RU2259897C1 - Method for making forgings by hot extrusion in extruding press having movable container - Google Patents

Abstract

FIELD: plastic metal working, possibly forging variable cross section parts by extrusion in hydraulic presses with movable container.

SUBSTANCE: method comprises steps of feeding heated blank to container; pressing out blank in container by means of pressure pad and extruding part of blank to die of die set; forming forging having constant cross section part and thickened part that is formed after upsetting remaining portion of blank; placing part of die set in container according to condition of joining their planes. Upsetting of remaining portion of blank for forming thickened part of forging is realized in cavity between joined planes of die set unit and container. Said cavity is formed due to moving die set unit relative to container before forming thickened part of forging. Upsetting operation is realized due to simultaneous motion of pressure pad and container.

EFFECT: possibility for making forging with complex outer and inner configurations, simplified assortment of technological tools, enhanced quality of forging.

2 cl, 9 dwg

Description

The invention relates to the processing of metals by pressure and can be used in stamping by extrusion of parts of variable cross section on hydraulic presses with a moving container.

It is known that the amount of plastic deformation that can be achieved without fracture (ultimate deformation) is influenced by many factors, the main of which are the mechanical properties of the metal (alloy), temperature and strain conditions, and the stress state diagram. The latter factor has a great influence on the value of ultimate strain. The greatest ultimate deformation is achieved in the absence of tensile stresses and an increase in compressive stresses. One of the most optimal schemes for metal forming is extrusion stamping, in which plastic deformation occurs under conditions of comprehensive, uneven compression, which allows to obtain a very large degree of deformation without destroying the workpiece, both in the direction coinciding with the movement of the punch and in the lateral direction, not coinciding with the movement of the punch. Hot extrusion as a technological operation of die forging is used to manufacture a wide range of parts (N. Sokolov. Hot stamping by extrusion of steel parts, M., Mechanical Engineering, 1967, pp. 25-31).

A known method of manufacturing forgings by extrusion, including sequentially performed operations: cutting a workpiece from long products in a stamp, reducing the rod and forming the external contour of the head by dialing metal into the conical cavity of the punch by pre-disembarkation and final shaping of the head. The workpiece is used with a diameter corresponding to the diameter of the end face of the head, followed by machining the chamfers and calibrating the diameter. Then, the cavity is formed, the end of the head is calibrated, and the volume is dosed by combined extrusion, and the external contour of the head is formed sequentially by its height during metal collection and final shaping by disembarkation, while the specified cavity profile is fixed with a mandrel (RF patent No. 2205722, 21 K 1/00).

The disadvantage of this method is its low versatility, a large number of transitions, the profitability of this technological scheme is manifested only in large-scale and mass production.

A known method of hot stamping of hollow products, in which the product is formed by one stroke of the punch, the outer side surface of the product is molded in a collapsible sleeve located in the press container. Forming is carried out by redistributing the flow of the metal stream while it is extruded into the main cavity and into the technological protrusions (radial and axial), after which the bottom is removed. The cross section of the technological protrusions is assigned taking into account the conditions of deformation and tool life (RF patent No. 2191654, B 21 J 5/06).

The disadvantage of this method is the difficulty in manufacturing a technological tool, in the selection and debugging of process parameters.

A known method of manufacturing a hollow cylindrical product, consisting of a pipe with a constant or variable cross-section of the outer side surface and a one-sided flange of piece cylindrical billets, including heating the workpiece, feeding the workpiece with an axial hole into the container, pressing the cylindrical part of the product into the gap between the working channel of the matrix and the movable press needle. In this case, the flange is shaped at the same time in the cavity formed by the end face of the container and the surface of the matrix holder (RF patent No. 2216419, 21 C 23/08).

The disadvantage of this method is the restrictions imposed by the fact that the compression cavity is rigidly attached and limited by the gap between the ends of the matrix holder and the container, as a result of which it is possible to obtain only products with one-sided flange thickening.

A known method of manufacturing hot extrusion stampings on presses with a movable container, comprising feeding the heated preform to the container, extruding the preform in the container with a press washer, compressing part of the preform into a matrix included in the matrix assembly, forming a stamping with part of a constant section and forming on said stamping thickening by precipitation of the remaining part of the workpiece (SU 632426 A, 15/11/1978, 21 C 23/08) - prototype.

The disadvantage of this method is the complexity and high cost of manufacturing the tool, the restrictions on the formation of thickenings of complex configuration and location along the axis of the manufactured product.

The problem to which this invention is directed, is to obtain stampings with a variable cross-section of the outer side surface on presses with a moving container, for example bar-shaped.

The technical result achieved during the implementation of the invention is to obtain for one technological transition stampings of complex internal and external configurations, including with a thickening on the outer surface, reducing the range of technological tools, improving the quality of surfaces and the stability of the geometric dimensions of products, reducing energy consumption and labor costs and increasing the capabilities of universal press equipment.

The specified technical result is achieved by the fact that in the proposed method for manufacturing hot stamping forgings on presses with a movable container, comprising supplying a heated billet to the container, pressing the billet in the container with a press washer, pressing a part of the billet into a matrix included in the matrix unit, with forming a stamping with a part of a constant cross-section and the formation of thickening on said stamping by precipitation of the remaining part of the workpiece, part of the matrix assembly is placed in a container from the conditions cheniya conjugation their planes, and the residue remaining portion of the preform in forming the thickening is carried out in the cavity between the mating planes of the matrix assembly and the container, which is formed by moving the container assembly with respect to the matrix prior to forming the thickening, and the precipitate is effected by simultaneous movement of the press washer and the container.

The method allows the use of forward, reverse and lateral extrusion, as well as their combinations. The matrix unit as part of the matrix holder and the matrix can be composed of several technologically advanced parts. In this case, stamping is formed from one heating with one set of tools. As a result of this, labor costs, energy consumption of the technological process are reduced, and the nomenclature of the technological tool is reduced. The optimal selection of metal forming processes, as well as the tool used allows you to expand the range of manufactured parts, increase their range in weight and size, as well as improve the accuracy of the size of stampings and the quality of their surfaces.

It is also possible in the manufacture of stampings, which along with the indicated thickening are thickened on the side surface, use a prefabricated matrix, and the formation of a thickening on the side surface is carried out in the cavity that is formed between the parts of the prefabricated matrix.

One of the components of the matrix has free axial movement, which is carried out simultaneously with the movement of the container.

Figures 1 and 2 show a flow chart of stamping a monolithic rod with a flange having recesses on the rear end of the stamping: in Fig. 1 - at the top is the initial position before pressing the die 1, container 2, workpiece 3 and press washer (with a figured protrusion) 4, below - extrusion of the rod 5 and the formation of a recess on the rear end of the workpiece; figure 2 at the top - the formation of a cavity 6 between the container and the matrix by the tap of the container, below - the formation of the flange 7 after settling the workpiece while moving the container and the press washer.

In Fig.3 - the same as in Fig.1 and 2 with the formation of the protrusion 8 at the rear end of the stamping.

In Fig.4 - the same as in Fig.1 and 2 with the formation of a conical flange 9.

In Fig.5 - the same as in Fig.1 and 2 with the formation of a stepped rod.

Figure 6 presents the technological scheme of stamping a glass with a flange, at the top - forming a glass by the method of backward extrusion into the gap between the press needle 10 and the container 2, below - stamping thickening formed by the withdrawal of the container 2 from the matrix 1.

7, stamping a hollow product with a flange: at the top - direct extrusion of the hollow element into the gap between the press needle 10 and the die plate 13, below - stamping of the thickening (flange) 11.

On Fig: at the top - direct extrusion of a hollow hollow element 12, below - stamping thickening.

In Fig.9: at the top is a diagram of the stamping of a hollow product with a flange 13 into a cavity formed by the end surface of the matrix and the container, at the bottom is a stamping of thickening on the side surface of the part into a cavity 14 formed between two parts of the precast matrix 15 and 16, and the cavity 14 is formed by jointly withdrawing the container 2 and the movable part of the matrix 16. The movable part of the matrix is collapsible, which ensures its removal after removing the part.

The industrial applicability of the claimed method of manufacturing stampings of variable cross-section by hot extrusion is confirmed by the following example of a specific implementation on a horizontal bar-shaped press with a force of 3150 tf. A shaped blank of VT6 titanium alloy is manufactured, having a shaft ⌀120 mm, 500 mm long, a flange ⌀295 mm and a height of 50 mm with a protrusion at the rear end ⌀140 mm and a height of 150 mm. A cylindrical billet with dimensions of ⌀197 × 385 mm is heated to a temperature of 950 ° C and loaded into a container of ⌀200 mm. The ⌀120 × 500 mm rod is pressed out into the die as far as it will go (stamp closure), and ⌀140 x 150 mm in the cavity of the press washer of the ridge, then the container is removed from the die holder at a distance corresponding to the undeformed part of the workpiece, and the container and press stamps form a flange of ⌀295 × 50 mm.

This method allows for a single installation of the workpiece to produce the design of complex internal and external stamping surfaces. The sequential design of the internal and external contours of the part reduces the stamping force, increases the tool life and improves the quality of the part. The invention provides a non-waste process, minimizing the specific efforts on the tool and increasing its durability, high quality products, expanding the technological capabilities of hot die forging to increase the complexity of the shape of the outer contour and cavity and improve the service properties of parts using metals and alloys of increased strength. The technological capabilities of universal hydraulic presses with a moving container are also greatly expanded.

Claims (2)

1. A method of manufacturing hot extrusion stampings on presses with a movable container, comprising supplying a heated preform to a container, extruding a preform in a container with a press washer, pressing a part of the preform into a matrix included in the matrix assembly, with forming a stamping with part of a constant section and forming the specified stamping thickening by precipitation of the remaining part of the workpiece, characterized in that part of the matrix node is placed in the container from the condition of ensuring the conjugation of their planes, and the sediment is left When the thickening is formed, the bulk of the preform is carried out in the cavity between the mating planes of the matrix assembly and the container, which is formed by moving the matrix assembly relative to the container before the thickening is formed, and the sediment is produced by synchronously moving the press washer and container. 2. The method according to claim 1, characterized in that in the manufacture of stampings having, along with the indicated thickening, a thickening on the side surface, use a precast matrix, and the formation of a thickening on the side surface is carried out in the cavity that is formed between the parts of the precast matrix.

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