JP3079209B2 - Individual drive control method for upper and lower canvas dryers - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control method for individually driving upper and lower canvases of a dryer for drying a long material made of paper and the like with the upper and lower canvases.

[0002]

2. Description of the Related Art In general, when individually driving upper and lower canvases for drying a long material such as paper, it is necessary to keep the load sharing ratio of each canvas driving device constant. FIG. 2 shows the conventional upper / lower canvas individual drive system in a paper passing state, and FIG. 3 shows a state before the paper passing is completed. Reference numeral 1 denotes a lower canvas drive roll for driving the lower canvas, which is driven by the electric motor 3. Reference numeral 2 denotes an upper canvas drive roll for driving the upper canvas, which is driven by the electric motor 6. The electric motor 3 becomes the master side of the dryer section, and is driven by the drive device 5 in synchronization with the line speed command (VL) 10. The electric motor 6 is on the helper side of the dryer section,
The driving device 8 controls the load sharing ratio setting unit 9 so that the load sharing ratio is constant with respect to the load 5i of the master drive device 5.

[0003]

However, in this conventional example, as is apparent from FIG. 3, before the completion of sheet feeding, the upper canvas is controlled by the load sharing ratio from the driving torque of the lower canvas (master side) whose speed is controlled. (Helper side), and the drive torque was passed to the same, and the same was true after the completion of paper passing. That is,
Before and after the completion of paper passing, the upper and lower canvases (helper side / master side) are controlled at a constant load sharing ratio.
Before the paper passing is completed, the upper and lower canvases are separated from each other, and a difference in mechanical loss between the two canvases causes a speed difference between the upper and lower canvases. Due to this speed difference, there is a problem that tension or slack occurs during paper passing, leading to paper breakage. Therefore, the present invention, while wiping such a disadvantage of the conventional example, regardless of before and after the completion of paper passing, while performing the alignment speed control,
An object of the present invention is to perform a control for preventing a paper break in consideration of fluctuations in drive torque of the upper and lower canvases on the helper side and the master side.

[0004]

In order to solve the above-mentioned problems, an individual drive control method for the upper and lower canvas dryers according to the present invention is to provide a method for controlling a long material made of paper and the equivalent material. In the method for driving a dryer that dries at a lower speed, a first method for controlling the speed of a lower canvas dryer is provided.
And a second device that controls the speed of the upper canvas dryer, controls the speed of both the upper and lower canvases before the completion of the paper passing, and the first device and the second device after the completion of the paper passing.
A load sharing ratio is calculated from the ratio of the driving torque detected by the second device, and a drawer provided in the second device is provided in accordance with a deviation between the detected load sharing ratio and a preset load sharing ratio.
The draw adjustment is performed by the control means.

[0005]

By the above means, the speed of each of the upper and lower canvases is controlled individually before the completion of the sheet feeding, so that there is no speed difference due to a difference in mechanical loss. Furthermore, after the completion of paper passing, the upper and lower canvases have a tight relationship via members such as paper, and it is difficult to control the speed independently. By calculating the ratio and automatically finely adjusting the mechanical loss adjustment drawer of the helper-side drive device according to the difference from the preset load sharing ratio, stable operation is always possible. .

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be specifically described based on one embodiment shown in FIG. In FIG. 1, components having the same functions as those of the conventional configuration shown in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted. A drive device 5 for moving the lower canvas (canvas) 30, which is the master side, in the direction of the arrow.
Drives the electric motor 3 according to the line speed command VL, rotates the lower canvas drive roll 1 via the connecting means 31,
Dry roll 3a with a canvas 30 suspended in a loop
3b, 3c and the canvas 30 are dry rolled 3a, 3b, 3c.
In cooperation with pinch rolls (pinch rolls) 1a to 1f pressed against the lower side, the canvas 30 on the lower side is driven by the line speed command V.
L is followed by an endless orbital motion, and the actual line speed is negatively fed back to the drive unit 5 via the speed detector 4 as a speed voltage 41, and is driven so that it becomes zero from the deviation from the line speed command VL. The device 5 is controlled. The driving device 8 that moves the upper canvas 20 on the helper side in the direction of the arrow drives the electric motor 6 in accordance with the line speed command VL. After adjusting the difference ε between the mechanical loss of the upper and lower dryers, the speed command (VL + ε) is added to the drive device 8, and the upper canvas drive roll 2 is rotated via the connecting means 61 to obtain the canvas. The dry rolls 6a, 6b, 6c are looped and the canvas 20 is connected to the dry rolls 6a, 6a,
In cooperation with the pinch rolls 2a to 2f pressed against 6b and 6c, the upper canvas 20 performs an endless orbital motion proportional to the line speed command VL, and the actual line speed is determined via the speed detector 7. The drive device 8 is negatively fed back to the drive device 8 as the speed voltage 71, and controls the drive device 8 so that the difference from the speed proportional to the line speed command VL becomes zero.

By the way, the upper and lower dryers are started from the state before the completion of the sheet passing shown in FIG. 3, and the paper 100a of the material to be dried is inserted between the lower canvas 30 and the dry roll 3a. The dried material is automatically passed as the canvases 30 and 20 move, and is discharged as dried paper 100b after the completion of the passing. As described above, since the paper is fed by starting from the no-load operation, it can be seen that one disturbance has occurred in the control system at this time after the completion of the paper feeding. Therefore, the speed of the upper canvas 20 is lower than that of the lower canvas 30.
There is no guarantee that the same line speed command VL is used. So, we detect how they share the load,
The gist of the present invention is that the load sharing ratio of the two is always adjusted and controlled to a preset load sharing ratio, and the speed of the upper canvas 20 is maintained at a speed following the line speed command VL. The present invention takes the following procedure as the method. Before the completion of the sheet feeding, the upper and lower canvases are controlled for the uniform speed in accordance with the same line speed command VL. The draw ε is given to the drive device 8 of the upper canvas dryer according to the mechanical characteristics of the upper and lower canvas dryers. The speed voltages 41, 7 detected from the speed detectors 4, 7 of the electric motors 3, 6 of the upper and lower canvas dryers after completion of the paper passing.
1, the closed loop speed control is performed so that the driving devices 5 and 8 reach the set speed. In this state, current signals 5i and 8i relating to the rotational torque of the electric motors 3 and 6 whose closed loop speed is controlled are derived. The current signals 5i and 8i are both supplied to the load sharing ratio detector 11 to calculate the detected load sharing ratio (5i / 8i) × 100% at this time. By the way, the set load sharing ratio of the electric motors 3 and 6 according to the type and shape of the material to be dried is set in the load sharing ratio setting unit 12 in advance. For the set load sharing ratio and the detected load sharing ratio respectively received by the subtractor 14, the latter is subtracted from the former and the deviation ±
Derive Δi. As shown in FIG. 1, the paper feed response switch 15 is turned off as shown in FIG. 1, but after the paper feed is completed, the paper feed response switch 15 is turned on. It is given as a fine adjustment. Accordingly, the value of the drive command from the draw commander 13 to the drive device 8 is (VL + ε ± Δi), and the speeds of the motors 3 and 6 of the upper and lower canvas dryers cooperate with each other, for example, for paper cutting. The control is performed so that no trouble occurs. That is, the load sharing ratio deviation ± Δi previously corresponds to the response of the driving device 8 and the load sharing ratio deviation ± Δi sequentially approaches zero without limit, the operating speed of the system is stabilized, and the line speed command VL +
ε [most likely ε = 0]. In this way, the mechanical loss of the draw command device 13 is reduced in accordance with the preset load sharing ratio of the load sharing ratio detector 11 and the deviation (± Δi) of the detected load sharing ratio (5i / 8i) × 100%. From the correction value ε, the system can continue operation at an appropriate speed.

Here, an embodiment of this embodiment will be described. Although the electric motors 3 and 6 may be DC motors, an induction motor is applied at present when vector control is generalized, and 5i and 8i are detected from the secondary current, and the motor torque (for the motor 3) τ = k · 5i · φ Where k is a constant and φ is the number of effective magnetic fluxes of the motor. The same applies to the motor 6. The motor torque τ is 5i, which is the detected value of the secondary current of the motors 3 and 6. 8i. The dry rolls 3a,.
6 are shown three by three in FIG. 1, for example, 10a
Approximately 15,16 pieces are formed in series, the diameter is about 1.5m, the width is 5,6m, and high temperature steam is flowed inside, and the outer surface is heated to dry the material to be dried. The canvases 30, 20 are made of so-called tough, flexible, water-absorbing fibers. When the materials to be dried 100a, 100b are paper (copy paper, note paper), etc., the line speed is 1000m / min. It travels on an endless track.

[0009]

As described above, according to the present invention, the speed control of the helper side of the upper canvas drive is made as precise as that of the master side of the lower canvas drive, and the load sharing of the drive device is completed after the completion of the sheet feeding. By calculating the rate and automatically finely adjusting the drawer on the helper side according to the deviation from the set value, stable operation including before and after passing paper is possible, and it is possible to prevent any unexpected disturbance. Immediately, the speed of the control system is stabilized to the commanded line speed command value, and it is possible to completely wipe off the occurrence of loosening from insufficient tension, such as cutting (paper cutting) due to excessive tension of the material to be dried, Stable drying of long objects is performed, reliability as a drying method is improved,
It is extremely useful in practice.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a specific circuit configuration according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a circuit configuration of a conventional example.

FIG. 3 is an explanatory diagram showing a state before completion of sheet passing in a conventional example.

[Explanation of symbols]

 1 Lower canvas drive roll 1a Pinch roll 1b Pinch roll 1c Pinch roll 1d Pinch roll 1e Pinch roll 1f Pinch roll 2 Upper canvas drive roll 2a Pinch roll 2b Pinch roll 2c Pinch roll 2d pinch roll 2e pinch roll 2f pinch roll 3 motor 3a lower dry roll 3b lower dry roll 3c lower dry roll 4 speed detector 5 driver 6 motor 6a upper dry roll 6b upper dry roll 6c upper dry Roll 7 Speed detector 8 Drive unit 9 Load sharing ratio detector 10 Line speed command (VL) 11 Load sharing ratio detector 12 Load sharing ratio setting unit 13 Draw command unit 14 Subtractor 15 Paper feed switch 20 Upper canvas 30 Lower canvas 100a Material to be dried (before drying) 100b Material to be dried (after drying)

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) D21F 1/00-13/12

Claims (1)

(57) [Claims] 1. A method of driving a dryer for drying a long material made of papers and the like with the upper and lower canvases, comprising: a first device for controlling the speed of a lower canvas dryer; A second device for controlling the speed of the dryer is provided. Before the completion of the paper passing, the speed of both the upper and lower canvases is controlled. After the completion of the paper passing, the ratio of the driving torque detected from the first device and the second device. The load sharing ratio is calculated from the calculated load sharing ratio, and the draw control is performed by the draw control means provided in the second device in accordance with the deviation between the detected load sharing ratio and a preset load sharing ratio. Individual drive control method for upper and lower canvas dryers.