Deformation detection mechanism, mobile body, and method for manufacturing deformation detection mechanism

Abstract

To provide a deformation detection mechanism capable of accurately detecting deformation of an article.SOLUTION: A deformation detection mechanism comprises a planar body including a plate-like member and a sensor portion disposed on a first main surface of the plate-like member, and a detection device including a control unit. The sensor portion has conductivity, and the plate-like member and the sensor portion are electrically insulated from each other. The control unit is electrically connected to the sensor portion and is configured to determine whether or not the sensor portion has been irreversibly deformed on the basis of a result of measurement of an electrical property of the sensor portion. When a bending load is applied to a surface opposite to the surface on which the sensor portion is disposed of the planar body by a three-point bending test method defined in JIS K 7074:1988, a bending stress at which the control unit determines that the sensor portion has been irreversibly deformed is defined as F1(MPa), and a bending strength of the planar body is defined as F2 (MPa), a relationship of 0.6<F1 / F2<1.4 is satisfied.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a deformation detection mechanism, a moving body, and a method for manufacturing a deformation detection mechanism. [Background technology]

[0002] Regardless of the type of item, deterioration over time and use is unavoidable. Parts that make up moving objects such as vehicles can become deformed or damaged due to factors such as heat generated by the engine, friction caused by the operation of the device, weather conditions, collisions with flying objects, or contact with other parts that have come off the moving object.

[0003] Since damage to vehicle parts can cause accidents, damage should be detected immediately and repairs or part replacements should be carried out. However, inspection of vehicle parts is only possible for technicians with specialized knowledge, and even for specialized technicians, inspecting parts in vehicles with complex structures is time-consuming. Therefore, it is desirable for a vehicle to be equipped with a device that immediately detects damage to a vehicle part and notifies the vehicle user, especially the driver.

[0004] Patent Document 1 discloses a crack detection system capable of detecting cracks that occur in real time in moving objects such as vehicle tire wheels during their operation. Patent Document 2 discloses a technology for detecting damage to a battery pack used in electric vehicles, etc., using a deformation sensor including a conductive coating applied to a protective plate made of an electrical insulator and an evaluation circuit that detects changes in the electrical resistance of the deformation sensor. Patent Document 3 discloses an automobile battery mechanism comprising a battery, a protective plate placed on one side of the battery, and a damage detection device having damage display means embedded in the protective plate. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-44007 [Patent Document 2] European Patent Application Publication No. 3392070 [Patent Document 3] US Patent Application Publication No. 2022 / 0029215 Summary of the Invention [Problem to be solved by the invention]

[0006] Damage detection devices are required to have sensors that reliably respond when the component being detected is damaged. However, for example, when a mobile object is hit by a flying object from the outside or when the mobile object runs over a curb or fallen object, even if the external appearance of the mobile object component is normal, damage may occur in an important functional component, such as an electric vehicle battery, on the opposite side of the impacted surface. Therefore, it is preferable that damage detection devices used in mobile object components, etc., can accurately detect damage that occurs on the opposite side of the impacted surface. However, conventional technologies have not sufficiently addressed the above issues, such as only being able to detect damage when the component is completely damaged.

[0007] Furthermore, it is important for a damage detection device to prevent false detections, where the sensor reacts even when the part is not actually damaged, but conventional technology does not adequately address how to prevent such false detections.

[0008] An object of the present invention is to provide a deformation detection mechanism for accurately detecting deformation of an article. [Means for solving the problem]

[0009] The deformation detection mechanism according to one embodiment of the present invention comprises: a planar body including a plate-like member and a sensor unit disposed on a first main surface of the plate-like member; a detection device including a control unit; A deformation detection mechanism comprising: The sensor unit has conductivity, the plate-like member and the sensor unit are electrically insulated from each other, the control unit is electrically connected to the sensor unit and is configured to determine whether or not the sensor unit has irreversibly deformed based on the result of measuring the electrical characteristics of the sensor unit, A bending load is applied to the surface of the planar body opposite to the surface on which the sensor unit of the planar body is disposed by the three-point bending test method defined in JIS K 7074:1988. When the control unit determines that the sensor unit has irreversibly deformed, the bending stress at that time is defined as F1 (MPa), and when the bending strength of the planar body is defined as F2 (MPa), the relationship 0.6 < F1 / F2 < 1.4 is satisfied.

[0010] A moving body according to an embodiment of the present invention is a moving body having a deformation detection mechanism according to an embodiment of the present invention, the moving body part is one or more selected from the group consisting of a battery housing, a battery protection plate, and a charging coil housing disposed at the bottom of the moving body, the deformation detection mechanism is disposed such that the first main surface of the plate-like member faces the interior of the moving body.

[0011] A method for manufacturing a deformation detection mechanism according to an embodiment of the present invention forms a deformation detection mechanism by disposing a sensor unit and a detection device on a plate-like member that is a part of a moving body.

Advantages of the Invention

[0012] According to the present invention, there is provided a deformation detection mechanism that accurately detects deformation of an article and a moving body provided with the deformation detection mechanism.

Brief Description of the Drawings

[0013] [Figure 1] It is a plan view of a deformation detection mechanism according to a first embodiment of the present invention. [Figure 2] It is a cross-sectional arrow view taken along line II-II of FIG. 1. [Figure 3]This is a diagram for explaining the three-point bending test method. [Figure 4] This is a diagram showing the state of damage of the plate-shaped member. [Figure 5] This is a cross-sectional view of the plate-shaped member in the second embodiment of the present invention. [Figure 6] This is a cross-sectional view of the plate-shaped member in the third embodiment of the present invention. [Figure 7] This is a diagram showing an example of a moving body provided with the deformation detection mechanism of the present invention. [Figure 8] This is a graph showing the measurement results of the three-point bending test in Example 1. [Figure 9] This is a graph showing the measurement results of the three-point bending test in Comparative Example 1.

Embodiments for Carrying out the Invention

[0014] First, the embodiments of the present invention will be listed and described. The present invention includes the aspects described in the following (1) to (19). (1) A planar body including a plate-shaped member and a sensor portion disposed on a first main surface of the plate-shaped member, A detection device including a control unit, A deformation detection mechanism comprising: The sensor portion has conductivity, The plate-shaped member and the sensor portion are electrically insulated from each other, The control unit is electrically connected to the sensor portion and is configured to determine whether the sensor portion has irreversibly deformed based on the result of measuring the electrical characteristics of the sensor portion. A bending load is applied to the surface of the planar body opposite to the surface on which the sensor portion is disposed by the three-point bending test method defined in JIS K 7074:1988. When the control unit determines that the sensor portion has irreversibly deformed, the bending stress at that time is defined as F1 (MPa), and when the bending strength of the planar body is defined as F2 (MPa), a deformation detection mechanism that satisfies the relationship of 0.6 < F1 / F2 < 1.4. (2) The specific bending strength of the plate-shaped member is 5 ((Pa) 1 / 2 / (kg / m 3)) or more. The deformation detection mechanism according to (1). (3) The deformation detection mechanism according to (1) or (2), which is configured to intermittently energize the sensor unit. (4) A deformation detection mechanism described in any one of (1) to (3), wherein the form of the sensor part is one or more selected from the group consisting of a linear shape, a fibrous shape, a film shape, a three-dimensional molded body shape, and combinations thereof. (5) The deformation detection mechanism according to (4), wherein the sensor portion is in the form of a film. (6) The conductive component of the sensor part contains at least one selected from the group consisting of copper, silver, gold, platinum, iron, tin, aluminum, nickel, and conductive carbon; The deformation detection mechanism according to (4) or (5), wherein the conductive component is present in an amount of 30 mass % or less in the sensor section. (7) The conductive component of the sensor part contains at least one conductive carbon selected from the group consisting of carbon black, graphite, carbon fiber, graphene, carbon nanotube, and carbon nanostructure, The deformation detection mechanism according to (6), wherein the conductive carbon is present in an amount of 20 mass % or less in the sensor portion. (8) The deformation detection mechanism described in (7), wherein the conductive component of the sensor portion includes a combination of at least one selected from the group consisting of graphite, carbon fiber, graphene, carbon nanotubes, and carbon nanostructures as the conductive carbon and carbon black. (9) The deformation detection mechanism according to any one of (1) to (8), wherein the sensor section has a portion having a thickness of 1.0 mm or less and a width of 20 mm or less. (10) The deformation detection mechanism according to any one of (1) to (9), wherein at least two portions of the sensor part are present with an interval of 100 mm or less. (11) The sensor unit includes two or more sensor units that are not electrically connected to each other on the first main surface, The deformation detection mechanism according to any one of (1) to (10), wherein the narrowest distance between the two or more sensor units is 100 mm or less. (12) The deformation detection mechanism according to any one of (1) to (11), wherein the plate-like member includes a fiber-reinforced resin. (13) The deformation detection mechanism according to any one of (1) to (12), wherein at least a part of the sensor unit is embedded in the plate-like member. (14) The deformation detection mechanism according to any one of (1) to (13), wherein a non-conductive protective layer is provided on a surface of the sensor unit that does not face the first main surface. (15) The deformation detection mechanism according to any one of (1) to (14), wherein the plate-like member has at least one shape selected from the group consisting of a honeycomb shape, a ribbed plate shape, and a corrugated shape. (16) A deformation detection mechanism described in any one of (1) to (15), wherein the planar body has at least a portion of a laminated structure of the plate-like member and a conductive material layer different from the sensor portion. (17) A deformation detection mechanism described in any one of (1) to (16), wherein the plate-like member is part or all of one or more mobile body parts selected from the group consisting of a battery housing, a battery protective plate, a charging coil housing, a door panel, a door panel inner, a bumper, and a crash can. (18) A moving body having the deformation detection mechanism according to (17), the movable body part is one or more selected from the group consisting of a battery housing, a battery protection plate, and a charging coil housing, which are arranged at the bottom of the movable body; The deformation detection mechanism is disposed so that the first main surface of the plate-like member faces an interior of the moving body. (19) A method for manufacturing a deformation detection mechanism according to any one of (1) to (17), in which a sensor part and a detection device are disposed on a plate-like member that is a part of a moving body to form a deformation detection mechanism.

[0015] Hereinafter, specific examples of the present invention will be described with reference to the drawings. The dimensions and positions of the components in the drawings are schematic and are not intended to limit the dimensions and positions of the components in the actual product.

[0016] (First embodiment) Fig. 1 is a schematic diagram of a deformation detection mechanism 1 according to a first embodiment of the present invention. As shown in Fig. 1, the deformation detection mechanism 1 includes a sheet body 10 and a detection device 20. Fig. 1 shows a plan view of the sheet body 10 and a block diagram of the detection device 20.

[0017] FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1. As shown in FIGS. 1 and 2, the planar body 10 includes a plate-shaped member 11 and a sensor unit 12 disposed on a main surface of the plate-shaped member 11. For the sake of explanation, the main surface of the plate-shaped member 11 on which the sensor unit 12 is disposed is defined as the first main surface 11a, and the main surface opposite the first main surface 11a is defined as the second main surface 11b. The deformation detection mechanism 1 is a mechanism that detects deformation of the plate-shaped member 11 due to an impact, assuming that the impact is primarily applied to the second main surface 11b of the plate-shaped member 11. Here, the main surface refers to a surface of the plate-shaped member that has a relatively larger area than the other surfaces. Specifically, the main surface refers to the two surfaces in the thickness direction of the plate-shaped member (the positive and negative directions of the Z axis). The areas of these two main surfaces may be the same or different.

[0018] The deformation detection mechanism 1 of the present invention is a mechanism for detecting deformation of a plate-shaped member 11. The plate-shaped member 11 may be any member of any article, for example, a part of a mobile object such as a vehicle, a ship, or an aircraft. More specifically, the plate-shaped member 11 may be part or all of one or more mobile object parts selected from the group consisting of a battery housing, a battery protection plate, a charging coil housing, a door panel, an inner door panel, a bumper, and a crash can.

[0019] In this embodiment, the plate-like member 11 is insulating. An example of an insulating plate-like member 11 is a member made of resin, and it may be a member made of fiber-reinforced resin. An object is said to be insulating when the object's electrical resistance (insulation resistance) is greater than 1 MΩ. However, even if the plate-like member 11 has an electrical resistance of 1 MΩ or less, the configuration of this embodiment can be adopted if the electrical resistance is sufficiently high compared to the sensor unit 12 and does not interfere with the measurement of electrical characteristics. The plate-like member 11 has a specific bending strength of 5 ((Pa) 1 / 2 / (kg / m 3 )) or more, and 1 / 2 / (kg / m 3 )) or more is more preferable, and 8 ((Pa) 1 / 2 / (kg / m 3 The upper limit of the specific bending strength of the plate-like member 11 is not particularly limited, but it is preferably 25 ((Pa) 1 / 2 / (kg / m 3 ))The following.

[0020] As the fiber reinforced resin constituting the insulating plate-like member 11, a known insulating material can be used, and as the matrix resin, either a thermosetting resin or a thermoplastic resin can be used.

[0021] Preferred thermosetting resins as the matrix resin include one or more selected from the group consisting of epoxy resins, vinyl ester resins, unsaturated polyester resins, diallyl phthalate resins, phenolic resins, maleimide resins, cyanate resins, benzoxazine resins, and dicyclopentadiene resins.

[0022] Examples of thermoplastic resins preferred as the matrix resin include one or more selected from the group consisting of polyolefin resins, polystyrene resins, thermoplastic polyamide resins, polyester resins, polyacetal resins (polyoxymethylene resins), polycarbonate resins, (meth)acrylic resins, polyarylate resins, polyphenylene ether resins, polyimide resins, polyethernitrile resins, phenoxy resins, polyphenylene sulfide resins, polysulfone resins, polyketone resins, polyether ketone resins, thermoplastic urethane resins, fluorine-based resins, and thermoplastic polybenzimidazole resins.

[0023] The reinforcing fibers contained in the fiber-reinforced resin may be continuous or discontinuous, but discontinuous fibers with a weight-average fiber length of 1 to 100 mm are preferred, as this makes it easier to mold the fiber-reinforced resin into a plate-shaped member and allows for the production of a plate-shaped member with excellent physical properties. The type of reinforcing fiber contained in the fiber-reinforced resin is preferably one or more types selected from the group consisting of carbon fiber, glass fiber, aramid fiber, basalt fiber, ceramic fiber, and metal fiber, as these are readily available and allow for the easy production of molded articles with the desired properties from the fiber-reinforced resin containing them. While carbon fiber and metal fiber are fibers made of conductive materials, if the fiber-reinforced resin containing them as reinforcing fibers is insulating, there is no problem in using them to construct the insulating plate-shaped member of this embodiment.

[0024] The fiber reinforced resin constituting the insulating plate-like member 11 is particularly preferably a cured product of SMC (sheet molding compound) containing glass fiber as the reinforcing fiber and a thermosetting resin as the matrix resin, or a fiber reinforced resin in which discontinuous glass fiber with a weight average fiber length of 1 mm to 100 mm is formed into a mat shape as the reinforcing fiber and is contained in a thermoplastic resin as the matrix resin, as these have the required physical properties, are lighter than other materials, and are more readily available.

[0025] In this embodiment, the planar shape of the plate-shaped member 11 is rectangular, but the planar shape of the plate-shaped member 11 is not particularly limited and may be polygonal, circular, elliptical, or a combination thereof. Furthermore, the plate-shaped member 11 is not necessarily limited to having a flat main surface, and may have irregularities or holes. More specifically, the plate-shaped member 11 may have at least one shape selected from the group consisting of a honeycomb shape, a ribbed plate shape, and a corrugated shape. A honeycomb shape is a shape in which a honeycomb structure is present in a planar view of the plate-shaped member 11.

[0026] The sensor unit 12 is a conductive sensor disposed on the main surface of the plate-like member 11. The sensor unit 12 of this embodiment is a strip-shaped film formed by applying a conductive paint-like composition, and as shown in FIG. 1, the strip-shaped film is folded over the entire main surface of the plate-like member 11, and is disposed so that both ends of the strip of the sensor unit 12 are close to each other. However, the arrangement of the sensor unit 12 is not particularly limited, and it may be linear with no folds. Multiple sensor units 12 that are not electrically connected to each other may be disposed at a predetermined interval. Examples of paints contained in the paint-like composition include one or more types selected from the group consisting of alkyd-based paints, urethane-based paints, epoxy-based paints, melamine-based paints, silicone-based paints, and (meth)acrylic-based paints.

[0027] Here, the sensor unit 12 being conductive means that the sensor unit 12 has conductivity to such an extent that a change in the electrical characteristics due to the presence or absence of deformation can be determined by measuring the electrical characteristics of the sensor unit 12. The electrical resistance (insulation resistance) of the sensor unit 12 may be, for example, 1 MΩ or less, and is preferably less than 0.1 MΩ. There is no particular lower limit to the electrical resistance of the sensor unit 12.

[0028] In this embodiment, the sensor unit 12 has a film-like shape. However, the shape of the sensor unit 12 is not limited thereto and may be one or more selected from the group consisting of linear, fibrous, membrane-like, three-dimensional, and combinations thereof. Here, a three-dimensional shape refers to a shape in which each of the height, width, and depth dimensions is not significantly smaller than the other two dimensions. Examples of a three-dimensional shape include a plate-like, rod-like, spherical, polyhedral, cone-like, pyramidal, irregular block, box-like, and a combination of two or more of these shapes. The sensor unit 12 may have one or more of the following: a curved surface, a slope, a thickness change, holes, etc. The plate-like shape may be any one of a honeycomb shape, a ribbed plate shape, a corrugated shape, etc. In this specification, a film-like shape refers to a shape with a thickness of less than 1.0 mm, and a plate-like shape refers to a shape with a thickness of 1.0 mm or more.

[0029] It is preferable that the sensor unit 12 has a thickness of 1.0 mm or less and a portion with a width of 20 mm or less. When the dimensions of the sensor unit 12 are within the above range, the sensor unit 12 is easy to form, is less likely to interfere with other components, and makes it easier to accurately detect deformation. The width of the sensor unit 12 is the dimension perpendicular to the direction in which the sensor unit 12 extends on the surface of the plate-like member 11. For example, in the cross-sectional view of Figure 2, the lateral dimension W of the sensor unit 12 is the width of the sensor unit 12.

[0030] It is preferable that at least two portions of the sensor unit 12 are spaced apart by a distance of 100 mm or less. The distance between the two portions of the sensor unit 12 means, for example, the distance G between two adjacent portions of the sensor unit 12 shown in the cross-sectional view of FIG. 2. In addition, in a planar view of the sheet body 10, it is preferable that the minimum distance from any position on the plate-like member 11 to the sensor unit 12 is 100 mm or less. When the sensor unit 12 is arranged as described above, the sensor unit 12 is arranged all over the plate-like member 11, and deformation occurring at any position on the plate-like member 11 can be easily detected by the sensor unit 12.

[0031] The sensor unit 12 may contain, as a conductive component, at least one selected from the group consisting of copper, silver, gold, platinum, iron, tin, aluminum, nickel, and conductive carbon. The abundance ratio of the conductive component in the sensor unit 12 may be 30% by mass or less, or 10% by mass or less. The abundance ratio of the conductive component in the sensor unit 12 may be 0.01% by mass or more, or 0.1% by mass or more. The conductive carbon as the conductive component may be, for example, at least one selected from the group consisting of carbon black, graphite, carbon fiber, graphene, carbon nanotubes, and carbon nanostructures. The abundance ratio of the conductive carbon in the sensor unit 12 may be 20% by mass or less, or 10% by mass or less. The abundance ratio of the conductive carbon in the sensor unit 12 may be 0.1% by mass or more, or 1% by mass or more. The conductive component of the sensor unit 12 may include a combination of at least one conductive carbon selected from the group consisting of graphite, carbon fiber, graphene, carbon nanotubes, and carbon nanostructures, and carbon black, and may particularly include a combination of carbon nanostructures and carbon black. Carbon nanostructures are highly conductive materials but are expensive, and when used alone, the viscosity of the dispersion increases, making handling difficult. Combining conductive carbon such as carbon nanostructures with carbon black reduces production costs by using relatively inexpensive carbon black, and produces a conductive composition with excellent conductivity and viscosity suitable for handling. When carbon black is used in combination with other conductive carbons, the abundance ratio of carbon black and other conductive carbons in the sensor unit 12 may be 0.1% by mass or more, or 1% by mass or more, respectively.

[0032] Examples of methods for forming the sensor unit 12 include a method of fixing a conductive object such as a conductive thread or a metal coil to the plate-like member 11 by adhesive bonding or fastening, a method of molding the conductive sensor unit 12 simultaneously with molding the plate-like member 11 using an insert molding technique, and a method of applying a fluid containing a conductive substance to the plate-like member 11. From the viewpoint of facilitating the formation of sensor units with fine and complex shapes, it is preferable to form the sensor unit 12 by applying a fluid containing a conductive substance.

[0033] Preferred examples of coating methods for fluids containing conductive materials include one or more methods selected from the group consisting of inkjet, squeegee, spin coating, screen printing, dispenser, dipping, and doctor blade. Among these, the dispenser method is preferred because it is less likely to cause unintended retention or blockage of conductive material in the coating device and makes it easier to form a sensor unit as designed even in complexly shaped parts of an insulating part-mounted body. An example of a device used for the dispenser method is the Mono Pump (registered trademark) from Heishin Soubi Co., Ltd. The dispenser method uses a device or system that dispenses a fixed amount of coating liquid depending on the movement speed of the dispenser or a table carrying the coated object. Specific methods of the dispenser method include the pneumatic method (syringe method) in which the coating material is delivered using compressed gas, the mechanical (volumetric) method in which the coating material is delivered using volumetric metering and motor drive, the jet method in which the coating material is sprayed from a nozzle, the tubing method in which pressure is applied to a tube to push the coating material out of the tube, the plunger method in which the coating material is mechanically compressed inside a cylinder and delivered, and the screw method in which the coating material is delivered by rotating a screw-shaped rod.

[0034] The sheet member 10 may have a multilayer structure or a laminated structure of an insulator and a conductor. The sheet member 10 may have at least a portion of a laminated structure of a plate-shaped member 11 and a conductive material layer different from the sensor unit 12. When the plate-shaped member 11 is insulating, the plate-shaped member 11 can serve as the insulating portion. For example, a conductive material layer different from the sensor unit 12 may be laminated on a portion of the first main surface 11a of the insulating plate-shaped member 11 where the sensor unit 12 is not located. The conductive material layer laminated on the plate-shaped member 11 can be a metal foil such as aluminum foil.

[0035] The detection device 20 is a device for detecting deformation of the plate-like member 11. As shown in FIG. 1 , the detection device 20 includes a control unit 21 and an output unit 22. The control unit 21 is electrically connected to the sensor unit 12 via an appropriate conductor 30, which is schematically depicted by a dashed line in FIG. 1 , and is configured to measure the electrical characteristics of the sensor unit 12. The electrical characteristic of the sensor unit 12 measured by the control unit 21 is, for example, the electrical resistance of the sensor unit 12. The control unit 21 determines whether the sensor unit 12 has irreversibly deformed based on the results of measuring the electrical characteristics of the sensor unit 12. For example, the control unit 21 continuously measures the electrical resistance of the sensor unit 12 and determines that the sensor unit 12 has irreversibly deformed when the electrical resistance of the sensor unit 12 exceeds a predetermined upper limit. The control unit 21 may be configured to determine that the sensor unit 12 has deformed when the electrical resistance exceeds the upper limit for a predetermined period of time, rather than immediately determining that the sensor unit 12 has irreversibly deformed when the electrical resistance exceeds the predetermined upper limit. This configuration reduces false detections. On the other hand, it is also possible that the sensor unit 12 may deform once and then further deform, causing the broken portion of the sensor unit 12 to contact again and return to the normal range, which could result in a missed detection. In consideration of such a risk, the time from when an electrical resistance exceeding the upper limit is first measured until the control unit 21 determines that the sensor unit 12 has been deformed may be shortened. In this way, the specific control method by the control unit 21 can be appropriately set depending on the type of plate-like member 11 and sensor unit 12, the usage environment, the level of risk of missed detection, etc.

[0036] The conductor 30 electrically connecting the control unit 21 and the sensor unit 12 can be selected from known electric wires or electric cables suitable for the usage environment. The sensor unit 12 may extend from the plate-like member 11 to the control unit 21, with a portion of the sensor unit 12 functioning as the conductor 30. The conductor 30 can be connected to the control unit 21 or the sensor unit 12 using known connection methods such as the use of terminals or adhesive bonding. Typical dimensions of the conductor 30 are a length of 0.3 mm or more and 5 mm or less, a diameter (width) of 0.5 mm or more and 5 mm or less, and a thickness of 0.3 mm or more and less than 5 mm.

[0037] The deformation detection mechanism 1 of this embodiment satisfies specific requirements in terms of its characteristics when a bending load is applied to the surface of the sheet body 10 opposite to the surface on which the sensor unit 12 is arranged (i.e., the surface on which the second main surface 11b of the plate-like member 11 exists) using the three-point bending test method defined in JIS K 7074:1988. FIG. 3 is a diagram for explaining the three-point bending test method. As shown in FIG. 3, according to the three-point bending test method defined in JIS K 7074:1988, the sheet body 10 (or a test piece cut out from it) is placed on two fulcrums 81 spaced a distance L apart, and a bending load is applied from above the sheet body 10 at the center position of the two fulcrums 81 using an indenter 82. At this time, the planar body 10 is placed on the fulcrum 81 so that the surface on which the sensor section 12 is arranged (i.e., the surface on which the first main surface 11a of the plate-like member 11 exists) faces downward, and a load is applied to the upper surface of the planar body 10 (i.e., the surface on which the second main surface 11b of the plate-like member 11 exists) using an indenter 82.

[0038] In the present invention, during the above-described bending test, the detection device 20 continuously measures the electrical characteristics (e.g., electrical resistance) of the sensor unit 12. When a load is applied to the planar body 10 in the bending test, typically, due to the deformation of the sensor unit 12, the electrical characteristics of the sensor unit 12 change significantly at a certain point. For example, when the sensor unit 12 breaks, the energization of the sensor unit 12 is interrupted and the electrical resistance increases extremely. The control unit 21 of the detection device 20 determines that the sensor unit 12 has been irreversibly deformed when the value of the electrical resistance of the sensor unit 12 falls outside a predetermined range. Then, the bending stress at the time when it is determined that the sensor unit 12 has been irreversibly deformed is defined as F1 (MPa). On the other hand, the bending strength of the planar body 10, which is defined as the maximum bending stress applied to the planar body 10 in the bending test, is defined as F2 (MPa).

[0039] In the present embodiment, F1 and F2 defined as above satisfy the relationship of 0.6 < F1 / F2 < 1.4. It is preferable that F1 and F2 satisfy 0.7 < F1 / F2 < 1.3, more preferably 0.8 < F1 / F2 < 1.2, and even more preferably 0.9 < F1 / F2 < 1.1. When 0.6 < F1 / F2, the bending stress F1 at which it is determined that the sensor unit 12 has been irreversibly changed is sufficiently large, so it is possible to prevent false detection in which deformation is detected even though the plate-like member has not deformed. When F1 / F2 < 1.4, the bending stress F1 at which it is determined that the sensor unit 12 has been irreversibly changed is sufficiently small, so it is possible to prevent detection omission in which deformation is not detected even though the plate-like member has deformed. Therefore, according to the configuration of the present embodiment in which F1 and F2 satisfy the above range, the deformation of the plate-like member 11 can be accurately detected by measuring the change in the electrical characteristics of the sensor unit 12.

[0040] F1 can be adjusted, for example, by changing the material of the sensor unit or dimensions such as the thickness of the sensor unit when using a conductive object such as a conductive thread or a metal coil as the sensor unit. When forming the sensor unit using a fluid containing a conductive substance, F1 can be adjusted by changing the abundance ratio of the conductive substance in the fluid, the fluid material, or dimensions such as the thickness of the sensor unit.

[0041] In the deformation detection mechanism 1, the sensor unit 12 is provided on the surface (i.e., first main surface 11a) opposite to the surface where an impact is expected to be applied (i.e., second main surface 11b) for the following reason: Fig. 4 is a schematic diagram showing how an object 92 collides from the outside with a member 90 supported by a support 91, causing the member 90 to deform. As shown in Fig. 4, when an impact is applied to one surface 90b of the member 90, deformation (for example, the occurrence of a crack C) is more likely to occur on the opposite surface 90a than on the surface 90b where the impact was applied.

[0042] Therefore, if, unlike the configuration of the deformation detection mechanism 1 of this embodiment, for example, the sensor unit 12 were arranged on the surface of the plate-shaped member 11 on which the impact is applied (second main surface 11b) or so as to be embedded inside the plate-shaped member 11, the sensor unit 12 would not deform even though deformation is occurring on the surface opposite to the surface on which the impact is applied, and the deformation of the plate-shaped member 11 may not be detected by the sensor unit 12. In the deformation detection mechanism 1 of this embodiment, the sensor unit 12 is provided on the surface of the plate-shaped member 11 opposite to the surface on which the impact is applied, making it easy to avoid the above-mentioned missed detections.

[0043] The control unit 21 may continuously energize the sensor unit 12 to determine whether or not there is deformation of the plate-like member 11, or may intermittently energize the sensor unit 12 to determine whether or not there is deformation of the plate-like member 11. Intermittently energizing the sensor unit 12 is preferable because it reduces power consumption.

[0044] The detection device 20 may be connected to a warning device (not shown) such as a warning lamp or warning alarm, and may be configured so that when the control unit 21 detects deformation of the sensor unit 12, it transmits a signal from the output unit 22 to activate the warning device. The warning lamp or warning alarm may be configured to notify the operator, passengers, or administrator (security company or automobile insurance agency) of the mobile object on which the deformation detection mechanism 1 is mounted, or a database that manages the soundness of parts, of the deformation. The detection device 20 may be configured using, for example, a programmable logic controller (PLC) or the like.

[0045] Second Embodiment Next, another embodiment of the present invention will be described. In the following, the same components as those in the embodiment already described will be given the same reference numerals, and the description thereof will be omitted as appropriate.

[0046] 5 is a cross-sectional view of a planar body 210 of a deformation detection mechanism according to a second embodiment, and corresponds to FIG. 2, which is a cross-sectional view of the planar body 10 in the first embodiment. The shape of the deformation detection mechanism of the second embodiment in plan view is substantially the same as the shape of the deformation detection mechanism 1 shown in FIG. 1, and therefore is not shown. As shown in FIG. 5, the planar body 210 of this embodiment has a layered structure of a plate-like member 211, an insulating film 213, and a sensor unit 212.

[0047] While the plate-shaped member 11 in the first embodiment is an insulating member, the plate-shaped member 211 in this embodiment is a conductive member. When the plate-shaped member 211 is conductive as in this embodiment, if the sensor unit 212 is provided directly on the plate-shaped member 211, electricity flows between the plate-shaped member 211 and the sensor unit 212, and the control unit 21 cannot properly measure the electrical characteristics of the sensor unit 212. Therefore, when the plate-shaped member 211 is conductive, the plate-shaped member 211 and the sensor unit 212 can be electrically insulated from each other by providing an insulating film 213 between the plate-shaped member 211 and the sensor unit 212 as in this embodiment. By employing such a configuration, deformation can be detected even in the case of a conductive plate-shaped member 211.

[0048] Examples of the conductive plate-shaped member 211 include a member made of a metal plate, a carbon fiber reinforced resin, etc. The lengths of the matrix resin and carbon fibers contained in the carbon fiber reinforced resin are the same as the lengths of the matrix resin and reinforcing fibers described above for the fiber reinforced resin of the plate-shaped member 11, which is the insulating member of the first embodiment.

[0049] The material of the insulating film 213 is not particularly limited, and examples include resin, film, paint, etc. The form of the insulating film 213 is not particularly limited as long as it can electrically insulate the sensor section 212 from the plate-shaped member 211. The insulating film 213 may be provided over the entire main surface of the plate-shaped member 211 on which the sensor section 212 is arranged, or may be provided partially on the main surface only at the position where the sensor section 212 is arranged.

[0050] As shown in FIG. 5 , the planar body 210 of this embodiment further includes a non-conductive protective layer 214 that protects the sensor unit 212. The non-conductive protective layer 214 is provided on the surface of the sensor unit 212 that does not face the first main surface 211a of the plate-like member 211. By providing the non-conductive protective layer 214, it is possible to prevent unintended current flow through the conductive sensor unit 212 and unintended damage to the sensor unit during maintenance by a specialized technician, and it is also possible to prevent breakage of the sensor unit 212 due to an impact from the surface opposite the plate-like member 211. The non-conductive protective layer 214 can be formed from, for example, a resin, a film, or a paint.

[0051] (Third embodiment) Fig. 6 is a cross-sectional view of a planar body 310 of a deformation detection mechanism according to a third embodiment, and corresponds to Fig. 2, which is a cross-sectional view of the planar body 10 according to the first embodiment. Note that the shape of the deformation detection mechanism according to the third embodiment in plan view is substantially similar to the shape of the deformation detection mechanism 1 shown in Fig. 1, and therefore is not shown. As shown in Fig. 6, the planar body 310 according to this embodiment has a plate-like member 311, a sensor unit 312, and an insulating coating 313. In this embodiment, the plate-like member 311 is conductive.

[0052] 6, in this embodiment, a recess is provided in the main surface of the plate-shaped member 311, and the sensor unit 312 is embedded in the plate-shaped member 311. By embedding the sensor unit 312 in the plate-shaped member 311, the thickness of the planar body 310 can be reduced. Furthermore, by embedding the sensor unit 312, it is possible to eliminate or reduce the portion that protrudes from the surface of the planar body 310, thereby reducing interference with adjacent members.

[0053] 6, in this embodiment, the sensor section 312 is coated with an insulating coating 313. In the second embodiment described above, insulation is ensured by interposing the insulating film 213 between the sensor section 212 and the plate-shaped member 211, but a configuration in which the sensor section 312 and the plate-shaped member 311 are electrically insulated by applying the insulating coating 313 to the sensor section 312, as in this embodiment, can also be employed.

[0054] The material of the insulating coating 313 is not particularly limited, but it may be a resin coating applied to the periphery of the sensor portion 312. An adhesive for fixing the sensor portion 312 to the plate-like member 311 may also be used as the insulating coating 313.

[0055] (Mobile) Fig. 7 is a diagram showing a vehicle 100, which is an example of a moving body of the present invention. The vehicle 100 has a deformation detection mechanism of the present invention, and Fig. 7 shows the vehicle 100 equipped with the deformation detection mechanism 1. The vehicle 100 has a battery protection plate disposed on the bottom of the vehicle 100, and the battery protection plate is configured as the plate-like member 11 of the deformation detection mechanism 1.

[0056] The deformation detection mechanism 1 provided in the vehicle 100 is disposed in the vehicle 100 so that the first principal surface 11a, on which the sensor unit 12 is provided, of the principal surfaces of the plate-shaped member 11 faces the interior R of the vehicle 100. By disposing the deformation detection mechanism 1 in this manner, the sensor unit 12 is located on a surface that is likely to deform when an impact is applied to the battery protection plate (plate-shaped member 11) from the underside of the bottom, so deformation of the battery protection plate can be accurately detected. Furthermore, in this configuration, the sensor unit 12 is installed inside the vehicle 100, so the risk of damage to the sensor unit 12 or false detection due to, for example, the effects of moisture or salt outside the vehicle 100 or wear during driving can be reduced.

[0057] In the above example, the deformation detection mechanism 1 is configured using a battery protection plate as a plate-like member, but a battery housing or a charging coil housing may also be used as the plate-like member.

[0058] (Method of manufacturing deformation detection mechanism) The deformation detection mechanism of the present invention may be retrofitted to an already manufactured moving object. Specifically, a part of the moving object may be considered as a plate-like member of the deformation detection mechanism of the present invention, and the deformation detection mechanism of the present invention may be formed by arranging a sensor unit and a detection device on the plate-like member. In the deformation detection mechanism of the present invention, the sensor unit is formed on the surface of the plate-like member rather than inside it, so the deformation detection mechanism can be retrofitted without replacing any moving object parts. For example, the deformation detection mechanism can be easily formed by applying an insulating material to the detection target portion of a metal door of an automobile to form an insulating film, and then applying a conductive material on the insulating film to provide a sensor unit and connecting it to a control device.

[0059] Although the present invention has been described in detail above by way of various exemplary embodiments, the present invention is not limited to these. The present invention also includes configurations in which modifications have been made, such as the addition, deletion, or substitution of components as appropriate, and the combination of some or all of the embodiments. [Example]

[0060] [Example 1] A conductive composition for forming a sensor part was prepared by mixing the conductive components, Cabot Corporation's carbon nanostructure ATHLOS™ CNS GPX802 (hereinafter referred to as CNS), and Cabot Corporation's carbon black (VULCAN™ XC72), with Cemedine's Super XL Black adhesive. The abundance ratio of each component to the entire conductive composition was 1.97 mass% for CNS and 3.90 mass% for XC72 (5.87 mass% for the conductive component (conductive carbon)).

[0061] Teijin Automotive Technologies' sheet molding compound material (reinforced fiber is glass fiber, matrix resin component is thermosetting resin) SMC959 molded plate (specific bending strength 10.5 (Pa) 1 / 2 / (kg / m 3 )) was cut into a roughly rectangular parallelepiped plate (plate-like member) with long sides of 140 mm, short sides of 25 mm, and a thickness of 2.5 mm. The conductive composition prepared above was applied to one main surface of the plate, and a sensor section measuring 130 mm in length, 3 mm in width, and 0.1 mm in thickness was formed along the long side and at the center of the short side, yielding a sheet. A deformation detection mechanism was fabricated by connecting both ends of the sensor section of this sheet to a control device including an electrical resistance meter. A three-point bending test method specified in JIS K 7074:1988 was used with this deformation detection mechanism in a manner similar to that illustrated in Figure 3 to determine the bending stress F1 and the bending strength F2 of the sheet when the control device determined that the sensor section had irreversibly deformed. A voltage of 12 V was applied to the sensor section, and the electrical resistance of the sensor section during the bending test was measured. Figure 8 is a graph showing the time changes in the electrical resistance and bending stress of the sensor section during the bending test of Example 1. As shown in Figure 8, in this example, the electrical resistance of the sensor section remained almost constant from the start of the bending test until approximately 160 seconds later, but then increased dramatically at a certain time, T1. The bending stress at time T1 was F1 (MPa), and in this example, F1 was 222 MPa. The bending strength (maximum bending stress in the bending test), F2, in this example was 227 MPa. The F1 / F2 ratio was approximately 0.98.

[0062] [Example 2] The conductive composition was prepared by mixing CNS and carbon black (Asahi AX-020) manufactured by Asahi Carbon Co., Ltd. in a urethane paint (hereinafter the same) at a concentration of 1.24 mass% and 1.87 mass% (conductive component (conductive carbon) concentration of 3.11 mass%), respectively. Furthermore, a molded sheet of SMC850 (specific bending strength 6.35 (Pa)) manufactured by Teijin Automotive Technologies Co., Ltd. was used as the sheet molding compound material. 1 / 2 / (kg / m 3The same procedure as in Example 1 was carried out except that the pressure of the sintered body was changed to 173 MPa. F1 was 173 MPa, F2 was 186 MPa, and F1 / F2 was about 0.93.

[0063] [Example 3] The same procedure as in Example 1 was carried out, except that a copper foil with a thickness of 18 μm, a width of 5 mm, and a length of 150 mm was used as the sensor part instead of the conductive composition. The copper foil was attached to a plate-shaped member using a cyanoacrylate adhesive. F1 was 185 MPa, F2 was 189 MPa, and F1 / F2 was approximately 0.98.

[0064] [Comparative Example 1] The planar body was a thermoplastic resin carbon fiber composite (CFRTP) Sereebo-I (carbon fiber weight average fiber length 20 mm; matrix resin is polyamide 6; specific bending strength 8.25 (Pa)) manufactured by Teijin Limited. 1 / 2 / (kg / m 3 The same procedure as in Example 1 was performed, except that a conductive thread (silver-plated polyamide 66 fiber) integrated by insert molding was used. The conductive thread constituting the sensor unit had a width of 0.1 mm and a length of 150 mm. Figure 9 is a graph showing the time changes in the electrical resistance and bending stress of the sensor unit during the bending test of Comparative Example 1. As shown in Figure 9, in this example, even when the bending stress began to decrease from its maximum value and reached approximately 130 seconds, when it is believed that the plate-shaped member would have broken, the conductive thread constituting the sensor unit did not break, and no significant change in the electrical resistance of the sensor unit was observed. F2 was 354 MPa, but F1 was not present, so the value of F1 / F2 could not be obtained.

[0065] Comparative Example 2 The same procedure as in Comparative Example 1 was carried out, except that the planar body was made by integrating copper foil and Sereebo-I by insert molding. The dimensions of the copper foil constituting the sensor unit were 50 μm thick, 5 mm wide, and 150 mm long. F2 was 422 MPa, but F1 did not exist because the copper foil maintained electrical conductivity even after the plate-like member was damaged, and the value of F1 / F2 could not be obtained.

[0066] Comparative Example 3 The same procedure as in Comparative Example 1 was carried out, except that a planar member was used in which a stainless steel felt and Sereebo-I were integrated by insert molding. The dimensions of the stainless steel felt were 5 mm thick, 10 mm wide, and 150 mm long. F2 was 371 MPa, but since the stainless steel felt maintained electrical conductivity even after the plate-like member was broken, F1 did not exist, and the value of F1 / F2 could not be obtained.

[0067] [Example 4] The same procedure as in Example 1 was carried out, except that the conductive composition was prepared by mixing CNS and carbon black (VULCAN XC72) into a urethane-based paint so that their abundance ratios were 1.75% by mass and 3.70% by mass (the abundance ratio of the conductive component (conductive carbon) was 5.45% by mass). F1 was 126 MPa, F2 was 193 MPa, and F1 / F2 was approximately 0.65.

[0068] [Example 5] The same procedure as in Example 1 was carried out, except that the sensor part was formed by applying a conductive composition consisting of the adhesive Super XL Black and CNS. The abundance ratio of CNS (abundance ratio of the conductive component (conductive carbon)) to the entire conductive composition was 2.67 mass%. F1 was 207 MPa, F2 was 217 MPa, and F1 / F2 was approximately 0.95.

[0069] [Example 6] The same procedure as in Example 2 was carried out, except that the sensor part was a conductive composition consisting of urethane paint and CNS. The abundance ratio of CNS (abundance ratio of conductive component (conductive carbon)) to the entire conductive composition was 2.63 mass%. F1 was 163 MPa, F2 was 175 MPa, and F1 / F2 was approximately 0.93.

[0070] [Example 7] The same procedure as in Example 2 was carried out, except that the sensor part was a conductive composition consisting of urethane paint and CNS. The abundance ratio of CNS (abundance ratio of conductive component (conductive carbon)) to the entire conductive composition was 1.84 mass%. F1 was 151 MPa, F2 was 155 MPa, and F1 / F2 was approximately 0.97.

[0071] According to the above examples, it is possible to adjust the value of F1 / F2 by adjusting the material and composition ratio of the sensor part, and it is found that deformation of the plate-like member can be detected by changes in the electrical characteristics of the sensor part. [Explanation of symbols]

[0072] 1. Deformation detection mechanism 10,210,310 Planar body 11,211,311 Plate-shaped members 11a, 211a First principal surface 11b,211b Second principal surface 12,212,312 Sensor section 20 Detection device 21 Control section 22 Output section 30 conductor 213 Insulating film 214 Non-conductive protective layer 313 Insulating Coating 81 Fulcrum 82 indenter 90 parts 90a Impact surface 90b opposite side 91 Support 92 Object 100 vehicles C Crack R Indoor

Claims

1. a planar body including a plate-like member and a sensor unit disposed on a first main surface of the plate-like member; a detection device including a control unit; A deformation detection mechanism comprising: the sensor portion is conductive, The plate-like member and the sensor unit are electrically insulated from each other, the control unit is electrically connected to the sensor unit and is configured to determine whether the sensor unit has irreversibly deformed based on a result of measuring an electrical characteristic of the sensor unit; A deformation detection mechanism that satisfies the relationship 0.6<F1 / F2<1.4 when a bending load is applied to the surface of the planar body opposite to the surface on which the sensor unit is located using the three-point bending test method defined in JIS K 7074:1988, and the bending stress at which the control unit determines that the sensor unit has irreversibly deformed is defined as F1 (MPa) and the bending strength of the planar body is defined as F2 (MPa).

2. The specific bending strength of the plate-like member is 5 ((Pa) 1 / 2 / (kg / m 3 2. The deformation detection mechanism according to claim 1, wherein the deformation detection mechanism is a deformation detection mechanism having a first end and a second end.

3. The deformation detection mechanism according to claim 1 , wherein the sensor unit is configured to be intermittently energized.

4. The deformation detection mechanism according to claim 1 , wherein the sensor portion has one or more shapes selected from the group consisting of a wire, a fiber, a film, a three-dimensional molded body, and combinations thereof.

5. The deformation detection mechanism according to claim 4 , wherein the sensor portion is in the form of a film.

6. the conductive component of the sensor portion contains at least one selected from the group consisting of copper, silver, gold, platinum, iron, tin, aluminum, nickel, and conductive carbon; The deformation detection mechanism according to claim 4 , wherein the conductive component is present in an amount of 30 mass % or less in the sensor portion.

7. the conductive component of the sensor unit contains at least one conductive carbon selected from the group consisting of carbon black, graphite, carbon fiber, graphene, carbon nanotubes, and carbon nanostructures; The deformation detection mechanism according to claim 6 , wherein the conductive carbon is present in an amount of 20 mass % or less in the sensor portion.

8. 8. The deformation detection mechanism according to claim 7, wherein the conductive component of the sensor portion includes a combination of carbon black and at least one selected from the group consisting of graphite, carbon fiber, graphene, carbon nanotubes, and carbon nanostructures as the conductive carbon.

9. The deformation detection mechanism according to claim 1 , wherein the sensor portion has a portion having a thickness of 1.0 mm or less and a width of 20 mm or less.

10. The deformation detection mechanism according to claim 1 , wherein at least two portions of the sensor portion are spaced apart by an interval of 100 mm or less.

11. the sensor unit includes two or more sensor units that are not electrically connected to each other on the first main surface, The deformation detection mechanism according to claim 1 , wherein the narrowest distance between the two or more sensor units is 100 mm or less.

12. The deformation detection mechanism according to claim 1 , wherein the plate-like member includes a fiber-reinforced resin.

13. The deformation detection mechanism according to claim 1 , wherein at least a portion of the sensor portion is embedded in the plate-like member.

14. The deformation detection mechanism according to claim 1 , wherein a non-conductive protective layer is provided on a surface of the sensor unit that does not face the first main surface.

15. 2. The deformation detection mechanism according to claim 1, wherein the plate-like member has at least one shape selected from the group consisting of a honeycomb shape, a ribbed plate shape, and a corrugated shape.

16. The deformation detection mechanism according to claim 1 , wherein the planar body has at least a portion having a laminated structure of the plate-like member and a conductive material layer different from the sensor portion.

17. 2. The deformation detection mechanism according to claim 1, wherein the plate-like member is part or all of one or more mobile body parts selected from the group consisting of a battery housing, a battery protection plate, a charging coil housing, a door panel, a door panel inner, a bumper, and a crash can.

18. A moving body having the deformation detection mechanism according to claim 17, the movable body part is one or more selected from the group consisting of a battery housing, a battery protection plate, and a charging coil housing, which are arranged at the bottom of the movable body; The deformation detection mechanism is disposed so that the first main surface of the plate-like member faces an interior of the moving body.

19. 2. The method for manufacturing a deformation detection mechanism according to claim 1, wherein the deformation detection mechanism is formed by arranging a sensor portion and a detection device on a plate-like member that is a part of the moving body.

Images