UA121434C2 - METHOD OF CUTTING MOVABLE MATERIAL - Google Patents

Abstract

The method of cutting the moving material into parts of a given length using scissors, the cutting tool of which can move in the direction of movement of the material, is that in each cutting cycle perform deceleration of the cutting tool relative to the material, then synchronize the movement of material and cutting tool during cutting off part of the material. In this case, to reduce the error when cutting part of a given length, the amount of movement of the material and the cutting tool is measured relative to a fixed reference point continuously throughout the cutting time of the material. After each cutting of the braking part of the cutting tool is performed by an amount equal to the difference between the specified length of the part and the distance of the required movement of the cutting tool during one cutting cycle, and during braking the speed of the cutting tool is limited according to the desired law. The application of the method provides cutting of the material into parts with high accuracy.

Description

The invention relates to cutting moving material into parts of a given length. This technological operation is widely used in various branches of industrial production. In the metallurgical industry, this operation is used in units of continuous pouring of steel for cutting slabs of a given length, on procurement, grade, sheet, pipe mills - for cutting rolled steel. This operation is also used in the production of building materials, plastic and glass products.

To implement this cyclic operation, special scissors are used, in which the cutting tool has the ability to move in the direction of movement of the material and, when cutting the part, have a speed synchronous with the material. According to the structural difference, scissors can be conditionally divided into two groups: "flying" and "flying". The design feature of scissors of the first group is that their cutting tool is located on a basic base (carriage), which performs a reciprocating movement in the direction of movement of the material, while the amount of movement

I. . 5. p. o for one cycle is zero. In such scissors, the cutting tool can be a guillotine, disc cutter, abrasive disc, gas cutter, laser device, etc. In scissors of the second group, the basic base is fixed. And the knives (upper and lower) move along closed tangent trajectories, and at the point of contact, when they converge, the part is cut off. at. . . . And, the material. Thus, during one cutting cycle, the knives move a distance of 7, which is equal to the length of the trajectory of their movement. For example, for drum shears, the path of movement of the knives is a circle with a radius equal to the distance from the axis of the drum to the knife. In crank-and-rock shears, the trajectory of the knives is an ellipse, the length of which is determined by the parameters of the mechanism's kinematic scheme.

The duration of the cycle of cutting off a part of the material of a given length consists of two time segments, the first of which is the duration of the process of deceleration (lag) of the cutting tool relative to the moving material by a length determined by the formula

And -

TP I. Iv (1) "Company . . . higher where: - lag of the cutting tool relative to the moving material;

I. the specified length of the part of the material to be cut off;

And, . . o - movement of the cutting tool during one cycle.

The second segment of the cycle is the duration of movement of the material and the synchronous cutting tool

With the speed during which the cutting of the material takes place, and the movement on this segment

And, is a given length of 7.

Thus, when decelerating the cutting tool, the material moves to a length determined by the formula

Im - 1. -iI2 (2) 2. Hm. . . in which: - movement of material during deceleration;

And, dosh. . Mr.

C is the length of the synchronization path of the speeds of the material and the tool.

The velocity diagram of the cutting tool during length deceleration must satisfy conditions (1) and (2). In most known ways of cutting moving material, the function of controlling the drive of the cutting tool is performed by the SARPRI system of automatic adjustment of the movement of the cutting tool.

SARPRI is a tracking system that in each cycle forms a diagram of the speed of the cutting tool during its deceleration according to the desired law, which also meets the condition (1).

An analogue of the proposed method is the method implemented by devices whose working principle is described in USSR copyright certificates Mo1212716, Mo1260121, Mo1304994.

SARPRI, which is part of these devices, monitors the speed and movement of the material, and to slow down the tool, it calculates the AUu signal to form the desired diagram of its speed. Signal A, added to the SARPRI feedback signal, is a forced mismatch that is worked out by the system. Due to this, the tool decelerates according to the formula by which signal A is calculated and meets condition (1).

The disadvantage of these devices is that the input of the specified braking value is indirect, and the actual result of its working out is not controlled by SARPRI. An error in the calculation of the AUu signal is the cause of the error in cutting off a part of the given length.

The closest analogue of the proposed method is the method of cyclic synchronization of moving objects, described in Patent of Ukraine Me36111 A dated April 16, 2001. It has the same drawback as the mentioned analogues. A positive solution is that the dU signal is added in each cycle to the signal and speed task for SARPRI, and the calculation of the AU signal is performed according to a universal formula that allows you to form the desired speed diagram of the cutting tool.

The proposed method makes it possible to increase the accuracy of cutting parts of a given length by eliminating the indicated shortcomings of analogues and the prototype due to the following: - first, the measurement of the movement of the material and the cutting tool is performed continuously during the entire time of cutting the material without zeroing the data in each cutting cycle; - secondly, for the SARPRI task, the length of the deceleration path at the beginning of each cycle, the Zm material movement signal, which is the task signal for SARPRI, is reduced by the value (1), and when the system works out a new task, the speed of the cutting tool is limited according to the desired diagram.

The implementation of the proposed method can be carried out using a system for cutting moving material, the functional scheme of which is shown in fig. 1. The system includes: - an absolute displacement sensor 2 (for example, an encoder) and a material speed sensor (for example, a tachogenerator, a pulse sensor), connected to the measuring roller 22; - "flying" scissors 4 with a drive 5, a movement sensor 7 (for example, an encoder), a speed sensor 6 (for example, a tachogenerator, a pulse sensor) and a material cutting sensor 9 connected to a cutting tool 8 mounted on a scissors carriage;

SARPRI is a two-circuit system of automatic adjustment, the internal circuit of which contains the adder 17, which performs the calculation of the speed mismatch of the cutting tool, the speed controller 18, the adjustable power source 19, the drive of the carriage 5 and the speed sensor of the carriage 6; the external circuit of movement adjustment includes: adder

From 10, which calculates the task of the deceleration path according to (1), the accumulating adder 12, i and M, which calculates the total amount of deceleration; adder 13, which is used to calculate the given movement of the cutting tool according to formula 5 z - Zm - B OM 2. 3 . . . And in which: - the task of moving the cutting tool;

Amendment material movement;

Mu 2. . - the number of cycles of cutting parts of the material, adder 14, which calculates the inconsistency of the movement of the cutting tool; regulator. In, . movement 15, the signal " at the output of which is a task for the internal circuit of the speed control of the cutting tool; the controller 15 can be, for example, a proportional or proportional-integral link; the external control circuit also includes an adjustable

In, . block 16 limiting the signal during the system's working out of the given braking path; closes the external circuit sensor of the movement of the cutting tool 7, 5. . signal "! which is applied to the input of adder 14.

SAPRPIA includes adder 11, which calculates the movement of material during deceleration according to the formula

Im - 1. -iI2 (4) as well as the computing unit 20, which limits with the help of the task unit 16 the speed of the cutting tool at the level of Mo according to the formula

Ho - UM Eau) (5) 5. UM. p, in which: - speed of the material;

Ir.

Pi is the relative value of the braking distance, which is calculated according to the formula

And I'm Ii

Pi I,

PM; (6)

EF) ! B is the control function of the braking process, in which

Them. the relative amount of movement of the material during one cycle, which is calculated by the formula

And - Zmts and

PM (7) b ! . in which - the movement of material from the beginning of the cycle.

Limitation block 16 forms a cutting tool speed assignment signal at its output according to the conditions

U" U, "uk with yu if Um 51 or

Uz U, with irR if u »1 (8)

In a. . where: C is the task of the speed of the cutting tool, and

In, a. . . . and" - task of the speed of the cutting tool from the movement controller.

Implementation of the proposed method is considered on the example of application for cutting. . -0. of material with "flying" shears, for which И» , and the desired law limiting the speed of the cutting tool is a parabolic law, which ensures minimum energy consumption by the carriage drive, and the control function K(/m) has the form

Em) - in m). (9)

In fig. 2nd fig. The diagrams of the speed and movement of the material and the cutting tool during the operation of SARPRI are shown. On these diagrams, the notation is introduced: ate. cart acceleration time; p. time of working out a new movement task;

Her . . . c - time of synchronous movement of the cart and material;

AND

TSO cycle time . 5 And Her

Before starting work, the initial values of the parameters are entered into the system; ; , and the cart is set to its initial position. When feeding the material 1 to the "flying" scissors using the feed roller 23, the sensor 24 fixes the front end of the material and issues a command to accelerate the cart to the speed of the material Um. After dispersal, starting from the moment Ir , SARPRI . . . Mr. And, monitors the movement of the material and during synchronous movement on the way - issues a command to

From cutting off the front end of the material (stripping). The moment of completion of stripping is the moment of the beginning of the first cycle of cutting a part of the material of the given length I. During each cycle, SARPRI performs the above functions. The error of cutting a part of a given length is primarily determined by the error of working out the braking path of the cutting tool. The positive effect of the proposed method is that the specified error is eliminated by the system during synchronous movement before cutting off part of the material. The method is universal, it can be used for any type of scissors.

In the given example of implementation of the proposed method of cutting the material, the parabolic control function ensures the minimization of energy consumption in the drive of the movement of the cutting tool due to its continuous movement during the entire cutting cycle.

But such a control principle cannot be applied when cutting moving material into parts of a significant given length. In this case, the drive for moving the cutting tool must function in the "start-stop" mode using the appropriate control function Em).

For flying scissors, the control function is defined by the following dependencies:

Os ki, (i) MT at m

Em) - Mt with Him Id (10) kO-b vuh zi t ZK 7 in any b -(i -KZH, -Is) (17).

The diagram of the function E(m) for flying scissors is shown in Fig. 4. For "flying" scissors, the cam function when working in the "start - stop" mode is given by the following dependencies: (m) - A m 2), when U» Is «m 5 Zir Is (12)

E(m)- U -(0y not -Up, Ir i i - " at 1-i "in, x1 in' which: Iv - Ir, -1c). is Io o) (iz)

The diagram of the control function of the "flying" scissors when working in the "start-stop" mode is shown in fig. 5.

In general, the control function k() can be any. It is determined by the developer of the cutting unit depending on its technological and design features. But, at the same time, the condition must be fulfilled

Ge(dm -i

M gave)

In each cutting cycle, as a result of braking, the lag of the cutting tool relative to the material is

Id IP 1 IL I. - I; g (U -Uo)y t g Um ko, Mu I t g pi --y sh (15)

Claims (1)

FORMULA OF THE INVENTION A method of cutting moving material into parts of a given length using scissors, the cutting tool of which can move in the direction of movement of the material, which consists in the fact that in each cutting cycle, the cutting tool is slowed down relative to the material, after which the movement of the material and the cutting tool are synchronized of the tool when cutting a part of the material, which differs in that in order to reduce the error when cutting a part of a given length, the movement of the material and the cutting tool are measured relative to a fixed reference point continuously during the entire time ZO of cutting the material, and after each cutting of the part, the braking of the cutting tool is performed by the amount , which is equal to the difference between the specified length of the part and the distance of the necessary movement of the cutting tool during one cutting cycle, and during deceleration, the speed of the cutting tool is limited according to the desired law no.