JPH0241366B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention provides a method for placing a wire rod wound into a coil shape on a conveyor by a rolling head.
The present invention relates to a method for controlling the rear end discharge position of a wire, which adjusts the relative position between a laying head and the wire so that the rear end position of the wire always coincides with a target point when the wire is discharged from the laying head.

[Technical background of the invention]

FIG. 1 shows an outline of a rolling line including a finishing mill, a laying pinch roll, a laying head, and a belt conveyor of a rolling mill for rolling wire rods.

After passing through a finishing mill FM and a laying pinch roll LP, the wire X is driven in the direction of arrow Y and supplied to a laying head LH. While passing through this laying head LH, the wire X is wound into a coil shape to form a coil CL. The coil CL is continuously placed on a belt conveyor BL driven in the direction of arrow Y'. The placed coils CL are collected and bundled at an end (not shown) of the belt conveyor BL and shipped.

FIG. 2 is an enlarged view showing the structure of the laying head LH, where a shows a front view thereof, and b shows a side view seen from the direction of arrow 2B. The laying head LH has an almost conical shape, and a worm wheel WH is fixed to the input end D of the wire X.
A worm W coupled to a racing head drive motor M2 meshes with the worm wheel WH. Therefore, the running head drive motor M
2 causes the laying head LH to rotate. Inside the laying head LH, a coiled pipe PI is fixed as shown by the dotted line, and the wire X that enters from the input end D is wound around a continuous ring-shaped coil CL by the rotation of the laying head LH, and is then transferred to the laying head. It is discharged from the reference position E of LH and placed on the belt conveyor BL.

Furthermore, as shown in Fig. 2b, the laying head LH
are respectively limit switch LS, reference position F,
A wire discharge target point B is provided, the details of which will be described later.

3a and 3b each show a state in which the wire X passes through the laying head LH and the formed coil CL is placed on the belt conveyor BL.

When the coil CL is placed on the belt conveyor BL at a position where the rear end A of the coil CL protrudes outside the coil CL as shown in Figure 3a, the coil CL comes into contact with peripheral equipment (not shown) around the belt conveyor BL. This may lead to a situation where the rolling line has to be stopped. Therefore, the rear end A of the coil CL is the third
As shown in FIG. b, it is desirable to place it on the belt conveyor BL so that it is inside the coil CL. For this reason, conventionally, the rear end of the coil CL placed on the belt conveyor BL and running had to be manually cut so that the rear end of the coil was positioned at point A shown in Figure 3b. It didn't happen.

But recently finishing mill FM as the above solution,
By controlling the rotational speed of the laying pinch roll LP, the running speed of the wire rod X is controlled, and the wire rod
The rotation angle position of the laying head LH when the rear end A is discharged from the discharge port E of the laying head LH is always kept constant, and the rear end A of the coil CL is
A device for controlling the relative position of the wire and the laying head has been devised to automatically control the wire to be discharged inside the wire.

FIG. 4 is a diagram showing an example of such a conventional relative position control device. In addition, the above-mentioned figures 1 to 4
In the drawings, the same parts are denoted by the same reference numerals, and their explanations in the drawings will be omitted.

In FIG. 4, the finishing mill FM is driven by a finishing mill drive motor M1, and this finishing mill drive motor M
1 is attached with a pulse oscillator PG1.
The laying pinch roll LP is driven by a laying pinch roll driving electric motor M3, and this laying pinch roll driving electric motor M3 has a pulse oscillator.
PG3 is installed. Also the rain head
LH is driven by a racing head drive motor M2, to which a pulse oscillator PG2 is attached. Further, a limit switch LS is attached to this pulse oscillator PG2. Upstream of the finishing mill FM, the detector _HD1 for the rolled material, that is, the wire rod
A wire rod X detector HD2 is provided at a position L ₁ (exiting the finishing mill FM), and a wire X detector HD3 is provided at a distance L ₂ immediately before the laying pinch roll LP. The rear end A of the wire X is the detector
Detected by each of HD1, HD2, and HD3.

As shown in Fig. 2b, when the discharge port E of the laying head LH, that is, the end of the pipe PI, rotates θ _R from the reference position F and reaches the wire rod discharge target point B, the rear end A of the wire X is discharged. When controlled as shown in Fig. 3b, the rear end A of the coil CL is
shall be placed in the desired position. Here θ _R
shall take a value from 0 to 1.

In the conventional relative position control method, the rear end discharge position θ
The predicted discharge position θ and target position θ _R
This is to make the difference between the two converge to zero.
The predicted discharge position θ (0≦θ≦1) at the rear end is determined by the following equation (1).

θ=θ _LB +L-1/π・D _LH × (1+K _LH )-k...(1) In equation (1), θ _LH is the rotational position of the discharge port E from the reference position F, and the pulse of the pulse oscillator PG2 Accumulate the count value and use this as the limit switch.
0 to 1 by resetting every rotation with LS
Detected as a value between . L is the distance from the trailing end tracking start point of the wire X to the discharge port E. For example, when starting from the wire detector HD1, the distance is L ₀ , and when starting from the detector HD2, the distance is L ₁ . .

1 represents the distance traveled by the rear end A from the rear end tracking starting point, D _LH represents the rotational diameter of the discharge port E, and K _LH represents the lead ratio of the laying head rotational speed relative to the wire. Here, the lead rate of the running head rotational speed will be explained. Generally, the lead ratio is the value obtained by dividing the speed of a certain machine by the speed of the reference machine when comparing the speed of a reference machine and the speed of a certain machine, that is, the speed ratio is 1.0 or more. Refers to the speed ratio when . Therefore, the lead ratio of the laying head rotational speed refers to a speed ratio of 1.0 or more to the finishing exit speed of the laying head rotational speed. k is a correction term for setting the predicted ejection position θ to a value between 0 and 1;
Given as a positive integer value. Note that 1 is shown below.
Determined by formula (2).

1=P ₁・C...(2) Here, P ₁ is the pulse count value after the tracking start, and after detecting the trailing edge with the detector HD1, the count value of the pulse oscillator PG1 is
After detecting the rear end in step 2, the count value of the pulse oscillator PG3 is inputted.

C is the wire rod movement length per pulse count value, and the corresponding value is switched and used for each of PG1 and PG3. For example, in K _LH , the tip of the wire is the detector.
It can be determined by integrating the pulse count value of the pulse oscillator PG2 from HD2 to the detector HD3 and calculating the ratio with the distance (L ₁ -L ₂ ).

[Problems with background technology]

As explained above, in the conventional discharge position control method, the momentary difference between the predicted discharge position θ of the rear end of the wire rod obtained by equation (1) and the target position θ _R is controlled by proportional control or proportional-integral control. Relative position control was performed by converting this into the rotational speed of the laying head as a correction term. In other words, in the conventional method, control is performed by accelerating the laying head LH when the difference between the predicted discharge position θ and the target position θ _R is less than 180° in the clockwise direction, and decelerating the laying head LH when the difference is 180° or more. I was doing it.

Even if position control is performed in the direction of accelerating the laying head LH, the acceleration rate of the laying head LH remains constant while the positional deviation is large, but as the positional deviation becomes small, the acceleration rate decreases. Generally, when the laying head LH is decelerated or the acceleration rate is reduced, if the wire is thin, the material may buckle or misroll may occur at the laying head LH. Also, the temperature drop is large at the rear end of the wire, which causes the material to lose its softness.
Even if it is wound into a coil shape with the laying head LH and discharged, the first half will not be wound and the coil diameter will widen.

Originally, in order to prevent the wire X from misrolling in the pipe PI, the laying head LH was placed against the wire X.
Although it has a constant lead rate (K _LH in the first equation), in order to avoid the expansion of the coil diameter mentioned above, in addition to the relative position control, only the laying head LH is accelerated in the latter half of the wire. By advancing further than the speed, so-called rear-end acceleration of the laying head is performed, which suppresses the expansion of the coil diameter.

On the other hand, the premise of the calculation formula for the rear end discharge position θ using equation (1) is that the laying head speed is operated at a constant speed ratio of the lead rate K _LH to the wire rod speed, and relative position control is performed based on this speed. At the point. Therefore, if the rear end of the laying head is accelerated while performing such relative position control, the lead rate _KLH will continue to increase,
The rear end acceleration always accelerates the rear head speed,
Control is performed by tracking the deviation from the wire speed. Therefore, since the rear end of the wire cannot be converged until it reaches the discharge port, there has been a drawback that relative position control and rear end acceleration cannot be performed simultaneously.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for controlling the discharge position of the trailing end of a wire, which can simultaneously control the relative position and accelerate the trailing end of the laying head without damaging the wire.

[Summary of the invention]

In order to achieve the above object, the present invention adjusts the relative position of the wire rod and the rolling head so that the rear end of the wire wound into a coil shape and discharged by the rotating layer head is located at a target point. The method for controlling the trailing end discharge position of a wire includes a first step of detecting the trailing end position of the wire at an arbitrary position before reaching the laying head and tracking the trailing end position; and after the first step has passed. The position of the wire discharge port of the laying head, its rotational speed, the rear end position of the wire, and its running speed are detected at any timing, and the position required for the discharge position of the rear end of the wire to coincide with the target point is determined. The present invention is characterized by comprising a second step of predicting and calculating an acceleration rate, and a third step of increasing a reference rotational speed of the laying head at the arbitrary timing based on the acceleration rate.

[Examples of the Invention] The present invention will be described in detail below based on Examples.

FIG. 5 is a schematic configuration diagram of a control device for implementing the present invention. The configuration diagram of a rolling line to which this invention is applied is the same as that shown in FIG. 4.

The pulse values of the pulse oscillators PG1 and PG3 are counted by pulse counters CTR1 and CTR3, respectively. Gates G1 and G3 of pulse counters CTR1 and CTR3 are opened by rear end detection signals from detectors HD1 and HD2, respectively. At that timing, the counter value is initialized. Therefore, the count values of the pulse counters CTR1 and CTR3 indicate the distance traveled by the rear end from the respective detectors HD1 and HD2. The pulse values of the pulse oscillator PG2 are counted by pulse counters CTR2 and CTR4, respectively. Since the pulse counter CTR4 is cleared by the limit switch LS every time the discharge port E comes to the reference position F, its output indicates the current position θ _LH of the discharge port E. Also pulse counter
CTR2 can obtain the running head speed V _LH as its output by applying a clock to gate G2.

FIG. 6 is a diagram showing the relationship between the actual speed of the reining head and time when the reining head continues to be accelerated at a constant acceleration rate α. Laying head speed
V _LH indicates the actual speed of the racing head, and V _REF indicates its speed reference. _Δtd is a value obtained by approximating the first-order delay of the speed control system when the speed reference V _REF is given using a fixed value of dead time. Actual speed during Δtd
V _LH does not change, and after Δt _d has elapsed, it is accelerated at the same acceleration rate as the speed reference V _REF . _t1 is the timing when the rear end is detected by the detector HD2, and the running head speed V _LH at that time becomes V _LHO . For t ₂ , the rear end of the wire is the discharge port E.
The timing has come. When the detector HD1 detects the rear end, acceleration is started at a constant acceleration rate, and when the rear end A reaches the discharge port E, the acceleration rate α is set such that the discharge port E has rotated to the target position θ _R. demand. This acceleration rate α is a value including the acceleration of the rear end of the racing head.

The shaded area shown in FIG. 6 indicates the rotating length L _LH of the laying head, and its value can be calculated using the following equation (3).

L _LH = V _LHO × (t ₂ − _{t 1} ) + 1/2α× (t ₂ − t ₁ −Δt _d ) ² …(3) However, t ₂ − _{t 1} = L ₀ /V _M …(4) be. Meanwhile, open the discharge port E (N+ΔN)
If the rotation is made to reach the target position θ _R , the following equation (5) is established.

L _LH = πD _LH × (N+ΔN) (5) Here, ΔN is the difference between the target value θ _R and the current value θ _LH , and is calculated by the following equation (6). Note that here ΔN is 0
It is a value between ~1, and N represents an arbitrary integer.

ΔN=θ _R −θ _LH (θ _R ≧θ _LH ) θ _R −θ _LH +1 (θ _R <θ _LH ) …(6) Here, substituting the minimum acceleration rate α _MIN for α in equation (3) to calculate the reining head. Find the rotating length L _LH of the
Find (N′+ΔN) using equation (7).

N′+ΔN=L _LH /πD _LH …(7) Here, N′ is determined as a value including the decimal point, so to ensure that it is corrected in the direction of acceleration, the value rounded up is set as N, and conversely, using equation (5), Find _LH .

Next, calculate the acceleration rate α larger than α _MIN from equation (3). If constant acceleration is performed using the acceleration rate α obtained in this way, when the rear end A reaches the discharge port E, the discharge port E will have reached the target position θ _R.

In addition, when the acceleration rate α is recalculated at an arbitrary timing after the rear end is detected by the detector HD2 and the acceleration rate α obtained initially is corrected using the result, the above-mentioned formula (3) and (4) ) expressions are shown below.
Replaced by formulas (3)′ and (4)′.

L _LH = V _LHM × (t ₂ − tm) + 1/2 α (t ₂ − tm) ² …(3)
′ t ₂ −tm=L−1/V _M …(4)′ Here, tm is the calculation timing, V _LHM is the running head speed at tm, and L is L ₀ before the trailing edge is detected by the detector HD2. , after detection, L ₁ is assigned respectively. Note that 1 is calculated using equation (2). The wire speed V _M is given by the following equation (8), for example.

V _M =V _FM ×(1+f) (8) Here, V _FM is the wire speed standard, and f is the material advancement rate. f can be determined, for example, from the count value of the pulse oscillator PG2 while the tip of the wire passes through the wire detectors HD2 to HD3. The above calculation is performed by the calculation device 1 shown in FIG. 5, and the acceleration rate 2 is outputted as a correction signal for the not-shown running head speed reference.

When the rear end is detected by the detector HD2 shown in FIG. 4, L in equation (4)' is set to _L1 , 1 is cleared once, and the pulse counter CTR3 is used. If a large error occurs when tracking the rear end of the wire using equation (2) using the count value of pulse counter CTR1, detect the rear end with detector HD2 and switch between L and 1. Acceleration rate α at time
changes significantly, so replace equation (3)′ with equation (3)″ shown below.In this case as well, the vehicle is accelerated at the acceleration rate before detection during Δt _d , and is accelerated at the new acceleration rate after Δt _d has elapsed. That will happen.

L _LH = V _LHM × (t ₂ − tm) + 1/2 α × (t ₂ − tm − Δt _d
) ² + 1/2α ₁ (t ₂ −tm−Δt _d +Δt _d ² )…(3)″ Here, α ₁ is the acceleration rate used before switching.Actual speed and time when controlled in this way Figure 7 shows the relationship between

〔Effect of the invention〕

As described above in detail based on the embodiments, in this invention, the laying head is continuously accelerated at a constant acceleration rate depending on the rear end position of the wire, the laying head speed, the laying head position and the wire rod speed, and the rear end of the wire is connected to the laying head discharge port. The relative position control of the wire is performed by calculating the acceleration rate that will cause the wire to be discharged from the optimum position, and accelerating the laying head speed using this acceleration rate. Therefore, relative position control and rear end acceleration can be performed at the same time. It has the advantage of being possible.

[Brief explanation of drawings]

Figure 1 is a diagram showing the configuration of a conventional rolling line, Figure 2 is a diagram showing the structure of the rolling head, Figure 3 is a diagram showing the rear end position of the coil discharged from the rolling head onto the belt conveyor, and Figure 4 is a diagram showing the structure of the rolling head. FIG. 5 is a block diagram of a rolling line to which the invention is applied, FIG. 5 is a diagram showing the configuration of a control device for carrying out the invention, and FIGS. 6 and 7 are diagrams for explaining the operation of the invention. . X...wire rod, LH...laying head, CL...coil, E...discharge port, F...reference position, B...wire discharge target point, A...rear end, PG1, PG2, PG3...pulse oscillator, HD1, HD2, HD3...detection equipment, CTR
1, 2, 3, 4... Pulse counter, V _LH ... Laying head speed, V _M ... Rolling material speed, 1... Arithmetic unit,
2...Acceleration rate.

Claims (1)

[Scope of Claims] 1. A rear end of the wire that adjusts the relative position of the wire to the rotating laying head so that the rear end of the wire wound into a coil and discharged is located at a target point. In the discharge position control method, a first step of detecting the rear end position of the wire rod at an arbitrary position before reaching the laying head and tracking the rear end position; and an arbitrary timing after the first step has passed. detecting the position of the wire discharge port of the laying head, its rotational speed, and the position of the rear end of the wire and its running speed, and predicting the acceleration rate necessary for the discharge position of the rear end of the wire to coincide with the target point; The second to calculate
A method for controlling a trailing end discharge position of a wire rod, comprising: a third step of increasing a reference rotational speed of the laying head at the arbitrary timing based on the acceleration rate.