JP7204613B2 - Roll displacement measuring device, roll displacement measuring method and coating device - Google Patents

Description

The technical field of the present specification relates to a roll displacement measuring device, a roll displacement measuring method, and a coating device.

An electrode of a lithium ion secondary battery is obtained by laminating a positive electrode active material or a negative electrode active material on a metal foil as a current collector. In the process of manufacturing an electrode for a lithium ion secondary battery, a coating layer is formed by coating a positive electrode active material or a negative electrode active material on a metal foil as a current collector, and the coating layer is dried. Also, if necessary, the dried coating layer is pressed. The film thickness of the coating layer defines the distance from the electrolyte solution or electrolyte layer to the current collector. Therefore, the film thickness of the coating layer affects various performances of the lithium ion secondary battery.

Some coating apparatuses have a coating section that coats a coating liquid onto a metal foil that is conveyed while being supported by a rotating backup roll. In that case, the approximate thickness of the coating layer is obtained by subtracting the thickness of the metal foil from the distance between the backup roll and the coating portion. That is, the distance between the fixed coating section and the rotating backup roll determines the film thickness of the coating layer. Therefore, when the coating layer is a concern, it is often sufficient to consider only the backup roll.

JP 2015-201318 A

On the other hand, Patent Literature 1 discloses a coating apparatus that defines the film thickness of the coating layer of the electrode of the lithium ion secondary battery by a roll pair (see FIG. 3 of Patent Literature 1, etc.). Here, the rotation directions of the first roll and the second roll in the roll pair are opposite to each other (see FIG. 3 of Patent Document 1, etc.). Although not explicitly stated in Patent Document 1, it is preferable that the rotation period of the first roll and the rotation period of the second roll in the roll pair are different. In this case, when the first roll has made one revolution, the second roll has made more or less than one revolution. Each time the first roll rotates, it faces a different part of the second roll. That is, the film thickness of the coating layer is affected by both the deviation from the cylindrical shape of the first roll and the deviation from the cylindrical shape of the second roll. Therefore, it is preferable to measure the shape of each of the first roll and the second roll.

Also, the first roll and the second roll press the raw material that will form the coating layer. As a result, the first roll and the second roll may undergo axial deformation due to continued use. In that case, the distance between the first roll and the second roll changes over time. Moreover, it is not easy to measure the gap between the first roll and the second roll having different rotation periods.

The problem to be solved by the technology of the present specification is to measure the shape of the first roll and the second roll in the roll pair that presses the material between the first roll and the second roll or the amount of change thereof. An object of the present invention is to provide a roll displacement measuring device, a roll displacement measuring method, and a coating device.

A roll displacement measuring device in a first aspect includes a roll pair having a first roll and a second roll, a material supply section that supplies a material between the first roll and the second roll, the first roll and the second roll. It has an imaging unit for imaging two rolls and a control unit. The first roll includes a first outer peripheral portion, a first side surface located at an end of the first outer peripheral portion, a first shaft that is a rotating shaft of the first roll protruding from the first side surface, and formed on the first side surface. and a first indicia. The second roll includes a second outer peripheral portion, a second side surface located at an end of the second outer peripheral portion, a second shaft that is a rotating shaft of the second roll protruding from the second side surface, and formed on the second side surface. and a second indicia. The first roll and the second roll press the material between the first perimeter of the first roll and the second perimeter of the second roll. The imaging unit images the first side surface and the first mark of the first roll, and the second side surface and the second mark of the second roll. The control unit has a radius function derivation unit. The radius function derivation unit derives a first radius function from the center of rotation of the first roll to the first outer circumference and a second radius function from the center of rotation of the second roll to the second outer circumference.
However, the distance between the intersection of the line segment connecting the rotation center of the first roll and the rotation center of the second roll and the outer circumference of the first side surface and the rotation center of the first roll with respect to the rotation angle of the first roll Define the function as the first radius function.
Also, the distance between the intersection of the line segment connecting the rotation center of the first roll and the rotation center of the second roll and the outer periphery of the second side surface and the rotation center of the second roll with respect to the rotation angle of the second roll Define the function as the second radius function.

This roll displacement measuring device can derive a first radius function from the rotation center of the first roll to the first outer periphery and a second radius function from the rotation center of the second roll to the second outer periphery. can. Using the first radius function and the second radius function, the gap between the first roll and the second roll can be calculated. The roll displacement measuring device can contactlessly calculate the gap between the first roll and the second roll.

In this specification, a roll displacement measuring device and a roll displacement measurement capable of measuring the shape of the first roll and the second roll in the roll pair that presses the material between the first roll and the second roll or the amount of change thereof A method and coating apparatus are provided.

It is a figure which shows the lamination structure of the electrode of 1st Embodiment. 1 is a diagram conceptually showing an electrode structure of a lithium ion secondary battery of a first embodiment; FIG. 1 is a schematic configuration diagram of a coating apparatus according to a first embodiment; FIG. It is the figure which looked at the 1st roll of the coating device of 1st Embodiment from the 3rd roll side. It is the figure which looked the 1st roll of the coating device of 1st Embodiment from the rotating shaft direction of the 1st roll. It is the figure which looked at the 1st roll and the 2nd roll in the coating device of a 1st embodiment from the upper part. It is the figure which looked at the 1st roll of the coating device of 1st Embodiment from the axial direction. FIG. 2 is a conceptual diagram for explaining a first radius function D1 (θ1), a second radius function D2 (θ2), and a gap G1 (θ1, θ2) in the coating apparatus of the first embodiment; 3 is a block diagram showing a control system of the coating device of the first embodiment; FIG. 4 is a flow chart showing a flow of calculating a gap G1 in the coating apparatus of the first embodiment; FIG. 10 is a diagram (part 1) for explaining marks on the first roll in the modified example of the first embodiment; FIG. 11 is a diagram (part 2) for explaining marks on the first roll in the modified example of the first embodiment; FIG. 10 is a conceptual diagram for explaining a first roll and a second roll in a coating device of a second embodiment; FIG. 11 is a conceptual diagram illustrating temporal change of a gap G2 (θ1, θ2) between a deformed first roll and a second roll in the coating apparatus of the second embodiment; It is the conceptual diagram which looked at the 1st roll and the 2nd roll in the coating device of 2nd Embodiment from the direction of a central axis. FIG. 10 is a block diagram showing a control system of a coating device according to a second embodiment; FIG. FIG. 11 is a conceptual diagram showing a gap function G2 (θ1, θ2) in the coating device of the second embodiment;

Hereinafter, specific embodiments will be described by taking a roll displacement measuring device, a roll displacement measuring method, and a coating device as examples. However, the technology herein is not limited to these embodiments.

(First embodiment)
1. 1. Electrode FIG. 1 is a diagram showing a laminated structure of an electrode 100 according to the first embodiment. The electrode 100 is manufactured by a coating device which will be described later. The electrode 100 constitutes an electrode body of a lithium ion secondary battery. A lithium ion secondary battery has an electrode 100 and an electrolyte. The lithium-ion secondary battery may additionally have a separator. Electrode 100 may also be used as a wound electrode body.

As shown in FIG. 1, electrode 100 has metal foil 110 and active material layer 120 . When the electrode 100 is a positive electrode, the material of the metal foil 110 is aluminum, for example. Active material layer 120 contains a positive electrode active material. Examples of the positive electrode active material include lithium nickelate, lithium manganate, and lithium cobaltate. Of course, materials other than the above may be used. When the electrode 100 is a negative electrode, the material of the metal foil 110 is copper, for example. Active material layer 120 contains a negative electrode active material. Examples of negative electrode active materials include carbon. The active material layer 120 may contain a binder and a thickener in addition to the above.

The film thickness H1 of the active material layer 120 is, for example, 30 μm or more and 80 μm or less. Of course, a numerical range other than the above may be used.

FIG. 2 is a diagram conceptually showing the electrode structure of the lithium ion secondary battery of the first embodiment. As shown in FIG. 2, the electrode body EB1 has a positive electrode current collector P1, a positive electrode active material layer P2, an electrolyte layer E1, a negative electrode active material layer N2, and a negative electrode current collector N1.

As shown in FIG. 2, the positive electrode current collector P1, the positive electrode active material layer P2, the electrolyte layer E1, the negative electrode active material layer N2, and the negative electrode current collector N1 are formed in this order. The cathode active material layer P2 is located between the cathode current collector P1 and the electrolyte layer E1. The negative electrode active material layer N2 is located between the negative electrode current collector N1 and the electrolyte layer E1.

The film thickness H1p of the positive electrode active material layer P2 defines the distance from the positive electrode current collector P1 to the electrolyte layer E1. Lithium ions may react with the positive electrode active material located near the electrolyte layer E1 as indicated by the arrow L1, or may react with the positive electrode active material located far from the electrolyte layer E1 as indicated by the arrow L2. .

The film thickness H1p of the positive electrode active material layer P2 is related to the average moving distance of lithium ions. Therefore, the film thickness H1p of the positive electrode active material layer P2 is related to various battery performances in the lithium ion secondary battery. The film thickness H1n of the negative electrode active material layer N2 is also related to the battery performance, as is the film thickness H1p of the positive electrode active material layer P2. Further, the film thickness H1p of the positive electrode active material layer P2 and the film thickness H1n of the negative electrode active material layer N2 are not necessarily the same.

2. Coating device 2-1. Configuration of Coating Apparatus FIG. 3 is a schematic configuration diagram of the coating apparatus 1000 of the first embodiment. As shown in FIG. 3, the coating apparatus 1000 includes a first roll 1100, a second roll 1200, a third roll 1300, a wet granule supply section 1400, an imaging section 1500, and a light irradiation section 1600. , and a control unit 1900 .

The first roll 1100 compresses the wet granules containing the positive electrode active material or the negative electrode active material together with the second roll 1200, and the coating layer formed in the space between the first roll 1100 and the second roll 1200. It is for forming. The first roll 1100 rotates in the direction of arrow J1.

The second roll 1200 compresses the wet granules containing the positive electrode active material or the negative electrode active material together with the first roll 1100 and the coating layer formed in the space between the first roll 1100 and the second roll 1200. It is for forming. The second roll 1200 rotates in the direction of arrow J2.

The third roll 1300 is a roll for transferring the coating layer on the first roll 1100 to the metal foil 110 while conveying the metal foil 110 . The third roll 1300 rotates in the direction of arrow J3. Then, the third roll 1300 feeds the metal foil 110 in the direction of the arrow K1 to the facing portion between the first roll 1100 and the third roll 1300, and the metal foil 110 in the direction of the arrow K2 between the first roll 1100 and the first roll 1100. It is delivered from the facing portion between the third roll 1300 .

The first roll 1100 is arranged between the second roll 1200 and the third roll 1300 . The central axes of the first roll 1100, the second roll 1200, and the third roll 1300 are preferably on the same plane in terms of design. The central axes of the first roll 1100, the second roll 1200 and the third roll 1300 are preferably parallel to each other. Further, the outer diameters of the first roll 1100, the second roll 1200 and the third roll 1300 are approximately the same.

The wet granule supply section 1400 is a material supply section for supplying wet granules between the first roll 1100 and the second roll 1200 . A wet granule is a coating material corresponding to the raw material of the coating layer. That is, the wet granules contain the positive electrode active material or the negative electrode active material. Further, a binder or the like other than the positive electrode active material or the negative electrode active material may be included.

The imaging unit 1500 is for imaging the first roll 1100 and the second roll 1200 . The imaging unit 1500 captures a video or image of the side surface of the first roll 1100 and the side surface of the second roll 1200 .

The light irradiation unit 1600 irradiates the side surface of the first roll 1100 and the side surface of the second roll 1200 with light. The light may be monochromatic light or white light. Also, the light may be visible light or infrared light.

The control section 1900 controls each section of the coating apparatus 1000 . The control unit 1900 calculates the distance between the first roll 1100 and the second roll 1200 from the video or image captured by the imaging unit 1500 . Details will be described later.

2-2. 4. Surroundings of Imaging Unit FIG. 4 is a view of the first roll 1100 of the coating apparatus 1000 of the first embodiment as viewed from the third roll 1300 side. FIG. 5 is a view of the first roll 1100 of the coating apparatus 1000 of the first embodiment as viewed from the rotation axis direction of the first roll 1100. FIG.

As shown in FIGS. 4 and 5, the first roll 1100 has a first outer periphery 1110, a first shaft 1120, and a first side surface 1111. As shown in FIGS. The first shaft 1120 extends in the central axis direction on both end sides of the first outer peripheral portion 1110 . The first shaft 1120 protrudes from the first side surface 1111 . The first side surface 1111 is a side surface located at the end of the first outer peripheral portion 1110 and connects the first outer peripheral portion 1110 and the first shaft 1120 . A first mark M1 is formed on the first side surface 1111 of the first roll 1100 .

As shown in FIGS. 4 and 5, the second roll 1200 has a second outer peripheral portion 1210, a second shaft 1220, and a second side surface 1211. As shown in FIGS. The second shaft 1220 extends in the central axis direction on both end sides of the second outer peripheral portion 1210 . The second shaft 1220 protrudes from the second side surface 1211 . The second side surface 1211 is a side surface located at the end of the second outer peripheral portion 1210 and connects the second outer peripheral portion 1210 and the second shaft 1220 . A second mark M2 is formed on the second side surface 1211 of the second roll 1200 .

The first roll 1100 and the second roll 1200 constitute a roll pair. The first roll 1100 and the second roll 1200 press the coating material between the first outer peripheral portion 1110 of the first roll 1100 and the second outer peripheral portion 1210 of the second roll 1200 to form a coating layer. The direction in which the first roll 1100 rotates is opposite to the direction in which the second roll 1200 rotates. The rotational angular velocity of the first roll 1100 is faster than the rotational angular velocity of the second roll 1200 .

The first roll 1100 and the third roll 1300 constitute a roll pair. The third roll 1300 conveys the metal foil 110 while supporting the metal foil 110 . A first outer peripheral portion 1110 of the first roll 1100 carries the coating layer formed by the first roll 1100 and the second roll 1200 . The first roll 1100 carries the coating layer carried by the first outer peripheral portion 1110 of the first roll 1100 at the position of the gap between the third roll 1300 and the first roll 1100. The third roll 1300 conveys the metal foil. 110.

As shown in FIG. 4, coating apparatus 1000 has mirror 1700 . The mirror 1700 is for causing the light reflected by the first side surface 1111 of the first roll 1100 and the second side surface 1211 of the second roll 1200 to enter the imaging section 1500 . The light irradiated from the light irradiation unit 1600 is irradiated toward the first side surface 1111 of the first roll 1100 and the second side surface 1211 of the second roll 1200 . The light emitted toward the first side surface 1111 of the first roll 1100 and the second side surface 1211 of the second roll 1200 is reflected by the first side surface 1111 of the first roll 1100 and the second side surface 1211 of the second roll 1200. be. The reflected light is reflected by the mirror 1700 and enters the imaging section 1500 .

Accordingly, the imaging unit 1500 can preferably photograph the first side surface 1111 of the first roll 1100 and the second side surface 1211 of the second roll 1200 . Further, the imaging unit 1500 can image the first mark M1 on the first roll 1100 and the second mark M2 on the second roll 1200 .

Note that the control unit 1900 creates a luminance histogram for the image captured by the imaging unit 1500 . The control unit 1900 sets a threshold value and binarizes the image. The control unit 1900 detects the ends of the first side surface 1111 of the first roll 1100 and the second side surface 1211 of the second roll 1200 from the binarized image. Here, it is preferable to use the modal method when setting the threshold. The control unit 1900 may detect the ends of the first side surface 1111 of the first roll 1100 and the second side surface 1211 of the second roll 1200 using a method other than the above.

3. Operation of Coating Apparatus 3-1. Coating by Coating Apparatus As shown in FIG. 3, the direction J1 in which the first roll 1100 rotates is opposite to the direction J2 in which the second roll 1200 rotates. The direction J1 in which the first roll 1100 rotates is opposite to the direction J3 in which the third roll 1300 rotates.

Here, the rotation period of the first roll 1100 is shorter than the rotation period of the second roll 1200 . That is, the rotational angular velocity of the first roll 1100 is faster than the rotational angular velocity of the second roll 1200 . Therefore, the coating layer formed to have a predetermined thickness between the first roll 1100 and the second roll 1200 is carried along with the first roll 1100 while adhering to the first roll 1100 .

The rotation period of the third roll 1300 is preferably shorter than the rotation period of the first roll 1100 . That is, the rotational angular velocity of the third roll 1300 is preferably faster than the rotational angular velocity of the first roll 1100 . This is because the coating layer on the first roll 1100 is suitably transferred to the metal foil 110 conveyed by the third roll 1300 .

Since each roll rotates as described above, the wet granule layer pressed in the gap (gap) between the first roll 1100 and the second roll 1200 is held by the first roll 1100. After being transported, it is transferred to the metal foil 110 transported by the third roll 1300 .

3-2. Monitoring On the other hand, the light irradiation unit 1600 irradiates the first side surface 1111 of the first roll 1100 and the second side surface 1211 of the second roll 1200 with light. The imaging unit 1500 photographs the first side surface 1111 of the first roll 1100 and the second side surface 1211 of the second roll 1200 . In this manner, the first roll 1100 and the second roll 1200 are monitored.

4. Distance between first roll and second roll 4-1. Positional Relationship FIG. 6 is a top view of the first roll 1100 and the second roll 1200 in the coating apparatus 1000 of the first embodiment.

As shown in FIG. 6, the first outer peripheral portion 1110 of the first roll 1100 and the second outer peripheral portion 1210 of the second roll 1200 form a gap G1. The first side surface 1111 of the first roll 1100 and the second side surface 1211 of the second roll 1200 are on the same plane U2.

The imaging unit 1500 photographs the first side surface 1111 of the first roll 1100 and the second side surface 1211 of the second roll 1200 . Therefore, the imaging unit 1500 focuses near the plane U2 including the first side surface 1111 of the first roll 1100 and the second side surface 1211 of the second roll 1200 . Therefore, the imaging unit 1500 does not photograph the vicinity of the plane U1 that is parallel to the plane U2 and that bisects the first outer peripheral portion 1110 of the first roll 1100 in the axial direction.

FIG. 7 is an axial view of the first roll 1100 of the coating apparatus 1000 of the first embodiment. FIG. 7 shows the rotation center O1 of the first roll 1100 and the rotation center O2 of the second roll 1200. As shown in FIG. Actually, the control unit 1900 obtains the rotation center O1 and the rotation center O2 from the information of the image captured by the imaging unit 1500 . The rotation center O1 coincides with the rotation center of the bearings that rotatably support the first roll 1100 . The rotation center O2 coincides with the rotation center of the bearings that rotatably support the second roll 1200 .

As shown in FIG. 7, a first mark M1 is formed on the first side surface 1111 of the first roll 1100 . A first mark M1 is a mark indicating the rotational position of the first roll 1100 . The position of the first mark M1 is defined as the 0° position of the first roll 1100 . As shown in FIG. 7, the first mark M1 is an "x" shaped mark. Note that the center of the "x" in the first mark M1 is the center of the first mark M1.

As shown in FIG. 7, a second mark M2 is formed on the second side surface 1211 of the second roll 1200 . A second mark M2 is a mark indicating the rotational position of the second roll 1200 . The position where the second mark M2 is located is defined as the 0° position of the second roll 1200 . As shown in FIG. 7, the second mark M2 is a "o" shaped mark. It should be noted that the center of the second mark M2 is defined as the center of the circle.

The imaging unit 1500 images the first side surface 1111 of the first roll 1100 and the first mark M1, and the second side surface 1211 of the second roll 1200 and the second mark M2. As will be described later, the coating apparatus 1000 determines the gap G1 between the first outer peripheral portion 1110 of the first roll 1100 and the second outer peripheral portion 1210 of the second roll 1200 from the video or image captured by the imaging section 1500. calculate.

4-2. Roll Shape The first outer circumference 1110 of the first roll 1100 and the second outer circumference 1210 of the second roll 1200 are preferably perfectly cylindrical outer surfaces. In practice, however, it is very difficult to manufacture a roll with a perfect cylindrical outer surface from the viewpoint of processing accuracy. In practice, the outer circumference of the roll deviates from a perfectly cylindrical outer surface. That is, in a cross section perpendicular to the central axis of the roll, the outer peripheral portion of the roll deviates from a perfect circle.

4-3. First Radius Function and Second Radius Function FIG. 8 shows the first radius function D1 (θ1), the second radius function D2 (θ2), and the gap G1 (θ1, θ2) in the coating apparatus 1000 of the first embodiment. FIG. 2 is a conceptual diagram for explanation; The first radius function D1 (θ1) is a function representing the distance from the rotation center O1 of the first roll 1100 to the first outer peripheral portion 1110 of the first roll 1100 at a certain angle θ1. The second radius function D2(θ2) is a function representing the distance from the center of rotation O2 of the second roll 1200 to the second outer peripheral portion 1210 of the second roll 1200 at an angle θ2.

Here, the rotational angular velocity of the first roll 1100 is faster than the rotational angular velocity of the second roll 1200 . That is, the rotation period of the first roll 1100 is shorter than the rotation period of the second roll 1200 . In FIG. 8, it is assumed that the reference point Q1 of the first roll 1100 and the reference point Q2 of the second roll 1200 face each other at the initial stage. However, when the first roll 1100 has made one revolution, the second roll 1200 has not yet made one revolution. Therefore, as time passes, the gap G1 between the first roll 1100 and the second roll 1200 changes.

Gap G1 is given by gap function G1(θ1, θ2). Given the angle θ1 of the first roll 1100 and the angle θ2 of the second roll 1200, the value of the gap G1 can be obtained from the gap function G1 (θ1, θ2). Gap function G1(θ1, θ2) is given by the following equation (1).
G1(θ1, θ2) = A1-D1(θ1)-D2(θ2) ………(1)
A1: Distance between the center of rotation of the first roll and the center of rotation of the second roll
D1(θ1): first radius function of the first roll
D2(θ2): Second radius function of second roll

Note that the distance A1 is a fixed constant.

5. Coating device control system (roll displacement measuring device control system)
FIG. 9 is a block diagram showing the control system of the coating device 1000 of the first embodiment. As shown in FIG. 9, the control unit 1900 includes an image acquisition unit 1910, a rotation angular velocity reception unit 1920, a mark determination unit 1930, a reference point setting unit 1940, a radius function derivation unit 1950, and a gap calculation unit 1960. , and other control unit 1990, and a storage unit MEM.

The video acquisition unit 1910 acquires video or image information captured by the imaging unit 1500 . The video acquisition unit 1910 may store the video or image information in the storage unit MEM.

Rotational angular velocity receiver 1920 receives the rotational angular velocities of first roll 1100 and second roll 1200 . The rotation angular velocity receiving unit 1920 receives the rotation angular velocity of the first roll 1100 and the second roll 1200 from, for example, a motor control unit that rotationally drives the first roll 1100 and a motor control unit that rotationally drives the second roll 1200. accept. Alternatively, input of the rotational angular velocities of first roll 1100 and second roll 1200 may be received from encoders of motors that rotationally drive first roll 1100 and second roll 1200 .

The mark discrimination unit 1930 identifies the first mark M1 on the first side surface 1111 of the first roll 1100 and the second mark M1 on the second side surface 1211 of the second roll 1200 from the information of the video or image captured by the imaging unit 1500. M2 and, are discriminated. Therefore, it is preferable to store the shapes of the first mark M1 and the second mark M2 in advance in the storage unit MEM. Then, the mark discrimination unit 1930 collates the information of the video or image acquired by the video acquisition unit 1910 with the information stored in the storage unit MEM, and determines the first mark M1 and the second mark M2 in the video or image. determine.

The reference point setting unit 1940 sets the reference point Q1 of the first roll 1100 and the reference point Q2 of the second roll 1200 from the first mark M1 and the second mark M2 determined by the mark determination unit 1930 . The reference point setting unit 1940 sets the intersection of the extension of the line connecting the center of rotation O1 of the first roll 1100 and the first mark M1 and the first outer peripheral portion 1110 of the first roll 1100 as the first reference point. Set Q1. Further, the reference point setting unit 1940 sets the intersection of the extension of the line segment connecting the rotation center O2 of the second roll 1200 and the second mark M2 and the second outer peripheral portion 1210 of the second roll 1200 to the second A reference point Q2 is set.

The reference point Q1 is a point on the boundary between the first outer peripheral portion 1110 and the first side surface 1111 of the first roll 1100 and on the extension of the line connecting the rotation center O1 and the first mark M1. The reference point Q2 is a point on the boundary between the second outer peripheral portion 1210 and the second side surface 1211 of the second roll 1200 and on the extension of the line connecting the rotation center O2 and the second mark M2.

Reference point Q1 and reference point Q2 are virtually set by control unit 1900 . Therefore, the first mark M1 and the second mark M2 are actually marked on the first roll 1100 and the second roll 1200, whereas the reference point Q1 and the reference point Q2 are marked on the first roll 1100 and the second roll 1200. 2 roll 1200 is not actually marked.

When setting the line segment connecting the rotation center O1 and the first mark M1, the rotation center O1 and the center of the first mark M1 are connected. When setting the line segment connecting the rotation center O2 and the second mark M2, the rotation center O2 and the center of the second mark M2 are connected.

Radius function derivation unit 1950 derives first radius function D1 (θ1) of first roll 1100 and second radius function D2 (θ2) of second roll 1200 . A first radius function D1 (θ1) indicates the distance from the rotation center O1 of the first roll 1100 to the first outer peripheral portion 1110 . An angle θ1 indicates an angle from the reference point Q1. A second radius function D2 (θ2) indicates the distance from the rotation center O2 of the second roll 1200 to the second outer peripheral portion 1210 . An angle θ2 indicates an angle from the reference point Q2.

Gap calculation section 1960 calculates first roll 1100 and second A gap function G1 between two rolls 1200 is calculated. At that time, the above formula (1) may be used.

Another control section 1990 controls each section of the coating apparatus 1000 . The other control unit 1990 may include, for example, three motor control units that rotationally drive the first roll 1100, the second roll 1200, and the third roll 1300. FIG.

The storage unit MEM stores in advance information on the shapes of the first mark M1 and the second mark M2. The storage unit MEM can also store a first radius function D1 (θ1) and a second radius function D2 (θ2). The storage unit MEM may, of course, store the gap function G1 (θ1, θ2). Alternatively, other information can be stored. For example, each unit of the control unit 1900 can appropriately use the storage unit MEM during each process.

6. Method for Measuring Roll Displacement FIG. 10 is a flow chart showing a flow for calculating the gap G1 in the coating apparatus 1000 of the first embodiment. First, the video acquisition unit 1910 acquires video or image information captured by the imaging unit 1500 (S101).

Next, the rotation angular velocity receiving unit 1920 receives the rotation angular velocity of the first roll 1100 and the second roll 1200 (S102). Here, S101 and S102 are preferably performed all the time.

Next, the mark discrimination unit 1930 discriminates between the first mark M1 of the first roll 1100 and the second mark M2 of the second roll 1200 from the video or image information acquired by the video acquisition unit 1910. (S103).

Next, the reference point setting unit 1940 sets the reference point Q1 of the first roll 1100 from the video or image information acquired by the video acquisition unit 1910 and the first mark M1, and the video acquisition unit 1910 A reference point Q2 of the second roll 1200 is set based on the obtained video or image information and the second mark M2 (S104). Also, at this time, the rotational angular velocities of the first roll 1100 and the second roll 1200 received by the rotational angular velocity receiving unit 1920 may be used. S103 and S104 may be performed once at the initial stage of operation of the coating apparatus 1000 . Alternatively, S103 and S104 may be performed each time a certain period of time elapses.

Next, the radius function derivation unit 1950 derives the radius of the first roll 1100 and the radius of the second roll 1200 (S105). Specifically, a first radius function D1 (θ1) of the first roll 1100 and a second radius function D2 (θ2) of the second roll 1200 are derived. Here, the angle θ1 is the rotation angle from the reference point Q1, and the angle θ2 is the rotation angle from the reference point Q2.

Next, the gap calculator 1960 calculates a gap function G1 (θ1, θ2) between the first roll 1100 and the second roll 1200 (S106). The gap function G1 (θ1, θ2) can be calculated from the first radius function D1 (θ1) and the second radius function D2 (θ2) as shown in Equation (1). The gap calculator 1960 can also calculate the gap G1 at each time by comparing the gap function G1 (θ1, θ2) with information on the rotational states of the first roll 1100 and the second roll 1200. FIG. In this case, the gap function G1(θ1, θ2) is also a function of time.

7. Effect of First Embodiment The coating device 1000 can derive the first radius function D1 (θ1) of the first roll 1100 and the second radius function D2 (θ2) of the second roll 1200 . Also, a gap function G1 (θ1, θ2) that defines the gap G1 between the first outer peripheral portion 1110 of the first roll 1100 and the second outer peripheral portion 1210 of the second roll 1200 can be calculated. At this time, the coating apparatus 1000 can measure the gap G1 without contact. Also, the measurement of the gap G1 can be performed inline.

8. Modification 8-1. Maximum and Minimum Film Thickness The storage unit MEM stores a first radius function (θ1), a second radius function (θ2), and a gap function G1 (θ1, θ2). The coating apparatus 1000 has a first radius function D1 (θ1) from 0° to 360° of the first roll 1100 . The angle θ1 is the rotation angle of the first roll 1100 . Also, the coating apparatus 1000 has a second radius function D2 (θ2) from 0° to 360° of the second roll 1200 . The angle θ2 is the rotation angle of the second roll 1200 .

Therefore, for example, the gap calculator 1960 can calculate the maximum and minimum values of the gap function G1 (θ1, θ2). The maximum and minimum values of the gap function G1 (θ1, θ2) indicate variations in the film thickness H1 of the coating layer of the electrode 100, which is the product. Also, the maximum and minimum values of the gap function G1 (θ1, θ2) indicate the accuracy of the coating device 1000, which is a manufacturing device.

8-2. Estimation of Film Thickness The controller 1900 can estimate the film thickness of the coating layer of the electrode 100 from the gap function G1 (θ1, θ2). The control unit 1900 has a film thickness estimation unit. If the first roll 1100 and the second roll 1200 are hardly deformed, the film thickness estimator estimates the film thickness of the coating layer of the electrode 100 manufactured by the coating device 1000 with high accuracy.

8-3. Sides of Rolls In the first embodiment, the first side 1111 of the first roll 1100 and the second side 1211 of the second roll 1200 are on the same plane U2. However, the first side surface 1111 and the second side surface 1211 may be positioned on different surfaces. Even in that case, the plane including the first side surface 1111 and the plane including the second side surface 1211 are preferably parallel. Also, the distance between the surface including the first side surface 1111 and the surface including the second side surface 1211 should be short. This is because the imaging unit 1500 can easily focus on the first side surface 1111 of the first roll 1100 and the second side surface 1211 of the second roll 1200 .

8-4. Marks As shown in FIG. 11, the first roll 1100 may have a mark M3 corresponding to an encoder on the first side surface 1111 . Even in this case, the coating apparatus 1000 can calculate the gap function G1 (θ1, θ2). Even when calculating the reference point, any position of the mark M3 may be determined in advance.

As shown in FIG. 12 , the first roll 1100 may have a plurality of marks M4 corresponding to encoders on the first side surface 1111 . The marks M4 are formed at constant rotation angles. Even in this case, the coating apparatus 1000 can calculate the gap function G1 (θ1, θ2).

As described above, the first mark M1 and the second mark M2 may be of any shape as long as the control unit 1900 can recognize their positions. In order to distinguish the first marking M1 or the second marking M2 from the video or image, the first marking M1 and the second marking M2 may be of different brightness than the first side 1111 and the second side 1211. preferable. In other words, the light reflectance of the first mark M1 and the second mark M2 is preferably different from the light reflectance of the side surface 1111 of the first roll 1100 and the side surface 1211 of the second roll 1200 . Of course, a high contrast between the sides of the roll and the markings is preferred.

8-5. Light Irradiation Unit The coating apparatus 1000 may not have the light irradiation unit 1600 . This is because the imaging unit 1500 can image the first side surface 1111 of the first roll 1100 and the second side surface 1211 of the second roll 1200 even without the light irradiation unit 1600 . The presence of the light irradiation unit 1600 improves the definition of the video or image. Therefore, the coating apparatus 1000 should have the light irradiation section 1600 .

8-6. Mirror Surface The first side surface 1111 of the first roll 1100 and the second side surface 1211 of the second roll 1200 are preferably mirror surfaces. This is because the contrast between the first mark M1 and the second mark M2 and their surroundings increases. If this contrast is large enough, the first side 1111 of the first roll 1100 and the second side 1211 of the second roll 1200 need not necessarily be mirror surfaces.

8-7. Pressing by Roll Pair In the first embodiment, the roll pair of the coating device 1000 presses the coating material. However, the technology of the first embodiment can be applied to devices other than the coating device as long as the material is pressed by the gap between the roll pairs. Examples of such devices include rolling mills. Of course, the technique of the first embodiment can also be applied to apparatuses other than the rolling apparatus.

8-8. Combination The above modifications may be freely combined.

(Second embodiment)
A second embodiment will be described. In the second embodiment, a coating device 1000 similar to that in the first embodiment is used. In the second embodiment, the case where the shaft of the first roll 1100 or the second roll 1200 is deformed will be described. Therefore, matters different from the first embodiment will be described.

1. Curvature of Central Axis of Rolls FIG. 13 is a conceptual diagram for explaining the first roll 1100 and the second roll 1200 in the coating apparatus 1000 of the second embodiment. In FIG. 13, the central axis of the first roll 1100 is curved and the central axis of the second roll 1200 is straight. For ease of understanding, the curvature of the roll is exaggerated.

The first roll 1100 and the second roll 1200 press and shape the wet granules. Therefore, deformation of the first roll 1100 or the second roll 1200 can sufficiently occur. For example, the straight central axis of the roll may be deformed into a bow shape.

FIG. 14 is a conceptual diagram illustrating temporal changes in the gap G2 (θ1, θ2) between the deformed first roll 1100 and second roll 1200 in the coating apparatus 1000 of the second embodiment. As shown in FIG. 14, the first roll 1100 rotates with the support points B1 and B2 as fixed ends.

FIG. 15 is a conceptual diagram of the first roll 1100 and the second roll 1200 in the coating apparatus 1000 of the second embodiment viewed from the direction of the central axis. FIG. 15 shows the case where the central axis of the first roll 1100 is curved as shown in FIG.

As shown in FIG. 15, the first roll 1100 has a case where it approaches toward the second roll 1200 and a case where it moves away. This is because the central axis of the first roll 1100 is curved. The gap function G2 (θ1, θ2) may take a minimum value G2a and a maximum value G2b.

2. Third Radius Function and Fourth Radius Function The third radius function D3 and the fourth radius function D4 are expressed as follows.
D3(θ1) = D1(θ1) - δ1(θ1)
D4(θ2) = D2(θ2) - δ2(θ2)
D1(θ1): first radius function of the first roll
D2(θ2): second radius function of the second roll
δ1(θ1): Deviation from perfect circle in first radius function D1(θ1)
δ2(θ2): Deviation from perfect circle in second radius function D2(θ2)

In this way, when the roll-specific deviation from perfect circle is canceled, the gap function G2 (θ1, θ2) is obtained by the following equation (2).
G2(θ1, θ2) = A1-D3(θ1)-D4(θ2) ………(2)

3. Control System of Coating Apparatus FIG. 16 is a block diagram showing the control system of the coating apparatus of the second embodiment. As shown in FIG. 16, the control section 2900 has a shape fitting section 2970 and a radius function determining section 2980 in addition to the sections of the first embodiment.

The shape matching unit 2970 subtracts a deviation from a perfect circle in the first radius function D1 (θ1), a third radius function D3 (θ1), and a deviation from a perfect circle in the second radius function D2 (θ2). Derive a fourth radius function D4(θ2).

A radius function determination unit 2980 determines the curvature of the central axes of the first roll 1100 and the second roll 1200 . The radius function determination unit 2980 determines that the central axis of the first roll 1100 is curved when the third radius function D3(θ1) changes according to the change in the rotation angle of the first roll 1100 . The radius function determination unit 2980 determines that the central axis of the second roll 1200 is curved when the fourth radius function D4 (θ2) changes according to the change in the rotation angle of the second roll 1200 .

4. Method for Detecting Deformation of Central Axis of Roll FIG. 17 is a diagram showing the gap function G2 (θ1, θ2) in the coating apparatus of the second embodiment. In FIG. 17, roll manufacturing errors are cancelled. As shown in FIG. 17, the third radius function D3(θ1) of the axially deformed first roll 1100 fluctuates for one cycle depending on the angle θ1. The fourth radius function D4(θ2) of the second roll 1200 that is not axially deformed is constant regardless of the angle θ2.

Radius function determination unit 2980 determines that the center axis of first roll 1100 is not curved when third radius function D3(θ1) is constant. The radius function determination unit 2980 determines that the central axis of the first roll 1100 is curved when the third radius function D3(θ1) changes according to the change in the angle θ1.

Actually, when the change in the third radius function D3(θ1) is smaller than a predetermined threshold, the radius function determining section 2980 determines that the center axis of the first roll 1100 is not curved. If the change in the third radius function D3(θ1) is greater than or equal to a predetermined threshold value, the radius function determining section 2980 determines that the central axis of the first roll 1100 is curved.

The radius function determination unit 2980 determines that the center axis of the second roll 1200 is not curved when the fourth radius function D4(θ2) is constant. The radius function determination unit 2980 determines that the center axis of the second roll 1200 is curved when the fourth radius function D4(θ2) changes according to the change in the angle θ2.

Actually, when the change in the fourth radius function D4 (θ2) is smaller than a predetermined threshold, the radius function determining section 2980 determines that the center axis of the second roll 1200 is not curved. When the change in the fourth radius function D4 (θ2) is equal to or greater than a predetermined threshold, the radius function determining section 2980 determines that the center axis of the second roll 1200 is curved.

5. Effects of Second Embodiment The coating apparatus of the second embodiment can detect deformation of the central axes of the first roll 1100 and the second roll 1200 . When the center axis of the roll is curved, the film thickness of the coating layer in the direction of the center axis of the roll varies. The coating apparatus of the second embodiment can detect the curvature of the central axis of the roll. In this case, the roll with the curved central axis should be replaced. Therefore, the coating apparatus of the second embodiment can suppress variations in the thickness of the coating layer caused by the curvature of the central axis of the roll.

6. Modification 6-1. Types of Rolls In the second embodiment, the central axis of the first roll 1100 is curved. However, even when the central axis of the second roll 1200 is curved, the second embodiment can be similarly applied. Also, the second embodiment can be similarly applied when both the first roll 1100 and the second roll 1200 have an abnormality. Moreover, the second embodiment may be applied to the third roll 1300 as well.

6-2. Estimation Unit The control unit 2900 may estimate the replacement timing of the first roll 1100 or the second roll 1200 .

6-3. Combination The first embodiment and modification and the second embodiment and modification may be freely combined.

DESCRIPTION OF SYMBOLS 1000... Coating apparatus 1100... 1st roll 1110... 1st outer peripheral part 1111... 1st side face 1120... 1st shaft 1200... 2nd roll 1210... 2nd outer peripheral part 1211... 2nd side face 1220... 2nd shaft 1300... 3 rolls 1400 wet granule supply unit 1500 imaging unit 1600 light irradiation unit 1900 control unit

Claims (9)

a roll pair having a first roll and a second roll;
A material supply unit that supplies material between the first roll and the second roll;
an imaging unit that images the first roll and the second roll;
a control unit;
In a roll displacement measuring device having
The first roll is
a first outer periphery;
a first side surface located at an end of the first outer peripheral portion;
a first shaft that is a rotating shaft of the first roll protruding from the first side surface;
a first mark formed on the first side;
The second roll is
a second outer periphery;
a second side surface located at the end of the second outer peripheral portion;
a second shaft that is a rotating shaft of the second roll protruding from the second side surface;
a second mark formed on the second side;
The first roll and the second roll are
pressing the material between the first perimeter of the first roll and the second perimeter of the second roll;
The imaging unit is
imaging the first side surface and the first mark of the first roll, and the second side surface and the second mark of the second roll;
The control unit
having a radius function derivation unit,
The radius function derivation unit
a first radius function from the center of rotation of the first roll to the first outer periphery;
deriving a second radius function from the center of rotation of the second roll to the second perimeter ;
However, the intersection of a line segment connecting the rotation center of the first roll and the rotation center of the second roll with the outer circumference of the first side surface and the distance between the rotation center of the first roll and the first A function for the rotation angle of the roll is defined as the first radius function,
The distance between the intersection of the line segment connecting the rotation center of the first roll and the rotation center of the second roll and the outer circumference of the second side surface and the rotation center of the second roll Define the function for the rotation angle as the second radius function,
A roll displacement measuring device comprising: In the roll displacement measuring device according to claim 1,
The control unit
having a gap calculator,
The gap calculator is
A roll displacement measuring device comprising calculating a gap function between the first roll and the second roll from the first radius function and the second radius function. In the roll displacement measuring device according to claim 1 or claim 2,
The control unit
Having a mark discrimination part,
The mark discrimination unit
A roll displacement measuring device, comprising distinguishing between the first mark of the first roll and the second mark of the second roll from information of a video or image captured by the imaging unit. In the roll displacement measuring device according to claim 3,
The control unit
having a reference point setting unit,
The reference point setting unit
A first reference point is set at an intersection of an extension of a line segment connecting the rotation center of the first roll and the first mark and the first outer peripheral portion of the first roll,
Roll displacement including setting an intersection of an extension of a line segment connecting the rotation center of the second roll and the second mark and the second outer peripheral portion of the second roll as a second reference point. measuring device. In the roll displacement measuring device according to any one of claims 1 to 4,
The control unit
having a form-fitting portion,
The shape conforming part is
a third radius function obtained by subtracting deviation from a perfect circle in the first radius function;
a fourth radius function obtained by subtracting deviation from a perfect circle in the second radius function;
A roll displacement measuring device comprising deriving a In the roll displacement measuring device according to claim 5,
The control unit
having a radius function determination unit;
The radius function determination unit
When the third radius function changes according to changes in the rotation angle of the first roll,
Determining that the central axis of the first roll is curved,
When the fourth radius function changes according to changes in the rotation angle of the second roll,
A roll displacement measuring device including determining that the central axis of the second roll is curved. In the roll displacement measuring device according to any one of claims 1 to 6,
A roll displacement measuring device, comprising: a light irradiation unit that irradiates light onto the first side surface of the first roll and the second side surface of the second roll. In a roll displacement measuring method for a roll pair having a first roll and a second roll,
The first roll is
a first outer periphery;
a first side surface located at an end of the first outer peripheral portion;
a first shaft that is a rotating shaft of the first roll protruding from the first side surface;
a first mark formed on the first side;
The second roll is
a second outer periphery;
a second side surface located at the end of the second outer peripheral portion;
a second shaft that is a rotating shaft of the second roll protruding from the second side surface;
a second mark formed on the second side;
The first roll and the second roll are
pressing the material between the first perimeter of the first roll and the second perimeter of the second roll;
The imaging unit
imaging the first side surface and the first mark of the first roll, and the second side surface and the second mark of the second roll;
The radius function derivation part is
a first radius function from the center of rotation of the first roll to the first outer periphery;
a second radius function from the center of rotation of the second roll to the second outer periphery;
to derive
However, the intersection of a line segment connecting the rotation center of the first roll and the rotation center of the second roll with the outer circumference of the first side surface and the distance between the rotation center of the first roll and the first A function for the rotation angle of the roll is defined as the first radius function,
The distance between the intersection of the line segment connecting the rotation center of the first roll and the rotation center of the second roll and the outer circumference of the second side surface and the rotation center of the second roll Define the function for the rotation angle as the second radius function,
A roll displacement measurement method comprising: a roll pair having a first roll and a second roll;
a material supply unit that supplies a coating material between the first roll and the second roll;
an imaging unit that images the first roll and the second roll;
a control unit;
In a coating device having
The first roll is
a first outer periphery;
a first side surface located at an end of the first outer peripheral portion;
a first shaft that is a rotating shaft of the first roll protruding from the first side surface;
a first mark formed on the first side;
The second roll is
a second outer periphery;
a second side surface located at the end of the second outer peripheral portion;
a second shaft that is a rotating shaft of the second roll protruding from the second side surface;
a second mark formed on the second side;
The first roll and the second roll are
pressing the coating material between the first outer peripheral portion of the first roll and the second outer peripheral portion of the second roll to form a coating layer;
a rotating direction of the first roll;
The direction in which the second roll rotates is opposite to the direction in which the second roll rotates,
The rotational angular velocity of the first roll is
Faster than the rotational angular velocity of the second roll,
The imaging unit is
imaging the first side surface and the first mark of the first roll, and the second side surface and the second mark of the second roll;
The control unit
having a radius function derivation unit,
The radius function derivation unit
a first radius function from the center of rotation of the first roll to the first outer periphery;
a second radius function from the center of rotation of the second roll to the second outer periphery;
to derive
However, the intersection of a line segment connecting the rotation center of the first roll and the rotation center of the second roll with the outer circumference of the first side surface and the distance between the rotation center of the first roll and the first A function for the rotation angle of the roll is defined as the first radius function,
The distance between the intersection of the line segment connecting the rotation center of the first roll and the rotation center of the second roll and the outer circumference of the second side surface and the rotation center of the second roll Define the function for the rotation angle as the second radius function,
Coating equipment including.

Images