RU2357830C2 - Method and device for thixotropic moulding of cylindrical work pieces - Google Patents

Abstract

FIELD: mechanics.

SUBSTANCE: inventions are referred to metallurgical mechanical engineering and may be used for items production from the cylindrical work pieces, mainly from aluminium alloys by thyxotropic moulding method. The work piece is heated together with a container, where it is put before heating and closed with a cup. The heated work piece is then deformed at press in a pre-heated closed die. The die includes a low semi-die with cavity, kick-off mechanism and upper semi-die fixed to the movable plate. The latter is provided with an open-end cylindrical opening. The heated container together heated work-piece and cup is mounted on the kick-off mechanism lifted above the end side of low semi-die and adjusted along the kick-off mechanism axis. After that the container is step-by-step removed from the working area during intermittent motion of the kick-off mechanism. Then press is closed with the upper semi-die and kick-off mechanism together with work piece and cup is brought to the lower position. Besides it is ensured that the work-piece is placed in the open-end opening of the upper semi-die. Then the cup is removed and work-piece is deformed by the punch setting in the open-end opening of the upper semi-die and in the cavity of the lower semi-die. Finally, the set work-piece is deformed by the upper semi-die and punch to the production of finished item.

EFFECT: increased productivity and quality of finished items, reduced consumption of metal.

2 cl, 7 dwg

Description

The invention relates to the field of metallurgical engineering and is used in the manufacture of various products from cylindrical billets mainly from aluminum alloys by the method of thixotropic shaping - thixostamping.

Before considering analogues, it is necessary to give the following explanations. The initial preform is obtained by continuous casting under conditions of constant mixing. In this case, a suspension is formed (a solid-liquid state in which the ratio of solid to liquid phases is determined by the heating temperature and depends on the type of material) with a globular microstructure, which ensures a very high fluidity and mold filling during further processing. This allows you to get finished products with high mechanical, and therefore operational properties. Tixoshtampovka is a technological process of re-heating a cast billet to a solid-liquid state with its subsequent stamping. Moreover, very strict requirements are imposed on temperature and time parameters, since the feasibility of thixo-stamping technology and the quality of the finished product depend on this. This technology allows you to replace steel with aluminum alloys, makes it possible to reduce energy costs, reduce weight, and also perform stamping on less powerful presses. However, the development of this promising area of metalworking is constrained by the high cost of cast billets, as well as the difficulty of working with a solid-liquid initial billet and maintaining its temperature in a narrow range (Metallurgy, Mechanical Engineering, 2001, No. 1, pp. 36-43).

Known hot volumetric stamping of steel gear from a cylindrical billet on a crank press in several transitions (see Ya. M. Okhrimenko. "Forging and Press Production Technology." M .: Mechanical Engineering, 1976, Fig. 234, pp. 387-388). The figure shows the finishing stream of an open type stamp. The lower matrix is made of an insert and an ejector. The upper matrix contains an insert, a fixed rod and an ejector.

The disadvantage of this method is the low quality of the finished product, due to the multi-position design of the stamp, which does not allow to withstand the temperature-time parameters of the process. Increased metal consumption, since an open stamp is used. Poor performance, which is obvious.

A known method and device for thixoforming of cylindrical parts according to patent RU 2248857 C2, published 03/27/2005, V23K1 / 38, including the deformation of a preheated cylindrical workpiece in a preheated stamp, and a device for implementing this method.

A disadvantage of the known technical solution is the need to perform several technological operations, which can lead to the possibility of increasing the time of the process, to the possibility of reducing the temperature of the workpiece and, as a result, to reduce the productivity of manufacturing products, as well as to reduce the quality of the finished product.

The technical task of the claimed method and device is to improve the quality of finished products, performance and reduce metal consumption. This is achieved by the fact that the technological process - thix-stamping is performed from one installation of a preheated initial billet, and continuously in two stages: precipitation and stamping. In addition, all preparatory operations (heating the workpiece, its transportation and installation in the stamp) up to the deformation of the workpiece is carried out in a container and a glass. This allows you to fully use the properties of the globular microstructure of the workpiece, as it can withstand the harsh temperature and time parameters of the stamping process. The mentioned placement of solid-liquid preform also eliminates its damage. Reduced metal consumption is also an important advantage of the proposed technical solution, due to the high cost of the original cast billet.

The task is achieved by the fact that the workpiece is placed in a container with an inner cup, then heated and mounted on the pusher along its axis, which is lifted above the end of the lower half-matrix, after which, during intermittent movement of the pusher, the container is sequentially dismantled, the stamp is closed on the inner diameter of the lower half-matrix upper half-matrix, lower the pusher with the workpiece to the lower position, placing the latter in the through cylindrical cavity of the upper half-matrix, and then remove the Akan, the blank is deposited with a punch in the cavity of the upper and lower half-matrices and finally the finished product is stamped with the upper matrix and punch. The method is implemented by a device in which a movable plate and a press slider are connected by means of hydraulic cylinders, and the device is equipped with a container, which is made in the form of two articulated two-arm levers, on one shoulders of which removable arms are fixed, and on opposite arms parallel to the axis of the said hinge two half rings are rigidly mounted, and inside the latter there are jumpers, on which a stack is located with the possibility of both interacting with their surfaces and dismantling upside down, and the bottom half rings wasted through the cylindrical bore.

The invention is illustrated by graphic materials, which show:

figure 1 - installation of the workpiece in the device;

figure 2 - removal of the glass from the device;

figure 3 - the beginning of the precipitation of the workpiece;

figure 4 - the beginning of the stamping;

figure 5 - the end of the stamping;

6 is a General view of a special container with a glass;

Fig.7 is a section aa in Fig.6 (rotated).

A device for thixo-stamping of a cylindrical billet 1 (see Fig. 1), placed in a special container 2 and closed by a glass 3, contains a pusher 4 and a housing 5 with a lower half-matrix 6. Above the lower half-matrix, an upper half-matrix 7 is located coaxially with it, which is mounted on a movable plate 8. A through cylindrical hole is made along the axis of the upper half-matrix. A punch 10 is mounted concentrically to the hole on the slider 9. The movable plate and the slider are connected by hydraulic cylinders 11. The stamping is carried out on a hydraulic press, the slider of which is moved by means of a power plunger cylinder and return cylinders. The container is made (see Fig.6) of two two-arm levers 12, which are connected by a hinge 13. On one shoulders 14 of the levers with the help of sleeves 15 with L-shaped grooves and protrusions 16 are mounted removable arms 17. On the opposite shoulders of 18 levers parallel to the axis of the hinge and symmetrically to each other two half rings 19 with jumpers 20 inside are rigidly fixed (see Fig. 7). In the lower part of the half rings, a cylindrical socket 21 is bore, interacting with the pusher when installing the workpiece in the device. All parts of the container and the glass are made of titanium alloy.

The thixo stamping method is as follows. The technological process is performed on a hydraulic press: the maximum force of the power plunger cylinder is P = 4000 kN, the total force of the hydraulic cylinders is 12-Pi = 800 kN. The press is equipped with sensors and control equipment for working in automatic mode. The finished product is a brake disc. Preparation - casting from aluminum alloy AL-9. The blank 1 is installed on the jumpers 20 (see Fig. 7) of the container 2 and closed with a glass 3, then the container is placed in a muffle furnace, the arms 17 are removed (see Fig. 6) and the blank is heated to 585 ° C. The stamping tool (keys 6, 7 and 10) is heated to 400 ° C and graphite grease is sprayed on it. The device is set to its original position (see Fig. 1), namely: raise the slider 10, lower the plate 8 relative to the slide with hydraulic cylinders 11, and the pusher 4 is lifted above the end of the lower half-matrix 6 (shown to the right of the axis of the pusher). The heated container 2 is installed on the pusher 4, centering it with a socket 21 (see Fig.7). Raise the pusher 2 and enter the glass 3 into the hole of the upper half-matrix 7 to a depth of H (shown to the left of the axis of the pusher), which prevents radial displacement of the glass during dismantling of the container. Half rings 19 are bred, while the blank 1 and the glass are mounted on the end of the pusher. Remove the container 2 from the working area. Lower the plate 8, close the stamp with the upper half-matrix 7 along the inner diameter of the lower half-matrix 6, and the glass with the workpiece is placed between the plate 8 and the slider 9 (see figure 2). Turn container 2 through 180 ° (socket 21 up) and, having placed glass 3 in it, clamp it with half rings 19. Hold the container in this position and lowering the pusher to its original position, set the workpiece in the through axial cylindrical hole of the lower half matrix 5. Then remove the container 2 with the glass 3. The device is prepared for deformation of the workpiece. The slider 9 is lowered and the blank 1 is upset with the punch 10 into the cylindrical cavity of the upper half-matrix 7, and then into the closed die cavity. In this case, the joint between the flange of the upper half-matrix and the end face of the lower half-matrix is revealed (see Fig. 4). Continue to lower the slider 9 and stamp the finished product with the upper semi-matrix 7 and the punch 10. Moreover, the gap h = 1 ... 3 mm (see figure 5). To remove the finished product from the end face of the upper half-matrix 7 (if necessary), raise the slider 9 to its original position, lower the plate 8, place the spacer in the cylindrical cavity of the upper half-matrix 7 and reverse the hydraulic cylinders 11 until the punch 10 interacts with the spacer. The finished product - the brake disk is removed from the lower half of the matrix 6 by the pusher 4, lifting it above the upper end of the housing 5. The technological process of thixo-stamping of the cylindrical workpiece is completed.

Claims (2)

1. The method of thixo-stamping of cylindrical billets, including the deformation of a preheated cylindrical billet in a preheated stamp, characterized in that the deformation is carried out on a press in a closed stamp containing a lower half-matrix with a cavity, a punch, an ejector and mounted on a movable plate kinematically connected with the press slider , the upper half-matrix, which has a through cylindrical hole and is configured to close the stamp on the inner diameter of the lower half-matrix s, and they deform the cylindrical billet preheated together with the container into which it is placed before heating and closed with a glass, the aforementioned heated container with a heated billet and glass is mounted on a pusher raised above the end of the lower half-matrix and placed along the axis of the pusher, after which during intermittent movement of the pusher, the container is sequentially removed from the working area, the stamp is closed with the upper half-matrix and the pusher with the cylindrical workpiece and the glass is lowered into the lower position e with the placement of the cylindrical workpiece in the through cylindrical hole of the upper half-matrix, after which the glass is removed and the cylindrical workpiece is deformed by its precipitation by the punch in the said through cylindrical hole of the upper half-matrix and in the cavity of the lower half-matrix, and the deposited workpiece is finally deformed by the upper half-matrix and punch to obtain the finished product . 2. A device for thixo-stamping of cylindrical billets, characterized in that it contains a movable plate connected to the press slider by means of hydraulic cylinders, on which an upper half-matrix is mounted, made with a through cylindrical hole, a punch installed on the press-slider concentrically referred to the opening, a case with a lower half-matrix, located coaxially with the upper half-matrix and made with a cavity, an ejector, a container for a cylindrical workpiece, made in the form of two articulated joints levers, removable handles mounted on one shoulder of the said two-arm levers, two half rings rigidly mounted on the opposite shoulders of the two-arm levers parallel to the axis of the hinge connecting them, and a glass, and the half rings are made with jumpers located in them to place the glass upside down and cylindrical on them a socket in the lower part for centering the container relative to the pusher, and the upper half-matrix is installed with the possibility of translational movement relative to the lower half-matrix.

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