RU210466U1 - DEVICE FOR HYDROMECHANICAL PRESSING WITH COUNTERPRESSURE - Google Patents

Abstract

The utility model relates to the processing of metals by pressure and can be used for processing hard-to-deform low-plastic materials to obtain a tool with high strength properties. The device for hydromechanical pressing with counterpressure contains a container, inside which there is a working and auxiliary chambers, having a transitional section between them, in which the matrix is placed, and through channels connecting them, as well as a press stamp installed from the side of the working chamber, and a high-pressure fluid regulator. pressure, fixed under the matrix from the side of the auxiliary chamber, which, together with the working chamber, is filled with high-pressure liquid, the device is additionally equipped with upper, middle and intermediate plates, a press stamp is fixed in the upper plate, a guide for centering the press stamp in the container, the middle plate is equipped with a device for creating counterpressure, consisting of two channels - vertical and horizontal, intersecting at right angles, the pressed mass moves in the vertical channel, in the horizontal - a bar with a conical hole, when moving between the channels, a a passage hole belted over the area, in which a counterpressure force occurs during the passage of the pressed mass, in the lower one there is a waste collector for materials used as counterpressure, while the channels for the passage of high-pressure liquid are located separately both in the container and in the middle plate. The technical result consists in expanding the technological capabilities of the device, increasing the reliability of operation and stabilizing the technological process of manufacturing products due to the introduction of additional pressure control. 1 ill.

Description

The utility model relates to the processing of metals by pressure and can be used for processing hard-to-deform, low-plastic materials to obtain a tool with high strength properties.

A device for hydromechanical pressing is known, containing a movable support, a punch holder mounted on it and a punch with a thickened shank, forming between themselves an annular cavity for the working fluid, a fixed support and a matrix movable in the axial direction placed inside it, as well as a container in contact with it at the end. a cavity made in it for the workpiece, and these cavities are interconnected by means of channels made in the matrix (Patent No. 183705, IPC B21C 23/22. Published 06/09/1968, Bull. No. 14).

The disadvantage of this device is the low durability of the dies (less than 5 parts) and the low quality of products, especially when extruding hard-to-deform materials, since when the matrix moves under the action of an axial force transmitted by the punch through the workpiece, the lubricant is displaced from the cavity under the matrix even before the plastic deformations, i.e. by the time the extrusion begins, the pressure of the lubricant in the cavity is insufficient to get into the contact zone of the deformation zone, which leads to a sharp increase in the deforming force and the appearance of defects in the extruded metal.

The closest analogue is a device for hydromechanical pressing with counterpressure, containing a container, on the inner sleeve of which there are working and auxiliary chambers connected by channels, a matrix installed in the transitional conical section of the sleeve, as well as a plunger installed on the side of the working chamber, a pressure regulator fixed fixed and docked with the container from the side of the auxiliary chamber, the support sleeve installed under the matrix at the end of the pressure regulator, while the inner sleeve of the container is made of two parts, one of which contains the chamber, the other contains the transition section and the auxiliary chamber, and the channels, connecting the working and auxiliary chambers are made in the transition section (Patent No. 1423241 IPC B21J 5/04, publ. 09/15/1985, Bull. No. 34).

из труднодеформируемого, хрупкого материала вследствие осевой неустойчивости, где L_д - длина детали, D_н - наружный диаметр детали. Кроме того, высокое давление жидкости создается непосредственно в полости заготовки с помощью плунжера, сжимающего жидкость, что ограничивает технологические возможности устройства.The disadvantage of this device is the instability of its operation when receiving long parts.

from a hard-to-deform, brittle material due to axial instability, where L _d is the length of the part, D _n is the outer diameter of the part. In addition, a high liquid pressure is created directly in the cavity of the workpiece using a plunger that compresses the liquid, which limits the technological capabilities of the device.

The technical result of the claimed utility model is to expand the technological capabilities of the device, increase the reliability of operation and stabilize the technological process of manufacturing products by introducing additional pressure control - a special autonomous source of high pressure fluid (intensifier or high pressure pump), which significantly expands the possibilities of hydrostatic molding, since allows you to vary the pressure over a wide range.

The improvement of methods of cold hydromechanical pressing with counterpressure makes it possible to eliminate the draft of the workpiece at the beginning of pressing, which is important for low-plasticity materials, the plasticity resource of which can be fully used already at the pre-pressing stage.

Hydromechanical pressing technologies are aimed at reducing contact friction forces, which makes it possible to process brittle materials with high resistance to deformation. The use of a lubricant reduces the deformation pressure by up to 40% and makes it possible to deform the material below the recrystallization temperature, which is especially important for reactive metals. Deformation in a cold (warm) state makes it possible to exclude oxidation and gas saturation of metals, as well as to reduce waste losses.

The specified technical result is achieved by the fact that the device for hydromechanical pressing with counterpressure contains a container, inside of which there is a working and auxiliary chambers, having a transitional section between them, in which the matrix is placed, and through channels connecting them, as well as a press stamp installed from the side working chamber, and a high-pressure fluid regulator, fixed under the matrix from the side of the auxiliary chamber, which, together with the working chamber, is filled with high-pressure fluid, the device is additionally equipped with upper, middle and intermediate plates, a press stamp is fixed in the upper plate, a guide is in the container for centering the press ram, in the middle plate there is a device for creating counterpressure, consisting of two channels - vertical and horizontal, intersecting at right angles, the pressed mass moves in the vertical channel, the bar with a conical hole moves in the horizontal channel , when moving between the channels, a through hole of variable area is created, in which, when the pressed mass passes, a counterpressure force arises, in the lower one there is a waste collector for materials used as counterpressure, while the channels for the passage of high-pressure liquid are located separately, as in a container, and in the middle slab and are connected to the power plant by a high-pressure pipeline.

The essence of the claimed utility model is illustrated by a diagram of the kinematic interaction of deforming tools (press ram, - high-pressure liquid, - pressure regulator, throttle, - counterpressure material). In FIG. 1 - diagram of a device for hydromechanical pressing with counterpressure:

left side of the device - initial position;

the right side of the device is the end position.

The device consists of a container 1 containing an upper working chamber 2 connected by channels 3, 4 through a pipeline 5 with a lower working chamber 6 located in the middle plate 7, rigidly bolted to the bottom plate 8, in which there is a through cavity 9 intended for removal of high pressure fluid 10 and waste materials to create backpressure 11 (graphite, metal, melt).

The pipeline 5 connects the channels 3 and 4 of the working chambers 2 and 6, located respectively in the upper and middle plates.

The upper plate 12 of the device holds the press ram 13 and guides it into the lower working chamber 6 through the centering sleeve 14 located in the container 1. A matrix 15 is installed in the lower part of the container 1, which, through the spacer 16, is in contact with the middle plate 7, with which the container 1 rigidly fastened with a clamping bar 17.

In the middle plate 7, a pressure regulator 18 (high pressure valve) is installed, connected to the lower working chamber 6, and through a pipeline 19 it is connected to a high-pressure hydraulic station (item not indicated), which regulates the set pressure in the upper 2 and lower 6 chambers, respectively. Also, in the middle plate 7, a counterpressure device is installed - a throttle 20 that regulates the flow area of the funnel, through which the material 11, which creates backpressure conditions (graphite, metal, melt), with the ability to seep, maintaining the specified, stable power parameters of the throttle and is removed into the waste collector 21 .

In the initial position, in the chamber 6 of the middle plate 7 on the counterpressure device 20, the material 11 is placed (or installed), the upper level of which should be at the level of the boundary of the calibrating hole of the matrix 15.

After the clamping bar 17 of the container 1 is fastened with the middle plate 7, the initial workpiece 22 and the guide 14 are installed in the matrix 15. The upper plate 12 is lowered until a predetermined gap is formed between the end of the press ram 13 and the workpiece 22.

After deformation, the workpiece 22 moves from chamber 2 to chamber 6 and, with the acquisition of new physical and mechanical properties in accordance with changes in the structure parameters, passes into the category of a semi-finished product or part 23.

The device works as follows.

The device is mounted on a P479 hydraulic press with a force of 4000 kN.

The lower plate 8 of the device assembled with the middle plate 7 is attached to the press table, the upper plate 12 - to the press slider.

A lead rod 11 is inserted into the lower chamber 6 of the middle plate 7 on the counterpressure device 20, which is used as a material for creating counterpressure, on which the matrix 15 is put on, while the upper end of the rod 11 is in contact with the calibrating belt of the matrix 15.

The matrix 15 is in contact with the spacer 16 and is centered by the conical part made in the lower part of the spacer, after which the workpiece 22 intended for deformation is inserted into the matrix 15. Then the container 1 is fixed to the intermediate plate by clamping bars 17.

The upper plate 12 is lowered and the press ram 13 is inserted into the working chamber 2 of the container 1 through the centering sleeve 14 until a predetermined gap Δ is formed between the end of the press ram 13 and the end of the workpiece 22 (Fig. 1, left side). The sealing of the press stamp 13 is carried out by chevron seals (fabric reinforced rubber), which are placed in a chevron package (chevron packing seal), consisting of support pressure rings laid between the chevron cuffs (position not indicated).

Then from the hydraulic station through pipeline 5 through channels 3 and 4 high-pressure liquid 10 is supplied to the upper working chamber 2 of the container 1 and the lower working chamber 6 of the middle plate 7, where the desired pressure level is created.

After that, the movement of the upper plate 12 begins. The movement of the press ram 13 first compresses the working fluid and creates counterpressure in the lower working chamber 6 of the middle plate 7, and after contact with the end face of the workpiece 22, it extrudes it through the calibrating hole of the matrix 15, while the lower end of the workpiece 22 presses on the lead rod 11, which acts as a counterpressure. The lead rod 11 is reduced by the backpressure device 20. The all-round pressure of the fluid 10 prevents the lead rod 11 from bending, which exerts the backpressure. The counterpressure force is controlled by changing the throttle opening of the counterpressure device 20.

Further downward movement of the press ram 13 causes an increase in the pressure of the working fluid 10 to the value necessary for the expiration of the workpiece material 22 through the matrix point 15. The excess pressure is regulated by the high pressure valve 18.

At the end of pressing, the pressure corresponds to the level set on the regulator 18 and the throttle 20. Using the control mechanisms of the hydraulic station in the working chambers 2 and 6, the high pressure is removed, after which the press stamp 13 is pulled back, removed from the upper working chamber 2 of the container 1. Then the clamps 17 are removed, the container 1 is raised and the item 23 is removed from the lower working chamber 6 of the middle plate 7.

The use of, for example, viscous antifriction mixtures as a working fluid 10 creates favorable conditions for the manifestation of the hydrodynamic effect of friction due to the high hydrostatic pressure of the working (lubricating) fluid and high strain rates. This helps to reduce contact friction during the extrusion process, reduce the unevenness of deformation over the cross section of the extruded material, improve the mechanical properties of products and increase the durability of dies.

Example

Before pressing, the blanks were covered with a consistent mixture of molybdenum disulfide. A mixture of glycerin and ethylene glycol was used as the working fluid 10. Stabilization of the excess high pressure was maintained by the fluid regulator 18, and the power level of the counterpressure was maintained by the throttle 20. At the end of the work, the high pressure was removed using a check valve.

Using the pressure regulator 18, the pressure can correspond to any given value - up to 2000 MPa.

The device allows for cold hydromechanical pressing of workpieces with a diameter of 40 mm with varying degrees of deformation ε _i from high-strength tool and refractory powder steels, heat-resistant alloys with a minimum counterpressure Р _pr ~ 350-400 MPa. The results of experimental work are presented in the table.

Profiles of various configurations are obtained by hydromechanical pressing with back pressure with an accuracy of diametrical dimensions corresponding to 9-10 grades and surface quality (Ra = 0.32-1.25 μm).

где L_д - длина детали, D_н - наружный диаметр детали.The use of the proposed device makes it possible to increase the degree of deformation of a hard-to-deform, brittle material during one-time extrusion of products up to 2, while simultaneously increasing the ratio of the length of the part to its cross section:

where L _d is the length of the part, D _n is the outer diameter of the part.

Claims (1)

A device for hydromechanical pressing with counterpressure, containing a container, inside which there is a working and auxiliary chambers, having a transitional section between them, in which the matrix is placed, and through channels connecting them, as well as a press stamp installed on the side of the working chamber, and a fluid regulator high-pressure, fixed under the matrix from the side of the auxiliary chamber, which, together with the working chamber, is filled with high-pressure liquid, characterized in that the device is additionally equipped with top, middle and intermediate plates, a press stamp is fixed in the top plate, a centering guide is in the container press ram, a device for creating counterpressure is installed in the middle plate, consisting of two channels - vertical and horizontal, intersecting at right angles, the pressed mass moves in the vertical channel, in the horizontal - a bar with a conical hole, when moving which In the lower part of the channel, a passage opening of variable area is created, in which a counterpressure force occurs during the passage of the compacted mass, in the lower part there is a waste collector for materials used as counterpressure, while the channels for the passage of high-pressure liquid are located separately both in the container and in the middle stove.

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