Tension control system of roll-to-roll facility

Abstract

A tension control system of a roll-to-roll facility, according to an embodiment of the present invention, may comprise: an unwinder provided to unwind a substrate; a re-winder provided to wind the substrate; and transfer rolls arranged between the unwinder and the re-winder to guide movement of the substrate. In addition, the tension control system of a roll-to-roll facility may comprise: a friction coefficient measurement unit including a measurement roll having a sensor provided on the surface thereof, wherein the measurement roll is arranged between the transfer rolls to measure a friction coefficient due to friction with the moving substrate; a dancer roll provided to guide the movement of the substrate while moving up and down in a direction perpendicular to the width direction of the substrate so that the tension of the substrate is changed; and a tension controller provided to control the operation of the dancer roll on the basis of the measured value of the friction coefficient measurement unit.

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. 10-2024-0120737, 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 the tension of the coating electrode (10) applied to the same transfer roll (130) is different at the front and rear ends 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] An object of the present invention is to provide a tension control system for a roll-to-roll equipment capable of preventing a tension cut phenomenon of a substrate by precisely adjusting the tension of the substrate and monitoring 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 equipment for manufacturing electrodes of secondary batteries as a roll-to-roll equipment to which an improved tension control system is applied.

[0023] A tension control system of a roll-to-roll equipment according 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. In addition, the tension control system of the roll-to-roll equipment may include a friction coefficient measuring unit configured to measure a friction coefficient due to friction between the measuring roll and the transport rolls, the friction coefficient measuring unit including a measuring roll having a sensor provided on a surface thereof and the measuring roll being arranged between the transport rolls to measure a friction coefficient with respect to a moving substrate, a dancer roll configured to guide the movement of the substrate while moving up and down in a direction perpendicular to the width direction of the substrate so as to change the tension of the substrate, and a tension controller configured to control the operation of the dancer roll based on a measurement value of the friction coefficient measuring unit.

[0024] The above sensor may be inserted into the surface of the measuring roll in a line shape to detect changes in the surface of the measuring roll due to friction with the substrate.

[0025] The sensor can be mounted on the measuring roll so as to be in contact with the substrate parallel to the roll axis of the measuring roll and in the same line as the surface of the measuring roll.

[0026] The above sensors may be provided in multiple numbers spaced apart at predetermined intervals along the circumferential direction of the measuring roll.

[0027] The above measuring roll may be provided with at least one line groove that is sunken into the surface of the measuring roll parallel to the roll axis and into which the sensor can be inserted.

[0028] The above sensor may be arranged to measure the vibration value of the measuring roll due to friction with the above substrate.

[0029] The above sensor may include a fiber Bragg grating (FBG) sensor.

[0030] The above sensor may be arranged to measure the positional displacement value of the measuring roll in the width direction of the above substrate.

[0031] The above sensor may include a piezoelectric sensor.

[0032] 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.

[0033] The load cell is mounted on the above-mentioned conveying roll and is provided to measure the vertical load of the substrate, and the tension controller may be provided 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 traveling substrate.

[0034] 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.

[0035] The above tension controller can divide the entire travel section of the substrate 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.

[0036] 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.

[0037] 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.

[0038] The tension controller may be configured to receive a measurement value from a dancer roll potentiometer mounted on the dancer roll and control the rotation speed of the drive roll.

[0039] 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.

[0040] The above measuring roll can be arranged between one of the driving rolls and an adjacent non-driving roll along the driving direction of the above described device.

[0041] The tension control system of a roll-to-roll equipment having the above configuration and structure has the following effects.

[0042] The above measuring roll can measure the coefficient of friction of the substrate due to friction with the substrate in a contact manner through a sensor provided on the surface of the measuring path while guiding the movement of the substrate.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] The operator can determine whether and to what extent unintended tension cuts occur during the running of the equipment through the division of the above multiple tension reference sections.

[0049] Figure 1 schematically illustrates the configuration of a rolling facility for performing a rolling process of an electrode for a secondary battery.

[0050] Figure 2 is a drawing for explaining the breakage of a material when a tension cut phenomenon occurs due to a difference in tension between the front and rear ends of a conveying roll.

[0051] 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.

[0052] 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.

[0053] Figure 5 schematically illustrates a perspective view of a measuring roll according to one embodiment of the present invention.

[0054] Fig. 6(a) is a cross-sectional view of a measuring roll without a sensor installed, and Fig. 6(b) is a cross-sectional view of a measuring roll with a sensor built into a line groove.

[0055] Figure 7 schematically illustrates a configuration diagram of a friction coefficient measuring unit according to one embodiment of the present invention.

[0056] FIG. 8 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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).

[0062] 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).

[0063] 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.

[0064] 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.

[0065] 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).

[0066] 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).

[0067] 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).

[0068] 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 movement direction (MD) of the substrate (10). The transfer roll (130) may have a width greater than the width of the substrate (10).

[0069] 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.

[0070] 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).

[0071] 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.

[0072] 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).

[0073] 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.

[0074] 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.

[0075] 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).

[0076] 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).

[0077] 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).

[0078] 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).

[0079] 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).

[0080] 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).

[0081] 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.

[0082] Hereinafter, the friction coefficient measurement unit will be described with reference to FIGS. 4 to 7.

[0083] FIG. 5 is a schematic perspective view of a measuring roll according to one embodiment of the present invention, FIG. 6(a) is a cross-sectional view of a measuring roll without a sensor installed, FIG. 6(b) is a cross-sectional view of a measuring roll with a sensor built into a line groove, and FIG. 7 is a schematic diagram of a configuration of a measuring roll according to the present embodiment.

[0084] 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 (150) may correspond to either or both of the driving roll (131) and the non-driving roll (133). The friction coefficient of a moving material may be measured through a sensor (151) provided on the surface of the measuring roll (150).

[0085] As illustrated in Fig. 4, the measuring roll (150) may be placed between the transfer rolls (130: 131, 133) throughout the entire travel section between the unwinder (110) and the rewinder (120). The measuring roll (150) may be concentratedly installed 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).

[0086] The above measuring roll (150) can be placed between one drive roll (131) and another drive roll (131) adjacent thereto along the driving direction (MD) of the above-described device (10).

[0087] In addition, the measuring roll (150) can be placed between one of the driving rolls (131) and the adjacent non-driving roll (133) along the driving direction (MD) of the substrate (10).

[0088] Referring to FIGS. 5 and 6, the measuring roll (150) may be provided with at least one line groove (158) that is sunken into the surface (157) of the measuring roll (150) and into which the sensor (151) can be inserted.

[0089] As illustrated in Fig. 6(a), the line groove (158) is provided by being sunken in the surface (157) of the measuring roll (150) parallel to the roll axis (159) of the measuring roll (150). A plurality of line grooves (158) are provided on the measuring roll (150). The plurality of line grooves (158) are provided at predetermined intervals along the circumferential direction of the measuring roll (150).

[0090] As shown in FIG. 5 and FIG. 6(b), the sensor (151) can be inserted and fixed into a line groove (158) of the measuring roll (150) so as to be in contact with the substrate (10) on the same line as the surface (157) of the measuring roll (150) and parallel to the roll axis (159) of the measuring roll (150). A plurality of sensors (151) can be mounted in each line groove (158) spaced apart at a predetermined interval along the circumferential direction of the measuring roll (150).

[0091] For example, the sensor (151) may be arranged to measure a vibration value generated on the surface (157) of the measuring roll (150) due to friction with the substrate (10). The 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 the vibration caused by the micro-deformation of the measuring roll (150) in the width direction (W) of the substrate (10).

[0092] For example, the sensor (151) may include a piezoelectric sensor. The piezoelectric sensor is a sensor that converts the physical force exerted by the substrate (10) on the measuring roll (150) into an electrical signal. The greater the force exerted by the substrate (10) on the measuring roll (150), the greater the frictional force may be.

[0093] For example, the sensor (151) may be arranged to measure the positional displacement value of the measuring roll (150) in the width direction (W) of the substrate (10). 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.

[0094] For example, the sensor (151) may be a fiber Bragg grating (FBG) that includes a fine fiber with a Bragg grating engraved on a single strand of optical fiber. A fiber Bragg grating (FBG) is a sensor that detects deformation of a structure, temperature changes, etc.

[0095] A Fiber Bragg Grating (FBG) is a structure with a periodically modulated refractive index within an optical fiber, which has the characteristic of reflecting light of a specific wavelength. When external factors such as temperature or stress change, the FBG's refractive index or period changes, allowing it to detect changes in the reflected wavelength. By measuring the changed reflected wavelength, a Fiber Bragg Grating (FBG) can detect conditions such as temperature, pressure, and strain.

[0096] The above-described plurality of measuring rolls (150) may be spaced apart at a predetermined interval throughout the entire travel section between the unwinder (110) and the rewinder (120). The measuring rolls (150) may be concentratedly installed 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).

[0097] The above measuring roll (150) may have a built-in wireless transmitter (154) and power supply (155).

[0098] The wireless transmitter (154) may be electrically connected to each sensor (151). The wireless transmitter (154) may be provided inside the measuring roll (150).

[0099] The power supply unit (155) may be configured to supply power to the sensor (151) 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.

[0100] Hereinafter, the tension controller (180) will be described with reference to FIG. 3 and FIG. 8.

[0101] FIG. 8 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 (150) in one embodiment of the present invention.

[0102] 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).

[0103] The above tension controller (180) may include a first processing unit (181) and a second processing unit (183).

[0104] 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).

[0105] 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).

[0106] 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).

[0107] 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.

[0108] 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. 8(b). As illustrated in FIG. 8(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.

[0109] The above rolls may include a transfer roll (130), a dancer roll (160), and a measuring roll (150).

[0110] The above tension controller (180) can calculate the measurement position with the maximum friction coefficient through the friction coefficient graph. Referring to Fig. 8(b), the maximum friction coefficient measurement positions may be P2 and P5.

[0111] 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).

[0112] 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).

[0113] 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.

[0114] For example, referring to FIG. 8(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.

[0115] The above tension controller (180) can precisely control the tension of the moving material (10) in the following manner.

[0116] 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). In the same manner, 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).

[0117] 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.

[0118] 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.

[0119] 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.

[0120] 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.

[0121] 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).

[0122] 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).

[0123] The above tension controller (180) can individually control the driving speed of the drive roll (131) for each tension reference section (191, 192, 193).

[0124] In addition, the tension controller (180) can control the driving speed of the rewinder (120) according to preset PLC control logic.

[0125] 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.

[0126] 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.

[0127] 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).

[0128] 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.

[0129] 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.

[0130] 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.

[0131] 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).

[0132] 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.

[0133] 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 friction coefficient measuring unit including a measuring roll having a sensor provided on the surface, wherein the measuring roll is arranged between the transport rolls to measure a coefficient of friction due to friction with a moving substrate; A dancer roll provided to guide the movement of the substrate by moving up and down in a direction perpendicular to the width direction of the substrate so that the tension of the substrate changes; and A tension control system for a roll-to-roll facility including a tension controller configured to control the operation of the dancer roll based on a measurement value of the friction coefficient measuring unit.

2. In paragraph 1, A tension control system for a roll-to-roll facility, wherein the sensor is inserted into the surface of the measuring roll in a line shape to detect changes in the surface of the measuring roll due to friction with the substrate.

3. In paragraph 2, A tension control system for a roll-to-roll equipment, characterized in that the sensor is mounted on the measuring roll so as to be in contact with the substrate in a direction parallel to the roll axis of the measuring roll and in the same line as the surface of the measuring roll.

4. In paragraph 2, A tension control system for a roll-to-roll equipment, wherein the above sensors are provided in multiple numbers spaced apart at predetermined intervals along the circumferential direction of the above measuring roll.

5. In paragraph 2, A tension control system for a roll-to-roll equipment, characterized in that the measuring roll is provided with at least one line groove that is sunken into the surface of the measuring roll parallel to the roll axis and into which the sensor can be inserted.

6. In paragraph 2, The above sensor is a tension control system of a roll-to-roll equipment that is configured to measure a vibration value of the measuring roll due to friction with the substrate or a positional displacement value of the measuring roll in the width direction of the substrate.

7. In paragraph 2, The above sensor is a tension control system for a roll-to-roll equipment including at least one of a fiber Bragg grating (FBG) sensor or a piezoelectric sensor.

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

9. In paragraph 1, It further includes a load cell mounted on the above conveying roll and configured to measure the vertical load of the above material, The tension controller is a tension control system of a roll-to-roll equipment that receives the measurement value of the load cell and the measurement value of the friction coefficient measurement unit and controls the operation of the dancer roll to control the tension of the moving material.

10. In paragraph 9, 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.

11. In paragraph 9, 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 situation.

12. In paragraph 11, 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.

13. In paragraph 1, 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.

14. In paragraph 13, 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. In paragraph 13, 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.

16. In paragraph 15, 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.

17. Unwinder provided to eject electrode materials; A rewinder provided to recommend the above description; A driving roll provided between the unwinder and the rewinder to generate tension applied to the electrode substrate for driving the substrate; A plurality of transfer rolls provided between the above unwinder and rewinder to guide the movement of the above-described material; A friction coefficient measuring unit including a measuring roll provided between the above-mentioned transfer rolls and a sensor for sensing the friction coefficient between the surface of the measuring roll and the substrate; A dancer roller provided to move in a direction perpendicular to the width direction of the electrode substrate so that the tension of the electrode substrate changes; and A secondary battery manufacturing facility including a controller configured to control the operation of the dancer roller based on the measured value of the friction coefficient measuring unit.

18. In paragraph 17, A secondary battery manufacturing facility characterized in that the controller calculates a widthwise load value of the electrode substrate based on the friction coefficient and controls the operation of the dancer roll based on the widthwise load value.

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