Roll press machine and roll press method using roll press machine

Abstract

To provide equipment including an inter-bearing rolling device capable of controlling an oil amount of an oil chamber of a thin cylinder by rotation of an electric motor without using a hydraulic pressure control servo valve and maintaining an inter-roll gap with high accuracy in a roll press machine.SOLUTION: An inter-bearing rolling device has a structure in which an oil chamber of a thin cylinder provided between upper and lower bearing boxes supporting a roll and an oil chamber in a pressure rising cylinder are connected to each other, an oil amount of the connected oil chamber of the pressure rising cylinder can be controlled by a ball screw and an AC servo motor. Even when an applied pressure between rolls varies largely due to the thin cylinder being arranged between the upper and lower bearings, a gap between the rolls is accurately maintained to a target dimension.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a roll press machine that is used to press materials such as lithium-ion batteries and that has an inter-bearing reduction device that can control the gap between the upper and lower rolls by disposing a cylinder between bearing housings that support the upper and lower rolls. [Background technology]

[0002] Patent Document 1 describes that a hydraulic screw-down device for steel using a hydraulic servo control valve is provided with a mechanism that makes it possible to adjust the pressure on the rod side of a piston incorporated in a screw-down cylinder that pushes up the rolls, using a pressure control valve or the like, depending on the rolling state.

[0003] Patent Document 2 describes that in a rolling mill or roll press, a booster cylinder is provided between a reduction cylinder that controls the gap between the upper and lower rolls to a desired dimension and a hydraulic pressure generating device that supplies oil to the reduction cylinder.

[0004] Patent Document 3 describes the placement of a hydraulic cylinder called a roll bender between work roll bearing housings in order to make the shape of the steel plate rolled by a conventional four-height rolling mill flatter. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 6-31326 [Patent Document 2] Patent No. 5959777 [Patent Document 3] Japanese Patent Application Laid-Open No. 2010-089121 Summary of the Invention [Problem to be solved by the invention]

[0006] In recent years, the development of energy-efficient manufacturing systems has become increasingly important in the production of EV batteries. To efficiently roll, rolling mills currently designed for mass production often use hydraulic pressure reduction devices consisting of hydraulic servo control valves and pressure reduction cylinders to generate large rolling forces between the rolls. In recent years, the use of hydraulic pressure reduction devices, which are hydraulically driven, has been increasing in the field of roll presses, which continuously press new materials such as battery electrode plates with rolls, to improve the thickness accuracy of the pressed electrode plates. However, hydraulic pressure reduction devices require hydraulic servo control valves that can inject and release minute amounts of oil to precisely control the amount of roll movement. Stable operation of hydraulic servo control valves requires a large amount of energy to continuously supply high-pressure hydraulic pressure. Replacing hydraulic pressure with electric motors to control roll position increases the motor's rotational speed to generate high torque, necessitating mechanical means such as gears to slow the rotational speed. The use of excessive mechanical means increases mechanical backlash, resulting in poor product thickness accuracy. In the battery manufacturing field, there is a demand for equipment that can manufacture electrode plates with high thickness precision using less energy, as well as a roll press machine that can easily press discontinuously coated electrode plates, as shown in Figure 4(b).

[0007] The use of the means described in Patent Document 1 is a system suitable for rolling mills that perform rolling operations at high speeds and high pressures. The reduction cylinder incorporated in the hydraulic reduction device can change the pressure on the rod side of the piston according to the rolling state, making it possible to improve rolling stability and the thickness accuracy of the rolled product. However, while the adoption of this mechanism can be expected to have the effect of slightly reducing the pressure on the head side of the piston, it cannot be expected to have the effect of significantly reducing the hydraulic pump pressure. A lot of energy is used to generate high-pressure hydraulic pressure even in roll press operations where there is little change in the material thickness.

[0008] The method described in Patent Document 2 describes a roll reduction device in which a boost cylinder is placed between a reduction cylinder and a pump unit, and the piston position of the boost cylinder can be moved back and forth by the rotational force of a motor via a screw shaft, allowing minute amounts of oil to be supplied and discharged from the boost cylinder to the reduction cylinder. Compared to the method described in Patent Document 1, this method eliminates unnecessary energy consumption. However, roll presses used to press electrode plates sometimes press discontinuously coated electrode plates, in which battery material is applied in islands on the surface of aluminum or copper foil. When materials with large thickness differences are continuously pressed with a large pressure, the upper and lower rolls come into contact in areas not coated with battery material, causing large impacts. When the pressing force is increased to improve battery performance, the method described in Patent Document 2, in which the reduction cylinder presses the roll from one direction, cannot avoid large impacts during the pressing process of discontinuously coated electrode plates.

[0009] This section explains the difference in function between the hydraulic cylinder called a roll bender attached to the work roll bearing housing described in Patent Document 3 and the cylinder located between the bearing housings described in this invention. The rolling mill for rolling steel plates described in Patent Document 3 is a four- or six-layer type with four or six upper and lower rolls. As shown in Figure 3, when a steel plate is sandwiched between the upper and lower work rolls and thinned by applying a strong rolling force, the work rolls deflect. This roll deflection causes thickness differences across the width of the rolled steel plate, which in turn causes elongation and deterioration of the steel plate shape. To prevent this deterioration of the steel plate shape, a work roll bender is installed in the bearing housing supporting the work rolls to generate a bender force in a direction that reduces the deflection caused by the rolling force. Since the work roll bender changes the force to correct the deflection of the work rolls, it does not have the function of controlling a constant gap between the work rolls. Since the present invention is a roll press machine with a double-layer roll, even if force is generated between the bearing housings, it cannot bend the rolls because there are no backup rolls. The cylinder of the present invention is intended to control the gap between the rolls, and has a different purpose and effect from the cylinder described in Patent Document 3. [Means for solving the problem]

[0010] Specifically, the present invention relates to a roll press machine having two upper and lower rolls that press a material, bearing housings that support the rolls, and a pressing cylinder that applies a force to the rolls to press the material, an inter-bearing cylinder is disposed between the bearing housings, the inter-bearing cylinder has a piston and an oil chamber, and is equipped with a mechanism for changing the amount of oil in the oil chamber that pushes out the piston; The present invention provides a roll press equipped with an inter-bearing screw-down device that changes the gap between the rolls supported by the bearing housings by changing the amount of oil in the oil chamber to overcome the pressure force of the screw-down cylinder.

[0011] The present invention provides a roll press machine equipped with an inter-bearing screw-down device that is provided in the above-mentioned roll press machine, in which a boost cylinder is arranged to precisely control the amount of oil in the inter-bearing cylinder oil chamber, the inter-bearing cylinder oil chamber and the boost cylinder oil chamber are connected, the position of the boost cylinder piston is moved by a screw and an electric servo motor, the amount of oil in the boost cylinder oil chamber is changed, and the position of the inter-bearing cylinder piston is changed, thereby maintaining the gap between the rolls at a target gap.

[0012] The present invention provides a roll press equipped with the above-mentioned inter-bearing reduction device, Provided is a roll press machine equipped with an inter-bearing reduction device that can press a continuously or discontinuously coated electrode plate having a coated portion thickness of 200 to 500 microns and an uncoated portion thickness of 10 to 20 microns to a coated portion thickness of 100 to 300 microns after pressing, by maintaining the gap between the rolls and the amount of oil in the inter-bearing cylinder oil chamber constant.

[0013] The present invention provides a roll press equipped with the above-mentioned inter-bearing reduction device, A position sensor that detects the vertical position of the piston is disposed on the piston that moves up and down in the pressing cylinder, and an inter-bearing pressing device having the function of detecting the roll position that moves up and down by the inter-bearing cylinder is provided.

[0014] Specifically, the present invention relates to a roll press machine having two upper and lower rolls that press a material, bearing housings that support the rolls, and a pressure cylinder that applies a force to the rolls to press the material, an inter-bearing cylinder is disposed between the bearing housings, the inter-bearing cylinder has a piston and an oil chamber, and is equipped with a mechanism for changing the amount of oil in the oil chamber that pushes out the piston; The present invention provides a roll press equipped with a roll reduction control method that changes the gap between the rolls supported by the bearing housings by changing the amount of oil in the oil chamber to overcome the pressure force of the reduction cylinder. [Effects of the Invention]

[0015] By controlling the amount of oil from the boost cylinder to the oil chamber of the bearing-to-bearing cylinder, it is possible to accurately change the distance between the upper and lower rolls, enabling thickness control that corresponds to minute changes in plate thickness with little energy.When pressing discontinuously coated electrode plates, even if materials with large thickness differences are pressed continuously with a large pressure, the gap between the upper and lower rolls is maintained constant, so the upper and lower rolls do not come into contact and cause large impacts, and the roll press speed can be increased, providing a roll press machine that can achieve high productivity. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a diagram showing an overall outline of a roll press machine according to an embodiment of the present invention; FIG. [Figure 2] FIG. 1 is a diagram illustrating an example of the structure of a booster device 100. [Figure 3] Diagram explaining the function of the work roll bender in a four-high rolling mill [Figure 4] FIG. 1 shows an electrode plate 20 pressed by a roll press machine. [Figure 5]A diagram showing an example of the force relationship inside a roll press machine [Figure 6] A diagram showing an example of a pressure booster device incorporated into a bearing housing. [Figure 7] A diagram explaining the problems with conventional presses for discontinuously coated electrode plates. [Figure 8] A diagram explaining the effect of placing a cylinder between bearings when pressing a discontinuously coated electrode plate. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0018] FIG. 1 is a diagram showing an overview of a roll press machine according to an embodiment of the present invention.

[0019] The roll press machine has a roll reduction device as a means for compressing the thickness of the electrode plate 20. The roll reduction device of the roll press machine is composed of a reduction cylinder 7 that applies pressure to the electrode plate 20, an upper roll 1 and a lower roll 2 that transmit the pressure force from the reduction cylinder 7 to the electrode plate 20, an upper bearing housing 3 that supports the upper roll 1, a lower bearing housing 4 that supports the lower roll 2, and a housing 5 that holds the pressure force of the reduction cylinder 7. Although not shown, it has a hydraulic pump unit that sends high-pressure hydraulic pressure to the reduction cylinder 7 to generate pressure.

[0020] When pressure is applied by the reduction cylinder 7, the upper roll 1 and the lower roll 2 come into contact with each other. In order to press the electrode plate 20 to the desired thickness and send it out to the exit side of the roll press machine, an inter-bearing reduction device 1000 is placed between the upper bearing housing 3 and the lower bearing housing 4 to maintain a constant gap between the upper and lower rolls 1 and 2. The inter-bearing reduction device 1000 is composed of an inter-bearing cylinder 6 and a pressure booster 100, and the oil chamber 62 of the inter-bearing cylinder 6 is connected to the pressure booster 100 by piping. The inter-bearing cylinder 6 is composed of a piston 61 that pushes up the upper bearing housing 3 and an oil chamber 62 that applies a pressing force to the piston 61. In Figure 1, the inter-bearing cylinder 6 is shown attached to the top of the lower bearing housing 4, but it may also be attached to the bottom of the upper bearing housing 3.

[0021] FIG. 2 is a diagram illustrating the structure and operation of the booster device 100.

[0022] The booster device 100 is composed of a mechanical unit 104 incorporating a booster cylinder 102 and a ball screw 101, and an AC servo motor 103. The booster cylinder 102 is composed of an oil chamber 1022 connected to the oil chamber 62 of the inter-bearing cylinder 6, a piston 1021 that applies pressure to the oil chamber 1022, and a seal 1023 that contains the high-pressure oil. The mechanical unit 104 is composed of a ball screw 101 that converts rotational force into axial movement force, and a bearing 105 that supports the ball screw 101.

[0023] The operation of the boost device 100 will now be described. When the AC servo motor 103 rotates in response to a signal from a computing device (not shown), the torque is transmitted to the ball screw 101 via the pulley 106 and timing belt 107. When the ball screw 101, supported by the bearing 105, rotates due to the torque from the pulley 107, the shaft of the ball screw 101 moves back and forth. The movement of the shaft of the ball screw 101 moves the piston 1021 of the boost cylinder 102, which is connected to the shaft of the ball screw 101, and changes the volume of the oil chamber 1022. The change in volume of the oil chamber 1022 sends oil from the oil chamber 1022 to the oil chamber 62 of the inter-bearing cylinder 6. Alternatively, oil returns from the oil chamber 62 of the inter-bearing cylinder 6 to the oil chamber 1022 of the boost cylinder 102. The cross-sectional area ratio of the oil chamber 62 in the inter-bearing cylinder 6 to the oil chamber 1022 in the boost cylinder 102 is about 10:1, so even if the piston 1021 of the boost cylinder 102 is moved by 10 microns, the movement of the piston 61 in the inter-bearing cylinder 6 is only 1 micron. The rotation of the AC servo motor 103 can control the gap between the upper and lower rolls 1 and 2 in 1 micron increments.

[0024] FIG. 3 is a diagram explaining the function of the work roll bender of a four-height rolling mill.

[0025] The work roll bender installed in the work roll bearing housing of a rolling mill controls the force of the cylinder to control the deflection of the work roll. The inter-bearing cylinder 6 of this invention controls the position of the upper roll 1 to maintain the gap between the upper and lower rolls 1 and 2, and the functions of the two are different.

[0026] FIG. 4 is a diagram showing the electrode plate 20 being pressed by a roll press machine.

[0027] 4(a) shows an electrode plate 20 in which an active material 201 that retains electrons is continuously applied to the top and bottom surfaces of a conductive metal foil 202. In lithium-ion batteries, the metal foil 202 is often made of aluminum foil with a thickness of 10 to 20 microns for the positive electrode, while copper foil or the like that is even thinner than 10 microns is often used for the negative electrode. 1(b) shows an electrode plate 20 in which active material 201 is discontinuously coated in islands on the surface of a metal foil. The thickness of the active material 201, including the metal foil 202, before pressing is 200 to 500 microns, and after pressing, the thickness is reduced to 100 to 300 microns. Figure (c) shows the cross section of part AA in (b). It can be seen that there is a large difference in thickness in the pressing direction. The active material 201 is coated with uncoated areas of approximately 30 to 50 mm arranged before and after the coated area.

[0028] A method for pressing the electrode plate 20 to the desired thickness will be described using Figure 1. Oil is supplied to the pressing cylinder 7 from a hydraulic unit (not shown) to press down the upper roll 1 to a position where the upper and lower rolls 1 and 2 come into contact. A constant hydraulic force is supplied to the pressing cylinder 7 to maintain the state in which the upper and lower rolls 1 and 2 are in contact. The pressing cylinder 7 is composed of a piston 71, an oil chamber 72 that presses down the piston 71 with hydraulic force, and a displacement sensor 73 that accurately measures the vertical position of the piston 71, which moves up and down with hydraulic force. The position of the piston 71 when the upper and lower rolls 1 and 2 are in contact is detected by the displacement sensor 73 and stored in a computing device (not shown).

[0029] Next, the AC servo motor 103 of the pressure boosting device 100 is rotated, and the rotational force is converted into axial movement force by the ball screw 101, moving the piston 1021 of the pressure boosting cylinder 102 and sending oil from the pressure boosting cylinder oil chamber 1022 to the oil chamber 62 of the inter-bearing cylinder 6. The oil sent to the inter-bearing cylinder oil chamber 62 causes the piston 61 of the inter-bearing cylinder to rise and contact the upper bearing housing 3. When the AC servo motor 103 is further rotated, the pushing force of the piston 61 of the inter-bearing cylinder exceeds the pushing force of the compression cylinder 7, pushing back the oil in the oil chamber 72 of the compression cylinder, and the upper bearing housing 3 begins to move upward. The upper bearing housing 3 starting to move from a stationary position marks a transition point where the upper and lower rolls 1, 2 transition from a contact state to a gap state. This transition point of the upper bearing housing 3 is stored in the calculation device as the rotation angle position of the AC servo motor 103. This position serves as the reference point for controlling the thickness of the electrode plate 20.

[0030] A calculation device or the like indicates the position of the upper roll 1 where the thickness of the electrode plate 20 at the exit side of the roll press machine becomes the target thickness, and calculates the additional oil amount required for the oil chamber 62 of the inter-bearing cylinder 6. In accordance with the calculation result, the AC servo motor 103 rotates to the required rotation angle, and the piston 1021 connected to the ball screw 101 moves accurately in the axial direction according to the feed pitch of the ball screw 101.

[0031] As the piston 1021 moves, high-pressure oil is sent from the boost cylinder oil chamber 1022 to the oil chamber 62 of the inter-bearing cylinder 6. The oil sent from the oil chamber 62 pushes up the piston 61 of the inter-bearing cylinder 6, and the upper roll 1 is pushed up from the zero gap position where the upper and lower rolls 1 and 2 are in contact with each other, and the gap between the upper and lower rolls 1 and 2 changes.

[0032] At the same time, the piston 71 of the compression cylinder 7 is also pushed up, and some of the oil in the oil chamber 72 is returned to the hydraulic unit. The change in position of the piston 71 is constantly detected by the displacement sensor 73. The displacement sensor 73 confirms that the desired gap has been created between the upper and lower rolls 1 and 2, and the pressing operation begins. If the thickness of the electrode plate 20 becomes thicker than the desired thickness, the AC servo motor 103 is rotated in the opposite direction, returning oil from the inter-bearing cylinder oil chamber 62 to the boost cylinder oil chamber 1022, pushing down the upper roll 1 and narrowing the gap between the upper and lower rolls 1 and 2.

[0033] To prevent the set gap between the upper and lower rolls 1 and 2 from changing even when the electrode plate 20 is pressed, the pressing cylinder 7 must apply a pressing force that overcomes the press reaction force generated by pressing the electrode plate 20. The position of the piston 61 of the pressure boost cylinder 102 is also maintained and controlled by the rotational force of the AC servo motor 103 so that the piston 61 is not pushed down by the pressing force of the pressing cylinder 7.

[0034] A thickness gauge is placed to measure the thickness of the electrode plate 20 as it is continuously pressed and moves to the exit side of the roll press. The thickness gauge is not shown in Figure 1. By measuring the thickness of the electrode plate 20 at the exit side of the roll press, it is possible to confirm whether the gap between the upper and lower rolls 1 and 2 is appropriate. If the thickness of the electrode plate 20 does not meet the desired accuracy, the necessary correction amount is calculated from the thickness error, and the AC servo motor 103 is rotated by the calculated rotation angle to correct the thickness of the electrode plate 20. The displacement sensor 73 of the pressing cylinder 7 also simultaneously confirms that the upper roll 1 has moved to the desired position.

[0035] In the present invention, an inter-bearing cylinder 6 is arranged between the upper and lower bearing housings 3, 4, and the arranged inter-bearing cylinder 6 has a piston 61 and an oil chamber 62, and is equipped with a boost cylinder 102 that changes the amount of oil in the oil chamber 62 that pushes out the piston 61. By changing the amount of oil in the oil chamber 62, the pressure applied by the press-down cylinder 7 can be overcome and the upper roll 1 supported by the upper bearing housing 3 can be pushed up or down, changing the gap between the upper and lower rolls 1, 2.

[0036] A boost cylinder 102 is provided to precisely control the amount of oil in the inter-bearing cylinder oil chamber 62, and the oil chamber 62 of the inter-bearing cylinder 6 and the oil chamber 1022 of the boost cylinder 102 are connected. The position of the piston 1021 of the boost cylinder 102 is moved by a ball screw 101 and an AC servo motor 103 to change the amount of oil in the boost cylinder oil chamber 1022, and by changing the position of the piston 61 of the inter-bearing cylinder 6, the gap between the rolls is controlled with high precision.

[0037] In the gap between the upper and lower rolls 1 and 2, a position sensor 73 is disposed on the piston 71 that moves up and down of the pressing cylinder 7 to detect the position of the piston in the up and down direction, and the position of the upper roll 1 that moves up and down by the pressing cylinder 7 is detected.

[0038] In the above explanation, the rolling down cylinder 7 is arranged between the upper bearing housing 3 and the housing 5, but this arrangement is not limited to this, and the same applies if the rolling down cylinder 7 is arranged between the lower bearing housing 4 and the housing 5.

[0039] FIG. 5 is a diagram showing an example of the force relationship inside the roll press machine.

[0040] The force relationships within the roll press machine will be explained using Figure 5. Considering the housing 5, there is a force F2 that presses the electrode plate 20 between the upper and lower rolls, a force F3 that tries to maintain the position of the piston 61 in the inter-bearing cylinder 6, and a force F1 that the housing 5 supports via the pressing cylinder 7.

[0041] The relationship between F1, F2, and F3 can be explained by F1=F3+F2 / 2···Equation 1. In order to press the inter-bearing cylinder 6 with a constant pressing force and prevent a gap from occurring between the inter-bearing cylinder 6 and the upper bearing housing 3, the total pressure force 2×F1 of the two pressing cylinders 7 must always be greater than the force F2 pressing against the electrode plate 20. The force F3 supported by the inter-bearing cylinder 6 can be found from the hydraulic pressure in the oil chamber 62 and the area of ​​the piston 61. Since equation 1 can always be used, if the force of the F1 pressing cylinder 7 is found using a load cell or the like, the pressing force F2 generated between the rolls can be found.

[0042] FIG. 6 is a diagram showing an example in which the booster device 100 is incorporated into the lower bearing housing 4. As shown in FIG.

[0043] FIG. 6 shows an example in which the booster device 100 is incorporated into the lower bearing housing 4 where the inter-bearing cylinder 6 is located, in order to make the roll press machine more compact. By incorporating the booster cylinder 102 of the booster device 100 into the lower bearing housing 4 and integrating the ball screw 101 and AC servo motor 103 and attaching them to the outer surface of the lower bearing housing 4, piping and the like are no longer necessary, making it possible to make the device more compact. Because the large roll bearing 8 is located in the center of the lower bearing housing 4, the inter-bearing cylinder 6 and booster cylinder 102 must be located in positions that do not interfere with the roll bearing, which places a limit on their size. The booster device 100 is not limited to being incorporated into the lower bearing housing 4, and it is preferable to place it near the inter-bearing cylinder 6.

[0044] FIG. 7 is a diagram illustrating a problem that occurs when a discontinuously coated electrode plate 20 is pressed using a conventional press.

[0045] As shown in Figure 4(c), the discontinuously coated electrode plate 20 has a coating thickness of 200 to 500 microns, while the uncoated portion is made of metal foil 202 with a thickness of approximately 10 microns. Despite this large thickness difference, the electrode plate 20 is sandwiched between the upper and lower rolls 1 and 2, pressed, and moved to the exit side. As shown in Figure 5, in a conventional roll press, when the electrode plate 20 is sandwiched between the upper and lower rolls 1 and 2 and pressure is applied by the pressure cylinder 7, the housing 5 stretches due to the applied pressure. When the coated portion 201 passes between the upper and lower rolls 1 and 2, the metal foil 202, which is 10 to 20 microns thick, is pressed, reducing the applied pressure between the upper and lower rolls 1 and 2, eliminating the stretching of the housing 5. The gap between the upper and lower rolls 1 and 2 suddenly disappears, causing contact between the upper and lower rolls 1 and 2, generating vibration and impact noise. When pressing the discontinuously coated electrode plate 20 using the conventional pressure method using the hydraulic pressure cylinder 7 shown in Figure 5, it was necessary to press at a slower speed because increasing the press speed increases the impact value generated between the rolls due to fluctuations in the pressing force.

[0046] FIG. 8 is a diagram illustrating the effect of the arrangement of the inter-bearing cylinder 6 when pressing the discontinuously coated electrode plate 20. In FIG.

[0047] By placing the inter-bearing cylinder 6, even if the pressure force F2 generated between the upper and lower rolls 1 and 2 becomes zero (F1 = F3 + F2 / 2...), the inter-bearing cylinder 6 still receives the pressure force F1 from the reduction cylinder 7, as explained in Equation 1 and Figure 3. The inter-bearing cylinder 6 also contains an oil chamber 62. When pressing materials with significantly different thicknesses, maintaining a constant oil volume in the inter-bearing cylinder oil chamber 62 across the gap between the upper and lower rolls 1 and 2 allows the oil chamber 62 to absorb sudden changes in the pressure force between the upper and lower rolls 1 and 2, like a fluctuating hydraulic damper. This eliminates collisions between the upper and lower rolls 1 and 2 due to expansion and contraction of the housing 5. This allows the press to be performed at a speed similar to that of the continuously coated electrode plate 20. This increases the productivity of the press process for discontinuously coated electrode plates 20. Furthermore, the significant reduction in impact force significantly reduces damage to equipment.

[0048] By maintaining a constant amount of oil in the oil chamber 62 of the inter-bearing cylinder 6 in the gap between the upper and lower rolls 1, 2, the electrode plate 20 to be pressed has a coated portion thickness of 200 to 500 microns and an uncoated portion thickness of 10 to 20 microns, and the discontinuously coated electrode plate 20 can be pressed so that the coated portion thickness after pressing is 100 to 300 microns. A roll press equipped with an inter-bearing reduction device 1000 is effective for pressing, at high speed, an electrode plate 20 having coated portions 201 arranged discontinuously in the longitudinal direction.

[0049] In the future, it is expected that the production of all-solid-state batteries, which are used in lithium-ion batteries and EVs, will increase. In the manufacturing process of all-solid-state batteries, it is expected that a positive electrode, solid separator, and negative electrode will be stacked and pressed using a roll press. The electrode plate 20 of all-solid-state batteries will be thicker than that of current lithium-ion batteries, and issues may become even more apparent when pressing the discontinuously coated electrode plate 20 shown in Figure 4(b). By using the inter-bearing press-down device 1000 of the present invention, which is equipped with an inter-bearing cylinder 6, it is possible to press the discontinuously coated electrode plate 20, which has a large thickness difference, at high speed while applying a high pressure between the upper and lower rolls 1 and 2. [Explanation of symbols]

[0050] 1000...Inter-bearing screw-down device, 100...Boost device, 1...Upper roll, 2...Lower roll, 3...Upper bearing housing, 4...Lower bearing housing, 5...Housing, 6...Inter-bearing cylinder, 61...Piston, 62...Oil chamber, 7...Screw-down cylinder, 71...Piston, 72...Oil chamber, 73...Displacement sensor, 8...Roll bearing, 101...Ball screw, 102...Boost cylinder, 1021...Piston, 1022...Oil chamber, 103...AC servo motor, 104...Mechanism, 105...Bearing, 106...Pulley, 107...Timing belt, 20...Electrode plate, 201...Active material (coated portion), 202...Metal foil (uncoated portion).

Claims

1. A roll press machine has two upper and lower rolls that press a material, bearing housings that support the rolls, and a pressure cylinder that applies a force to the rolls to press the material, an inter-bearing cylinder is disposed between the bearing housings, the inter-bearing cylinder has a piston and an oil chamber, and is equipped with a mechanism for changing the amount of oil in the oil chamber that pushes out the piston; A roll press machine equipped with an inter-bearing screw-down device that changes the gap between the rolls supported by the bearing housings by changing the amount of oil in the oil chamber to overcome the pressure force of the screw-down cylinder.

2. In the roll press equipped with the inter-bearing reduction device according to claim 1, a pressure booster cylinder disposed to control the amount of oil in an inter-bearing cylinder oil chamber; the pressure booster cylinder oil chamber is connected to the pressure booster cylinder oil chamber; the position of the piston of the pressure booster cylinder is moved by a screw and an electric servo motor to change the amount of oil in the pressure booster cylinder oil chamber, and the gap between the rolls is controlled by changing the position of the piston of the inter-bearing cylinder.

3. In the roll press equipped with the inter-bearing reduction device according to claim 1, A roll press machine equipped with an inter-bearing reduction device that can press a continuously or discontinuously coated electrode plate having a coated portion thickness of 200 microns to 500 microns and an uncoated portion thickness of 10 microns to 20 microns, by maintaining the gap between the rolls and the amount of oil in the inter-bearing cylinder oil chamber constant, so that the coated portion thickness of the pressed electrode plate is 100 microns to 300 microns after pressing.

4. In the roll press equipped with the inter-bearing reduction device according to claim 1, A roll press machine equipped with an inter-bearing screw-down device that has the function of detecting the roll position moving up and down by the inter-bearing cylinder, by arranging a position sensor to detect the up and down position of the piston on the piston that moves up and down in the screw-down cylinder.

5. A roll press machine has two upper and lower rolls that press a material, bearing housings that support the rolls, and a pressure cylinder that applies a force to the rolls to press the material, an inter-bearing cylinder is disposed between the bearing housings, the inter-bearing cylinder has a piston and an oil chamber, and is equipped with a mechanism for changing the amount of oil in the oil chamber that pushes out the piston; A roll press machine equipped with a roll reduction control device that changes the amount of oil in the oil chamber to overcome the pressure force of the reduction cylinder and change the gap between the rolls supported by the bearing housing.

Images