Sensor member

Abstract

To provide a sensor member that is applied to a sensor for detecting pressure and strain.SOLUTION: The sensor member 10 includes a braided string 20 formed by flat-knitting a conductive yarn 21 into a tubular shape. The sensor member 10 includes an insulating substrate 80. The braided string 20 is attached onto the substrate 80 by a sewing thread.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a sensor member used in a sensor for detecting an external force. [Background technology]

[0002] Patent Document 1 discloses a touch-sensitive textile device having a woven fabric made of conductive yarn. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-57398 A Summary of the Invention [Problem to be solved by the invention]

[0004] In textile devices, there is a demand for detecting pressure and strain as external forces. Here, when the sensor is made of a woven fabric as disclosed in Patent Document 1, the woven fabric with conductive threads woven therein constitutes the detection unit. Since it is a woven fabric, the detection unit has the property of being difficult to stretch when pulled. A detection unit that is resistant to pulling in this way may not be suitable for detecting strain. [Means for solving the problem]

[0005] The sensor member for solving the above problem comprises a braided cord formed by flat-knitting a conductive thread into a tubular shape, and an insulating base material, and the braided cord is attached to the base material by a sewing thread. Effect of the Invention

[0006] According to the present invention, it is possible to provide a sensor member for a sensor capable of detecting pressure and strain. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram showing an embodiment of a sensor member. [Diagram 2] FIG. 2 is an enlarged view showing the structure of the braided cord in the sensor member of FIG. [Diagram 3] FIG. 3 is an enlarged view showing the structure of the braided cord in the sensor member of FIG. [Figure 4] FIG. 4 is a cross-sectional view showing a cross-sectional structure of the braided cord in the sensor member of FIG. [Diagram 5] FIG. 5 is a schematic diagram illustrating the braid sewn to the base material in the sensor member of FIG. [Figure 6] FIG. 6 is a schematic diagram illustrating the braid sewn to the base material in the sensor member of FIG. [Figure 7] FIG. 7 is a schematic diagram showing a sensor member according to a modified example. [Figure 8] FIG. 8 is a schematic diagram showing a sensor member according to another modified example. [Figure 9] FIG. 9 is a schematic diagram showing a sensor member according to another modified example. [Figure 10] FIG. 10 is a schematic diagram showing a sensor member according to still another modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, one embodiment of the sensor member will be described with reference to FIGS. As shown in Fig. 1, the sensor member 10 includes a braided cord 20 and a substrate 80. The braided cord 20 is attached to the substrate 80 by a sewing thread. In the sensor member of this embodiment, as shown in Fig. 1, one braided cord 20 is attached to the substrate 80.

[0009] The substrate 80 is, for example, a fabric. Examples of the fabric include knitted fabric, nonwoven fabric, and resin sheet. The substrate 80 is preferably a stretchable fabric. The substrate 80 is insulating.

[0010] Fig. 1 shows an example of use of the sensor member 10. Fig. 1 illustrates a detection device 90 and wiring 91, 92 connecting 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 also be capable of detecting the electrical resistance and capacitance of the braided cord 20.

[0011] Although details will be described later, a sensor incorporating the sensor member 10 can detect an external force acting on the braided cord 20 by detecting one or more of the electrical resistance and capacitance of the braided cord 20.

[0012] <Structure of the braided cord> As shown in Fig. 1 to Fig. 3, the braided cord 20 is formed by knitting a conductive thread 21. The conductive thread 21 may be a thread made of a known conductive fiber.

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

[0014] The knitted cord 20 is, for example, a "knitted cord made with several knitting needles." More specifically, it is a "string with a flat knit structure made with several knitting needles." The number of knitting needles is not particularly limited, but the more knitting needles there are, the thicker the knitted cord 20 will be. The number of knitting needles is, for example, three. Such a string with a flat knit structure is sometimes called a lily knit. Flat knitting is also called stockinette knitting or plain knitting.

[0015] As an example, the braided cord 20 is formed by flat-knitting the conductive thread 21 into a tubular shape. It is particularly preferable that the braided cord 20 is formed by flat-knitting a single conductive thread 21 into a tubular shape.

[0016] A cylindrical structure is a structure having a peripheral wall with a circular cross section. In the braided cord 20, the braided structure corresponds to the peripheral wall. In the braided cord 20, the inside of the peripheral wall formed by the braided structure is hollow. In other words, the braided cord 20 does not have a core material.

[0017] The term "annular" may refer to any structure that forms a loop, i.e., a continuous shape with no ends. "Annular" shapes include circles, ellipses, and polygons with sharp or rounded corners. "Annular" shapes are not limited to the above shapes.

[0018] 1 to 4, the central axis C1 is shown as a line along the axial center of the braided cord 20. Figures 2 and 3 show a knitted structure formed by flat knitting. As shown in Figures 2 and 3, the braided cord 20 has stitches arranged so as to be continuous in the horizontal direction. Here, the horizontal direction corresponds to the circumferential direction of the tubular braided cord 20, i.e., the circumferential direction around the central axis C1.

[0019] FIG. 2 shows the state in which the stitches of the braided cord 20 are loose. FIG. 3 shows the state in which the stitches of the braided cord 20 are not loose. For example, when a force is applied to the braided cord 20 in the state shown in FIG. 2 so as to stretch the braided cord 20 along the central axis C1, the interval between adjacent stitches becomes narrower, and the number of contact points between adjacent stitches increases. 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 the state shown in FIG. 3 so as to contract the braided cord 20 along the central axis C1, the interval between adjacent stitches becomes wider, and the number of contact points between adjacent stitches decreases. As a result, the braided cord 20 approaches the state shown in FIG. 2. In this way, the braided cord 20 has elasticity.

[0020] The coarseness of the stitches of the braided cord 20 is not particularly limited. For example, the braided cord 20 may be configured so that there are gaps between the threads as shown in FIG. 3. The coarseness of the stitches can be adjusted, for example, by adjusting the tension with which the braided cord is pulled when the braided cord is formed by braiding the threads. Note that the finer the stitches, the thinner the braided cord 20 will be.

[0021] The structure of the tubular braided cord 20 will be described with reference to FIG. The braided cord 20 is configured so that, when an external force is applied from a radial direction of the tubular braided cord 20, the braided structures facing each other across the central axis C1 of the braided cord 20 can come into contact with each other.

[0022] In Fig. 4, pressure P1, which is an external force applied from the radial direction of the braided cord 20, is shown as a hollow arrow. Here, the radial direction corresponds to a direction perpendicular to the central axis C1. Fig. 4 illustrates the braided cord 20 in a state deformed by pressure P1. The two-dot chain line in Fig. 4 indicates the braided cord 20 before deformation.

[0023] As shown in Fig. 4, when pressure P1 is applied to the braided cord 20, the braided cord 20 is deformed such that the braided structure of the portion to which pressure P1 is applied approaches the braided structure facing on either side of the central axis C1. Note that the braided cord 20 can be deformed even if the force applied to the braided cord 20 is not necessarily from the radial direction. The braided cord 20 can also be deformed such that the braided structures facing on either side of the central axis C1 approach each other.

[0024] Furthermore, when pressure P1 is applied to the knitted cord 20 as shown in Fig. 4, the state of the stitches may change as described with reference to Fig. 2 and Fig. 3. For example, when pressure P1 is applied to the knitted cord 20, the stitches become more likely to come into contact with each other.

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

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

[0027] The sewing method using the sewing threads is not particularly limited, but in the example shown in Figs. 5 and 6, the upper thread 51a and the lower thread 51b, which are the sewing threads, are staggered. The upper thread 51a and the lower thread 51b are, for example, non-conductive threads, or may be conductive threads.

[0028] 5 and 6, the braided cord 20 is sewn to the substrate 80 by a sewing thread forming a stitch across the braided cord 20. As shown in FIG. 5, the braided cord 20 is disposed between the substrate 80 and the upper thread 51a.

[0029] In the sensor member 10, it is preferable that the braided cord 20 is not pressed down by the sewing thread so as not to restrict the stretching of the braided cord 20. It is preferable that the sensor member 10 allows the braided cord 20 to move between the stitches made by the sewing thread.

[0030] <Action of this embodiment> The operation of this embodiment will be described. As described with reference to Figs. 2 and 3, the braided cord 20 has elasticity. As the braided cord 20 stretches, the manner in which the stitches formed by the conductive thread 21 contact each other changes. Specifically, when the braided cord 20 is loosened as shown in Fig. 2, there are few places where the stitches contact each other. On the other hand, when the braided cord 20 is not loosened as shown in Fig. 3, there are more places where the stitches contact each other compared to the state shown in Fig. 2. Therefore, in the state shown in Fig. 3, the resistance value is lower than that in the state shown in Fig. 2. Note that when a force is applied to further stretch the braided cord 20 from the state shown in Fig. 3, the braided cord 20 becomes taut. In the taut state of the braided cord 20, the resistance value is further lower than that in the state shown in Fig. 3. In this way, when the braided cord 20 stretches, the electrical resistance of the braided cord 20 changes before and after the stretching.

[0031] As described with reference to Fig. 4, the braided cord 20 is configured so that the braided structures facing each other across the central axis C1 can come into contact with each other. When the braided structures come into contact with each other, the resistance value changes before and after the contact. In this way, 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 that detects pressure based on the change in electrical resistance in the braided cord 20. The sensor member 10 can also be used as a sensor that detects strain based on the change in electrical resistance in the braided cord 20. Pressure and strain are each a type of external force applied to the braided cord 20.

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

[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 a change in capacitance in the braided cord 20.

[0035] Effects of this embodiment The effects of this embodiment will be described. (1) A sensor using the sensor member 10 can detect pressure and strain by detecting changes in the electrical resistance of the braided cord 20.

[0036] (2) A sensor using the sensor member 10 can detect a contact by detecting a change in the capacitance of the braided cord 20. (3) By detecting both the change in electrical resistance and the change in capacitance, it is possible to determine whether the object that has come into contact with the sensor member 10 is a person or an object. For example, when a person comes into contact, the electrical resistance and capacitance change. On the other hand, when an object comes into contact, the electrical resistance changes but the capacitance does not change.

[0037] (4) The sensor member 10 includes a braided cord 20 made of conductive thread in addition to the base material 80. The braided cord 20 sewn to the base material 80 constitutes an area capable of detecting an external force, and therefore the area of ​​the area capable of detecting an external force correlates with the length of the braided cord 20. Hereinafter, the area capable of detecting an external force will be referred to as the detection section. For example, the shorter the braided cord 20, the easier it is to configure a smaller detection section. The longer the braided cord 20, the easier it is to configure a larger detection section. In this way, the sensor member 10 makes it easy to set detection sections of various sizes.

[0038] (5) Here, if a sensor using a woven fabric with conductive thread woven in is taken as a comparative example, the part with the conductive thread woven in the comparative example becomes the detection part. Since the detection part is a woven fabric, it may be difficult to freely set the position, size, shape, etc. of the detection part. In contrast, according to the sensor member 10 of the present embodiment, the detection part can be configured by arranging the braided cord 20, so there are fewer restrictions on setting the position, size, shape, etc. of the detection part.

[0039] (6) The braided cord 20 made of conductive thread has flexibility. Since the braided cord 20 has flexibility, the braided cord 20 as the detection unit can be arranged along the shape of the installation surface even if the base material 80 is not limited to a flat surface but is a curved surface, has a bent corner, or the like.

[0040] (7) By using conductive yarns with different resistance values, the resistance value of the braided cord 20 made of conductive yarn can be changed. In addition, the resistance value of the braided cord 20 can also be changed by changing the coarseness of the stitches when braiding the braided 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 effect can be obtained. By stretching the base material 80, the sensor member 10 can stretch, for example, in the axial direction of the braided cord 20. Therefore, compared to when the base material 80 is not easily stretchable, the electrical resistance is more likely to change in response to strain. This makes it easier to detect strain.

[0042] <Application form> The application form of this embodiment is not particularly limited, but can be used, for example, as follows. The sensor member 10 can be used as a seating sensor by being applied to chairs in automobiles, wheelchairs, airplanes, trains, bullet trains, theaters, and the like.

[0043] The sensor member 10 can be used as a measuring device for detecting the flexion of a joint, for example, by being attached to clothing or the like. The sensor member 10 can be used, for example, as an operation switch that detects depression.

[0044] (Example of change) This embodiment can be modified as follows: This embodiment and the following modifications can be combined with each other to the extent that no technical contradiction occurs.

[0045] As in the sensor member 110 shown in FIG. 7, the braided cord 120 may be folded back so that the braided cord 120 is arranged on the substrate 80 in a planar manner. 7, the braided cord 120 extends linearly along the first side 110a and changes direction by 180 degrees at the folded-back portion 121. The linear extending portion and the portion changing direction by 180 degrees are alternately repeated, so that a plurality of folded-back portions 121 are lined up along the second side 110b perpendicular to the first side 110a. The braided cord 120 is arranged so as not to leave any gaps.

[0046] In the sensor member 110 shown in FIG. 7, the knitted cord 120 is sewn to the base material 80 by zigzag stitching using sewing thread 51, as in the above embodiment. According to the above configuration, the detection portion for detecting pressure can be arranged in a planar manner.

[0047] The braids may be arranged in a plane along the stretch direction of the base material. For example, the braids may be arranged so that the ratio of the area in which the length direction of the braids coincides with the direction in which the base material is likely to stretch is large in the detection unit.

[0048] 7 shows an example of the sensor member 110 in which the braided cords 120 are arranged in a planar manner so as to leave no gaps. Alternatively, the braided cords may be sewn onto the base material 80 so as to form gaps between adjacent braided cords.

[0049] By using a flexible braided string, various shapes can be created with the braided string, such as the surface shape shown in Fig. 7. For example, the braided string may be arranged as in sensor member 210 shown in Fig. 8.

[0050] In the sensor member 210 shown in FIG. 8, the braided cord 220 has 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 in a direction away from the curved portion 221.

[0051] In the sensor member 210 shown in FIG. 8, the knitted cord 220 is sewn to the base material 80 by zigzag stitching using sewing thread 51, as in the above embodiment. It is not essential to provide a portion where the braided cord is folded back 180 degrees when arranging the braided cord in a planar shape. By combining braided cords arranged to be curved, braided cords arranged to be bent, etc., various shapes can be formed using the braided cords. Examples of shapes that can be formed using the braided cords include circles, polygons, spirals, and geometric patterns.

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

[0053] 7, the sensor member 310 is not sewn to the base material 80 between the folded-back portion 121 and the next folded-back portion 121 in the length direction of the braided cord 120. That is, 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 is aligned 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 sensor member 310 provides the following functions and effects. When sewing the braided cord to the base material, if the force with which the sewing thread presses the braided cord against the base material is excessively large, the braided cord may be crushed by the sewing thread. If the braided cord used as a detection part in a sensor is crushed in the absence of an external force, there is a problem that the accuracy of the sensor is reduced.

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

[0056] 7, the sensor member 310 is more likely to stretch in the direction along the first side 110a. In particular, when a stretchable fabric is used as the base material 80, the sensor member 310 is more likely to stretch in the direction along the first side 110a.

[0057] Furthermore, according to sensor member 310, the portion of knitted cord 120 that is not sewn to base material 80 can be separated from base material 80. Therefore, even if base material 80 is deformed, for example, bent, knitted cord 120 can follow the deformation of base material 80 without applying unnecessary force to knitted cord 120.

[0058] In the above embodiment, the sensor member is configured by sewing the braided string to one base material. The sensor member may be configured by sewing the braided string to multiple base materials. For example, the sensor member may be configured as shown in FIG. 10.

[0059] 10 shows a sensor member 410. The sensor member 410 includes 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 disposed with a gap therebetween.

[0060] The sensor member 410 includes a braided string 420. The braided string 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 that sews the braided string 420 to the first base material 81 and the second base material 82.

[0061] The sensor member 410 has the braided strings 420 arranged in a plane, similar to the sensor member 310 shown in FIG. 9. ... braided strings 420 are not sewn to the base material between the folded-back portion 421 and the next folded-back portion 421 in the length direction of the braided string 420, similar to the sensor member 310 shown in FIG. 9. That is, the portion of the braided string 420 that extends linearly along the first side is not sewn to the base material. Then, one of the portions of the braided string 420 that are aligned along the second side perpendicular to the first side is sewn to the first base material 81, and the other of the portions that are aligned along the second side is sewn to the second base material 82. For example, as shown in FIG. 10, the braided string 420 is sewn to the end of the first base material 81 that faces the second base material 82. The braided string 420 is sewn to the end of the second base material 82 that faces the first base material 81.

[0062] The sensor member 410 provides the following functions and effects. In the sensor member 410, when a force is applied that separates the first base material 81 and the second base material 82 from each other, the braided cord 420 is likely to stretch. In the sensor member 410, the braided cord 420 is more likely to stretch than in the sensor member 310 shown in FIG.

[0063] The sensor member 410 may be used, for example, as 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. There is no particular limitation on the arrangement of the first base material 81 and the second base material 82 when using the sensor member 410. For example, the first base material 81 and the second base material 82 may be arranged side by side horizontally, or the first base material 81 and the second base material 82 may be arranged side by side vertically.

[0064] 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, but 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] 9 and 10 show an example of a sensor member in which a braided cord is arranged in a planar shape. The configuration in which a part of the braided cord is attached to a substrate and another part of the braided cord is not attached to the substrate as shown in Fig. 9 and 10 can be applied to other sensor members besides the braided cord arranged in a planar shape.

[0066] In the above embodiment, the sensor member has one braided string attached to the base material. However, two or more braided strings may be attached to the base material. In the above embodiment, an insulating cloth, a cushioning material, or the like may be attached so as to cover the braided cord 20 attached to the base material 80. In other words, the braided cord made of conductive yarn may be exposed or may be covered. [Explanation of symbols]

[0067] 10...Sensor member 20…braided cord 21...Conductive thread 51...Sewing thread 51a...Upper thread 51b…Bobbin thread 80...Base material 110...Sensor member 120…braided cord 121…Folded section C1…center axis P1…Pressure

Claims

1. A braid formed by flat-knitting a conductive thread into a tubular shape; An insulating base material, The braid is attached to the substrate by a sewing thread. Sensor component.

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

3. The braid is sewn to the substrate by the sewing thread forming a stitch across the braid. The sensor member according to claim 1 .

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

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

6. Pressure can be detected by detecting the change in electrical resistance in the braid. The sensor member according to any one of claims 1 to 5.

7. Touch can be detected by detecting a change in capacitance in the braid. The sensor member according to claim 6.

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