JP7121948B2 - Apparatus for Acquiring Information on Elongation Occurrence of Strip Electrode Plate, Method for Acquiring Information on Occurrence of Wrinkles on Electrode Band, Display Device for Information on Occurrence of Wrinkles on Electrode Strip, and Control Device for Roll Press Device - Google Patents

Description

The present invention relates to an apparatus and method for measuring the elongation rate including wrinkles on the surface of an electrode plate using a laser displacement meter in equipment for manufacturing electrode plates used in batteries.

As shown in Patent Document 1, in order to accurately measure the elongation rate of a steel sheet stretched by a rolling mill or a bridle roll, rotary length measuring instruments are attached to the entrance and exit sides of the rolling mill. It is stated that the elongation rate is obtained from the difference in length.

Patent Literature 2 describes that light from a plurality of rod-shaped light sources is reflected on the steel plate surface, the reflected light is photographed by a camera, and the steepness is obtained by comparison with a reference plane plate.

Patent Literature 3 describes the use of a laser displacement meter to measure minute irregularities on the surface of a cold-rolled steel sheet having a thickness of 0.4 mm or less in detail.

JP 2007-108036 JP 2011-099821 JP 2009-243907

A secondary battery made of lithium ion or the like is made by coating the surface of a metal foil such as aluminum or copper with an active material that has the ability to transfer electrons in the longitudinal direction. The electrode plate coated with the active material has an uncoated portion that becomes a current-carrying terminal portion when assembled as a battery. Since the electrode plate has a band-shaped coated portion and an uncoated portion in the width direction, when the coated portion and the uncoated portion are pressed simultaneously by press rolls, the coated portion is sandwiched between the upper and lower pressing rolls. The active material and metal foil become thinner and stretch longer in the longitudinal direction. However, since the uncoated portion is thinner than the coated portion, it is sandwiched between the press rolls and is not pressed. Therefore, since the electrode plate is not stretched in the longitudinal direction, wrinkles are generated in the electrode plate due to the coexistence of the elongated portion of the electrode plate that has been stretched in a band shape in the width direction and the portion that is not stretched and has the same length. . It was difficult to measure the difference in elongation between the coated portion and the uncoated portion, which causes wrinkles, while the electrode plate was moving.

The uncoated portion of the metal foil used for the electrode plate has a thickness of 20 μm or less. The shape of the metal foil changes if a rotary length measuring instrument having a thickness is placed on it. If a length measuring instrument can be placed on the object to be measured, the outer surface length can be measured accurately. However, electrode plates require different measurement conditions than rolled steel plates, and the length cannot be measured accurately using a length measuring instrument. Accurate measurement of the electrode plate is difficult without a non-contact type measuring instrument.

When the means of Patent Document 2 is used, it is possible for the metal foil portion to reflect the light from the rod-shaped light source, but for the coated portion where the active material is applied, the active material has a color close to black, and the glossiness is reduced. Since there is no , it is impossible to reflect the light from the rod-shaped light source like a metal foil. Accurate elongation cannot be measured due to differences in light reflection conditions from the light source.

In the means of Patent Document 3, the tension distribution in the width direction of the steel plate is measured by a contact roll in the equipment for rolling the thin steel plate, the produced steel plate is placed on the surface plate, and the shape of the steel plate surface is measured with a laser. It is stated to be measured with a rangefinder. There is no mention of measuring the elongation of the surface unevenness of the steel plate with a laser rangefinder while the thin steel plate moves while being rolled thin.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a measuring apparatus and method using a laser displacement gauge in order to accurately measure the length of an electrode plate used in a lithium ion battery or the like in the longitudinal direction.

Specifically, the present invention relates to a measuring method for measuring the distance to the surface of an electrode plate moving in one direction by irradiating the surface of the electrode plate with a laser beam from a laser transmitter placed at a fixed position. The amount of change in the distance due to the unevenness of the electrode plate surface is defined as a measured value A, and the length of the electrode plate moved at the time when the change occurs is defined as a measured value B. A and B were measured in an infinitely short time. From the two measured values, the surface length of the electrode plate including the unevenness is obtained as a calculated value C, and the measured value B and the calculated value C are accumulated by a certain amount, and the formula λ = (C - B) / B is the elongation rate of the electrode plate.

The present invention relates to the method for measuring the elongation rate of an electrode plate described above, wherein the electrode plate has a plurality of coated portions coated with an active material on the electrode foil and uncoated portions not coated with the active material. A laser oscillator is arranged at one or more places on the processed part and at one or more places on the uncoated part, and the distance to the surface of the electrode plate is continuous in the moving direction of the electrode plate. We propose a method for measuring the elongation rate of an electrode plate, which is characterized by measuring the

According to the present invention, in the above-described electrode plate elongation measuring method, a laser beam is emitted perpendicularly to the moving direction of the electrode plate while the electrode plate of the object to be measured moves horizontally on the guide rolls. The electrode plate and a laser oscillator are arranged, and the laser oscillator measures the distance to the electrode plate 1000 times or more per second, and at the same time, a device capable of measuring the horizontal movement distance of the electrode plate is arranged. We propose an electrode plate elongation measuring device characterized by:

According to the present invention, in the method for measuring the elongation rate of the electrode plate described above, a plurality of laser transmitters are arranged in the vertical width direction of the electrode plate, and the thickness of the electrode plate is continuously measured at a plurality of positions in the width direction of the electrode plate. At the same time as measuring, the electrode plate elongation rate λ is obtained from the measurement data of the laser oscillator and the movement amount of the electrode plate, and a device is arranged that can simultaneously measure the elongation rate λ at a plurality of points in the width direction of the electrode plate. We propose an electrode plate elongation measuring device that

In the method for measuring the elongation rate of the electrode plate described above, the present invention provides the length of the electrode plate from the reference point of the moving electrode plate to the position measured by the laser oscillator and the elongation of the electrode plate obtained by the laser oscillator. An electrode plate elongation rate measuring device is proposed, characterized by having a device for storing in association with a value indicating the state of.

When the coated portion and the uncoated portion of the electrode plate are pressed and compressed with a roll press, a difference in elongation of the metal foil occurs. The coated and uncoated portions of the electrode plate are irradiated with a laser beam, and the surface irregularities of the coated and uncoated portions are determined from the reflected wave of the laser beam. The uneven state is used as data as a change in the distance from the reference point, and the outer length of the electrode plate including the unevenness is calculated from this distance change data and the amount of movement of the electrode plate in the longitudinal direction. Calculate and display the elongation rate λ of the plate. From the obtained elongation rate λ, the state of occurrence of wrinkles in the electrode plate can be understood numerically, and can be used for control.

It is a figure which shows the example of the whole system of an elongation occurrence state information acquisition apparatus. FIG. 4 is a diagram showing an example of a flow of measurement using a laser displacement meter; 1 is a diagram showing an overall outline of a roll press facility having an occurrence state information acquisition device of . FIG. 4 is a diagram showing an example of an electrode plate coated with an active material in stripes; It is a cross-sectional view in the width direction of the electrode plate. It is a figure which shows an example of the rolling state by the rolling roll of a metal strip material. FIG. 4 is a plan view showing an example of wrinkles on an electrode plate; 7 is a cross-sectional view of electrode plates R, S, and T in FIG. 6; FIG. FIG. 4 is a diagram showing an example of measuring the distance to the surface of an electrode plate with a laser oscillator; FIG. 4 is a diagram showing an example of measuring unevenness on the surface of a moving electrode plate with a laser oscillator. FIG. 4 is a diagram for explaining a method of calculation from a movement length X of the electrode plate surface and a laser oscillator measurement value Y; FIG. 4 is a diagram showing an example of displaying an electrode plate elongation rate λ on a screen; It is a figure which shows an example which equipped the uncoated part rolling apparatus in the roll press. It is a figure which shows one Example of an uncoated part rolling apparatus. FIG. 4 is a tilt view showing an example of arranging laser oscillators for continuously measuring the thickness of the electrode plate in the width direction at a plurality of positions. It is a DD arrow directional view of Fig.14 (a). It is an example which shows the state which pressurizes an electrode plate with a roll press machine. It is a figure which shows an example of the flatness of a metal band board|plate material. It is X sectional drawing of Fig.16 (a). FIG. 10 is a diagram showing a flow of associating the elongation rate of the electrode plate with the distance from the reference point;

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram for explaining the overall system of an elongation occurrence state information acquiring apparatus for measuring the elongation length of an electrode plate 300 using a laser displacement meter 200 according to an embodiment of the present invention. FIG. 2 is a diagram showing an example of a measurement flow using a laser displacement meter.

The laser displacement meter 200 includes a laser oscillator 201 , an arithmetic device 204 and a rotation sensor 155 . The elongation occurrence state information acquiring device 1 calculates the measurement data sent from the laser oscillator 201 and the rotation sensor 155 by the arithmetic device 204, and performs the measurement in the flow of S1 to S7 as shown in FIG. Details will be described in the following examples.

FIG. 3 shows an overall outline of roll press equipment for pressing the electrode plate 300 .

On the entrance side of the roll press machine 100, there is provided a coil unwinder 151 for attaching a coil before pressing in which the electrode plate 300 for the lithium ion battery is coiled, and on the exit side of the roll press machine 100, there is a roll. A coil winder 152 is provided for coiling the pressed electrode plate 300 . A heating roll 102 capable of raising the temperature of the electrode plate 300 to about 150° C. in order to make the electrode plate 300 more compressible, a dancer roll 153 controlling the tension of the wound electrode plate 300 to be constant, and supporting the electrode plate 300 smoothly. A plurality of guide rolls 154 to be conveyed and a laser displacement meter 200 for measuring the surface shape of the electrode plate 300 with a laser beam 202 are arranged.

A roll press machine 100 is equipped with upper and lower press rolls 101, and an electrode plate 300 (FIG. 4(b)) having a metal foil 301 coated with an active material 302 is sandwiched between the press rolls 101 and passed while being pressed. , compressing the active material 302 . The roll press machine 100 is provided with a bearing box 103 that holds the upper and lower press rolls 101 and a housing 104 that supports the pressing force and holds the bearing box 103 from the outside.

FIG. 4 is a diagram showing an example of an electrode plate 300 coated with an active material in stripes.

4A shows a plane of the electrode plate 300, and FIG. 4B shows a cross section of the electrode plate 300 in the width direction.

As an example, the electrode plate 300 is of a lithium ion battery. As shown in FIG. 4, active material 302 is coated in stripes on the surface of strip-shaped metal foil 301 (aluminum foil, copper foil, etc.). Since the uncoated portion 301 becomes a current-carrying terminal portion in the process of assembling the battery, the active material 302 is not coated and the metal foil 301 is exposed. Although the cross-sectional view of the electrode plate 300 shown in FIG. 4B shows the thickness, the thickness of the metal foil 301 is about 10 to 20 microns, and the thickness of the coating portion 302 is the thickness of the upper and lower active materials. The total thickness of metal foil 301 is 200 to 250 microns before pressing. When the electrode plate 300 is roll-pressed by the upper and lower press rolls 101, the active material of the coated portion 302 is compressed and the thickness is reduced to about 100 to 140 microns. The uncoated portions 301a and 301b do not contact with the upper and lower press rolls 101 and are not subjected to press load, so they are not stretched.

FIG. 5 is a diagram showing an example of a state of rolling a metal strip material by rolling rolls.

Ordinarily, even if a thin metal strip 500 (hereinafter referred to as a metal strip) is rolled, surface unevenness caused by a difference in elongation becomes a problem, and flatness is evaluated by means of steepness. In the electrode plate 300, the difference in thickness between the coated portion 302 and the uncoated portion 301 produces a pressed portion and a non-pressed portion, resulting in a large difference in elongation. On the surface of the electrode plate 300, surface unevenness occurs which is different from that of the metal strip material. The difference between the rolling of the metal strip material and the roll pressing of the electrode plate 300 will be described in detail below.

FIG. 15 is an example showing a state in which the electrode plate is pressed by a roll press.

FIG. 16(a) is a diagram showing an example of the flatness of the metal strip material.

FIG. 16(b) is a cross-sectional view of FIG. 16(a).

In the case of a metal strip material, as shown in FIG. 5, rolling is performed by upper and lower cylindrical rolling rolls 501 so that a uniform rolling force (linear pressure) is generated in the material to be rolled in the width direction of the metal strip material 500. The pressing force between the rolls 501 is controlled. However, even if a uniform rolling force is applied in the width direction, the material to be rolled can be affected by slight differences in conditions, such as changes in roll diameter caused by temperature differences in the axial direction of the rolls and deflection of the roll shafts caused by the rolling force. A difference in elongation occurs at the center or end of the sheet, and the difference in elongation appears as unevenness on the surface. In rolling, as a means of comparing the flatness, the surface unevenness in the longitudinal direction of the steel sheet is measured as shown in FIG. is used to calculate the steepness. The degree of steepness is obtained by the formula of H/P.

Changes in roll diameter and deflection occur gradually due to changes in rolling time and other conditions.

After rolling, the surface unevenness of the metal strip material has a certain length (100 m or more), and the pitch of the peaks is almost the same, and the height of the peaks remains the same. The magnitude of the surface unevenness of the metal strip material can be evaluated by the degree of steepness. The pitch between crests is also affected by the thickness of the plate, but if the thickness of the metal strip material is 0.3 mm, the pitch between crests is 300 to 600 mm. Therefore, even if the surface unevenness is measured at intervals of about 10 mm, the steepness measurement accuracy is not significantly affected.

As shown in FIG. 15, when the electrode plate 300 is pressed by the roll press machine 100, the coated portion 302 of the electrode plate 300 is pressed by upper and lower press rolls so as to generate a uniform rolling force (linear pressure) like the strip material. The pressing force between 101 is controlled, and elongation occurs in the longitudinal direction after pressing. However, since the uncoated portion 301 does not come into contact with the upper and lower press rolls 101 at all, no elongation occurs due to rolling. Therefore, a large difference in elongation occurs at the boundary between the coated portion 302 and the uncoated portion 301 .

FIG. 6 is a plan view showing an example of wrinkles on the electrode plate.

As shown in FIG. 6, due to the large difference in elongation, different surface irregularities and wrinkles occur between the coated portion 302 and the uncoated portion 301 . This is very different from the cause of surface unevenness of the metal strip material 500 and the electrode plate 300 .

Furthermore, the coated portion 302 of the electrode plate 300 has a three-layer structure (sandwich structure) because the active material is attached to the upper and lower surfaces of the metal foil 301 . Even if the same difference in elongation occurs in the electrode plate 300, the surface unevenness is not a uniform waveform like a sine wave, but a non-uniform waveform due to differences in hardness of the active material and drying conditions. Due to such a difference, the electrode plate 300 cannot use the steepness concept used when evaluating the elongation state (flatness) of the metal strip material 500 during rolling.

FIG. 7 is a cross-sectional view of electrode plates R, S, and T in FIG.

FIG. 7 shows that the coated portion 302 and the uncoated portion 301 have a large difference in the unevenness of the surface.

In this way, the electrode plate 300 has different uneven surface shapes depending on the position in the width direction due to the influence of the uncoated portion 301 . Therefore, as a means for judging the size of the surface unevenness of the electrode plate 300, the length of the surface profile generated by the roll press is accurately measured and calculated, and the length of the electrode plate actually stretched without being affected by the surface unevenness is calculated. A suitable means is to evaluate the size of the surface unevenness by measuring the surface roughness.

At this time, since the metal foil 301 in the uncoated portion is thin and soft, the pitch of the surface unevenness is about 6 to 10 mm, which is shorter than that in the coated portion. The pitch between crests is about 1/50 compared to metal strips. Means for accurately measuring the outer surface length of the electrode plate 300 having different surface irregularities while moving will be described below.

After being pressed by the roll press machine 100, the electrode plate 300 moves horizontally while being held by the guide rolls 154 as shown in FIG. Since the electrode plate 300 moves horizontally in close contact with the guide roll 154, the moving speed of the electrode plate 300 is measured from the number of revolutions of the guide roll 154 or the like. Furthermore, the dancer roll 153 functions to control the tension of the electrode plate 300 so that the electrode plate 300 moves with a constant tension, and the electrode plate 300 moves between the guide rolls 154 without vibration. do.

FIG. 8 is a diagram showing an example of measuring the distance to the surface of the electrode plate with a laser oscillator.

The laser oscillator 201 is attached at a position perpendicular to the moving direction of the electrode plate 300 where the laser beam 202 is irradiated. A laser beam 202 emitted from a laser oscillator 201 is reflected by the electrode plate 300 and received by the laser oscillator 201 again. A reference position 203 is a position where the laser oscillator 201 is fixed. As shown in FIG. 8, the distance Y1 until the laser beam 202 emitted from the laser oscillator 201 is reflected on the surface of the electrode plate 300 is measured.

Since the electrode plate 300 moves from the input side to the output side at a constant speed, as shown in FIG. The distances from the reference position 203 to the uneven surface of the electrode plate 300 are continuously measured by Y2, Y3, and Y4 each time the electrode plate moves horizontally by X. FIG.

FIG. 9 is a diagram showing an example of measuring unevenness on the surface of a moving electrode plate with a laser oscillator.

FIG. 9 is displayed on the assumption that the electrode plate 300 is fixed and the laser oscillator 201 horizontally moves the position of the reference position 203 in order to make the movement of FIG. 8 easier to understand.

FIG. 10 is a diagram for explaining a method of calculation from the moving length X of the electrode plate surface and the measured value Y of the laser oscillator.

In FIG. 10, from the distance (Y) measured by the laser oscillator 201 from the reference point 203 to the surface of the electrode plate 300 and the amount of horizontal movement (X) of the electrode plate 300, the outer shape length of the uneven surface of the electrode plate 300 is calculated. A method to obtain by calculation is described. When the electrode plate 300 moves by X in the horizontal direction, if the measured distance value Y1 changes to Y2, the unevenness change amount of the electrode plate 300 is Y1-Y2. By assuming that the curve of the outer shape of the electrode plate 300 at this time is a straight line, the length (C) of the longer side of the right-angled triangle becomes the outer shape length of the unevenness of the electrode plate 300 . Therefore, the side length C1 is calculated by Equation 1 according to the Pythagorean theorem.

formula 1

In order to reduce the deviation between the actual profile curve and the approximate profile length obtained by calculation, the time for measuring Y should be made as short as possible, the amount of movement of X should be made extremely small, and the number of divisions should be increased. The deviation between the length and the actual outline length approaches zero limitlessly.

In the case of the electrode plate 300 moving at 120 m/min, in order to measure the change amount Y every 1 mm of the movement amount X, the electrode plate 300 moves 2 m/sec, so measurement and calculation by the laser oscillator 201 are required 2000 times/sec. It is necessary to arrange the laser displacement meter 200 capable of such high-speed measurement and calculation. Alternatively, if more accurate measurement is required, the deviation between the actual outer length and the calculated value can be made as close to zero as possible by lowering the moving speed of the electrode plate 300 .

Next, the necessity of measuring the amount of change Y for every 1 mm of the amount of movement X will be described. The material of the metal foil 301 used for the electrode plate 300 is thin, and since aluminum foil, copper foil, or the like is used, the periodic length of the irregularities is extremely shorter than that of the steel plate. In the aluminum foil having a thickness of 20 microns used for the uncoated portion 301 of the electrode plate 300, the pitch of the surface unevenness is about 6 to 10 mm.

In addition, the "Method for measuring flatness of flatness of copper and copper alloy plates" defined by the Japan Copper and Brass Association Technical Standards stipulates as follows. The target copper material has a thickness of 50 microns to 500 microns and a width of 15 mm to 700 mm. This thin copper plate is cut out, placed on a measuring table of 500 mm or more, and the amount of change in the uneven shape displayed using the laser displacement meter 200 is measured in units of 1 micron. At the same time, the longitudinal direction requires measurements every 1 mm.

In this way, in order to accurately measure the ruggedness displayed by the foil-like thin metal and determine the amount of elongation, it is necessary to digitize the change in the height direction every 1 mm in the longitudinal direction. As shown in FIG. 16, the Japan Copper and Brass Association obtains the height difference (H) and the pitch (P) of the unevenness from the cut sample material, and expresses the state of elongation by the degree of steepness.

With the roll press machine, it is necessary to grasp the state of elongation of the electrode plate 300 during production. You need to measure the change in height. When the electrode plate 300 moves at a high speed, the speed is 120 m/min. Therefore, in order to measure the distance from the reference to the surface of the electrode plate 300 at a pitch of 1 mm, the laser displacement meter 200 measures the distance 2000 times per second. must be calculated. In the case of low speed, the moving speed of the electrode plate 300 is about 60 m/min. Therefore, 1,000 distance measurements per second are required to perform similar measurements at a pitch of 1 mm.

The method of displaying the elongation state by steepness assumes that the uneven shape to be displayed continues in the same state. Since the electrode plate 300 has the active material 302 bonded to both sides, it is difficult to assume that the displayed uneven shape will continue in the same state. Therefore, as described above, the length of extension of the electrode plate 300 is obtained and quantified by using the method of calculating the outer length of the uneven shape to be displayed.

C is the accumulated value obtained by adding n pieces of C1, C2, C3, and C4 calculated by the calculation device 204 according to Equation 1. The obtained C value becomes the outer shape length including the uneven shape to be displayed. The moving distance B can be obtained by calculating the moving distance B=n×X of the electrode plate 300 . If the elongation is large, the outer length becomes longer, so the C value becomes larger. If there is no elongation, the outer length C value and the movement length B value become the same. The elongation rate λ of the electrode plate 300 is obtained by Equation (2). The elongation rate λ represents the ratio of elongation to the reference length B.

formula 2

The closer the elongation rate λ is to 0%, the less uneven the electrode plate 300 is. It can be determined that the electrode plate 300 has no expansion difference. When comparing the occurrence state of the difference in elongation, the elongation rate λ per unit length can be obtained by dividing the elongation length CB including the actual unevenness by the movement length B. By comparing a plurality of λ in the width direction, the state of overall differential expansion (wrinkles) of the electrode plate 300 can be evaluated. By comparing the λ values at any location in the longitudinal direction, the state of occurrence of differential elongation (wrinkles) can be evaluated under the same conditions. In this way, it is possible to obtain wrinkle occurrence status information on the electrode plate 300 .

The electrode plate 300 has a strip-shaped portion 302 coated with the active material 302 and an uncoated portion 301 not coated with the active material 302 in the width direction. Only the metal foil 301 of the electrode plate 300 is stretched. In order to compare the difference in elongation between the coated portion 302 and the uncoated portion 301 by the elongation rate λ, a laser oscillator 201 as shown in FIG. . At least one laser oscillator 201 is also arranged in the uncoated portion 301 at the same position in the width direction. In particular, a large amount of difference in elongation (wrinkles) occurs near the boundary line between the coated portion 302 and the uncoated portion 301. Therefore, the laser oscillator is applied to each of the coated portion 302 and the uncoated portion 301 of the electrode plate 300 near the boundary line. 201 is arranged, and the elongation rate λ is obtained and displayed.

Using the obtained elongation rate λ of each of the coated portion 302 and the uncoated portion 301 of the electrode plate 300, which side of the coated portion 302 or uncoated portion 301 the difference in elongation (wrinkle) occurs is determined. to decide. As a criterion for judgment, the difference in elongation (wrinkles) is more generated in the direction where the elongation rate λ is larger. In the roll press machine 100 having equipment for controlling the elongation of the electrode plate 300, the control function is used to control the elongation rate λ to be smaller.

Specific means for reducing the difference in elongation (wrinkles) between the coated portion 302 and the uncoated portion 301 will be described below. Since a large difference in elongation occurs along the boundary line between the coated portion 302 and the uncoated portion 301 of the electrode plate 300, a different control means is required than in the case where elongation occurs over a wide area such as the rolling of a metal plate. .

FIG. 12 is a diagram showing an example in which an uncoated portion rolling device is provided in a roll press.

FIG. 13 is a diagram showing an embodiment of an uncoated portion rolling device.

A specific example will be described with reference to FIGS. 12 and 13. FIG.

An uncoated portion rolling device 400 capable of rolling only the metal foil of the uncoated portion 301 is arranged on the entrance side of the press roll 101 . The uncoated portion rolling device 400 is disposed in the roll press machine 100, and has a lower roll 402 and a lower roll having a diameter difference in the roll axial direction so that only the cylindrical upper roll 401 and the uncoated portion 301 can be pressed. It comprises a bearing 404 that holds 402 and a pusher 403 that sandwiches the uncoated portion 301 between upper and lower rolls 401 and 402 to generate a desired pressing force.

When a difference in elongation occurs between the coated portion 302 and the uncoated portion 301 of the electrode plate 300, the force of the pusher 403 is controlled to reduce the difference in elongation, and the pressing force between the upper and lower rolls 401 and 402 is adjusted. . When the difference in elongation is reduced to the target range, the pressing force between the upper and lower rolls 401 and 402 is controlled to be constant. In the embodiment, two upper and lower rolls are arranged to roll the uncoated portion 301, but the mechanism is not limited to this. By having a mechanism capable of controlling the pressing force of , it is possible to correct the difference in elongation between the coated portion 302 and the uncoated portion 301 . The means for reducing the difference in expansion between the coated portion 302 and the uncoated portion 301 of the electrode plate 300 is not limited to the above means.
The overall system and measurement flow of the laser displacement meter 200 will be described with reference to FIGS. 1 and 2. FIG. The rotation of the press roll 101 causes the electrode plate 300 to move on the guide roll 154, and measurement data Y measured by a laser oscillator 201 provided on the exit side of the press roll 101 is sent to an arithmetic unit 204 such as a sequencer. A pulse from the rotation sensor 155 attached to the guide roll 154 is sent to the arithmetic unit 204, and the movement amount X required in Equation 1 is obtained from the diameter of the guide roll 154 and the rotation angle of the rotation sensor 155. The calculation unit 204 performs high-speed calculation on the X and Y data sent, and displays the obtained elongation rate λ on the screen display 205 . Although the calculation flow is short, it is necessary to measure 1000 to 2000 times per second and display the calculation instantaneously in order to obtain the outer length accurately. The method for measuring the amount of movement X is not limited to the rotation sensor 155 .

Further, a reference point is provided in the longitudinal direction of the electrode plate 300 so that the position measured by the laser oscillator 201 can be stored as a distance from the reference point. Specifically, an opening is provided in the electrode plate 300, and an optical sensor 155 for recognizing light passing through the opening is arranged. When the opening passes, the optical sensor 156 sends a signal to the computing device 204 to recognize it as a reference point. The rotation sensor 155 attached to the guide roll 154 calculates the distance of the electrode plate 300 from the reference point, and recognizes the position of the electrode plate 300 in the longitudinal direction. The method of recognizing the reference point is not limited to recognizing light passing through the opening, and the connection point between the leading electrode plate 300 and the rear electrode plate 300 can also be used as the reference point. The elongation rate λ of the electrode plate 300 measured by the above method is associated with the longitudinal distance from the reference point and stored as data in the storage device of the arithmetic unit 204 or the like. As shown in FIG. 17, the longitudinal position of the electrode plate 300 and the elongation rate data are associated with each other and recorded in the arithmetic device 204 by the flow from S1 to S8.

The elongation data of the electrode plate 300 can be used when a quality problem occurs in the next process. The stored elongation rate is not limited to λ calculated by Equation 2. It is also possible to store the height (H) of the peak caused by the elongation as shown in FIG. is.

FIG. 11 is a diagram showing an example of displaying the electrode plate elongation rate λ on the display screen.
When the electrode plate 300 having a wide coated portion 302 is roll-pressed, the laser oscillator 201 is placed in the entire width of the coated portion 302 and the uncoated portion 301 to measure and calculate the elongation rate λ of the electrode plate. A display such as that shown in FIG. The measured position is displayed on the horizontal axis, and the elongation rate λ is displayed on the vertical axis to display the measurement result. It is possible to determine at a glance the state of occurrence of differential elongation (wrinkles) from the elongation rate λ of the electrode plate 300 in the width direction. The screen display 205 can continuously display the elongation rate λ that changes one after another as the electrode plate 300 moves.

In the above description, it is described that the length of the outer shape including the unevenness of the surface of the electrode plate 300 is obtained in the roll press equipment, and the elongation rate λ is calculated from the reference length and displayed. This measurement device and method are not limited to the roll press equipment, and the active material coating device and the drying device upstream of the roll press equipment also apply the active material 302 to the metal foil 301 in the same manner as the roll press equipment. , Since it is dried, it is easy to cause a difference in elongation due to heat or the like. An elongation occurrence state information acquiring apparatus and method capable of displaying the state of the elongation difference occurring in the electrode plate 300 by the elongation rate λ is effective.

FIG. 14(a) is a tilted view showing an example in which laser oscillators for continuously measuring the thickness of the electrode plate in the width direction are arranged at a plurality of positions.

FIG. 14(b) is a front view of FIG. 14(a).

It is also possible to measure the thickness of the electrode plate 300 and measure the elongation rate λ at the same time. As shown in FIG. 14( a ), there is a plate thickness gauge that measures the thickness of the electrode plate 300 in the width direction with a laser displacement gauge 200 . In this plate thickness gauge, laser oscillators 201 are arranged above and below the electrode plate 300, and are adjusted so that the upper and lower laser beams 202 are aligned as shown in FIG. 14(b). The thickness of the electrode plate 300 is the remainder obtained by subtracting the distance Y to the electrode plate 300 measured by the upper and lower laser oscillators 201 from twice the distance of the upper and lower reference positions 203 . By arranging a plurality of laser oscillators 201 vertically in the width direction of the electrode plate 300, the thickness difference in the width direction of the electrode plate 300 can be measured at the same time. This thickness measurement method has already been implemented. Furthermore, considering the amount of change in distance data Y from this laser oscillator 201 and the movement length X in the movement direction of the electrode plate 300 described above, the outer circumference length C of the electrode plate 300 is obtained, and from the reference movement amount B The elongation rate λ in the longitudinal direction can also be measured continuously at a plurality of points in the width direction.

DESCRIPTION OF SYMBOLS 1... Elongation occurrence state information acquisition apparatus 100... Roll press machine 101... Press roll 102... Heating roll 104... Housing 151... Coil unwinding machine 152... Coil unwinding machine 153... Dancer roll 154... Guide roll 155 Rotation sensor 156 Optical sensor 200 Laser displacement meter 201 Laser oscillator 202 Laser beam 203 Reference position 204 Arithmetic device 205 Screen display 300 Electrode plate 301 Metal foil (uncoated portion) 302 Active material (coated portion) 400 Uncoated portion rolling device 401 Upper roll 402 Lower roll 403 Pusher 500 Metal strip material 501 rolling roll

Claims (5)

A strip-shaped electrode plate, which is a battery material and has a thin metal foil surface coated with an active material, has a strip -shaped coated portion coated with the active material and an uncoated portion made of the metal foil. A laser beam is emitted from a laser oscillator to the plate, and the amount of change in distance A from the reference point to the surface of the electrode plate is measured after a certain period of time. B is measured to obtain measured value data for the amount of change in the distance A between the coated portion and the uncoated portion and the moved length B of the strip electrode plate,
Obtaining elongation data of the coated and uncoated portions from the two measured value data, and obtaining differential elongation information of the coated and uncoated portions from the elongation data.
An apparatus for obtaining information on the occurrence of elongation of a strip-shaped electrode plate , characterized by: 2. In the device for obtaining information on occurrence of elongation of a strip-shaped electrode plate according to claim 1, the value obtained by accumulating the distance change amount A is defined as the accumulated value C, and the measured value B and the accumulated value C are set to 200 to 1000. Elongation occurrence state information of a strip-shaped electrode plate , characterized in that the elongation rate λ of the coated portion and the uncoated portion is obtained by accumulating the individual pieces and obtaining the elongation rate λ of the coated portion and the uncoated portion by the formula λ={(C−B)/B}×100. Acquisition device. 3. In a roll press device control device comprising the device for obtaining information on the state of elongation of a strip-shaped electrode plate according to claim 1 or 2, the coated portion obtained by the device for obtaining information on the state of elongation and a control device for a roll press equipped with an elongation occurrence state information acquisition device for a strip-shaped electrode plate , characterized in that control is performed so as to reduce the difference in elongation of an uncoated portion . A strip-shaped electrode plate, which is a battery material and is made by coating an active material on the surface of a thin metal foil that moves on a production line, has a strip-shaped portion coated with the active material and an uncoated portion made of metal foil. ,
A laser beam is emitted from a laser oscillator to the strip-shaped electrode plate, and measured value data on the amount of change in distance A between the coated and uncoated portions by a laser displacement meter that measures the distance from the reference point to the surface of the electrode plate. is obtained, and measurement data on the movement length B of the electrode strip is obtained by a rotation sensor that measures the movement length B of the electrode strip that has moved in a direction perpendicular to the laser beam for a certain period of time, Differential elongation information is acquired from the two measured value data, and wrinkle occurrence status information is acquired based on the differential elongation information.
A method for acquiring wrinkle occurrence status information on a strip-shaped electrode plate moving on a production line , characterized by: A strip-shaped electrode plate, which is a battery material and is made by coating an active material on the surface of a thin metal foil that moves on a production line, has a strip-shaped portion coated with the active material and an uncoated portion made of metal foil. ,
A laser beam is emitted from a laser oscillator to the strip-shaped electrode plate, and the distance from the reference point to the surface of the electrode plate is measured to obtain measured value data for the amount of change in distance A for each of the coated and uncoated portions. and measuring the moving length B of the strip-shaped electrode plate moved in a direction perpendicular to the laser beam for a certain period of time to acquire measurement value data about the moving length B of the strip-shaped electrode plate,
Obtain the elongation data of the coated part and the uncoated part from the two measured value data,
On the screen of the screen display device, the horizontal axis is the measured position and the vertical axis is the elongation rate data, and the wrinkle occurrence status information of the strip electrode plate is displayed.
A wrinkle generation information display device for a strip-shaped electrode plate moving on a production line .

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