RU2039615C1 - Pattern shape blanks production method - Google Patents

Abstract

FIELD: pattern shapes blanks rolling. SUBSTANCE: method to produce blanks mainly of pattern shape provides for cutting of rolling by measured blanks, their feeding into zone of press, reduction of edge distorted areas with subjecting blank seats to efforts of end push and following rolling till finished piece. In the case width of wall reduction zone is chosen less than minimum space between seats and reduction of edge areas is exercised in several stages. On first stage wall form distortions are eliminated. On second stage seats are reduced till clearance disappear and seats levelling. On third stage wall is reduced with simultaneous application of end push efforts to seats. Then end push is taken off and wall is finally reduced till seats are brought to nominal size by width. EFFECT: pattern shape blanks production method is used in pattern shapes rolling production. 6 dwg

Description

 The invention relates to the processing of metals by pressure and can be used in the manufacture of blanks for rolling shaped sections.

A known method of forming blanks, including pre-compression of their ends by the strikers of the press to create external "hard" zones that reduce the amount of rolling at the front and rear ends [1]
However, the loss of metal for trimming is quite large, since in the process of crimping the ends a roll is already formed, which cannot be eliminated during subsequent rolling.

As a prototype, a method for producing blanks was adopted, including the compression of the end sections with the application of back pressure from the end side, the supply of the workpiece in the opposite direction from the initial direction, the final compression of the end section when removing the back pressure from the end and the simultaneous application of back pressure to the side surfaces [2]
The disadvantages of this method include the low quality of the obtained workpieces, the difficulty of implementing the process, the complexity and cumbersome equipment required to complete the method.

 The cutting of shaped blanks on blooming scissors is accompanied by a significant distortion of the profile at the points of separation of the roll into measured lengths with the formation of a burr at the ends. The width in the part where the cutting begins, decreases slightly, and where this process ends, on the contrary, increases, and the distance between the inner faces of the shelves also decreases. Due to the fact that in the prototype method only a support of the side faces is provided, in the process of compressing the wall, the profile width will increase due to the outflow of metal from under the strikers by an amount equal to the difference between the largest size in width at the end of cutting and the nominal size. During subsequent rolling, this part will be cut off by the side faces of the caliber with the formation of sunsets, which reduce the surface quality of the finished profile. The use of strikers to compress the wall with a width equal to the distance between the inner faces of the shelves leads to the formation of sunsets on the inner surface of the profile, which reduces the quality of the products. In addition, since the strikers, squeezing the wall, are clamped shelves of the workpiece, taking into account also the shrinkage of the metal when it cools, the process is hindered due to the need for an additional device to remove the workpiece from the strikers.

 The problem that the invention solves is to eliminate the formation of sunsets.

 This is solved by forming such an end of the workpiece, in which the width of the profile on the crimped section does not exceed its nominal size, and is achieved by the fact that in the known method for producing workpieces, mainly shaped profile, including cutting the rolled into measuring workpieces, feeding into the press zone, crimping the end sections with the application of efforts to support the shelves and subsequent rolling to the finished product, according to the invention, the width of the compression zone of the wall is chosen less than the minimum distance between the shelves, and the compression of the end sections are carried out in three stages: at the first, the distortion of the shape of the wall is eliminated; on the second, they squeeze the shelves until a gap is selected and the shelves are aligned; on the third, the wall is squeezed with the simultaneous application of support forces to the shelves, then the support is removed and the wall is finally crimped until the shelves are brought out to the nominal width.

 In FIG. 1 shows the initial position of the workpiece, strikers and section AA; in FIG. 2 alignment of the end of the wall and section BB; in FIG. 3 compression of the shelves to the choice of gaps between the strikers and shelves, alignment of the outer faces of the shelves, section BB; in FIG. 4 compression of the end of the wall with the application of pressure support to the shelves, section G-G; in FIG. 5 intermediate position of the workpiece and the strikers when removing backwater from the shelves, section DD; in FIG. 6 final compression of the end of the wall, section EE.

 The method is implemented as follows.

 The workpiece 1 is fed to the lower press head 2 and clamped from above by the upper striker 3 (Fig. 1), the width of the strikers 2 and 3 is chosen less than the distance between the inner faces of the shelves. During the lower striker 2 align the end 4 of the wall, distorted when cutting on scissors (Fig. 2). By force on the shelves 5 of the workpiece 1, they are crimped until the outer faces of the shelves are aligned and the gap between the strikers 2, 3 and the inner faces of the shelves is selected. In this case, the width of the workpiece 1 at the crimped end portion is less than the nominal width of the workpiece (Fig. 3). The process may be accompanied by plastic deformation of the shelves with a slight broadening of the metal.

 During the lower striker 2, the end section of the wall is crimped without removing the force from the shelves. The crimping process is accompanied by the displacement of metal from under the strikers 3 and 2 with the formation of the transition section 6 and the "tongue" 7 along the wall (Fig. 4). After removing the force from the end sections of the shelves (Fig. 5), the final formation of the wall 8 is made until the width of the shelves is aligned along the entire length of the workpiece (Fig. 6). In order to prevent the width of the end section of the workpiece from becoming larger than its nominal size, the metal flow in the transverse direction is limited by supporting the shelves. Due to repeated compression along the wall, the strikers 2 and 3 are released from the compressive action from the shelves. A blank with a formed front end is fed through the working space of the press and the rear end is similarly crimped. A fully formed workpiece is fed to the rolling mill.

 PRI me R. It is required to obtain a shaped workpiece with crimped ends for rolling a normal I-beam 55BI according to GOST 26020-83, steel grade Art. 3sp. The shaped section roll formed on blooming is preliminarily cut into measuring billets 4.5 m long. The I-beam has the following nominal dimensions: wall thickness 130 mm, wall width 370 mm, shelf thickness 105 mm, shelf width 350 mm, total width (height) 530 mm

At the front and rear ends of the workpiece, the profile is distorted and has the following dimensions: the profile width from the burr side is 575 mm, the wall width from the burr side (the distance between the inner faces of the shelves) is 340 mm. To form the ends of the shaped workpieces, a double-acting hydraulic press is used with strikers 320 mm wide for wall compression and flat strikers for side compression on the side of the shelves. After preheating in the reheating furnace to a temperature of 1200 ^o C I-beam blank is fed into the working space of the hydraulic press, is mounted on the lower movable upper anvil and clamp the striker, wherein the amount crimped portion is 150 mm. The side strikers squeeze the shelves until the outer faces of the shelves are aligned and the gap between the vertical strikers and the inner faces of the shelves is selected. As a result of this technique, the total profile width in the crimped section decreases by 50 mm. In the course of the lower striker, the end section of the wall is squeezed without removing the force from the shelves. The absolute reduction is 70 mm. Due to the displacement of metal from under the strikers, a “tongue” is formed along a wall 70 mm long.

 The crimping process is also accompanied by the departure of the incompressible part of the workpiece from the strikers with the formation of the transition section. The side strikers are diverted from the shelves of the workpiece and set with a gap between them equal to the nominal width of the profile 530 mm. In the course of the lower striker, they finally compress the wall until the outer faces of the shelves of the lateral strikers touch. As a result, the width of the profile in the crimped section becomes the same with the incompressible rest of the workpiece. The size of the "tongue" on the wall increases by 10 mm, and the vertical strikers are freed from the compressive effect from the shelves. The design force at the end of the deformation process is 600 tf. A blank with a fully formed front end is fed through the working space of the press and the rear end is compressed in a similar way, after which it is sent using transport conveyors to the crimping stand for rolling in reverse mode.

Claims (1)

 METHOD FOR OBTAINING SHAPED PROFILE Billets, including cutting rolled to measured billets, feeding into the press zone, crimping the end distorted sections of the workpiece in several stages with the application of supporting forces to the shelves, on the first of which the walls are leveled, and subsequent rolling to the finished product, characterized in that the width of the zone of compression of the wall is chosen less than the minimum distance between the shelves, and the compression of the end sections is carried out in three stages, the second of which compress the shelves to select the gap and align the shelves, by three tem crimped wall with simultaneous application pressurization force to the shelves, and then removed backwater definitively crimped to wall clearance shelves on the nominal size of the workpiece width.

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