JPS6343513B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to a device for controlling a bone dry basis weight profile to match a desired pattern in a paper machine control device.

<Prior Art> The problems of the conventional apparatus will be explained with reference to the configuration diagrams of the paper machine control apparatus shown in FIGS. 4 and 5 and the operation diagrams shown in FIGS. 6 and 7. In Fig. 4, 1 is a seed box, 2 is a seed opening valve, 3 is a fan pump, and 4 is a seed box.
is stock inlet, 5 is slice lip, 6 is
1 is a wire part, 7 is a suction box, 8 is a spray part, 9 is a dryer, 10 is a calendar, 11 is a reel, 12 is a paper that becomes a product wound on the reel, and 13 is a silo for collecting white water.
Reference numeral 14 denotes a basis weight sensor that scans the product 12 in the width direction and measures its basis weight and moisture content, and is realized by, for example, a combination of a β-ray basis weight meter and a near-infrared moisture meter.
15 is a control device which processes the information from the sensor to calculate the profile of the absolute dry basis weight in the width direction of the product, and controls the seed mouth valve 2 and the slice lip 5 according to the deviation from the desired profile pattern. send a signal. In addition, a dryer 9 is used to control the moisture content.
Send control signals to.

FIG. 5 is an enlarged perspective view of the stock inlet 4, slice lip 5, and wire part 6.
The opening degree pattern can be finely adjusted by adjusting the opening degree of each of the plurality of slice crew groups 51 that are attached in parallel with each other. Reference numerals 16 and 17 denote no deckles provided to prevent the paper stock discharged from the end of the slice lip from being discharged to the outside of the wire part.

FIG. 6 is an explanatory diagram of the operation, in which the horizontal axis represents the paper width L, and the vertical axis represents the absolute dry basis weight BD. S ₁ , S _{2 .} . . S _M indicates the position corresponding to each of the slide screw groups.
E _P is the absolute dry basis weight profile calculated based on the information from the sensor, _P is its average value,
S _P is the desired profile setting pattern.
The opening degree of the seed opening valve 2 is controlled by a control signal based on the deviation between E _P and S _P , and the control device 15 executes control so that _P matches S _P. When _P and S _P match, the opening degree of the slice lip is changed through each slice screw group based on the deviations ΔP ₁ , ΔP ₂ ...ΔP _o between the desired profile and the profile at each actual screw position. regulated by the control device 15. Adjustment of the slice screw causes deformation of the slice lip in that area and changes the amount of stock discharged, which changes the absolute dry amount, so multiple groups of slice screws are adjusted based on the deviation at each screw position. This allows control to accurately match the desired profile.

However, since adjustment using a slice screw generally causes deformation of the relevant portion of the slice lip, there is a drawback that interference occurs with the opening degrees of adjacent slice lips with the screw as the center.

For example, as shown in Fig. 7, when the slice lip is pressed down by the i-th slice screw S _i , the adjacent (i+1)-th and (i-1)-th slice screw positions receive a downward force. Downward, the (i-2)th and (i+2)th slice screw positions are the (i+1)th and (i-
1) As the slicing lip opening degree increases as a result of an upward force being applied to the fulcrum at the 2nd position, the pattern of the bone-dry profile BD changes from a broken line to a solid line.

Therefore, in the conventional control device, when adjusting the opening degree of each slice screw, it is necessary to memorize the interference pattern shown in Fig. 7 in advance and execute the slice screw adjustment taking into account the influence of mutual interference. It was hot. However, this interference pattern of bone dry basis weight is created from mutual interference due to the deformation of the slice lip portion and mutual interference due to reflection of the paper stock by Nordeckel. Furthermore, due to the presence of slice-lip backlash, the interference pattern is not uniform even for the same brand.

Therefore, control that takes interference patterns into account requires complex software processing, has many uncertainties, and often does not go well.

<Problems to be Solved by the Invention> An object of the present invention is to provide a control device capable of highly accurate adjustment of a profile pattern without taking into account the interference pattern of slice lips.

<Means for Solving the Problems> The structural feature of the present invention is that the paper material discharged from the stock inlet onto the wire part is adjusted by controlling the opening degree of the slice lip at a plurality of locations, thereby reducing the absolute dry basis weight. In a paper machine control device that controls the paper machine to a desired profile pattern, a bone dry basis weight measurement means and a paper machine control device that controls a paper machine to obtain a desired profile pattern, and a bone dry basis weight measuring means, and a paper machine control device that controls the paper machine to obtain a desired profile pattern. means for calculating the appropriate opening; and adjusting means for controlling the opening at each of the plurality of locations of the slide lip using the output of the calculation means as a set value and the opening at each of the plurality of locations of each of the slice lips as a feedback value. The point is that it is equipped.

<Operation> The openings of the slice lip at a plurality of locations are fed back to the adjusting means as an opening signal and compared with the opening setting signal, and the slice screw is controlled so that the opening signal matches the setting signal. Therefore, mutual interference essentially does not occur, and there is no need to control the slice rip in consideration of the interference pattern.

<Embodiment> The present invention can be realized without newly installing special mechanical elements by actively utilizing the function of a slice screw with an opening transmitter.

Conventionally, the opening transmitting function installed in slice screws is used only to check to prevent permanent distortion of the slice lip, that is, to check the absolute value limit of the opening and the relative limit of adjacent openings. In the present invention, this opening signal is used as a feedback signal for controlling the slice lip opening.

FIG. 1 is a block diagram of the main parts showing one embodiment of the present invention, and the same components as in FIGS. 4 and 5 are given the same reference numerals and their explanations will be omitted. Control device 15
151 displays various data on CRT,
Operator's console for setting desired profiles and performing various keyboard operations;
152 is a cubicle-shaped operator's console provided when on-site operation is required;
3 is a field control station that calculates the absolute dry basis weight of the product based on the information e _i from the sensor 14, and also calculates the slice lip size using an appropriate control algorithm by comparing it with the desired profile pattern set from the operator's console. Opening setting signal for each slice screw
In addition to calculating h _is , the current opening signal h _io of each slice screw is received as a feedback signal and a control signal W _io for each slice screw is calculated using an appropriate algorithm so that the opening setting signal and _h is match. Calculate and supply.

In the embodiment shown in FIG. 2, an adjustment section 154 for controlling the opening degree for each slice screw is provided independently. In this case, the field control station 153 controls the calculated value of the opening degree for each slice screw. The setting signal h _is as the adjustment part 1
It only has the function of sending calls to 54.

FIG. 3 is a flowchart showing the signal processing procedure in the field control station in FIG. 1. A shows the procedure for calculating the opening degree setting value _his of each slice lip from the absolute dry basis weight profile based on the information from the basis weight sensor and the desired profile pattern. B shows the procedure for calculating the control signal W _io to the slice screw based on the difference between the slice lip opening reading signal h _io and the above-mentioned _his .

<Effects> According to the present invention, the opening degree at each position of the slice lip is calculated based only on the deviation between the measured value of basis weight and the desired profile pattern by using the opening feedback signal of the slice screw. Since the opening is accurately controlled by the conventional method, there is no need to calculate the opening using a complicated algorithm that takes interference patterns into account, and only needs to consider an algorithm that eliminates mutual interference caused by reflections from the no-details at both ends. , the software load on the field control station is significantly improved.

Even when the slice lip opening degree is controlled using an algorithm that takes into account the interference pattern in the conventional device, it is difficult to achieve good controllability due to other uncertain factors as described above. However, the present invention provides a simpler method. A significant improvement in controllability can be expected with the software configuration.

[Brief explanation of drawings]

1 and 2 are block diagrams showing one embodiment of the present invention, FIG. 3 is a flowchart showing the procedure of signal processing in the device of the present invention, and FIGS. 4 and 5 show an example of a conventional device. The configuration diagram, FIG. 6, and FIG. 7 are explanatory diagrams of the operation. 4...Stock inlet, 5...Slice lip, 51...Slice screw, 6...Wire part, 9...Dryer, 10...Calendar,
11...Reel, 12...Product (paper), 14...
Basis weight sensor, 15...control device.

Claims (1)

[Claims] 1. In a paper machine control device that controls the absolute dry basis weight to a desired profile pattern by adjusting the stock discharged onto the wire part from the stock inlet by controlling the opening degree at multiple points of the slice lip, and means for calculating the proper opening of each of the plurality of locations of the slice lip, which has an opening signal transmission function based on the deviation between the measured bone dry basis weight and the desired profile pattern;
A paper machine control device comprising: an adjusting means for controlling the opening degrees of each of the plurality of positions of the slice lip using the output of the calculation means as a setting signal and the opening degree signal of each of the plurality of positions of each slice lip as a feedback signal.