RU2111824C1 - Apparatus for waste-free production of flat axially symmetrical blanks - Google Patents

Abstract

FIELD: plastic metal working, namely structures of die sets for waste-free production of flat axially symmetrical blanks (cylindrical or polyhedral). SUBSTANCE: apparatus includes die, punch coaxially mounted in said die, knocking out member, housing, upper and lower plates and slide. Apparatus is provided with guiding sleeve, reverse stroke limit ring, vernier nut with locking nut, elastic shock absorbing member and pushers. Novelty is realization of closed upsetting mode of blank in conditions of gapless fit of die, punch and knocking out member. Outer surface of die is cone one, it narrows downwards and is arranged in casing with reciprocal inner cone surface. Lower end of die rests upon pushers that may perform reciprocation motion in openings of housing and lower plate. Upper end of die rests onto lower end of guiding sleeve. Said vernier nut fixed by locking nut is secured to upper part of punch and it is joined with guiding sleeve and reverse stroke limit ring in such a way that cavity is formed between said vernier nut, limit ring, guiding sleeve and punch for embedding said elastic shock absorbing member. EFFECT: improved design. 1 dwg

Description

 The invention relates to the processing of metals by pressure, in particular, to the design of a device for waste-free manufacturing of axisymmetric flat (cylindrical or multifaceted) billets, for example, billets for the production of tubular tubes.

 It is known that the manufacturing process of plane axisymmetric blanks from flat square or shaped initial blanks is carried out in stamps with a closed matrix [1]. In such devices, the punch and the ejector enter the matrix in a sliding fit.

 The disadvantage of this kind of device is that in the process of stamping - precipitation, a deformable workpiece inevitably presses on the matrix wall and deforms it elastically. The inner diameter of the matrix increases, and the diameters of the punch and the ejector remain almost the same. Due to this, a radial clearance arises between the punch, the ejector and the die, where the deformable metal flows, forming a burr. This burr must be removed during further redistribution, which involves the use of additional equipment and unproductive expenses.

 Known devices (stamps) do not solve this problem.

 Known, for example, a stamp for seamless stamping [4], containing the upper and lower plates and their corresponding power cylinders, equipped with hollow and additional pistons, coaxial with punches and half-matrixes, in which the hollow piston of one of the power cylinders is rigidly connected to the corresponding plate and half-matrix and the punch corresponding to another power cylinder is fixed in its bottom part concentrically to its additional piston rigidly connected to the corresponding half-matrix.

 Also known is a device for settling axisymmetric workpieces, which can be considered the closest analogue of the claimed technical solution. It contains an upper plate with a punch, a lower plate with a matrix, equipped with means for fixing the workpiece relative to its working surface, mounted on spring-loaded rods. The device is equipped with wedges mounted on the upper plate, and the fixing means is made in the form of horizontal-shaped centering cushions located with the possibility of horizontal movement in the guides, one shelf of each of which is made with a prismatic working surface, and the other with the possibility of interaction of its inclined surface with its corresponding wedge.

 Despite the improvements described in [4 and 5], burrs on already formed workpieces nevertheless form.

The authors performed an analysis of the above disadvantages. It was found that the value of the resulting burrs depends on the ratio of the characteristics of the strength of the wrought metal (mainly temporary fracture resistance, σ _c ), thickness h and diameter d of the resulting products.

It was found that, for metals with characteristics σ _in the range of 6–12 MPa and h / d ≤ 2, the formation of burrs is not excluded, but more favorable conditions are created to exclude the formation of coarse burrs, and with closed stamping-deposit more durable metals with characteristics σ _in > 12 MPa and a ratio of 0.3 ≤ h / d ≤ 0.6, the formation of coarse burrs is most likely.

 Based on the studies, the authors came to the conclusion that the process of pressing-stamping should occur in a tight fit of the punch, ejector and die, and this can provide the proposed device.

 The proposed device consists of a matrix 1 with a conical outer surface mounted in a ferrule 2 having a mating inner conical surface. Both the matrix 1 and the clip 2, with the possibility of relative movement, are placed in the housing 3 of the device, resting on its lower plate 4.

 The matrix 1 is supported by its lower end on the pushers 5, placed in the holes of the housing 3 and the lower plate 4 and having the possibility of reciprocating motion.

 A pusher 6 enters the matrix 1 along the sliding fit and, through the guide sleeve 7, which rests on the upper end of the matrix 1, the punch 8. The upper part of the punch 8 is equipped with a vernier nut 9, the position of which is fixed by the lock nut 10.

 The vernier nut 9 is threadedly connected to the backstop restriction ring 11, which tightly fits the guide sleeve 7 with its lower part. A cavity is formed between the punch 8, the nonius 9 nut and the stop ring 11 and the sleeve 7 element 12 made of polyurethane or other similar material. The punch 8 is driven by a press slider 13, rigidly connected to the upper plate 14.

 The device operates as follows.

 At the beginning of the closed draft operation cycle, the slider 13 and the upper part of the stamp fixed on it, containing parts 7, 8, 9, 10, 11, 12, 13, are in the highest position. In this case, by the action of the elastic element 12, the sleeve 7 is shifted downward by Δ and abuts with its shoulder against the collar of the ring 11. The elastic element is compressed to the required initial force. At this time, an initial preform is introduced into the cavity of the matrix. Then the slider 13 is moved down. In this case, the punch 8 and the ejector 6 enter along the sliding fit into the matrix 1, and the sleeve 7 is in contact with the end face of the matrix and, under the force of the compressible elastic element 12, presses the matrix 1 into the conical holder 2. Axial movement of the matrix in the conical holder causes elastic ring compression of the matrix, which eliminates the radial clearance between the punch 8, the ejector 6 and the matrix 1.

 The value of the axial penetration of the matrix 1 into the holder 2 depends on the force developed by the elastic element 12 and the stroke Δ, which in turn depends on the mechanical characteristics of the workpiece material, its geometric parameters and the degree of deformation during upsetting. For each type of product and material, the position of the vernier nut 9 is determined experimentally. Further movement of the punch in the matrix already under conditions of a clearance-free fit, excluding the formation of a burr, the process of closed draft of the workpiece is carried out until the finished product is obtained.

 After the end of the closed draft process, the existing load is removed from the punch during the reverse stroke of the slider and removed from the matrix. By acting on the matrix 1, the pushers 5 move the matrix 1 up by an amount equal to its downward movement, thereby removing its elastic deformation, raise the punch 8 to its original upper position and at the same time use the ejector 6 to remove the finished product from the matrix 1, lower the ejector 6 to its original position and repeat the cycle again.

 The closed draft mode under conditions of a gapless landing of the matrix, punch and ejector completely eliminates the possibility of burr formation (flash) and significantly reduces the cost of further redistribution.

Sources of information
1. Golovin V.A., Rokoshin G.S., Novrotsky A.G. Technology and equipment for cold stamping. - M.: Mechanical Engineering, 1987, p. 352.

 2. Rebelsky A. V. Fundamentals of designing processes of hot die forging. - M.: Mechanical Engineering, 1965, p. 248.

 3. Forging and stamping production. 1992, p. 10-12.

 4. Copyright certificate of the USSR N 709233, cl. B 21 J 13/02, 09/07/76.

 5. RF patent N 2011465, cl. B 21 J 13/02, 10/15/91.

Claims (1)

 A device for non-waste manufacturing of axisymmetric flat blanks, comprising a matrix with a coaxial punch and an ejector placed in it, a housing, an upper and lower plate and a slider, characterized in that it is additionally equipped with a guide sleeve, a backstop ring, a nonus nut with a lock nut, an elastic element-shock absorber and pushers, while the outer surface of the matrix is made conical with a narrowing down and placed in a holder with an internal conical surface, the lower end of the matrix it is supported by pushers having the possibility of reciprocating movement in the openings of the housing and the lower plate, and its upper end rests on the lower end of the guide sleeve, while on the upper part of the punch there is a nonius nut fixed by a lock nut, and a nonius nut is paired with a guide sleeve a backstop restriction ring so that between the nonus nut, a backstop limit ring, a guide sleeve and a punch a cavity is formed in which an elastic shock absorber element is placed.