Tension control system of roll-to-roll facility

Abstract

The tension control system of a roll-to-roll facility related to the present embodiment may comprise: a load cell which comprises an unwinder provided to unwind a substrate, a rewinder provided to wind the substrate, and transfer rolls arranged between the unwinder and the rewinder to guide travelling of the substrate, and is provided to measure a vertical load of the travelling substrate; a friction coefficient measuring unit provided to measure a friction coefficient between the travelling substrate and the transfer rolls; a dancer roll which guides the travelling of the substrate and is provided to be movable in a direction perpendicular to the width direction of the substrate; and a tension controller provided to receive a measured value input from the load cell and a measured value input from the friction coefficient measuring unit to control operation of the dancer roll so as to control tension of the travelling substrate.

Description

Tension control system for roll-to-roll equipment

[0001] The present invention relates to a tension control system for a roll-to-roll facility, and more particularly, to a tension control system for a roll-to-roll facility for precisely adjusting the tension of a substrate by taking into account the frictional force of the substrate running on the roll-to-roll facility.

[0002] This application claims the benefit of priority to Republic of Korea Patent Application No. 10-2024-0120736, filed September 5, 2024, the entire contents of which are incorporated herein by reference.

[0003] Lithium secondary batteries are not only used as an energy source for mobile devices, but are also being used as a power source for electric vehicles (EVs) and hybrid electric vehicles (HEVs). Their use is also expanding to include auxiliary power sources through grid integration.

[0004] The manufacturing process for these lithium secondary batteries is broadly divided into three stages: the electrode process, the assembly process, and the formation process. The electrode process is further subdivided into the active material mixing process, the electrode coating process, the rolling process, and the coiling process.

[0005] Among the above electrode processes, the rolling process is a process of compressing the coated electrode to a desired thickness by passing it between two rolling rolls, i.e., an upper roll and a lower roll, in order to increase the capacity density of the electrode substrate after the coating process and to increase the adhesion between the electrode current collector and the electrode active material.

[0006] Figure 1 is a schematic diagram of a rolling facility for performing a rolling process of an electrode for a secondary battery, and Figure 2 is a drawing for explaining the breakage of a substrate when a tension cut phenomenon occurs due to a difference in tension between the front and rear ends of a conveying roll.

[0007] Referring to FIG. 1, the rolling equipment (100) may include an unwinder (110), a rewinder (120), a plurality of transfer rolls (130), and a pair of rolling rolls (140). The plurality of transfer rolls (130) are arranged between the unwinder (110) and the rewinder (120) to guide the movement of the coating electrode (10).

[0008] Referring to Fig. 2, the coated electrode (10) may include a holding portion (11) and a non-holding portion (12). Here, the holding portion (11) is a portion that includes a coating layer in which an electrode active material is coated on an electrode current collector. The non-holding portion (12) is a portion in which the coating layer does not exist.

[0009] The above-mentioned coating electrode (10) is moved roll-to-roll from an unwinder (110) to a rewinder (120) along a plurality of transfer rolls (130), and is hot-rolled through a rolling roll (140) and then wound on a rewinder (120).

[0010] When the above-mentioned coating electrode (10) is hot rolled, the heat temperature and / or rolling strength applied to the holding portion (11) and the non-holding portion (12) are different due to the difference in thickness between the holding portion (11) and the non-holding portion (12), so that there is a high possibility that a tension cut phenomenon may occur due to deformation of the coating electrode (10) during driving.

[0011] The above-mentioned tension cut phenomenon is a phenomenon in which a difference occurs between the tension of the coating electrode (10) applied to the front end of the transfer roll (130) and the tension of the coating electrode (10) applied to the rear end of the transfer roll (130) while the coating electrode (10) enters the front end of the transfer roll (130) along the travel direction and travels to the rear end of the transfer roll (130).

[0012] For example, if the tension of the coating electrode (10) applied to the front end of the transfer roll (130) is 160 N and the tension of the coating electrode (10) applied to the rear end of the transfer roll (130) is 200 N, and if the tension of the coating electrode (10) applied to the same transfer roll (130) differs between the front end and the rear end of the transfer roll (130), the coating electrode (10) may experience a tension cut phenomenon in the width direction of the electrode along the transfer roll (130).

[0013] The above tension cut phenomenon may occur mainly when the coating electrode (10) enters the transport path at a large entry angle, such as in the S-shaped curve section (the dotted box section in Fig. 1), and / or due to frictional force between the transport roll (130) and the coating electrode (10).

[0014] If a tension cut occurs in the coating electrode (10) while it is running, the coating electrode (10) may be broken in the width direction of the coating electrode (10).

[0015] When the coating electrode (10) is broken, the rolling equipment (100) must be stopped, the broken portion (13) of the coating electrode (10) must be removed, and then the coating electrode (10) must be reconnected. There was a problem that the productivity of the coating electrode (10) was reduced because the rolled coating electrode (10) could not be produced during the stoppage time of the rolling equipment (100).

[0016] Conventional rolling equipment (100) controls the tension of the coating electrode (10) by controlling the travel speed of the transfer roll (130) and the position of the dancer roll based on the vertical load value of the coating electrode (10) via a load cell. However, tension control based on the dancer roll cannot sufficiently satisfy the required precision.

[0017] The purpose of the present invention is to solve the problems of conventional secondary battery roll-to-roll equipment.

[0018] Through one embodiment of the present invention, it is intended to provide a tension control system for a roll-to-roll equipment that precisely controls the tension of a moving material by receiving feedback on the frictional force of the moving material, thereby resolving a problem caused by a tension cut phenomenon of a moving material.

[0019] Through one embodiment of the present invention, it is intended to provide a tension control system for a roll-to-roll equipment capable of measuring a coefficient of friction due to friction with a substrate while guiding the movement of the substrate through a measuring roll.

[0020] Through one embodiment of the present invention, it is intended to provide a tension control system for a roll-to-roll equipment capable of calculating a friction value (=horizontal load value) of a substrate through a friction coefficient of the substrate obtained through a measuring roll, and precisely adjusting the tension of a moving substrate based on the friction value of the substrate and the vertical load value of the substrate.

[0021] Through one embodiment of the present invention, it is intended to provide a tension control system for a roll-to-roll equipment that can prevent a tension cut phenomenon of a substrate by precisely adjusting the tension of the substrate and monitor a position where a tension cut may occur in a moving substrate.

[0022] In addition, through one embodiment of the present invention, it is intended to provide a roll-to-roll facility for manufacturing electrodes of secondary batteries as a roll-to-roll facility to which an improved tension control system is applied.

[0023] A tension control system of a roll-to-roll equipment related to the present embodiment may include an unwinder configured to unwind a substrate, a rewinder configured to wind the substrate, and transport rolls arranged between the unwinder and the rewinder to guide the movement of the substrate, and may include a load cell configured to measure a vertical load of the substrate while it is being moved, a friction coefficient measuring unit configured to measure a friction coefficient between the substrate while it is being moved and the transport roll, a dancer roll configured to guide the movement of the substrate and move in a direction perpendicular to the width direction of the substrate, and a tension controller configured to receive a measurement value of the load cell and a measurement value of the friction coefficient measuring unit and control the operation of the dancer roll to control the tension of the substrate while it is being moved.

[0024] The measurement value of the above friction coefficient measuring unit is a friction coefficient value. In addition, the measurement value of the load cell may be a vertical load value of the substrate. The tension controller may calculate a friction value of the substrate based on the friction coefficient value. The friction value of the substrate may be a horizontal load value of the substrate in the width direction of the substrate. In addition, the tension controller may calculate a tension value of the substrate using the friction value of the substrate and the vertical load value of the substrate as input values.

[0025] The above friction coefficient measuring unit may include a measuring roll having a built-in sensor, and the sensor may be arranged to measure the friction coefficient by detecting a change in the surface of the measuring roll in the width direction of the substrate due to friction between the moving substrate and the measuring roll.

[0026] The above sensor may be provided in multiple numbers and mounted on the inner wall of the measuring roll in the width direction of the above substrate.

[0027] The above measuring roll is equipped with a wireless transmitter connected to the sensor, and the wireless transmitter can wirelessly transmit the measurement value of the sensor to the tension controller.

[0028] The above sensor may be arranged to measure a vibration value occurring on the surface of the measuring roll.

[0029] The above sensor may be arranged to measure the positional displacement value of the measuring roll in the width direction of the above substrate.

[0030] The above sensor may include a strain gauge.

[0031] The above tension controller can control tension feedback in a PID (Proportional-Integral-Derivative) manner based on the measured value of the load cell and the measured value of the friction coefficient measuring unit.

[0032] The above tension controller can divide the entire travel section between the unwinder and the rewinder into multiple tension reference sections based on the measured value of the friction coefficient measuring unit, and visualize the division status.

[0033] It may include a display unit connected to the tension controller and configured to display the partition status of the plurality of tension reference sections.

[0034] The above-mentioned transport roll includes a drive roll equipped with a drive motor and a non-driven roll that guides the movement of the material while idling during operation of the drive roll, and the measuring roll may correspond to either or both of the drive roll and the non-driven roll.

[0035] The above measuring roll can be arranged between one drive roll and another drive roll adjacent thereto along the travel direction of the above described device.

[0036] The above measuring roll can be arranged between one of the driving rolls and an adjacent non-driving roll along the traveling direction of the above described device.

[0037] The tension controller may be configured to receive a measurement value of a dancer roll potentiometer mounted on the dancer roll and control the rotation speed of the drive roll. The measurement value of the dancer roll potentiometer may be a positional displacement value of the dancer roll. The tension controller may control the rotation speed of the drive roll around the dancer roll based on the positional displacement value of the dancer roll.

[0038] In order to achieve the above-described object, according to one embodiment of the present invention, there is provided a secondary battery manufacturing facility including: a load cell configured to measure a vertical load of a moving electrode substrate; a friction coefficient measuring unit configured to measure a friction coefficient between the moving electrode substrate and a conveying roll; a drive roll configured to generate tension applied to the electrode substrate for moving the electrode substrate; a dancer roll configured to adjust tension applied to the electrode substrate as a position is adjusted in a direction perpendicular to a width direction of the electrode substrate; a dancer roll potentiometer configured to detect a position of the dancer roll; and a controller configured to control the position of the dancer roll based on a measurement value of the load cell and a measurement value of the friction coefficient measuring unit, and to control the speed of the drive roll based on a measurement value of the dancer roll potentiometer.

[0039] The above secondary battery manufacturing equipment may be a rolling equipment, and may be equipment in which rolling is performed as the electrode substrate is moved between a rewinder and an unwinder. A rolling roll may be provided between the rewinder and the unwinder, and a driving roll for moving the electrode substrate and a conveying roll for guiding the movement of the electrode substrate may be provided.

[0040] The conveying rolls may be provided in multiple numbers as non-driven rolls. The driving rolls may be provided in multiple numbers, and the space between the rewinder and unwinder may be divided into multiple zones based on the driving rolls. A tension control system may be provided for each of the divided zones.

[0041] The speed of the drive roll can be controlled, and as the speed of the drive roll increases, the force pulling the electrode substrate, i.e. the tension, can increase. The speed control of the drive roll can be performed based on the detection value of the dancer roll potentiometer.

[0042] Meanwhile, as the position of the dancer roll changes, the tension applied to the electrode substrate near the dancer roll changes. That is, the tension applied to the nearby electrode substrate can be detected through a load cell, and the position of the dancer roll can be controlled to change based on the detected tension.

[0043] In this embodiment, the position control of the dancer roll can be performed based on not only the vertical sensing value, i.e., the load that presses the conveying roll in the vertical direction, but also the horizontal sensing value, i.e., the friction coefficient between the conveying roll and the electrode substrate, which is the horizontal movement applied to the conveying roll, can be utilized.

[0044] Through this, the feedback control response speed of the dancer roll can be significantly shortened. This is because, according to the present embodiment, an anti-windup technique can be applied to prevent the windup phenomenon that occurs in the integrator for feedback control. In other words, a limit can be set using the friction coefficient to prevent the integrator from continuously accumulating errors when the control signal is saturated.

[0045] The tension control system of a roll-to-roll equipment having the above configuration and structure has the following effects.

[0046] The above measuring roll can measure the coefficient of friction of the substrate due to friction with the substrate in a non-contact manner through a built-in sensor while guiding the movement of the substrate.

[0047] The above tension controller can calculate the friction value (=horizontal load value) of the substrate through the friction coefficient of the substrate obtained through the above measuring roll.

[0048] The above tension controller calculates a tension value based on the vertical load value of the substrate and the frictional force value of the substrate obtained through the load cell, and can precisely adjust the tension of the moving substrate with the calculated tension value.

[0049] That is, in the past, only the vertical load value of the substrate measured by the load cell was considered to control the tension of the substrate through the dancer roll. Compared to the past, the present invention calculates the tension value of the substrate by considering the frictional force of the substrate in addition to the vertical load value of the substrate measured by the load cell, thereby allowing for more precise control of the tension of the moving substrate than in the past.

[0050] The present invention can prevent a tension cut phenomenon of a substrate due to frictional force of the substrate and a breakage of the substrate due to the tension cut phenomenon by precisely adjusting the tension of a moving substrate.

[0051] In addition, the present invention divides the entire section between the unwinder and the rewinder into a plurality of tension reference sections through the friction coefficient obtained for each position of the measuring roll in the driving direction of the above-described device, and can visualize the division details of the plurality of tension reference sections.

[0052] The operator can determine whether and to what extent unintended tension cuts occur during the operation of the equipment through the division of the above multiple tension reference sections.

[0053] Figure 1 schematically illustrates the configuration of a roll-to-roll facility in the rolling process of a secondary battery electrode.

[0054] Figure 2 is a drawing for explaining the breakage of a substrate when a tension cut phenomenon occurs due to a difference in tension between the front and rear ends of a conveying roll in a section where the frictional force of the substrate against the conveying roll is large.

[0055] FIG. 3 is a schematic diagram illustrating a configuration of a tension control system of a roll-to-roll equipment according to one embodiment of the present invention.

[0056] FIG. 4 is a schematic diagram illustrating the arrangement of a feed roll, a measuring roll, and a dancer roll according to the direction of travel of a substrate according to one embodiment of the present invention.

[0057] Figure 5 schematically illustrates a configuration diagram of a friction coefficient measuring unit according to one embodiment of the present invention.

[0058] FIG. 6 is a drawing for explaining a process of visualizing the division situation of a tension reference section from a friction coefficient obtained for each position of a measuring roll in one embodiment of the present invention.

[0059] Hereinafter, a tension control system of a roll-to-roll equipment related to one embodiment of the present invention will be described with reference to the attached drawings.

[0060] A tension control system of a roll-to-roll equipment according to one embodiment of the present invention is for precisely adjusting the tension of a material by considering the frictional force of the material running on the roll-to-roll equipment.

[0061] Figure 1 schematically illustrates the configuration of a roll-to-roll facility used in the rolling process of a secondary battery electrode, and can be applied similarly or identically to one embodiment of the present invention. Therefore, a detailed description of the general configuration or common configuration of the roll-to-roll facility is omitted.

[0062] FIG. 3 is a schematic diagram illustrating a configuration of a tension control system of a roll-to-roll equipment according to one embodiment of the present invention, and FIG. 4 is a schematic diagram illustrating an arrangement state of a feed roll, a measuring roll, and a dancer roll according to a traveling direction of a substrate according to one embodiment of the present invention.

[0063] Referring to FIGS. 3 and 4, the tension control system (1000) of the roll-to-roll equipment related to the present embodiment may include an unwinder (110) configured to unwind a substrate (10), a rewinder (120) configured to wind the substrate (10), and transport rolls (130) arranged between the unwinder (110) and the rewinder (120) to guide the movement of the substrate (10).

[0064] In addition, the tension control system (1000) of the roll-to-roll equipment may include a load cell (135) configured to measure the vertical load of the moving material (10) and a friction coefficient measuring unit (150) configured to measure the friction coefficient between the moving material (10) and the conveying roll (130).

[0065] In addition, the tension control system (1000) of the roll-to-roll equipment may include a dancer roll (160) that guides the movement of the substrate (10) and is provided to be movable in a direction (H) perpendicular to the width direction (W) of the substrate (10), and a tension controller (180) that receives a measurement value of the load cell (135) and a measurement value of the friction coefficient measurement unit (150) to control the operation of the dancer roll (160) and control the tension of the substrate (10) during movement.

[0066] The above roll-to-roll equipment (100) may be a secondary battery manufacturing equipment. Referring to FIGS. 1 and 4, the roll-to-roll equipment (100) may include an unwinder (110), a plurality of transfer rolls (130), a friction coefficient measuring unit (150), a plurality of dancer rolls (160), and a rewinder (120). The friction coefficient measuring unit (150) is a roll having a built-in sensor (151 to 153) for measuring a friction coefficient.

[0067] For example, the roll-to-roll equipment (100) may be a rolling equipment including a pair of rolling rolls (140). The pair of rolling rolls (140) are arranged between the unwinder (110) and the rewinder (120) to roll a moving substrate (10).

[0068] The above unwinder (110) is a device designed to unwind the substrate (10). The above rewinder (120) is connected to the unwinder (110) via the substrate (10) and is a device designed to wind the substrate (10).

[0069] The plurality of transfer rolls (130) and the plurality of dancer rolls (160) are installed between the unwinder (110) and the rewinder (120). The plurality of transfer rolls (130), the plurality of measuring rolls (150), and the plurality of dancer rolls (160) are for guiding the movement of the substrate (10) from the unwinder (110) to the rewinder (120).

[0070] Referring to FIGS. 1 and 4, the transfer roll (130) may be arranged to guide the movement of the substrate (10) from the unwinder (110) toward the rewinder (120). A plurality of transfer rolls (130) may be spaced apart from each other along the travel direction (MD) of the substrate (10). The transfer roll (130) may have a width greater than the width of the substrate (10).

[0071] The above-mentioned transfer roll (130) may include a drive roll (131) equipped with a drive motor and a non-drive roll (133) that guides the movement of the substrate (10) while idling when the drive roll (131) is in operation.

[0072] A plurality of transport rolls (130) may be equipped with load cells (135). The load cells (135) are provided to measure the vertical load value of the substrate (10) traveling along the transport rolls (130). The vertical load value of the substrate (10) may be the load value of the substrate in the direction of gravity, i.e., the height direction (H).

[0073] The dancer roll (160) can be arranged between the transfer rolls (130) to guide the movement of the substrate (10). The dancer roll (160) can guide the movement of the substrate (10) by moving up and down in the height direction (H) so that the tension of the substrate changes.

[0074] A dancer roll potentiometer (165) is mounted on the dancer roll (160) and can measure changes in the position of the dancer roll (160). The dancer roll potentiometer (165) can transmit the measured value to a tension controller (180).

[0075] The dancer roll (160) can be raised or lowered in the height direction (H) perpendicular to the floor surface through the dancer roll position adjustment unit (170). The dancer roll position adjustment unit (170) can be provided to adjust the position of the dancer roll (160) in the height direction (H) based on the tension value. The dancer roll position adjustment unit (170) can include a reciprocating cylinder or a motor.

[0076] The above-mentioned substrate (10) may be a coated electrode. Referring to FIG. 2, the coated electrode (10) may include a holding portion (11) and a non-conductive portion (12). Here, the holding portion (11) is a portion that includes a coating layer in which an electrode active material is coated on an electrode current collector. The non-conductive portion (12) is a portion where the coating layer does not exist.

[0077] The above-mentioned material (10) can be driven from the unwinder (110) toward the rewinder (120) along a plurality of transfer rolls (130) and hot-rolled while passing through the pair of rolling rolls (140).

[0078] The above-mentioned substrate (10) may undergo various deformations during hot rolling, such as shape deformation, strength increase, ductility deformation, and residual stress generation. Accordingly, a tension cut phenomenon may occur while the substrate (10) is traveling from the rear end of the rolling roll (140) toward the rewinder (120).

[0079] The above-mentioned tension cut phenomenon is a phenomenon in which the tension of the substrate (10) at the front end of the transfer roll (130) and the tension of the substrate (10) at the rear end of the transfer roll (130) are different from each other when the substrate (10) is traveling on the same transfer roll (130). If a tension cut occurs in the traveling substrate (10), the substrate (10) may be broken in the width direction (W) of the substrate (10).

[0080] When the substrate (10) is broken, the roll-to-roll equipment (100) must be stopped, the broken portion of the substrate (10) must be removed, and then the substrate (10) must be reconnected. There was a problem in that the productivity of the substrate (10) was reduced because the rolled substrate (10) could not be produced during the stoppage time of the roll-to-roll equipment (100).

[0081] The present invention is to precisely adjust the tension of a moving material (10) to solve various problems caused by the tension cut phenomenon of a moving material (10).

[0082] The tension control system (1000) of the above roll-to-roll equipment measures the coefficient of friction of the substrate (10) through the coefficient of friction measurement unit (150), and can calculate the tension value of the substrate (10) more accurately than before based on the friction value of the substrate (10) and the vertical load value of the substrate (10) through the tension controller (180).

[0083] The tension control system (1000) of the above roll-to-roll equipment can more precisely adjust the tension of the moving substrate (10) by considering the frictional force of the substrate (10), thereby preventing breakage of the substrate (10) in a section where the frictional force of the substrate (10) is strong, such as an S-curve section.

[0084] Hereinafter, the friction coefficient measuring unit (150) will be described with reference to FIGS. 3 and 5. FIG. 5 schematically illustrates the configuration of the friction coefficient measuring unit according to one embodiment of the present invention.

[0085] The above friction coefficient measuring unit (150) is provided in a roll shape. For convenience of explanation, the friction coefficient measuring unit (150) may be referred to as a "measuring roll" and may be indicated by the drawing number 150. The measuring roll, which is the friction coefficient measuring unit (150), may correspond to either or both of the driving roll (131) and the non-driving roll (133). The measuring roll (150) is provided with a built-in sensor (151 to 153) to measure the friction coefficient of a moving material.

[0086] The above friction coefficient measuring part, the measuring roll (150), can be placed between the transfer rolls (130: 131, 133) in the entire travel section between the unwinder (110) and the rewinder (120). The measuring roll (150) can be installed in a concentrated area in a section where a tension cut phenomenon of the substrate (10) is likely to occur, such as an S-shaped curve section of the substrate (10).

[0087] The above measuring roll (150) may be arranged between one drive roll (131) and another drive roll (131) adjacent thereto along the running direction (MD) of the substrate (10). In addition, the above measuring roll (150) may be arranged between one drive roll (131) and a non-driven roll (133) adjacent thereto along the running direction (MD) of the substrate (10).

[0088] The plurality of sensors (151 to 153) may be mounted on the inner wall (158) of the measuring roll (150) parallel to the roll axis (159) of the measuring roll (150). The plurality of sensors (151 to 153) may be arranged to detect surface changes of the measuring roll (150) in the width direction (W) of the substrate (10) due to friction with the substrate (10).

[0089] For example, the sensors (151 to 153) may be arranged to measure vibration values ​​generated on the surface of the measuring roll (150) due to friction with the substrate (10). Micro-deformation of the measuring roll (150) due to friction with the substrate (10) may occur irregularly. At this time, the sensor (151) may be arranged to detect vibrations resulting from micro-deformation of the measuring roll (150) in the width direction (W) of the substrate (10).

[0090] As another example, the sensors (151 to 153) may be arranged to measure the positional displacement value of the measuring roll (150) in the width direction (W) of the substrate (10). The sensors (151 to 153) may include strain gauges. The sensor (151) may measure the micro-morphological change of the surface (157) of the measuring roll (150) of the substrate (10) as the positional displacement value.

[0091] The above plurality of sensors (151 to 153) can be arranged in a row at equal intervals in the width direction (W) of the substrate (10), including the central point of the measuring roll (150).

[0092] The above plurality of sensors (151 to 153) may include a first sensor (151) to a third sensor (153).

[0093] The first sensor (151) can be mounted on the inner wall (158) of the measuring roll (150) at the center point of the measuring roll (150).

[0094] The second sensor (152) may be mounted on the inner wall (158) of the measuring roll (150) at a point spaced to the left in the width direction (W) of the substrate (10) from the center point of the measuring roll (150).

[0095] The third sensor (153) may be mounted on the inner wall (158) of the measuring roll (150) at a point spaced to the right in the width direction (W) of the substrate (10) from the central point of the measuring roll (150).

[0096] The friction coefficient measuring unit (150) can calculate the friction coefficient of the substrate (10) based on the sensing values ​​of the plurality of sensors (151 to 153). The friction coefficient measuring unit (150) can measure the friction coefficient of the substrate (10) by comparing the second sensing value of the second sensor (152) and the third sensing value of the third sensor (153) based on the first sensing value of the first sensor (151).

[0097]

[0098] The above measuring roll (150) may have a built-in wireless transmitter (154) and power supply (155).

[0099] The wireless transmitter (154) may be electrically connected to each sensor (151 to 153). The wireless transmitter (154) may be mounted on the inner wall (158) of the measuring roll (150).

[0100] The wireless transmitter (154) can wirelessly transmit the measurement values ​​of the sensors (151 to 153) to the tension controller (180). The wireless transmitter (154) transmits the first sensing value to the third sensing value to the tension controller (180). The tension controller (180) can calculate the coefficient of friction by finitely analyzing the input sensing values ​​according to a preset algorithm.

[0101] The power supply unit (155) may be configured to supply power to the plurality of sensors (151 to 153) and the wireless transmitter (154). For example, the power supply unit (155) may be a device that converts the rotational power of the roll shaft (159) of the measuring roll (150) into electric energy and stores the electric energy. As another example, the power supply unit (155) may include a battery.

[0102] Hereinafter, the tension controller (180) will be described with reference to FIGS. 3 and 6.

[0103] FIG. 6 is a drawing for explaining a process of dividing a tension reference section from a friction coefficient obtained according to the position of a measuring roll in one embodiment of the present invention.

[0104] The above tension controller (180) may be provided to control the tension of the moving material (10) by receiving the measurement value of the load cell (135) and the measurement value of the friction coefficient measurement unit (150) and controlling the operation of the dancer roll (160).

[0105] The above tension controller (180) may include a first processing unit (181) and a second processing unit (183).

[0106] The first processing unit (181) can calculate the frictional force value of the substrate (10) based on the frictional coefficient. The frictional force value is a horizontal load value in the width direction (W) of the substrate. The frictional force value of the substrate (10) can vary depending on the frictional coefficient measured according to the position of the measuring roll (150).

[0107] The second processing unit (183) can calculate the tension value of the substrate (10) based on the frictional force value of the substrate (10) and the vertical load value of the substrate (10). The second processing unit (183) can calculate the tension value of the substrate (10) for each tension reference section. The vertical load value of the substrate (10) is a measurement value of the load cell (135).

[0108] The above tension controller (180) can control tension feedback in a PID (Proportional-Integral-Derivative) manner based on the measurement value of the load cell (135) and the measurement value of the friction coefficient measurement unit (150).

[0109] The above tension controller (180) can output the tension value of the substrate (10) according to a preset tension calculation algorithm using the vertical load value and the friction force value as input values.

[0110] The tension controller (180) can generate a friction coefficient graph based on the friction coefficient obtained according to the position of the measuring roll (150) as shown in Fig. 6(a). The tension controller (180) can output the position of the measuring roll (150) with the maximum friction coefficient through the friction coefficient graph.

[0111] For example, the tension controller (180) can generate a friction coefficient graph according to the position of the measuring roll (150), as illustrated in FIG. 6(b). As illustrated in FIG. 6(b), there is a deviation in the friction coefficient depending on the position of the measuring roll (150). Depending on the installation position between the conveying roll (130) and the measuring roll (150), the greater the inclination angle of the substrate (10) caught on the conveying roll (130) and the measuring roll (150), the greater the frictional force of the measuring roll (150) against the substrate (10). As the frictional force increases, the stress applied to the substrate (10) increases, and accordingly, the possibility of the substrate (10) breaking also increases.

[0112] The above rolls may include a transfer roll (130), a dancer roll (160), and a measuring roll (150).

[0113] The above tension controller (180) can calculate the measurement position with the maximum friction coefficient through the friction coefficient graph. Referring to Fig. 6(b), the maximum friction coefficient measurement positions may be P2 and P5.

[0114] The above tension controller (180) divides the entire travel section of the substrate (10) into a plurality of tension reference sections by using the section between two consecutive maximum friction coefficients of the friction coefficient graph as the tension reference section, and can display this on the display section (190).

[0115] The display unit (190) may be connected to the tension controller (180) and configured to display the division status of the plurality of tension reference sections. The division status of the plurality of tension reference sections may vary depending on the tension of the material (10) running on the roll-to-roll equipment (100).

[0116] The operator can determine whether and to what extent an unintended tension cut occurs in a particular tension reference section during the driving of the substrate (10) through the division of the above-mentioned plurality of tension reference sections.

[0117] For example, referring to FIG. 6(c), the display unit (190) can be divided into a total of three tension reference sections, with measurement locations P2 and P5 as boundaries. For example, the plurality of tension reference sections can be divided into a first section (191) including measurement locations P1 and P2, a second section (192) including measurement locations P2 to P5, and a third section (193) including measurement locations P5 and P6.

[0118] The above tension controller (180) can precisely control the tension of the moving material (10) in the following manner.

[0119] The tension controller (180) can calculate the first tension value of the first section (191) based on the friction coefficient and vertical load value measured in the first section (191).

[0120] The tension controller (180) can individually adjust the position of the dancer roll (160) installed in the first section (191) based on the first tension value so that the material (10) running in the first section (191) runs at a preset tension.

[0121] For example, the tension controller (180) can adjust the position of the dancer roll (160) in a direction that relieves tension of the substrate (10) when the first tension value is greater than the preset tension. Alternatively, the tension controller (180) can adjust the position of the dancer roll (160) in a direction that tensions the substrate (10) when the first tension value is less than the preset tension.

[0122] In the same manner as above, the tension controller (180) can calculate the second tension value of the second section (192) and the third tension value of the third section (193).

[0123] In addition, the tension controller (180) can individually adjust the position of the dancer roll (160) installed in the second section (192) based on the second tension value so that the material (10) running in the second section (192) runs at a preset tension.

[0124] In addition, the tension controller (180) can individually adjust the position of the dancer roll (160) installed in the third section (193) based on the third tension value so that the material (10) running in the third section (193) runs at a preset tension.

[0125] The tension controller (180) may include a PLC (Programmable Logic Controller). The tension controller (180) may be configured to receive a measurement value of a dancer roll potentiometer (165) mounted on a dancer roll (160) and control the rotation speed of the drive roll according to a preset PLC control logic. The measurement value of the dancer roll potentiometer (165) may be a positional displacement value of the dancer roll (160).

[0126] The tension controller (180) can control the rotation speed of the drive roll (131) around the dancer roll (160) based on the position displacement value of the dancer roll (160). The tension controller (180) can control the rotation speed of the drive roll (131) for each of the plurality of tension reference sections (191, 192, 193).

[0127] The above tension controller (180) can individually control the driving speed of the drive roll (131) for each tension reference section (191, 192, 193).

[0128] In addition, the tension controller (180) can control the driving speed of the rewinder (120) according to preset PLC control logic.

[0129] The above roll-to-roll equipment (100) can precisely adjust the tension of the above substrate (10), thereby preventing breakage of the above substrate (10) due to a tension cut phenomenon occurring in a portion where tension greater than the set tension is applied.

[0130] The conventional roll-to-roll equipment (100) adjusted the tension of the substrate (10) using a PID control method based on a load cell (135). The PID control method based on a load cell (135) may cause a windup phenomenon due to the accumulated value of one variable, i.e., the vertical load value of the substrate (10). If a wide-up phenomenon occurs, there was a problem that the processing speed of the PID control slowed down.

[0131] In contrast, the roll-to-roll equipment (100) according to the present invention can adjust the tension of the substrate (10) through PID control based on a measuring roll (150) and a load cell (135).

[0132] The PID control method based on the above measuring roll (150) and load cell (135) uses the vertical load value of the substrate (10) and the friction force value as variables.

[0133] The PID control method based on the above measuring roll (150) and load cell (135) can rapidly improve the processing speed of PID control by alleviating the windup phenomenon as two variables, i.e., the vertical load value of the substrate (10), which is an existing variable, and the friction force value, which is an additional variable, are accumulated.

[0134] The PID control method based on the above measuring roll (150) and load cell (135) can calculate the tension value applied to the substrate (10) through two variables (i.e., the vertical load value and the frictional force value of the substrate (10)), thereby calculating the tension value of the substrate at a faster speed and with greater accuracy than before.

[0135] The present invention can increase the processing speed of PID control and shorten the feedback speed when controlling the tension of the above-mentioned substrate (10).

[0136] The preferred embodiments of the present invention described above are disclosed for the purpose of illustration, and those skilled in the art having ordinary knowledge of the present invention will be able to make various modifications, changes, and additions within the spirit and scope of the present invention, and such modifications, changes, and additions should be considered to fall within the scope of the following claims.

[0137] As described in the detailed description of the invention.

Claims

1. A tension control system for a roll-to-roll equipment including an unwinder configured to unload a material, a rewinder configured to wind the material, and transport rolls arranged between the unwinder and the rewinder to guide the movement of the material. A load cell designed to measure the vertical load of a moving object; A friction coefficient measuring unit configured to measure the friction coefficient between the above-described moving material and the conveying roll; A dancer roll that guides the driving of the above-mentioned device and is provided to move in a direction perpendicular to the width direction of the device; and A tension control system for a roll-to-roll facility including a tension controller configured to control the operation of the dancer roll by receiving a measurement value of the load cell and a measurement value of the friction coefficient measurement unit, thereby controlling the tension of the moving material.

2. In paragraph 1, The above friction coefficient measuring unit includes a measuring roll having a built-in sensor, The above sensor is a tension control system of a roll-to-roll equipment that detects surface changes of the measuring roll in the width direction of the substrate due to friction between the moving substrate and the measuring roll and measures the coefficient of friction.

3. In paragraph 2, A tension control system for a roll-to-roll equipment, characterized in that the above sensor is mounted on the inner wall of the measuring roll in the width direction of the above material and is provided in multiple numbers.

4. In paragraph 2, The above measuring roll is additionally equipped with a wireless transmitter connected to the sensor, A tension control system for roll-to-roll equipment, characterized in that the wireless transmitter wirelessly transmits the measurement value of the sensor to the tension controller.

5. In paragraph 2, The above sensor is a tension control system of a roll-to-roll facility designed to measure the vibration value occurring on the surface of the measuring roll.

6. In paragraph 2, The above sensor is a tension control system of a roll-to-roll facility configured to measure the positional displacement value of the measuring roll in the width direction of the above substrate.

7. In paragraph 6, The above sensor is a tension control system of a roll-to-roll equipment including a strain gauge.

8. In paragraph 1, A tension control system for a roll-to-roll equipment, characterized in that the tension controller performs tension feedback control in a PID (Proportional-Integral-Derivative) manner based on the measured value of the load cell and the measured value of the friction coefficient measuring unit.

9. In paragraph 8, A tension control system for a roll-to-roll equipment, characterized in that the tension controller divides the entire travel section of the material between the unwinder and the rewinder into a plurality of tension reference sections based on the measured value of the friction coefficient measuring unit and visualizes the division status.

10. In paragraph 9, A tension control system for a roll-to-roll equipment, further comprising a display unit connected to the tension controller and configured to display the segment status of the plurality of tension reference sections.

11. In paragraph 2, The above-mentioned transfer roll includes a drive roll equipped with a drive motor and a non-drive roll that guides the movement of the above-mentioned material while idling during the operation of the drive roll. A tension control system for a roll-to-roll equipment, characterized in that the above measuring roll corresponds to one or both of the above driving roll and the above non-driving roll.

12. In paragraph 11, A tension control system for a roll-to-roll equipment, characterized in that the above measuring roll is arranged between one drive roll and another drive roll adjacent thereto along the driving direction of the above device.

13. In paragraph 11, A tension control system for a roll-to-roll equipment, characterized in that the above measuring roll is arranged between one of the driving rolls and an adjacent non-driving roll along the driving direction of the above equipment.

14. In paragraph 11, A tension control system for a roll-to-roll facility, characterized in that the tension controller is configured to control the rotation speed of the drive roll by receiving a measurement value from a dancer roll potentiometer mounted on the dancer roll.

15. A load cell designed to measure the vertical load of the electrode substrate while it is running; A friction coefficient measuring unit configured to measure the friction coefficient between the above-described moving electrode substrate and the conveying roll; A driving roll that generates tension applied to the electrode substrate for driving the electrode substrate; A dancer roller configured to control tension applied to the electrode substrate as the position is adjusted in a direction perpendicular to the width direction of the electrode substrate; A dancer roll potentiometer for detecting the position of the dancer roll; A secondary battery manufacturing facility including a controller that controls the position of the dancer roll based on the measured value of the load cell and the measured value of the friction coefficient measuring unit, and controls the speed of the driving roll based on the measured value of the dancer roll potentiometer.

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