Roll reduction device and roll reduction method for roll press machine

Abstract

To provide a roll reduction device for a roll press machine suitable for energy-saving production, which does not use a hydraulic pump or tank to generate high pressure in order to press an electrode sheet between two rolls with high pressure. [Solution] The roll reduction device that pressurizes the electrode sheet connects the head-side oil chamber of the reduction cylinder with the head-side oil chamber of cylinder A and the head-side oil chamber of cylinder B with piping, and raises and lowers the reduction cylinder piston within the desired range. The roll reduction device can operate and control the movement of the reduction cylinder piston by switching between cylinder A and cylinder B to supply the hydraulic force required by the reduction cylinder without using a hydraulic pump or tank.

Description

[Technical Field]

[0001] The present invention relates to a roll reduction device used in a roll press machine that pressurizes materials such as lithium ion batteries, and which combines two means, a cylinder and an electric motor, without using a hydraulic pump or tank. [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 material is sandwiched between the rolls, and a pressure booster cylinder is provided between a reduction cylinder that controls the gap between the rolls to a desired dimension, and a hydraulic pressure generator that supplies oil to the reduction cylinder. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 6-031326 [Patent Document 2] Patent No. 5959777 Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, the spread of electric vehicles has led to the mass production of lithium-ion batteries. The goal of vehicle electrification is to reduce carbon dioxide emissions by switching from fossil fuels to electrical energy. However, the increase in carbon dioxide emissions during the lithium-ion battery manufacturing process has become a problem, leading the EU to institutionalize the disclosure of carbon dioxide emissions during the battery manufacturing process. In the field of roll presses, which continuously press new materials such as battery electrode sheets with rolls, the use of hydraulic pressure reduction devices has increased to improve the thickness accuracy of the pressed electrode sheets. However, the introduction of hydraulic pressure reduction devices requires a hydraulic servo control valve capable of injecting and emitting 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 power to control roll position increases the motor's rotational speed to generate high torque, requiring mechanical means such as gears to slow the rotational speed. The use of excessive mechanical means increases mechanical backlash, resulting in issues with reduced thickness accuracy in the product. There is a strong demand for equipment that can simultaneously achieve two needs: reducing energy consumption and ensuring precision in electrode sheet thickness in the roll press process required in the battery manufacturing process.

[0006] Among electrode sheets, sulfide-based materials with high lithium ion conductivity are often used, particularly as materials for the solid electrolyte layer. Sulfide-based materials generate dangerous hydrogen sulfide when they react with moisture in the air. For this reason, equipment used to process sulfide-based materials must be installed in a space isolated from the atmosphere called a glove box. When placing a roll press machine inside a glove box, it is recommended that pump units, etc., whose hydraulic oil comes into contact with the atmosphere, not be brought inside the glove box.

[0007] The use of the means described in Patent Document 1 is a system suitable for rolling mills that perform metal rolling operations at high speeds and high pressures. The pressure reduction cylinder incorporated into the hydraulic pressure 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, a pump and tank are required to deliver high-pressure oil that constantly operates the hydraulic servo control valve.

[0008] Patent Document 2 describes a roll reduction device that uses the means to place a boost cylinder between the reduction cylinder and the pump unit, and that allows the piston position of the boost cylinder to be moved back and forth by the rotational force of a motor via a screw shaft, thereby enabling minute adjustment of the roll position. It also describes connecting an accumulator to the rod side of the boost cylinder, and adding hydraulic force to the rod side in addition to the piston thrust from the screw. However, it requires the placement of a pressure oil pump and tank near the roll press machine to supply pressurized oil.

[0009] Therefore, an object of the present invention is to provide a roll reduction device for a roll press machine that is suitable for energy-saving production and does not require a hydraulic pump or tank to generate high pressure in order to press an electrode sheet between two rolls with a high pressure. [Means for solving the problem]

[0010] Specifically, the roll reduction device for a roll press machine of the present invention is a reduction cylinder for hydraulically raising and lowering a piston to press an electrode sheet sandwiched between rolls, the reduction cylinder being divided into a head-side oil chamber and a rod-side oil chamber by the piston, an A cylinder connected to the head-side oil chamber of the reduction cylinder, and a B cylinder divided into a connection side to the head-side oil chamber and a connection side to the rod-side oil chamber of the reduction cylinder, and is characterized in that the connection between the head-side oil chamber of the A cylinder, which raises and lowers the electrode sheet within a range that can be pressed, and the B cylinder, which raises and lowers the electrode sheet within a wider range than the A cylinder, can be switched depending on the movement range of the piston of the reduction cylinder.

[0011] The present invention is characterized in that, in the above-described roll reduction device for a roll press machine, the A cylinder has an A piston for forming an A head-side oil chamber connected to the head-side oil chamber by piping, and the movement of the A piston is controlled by a control drive motor that drives a screw engaging body connected to the A piston.

[0012] The present invention is characterized in that, in the above-described roll reduction device for a roll press, the B cylinder has a B piston that separates a B head-side oil chamber that is connected to the head-side oil chamber by a pipe, and a B rod-side oil chamber that is connected to the rod-side oil chamber by a pipe via an accumulator, and a worm jack connected to the B piston is rotationally driven by an electric motor, and when the reduction cylinder is raised and lowered by movement of the B piston, the amount of change in volume of the rod-side oil chamber and the amount of change in volume of the B rod-side oil chamber are corrected by the accumulator.

[0013] The present invention is characterized in that, in the roll reduction device for a roll press machine described above, the A cylinder and the B cylinder are connected to the head-side oil chamber via a shutoff valve, and when the piston moves to a target position, the B cylinder is shut off by the shutoff valve, thereby allowing the piston of the reduction cylinder to be raised and lowered by hydraulic pressure from the A cylinder and the B cylinder without using a hydraulic pump and a tank.

[0014] Specifically, the roll reduction method for a roll press machine of the present invention is characterized in that a head-side oil chamber and a rod-side oil chamber separated by a piston are formed in a reduction cylinder that hydraulically raises and lowers a piston to press an electrode sheet sandwiched between rolls, an A cylinder is connected to the head-side oil chamber of the reduction cylinder, and a B cylinder is connected separately to one side connected to the head-side oil chamber and the other side connected to the rod-side oil chamber of the reduction cylinder, and the connection between the A cylinder, which raises and lowers the electrode sheet within a range that can be pressed, and the B cylinder, which raises and lowers the electrode sheet within a wider range than the A cylinder, and the head-side oil chamber is switched depending on the movement range of the piston of the reduction cylinder. [Effects of the Invention]

[0015] By using this device in the roll press process for manufacturing electrode sheets, a hydraulic pump and tank that generate high-pressure hydraulic pressure to apply pressure to the rolls are no longer necessary. The pressure is applied to the rolls using the rotational force of an electric motor, which pushes up the piston of the pressure cylinder, reducing energy consumption. This also leads to reduced carbon dioxide emissions. Furthermore, in the case of a roll press machine used inside a glove box, there is no need to install a hydraulic pump inside the glove box, eliminating the risk of the hydraulic oil in the tank coming into contact with the atmosphere. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a diagram showing an overall outline of a roll reduction device for a roll press machine according to the present invention. [Figure 2] FIG. 2 is a diagram showing a control circuit of a roll reduction device for a roll press machine. DETAILED DESCRIPTION OF THE INVENTION

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

[0018] FIG. 1 shows an overall outline of a roll reduction device for a roll press according to the present invention.

[0019] An electrode sheet 500 or electrode plate (collectively referred to as electrode sheet in this specification) that constitutes the power storage portion of a lithium-ion battery is sandwiched between upper and lower rolls 202, the upper roll is fixed, and the lower roll is pushed up to compress the electrode sheet 500 to the desired thickness. Alternatively, the lower roll may be fixed and the upper roll pushed down. A roll press machine 200 is often used in the pressing process that compresses this electrode sheet 500. The roll press machine 200 is used in the manufacturing process of electrode sheets 500 for lithium-ion batteries, which are a typical material to be compressed, and is also used in the compression and pressing processes of materials other than batteries.

[0020] The roll press machine 200 sandwiches the electrode sheet 500 between two upper and lower rolls 202 that rotate in one direction, and the coil-shaped electrode sheet 500 is generally fed from an unwinding device 205, pressed and compressed by the rotating upper and lower rolls 202, and then wound into a coil by a winding device 206.

[0021] In order to apply a pressure to the electrode sheet 500 with one of the rolls 202, a pressure cylinder 201 is arranged below or above the roll 202. It is composed of a load cell 203 that measures the pressure from the pressure cylinder 201, and a housing 204 that holds the pressure. In FIG. 1, the pressure cylinder 201 arranged below the roll 202 has a mechanism that allows a piston 2011 to move up and down using hydraulic force, and is able to apply a pressure to the roll 202. Inside the pressure cylinder 201 is a displacement meter 2014 that constantly and accurately measures the vertical position of the piston 2011.

[0022] The compression cylinder 201 is divided into a head-side oil chamber 2012 and a rod-side oil chamber 2013 by a piston 2011. The hydraulic pressure in the head-side oil chamber 2012 becomes the force that moves the piston 2011 in the upward direction, that is, the roll pressure force. The rod-side oil chamber 2013 also has a certain pressure, and the forces of the rod-side oil chamber 2013 and the head-side oil chamber 2012 in the compression cylinder 201 balance each other via the piston 2011, so that the rolls 202 can always maintain a constant position even when there is no load between them.

[0023] The compression cylinder 201 is connected to the A cylinder 100 via piping 209. The A cylinder 100 is composed of a cylinder section 101, a drive body 102, and a control drive motor 103 that provides rotational force to the drive body 102. The cylinder section 101 has a head-side oil chamber 1012 that is pressurized by a piston 1011, and the drive body 102 is composed of an outer case 1024 that connects to the cylinder section 101, a ball screw 1021 that converts the rotational force of the control drive motor 103 into linear motion, a rotating box 1022 that supports the ball screw 1021, and a bearing 1023 that fixes the rotating box 1022 in the axial direction while maintaining rotation. The rotational torque of the control drive motor 103 is transmitted to the nut portion of the ball screw 1021 via a timing belt 104 or the like, and is converted into axial force on the screw shaft of the ball screw 1021 by the action of the threads of the thread engagement body. The tip of the screw shaft of the ball screw 1021 is connected to the rod shaft of the piston 1011. The piston 1011 is configured to move in the axial direction via the ball screw 1021 as the control drive motor 103 rotates.

[0024] The piston 1011 of the A cylinder, which supplies high hydraulic pressure to the head-side oil chamber 2012 of the compression cylinder 201, has a narrow diameter and is designed to easily generate high hydraulic pressure. For example, if the piston diameter of the piston 1011 of the A cylinder 100 is 40 mm, the area of ​​the piston 1011 is 12.56 cm 2 If the piston 1011 is pressed with a force of 2 tons, the internal pressure of the head-side oil chamber 1012 will rise to 16 MPa. This high hydraulic pressure acts on the area of ​​the head-side oil chamber 2012 of the compression cylinder piston 2011 according to Pascal's principle, generating a high pressure force. This pressure force can press the electrode sheet 500 to the desired thickness.

[0025] If the piston 1011 of the A cylinder 100 has a piston diameter of 40 mm and moves 1 mm, the discharge volume from the head-side oil chamber 1012 will be 1.26 cc. If the piston 2011 of the compression cylinder 201 has a diameter of 250 mm, when a discharge volume of 1.26 cc is pressed, the piston 2011 will only rise 0.0256 mm, or 25.6 microns. However, since the thickness change is small during the process of continuously pressing the electrode sheet 500, a movement range of 25 microns makes it possible to control the thickness of the continuously compressed electrode sheet 500. If the stroke of the A cylinder 100 is 100 mm, the piston 2011 of the compression cylinder 201 can be raised and lowered 2.56 mm. This allows for a wide range of electrode sheet 500 thicknesses to be accommodated.

[0026] For example, in the case of a compression cylinder 201 with a piston 2011 diameter of 250 mm, a compression force of 10.2 MPa is required to generate a compression force of 50 tons. The hydraulic pressure in the head-side oil chamber 1012 of cylinder A is 10.2 MPa, the same as the head-side oil chamber 2012 of the compression cylinder 201, but because the piston diameter is 40 mm, the required compression force of the piston 1011 is 1.28 tons. The control drive motor 103 must generate a rotational torque in the drive body 102 such that the compression force of the ball screw 1021 is 1.28 tons. The compression force required by the piston 1011 is smaller than the compression force required by the compression cylinder 201. If a compression force of 50 tons is to be generated with one compression cylinder 201, under the conditions described above, this can be achieved by using a single 0.2 kW AC servo motor with a reducer as the control drive motor 103. The roll press machine 200 has two pressing cylinders 201, so the pressure between the rolls 202 is 100 tons. A roll press machine 200 with a pressure of 100 tons can press an electrode sheet 500 with a width of 500 mm with a linear pressure of 2 tons / cm.

[0027] Although the A cylinder 100 has a narrow lifting range of about 2 to 3 mm for the reduction cylinder 201, this is sufficient for the pressing process from the unwinding device 205 to the winding device 206. However, after pressing one coil is completed, a wider roll gap must be created in order to thread a new electrode sheet 500 from the entry side to the exit side. When replacing the roll 202 with a new roll 202, the piston 2011 of the reduction cylinder 201 must be lowered another 10 mm or so in order to pull it out of the housing 204. In this case, the B cylinder 300 is required.

[0028] To significantly lower the piston 2011 of the compression cylinder 201, it is necessary to move the oil in the head-side oil chamber 2012 to another location. A suitable location for this is the head-side oil chamber 3012 of cylinder B 300, which is connected to the head-side oil chamber 2012 by piping 209. If the diameter of piston 2011 of compression cylinder 201 is 250 mm and the lift range of piston 2011 is 10 mm, the volume of head-side oil chamber 2012 is 490 cc, and if the diameter of head-side oil chamber 3012 of cylinder B 300 is 80 mm and the stroke is 98 mm, 490 cc of oil can be moved to head-side oil chamber 3012.

[0029] The cylinder portion 301 constituting the B cylinder 300 is divided by the piston 3011 into a head-side oil chamber 3012 and a rod-side oil chamber 3013. As the piston 3011 moves left and right as shown in the figure, the amount of oil in each of the head-side oil chamber 3012 and the rod-side oil chamber 3013 changes. The piston 3011 is connected to the tip of a screw 3021 of a worm jack 302. The worm jack 302 has a nut 3022 that meshes with the screw 3021, and the nut 3022 has a thread engaging member that engages with the thread groove. The rotational force of an electric motor 303 connected to the worm jack 302 is reduced by a worm gear 3023 of the worm jack 302, causing the nut 3022 to rotate. The device is not limited to the worm jack 302, and a device having a structure that can push and pull the piston 3011 of the B cylinder 300 back and forth via the thread engaging member using the rotational force of the electric motor 303 may be provided.

[0030] To move the piston 3011 of the B cylinder 300 by 98 mm, the electric motor 303 of the worm jack 302 connected to the piston 3011 is rotated, and the piston 3011 can be moved 98 mm to the right as shown in the figure. Conversely, to raise the piston 2011 of the compression cylinder 201, the piston 3011 of the B cylinder 300 is pushed to the left as shown in the figure, and the oil in the head-side oil chamber 3012 is returned to the head-side oil chamber 2012 of the compression cylinder 201, thereby pushing up the piston 2011. Using the B cylinder to raise and lower the piston 2011 of the compression cylinder 201 over a wide range is effective when the electrode sheet 500 is not pressurized. If a large pressure force is required between the rolls 202, the cross-sectional area of ​​the oil chamber of the B cylinder 300 is larger than that of the A cylinder 100, so a high-output worm jack 302 is required, which would result in a large device and is not practical.

[0031] A shutoff valve 208 is provided to switch between the A cylinder 100 and the B cylinder 300 depending on the range of movement of the piston 2011 of the compression cylinder 201. As described above, by selectively using the circuits that send oil from the head-side oil chamber 2012 of the compression cylinder 201 to the A cylinder 100 and the B cylinder 300, it is possible to adequately control the elevation position of the roll 202 and the pressure force without using a hydraulic pump.

[0032] Since the compression cylinder 201 requires a stroke of at least 10 mm, the oil volume in the compression cylinder rod-side oil chamber 2013 changes depending on the position of the piston 2011. For example, suppose the diameter of the piston 2011 of the compression cylinder 201 is 250 mm and the diameter on the rod side is 170 mm. When the piston 2011 has an elevation stroke of 10 mm from the lower limit to the upper limit, the amount of change in the oil volume in the rod-side oil chamber 2013 of the compression cylinder 201 is 264 cc.

[0033] When the piston 2011 of the compression cylinder 201 rises 10 mm, oil is sent from the head-side oil chamber 3012 of the B cylinder 300 to the head-side oil chamber 2012. When the piston 3011 moves 98 mm to the left in the illustration, the oil volume in the head-side oil chamber 3012 decreases, and conversely, the oil volume in the rod-side oil chamber 3013 increases. The rod-side oil chamber 2013 of the compression cylinder 201 and the rod-side oil chamber 3013 of the B cylinder 300 are connected by piping, and the change in oil volume of 264 cc released from the rod-side oil chamber 2013 of the compression cylinder 201 is moved to the rod-side oil chamber 3013. By connecting the rod-side oil chamber 2013 of the compression cylinder 201 and the rod-side oil chamber 3013 of the B cylinder 300 by piping, the change in oil volume in the rod-side oil chamber 2013 of the compression cylinder 201 can be accumulated.

[0034] When the compression cylinder piston 2011 strokes up and down, it is desirable that the volume change of the compression cylinder rod-side oil chamber 2013 and the volume change of the rod-side oil chamber 3013 of the B cylinder 300, which are connected by a pipe, be the same or similar. However, when the components that make up the B cylinder 300 are standardized, it is difficult to make the volume changes the same. To compensate for the difference in volume change between the compression cylinder rod-side oil chamber 2013 and the rod-side oil chamber 3013 of the B cylinder 300, the rod-side oil chamber 2013 of the compression cylinder piston 2011 and the rod-side oil chamber 3013 of the B cylinder 300 are connected by a pipe via an accumulator 207. The difference in volume change between the two rod-side oil chambers can be compensated for by releasing or accumulating oil stored in the accumulator 207, allowing for smooth oil flow between the two rod-side oil chambers. The pressure change in the rod side oil chamber 2013 of the compression cylinder 201 can also be reduced.

[0035] When the worm jack 302 connected to the piston 3011 of the B cylinder 300 is rotationally driven by the electric motor 303, and the movement of the piston 3011 of the B cylinder 300 causes the piston 2011 of the compression cylinder 201 to rise and fall, the accumulator 207 corrects the amount of change in volume of the rod side oil chamber 2013 of the compression cylinder 201 so that the amount of change in volume of the rod side oil chamber 3013 of the B cylinder 300 becomes approximately the same.

[0036] In order to generate a constant hydraulic force (internal pressure) in the head side oil chamber 2012 of the compression cylinder 201, it is necessary to apply a pressing force from the rod side oil chamber 2013 to the head side oil chamber 2012 via the piston 2011 in the compression cylinder 201. The reason for this is to increase the compressibility of the piston 2011, and it is desirable to always generate an internal pressure of 2 to 3 MPa in the head side oil chamber 2012.

[0037] By utilizing the gas pressure inside the accumulator 207 cylinder, the desired hydraulic pressure can be sent from the accumulator 207 to the rod side oil chamber 2013 of the compression cylinder 201 and the rod side oil chamber 3013 of the B cylinder 300. In the compression cylinder 201, this hydraulic pressure from the accumulator 207 becomes a pressing force on the head side oil chamber 2012. In the B cylinder 300, it becomes the internal pressure of the rod side oil chamber 3013.

[0038] When the piston 2011 of the compression cylinder 201 is raised, the volume of the rod-side oil chamber 2013 of the compression cylinder 201 decreases, and oil having hydraulic pressure is pushed out from the rod-side oil chamber 2013 and supplied to the rod-side oil chamber 3013 of the B cylinder 300. The oil supplied to the rod-side oil chamber 3013 of the B cylinder 300 generates a force pushing the B cylinder piston 3011 to the left as shown in the figure. This force is added to the force from the worm jack 302 and becomes a force pushing the B cylinder 300 piston 3011 to the left.

[0039] By efficiently using the gas pressure of the accumulator 207 and the torque of the electric motor 303 driving the worm jack 302, the compression cylinder piston 2011 can be accurately moved to the desired position with minimal energy, while maintaining the compressibility of the piston 2011. After the compression cylinder piston 2011 is moved to the desired position using oil at 5 MPa or less discharged from the head-side oil chamber 3012 of the B cylinder 300, the shutoff valve 208 blocks the movement of oil between the compression cylinder 201 and the B cylinder 300. Next, the compression cylinder 201 controls the thickness of the electrode sheet 500 with micron-level precision using the A cylinder 100. The electric motor 303 of the B cylinder 300 moves the piston 2011 up and down over a wide range, and a high hydraulic pressure of 10 to 20 MPa generated by the control drive motor 103 of the A cylinder 100 can be applied to the piston 2011. The action of both cylinders makes it possible to control the pressure on the electrode sheet 500 and the position of the roll 202 without using a hydraulic pump or tank.

[0040] Assuming that the diameter of the compression cylinder piston 2011 as assumed above is 250 mm, if the diameter of piston 3011 of cylinder B 300 is 80 mm, the output of electric motor 303 required to push and pull worm jack 302 will be approximately 0.2 kW. Furthermore, in normal electrode sheet 500 production, cylinder B 300 is used to widen the gap between rolls 202 mainly when threading new electrode sheet 500, so the energy consumed by cylinder B 300 is small.

[0041] Assuming the maximum pressurizing force of the roll press machine 200 assumed above is 100 tons, continuous pressure control of the electrode sheet 500 requires the operation of the control drive motor 103 of the A cylinder 100. To operate the A cylinder 100, two control drive motors 103 of approximately 0.2 kW are used, one on the operating side and one on the drive side. In the case of thickness control using a hydraulic servo valve, which is used in many roll press machines 200, a motor of approximately 11 kW to 15 kW is used to operate the pump that sends high-pressure (21 to 25 MPa) oil to the hydraulic servo valve. When operating the roll press machine 200 continuously, the method of this invention requires significantly less energy than conventional thickness control methods using hydraulic servo valves. This is a highly energy-efficient device, and is effective in reducing carbon dioxide emissions.

[0042] The present invention has been described as being used primarily as a roll reduction device that presses the roll 202 in a roll press machine 200 that performs roll pressing work on a battery electrode sheet 500. However, it is not limited to roll pressing work, and it can also be used as a roll reduction device that generates the reduction force required for rolling when elongating a non-ferrous metal with a thin plate thickness similar to that of the electrode sheet 500.

[0043] FIG. 2 shows a control circuit for the roll reduction device of the roll press machine 200.

[0044] A control device 400 is provided to control the roll reduction device of the roll press machine 200. First, oil is sent from the B cylinder 300 to the reduction cylinder 201, and the rise of the piston 2011 is stopped before the upper and lower rolls 202 come into contact. The position of the piston 2011 is transmitted to the control device 400 by a signal from a displacement meter 2014 incorporated in the reduction cylinder 201. The shutoff valve 208 is switched from an open to a closed state by a signal from the control device 400. Oil is sent from the head-side oil chamber 1012 of the A cylinder 100 to the head-side oil chamber 2012 of the reduction cylinder 201, and the upper and lower rolls 202 come into contact with each other.

[0045] The contact between the upper and lower rolls 202 is detected by a load cell 203 and transmitted to a control device 400. The position of the piston 2011 of the pressure cylinder 201, which is in contact with the upper and lower rolls 202, is detected by a displacement meter 2014 and transmitted to the control device 400. The position of the piston, where the upper and lower rolls 202 are in contact, becomes the reference position for control.

[0046] In order to thread the electrode sheet 500 between the upper and lower rolls 202, the lower roll 202 is lowered by 2 to 3 mm from the reference position. The shutoff valve 208 is opened, and the worm jack 302 of the B cylinder 300 is moved to the right as shown in the figure, and oil is transferred from the head-side oil chamber 2012 of the compression cylinder to the head-side oil chamber 3012 of the B cylinder 300. The position of the piston 2011 is recognized by the displacement meter 2014, and when the piston 2011 has lowered to the target position, a signal from the control device 400 stops the rotation of the electric motor 303.

[0047] After the electrode sheet 500 has been passed between the upper and lower rolls 202, oil is passed from the B cylinder 300 to the reduction cylinder 201, the piston 2011 is raised, and the lower roll 202 is brought into contact with the electrode sheet 500. After contact, the shutoff valve 208 is closed, allowing oil to pass only from the A cylinder 100 to the head-side oil chamber 2012 of the reduction cylinder 201. In this state, the roll 202 is rotated, and while pressing, high-pressure oil is passed between the head-side oil chamber 1012 of the A cylinder 100 and the head-side oil chamber 2012 of the reduction cylinder 201, thereby controlling the thickness of the electrode sheet 500 so that the electrode sheet 500 has a target thickness.

[0048] To disable the B cylinder 300 without using the shutoff valve 208, it is also possible to brake the electric motor 303, immobilize the worm jack 302, and stop the movement of the B cylinder 300 piston 301.

[0049] Although the embodiments of the present invention have been described above, the present invention is not limited to these.

[0050] A roll reduction device for a roll press machine uses pressure oil to move the piston of a reduction cylinder incorporated into the housing of the roll press machine up and down, applying pressure between the rolls to press an electrode sheet. In this roll reduction device for a roll press machine, cylinder A has a piston incorporated into the cylinder section, a screw shaft connected to the piston and having a thread groove on its surface, and a screw engaging body that engages with the thread groove, and is composed of a drive body that drives the screw shaft, and a control drive motor that is connected to the drive body and controls the movement of the piston. Cylinder B is composed of a cylinder section and drive body that raises and lowers the piston of the reduction cylinder over a wide range, and the head-side oil chamber of the piston of the reduction cylinder is connected to both cylinder A and cylinder B, and oil is sent to the head-side oil chamber of the reduction cylinder by switching between cylinder A and cylinder B depending on the range of movement of the piston of the reduction cylinder.

[0051] In the roll reduction device for a roll press, the rod-side oil chamber of the piston of the reduction cylinder and the rod-side oil chamber of the B cylinder are connected by piping via an accumulator.

[0052] In the roll reduction device for the roll press machine, when the piston of the reduction cylinder moves up and down, the amount of change in the volume of the rod-side oil chamber of the reduction cylinder is the same as or close to the amount of change in the volume of the rod-side oil chamber of the B cylinder connected by piping.

[0053] In the roll reduction device for a roll press machine, the B cylinder, which is connected to the A cylinder via a shutoff valve, is composed of a piston incorporated in the cylinder portion, a screw shaft connected to the piston incorporated in the drive body and having a thread groove on its surface, and a screw engaging body that engages with the thread groove, and a drive motor that rotates and drives the screw engaging body, and the piston of the reduction cylinder moves up and down by hydraulic force generated by the control drive motor of the A cylinder and the drive motor of the B cylinder, so no hydraulic pump or tank is required. [Explanation of symbols]

[0054] 100:A cylinder 101: Cylinder section 102: Drive body 103: Control drive motor 104: Timing belt 1011: Piston 1012: Head side oil chamber 1021: Ball screw 1022: Rotating box 1023: Bearing 1024: Outer case 200: Roll press machine 201: Compression cylinder 2011: Piston 2012: Head side oil chamber 2013: Rod side oil chamber 2014: Displacement meter 202: Roll 203: Load cell 204: Housing 205: Unwinding device 206: Winding device 207: Accumulator 208:Shut-off valve 209: Piping 300: B cylinder 301: Cylinder section 3011: Piston 3012: Head side oil chamber 3013: Rod side oil chamber 302: Worm jack 3021:Screw 3022: Nut 3023: Worm gear 303: Electric motor 400: Control device 500: Electrode sheet

Claims

1. A roll press machine that sandwiches an electrode sheet between rolls that rotate in one direction and continuously applies pressure to the electrode sheet, the roll press cylinder being divided into a head-side oil chamber and a rod-side oil chamber by a piston; an A cylinder connected to the head side oil chamber of the compression cylinder; a B cylinder which is divided into a connection side of the compression cylinder to the head side oil chamber and a connection side to the rod side oil chamber, The A cylinder and the B cylinder are connected to the head-side oil chamber via a shutoff valve, and when the piston moves to a target position, the B cylinder is shut off by the shutoff valve, thereby allowing the piston of the compression cylinder to be raised and lowered by hydraulic pressure from the A cylinder and the B cylinder without using a hydraulic pump or a tank; The connection between the A cylinder, which raises and lowers the electrode sheet within a range in which it can be pressed, and the B cylinder, which raises and lowers the electrode sheet within a wider range than the A cylinder so that it can be replaced, and the head-side oil chamber is switched depending on the movement range of the piston of the pressing cylinder. A roll reduction device for a roll press machine.

2. The A cylinder has an A piston for forming an A head-side oil chamber connected to the head-side oil chamber by a pipe, and the movement of the A piston is controlled by a control drive motor that drives a screw engaging body connected to the A piston.

2. The roll reduction device for a roll press according to claim 1.

3. The B cylinder has a B piston that separates a B head-side oil chamber that is connected to the head-side oil chamber by a pipe and a B rod-side oil chamber that is connected to the rod-side oil chamber by a pipe via an accumulator, and a worm jack connected to the B piston is rotationally driven by an electric motor, and when the compression cylinder is raised and lowered by the movement of the B piston, the amount of change in volume of the rod-side oil chamber and the amount of change in volume of the B rod-side oil chamber are corrected by the accumulator.

2. The roll reduction device for a roll press according to claim 1.

4. A roll press machine has a head-side oil chamber and a rod-side oil chamber separated by a piston in a pressing cylinder of the roll press machine, which sandwiches an electrode sheet between rolls rotating in one direction and continuously applies pressure to the electrode sheet, The A cylinder is connected to the head side oil chamber of the compression cylinder, The B cylinder is connected to the head side oil chamber of the compression cylinder and the rod side oil chamber, The A cylinder and the B cylinder are connected to the head-side oil chamber via a shutoff valve, and when the piston moves to a target position, the B cylinder is shut off by the shutoff valve, thereby allowing the piston of the compression cylinder to be raised and lowered by hydraulic pressure from the A cylinder and the B cylinder without using a hydraulic pump or a tank; The connection between the head-side oil chamber and the A cylinder, which raises and lowers the electrode sheet within a range in which it can be pressed, and the B cylinder, which raises and lowers the electrode sheet within a range wider than that of the A cylinder so that the electrode sheet can be replaced, is switched according to the range of movement of the piston of the pressing cylinder. A roll reduction method for a roll press machine.

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