Steering wheel touch sensor and method of manufacturing thereof

Abstract

The present invention relates to a steering wheel touch sensor and a method for manufacturing the same, and more specifically, to a steering wheel touch sensor and a method for manufacturing the same, wherein the sensor is made of a fabric using a conductive thread with a plated surface to impart elongation and realize capacitance, thereby enabling the measurement and detection of the magnitude of the current in a capacitive manner according to the contact area when a driver grips the steering wheel with their hand.

Description

Technology Field

[0001] The present invention relates to a steering wheel touch sensor and a method for manufacturing the same. More specifically, it relates to a steering wheel touch sensor utilizing a conductive fabric and a method for manufacturing the same, wherein the raw material required for the production of a steering wheel is imparted with stretchability due to the inevitable leather wrapping process inherent in the characteristics of steering wheel manufacturing, and a fabric made of conductive thread with a plated surface to implement capacitance is produced, thereby enabling the magnitude of current to be measured and detected in a capacitive manner according to the contact area when a driver grips the steering wheel with their hand. Background Technology

[0002] Recently, due to the rapid development of the automotive industry, active research is underway to maximize driving performance and enhance driver convenience through technologies such as autonomous driving, autopilot, and driver assistance systems.

[0003] Generally, autonomous vehicles are increasingly being used as a means to reduce traffic accidents and improve traffic efficiency by independently recognizing the driving environment, judging the situation, and controlling the operation without driver intervention. However, even with autonomous vehicles, situations requiring driver intervention may occur, and in such situations, control of the vehicle must be immediately granted to the driver.

[0004] Therefore, for safe driving, control must be immediately granted to the driver while the driver is gripping the steering wheel, and to this end, it is necessary to accurately and quickly detect the driver's hands-on or hands-off state regarding the steering wheel.

[0005] However, conventionally, whether a driver is gripping the steering wheel is detected through the movement of the steering wheel using a camera, infrared sensor, or torque sensor. However, misrecognition occurs depending on the surrounding environment, and in the case of a torque sensor, there are many instances where the sensor fails to detect the grip even though the driver is gripping the steering wheel because the movement of the steering wheel is small in straight sections such as highways. Prior art literature

[0006] Republic of Korea Published Patent Application No. 10-2019-0083930 (Date of publication: July 15, 2019) The problem to be solved

[0007] The objective of the present invention is to provide a steering wheel touch sensor utilizing a conductive fabric and a method for manufacturing the same, wherein the raw material required for the production of a steering wheel is imparted with stretchability due to the inevitable leather wrapping process inherent in the manufacturing characteristics of a steering wheel, and a fabric made of conductive thread with a plated surface to implement capacitance is produced, thereby enabling the magnitude of current to be measured and detected in a capacitive manner according to the contact area when a driver grips the steering wheel with their hand. means of solving the problem

[0008] A steering wheel touch sensor according to an embodiment of the present invention for solving the above problem is a HOD (Hands Off Detection) steering wheel touch sensor mounted on a steering wheel of a vehicle, comprising a touch sensor layer that is coupled to cover and wrap around a steering wheel frame and detects the hands-on or hands-off state of a driver riding in the vehicle, wherein the touch sensor layer is made of a fabric woven such that the weft and warp threads cross at least once, and at least one of the weft and warp threads is formed as a plated conductive thread to have conductivity.

[0009] The above fabric is woven in a warp or weft knit structure.

[0010] The above-mentioned plated conductive thread has a polymer fiber having a thickness of 10 to 60 denier and a plating layer plated to cover the surface of the polymer fiber, and the plating layer has a thickness of 30 to 150 μm.

[0011] The above-mentioned plated conductive thread is coated on the above-mentioned plating layer and further includes an antifouling and moisture-proof coating layer having a thickness of 5 to 50 μm.

[0012] The above antifouling and moisture-proof coating layer comprises 10 to 30 weight% binder resin, 5 to 15 weight% antifouling agent, 1 to 5 weight% slip agent, and the remainder being polyester-based urethane resin.

[0013] A method for manufacturing a steering wheel touch sensor according to an embodiment of the present invention for solving the above problem comprises: a step of forming a touch sensor layer for detecting the hands-on or hands-off state of a driver riding in the vehicle; and a step of coupling the touch sensor layer to wrap around and cover a steering wheel frame, wherein the touch sensor layer is made of a fabric woven such that the weft and warp threads cross at least once, and at least one of the weft and warp threads is formed as a plated conductive thread to have conductivity.

[0014] The above-mentioned plated conductive thread has a polymer fiber having a thickness of 10 to 60 denier and a plating layer plated to cover the surface of the polymer fiber, and the plating layer has a thickness of 30 to 150 μm.

[0015] The above-mentioned plated conductive thread is coated on the above-mentioned plating layer and further includes an antifouling and moisture-proof coating layer having a thickness of 5 to 50 μm.

[0016] The above antifouling and moisture-proof coating layer comprises 10 to 30 weight% binder resin, 5 to 15 weight% antifouling agent, 1 to 5 weight% slip agent, and the remainder being polyester-based urethane resin. Effects of the invention

[0017] The steering wheel touch sensor and the method for manufacturing the same according to the present invention are implemented to detect the position and area of ​​the grip by quantifying the change in capacitance value according to the contact area when a driver grips the steering wheel with their hand, by fabricating a steering wheel touch sensor made of a fabric using a conductive thread with a plated surface to impart stretchability and realize capacitance.

[0018] To this end, the steering wheel touch sensor and the method for manufacturing the same according to the present invention are formed such that the touch sensor layer is composed of a fabric knit structure in which the warp and weft threads cross at least once, thereby enabling excellent stretchability and allowing for easy attachment when wrapping and covering the steering wheel frame. In addition, this knit structure prevents thread unraveling on the cut surface after cutting by die cutting, laser cutting, or cutting machine, thereby reducing defects caused by short circuits between upper and lower sensors or between front and rear sensors.

[0019] In addition, the steering wheel touch sensor and the method of manufacturing the same according to the present invention are formed such that at least one of the weft and warp threads is plated with a conductive thread, thereby enabling easy detection of whether the driver is gripping the wheel in a capacitive type by securing excellent conductivity.

[0020] In addition, the steering wheel touch sensor and the method for manufacturing the same according to the present invention can improve the reliability of the touch sensor layer by ensuring that the conductive seal further includes an antifouling and moisture-proof coating layer, thereby providing excellent antifouling and moisture-proof properties and reliably protecting the plated conductive seal from contaminants or moisture. Brief explanation of the drawing

[0021] FIG. 1 is a perspective view showing a steering wheel including a steering wheel touch sensor according to an embodiment of the present invention. FIG. 2 is a schematic diagram showing a steering wheel including a steering wheel touch sensor according to an embodiment of the present invention. Figure 3 is a schematic diagram illustrating the structure of a fabric woven with a transverse knit structure. Figure 4 is a schematic diagram illustrating the fabric structure woven with a warp-knit structure. Figure 5 is a measured photograph showing a fabric woven with a warp-knit structure. FIG. 6 is a schematic diagram showing a plated conductive thread used to manufacture a steering wheel touch sensor according to an embodiment of the present invention. FIG. 7 is a process flowchart illustrating a method for manufacturing a steering wheel touch sensor according to an embodiment of the present invention. Specific details for implementing the invention

[0022] Hereinafter, preferred embodiments of the present invention and the physical properties of each component are described in detail. This description is intended to be sufficient for a person skilled in the art to easily practice the invention, and does not imply that the technical scope and concept of the present invention are limited thereby.

[0023] Hereinafter, a steering wheel touch sensor and a method for manufacturing the same according to a preferred embodiment of the present invention will be described with reference to the attached drawings.

[0024] FIG. 1 is a perspective view showing a steering wheel including a steering wheel touch sensor according to an embodiment of the present invention, and FIG. 2 is a schematic diagram showing a steering wheel including a steering wheel touch sensor according to an embodiment of the present invention.

[0025] Referring to FIGS. 1 and 2, a steering wheel (100) including a steering wheel touch sensor according to an embodiment of the present invention may include an insulating layer (110), a touch sensor layer (120) disposed on the upper surface of the insulating layer (110), an electromagnetic shielding layer (130) disposed on the lower surface of the insulating layer (110), a heater layer (140) disposed on the lower surface of the electromagnetic shielding layer (130), a steering wheel frame (150) disposed on the lower surface of the heater layer (140), and a cover layer (160) disposed on the upper surface of the touch sensor layer (120).

[0026] Here, the steering wheel touch sensor (100) can be interpreted to mean including a touch sensor layer (120). Additionally, the steering wheel touch sensor (100) can also be interpreted to mean including an insulating layer (110), a touch sensor layer (120), and an electromagnetic shielding layer (130).

[0027] A steering wheel touch sensor according to an embodiment of the present invention having the above-described configuration is a HOD (Hands Off Detection) steering wheel touch sensor (120) mounted on a steering wheel (100) of a vehicle, which is coupled to cover and surround a steering wheel frame (150), and includes a touch sensor layer (120) for detecting the hands-on or hands-off state of a driver riding in the vehicle.

[0028] In addition, the steering wheel touch sensor according to an embodiment of the present invention may further include a control unit (not shown) for determining whether the vehicle driver is gripping the steering wheel (100) based on a signal detected by the touch sensor layer (120), in addition to the touch sensor layer (120).

[0029] The steering wheel touch sensor according to an embodiment of the present invention is manufactured using a fabric made of a conductive thread (125 in FIG. 3) with a plated surface to provide elongation and to implement capacitance, thereby enabling the measurement and detection of voltage changes in a capacitive type according to the contact area when the driver grips the steering wheel (100) with their hand.

[0030] To this end, the touch sensor layer (120) is preferably made of a fabric woven such that the warp and weft threads cross at least once. In this way, by making the touch sensor layer (120) into a fabric structure, it is possible to secure excellent stretchability, so that it can be easily attached when wrapping and covering the steering wheel frame (150).

[0031] In addition, the touch sensor layer (120) is formed by a conductive thread in which at least one of the warp and weft threads is plated, thereby ensuring excellent conductivity and making it easy to detect whether the driver is gripping it in a capacitive type.

[0032] Figure 3 is a schematic diagram illustrating the structure of a fabric woven with a warp knitting structure, Figure 4 is a schematic diagram illustrating the structure of a fabric woven with a warp knitting structure, and Figure 5 is a photograph showing the actual fabric woven with a warp knitting structure.

[0033] First, as illustrated in FIG. 3, the steering wheel touch sensor according to an embodiment of the present invention may have a fabric structure woven in a cross-knit structure by using a plated conductive thread (125) as at least one of a weft and a warp thread, and crossing the weft and warp threads at least once. This fabric structure woven in a cross-knit structure is woven into a rigid structure, ensuring excellent durability and preventing lateral unraveling after punching.

[0034] Additionally, as illustrated in FIGS. 4 and 5, the steering wheel touch sensor according to an embodiment of the present invention may have a fabric structure woven in a warp-knit structure by using a plated conductive thread (125) as at least one of a weft and a warp thread, and crossing the weft and warp threads at least once. Although the durability of such a fabric structure woven in a warp-knit structure is somewhat inferior to that of a flat-knit structure, excellent elongation is possible.

[0035] At this time, considering that the steering wheel touch sensor according to the embodiment of the present invention is mounted in a manner that wraps around and covers the steering wheel frame, it is important to ensure elongation, which is a property of stretching well, so it is more desirable to apply a fabric structure woven in a warp knitting structure rather than a fabric structure woven in a transverse knitting structure.

[0036] Meanwhile, FIG. 6 is a schematic diagram showing a plated conductive thread used to manufacture a steering wheel touch sensor according to an embodiment of the present invention.

[0037] As illustrated in FIG. 6, the steering wheel touch sensor according to an embodiment of the present invention is formed from a conductive thread (125) in which at least one of the weft and warp threads is plated, and thus has conductivity.

[0038] Here, the plated conductive thread (125) has a polymer fiber (125a) having a thickness of 10 to 60 denier and a plating layer (125b) plated to cover the surface of the polymer fiber (125a).

[0039] One or more types selected from polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polypropylene terephthalate (PPT), polynaphthalene terephthalate (PEN) resin, polylactic acid (PLA), nylon, etc. may be used as polymer fibers (125a), but are not limited thereto. If the thickness of the polymer fiber (125a) becomes thinner than 10 denier, it may be difficult to secure the strength of the conductive thread (125), and if the thickness of the polymer fiber (125a) exceeds 60 denier, it may be difficult to secure elongability due to a decrease in elongation.

[0040] The plating layer (125b) may be made of one or more alloy materials selected from copper (Cu), nickel (Ni), titanium (Ti), aluminum (Al), gold (Au), silver (Ag), and chromium (Cr), which have excellent conductivity. It is preferable that the plating layer (125b) has a thickness of 30 to 150 μm, more preferable that it has a thickness of 50 to 100 μm, and most preferable that it has a thickness of 70 to 90 μm. If the thickness of the plating layer (125b) is too thin, such as less than 30 μm, it may be difficult to ensure conductivity, and if the thickness of the plating layer exceeds 100 μm and is formed with an excessive thickness, the elongation of the conductive thread (125) may be reduced, and there is a risk that the ductility may rapidly decrease.

[0041] Additionally, the plated conductive seal (125) further includes an antifouling and moisture-proof coating layer (125c) coated on the plating layer (125b).

[0042] It is preferable that the antifouling and moisture-proof coating layer (125c) has a thickness of 5 to 50 μm, more preferable that it has a thickness of 10 to 40 μm, and most preferable that it has a thickness of 25 to 35 μm. If the thickness of the antifouling and moisture-proof coating layer (125c) is too thin, less than 5 μm, it is difficult to properly perform the antifouling function, and if the thickness of the antifouling and moisture-proof coating layer (125c) is formed too thick, exceeding 50 μm, there is a problem of reducing strength.

[0043] The antifouling and moisture-proof coating layer (125c) comprises 10 to 30 weight% binder resin, 5 to 15 weight% antifouling agent, 1 to 5 weight% slip agent, and the remainder being polyester-based urethane resin.

[0044] One or more binder resins selected from polyimide, polyethersulfone, polycarbonate, polypropylene, polyethylene, polyethylene terephthalate (PET) may be used.

[0045] It is preferable that the binder resin be added in a content ratio of 10 to 30 weight percent of the total weight of the antifouling and moisture-proof coating layer (125c), more preferable that it be added in a content ratio of 15 to 25 weight percent, and most preferable that it be added in a content ratio of 17 to 23 weight percent. If the content of the binder resin is less than 10 weight percent, it may be difficult to ensure dispersibility, and if the content of the binder resin is excessively added in excess of 30 weight percent, the content of the antifouling agent is relatively reduced, which may make it difficult to ensure the antifouling function.

[0046] Antifouling agents are used to prevent the adhesion of contaminants and to facilitate the removal of attached contaminants. Fluorine-containing alkyl compounds, fluorine-containing alkanols, fluorine-containing silane coupling agents, and fluorine-containing silicon compounds may be used as antifouling agents.

[0047] It is preferable that the antifouling agent be added in a content ratio of 5 to 15 weight percent of the total weight of the antifouling and moisture-proof coating layer (125c), more preferable that it be added in a content ratio of 7 to 13 weight percent, and most preferable that it be added in a content ratio of 9 to 12 weight percent. If the content of the antifouling agent is less than 5 weight percent, there is a risk that the antifouling function may not be properly implemented, and if the content of the antifouling agent is added in excess of 15 weight percent, there is a risk that the durability may be reduced.

[0048] Slip agents are organic or inorganic particles with uniformly distributed fine particles that are uniformly applied to a coating film to form micro-protrusions, thereby exhibiting a high water contact angle. They are used to improve surface properties such as slip resistance, wear resistance, and scratch resistance. Suitable slip agents include copolymers of olefins, silicones, fluorine-based and fluorine-containing olefins, urethanes, and acrylics.

[0049] It is preferable that the slip agent be added in a content ratio of 1 to 5 weight percent of the total weight of the antifouling and moisture-proof coating layer (125c), and more preferable that it be added in a content ratio of 2.5 to 3.5 weight percent. If the content of the slip agent is less than 1 weight percent, the slip properties, wear resistance, and scratch resistance are not improved, and if the content of the slip agent is added in excess of 5 weight percent, the viscosity increases, fluidity decreases, and re-aggregation between particles occurs, resulting in a problem of reduced dispersibility.

[0050] Polyester-based urethane resins are used to improve adhesion and strengthen the durability of the coating film. Specifically, a polyester-based urethane resin may be used that is manufactured by copolymerizing a polyurethane component consisting of a dicarboxylic acid component, a glycol component, and a diisocyanate component with a polyester component containing OH groups and COOH groups.

[0051] Each component of the polyester-based urethane resin is not specifically limited to those generally used in the field, but specifically, when using a copolymer of a urethane component and an ester component in a weight ratio of 1:1, adhesion and durability can be further improved.

[0052] It is preferable that such polyester-based urethane resin be added in an amount of 20 to 70 weight percent of the total weight of the antifouling and moisture-proof coating layer (125c), and more preferable that it be added in an amount of 40 to 60 weight percent. If the content of the polyester-based urethane resin is added in an amount less than 20 weight percent, it may be difficult to ensure durability, and if the content of the polyester-based urethane resin is added in an excessive amount exceeding 70 weight percent, there is a problem of reducing the antifouling function.

[0053] Additionally, the antifouling and moisture-proof coating layer (125c) may further include 0.5 to 2.0 weight% of isophorone diisocyanate and 0.1 to 1.5 weight% of diphenyl-iso-octyl-phosphite. At this time, it was confirmed that the antifouling and moisture-proof coating layer (125c) is most advantageous for securing excellent strength without increasing elongation when isophorone diisocyanate and diphenyl-iso-octyl-phosphite are added in combination.

[0054] Isophorone diisocyanate is added to the antifouling and moisture-proof coating layer (125c) to increase elongation without reducing strength. If the content of isophorone diisocyanate is less than 0.5 weight%, the amount added is negligible, making it difficult to properly exert the effect of increasing elongation, and if the content of isophorone diisocyanate exceeds 2.0 weight%, there is a risk of reducing strength.

[0055] Diphenyl-iso-octyl-phosphite is added to the antifouling and moisture-proof coating layer (125c) to increase strength while minimizing the reduction in elongation. If the content of diphenyl-iso-octyl-phosphite is less than 0.1 weight%, it is difficult to achieve a strength-enhancing effect, and if diphenyl-iso-octyl-phosphite is added in excess of 1.5 weight%, it may act as a factor that increases the surface resistance value.

[0056] The steering wheel touch sensor according to the embodiment of the present invention described above is manufactured by using a fabric made of conductive threads with a plated surface to impart stretchability and implement capacitance, thereby quantifying the change in capacitance value according to the contact area when the driver grips the steering wheel with their hand, and measuring and detecting the position and area of ​​the grip.

[0057] To this end, the steering wheel touch sensor according to an embodiment of the present invention is formed with a fabric knit structure in which the touch sensor layer is woven such that the warp and weft threads cross at least once, thereby enabling excellent elongation and allowing for easy attachment when wrapping and covering the steering wheel frame. In addition, this knit structure prevents thread unraveling on the cut surface after cutting by die cutting, laser cutting, or cutting machine, thereby reducing defects caused by short circuits between upper and lower sensors or between front and rear sensors.

[0058] In addition, the steering wheel touch sensor according to the embodiment of the present invention is formed such that at least one of the weft and warp threads is plated with a conductive thread, thereby securing excellent conductivity and making it easy to detect whether the driver is gripping it as a capacitive type.

[0059] In addition, the steering wheel touch sensor according to an embodiment of the present invention has excellent antifouling and moisture-proof properties because the conductive seal further includes an antifouling and moisture-proof coating layer, thereby reliably protecting the plated conductive seal from contaminants or moisture, and thus improving the reliability of the touch sensor layer.

[0060] Hereinafter, a method for manufacturing a steering wheel touch sensor according to an embodiment of the present invention will be described.

[0061] FIG. 7 is a process flowchart illustrating a method for manufacturing a steering wheel touch sensor according to an embodiment of the present invention.

[0062] As shown in FIG. 7, the method for manufacturing a steering wheel touch sensor according to an embodiment of the present invention includes a step of forming a touch sensor layer (S210) and a step of bonding the touch sensor layer to a steering wheel frame (S220).

[0063] Touch sensor layer formation step

[0064] In the touch sensor layer formation step (S210), a touch sensor layer is formed to detect the hands-on or hands-off state of a driver riding in a vehicle.

[0065] The touch sensor layer is formed with a conductive thread in which at least one of the weft and warp threads is plated, and thus has conductivity.

[0066] Here, the plated conductive thread has a polymer fiber with a thickness of 10 to 60 denier and a plating layer plated to cover the surface of the polymer fiber.

[0067] One or more polymer fibers selected from polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polypropylene terephthalate (PPT), polynaphthalene terephthalate (PEN) resins, polylactic acid (PLA), nylon, etc., may be used, but are not limited thereto. If the thickness of the polymer fiber becomes thinner than 10 denier, it may be difficult to secure the strength of the conductive thread, and if the thickness of the polymer fiber exceeds 60 denier, it may be difficult to secure elongation due to a decrease in elongation.

[0068] The plating layer may be made of one or more alloy materials selected from copper (Cu), nickel (Ni), titanium (Ti), aluminum (Al), gold (Au), silver (Ag), and chromium (Cr), which have excellent conductivity. It is preferable for the plating layer to have a thickness of 30 to 150 μm, more preferable for a thickness of 50 to 100 μm, and most preferable for a thickness of 70 to 90 μm. If the thickness of the plating layer is too thin, less than 30 μm, it may be difficult to ensure conductivity, and if the thickness of the plating layer is formed with an excessive thickness exceeding 100 μm, the elongation of the thread may decrease, causing a rapid decline in elongation, or cracks may occur in the plating layer during repeated shrinkage and expansion, which may actually lower electrical conductivity.

[0069] In addition, the plated conductive thread further includes an antifouling and moisture-proof coating layer coated on the plating layer.

[0070] It is preferable that such an antifouling and moisture-proof coating layer have a thickness of 5 to 50 μm, more preferable that it have a thickness of 10 to 40 μm, and most preferable that it have a thickness of 25 to 35 μm. If the thickness of the antifouling and moisture-proof coating layer is too thin, less than 5 μm, it is difficult to properly perform the antifouling function, and if the thickness of the antifouling and moisture-proof coating layer is formed too thick, exceeding 50 μm, there is a problem of reducing elongation.

[0071] The antifouling and moisture-proof coating layer comprises 10 to 30 weight% binder resin, 5 to 15 weight% antifouling agent, 1 to 5 weight% slip agent, and the remainder being polyester-based urethane resin.

[0072] In addition, the antifouling and moisture-proof coating layer may further include one or more of isophorone diisocyanate 0.5 to 2.0 wt% and diphenyl-iso-octyl-phosphite 0.1 to 1.5 wt%. At this time, it was confirmed that the antifouling and moisture-proof coating layer is most advantageous for securing excellent strength without increasing elongation when isophorone diisocyanate and diphenyl-iso-octyl-phosphite are added in combination.

[0073] Step of combining the touch sensor layer with the steering wheel frame

[0074] In the step of combining the touch sensor layer with the steering wheel frame (S220), the touch sensor layer is combined to wrap around and cover the steering wheel frame.

[0075] In this step, when considering that a steering wheel touch sensor including a touch sensor layer is mounted in a way that wraps around and covers the steering wheel frame, it is important to ensure stretchability, so it is more desirable to apply a fabric structure woven with a warp knitting structure rather than a fabric structure woven with a warp knitting structure.

[0076] The steering wheel touch sensor manufactured by the method according to the embodiment of the present invention described above is fabricated using a conductive thread with a plated surface to impart stretchability and implement capacitance, thereby enabling the measurement and detection of the magnitude of the current in a capacitive manner according to the contact area when the driver grips the steering wheel with their hand.

[0077] To this end, the steering wheel touch sensor manufactured by the method according to the embodiment of the present invention is formed with a fabric structure in which the touch sensor layer is woven such that the warp and weft threads cross at least once, thereby enabling excellent elongation and making it easy to attach when wrapping and covering the steering wheel frame.

[0078] In addition, by forming a touch sensor layer manufactured by the method according to an embodiment of the present invention such that at least one of the weft and warp threads is formed as a conductive thread that has been plated, it is possible to easily detect whether the driver is gripping it as a capacitive type by securing excellent conductivity.

[0079] In addition, since the conductive thread manufactured by the method according to the embodiment of the present invention further includes an antifouling and moisture-proof coating layer, the antifouling and moisture-proof properties are excellent, allowing the plated conductive thread to be reliably protected from contaminants or moisture, thereby improving the reliability of the touch sensor layer.

[0080] Examples

[0081] Hereinafter, the structure and operation of the present invention will be explained in more detail through preferred embodiments of the present invention. However, these are presented as preferred examples of the present invention and should not be interpreted in any way as limiting the present invention.

[0082] Details not listed here can be sufficiently technically inferred by a person skilled in this field, so their explanation will be omitted.

[0083] 1. Specimen preparation

[0084] Example 1

[0085] A conductive thread was manufactured by forming a plating layer with a thickness of 90 μm by plating copper (Cu) on the surface of a 30 denier polyethylene terephthalate (PET) fiber using an electroplating method, and then forming an antifouling and moisture-proof coating layer with a thickness of 35 μm on the plating layer.

[0086] At this time, the antifouling and moisture-proof coating layer was composed of 20 wt% polyethersulfone as a binder resin, 10 wt% fluorine-containing alkyl compound as an antifouling agent, 3 wt% olefin-based slip agent as a slip agent, and the remainder being polyester-based urethane resin.

[0087] Next, a touch sensor layer formed of a fabric structure was manufactured by using a conductive thread as the weft and a nylon fiber with a thickness of 30 denier as the warp to weave in a transverse knit structure.

[0088] Example 2

[0089] A conductive thread was manufactured by forming a plating layer with a thickness of 70 μm by plating copper (Cu) on the surface of a 40 denier polyethylene terephthalate (PET) fiber using an electroplating method, and then forming an antifouling and moisture-proof coating layer with a thickness of 25 μm on the plating layer.

[0090] At this time, for the antifouling and moisture-proof coating layer, a composition was used comprising 23 wt% polyethersulfone as a binder resin, 12 wt% fluorine-containing alkyl compound as an antifouling agent, 2 wt% olefin-based slip agent as a slip agent, and the remainder being polyester-based urethane resin.

[0091] Next, a touch sensor layer having a fabric structure was manufactured by using a conductive thread as the weft and a nylon fiber with a thickness of 40 denier as the warp to weave in a transverse knit structure.

[0092] Example 3

[0093] A conductive thread was manufactured by forming a plating layer with a thickness of 75 μm by plating copper (Cu) on the surface of a 30 denier polyethylene terephthalate (PET) fiber using an electroplating method, and then forming an antifouling and moisture-proof coating layer with a thickness of 27 μm on the plating layer.

[0094] At this time, as the antifouling and moisture-proof coating layer, a composition comprising 21 wt% polyethersulfone as a binder resin, 12 wt% fluorine-containing alkyl compound as an antifouling agent, 4 wt% olefin-based slip agent as a slip agent, 1.0 wt% isophorone diisocyanate, and the remainder being polyester-based urethane resin was used.

[0095] Next, a touch sensor layer having a fabric structure was manufactured by using a conductive thread as the weft and a nylon fiber with a thickness of 30 denier as the warp, and weaving it in a warp-knitted structure.

[0096] Example 4

[0097] A conductive thread was manufactured by forming a plating layer with a thickness of 80 μm by plating copper (Cu) on the surface of a 40 denier polyethylene terephthalate (PET) fiber using an electroplating method, and then forming an antifouling and moisture-proof coating layer with a thickness of 23 μm on the plating layer.

[0098] At this time, as the antifouling and moisture-proof coating layer, a composition was used comprising 18 wt% polyethersulfone as a binder resin, 11 wt% fluorine-containing alkyl compound as an antifouling agent, 3 wt% olefin-based slip agent as a slip agent, 1.0 wt% isophorone diisocyanate and 0.5 wt% diphenyl-iso-octyl-phosphite, and the remainder being polyester-based urethane resin.

[0099] Next, a touch sensor layer having a fabric structure was manufactured by using a conductive thread as the weft and a nylon fiber with a thickness of 40 denier as the warp, and weaving it in a warp-knitted structure.

[0100] Comparative Example 1

[0101] A conductive thread was manufactured by plating copper (Cu) onto the surface of a 30-denier polyethylene terephthalate (PET) fiber using an electroplating method to form a plating layer with a thickness of 90 μm.

[0102] Next, a touch sensor layer having a fabric structure was manufactured by using a conductive thread as the weft and a nylon fiber with a thickness of 30 denier as the warp, and weaving it in a warp-knitted structure.

[0103] Comparative Example 2

[0104] A conductive thread was manufactured by forming a plating layer with a thickness of 90 μm by plating copper (Cu) on the surface of a 40 denier polyethylene terephthalate (PET) fiber using an electroplating method, and then forming an antifouling and moisture-proof coating layer with a thickness of 35 μm on the plating layer.

[0105] At this time, for the antifouling and moisture-proof coating layer, a composition was used comprising 35 wt% polyethersulfone as a binder resin, 4 wt% fluorine-containing alkyl compound as an antifouling agent, 5 wt% olefin-based slip agent as a slip agent, and the remainder being polyester-based urethane resin.

[0106] Next, a touch sensor layer having a fabric structure was manufactured by using a conductive thread as the weft and a nylon fiber with a thickness of 40 denier as the warp, and weaving it in a warp-knitted structure.

[0107] 2. Evaluation of physical properties

[0108] Table 1 shows the results of the physical property evaluation for specimens prepared according to Examples 1 to 4 and Comparative Examples 1 to 2.

[0109] 1) Robbers and believers

[0110] Measurements were taken using an automatic tensile testing machine (Textechno) at a speed of 50 cm / min and a gripping distance of 50 cm. Strength and elongation were defined as the value (g / de) obtained by dividing the applied load by the denier (de) when a constant force is applied to the fiber to stretch it until it breaks, and elongation as the value (%) representing the initial length as a percentage of the elongated length.

[0111] 2) Electrical resistance

[0112] Electrical resistance (Ω / cm) was measured according to ASTM D257.

[0113] 3) Stain resistance

[0114] The visual inspection level when writing or erasing with an oil-based pen (Monami blue name pen) was evaluated. Stain resistance was assessed based on writing and erasing. (◎: Excellent, ○: Excellent, △: Average, ×: Poor)

[0115] division Strength (g / de) believers (%) Electrical resistance value (Ω / cm) Stain resistance Example 1 5.11 76.2 1.4 ◎ / ◎ Example 2 5.47 75.7 1.7 ◎ / ◎ Example 3 5.13 77.6 1.9 ◎ / ◎ Example 4 5.67 78.3 1.8 ◎ / ◎ Comparative Example 1 4.69 69.4 1.2 X / X Comparative Example 2 5.14 67.8 1.3 △ / △

[0116] As shown in Table 1, it was confirmed that the specimens according to Examples 1 to 4 satisfied all of the target values, including strength of 5.0 to 6.0 g / de, elongation of 70 to 85%, and electrical resistance of 2.0 Ω / cm or less.

[0117] In addition, it was confirmed that the specimens according to Examples 1 to 4 exhibited excellent stain resistance.

[0118] On the other hand, in the case of the specimen according to Comparative Example 1, the electrical resistance value satisfied the target value, but the strength and elongation did not satisfy the target value, and the antifouling and moisture-proof coating layer was not formed, so the stain resistance was poor.

[0119] In addition, in the case of the specimen according to Comparative Example 2, the electrical resistance value and strength satisfied the target values, but the elongation did not satisfy the target value, and the stain resistance was only at an average level due to the addition of a large amount of binder resin and a small amount of antifouling agent.

[0120] In addition, as with the specimen according to Example 4, when isophorone diisocyanate and diphenyl-iso-octyl-phosphite are combined and added as an antifouling and moisture-proof coating layer, it was confirmed that the best physical properties are achieved, such as having excellent strength and elongation.

[0121] Although the embodiments and comparative examples of the present invention have been described in detail as above, the scope of the present invention is not limited thereto, and the scope of the present invention extends to those that are substantially equivalent to the embodiments of the present invention. Explanation of the symbols

[0122] 100 : Steering wheel 110: Insulating layer 120 : Touch sensor layer 125 : Conductive thread 125a: Polymer fiber 125b: Plating layer 125c: Antifouling and moisture-proof coating layer 130 : Electromagnetic shielding layer 140 : Heater layer 150: Steering wheel frame 160 : Cover layer S210: Touch sensor layer formation step S220: Step of combining the touch sensor layer with the steering wheel frame

Claims

Claim 1 A steering wheel touch sensor for HOD (Hands Off Detection) mounted on a steering wheel of a vehicle, comprising a touch sensor layer coupled to wrap around and cover a steering wheel frame and for detecting a hands-on or hands-off state of a driver riding in the vehicle, wherein the touch sensor layer is made of a fabric woven such that the weft and warp threads cross at least once, and wherein at least one of the weft and warp threads is formed as a plated conductive thread to have conductivity. Claim 2 A steering wheel touch sensor according to claim 1, characterized in that the fabric is woven in a warp or weft structure. Claim 3 A steering wheel touch sensor according to claim 1, wherein the plated conductive thread comprises a polymer fiber having a thickness of 10 to 60 denier and a plating layer plated to cover the surface of the polymer fiber, and the plating layer has a thickness of 30 to 150 μm. Claim 4 A steering wheel touch sensor according to claim 3, further comprising: an antifouling and moisture-proof coating layer having a thickness of 5 to 50 μm, wherein the plated conductive thread is coated on the plating layer. Claim 5 A steering wheel touch sensor according to claim 4, wherein the antifouling and moisture-proof coating layer comprises 10 to 30 weight% binder resin, 5 to 15 weight% antifouling agent, 1 to 5 weight% slip agent, and the remainder being polyester-based urethane resin. Claim 6 A method for manufacturing a HOD (Hands Off Detection) steering wheel touch sensor mounted on a steering wheel of a vehicle, comprising: a step of forming a touch sensor layer for detecting a hands-on or hands-off state of a driver riding in the vehicle; and a step of coupling the touch sensor layer to wrap around and cover a steering wheel frame; wherein the touch sensor layer is made of a fabric woven such that the weft and warp threads cross at least once, and at least one of the weft and warp threads is formed as a plated conductive thread to have conductivity. Claim 7 A method for manufacturing a steering wheel touch sensor according to claim 6, wherein the plated conductive thread comprises a polymer fiber having a thickness of 10 to 60 denier and a plating layer plated to cover the surface of the polymer fiber; and wherein the plating layer has a thickness of 30 to 150 μm. Claim 8 A method for manufacturing a steering wheel touch sensor according to claim 7, wherein the plated conductive thread is coated on the plating layer and further comprises an antifouling and moisture-proof coating layer having a thickness of 5 to 50 μm. Claim 9 A method for manufacturing a steering wheel touch sensor according to claim 8, wherein the antifouling and moisture-proof coating layer comprises 10 to 30 weight% of binder resin, 5 to 15 weight% of antifouling agent, 1 to 5 weight% of slip agent, and the remainder being polyester-based urethane resin.

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