JP5842666B2 - Cloth pressure sensor heater - Google Patents

Description

  The present invention relates to a cloth-like pressure sensor heater capable of warming while measuring pressure.

  A combination of a planar pressure sensor and a heater used for a vehicle seat is, for example, described in Patent Document 1 below, in which a heating element serving as a heater is installed on a sensor mat for measuring pressure. A heating element is known.

  The sensor mat alone has a sensor function. However, if the sensor mat is to have another function, it is expected that when the sensor unit is short-circuited, the additional function is also short-circuited. For example, in combination with a heater, there is a possibility that heat will not be generated at a portion where heat is to be generated, but heat will be generated at a conduction portion that supplies electric power, or overheating at a short-circuit portion.

Japanese translation of PCT publication No. 2003-533311

  Then, even if it is a case where a sensor part short-circuits and the heater part which is the additional function short-circuits, this invention aims at suppressing the heat_generation | fever of the conduction | electrical_connection part which supplies electric power, or the overheating of a short circuit part.

  In the present invention, the first fiber layer includes a first conductive portion having conductivity, the second fiber layer facing the first fiber layer includes a second conductive portion having conductivity, and the third fiber layer includes An electrical connection between the first conductive portion and the second conductive portion is provided, and the first conductive portion and the second conductive portion are electrically connected to each other and electrically connected between the first conductive portion and the second conductive portion. When the electrical resistance value measuring means for measuring the resistance value and the electrical resistance value measured by the electrical resistance value measuring means exceed a predetermined value corresponding to a state in which the first conduction portion and the second conduction portion are short-circuited, And control means for applying a voltage between the first conduction part and the second conduction part to generate heat in the connecting yarn.

  According to the present invention, when the electrical resistance value between the first conduction part and the second conduction part exceeds a predetermined value corresponding to the short-circuit between these conduction parts, a voltage is applied to the intermediate layer. Since the heat is generated, the intermediate layer is prevented from generating heat below a predetermined value corresponding to the time of short circuit, and heat generation of the conduction part supplying power and overheating of the short circuit part can be suppressed.

It is a perspective view which shows the knitting method of the cloth-like pressure sensor heater concerning one Embodiment of this invention. It is a perspective view showing the whole cloth-like pressure sensor heater composition concerning one embodiment of the present invention. It is a top view which shows the example of a shape of the knitted fabric (flat knitting) used for a cloth-like pressure sensor heater. It is a top view which shows the example of a shape of the knitted fabric (rubber knitting) used for a cloth-like pressure sensor heater. It is a schematic diagram which shows the state which connects the upper layer and lower layer of a cloth-like pressure sensor heater with a connection thread, (a) is connected with one connection thread, (b), (c) is connected with a plurality of connection threads. Show things. It is a schematic diagram which shows the state which connects the upper layer and lower layer of a cloth-like pressure sensor heater with a connection thread | yarn, (a) is what wound one connection thread | yarn sequentially in one direction, and wound it in the reverse direction sequentially. Fig. 2 (b) shows a configuration in which one connecting yarn is connected so as to form a loop between upper and lower layers. It is a perspective view which shows another example with respect to the cloth-like pressure sensor heater of FIG. It is a perspective view which shows another example with respect to the cloth-like pressure sensor heater of FIG. It is effect | action explanatory drawing which shows the principle which a cloth-like pressure sensor heater works as a pressure sensor. It is a correlation diagram of the length of an intermediate | middle layer (connection thread | yarn), and an electrical resistance value. It is an action explanatory view showing the state where connected yarns contacted each other by receiving a force that the intermediate layer bends due to pressure acting on the cloth pressure sensor heater. It is a flowchart which shows the control operation of the heat generation output by the heat generation amount control means. It is a timing chart which shows an example of control of Drawing 12. 14 is a timing chart showing an example different from FIG. 13. It is a perspective view which shows the state which set the cloth-like pressure sensor heater to the vehicle seat. 1 is an overall configuration diagram of a wet spinning apparatus showing a state in which conductive polymer fibers are produced by a wet spinning method. It is an external view of a conductive polymer fiber, (a) shows one, (b) shows the state bundled multiple pieces.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  The cloth-like pressure sensor heater 1 shown in FIGS. 1 and 2 includes an upper layer 3 as a first fiber layer, a lower layer 5 as a second fiber layer at a position facing the upper layer 3, and the upper layer 3 and the lower layer 5. It is comprised with the cloth-like member of the three-layer structure which has the intermediate | middle layer 7 as a 3rd fiber layer located in between. That is, this cloth-like pressure sensor heater 1 has air permeability, stretchability, and flexibility by being constituted by a cloth-like member.

  The upper layer 3 and the lower layer 5 are each provided with a first conductive portion 9 and a second conductive portion 11 having conductivity, and the intermediate layer 7 is composed of a conductive connecting yarn 12 that becomes a resistance variable heating layer, The first and second conducting portions 7 and 9 are entangled and connected so as to conduct each other. Here, the term “entanglement” refers to a state in which the connecting yarn 12, the first conducting portion 9 and the second conducting portion 11 are connected by being entangled so as to be electrically connected to each other. .

  The plurality of upper layers 9 are connected to each other by a non-conductive portion 13 made of non-conductive fibers, for example, and the plurality of lower layers 11 are also connected to each other by non-conductive portions 15 made of non-conductive fibers. Connected.

  In FIG. 1, the conducting portions 9 (11) and the non-conducting portions 13 (15) are alternately arranged one by one in the left-right direction in FIG. 1, but the conducting portions 9 (11) and the non-conducting portions are arranged. A plurality of portions 13 (15) are continuously connected in the left-right direction in FIG. 1, and the plurality of conducting portions 9 (11) and the plurality of non-conducting portions 13 (15) in the left-right direction in FIG. May be arranged alternately. At that time, in FIG. 1, the connecting yarn 12 of the intermediate layer 7 includes a connecting portion between the conductive portion 9 and the non-conductive portion 13 of the upper layer 3 and a connecting portion between the conductive portion 11 and the non-conductive portion 15 of the lower layer 3. The connecting yarns 12 may be connected to each other without being in contact with the non-conducting portions 13 and 15, and may not be in contact with the conducting portions 9 and 11. The non-conductive portions 13 and 15 may be connected to each other.

  As shown in FIG. 2, the cloth-shaped pressure sensor heater 1 generates electric resistance value measuring means 17 for measuring the resistance value of an arbitrary portion of the intermediate layer 7 which is a variable resistance heat generating layer, and generates heat in the intermediate layer 7. And a calorific value control means 19 as a control means for use as a layer. The heat generation amount control means 19 applies a voltage between the first conduction part 9 and the second conduction part 11 based on the electrical resistance value measured by the electrical resistance value measurement means 17 to cause the intermediate layer 7 to generate heat.

  Although the cloth-like pressure sensor heater 1 is composed of a cloth-like member, a general knitted fabric as an example of the cloth-like member is one or several yarns as shown in FIGS. 21 is a knitted fabric made continuously by making a loop and hooking the next yarn 21 on the loop to make a new loop. Generally, a knitted fabric knitted with a flat knitting machine is called a knitted product (flat knitting in FIG. 3 and rubber knitting in FIG. 4), and a knitted fabric is knitted in a cloth shape with a circular knitting machine or a warp knitting machine. Call.

  In the present embodiment, the knitted fabric is three-dimensionally formed with the upper layer 3, the lower layer 5 and the intermediate layer 7 as shown in FIGS. 1 and 2, and the connecting yarn 12 of the intermediate layer 7 is used as a resistance variable heating layer. Provide a pressure sensing function and a heat generation function. In addition, as for the three-dimensional knitted fabric generally marketed, there is a fusion manufactured by Asahi Kasei Fibers Corporation.

  At this time, the intermediate layer 7 described above may be formed by connecting the upper and lower layers 3 and 5 with a single connecting thread 12 as shown in FIG. 5A, but as shown in FIGS. 5B and 5C. The unconnected portion 25 is not necessarily connected by a single thread, and a plurality of short connected threads 27 and 29 may be used. When using a plurality of short connecting yarns 27 and 29, the ends of the connecting yarns 27 and 29 in the non-connecting portion 25 are fixed to the upper and lower layers 3 and 5 by an appropriate connecting means or connecting method. Become.

  Further, the intermediate layer 7 is not limited to one in which one connecting yarn 12 is connected so as to be sequentially wound in one direction between the upper layer 3 and the lower layer 5 as shown in FIG. For example, as shown in FIG. 6 (a), one connecting thread 12 is wound sequentially in one direction (right direction in FIG. 6), and the reverse direction (left side in FIG. 6) Direction) and may be connected by crossing each other. As shown in FIG. 6B, one connecting thread 31 is connected so as to form a loop between the upper and lower layers 3 and 5. May be. Alternatively, a plurality of these connecting directions may be combined.

  In addition, one connecting yarn itself used in the intermediate layer 7 may form a twisted yarn composed of a plurality of yarns. It is also possible to change the amount of change in the resistance value depending on the density of the components related to the conductivity in the twisted yarn.

  The connecting yarns of the first conducting portion 9 and the second conducting portion 11 installed in the upper and lower layers 3 and 5 and the resistance variable heat generating layer (intermediate layer 7) are made of a conductive material. The conductive material mentioned here is a metal wire such as gold, silver, copper or nichrome, carbon-based material such as carbon or graphite, or particles made of a semiconductor such as metal or metal oxide, acetylene-based or complex 5-membered ring. It indicates a conductive polymer or the like as a conductive resin such as phenylene, phenylene or aniline.

  Examples of carbon-based materials include carbon fibers, carbon powders, etc. in addition to those that are generally commercially available such as carbon fiber bodies (Torayca (Toray Industries, Inc.), Donakabo (Osaka Gas Chemicals, etc.)). It is also possible to use a fiber or the like that is spun by mixing.

On the other hand, examples of particles include carbon-based powders such as carbon black and ketjen black, and metal fine particles such as carbon-based, iron, and aluminum, and tin oxide (SnO ₂ ) and zinc oxide (ZnO) as conductive fine particles. Etc.

  These materials can be used alone, or can be used such that the surface of another material is coated by vapor deposition or coating, the core material is used, and the surface is coated with another material.

  Among these, it is desirable to use carbon fiber or carbon powder from the viewpoint of easy availability in the market and specific gravity.

  As a material used for the connecting yarn 12 of the intermediate layer 7, it is particularly preferable to use a conductive polymer fiber.

  In the present embodiment, the fiber refers to a fiber that is spun by a method such as melt spinning, wet spinning, electrospinning, or the like, or a fiber that is cut out of a film and has flexibility. The diameter and width of such a fiber is about several μm to several hundreds μm per one. When forming a woven fabric or knitted fabric, weaving or knitting ease, weaving or knitting after weaving or knitting It is preferable because of its softness as a fabric and ease of handling as a fabric.

  By making these fibers (see FIG. 17 (a)) into bundles of tens to thousands (bundle shape, see FIG. 17 (b)), handling as fibers becomes easy. At this time, twisting may be applied.

  In the present embodiment, a woven fabric is formed using these one fiber or bundle-like fiber, or a combination of one fiber and a bundle-like fiber.

  Here, the conductive polymer fiber refers to a conductive material excluding the metal, among the conductive materials described above. Since metal is a conductor having a particularly low electrical resistivity, it is necessary to use an extremely thin fiber or to increase the distance between the upper layer 3 and the lower layer 5 in order to generate heat efficiently in the intermediate layer 7. come. When thin fibers are used, even if it is desired to generate heat at an arbitrary portion or area, heat is generated at almost points, and the air around the metal fibers becomes a heat insulating layer, so that it is difficult to obtain a warming effect. When the distance is increased, the softness of the metal fibers becomes a neck, and the metal fibers alone cannot support the force in the compression direction of the cloth. As a result, the heat generation efficiency is reduced.

  Conductive polymer fibers such as materials used for general fibers described later, that is, dispersed in a polymer, coated, or fiberized per se, are conductive materials excluding such metals. Call it.

  As the conductive material, it is particularly preferable to use a conductive polymer fiber using a semiconductor, a conductive polymer, or a carbon fiber.

  The blending amount of these conductive materials in the conductive polymer fiber is preferably 0.5 to 30 vol%. If the blending amount of these conductive materials is less than 0.5 vol%, the amount of the mixed conductive materials is small, so that the performance is not substantially changed from the case where it is not added, and the cost is only increased, which is not preferable. When the blending amount exceeds 30 vol%, when mixed into the matrix resin, the viscosity when the mixed resin is melted increases, so that the spinnability is further greatly reduced and fiberization tends to be difficult. There is.

  For these matrix resins, general-purpose resins such as polyamides such as nylon 6 and nylon 66, polyethylene terephthalate, polyethylene terephthalate containing a copolymer component, polybutylene terephthalate, and polyacrylonitrile may be used alone or in combination. From the viewpoint of sex. Although it is physically possible to use natural fibers, synthetic fibers are more stable in obtaining quality such as variations in fiber diameter and physical properties in the fiber length direction when considering sensing performance and heater performance. From the viewpoint of cost and availability, synthetic fibers are preferable.

In order to obtain the sensing and heat generation functions as described above, it is preferable to use a conductive material having a resistivity range of about 10 ⁻³ to 10 ² Ω · cm. This is because when a woven fabric or knitted fabric is used, the conductive polymer fiber will act as a resistor, and if the resistance value is too small (10 ^-3 Ω · cm or less), the conducting part will generate heat, It will come off from warming the part. On the other hand, if it is over 10 ² Ω · cm and too large, it will be difficult for the current for heat generation to flow, and sufficient heat generation will not be obtained. A more preferable range is about 10 ⁻² to 10 ¹ Ω · cm, so that the heat generation function can be more efficiently exhibited.

  Here, the electrical resistivity refers to a resistivity determined in accordance with JIS K 7194 (a resistivity testing method using a 4-probe method for conductive plastics).

  Of these conductive polymer fibers exhibiting electrical resistivity, conductive polymer fibers containing at least one of conductive polymer polypyrrole, PEDOT / PSS, polyaniline, and PPV are more preferable. .

  Among these, as a material that can be easily obtained as a fiber, PEDOT / PSS (Bayer) in which poly (4-styrenesulfonate) (PSS) is doped into poly (3,4-ethylenedioxythiophene) (PEDOT), a thiophene-based conductive polymer. Clevios), phenylene polyparaphenylene vinylene (PPV), pyrrole polypyrrole, and the like.

  Among these conductive materials, these materials can be easily fiberized by a method such as wet spinning or electrospinning, and are preferable as materials satisfying the above-described electrical resistivity.

  For example, thiophene, pyrrole, and aniline can be manufactured by wet spinning. For example, the above PEDOT / PSS aqueous dispersion is easily extruded from a cylinder into acetone (see FIG. 16). A polymer fiber can be obtained.

  By employ | adopting such a process, the conductive polymer fiber which forms the cloth-like pressure sensor heater 1 can be manufactured easily.

  The conductive material used for the connecting yarns of the first conductive portion 9 and the second conductive portion 11 and the variable resistance heating layer (intermediate layer 7) may be a single material or a plurality of materials. There is no particular limitation.

  Moreover, it is preferable to use the material whose electrical resistivity is lower than the intermediate | middle layer 7 which is a resistance variable heat_generation | fever layer for the 1st conduction | electrical_connection part 9 and the 2nd conduction | electrical_connection part 11 in order to raise a sensing precision. The shape of the material forming the first conductive portion 9 and the second conductive portion 11 is not limited to the knitted fabric made of fibers as shown in FIG. In order to provide air permeability, the upper layer 3 and the lower layer 5 are preferably made of fibers. However, as shown in FIGS. 2, 7, and 8, non-conductive other materials (cores) constituting the upper layer 3 and the lower layer 5 are used. It is also possible to form the first and second conductive portions 9 and 11 by applying a conductive paint or the like to the surface of the material. Examples of the conductive paint include Dotite manufactured by Fujikura Kasei Co., Ltd.

  As the cloth-like pressure sensor heater 1, the first and second conducting portions 9 and 11 are substantially the same as general fibers forming the non-conducting portions 13 and 15 in the sense of avoiding a sense of incongruity due to a difference in partial hardness. It is also possible to use a metal wire having a cross-sectional area or a conductive fiber, for example, a stranded wire obtained by twisting a metal such as nickel.

  General fibers forming the non-conductive portions 13 and 15 include fibers made of general-purpose resins such as polyamides such as nylon 6 and nylon 66, polyethylene terephthalate, polyethylene terephthalate containing a copolymer component, polybutylene terephthalate, and polyacrylonitrile. It is preferable from the viewpoint of cost and practical use that these are used alone or in combination.

  Further, the shape of the upper and lower layers 3 and 5 is not particularly problematic as long as it forms a breathable cloth shape, but it is resistant to use a woven fabric, a nonwoven fabric, a knitted fabric or the like made of the above-mentioned generally used fibers. This is also preferable from the viewpoint of fixing the variable heat generating layer (intermediate layer 7) and the purpose of uniform deformation due to pressure.

  In FIG. 2, a plurality of first and second conducting portions 9 and 11 are provided, but at least either the upper layer 3 or the lower layer 5 forms the first and second conducting portions 9 and 11 in a striped pattern or block shape. It only needs to be arranged. For example, in FIG. 7, only the upper layer 3 has a striped pattern composed of the first conductive portion 9 and the nonconductive portion 13, and in this case, the entire lower layer 5 becomes a conductive portion (second conductive portion 11 </ b> A). Further, not only when the stripe patterns of the upper and lower layers 3 and 5 are parallel to each other as shown in FIG. 2, but also composed of the conductive portion (second conductive portion 11B) and the non-conductive portion 13B of the lower layer 5 as shown in FIG. The striped pattern may be orthogonal to the striped pattern of the upper layer 3.

  The electric resistance value measuring means 17 for measuring the resistance value of an arbitrary part of the intermediate layer 7 is a method of measuring a voltage ratio with a resistance meter, an LCR meter, or a reference resistance based on the measurement principle by a voltmeter. Etc. are used alone or in combination. Further, as the heat generation amount control means 19 used for generating heat at an arbitrary portion of the intermediate layer 7, a commonly used switching element, relay or the like is used alone or in combination.

  The electrical resistance value measuring means 17 and the calorific value control means 19 are electrically connected to the first and second conducting portions 9 and 11 of the upper and lower layers 3 and 5. At that time, as shown in FIG. 2, one end in the longitudinal direction of the conducting portion 9 of the upper layer 3 and the other end in the longitudinal direction of the conducting portion 11 of the lower layer 5 are connected by wiring. In FIG. 1, only the wiring connections for the pair of conductive portions 9 and 11 that face each other are illustrated, but the conductive portions 9 and the conductive portions 11 that are located at other positions that face each other are similarly separated from each other. The electrical resistance value measuring means 17 and the heat generation amount controlling means 19 are connected by wiring. In other words, the electrical resistance value measuring means 17 and the heat generation amount control means 19 are individually connected corresponding to the pair of conducting portions 9 and conducting portions 11 that are in positions facing each other.

  A cloth-like pressure sensor heater is provided by appropriately providing a plurality of combinations of the pair of conducting portions 9 and 11 at the positions facing each other and the corresponding resistance value measuring means 17 and heat generation amount controlling means 19. It is possible to generate heat by measuring the resistance value of a required part of 1.

  Next, the principle that the cloth-like pressure sensor heater 1 functions as a pressure sensor will be described with reference to FIGS. The electric resistance of the intermediate layer 7 which is a variable resistance heating layer changes in an analog (continuous) manner in accordance with the pressure P applied from the upper layer 3 side, and this electric resistance value is measured by the electric resistance value measuring means 17. To detect.

  FIG. 9 shows that the cloth layer pressure sensor heater 1 receives the pressure P described above and the intermediate layer 7 is compressed and bent and deformed, so that the vicinity of the upper layer 3 and the lower layer 5 of the intermediate layer 7 becomes the first conductive portion 9. The state which contacted the 2nd conduction | electrical_connection part 11 is typically shown (refer intermediate | middle layer 7 on the right side in FIG. 9). The intermediate layer 7 (the left side in FIG. 9) at a site that hardly receives the pressure P is self-sustained between the first conductive portion 9 of the upper layer 3 and the second conductive portion 11 of the lower layer 5, and is almost the original length. L is kept. On the other hand, the contact portion C <b> 1 is generated between the first conductive portion 9 of the upper layer 3 and the connecting yarn 12 of the intermediate layer 7 in the intermediate layer 7 at the site receiving the pressure P. Similarly, a contact portion C2 is also generated between the second conducting portion 11 of the lower layer 5 and the connecting yarn 12 of the intermediate layer 7, and the substantial length of the connecting yarn 12 of the intermediate layer 7 is shortened to L ′. (L> L ′).

  The initial length L of the connecting yarn 12 in FIG. 9 is expressed as the following equation 1 as a function of the pressure P. The coefficient α is a value that is approximately the reciprocal of the spring constant corresponding to the compression direction of the cloth.

Formula 1 ... L = αP
L: Length [mm], P: Pressure [Pa], α: Coefficient [mm / Pa]
The relationship between the length L and the resistance value R at this time is approximately expressed as a function of the resistance value R as shown in the following equation 2. As shown in FIG. 9, when the pressure P is received, since L ′ is shorter than L, the value of R becomes small. The relationship between the length L and the resistance value R is shown in FIG.

Formula 2 ... R = ρL / S
R: resistance value [kΩ], ρ: resistivity [Ω · mm], L: length [mm], S: cross-sectional area [mm ² ]
Further, the resistance value R is also a function of the cross-sectional area S from the above equation 2, and this change is schematically shown in FIG. In FIG. 11, there are a connecting yarn 12 of the intermediate layer 7 connected to the first conductive portion 9 of the upper layer 3 and a connecting yarn 12 ′ of the intermediate layer 7 connected to the non-conductive portions 13 and 15.

  At this time, when the pressure P acts on the cloth-like pressure sensor heater 1 from the upper layer 3 side, the intermediate layer 7 receives a bending force, and the connecting yarns 12 and 12 ′ contact each other. At this time, what is connected to the first and second conducting portions 9 and 11 (the connecting yarn 12) is in contact with what is in contact with the non-conducting portions 13 and 15 (the connecting yarn 12 ′). The cross-sectional area S increases so as to become a pseudo-cross-sectional area S ′. Thereby, since the cross-sectional area S in Formula 2 becomes large, the resistance value R becomes small by applying pressure as described above.

  Actually, these changes in the resistance value R do not occur independently, but are continuously deformed simultaneously. As a result, the final output shows a change in resistance value as shown in FIG. 10, and this functions as a pressure sensor.

  Next, the principle that the cloth pressure sensor heater 1 works as a heater simultaneously with the sensing function as described above will be described. The principle is that by supplying current to the connecting yarn 12 of the intermediate layer 7 that is conductive to the first and second conductive portions 9 and 11, Joule heat is generated and functions as a heater.

  At this time, if the pressure applied to the cloth-like pressure sensor heater 1 exceeds the pressure limit of sensing, the resistance value of the intermediate layer 7 between the upper and lower layers 3 and 5 is the lowest value, that is, the upper The short circuit value between the lower layers 3 and 5 will be shown. In this state, since the intermediate layer 7 has no resistance corresponding to the heater, the first and second conductive portions 9 and 11 generate heat or overheat.

  In the present embodiment, the resistance value R measured by the electrical resistance value measurement means 17 is the first and second conduction parts 9 as means for suppressing such heat generation and overheating of the first and second conduction parts 9 and 11. , 11 is controlled so as not to generate heat output from the heat generation amount control means 19 when the value is equal to or less than a predetermined value T corresponding to a state where the two are short-circuited. That is, in the present embodiment, the calorific value control means 19 performs the first conduction unit 9 in a state where the electrical resistance value measured by the electrical resistance value measurement means 17 exceeds a preset first threshold value (predetermined value T). A voltage is applied between the second conductive part 11 and the intermediate layer 7 (the connecting yarn 12) to generate heat.

  Subsequently, the control of the heat generation output by the heat generation amount control means 19 will be described as a first embodiment with reference to the flowchart of FIG. First, a determination value for performing output determination to the cloth-like pressure sensor heater 1 by the heat generation amount control means 19 is initialized and set (step S1). Thereafter, resistance value data for each measurement point measured by the plurality of electrical resistance value measuring means 17 is acquired (step S2), and the pressure application state to the cloth-like pressure sensor heater 1 is estimated.

  Next, the resistance value R measured by the electrical resistance value measuring means 17 is a predetermined value T corresponding to a short circuit between the first and second conducting parts 9 and 11 due to the pressure application state estimated in the process of step S2. It is determined whether it is larger (for example, 0.2Ω) or not (step S3). Here, when the measured resistance value R exceeds the predetermined value T (YES in step S3), a heat generation output as a heater is performed assuming that there is no short circuit (step S4). On the contrary, when the resistance value R does not exceed the predetermined value T and is equal to or smaller than the predetermined value T (NO in step S3), the heat generation output as the heater is not performed because the short circuit is caused (step S5).

  When the heat generation output as the heater is performed and when the heat generation output as the heater is not performed and the processes in steps S4 and S5 are completed, the process returns to step S2, and the resistance value R is measured again.

  Next, FIG. 13 shows an example of a timing chart corresponding to the above-described control operation. Here, an example of control when the target temperature of the heater is 40 ° C. is shown.

  In this timing chart, the time when the process of step S1 in FIG. At this stage, the resistance value R indicates the maximum value Max that is the second threshold value corresponding to the pressure P = 0 (zero). At this time, the heat generation output from the heat generation amount control means 19 is also maximized, and the heater temperature of the heat generating portion is 40 ° C. with this output.

  At time T11, since a decrease in resistance value R corresponding to an increase in pressure P is observed, the resistance value R acquired in the process of step S2 is small, but here the predetermined value T (the value at the time of short circuit) is still here. Is exceeded (YES in step S3), the heater heat generation output is continued (step S4), and the heater temperature is maintained at 40 ° C.

  At time T12, since the resistance value R corresponding to a further increase in pressure P has become a resistance value R corresponding to a short circuit due to a decrease in the resistance value R, the resistance value R is determined to be equal to or less than the predetermined value T (NO in step S3). The heater does not output heat (step S5). As a result, the heater temperature returns to room temperature.

  At time T13, an increase in the resistance value R corresponding to the decrease in the pressure P is observed, so the resistance value R acquired in the process of step S2 increases and becomes a value exceeding the predetermined value T (YES in step S3). The heater heat output is performed again (step S4). Thereby, the heater temperature also rises to 40 ° C. again.

  Thereafter, at time T14, similarly to time T12, the resistance value R is again equivalent to a short circuit, so the heater is turned off (off). At time T15, the pressure P is reduced and the heater is turned on (on), as at time T13. At the subsequent time T16, the heater remains ON at the resistance value R corresponding to the pressure P = 0, and further, at the time T17, the resistance value R decreases as the pressure increases. It remains.

  Thus, in this embodiment, even if the sensor unit is short-circuited and the heater unit as an additional function is short-circuited, the electrical resistance value becomes a low predetermined value T such as 0.2Ω due to the short-circuit of the sensor unit. In this case, since the intermediate layer 7 (the connecting yarn 12) does not generate heat, the heat generation of the conduction portions 9 and 11 for supplying power and the overheating of the short-circuit portion can be suppressed. At this time, in the present embodiment, since the cloth pressure sensor heater 1 itself maintains air permeability, flexibility, and stretchability, it is possible to suppress unpleasant feeling of use such as uncomfortable feeling and stuffiness.

  In the first embodiment according to the flowchart of FIG. 12 and the timing chart of FIG. 13, even if the pressure P indicates 0 (zero), heat output is performed. In this example, the cloth-like pressure sensor heater 1 is preferably applied to a vehicle seat, which will be described later, and warmed before sitting on the seat, for example, when preheating is performed.

  On the other hand, the timing chart of FIG. 14 according to the second embodiment shows an example in which no heat generation output is performed even when the pressure P indicates 0 (zero). Assuming a scene where the cloth-like pressure sensor heater 1 of the present embodiment is actually used, a portion where no pressure is applied is a portion where a person is not in contact. If it is not preferable, it is preferable to use the control shown in the example of FIG.

  Specifically, in the timing chart of FIG. 14, the time when the process of step S1 of FIG. At this stage, the resistance value R indicates the maximum value Max of the resistance value corresponding to the pressure P = 0 (zero). At this time, there is no heat output from the heat generation amount control means 19, and the heater temperature of the heat generating portion is normal.

  That is, according to the flowchart in this example, the process corresponding to step S3 of the flowchart of FIG. 12 (referred to as step S3 ′) determines whether or not the resistance value R is larger than the predetermined value T and smaller than the maximum value Max. It will be determined. The processing of other steps is the same as that in FIG.

  If the resistance value R is larger than the predetermined value T and smaller than the maximum value Max (YES in step S3 ′), the heater is heated, and the resistance value R is equal to or less than the predetermined value T or the maximum value Max. In the above case (NO in step S3 ′), the heater heat generation processing is not performed. That is, in the present embodiment, when the electrical resistance value measured by the electrical resistance value measuring means 17 is in a certain range exceeding the predetermined value T and less than the maximum value Max, the first conducting portion 9 and the second conducting portion 11 are used. A voltage is applied between them to cause the connecting yarn 12 to generate heat.

  Returning to the time chart of FIG. 14, at time T21, a decrease in the resistance value R corresponding to the increase in the pressure P is observed, so that the resistance value R acquired in the process of step S2 is small. Since T (value at the time of short circuit) is exceeded and below the maximum value Max (YES in step S3 ′), the heater heat output is turned on (step S4), and the heater temperature indicates 40 ° C.

  At time T22, since the resistance value R corresponding to a further increase in the pressure P has become a resistance value R corresponding to a short circuit due to a decrease in the resistance value R, the resistance value R acquired in the process of step S2 becomes smaller. R is determined to be equal to or less than a predetermined value T (NO in step S3 ′), and the heater does not output heat (step S5). As a result, the heater temperature returns to room temperature.

  At time T23, an increase in the resistance value R corresponding to the decrease in the pressure P is observed. Therefore, the resistance value R acquired in the process of step S2 is increased, exceeds the predetermined value T, and falls below the maximum value Max. Therefore (YES in step S3 ′), the heater heat output is performed again (step S4). Thereby, the heater temperature also rises to 40 ° C. Thereafter, at time T24, the resistance value R again corresponds to a short circuit, so that the heater is turned off. At time T25, the pressure P decreases and the heater is turned on. At time T26, the heater is turned off at the resistance value R corresponding to pressure P = 0 (zero). Then, the heater is turned on when the resistance value R decreases as the pressure P increases.

  In the present embodiment, as in the first embodiment, heat generation of the conduction portions 9 and 11 for supplying power and overheating of the short-circuit portion can be suppressed, and the cloth pressure sensor heater 1 itself is air permeable and flexible. Since the elasticity is maintained, it is possible to suppress unpleasant feeling of use such as discomfort and stuffiness during use.

  Further, in the present embodiment, the heater heating is performed when the electrical resistance value measured by the electrical resistance value measuring means 19 is not less than the maximum value Max, that is, when the cloth-like pressure sensor heater 1 is not under pressure and is not used. I try not to. For this reason, it can contribute to power saving.

  In the control described above, when the heat generation amount control means 19 performs the heater heat generation output, the heat generation output is small when the resistance value R measured by the electric resistance value measurement means 17 is large, and the heat generation is generated when the resistance value R is small. Control to increase the output can be performed. Thereby, heater temperature can be made constant with respect to target temperature, and the stable output as a heater can be performed.

  The cloth-like pressure sensor heater 1 as described above can be used, for example, for a vehicle seat 33 as shown in FIG. The seat 33 mainly includes a seat cushion 35, a seat back 37, and a headrest 39, and the cloth-like pressure sensor heater 1 formed in substantially the same shape as the seat cushion 35 is set on the seat cushion 35. The cloth-like pressure sensor heater 1 in an actual use state as shown in FIG. 15 is used with a separate cover.

  When measuring the pressure distribution due to a change in posture when the occupant sits on the seat cushion 35 via the cloth-like pressure sensor heater 1, the cloth-like pressure sensor heater 1 itself maintains air permeability and flexibility. Therefore, an unpleasant feeling of use such as a feeling of strangeness or stuffiness during use can be suppressed. At the same time, since there is the control at the time of the short circuit described above, the power supply to the heater is stopped at the time of the short circuit, so that the heat generation and abnormal overheating of the conduction part can be suppressed. In addition to the application to such a vehicle, it can be used as a bed sheet in a hospital, a nursing facility, or the like, so that it can be used for heating by a heater while measuring a position where pressure is applied.

  In each of the above-described embodiments, the connecting yarn 12 is made of a conductive fiber containing a metal, and the cloth-like pressure sensor heater 1 in each of the embodiments can be manufactured using this conductive fiber.

  Further, in each of the above-described embodiments, the conductive fiber includes a semiconductor, and the cloth-like pressure sensor heater 1 in each embodiment can be manufactured using such a conductive fiber.

  Further, in each of the above-described embodiments, the conductive fiber includes a conductive resin, and the cloth-like pressure sensor heater 1 in each embodiment can be manufactured using such a conductive fiber.

  Further, in each of the above-described embodiments, the conductive fiber includes carbon, and the cloth-like pressure sensor heater 1 in each embodiment can be manufactured using such a conductive fiber.

  Further, in each of the above-described embodiments, the surface of the fiber having conductive fibers as a core is coated with, for example, silver as a conductor, and the cloth-like pressure sensor heater 1 according to each embodiment is manufactured using such conductive fibers. Is possible.

  Next, an example of an apparatus for producing conductive polymer fibers will be described.

  A wet spinning apparatus 41 shown in FIG. 16 accommodates acetone (Wako Chemical Co., Ltd .: 019-00353) as a solvent phase in a wet spinning solvent tank 43, and a microsyringe (Ito Co., Ltd.) is placed in the wet spinning solvent tank 43. A plurality of conductive polymer fibers 49a are generated using MS-GLL100 (manufactured by Seisakusho Co., Ltd., needle inner diameter 260 μm) 45.

  The microsyringe 45 is composed of a spinning stock solution obtained by mixing an aqueous dispersion of the conductive polymer PEDOT / PSS once filtered (Clevios manufactured by Starck) and a 7 wt% aqueous solution of polyvinyl alcohol (PVA: manufactured by Kanto Chemical Co., Ltd.). It extrudes from the cap needle 47 at a speed of 2 μL / min. Thereby, the above-described plurality of conductive polymer fibers 49a having a diameter of about 10 μm can be obtained by a wet spinning method.

  In a state where the plurality of conductive polymer fibers 49 a are bundled to form one fiber 49, the fiber feeding rollers 53 and 55 of the fiber feeder 51 arranged outside the wet spinning solvent tank 43 are put in the coating tank 57. Send it in. In the coating tank 57, for example, silver as a conductor is coated on the surface of the conductive polymer fiber 49. The coated conductive polymer fiber 49 is pulled out again, sent to the dryer 61 by the fiber feed roller 59 of the fiber feeder 51 and dried, and the dried conductive polymer fiber 63 is wound around the fiber winder 65. take.

  Then, the conductive polymer fiber 63 is a conductive polymer fiber 67 having an appropriate length shown in FIG. 17A, and a plurality of (for example, twelve) conductive polymer fibers 67 are formed as shown in FIG. 17B. ) Used as a bundle of bundles to fabricate the cloth-like pressure sensor heater 1.

  Hereinafter, the present invention will be described more specifically based on examples.

[Example 1]
The conductivity of the conductive polymer fiber obtained by the wet spinning method shown in FIG. 16 (but not coated in the coating tank 57) is expressed by the above-mentioned JIS K 7194 (the resistivity of the conductive plastic by the 4-probe method). The electrical resistivity (Ω · cm) obtained by measurement according to the test method was about 10 ⁻¹ Ω · cm. This conductive polymer fiber was used as the intermediate layer 7 which is a variable resistance heating layer.

  As the fibers for the first and second conducting portions 9 and 11 (11A and 11B) of the upper layer 3 and the lower layer 5, silver-coated fibers (manufactured by Shaoxing Yuka Textile Co., Ltd.) were used. Polyester fibers (manufactured by Chuo Textile Material, Gunze Polina) were used for the non-conducting portions 13 and 15 (15B).

  Using a circular knitting machine manufactured by Fukuhara Seiki Co., Ltd., gauge, number of units, variable resistance heating layer (intermediate layer 7) between upper and lower layers is 10mm, and the amount of conductive polymer fiber per unit area is 10% Adjustments were made to

  The upper layer 3 has a striped structure in which a conductive portion (first conductive portion 9) having a width of 10 mm and a non-conductive portion 13 having a width of 2 mm are repeatedly formed, and the lower layer 5 has a cloth shape as a conductive portion 11A as shown in FIG. A pressure sensor heater 1 was obtained. The shape of the cloth-shaped pressure sensor heater 1 was approximately square with a length of 20 cm and a width of 20 cm.

  As the electrical resistance value measuring means 17, wiring connection was made to the input terminal of R7C manufactured by M Systems Giken through a voltage follower formed by an operational amplifier (TL071 manufactured by Texas Instruments). As shown in FIG. 2, the heat generation amount control means 19 includes one end portion in the longitudinal direction of each conducting portion 9 of the upper layer 3 in FIG. 7 and the other end portion of the conducting portion 11A in the lower layer 5 along the longitudinal direction. The cloth-like pressure sensor heater 1 capable of measuring and generating heat was obtained by dividing the whole cloth-like pressure sensor heater 1 into 16 places.

  The control is based on the flowchart of FIG. 12 and performs control to generate heat even when the pressure P = 0 (zero) shown in the time chart of FIG. The change range of the electric resistance value R obtained by the electric resistance value measuring means 17 was confirmed in advance to be 11Ω to 1.2Ω, and the predetermined value T corresponding to the short circuit was set to 1.2Ω.

Voltage 2V-12V was applied according to the change of the resistance value R for each stripe pattern when the pressure P was applied to 0-2.94 × 10 ³ Pa for each stripe pattern of the upper layer 3. At the same time, it was confirmed that the temperature at the time when there was a heat generation output at an arbitrary part of 16 divisions was almost constant at 41 ° C. The heat generation of the conduction parts 9 and 11A was not confirmed.

[Example 2]
The lower layer 5 is formed of polyester fiber, and the lower layer 5 has a 10 mm wide conductive portion (second conductive portion 11B) and a 2 mm width so as to intersect the stripe pattern of the upper layer 3 at 90 degrees as shown in FIG. The non-conductive portion 15B is repeated. In this case, the conductive portion (second conductive portion 11B) of the lower layer 5 was formed by applying a conductive paste (made by Fujikura Kasei Co., Ltd., Dotite) to the polyester fiber. Except this, it carried out similarly to Example 1, and obtained the cloth-like pressure sensor heater 1 which can measure and heat_generate | generate by dividing 256 places.

  The control is based on the flowchart of FIG. 12 and performs the control not to generate heat when the pressure P = 0 (zero) shown in the time chart of FIG. The change range of the resistance value obtained by the electrical resistance value measuring means 17 was confirmed in advance to be 116Ω to 20Ω, and the predetermined value T corresponding to the short circuit was set to 20Ω.

A voltage of 2 V to 12 V is applied according to a change in resistance value R at each intersection when pressure is applied to 0 to 2.94 × 10 ³ Pa at each intersection of the stripe pattern between the upper layer 3 and the lower layer 5. did. It was confirmed that the temperature when there was an exothermic output at an arbitrary part of 256 divisions was almost constant at 40 ° C. Heat generation in the conductive portions 9 and 11B was not confirmed.

[Comparative Example 1]
As the resistance variable heat generation layer (intermediate layer 7), a polyester fiber (Gunze Polina, manufactured by Chuo Textile Materials Co., Ltd.) having no resistance variable ability and heat generation ability was used. Other upper layer 3 and lower layer 5 fibers are the same as in Example 1, using a circular knitting machine manufactured by Fukuhara Seiki Co., Ltd. (Intermediate layer 7) A cloth having a three-layer structure was produced so that the thickness was 10 mm.

  Each of the upper layer 3 and the lower layer 5 has a striped pattern structure in which a conductive portion having a width of 10 mm and a non-conductive portion having a width of 2 mm are repeatedly formed. The electrical resistance value measuring means 17 and the calorific value control means 19 were provided so as to connect the upper layer 3 and the lower layer 5 as in the first embodiment.

  The measured resistance value was infinite when no pressure was applied, and was almost 0 (zero) Ω at the maximum pressure in the evaluation range, indicating a short circuit. At the time of the short circuit, heat generation at 33 ° C. was confirmed in the conduction portion divided into 16 parts.

  In addition, the measurement of the resistance value and the heat generation temperature in the above-described Examples 1 and 2 and the comparative example was performed in a constant temperature bath at a temperature of 25 ° C. and a humidity of 60% RH.

1 Cloth pressure sensor heater 3 Upper layer (first fiber layer)
5 Lower layer (second fiber layer)
7 Intermediate layer (third fiber layer)
DESCRIPTION OF SYMBOLS 9 1st conduction | electrical_connection part 11,11A, 11B 2nd conduction | electrical_connection part 12 Connection thread | yarn of an intermediate | middle layer 17 Electrical resistance value measurement means 19 Heat generation amount control means (control means)
T Predetermined value of electrical resistance (first threshold)
Max Maximum electric resistance value (second threshold)

Claims (8)

A cloth shape having a first fiber layer, a second fiber layer provided at a position facing the first fiber layer, and a third fiber layer provided between the first fiber layer and the second fiber layer A pressure sensor heater,
The first fiber layer includes a first conductive portion having conductivity,
The second fiber layer includes a second conductive part having conductivity,
The third fiber layer includes a conductive connecting yarn that is connected to the first fiber layer and the second fiber layer, and electrically connects the first conduction part and the second conduction part,
An electrical resistance value measuring means for measuring an electrical resistance value between the first conducting portion and the second conducting portion;
When the electrical resistance value measured by the electrical resistance value measuring unit exceeds a predetermined value corresponding to a state in which the first conducting part and the second conducting part are short-circuited, the first conducting part and the second conducting part A cloth-like pressure sensor heater, comprising: a control means for applying a voltage to the conduction portion to generate heat in the connecting yarn.   The control means applies a voltage between the first conduction part and the second conduction part when the electrical resistance value measured by the electrical resistance value measurement means is in a certain range exceeding the predetermined value. The cloth-like pressure sensor heater according to claim 1, wherein the connecting yarn generates heat.   The cloth-like pressure sensor heater according to claim 1 or 2, wherein the connecting yarn is made of a conductive fiber.   The cloth-like pressure sensor heater according to claim 3, wherein the conductive fiber includes a semiconductor.   The cloth-like pressure sensor heater according to claim 3, wherein the conductive fiber comprises a conductive resin.   The cloth-like pressure sensor heater according to claim 3, wherein the conductive fiber contains carbon.   The cloth-like pressure sensor heater according to claim 3, wherein a conductor is coated on a surface of the fiber in which the conductive fiber is a core. The cloth-like pressure sensor heater according to any one of claims 3 to 7, wherein an electrical resistivity of the conductive fiber is 10 ^-3 to 10 ² Ω · cm.

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