JP2012137404A - Flatness measuring device and flatness measuring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flatness measuring device and a flatness measuring method capable of correcting the influence of the vibration of a conveyor belt.SOLUTION: A flatness measuring device comprises a conveyor belt 34, a roll for driving by rotating the conveyor belt 34, a first sensor 38 for detecting the vibration of the conveyor belt 34, a second sensor 40 for measuring the height position of the tip of a sheet 32, and a control part for receiving and analyzing a signal from the first sensor 38 and a signal from the second sensor 40. When the control part determines that there is no connecting part of the conveyor belt 34 on the roll, the control part calculates flatness in which the influence due to vibration of the conveyor belt 34 is corrected based on the signal from the first sensor 38 when the flatness of the sheet is calculated based on the signal from the second sensor 40, and when the control part determines that there is a connecting part of the conveyor belt 34 on the roll, the control part does not calculate the flatness of the sheet 32.

Description

  The present invention relates to a flatness measuring device and a flatness measuring method for measuring the flatness of a sheet conveyed on a conveyor belt.

  In plate making such as electrophotographic plate making in recent years, lithographic printing plates (PS plates: Pre-Sensitized Plates) such as photosensitive printing plates and heat-sensitive printing plates are widely used. A lithographic printing plate is generally obtained by performing surface treatment such as graining, anodizing, silicate treatment, and other chemical conversion treatment alone or in combination on a support such as a sheet-like aluminum plate, and then photosensitive layer or heat-sensitive layer. In general, it is formed into a strip shape, and is cut into a desired size by a predetermined processing line to obtain a final product.

  By the way, these PS plates are made into products by rewinding the belts on a roll and flattening them with a decal device and cutting them to a predetermined length.

  However, the curl may not be completely corrected by the decurling device, or may be curled in the opposite direction due to overcorrection, so that the PS plate cut to a predetermined length (hereinafter also referred to as a sheet). It is necessary to measure whether the flatness of the plate has reached a specified value.

  This is because if the flatness does not reach the specified value, problems such as the upper sheet scratching the photosensitive layer of the lower sheet occur when the sheets are stacked. A flatness measuring method for calculating the amount of curling is disclosed in Patent Document 1. In Patent Document 1, a distance measuring device that measures the distance to the surface of a displacement amount due to sagging of the unsupported tip of the web in the longitudinal direction is measured in a longitudinal direction. A method for measuring the flatness is described in which a plurality are positioned and measured, and the amount of curl is calculated based on the measured value.

  This makes it possible to measure on-line the flatness of a thin sheet where the downward sled becomes flat under its own weight on-line.

JP-A-6-50751

  However, in the conventional flatness measuring method, an error is included in the flatness measurement due to the influence of the vibration of the conveyor belt carrying the PS plate.

  The present invention is intended to provide a flatness measuring device and a flatness measuring method capable of correcting the influence of the vibration of the conveyor belt in view of such circumstances.

  The problems of the present invention can be solved by the following inventions.

  That is, the flatness measuring device of the present invention includes a conveyor belt for conveying a flat sheet, a roll installed at the front end of the conveyor belt in the conveying direction, and driven by rotating the conveyor belt, From the first sensor for detecting the vibration of the conveyor belt, the second sensor for measuring the height position of the leading edge of the sheet protruding from the leading edge of the conveying direction of the conveyor belt, and the first sensor And a control unit for receiving and analyzing the signal from the second sensor, and the control unit analyzes the signal from the first sensor, When it is determined that the connecting portion is not on the roll, when calculating the flatness of the sheet based on the signal from the second sensor, the coherence is based on the signal from the first sensor. The influence of vibration of Beaberuto calculates the flatness corrected, when the connection portion of the conveyor belt is determined to be on the roll is in the main characterized in that it does not calculate the flatness of the sheet.

  Thereby, the flatness measurement which correct | amended the influence by the vibration of a conveyor belt is attained. Further, the front end portion of the sheet is flipped up by the influence of the convex portion of the connection portion (joint) of the conveyor belt, and flatness measurement including an error due to measurement of the value can be avoided.

  Further, the flatness measuring device of the present invention is a conveyor belt for conveying a flat sheet, a roll installed at the front end of the conveyor belt in the conveying direction and driven by rotating the conveyor belt, From the first sensor for detecting the vibration of the conveyor belt, the second sensor for measuring the height position of the leading edge of the sheet protruding from the leading edge of the conveying direction of the conveyor belt, and the first sensor And a control unit for receiving and analyzing the signal from the second sensor, and the control unit determines the flatness of the sheet based on the signal from the second sensor. The main feature is to calculate the flatness in which the influence of the vibration of the conveyor belt is corrected based on the signal from the first sensor.

  Thereby, the flatness measurement which correct | amended the influence by the vibration of a conveyor belt is attained. Further, it is possible to measure the flatness with the influence of the convex portion of the connecting portion (joint) of the conveyor belt corrected.

  Furthermore, in the flatness measuring apparatus according to the present invention, the control unit analyzes the signal from the first sensor, and when the vibration amplitude of the conveyor belt is reduced to 50% or less, the connection unit of the conveyor belt Is the main feature.

  This makes it possible to reliably detect that the connection portion of the conveyor belt is on the roll.

  Furthermore, in the flatness measuring apparatus according to the present invention, when the control unit has continued for 2 mSEC or more when the amplitude of vibration of the conveyor belt is reduced to 50% or less, the connection part of the conveyor belt is placed on the roll. The main feature is to judge that there is.

  This makes it possible to more reliably detect that the connection portion of the conveyor belt is on the roll.

  The flatness measuring method of the present invention is a flatness measuring method of a flat sheet that is placed on a conveyor belt driven by a rotating roll and conveyed, and the first sensor is the conveyor. A first sensor detecting step for detecting a vibration of the belt and transmitting the detected first data signal to the control unit; and a height of the leading end of the sheet protruding from the leading end in the conveying direction of the conveyor belt by the second sensor. A second sensor detecting step of measuring a position and transmitting a second data signal to the control unit; and the control unit analyzes the first data signal, and a connection portion of the conveyor belt is on the roll. When the flatness of the sheet is calculated based on the second data signal, the influence due to the vibration of the conveyor belt is corrected based on the first data signal. Calculating a stand, connecting portions of the conveyor belt when it is determined to be on the roll is in that it comprises a non a flatness calculation step calculating a flatness of the sheet to the main features.

  Thereby, the flatness measurement which correct | amended the influence by the vibration of a conveyor belt is attained. Further, the front end portion of the sheet is flipped up by the influence of the convex portion of the connection portion (joint) of the conveyor belt, and flatness measurement including an error due to measurement of the value can be avoided.

  Furthermore, the flatness measuring method of the present invention is a flatness measuring method of a flat sheet placed and conveyed on a conveyor belt driven by a rotating roll, wherein the first sensor is the conveyor. A first sensor detecting step for detecting a vibration of the belt and transmitting the detected first data signal to the control unit; and a height of the leading end of the sheet protruding from the leading end in the conveying direction of the conveyor belt by the second sensor. A second sensor detecting step of measuring a position and transmitting a second data signal to the control unit; and when the control unit calculates the flatness of the sheet based on the second data signal, And a flatness calculating step of calculating a flatness obtained by correcting the influence of the vibration of the conveyor belt based on the first data signal.

  Thereby, the flatness measurement which correct | amended the influence by the vibration of a conveyor belt is attained. Further, it is possible to measure the flatness with the influence of the convex portion of the connecting portion (joint) of the conveyor belt corrected.

  Furthermore, in the flatness measuring method of the present invention, in the flatness calculating step, the control unit analyzes the first data signal, and when the amplitude of vibration of the conveyor belt is reduced to 50% or less, The main feature is that it is determined that the connection portion of the conveyor belt is on the roll.

  This makes it possible to reliably detect that the connection portion of the conveyor belt is on the roll.

  Further, in the flatness measuring method of the present invention, in the flatness calculating step, when the time during which the amplitude of the vibration of the conveyor belt is reduced to 50% or less continues for 2 mSEC or more, the control unit connects the conveyor belt. The main feature is that the part is determined to be on the roll.

  This makes it possible to more reliably detect that the connection portion of the conveyor belt is on the roll.

It is explanatory drawing of the flatness measuring apparatus of this invention. It is a schematic side view of a flatness measuring unit. It is a schematic front view of a flatness measurement part. 3 is a measurement timing chart of sensors X, Y, and Z. It is the figure which showed the behavior change of the sheet | seat front-end | tip in a belt junction part. It is the figure which measured the vibration of the belt of the part which is not a belt junction part. It is the figure which measured the vibration of the belt of a belt junction part. It is a flowchart of the flatness measuring method of a 1st embodiment. It is a flowchart of the flatness measuring method of 2nd Embodiment. It is a flowchart of the flatness measuring method of 3rd Embodiment. It is the figure which measured the vibration of the belt when a belt junction part exists on a delivery side roll.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings. Here, in the drawing, portions indicated by the same symbols are similar elements having similar functions. In addition, in the present specification, when a numerical range is expressed using “˜”, upper and lower numerical values indicated by “˜” are also included in the numerical range.

<Configuration of sheet flatness measuring device>
An embodiment of a sheet flatness measuring apparatus according to the present invention will be described with reference to the drawings. FIG. 1 is an explanatory diagram of a flatness measuring apparatus according to the present invention.

  As shown in FIG. 1, the flatness measuring device of the present invention includes a cutting unit 10 for cutting a thin metal plate such as aluminum wound in a roll shape into a sheet shape, and a metal plate cut into a sheet shape. And a flatness measuring unit for measuring the flatness.

  Here, in the description of the present embodiment, an example in which a cutting unit is provided will be described. However, the embodiment is not limited to having a cutting unit, and may include a part having other functions. Alternatively, a single measuring unit is included in the range of the flatness measuring device of the present invention.

  First, the cutting unit 10 will be described. The cutting unit 10 corrects the curl of the metal plate 17, the roll 12 on which the metal plate is wound in a roll shape, the transport rollers 13, 14 and 15 for transporting the metal plate 17 drawn from the roll 12. A decurling device 16 for feeding, feed rollers 20 and 20 which are driven by a motor 18 to send the metal plate 17 to the next process, and a cutter 22 which cuts the metal plate 17 sent from the feed roller 20 into a predetermined length, It is mainly composed of.

  The roll 12 is formed by winding a thin metal plate such as aluminum. However, the roll 12 is not limited to metal, and may be a film formed of resin or the like. The conveyance rollers 13, 14, and 15 convey the metal plate 17 by being driven to rotate by a driving unit (not shown).

  The decurling device 16 is constituted by, for example, two rollers 24 and 25 having a small diameter, and corrects curl of the metal plate 17 by repeatedly bending and applying tension. The feed rollers 20 and 20 are rotationally driven by the motor 18 and supply the metal plate 17 to the cutter 22. The cutter 22 cuts the metal plate 17 fed from the feed rollers 20 and 20 into a predetermined length.

  Next, the flatness measuring unit 30 will be described. The flatness measuring unit 30 includes an upstream conveyor belt 34 for conveying a sheet 32 that is a metal plate cut to a predetermined length by the cutter 22, a sensor X36 for detecting the sheet 32, and an upstream conveyor belt. A sensor Y38 for detecting the vibration of the sheet 34, a sensor Z40 for detecting the amount of sagging of the leading end of the sheet 32, a downstream conveyor belt 42 for conveying the sheet 32 sent from the upstream conveyor belt 34, And a control unit (not shown).

  The upstream conveyor belt 34 is driven by the exit roll 50 and conveys the sheet 32 cut to a predetermined length by the cutter 22 to the downstream conveyor belt 42.

  The sensor X36 is installed on the upstream conveyor belt 34 at a position away from the output roll 50 by a predetermined distance toward the cutter 22, and detects that the conveyed sheet 32 has reached a predetermined position. The sensor Y38 is installed on the exit roll and detects the vibration of the surface of the upstream conveyor belt 34.

  Two sensors Z40, 40 are installed at positions separated from the exit roll 50 in the direction of the downstream conveyor belt 42 by a predetermined distance, and are in the height direction of the leading end portion of the sheet 32 protruding from the upstream conveyor belt 34. Measure the position (sag). The downstream conveyor belt 42 receives and conveys the sheet 32 from which the amount of sag has been measured from the upstream conveyor belt 34.

  The control unit (not shown) receives signals from the sensor X36, the sensor Y38, and the sensor Z40, and calculates the flatness of the sheet 32 from the received signals. Further, the control unit corrects the curl too much so as to improve the flatness based on the calculated flatness, that is, to further correct the curl if the curl remains. If the curl is attached in the opposite direction, the degree of correction is controlled by changing the position of the rollers 24 and 25 of the decal device 16 and adjusting the tension so as to weaken the correction of the curl. .

  Next, the flatness measuring unit 30 will be described in more detail with reference to the drawings. FIG. 2 is a schematic side view of the flatness measuring unit. FIG. 3 is a schematic front view of the flatness measuring unit.

  2 and 3, the conveying direction of the sheet 32 (left and right direction in FIG. 2) is the horizontal direction, the vertical direction in FIGS. 2 and 3 is the height direction, and the width direction of the upstream conveyor belt 34 (FIG. 3). In the horizontal direction, the sensor X36 has a horizontal direction at a position away from the rotation center axis of the exit roll 50 by a predetermined distance C in the direction opposite to the transport direction, and the height direction is The longitudinal direction is installed above the upstream conveyor belt 34 so as to be positioned at the center in the longitudinal direction of the exit side roll 50.

  The sensor Y38 has a horizontal direction at the position of the rotation center axis of the exit roll 50, a height direction above the upstream conveyor belt 34, and a vertical direction at the side end from the upstream conveyor belt 34. Installed to be located.

  The sensor Z40 has a horizontal direction at a position away from the rotation center axis of the exit roll 50 by a predetermined distance A in the transport direction, a height direction above the upstream conveyor belt 34, and a vertical direction It is installed so as to be located at two positions that are inward by B from both side ends of the conveyed sheet 32.

  The sensor X36 is an optical sensor, for example, and detects the sheet 32 conveyed on the upstream conveyor belt. The sensor Y38 starts detecting the vibration of the belt surface of the upstream conveyor belt 34 from when the sensor X36 detects the sheet. As the sensor Y38, an optical sensor or the like can be preferably used.

  The sensor Z40 detects the height of the leading end of the sheet 32 for a predetermined time after the sensor X36 detects the sheet 32 and the sheet 32 is separated from the detection area of the sensor X36 by conveyance and the sensor X36 stops detecting the sheet 32. Measure the position (sag amount).

  Therefore, it is desirable that the lateral position C of the sensor X36 is set so that the leading end of the sheet 32 protrudes from the exit roll by the predetermined position A immediately after the sheet 32 passes the detection position of the sensor X36. . As a result, the position of the sheet 32 is determined depending on whether the sensor X36 detects the sheet 32 (hereinafter also referred to as detection ON) or not (hereinafter also referred to as detection OFF). Based on this, the sensor Y38, The activation timing of the sensor Z40 or the timing for reading signals from the sensor Y38 and the sensor Z40 can be determined.

<Operation of sheet flatness measuring device>
Next, an embodiment of the operation of the sheet flatness measuring device of the present invention will be described. With reference to FIG. 1, the metal plate 17 drawn from the roll 12 is conveyed by the conveying rollers 13 and 14, and the curl is corrected by the decurling device 16.

  The metal plate 17 whose curl has been corrected is transported by the transport roller 15 and sent to the feed roller 20. The feed roller 20 is driven by the motor 18 to feed the metal plate 17 to the cutter 22 by a predetermined length.

  The cutter 22 cuts the metal plate 17 by a predetermined length. The cut sheet 32 as the metal plate 17 is placed on the upstream conveyor belt 34 and conveyed. Here, it demonstrates with reference to FIG.2, FIG.3, FIG.4. FIG. 4 is a measurement timing chart of the sensors X, Y, and Z. When the leading end of the sheet 32 conveyed by the upstream conveyor belt 34 reaches the detection position of the sensor X36, the sensor X36 transmits a detection ON signal to a control device (not shown).

  When receiving the detection ON signal from the sensor X36, the control device starts receiving the signal from the sensor Y38. The sensor Y38 is composed of, for example, a non-contact high-sensitivity minute displacement sensor or the like, and detects minute vertical vibrations of the belt of the upstream conveyor belt 34 (hereinafter sometimes simply referred to as a belt).

  Thereafter, when the sheet 32 is further conveyed and the trailing end of the sheet 32 in the conveyance direction is separated from the detection position of the sensor X36, the sensor X36 transmits a detection OFF signal to the control device. The control device that has received the detection OFF signal starts receiving the signal from the sensor Z40. The sensor Z40 measures the height position (the amount of sag) of the leading end of the sheet 32 that protrudes from the exit side roll 50 in the carry-out direction, and transmits a measurement result signal to the control device.

  The control device calculates the flatness that corrects the influence of the vibration of the belt from the height position (sagging amount) of the leading end of the sheet 32 measured by the sensor Z40 and the vibration of the belt measured by the sensor Y38. The value is transmitted to the external device.

  Based on the calculated flatness, the control device controls the decal device 16 so as to increase the degree of correction when the correction of the curl of the sheet 32 is insufficient. If there is a curl in the direction, the decurling device 16 is controlled so as to reduce the degree of correction.

  Further, when the calculated flatness is out of the predetermined value range, the control device transmits an error signal to the operator, or the sheet 32 whose flatness is out of the predetermined range is regarded as a defective product. It is also possible to control to convey the defective product to a place where it is stocked by a conveying means (not shown).

  After a predetermined time has elapsed from the start of measurement by the sensor Z40, the sensor Y38 and the sensor Z40 end the measurement. Here, when the control device analyzes the signal from the sensor Y38 and determines that the joint portion of the belt is on the output side roll 50 from the vibration waveform of the belt, the sensor Y38, sensor at that time It is also possible to stop calculating the flatness from the signal of Z40 and transmit the average value of the flatness of the sheet conveyed before and after the sheet at that time to the external device as the flatness of the sheet at that time. Thereby, it is possible to avoid flatness measurement that is highly likely to include an error.

  Alternatively, even if it is determined that the joint portion of the belt is on the outgoing roll 50, the flatness may be calculated from the signals of the sensors Y38 and Z40 and the value may be transmitted to an external device. In this case, when the flatness is calculated based on the signal from the sensor Z40, the flatness can be calculated by correcting the belt vibration including the influence of the joint portion based on the signal from the sensor Y38.

<< Flatness calculation method with corrected belt joint vibration >>
Next, a method for calculating the flatness in which the vibration at the belt joint is corrected will be described with reference to the drawings. FIG. 5 is a diagram showing a change in the behavior of the sheet front end at the belt joining portion. FIG. 6 is a diagram in which the vibration of the belt at a portion other than the belt joint is measured. FIG. 7 is a diagram in which the vibration of the belt at the belt joining portion is measured.

  Referring to FIG. 5, FIG. 5A shows the amount of sag of the sheet 32 when the belt joining portion is not on the exit roll 50, and FIG. 5B shows the belt joining portion being the exit roll. The amount of sagging of the sheet 32 when existing on the surface is shown.

  As can be seen from this figure, when the leading end of the sheet 32 is lifted or flipped up by the convex portion of the belt joint, the sagging amount of the sheet 32 is affected by the original value (affected by the belt joint). There is a problem of deviation. When the belt joining portion exists in the range of 90 degrees of the exit side roll 50 shown in FIG. 5B (the range of 90 degrees on the upper right when the circle of the exit side roll section is divided into four equal parts by 90 degrees). In particular, it has been found that the influence on the amount of sagging is large.

  Here, the results of measuring the vertical vibration of the belt will be described with reference to FIGS. FIG. 5 in which the vertical vibration of the belt when there is no belt joint portion on the output side roll 50 and FIG. 6 in which the vertical vibration of the belt when there is a belt joint portion on the output side roll 50 are measured. A comparison shows that the amplitude changes greatly.

  In particular, when FIG. 6 is seen, the amplitude of the belt is greatly decreased and the position of the belt is greatly changed from around the belt movement amount of −15 mm where the belt joining portion has moved onto the exit side roll 50.

  As can be seen from FIGS. 6 and 7, the amplitude is about 0.2 mm when the belt joint is not on the output roll 50, and the amplitude is about 0.2 mm when the belt joint is on the output roll 50. 0.1 mm or less. Therefore, when the amplitude is 50% or less, it can be determined that the belt joining portion has moved onto the exit side roll 50.

  Here, in the measurement of FIGS. 6 and 7, the displacement of the belt was measured by installing a sensor of a high-precision laser displacement meter (manufactured by Keyence Corporation, model number: LK-H055) at the position of the sensor Y in FIG. .

  Therefore, when the sensor Y38 detects that the vibration amplitude of the belt is 50% or less, the control unit has a belt joint portion on the exit side roll 50, and therefore the measured value of the sensor Z40 indicates the belt. It can be determined that an error due to the influence of bonding is included.

  Reference is now made to FIG. FIG. 11 is a diagram in which the vibration of the belt is measured when the belt joint exists on the exit roll. The measurement conditions are the same as above. In this figure, the vertical axis represents amplitude and the horizontal axis represents time. As shown in FIG. 11, the belt joint moves from the position of −8 ms (mSEC) onto the exit roll, and accordingly, the amplitude decreases to about 50% or less. Furthermore, it can be seen that the time during which the amplitude is reduced to about 50% or less continues from −8 ms to +26 ms on the horizontal axis, and the amplitude is 50% or less for about 28 ms.

  As a result of repeated evaluations by the inventors, it was found that the amplitude was 50% or less for a minimum of 2 ms when the belt joint moved on the exit roll. Therefore, the determination that the belt joint portion exists on the output roll can be determined that the belt joint portion exists when the duration of the amplitude of 50% or less is 2 ms or more. When the duration of the amplitude of 50% or less is 10 ms, it can be determined with more certainty that the belt junction exists when the duration of the amplitude is 50% or less is 20 ms.

  When the control unit determines that the error is included in the measurement value of the sensor Z40, the control unit discards the measurement value of the sensor Z40, calculates an average value of the measurement values of the two sheets before and after the conveyance of the sheet at this time, The value can be transmitted to the external device as the flatness of the sheet at this time.

  Here, a method for calculating the flatness by correcting the error of the measured amount of sagging of the sheet 32 due to the vibration of the belt shown in FIGS. 6 and 7 will be described.

  The inventors of the present invention have intensively found that the flatness of the sheet 32 corrected for the influence of the belt vibration is calculated by the following expression 1.

y = a ₁ cos (b ₁ y ₁ ) + a ₂ sin (b ₂ y ₂ ) + C (Formula 1)
y = flatness, y ₁ = sheet sagging amount, y ₂ = belt vibration amplitude,
a ₁ , b ₁ , a ₂ , b ₂ , and C are constants, and are values obtained by flowing a sheet in advance and measuring the flatness with another measuring device.

  By calculating the flatness according to Equation 1, it is possible to reduce the measurement error of the sheet droop amount due to the vibration of the belt. In addition, even when the belt joining portion as shown in FIG. 7 is present on the exit side roll 50, it becomes possible to reduce the measurement error of the drooping amount due to the vibration.

<First Embodiment>
Next, a flatness measurement method according to the first embodiment of the present invention will be described with reference to the drawings. FIG. 8 is a flowchart of the flatness measuring method according to the first embodiment.

  Referring to FIG. 8, the sheet 32 is conveyed on the upstream conveyor belt 34, the sensor X detects the sheet, and sends a signal to the control device (step S10). Next, the control device causes the sensor Y to start measurement (step S20). At this time, the control device can cause the sensor Z to start measurement after a predetermined time has elapsed (the predetermined time includes 0 seconds), or start the measurement to the sensor Z when the sensor X is turned off. After that, the measurement is terminated after the elapse of a predetermined time or at a predetermined timing (step S30).

  The control device ends the measurement of the sensor Y (step S40). The timing at which the measurement of the sensor Y is finished can be synchronized with the timing at which the measurement of the sensor Z is finished.

  Based on the measurement of the vibration of the belt received from the sensor Y, the control unit determines whether or not the belt joint portion exists on the outgoing roll from the change in the amplitude (step S50).

  When it is determined that the belt joining portion exists on the exit roll, the control unit calculates an average value of the flatness of the sheet conveyed before and after the sheet at that time (step S60), and the value is calculated as the flatness. To the external device (step S70).

  When it is determined in step S50 that the belt joining portion does not exist on the exit roll, the control device calculates the flatness from the amount of sagging of the sheet leading end measured by the sensor Z (step S80), and the value is calculated. Is output as the flatness (step S90). In this case, the flatness is calculated using the following equation.

y = d ₁ y ₁ + E (y = flatness, y ₁ = sheet sagging amount)
Here, d ₁ and E are constants obtained by flowing a sheet in advance and measuring the flatness with another measuring device.

<Second Embodiment>
Next, a flatness measurement method according to a second embodiment of the present invention will be described with reference to the drawings. FIG. 9 is a flowchart of the flatness measuring method according to the second embodiment.

  Referring to FIG. 9, the sheet 32 is conveyed on the upstream conveyor belt 34, and the sensor X detects the sheet and sends a signal to the control device (step S110). Next, the control device causes the sensor Y to start measurement (step S120). At this time, the control device can cause the sensor Z to start measurement after a predetermined time has elapsed (the predetermined time includes 0 seconds), or start the measurement to the sensor Z when the sensor X is turned off. After that, the measurement is terminated after the elapse of a predetermined time or at a predetermined timing (step S130).

  The control device ends the measurement of sensor Y (step S140). The timing at which the measurement of the sensor Y is finished can be synchronized with the timing at which the measurement of the sensor Z is finished.

  The control device calculates the flatness from the amount of sagging of the leading end of the sheet measured by the sensor Z (step S180). At this time, correction is performed based on the belt vibration data measured by the sensor Y (step S182). . For the correction, Equation 1 can be used. The control device outputs the corrected flatness (step S190).

<Third Embodiment>
Next, a flatness measurement method according to a third embodiment of the present invention will be described with reference to the drawings. FIG. 10 is a flowchart of the flatness measuring method according to the third embodiment.

  Referring to FIG. 10, sheet 32 is conveyed on upstream conveyor belt 34, sensor X detects the sheet and sends a signal to the control device (step S210). Next, the control device causes the sensor Y to start measurement (step S220). At this time, the control device can cause the sensor Z to start measurement after a predetermined time has elapsed (the predetermined time includes 0 seconds), or start the measurement to the sensor Z when the sensor X is turned off. After that, the measurement is terminated after the elapse of a predetermined time or at a predetermined timing (step S230).

  The control device ends the measurement of the sensor Y (step S240). The timing at which the measurement of the sensor Y is finished can be synchronized with the timing at which the measurement of the sensor Z is finished.

  Based on the measurement of the vibration of the belt received from the sensor Y, the control unit determines whether or not the belt joint portion exists on the outgoing roll from the change in the amplitude (step S250).

  When it is determined that the belt joint exists on the exit roll, the control unit calculates an average value of the flatness of the sheet conveyed before and after the sheet at that time (step S260), and the value is calculated as the flatness. To the external device (step S270).

  When it is determined in step S250 that the belt joining portion does not exist on the exit roll, the control device calculates the flatness from the amount of sagging of the sheet leading end measured by the sensor Z (step S280). At this time, correction is performed based on the vibration data of the belt measured by the sensor Y (step S282). For the correction, Equation 1 can be used. The control device outputs the corrected flatness (step S290).

  DESCRIPTION OF SYMBOLS 10 ... Cutting part, 12 ... Roll, 13 ... Conveyance roller, 15 ... Conveyance roller, 16 ... Decal device, 17 ... Metal plate, 18 ... Motor, 20 ... Roller, 22 ... Cutter, 24 ... Roller, 30 ... Flatness measurement Part 32 ... sheet 34 ... upstream conveyor belt 36 ... sensor X 38 ... sensor Y 40 ... sensor Z 42 ... downstream conveyor belt 50 ... exit roll

Claims (8)

A conveyor belt for conveying a flat sheet;
A roll installed at the front end of the conveyor belt in the transport direction and driven by rotating the conveyor belt;
A first sensor for detecting vibrations of the conveyor belt;
A second sensor for measuring the height position of the leading edge of the sheet protruding from the leading edge of the conveyor belt in the conveyance direction;
A control unit for receiving and analyzing the signal from the first sensor and the signal from the second sensor;
With
When the control unit analyzes the signal from the first sensor and determines that the connection portion of the conveyor belt is not on the roll, the control unit determines whether the sheet is flat based on the signal from the second sensor. When calculating the degree, when calculating the flatness corrected for the influence of the vibration of the conveyor belt based on the signal from the first sensor, and determining that the connecting portion of the conveyor belt is on the roll A flatness measuring device that does not calculate the flatness of the sheet. A conveyor belt for conveying a flat sheet;
A roll installed at the front end of the conveyor belt in the transport direction and driven by rotating the conveyor belt;
A first sensor for detecting vibrations of the conveyor belt;
A second sensor for measuring the height position of the leading edge of the sheet protruding from the leading edge of the conveyor belt in the conveyance direction;
A control unit for receiving and analyzing the signal from the first sensor and the signal from the second sensor;
With
The controller, when calculating the flatness of the sheet based on the signal from the second sensor, calculates the flatness corrected for the influence of the vibration of the conveyor belt based on the signal from the first sensor. Flatness measuring device to calculate.   The said control part analyzes the signal from the said 1st sensor, and when the amplitude of the vibration of the said conveyor belt reduces to 50% or less, it judges that the connection part of the said conveyor belt exists on the said roll. The flatness measuring apparatus according to 1.   4. The flatness according to claim 3, wherein the controller determines that the conveyor belt connecting portion is on the roll when the time when the amplitude of vibration of the conveyor belt is reduced to 50% or less continues for 2 mSEC or more. measuring device. A method for measuring the flatness of a flat sheet that is placed and conveyed on a conveyor belt driven by a rotating roll,
A first sensor detecting step of detecting a vibration of the conveyor belt and transmitting a detected first data signal to the control unit;
A second sensor detecting step of measuring a height position of the leading edge of the sheet protruding from the leading edge of the conveying direction of the conveyor belt, and transmitting a second data signal to the control unit;
When the control unit analyzes the first data signal and determines that the connecting portion of the conveyor belt is not on the roll, the control unit calculates the flatness of the sheet based on the second data signal. When calculating the flatness corrected for the influence of the vibration of the conveyor belt based on the first data signal and determining that the connecting portion of the conveyor belt is on the roll, the flatness of the sheet Flatness calculation step that does not calculate
A flatness measurement method comprising: A method for measuring the flatness of a flat sheet that is placed and conveyed on a conveyor belt driven by a rotating roll,
A first sensor detecting step of detecting a vibration of the conveyor belt and transmitting a detected first data signal to the control unit;
A second sensor detecting step of measuring a height position of the leading edge of the sheet protruding from the leading edge of the conveying direction of the conveyor belt, and transmitting a second data signal to the control unit;
When the control unit calculates the flatness of the sheet based on the second data signal, the flatness calculates the flatness corrected for the influence of vibration of the conveyor belt based on the first data signal. A calculation step;
A flatness measurement method comprising:   In the flatness calculation step, the control unit analyzes the first data signal, and when the amplitude of vibration of the conveyor belt is reduced to 50% or less, the connection portion of the conveyor belt is on the roll. The flatness measuring method according to claim 5, which is determined as follows.   In the flatness calculation step, the controller determines that the conveyor belt connecting portion is on the roll when the time during which the amplitude of the vibration of the conveyor belt is reduced to 50% or less continues for 2 mSEC or more. Item 8. The flatness measurement method according to Item 7.

Images