RU2443496C1 - Method of producing articles with cavities by thixomoulding and closed mould to this end - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to metallurgy and may be used in moulding complex-shape articles from aluminium alloys by thixomoulding. Billet is deformed in closed mould at press. Billet is pierced by top male die and bottom fixed male die. At the same time, deformed metal is supported by press pusher forced downward by metal pressure. Note here that cavity for surplus metal is formed. Then die forging is carried out by acting by pusher on surplus metal. Note also that pusher diameter is defined by relationship cited in description.

EFFECT: uniform filling of mould cavities, higher quality of moulded articles.

2 cl, 3 dwg

Description

The group of inventions relates to the field of metallurgical engineering and can be used in the manufacture of products of complex configuration, mainly from aluminum alloys, by the method of thixotropic molding - by stamping.

The initial billet is obtained by continuous casting with constant stirring of the melt, which provides a globular microstructure to the billet metal.

Tixoshtampovka is a technological process, including heating a pre-globularized workpiece to a solid-liquid state and its deformation in stamps. This technology allows to obtain accurate products with high mechanical properties, low energy consumption due to the reduction of stamping efforts (see the journal "Metallurgy Engineering" No. 1, 2001, p. 36-43).

A known method of stamping products with an internal hole with firmware in a closed stamp, including firmware with simultaneous support of ring punches and subsequent stamping of the product by acting on ring punches, and the stamping device contains a closed stamp with punches for firmware and back-up of deformable metal (SU 419289 A, B21J 5 / 10, 08/07/1974).

The disadvantage of this method is that this stamping operation can only be carried out on special multi-plunger presses.

A known method for producing products with thixolithic cavities, including the deformation of the workpiece in a closed stamp on the press (RU 2356677 C2, B21J 5/06, 05/27/2009). A closed stamp for receiving articles with thixolithic cavities contains a container, a matrix, a pusher mounted with the possibility of longitudinal movement.

The technical result provided by the inventions is to improve the quality of products of complex configuration during their manufacture on conventional presses by stamping by ensuring uniform filling of the workpiece with all the metal cavities in the metal.

In order to achieve the indicated technical result in a method for producing products with a thixo-stamping cavity, including deforming a workpiece in a closed stamp on a press, in accordance with the invention, the workpiece is deformed by flashing it with an upper punch for flashing and a lower stationary punch of a stamp with simultaneous support of the deformable metal and subsequent stamping, in this case, the deformable metal is supported by the pusher of the stamp when it is moved down under the metal pressure to cavities for excess metal, and stamping is performed by exposing the excess metal with a pusher, and the diameter of the pusher d _t is determined from the dependence:

where R _t - the force of the pusher;

P _ol - the pressure of the press;

D _p - the diameter of the upper punch for firmware.

A closed stamp for receiving products with a thixolithic cavity, containing a container, a matrix mounted with the possibility of longitudinal movement of the pusher, is equipped with an upper punch for firmware and a lower stationary punch made with a cavity, the pusher is installed in the said cavity of the lower punch and is equipped with a hydraulic cylinder, the drive of which is made with adjustable safety valve, adjusted to the required pressure of the support of the pusher.

The invention is illustrated by graphic materials, which show:

figure 1 - the beginning of stamping firmware;

figure 2 - the end of the stamping firmware;

figure 3 - stamping.

The closed stamp consists of a container 1, inside of which two half-matrixes 2, 3 and a lower fixed punch 4 with a rod of the pusher 5 inside it are installed. The container 1 is mounted on the lower cross member of the press 6. The upper punch for firmware 7 is installed on the movable cross member of the press (not shown in FIG.).

The thixo stamping method is as follows. The preformed blank 8 with a globular structure is heated to a stamping temperature and placed in a closed stamp. During the press, the upper punch for firmware 7 upsets the metal of the workpiece 8 and moves it, filling the cavities formed in closed semi-matrices 2, 3 of the stamp.

The deformation of the metal of the workpiece 8 is carried out with a back-up, ensuring uniform filling of all the cavities of the half-matrix 2, 3 with metal. Excess metal and metal that does not fill up some places of the cavity of the half-matrix 2, 3 due to insufficient stamping moves into the cavity 9 formed when the plunger rod 5 is moved down in the lower stationary punch 4. The required pressure support pusher 5 is achieved by an adjustable safety valve (not shown), installed in the actuator (not shown) of the hydraulic cylinder olkatelya 5.

To ensure the stamping of the product 8, it is necessary to create significantly greater specific stamping forces. This is achieved by the fact that the diameter of the pusher 5 is selected from the condition that the specific forces created in the cavities of the semi-matrices 2, 3 during the course of the pusher 5 are 2 ... 4 greater than the specific forces created by the punch 7 during firmware.

, а удельные усилия, создаваемые толкателем при доштамповке,

то окончательно зависимость для определения диаметра d_т толкателя можно представить в виде:Thus, if the specific forces created by the punch for firmware,

, and the specific forces created by the pusher during stamping,

then finally the dependence for determining the diameter d _{t of the} pusher can be represented as:

where R _t - the force of the pusher;

P _ol - the pressure of the press;

D _p - the diameter of the upper punch for firmware.

The interval from 2 to 4 is selected from the following considerations. The lower limit of "2" provides the necessary force for doshtamovki. The upper value "4" is limited by the strength of the die tooling.

The claimed method and stamp for producing products by thix-stamping allow to expand technological capabilities by obtaining products of complex configuration, for example with asymmetric cavities and through holes, to improve the quality of products due to the operation of stamping.

Claims (2)

1. A method of obtaining products with thixolithic stamping cavities, comprising deforming a workpiece in a closed stamp on a press, characterized in that the workpiece is deformed by flashing it with an upper punch for flashing and a lower stationary punch of a stamp with simultaneous support of the deformable metal and subsequent stamping, while supporting the deformable metal is carried out by a pusher of a stamp when it is moved down under metal pressure to form a cavity for excess metal, and punching is performed the impact of the pusher on the excess metal, while the diameter of the pusher d _t is determined from the dependence:

,
where R _t - the force of the pusher;
P _ol - the pressure of the press;
D _p - the diameter of the upper punch for firmware. 2. A closed stamp for receiving products with a thixoforming cavity, containing a container, a matrix, a pusher mounted with the possibility of longitudinal movement, characterized in that it is equipped with an upper punch for firmware and a lower stationary punch made with a cavity, the pusher is installed in the said cavity of the lower punch and equipped with a hydraulic cylinder, the actuator of which is made with an adjustable safety valve, tuned to the required pressure support pusher.

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