JPH0639918Y2 - Web cutting device - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a web cutting device for cutting a running web to a predetermined length, and more specifically, to check the position of a defect in the web and change the cutting length. It relates to the device.

[0002]

2. Description of the Related Art A long web, such as a plastic film, a paper or a cloth, is cut by a web cutting machine to a predetermined length during its running. It is necessary to exclude the containing sheet as a defective product. As a web cutting machine having a function of eliminating this defective product, for example, as described in Japanese Patent Laid-Open No. 50-103779, a web cutting device for measuring the amount of transferred web and always cutting it to a constant length. It is known that a defect detection section is provided in the front part of the above, and a gate for switching the transfer direction of the cut sheet between two directions is arranged in the rear part.

Normally, the cut sheet is sent to a good-quality layboy. However, when the defect detecting section detects a defect in the web, the gate is operated to turn the defective defective sheet into a defective good layboy. I am supposed to send it. This web cutting machine can cut a running web to a predetermined length and automatically remove defective defective sheets, but there are the following problems.

[0004]

FIG. 6 shows a sheet cut by the above-mentioned conventional apparatus. Reference numeral 1 indicates a non-defective sheet, reference numeral 2 indicates a defective sheet, and the defective sheet 2 includes all or a part of the defect range 3 indicated by a chain double-dashed line. Pinholes, wrinkles, thickness unevenness, etc. are generated in the defect portion 4 indicated by X, and the defect portion 4 is inspected in advance by, for example, an optical defect inspection device, and a defect mark 5 near the edge of the web. Is attached.

Since there is a high probability that another defect has occurred near the defect point 4, the range taken by the distance N before and after the defect is considered to be the defect range 3 in view of safety.
In (a) to (c) of FIG. 6, the (i + 2) th sheet is a defective sheet including the defect range 3, and in (d), the (i + 1) th and (i + 2) th sheets are defective sheets. Yes, eliminated after cutting.

This conventional apparatus has a drawback that the non-defective utilization rate of the web is low because it always cuts to a constant length L regardless of the presence or absence of the defect portion 4.

It is an object of the present invention to provide a web cutting device capable of shortening the length excluded as a defective sheet even when the defect occurrence rate is the same, thereby improving the yield. It is a thing.

[0008]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a defect detection unit for detecting a defect in a web and generating a signal, and a web transfer after the defect detection signal is input. A defect position measuring unit that measures the amount and outputs a signal indicating the position of the defect, a unit that specifies a good product cutting length L that is a regular length of the sheet, and a unit that is shorter than the good product cutting length L Means for designating the minimum cutting length M capable of sufficiently covering the range 2N, and the good cutting length L and the minimum cutting
The signal from the defect position measuring unit is monitored while referring to the length M.
And cut from the determined cutting position to the next cutting position
A determination unit for setting the length Y is provided, and the determination unit sets the length Y.
The cutter is operated based on the cutting length Y
is there. The judgment section cuts when the web is not defective.
If the length Y is set to the non-defective cutting length L and there is a defect,
Depending on the position of the defect, the cutting length Y is set as the minimum cutting length M.
Or the trailing edge of the defect area 2N is the next cutting position.
Set the cutting length so that

[0009]

Operation: While the web is running, the defect detection unit
If a defect is detected, it is detected by measuring the web transfer amount.
The position measuring unit outputs a signal indicating the moving position of the defect. Good
The minimum length that can sufficiently cover the product cutting length L and the defect range 2N
The cutting length M (M <L) is designated in advance. these
The two types of cutting lengths L and M are the same as the signal from the defect position measuring unit.
Input to the judgment section, and the judgment section
Based on the determined cutting position to the next cutting position,
Set the cutting length. Cutting length Y when the web is defective
The method of setting the
It is changed depending on the position. Determined cutting position
If the defect range 2N is included in the minimum cutting length M from the position
The cutting length Y of the mushroom becomes the minimum cutting length M. Determined cutting position
To the non-defective cutting length L includes the leading edge and the trailing edge of the defect range 2N.
When it is rare or from the determined cutting position, the good cutting length
Only the front end of the defect range 2N is included in L and the rear end is included.
If not, the defect range is 2 regardless of the cut length L of the good product.
The cutting length Y is set so that the rear end of N becomes the next cutting position.
Is, one defect range 2N cutting always to enter a single defective sheets is performed.

[0010]

EXAMPLE FIG. 2 shows an outline of a web cutting machine, in which a web 11 is continuously drawn from a web roll 10 and cut into a sheet 15 by a cutter 14 composed of an upper blade 12 and a lower blade 13. . Length Y of this sheet 15
4 is normally cut to a regular good product cutting length L, but when there is a defect range 17 with a distance N before and after the defect portion 16, the minimum cutting length is M. Sometimes, so that M near the rear end of the defect area 17 is cut,
It is set within the range of ≦ Y <(L + 2N). In order to distinguish the non-defective sheet from the defective sheet, the non-defective sheet having the length L is denoted by reference numeral 15a, and the defective sheet including the defect range 17 is denoted by reference numeral 15b. It is attached.

The defect point 16 is inspected in advance by a defect inspection apparatus immediately after the web 11 is manufactured, and an optical defect mark 18 is attached to the vicinity of the extended edge of the defect point 16 and then wound into a roll. ing. In order to detect the defect mark 18, a defect detection sensor 20 such as a photo sensor is arranged in front of the cutter 14, and when the defect mark 18 is detected, a defect detection signal is sent to the cutting length setting unit 21.

The cutting length setting unit 21 calculates a judgment formula described later to set the length Y of the sheet 15 to a non-defective cutting length L or a defective cutting length such that M ≦ Y <(L + 2N).
In order to make this determination, necessary data is input from the input unit 22, and a movement pulse from the pulse generator 23 is further added,
The cutting completion signal from the cutting control unit 24 indicates the cutting length setting unit 2
Input to 1. The pulse generator 23 is disposed between the defect detection sensor 20 and the cutter 14, and the web 1
One moving pulse is generated each time 1 is sent for a fixed distance. A rotary encoder is used as the pulse generator 23 and is connected to one of a pair of nip rollers 25 and 26 that nip and rotate the web 11.

The cutting control unit 24 includes a cutting length setting unit 21.
The rotation of the motor 27 is controlled according to the cut length of the sheet determined in step S4. The motor 27 drives the cutter 14 to cut the web 11 into a predetermined length. Length L
The non-defective sheet 15a cut into pieces is sequentially conveyed by the belts 30 and 31 and is accumulated on the product accumulating device 32. M
The defective sheet 15b cut into the defective product cutting length satisfying ≦ Y <(L + 2N) is processed by the sorting gate 33 arranged between the belt 30 and the belt 31, and the defective product collecting device 34 is provided.
Accumulated in.

The distribution gate 33 rotates clockwise about the shaft 35 as shown by the chain double-dashed line, and the leading end of the distribution gate 33 is put in the transfer path of the sheet 15 to cause the defective sheet 15 to pass.
Since the sheet b is received, the transfer direction of the defective sheet 15b can be changed so as to be directed to the defective product accumulating device 35. The distribution gate 33 is operated by a gate control unit 36 which inputs a signal from the cutting length setting unit 21.

FIG. 1 shows an essential part of an embodiment of the present invention. The cutting length setting unit 21 includes a subtraction counter 40 that tracks the defect position 18, and a determination unit 41 that calculates a determination formula to determine the cutting length Y of the sheet. The input unit 22 includes a tracking length setting device 42,
It comprises a defect range setting device 43, a non-defective cutting length setting device 44, and a minimum cutting length setting device 45.

The tracking length setting device 42 is for specifying the defect detection sensor 20 and the distance D to the cutter 14, and the defect range setting device 43 is for the defect location 1.
This is for designating the distance N between 6 and the end of the defect range 17. The non-defective cutting length setting device 44 has a product length L.
And the minimum cutting length setting device 45 is for specifying the above-mentioned minimum cutting length M. This minimum cutting length M can be cut by the cutter 14 and covers the defect range 17 sufficiently. It is the length that can be done.

Next, the operation of the present invention will be described. When the defect detection signal is input from the defect detection sensor 20, the subtraction counter 40 is preset to the content corresponding to the tracking length D, and is counted down by the moving pulse from the pulse generator 23. Therefore, the subtraction counter 40 tracks the position of the defective portion 18, and has a content corresponding to the distance with the cutting position by the cutter 14 as the origin. When the cutter 14 operates to cut the web 11, the cutting control unit 24 sends a cutting completion signal to the subtraction counter 40 and the determination unit 41, respectively.

Each time this disconnection is completed, the judgment unit 41 reads the content C of the subtraction counter 30 and uses the following judgment formula (1).
According to (2) and (2), the cutting length of two times ahead (next time) or three times ahead is calculated. The calculated cutting length is sequentially stored internally and is read by the cutting control unit 24 as the next cutting length each time cutting is completed.

In the following judgment formula, Y _i is the cutter 1
4 shows the cutting length of the i-th sheet that has been cut by the i-th operation, C _i shows the value of the subtraction counter 40 at that time, and Y _{i + 1} is decided by the previous calculation and cut next time. The cut length of the scheduled (i + 1) th sheet is shown.
In addition, L indicates a non-defective cutting length, M indicates a minimum cutting length of the cutter 14, and N indicates a distance treated as a defect range before and after the defective portion 16.

Y _{i + 1} + M−N <C _i <Y _{i + 1} + L + N (1) Y _{i + 1} + L + N ≦ C _i ≦ Y _{i + 1} + L + M−N (2)

At the completion of cutting the i-th sheet,
The determination unit 41 determines the content C _i of the subtraction counter 40 at that time according to the discriminants (1) and (2). However, since the judgment formula (1) and the judgment formula (2) are not satisfied at the same time, there are the following three types of processing depending on the judgment result.

If the judgment formula (1) is satisfied, the cutting length Y _{i + 2} of the (i + 2) th sheet to be cut in order to cut the rear end of the defect range is the content of the subtraction counter 40. using the values of C _i is set to _{(C i -Y i + 1 +} N). However, Y _{i + 2 has} already been determined by the previous (i−1) th determination.
If is reserved, the reserved cutting length is preferentially set.

Next, when the judgment formula (2) is satisfied,
The length Y _{i + 3} of the (i + 3) th sheet to be cut is reserved as the minimum cutting length M. If the determination formula (2) is not satisfied, Y _{i + 3} is undecided, but the determination is made at the next (i + 1) th cutting completion time. The cutting length Y _{i + 1} of the next (i + 1) th sheet is
It has already been determined by the determination at the -1) -th cutting completion time point, and is read by the cutting control unit 24 at the i-th cutting completion time point.

According to the above judgment, the non-defective sheet 15a which does not include the defect range 17 is cut into the non-defective cutting length L. On the other hand, the defective sheet 15b including the defect range 17 is cut while the cutting length Y is controlled so as to cut the rear end of the defect range 17 according to the position of the defect range, and is rejected as a defective product. In this case, the cut length Y of the defective sheet 15b is
The range is M ≦ Y <(L + 2N).

FIG. 3 shows the relationship between the judgment formulas (1) and (2) and the content C _i of the subtraction counter. The values of the content C _i of the subtraction counter are (a), (a), (c). ),
(D) It is divided into four cases.

First, when the judgment formula (1) is satisfied, (a)
If there is C _{i in} the range of Y _{i +2} becomes (C _i −Y _{i + 1} +
By setting to N), the rear end of the defective portion is cut, and the sheet is rejected as a defective product including the defective portion. In case when the judgment formula (1) is not established that there is a C _i to one of the range of (A) or (c) or (d), when in the range C _i is (c) or (d) , Y _{i + 2} is set to the non-defective product cutting length L and cut as a non-defective product.

When C _i is in the range of (a), it means that the next cutting length Y _{i + 1} has already been set by the judgment at the time of the completion of the (i−1) th cutting of the previous time. The cutting length Y is set to the good cutting length L and cut as a good product, or set as M ≦ Y <(L + 2N) and cut as a defective product.

Next, when the judgment formula (2) is satisfied, (c)
In the case where C _i is in the range of Y, Y _{i + 2} has already been set to L due to the defect of the judgment formula (1), but Y _{i + 3} is further reserved to the minimum cutting length M and the defect range is set to The sheet including (i + 3) th is cut and rejected as a defective product.
In this case, at the next (i + 1) th determination, the content C _{i + 1} of the subtraction counter falls within the range of (A), and the cutting length Y _{i + 3} becomes L according to the determination formula (1). Only in this case, the i-th determination of the previous time is prioritized and Y _{i + 3} is set to the already reserved minimum cutting length M. In order to handle this exception, the determination unit 41 needs to store that the determination expression (2) is satisfied and Y _{i + 3} has already been reserved.

When neither the judgment formula (2) nor the judgment formula (1) is satisfied, there is C _{i in} the range of (a) or (d), and when C _i is in the range of (d). Is the defect point 1
Since 6 is not yet sufficiently close to the cutter 14, the defective portion is out of the judgment range, Y _{i + 2} is set to L as a non-defective product, and the cutting length of the defective sheet including the defect range is set at the time of completion of cutting on and after the next time. Will be judged. Further, when C _i is in the range of (a), as described above, the next cutting length Y _{i + 1} is already set by the judgment at the time of the completion of the (i−1) th cutting last time.

As described above, the determination unit 41 determines the cutting length Y of the sheet to be cut after two or three times, sends them to the cutting control unit 24 and stores them in the memory, etc., and the cutting order. The cutter 14 is operated to cut the web 11 so that a preset cutting length is obtained when the web 11 comes.

FIG. 4 shows the cut lengths Y _{i + 2 of} the (i + 2) th and (i + 3) th sheets, which are determined at the time when the cutting of the i-th sheet is completed, and the defect location relationship in each case. It was done. At this time, the determination is made by (a), (b), (c), (d), (e), depending on the value of the content C _i of the subtraction counter according to the position of the defective portion 16.
(F), (g), and (h) are divided into two cases. Among them, (a) is the same as (g) in the (i + 1) th determination, and (h) is Since it is the same as the case (b) of the (i-1) th determination, the determination at the time of completion of cutting the i-th sheet may be considered separately for a total of six cases. Hereinafter, each case will be described.

In the case of (a), the defective portion 16 is not yet sufficiently close to the cutter 14, so the defective portion is outside the judgment range of this time, which is the case of (d) in FIG. This is the same as the case (g) of the determination to be performed next time (i + 1) th due to the progress of the web.

In the cases of (b) to (d), which corresponds to the case of (c) in FIG. 3, the cutting length Y _{i + 2} of the non-defective sheet 15a to be cut at the (i + 2) th is set to the non-defective cutting length L. Since the determination formula (2) is further established, the length Y _{i + 3 of the} (i + 3) th defective sheet 15b to be cut is set to the minimum cutting length M. In this case, the defective sheet 1 to be cut (i + 3) th in the conventional cutting device not according to the present invention
Since the length Y _{i + 3 of} 5b is also set to the non-defective product cutting length L, it is cut and rejected as a defective product including the non-defective portion after the defect range. Therefore, according to the present invention, the difference (LM) between the good cutting length L and the minimum cutting length M is (i + 4).
It is included in the second non-defective sheet 15a and can be effectively used.

In the case of (e) to (g), which corresponds to the case of (a) in FIG. 3, the cutting length Y _{i + 2} of the defective sheet 15b to be cut at the (i + 2) th time is the subtraction counter 4
It is set to (C _i −Y _{i + 1} + N) using the value of the content C _i of 0. When the (i + 2) th cutting is performed, the cutter 14 cuts the rear end of the defect area 17, so that the defect area 1
7 is only one defective sheet 15b cut at this time
Are excluded from the non-defective portion immediately after the defect range 17, but are included in the (i + 3) th non-defective sheet 15a. In this case, only one defective sheet 15b to be eliminated
The cutting length Y of is in the range of M ≦ Y <(L + 2N).

In the case of the above (e), in the conventional cutting device not according to the present invention, the defective sheet having the length L cut at the (i + 2) th and the length L cut at the (i + 3) th are cut.
Since it is divided into two defective sheets in total,
The total length excluded as a defective product is (2L). Also in the improved cutting device as disclosed in, for example, Japanese Patent Laid-Open No. 57-138904, a defective sheet having a length L cut at (i + 2) th and a minimum cutting length cut at (i + 3) th. Since the defective sheet of M is divided into two defective sheets in total, the total length excluded as a defective product is (L + M).

On the other hand, according to the present invention, the cut length Y of the rejected defective sheet 15b is shorter than that of the conventional one, and L <Y <
There is only one sheet in the range of (L + 2N), and the non-defect portion immediately after the defect area is not included. Therefore, compared with the conventional cutting device, at least the difference (L-2N) or (M-2N) can be effectively utilized as a good product sheet (generally, N is sufficiently smaller than L and M). is there).

In the case of (f), the value of (C _i −Y _{i + 1} + N) set as the cutting length Y _{i + 2} of the defective sheet 15b is equal to L. Further, in the case of (g), in the conventional cutting device not according to the present invention, the product is cut with a good product cutting length L while including the defect range, and is rejected as a defective product. Also in the improved cutting device as disclosed in, for example, Japanese Patent Application Laid-Open No. 57-138904, the cutting length after (i + 2) th is set to the minimum cutting length M, and at least two or more continuous defective sheets are formed. , There is no choice but to cut continuously until the defect area is eliminated. In this case, the total length excluded as a defective product is an integral multiple of M, but may be larger than L. In addition, the non-defective portion after the defect range is included and cut and rejected as a defective product.

On the other hand, according to the present invention, the cut length Y to the rejected defective sheet 15 is shorter than the good product cut length L, and there is only one sheet in the range of M <Y <L. Since the non-defective portion immediately after is not included, the non-defective portion can be effectively used as a non-defective sheet.

In the case of (h), which corresponds to the case of (a) in FIG. 3, the judgment (b) made at the (i-1) th time last time is performed.
Will be the same as In this case, the next cutting length Y _{i + 1} is determined by the judgment at the time of the completion of the (i−1) th cutting of the previous time.
Is already set.

Generally, since the defect occurrence rate is small and a margin of length N is provided before and after the defect portion 16, there is practically no problem in the above embodiment. However, if the defect is of length N
When the defect occurs in a range exceeding the range, another defect part may be detected by the defect detection sensor 20 while one defect part is being tracked. To deal with this special case, it is necessary to provide a plurality of subtraction counters 40, preset them in order when a defect is detected, track each defect point, and calculate the judgment formulas for all the subtraction counters when cutting is completed. Good.

Next, in order to confirm the effect of the device of the present invention, the defect range 2N is set to 300 mm and the minimum cutting length M is set to 370 mm and 500 mm, respectively. Cutting length L of 370 mm, 400 mm, 1 or less
The average NG magnification r was determined by changing the distance from 300 mm by 100 mm, and the calculation result is shown in FIG. This average NG magnification r
Is the ratio of the length of defective products to the length of non-defective products per defect, assuming that the defect occurrence rate is always uniform, and is given by the following equation.

[0042]

[Equation 1]

To compare with the average NG magnification of the present invention,
The average NG magnification r ₀ was determined for conventional sizing. In this conventional example, since L = M, the following is obtained. r ₀ = (L + 2N) / L

In FIG. 5, the average NG by the conventional constant-size cutting is shown.
The curve of the magnification r ₀ is indicated by α, and the average NG magnification curve of the present invention is indicated by β and γ. Here, the curve β is the minimum cutting length M
Is an average NG magnification curve when 370 mm is set to
Is when the minimum cutting length M is 500 mm. As can be seen from FIG. 5, when the non-defective cutting length L is 600 mm and the minimum cutting length M is 500, in the present invention, the average NG is NG.
The magnification is "1.06", and the conventional one is "1.5".
Since it is "0", the length of the defective sheet is shortened and the yield is improved in the present invention.

[0045]

According to the present invention, when there is no defect in the web, it cuts to the proper non-defective cutting length L, but when there is a defect in the web, the range of this defect falls within one defective sheet. As described above, the minimum cutting length or the length that cuts from the trailing edge of the defect is set, and the cutter is activated according to the determination result. Can be shortened. Therefore, in the present invention, since the normal portion of the web can be effectively used, the yield can be significantly improved as compared with the conventional sizing.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of the present invention.

FIG. 2 is a schematic view of a web cutting machine using an embodiment of the present invention.

FIG. 3 is an explanatory diagram showing parameters of a judgment formula.

FIG. 4 is an explanatory view showing a cut state of a web according to the present invention.

FIG. 5 is a graph in which an average NG magnification is determined and plotted for an example of the present invention and a conventional example.

FIG. 6 is an explanatory diagram showing a conventional web cutting state.

[Explanation of symbols]

 11 web 14 cutter 15 sheet 15a non-defective sheet 15b defective sheet 16 defect location 17 defect range 18 defect mark 20 defect detection sensor 23 pulse generator 33 distribution gate

Claims (4)

[Scope of utility model registration request] 1. A cutter is arranged in a web transfer path,
In a web cutting device that cuts a running web into sheets, a defect detection unit that detects defects in the web and generates a signal, and measures the transfer amount of the web after the defect detection signal is input to detect defects. Defect position measuring unit that outputs a signal that indicates the position, means for specifying the good product cutting length that is the regular length of the sheet, and the minimum cutting that is shorter than this good product cutting length and that can sufficiently cover the range of defects A means for designating the length and monitoring the defect position signal from the defect position measuring unit,
The cutting length from the determined cutting position to the next cutting position is missing.
It is a judgment unit that sets according to the position of the pit,
If there is no defect, the above-mentioned good product cutting length is taken as the cutting length.
And set if there is a defect in the web
Cuts that have a determined leading and trailing edge of the defect range.
When included in the minimum cutting length from the position,
The cutting length is the cutting length that has been determined as the leading and trailing edges of the defect range.
Determined when included in the cut length of non-defective products from the cut position
From the cutting position to the rear end of the defect range
And a good product from the cutting position where the front edge of the defect range has already been determined
Included in the cutting length, and the trailing end of the defect range is the non-defective product
When it is not included in the length, it is defective from the determined cutting position.
The web cutting device is provided with a judging section for setting a cutting length up to the rear end of the range, and cuts the web by operating the cutter according to a signal from the judging section. 2. The web cutting device according to claim 1, wherein the defect detection unit detects a defect mark formed on the web to indicate a defective portion. 3. The defect position measuring unit includes a pulse generator that generates one web movement pulse every time the web is fed by a predetermined amount, and a defect detecting unit and a cutter when the defect detection signal is input. 3. The web cutting device according to claim 2, wherein the distance to is preset and the subtraction counter subtracts by the web moving pulse. 4. The non-defective cutting length is L, the minimum cutting length is M,
The distance between the defect detector and the cutter is D, before and after the defect
N is the defect range and the i-th cutting length is Y_i, I-th cut
The content of the subtraction counter at the time of completion of disconnection is C_iage
Then, the judgment unit calculates the following judgment formula,_{i + 1}+ M-N <C_i<Y_{i + 1}If + L + N holds, the (i + 2) th cut
The cutting length of the_i-Y _{i + 1}+ N), and
In this case, set the cutting length L to good product, and use the following judgment formula Y_{i + 1}+ L + N ≤ C_i≤ Y_{i + 1}If + L-N + M is satisfied, the (i + 3) th cut is performed.
The cutting length of the switch is set to M in advance.
3. The web cutting device according to 3.