JP5883917B1 - Seating sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seating sensor excellent in resistance to static electricity. SOLUTION: Pressure sensitive switches SW1 and SW2 having a pair of electrodes disposed on a pair of insulating sheets 10s and 20s and facing each other through an opening 31 formed in a spacer 30 disposed between the pair of insulating sheets. A switch unit SWB1 having at least one and a circuit unit CI1 having a resistance element R1 disposed between the pair of insulating sheets 10s and 20s and electrically connected in parallel to the switch unit SWB1, and disposed between the pair of insulating sheets. And a ground wiring 60 connected to the ground side with respect to the circuit unit CI1. The ground wiring 60 surrounds the circuit unit CI1 when the pair of insulating sheets 10s and 20s is viewed in plan. [Selection] Figure 3

Description

  The present invention relates to a seating sensor suitable when static electricity is generated in a seat.

  As one of safety systems in vehicles, an alarm system for warning that a seat belt is not worn when riding is put into practical use. In this alarm system, a warning is issued when the seat belt is not detected while a person is seated. As a sensor for detecting the seating of the person, a seating sensor for detecting a load caused by the seating may be used.

  Patent Document 1 listed below describes a seating sensor that detects which seat among a plurality of seats an occupant is seated on. This seating sensor includes a plurality of sets of a sensor unit and a resistance element connected in parallel to the sensor unit between a pair of terminals, and the plurality of sets are connected in series to each other. The resistance values of the resistance elements in each of the plurality of sets are different from each other, and the total resistance value is different for each combination of the resistance elements.

  With such a configuration, the resistance between the terminals is different for each combination of detection or non-detection in each set of sensor units. Accordingly, by assigning one set of sensor unit and resistance element to each seat, it is determined whether or not there are seats on a plurality of seats based on signals output from a pair of terminals connected to the sensor unit. be able to.

JP 2013-16285 A

  As described above, the seating sensor described in Patent Document 1 can detect a seat on which an occupant is seated based on a resistance value. Therefore, it is important that the resistance value of each resistor does not change. By the way, when an occupant sits on a seat, static electricity may occur. When current due to static electricity flows through the resistance element in the seating sensor, the resistance element generates heat, and the resistance value of the resistance element may change.

  Then, an object of this invention is to provide the seating sensor which is excellent in the tolerance with respect to static electricity.

  In order to solve the above-described problems, a seating sensor according to the present invention has a pair of electrodes disposed on a pair of insulating sheets and facing each other through an opening formed in a spacer disposed between the pair of insulating sheets. Between the pair of insulating sheets and at least one circuit unit having a switch element having at least one pressure-sensitive switch and a resistance element arranged between the pair of insulating sheets and electrically connected to the switch part in parallel. A ground wiring that is arranged and connected to the ground side with respect to the at least one circuit portion, and the ground wiring surrounds at least one of the circuit portions when the pair of insulating sheets are viewed in plan view. It is what.

  When a resistance element is arranged in a seating sensor using a pressure-sensitive switch in which electrodes are arranged between insulating sheets such as a membrane switch, the resistance element is generally an insulating sheet like the seating sensor described in Patent Document 1. Arranged between. This resistance element is used to detect which circuit unit the switch unit is turned on, and is electrically connected to the switch unit in parallel. When static electricity falls on the seating sensor having such a configuration, the static electricity does not pass through the insulating sheet perpendicularly to the surface but flows from between the pair of insulating sheets to an internal circuit. At this time, according to the seating sensor of the present invention, since the ground wiring arranged between the pair of insulating sheets surrounds the circuit portion having the pressure sensitive switch and the resistance element, static electricity is externally provided between the pair of insulating sheets. Even if it falls through, static electricity tends to flow to the ground wiring. Therefore, static electricity is prevented from dropping at least in the circuit portion surrounded by the ground wiring. In addition, since the ground wiring is connected to the ground side with respect to the circuit portion, static electricity flowing in the ground wiring is suppressed from flowing to the circuit portion. That is, static electricity is suppressed from flowing through the resistance element. For this reason, since the said seating sensor can suppress that a resistance value changes with static electricity, it is excellent in the tolerance with respect to static electricity.

  The opening is preferably connected to an external space via an air vent formed in the spacer, and the ground wiring is provided at a position overlapping the air vent when the pair of insulating sheets are viewed in plan. .

  In a structure in which air in a predetermined space by an opening between a pair of electrodes is released to the outside through an air bend, static electricity tends to enter between the electrodes from the air bend. Thus, by arranging the ground wiring at a position overlapping with the air bend as described above, static electricity entering from the air bend can easily flow into the ground wiring.

  In this case, it is preferable that the portion of the ground wiring that overlaps with the air vent is wider than at least a part of the portion of the ground wiring that does not overlap with the air vent.

  By increasing the width of the position overlapping the air bend where the intrusion of static electricity easily occurs in the ground wiring, the electrical withstand voltage at the position can be increased. Moreover, it becomes easier to absorb static electricity. Therefore, resistance to static electricity can be further increased.

  The air vent may be formed including a slit formed in the spacer, and the ground wiring may be provided at a position overlapping the slit when the pair of insulating sheets are viewed in plan.

  The slit formed in the spacer extends in the surface direction of the spacer. By extending the air bend in the direction of the spacer surface in this way, it is possible to prevent the air bend and the ground wiring from overlapping when the position of the ground wiring is slightly displaced, such as when the seating sensor is bent. Can do.

  The air vent is formed including an opening formed in at least one of the pair of insulating sheets, and the ground wiring is formed in the insulating sheet when the pair of insulating sheets are viewed in plan. It is good also as providing in the position which overlaps.

  By forming the air bend perpendicularly to the surface direction of the insulating sheet in this way, not only the static electricity that enters between the insulating sheets but also the static electricity that enters between the insulating sheets from the surface of the insulating sheet can be easily absorbed. Can do.

  The resistance element and the ground wiring are preferably formed in the same layer.

  By forming the resistive element and the ground wiring in the same layer, static electricity flowing along the surface direction of the insulating layer is generated in the resistive element rather than forming the insulating layer and the ground layer in separate layers. It is possible to further reduce the flow. Therefore, such a configuration can further protect the resistance element from static electricity.

  Further, the resistance element is disposed on a surface of one of the pair of insulating sheets, and on a surface opposite to a surface on which the resistance element is disposed in the insulating sheet on which the resistance element is disposed. It is preferable that a moisture-proof member having a higher moisture resistance than the insulating sheet is disposed so as to cover the resistance element.

  When the seating sensor is disposed in a humid environment, moisture in the air may enter the seating sensor through the insulating sheet. In this case, when the resistance element is arranged on the surface of the insulating sheet, the resistance value of the resistance element tends to change due to the intruding moisture. Therefore, by disposing the moisture-proof member as described above, it is possible to suppress the resistance value of the resistance element from changing even in a humid environment.

  As described above, according to the present invention, a seating sensor having excellent resistance to static electricity is provided.

It is a perspective view which shows the seating sensor which concerns on 1st Embodiment of this invention. It is an exploded view of the seating sensor shown in FIG. It is a top view which shows the seating sensor shown in FIG. It is sectional drawing of the seating sensor in the surface which passes a pressure-sensitive switch shown in FIG. It is an equivalent circuit schematic of the seating sensor shown in FIG. It is sectional drawing of the seating sensor in the surface which passes along the VV line | wire of FIG. It is a figure which shows the seating sensor which concerns on 2nd Embodiment of this invention by the method similar to FIG. It is a figure which shows the seating sensor which concerns on 3rd Embodiment of this invention by the method similar to FIG.

  DESCRIPTION OF EMBODIMENTS Hereinafter, a preferred embodiment of a seating sensor according to the present invention will be described in detail with reference to the drawings. In the following description, the term “connection” may mean an electrical connection.

(First embodiment)
It is a perspective view which shows the seating sensor which concerns on 1st Embodiment of this invention. As shown in FIG. 1, the seating sensor 1 mainly includes a first electrode sheet 10 as one electrode sheet, a second electrode sheet 20 as the other electrode sheet, a spacer 30, and moisture-proof members 41 to 43. As a major component. In addition, the seating sensor 1 of this embodiment is a seating sensor arrange | positioned at three-seat seats, such as a rear seat of a vehicle.

  FIG. 2 is an exploded view of the seating sensor of FIG. Specifically, FIG. 2 (A) is a diagram showing the second electrode sheet 20, FIG. 2 (B) is a diagram showing the spacer 30, and FIG. 2 (C) shows the first electrode sheet 10. FIG. 2D is a view showing the moisture-proof members 41 to 43. FIG. 2 is a view of each sheet as viewed from the second electrode sheet 20 side.

  The first electrode sheet 10 which is one electrode sheet includes a first insulating sheet 10s as one insulating sheet, first electrodes 11 to 16, terminals En and Ep, resistance elements R1 to R3, and first Electrodes 11 to 16, terminals En and Ep, and wiring for electrically connecting resistance elements R1 to R3 are provided as main components.

  The first insulating sheet 10s is made of a flexible sheet, is connected to a substantially rectangular main block Bm, and one end in the longitudinal direction of the main block Bm, and has a substantially rectangular shape with a smaller area than the main block Bm. It consists of sub-block Bs. The first insulating sheet 10s is made of an insulating material, and examples of such a material include resins such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polyimide (PI).

  The first electrodes 11 to 16 each have a substantially circular shape, and are arranged in a straight line on one surface of the first insulating sheet 10s. The surface on which the first electrodes 11 to 16 are disposed is a surface on the side facing the second electrode sheet 20.

  The resistance elements R1 to R3 are provided on one surface of the first insulating sheet 10s on which the first electrodes 11 to 16 are provided. The resistive element R1 is disposed between the first electrode 11 and the first electrode 12, the resistive element R2 is disposed between the first electrode 13 and the first electrode 14, and the resistive element R3 is disposed on the first electrode. 15 and the first electrode 16. The resistance values of the resistance elements R1 to R3 are different from each other, and the total resistance value is different for each combination of the resistance elements R1 to R3. For example, when the resistance values of the resistance elements R1 to R3 having the same resistance value per unit length are set to 4: 2: 1, the resistance values of the resistance elements R1 to R3 are R1: R2: R3 = 4: 2: 1.

  The resistance elements R1 to R3 are made of, for example, printing resistors and are made of a material having a higher resistance value than the wiring, and are made of, for example, a mixture of conductive particles and a resin binder. Examples of the conductive particles include metal particles, semiconductor particles such as indium-doped tin oxide, and carbon-based particles such as graphite and carbon black. Carbon-based particles whose resistance value can be easily adjusted are preferable. Examples of the resin binder include silicone rubber resin, polyurethane resin, epoxy resin, phenol resin, and polyester resin.

  The first electrode 11 and the resistance element R1 are connected to each other by a wiring 51a, and the resistance element R1 and the first electrode 12 are connected to each other by a wiring 51b. The first electrode 12 and the first electrode 13 are connected to each other by a wiring 52. The first electrode 13 and the resistance element R2 are connected to each other by a wiring 52a, and the resistance element R2 and the first electrode 14 are connected to each other by a wiring 52b. The first electrode 14 and the first electrode 15 are connected to each other by a wiring 53. The first electrode 15 and the resistance element R3 are connected to each other by a wiring 53a, and the resistance element R3 and the first electrode 16 are connected to each other by a wiring 53b. Therefore, the first electrode 11, the resistor element R1, the first electrode 12, the first electrode 13, the resistor element R2, the first electrode 14, the first electrode 15, the resistor element R3, and the first electrode 16 are connected in this order. The

  The terminals En and Ep have a substantially rectangular shape, and are disposed on the same surface as the surface on which the first electrodes 11 to 16 are disposed in the sub-block Bs of the first insulating sheet 10s. The terminal Ep is a plus terminal and is connected to a terminal on the positive side of the device to which the seating sensor 1 is connected. On the other hand, the terminal En is a ground terminal and is connected to a terminal on the ground side of the device to which the seating sensor 1 is connected.

  The terminal Ep and the first electrode 11 are connected to each other by a wiring 51. On the other hand, the terminal En is connected to the ground wiring 60. The ground wiring 60 is disposed on the same surface as the surface on which the first electrodes 11 to 16 are disposed, and includes a first wiring portion 61, a second wiring portion 62, and a third wiring portion 63. When the first insulating sheet 10s is viewed in plan, the first wiring portion extends substantially parallel to the arrangement of the first electrodes 11 to 16 and the resistance elements R1 to R3, and in the surface direction of the first insulating sheet 10s. It overlaps with the first electrodes 11 to 16 and the resistance elements R1 to R3. The second wiring portion 62 extends substantially perpendicular to the first wiring portion 61 on the side opposite to the terminal En side with respect to the first electrode 16, and one end is connected to the first wiring portion 61. The third wiring portion 63 extends substantially parallel to the first wiring portion 61 on the side opposite to the first wiring portion 61 side with respect to the first electrodes 11 to 16 and the resistance elements R1 to R3. The second wiring portion 62 is connected to the other end and overlaps the first electrodes 11 to 16 and the resistance elements R1 to R3 in the surface direction of the first insulating sheet 10s. Thus, the ground wiring 60 surrounds the first electrodes 11 to 16 and the resistance elements R1 to R3 when the first insulating sheet 10s is viewed in plan.

  The second electrode sheet 20 that is the other electrode sheet includes a second insulating sheet 20s as the other insulating sheet, second electrodes 21 to 26 formed on the surface of the second insulating sheet 20s, and wirings 71 to 73. As a main component.

  The second insulating sheet 20s is made of a flexible sheet, and has the same shape as the main block Bm in the first insulating sheet 10s. The second insulating sheet 20s has an insulating property, and is made of the same material as the first insulating sheet 10s, for example. The flexibility of the second insulating sheet 20s is approximately the same as that of the first insulating sheet 10s, but may be different.

  The second electrodes 21 to 26 have the same configuration as the first electrodes 11 to 16 and are arranged on the surface facing the first electrode sheet 10. Further, when the second electrode sheet 20 is overlapped with the main block Bm of the first electrode sheet 10, the first electrode 11 and the second electrode 21 overlap, and the first electrode 11 and the second electrode 21 overlap. The first electrode 11 and the second electrode 21 overlap, the first electrode 12 and the second electrode 22 overlap, the first electrode 13 and the second electrode 23 overlap, and the first electrode 14 and the second electrode 24 The second electrodes 21 to 26 are arranged so that the first electrode 15 and the second electrode 25 overlap, and the first electrode 16 and the second electrode 26 overlap.

  The second electrode 21 and the second electrode 22 are connected to each other by a wiring 71, the second electrode 23 and the second electrode 24 are connected to each other by a wiring 72, and the second electrode 25 and the second electrode 26 are connected to each other by a wiring 73. Are connected to each other.

  The spacer 30 is made of a flexible insulating sheet, and is made of the same material as the first insulating sheet 10s, for example. The outer shape of the spacer 30 substantially matches the second electrode sheet 20.

  Openings 31 to 36 having the same size are formed in the spacer 30. The openings 31 to 36 have a substantially circular periphery, and have a diameter slightly smaller than the diameters of the first electrodes 11 to 16 and the second electrodes 21 to 26. When the spacer 30 is overlapped with the main block Bm and the second electrode sheet 20 of the first electrode sheet 10 and the spacer 30 is viewed in plan, the opening 31 is inside the peripheral edges of the first electrode 11 and the second electrode 21. The opening 32 is located inside the peripheral edges of the first electrode 12 and the second electrode 22, the opening 33 is located inside the peripheral edges of the first electrode 13 and the second electrode 23, and the opening 34 is the first electrode. 14 and the second electrode 24, the opening 35 is located inside the first electrode 15 and the second electrode 25, and the opening 36 is located inside the first electrode 16 and the second electrode 26. The openings 31 to 36 are formed so as to be positioned at the positions.

  Further, the spacer 30 is formed with slits 31 s to 36 s that are air bends. The slit 31 s spatially connects the opening 31 to the outside of the spacer 30, the slit 32 s spatially connects the opening 32 to the outside of the spacer 30, and the slit 33 s spatially connects the opening 33 to the outside of the spacer 30. The slit 34s spatially connects the opening 34 to the outside of the spacer 30, the slit 35s spatially connects the opening 35 to the outside of the spacer 30, and the slit 36s spatially connects the opening 36 to the outside of the spacer 30. doing. In the present embodiment, when the spacer 30 is viewed in plan, the slits 31 s, 33 s, and 35 s are formed on one side of the spacer 30, and the slits 32 s, 34 s, and 36 s are formed on the other side of the spacer 30. Has been.

  Note that an adhesive (not shown) for bonding to the first electrode sheet 10 and the second electrode sheet 20 is applied to both surfaces of the spacer 30.

  In the present embodiment, the moisture-proof members 41 to 43 have a substantially rectangular shape, and have a moisture permeability lower than that of the first insulating sheet 10s, that is, a sheet-like member having excellent moisture resistance. When the first insulating sheet 10s is a sheet made of the resin as described above, examples of the sheet constituting the moisture-proof members 41 to 43 include a metal layer, a glass foil, and a metal layer or glass on the surface of a resinous sheet. Examples thereof include a sheet provided with a layer. As a sheet | seat with which the metal layer was provided, the sheet | seat by which metals, such as aluminum, were vapor-deposited on the surface of a resin sheet can be mentioned, for example. Moreover, as a sheet | seat with which the glass layer was provided, the sheet | seat by which the thin glass layer was stuck on the surface of the resin sheet can be mentioned. Further, examples of the moisture-proof members 41 to 43 include those in which a metal layer is formed on the first insulating sheet 10s by vapor deposition or the like. The thickness of the metal layer is preferably 5 nm or more and 100 nm or less. When the thickness of the metal is 5 nm or more, moisture resistance can be sufficiently secured. In addition, when metal foil is used for the moisture-proof members 41 to 43, it is preferable that the thickness of the metal foil is 10 μm or more and 0.1 mm or less. In addition, sufficient strength can be ensured by setting the thickness of the metal foil to 10 μm or more, and sufficient restorability can be ensured when the seating sensor 1 is bent by setting the thickness of the metal foil to 0.1 mm or less. it can.

  FIG. 3 is a plan view of the seating sensor 1 from the first electrode sheet 10 side. For ease of understanding, the first electrodes 11 to 16 of the first electrode sheet 10, the resistance elements R1 to R3, the wiring, the second electrodes 21 to 26 of the second electrode sheet 20, and the wiring are indicated by broken lines, The openings 31 to 36 and the slits 31 s to 36 s of the spacer 30 are indicated by dotted lines.

  As illustrated in FIG. 3, the first electrode sheet 10, the spacer 30, and the second electrode sheet 20 are attached in this order, and the first electrodes 11 to 16 and the resistance elements R <b> 1 to R <b> 3 of the first electrode sheet 10. The wirings, the second electrodes 21 to 26 of the second electrode sheet 20, and the wiring are located between the first insulating sheet 10s and the second insulating sheet 20s. Then, the pressure sensitive switch SW1 is configured to face the first electrode 11 and the second electrode 21. FIG. 4 is a cross-sectional view of the seating sensor 1 on a plane passing through the pressure sensitive switch SW1. In FIG. 4, the first electrode sheet 10 is shown on the upper side. As shown in FIG. 4, the first electrode 11 and the second electrode 21 face each other through the opening 31 and are separated from each other in a state where no pressure is applied. Similarly, the first electrode 12 and the second electrode 22 are opposed to each other through the opening 32 to constitute the pressure sensitive switch SW2, and the first electrode 13 and the second electrode 23 are opposed to each other through the opening 33 to sense the pressure. The pressure switch SW3 is configured, the first electrode 14 and the second electrode 24 are opposed to each other via the opening 34 to configure the pressure sensitive switch SW4, and the first electrode 15 and the second electrode 25 are configured via the opening 35. The pressure-sensitive switch SW5 is opposed to each other, and the first electrode 16 and the second electrode 26 are opposed to each other through the opening 36 to constitute the pressure-sensitive switch SW6.

  FIG. 5 is a diagram showing an equivalent circuit of the seating sensor 1. As shown in FIG. 5, the pressure sensitive switch SW1 and the pressure sensitive switch SW2 are connected in series, and the pressure sensitive switch SW1 and the pressure sensitive switch SW2 form a first switch unit SWB1. Similarly, the pressure sensitive switch SW3 and the pressure sensitive switch SW4 are connected in series, and the pressure sensitive switch SW3 and the pressure sensitive switch SW4 form the second switch part SWB2, and the pressure sensitive switch SW5 and the pressure sensitive switch SW6 are connected in series. Then, the pressure switch SW5 and the pressure switch SW6 form a third switch unit SWB3. Further, the resistor element R1 and the first switch unit SWB1 are electrically connected in parallel, the resistor element R2 and the second switch unit SWB2 are electrically connected in parallel, and the resistor element R1 and the third switch unit SWB3 Are electrically connected in parallel.

  In the present embodiment, one detection circuit unit CI1 for detecting seating is formed by the first switch unit SWB1 including the pressure sensitive switch SW1 and the pressure sensitive switch SW2 and the resistance element R1, and the pressure sensitive switch SW3 and the pressure sensitive switch are formed. Another detection circuit unit CI2 for detecting seating is formed by the second switch unit SWB2 composed of SW4 and the resistor element R2, and the third switch unit SWB3 composed of the pressure sensitive switch SW5 and the pressure sensitive switch SW6 and the resistor Still another detection circuit unit CI3 for detecting the seating with the element R3 is formed. These three detection circuit units CI1 to CI3 are connected in series.

  Further, as apparent from FIG. 3, in the detection circuit unit CI1, the resistance element R1 is arranged at a position sandwiched between the pressure sensitive switch SW1 and the pressure sensitive switch SW2, and the pressure sensitive switch SW1, the resistance element R1, and the pressure sensitive switch are arranged. SW2 is arranged in a straight line. Similarly, in the detection circuit unit CI2, the resistance element R2 is disposed at a position between the pressure sensitive switch SW3 and the pressure sensitive switch SW4, and the pressure sensitive switch SW3, the resistive element R2, and the pressure sensitive switch SW4 are arranged in a straight line. It is out. Similarly, in the detection circuit unit CI3, the resistance element R3 is disposed at a position between the pressure sensitive switch SW5 and the pressure sensitive switch SW6, and the pressure sensitive switch SW5, the resistive element R3, and the pressure sensitive switch SW6 are linearly arranged. Are lined up.

  As is clear from FIGS. 3 and 5, the ground wiring 60 is connected to the ground side with respect to these three detection circuit portions CI <b> 1 to CI <b> 3. Further, the ground wiring 60 surrounds the first electrodes 11 to 16 and the resistance elements R1 to R3 as described above when the first insulating sheet 10s is viewed in plan view, and thus the first insulating sheet 10s and the second insulating sheet 20s. When a pair of insulating sheets made of is viewed in plan, each of the detection circuit portions CI1 to CI3 is surrounded. Further, when the pair of insulating sheets are viewed in plan, the first wiring portion 61 of the ground wiring 60 overlaps with the slits 32 s, 34 s and 36 s formed on one side surface of the spacer 30, and the third wiring portion 63. Overlaps the slits 31 s, 33 s, and 35 s formed on the other side surface of the spacer 30. Further, since the ground wiring 60 and the resistance elements R1 to R3 are respectively provided on one surface of the first insulating sheet 10s, the ground wiring 60 and the resistance elements R1 to R3 are provided in the same layer.

  FIG. 6 is a cross-sectional view of the seating sensor 1 on a plane passing through the line VV in FIG. 3, that is, a plane passing through the resistance element R1. In FIG. 4, the first electrode sheet 10 is shown on the upper side. As is clear from FIGS. 3 and 6, the moisture-proof member 41 is attached to the surface of the first electrode sheet 10 opposite to the surface on which the first electrode 11 and the resistor element R <b> 1 are disposed. When the first insulating sheet 10s is viewed in plan, the moisture-proof member 41 is attached to a position that covers at least the resistance element R1. Similarly, the moisture-proof member 42 and the moisture-proof member 43 are attached to the surface to which the moisture-proof member 41 of the first electrode sheet 10 is attached, and when the first insulating sheet 10s is viewed in plan, the moisture-proof member 42 is a resistance element. R2 is covered, and the moisture-proof member 43 covers the resistance element R3.

  Next, detection of seating by the seating sensor 1 will be described.

  As described above, the seating sensor 1 of the present embodiment is a seating sensor disposed on a three-seat seat such as a rear seat of a vehicle. For this reason, in the three-seat seat, the detection circuit unit CI1 is located in the seat at one end, the detection circuit unit CI2 is located in the center seat, and the detection circuit unit CI3 is located in the seat at the other end. The seating sensor 1 is arranged. The terminal Ep is connected to the positive terminal of an external measuring instrument (not shown), and the terminal En is connected to the ground terminal of the measuring instrument.

  In this state, for example, when an occupant is seated in a seat at one end, the pressure sensitive switch SW1 and the pressure sensitive switch SW2 are turned on. For this reason, the resistance element R1 and the wiring 71 are connected in parallel, and the resistance value between the pressure sensitive switch SW1 and the pressure sensitive switch SW2 decreases. Similarly, when an occupant is seated in the inner seat, the pressure sensitive switch SW3 and the pressure sensitive switch SW4 are turned on, the resistance element R2 and the wiring 72 are connected in parallel, and the pressure sensitive switch SW3 and the pressure sensitive switch SW4 are connected. The resistance value during Similarly, when an occupant is seated on the seat at the other end, the pressure sensitive switch SW5 and the pressure sensitive switch SW6 are turned on, the resistance element R3 and the wiring 73 are connected in parallel, and the pressure sensitive switch SW5 and the pressure sensitive switch SW6. The resistance value between and decreases.

  As described above, the resistance values of the resistance elements R1 to R3 are different from each other, and the total resistance value is different for each combination of the resistance elements R1 to R3. For example, when the resistance value of the resistance element R1 is 4, the resistance value of the resistance element R2 is 2, and the resistance value of the resistance element R3 is 1, the resistance value of the seating sensor 1 is as follows according to the seating of the occupant: Is different. In the following description, it is assumed that resistances other than the resistance elements R1 to R3 can be ignored. When the passenger is not sitting, the resistance of the seating sensor 1 is 7. When the occupant is seated in the seat at one end, the resistance of the seating sensor 1 is 3. When the occupant is seated in the inner seat, the resistance of the seating sensor 1 is 5. When the passenger is seated on the seat at the other end, the resistance of the seating sensor 1 is 6. When the occupant is seated on the seat at one end and the seat inside, the resistance of the seating sensor 1 is 1. When the occupant is seated on the seat at one end and the seat at the other end, the resistance of the seating sensor 1 is 2. When the occupant is seated in the seat inside and the seat at the other end, the resistance of the seating sensor 1 is 4. When the occupant is seated in all three seats, the resistance of the seating sensor 1 is zero. In this way, it is possible to detect where the occupant is seated.

  Next, the durability of the seating sensor 1 will be described.

  When the occupant sits down, static electricity may be generated due to friction between the occupant's clothes and the skin of the seat, and the static electricity may enter the seating sensor 1. In this case, the static electricity does not pass through the first insulating sheet 10s and the second insulating sheet 20s perpendicularly to the surface but falls between the first insulating sheet 10s and the second insulating sheet 20s to the internal circuit. However, according to the seating sensor 1 of the present embodiment, the ground wiring 60 disposed between the pair of insulating sheets composed of the first insulating sheet 10s and the second insulating sheet 20s is provided with the pressure sensitive switches SW1 to SW6 and the resistance elements R1 to R1. The detection circuit units CI1 to CI3 having R3 are surrounded. Therefore, even when static electricity falls from the outside of the seating sensor 1 to an internal circuit through a pair of insulating sheets, the static electricity tends to flow to the ground wiring 60. Accordingly, static electricity is prevented from flowing through at least the detection circuit units CI1 to CI3 surrounded by the ground wiring 60. In addition, the ground wiring 60 is connected to the ground side with respect to the detection circuit units CI1 to CI3. For this reason, it is suppressed that the static electricity which flows into the ground wiring 60 flows into detection circuit part CI1-CI3 containing resistance element R1-R3. Therefore, the seating sensor 1 of the present embodiment is excellent in resistance to static electricity, and can suppress the resistance values of the resistance elements R1 to R3 from being changed by static electricity.

  Further, when an air bend is formed as in the seating sensor 1 of the present embodiment, static electricity tends to enter a circuit in the seating sensor 1 from the air bend. However, in the seating sensor 1 of the present embodiment, when the pair of insulating sheets are viewed in plan, as described above, the first wiring portion 61 of the ground wiring 60 overlaps the slits 32s, 34s, and 36s that are air bends, The three wiring portions 63 overlap with the slits 31s, 33s, and 35s that are air bends. Accordingly, static electricity that enters the seating sensor 1 through the air bend easily flows to the ground wiring 60. Thus, in the seating sensor 1 of the present embodiment, static electricity is further suppressed from flowing to the detection circuit units CI1 to CI3, and changes in resistance values of the resistance elements R1 to R3 are further suppressed.

  Further, since the air bend includes slits 31 s to 36 s extending in the surface direction of the spacer 30, when the seating sensor is bent and used or when the seating sensor 1 is manufactured, the position of the ground wiring 60 is slightly shifted. It is possible to prevent the air bend and the ground wiring 60 from overlapping.

  Furthermore, in the seating sensor 1 of the present embodiment, the first wiring portion 61 of the ground wiring 60 that surrounds the detection circuit portions CI1 to CI3 is formed in the spacer 30 when the pair of insulating sheets is viewed in plan as described above. The third wiring portion 63 overlaps the slits 31 s, 33 s, and 35 s formed in the spacer 30. That is, the seating sensor 1 of the present embodiment has a plurality of pressure sensitive switches SW1 to SW6, and slits 32s, 34s, 36s connected to the respective openings 32, 34, 36 of at least one pressure sensitive switch SW2, SW4, SW6. Extends to one side of the arrangement of the plurality of pressure sensitive switches SW1 to SW6, and slits 31s, 33, 35s connected to the respective openings 31, 33, 35 of at least one other pressure sensitive switch SW1, SW3, SW5 are provided. The ground wiring 60 extends to the other side of the row of the pressure sensitive switches SW1 to SW6, and the ground wiring 60 extends to the slits 32s, 34s, 36s extending to one side of the row of the pressure sensitive switches SW1 to SW6 and the other side. Overlaps both of the slits 31s, 33, and 35s. For this reason, even when static electricity enters the seating sensor 1, static electricity easily enters from both sides with respect to the detection circuit units CI1 to CI3, and a high voltage is applied to only a part of the ground wiring 60. Can be suppressed.

  In the seating sensor 1 of the present embodiment, as described above, the ground wiring 60 and the resistance elements R1 to R3 are provided in the same layer. Therefore, it is possible to suppress static electricity from flowing through the resistance elements R1 to R3, compared to the case where the ground wiring 60 and the resistance elements R1 to R3 are not provided in the same layer.

  Moreover, the seating sensor 1 of this embodiment has the moisture-proof members 41-43 which are more moisture-proof than the 1st insulating sheet 10s, and these moisture-proof members 41-43 are resistance elements on the 1st insulating sheet 10s. It arrange | positions in the position which covers resistance element R1-R3 on the surface on the opposite side to the surface where 41-43 is arrange | positioned. Therefore, the moisture-proof members 41 to 43 block moisture in the air that permeates through the first insulating sheet 10s, and water is prevented from entering the resistance elements R1 to R3. Thus, it can suppress that the resistance value of resistance element R1-R3 changes with water by suppressing that water penetrate | invades into resistance element R1-R3. In particular, when the resistor elements R1 to R3 contain a binder resin and the binder resin is made of a material that easily undergoes hydrolysis, such as a polyester resin, the resistance value tends to change greatly when water enters the resistor elements R1 to R3. Therefore, it is preferable that the resistance elements R1 to R3 are covered with the moisture-proof members 41 to 43 as in the present embodiment.

  In the seating sensor 1 of the present embodiment, the resistance element 41 is disposed between the pressure sensitive switch SW1 and the pressure sensitive switch SW2. Therefore, even if moisture enters between the first insulating sheet 10s and the second insulating sheet 20s, the moisture located on the side opposite to the resistance element 41 side with respect to the pressure sensitive switch SW1 and the pressure sensitive switch SW2 The moisture located on the side opposite to the reference resistance element 41 side can be prevented from reaching the resistance element 41 by the pressure sensitive switch SW1 or the pressure sensitive switch SW2. Similarly, the resistive element 42 is disposed between the pressure sensitive switch SW3 and the pressure sensitive switch SW4, and the resistive element 43 is disposed between the pressure sensitive switch SW5 and the pressure sensitive switch SW6. Therefore, even if moisture enters between the first insulating sheet 10s and the second insulating sheet 20s, the moisture located on the opposite side of the resistance element 42 with respect to the pressure sensitive switch SW3 and the pressure sensitive switch SW4 The moisture located on the side opposite to the reference resistive element 42 can be prevented from reaching the resistive element 42 by the pressure sensitive switch SW3 and the pressure sensitive switch SW4, and the resistive element based on the pressure sensitive switch SW5 is used. The pressure sensitive switch SW5 and the pressure sensitive switch SW6 indicate that moisture located on the opposite side to the 43 side and moisture located on the opposite side of the resistive element 43 with respect to the pressure sensitive switch SW6 reach the resistive element 43. Can be blocked.

(Second Embodiment)
Next, a second embodiment of the present invention will be described in detail with reference to FIG. In addition, about the component which is the same as that of 1st Embodiment, or equivalent, except the case where it demonstrates especially, the same referential mark is attached | subjected and the overlapping description is abbreviate | omitted.

  FIG. 7 is a view showing the seating sensor of the present embodiment in the same manner as in FIG. The seating sensor 2 is different from that of the first embodiment in that the portion of the ground wiring 60 that overlaps the slits 31s to 36s that are air bends is wider than at least a part of the portion of the ground wiring 60 that does not overlap the slits 31s to 36s. Different from the seating sensor 1. Specifically, in the ground wiring 60, a portion 60a overlapping with the slit 31s is sandwiched between ground wirings thinner than the portion 60a. Similarly, the part 60b overlapping with the slit 32s, the part 60c overlapping with the slit 33s, the part 60d overlapping with the slit 34s, the part 60e overlapping with the slit 35s, and the part 60f overlapping with the slit 36s are respectively from these parts. Is also sandwiched between thin wires.

  When static electricity enters from the air bend and flows to the ground wiring, the voltage at the portion where the air bend and the ground wiring overlap is higher than the other portions. For this reason, with the configuration of the present embodiment, the withstand voltage against static electricity entering from the slits 31s to 36s can be improved. Therefore, the seating sensor 2 of this embodiment can make resistance to static electricity higher.

(Third embodiment)
Next, a third embodiment of the present invention will be described in detail with reference to FIG. In addition, about the component which is the same as that of 1st Embodiment, or equivalent, except the case where it demonstrates especially, the same referential mark is attached | subjected and the overlapping description is abbreviate | omitted.

  FIG. 8 is a view showing the seating sensor of the present embodiment in the same manner as in FIG. As shown in FIG. 8, in the seating sensor according to the present embodiment, the air bend connected to the openings 31 to 36 includes an opening formed in the second insulating sheet 20 s, a slit formed in the spacer 30, and the openings 31 to 36. And an opening formed separately.

  Specifically, in the second insulating sheet 20s, at a position overlapping the first wiring portion 61 when the second electrodes 21, 23, 25 are moved in a direction perpendicular to the direction in which the second electrodes 21-26 are arranged, Openings 21h, 23h, and 25h that are smaller in diameter than the second electrodes 21, 23, and 25 and larger than the line width of the ground wiring 60 are formed. Similarly, when the second electrodes 22, 24, 26 are moved in a direction perpendicular to the direction in which the second electrodes 21-26 are arranged, the second electrodes 22, 24, 26 are positioned so as to overlap with the third wiring portion 63. Also, openings 22h, 24h, and 26h having a small diameter and larger than the line width of the ground wiring 60 are formed.

  In addition, openings 31h to 36h are formed at positions where the spacers 30 overlap the openings 21h to 26h of the second insulating sheet 20s. Further, the spacer 30 is formed with slits 31s to 36s that connect the openings 31 to 36 and the openings 31h to 36h.

  Furthermore, each part 60a-60f which overlaps opening 21h-26h and opening 31h-36h in the 1st wiring part 61 of the 1st electrode sheet 10 is made into the shape match | combined with the shape of the said opening. As a result, the portions 60 a to 60 f overlapping the openings 21 h to 26 h and the openings 31 h to 36 h in the ground wiring 60 are wider than the portions not overlapping the openings 21 h to 26 h and the openings 31 h to 36 h in the ground wiring 60.

  In the seating sensor of the present embodiment, when the electrodes facing each other of the first electrodes 11 to 16 and the second electrodes 21 to 26 are in contact with each other to detect the seating of the occupant, air in a predetermined space by the openings 31 to 36 Passes through the slits 31s to 36s, the openings 31h to 36h, and the openings 21h to 26h and is discharged to the outside. That is, in this embodiment, the air bend with respect to each of the openings 31-36 is formed of the slits 31s to 36s, the openings 31h to 36h, and the openings 21h to 26h.

  By the way, when such an air bend is formed, static electricity tends to enter from the air bend. However, in the seating sensor of the present embodiment, the ground wiring 60 is disposed at a position overlapping the openings 21h to 26h and the openings 31h to 36h. Moreover, the portions 60a to 60f overlapping the openings 21h to 26h and the openings 31h to 36h in the first wiring portion 61 of the ground wiring 60 are made wider than the portions overlapping the openings 21h to 26h and the openings 31h to 36h. Accordingly, static electricity that enters from the openings 21 h to 26 h tends to flow to the ground wiring 60. Thus, according to the seating sensor of the present embodiment, it is possible to suppress static electricity from flowing through the detection circuit portions CI1 to CI3 and changing the resistance values of the resistance elements R1 to R3 due to static electricity.

  Although the present invention has been described above by taking the first to third embodiments as examples, the present invention is not limited to these.

  Although the case where there are three detection circuit units has been described in the above embodiment, the present invention is not limited to this. For example, only one detection circuit unit may be provided, and this one detection circuit unit may be surrounded by a ground wiring.

  Even in the case of having a plurality of detection circuit units, the ground wiring may surround at least one detection circuit unit. In this case, it is possible to suppress static electricity from flowing through at least the detection circuit portion surrounded by the ground wiring, and to prevent the resistance value of the resistance element of the detection circuit portion from changing.

  Further, in the above embodiment, the ground wiring 60 surrounds the outer periphery of the detection circuit units CI1 to CI3 over the entire circumference. However, the ground wiring 60 may be, for example, an extent that surrounds 50% or more of the outer periphery of the detection circuit units CI1 to CI3, and more preferably an extent that surrounds 75% or more, as in the above embodiment. It is more preferable to surround the entire circumference. For example, in the above embodiment, the first wiring portion 61 and the third wiring portion 63 may be electrically connected by some method, and the second wiring portion 62 may be omitted.

  Hereinafter, the content of the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

(Example)
A sample having a detection circuit unit similar to the detection circuit unit CI1 of the seating sensor 1 shown in FIG. 3 and having the detection circuit unit surrounded by ground wiring in the same manner as the seating sensor 1 was prepared. One electrode (corresponding to the first electrode 11) of one pressure-sensitive switch of this detection circuit unit is connected to the positive terminal, and one electrode (corresponding to the first electrode 12) of the other pressure-sensitive switch is connected to the ground electrode. The ground electrode was grounded. Further, the resistance value of the resistance element of this detection circuit portion was 1025Ω. To this sample, static electricity of 25 kV, 330 pF, and output resistance 330Ω was dropped 10 times. Thereafter, when the resistance value of the resistance element was measured, there was no change in the resistance value.

(Comparative example)
A sample similar to the example was prepared except that the ground wiring did not surround the detection circuit portion and the resistance value of the resistance element was 1023Ω. Static electricity was dropped on this sample in the same manner as in the example. Thereafter, when the resistance value of the resistance element was measured, it was 708Ω. Therefore, in the comparative example, it was found that the resistance value of the resistance element changes due to static electricity.

  From the above, according to the seating sensor of the present invention, it was confirmed that the change in the resistance value of the resistance element can be suppressed even when static electricity flows.

  As described above, according to the present invention, a seating sensor having excellent resistance to static electricity is provided and can be used for a vehicle seat device or the like.

1, 2 ... Seating sensor 10 ... 1st electrode sheet 10s ... 1st insulating sheet 11-16 ... 1st electrode 20 ... 2nd electrode sheet 20s ... 2nd insulating sheet 21 ... 26 ... 2nd electrodes 21h to 26h ... Opening 30 ... Spacers 31 to 36 ... Opening 31h to 36h ... Opening 31s to 36s ... Slits 41 to 43 ... Moisture-proof member 60 ... ground wirings CI1 to CI3 ... detection circuit units En, Ep ... terminals R1 to R3 ... resistance elements SW1 to SW6 ... pressure sensitive switches SWB1 to SWB3 ... first to third switches Part

Claims (6)

A switch unit having at least one pressure-sensitive switch disposed on a pair of insulating sheets and having a pair of electrodes facing each other through an opening formed in a spacer disposed between the pair of insulating sheets, and the pair of pairs At least one circuit portion having a resistance element disposed between insulating sheets and electrically connected to the switch portion in parallel;
A ground wiring disposed between the pair of insulating sheets and connected to the ground side with respect to the at least one circuit unit;
With
The ground wiring, enclose at least one of the circuit portions when viewed from the pair of insulating sheets,
The opening is connected to an external space through an air vent formed in the spacer,
The seating sensor according to claim 1, wherein the ground wiring is provided at a position overlapping the air vent when the pair of insulating sheets are viewed in plan . Site overlapping the air vent in the ground wiring seating sensor according to claim 1, characterized in that wider than the at least a portion of the portion does not overlap with the air vent in the ground wiring. The air vent is formed including a slit formed in the spacer,
The seating sensor according to claim 1 or 2 , wherein the ground wiring is provided at a position overlapping with the slit when the pair of insulating sheets are viewed in plan. The air vent is formed including an opening formed in one of the pair of insulating sheets,
The seating sensor according to any one of claims 1 to 3 , wherein the ground wiring is provided at a position overlapping the opening of the air bend when the pair of insulating sheets are viewed in plan. The seating sensor according to any one of claims 1 to 4 , wherein the resistance element and the ground wiring are formed in the same layer. A switch unit having at least one pressure-sensitive switch disposed on a pair of insulating sheets and having a pair of electrodes facing each other through an opening formed in a spacer disposed between the pair of insulating sheets, and the pair of pairs At least one circuit portion having a resistance element disposed between insulating sheets and electrically connected to the switch portion in parallel;
A ground wiring disposed between the pair of insulating sheets and connected to the ground side with respect to the at least one circuit unit;
With
The ground wiring surrounds at least one of the circuit parts when the pair of insulating sheets is viewed in plan view,
The resistance element is disposed on the surface of one of the pair of insulating sheets,
On the surface of the insulating sheet on which the resistive element is disposed, on the surface opposite to the surface on which the resistive element is disposed, a moisture-proof member having higher moisture resistance than the insulating sheet is disposed so as to cover the resistive element. the sitting sensor you wherein a.

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