JP5328876B2 - Roll press equipment - Google Patents

Description

  The present invention relates to a roll press facility, and more particularly, to a roll press facility including a mechanism for correcting deflection of a roll.

  Roll press equipment is used for compression processing of electrode materials for lithium ion secondary batteries. The required thickness accuracy after compression processing of materials is strict, for example, about ± 2 μm. In recent years, higher accuracy has been desired (± 1-2 μm). Therefore, if the deflection of the roll due to the reaction force applied from the material during compression is not corrected, variations in the width direction of the finished thickness occur such that both edge portions of the material become thinner than the vicinity of the central portion. Therefore, for example, as described in Patent Document 1, by correcting the deflection of the roll, thickness variation in the width direction of the material is suppressed, and processing is performed with high accuracy.

  In addition, the setting of the roll interval and the correction of the deflection of the roll are set by manually adjusting the pressure of the hydraulic cylinder while measuring the thickness of the electrode material after pressing.

  In addition, feedback control of the thickness measurement result and adjustment control of the roll gap are performed in a rolling mill or the like as described in Patent Documents 2 to 5, for example.

  Patent Document 6 discloses that when a nonwoven fabric is thermocompression bonded with a heating roll, the thickness is measured at three locations in the width direction and fed back to a roll clearance adjusting device to adjust the thickness in the width direction. .

Japanese Patent No. 3937561 JP-A-7-39914 JP-A-7-108551 JP 2003-53759 A JP 2001-332248 A JP 7-189137 A JP 2011-181348 A

  In the compression process of the lithium ion secondary battery electrode material, the coiled electrode material is unwound and continuously compressed by a roll press. The thickness accuracy after compression processing is strict at about ± 1 to 2 μm in both the width direction and the flow direction. Further, the length of one coil tends to be long, and the continuous processing time tends to be long. During continuous processing, a minute roll shape change occurs due to a minute temperature change inside the roll due to heat generated by roll rotation or compression processing. About the thermal deformation of this roll, it can reduce by the method of patent document 7, for example.

  However, according to the study by the present inventors, it has been found that if the continuous processing time becomes long, a thickness of several μm is generated in the thickness after compression, and the thickness after compression may be out of the target thickness range (allowable value). did. In order to prevent this, it is conceivable that the line is stopped in the middle of one coil, the pressure condition is manually reset, the thickness is adjusted within the target thickness range, and the line operation is restarted. This takes time and yields worse.

  In Patent Document 1, changing the pressurizing condition during continuous machining is not performed. Further, in Patent Documents 2 to 5, considering that the pressing condition changes based on the change in the plate thickness on the entry side and the plate thickness on the exit side changes, the thickness after processing is measured to determine the roll gap. However, there is no idea of adjusting the thickness at multiple locations in the width direction within the target thickness range, and in particular, pressurizing conditions based on the thermal deformation of the roll during continuous processing (especially the addition of deflection correction). The resetting of pressure conditions has not been studied at all. Patent Document 6 describes that a thickness is measured at three locations in the width direction, and an electric worm jack is provided separately from a device that performs reverse bend, and the roll clearance is adjusted by bending by the electric worm jack. Yes. However, it is intended to eliminate variation in the width direction, and it is not considered to adjust the width direction so that it is within the target thickness range, and pressurization based on thermal deformation of the roll during continuous processing The resetting of conditions has not been studied at all.

  An object of the present invention is to perform compression processing (press) with high accuracy (with the thickness within the target thickness range in the entire range in the width direction) even in long-term continuous processing in a roll press facility having a mechanism for correcting the deflection of the roll. It is to provide a roll press facility capable of performing the above.

  The present invention, in a roll press facility equipped with a bend mechanism for correcting the deflection of the roll, measures the thickness at a plurality of locations in the width direction of the compressed material, and the thickness within the target thickness range over the entire width direction of the material. Thus, feedback control of the press mechanism that adjusts the roll gap and the bend mechanism that corrects the deflection of the roll is performed singly or in combination according to the state of the difference between the measured thickness values at a plurality of locations and the target thickness. It is characterized by that.

  According to the present invention, it is possible to improve the thickness accuracy of a material after compression processing in both the width direction and the flow direction even in long-term continuous processing.

The front view of the roll press machine main body in the roll press equipment which is one Example of this invention. The front view of the roll press machine main body in the roll press equipment which is another Example of this invention. The front view of the roll press machine main body in the roll press equipment which is another Example of this invention. The line general view of the roll press equipment which is one Example of this invention. The figure explaining the control flow in the roll press equipment which is one Example of this invention.

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

  The roll press machine main body in the roll press facility loads the upper roll 1, the lower roll 2, the main bearing box 4 that holds and holds the main bearings that pivotally support the upper roll and the lower roll, and the main bearing box of the lower roll. In addition, a press cylinder 5 for generating a press load on the material 3 between the upper roll 1 and the lower roll 2 is provided. The main bearing box and press cylinder of the upper roll are supported by a housing (not shown). Each of the upper roll and the lower roll is provided with a roll drive mechanism (not shown). Further, the roll press machine main body is provided with a bend mechanism that corrects the deflection of the roll, which includes a bend cylinder 7 and a bend bearing box 6 that holds and holds the bend bearing.

  The press cylinder 5 is a main component of the press mechanism that adjusts the roll gap. The press cylinder 5 is configured to be position-controllable by a control command from a control panel described later. That is, the press cylinder has a position detector (not shown) such as a magnescale inside or outside, and a system capable of position control using a servo valve in the hydraulic system is employed.

  The bend cylinder 7 can be set with a pressurizing force by a control command from a control panel described later. The bend cylinder employs a proportional control valve (solenoid valve) for pressure setting. The bend bearing housing 6 is provided on both outer sides of the main bearing housing 4. The bend mechanism for correcting the deflection of the roll according to this embodiment is a bend tension type, and a bend cylinder 7 is provided between the bend bearing box of the upper roll and the bend bearing box of the lower roll, and the roll according to the processing load on the material. The deflection of the roll is corrected by applying a load to the roll in the opposite direction to the deflection. The arrows in the figure are images of the direction and magnitude of the load applied by each cylinder. Each cylinder uses hydraulic pressure. Hydraulic cylinders can handle high loads and can be processed stably by using incompressible fluid (hydraulic fluid).

  FIG. 4 shows an overall line diagram of a roll press facility according to an embodiment of the present invention. A roll press machine main body is provided with an unwinder 12 on which a pre-press coil 8 in which a material 3 such as a lithium ion secondary battery electrode material is wound in a coil shape is mounted. Is provided with a winder 13 for winding the material after pressing to form a coil 9 after pressing. Further, a thickness meter 10 for measuring the thickness of the pressed material 3 is installed on the exit side of the roll press machine main body. Based on the thickness measurement value from the thickness gauge 10, the control panel 11 performs an operation for obtaining the control value (correction amount) of press cylinder position control and bend cylinder pressure control, and the control value is output to the roll press machine body. The hydraulic pressure of the press cylinder and bend cylinder is controlled by the value.

  In this embodiment, the thickness gauge 10 has a thickness in three directions (three regions or three locations) on the operation side (side without the roll drive mechanism), the center, and the drive side (side with the roll drive mechanism) in the width direction. It is configured to measure. The thickness measurement points may be at least two points in the width direction, but it is desirable to measure the thickness at three points. Further, the thickness may be measured by fixing the measuring device at three places, or the thickness may be measured by moving the measuring device in the width direction. When continuously measuring in the width direction, three regions of the operation side, the center, and the drive side may be set, and the average value of the measured values in the range may be used for control.

  The thickness meter 10 is not specified in the measurement method as long as the material thickness can be measured continuously or intermittently during line operation. For example, as a thickness gauge measurement method, the top surface position of the material on the guide roll is detected by a laser sensor, and the position of the guide roll is detected by a magnetic sensor, and the material thickness is measured from the positional relationship. And a method of measuring the position of both surfaces of the material with a laser sensor and measuring the thickness of the material from the positional relationship.

  Next, the control flow in the roll press equipment which is one Example of this invention is demonstrated using FIG.

  In the present embodiment, the thickness is measured at three points on the operation side, the center, and the drive side, and the press cylinder position control and the bend cylinder pressure control are performed according to the situation of the thickness at the three points. Thickness control also sets a threshold value within the target thickness accuracy (target thickness range), and press cylinders so that the thickness measurement value from the thickness gauge falls within the threshold value when it deviates from the threshold value. This is done by changing the position and bend cylinder pressure alone or in combination.

  The control flow will be described based on FIG. A thickness measurement value of the material 3 compressed by the press roll machine main body is input from the thickness gauge 10 to the main control panel 11-1. The measured thickness value is obtained by the main control panel after the material whose pressing conditions have been changed passes through the thickness gauge 10. That is, when the path line length of the press body and the thickness gauge is L1, and the material feed length after changing the pressing conditions is L2, the thickness measurement value is acquired when L2 ≧ L1. The material feed length L2 after changing the pressing conditions is detected based on information from the pulse generator 16 attached to the drive motor 15 that drives the roll and the information from the inverter 17 that drives the drive motor 15.

  In this embodiment, the measuring instrument is moved in the width direction and the thickness is continuously measured in the width direction. In the main control panel, the drive side, the center, and the operation side are based on the measured thickness values. The measured values of the region (driving side thickness Td, central portion thickness Tc, operation side thickness Tw) are extracted.

Three thickness measurement values from the main control panel are input to the thickness feedback control panel 11-2. When the target thickness is Ta and the target thickness accuracy (target thickness range) is Ta ± ΔP, in order to ensure that each thickness measurement value is the target thickness accuracy (target thickness range), in this embodiment, the target thickness A threshold value Ta ± Δt smaller than the accuracy (target thickness range) Ta ± ΔP is set (a threshold value that satisfies Δt <ΔP is set).
Further, in this embodiment, when the thickness measurement value is out of the threshold value, the press mechanism for adjusting the roll gap and the bend for correcting the deflection of the roll according to the situation of the thickness measurement value at the three locations. The feedback control of the mechanism is performed alone or in combination.

  That is, in this embodiment, first, either one or both of the drive side thickness Td and the operation side thickness Tw is caused by a difference in absolute value between the measured thickness value and the target thickness Ta due to thermal deformation of the roll or the like from Δt. When it becomes larger, both the press cylinder position and the bend cylinder pressure are changed (reset). That is, in this case, since the roll gap is not in an appropriate range, the press cylinder position is reset (correction amount is calculated). Since the press cylinder position (roll gap) is changed, the pressure on the material and the press pressure (press cylinder pressure) change. In this case, since the control is performed so that the deflection correction amount is not changed (the deflection correction amount is maintained), in order to maintain the deflection correction amount, the deflection correction is performed in accordance with the change of the press pressure. Set the bend cylinder pressure again (calculate the bend pressure adjustment amount).

  When the difference (absolute value) between the target thickness Ta for both the drive side thickness Td and the operation side thickness Tw is equal to or less than Δt, the difference (absolute value) between the center thickness Tc and the target thickness Ta is compared with Δt. If the difference is larger than Δt, the roll deformation at the center is large, so that only the bend cylinder pressure is reset so that the deflection correction amount is changed (the bend pressure correction amount is calculated). When the bend cylinder pressure is changed, the pressure of the press cylinder changes. In this case, a servo valve is used in the hydraulic system so that the position of the press cylinder does not change (the position of the lower roll does not change). Position control is performed by the system.

  When the difference is equal to or less than Δt, the measured values in the three regions (driving side thickness Td, central portion thickness Tc, operation side thickness Tw) are all within the threshold value, and therefore within the target thickness accuracy (target thickness range). Neither cylinder position nor bend cylinder pressure is changed (reset).

  Then, the above control flow is repeated at the next thickness measurement timing.

  The roll gap correction amount is calculated in the opening direction (lower roll position lowering direction) or the closing direction (lower roll position depending on the difference (including positive and negative) between the target thickness Ta and the driving side thickness Td or the operation side thickness Tw. As the amount of movement in the direction of increasing There are a case where the roll gap on both the driving side and the operation side is corrected, and a case where either one is corrected. The difference may be used as the movement amount as it is, or the difference multiplied by a predetermined coefficient may be used as the movement amount.

  The bending correction bend pressure adjustment calculation is performed after calculating the roll gap correction amount. Here, the bend becomes the same as the previous deflection correction amount using the same calculation method as the conventional roll deflection correction based on the material width and the press pressure after the roll gap correction so that the previous deflection correction amount is maintained. Calculate pressure (bend cylinder pressure).

  In the bend pressure correction amount calculation, depending on the difference (including positive and negative) between the target thickness Ta and the central portion thickness Tc, the deflection correction amount is adjusted to increase or decrease by a predetermined amount. Based on this, the bend pressure (bend cylinder pressure), which is the deflection correction amount after the change, is calculated by the same calculation method as the conventional roll deflection correction.

  The roll gap correction amount and the bend pressure correction amount (or deflection correction bend pressure adjustment amount) calculated by the thickness feedback control panel 11-2 are input to the bend pressure control system and the roll gap control system of the main control panel 11-1. The Further, the material feed length count after changing the press condition is reset to zero (L2 = 0).

  In the roll gap control system, the lower roll position reflecting the roll gap correction amount is obtained, and the press cylinder position control is performed by a system using a servo valve in the hydraulic system so that the lower roll moves to this lower roll position. Do.

  In the bend pressure control system, the pressure applied to the bend cylinder is controlled by a system using a proportional control valve (solenoid valve) so that the bend pressure reflects the bend pressure correction amount.

  In this example, the thickness of the material after pressing was measured at three locations, and when the thickness measurement value was out of the threshold value, the press condition (roll The gap, that is, the lower roll position and the bend cylinder pressure) is corrected so that the thickness of the material is kept within the target range in the width direction. It becomes possible to improve the thickness accuracy of the subsequent material in both the width direction and the flow direction.

  In the above embodiment, the thickness feedback control is continuously performed during line operation. However, since the thickness change of the material after pressing is considered to be mainly caused by the thermal deformation of the roll, the thickness feedback control is performed on the roll. You may make it carry out at the time when the influence of a thermal deformation becomes large. Further, the temperature rise of the main bearing box may be monitored, and feedback control may be performed when the temperature rises above a predetermined temperature.

  Further, the thickness control in this embodiment is effective even in the initial stage of compression processing. That is, conventionally, in the initial stage of line operation, the load condition is repeatedly changed to the target thickness and the processing condition is manually set. Therefore, it takes time and the yield is deteriorated. If the control of the present embodiment is used in the initial stage of coil compression processing, automatic conditions can be determined in the initial stage of compression processing.

  Another embodiment of the present invention is shown in FIG. The roll press machine main body in the present embodiment is obtained by changing the bend cylinder from the so-called bend tension type to the bend tension type in the first embodiment. Others are the same as in the first embodiment. In the present embodiment, the same operational effects as those of the first embodiment can be obtained.

  Another embodiment of the present invention is shown in FIG. The roll press machine main body in the present embodiment is the one in which the preload cylinder 14 for preventing the upper roll from rattling is installed in the first embodiment.

  A preload cylinder 14 is provided as a mechanism for applying an upward load that cancels the weight of the upper roll 1 to the upper roll 1, separately from the mechanism for correcting the deflection of the roll. In this embodiment, the preload cylinder 14 is installed in the upper roll bend bearing box 6. However, a preload bearing box is separately provided between the upper roll main bearing box 4 and the bend bearing box 6. Alternatively, a preload cylinder 14 may be installed. The arrows in the figure are images of the direction and magnitude of the load applied by each cylinder. For the preload cylinder, other means such as an air cylinder and a spring may be used in addition to the hydraulic cylinder. However, hydraulic pressure is desirable for stability. Further, since there is no need to change the load as in the case of a press cylinder or a bend cylinder, a mechanism for making the load variable is unnecessary.

  In addition, the preload load by the preload cylinder is much smaller than the press load and bend correction load, and it is not necessary to change the load. By adjusting the preload cylinder diameter (by reducing it), the hydraulic pressure is unstable and low. The equipment can be operated in a stable pressure range by removing the pressure range, and it is easy to make fine adjustments.

  The preload cylinder 14 of this embodiment pulls up the bend bearing housing 6 so as to apply a load in an upward direction to the upper roll. As a result, the roll support shaft of the upper roll is pressed above the main bearing of the main bearing housing 4 to eliminate backlash (gap) between the roll support shaft and the main bearing.

In relation to the target post-processing thickness accuracy (for example, ± 2 μm or less), it is desirable that the upper roll be surely pressed upward to suppress swinging. In other words, the upper roll is lifted by its own weight in order to eliminate the play in the structure of the upper roll, eliminate the oscillation inside the bearing, stabilize the vertical position of the roll, and perform accurate press processing. It is desirable to win and press more firmly. Accordingly, the preload load by the preload cylinder 14 is set not only to lift the weight of the roll but also to press it to a certain extent. However, since the pressing force affects the amount of deflection of the roll, it is necessary not to perform it excessively.

  From such a viewpoint, the preload load (pressing force) is preferably a load of about 1 to 3 times the roll weight. This is because when a load of 3 times or more is applied, the deflection correction effect is increased and the material thickness accuracy is affected. Further, even if the weight is equivalent to about 1 times the roll weight, rattling and swinging can be suppressed in consideration of the reaction force from the material 3 and the load from the bend cylinder 7. In order to prevent the deflection correction effect by the preload cylinder from becoming large and to further ensure the suppression of the swing, a load of 1.5 to 2 times the roll weight is optimal.

  Unlike the press mechanism and bend mechanism, the preload cylinder load is not changed by feedback control. Others are the same as in the first embodiment.

  According to the present embodiment, in addition to the effects of the first embodiment, the following effects are obtained. In a conventional roll press facility, a load is applied to the upper roll by a bend cylinder (deflection correction cylinder) force, and the upper roll is pressed upward. However, when the sum of the deflection compensation load and the reaction force from the material is at the same level as the roll's own weight, it moves downward by the backlash of the roll, and the position on the rolling surface of the bearing part moves slightly due to the rotation of the shaft. Unstable operation in which the roll position changes downward, resulting in poor product thickness accuracy. In the present embodiment, the upper roll is reliably pressed upward by an independent mechanism different from the deflection correction mechanism, so that stable and accurate processing can be performed without adversely affecting the deflection correction.

Further, when the pressure is set to 15 to 20% or less as compared with the maximum pressure of the hydraulic pressure reducing valve specification, the hydraulic pressure becomes unstable. For example, when the maximum pressure of the pressure reducing valve specification is 21 MPa, an area below about 3 MPa becomes an unstable region, so that the upward pressing force becomes unstable and accurate press working cannot be performed. In this embodiment, by using an independent preload cylinder as an appropriate small-diameter cylinder, the stable region of the hydraulic pressure reducing valve can be used to reliably hold the upper roll upward. The roll press equipment requires a large pressure, so a large diameter cylinder is used to adjust the load. When low linear pressure (light load) is set, adjustment is difficult because the load changes greatly with slight pressure adjustment. In the present embodiment, the upper roll can be reliably pressed upward regardless of the set load of the roll press facility by making the independent preload cylinder an appropriate small diameter cylinder.

  DESCRIPTION OF SYMBOLS 1 ... Upper roll, 2 ... Lower roll, 3 ... Material, 4 ... Main bearing box, 5 ... Press cylinder, 6 ... Bend bearing box, 7 ... Bend cylinder, 8 ... Coil before press, 9 ... Coil after press, 10 ... Thickness gauge, 11 ... control panel, 11-1 ... main control panel, 11-2 ... thickness feedback control panel, 12 ... unwinding machine, 13 ... winder, 14 ... preload cylinder, 15 ... drive motor, 16 ... pulse Generator, 17 ... inverter.

Claims (5)

A roll press facility used for compression processing of a lithium ion secondary battery electrode material,
An upper roll, a lower roll, a main bearing box that pivotally supports the upper and lower rolls, a load is applied to the main bearing box to adjust a roll gap between the upper and lower rolls, and the lithium ion secondary battery electrode material A roll press machine main body provided with a press mechanism that applies a compressive load to and a bend mechanism that applies a load to the bend bearing housings provided on both outer sides of the main bearing housing to correct the deflection of the upper and lower rolls;
An unwinder that is provided on the entrance side of the roll press machine body, and that is mounted with a pre-press coil in which the lithium ion secondary battery electrode material is wound in a coil shape;
A winder provided on the outlet side of the roll press machine main body, winding the lithium ion secondary battery electrode material after compression processing to form a coil after pressing;
The thickness of the compression-processed lithium ion secondary battery electrode material installed on the upstream side of the winder at the exit side of the roll press machine main body is set at three locations on the operation side in the width direction , the central portion, and the drive side Thickness gauge to measure with,
Based on the thickness measurement value from the thickness gauge, comprising a press mechanism for adjusting the roll gap of the roll press machine body and a control device for calculating a control value to the bend mechanism,
The press mechanism includes a press cylinder and performs press cylinder position control by a control command from the control device,
The bend mechanism includes a bend cylinder and performs bend cylinder pressure control by a control command from the control device,
The control device is provided at three locations on the operation side, the central portion, and the drive side so that the thickness is within the target thickness range in the entire range in the width direction of the compressed lithium ion secondary battery electrode material. Depending on the state of difference between the measured thickness value and the target thickness, feedback control of the press mechanism and the bend mechanism is performed alone or in combination, and a threshold value is set within the target thickness range, A roll characterized by performing feedback control of the press mechanism and the bend mechanism individually or in combination so that the thickness measurement value from the thickness gauge falls within the threshold value when the measured value deviates from the threshold value. Press equipment. In claim 1,
When the control device has Ta as the target thickness, Ta ± ΔP as the target thickness range, and Ta ± Δt as a threshold smaller than the target thickness range Ta ± ΔP,
When one or both of the drive-side thickness measurement value Td and the operation-side thickness measurement value Tw is greater than Δt, the press mechanism and the bend mechanism A roll press facility characterized by combining feedback control. In claim 1,
When the control device has Ta as the target thickness, Ta ± ΔP as the target thickness range, and Ta ± Δt as a threshold smaller than the target thickness range Ta ± ΔP,
The difference between the drive-side thickness measurement value Td and the operation-side thickness measurement value Tw is the difference between the target thickness Ta and Δt or less, and the difference between the central portion thickness Tc and the target thickness Ta. A roll press facility characterized in that only the bend mechanism performs feedback control when becomes larger than Δt. In claim 2 or 3,
The thickness gauge is for measuring a thickness continuously in the width direction by moving a measuring instrument in the width direction. In the control device, based on the thickness measurement value, the driving side, the central portion, and the operation A roll press facility characterized by extracting measured thickness values at three locations on the side. In any one of Claims 1-4,
A roll press facility characterized in that a mechanism for applying an upward load that cancels the weight of the upper roll to the upper roll of the roll press machine main body is provided separately from the bend mechanism.

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