Sensor component and seat sensor

Abstract

This invention provides a sensor component applicable to sensors that detect contact. [Solution] The sensor member 10 includes a braided cord 20 formed by braiding conductive thread 21 into a tubular shape using a flat knitting method. The sensor member 10 includes an insulating base material 80. The braided cord 20 is attached to the base material 80 by sewing thread, and contact can be detected by detecting a change in capacitance in the braided cord 20.

Description

Technical Field

[0001] The present invention relates to a sensor member used for a sensor that detects an external force and a seating sensor.

Background Art

[0002] Patent Document 1 discloses a touch-sensing textile device including a fabric made of conductive yarn.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a textile device, there is a requirement to detect contact as an external force.

Means for Solving the Problems

[0005] The sensor member for solving the above problems includes a knitted cord formed by knitting a conductive yarn into a cylindrical shape by plain knitting, and an insulating base material. The knitted cord is attached to the base material by a sewing thread, and contact can be detected by detecting a change in capacitance in the knitted cord. <管理番号

Effects of the Invention

[0006] [[ID=管理番号0000049]]According to the present invention, it is possible to provide a sensor member of a sensor capable of detecting contact and a seating sensor.

Brief Description of the Drawings

[0007] [Figure 1] FIG. 1 is a schematic view showing an embodiment of the sensor member. [Figure 2]Figure 2 is an enlarged view showing the structure of the braided cord in the sensor component of Figure 1. [Figure 3] Figure 3 is an enlarged view showing the structure of the braided cord in the sensor component of Figure 1. [Figure 4] Figure 4 is a cross-sectional view showing the cross-sectional structure of the braided cord in the sensor member of Figure 1. [Figure 5] Figure 5 is a schematic diagram illustrating the braided cord sewn to the base material in the sensor component shown in Figure 1. [Figure 6] Figure 6 is a schematic diagram illustrating the braided cord sewn to the base material in the sensor component shown in Figure 1. [Figure 7] Figure 7 is a schematic diagram showing a modified sensor component. [Figure 8] Figure 8 is a schematic diagram showing sensor components in other modified examples. [Figure 9] Figure 9 is a schematic diagram showing a sensor component in another modified example. [Figure 10] Figure 10 is a schematic diagram showing yet another modified example of the sensor component. [Modes for carrying out the invention]

[0008] An embodiment of the sensor component will be described below with reference to Figures 1 to 6. As shown in Figure 1, the sensor member 10 comprises a braided cord 20 and a base material 80. The braided cord 20 is attached to the base material 80 by sewing thread. In this embodiment, as shown in Figure 1, a single braided cord 20 is attached to the base material 80.

[0009] The base material 80 is, for example, a fabric. Examples of fabrics include knitted fabrics, nonwoven fabrics, and resin sheets. Preferably, the base material 80 is a stretchable fabric. The base material 80 is insulating.

[0010] FIG. 1 shows an example of use of the sensor member 10. FIG. 1 illustrates a detection device 90 and wirings 91 and 92 that connect the detection device 90 and the braided cord 20. The detection device 90 can detect, for example, the electrical resistance of the braided cord 20. The detection device 90 can detect, for example, the capacitance of the braided cord 20. The detection device 90 may be capable of detecting the electrical resistance and capacitance of the braided cord 20.

[0011] Although details will be described later, according to the sensor applying the sensor member 10, by detecting one or more of the electrical resistance and capacitance in the braided cord 20, the external force applied to the braided cord 20 can be detected

[0012] <Structure of the braided cord> As shown in FIGS. 1 to 3, the braided cord 20 is formed by braiding conductive yarns 21. As the conductive yarn 21, a yarn made of a known fiber having conductivity can be adopted.

[0013] The braided cord 20 may be formed by one yarn, or may be formed by two or more yarns. When the braided cord 20 is formed by braiding two or more yarns, not all of the yarns constituting the braided cord 20 need to be conductive yarns. It is sufficient that one or more of the yarns constituting the braided cord 20 are the conductive yarns 21.

[0014] The braided cord 20 is, for example, "a braided cord made with several knitting needles". More specifically, it is "a cord of a plain weave made with several knitting needles". The number of knitting needles is not particularly limited, but the more the number of knitting needles, the thicker the braided cord 20 becomes. The number of knitting needles is, for example, three. Such a cord of plain weave may also be called a lily cord. Note that plain weave is also called jersey weave and天竺編み (I'm not sure what this specific Japanese term "天竺編み" exactly means in English, it might be a specific type of weave name, but for now I'll keep it as is).

[0015] As an example, the braided cord 20 is formed by knitting the conductive yarn 21 into a tubular shape by plain weave. It is particularly preferable that the braided cord 20 is formed by knitting one conductive yarn 21 into a tubular shape by plain weave.

[0016] A tubular shape is a structure having a circumferential wall with an annular cross-section. In the braided cord 20, the braided structure corresponds to the circumferential wall. The braided cord 20 is hollow inside the circumferential wall formed by the braided structure. That is, the braided cord 20 does not have a core material.

[0017] The term "annular" may refer to a loop, i.e., any structure forming a continuous shape without ends. Examples of the "annular" shape include a circular shape, an elliptical shape, and a polygon having sharp or rounded corners. The "annular" shape is not limited to the above shapes.

[0018] In FIGS. 1 to 4, a central axis C1 is shown as a line along the axis of the braided cord 20. FIGS. 2 and 3 show a braided structure formed by plain knitting. As shown in FIGS. 2 and 3, the braided cord 20 includes stitches arranged to be continuous in the lateral direction. Here, the lateral direction corresponds to the circumferential direction of the tubular braided cord 20, i.e., the circumferential direction centered on the central axis C1.

[0019] FIG. 2 shows a state where the stitches of the braided cord 20 are loose. FIG. 3 shows a state where the stitches of the braided cord 20 are not loose. For example, when a force is applied to the braided cord 20 in FIG. 2 so as to stretch it along the central axis C1, the interval between adjacent stitches becomes narrower, and thus the contact portions between adjacent stitches increase. As a result, the braided cord 20 approaches the state shown in FIG. 3. For example, when a force is applied to the braided cord 20 in FIG. 3 so as to contract it along the central axis C1, the interval between adjacent stitches becomes wider, and thus the contact portions between adjacent stitches decrease. As a result, the braided cord 20 approaches the state shown in FIG. 2. Thus, the braided cord 20 has elasticity.

[0020] In the braided cord 20, the coarseness of the stitches is not particularly limited. For example, as shown in FIG. 3, the braided cord 20 may be configured such that there are gaps between the yarns. The coarseness of the stitches can be adjusted, for example, by adjusting the tension for pulling the cord after knitting when forming the braided cord by knitting the yarns. Note that the finer the stitches, the thinner the braided cord 20.

[0021] The structure of the tubular braided cord 20 will be explained using Figure 4. The braided cord 20 is configured such that when an external force is applied from the radial direction of the tubular braided cord 20, the braided structures facing each other across the central axis C1 of the braided cord 20 come into contact with each other.

[0022] Figure 4 shows the pressure P1, an external force applied to the braided cord 20 from the radial direction, as a white arrow. Here, the radial direction corresponds to the direction perpendicular to the central axis C1. Figure 4 illustrates the braided cord 20 in a deformed state due to the pressure P1. The dashed line in Figure 4 shows the braided cord 20 before deformation.

[0023] As shown in Figure 4, when pressure P1 is applied to the knitted cord 20, the cord 20 deforms so that the knitted structure in the area where pressure P1 is applied approaches the knitted structure opposite it across the central axis C1. The cord 20 can deform even if the force applied to it is not necessarily from the radial direction. Furthermore, the cord 20 can also deform so that the knitted structures opposite each other across the central axis C1 move closer together.

[0024] Furthermore, as shown in Figure 4, when pressure P1 is applied to the braided cord 20, changes in the state of the stitches may occur, as explained using Figures 2 and 3. For example, when pressure P1 is applied to the braided cord 20, the stitches become more likely to come into contact with each other.

[0025] <Braided cord sewn onto the base material> An example of a braided cord 20 sewn to a base material 80 will be explained using Figures 5 and 6. Figure 5 shows the front surface 80a, which is one side of the base material 80. Figure 6 shows the back surface 80b of the base material 80, which is opposite to the front surface 80a. In this embodiment, the sensor member 10 has the braided cord 20 attached to the front surface 80a of the base material 80.

[0026] The method for sewing the braided cord 20 to the base material 80 is not particularly limited, and hand sewing, machine sewing, embroidery, etc., can be used. Below, as an example, a configuration in which the braided cord 20 is sewn on by machine sewing will be described.

[0027] The method of sewing with the sewing thread is not particularly limited, but in the examples shown in Figures 5 and 6, the upper thread 51a and lower thread 51b, which are the sewing threads, are sewn in a zigzag pattern. The upper thread 51a and the lower thread 51b are, for example, non-conductive threads. The upper thread 51a and the lower thread 51b may be conductive threads.

[0028] As shown in Figures 5 and 6, the braided cord 20 is sewn to the base material 80 by sewing threads that form a seam across the braided cord 20. As shown in Figure 5, the braided cord 20 is positioned between the base material 80 and the upper thread 51a.

[0029] In the sensor member 10, it is preferable that the braided cord 20 is not held down by the sewing thread so that the stretching and contraction of the braided cord 20 is not suppressed. It is preferable that the sensor member 10 allows the braided cord 20 to move between the stitches of the sewing thread.

[0030] <Operation of this embodiment> The operation of this embodiment will now be described. As explained using Figures 2 and 3, the braided cord 20 is elastic. When the braided cord 20 stretches or contracts, the way in which the stitches formed by the conductive thread 21 come into contact with each other changes. Specifically, as shown in Figure 2, when the braided cord 20 is loose, there are fewer points of contact between the stitches. On the other hand, as shown in Figure 3, when the braided cord 20 is not loose, there are more points of contact between the stitches compared to the state shown in Figure 2. Therefore, in the state shown in Figure 3, the resistance value decreases compared to the state shown in Figure 2. Furthermore, if a force is applied to stretch the braided cord 20 further from the state shown in Figure 3, the braided cord 20 becomes taut. In the taut state of the braided cord 20, the resistance value decreases even further than in the state shown in Figure 3. Thus, when the braided cord 20 stretches or contracts, the electrical resistance of the braided cord 20 changes before and after the stretching or contraction.

[0031] As explained using Figure 4, the braided cord 20 is configured so that opposing braided structures on either side of the central axis C1 are in contact with each other. When the braided structures come into contact with each other, the resistance changes before and after contact. Thus, when the braided structures of the braided cord 20 come into contact with each other, the electrical resistance of the braided cord 20 decreases.

[0032] As described above, the sensor member 10 can be used as a sensor to detect pressure based on a change in the electrical resistance of the braided cord 20. Furthermore, the sensor member 10 can be used as a sensor to detect strain based on a change in the electrical resistance of the braided cord 20. Pressure and strain are both types of external forces applied to the braided cord 20.

[0033] For example, the magnitude of the pressure can be measured by using a calculation map that represents the relationship between the magnitude of the pressure applied to the braided cord 20 and the change in electrical resistance when that pressure is applied. The calculation map can be calculated in advance through experiments or other means.

[0034] When a person approaches the conductive braided cord 20, a change in capacitance occurs. As described above, the sensor member 10 can be used as a sensor that detects contact based on changes in capacitance in the braided cord 20.

[0035] <Effects of this embodiment> The effects of this embodiment will now be explained. (1) A sensor to which the sensor member 10 is applied can detect pressure and strain by detecting changes in the electrical resistance of the braided cord 20.

[0036] (2) With a sensor to which the sensor member 10 is applied, contact can be detected by detecting a change in capacitance in the braided cord 20. (3) By detecting both changes in electrical resistance and capacitance, it is possible to determine whether the object in contact with the sensor member 10 is a person or an object. For example, when a person makes contact, both electrical resistance and capacitance change. On the other hand, when an object makes contact, the electrical resistance changes, but the capacitance does not.

[0037] (4) The sensor member 10 includes a braided cord 20 made of conductive thread, separate from the base material 80. The braided cord 20 sewn to the base material 80 constitutes a region capable of detecting external forces, so the area of ​​the region capable of detecting external forces correlates with the length of the braided cord 20. Hereinafter, the region capable of detecting external forces will be referred to as the detection area. For example, the shorter the braided cord 20, the easier it is to configure a smaller detection area. The longer the braided cord 20, the easier it is to configure a larger detection area. Thus, the sensor member 10 makes it easy to set detection areas of various sizes.

[0038] (5) In the comparative example, if we consider a sensor using a fabric woven with conductive threads, the portion woven with conductive threads becomes the detection unit. Because the detection unit is a fabric, it can be difficult to freely set the position, size, shape, etc. of the detection unit. In contrast, with the sensor member 10 of this embodiment, the detection unit can be constructed by arranging the braided cord 20, so there are fewer restrictions when setting the position, size, shape, etc. of the detection unit.

[0039] (6) The braided cord 20 made of conductive yarn is flexible. Because the braided cord 20 is flexible, the braided cord 20 as a detection part can be positioned along the shape of the installation surface, even if the base material 80 is not flat, but curved, has a bent corner, etc.

[0040] (7) By using conductive threads with different resistance values, the resistance value of the braided cord 20 made of conductive threads can be changed. In addition, the resistance value of the braided cord 20 can be changed by changing the coarseness of the stitches when braiding the cord 20. This makes it possible to adjust the range of detectable external forces.

[0041] (8) By using a stretchable fabric as the base material 80, the following effects can be obtained. By stretching the base material 80, the sensor member 10 can expand and contract in the axial direction of the braided cord 20, for example. Therefore, compared to the case where the base material 80 is not easily stretchable, changes in electrical resistance in response to strain are more likely to occur. This makes it easier to detect strain.

[0042] <Application form> The application of this embodiment is not particularly limited, but it can be used, for example, as follows. The sensor component 10 can be used as a seating sensor by applying it to, for example, seats in automobiles, wheelchairs, airplanes, trains, bullet trains, theaters, etc.

[0043] The sensor member 10 can be used as a measuring instrument to detect joint flexion, for example, by being applied to clothing or the like. The sensor member 10 can be used, for example, as an operating switch to detect a press.

[0044] (Example of change) This embodiment can be implemented with the following modifications. This embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically.

[0045] As shown in Figure 7, the braided cord 120 may be folded back, so that the braided cord 120 is arranged in a planar manner on the base material 80. In the example shown in Figure 7, the braided cord 120, which extends linearly along the first side 110a, changes direction by 180 degrees at the folded-over portion 121. The alternating pattern of linearly extending sections and sections that change direction by 180 degrees results in multiple folded-over portions 121 lined up along the second side 110b, which is perpendicular to the first side 110a. The braided cords 120 are arranged without any gaps.

[0046] In the sensor member 110 shown in Figure 7, the braided cord 120 is sewn to the base material 80 using a zigzag stitch with sewing thread 51, similar to the embodiment described above. According to the above configuration, the detection unit for detecting pressure can be arranged in a planar manner.

[0047] The braided cords may be arranged in a planar manner along the direction of expansion and contraction of the base material. For example, it is preferable to arrange the braided cords so that the proportion of the detection area where the length direction of the braided cords coincides with the direction in which the base material is easily expanded and contracted is large.

[0048] Figure 7 above illustrates a sensor member 110 in which braided cords 120 are arranged in a planar manner without any gaps. Alternatively, the braided cords may be sewn onto the base material 80 in such a way that gaps are formed between adjacent braided cords.

[0049] By employing flexible braided cords, various shapes can be created using the braided cords, such as the planar shape shown in Figure 7. For example, the braided cords may be arranged as shown in the sensor member 210 in Figure 8.

[0050] In the sensor member 210 shown in Figure 8, the braided cord 220 comprises a curved portion 221 that is curved in a U-shape, and a side portion 222 that is continuously connected to the end of the curved portion 221 and extends away from the curved portion 221.

[0051] In the sensor member 210 shown in Figure 8, the braided cord 220 is sewn to the base material 80 using a zigzag stitch with sewing thread 51, similar to the embodiment described above. It is not essential to include a section where the braided cords are folded back 180 degrees when arranging them in a planar manner. By combining braided cords arranged in a curved manner, braided cords arranged in a bent manner, etc., various shapes can be formed using braided cords. Examples of shapes that can be formed with braided cords include circles, polygons, spirals, geometric patterns, and so on.

[0052] Figure 7 illustrates a sensor member 110 in which detection units for detecting pressure are arranged in a planar manner. A sensor member with detection units arranged in a planar manner may also be configured as shown in Figure 9. Figure 9 shows the sensor member 310. In the sensor member 310, the braided cords 120 are arranged in a planar manner. The folded portions 121 of the braided cords 120, which are arranged in a planar manner, are sewn to the base material 80 using sewing thread 51.

[0053] Unlike the sensor member 110 shown in Figure 7, the sensor member 310 is not sewn to the base material 80 between one folded portion 121 and the next folded portion 121 in the longitudinal direction of the braided cord 120. In other words, the portion of the braided cord 120 that extends linearly along the first side 110a is not sewn to the base material 80. On the other hand, the portion of the braided cord 120 that runs along the second side 110b is sewn to the base material 80. In other words, the end of the braided cord 120 that extends linearly along the first side 110a is sewn to the base material 80.

[0054] The following actions and effects can be obtained with the sensor component 310. When sewing a braided cord to a base material, if the force pressing the cord down with the sewing thread is excessive, the cord may be crushed by the sewing thread. If the braided cord used as the detection part of a sensor is crushed even when no external force is applied to it, there is a problem that the accuracy of the sensor will decrease.

[0055] In this regard, with the sensor member 310, the portion of the braided cord 120 sewn to the base material 80 is only a part of the braided cord 120. Therefore, in the portion of the braided cord 120 that is not sewn to the base material 80, the braided cord 120 is not crushed by the sewing thread 51. This makes it possible to suppress a decrease in the accuracy of the sensor to which the sensor member 310 is applied.

[0056] Furthermore, the sensor member 310 is more stretchable in the direction along the first side 110a compared to the sensor member 110 shown in Figure 7. In particular, if a stretchable fabric is used as the base material 80, the sensor member 310 becomes even more stretchable in the direction along the first side 110a.

[0057] Furthermore, the sensor member 310 allows the portion of the braided cord 120 that is not sewn to the base material 80 to detach from the base material 80. Therefore, even if the base material 80 is deformed, for example by bending, the braided cord 120 can follow the deformation of the base material 80 without any unnecessary force being applied to the braided cord 120.

[0058] In the above embodiment, a sensor member was illustrated in which a braided cord is sewn onto a single base material. The sensor member may be constructed by sewing braided cords onto multiple base materials. For example, the sensor member may be constructed as shown in Figure 10.

[0059] Figure 10 shows the sensor member 410. The sensor member 410 comprises a first base material 81 and a second base material 82. In the sensor member 410, the first base material 81 and the second base material 82 are arranged with a gap between them.

[0060] The sensor member 410 includes a braided cord 420. The braided cord 420 is sewn to the first base material 81 and the second base material 82 so as to connect the first base material 81 and the second base material 82. The sensor member 410 includes a sewing thread 51 for sewing the braided cord 420 to the first base material 81 and the second base material 82.

[0061] The sensor member 410, like the sensor member 310 shown in Figure 9, has braided cords 420 arranged in a planar manner. Similar to the sensor member 310 shown in Figure 9, the portion of the braided cord 420 between one folded portion 421 and the next in the longitudinal direction is not sewn to the base material. That is, the portion of the braided cord 420 extending linearly along the first edge is not sewn to the base material. Furthermore, one portion of the braided cord 420 aligned along the second edge perpendicular to the first edge is sewn to the first base material 81, and the other portion aligned along the second edge is sewn to the second base material 82. For example, as shown in Figure 10, the braided cord 420 is sewn to the end of the first base material 81 facing the second base material 82. The braided cord 420 is sewn to the end of the second base material 82 facing the first base material 81.

[0062] The following actions and effects can be obtained with the sensor component 410. In the sensor member 410, the braided cord 420 stretches easily when a force is applied that causes the first base material 81 and the second base material 82 to move away from each other. Compared to the sensor member 310 shown in Figure 9, the braided cord 420 of the sensor member 410 stretches more easily.

[0063] One example of an application for the sensor member 410 is a switch that operates by fixing the first base material 81 and pulling the second base material 82 away from the first base material 81. Furthermore, there are no particular restrictions on the arrangement of the first substrate 81 and the second substrate 82 when using the sensor member 410. For example, the first substrate 81 and the second substrate 82 may be arranged horizontally, or they may be arranged vertically.

[0064] Figure 10 illustrates a configuration in which one end 420a of the braided cord 420 is attached to the first base material 81 and the other end 420b of the braided cord 420 is attached to the second base material 82. However, both ends of the braided cord 420 may be attached to a single base material. For example, both ends of the braided cord 420 may be attached to the first base material 81, or both ends of the braided cord 420 may be attached to the second base material 82.

[0065] Figures 9 and 10 illustrate sensor components in which braided cords are arranged in a planar manner. The configuration shown in Figures 9 and 10, in which a portion of the braided cord is attached to the base material while the other portion is not attached to the base material, can be applied to sensor components other than those in which braided cords are arranged in a planar manner.

[0066] • In the above embodiment, a sensor member in which one braided cord is attached to the base material was illustrated. Two or more braided cords may be attached to the base material. In the above embodiment, an insulating cloth, cushioning material, etc., may be attached to cover the braided cord 20 attached to the base material 80. That is, the braided cord made of conductive yarn may be exposed or covered.

[0067] The technical concept is described below. In textile devices, there is a demand to detect pressure and strain as external forces.

[0068] In this case, if the sensor is constructed from a woven fabric as disclosed in Patent Document 1, the woven fabric with conductive threads woven into it constitutes the detection unit. Because it is a woven fabric, it has the property of not stretching easily when the detection unit is pulled. A detection unit that has such resistance to stretching may not be suitable for detecting strain.

[0069] The sensor component of technical concept 1 comprises a braided cord formed by braiding conductive threads into a tubular shape using a flat braiding method, and an insulating base material, wherein the braided cord is attached to the base material by sewing thread.

[0070] According to this technical concept 1, it is possible to provide a sensor component for a sensor that can detect pressure and strain. Technical idea 2 is the aforementioned sensor member that can detect pressure by detecting a change in the electrical resistance of the braided cord. [Explanation of Symbols]

[0071] 10...Sensor component 20... Braided cord 21... Conductive thread 51... Sewing thread 51a...Upper thread 51b…Bobbin thread 80...Base material 110...Sensor component 120... Braided cord 121...Folded section C1…center axis P1... Pressure

Claims

1. A braided cord formed by braiding conductive threads into a tubular shape using a flat braiding technique, It comprises an insulating substrate, The braided cord is attached to the base material by sewing thread, Contact can be detected by detecting a change in capacitance in the braided cord. Sensor component.

2. The base material is a stretchable fabric. The sensor member according to claim 1.

3. The braided cord is sewn to the base material by the sewing thread, which forms a seam that crosses over the braided cord. The sensor member according to claim 1.

4. The braided cords are arranged in a planar manner on the substrate. The sensor member according to claim 1.

5. The aforementioned braided cord is configured such that when an external force is applied from the radial direction of the tubular braided cord, the braided structures facing each other across the central axis of the cord come into contact. The sensor member according to claim 1.

6. A seating sensor using the sensor member described in any one of claims 1 to 5.

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