JP4780058B2 - Pressure sensor - Google Patents

Description

      The present invention provides a pressure-sensitive sensor suitable for detecting pressure on a two-dimensional plane, two-dimensional curved surface, and free-form surface, measuring a pressure distribution, and measuring temporal changes in these pressures.

      As a pressure-sensitive sensor capable of measuring pressure distribution on a flat surface, a conductive elastomer whose resistance changes with pressure is used, and the upper and lower electrode parts have a matrix structure in order to extract the change in resistance value. Although there is a method of using a flexible substrate (FPC) wired in this way, this method cannot cope with a free-form surface because the FPC is not very flexible.

      As a pressure-sensitive sensor capable of dealing with a free-form surface, as shown in Patent Document 1, there is a method of creating a connecting portion that keeps a certain distance between an upper electrode portion and a lower electrode portion. Then, since the electrode part and the spacer are integrated, it is not possible to adjust the sensitivity at any time by changing the spacer.

      In addition, as a method of electrically connecting the cloth matrix electrode and the lead wire, there is a method of soldering the lead wire to a flexible substrate (FPC) and sewing the FPC to the cloth matrix electrode with a conductive thread. In the method, the flexibility of the joint portion joined to the cloth matrix electrode by FPC is lowered, and there is a restriction on the correspondence to the free curved surface.

JP 2006-284276 A

      In this way, it is possible to realize a flexible electrode part that can be applied to a free-form surface, and by separating the electrode part and spacer, sensitivity adjustment can be performed at any time by changing the spacer even in the same electrode part. Furthermore, the present invention solves the problem of the conventional product in which the connection between the electrode portion and the lead wire portion does not impair the flexibility as in the case of using a flexible substrate (FPC). is there.

The present invention provides an upper cloth portion and a lower cloth portion having a conductive portion made of a plurality of conductive yarns sewn by a main stitch substantially linearly in parallel with a non-conductive cloth portion, The conductive parts are overlapped so that they are perpendicular to each other, and a spacer whose electrical property values such as resistance value and capacitance change by pressing is sandwiched between the upper and lower cloth parts. More preferably, the conductive thread of the conductive part is sewn to the non-conductive cloth part by the main sewing of the sewing machine, and the conductive thread is composed of stranded wires. Furthermore, the width of the electrode portion is adjusted by sewing a plurality of conductive yarns at intervals where the conductive yarns are in electrical contact with each other.
Further, in the pressure sensor of the present invention, as a method of joining the lead wire for connecting the electrode portion for extracting the electrical characteristics of the spacer and the outside, the tip of the lead wire is U-shaped or O-shaped. The U-shaped or O-shaped portion and the electrode portion are sewn with the conductive thread to create and connect an electrical joint.

      The pressure sensor electrode according to the present invention realizes measurement of pressure corresponding to a free-form surface, which is a problem, by creating a highly flexible cloth matrix electrode by sewing a conductive thread on a non-conductive cloth. In addition, the connection between the electrode portion and the lead wire is also sewn with a conductive thread, so that it is possible to retain the electrical joint while maintaining flexibility.

      The cloth matrix electrode according to the present invention includes an upper cloth portion and a lower cloth portion having a conductive portion made of a plurality of conductive threads sewn by a main stitch substantially in a straight line with a non-conductive cloth portion. An elastomer whose electrical characteristics such as resistance value and capacitance change when the cloth part is overlapped so that the conductive parts are perpendicular to each other and is pressed between the upper and lower cloth parts. By sandwiching the pressure sensor of the system, it is possible to create a pressure sensor that is flexible and can measure pressure changes over time. In addition, the sensitivity can be adjusted at any time by changing the pressure sensor.

FIG. 1 is a structural view of the present invention. Reference numerals 1 and 2 denote a plurality of conductive yarns 3 and 4 sewn by main stitching substantially in a straight line with respect to non-conductive cloth portions 5 and 6, respectively. An upper fabric portion and a lower fabric portion. The upper fabric portion 1 and the lower fabric portion 2 are overlapped so that the conductive yarns 3 and 4 are perpendicular to each other, and pressure is applied between the upper fabric portion 1 and the lower fabric portion 2 so that resistance value and electric A spacer 9 in which an electric characteristic value such as a capacitance changes is sandwiched.
As shown in FIG. 2, these laminates are covered with exteriors 10 and 11 as necessary.

As shown in FIG. 3, the conductive yarns 3 and 4 are sewn to the non-conductive cloth portion 5 by the main sewing of the sewing machine. The conductive yarns used for the upper thread 12 and the lower thread 13 are Consists of stranded wires.
This is because, in the state of a simple thread with less tension, even if the thread component is good, the conductive material is cut off during sewing, and the continuity between long threads is lost, and the resistance value increases. In other words, in the case of a thread that is not applied, the conductive fibers are separated, and the conductive fibers are connected between the adjacent electrode parts. This is because it may be impossible to use the electrode portion as an electrode part, and it is necessary to use a more stringy thread.
As shown in FIG. 4, the width of the electrode portion 15 is adjusted by sewing a plurality of upper threads 12 and 14 at intervals where the conductive threads are in electrical contact with each other. That is, when the electrode portion 15 is made of one conductive thread, if the one thread is broken, the electrode portion is disconnected. Further, as a feature of the main sewing, the upper thread 12 is periodically buried in the cloth.
When the electrode portion is made of a plurality of conductive yarns, even if one conductive yarn is cut, the conductive state is maintained by other conductive yarns. Further, as a feature of the main stitching, when the upper thread 12 is periodically buried in the cloth, the sewing is performed by shifting and sewing so that the upper thread 14 is not buried in the portion where the upper thread 12 is buried. Can be secured.

In such a pressure-sensitive sensor, it is necessary to draw out the lead wire, but using a flexible substrate (FPC) as in the past, the lead wire is joined to the FPC with solder, and the flexible substrate and the cloth matrix electrode are In the method of joining by sewing with a conductive thread, it was difficult to ensure flexibility at the joint. In addition, when the FPC and the cloth matrix electrode are sewn with the conductive thread, the FPC may be broken.
Therefore, in the present invention, as shown in FIG. 5, the lead wire 16 has a U-shaped lead wire portion 18, and the U-shaped portion is connected to the electrode portion 15 with a conductive thread like a joint portion 19. By sewing, the electrode portion 15 and the lead wire 16 are physically and reliably connected electrically with low resistance.

Structure diagram of pressure sensor Cross section of pressure sensor Relationship between upper thread and lower thread in case of lockstitch How to sew to widen the electrode width How to sew the connection between electrode and lead wire with conductive thread Structure diagram of cloth matrix electrode

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Upper cloth part 2 Lower cloth part 3, 4 Conductive thread 5, 6 Non-conductive cloth part 7, 8, 16 Lead wire 9 Spacer 10, 11 Exterior part 13 Lower thread 12, 14 Upper thread 15 Electrode part 16 Lead wire 17 Clothing part 18 Conductor part 19 Joint part

Claims (2)

An upper cloth part and a lower cloth part having electrode parts made of a plurality of conductive threads sewn in a substantially straight line substantially parallel to a non-conductive cloth part, the electrode parts being perpendicular to each other In a pressure sensitive sensor in which a spacer whose value changes in resistance value, capacitance, etc. by pressing between the upper cloth part and the lower cloth part is sandwiched in such a manner, the conductive yarn is more made from the line, and sewn in the sewing, the electrode portion that is sewn shifted at substantially the same straight line as conductive yarns a plurality of contacts electrically mutually different threading position This is a pressure-sensitive sensor. The tip of the lead wire is U-shaped or O-shaped, and the U-shaped or O-shaped portion and the electrode portion are sewn with the conductive thread to have an electrical joint. The sensor according to claim 1.

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