RU2304481C2 - Method for progressive multi-row blanking and die set for performing the same - Google Patents

Abstract

FIELD: plastic working of metal, possibly manufacture of complex -shape parts.

SUBSTANCE: method comprises steps of blanking parts having protrusions spaced by pitch from sheet by transitions; basing sheet at each transition beginning from second one along contour of blanked part and moving it by predetermined stroke while shifting sheet normally relative to stroke motion to one side; preliminarily cutting out sheet by angle relative to rolling direction; determining value of said angle according to given formula depending upon pitch value of protrusions of blanked part and motion stroke of sheet. Blanking is realized in die set having punch, die, fixing member with working surface for basing sheet at all transitions, stripper with lateral basic surface. Said surface of stripper is inclined relative to working surface of fixing member for providing shift of contour of blanked part by pitch preset at each transition of blanking operation.

EFFECT: simplified blanking process, lowered cost of used fitting of die set.

2 cl, 3 dwg

Description

The invention relates to the processing of metals by pressure and can find application in the manufacture of parts of complex shape.

It is known that when cutting parts from the strip to ensure the exact pitch of the feed, a step knife is used (see V.M. Anikin, Yu.S. Lukashin. Handbook of dies constructor for cold stamping. M .: MASHGIZ, 1960, p. 141) .

The disadvantages of this method are the high cost of the stamp, additional waste due to the cut edge and the supply of material in one direction, which excludes cutting in a checkerboard pattern with one punch.

A known method of sequential multi-row cutting, including cutting parts from the strip through the transitions in the stamp with the base of the strip at each transition and moving it to a predetermined step, while the basing of the strip, starting from the third transition, is carried out along the contour of the parts cut down at previous transitions. To implement the method, a stamp is used for sequential multi-row cutting, containing a punch, a die with a working hole and a latch mounted at the working hole of the matrix (see AC 1175593, M.cl. B21B 28/06, 28/14, 30.08.85).

The disadvantage of this method is the need for stepwise trimming of the side edges for preliminary forming on the strip of profile elements of the manufactured part, which increases the waste, and the disadvantage of the stamp is the inability to cut in a checkerboard pattern with one punch, which makes the stamp difficult and expensive, and the technological effort increases by a multiple of punches.

The closest in technical essence and the achieved result is a method of sequential multi-row cutting and a stamp for its implementation, which includes cutting parts from a sheet by transitions in a stamp with the base of the sheet at each transition, at the first in the temporary stop, which is removed at the second transition, and starting from the third - along the contour of the part and its alternate displacement in opposite directions perpendicular to the stepwise movement (see RF patent No. 2208494, M.cl. B21D 28/08, B26F 1/44) - prototype.

The disadvantage of this method is the difficulty of basing - three options, and the disadvantage of the stamp is the complexity of the design due to the need to manufacture and use a temporary emphasis.

An object of the invention is to simplify the manufacturing method by reducing the options for basing, reducing the cost of die tooling by eliminating temporary emphasis.

This technical problem is solved by the fact that in the method of sequential multi-row cutting, including cutting parts from the sheet by transitions in a stamp with the sheet based on each transition, starting from the second, along the part’s contour and moving it by a predetermined step with shifting it to the side, perpendicular to the stepwise movement, according to the invention, the sheets are pre-cut in relation to the direction of the rental at an angle, the value of which is determined by the formula:

α = arcctg (2T / S),

where S is the magnitude of the step of the protrusions on the cut parts, mm;

T is the step size of the sheet, mm.

In this case, the displacement of the sheet in the direction perpendicular to the stepwise movement is carried out in one direction.

The problem is also solved by the fact that the stamp for sequential multi-row cutting, containing a punch and a die for cutting the sheet along the transitions of parts having spaced protrusions, a latch with a working surface for basing the sheet and a puller with a lateral base surface, according to the invention, the working surface of the latch with the ability to base the sheet at all transitions, and the base surface of the puller is located at an angle to the working surface of the latch, providing a shift of the contour of the part adavaemy whenever the cutting step.

The use of the method and the stamp for successive multi-row cutting allows to simplify the basing process when cutting parts of complex shape with protrusions and depressions and makes the stamp cost minimal.

The invention is illustrated by drawings:

figure 1 - the basing of the sheet at the first transition;

figure 2 - sheet basing on the second and subsequent transitions;

figure 3 - stamp for sequential multi-row cutting, General view.

The method of sequential multi-row cutting is as follows.

The sheets are pre-cut at an angle α to the direction of the rental, which is determined by the formula:

α = arcctg (2T / S),

where S is the magnitude of the step of the protrusions on the cut parts, mm;

T is the step size of the sheet, mm,

however, the displacement of the sheet in the direction perpendicular to the stepwise movement is carried out in one direction.

Then carry out the cutting of parts from a sheet in a stamp. At the first transition, the sheet is based on the end face at a distance equal to the L value of the jumper from the edge of the matrix, and at a distance equal to the F value of the jumper from the side edge to the edge of the matrix.

Starting from the second transition, after cutting down the window, the sheet is based on the contours of the parts onto the retainer, while at each step the sheet is shifted to the side by S / 2, forming a checkerboard pattern of the protrusions of the part, and forward by T by the following ratio:

T = H-N,

where T is the magnitude of the step of movement of the sheet, mm, while the displacement of the sheet in the direction perpendicular to the step movement is carried out in one direction;

H is the width of the part, mm;

N is the amount of overlap of the protrusions, mm;

and to the side by the value of M = S / 2.

The stamp for successive multi-row cutting includes an upper plate 1 on which a punch 2 is mounted, a lower plate 3 on which a matrix 4 is mounted with a stationary puller 5 located on it with a base surface 6 and a retainer 7, the protrusions of which form the base surface 8.

The stamp works as follows.

The sheet is fixed on the base surfaces 6, 8 of the puller 5 and the latch 7, respectively, after which the first cutting is done, from the second transition the sheet is set with cut windows on the latch 7 and sequentially, feeding the strip forward and shifting it at each step to the side, cut all the material.

Claims (2)

1. A method of sequential multi-row cutting, including cutting down from a sheet of parts having protrusions arranged in steps, along transitions based on the sheet at each transition, starting from the second, along the contour of the cut part and moving the sheet to a predetermined step with its displacement perpendicular to the step displacement, different the fact that the sheet is pre-cut at an angle α to the direction of the rental, the value of which is determined by the following formula: α = arc ctg (2T / S), where S is the step size of the protrusions of the cut part, mm; T is the step size of the sheet, mm, and the displacement of the sheet perpendicular to the stepwise movement is carried out in one direction. 2. A stamp for successive multi-row cutting, containing a punch and a die for cutting from a sheet according to transitions of parts having stepwise arranged protrusions, a latch with a working surface for basing the sheet and a puller with a lateral base surface, characterized in that the working surface of the latch is made with the possibility basing of the sheet at all transitions, and the base surface of the puller is located at an angle to the working surface of the latch, providing a shift of the contour of the cut part to the set at each transition de cutting step.

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