SU1750791A1 - Die for bending brackets and calibrating bracket angle portions - Google Patents

Abstract

Use: when bending staples with horizontal shelves. SUMMARY OF THE INVENTION: The stamp contains a matrix with calibration inserts installed in it, an ejector and an insert movement mechanism made in the form of two-arm levers installed in the groove of the support plate with the possibility of rotation around their longitudinal axes and interacting with one shoulder 2 ejector .

Description

This invention relates to sheet metal working, in particular to bending dies.

Stamps for bending parts of the type of staples with horizontal shelves are known, comprising a punch with shoulders rigidly connected to the movable part of the punch; matrix and spring-loaded ejector located at the bottom of the stamp.

However, in such dies, the nature of the deformation of the workpiece during bending is significantly different from pure bending, since the number of shoulders approaching the matrix and the vertical shelves overlap through the edges of the matrix and are pushed into the corners between the vertical walls and the shoulders. As a result, the workpiece is subjected to stretching and stresses arise in it, which, after the part leaves the die, distort its shape. The radius of rounding of the corners between the vertical and horizontal flanges of the part in such dies should be at least 2-3 thicknesses of the material being processed.

A stamp is known that contains an upper movable tile with a punch, on which rotary strips are mounted on the axles, and a matrix, the Punch being spring-loaded relative to the upper plate.

The undersupply of this design is the need to create a large force of the springs acting on the punch, which leads to an increase in the size of the upper part of the die. In addition, when bending vertical shelves, if the radius of the working edges of the matrix is less than 2-3 material thicknesses, their elongation and thinning is possible.

The closest technical solution to the present invention is a stamp for bending and calibrating staples containing a composite punch and a cam, interacting at the end of bending with the punch making parts, where the punch has a radius greater than that specified on the part, and is provided with calibration inserts arranged with ability to move in the slots provided therein and

cl

with

Xi

§

Xi

h

interacting at one end with the cam, and the other with the workpiece.

The disadvantages of this stamp are that the punch is spring-loaded to the upper part of the stamp, and the fact that the calibration of angles from larger to smaller radius is performed with a clamped part flange, which leads to an increase in the required bending force and thinning of the material, t. e. the quality of the workpiece deteriorates.

The purpose of the invention is the expansion of technological capabilities by obtaining brackets with horizontal shelves and calibrated angles between the shelves and walls.

This goal is achieved in that the stamp is provided with a base plate with grooves placed along the bending edges of the die and having an inner quarter — a cylindrical wall and an outer inclined flat, and an ejector mounted in the working window of the die — designed to calibrate the angle in the form of a double arm installed in the corresponding groove of the base plate with the ability to interact with its walls, and one shoulder with the insert, the other with the ejector.

FIG. Figure 1 shows a stamp for bending staples with horizontal shelves at the start (left half) and ending (right half) of bending angles; on .fig. 2 - the node in FIG. one.

The stamp contains a punch 1 rigidly connected with the upper part of the stamp, a matrix 2 with working edges of radius R installed in a holder 3 fixed on the bottom plate 4. In the matrix 2 there are calibration inserts 5 of radius r of the part 6 specified by the drawing, and an ejector 7, connected by means of a pusher 8 with a buffer (not shown), and in the bottom plate - two shoulders levers 9 with axes of rotation O and shoulders I and 12.

The stamp works as follows.

The workpiece 6 is laid on the matrix 2 and fixed by one of the known cfiocobs (not shown). When the upper part of the die goes down, the punch 1 begins to bend the workpiece at the working edges of the radius R of the matrix 2. Since R g is chosen according to the standards because of the reduction of friction forces during the bending process, the bending force is reduced compared to the bending in the die whose cutting edges are made With a radius of r, given by the drawing. After the formation of the greater part of the straight sections on the vertical shelves of the workpiece 6, the flexible calibration of the angles with a radius of r defined by the drawing begins. In the moment

the beginning of the bending-calibration of the item b and the movable parts of the stamp are arranged as shown in FIG. 1 (left half). In this case, the gap between the shoulders of the PT of the punch 1 and the horizontal working planes of the PM of the matrix 2 is equal to h + S, where h is the stroke of the ejector 7, necessary for turning the double-arm levers 9;

S is the thickness of the material being processed.

Next, the punch 1 produces a flexible horizontal shelf of the part 6. The ejector 7, making a move h and affecting the g arms 9, causes them to turn around

the axes O, while the shoulders AND the levers 9 move the calibration inserts 5, which complete the bending of the vertical shelves of the part b and calibrate with a radius g given by its drawing, the angles between its horizontal and

vertical shelves. The final design of the horizontal shelves takes place not in an enclosed space, but in a decreasing gap between the PM and PM surfaces, which reduces the bending effort and improves the quality of the part 6. From FIG. 1 and 2 it follows that in order for the stamp to work properly, the equality

0.41 (r-r). h

lila

or 11-0,41 (rr).

During the reverse course of the upper part of the stamp, the ejector 7 from the buffer by

pusher 8 and punch 1 return to their original position. Finished part 6 is removed. The workpiece is laid on the die 2 and, when the punch 1 moves downward at the initial moment, the calibration inserts 5 return the double shoulders levers 9 to the initial position. The return of the calibration of the inserts 5 and two shoulders of the levers 9 can also be carried out additionally mounted in the stamp springs (not shown) to

Beginning are flexible. Then the cycle repeats.

Use in the stamp for bending staples with horizontal shelves of the mechanism for moving the calibration inserts in the form of double-arm levers with the possibility of rotation

around its longitudinal axes, it reduces energy consumption and improves the quality of processed products.

Claims (1)

Claims of the Invention Stamp for bending staples and calibrating their corner portions, including a movable punch, a fixed die, installed in insert guide grooves for calibrating the corner portions, as well as corresponding mechanisms for their movement, characterized in that in order to expand technological capabilities by obtaining brackets with horizontal shelves and calibrated corners between the shelves and walls, it is provided with a base plate with grooves placed along the bending edges of the matrix and having an inner quarter-cylindrical wall and an outer inclined flat, and The ejector installed in the working window of the matrix, guide grooves for the VSTEROK are placed in the matrix, each insert movement mechanism is made in the form of a double-arm lever installed in the corresponding slot of the base plate with the possibility of interaction with its walls, as well as one shoulder with the insert, the other with the ejector. Mon gi I 3 4 eight