2-VaikI -1,8.8,

I-I-2,5.8, 0.8-NePtakh-H, 0.6-NePtips0.8-H, r-v, where Г is the length of the matrix cavity; at the same time GI 2 2.58,

B - the width of the cavity of the matrix;

H - the depth of the cavity of the matrix; - the maximum length of the saddle-shaped rubber insert; ""- the minimum length of the saddle-shaped rubber insert;

Bird - the maximum height of the saddle-shaped rubber insert;

Ntip - the minimum height of a saddle-shaped rubber insert in the plane of its symmetry, which passes through its maximum height;

Y - the maximum width of the saddle-shaped rubber insert - allows you to ensure a more even distribution of the pressure pulse on the workpiece and prevent reversible deflection of the workpiece during deformation and its destruction during final molding, and due to this, improve the quality of electrohydraulic stamping.

Zo The saddle-shaped shape of the rubber insert with a Young's modulus of rubber of at least 5 MPa prevents the formation of large bends of the workpiece during its extraction from the flanges, which lead to its destruction during final molding, and provides a sufficiently large resistance to the movement of the workpiece into the cavity of the matrix near its elongated sides, preventing excessive extraction of the workpiece from the flanges. Also, the saddle-shaped rubber insert provides a fairly slow increase in resistance to the load, preventing the workpiece from collapsing.

The essence of the useful model is explained by the drawings, where in fig. 1 shows a drawing of a saddle-shaped rubber insert, in fig. 2 - a saddle-shaped rubber insert in axonometry, in fig. C is a longitudinal section of the device during primary deformation of the workpiece when placing a saddle-shaped rubber insert in the matrix, and in Fig. 4 - during final molding - when removing the saddle-shaped rubber insert from the matrix.

The method is carried out as follows.

Rubber with a Young's modulus of at least 5 MPa is pre-selected, then, based on the geometric dimensions of the matrix 1, the dimensions of the rubber liner 2 are determined from the ratios and given a saddle-shaped shape (Fig. 1, Fig. 2, Fig. 3).

I-2,2-VaikI -1,8.8,

I-I-2,5.8, 0.8-NePtakh-H, 0.6-NePtips0.8-H, r-v, where Г is the length of the matrix cavity; at the same time GI 2 2.58,

B - the width of the cavity of the matrix;

H - the depth of the cavity of the matrix;

I - the maximum length of the saddle-shaped rubber insert; ""- the minimum length of the saddle-shaped rubber insert;

Bird - the maximum height of the saddle-shaped rubber insert;

Ntip - the minimum height of the saddle-shaped rubber insert in the plane of its symmetry, passing through its maximum height (Fig. 2);

Jur - the maximum width of the saddle-shaped rubber insert.

Next, a saddle-shaped rubber insert 2 is installed in the cavity Z of the matrix 1, coaxially with the cavity of the matrix (Fig. 3). A flat workpiece 4 is placed on the flange of the matrix 1 and it is pressed with the flange of the discharge chamber 5 to the base 6. The electrode system 7 connected to the pulse current generator (GIS) is installed (not shown in the drawing). The cavity of the discharge chamber 8 is filled with liquid. A high voltage is applied to electrodes 7 from the GIS. When a high-voltage electric discharge is carried out in the liquid, pressure waves are formed in the discharge chamber 5, which load the workpiece 4. Under the action of pressure pulses, the workpiece 4 is deformed and pulled out from the flanges of the matrix 1 and the discharge chamber 5, and begins to fill the cavity of the matrix 3. Saddle-shaped rubber insert 2 limits the extraction of the workpiece 4 from the flanges near the elongated sides of the cavity of the matrix 3, reducing the pressure drop on the workpiece 4 from the discharge waves generated during its movement. As a result, the pressure on the workpiece 4 decreases more slowly, which gives time for greater extraction of the workpiece from the flanges near the short sides of the cavity of the matrix 3. At the same time, the cavity of the matrix with material of the workpiece in its corners is more fully filled during deformation. Holes 9 are made in matrix 1 to allow air to escape from cavity C. Then they proceed to the second stage of stamping - final molding (Fig. 4). The deformed workpiece 4 is extracted from the matrix 1, the rubber insert of the saddle-shaped shape 2 is removed, the deformed workpiece 4 is installed in the matrix 1, it is clamped between the matrix 1 and the discharge chamber 5, and high-voltage electric discharges are carried out until the workpiece 4 takes the required shape.

Example.

Stamping of a flat workpiece made of high-strength steel of the VN240 brand (standard

Ategisap Zosieiu Tog Teviipd apa Maiegiaai5 ABTM A715) with a thickness of 0.65 mm in two ways.

The first method without the installation of a rubber insert, and the second - according to the claimed method.

Based on the dimensions of the cavity of the matrix (I - 120 mm, B - 40 mm, No 20 mm), the dimensions of the saddle-shaped rubber insert were determined I-40mm, II-20mm, Ntakh-1bmm, Ptyp-12mm. Next, a saddle-shaped rubber insert was installed in the cavity of the matrix and the initial deformation of the workpiece was carried out. Then the deformed workpiece was pulled out of the matrix and the saddle-shaped rubber insert was removed. The deformed workpiece was again installed in the matrix and

They finished the stamping process.

The results of stamping according to two methods of preparation are shown in: fig. 5, 6, 7 - without an insert, in fig. 8, 9, 10 - with a saddle-shaped rubber insert, according to the claimed method.

The obtained results showed that the use of a saddle-shaped rubber liner provides electrohydraulic stamping of an elongated box-shaped part with specified radii of curvature in the corners of the matrix, while without the use of a liner, after the first discharge, the workpiece acquires a shape that is significantly different from the specified shape of the part and it cannot be corrected with subsequent discharges.

Thus, the improvement of the claimed method allows to ensure a more even distribution of the pressure pulse on the workpiece and to prevent the reversible deflection of the workpiece during deformation and its destruction during final forming, and due to this, to improve the quality of electrohydraulic stamping.

Claims (1)

USEFUL MODEL FORMULA The method of electrohydraulic stamping of parts of an elongated box shape, which includes the primary deformation of the sheet blank and its final shaping by the action of liquid pressure pulses on the blank sandwiched between the matrix and the discharge chamber, which carry out the primary deformation of the blank when the rubber liner is previously placed in the matrix, and the final shaping - when removing the rubber insert from the matrix, which is distinguished by the fact that a saddle-shaped rubber insert is used, and the Young's modulus of the rubber is not less than 5 MPa, and its dimensions are determined in advance from the ratios: I-2,2-VaikI -1,8.8, I-I-2,5.8, 0.8-NePtakh-H, 0.6-NePtips0.8-H, r-v, where Г is the length of the matrix cavity; while 1 22.5.8, B is the width of the matrix cavity; because H is the depth of the cavity of the matrix;