RU2747203C1 - Line for rotary cutting of metal strip and rotary cutting device for it - Google Patents

Abstract

FIELD: treatment of metals.SUBSTANCE: invention relates to the treatment of metals by pressure and can be used in the production of perforated metal strips or metal profiles with holes used in construction when performing finishing and construction works. The line for rotary slotting processing of a metal strip or tape includes a rotary slotting device containing a punch holder with punches and a matrix holder with dies. The dies are made of a closed contour in the form corresponding to the shape of the punch, and are discretely located along the outer surface of the matrix holder with possibility of interaction with the punches during rotation. The size of the dies and punches is such that the gap between the adjacent working surfaces of the punch and the die is no more than 0.015 mm. The depth of entry of the punch into the matrix is ​​from 0.05 to 0.18 mm.EFFECT: the quality of the finished product is improved by eliminating the deformation of the metal strip or tape when holes are formed in it and reducing the heating of the working surfaces of the tools.2 cl, 4 dwg

Description

The invention relates to a device for perforating a metal strip or tape for the production of metal strips with holes (perforation) or metal profiles with holes (perforation), which can be used, in particular, in construction when performing finishing and construction works performed when leveling walls, floors , ceilings in buildings and structures.

Known methods of perforating a metal strip by cold stamping, when technological holes are cut (punched) by a stamp, is a process of plastic deformation of the body material associated with the movement of particles relative to each other. When cutting technological holes with a stamp in the zone of plastic deformations, under the influence of dynamic loads transmitted from the flywheel to the connecting rod mechanism of the crank-connecting rod press, the particles of the body material shift, which is accompanied by the release of a large amount of thermal energy. During the operation of the die, the heat accompanying the punching process accumulates on the working parts of the punch, and this leads to low-temperature tempering of the hardened surfaces of the punches and the matrix, in addition, since usually the metal strip (tape) has a zinc coating that protects the metal from corrosion during punching , a thermochemical process takes place, causing the evaporation of zinc and its adhesion on the working surfaces of the matrix and punches, and this leads to a decrease in the technological gaps between the working surfaces of the matrix and punches and, accordingly, to an increase in friction between the matrix and punches and an even greater release of heat. As a result, the service life of the stamp decreases, because The crystal lattice of the working surfaces of the punch matrix is subjected to low-temperature tempering, as a result of which the hardness of the working surfaces of the dies and punches is lost and it is necessary to regularly sharpen the working surfaces of the stamp, and after a while, change it to a new one.

A device for continuous rotational formation of an array of closely spaced holes in a strip to be processed is known (see WO2005087454A1, 22.09.2005), comprising a first cylindrical female matrix having a plurality of spaced recesses formed along its perimeter and installed with the possibility of rotation in the frame, a second cylindrical matrix, having a plurality of alternating punches and recesses formed along its periphery and installed with the possibility of rotation in the specified frame for mating the punches of the second matrix with the corresponding recesses in the first matrix, and a cylindrical punch holder having a plurality of spaced punches located on its periphery, installed with the possibility of rotation in the specified frame for mating its punches with corresponding recesses in the second die. Each of the punches has a shoulder formed on each side of the punch to support the material to be processed and to limit the indentations when mating with punches with holes in the die.

This device is designed for a specific task - punching closely spaced holes in a strip.

The closest analogue of the claimed invention is a line for the production of a metal strip with holes CN106180368A, 2016. The line includes a belt (strip) positioning unit, a press-slot mechanism, a rolling-straightening unit. The positioning element consists of two symmetrical blocks made with through grooves for positioning the tape (strip) and the mounting shaft mounted on the line frame. Moving blocks along the shaft allows you to quickly and easily reconfigure to other standard sizes of strips. The clamping-slotting mechanism is installed on the frame and consists of two parallel vertical shafts with a fixed cutting tool. A rotary slotted head with a strip clamping mechanism is fixed on the upper shaft. The rotary-slotted head has the shape of a disk with protrusions (punches) evenly spaced around the circumference. The clamping mechanism is in the form of discs and is located symmetrically relative to the rotary slotted head. A head (matrix) made in the form of a roller and having a recess formed along the circumference in the form of a continuous groove (groove) located around the circumference along the entire perimeter of the roller is fixed on the lower shaft. The strip straightening mechanism unit is also fixed on the line frame and consists of two vertically parallel shafts equipped with straight strip straightening rollers. During operation, the metal strip is fed through the positioning device into the zone of the press-slot mechanism rotating towards each other with the cutting tool attached to them. When rotating the shafts, the tool interacts with the metal strip and forms a hole in it. The holes are formed due to the protrusions (punches) located on the upper shaft, when they enter the recess (groove) of the roller (matrix) located on the lower shaft. After the end of the hole formation, the metal strip passes through the straightening mechanism block to eliminate the negative consequences caused by the mechanical action of the rotary slotted head tool on the metal strip (strip).

The disadvantages of the closest analogue include the fact that when using it, it is impossible to obtain a high-quality product with the formation of a hole in a metal strip in a rotary-slotted way. The formation of a hole in the metal strip is carried out with a deep entry of the protrusions - punches into the recess in the form of a continuous groove along the perimeter of the shaft - into the matrix. In this case, the trajectory of the punch exit from the zone of formation of the hole contour is determined not by a linear movement, but by an angular one. As a result, when leaving the formed hole on the upper surface of the metal strip, the punch picks up the edge of the finished hole in the strip. This leads to deformation of the metal strip, and such deformation cannot be corrected through the correct devices. With a large entry of the punch into the thickness of the metal, the withdrawal begins to twist due to the absence of a closed contour in the matrix. These disadvantages are described for a single-row shaping contour. With two-three-row formation of the contour, the disadvantages of the technology of the closest analogue increase significantly, which leads to the impossibility of using it for two-three-row hole formation.

The line for rotary slot processing of a metal strip, like the closest analogue, contains an unwinder, a compensation looper, a receiving roller table and a rotary slotting device, which includes an interacting punch holder with punches located on its outer surface, and a matrix holder with dies placed in it , while the punch holder and the matrix holder are made with the possibility of synchronous rotation about parallel axes.

The technical problem solved by the claimed invention is to eliminate the disadvantages of the closest analogue, namely, to obtain holes of a given shape in a metal strip by a rotary-slotted method without deforming the strip, as well as to increase the productivity of the line, i.e. metal strip processing speed.

This technical problem is solved as follows.

To obtain high-quality products using the rotary cut method, it is necessary to fulfill a number of technological conditions, namely:

- the shaping contour along the perimeter in the matrix must be closed, i.e. continuous groove inherent in the device - the closest analogue, in the claimed device is replaced by discrete holes in the matrix corresponding to the shape of the punches;

- regardless of the metal thickness, it is necessary to maintain the punch entry depth into the matrix from 0.05 mm to 0.18 mm. This is necessary in order to avoid collision of the working parts of the die and punches, and undermining the hole from the side of the upper surface of the strip facing the punch, with the formation of edges or burrs.

The technical result due to the use of the claimed invention consists in improving the quality of the finished product by eliminating the deformation of the metal strip when holes are formed in it, ensuring the possibility of using the device both for processing a metal strip with a single-row arrangement of holes, and with a multi-row arrangement of holes in one pass of a metal strip. strip, which leads to an increase in productivity during this work, as well as an increase in the processing speed of a metal strip. At the same time, due to a decrease in the heating of the working surfaces of working tools, their resource increases.

The achievement of the technical result is due to the fact that in the claimed line in the device for rotary-slot processing of a metal strip (hereinafter referred to as the rotary slotting device) the matrices are discretely located on the outer surface of the matrix holder with the possibility of interaction during rotation with the punches of the punch holder rotating synchronously with the matrix holder, while a constant and uniform gap is ensured between the working surfaces of the punches and dies of a closed loop, corresponding in shape to the outer contour of the punches, while the double-sided gap between the working surfaces of the dies and punches in the device (difference in dimensions) is no more than 0.03 mm, i.e. the distance between adjacent working surfaces of the punch and the matrix is no more than 0.015 mm, and the depth of the punch entry into the matrix is from 0.05 mm to 0.18 mm for any thickness of the processed strip. In this case, a high quality of perforation is ensured and the impact of the working parts of the punches and dies during their entry and exit from the working area is prevented. In a particular case, with a cylindrical punch and a cylindrical die, the die diameter exceeds the punch diameter by no more than 0.03 mm.

In the known from the prior art rotary-slotting means for processing a metal strip or when punching out a punch, the entry of the punch into the matrix is usually attempted to be within the range of 0.05 mm to 0.15 mm, and this is done for other purposes - to preserve the resource of the tooling, so that when sharpening the workers remove as little metal layer as possible.

The presence of a constant double-sided gap of no more than 0.03 mm (no more than 0.015 mm on one side) between the working surfaces when the punches enter the working zone of the matrix to a depth of 0.18 mm, determines the combined process of forming a hole in the processed metal strip, which consists of a combination cutting and cutting. As a result, the deformation of the processed strip is eliminated and the result is a finished product of high quality, namely, the holes in the strip (or tape) are made without deformation due to a different mechanism for forming a hole in the metal strip.

The execution of a closed-loop matrix, the same shape as a punch, and with dimensions that provide a distance between adjacent working surfaces of less than 0.015 mm, allows you to obtain the following effects in the interaction "punch - metal strip - matrix": from the moment of contact of the punch with the upper surface of the metal being processed strip and with its further angular movement, the working surface of the punch cuts into the material of the processed strip (the cutting process is carried out), this happens until the punch reaches about a third of the material thickness, then with further angular movement of the punch in the rest of the strip thickness (2/3 of the total thickness) the destruction of the strip material occurs under the action of the axial component of the force created by the punch - hole punching with separation of the withdrawal from the strip (the withdrawal material breaks off from the strip), and the closed matrix contour limits the size of the hole to be punched along the lower surface of the metal strip being processed.

Thus, with the above size of the gap between the die and the punch for any thickness of the metal (for example, steel), one third of the size of the thickness of the processed strip is separated by cutting. In this zone, one can observe a shiny band at the end of the cutting part (on the cut-off piece), and two-thirds of the thickness of the band falls on the cleavage (a matte band is visible - moiré stripes). As a result, the cut-out waste, like the hole in the strip, has a pyramidal shape: the size of the base of the waste (chip) along the lower surface is larger than the size of the upper surface by the size of the gap between the punch and the die. At the same time, it is essential to perform a closed-loop matrix, in a shape corresponding to the shape of the punch and having a gap of not more than 0.015 mm, which limits the cleavage area - the cleavage (lower diameter of the cut-out waste) occurs on an area exceeding the cross-sectional area of the punch and equal to the cross-sectional area of the hole in the matrix.

Due to the fact that the resulting hole in the processed strip has a diameter less in the upper third of the strip thickness than in the lower two thirds of the thickness, when leaving the formed hole on the upper surface of the metal strip, the punch can pick up the edge of the finished hole only in its upper part ( 1/3 of the strip thickness) - then the hole expands and the punch cannot contact the walls of the hole. The force that arises when the edge of the finished hole is picked up, deforming the strip, causes only elastic deformation (due to the insignificance of this force), while after the punch leaves the finished hole, the elastic forces lead to the restoration of the flat shape of the strip due to the elastic properties of the metal from which the processed strip is made ...

The product - a metal strip, processed with a rotary slotting device according to the claimed invention, does not require additional straightening after the holes are formed. In this case, the product is obtained of high quality, regardless of the width of the metal strip and how many rows of holes need to be processed. The process of cutting-punching holes by the rotary method occurs in such a way that the interaction of the strip material and the punch occurs first at their point contact, and then gradually (sequentially) as the punch moves angularly, that is, during cutting, the process of processing the strip material, starting at one point , gradually turns into symmetrical dual cutting points along the working surfaces of the punch and the hole in the matrix. Since, when cutting a hole, the strip experiences a point load from the applied force to deform the strip material, there is no significant heat release, due to which the service life of the working surfaces of the punch and die is preserved much longer.

The claimed invention overcomes the problems inherent in other methods of cold forming, since the time required for reciprocating movement of the slider and indexing the center-to-center dimensions along the holes is not required, which makes it possible to obtain a perforated metal strip without distorted dimensional and ergonomic characteristics at a very high productivity rate. Also, the claimed invention in terms of energy and metal consumption is several times superior in performance to equipment for the cold stamping method.

The invention is illustrated by drawings, which show:

in fig. 1 is a general view of a line for rotary slot processing of a metal strip;

in fig. 2 is a schematic view of a rotary slotting device,

in fig. 3 - a fragment of a line for rotary slotted processing of a metal strip;

in fig. 4 is a sectional view of the rotary slotting device.

In the drawings, the numbers indicate:

1 - decoiler;

2 and 4 - a device for controlling the length of a loop of a metal strip or tape;

3 - rotary slotting device;

5 - profiling device - tooling, designed to perform the operation by the method of successive bending of a metal strip or tape;

6 - control panel (electrical cabinet with control circuits);

7 - packing table, designed for work related to product labeling, assembly and packaging;

8 - cut-off mechanism, for example, hydraulic cut-off head - tooling technological equipment, driven by oil under pressure;

9 - processed metal strip or tape (strip).

10 - frame of the rotary slotting device;

11 - punch holder of the rotary slotting device;

12 - matrix holder of the rotary slotting device;

13 - block for metal thickness control;

14 - receiving and tensioning unit;

15 - receiving device;

16 - positioning device;

17 - matrix;

18 - punch;

19 - body of the punch holder unit;

20 - upper shaft;

21 - lower shaft;

22 - thrust roller tapered bearings;

23 - nut with a locking device;

24 and 25 - gears of the gear block mounted on the upper shaft;

26 - drive gear mounted on the lower shaft.

Shown in FIG. 1 line consists of an unwinder 1, a device 2 for controlling the loop length of a metal strip or tape (hereinafter strip 9), a positioning device 16 (see also Fig. 3), a rotary slotting device 3, a device 4 for controlling the length of a loop of a metal strip 9 , roll forming device 5, cutting mechanism 8, packing table 7.

Uncoiler 1, which is a device for unwinding the turns of a roll of metal strip 9 (strip) and keeping it from lateral displacement, works in conjunction with devices 2 and 4 for loop length control, which are a mechanism that compensates for asynchrony in the operation of technological equipment due to looping caused by control errors and increased mounting clearances in the units and mechanisms of the equipment. The task of the decoiler 1 and the loop length control devices 2 and 4 is to ensure the correct feeding of the metal strip 9 into the automatic feeding mechanism of the feeding device. If the loop size decreases during operation, the strip tension causes the upper control sensor of device 2 or device 4 to control the loop length to touch. The sensor registers the touch and a signal is sent through the actuator unit to turn on the unwinder 1 mechanism. As the loop size increases, when the lower sensor is touched, the same thing happens, but only with the command to stop the unwinder 1.

The rotary slotting device consists of two identical blocks of punch holder 11 and matrix holder 12 (see Fig. 4), each of which contains a housing 19 with shafts located in them, upper 20 and lower 21. Assembly of the punch holder 11 (housing 19 - shaft 20 ) and the matrix holder 12 (housing 19 - shaft 21) is made through symmetrically located thrust roller tapered bearings 22. To eliminate gaps in the block, the assembly is made with a guaranteed light interference of the mentioned tapered bearings 22. The tension is carried out by a nut 23 with a locking device. On the upper shaft 20 of the block, on one side of it, an assembly of a punch holder 12 with punches 18 is fixed, and on the other end of the upper shaft 20, a block of gears with gears 24 and 25 is fixed. The punch holder 11 is cylindrical with evenly spaced mounting holes for punches 18 along the perimeter.

On the lower shaft 21, on one side of the shaft, an assembly of the matrix holder 11 with matrices 17 is fixed, and at the other end a drive gear 26 is fixed. The matrix holder 11 is also cylindrical in shape with holes evenly spaced around the perimeter for seating the matrices 17. Fitting the matrices 17 into the matrix holder 12 and landing punches 18 in the punch holder 11 is carried out, preferably, with an interference of 0.005 mm.

The relative position of the punches 18 and the dies 17 is made in such a way that, depending on the thickness of the strip 9, the depth of entry of the punch into the matrix is from 0.05 mm to 0.18 mm, while the size of the punches and dies is made in accordance with each other - double-sided the gap between the working surfaces of the dies 17 and punches 18 is not more than 0.03 mm, i.e. the distance between adjacent working surfaces of the punch and die (anywhere on the perimeter of the punch) is no more than 0.015 mm.

Removal of the cut waste when punching strip 9 occurs automatically through the hole in the matrix. For resharpening the working surfaces of the dies 17, means are provided for extending the matrix with a screw, which is also a support of the matrix from the failure. The head of the screw is made with a hexagon wrench, which is not an obstacle for the removal of cut waste. The rotary slotting device is attached to the frame 10 and is driven by a geared motor (not shown).

In the roll forming device 5, the workpiece is sequentially bending by operation by the method of sequential rolling of the workpiece, between the upper and lower rollers. The product at the exit from the profiling device is cut to the required size by a cut-off mechanism 8 with a hydraulic cut-off head, which is driven by a hydraulic unit.

The block 13 for controlling the thickness of the metal is designed to control the maximum deviation of the thickness of the strip 9. Block 13 includes two axle boxes on the shafts of which the rollers are fixed. The rollers rotate independently of each other due to contact with the strip 9. Block 13 is attached to the plate, which in turn is attached to the frame 10. The actuation of block 13, causing the strip 9 to move, occurs when the maximum deviation of the thickness of the strip 9 from the nominal size exceeds the limit.

The take-up unit 14 serves to receive the perforated strip 9 from the working area of the rotary-slot device. The take-up and tensioning unit 14, as well as the unit 13 for controlling the thickness of the metal, has two axle boxes and is attached to the plate (pos. 16 fig. 4), which in turn is attached to the frame 10. The unit 14 is driven by gears fixed on the axle box shafts. The torque is transmitted to the shafts from the lower gear 26 of the rotor-cutting device.

The receiving device 15 and the positioning device 16 are structurally identical, they serve to guide and hold the strip in the working area of the rotary-slot device. Both devices 15 and 16 consist of a housing with a cover. The housing contains two rows of symmetrically located bearings, which are guiding elements for the strip 9. Assembled devices 15 and 16 have a rectangular groove for the entry of the strip 9. Due to their use as guide bearings, the minimum friction resistance is ensured.

The device operates as follows.

The strip 9 is fed through the positioning device 16 into the working area of the rotary slotting device. During the rotation of the die holder 12 and the punch holder 11, the strip 9, guided through the positioning device 16, is perforated in the first stage by sequentially entering the transverse rows of punches 18 into the transverse rows of mating depressions of the die 17.

Further, with the cut holes, the strip 9 is fixed on the punches 18 and moves along the surface of the die holder 12 into the zone of the sequential exit of the punches 18 from the recesses of the matrices 17. At the moment of passing the mating surfaces of the punches and matrices of the axial line of the rotary slot device, the next row of punches and matched matrices interacts strip and makes cutting in strip 9 of the next transverse row of holes. Thus, by rotation, the punches 18 move the strip 9.

Power consumption of the rotary slotting device 750 W (crank-connecting rod press 11000-15000 WT), the mass of the rotary slotting device 250 kg, the weight of the crank-connecting rod press from 3000 kg and more.

Example: when punching a metal strip with a diameter of 4.5 mm and a thickness of 1.5 mm, the applied force is 1326 kg, and when the hole is rotated and slotted, the force is 530 kg. With such a difference in dynamic loads, the release of heat on the working surfaces of the dies and punches of the proposed device will differ in the smaller direction and, as a consequence, lead to better wear resistance of the nodes of the claimed device and allows to increase the processing speed of the metal strip, and the claimed device excludes plastic deformation of the metal strips, the deformation remains within the elasticity, which makes it possible to successfully use the claimed device both for the formation of a single-row arrangement of holes, and to form holes in several rows in one pass of a metal strip (increase in productivity).

Claims (2)

1. Line for rotary slot processing of a metal strip or tape, containing an unwinder, a device for controlling the loop length of a metal strip or tape, a positioning device, a rotary slotting device with a punch holder with punches and a matrix holder with dies and a cutting mechanism, characterized in that the dies The rotary slotting device is made of a closed loop in a shape corresponding to the shape of the punch, and discretely located along the outer surface of the die holder with the possibility of interaction with the punch holder during rotation, while the size of the dies and punches is such that the gap between adjacent working surfaces of the punch and the matrix is no more than 0.015 mm, and the depth of entry of the punch into the matrix is from 0.05 to 0.18 mm. 2. Rotary slotting device containing a punch holder with punches and a matrix holder with dies, characterized in that the dies are made of a closed contour in a shape corresponding to the shape of the punch, and are discretely located on the outer surface of the matrix holder with the possibility of interaction during rotation with the punches of the punch holder, while the size dies and punches is such that the gap between adjacent working surfaces of the punch and the matrix is not more than 0.015 mm, and the depth of the punch entry into the matrix is from 0.05 to 0.18 mm.

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