JPH0780602B2 - Papermaking speed difference controller for paper machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a machine speed difference control device for a paper machine.

(Prior Art) In a paper machine driven by a sectional drive system, various papers are produced by the same paper machine in order to make various papers.
We operate by setting weighing, dehydration rate, drying rate, pressure, and speed difference (draw) for each part (each part).

Generally, a paper machine comprises a wire part, a press part, a dryer part, a calendar part, and a reel part, and a drive controller controls the speed of an electric motor directly connected to the main drive roll of each part.

It also has a machine speed difference setting device for each set (each part) and a machine speed reference setting device for setting the paper making speed, and the speed reference calculator calculates the speed reference of each part from each set value of these setting devices. Calculated (papermaking speed reference set value x papermaking speed difference set value).

When changing the machine speed difference, the machine speed difference of each part is changed at a uniform change rate (relative to time) for each part by the machine speed difference change rate setting device.

However, when all (all parts) are changed at the same time, it is necessary to change the speed difference because the change rate of the speed difference of each part is uniform even though the change amount of the speed difference of each part is different. The time will be different for each copy.

(Problems to be Solved by the Invention) In the conventional paper-making-speed difference control device, the paper-making speed difference changing rate of each part is uniform with respect to time, although the paper-making speed difference changing amount of each part is different. The time required to change the difference differs for each copy (for each part).

For example, when changing the speed difference of all parts simultaneously according to the type of paper making speed, the difference in the time to complete the change of the speed difference appears between each part. It is difficult to change the speed difference at the same time, increasing the amount of waste paper and reducing the operating efficiency.

The present invention is to eliminate the above problems, and an object of the present invention is to provide a machine speed difference control device for making the time to complete the change of machine speed difference constant in all parts. There is a thing.

[Structure of Invention]

(Means for Solving the Problem) The present invention provides a machine speed difference change time calculator that calculates the machine speed difference change time of each part from the set value of the machine speed difference setter and the set value of the machine speed change rate setter. From the time comparator that compares the machine speed difference change time of each part calculated by this machine speed difference change time calculator, and the machine speed difference change time and the set value of the machine speed difference setter selected by this time comparator, This is a machine speed difference control device for a machine machine, which further comprises a machine speed difference change rate calculator for calculating the machine speed difference change rate of each part.

(Operation) The time difference is calculated by comparing the machine speed difference change time of each part calculated by the machine speed difference change time calculator, and the longest time is selected. The time required to change from the current machine speed difference to the next machine speed difference is calculated by the machine speed difference change rate calculation circuit based on the selected machine speed difference change time and the set value of the machine speed difference setter of each part. The machine speed difference change rate is calculated for each copy so that it remains constant over all copies.

(Example) FIG. 1 shows an example of the present invention.

The machine speed difference change time calculator 12 of each part determines each part from the set values (α, β, γ, δ, ε) of the machine speed difference setter 8 and the set value η of the machine speed difference change rate setter 11 of each part. Change speed difference time (T _α ,
T _β , T _γ , T _δ , T _ε ) is calculated from the following equation.

T _α = α × η, T _β = β × η, T _γ = γ × η, T _δ = δ × η, T _ε = ε × η Further, in the time comparator, the speed difference change time of each part described above is changed. T _α
˜T _ε are compared, and the one with the longest time is obtained from this, and the time selection value T is output.

T = [T _α , T _β , T _γ , T _δ , T _ε ] _mAx The purpose of selecting the longest time here is to specify the longest time required to change the machine speed difference in the part where the time required for changing the machine speed difference is the other part. This is to match the change time.

Further, at the machine speed difference change rate 14 of each part, the time selection value T of the time comparator 13 and the set values (α, β, γ,
δ and ε), the rate of change in the machine speed difference of each part (η _α , η _β , η _γ , η _δ , η _ε ) is calculated from the following equation.

η _α = α / T, η _β = β / T, η _γ = γ / T, η _δ = δ / T, η _ε = ε / T In this η _α ~ η _ε , the machine speed difference change time is T In this case, it means the rate of change in the machine speed difference from the current machine speed difference to the next machine speed difference in each part.

In the speed reference calculation circuit 10 of each part, it is the set value of the machine speed reference setter 9. The machine speed standard and the set value of machine speed difference setting device 8 (α
.About..epsilon.) And the time selection value T of the time comparator 13, the speed reference is calculated for each part.

The calculated value of the speed reference calculator 10 is input to the drive control device 7 of each part as the speed reference of each part, and the drive control device 7 speed-controls the electric motor 6 for driving each part.

The set value of the paper making speed difference setter 8 varies depending on the type of paper making, and therefore the amount of change in the paper making speed difference from the current paper making speed difference to the next paper making speed difference differs from part to part.

However, the machine speed difference change rate calculator 14 receives the selected value T of the time comparator 13 to calculate the machine speed difference change amount / selected value T for each part, and the machine speed difference change amount of each part is different. Regardless, the machine speed change rate is calculated such that the time relating to the machine speed difference change is constant (selected value T) over all parts (wire part to reel part).

Then, the speed reference calculator 10 of each part calculates the speed reference based on the papermaking speed difference change rate calculated by the papermaking speed difference change rate calculator 14.

Therefore, the change of the paper making speed of each part can be completed in a constant time (selection value T) over all the parts.

In FIG. 2, 21 is the amount of change in the speed difference of wire part 1,
22 is the amount of change in the machine speed difference of the place part 2, 23 is the amount of change the machine speed difference of the dryer part 3, 24 is the amount of change the machine speed difference of the calendar part 4, 25 is the amount of change the machine speed difference of the reel part 5, 26 is the The machine speed after changing the machine speed difference, 27 is the machine speed before changing the machine speed difference, 31 is the time for changing the machine speed difference according to the present invention, and 32 is the time for changing the machine speed difference according to the prior art.

〔The invention's effect〕

According to the present invention, when changing the machine speed difference when the amount of change of the machine speed difference of each part is different, the rate of change of the machine speed difference can be calculated so that the time required for changing the machine speed difference of each part is always constant. And
By controlling the speed of each part based on this rate of change in the speed difference, it is possible to complete the difference in speed simultaneously across all parts when changing the difference in the speed of caution, which is highly efficient and stable. It is possible to change the speed difference.

[Brief description of drawings]

FIG. 1 is a block diagram of a machine speed difference control device showing an embodiment of the present invention, and FIG. 2 is an operation explanatory view of the machine speed difference control device. 8: Papermaking speed difference setter, 9: Papermaking speed reference setter 10: Papermaking speed reference calculator 11: Papermaking speed change rate setting device 12: Papermaking speed change time calculator 13: Time comparison Device 14 ... Machine speed difference change rate calculator

Claims (1)

[Claims] 1. A machine speed reference setting device for setting a machine speed reference of a paper machine, and a machine speed difference setting for setting a machine speed difference of each part including a wire part, a press part, a dryer part, a calendar part and a sole part. Machine, a machine speed difference change rate setter for setting the machine speed difference change rate, and a speed reference for calculating the speed reference of each part from the set value of the machine speed reference setter and the set value of the machine speed difference setter In a machine speed difference control device for a paper machine, which comprises an arithmetic circuit, a machine speed difference for calculating the machine speed difference change time of each part from the set value of the machine speed difference setter and the set value of the machine speed change rate setter. A change time calculator, a time comparator for comparing the machine speed difference change time of each part calculated by this machine speed difference change time calculator, and a machine speed difference change time and the machine speed difference set by this time comparator Change the machine speed difference of each part again from the set value of the setting device And a machine speed difference change rate calculator for calculating the machine speed difference, and the time required for changing the machine speed difference at each part is controlled to be constant over the entire wire part to reel part. Machine speed difference control device for paper machines.