JPH062380B2 - Lot change control method for corrugated board production process by learning measurement - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a corrugated board sheet production process, etc., which needs to automatically and efficiently cope with the demands of various types of small-quantity production.
The present invention relates to a control method which is useful when a plurality of long webs are combined and processed, and further cut into a rectangular shape to be applied to a production process for producing a product. In particular, in the corrugated board sheet production process in which the amount of sheets staying in the process constantly fluctuates and heat shrinkage occurs in the drying step, etc., the momentarily changing staying sheet length in the process in order to efficiently meet the demand for small-lot production of various types. In order to make sure of that, the learning measurement method is aimed at improving the measurement accuracy by learning by using the computer for calculation provided in the control system of the process concerned.
In addition, the present invention also relates to a lot change control method that enables production of ordered products immediately before lot change for brand change based on the measured values without excess or deficiency.

[Prior Art and Problems Thereof] The present invention relates to a production line for continuously producing corrugated cardboard sheets obtained by cutting a long base paper roll into a rectangular shape through a corrugator, and particularly in a production lot of various small quantities. Since it is a learning control method that is applied to obtain a product according to, and has a remarkable effect, the following is a description of what kind of method has been adopted so far in manufacturing the corrugated cardboard sheet even as the conventional technology. To explain.

As is well known, the corrugated board is obtained by laminating a flat liner paper and a corrugated core paper, which are laminated together. For each of the base papers, a long web material is supplied to the corrugator in a rolled-up form (hereinafter referred to as a “master”), and the heat, adhesive coating, and laminating are performed while sequentially feeding the corrugator. To give a predetermined cardboard, and then cut it into a rectangular shape to form a cardboard sheet as the final product.
In some cases, it is shipped as it is, but in most cases, the above-mentioned sheet is guided online to the next box-making step, and made into a predetermined cardboard box.

By the way, FIG. 9 is a schematic view showing a manufacturing process of a corrugated board sheet which is currently widely used.
Reference numeral 1e is a mill roll stand for setting the original fabric, which has an auto-splicer mechanism. Code 12a
-12c are preheaters to preheat to promote adhesion in the next single facer. Although not shown in the drawings, 13a to 13b are single facers and 13c is a double facer, although not shown in the figure, means for preheating the core raw material or the single-sided corrugated board is incorporated in each of these devices. 14a
And 14b is a cushion part to prevent the change of the processing speed when changing the slitter scorer based on the specification change and changing the processing speed as a bridge so as to store single-sided corrugated board made of single facer. It is a part that is dried in a natural state to sufficiently dissipate moisture. Reference numeral 15 is a dryer, 16 is a slitter and scorer, and 17 is a rotary cutter. Therefore, the mill roll stands 11a to 11e have the symbols L1, L2, L3, L4 or L.
5 and L6 are used as a liner stock, for example, L
When the stock 1 is completely consumed, the auto-splicer mechanism incorporated therein automatically switches to the spare stock L2 and automatically splices it. These liner rolls are made into a single-faced corrugated board with single facers 13a and 13b in a long form while being subjected to a predetermined corrugation in accordance with a conventional method, and then continuously guided to a double facer 13c to become a composite double-faced corrugated board. Then, this is cut into a predetermined width with a slitter 16 and then cut into a predetermined length with a cutter 17 to obtain a rectangular corrugated cardboard sheet.

Although a corrugated board sheet is obtained through the above-described processing steps, until the sheet of the final product is obtained, as described above, the base paper itself is stretched due to the adhesion. Or, dimensional changes during processing such as shrinkage of the base paper during drying are inevitable.

By the way, the product such as the corrugated cardboard sheet is generally one in which a predetermined number of products having a predetermined quality and size are prepared and supplied to a customer, and it is usually called one production lot. A raw material is prepared to satisfy the corresponding length to obtain a predetermined number of products according to the production lot. But in general,
As mentioned above, since the length of the raw material changes during processing, the production equipment is operated after anticipating it empirically. On the other hand, since the shortage of the number of products is not allowed, The reality is that the manufacturing is performed with the number of sheets exceeding the ordered number. In this way, manufacturers have no choice but to finish products in excess of the quantity ordered, and when demand for high-mix low-volume products increases recently, such waste can be minimized. There is a demand for the development of such new technologies.

However, at present, no technology has been established to grasp the amount of stay and the expansion and contraction of the web material in each bridge, which is a cushion part during processing, throughout the production line. Since it was only possible to know the actual length, it was not possible to eliminate the above waste.

[Problems to be Solved by the Invention] In the present invention, the amount of sheet staying in a portion including the preheater, the single facer, the bridge, etc., which constantly fluctuates depending on the operating condition and the working condition, heat shrinkage after bonding, and the like are described. (EN) A lot change control method capable of measuring an accurate value of a sheet length from a raw material feeding portion to a processing end, and supplying an ordered product immediately before lot change without excess or deficiency based on the measured value.

[Means for Solving the Problems] In order to achieve the above object, the present invention is a corrugated board production process that employs a multi-type, small-quantity production method, and at the time of lot exchange for changing the original fabric brand, the new original fabric (feeding-out at the time of the exchange) The total sheet length of the entire processing line from the (position) seam to the cutting end of the cutter that performs cutting as the final product is measured and learned based on the operating data, and the measured values ensure that there is no excess or deficiency of the ordered products immediately before the lot change. It is characterized by changing lots so that it can be produced.

The learning measurement consists of a roll-out part of the corrugated board production process, a bridge part that is a cushion part, and a detection part consisting of a rotation side length sensor and a detection sensor that detects the seam of the base paper at the processing end just before the cutter. The continuous amount of the sheet passing through the portion is provided, and the sheet is measured at the portion where the processing length varies from the original sheet feeding portion to the bridge outlet by performing learning measurement by the control computer provided in the control system of the process. Continuously measure the sheet length of the entire processing line from the feed-out portion to the end of processing, taking into account the amount of stay and the amount of sheet shrinkage in the process.

In learning measurement, the sheet retention amount for each passage of the original fabric is compared with the retention amount calculated after passing through the previous joint, and the side length sensor at the bridge exit per rotation is compared. Make a correction.

Furthermore, the learning measurement is performed by comparing the theoretical length calculated from the actual number of finished products each time the lot is exchanged with each lot length indicated by the side length sensor provided at the material feeding portion and the processing end, and per rotation of each sensor. Calibrate the length of.

In learning measurement, the integrated values of the above-mentioned raw fabric feeding section, the outlet of the cushion part, and the measurement sensor provided at the machining end are compared for long-term operation so that the values match based on the integrated value of the measurement sensor at the machining end. Calibrate the length per sensor rotation.

[Examples] Hereinafter, the present invention will be specifically described based on illustrated examples, but the scope of the present invention is not limited to these examples.

FIG. 1 is a schematic system diagram when the present invention is applied to the manufacturing process of the double-sided composite corrugated board sheet shown in FIG.
As described in FIG. 9, the roll rolls L1, L2, L3, L4, L5, L6 for liners are set on the mill roll stands 11a, 11c, 11e incorporating the auto splicer so that they can be switched. , The other stands 11b, 11d conceptually shows the state in which the core material is set, and the dotted line in the figure indicates, for example, that the liner material L1 is exhausted. , Is switched to the other original L2 that was set on the same stand, and automatic paper splicing is performed via the auto-splicer mechanism to continuously feed out the original. Then, the base paper fed out from each of the above-mentioned stocks is preheater 12a, 12b, which preheats respectively.
After passing through 12c, the single facers 13a and 13b guide the single-sided corrugated board to the bridges 14a and 14b, and then the double facer 13c guides the continuous double-sided corrugated board sheet. The composite corrugated board thus formed has a slitter 16 as shown in FIG.
After being processed to the product width through, if necessary, after being subjected to ruled lines, it is cut into a predetermined length with the rotary cutter 17,
It is carried to the delivery 18 and carried to the next line.

In the present invention, as an example, in the production line of the double-sided composite corrugated board sheet, as described above, depending on the operating condition or the operating condition, in other words, heating and bonding to the base paper,
Slitter when replacing the material. Seat length variation parts such as cushion bridges at the time of switching the scorer are lx and l in FIG.
The portion indicated by y, in particular, the sheet length staying in ly is a portion that fluctuates greatly at all times. Further, lz is contracted by the drying part, and varies depending on the brand, particularly in the range of 0.5 to 1.5 m / 1000 m, but in general the same brand hardly changes, so it is referred to as a short-cycle invariant site. In the position immediately after the feeding of each of the above-mentioned raw materials, in the raw material for the liner excluding the core,
Before the preheaters 12a to 12c, a detection sensor denoted by D1, D2, D3 is attached, and by the sensor, a seam between the base paper and the base paper existing in the original fabric itself (usually, a marking is made by interleaving paper). Existing) and a seam to be attached when replacing the original fabric (a portion marked with silver paper or the like as an example), and the counter described later is driven by the detection signal.

Further, rotary type unit length measuring sensors S1, S2, S3 are arranged at positions immediately after the respective detection sensors, and thereby the length of the base paper passing through the positions is measured. In the same manner as described above, the detection sensors D4, D5 and the unit length measuring sensors S4, S5 are arranged at the exits immediately after the bridges 14a, 14b, and the detection sensor D6 unit length measuring sensor S6 is arranged immediately before the rotary cutter 17. , The range from the unwinding position of the material to the cutter 17, that is, the web changes from a long form to a sheet form, and the length of the entire sheet before being cut into a rectangular shape can be grasped. . In other words, as described above, the range of (l _x + l _y ) in the figure, which is a part where the base paper and the sheet length always greatly fluctuate, and the range of l _z , which is the short-cycle invariant part, are defined. The detection sensors D1 to D6 and the unit length measurement sensors S1 to S6 are provided so that the actual sheet length at the added portion can always be measured.

FIG. 2 is a block diagram showing an example of a distributed control system having a hierarchical structure for controlling each part based on each measurement data, and reference numeral 1 is a control computer, 2 and 3.
Is a control station for each of the single facer parts, 4 is a control station for the double facer parts, and 5 is a control station for the cutter parts. Data inputted through the respective stations is transferred to the data way 6. Control computer 1 via
On the other hand, the control computer 1 is configured to perform necessary calculations and corrections described later by the built-in measurement calculation function and feed back to each station.

That is, each of the control stations 2 to 4 described above has the original L
The control station 5 controls the auto splicer and the single facer for 1, L2, etc., while the control station 5 controls the crease and width direction slitter, the rotary cutter 17, and the delivery 18. Then, as described later, while the addition and subtraction of the unit length of each unit length measurement sensor and the learning measurement are performed by the operation of each detection sensor described above, the sheet length up to the processing end of the original sheet feeding portion is always accurately measured and Lots are appropriately changed according to the order situation, and production is done without excess or deficiency.

The operation of the unit length measurement sensor group of the detection sensor group and the measurement calculation function of the control computer will be described for the liner original fabric L1 series with reference to the drawings and flowcharts of FIG. 3 and subsequent figures.

In FIG. 3, the raw paper is changed from lot 1 to lot n by changing the brand, and each lot is composed of several original fabrics of the same brand depending on the order.

In addition, it is assumed that the order from the order 1 to the order 1 is performed in the lot 1, and in the order 1-1 to the order 1,
The figure shows a situation in which the lot is changed from lot 1 to lot 2 without excess or deficiency by measuring an accurate value of the sheet length from the material feeding portion to the end of the processing.

Fig. 4 shows the detection sensor provided in the production process of the L1 series of raw fabrics for liners and the counters for performing the required integration. Figs. 5, 6, 7, and 8 show the learning measurement. A flow chart for lot change is shown.

As shown in FIG. 4, a detection sensor D1 and a unit length measuring sensor S1 for detecting the seaming interleaving paper, which is a marking, are provided at the feeding portion of the liner material, and the seaming interleaving paper is also provided at the exit of the bridge. Detection sensor D4 and unit length measurement sensor S4
Is equipped with a detection sensor and length measurement sensor at the processing end.
D6 and S6 are provided, and each length measurement sensor is provided with a wheel that contacts and rotates as S1, S4 and S6 as the base paper travels, and directly connects a rotary encoder that outputs a predetermined pulse for each rotation of the wheel. The counter C1 for integrating the number of pulses
C11 is provided in the correction calculation unit of the control computer 1. Counters C1, C4A, C4B, C8A, C8B, C10 are designed to integrate S1 pulses, counters C2, C5A, C9 are designed to integrate S4 pulses, and C3, C5B, C11 are integrated S6 pulses. In this way, each has the illustrated function.

By the detection sensor, the length measurement sensor, the group of counters, and the measurement calculation function of the control system, learning measurement of I to III described below is performed. That is, I: The accumulated value of the sheet at the portion where the processing length varies and the sheet length at all processing lines are updated and corrected to the corresponding values of the new joint paper at every passage of the joint paper, and the measured integrated value ΣS1 from the previous joint to this joint -S4 is corrected by comparing ΣS6 with the new amount of stay measured by passing through the new seam machining length variation area.

II: The product of the number of finished products and the product length in the lot is compared with ΣS1 and ΣS6, and S1 and S6 are corrected for each lot exchange.

ΣS1 = total length of the sheet that has passed the detection sensor D1 and measured by the length measurement sensor S1.

ΣS6 = total length of the sheet that has passed the detection sensor D6 and measured by the length measurement sensor S6.

III; ΣS1ΣS when running for a long time, for example 100,000 m
4 and ΣS6 are compared and S1 and S4 are corrected for S6.

A procedure for starting the method for carrying out the learning measurement will be described with reference to the drawings. At the time of starting, first, manually feed out the liner base paper from the original fabric L1 and thread this to the front of the rotary cutter 17, and then to the raw paper located immediately before the detection sensor D1 of the original fabric feeding part, Stick a slip sheet showing the first seam.

When the detection sensor D1 detects the passage of the seam at the stage in the flowchart of FIG. 5, the counters C1, C2, C3, C4, C4A, C4B start counting at the stage, of which the counters C1 to C3 are 100000 m. Is a counter for use, which is reset after the integrated value of the counter reaches 100000 m and the predetermined calculation or storage by the control computer is completed, and starts the integration again from 0. Specifically, the counters C1, C4A , C4B is a length measuring sensor S1
The counter C2 simultaneously starts the integration of the number of pulses of the length measurement sensor S4, and the counter C3 simultaneously starts the integration of the number of pulses of the length measurement sensor S6.

As shown in Fig. 4, the same position as the mounting position of the length measurement sensor S1
Between the mounting positions of S4, there is a machining length variation part indicated by the symbol l _x + l _y , that is, a slitter due to a specification change, a slitter accompanying a specification change, and a cushion part for not affecting the front and rear processes when changing the scorer. In addition, a drying part that causes heat shrinkage to the sheet is provided at l _{z, and} it is necessary to continue accurate measurement of the sheet length that constantly changes due to these working conditions.
The holdup of the sheet in the _{x + l y A = S 1-1} × C4
In _{A-S 4-1 × C5A + (} lx + ly obtained at the previous joint passage) _{However, S 1-1, S 4-1, S} 6-1 , etc., the length measuring sensor _{S 1, S 4, S 6,} etc. The length per unit rotation. Then, the sheet length of all processing lines l _x + l _y + l _z is calculated by B = S _1-1 × C4B-S _6-1 × C5B + (l _x + l _y + l _{y obtained} when the joint passed last time). There is. That is, as clearly shown in the stage of FIG. 5, the counter A, C1, C2, C3, C4A, and C4B are operated together with the operation of C1, C2, C3, C4A, and C4B.
Activate B at the same time. By the way, counters C5A and C5
Since B operates only after reaching the following stages and, respectively, before the operation, the values of counters A and B show the values of C4A and C5A.

Then, when the detection sensor D4 detects the passage of the joint No. 1 on the stage, the counter C5A is detected on the stage.
Starts to operate and starts counting the number of pulses of the length measurement sensor S4, and at the stage, detects the passage of joint No. 1 sensor D6
When it is detected, the counter C5B starts to operate in the stage, the pulse number of the length measurement sensor S6 is started to be integrated, and after that, the stay amount and the sheet length of all processing lines are measured.
It is continuously performed by A and B.

As described above, the original fabric generally has one or two seams, and the seams are marked with interleaving paper. In addition, one of the two originals set on the roll stand is consumed up and the other original is consumed.
Even when switching to L2, the joints between them are marked with silver paper, so when the joint NO.2 from any of the joints passes the detection sensor D1, the sensor detects the passage. To do. That is, when the detection sensor D1 detects passage of NO.2 at the stage on the stage, the counters C8A and C8B start operating on the stage, and the length measurement sensor S1
Separately start the integration of the number of pulses. Next, when the detection sensor D4 detects the passage of the seam on the stage, the counter C8A stops on the stage, the retention of the new raw paper introduced into the processing line via the new seam is measured, and at the same time, it is indicated by A above. The measured value that had been updated is numerically updated to the new retention amount in stage 10a.

On the stage, the counter C9 that measures the length of the base paper from the seam No. 1 to the next seam is activated,
The integration of the number of pulses in the length measurement sensor S4 is started, stopped at the stage, and the length from the seam NO.1 to NO.2 is measured.

Then, on the stage, the ratio of the sheet length C9 between the seams to the value of A just before the update and the value of C8A ε1 (%)
Then, the length measuring sensor S4 is corrected on the stage based on ε1. That is, the length per one rotation of S4 up to now is corrected to (1-ε ₁ ) times, and the above-mentioned is classified according to the paper quality (eg, K liner, K'liner, J liner, etc.) of the base paper. The data ε1 is saved.

Then, when the detection sensor D6 detects the passage of the joint NO.2 at the stage, the stage starts operation based on the detection of the passage of the joint NO.2 together with the counter C8A by the detection sensor D1 and integrates the pulses of the measurement sensor S1. Had counter C8
B is stopped, and as a result, the measured value of the sheet length B of all the processing lines that started continuous measurement at stage 2a is
It is updated to the value measured by C8B in 14a.

As described above, the calculation and correction processes are performed in the order from the stage to the stage 14a every time the joint of the base paper passes the detection sensor.

Next, the calculation correction process at the time of lot exchange due to the change of the brand of base paper will be described by the stages and below.

When the detection sensor D1 detects the passage of the lot-changing seam of the lot NO (n-1) lot on the stage, the lot length measuring counter C10 operates on the stage, and then on the stage, the passage of the seam is detected by the sensor D6. Is detected,
Similarly, the counter 11 is activated and the measurement sensors S1 and S6 respectively
Pulse and start integration. Next, when the D1 detects the passage of the NO.n lot lot changing seam at the stage, the counter C10 is stopped at the stage to obtain the NO (n-1) lot measurement length ΣS1n, while the stage NO.n
When the detection sensor D6 detects the passage of the lot replacement seam of the lot, the counter C11 is stopped and the measurement length ΣS6n of the NO (n-1) lot is obtained.

Then, at the stage, ΣS1n and ΣS6n are compared with the planned length (the planned logical value, which is the logical length obtained by the product of the number of manufactured products and the product length in the lot), and the values of ε2 and ε2 ′ are determined. Each of them is calculated, and then the correction coefficient is changed according to the quality of the original paper (K liner, K'liner, J liner) by the calculated value on the stage.
Correct S1 and S6 and save ε2 and ε2 'data.

Next, while repeating the above series of correction calculations, when the value of the counter C3 exceeds 100,000 mm on the stage, ε3 and ε4 are obtained by the stage calculation processing, and ε3 is calculated by the step.
S1 is corrected, S4 is corrected by ε4 on the stage, and data is saved. FIG. 8 shows a flowchart of the lot change control associated with the brand change.

As shown in the figure, the value of the counter B, which is continuously measured at the stage 2a, is read at the stage. Then, when the theoretical length of the remaining order assigned to the lot at the stage and the value of B are compared and the values become equal, the stage sends a timing signal for lot change to the splicer to perform the required lot change. Therefore, it is possible to produce a predetermined order without excess or deficiency.

Although the learning measurement control by the above flow chart is described only for the liner original fabric, the learning measurement can be applied to the series of the original fabrics L3 and L4.

The following table shows the result of the lot change of the process in which the lot change control method of the corrugated board production process by the learning measurement of the present invention is actually used.

As shown in the table, during the operation time of 73 minutes, the lots are changed about every 8 minutes due to 9 changes of brands, during which 46 orders are processed at an average operation speed of 120 to 180 m / min, and the order is over or under. We were able to achieve excellent results in 3 cases of number +1 and 2 cases of -1.

[Advantages of the Invention] Since the present invention has the above-described configuration, the following effects are exhibited. That is, high-precision measurement of the sheet length staying in the variable portion and the entire processing line is always performed by the length measuring sensors provided at both ends of the processing length changing portion and the processing cutting end on the processing production line and the measuring function provided in the control system. Since it is carried out continuously and the lots are changed based on the measured value in comparison with the number of remaining orders in the relevant lot, it is possible to produce the ordered products without excess or deficiency, and especially the corrugated cardboard production process that is suitable for a wide variety of small-volume production. In the case of, you can produce efficiently.

In addition, since the detection part consisting of the seam detection sensor and the measurement sensor is installed at the fabric repeat part, the exit of the bridge, and the machining end, there is a machining length variation part that has a short cycle variation factor including the cushion part in the cardboard production process. Sheet length staying on all processing lines can be measured separately.
It is possible to efficiently correct the measured value for each cause.

Furthermore, since the measurement is performed for each seam of the base paper, it is possible to correct the measurement error due to the change in the paper quality of the base paper each time, and it is also possible to correct the correction error for each lot and the accumulated error due to long-term work. Not only can the accuracy of measured values be improved, but the effect of being able to respond to major changes in paper quality due to brand changes is also demonstrated.

[Brief description of drawings]

FIG. 1 is a system diagram showing a schematic process when the present invention is applied to a production process of AB flute double-sided composite corrugated board,
Fig. 2 is a block diagram showing the same control system, Fig. 3 is a diagram showing the allocation situation of a large number of order processing orders using a group of stocks of multiple brands in a variety of small-quantity production, and Fig. 4 is a stock for a liner. Layout of the detection sensor and unit length measuring sensor in the L1 series production line, FIGS. 5 to 8 are flowcharts showing the state of lot measurement control by learning measurement of the present invention, and FIG. 9 is a conventional AB flute double-sided composite corrugated board It is a side view of the production process of. 1 ... Control computer, 2 ... AF station, 3 ... B
F station, 4 ... DF station, 5 ... Cutter tip station, 6 ... Data way, 11a-11e ... Auto splicer, 12a-12c ... Preheater, 13a-13b ... Sugar facer, 13c ... Double facer, 14a, 14b ... Bridge,
17 ... slitter, scorer, 18 ... cutter.

Claims (1)

[Claims] 1. A raw material feeding section of a corrugated board production process,
A detection sensor (D ₁ , D ₄ , D ₆ ) for detecting the seam of the base paper and a rotary unit length measuring sensor (S ₁ , S) are provided at the exit of the bridge, which is the cushion part, and the processing end just before the cutter, respectively. ₄ ) S ₆ ) is provided, and a) every time the original seam passes, the number of pulses corresponding to the number of rotations of the length measuring sensor is counted through each of the above-mentioned detection parts, and The sheet length between each seam is continuously measured by the product of the length per rotation of the length measuring sensor, and (2) and in the same manner, from the measurement value at the detection portion of the original fabric feeding portion to the detection portion at the bridge outlet. By calculating so as to subtract the measured value, the machining length variation portion (lx + l) from the original fabric feeding portion to the bridge outlet is calculated.
c) The sheet retention amount in y) is calculated and measured, and c) Further, the sheet measured on the entire end of the processing line from the original feeding section to the processing end by using the value measured by the detection part provided at the processing end just before the cutter. Length (lx + ly +
lz) is constantly calculated in parallel with the above, and d) the latest measurement value of the sheet length between seams measured each time the seam of the original fabric passes is updated each time, and 1x + ly) and the value of the ratio ε (%) of the sheet length to the measured value calculated from the passage of the previous seam to the passage of the current seam of the length measurement sensor S _{4 at} the detection site of the bridge exit. The value per revolution is corrected, and e) Each time the lot is exchanged, the theoretical length calculated from the actual number of finished products and each lot length shown on the length measuring sensor provided at the raw material feeding part and the processing end A method for controlling lot change in a corrugated board production process by learning measurement, which is characterized in that the scale correction per one rotation of the length measuring sensors S ₁ and S ₆ is performed in comparison with.