JP6707710B2 - Load detection sensor - Google Patents

Description

The present invention relates to a load detection sensor, which is suitable for detecting a load due to sitting or the like.

As one of safety systems in vehicles, an alarm system has been put into practical use that warns that the seat belt is not worn when the passenger is in the vehicle. In this alarm system, a warning is issued when the seat belt is not sensed while the seating of a person is sensed. As a device for detecting the seating of a person, a load detection sensor for detecting the load due to the seating may be used.

As a load detection sensor, the following Patent Document 1 discloses a configuration having a pair of resin films and a pair of electrodes provided on the respective films and facing each other with a predetermined distance therebetween. The pair of films of the load detection sensor described in Patent Document 1 below are attached to each other by an adhesive that is placed except between the electrodes facing each other.

JP, 09-315199, A

However, adhesives generally tend to soften with increasing temperature. Therefore, when the load detection sensor described in Patent Document 1 is placed in an environment in which the temperature is high, such as the inside of a car in the hot sun, the load required for the electrodes provided on each film to contact decreases. Is concerned. On the other hand, when the load detection sensor described in Patent Document 1 is placed in an environment where the temperature is as low as −40° C., the load required for the electrodes provided on each film to contact due to the hardening of the adhesive agent There is concern that it will increase.

Further, the pressure-sensitive adhesive may undergo creep deformation when pressed for a long period of time. When the pressure-sensitive adhesive undergoes creep deformation, the distance between the resin films changes, which may change the load required for the electrodes provided on each film to contact each other.

As described above, in the load detection sensor of Patent Document 1, the load required for the electrodes provided on the film to come into contact with each other changes due to the temperature change and the secular change, and there is a captive that cannot properly detect the load. ..

Then, an object of this invention is to provide the load detection sensor which can detect a load appropriately.

In order to solve the above problems, a load detection sensor of the present invention includes a first electrode sheet having a first electrode, a second electrode sheet having a second electrode facing the first electrode, and the first electrode sheet. A spacer interposed between the second electrode sheet and having an opening between the first electrode and the second electrode, an annular member arranged in the opening, the spacer and the first electrode sheet. And an adhesive layer disposed on at least one of the spacer and the second electrode sheet, wherein the annular member is exposed to the opening and the first electrode sheet. It is characterized in that it is in contact with at least one of the second electrode sheets and is not adhered to both the first electrode sheet and the second electrode sheet.

In such a load detection sensor, the first electrode sheet exposed in the opening of the spacer and the second electrode sheet exposed in the opening of the spacer are supported by the annular member arranged in the opening. This annular member is not adhered to both the first electrode sheet exposed in the opening of the spacer and the second electrode sheet exposed in the opening of the spacer. Therefore, as compared with the case where the annular member is adhered to at least one of the first electrode sheet and the second electrode sheet with the adhesive layer, it is less affected by the temperature change of the adhesive layer.
That is, the adhesive layer tends to be softened in a high temperature environment and hardened in a low temperature environment. Therefore, when there is no annular member, the adhesive layer in the edge portion of the opening of the spacer changes according to the temperature environment, and the first electrode sheet and the second electrode sheet that bend so as to enter the opening of the spacer are formed. Deflection changes. This change in the bending method changes the load required for the first electrode and the second electrode to come into contact with each other. On the other hand, since the annular member arranged in the opening of the spacer is not adhered to both the first electrode sheet and the second electrode sheet, the temperature environment change due to the adhesive layer at the edge portion of the opening of the annular member. Does not happen. For this reason, at least one of the first electrode sheet and the second electrode sheet is pressed, and the bending manner of bending so as to enter the inside of the annular member in the opening of the spacer does not substantially change. Therefore, as compared with the case where the annular member is adhered to at least one of the first electrode sheet and the second electrode sheet with the adhesive layer, the change in the load necessary for the first electrode and the second electrode to contact each other is suppressed. it can.
In addition, the presence of the annular member makes it difficult to apply a load to the adhesive layer, makes it difficult for the adhesive layer to undergo creep deformation, and even if the load detection sensor is pressed for a long period of time and the adhesive layer undergoes creep deformation, The distance between the electrode sheet and the second electrode sheet can be kept substantially constant by the annular member. As a result, the change in load required for the first electrode and the second electrode to come into contact with each other due to the creep deformation is reduced.
In this way, a load detection sensor capable of appropriately detecting the load is realized.

Further, it is preferable that the annular member is in contact with both the first electrode sheet and the second electrode sheet.

In this case, since there is no gap between the annular member and the first electrode sheet exposed in the opening of the spacer and the second electrode sheet exposed in the opening of the spacer, the first electrode sheet and the second electrode sheet are The annular member can support more stably. Therefore, the change in the load required for the first electrode and the second electrode to contact each other can be further reduced.

Further, at least a part of the outer peripheral surface of the annular member is preferably separated from the spacer.

Since the load detection sensor is present in a high temperature environment, the adhesive layers arranged at least between the spacer and the first electrode sheet and between the spacer and the second electrode sheet are softened and flowed to the opening side. Also, the adhesive layer can be housed in the gap between the annular member and the spacer. Therefore, the softened adhesive layer is prevented from flowing between the annular member and the first electrode sheet or the second electrode sheet. As a result, the change in the load required for the first electrode and the second electrode to come into contact with each other can be further reduced.

Further, it is preferable that the annular member and the spacer are made of the same material.

In such a case, the expansion of the annular member and the spacer due to the presence of the load detection sensor in a high temperature environment is about the same. Therefore, the distance between the first electrode sheet and the second electrode sheet is kept substantially constant. Therefore, the change in the distance between the electrodes due to the thermal expansion is reduced. As a result, the change in load can be further reduced.

Further, it is preferable that the annular member has a vent hole for venting air in the opening of the spacer.

In this case, the first electrode sheet or the second electrode sheet is bent so as to enter the inside of the annular member in the opening of the spacer, and when the first electrode and the second electrode come into contact with each other, Air is exhausted through the vent. Therefore, it is possible to prevent the bending of the second electrode sheet from being suppressed by the air in the opening of the spacer, and it is possible to prevent the load detection sensor from making an erroneous detection.

Further, the spacer has a slit connected to the opening, at least one of the first electrode sheet and the second electrode sheet has an air vent, is disposed in the slit, the annular member of It is preferable to include a communication member that connects the ventilation port and the air vent port.

In this case, the first electrode sheet or the second electrode sheet is bent so as to enter the inside of the annular member in the opening of the spacer, and when the first electrode and the second electrode come into contact with each other, Air is discharged to the outside of the load detection sensor from the air vent through the communication member. Therefore, it is possible to prevent the bending of the first electrode sheet or the second electrode sheet from being suppressed by the air in the opening of the spacer, and it is possible to prevent the load detection sensor from making an erroneous detection.

Further, the spacer has a slit connected to the opening, and at least one of the first electrode sheet and the second electrode sheet has a pair of wirings which are adjacent to each other and are separated from each other, and an air vent. The end portions of the pair of wirings are located inside the annular member, are disposed in the slit, and serve as a communication passage that connects the inside of the annular member and the air vent in the opening of the spacer. It is preferable to include a communication path forming member that forms a gap between the pair of wirings.

In this case, when at least one of the first electrode sheet and the second electrode sheet bends so as to enter the inside of the annular member in the opening of the spacer and the first electrode and the second electrode come into contact with each other, the spacer The air inside the annular member inside the opening is discharged to the outside of the load detection sensor from the air vent through the gap between the pair of wires formed by the communication path forming member. Therefore, it is possible to prevent the bending of the first electrode sheet or the second electrode sheet from being suppressed by the air inside the annular member, and prevent the load detection sensor from erroneously detecting the bending of the electrode sheet due to the air. can do.

Further, when the sheet surface of the first electrode sheet is viewed in a plan view, it is preferable that the annular member overlaps the first electrode and the second electrode.

In this case, the annular member is interposed between the first electrode and the second electrode. Therefore, even if there are variations in the thickness of the first electrode and the second electrode itself, the distance between the first electrode and the second electrode is kept substantially constant by the annular member. Therefore, the variation in the distance between the first electrode and the second electrode in the plurality of load detection sensors can be reduced by the annular member, and the first electrode and the second electrode contact each other between the load detection sensors. Variations in the load required for are reduced.

Further, it is preferable that the total thickness of the spacer and the adhesive layer is approximately the same as the total height of the annular member, the thickness of the first electrode, and the thickness of the second electrode.

In this case, even if the annular member is not adhered to the first electrode sheet and the second electrode sheet, the annular member is prevented from moving within the opening of the spacer. In addition, it is possible to prevent stress from being generated in the direction in which the spacer and the electrode sheet that are bonded by the adhesive layer are separated from each other under no load when no load is applied to the load detection sensor.

Further, when the sheet surface of the first electrode sheet is viewed in a plan view, it is preferable that the annular member does not overlap the first electrode and the second electrode.

In this case, it is possible to make the first electrode and the second electrode less likely to be damaged as compared with the case where the annular member overlaps the first electrode and the second electrode.

Further, it is preferable that the total thickness of the spacer and the adhesive layer is approximately the same as the height of the annular member.

In this case, even if the annular member is not adhered to the first insulating sheet and the second insulating sheet, the annular member is suppressed from moving within the opening of the spacer. In addition, it is possible to prevent stress from being generated in the direction in which the spacer and the electrode sheet that are bonded by the adhesive layer are separated from each other under no load when no load is applied to the load detection sensor.

As described above, according to the present invention, it is possible to provide a load detection sensor capable of appropriately detecting a load.

It is an exploded view showing composition of a load detection sensor of a 1st embodiment. It is sectional drawing which shows the structure of a load detection sensor. It is a figure which shows the ON state of a load detection sensor. It is an exploded view showing composition of a load detection sensor unit of a 2nd embodiment. It is sectional drawing which shows a mode that the load detection sensor unit was attached to the S spring of the seat apparatus. It is an exploded view of a load detection sensor in a 2nd embodiment. It is sectional drawing of the load detection sensor in 2nd Embodiment. It is a figure which shows the mode that the sheet surface of the 1st electrode sheet in the load detection sensor was planarly viewed. It is a figure which shows the ON state of a load detection sensor unit. It is sectional drawing which shows the load detection sensor of 3rd Embodiment. It is an exploded view showing composition of a load detection sensor of a 4th embodiment. It is a figure which shows a mode that the load detection sensor was planarly viewed from the 2nd electrode sheet side. It is an exploded view showing composition of a load detection sensor of a 5th embodiment. It is a figure which shows the cross section of the load detection sensor in XX of FIG. It is an exploded view showing composition of a load detection sensor of a 6th embodiment. It is a table which shows some experimental conditions and an experimental result. It is a table which shows some other experimental conditions and an experimental result.

Hereinafter, preferred embodiments of a load detection sensor unit according to the present invention will be described in detail with reference to the drawings. It should be noted that, for ease of understanding, the scale in each drawing may differ from the scale described in the following description.

(1) First Embodiment FIG. 1 is an exploded view showing the configuration of the load detection sensor of the first embodiment, and FIG. 2 is a sectional view showing the configuration of the load detection sensor. As shown in FIGS. 1 and 2, the load detection sensor 5A includes a first electrode sheet 6, a second electrode sheet 7, a spacer 8, an annular member 9 and an adhesive layer 10 as main constituent elements. The adhesive layer 10 is omitted in FIG. 1 for convenience.

The first electrode sheet 6 has a first insulating sheet 61 and a first electrode 62. The first insulation sheet 61 is a flexible resin insulation sheet. Examples of the material of the first insulating sheet 61 include resins such as polyethylene terephthalate (PET), polyimide (PI) and polyethylene naphthalate (PEN).

The first electrode 62 is one switch element that constitutes the switch SW (FIG. 2) of the load detection sensor 5A, and is, for example, a substantially circular metal print layer. The first electrode 62 is arranged on one surface of the first insulating sheet 61, and is electrically connected to one of the pair of terminals via the first wiring 63.

The second electrode sheet 7 has a second insulating sheet 71 and a second electrode 72. The second insulating sheet 71 is arranged closer to the pressing portion PP (FIG. 2) than the first electrode sheet 6, and is a flexible film-shaped insulating sheet. The pressing portion PP presses the switch SW (FIG. 2) of the load detection sensor 5A, and is fixed to another member different from the load detection sensor 5A, for example. In FIG. 2, the tip of the pressing portion PP has a planar shape, but it may have a convex curved surface shape. The tip of the pressing portion PP is not in contact with the second insulating sheet 71 of the second electrode sheet 7, but it may be in contact therewith. As the material of the second insulating sheet 71, similar to the first insulating sheet 61, a resin such as PET, PI, or PEN can be used. The material of the second insulating sheet 71 and the material of the first insulating sheet 61 may be the same or different.

The second electrode 72 is the other switch element that constitutes the switch SW (FIG. 2) of the load detection sensor 5A, and is, for example, a substantially circular metal print layer. The second electrode 72 is disposed on one surface of the second insulating sheet 71, and is electrically connected to the other of the pair of terminals via the second wiring 73. The size of the second electrode 72 is the same as that of the first electrode 62 in this embodiment.

The spacer 8 is interposed between the first electrode sheet 6 and the second electrode sheet 7 and is a flexible resin insulating sheet. As the material of the spacer 8, as with the first insulating sheet 61 and the second insulating sheet 71, a resin such as PET, PI or PEN can be used. The material of the spacer 8 and the material of the first insulating sheet 61 or the second insulating sheet 71 may be the same or different.

Further, the spacer 8 has an opening 81 penetrating from one surface side of the spacer 8 to the other surface side thereof. The peripheral shape of the opening 81 is, for example, substantially circular, and the opening 81 is formed so that its diameter is larger than the diameters of the first electrode 62 and the second electrode 72.

Further, the spacer 8 has a slit 82 that connects the space inside the opening 81 and the space outside the load detection sensor 5A. The slit 82 serves as an air vent when the spacer 8 is superposed on the first electrode sheet 6 and the second electrode sheet 7. The air vent is a passage for extracting the air in the opening 81 to the outside of the load detection sensor 5A.

The annular member 9 is an annular member arranged in the opening 81 of the spacer 8. The outer diameter of the annular member 9 is smaller than the diameter of the opening 81 of the spacer 8, and the inner diameter of the annular member 9 is larger than the diameters of the first electrode 62 and the second electrode 72. The height of the annular member 9 is the thickness of the adhesive layer 10 between the first insulating sheet 61 and the spacer 8, the thickness of the adhesive layer 10 between the second insulating sheet 71 and the spacer 8, and the thickness of the spacer 8. It is said to be about the same as the sum of Sato. The annular member 9 does not overlap the annular member 9 with the first electrode 62 and the second electrode 72 when the sheet surface of the first electrode sheet 6 is viewed in a plan view.

Examples of the material of the annular member 9 include a resin such as PET, PI, or PEN, similar to the first insulating sheet 61, the second insulating sheet 71, and the spacer 8. The material of the annular member 9 and the material of the spacer 8, the first insulating sheet 61, or the second insulating sheet 71 may be the same or different. However, in order to reduce the change in height with the annular member 9 due to expansion of the spacer 8 and the adhesive layer 10, it is preferable that the spacer 8 and the annular member 9 are made of the same material.

Further, the annular member 9 has a vent hole 91 for venting air inside the annular member 9 of the openings 81 of the spacer 8, that is, in the opening of the annular member 9. In the present embodiment, the vent hole 91 is a slit cut from one end to the other end in the height direction of the annular member 9, but is a through hole penetrating from the outer peripheral surface to the inner peripheral surface of the annular member. It may be. In the case of the annular member 9 of the present embodiment, a part of the annular member 9 in the circumferential direction is interrupted by the vent 91. The length of the discontinuous portion along the circumferential direction of the annular member 9 is preferably ⅕ or less of the entire length of the annular member 9 including the discontinuous portion in the circumferential direction. Further, in the present embodiment, there is one discontinuous portion, but there may be a plurality of discontinuous portions. However, when there are a plurality of discontinuous portions, the total length of the discontinuous portions along the circumferential direction of the annular member 9 is ⅓ of the entire length of the annular member 9 including the discontinuous portions in the circumferential direction. The following is preferable. Thus, as long as the annular member 9 extends in the shape of a ring, the annular member 9 may be interrupted at one place or intermittently. However, from the viewpoint of suppressing an increase in the number of assembling steps due to the annular member 9 being divided into a plurality of members, and the load being changed due to the annular member being eccentrically arranged due to vibration or the like due to the annular member 9 being divided into a plurality of members From the viewpoint of suppressing the above, it is preferable that the number of discontinuous points is one or less.

The adhesive layer 10 is arranged both between the first insulating sheet 61 of the first electrode sheet 6 and the spacer 8 and between the second insulating sheet 71 of the second electrode sheet 7 and the spacer 8. The adhesive layer 10 is not particularly limited as long as the first insulating sheet 61, the second insulating sheet 71 and the spacer 8 are bonded together. Examples thereof include a pressure-sensitive adhesive, an adhesive, and a double-sided tape formed by providing a pressure-sensitive adhesive or an adhesive on both sides of a base material such as PET or a nonwoven fabric. Examples of the material of the adhesive layer 10 include a thermoplastic resin, a thermosetting resin, a photocurable resin, and the like. Note that examples of the above-mentioned pressure-sensitive adhesive include a silicon-based pressure-sensitive adhesive, a urethane-based pressure-sensitive adhesive, an acrylic pressure-sensitive adhesive, and the like. Such an adhesive layer 10 may be arranged over the entire surface between the first insulating sheet 61, the second insulating sheet 71 and the spacer 8, and the first insulating sheet 61, the second insulating sheet 71 and the spacer 8 may be provided. It may be scattered and arranged in a plurality of parts between and. Further, it is preferable that the elastic modulus of the annular member 9 is larger than the elastic modulus of the adhesive layer 10.

The load detection sensor 5A is configured by combining the above components. That is, in a state where the annular member 9 is arranged in the opening 81 of the spacer 8, the first electrode sheet 6 is adhered to the one surface side of the spacer 8 with the adhesive layer 10 and the second electrode is adhered to the other surface side of the spacer 8. The load detection sensor 5A is configured by bonding the electrode sheet 7 with the bonding layer 10.

In the load detection sensor 5A, the annular member 9 includes the first insulating sheet 61 exposed on one opening surface side of the opening 81 of the spacer 8 and the first insulating sheet 61 exposed on the other opening surface side of the opening 81. The two insulating sheets 71 are in contact with each other. Specifically, one end of the annular member 9 contacts an inner peripheral portion exposed from the opening 81 in the first insulating sheet 61, and the other end of the annular member 9 extends from the opening 81 in the second insulating sheet 71. It contacts the exposed inner circumference. Therefore, the annular member 9 can support the inner peripheral portion exposed from the opening 81 of the first insulating sheet 61 and the inner peripheral portion exposed from the opening 81 of the second insulating sheet 71. However, the annular member 9 includes a first insulating sheet 61 exposed on one opening surface side of the opening 81 of the spacer 8 and a second insulating sheet 71 exposed on the other opening surface side of the opening 81. It is non-adhesive to both sides.

Further, in the load detection sensor 5A, the outer peripheral surface of the annular member 9 is arranged in a state of being separated from the spacer 8, and the vent hole 91 of the annular member 9 is connected to the outside of the load detection sensor 5A through the slit 82 of the spacer 8. Communicate. Note that only a part of the outer peripheral surface of the annular member 9 may be in contact with the spacer 8. That is, the outer peripheral surface of the annular member 9 may be separated from at least a part of the spacer 8.

Further, in the load detection sensor 5A, the first electrode 62 is located inside one opening end of the annular member 9, and the second electrode 72 is located inside the other opening end of the annular member 9. The first electrode 62 and the second electrode 72 face each other via the inside of the annular member 9 to form a switch SW.

Next, detection of the load by the load detection sensor 5A of the present embodiment will be described.

FIG. 3 is a diagram showing an ON state of the load detection sensor 5A. The pressing portion PP receives the load and moves downward to come into contact with the surface of the second insulating sheet 71 of the second electrode sheet 7 opposite to the surface on the spacer 8 side, and the second insulating sheet 71. Press. The second insulating sheet 71 is bent by the pressing portion PP so as to enter the inside of the annular member 9, so that the second electrode 72 comes into contact with the first electrode 62 and the switch SW of the load detection sensor 5A is turned on. Becomes At this time, the load is detected by a vehicle control unit (not shown) electrically connected to the second electrode 72 and the first electrode 62.

When the second insulating sheet 71 bends, the air inside the annular member 9 is discharged to the outside of the annular member 9 through the ventilation holes 91 of the annular member 9, and the air inside the opening 81 of the spacer 8 is slit 82. Is discharged through. Therefore, it is avoided that the bending of the first insulating sheet 61 and the second insulating sheet 71 is suppressed by the air inside the annular member 9 and the opening 81 of the spacer 8, and the switch SW of the load detection sensor 5A is appropriately set. It turns on.

As described above, the load detection sensor 5A according to the present embodiment includes the first electrode sheet 6 having the first electrode 62, the second electrode sheet 7 having the second electrode 72 facing the first electrode 62, and the first electrode. The spacer 8 is provided between the sheet 6 and the second electrode sheet 7 and has an opening 81 between the first electrode 62 and the second electrode 72. Further, the load detection sensor 5A is arranged between the annular member 9 arranged in the opening 81 of the spacer 8, the spacer 8 and the first electrode sheet 6, and the spacer 8 and the second electrode sheet 7. And an adhesive layer 10.

In such a load detection sensor 5A, since the annular member 9 is arranged in the opening 81 of the spacer 8, the inner peripheral portion exposed from the opening 81 of the first electrode sheet 6 and the opening 81 of the second electrode sheet 7 are exposed. The inner peripheral portion of the ring member 9 is supported by the annular member 9. The annular member 9 is not bonded to both the first electrode sheet 6 exposed in the opening 81 of the spacer 8 and the second electrode sheet 7 exposed in the opening 81 of the spacer 8.

Therefore, compared with the case where the annular member 9 is adhered to at least one of the first electrode sheet 6 and the second electrode sheet 7 with the adhesive layer 10, the influence of the temperature change of the adhesive layer is less likely to occur.

That is, the adhesive layer 10 tends to be softened in a high temperature environment and hardened in a low temperature environment. Therefore, when the annular member 9 is not provided, the adhesive layer 10 at the edge portion of the opening 81 of the spacer 8 changes depending on the temperature environment and bends so as to enter the opening 81 of the spacer 8. Also, the bending method of the second electrode sheet 7 changes. Due to this change in the bending method, the load required for the first electrode 62 and the second electrode 72 to contact each other changes. On the other hand, in the present embodiment, since the annular member 9 arranged in the opening 81 of the spacer 8 is not adhered, the temperature environment due to the adhesive layer 10 does not change at the edge portion of the opening of the annular member 9. .. For this reason, the second electrode sheet 7 is pressed and bent so as to enter the inside of the annular member 9, and the bending method does not substantially change. Therefore, compared with the case where the annular member 9 is adhered to at least one of the first electrode sheet 6 and the second electrode sheet 7 with the adhesive layer, it is necessary for the first electrode 62 and the second electrode 72 to come into contact with each other. The change in load can be suppressed.

Further, the presence of the annular member 9 makes it difficult for a load to be applied to the adhesive layer 10 and makes it difficult for the adhesive layer 10 to undergo creep deformation, and even if the load detection sensor 5A is pressed for a long period of time, the adhesive layer 10 undergoes creep deformation. However, the distance between the first electrode sheet 6 and the second electrode sheet 7 is kept substantially constant by the annular member 9. As a result, it is possible to reduce the change in the load required for the first electrode 62 and the second electrode 72 to come into contact with each other due to the creep deformation.

In this way, the load detection sensor 5A capable of appropriately detecting the load is realized.

Further, the annular member 9 of the present embodiment is in contact with both the first electrode sheet 6 exposed in the opening 81 of the spacer 8 and the second electrode sheet 7 exposed in the opening 81 of the spacer 8.

Therefore, since there is no gap between the annular member 9 and the first electrode sheet 6 exposed in the opening 81 of the spacer 8 and the second electrode sheet 7 exposed in the opening 81 of the spacer 8, the first electrode sheet 6 and The annular member 9 can more stably support the second electrode sheet 7. Therefore, it is possible to further reduce the change in load required for the first electrode 62 and the second electrode 72 to come into contact with each other.

Further, the outer peripheral surface of the annular member 9 of the present embodiment is separated from the spacer 8. Therefore, since the load detection sensor 5A is present in a high temperature environment, the adhesive layer 10 between the spacer 8 and the first electrode sheet 6 and the adhesive layer 10 between the spacer 8 and the second electrode sheet 7 are softened. Even if the fluid flows into the opening 81, it can be accommodated in the gap between the annular member 9 and the spacer 8. Therefore, it is possible to prevent the softened adhesive layer 10 from flowing between the annular member 9 and the first electrode sheet 6 or the second electrode sheet 7. As a result, it is possible to further reduce the change in the load required for the first electrode 62 and the second electrode 72 to come into contact with each other.

Further, the annular member 9 of the present embodiment has a vent hole 91 for venting air inside the annular member 9 inside the opening 81 of the spacer 8. Therefore, when the second electrode sheet 7 bends so as to enter the inside of the annular member 9 and the first electrode 62 and the second electrode 72 come into contact with each other, the air inside the annular member 9 is exhausted from the vent 91. To be done. Therefore, it is possible to prevent the bending of the second electrode sheet 7 from being suppressed by the air inside the annular member 9, and it is possible to prevent erroneous detection by the load detection sensor.

When the annular member 9 and the spacer 8 are made of the same material, the expansion of the annular member 9 and the spacer 8 due to the presence of the load detection sensor 5A in the high temperature environment is about the same. Therefore, the distance between the first electrode sheet 6 and the second electrode sheet 7 is kept substantially constant. Therefore, when the annular member 9 and the spacer 8 are made of the same material, the change in the distance between the electrodes due to the thermal expansion is reduced. As a result, the change in load can be further reduced.

The annular member 9 does not overlap the annular member 9 with the first electrode 62 and the second electrode 72 when the sheet surface of the first electrode sheet 6 is viewed in a plan view. By doing so, compared to the case where the annular member 9 overlaps the first electrode 62 and the second electrode 72, it is possible to make the first electrode 62 and the second electrode 72 less likely to be damaged.

The height of the annular member 9 is the thickness of the adhesive layer 10 between the first insulating sheet 61 and the spacer 8, the thickness of the adhesive layer 10 between the second insulating sheet 71 and the spacer 8, and the thickness of the spacer 8. It is said to be about the same as the sum of Sato.

In this case, even if the annular member 9 is not adhered to the first insulating sheet 61 and the second insulating sheet 71, the annular member 9 is suppressed from moving within the opening 81 of the spacer 8. Further, it is possible to prevent the stress from being generated in the direction in which the spacer and the electrode sheet adhered by the adhesive layer 10 are peeled off under no load applied to the load detection sensor 5A.

(2) Second Embodiment Next, a load detection sensor unit will be described as a second embodiment. The same components as those described above are designated by the same reference numerals, and unless otherwise specified, duplicated description will be omitted.

FIG. 4 is an exploded view showing the configuration of the load detection sensor unit of the second embodiment, and FIG. 5 is a cross-sectional view showing a state in which the load detection sensor unit is attached to the S spring of the seat device. Note that, in FIG. 5, the load detection sensor 5B is not shown in a cross section for convenience. As shown in FIGS. 4 and 5, the load detection sensor unit 100 includes the support plate 2, the upper case 4, and the load detection sensor 5B as main components.

The support plate 2 has a mounting portion 21 on which the load detection sensor 5B is mounted, and a pair of hook portions 22 connected to the mounting portion 21. The mounting portion 21 includes a wide main block mounting portion 21m and a tail block mounting portion 21t extending from the main block mounting portion 21m and having a width narrower than that of the main block mounting portion 21m. In the present embodiment, the hook portion 22 is connected to the main block mounting portion 21m. Further, in the present embodiment, the mounting portion 21 and the pair of hook portions 22 are integrally molded by bending a metal plate. The plate thickness of the support plate 2 is 0.8 mm, for example.

The main block 50m of the load detection sensor 5B is arranged on the surface of the main block mounting portion 21m facing the seat cushion SC. Further, as shown in FIG. 4, a plurality of circular through holes 20H penetrating the support plate 2 are formed in the main block mounting portion 21m, and further a plurality of generally rectangular case stopping openings 24 are formed. There is.

Note that, as shown in FIG. 5, the main block mounting portion 21m is provided between two S springs BN facing each other among the plurality of S springs BN that are lined up in the opening of the seat frame in the seat device of the vehicle. The size is such that it can be placed. The S spring BN is a spring meandering in an S shape.

Further, the tail block mounting portion 21t has a substantially rectangular shape, and extends in a direction substantially perpendicular to the direction connecting the pair of hook portions 22 when the main block mounting portion 21m is viewed in a plan view. The tail block 50t of the load detection sensor 5B is arranged on the surface of the tail block mounting portion 21t facing the seat cushion SC. In the present embodiment, the width of the tail block mounting portion 21t in the direction perpendicular to the extending direction is smaller than the width of the tail block 50t of the load detection sensor 5B, and the tail block mounting portion 21t extends in the extending direction. Is shorter than the length of the tail block 50t of the load detection sensor 5B.

The upper case 4 is a member that covers the main block 50m mounted on the main block mounting portion 21m of the mounting portion 21 and protects the switches SW and the like of the main block 50m. Further, as shown in FIG. 5, the upper case 4 is also a pressing member that presses the switch SW of the load detection sensor 5B when pressed by the seat cushion SC.

The upper case 4 has a top wall 45 and a frame wall 48. In this embodiment, the top wall 45 is a plate-shaped member having a substantially rectangular shape. Further, the frame wall 48 of the upper case 4 is divided into a plurality of parts and is connected to the top wall 45 along the outer periphery of the top wall 45. A hook piece 47 is connected to the top wall 45 between each of the plurality of divided frame walls 48. Each hook piece 47 is configured to be fitted into the case stop opening 24 in the main block mounting portion 21m of the support plate 2. By fitting each hook piece 47 into the case stopper opening 24, relative movement of the support plate 2 and the upper case 4 in the mounting surface direction of the main block mounting portion 21m is restricted.

The top wall 45 of the upper case 4 is provided with a pressing portion 46 protruding from the bottom surface of the support plate 2 on the side facing the mounting portion 21. The tip of the pressing portion 46 has a planar shape. The tip of the pressing portion 46 may have a convex curved surface shape. In the case of the present embodiment, in the state where the upper case 4 covers the load detection sensor 5B mounted on the mounting part 21 and the hook pieces 47 corresponding to the case stop openings 24 are fitted, the tip of the pressing part 46 is Although it is in contact with the load detection sensor 5B, it may not be in contact with it.

The upper surface 45S of the top wall 45 of the upper case 4 is separated from the lower surface of the seat cushion SC when the load detection sensor unit 100 is attached to the pair of S springs BN as shown in FIG. You can do it. The upper surface 45S has a planar shape. The upper surface 45S is a pressure receiving surface that receives pressure from the seat cushion SC, and the area of the upper surface 45S is larger than the area of the portion of the pressing portion 46 that contacts the switch SW of the load detection sensor 5B.

The upper case 4 is made of a material harder than the seat cushion SC. Therefore, the pressing portion 46 that is a part of the upper case 4 is also made of a material harder than the seat cushion SC. Since the seat cushion SC is generally made of foamed urethane resin, examples of the material for the upper case 4 include polycarbonate (PC), polybutylene terephthalate (PBT), polyamide (PA), phenol resin, and epoxy resin. Resins of

As described above, the load detection sensor 5B includes the substantially rectangular main block 50m and the tail block 50t that is connected to the main block 50m and has a width narrower than that of the main block 50m. A switch SW is provided in the main block 50m. A through hole 50H is formed near each vertex of the main block 50m. These through holes 50H are formed in a positional relationship overlapping with the plurality of through holes 20H formed in the mounting portion 21 of the support plate 2. The tail block 50t is connected to the main block 50m and extends away from the main block 50m.

FIG. 6 is an exploded view of the load detection sensor according to the second embodiment, and FIG. 7 is a sectional view of the load detection sensor according to the second embodiment. As shown in FIGS. 6 and 7, the load detection sensor 5B in this embodiment includes a first electrode sheet 56, a second electrode sheet 57, a spacer 58, an annular member 59, and an adhesive layer 10 as main constituent elements. .. The adhesive layer 10 is omitted in FIG. 6 for convenience.

The first electrode sheet 56 has a first insulating sheet 56s, a first electrode 56e, and a first terminal 56c.

The first insulation sheet 56s is a flexible resin insulation sheet. The first insulating sheet 56s includes a main block 56m and a tail block 56t connected to the main block 56m. The shape of the tail block 56t is such that the tip portion on the side opposite to the main block 56m is narrower than the other portions of the tail block 56t. Further, a through hole 56H is formed in the main block 56m. The through hole 56H is a part of the through hole 50H of the load detection sensor 5B. Examples of the material of the first insulating sheet 56s include resins such as PET, PI, and PEN.

The first electrode 56e is provided on one surface in the approximate center of the main block 56m. The first electrode 56e is formed of a conductor layer and is, for example, a substantially circular metal print layer. The first terminal 56c is formed of a conductor layer, and is, for example, a substantially square metal layer. The first terminal 56c is provided on the surface of the tail block 56t on the side on which the first electrode 56e is provided. Further, the first electrode 56e and the first terminal 56c are electrically connected to each other via the first wiring 56w.

The second electrode sheet 57 has a second insulating sheet 57s, a metal plate 60, a metal adhesive layer 70, a second electrode 57e, and a second terminal 57c. The second electrode sheet 7 of the first embodiment is composed of one layer of the second insulating sheet 71, whereas the second electrode sheet 57 of the present embodiment is the second insulating sheet 57s and the metal plate 60. It is composed of two layers.

The second insulating sheet 57s is arranged closer to the seat cushion SC (FIG. 4) than the first electrode sheet 56, and is a resin insulating sheet like the first insulating sheet 56s. In the case of the present embodiment, the thickness of the second insulating sheet 57s is made smaller than the thickness of the first insulating sheet 56s and less than the thickness of the metal plate 60. Also, the second insulating sheet 57s has the same shape as the main block 57m of the same shape as the main block 56m of the first insulating sheet 56s, and the shape of the tail block 56t of the first insulating sheet 56s that is connected to the main block 57m and is the same except for the tip portion. The tail block 57t has a shape. The tip portion of the tail block 57t has a width narrower than other portions of the tail block 57t, and when the first insulating sheet 56s and the second insulating sheet 57s are overlapped, the tail block 56t of the first insulating sheet 56s is stacked. And the tip portion of the tail block 57t of the second insulating sheet 57s do not overlap each other. A through hole 57H is formed in the main block 57m. The through hole 57H is a part of the through hole 50H of the load detection sensor 5B, like the through hole 56H of the first insulating sheet 56s. Examples of the material of the second insulating sheet 57s include resins such as PET, PI, or PEN, and the material of the second insulating sheet 57s and the material of the first insulating sheet 56s may be the same or different. good.

The metal plate 60 is attached to one surface of the second insulating sheet 57s by the metal adhesive layer 70. In the present embodiment, the metal plate 60 is attached to the surface of the main block 57m, which is a part of the second insulating sheet 57s, on the seat cushion SC side. A through hole 60H is formed in the metal plate 60. The through hole 60H is a part of the through hole 50H of the load detection sensor 5B. The material of such a metal plate 60 is not particularly limited, but examples thereof include copper and stainless steel.

The metal adhesive layer 70 is arranged between the main block 57m of the second insulating sheet 57s and the metal plate 60. The metal adhesive layer 70 is not particularly limited as long as the second insulating sheet 57s and the metal plate 60 are bonded together. Examples thereof include a pressure-sensitive adhesive, an adhesive, and a double-sided tape formed by providing an adhesive layer on both sides of a base material such as PET or nonwoven fabric. Examples of the material of the adhesive layer for metal 70 include a thermoplastic resin, a thermosetting resin, a photocurable resin, and the like. The material of the adhesive layer for metal 70 and the material of the adhesive layer 10 may be the same or different. Here, the glass transition point Tg of the adhesive layer for metal 70 is preferably 85° C. or higher. Since the glass transition point Tg is 85° C. or higher, it is difficult for the glass to flow even in an environment where the temperature becomes high, such as the inside of a car in the hot sun. Therefore, false detection of seating due to the flow of the metal adhesive layer 70 is suppressed. You can The metal adhesive layer 70 may be arranged over the entire surface between the second insulating sheet 57s and the metal plate 60 as long as the second insulating sheet 57s and the metal plate 60 are bonded together. The sheet 57s and the metal plate 60 may be scattered and arranged at a plurality of sites.

The second electrode 57e has the same configuration as the first electrode 56e, and is provided on one surface of the second insulating sheet 57s at approximately the center of the main block 57m. Further, the position where the second electrode 57e is provided is a position where it overlaps with the first electrode 56e when the first electrode sheet 56 and the second electrode sheet 57 are stacked. The second terminal 57c has the same configuration as the first terminal 56c, and is provided on the surface of the tail block 57t on the side where the second electrode 57e is provided. In addition, as described above, when the first insulating sheet 56s and the second insulating sheet 57s are overlapped with each other, the tip portions of the respective insulating sheets do not overlap each other, so that the first terminal 56c and the second terminal 57c have the first insulating sheet. It is exposed without being located between the sheet 56s and the second insulating sheet 57s. The second electrode 57e and the second terminal 57c are electrically connected to each other via the second wiring 57w.

The spacer 58 is arranged between the first electrode sheet 56 and the second electrode sheet 57 and is a flexible resin insulating sheet. The spacer 58 includes a main block 58m and a tail block 58t connected to the main block 58m. The outer shape of the main block 58m is similar to the outer shape of the main blocks 56m and 57m of the first insulating sheet 56s and the second insulating sheet 57s. The tail block 58t has a shape excluding the narrow tip portions of the tail blocks 56t, 57t of the first insulating sheet 56s and the second insulating sheet 57s. Through holes 58H are formed in the spacers 58 similarly to the first insulating sheet 56s and the second insulating sheet 57s. The through hole 58H is a part of the through hole 50H of the load detection sensor 5B. As a material of such a spacer 58, a resin such as PET, PI, or PEN can be used as in the case of the first insulating sheet 56s and the second insulating sheet 57s. The material of the spacer 58 may be the same as or different from the material of the first insulating sheet 56s or the second insulating sheet 57s.

Further, the main block 58m of the spacer 58 has an opening 58c penetrating from one surface side of the spacer 58 to the other surface side. The first electrode 56e and the second electrode 57e face each other through the opening 58c. The peripheral shape of the opening 58c is, for example, a substantially circular shape, and the opening 58c is formed so that its diameter is smaller than the diameters of the first electrode 56e and the second electrode 57e.

The opening 81 of the spacer 8 of the first embodiment is formed so that its diameter is larger than the diameters of the first electrode 62 and the second electrode 72. On the other hand, the opening 58c of the spacer 58 of the present embodiment is formed so that the diameter thereof is smaller than the diameters of the first electrode 56e and the second electrode 57e. Therefore, when the spacer 58 is overlapped with the first electrode sheet 56 and the second electrode sheet 57, the opening 58c of the present embodiment is located inside the peripheral edges of the first electrode 56e and the second electrode 57e. To do.

Further, the spacer 58 has a slit 58b that connects the space inside the opening 58c and the space outside the load detection sensor 5B. The slit 58b becomes an air vent when the first electrode sheet 56, the spacer 58, and the second electrode sheet 57 are overlaid on each other. The air vent is a passage for extracting the air in the opening 58c to the outside of the load detection sensor 5B.

The annular member 59 is an annular member arranged in the opening 58c of the spacer 58. The outer diameter of the annular member 59 is smaller than the diameter of the opening 58c of the spacer 58 and smaller than the diameters of the first electrode 56e and the second electrode 57e.

While the inner diameter of the annular member 9 of the first embodiment is made larger than the diameters of the first electrode 62 and the second electrode 72, the inner diameter and the outer diameter of the annular member 59 of the present embodiment are both The diameter is made smaller than the diameter of the first electrode 56e and the second electrode 57e. Therefore, as shown in FIG. 8, when the spacer 58 is overlapped with the first electrode sheet 56 and the second electrode sheet 57 and the sheet surface of the main block 57m of the second electrode sheet 57 is seen in a plan view, The member 59 and the second electrode 57e overlap. Further, as shown in FIG. 7, the total of the height of the annular member 59, the thickness of the first electrode 56e, and the thickness of the second electrode 57e is equal to the thickness of the adhesive layer 10 between the first insulating sheet 61 and the spacer 8. The total thickness of the adhesive layer 10 between the second insulating sheet 71 and the spacer 8 and the thickness of the spacer 8 is approximately the same. The elastic modulus of the annular member 59 is preferably larger than the elastic modulus of the adhesive layer 10 as in the first embodiment.

As the material of the annular member 59, a resin such as PET, PI, or PEN can be used as in the case of the first insulating sheet 56s, the second insulating sheet 57s, and the spacer 58. The material of the annular member 59 and the material of the spacer 58, the first insulating sheet 56s, or the second insulating sheet 57s may be the same or different. However, it is preferable that at least the spacer 58 and the annular member 59 are made of the same material in order to reduce the change in the height of the annular member 59 due to the expansion of the spacer 58.

Further, the annular member 59 has a vent hole 59b for venting air inside the annular member 59 in the opening 58c in the spacer 58. In the present embodiment, the vent hole 59b is a slit cut from one end to the other end in the height direction of the annular member 59, but is a through hole penetrating from the outer peripheral surface to the inner peripheral surface of the annular member. It may be. Similar to the annular member 9 of the first embodiment, the annular member 59 of the present embodiment includes a case where it is interrupted at one place or intermittently as long as it extends in the shape of a ring. However, it is preferable that the number of discontinuous points is one or less.

The load detection sensor 5B is configured by combining the above components. That is, with the annular member 59 arranged in the opening 58 c of the spacer 58, the first electrode sheet 56 is adhered to the one surface side of the spacer 58 with the adhesive layer 10 and the second electrode sheet is adhered to the other surface side of the spacer 58. The load detection sensor 5B is configured by bonding the electrode sheet 57 with the bonding layer 10.

In the load detection sensor 5B, the through holes 56H, 57H, 58H overlap each other to form the through hole 50H. In addition, the first electrode 56e of the first electrode sheet 56 exposed on one opening surface side of the opening 58c of the spacer 58 and the second electrode sheet 57 exposed on the other opening surface side of the opening 58c. The second electrode 57e and the second electrode 57e face each other to form a switch SW.

Further, the annular member 59 is in contact with both the first electrode 56e and the second electrode 57e. Specifically, one end of the annular member 59 is in contact with the first electrode 56e of the first electrode sheet 56 along the inner circumference of the opening 58c, and the other end of the annular member 59 is the inner circumference of the opening 58c. And contacts the second electrode 57e of the second electrode sheet 57. Therefore, the annular member 59 can support the first electrode sheet 56 and the second electrode sheet 57. However, although the annular member 59 is in contact with the first electrode 56e of the first electrode sheet 56, it is not adhered to the first electrode 56e. Similarly, the annular member 59 is in contact with the second electrode 57e of the second electrode sheet 57, but is not bonded to the second electrode 57e.

Further, in the load detection sensor 5B, the outer peripheral surface of the annular member 59 is arranged in a state of being separated from the spacer 58, and the ventilation hole 59b of the annular member 59 is connected to the outside of the load detection sensor 5B through the slit 58b of the spacer 58. Communicate. A part of the outer peripheral surface of the annular member 59 may be in contact with the spacer 58. That is, the outer peripheral surface of the annular member 59 may be separated from at least a part of the spacer 58.

A signal cable 19 connected to a control device (not shown) is connected to the first terminal 56c and the second terminal 57c of the load detection sensor 5B. The first terminal 56c and the second terminal 57c are connected to the respective signal cables 19 by a conductive paste or soldering.

The load detection sensor 5B having the above configuration is arranged on the support plate 2 as shown in FIG. Specifically, the main block 50m of the load detection sensor 5B having the switch SW is arranged on the main block mounting portion 21m of the support plate 2, and the tail block 50t of the load detection sensor 5B is mounted on the tail block mounting of the support plate 2. It is arranged on the part 21t. The first terminal 56c and the second terminal 57c provided on the tail block 50t are in a state of protruding from the tail block mounting portion 21t. Therefore, the first terminal 56c and the second terminal 57c are located in a region that does not overlap the support plate 2. Then, the respective signal cables 19 connected to the first terminal 56c and the second terminal 57c of the load detection sensor 5B are led away from the support plate 2.

In this way, with the load detection sensor 5B arranged on the support plate 2, the end portion of the tail block 50t including the first terminal 56c and the second terminal 57c to which the signal cable 19 is connected is protected by the protective resin 18. It is covered. The protective resin 18 is made of, for example, a thermoplastic resin such as a polyamide resin, a polyimide resin, an olefin resin, a urethane resin, or an acrylic resin, or a resin such as a photocurable resin.

Further, as described above, in the state where the upper case 4 covers the load detection sensor 5B mounted on the support plate 2 and the hook pieces 47 are fitted in the case stop openings 24, the pressing portion 46 is The tip of the metal plate 60 of the load detection sensor 5B contacts the position overlapping the switch SW. Further, in this state, each rib 49 is inserted into the through hole 50H of the load detection sensor 5B and the through hole 20H of the support plate 2. Therefore, even if the support plate 2 and the first insulating sheet 56s are not adhered to each other, the relative movement of the switch SW of the load detection sensor 5B and the pressing portion 46 of the upper case 4 is restricted. That is, the rib 49 can be understood as a movement restricting member that restricts relative movement between the load detection sensor 5B and the support plate 2 in the surface direction of the support plate 2.

Next, detection of a load by the load detection sensor unit 100 of this embodiment will be described.

FIG. 9 is a diagram showing an ON state of the load detection sensor unit. When a person sits on the seat device, the lower surface of the seat cushion SC moves downward, and the lower surface of the seat cushion SC contacts the upper surface 45S of the upper case 4 and presses the upper surface 45S. Then, when the lower surface of the seat cushion SC further moves downward, the tip of the pressing portion 46 presses the metal plate 60 of the second electrode sheet 57 in the load detection sensor 5B as shown in FIG. Due to the bending, the main block 57m of the second insulating sheet 57s is bent so as to enter the inside of the annular member 59. Therefore, the second electrode 57e contacts the first electrode 56e, and the switch SW of the load detection sensor 5B is turned on. The seating is detected by a vehicle control unit (not shown) connected to the signal cable 19. At this time, in this embodiment, since the surface of the first insulating sheet 56s on the support plate side of the main block 56m is not adhered to the support plate 2, at least the peripheral portion of the switch SW follows the bending of the metal plate 60. Therefore, the switch SW is easily turned on.

When the second electrode sheet 57 bends, the air in the opening of the annular member 59 and the opening 58c of the spacer 58 is discharged through the slit 58b. Therefore, it can be avoided that the bending of the first electrode sheet 56 and the second electrode sheet 57 is suppressed by the air in the opening of the annular member 59 and the opening 58c of the spacer 58, and the switch SW of the load detection sensor 5A is appropriately set. It turns on.

As described above, the load detection sensor 5B according to the present embodiment includes the first electrode sheet 56 having the first electrode 56e, the second electrode sheet 57 having the second electrode 57e facing the first electrode 56e, and the first electrode. The spacer 58 is provided between the sheet 56 and the second electrode sheet 57 and has an opening 58c between the first electrode 56e and the second electrode 57e. The load detection sensor 5B is arranged between the annular member 59 arranged in the opening 58c of the spacer 58, between the spacer 58 and the first electrode sheet 56, and between the spacer 58 and the second electrode sheet 57. And an adhesive layer 10.

In such a load detection sensor 5B, since the annular member 59 is arranged in the opening 81 of the spacer 8, the inner peripheral portion exposed from the opening 81 of the first electrode sheet 56 and the opening 81 of the second electrode sheet 57 are exposed. The inner peripheral portion of the circular member 59 is supported by the annular member 59. The annular member 59 is not adhered to both the first electrode sheet 56 exposed in the opening 58c of the spacer 58 and the second electrode sheet 57 exposed in the opening 58c of the spacer 58.

Therefore, as compared with the case where the annular member 59 is adhered to at least one of the first electrode sheet 56 and the second electrode sheet 57 with the adhesive layer 10, the influence of the temperature change of the adhesive layer can be suppressed.

That is, the adhesive layer 10 tends to be softened in a high temperature environment and hardened in a low temperature environment. Therefore, if the annular member 59 is not provided, the first electrode sheet 56 that bends so that the adhesive layer 10 at the edge portion of the opening 58c of the spacer 58 changes according to the temperature environment and enters the opening 58c of the spacer 58. Also, the bending method of the second electrode sheet 57 changes. Due to this change in the bending method, the load required for the first electrode 56e and the second electrode 57e to contact each other changes. On the other hand, in this embodiment, since the annular member 59 arranged in the opening 58c of the spacer 58 is not adhered, the temperature environment due to the adhesive layer 10 does not change at the edge portion of the opening of the annular member 59. .. For this reason, the second electrode sheet 57 is pressed so that it flexes so as to enter the opening of the annular member 59. Therefore, compared with the case where the annular member 59 is adhered to at least one of the first electrode sheet 56 and the second electrode sheet 57 with the adhesive layer, the load required for the first electrode 56e and the second electrode 57e to contact each other. The change of can be suppressed.

Further, the presence of the annular member 59 makes it difficult for a load to be applied to the adhesive layer 10 and makes it difficult for the adhesive layer 10 to undergo creep deformation, and even if the load detection sensor 5B is pressed for a long period of time, the adhesive layer 10 undergoes creep deformation. However, the distance between the first electrode sheet 56 and the second electrode sheet 57 can be kept substantially constant by the annular member 59. As a result, the change in load required for the first electrode 56e and the second electrode 57e to come into contact with each other due to the creep deformation is reduced.

As described above, according to the load detection sensor 5B of the present embodiment, it is possible to appropriately detect the load, like the load detection sensor 5A of the first embodiment.

In addition, the annular member 59 of the present embodiment is formed on both the first electrode sheet 56 exposed in the opening 58c of the spacer 58 and the second electrode sheet 57 exposed in the opening 58c of the spacer 58, as in the first embodiment. Touching.

Therefore, since there is no gap between the annular member 59 and the first electrode sheet 56 exposed in the opening 58c of the spacer 58 and the second electrode sheet 57 exposed in the opening 58c of the spacer 58, the first electrode sheet 56, The annular member 59 can more stably support the second electrode sheet 57. Therefore, the change in the load required for the first electrode 56e and the second electrode 57e to come into contact with each other can be further reduced.

Further, the outer peripheral surface of the annular member 59 of the present embodiment is separated from the spacer 58 as in the first embodiment. Therefore, since the load detection sensor 5B is present in a high temperature environment, the adhesive layer 10 between the spacer 58 and the first electrode sheet 56 and the adhesive layer 10 between the spacer 58 and the second electrode sheet 57 are softened. Even if it flows to the opening 58c by the above, it can be contained in the gap between the annular member 59 and the spacer 58. Therefore, the softened adhesive layer 10 is prevented from flowing between the annular member 59 and the first electrode sheet 56 and the second electrode sheet 57. As a result, the change in the load required for the first electrode 56e and the second electrode 57e to come into contact with each other can be further reduced.

Further, the annular member 59 of the present embodiment has the vent hole 59b for venting the air inside the annular member 59 in the opening 81 of the spacer 8 as in the first embodiment. Therefore, when the second electrode sheet 57 bends so as to enter the inside of the annular member 59 and the first electrode 56e and the second electrode 57e come into contact with each other, the inside of the annular member 59 within the opening 81 of the spacer 8 is formed. Air is discharged from the vent hole 59b. Therefore, it is possible to prevent the bending of the second electrode sheet 57 from being suppressed by the air in the opening 81 of the spacer 8, and it is possible to prevent the load detection sensor 5B from making an erroneous detection.

By the way, as described above, the diameter of the opening 81 of the spacer 8 of the first embodiment is larger than the diameter of the first electrode 62 and the second electrode 72. The diameter of the opening 58c is smaller than the diameters of the first electrode 56e and the second electrode 57e. Therefore, the opening 58c of the spacer 58 of the present embodiment is located inside the peripheral edges of the first electrode 56e and the second electrode 57e. The annular member 59 is not adhered to the first electrode 56e of the first electrode sheet 56 exposed in the opening 58c of the spacer 58 and the second electrode 57e of the second electrode sheet 57 exposed in the opening 58c. Touch in the state of. Therefore, in the load detection sensor 5B of the present embodiment, the annular member 59 and the first electrode 56e and the second electrode 57e overlap each other when the sheet surface of the first electrode sheet 56 is viewed in a plan view. The first electrode 56e and the second electrode 57e may have dummy electrodes that are not connected to the first wiring 56w and the second wiring 57w, and the dummy electrodes may overlap the annular member 59.

An annular member 59 is interposed between the first electrode 56e and the second electrode 57e. Therefore, even if there are variations in the thickness of the first electrode 56e and the second electrode 57e themselves, the distance between the first electrode 56e and the second electrode 57e is kept substantially constant by the annular member 59. .. Therefore, the variation in the distance between the first electrode 56e and the second electrode 57e in the plurality of load detection sensors 5B can be reduced by the annular member 59. As a result, it is possible to reduce the variation in the load required for the first electrode 56e and the second electrode 57e to come into contact between the plurality of load detection sensors 5B.

The total thickness of the spacer 58 and the adhesive layer 10 is approximately the same as the total height of the annular member 59, the first electrode 56e, and the second electrode 57e.

Therefore, even if the annular member 59 is not adhered to the first electrode sheet 56 and the second electrode sheet 57, the annular member 59 is prevented from moving within the opening 58c of the spacer 58. In addition, it is possible to prevent stress from being generated in the direction in which the spacer 58 and the first electrode sheet 56 and the second electrode sheet 57 that are bonded by the adhesive layer 10 are peeled off under no load when no load is applied to the load detection sensor 5B. obtain.

Further, in the present embodiment, the second electrode sheet 57 has the metal plate 60, and the metal plate 60 is bonded to the second insulating sheet 57s made of resin via the metal adhesive layer 70. Compared to resin, metal is less likely to change its flexibility in response to changes in environmental temperature, and therefore tends to cause less creep and less tendency to push. However, in this embodiment, since the metal plate 60 is bonded to the second insulating sheet 57s made of resin through the metal adhesive layer 70, the pressing of the second electrode sheet 57 is released, and the position when not pressed. When the metal plate 60 returns to the above position, the metal plate 60 can return the second insulating sheet 57s made of resin to this position. Therefore, even when the environmental temperature around the load detection sensor 5B changes, it is difficult for the second insulating sheet 57s made of resin to have a pushing habit, and the load applied according to the sitting or the like due to the pushing habit. Can be suppressed. As a result, the load applied according to seating or the like can be appropriately detected. By using the annular member 59 in combination, it is possible to detect the load applied according to the seating condition and the like.

Further, in the present embodiment, since the thickness of the second insulating sheet 57s is less than the thickness of the metal plate 60, when the thickness of the second insulating sheet 57s is the thickness of the metal plate 60 or more, In comparison, the amount of deformation of the second insulating sheet 57s made of resin can be reduced. That is, the case is similar to the case where the second electrode sheet is composed of only the metal plate 60 without the second insulating sheet 57s. Therefore, it is possible to reduce variation in the load required for the first electrode 56e and the second electrode 57e to come into contact with each other due to temperature change.

In addition, in the present embodiment, the thickness of the second insulating sheet 57s is less than the thickness of the first insulating sheet 56s. Therefore, the load detection sensor 5B can be made thinner, and erroneous detection of the load due to temperature change can be suppressed.

(3) Third Embodiment Next, a load detection sensor unit will be described as a third embodiment. The same components as those described above are designated by the same reference numerals, and unless otherwise specified, duplicated description will be omitted.

FIG. 10 is a sectional view showing the load detection sensor of the third embodiment. As shown in FIG. 10, the load detection sensor 5C of the present embodiment is different in that a metal sheet 101 is used instead of the second insulating sheet 71 of the second electrode sheet 7 in the first embodiment.

The metal sheet 101 is a flexible thin metal sheet and is bonded to the spacer 8 by the adhesive layer 10. The material of the metal sheet 101 is not particularly limited as long as it is a metal, and examples thereof include copper and stainless steel.

In the case of the present embodiment, the portion of the metal sheet 101 facing the first electrode 62 via the opening 81 of the spacer 8 is the second electrode 72. That is, a part of the metal sheet 101 also serves as the second electrode 72. Note that, for example, a metal layer of the same material as or a different material from the metal sheet 101 may be arranged as the second electrode 72 at a portion of the metal sheet 101 that faces the first electrode 62 via the opening 81 of the spacer 8. ..

Even such a load detection sensor 5C has the same effects as those described above for the load detection sensor 5A of the first embodiment and the load detection sensor 5B of the second embodiment. Further, in the present embodiment, the metal sheet 101 is adopted instead of the second insulating sheet 71.

As described above, the flexibility of the metal is less likely to change in response to the change of the environmental temperature than the resin, so that the creep is less likely to occur and the pushing tendency is less likely to occur. Therefore, the load detection sensor 5C can suppress the erroneous detection of the load applied according to the sitting or the like due to the creep or the pushing tendency, and as a result, appropriately detect the load applied according to the sitting or the like. You can

(4) Fourth Embodiment Next, a load detection sensor unit will be described as a fourth embodiment. The same components as those described above are designated by the same reference numerals, and unless otherwise specified, duplicated description will be omitted.

FIG. 11 is an exploded view showing the configuration of the load detection sensor of the fourth embodiment, and FIG. 12 is a view showing a state in which the load detection sensor is viewed in plan from the second electrode sheet side. As shown in FIGS. 11 and 12, the load detection sensor 5D according to the present embodiment includes a first electrode sheet 66, a second electrode sheet 67, a spacer 68, a plurality of annular members 9A to 9D, a communication member 80, and an adhesive layer 10. And are provided as main components. The adhesive layer 10 is omitted in FIG. 11 for convenience.

The first electrode sheet 66 has a first insulating sheet 66s, first electrodes 66e1 to 66e4, a first terminal 66c1, and a second terminal 66c2.

The first insulating sheet 66s is a flexible resin insulating sheet, and has, for example, an H shape. The first insulating sheet 66s includes a first main block B1, a second main block B2, a connecting block B3 connecting the first main block B1 and the second main block B2, and a tail block B4 extending from the connecting block. Consists of. The first main block B1 and the second main block B2 are strip-shaped blocks. The connection block B3 is a band-shaped block that connects intermediate portions in the longitudinal direction of the first main block B1 and the second main block B2. The tail block B4 is smaller than the connecting block B3, and is a substantially rectangular block protruding from the end of the intermediate portion in the longitudinal direction of the connecting block B3. Examples of the material of the first insulating sheet 56s include resins such as PET, PI, and PEN.

The first electrodes 66e1 to 66e4 are formed of conductor layers and are, for example, substantially circular metal print layers. The first electrode 66e1 and the first electrode 66e2 are arranged on one surface of the first main block B1, and are arranged in the same straight line in the present embodiment. The first electrode 66e3 and the first electrode 66e4 are arranged on the same surface as the surface of the second main block B2 on which the first electrode 66e1 and the first electrode 66e2 are arranged. Lined up.

The first terminal 66c1 and the second terminal 66c2 are formed of conductor layers and are, for example, substantially square metal sheets. The first terminal 66c1 and the second terminal 66c2 are arranged on the same surface as the surface of the tail block B4 on which the first electrodes 66e1 to 66e4 are arranged.

The first electrode 66e1 and the first electrode 66e2 are electrically connected by the first wiring 66w1, and the first electrode 66e3 and the first electrode 66e4 are electrically connected by the first wiring 66w2. The first wiring 66w1 and the first terminal 66c1 are electrically connected by the first wiring 66w3, and the first wiring 66w2 and the second terminal 66c2 are electrically connected by the first wiring 66w4.

The second electrode sheet 67 has a second insulating sheet 67s and a plurality of second electrodes 67e1 to 67e4.

The second insulating sheet 67s is a flexible film-shaped insulating sheet, and has, for example, an H shape. In the case of the present embodiment, the second insulating sheet 67s includes a first main block B11, a second main block B12, and a connecting block B13 connecting the first main block B11 and the second main block B12. The first main block B11 has the same shape and size as the first main block B1 in the first insulating sheet 66s, and the second main block B12 has the same shape and size as the second main block B2 in the first insulating sheet 66s. .. The connection block B13 has the same shape and size as the connection block B3 in the first insulating sheet 66s. As the material of the second insulating sheet 67s, as with the first insulating sheet 66s, a resin such as PET, PI or PEN can be used. The material of the second insulating sheet 67s may be the same as or different from the material of the first insulating sheet 66s.

In addition, the second insulating sheet 67s has an air vent 67op that penetrates from the one surface side to the other surface side of the second insulating sheet 67s. The air vent 67op is an opening for venting the air in the openings of the annular members 9A to 9D to the outside of the load detection sensor 5D, and the second electrode 67e1 when the sheet surface of the second electrode sheet 67 is viewed in a plan view. It is provided at a position that does not overlap with ~67e4. For example, the air vent 67op is provided in the connection block B3.

The second electrodes 67e1 to 67e4 are formed of conductor layers and are, for example, substantially circular metal print layers. The second electrode 67e1 and the second electrode 67e2 are arranged on one surface of the first main block B11, and the second electrode 67e3 and the second electrode 67e4 are arranged on the second electrodes 67e1 and 67e2 of the second main block B12. Placed on the same surface as In the case of this embodiment, the second electrodes 67e1 to 67e4 have the same size as the first electrodes 66e1 to 66e4. The second electrodes 67e1 and 67e2 are arranged at the same positions as the first electrodes 66e1 and 66e2 relative to the first main block B1, and the second electrodes 67e3 and 67e4 are arranged at the second main block. The relative positions are the same as the positions of the first electrodes 66e3 and 66e4 with respect to B2.

The second electrode 67e1 and the second electrode 67e2 are electrically connected by the second wiring 67w1, the second electrode 67e3 and the second electrode 67e4 are electrically connected by the second wiring 67w2, and the second wiring 67w1 is connected. The second wire 67w2 is electrically connected to the second wire 67w3.

The spacer 68 is disposed between the first electrode sheet 66 and the second electrode sheet 67 and is a flexible resin insulating sheet. In the case of the present embodiment, the spacer 68 has, for example, an H shape, and includes a first main block B21, a second main block B22, and a connecting block B23 connecting the first main block B21 and the second main block B22. Become. The first main block B21 has the same shape and size as the first main block B1 in the first insulating sheet 66s, and the second main block B22 has the same shape and size as the second main block B2 in the first insulating sheet 66s. .. The connection block B23 has the same shape and size as the connection block B3 in the first insulating sheet 66s. As a material of such a spacer 68, as with the first insulating sheet 66s and the second insulating sheet 67s, a resin such as PET, PI, or PEN can be used. The material of such a spacer 68 may be the same as or different from the material of the first insulating sheet 66s or the second insulating sheet 67s.

Further, the first main block B21 of the spacer 68 has openings 68A and 68B penetrating from one surface side of the spacer 68 to the other surface side thereof. The first electrode 66e1 and the second electrode 67e1 face each other through the opening 68A, and the first electrode 66e2 and the second electrode 67e2 face each other through the opening 68B. Similarly, the second main block B22 of the spacer 68 has openings 68C and 68D penetrating from one surface side of the spacer 68 to the other surface side. The first electrode 66e3 and the second electrode 67e3 face each other through the opening 68C, and the first electrode 66e4 and the second electrode 67e4 face each other through the opening 68D. The peripheral shapes of the openings 68A to 68D are, for example, substantially circular, and the diameters of the openings 68A to 68D are formed to be larger than the diameters of the first electrodes 66e1 to 66e4. Therefore, when the spacer 68 is overlapped with the first electrode sheet 66 and the second electrode sheet 67 and the spacer 68 is viewed in a plan view, the openings 68A to 68D of the present embodiment correspond to the peripheral edges of the corresponding first electrodes 66e1 to 66e4. Located on the outside.

Further, the spacer 68 has a slit 68b connected to each of the openings 68A to 68D and communicating with each of the openings 68A to 68D. The slit 68b is located inside the edge of the spacer 68 without opening at the edge. In the case of this embodiment, the shape of the slit 68b is, for example, an H shape.

The annular members 9A to 9D have the same configuration as the annular member 9 of the first embodiment described above, and have vent holes 91A to 91D.

The communication member 80 is a member that connects the air vents 91A to 91D of the respective annular members 9A to 9D and the air vent 67op provided in the second electrode sheet 67, and is disposed in the slit 68b of the spacer 68. The communication member 80 has, for example, an H shape similar to the slit 68b, and is connected to the respective annular members 9A to 9D via the vent holes 91A to 91D of the respective annular members 9A to 9D. The communication member 80 may be connected to each of the annular members 9A to 9D by integral molding, or may be connected to each of the annular members 9A to 9D by a predetermined fixture. Further, in the present embodiment, the communication member 80 has a pair of flat plates arranged in parallel, and the space between the flat plates is a passage that connects the annular members 9A to 9D and the air vent 67op, but it is in the shape of a groove or a tube. It may be a passage.

When the spacer 68 is overlapped with the first electrode sheet 66 and the second electrode sheet 67 with the communication member 80 arranged in the slit 68b of the spacer 68, the second insulation of the second electrode sheet 67 is obtained. The air vent 67op provided in the seat 67s and the communication member 80 communicate with each other. Therefore, the openings of the annular members 9A to 9D communicate with the air vent 67op through the communication member 80. That is, the communication member 80 becomes an air vent.

The load detection sensor 5D is configured by combining the above components. That is, the corresponding annular members 9A to 9D are arranged in the openings 68A to 68D of the spacer 68, and the communication member 80 is arranged in the slit 68b of the spacer 68. In this state, the first electrode sheet 66 is adhered to the one surface side of the spacer 68 with the adhesive layer 10, and the second electrode sheet 67 is adhered to the other surface side of the spacer 68 with the adhesive layer 10 to detect the load. The sensor 5D is configured.

In the load detection sensor 5D, the annular members 9A to 9D include the first insulating sheet 66s exposed on one opening surface side of the openings 68A to 68D of the spacer 68 and the other opening surface side of the openings 68A to 68D. It is in contact with both the second insulating sheet 67s exposed to the outside in a non-adhesive state. Further, as described above, the openings 68A to 68D of the annular members 9A to 9D communicate with the air vent 67op provided in the second insulating sheet 67s of the second electrode sheet 67 through the communicating member 80, and outside the load detection sensor 5D. Communicate with.

Further, in the load detection sensor 5D, the first electrodes 66e1 to 66e4 are located inside one opening end of the annular members 9A to 9D, and the second electrodes 67e1 to 67e4 are located inside the other opening end of the annular member 9. To do. The first electrodes 66e1 to 66e4 and the second electrodes 67e1 to 67e4 face each other through the openings 68A to 68D of the annular members 9A to 9D to form switches SW1 to SW4, respectively.

As described above, even the load detection sensor 5D described above has the same effects as those described above for the load detection sensor 5A of the first embodiment and the load detection sensor 5B of the second embodiment. Further, in this embodiment, a plurality of switches each including a first electrode and a second electrode as a set are provided, and openings 68A to 68D of the spacer 68 and annular members 9A to 9D are provided for each of the switches SW1 to SW4. In addition, the spacer 68 has a slit 68b that connects the openings 68A to 68D, and the second electrode sheet 67 has an air vent 67op. The load detection sensor 5D of the present embodiment is provided with a communication member 80 that is disposed in the slit 68b and that connects the annular members 9A to 9D and the air vent 67op.

In the load detection sensor 5D, the second electrode sheet 67 is bent so as to enter the inside of the annular member 9A, and when the first electrode 66e1 and the second electrode 67e1 come into contact with each other, the openings 68A to 68D of the spacer 68 are provided. The air inside the annular member 9A is discharged to the outside of the load detection sensor 5D through the communication member 80 through the air vent 67op. Similarly, when the second electrode sheet 67 bends so as to enter the insides of the annular members 9B to 9D, the air inside the annular members 9B to 9D in the openings 68A to 68D of the spacer 68 passes through the communication member 80. The air is discharged from the air vent 67op to the outside of the load detection sensor 5D.

Therefore, it is avoided that the bending of the second electrode sheet 67 is suppressed by the air inside the annular members 9A to 9D in the openings 68A to 68D of the spacer 68, and the load detection sensor 5D is prevented from erroneous detection. can do.

(5) Fifth Embodiment Next, a load detection sensor unit will be described as a fifth embodiment. The same components as those described above are designated by the same reference numerals, and unless otherwise specified, duplicated description will be omitted.

FIG. 13 is an exploded view showing the configuration of the load detection sensor of the fifth embodiment. As shown in FIG. 13, in the load detection sensor 5E of the present embodiment, air discharge slits 67s1 to 67s4 are provided in the second electrodes 67e1 to 67e4, respectively. Further, in the annular members 9A to 9D of the present embodiment, the vent holes 91A to 91D are omitted, and the annular members 9A to 9D extend in a ring shape without interruption.

Further, in the load detection sensor 5E of the present embodiment, a pair of wirings PW1 to PW3 adjacent to each other and spaced apart from each other is provided instead of the second wirings 67w1 to 67w3 of the fourth embodiment. Further, in the load detection sensor 5E of the present embodiment, a communication passage forming member 85 is provided instead of the communication member 80 of the fourth embodiment.

The pair of wirings PW1 to PW3 are arranged on one surface of the second electrode sheet 67 in a state of being separated from each other and adjacent to each other. One end of the pair of wirings PW1 is electrically connected to the second electrode 67e1 and is located inside the annular member 9A. The other ends of the pair of wirings PW1 are electrically connected to the second electrode 67e2 and are located inside the annular member 9B. One end of the pair of wirings PW2 is electrically connected to the second electrode 67e3 and is located inside the annular member 9C. The other ends of the pair of wirings PW2 are electrically connected to the second electrode 67e4 and are located inside the annular member 9D. The pair of wirings PW3 electrically connects one of the pair of wirings PW1 and one of the pair of wirings PW2 adjacent thereto. In the example shown in FIG. 13, the pair of wirings PW1 to PW3 are arranged in parallel, but they may not be parallel as long as they are separated from each other and adjacent to each other.

The communication path forming member 85 is made of, for example, an H-shaped plate material, and is connected to the respective annular members 9A to 9D. FIG. 14 is a view showing a cross section of the load detection sensor 5E taken along line XX in FIG. As shown in FIG. 14, when the spacer 68 is overlapped with the first electrode sheet 66 and the second electrode sheet 67, the communication path forming member 85 is brought into contact with the pair of wirings PW1 and thereby the second electrode sheet. The gap AR between the pair of wirings PW1 is closed from the side opposite to the one surface of 67. Similarly, when the spacer 68 is overlapped with the first electrode sheet 66 and the second electrode sheet 67, the communication path forming member 85 is also brought into contact with the pair of wirings PW2 and PW3, whereby the second electrode sheet 67 is formed. The gap AR between the pair of wirings PW2 and PW3 is closed from the side opposite to the one surface. The communication path forming member 85 is not adhered to the pair of wirings PW1 to PW3, the first electrode sheet 66, and the second electrode sheet 67.

Therefore, when the spacer 68 is overlapped with the first electrode sheet 66 and the second electrode sheet 67, the communication path forming member 85 sets the gap between the pair of wirings PW1 to PW3 inside the annular members 9A to 9D. Each of the air discharge slits 67s1 to 67s4 of the located second electrodes 67e1 to 67e4 is formed as a communication path that communicates with the air vent 67op.

Therefore, in the load detection sensor 5E of the present embodiment, when the second electrode sheet 67 is bent so as to enter the inside of the annular member 9A and the first electrode 66e1 and the second electrode 67e1 come into contact with each other, the spacer 68 The air inside the annular member 9A in the openings 68A to 68D flows to the air discharge slit 67s1 of the second electrode 67e1. Then, it flows into the gap AR between the pair of wirings PW1 and PW3 formed by the communication path forming member 85, and is discharged to the outside of the load detection sensor from the air vent 67op through the gap AR.

Therefore, in the load detection sensor 5E of the present embodiment, the bending of the second electrode sheet 67 is suppressed by the air inside the annular members 9A to 9D in the openings 68A to 68D of the spacer 68, as in the fourth embodiment. This can be avoided, and the load detection sensor 5E can be prevented from making an erroneous detection. In addition to this, in the present embodiment, since the vent holes 91A to 91D do not have to be provided in the annular members 9A to 9D, the durability of the annular members 9A to 9D itself is improved. Therefore, the annular members 9A to 9D can more stably support the first electrode sheet 66 and the second electrode sheet 67. As a result, it is possible to suppress a change in load necessary for the first electrodes 66e1 to 66e4 and the second electrodes 67e1 to 67e4 to contact each other.

Further, in the load detection sensor 5E of the present embodiment, the communication path forming member 85 itself is not adhered to the pair of wirings PW1 to PW3, the first electrode sheet 66, and the second electrode sheet 67. Therefore, it is possible to avoid filling the gap AR between the pair of wirings PW1 and PW3 formed by the communication path forming member 85 with the adhesive layer. Further, since the communication path forming member 85 itself can support the first electrode sheet 66 and the second electrode sheet 67 without adhering to the pair of wirings PW1 to PW3 and the first electrode sheet 66, the first electrode sheet. The adhesive layer 10 between 66 and the second electrode sheet and the spacer 68 can be reduced.

(6) Sixth Embodiment Next, a load detection sensor unit will be described as a sixth embodiment. The same components as those described above are designated by the same reference numerals, and unless otherwise specified, duplicated description will be omitted.

FIG. 15 is an exploded view showing the configuration of the load detection sensor of the sixth embodiment. As shown in FIG. 15, the load detection sensor 5F in the present embodiment includes a first electrode sheet 110, a second electrode sheet 120, a spacer 130, and a fitting member 140 as main constituent elements.

The first electrode sheet 110 has a first insulating sheet 110s and a first conductive layer 110e.

The first insulation sheet 110s is a flexible resin insulation sheet. The first insulating sheet 110s includes a main block 110m and a tail block 110t connected to the main block 110m. The tail block 110t has a shape narrower than that of the main block 110m. An air vent 110h is formed near the center of the main block 110m. Examples of the material of the first insulating sheet 110s include resins such as PET, PI, and PEN.

The first conductive layer 110e has a first electrode 111, a first terminal 113, and a first wiring 112, and is provided on one surface of the first insulating sheet 110s. In FIG. 15, for easy understanding, the first conductive layer 110e and the first insulating sheet 110s are disassembled and described, and the arrangement position of the first conductive layer 110e is shown by a broken line in the first insulating sheet 110s. ..

The first electrode 111 is provided on the end side of the main block 110m. The first electrode 111 is made of a conductor layer and is, for example, a metal printing layer. The first electrode 111 of the present embodiment is composed of a substantially circular central electrode portion 111p and a substantially circular ring-shaped outer electrode portion 111r surrounding the outer periphery of the central electrode portion 111p. A gap 111s is formed between them. The first terminal 113 is made of a conductor layer and is, for example, a substantially square metal layer. The first terminal 113 is provided on the tail block 110t. Further, the first electrode 111 and the first terminal 113 are electrically connected to each other via the first wiring 112.

The first wiring 112 is formed including a pair of wirings separated from each other. A slit-shaped gap 112s is formed between the pair of wires. The pair of wirings are connected by a ring portion 112r formed in a substantially ring shape. An opening 112h is formed by the ring portion 112r, and the opening 112h communicates with the gap 112s. The first wiring 112 having a pair of wirings extends to the central electrode portion 111p of the first electrode 111, and the gap 112s also extends to the central electrode portion 111p.

As shown by the broken line in FIG. 15, in a state where the first conductive layer 110e is arranged on one surface of the first insulating sheet 110s, the opening 112h of the first conductive layer 110e and the air vent 110h of the first insulating sheet 110s. And overlap. That is, when the first electrode sheet 110 is viewed in a plan view, the ring portion 112r of the first wiring 112 surrounds the air vent 110h of the first insulating sheet 110s.

The second electrode sheet 120 has a second insulating sheet 120s and a second conductive layer 120e.

The second insulating sheet 120s is a resin insulating sheet, like the first insulating sheet 110s. The second insulating sheet 120s includes a main block 120m having the same shape as the main block 110m of the first insulating sheet 110s, and a tail block 120t having the same shape as the tail block 110t of the first insulating sheet 110s connected to the main block 120m. Consists of. However, when the first insulating sheet 110s and the second insulating sheet 120s are stacked, the tail block 110t of the first insulating sheet 110s and the tail block 120t of the second insulating sheet 120s do not overlap with each other. Examples of the material of the second insulating sheet 120s include the same material as the material of the first insulating sheet 110s, and the material of the second insulating sheet 120s and the material of the first insulating sheet 110s may be the same or different. ..

The second conductive layer 120e has the second electrode 121, the second terminal 123, and the second wiring 122, and is provided on one surface of the second insulating sheet 120s. One surface of the second insulating sheet 120s is a surface facing the one surface of the first insulating sheet 110s on which the first conductive layer 110e is provided. In FIG. 15, for ease of understanding, the second conductive layer 120e and the second insulating sheet 120s are disassembled and described like the first electrode sheet 110, and the second conductive layer 120e is arranged on the second insulating sheet 120s. The position is indicated by a dashed line.

The second electrode 121 is provided on the end side of the main block 120m and faces the first electrode 111 when the first electrode sheet 110 and the second electrode sheet 120 are overlapped with each other. The second electrode 121 is made of the same conductor layer as the first electrode 111. Like the first electrode 111, the second electrode 121 of the present embodiment includes a substantially circular central electrode portion 121p and a substantially circular ring-shaped outer electrode portion 121r surrounding the outer periphery of the central electrode portion 121p. A slit 121s is formed between the portion 121p and the outer electrode portion 121r. The second terminal 123 is made of a conductor layer, and is, for example, a substantially square metal layer. The second terminal 123 is provided on the tail block 120t. The second electrode 121 and the second terminal 123 are electrically connected to each other via the second wiring 122. The second wiring 122 extends to the central electrode portion 121p.

The spacer 130 is disposed between the first electrode sheet 110 and the second electrode sheet 120 and is a flexible resin insulating sheet. The spacer 130 has an outer shape similar to that of the main block 120m of the first insulating sheet 110s and the second insulating sheet 120s. Examples of the material of the spacer 130 include the same materials as those of the first insulating sheet 110s and the second insulating sheet 120s. The material of the spacer 130 may be the same as or different from the material of the first insulating sheet 110s or the second insulating sheet 120s. Adhesive layers (not shown) that are adhered to the first insulating sheet 110s and the second insulating sheet 120s are arranged on both surfaces of the spacer 130.

An opening 130h is formed in the spacer 130. The opening 130h includes a first opening 131 which is a substantially circular opening, and a second opening 132 which is a substantially rectangular slit and is connected to the first opening 131. In this way, the opening 130h is composed of a circular opening and a slit connected to this opening, and has a substantially keyhole shape.

The fitting member 140 is a member fitted into the opening 130h of the spacer 130. The fitting member 140 includes an annular member 141 and a communication passage forming member 142 connected to the annular member 141, and the annular member 141 and the communication passage forming member 142 are integrated.

The annular member 141 is formed in a ring shape, and the opening 140h is surrounded by the annular member 141. The outer shape of the annular member 141 is circular like the first opening 131 of the opening 130h, and its outer diameter is slightly smaller than the diameter of the first opening 131 so that it can be fitted into the first opening 131. To be done. The inner diameter of the annular member 141 is made larger than the central electrode portion 111p of the first electrode 111 and the central electrode portion 121p of the second electrode 121.

The communication path forming member 142 has substantially the same shape as the second opening 132 in the opening 130h of the spacer 130. However, the communication path forming member 142 is formed to be slightly smaller than the second opening 132 so that it can be fitted into the second opening 132.

Examples of the material of the fitting member 140 include the same materials as the first insulating sheet 110s, the second insulating sheet 120s, and the spacer 130. The material of the fitting member 140 and the material of the spacer 130, the first insulating sheet 110s, and the second insulating sheet 120s may be the same or different. However, in order to reduce the relative change in the height of the spacer 130 and the height of the fitting member 140 due to the expansion of the spacer 130, the spacer 130 and the fitting member 140 are preferably made of the same material. Further, no adhesive layer is arranged on both surfaces of the fitting member 140.

The fitting member 140 is fitted into the opening 130h of the spacer 130, the first electrode sheet 110, the spacer 130, and the second electrode sheet 120 are overlapped with each other, and when the annular member 141 is seen in a plan view, it is located inside the opening 140h of the annular member 141. The central electrode portion 111p of the first electrode 111 and the central electrode portion 121p of the second electrode 121 are located. Further, a portion of the first wiring 112 of the first electrode sheet 110, which is composed of a pair of wirings, is in contact with the communication path forming member 142 up to the ring portion 112r. Therefore, similarly to the fifth embodiment, in this embodiment as well, a pair of wirings of the first wiring 112, the first insulating sheet 110s, and the communication path forming member 142 form a ventilation path. As described above, since the adhesive layers are not arranged on both surfaces of the fitting member 140, it is possible to prevent the ventilation passage from being filled with the adhesive. Further, as described above, the gap 112s between the first wirings 112 formed of a pair of wirings extends to the central electrode portion 111p of the first electrode 111. Therefore, the gap 112s communicates with the opening 140h. Furthermore, as described above, the ring portion 112r of the first wiring 112 surrounds the air vent 110h of the first insulating sheet 110s. Therefore, the air vent port 110h and the gap 112s communicate with each other. In this way, the opening 140h and the air vent 110h communicate with each other through the ventilation passage.

Therefore, in the load detection sensor 5F of the present embodiment, at least one of the first electrode sheet 110 and the second electrode sheet 120 bends so as to enter the inside of the opening 140h of the annular member 141, and the first electrode 111 and the second electrode The air in the opening 140h of the annular member 141 when coming into contact with the air duct 121 is vented through an air passage formed by the first wiring 112 sandwiching the gap 112s, the first insulating sheet 110s, and the communication passage forming member 142. It is discharged from the load detection sensor 5F from 110h.

Therefore, in the load detection sensor 5F of the present embodiment, the bending of at least one of the first electrode sheet 110 and the second electrode sheet 120 is similar to that of the opening 140h of the annular member 141, as in the fourth and fifth embodiments. It is possible to suppress the suppression by the air inside, and to prevent the load detection sensor 5E from making an erroneous detection.

(7) Modified Example In the above embodiment, the adhesive layer 10 is arranged between the first electrode sheet and the spacer and between the second electrode sheet and the spacer, but it is arranged only in either one. It may be. In addition, when the adhesive layer is not disposed on one side between the first electrode sheet or the second electrode sheet and the spacer, for example, the spacer is formed by providing a curable resin on the first electrode sheet or the second electrode sheet and curing the resin. The spacer can be formed and the spacer can be directly bonded to the first electrode sheet or the second electrode sheet. It is also possible to form a ring-shaped member by providing a curable resin on the first electrode sheet or the second electrode sheet and curing the resin, and directly bond the ring-shaped member to the first electrode sheet or the second electrode sheet.

In the above embodiment, the annular member was in contact with both the first electrode sheet and the second electrode sheet, but it may be in contact with only one of the first electrode sheet and the second electrode sheet. In short, the annular member may be in contact with at least one of the first electrode sheet and the second electrode sheet.

In the above embodiment, the sheet of the first electrode sheet is the flexible resin insulating sheet, but may be, for example, a substrate having no flexibility or a metal sheet. Alternatively, it may be composed of two layers of an insulating sheet and a metal sheet.

INDUSTRIAL APPLICABILITY The load detection sensor of the present invention has applicability as long as it detects the presence/absence of a load on a detection object whose load should be detected. For example, there is a form in which the load detection sensor is arranged below the seat cushion of the care bed. Even in such a form, the load detection sensor can detect the load, and based on the detection result of the load detection sensor, it is possible to obtain information indicating whether or not a person is present on the seat cushion. Further, it may be used as a switch of an electronic device to detect the presence or absence of a load.

Next, the contents of the experiment will be described with reference to examples and comparative examples relating to the above-described embodiment. However, the present invention is not limited to the following examples and comparative examples.

The load detection sensor of Comparative Example 1, the load detection sensor of Example 1, and the load detection sensor of Example 2 were prepared, and an experiment was conducted in which a load was applied to each load detection sensor under different temperature environments. ..

As the load detection sensor of Comparative Example 1, a load detection sensor having a configuration in which the annular member 9 is omitted from the load detection sensor 5A in the first embodiment is prepared. As the load detection sensor of Example 1, the second electrode sheet 7 of the first embodiment is configured by two layers of the second insulating sheet 57s and the metal plate 60 of the second embodiment, and the other constituent elements are the above-mentioned elements. A load detection sensor having the same components as in the first embodiment was prepared. As the load detection sensor of Example 2, a load detection sensor corresponding to the load detection sensor 5C of the third embodiment was prepared.

The first insulating sheet of each of the load detection sensor of Comparative Example 1, the load detection sensor of Example 1, and the load detection sensor of Example 2 is a PET sheet having a thickness of 75 μm, and the spacer is a PET sheet having a thickness of 50 μm. And The adhesive layer was an acrylic adhesive layer having a thickness of 25 μm on the first insulating sheet side and an acrylic adhesive layer having a thickness of 25 μm on the second insulating sheet side. The second insulating sheet of each of the load detection sensor of Comparative Example 1 and the load detection sensor of Example 1 was a PET sheet having a thickness of 100 μm. The metal plate of each of the load detection sensor of Example 1 and the load detection sensor of Example 2 is a SUS301 sheet having a thickness of 0.1 mm, and the adhesive layer between the metal plate and the insulating sheet has a thickness of 24 μm. Was used as the acrylic adhesive layer.

Furthermore, the diameter of the spacer of each of the load detection sensor of Comparative Example 1, the load detection sensor of Example 1, and the load detection sensor of Example 2, and the load detection sensor of Example 1 and the load detection sensor of Example 2 The inner diameter and material of the annular member are shown in FIG. The opening diameter of the spacer shown in FIG. 16 means the diameter of the spacer, the ring diameter shown in FIG. 16 means the inner diameter of the annular member, and the ring material shown in FIG. 16 means the material of the annular member.

(Experiment 1)
The load detection sensor of the comparative example, the load detection sensor of the first embodiment, and the load detection sensor of the second embodiment are arranged under respective temperature environments of −40° C., 25° C., and 85° C., and the load detection sensor is the second one. The load (on load) applied when the pair of electrodes was pressed by being pressed from the electrode sheet side was measured. In addition, in FIG. 16, with respect to the on-load measured in the temperature environment of 25° C., the increase/decrease of the on-load measured in the temperature environment of −40° C. and the on-load measured in the temperature environment of 85° C. It represents.

As shown in FIG. 16, compared with Comparative Example 1 having no annular member, Example 1 and Example 2 provided with the annular member changed to 85° C. even when the temperature was changed to −40° C. with reference to room temperature. However, the variation in the on-load at that temperature is small. That is, it has been found that if the annular member is provided, the load can be detected in the same manner as in the normal temperature environment, regardless of whether the temperature is higher or lower than normal temperature.

(Experiment 2)
The load detection sensor of Comparative Example 1, the load detection sensor of Example 1 and the load detection sensor of Example 2 are arranged under a temperature environment of 80° C. Pressed for only time. Then, the on-load at room temperature was measured, and the change rate with respect to the on-load at room temperature measured before the pressing was obtained as the on-load change rate after the high temperature constant load test. The result is shown in FIG.

As shown in FIG. 16, in comparison with Comparative Example 1 in which the annular member is not provided, Example 1 and Example 2 provided with the annular member have a change in on-load even if they are continuously pressed in a high temperature environment for a long period of time. The rate is getting smaller. That is, it has been found that if the annular member is provided, the load can be detected in the same manner as in the normal temperature environment even if the pressing is continued for a long time in the high temperature environment.

Further, the load detection sensor of Comparative Example 2 and the load detection sensor of Example 3 were prepared, and an experiment was performed in which a load was applied to each load detection sensor under different temperature environments.

As the load detection sensor of Comparative Example 2, a load detection sensor having a configuration in which the annular member 9 is omitted from the load detection sensor 5A in the first embodiment is prepared. As the load detection sensor of Example 3, a load detection sensor corresponding to the load detection sensor 5A of the first embodiment was prepared.

The first insulating sheet of each of the load detection sensor of Comparative Example 2 and the load detection sensor of Example 3 was a PET-made sheet having a thickness of 100 μm, and the spacer was a PET-made sheet having a thickness of 50 μm. The adhesive layers of the load detection sensor of Comparative Example 2 and the load detection sensor of Example 3 each have an acrylic adhesive layer having a thickness of 25 μm on the first insulating sheet side and an acrylic adhesive layer having a thickness of 25 μm on the second insulating sheet side. Layered. The second insulating sheet of each of the load detection sensor of Comparative Example 2 and the load detection sensor of Example 3 was a sheet made of PET and having a thickness of 100 μm.

Furthermore, the diameters of the spacers of the load detection sensor of Comparative Example 2 and the load detection sensor of Example 3, and the inner diameter and material of the annular member are shown in FIG. The opening diameter of the spacer shown in FIG. 17 means the diameter of the spacer, the ring diameter shown in FIG. 16 means the inner diameter of the annular member, and the ring material shown in FIG. 16 means the material of the annular member. The outer diameter of the annular member is 11 mm, and the height of the annular member is 100 μm.

The load detection sensor of Comparative Example 2 and the load detection sensor of Example 3 are arranged under respective temperature environments of −40° C., 25° C., and 85° C., and the load detection sensor is pressed from the second electrode sheet side. The load (on load) applied at the time when the pair of electrodes contact each other was measured. In addition, in FIG. 17, with respect to the ON load measured in the temperature environment of 25° C., the increase/decrease in the ON load measured in the temperature environment of −40° C. and the ON load measured in the temperature environment of 85° C. It represents.

As shown in FIG. 17, in comparison with Comparative Example 2 having no annular member, Example 3 provided with the annular member has a temperature of −40° C. or 85° C. with respect to room temperature. The variation in on-load with temperature is small. That is, it has been found that if the annular member is provided, the load can be detected in the same manner as in the normal temperature environment, regardless of whether the temperature is higher or lower than normal temperature.

5A to 5F... Load detection sensor 6, 56, 66, 110... First electrode sheet 7, 57, 67, 120... Second electrode sheet 8, 58, 68, 130... Spacer 9, 9A to 9D, 59, 141... Annular member 10... Adhesive layer 80... Communication members 85, 142... Communication path forming member 101... Metal sheets SW, SW1 to SW4... Switches

Claims (11)

A first electrode sheet having a first electrode;
A second electrode sheet having a second electrode facing the first electrode;
A spacer interposed between the first electrode sheet and the second electrode sheet and having an opening between the first electrode and the second electrode;
An annular member arranged in the opening,
An adhesive layer disposed on at least one of the spacer and the first electrode sheet and between the spacer and the second electrode sheet,
Equipped with
The annular member contacts at least one of the first electrode sheet exposed in the opening and the second electrode sheet exposed in the opening, and is not bonded to both the first electrode sheet and the second electrode sheet. A load detection sensor characterized in that The load detection sensor according to claim 1, wherein the annular member is in contact with both the first electrode sheet and the second electrode sheet. The load detection sensor according to claim 1 or 2, wherein at least a part of an outer peripheral surface of the annular member is separated from the spacer. The load detection sensor according to any one of claims 1 to 3, wherein the annular member and the spacer are made of the same material. The load detection sensor according to any one of claims 1 to 4, wherein the annular member has a vent for venting air in the opening of the spacer. The spacer has a slit connected to the opening,
At least one of the first electrode sheet and the second electrode sheet has an air vent,
The load detection sensor according to claim 5, further comprising a communication member arranged in the slit, the communication member communicating the air vent and the air vent of the annular member. The spacer has a slit connected to the opening,
At least one of the first electrode sheet and the second electrode sheet has a pair of wirings spaced apart from each other and adjacent to each other, and an air vent,
The ends of the pair of wirings are located inside the annular member,
A communication passage forming member that is disposed in the slit and that forms a gap between the pair of wirings as a communication passage that connects the inside of the annular member in the opening of the spacer and the air vent port. The load detection sensor according to any one of claims 1 to 4. The annular member and the first electrode and the second electrode overlap each other when the sheet surface of the first electrode sheet is viewed in a plan view. Load detection sensor. The total thickness of the spacer and the adhesive layer is approximately the same as the total height of the annular member, the thickness of the first electrode, and the thickness of the second electrode. 8. The load detection sensor according to item 8. 8. The annular member does not overlap the first electrode and the second electrode when the sheet surface of the first electrode sheet is viewed in a plan view. The load detection sensor described. The load detection sensor according to claim 10, wherein the total thickness of the spacer and the thickness of the adhesive layer is approximately the same as the height of the annular member.

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