A vertical continuous casting billet length measurement and compensation method

Abstract

The present invention discloses a method for measuring and compensating the length of vertical continuous casting billets, belonging to the technical field of length measurement of vertical continuous casting billets. The specific technical solution is as follows: It consists of a measuring wheel, an encoder, a pulse conversion module, a high-precision timer, a programmable controller, a transmission chain, a rotating shaft, etc. The encoder, the pulse conversion module, the high-precision timer, and the programmable controller are interconnected with each other through communication cables. During production, when the high-precision timer reaches the timing time, it sends a compensation pulse signal to the programmable controller. When the programmable controller receives the compensation pulse signal, it calculates the slip compensation amount of the measuring wheel, calculates the current billet length after compensating for the slip of the measuring wheel, and at the same time sends a reset pulse signal to the high-precision timer to start the next cycle. In this way, the slip compensation is carried out once every time the measuring wheel rotates one circle, thereby correcting the measured value of the billet length and completely solving the problem of inaccurate billet length measurement caused by the slip of the measuring wheel during the production process of the vertical continuous casting machine.

Description

Technical Field

[0001] The invention belongs to the technical field of vertical continuous casting billet length measurement, and particularly relates to a vertical continuous casting billet length measurement compensation device. Background Art

[0002] In the production of a stainless steel vertical continuous caster, all equipment is vertically arranged from the bottom of the upper mold to the lower cutting cart, and the entire stainless steel casting billet is vertical. The vertically downward moving stainless steel slab with a certain speed needs to be cut according to the planned fixed length, which requires measuring the length of the vertically downward moving billet.

[0003] The currently adopted measurement method is that the measuring wheel leans against the surface of the stainless steel billet. As the billet descends, the measuring wheel rotates synchronously. The measuring wheel drives the measuring wheel encoder to rotate synchronously through a chain drive device and a rotating shaft, and the encoder signal is transmitted to the PLC, thereby automatically calculating the length of the billet. The measuring wheel rotates as the billet descends by relying on the friction force between it and the billet. However, in actual production, due to the influence of factors such as the self-weight and extrusion force of the measuring wheel, the friction force between the measuring wheel and the billet will change, resulting in the measuring wheel slipping, that is, during the continuous descent of the billet, the measuring wheel will have an instantaneous stop, which affects the accuracy of the billet length measurement. During the downward movement of the billet, the temperature reaches about 1000 degrees, and the temperature on the measuring wheel is also very high. Once the measuring wheel slips, there is no way to deal with it at this time. Currently, there is no good solution to the problem of inaccurate billet length measurement caused by the slipping of the measuring wheel in the production of vertical continuous casters. Summary of the Invention

[0004] To solve the technical problem of inaccurate billet length measurement caused by the slipping of the measuring wheel during the production of vertical continuous casters, the invention provides a vertical continuous casting billet length measurement compensation device, which performs a slipping compensation every time the measuring wheel rotates one circle, thereby correcting the billet length measurement value.

[0005] To achieve the above object, the technical solution adopted by the invention is: a vertical continuous casting billet length measurement compensation device, the compensation device includes a measuring wheel arranged close to the stainless steel billet, the measuring wheel is connected to the rotating shaft through a transmission chain, the rotating shaft is coaxially connected to the encoder, and the encoder is responsible for converting the displacement signal when the stainless steel billet descends into a coded signal and sending it to the pulse conversion module; the pulse conversion module is responsible for converting the coded signal measured by the encoder into a series of 24V pulse signals and sending them to the programmable controller; the high-precision timer can set the timing time t. After receiving the reset pulse signal from the programmable controller, the high-precision timer starts timing from 0. After every set timing time t, it outputs a 24V compensation pulse signal to the programmable controller. The programmable controller conducts two-way communication with the high-precision timer and the operation panel.

[0006] Before normal production, determine the timing time t according to the downward speed of the stainless steel billet during normal production and the distance traveled by the encoder in one revolution when the measuring wheel does not slip during the downward process.

[0007] Let the downward speed of the stainless steel billet during normal production be v, and the circumference of the measuring wheel be l, then t = l / v.

[0008] Set that when the encoder rotates one revolution, the pulse conversion module outputs 1024 pulse signals of 24V, and determine the number of pulse signals n output by the pulse conversion module when the measuring wheel rotates one revolution and the length p of the steel billet represented by a single pulse signal according to parameters such as the circumference of the measuring wheel and the chain transmission ratio.

[0009] During normal production, when the head of the stainless steel billet travels a certain distance to the horizontal position of the operating measuring wheel, the operator issues a production instruction from the operation panel. After receiving this instruction, the programmable logic controller makes the measuring wheel instantly close to the downward-moving stainless steel billet. At the moment when the measuring wheel closes to the stainless steel billet, there are two aspects of execution programs.

[0010] On the one hand, the encoder rotates as the measuring wheel rotates, converts the displacement signal of the downward movement of the stainless steel billet into a coded signal and sends it to the pulse conversion module. The pulse conversion module converts the coded signal measured by the encoder into a series of 24V pulse signals and sends them to the programmable logic controller. On the other hand, the programmable logic controller sends a reset pulse signal to the high-precision timer to reset the high-precision timer and start timing. After the high-precision timer starts, it starts timing from 0. When the timing time t arrives, the high-precision timer sends a compensation pulse signal to the programmable logic controller.

[0011] When the programmable logic controller receives the series of pulse signals transmitted by the pulse conversion module and the compensation pulse signal sent by the high-precision timer, it needs to perform calculation and processing. First, call two counters C1, C2 and a register f inside the programmable logic controller. The programmable logic controller converts the received series of pulse signals into the number of pulses and stores them in the counters C1 and C2 at the same time.

[0012] The programmable logic controller calculates the current steel billet length L = C1 * p according to the length p of the steel billet corresponding to a single pulse signal in the series of pulse signals.

[0013] When the programmable logic controller receives the compensation pulse signal, the count value in counter C2 is passed to register f. At the same time, counter C2 is cleared, and the calculation of the measurement wheel slip compensation amount is performed. When the measurement wheel slips, it is manifested as the instantaneous stop of the measurement wheel. During this period, the encoder does not send out encoding signals, which actually results in the measured length being less than the actual length. The measurement wheel slip compensation amount = (n - f) * p. Then, the current billet length L after compensating for the measurement wheel slip is calculated as L = L + (n - f) * p. After C2 is cleared, it continues to store the number of values of the series of pulse signals. In this way, the value stored in C2 is always between 0 and n.

[0014] Among them, C1 is counter 1, which always stores the number of pulses converted from the series of pulse signals in the programmable logic controller.

[0015] C2 is counter 2, which stores the number of pulses converted from the series of pulse signals in the programmable logic controller. When the programmable logic controller receives the compensation pulse signal, the count value in counter C2 is passed to register f. At the same time, counter C2 is cleared. After C2 is cleared, it starts from zero and continues to store the number of values of the series of pulse signals. The value stored in C2 is always between 0 and n.

[0016] n is the number of pulse signals output by the pulse conversion module when the measurement wheel rotates one circle without slipping during the downward movement of the billet.

[0017] f is a register that receives and stores the count value in counter C2 when the programmable logic controller receives the compensation pulse signal.

[0018] At the same time as the counter is cleared, the programmable logic controller sends a reset pulse signal to the high-precision timer again to reset the high-precision timer and start timing from zero again to start the next cycle.

[0019] In this way, the slip compensation is performed once every time the measurement wheel rotates one circle, thereby correcting the measured value of the billet length. If a certain circle of the measurement wheel does not slip, then n = f, and the compensation amount = 0, which is equivalent to not performing compensation.

[0020] Compared with the prior art, the specific beneficial effects of the present invention are as follows: The present invention discloses a vertical continuous casting billet length measurement and compensation device, which is equipped with core devices such as an encoder, a pulse conversion module, and a high-precision timer. By compensating for the measurement error caused by slip every time the measurement wheel rotates one circle, the problem that the measured length of the billet is inaccurate due to the slip of the measurement wheel during the production process of the vertical continuous casting machine is completely solved, and the measurement accuracy is greatly improved. The present invention avoids the phenomenon that the actual length of the fixed length is longer than the planned fixed length during the first cutting of the billet and the need to cut off the excess length during the second cutting, avoiding waste of billet materials, and at the same time laying a foundation for the precise control of the subsequent hot rolling and cold rolling processes. Description of the Drawings

[0021] Figure 1 Schematic structural diagram of the compensation device of the present invention.

[0022] Figure 2 Schematic diagram of the signal transmission relationship of the present invention.

[0023] Figure 3 Flowchart of the compensation method of the present invention.

[0024] In the figure, 1 is a stainless steel billet, 2 is a measuring wheel, 3 is a transmission chain, 4 is a shaft, 5 is a pulse conversion module, 6 is an operation panel, 7 is a programmable logic controller, 8 is a timer, and 9 is an encoder. Specific embodiments

[0025] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clear and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0026] As Figures 1-3 shown, a vertical continuous casting billet length measurement compensation device, for a certain on-site vertical continuous casting production link, consists of a measuring wheel 2, an encoder 9, a pulse conversion module 5, a high-precision timer 8, a programmable logic controller 7, a transmission chain 3, a rotating shaft 4, etc. to form a stainless steel billet length measurement compensation device. The encoder 9, the pulse conversion module 5, the high-precision timer 8, and the programmable logic controller 7 are connected to each other through communication cables. Among them, the encoder 9 is responsible for converting the displacement signal when the stainless steel billet descends into a coded signal and sending it to the pulse conversion module 5; the pulse conversion module 5 is responsible for converting the coded signal measured by the encoder 9 into a series of 24V pulse signals and sending them to the programmable logic controller 7; the high-precision timer 8 can set the timing time t. After receiving the reset pulse signal from the programmable logic controller 7, the high-precision timer 8 starts timing from 0. After every set timing time t, it outputs a 24V compensation pulse signal to the programmable logic controller 7. The programmable logic controller 7 and the operation panel 6 perform two-way communication, and the high-precision timer 8 and the operation panel 6 perform two-way communication.

[0027] Before normal production, according to the downward speed of the stainless steel billet during normal production and the distance traveled by the encoder 9 when the measuring wheel 2 does not slip during the downward process, the timing time t is determined. It is set that when the encoder 9 rotates one circle, the pulse conversion module 5 outputs 1024 24V pulse signals, and according to parameters such as the circumference of the measuring wheel 2 and the chain transmission ratio, the number of pulse signals n output by the pulse conversion module 5 when the measuring wheel 2 rotates one circle and the length p of the billet represented by a single pulse signal are determined.

[0028] During normal production, when the head of the stainless steel billet 1 reaches a certain distance from the horizontal position of the measuring wheel 2 during operation, the operator issues a production instruction from the operation panel 6. After receiving this instruction, the programmable logic controller 7 causes the measuring wheel 2 to immediately press against the descending stainless steel billet. At the moment when the measuring wheel 2 presses against the stainless steel billet 1, there are two aspects of the execution program:

[0029] On the one hand, the encoder 9 rotates as the measuring wheel 2 rotates, converts the displacement signal of the descending stainless steel billet into a coded signal, and sends it to the pulse conversion module 5. The pulse conversion module 5 converts the coded signal measured by the encoder 9 into a 24V serial pulse signal and sends it to the programmable logic controller 7. On the other hand, the programmable logic controller 7 sends a reset pulse signal to the high-precision timer 8 to reset the high-precision timer 8 and start timing. After the high-precision timer 8 is started, it starts counting from 0. When the timing time t arrives, the high-precision timer 8 sends a compensation pulse signal to the programmable logic controller 7.

[0030] When the programmable logic controller 7 receives the serial pulse signal from the pulse conversion module 5 and the compensation pulse signal from the high-precision timer 8, it needs to perform calculation and processing. First, two counters C1, C2 and a register f are called inside the programmable logic controller 7. The programmable logic controller 7 converts the received serial pulse signal into the number of pulses and stores them in the counters C1 and C2 at the same time.

[0031] The programmable logic controller 7 calculates the current billet length L = C1 * p according to the billet length p corresponding to a single pulse signal in the serial pulse signal.

[0032] When the programmable logic controller 7 receives the compensation pulse signal, the count value in the counter C2 is passed to the register f, and at the same time the counter C2 is cleared, and the slip compensation amount of the measuring wheel 2 is calculated. The slip compensation amount of the measuring wheel 2 = (n - f) * p, and then the current billet length L after slip compensation of the measuring wheel 2 is calculated as L = L + (n - f) * p. After C2 is cleared, it continues to store the number value of the serial pulse signal. In this way, the value stored in C2 is always between 0 and n.

[0033] At the same time as the counter is cleared, the programmable logic controller 7 sends a reset pulse signal to the high-precision timer 8 again to reset the high-precision timer 8 and start counting from zero again to start the next cycle.

[0034] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention should be included within the scope of the present invention.

Claims

1. A method for measuring and compensating the length of a vertical continuous casting billet, characterized in that, The compensation device includes a measuring wheel arranged closely to the stainless steel billet. The measuring wheel is connected to a rotating shaft through a transmission chain, and the rotating shaft is coaxially connected to an encoder. The encoder converts the displacement signal of the stainless steel billet during its downward movement into a coded signal and transmits it to a pulse conversion module. The pulse conversion module converts the coded signal measured by the encoder into a series of 24V pulse signals, and then transmits the converted pulse signals to a programmable logic controller. There is two-way communication between the programmable logic controller and a timer. The timer sets the timing time t. After receiving a reset pulse signal from the programmable logic controller, the timer starts timing from 0. After every set timing time t, it outputs a 24V compensation pulse signal to the programmable logic controller. There is two-way communication between the programmable logic controller, the timer and the operation panel; The specific compensation method is as follows:

1. Before normal production, according to the downward speed of the stainless steel billet during normal production and the distance traveled by the encoder when the measuring wheel does not slip during the downward movement, determine the timing time t. Set that when the encoder rotates one circle, the pulse conversion module outputs 1024 24V pulse signals. And according to the circumference of the measuring wheel and the chain transmission ratio, determine the number of pulse signals n output by the pulse conversion module when the measuring wheel rotates one circle and the length p of the steel billet represented by a single pulse signal; 2. During normal production, when the head of the stainless steel billet reaches the horizontal position of the measuring wheel, the operator issues a production instruction from the operation panel. After receiving this instruction, the programmable logic controller makes the measuring wheel instantly close to the stainless steel billet. At the moment when the measuring wheel clings to the stainless steel billet, two signals are generated: 1). The encoder rotates along with the measuring wheel and converts the displacement signal of the stainless steel billet during its downward movement into a coded signal and sends it into the pulse conversion module. The pulse conversion module converts the coded signal measured by the encoder into a series of 24V pulse signals and sends them to the programmable logic controller; 2). The programmable logic controller sends a reset pulse signal to the timer to reset the timer and start timing. After the timer starts, it starts timing from 0. After the timing time t, the timer sends a compensation pulse signal to the programmable logic controller; The programmable logic controller receives the series of pulse signals transmitted by the pulse conversion module and the compensation pulse signal sent by the timer. The programmable logic controller calculates and processes the signals. First, it needs to call two counters C1, C2 and a register f inside the programmable logic controller. The programmable logic controller converts the received series of pulse signals into the number of pulses and stores them in counters C1 and C2 at the same time; The programmable logic controller calculates the current steel billet length L = C1 * p according to the length p of the steel billet corresponding to a single pulse signal in the series of pulse signals; When the programmable logic controller receives the compensation pulse signal, the count value in counter C2 is passed to register f, and at the same time counter C2 is cleared, and the measurement wheel slip compensation amount is calculated. The measurement wheel slip compensation amount = (n - f) * p. Then calculate the current steel billet length after the measurement wheel slip compensation as L + (n - f) * p. After C2 is cleared, it continues to store the number value of the series of pulse signals. The value stored in C2 is always between 0 - n; When the counter is cleared, the programmable logic controller sends a reset pulse signal to the timer again to reset the timer, and the timer starts counting from zero again to begin the next cycle. In this way, slip compensation is performed once every revolution of the measuring wheel, thereby correcting the measured value of the billet length. If there is no slip in a certain revolution of the measuring wheel, then n = f and the compensation amount = 0, which is equivalent to not performing compensation.

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