JP2018203066A - Load detection sensor - Google Patents

Abstract

To provide a load detection sensor capable of detecting a load properly.SOLUTION: A load detection sensor 5A includes: a first electrode sheet 6 having a first electrode 62; a metal plate 71 overlapped with the first electrode 62 in a direction orthogonal to a sheet surface of the first electrode sheet 6 and arranged along the sheet surface; a second electrode sheet 7 having a second electrode 72 which is part of the metal plate 71 facing the first electrode 62; a spacer 8 interposed between the first electrode sheet 6 and the second electrode sheet 7 and having an opening 81 between the first electrode 62 and the second electrode 72; and a second adhesion layer 10 arranged between the spacer 8 and the second electrode sheet 7. The metal plate 71 has a protrusion 90 protruding to the first electrode sheet 6 side. The protrusion 90 is arranged at a place other than a center of the opening 81 of the spacer 8, and at least part of the first electrode 62 and the second electrode 72 is arranged further on the center side of the opening 81 than the protrusion 90.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a load detection sensor, which is suitable for detecting a load caused by seating or the like.

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

  As a load detection sensor, a configuration including a pair of resin films and a pair of electrodes provided on the respective films and facing each other with a predetermined interval is disclosed (see Patent Document 1). A pair of film of the following patent document 1 is bonded together by the adhesive arrange | positioned except between between the electrodes which mutually oppose.

JP 09-315199 A

  However, the pressure-sensitive adhesive generally tends to soften with an increase in temperature. Therefore, when the load detection sensor of the above-mentioned patent document 1 is placed in an environment where the temperature is high, such as in an automobile under a hot sun, the load necessary for the electrodes provided on each film to come in contact may decrease. Concerned. On the other hand, when the load detection sensor of Patent Document 1 is placed in an environment where the temperature is as low as about −40 ° C., the load required for the electrodes provided on each film to contact increases due to the hardened adhesive. There is a concern that

  Further, the pressure-sensitive adhesive may undergo creep deformation when pressed for a long time. When the adhesive is creep-deformed, the distance between the resin films changes, and there is a concern that the load required for the electrodes provided on the films to contact each other changes.

  Thus, in the load detection sensor of the above-mentioned patent document 1, the load required for the electrode provided on the film to contact changes, 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-described problem, a load detection sensor according to the present invention includes a first electrode sheet having a first electrode, and the first electrode overlapping with the first electrode in a direction orthogonal to the sheet surface of the first electrode sheet, along the sheet surface. And a second metal plate disposed on a part of the metal plate facing the first electrode or on the first electrode sheet side with respect to the first electrode. A second electrode sheet having electrodes, 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, and the spacer An adhesive layer disposed between the second electrode sheet and the metal plate having a protrusion protruding toward the first electrode sheet, the protrusion being the opening in the opening. The first electrode is disposed outside the center of the first electrode At least a portion of the fine the second electrode is characterized in that than the protrusion is disposed on the center side of the opening.

In such a load detection sensor, when the second electrode sheet is pressed from the surface on the side opposite to the surface on the spacer side, the metal plate is supported by the protrusions arranged in the opening of the spacer. For this reason, compared with the case where a metal plate is not supported by a projection part, the 2nd electrode sheet becomes difficult to be influenced by the temperature change of an adhesion layer.
That is, the adhesive layer tends to be softened under a high temperature environment and hardened under a low temperature environment. For this reason, when the metal plate is not supported by the protrusion, the adhesive layer at the edge portion of the opening of the spacer changes according to the temperature environment, and the bending method of the second electrode sheet that enters the opening of the spacer changes. . The load required for the first electrode and the second electrode to contact with each other changes due to the change in the bending method. In contrast, in the load detection sensor of the present invention, the metal plate is supported by the protrusions. For this reason, the metal plate portion on the center side of the opening is easily bent toward the first electrode sheet with the protrusion as a fulcrum. Since this metal plate portion is located in the opening of the spacer and has no adhesive layer, even if the adhesive layer disposed between the spacer and the second electrode sheet changes according to the temperature environment, the metal plate portion The way of bending is almost unchanged. Therefore, it is possible to reduce a change in load necessary for the first electrode and the second electrode to contact each other.
In addition, since the metal plate is supported by the protrusions, it is difficult for a load to be applied to the adhesive layer, and the adhesive layer is difficult to creep. Even if the adhesive layer is creep-deformed by pressing the load detection sensor for a long time, the distance between the first electrode sheet and the second electrode sheet is held substantially constant by the protrusion. As a result, a change in load necessary for the first electrode and the second electrode to come into contact with the creep deformation is reduced.
As described above, according to the load detection sensor of the present invention, it is possible to reduce a change in load necessary for the first electrode and the second electrode to come into contact with a temperature change or a secular change. Thus, a load detection sensor that can appropriately detect the load is realized.

  Moreover, it is preferable that the said protrusion part is in contact with the said 1st electrode sheet.

  In this case, the metal plate can be supported more stably than the case where the protrusion is not in contact with the first electrode sheet. As a result, the first electrode and the second electrode are in contact with each other. Necessary changes in load can be further reduced.

  The number of the protrusions is preferably plural.

  In this case, the metal plate can be stably supported as compared with the case where there is one protrusion, and as a result, a change in load necessary for the first electrode and the second electrode to contact each other is changed. Can be further reduced.

  Moreover, it is preferable that the said protrusion part is cyclic | annular.

  In this case, for example, the metal plate can be stably supported more easily than in the case where the protruding portion has a rod shape, and as a result, a change in load necessary for the first electrode and the second electrode to contact each other can be reduced. Further reduction can be achieved.

  Moreover, it is preferable that the said metal plate is directly adhere | attached on a spacer through the said contact bonding layer.

  In this case, since the metal plate and the spacer are in close contact with each other through the adhesive layer, the load detection sensor can be made thinner than when the insulating sheet is interposed between the metal plate and the spacer. In addition, since the distance from the metal plate to the first electrode is reduced, the height of the protrusion protruding from the metal plate can be reduced, and as a result, the durability of the protrusion can be improved.

  The second electrode sheet may further include an insulating sheet disposed between the metal plate and the spacer, and the second electrode may be disposed on a surface of the insulating sheet on the spacer side. preferable.

  In this case, since the insulation of the second electrode is ensured by the insulating sheet, even if static electricity or the like is applied to the metal plate from the outside, the load can be properly detected, and damage to the second electrode can be prevented. .

  Moreover, it is preferable that the said insulating sheet has a through-hole penetrated from the one surface to the other surface of the said insulating sheet, and the said projection part is penetrated by the said through-hole.

  When it does in this way, a projection part can control the relative shift | offset | difference of the sheet surface direction of a metal plate and a 2nd insulating sheet not only to support a metal plate. Accordingly, since it is not necessary to bond the metal plate and the second insulating sheet with the adhesive layer, the influence of the second electrode sheet due to the temperature change of the adhesive layer can be further reduced as described above.

  Further, it is preferable that the first electrode and the second electrode are disposed only on the center side of the opening with respect to the protrusion.

  In this case, it is possible to make it harder to damage the first electrode and the second electrode than in the case where the first electrode and the second electrode overlap with the protrusion.

  In addition, the first electrode and the second electrode extend from the center of the opening to the outside of the protrusion with respect to the protrusion, and the first electrode and the second electrode have a thickness direction. It is preferable that a through hole penetrating therethrough is provided, and the protruding portion is disposed in the through hole.

  In this case, even if the diameter of the first electrode is large, the protrusion can be made non-contact with the first electrode. Accordingly, it is possible to prevent damage to the first electrode due to rubbing or abrasion between the protrusion and the first electrode. Further, it is possible to prevent the scraping of the first electrode from being caused by rubbing between the protrusion and the first electrode. Furthermore, it is not necessary to consider the thickness variation of the first electrode, and as a result, the change in load necessary for the first electrode and the second electrode to contact each other can be further reduced.

  The first electrode and the second electrode are preferably larger than the opening.

  In this case, the end of the first electrode is disposed between the sheet of the first electrode sheet and the spacer, and the end of the second electrode is disposed between the sheet of the second electrode sheet and the spacer. . For this reason, even if the thickness of the first electrode or the second electrode varies, the distance between the first electrode and the second electrode can be made substantially constant by the spacer. Therefore, it is possible to further reduce the change in load necessary for the first electrode and the second electrode to contact each other.

  As described above, according to the present invention, it is possible to provide a load detection sensor that can appropriately detect a load.

It is an exploded view which shows the structure of the load detection sensor of 1st Embodiment. It is sectional drawing which shows a part of load detection sensor of FIG. It is a figure which shows the ON state of the load detection sensor of 1st Embodiment. It is an exploded view which shows the structure of the load detection sensor of 2nd Embodiment. It is sectional drawing which shows a part of load detection sensor of FIG. It is a figure which shows the ON state of the load detection sensor of 2nd Embodiment. It is a figure which illustrates a mode that the projection part of the load detection sensor of a 2nd embodiment was made annular, and the load detection sensor was planarly viewed from the sheet surface side of the 2nd electrode sheet. It is sectional drawing shown from the same viewpoint as FIG. 5 when the electrode of the load detection sensor of 2nd Embodiment is enlarged. It is a figure which shows a mode that the load detection sensor shown in FIG. 8 was planarly viewed from the sheet | seat surface side of the 2nd electrode sheet. It is a table | surface which shows a part of experimental condition and an experimental result.

  Hereinafter, a preferred embodiment of a load detection sensor unit according to the present invention will be described in detail with reference to the drawings. For ease of understanding, the scale of each figure may be different from the scale described in the following description.

(1) First Embodiment FIG. 1 is an exploded view showing a configuration of a load detection sensor of a first embodiment, and FIG. 2 is a cross-sectional view showing a part of the load detection sensor of FIG. As shown in FIGS. 1 and 2, the load detection sensor 5 </ b> A includes a first electrode sheet 6, a second electrode sheet 7, a spacer 8, a first adhesive layer 9, and a second adhesive layer 10 as main components. Prepare. In addition, the 1st contact bonding layer 9 and the 2nd contact bonding layer 10 are abbreviate | omitted in FIG.

  The first electrode sheet 6 includes a substrate 61, a first electrode 62, a first contact portion 63 (FIG. 1), a sheet through hole 64 (FIG. 1), and first wirings 65A and 65B (FIG. 1). The substrate 61 is a resin insulating sheet having no flexibility. Examples of the material of the substrate 61 include a resin such as a phenol resin or an epoxy resin.

  The first electrode 62 is one switch element constituting 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 disposed on one surface of the substrate 61.

  The first contact portion 63 is a portion that maintains electrical connection with the second contact portion 73 (FIG. 1) of the second electrode sheet 7 even when no external pressure is applied to the load detection sensor unit 1. The print layer. In the present embodiment, the first contact portion 63 is electrically connected to the contact area AR1 where the second contact portion 73 of the second electrode sheet 7 contacts and the contact area AR1, and the second contact portion 73 is not in contact. It is comprised with non-contact area | region AR2. The external pressure is a pressing force applied to the load detection sensor unit 1 from the vehicle seat in accordance with the seating of the person.

  The sheet through hole 64 is a hole penetrating from one surface of the substrate 61 to the other surface. The sheet through hole 64 of the present embodiment includes a first sheet through hole 64A, a second sheet through hole 64B, and pin through holes 64C and 64D.

  The first sheet through-hole 64 </ b> A has an opening located in a region where the first electrode 62 is disposed, and communicates with the through-hole provided in the first electrode 62. A tubular first conductive member is provided on the inner peripheral surface of the first sheet through-hole 64A, and the first electrode 62 disposed on one surface of the substrate 61 via the first conductive member. Are electrically connected to the first wiring 65 </ b> A disposed on the other surface of the substrate 61. The space surrounded by the tubular first conductive member in the first sheet through hole 64A and the through hole provided in the first electrode 62 are an exhaust path SP that discharges air in the opening 81 of the spacer 8. Is done.

  The opening of the second sheet through hole 64B is located in a region where the first contact portion 63 is disposed. In the present embodiment, the opening of the second sheet through hole 64B is positioned in the non-contact area AR2 of the first contact portion 63.

  The second sheet through hole 64B is filled with a second conductive member, and the first contact portion 63 disposed on one surface of the substrate 61 via the second conductive member, and the substrate The first wiring 65 </ b> B disposed on the other surface of 61 is electrically connected. Since the second conductive member is filled in the second sheet through hole 64B, there is no space corresponding to the exhaust path SP.

  The pin through holes 64C and 64D are through holes through which pin terminals are inserted. Tubular terminals are provided on the inner peripheral surfaces of the pin through holes 64C and 64D, and the inner diameter of the terminals is approximately the same as the outer diameter of the pin terminals.

  The first wiring 65 </ b> A is a wiring that is part of an electrical path between one of the pair of terminals and the first electrode 62. In the present embodiment, one end of the first wiring 65A is connected to a tubular terminal provided on the inner peripheral surface of the pin through hole 64D, and the other end of the first wiring 65A is the inner peripheral surface of the first sheet through hole 64A. It connects with the tubular 1st electroconductive member provided in. The first conductive member is electrically connected to the first electrode 62 as described above. Thus, one of the pair of terminals and the first electrode 62 are connected through the first wiring 65A.

  The first wiring 65 </ b> B is a wiring that is a part of an electrical path between the other of the pair of terminals and the second electrode 72. In the present embodiment, one end of the first wiring 65B is connected to a tubular terminal provided on the inner peripheral surface of the pin through hole 64C, and the other end of the first wiring 65B is filled into the second sheet through hole 64B. The second conductive member is electrically connected. The second conductive member is electrically connected to the first contact portion 63 as described above, and the first contact portion 63 and the second contact portion 73 do not apply external pressure to the load detection sensor unit 1 as described above. In some cases, the electrical connection is maintained. Thus, the other of the pair of terminals and the second electrode 72 are connected through the first wiring 65B.

  The second electrode sheet 7 includes a metal plate 71, a second electrode 72, a second contact portion 73 (FIG. 1), and a protrusion 90. The metal plate 71 is a thin metal plate having flexibility. The metal plate 71 overlaps the first electrode 62 in a direction orthogonal to the sheet surface of the first electrode sheet 6, and is disposed on the pressing portion PP (FIG. 2) side of the first electrode sheet 6 along the sheet surface. The The pressing part PP presses the switch SW 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 may have a convex curved shape. Moreover, although the front-end | tip of the press part PP is made non-contact with the metal plate 71, you may contact. The material of the metal plate 71 is not particularly limited as long as it is a metal, and examples thereof include copper and stainless steel.

  In a portion of the metal plate 71 of the present embodiment that faces the first electrode 62, a second electrode 72 that is the other switch element constituting the switch SW (FIG. 2) of the load detection sensor 5A is disposed. In the present embodiment, a part of the metal plate 71 also serves as the second electrode 72. However, for example, a metal layer made of the same material as or different from the metal plate 71 may be disposed as the second electrode 72 on the surface of the metal plate 71 facing the first electrode 62.

  The second contact portion 73 is a portion where electrical connection with the first contact portion 63 (FIG. 1) of the first electrode sheet 6 is maintained even when no external pressure is applied to the load detection sensor unit 1. The second contact portion 73 of the present embodiment plastically deforms a predetermined portion different from the portion to be the second electrode 72 in the metal plate 71 so that the predetermined portion is orthogonal to the thickness direction of the metal plate 71. It is formed as a leaf spring that is always inclined with respect to the surface.

  The protruding portion 90 is a portion protruding from the metal plate 71 toward the first electrode sheet 6 side. In the present embodiment, the protrusion 90 has a rod shape, and the height of the protrusion 90 is determined by the thickness of the first adhesive layer 9 between the substrate 61 and the spacer 8 and the height between the metal plate 71 and the spacer 8. 2 The thickness is equal to the sum of the thickness of the adhesive layer 10 and the thickness of the spacer 8. In the present embodiment, the number of the protrusions 90 is five, and for example, the protrusion 90 is positioned at the apex of a regular pentagon. Such a protrusion 90 may be provided by pressing the substrate 61 as shown in FIGS. 1 and 2, or may be provided by bonding a rod-shaped metal member to the substrate 61, etc. May be repeatedly printed on the substrate 61.

  The spacer 8 is interposed between the first electrode sheet 6 and the second electrode sheet 7 and is a flexible resin insulating sheet. Examples of the material of the spacer 8 include resins such as polyethylene terephthalate (PET), polyimide (PI), and polyethylene naphthalate (PEN).

  The spacer 8 has an opening 81 that penetrates from one surface side of the spacer 8 to the other surface side. The peripheral shape of the opening 81 is, for example, a substantially circular shape, and the diameter of the opening 81 is larger than the diameter of the first electrode 62.

  The spacer 8 of the present embodiment has a contact opening 83. The contact opening 83 is an opening for electrically connecting the first contact portion 63 disposed on the substrate 61 and the second contact portion 73, which is a leaf spring facing the first contact portion 63. . Through this contact opening 83, the second contact portion 73 formed as a leaf spring that is always inclined with respect to the surface of the metal plate 71 perpendicular to the thickness direction is in contact with the first contact portion 63. Thereby, the electrical connection between the first contact portion 63 and the second contact portion 73 is maintained even when no external pressure is applied to the load detection sensor unit 1.

  The first adhesive layer 9 is an adhesive layer disposed between the substrate 61 of the first electrode sheet 6 and the spacer 8. The first adhesive layer 9 is not particularly limited as long as the substrate 61 and the spacer 8 are bonded. Examples thereof include a pressure-sensitive adhesive, an adhesive, and a double-sided tape configured by providing a pressure-sensitive adhesive or an adhesive on both surfaces of a base material such as PET or nonwoven fabric. Examples of the material of the first adhesive layer 9 include a thermoplastic resin, a thermosetting resin, and a photo-curing resin. Examples of the pressure-sensitive adhesive include a silicon-based pressure-sensitive adhesive, a urethane-based pressure-sensitive adhesive, and an acrylic pressure-sensitive adhesive. The first adhesive layer 9 may be disposed over the entire surface between the substrate 61 and the spacer 8 as long as the substrate 61 and the spacer 8 are bonded to each other. It may be scattered and arranged in the part.

  The second adhesive layer 10 is an adhesive layer disposed between the metal plate 71 of the second electrode sheet 7 and the spacer 8. The second adhesive layer 10 is not particularly limited as long as the spacer 8 and the metal plate 71 are bonded. Examples thereof include a pressure-sensitive adhesive, an adhesive, and a double-sided tape configured by providing an adhesive layer on both surfaces of a base material such as PET or nonwoven fabric. Examples of the material of the second adhesive layer 10 include a thermoplastic resin, a thermosetting resin, a photocurable resin, and the like. Note that the material of the second adhesive layer 10 may be the same as or different from the material of the first adhesive layer 9. Here, the glass transition point Tg of the second adhesive layer 10 is preferably 85 ° C. or higher. Since the glass transition point Tg is 85 ° C. or higher, it is difficult to flow even in an environment where the temperature is high, such as in a car under hot weather, so that it is possible to suppress erroneous detection of a load due to the flow of the second adhesive layer 10. Can do. The second adhesive layer 10 may be disposed over the entire surface between the spacer 8 and the metal plate 71 as long as the spacer 8 and the metal plate 71 are bonded to each other. It may be scattered and arranged in a plurality of parts. In the present embodiment, the metal plate 71 and the spacer 8 are directly bonded via the second adhesive layer 10.

  The load detection sensor 5A is configured by combining the above components. That is, the substrate 61 of the first electrode sheet 6 is bonded to the one surface side of the spacer 8 with the first adhesive layer 9, and the metal plate 71 of the second electrode sheet 7 is bonded to the other surface side of the spacer 8. The load detection sensor 5 </ b> A is configured by bonding at 10.

  In this load detection sensor 5 </ b> A, the first electrode 62 is located inside the inner wall of the opening 81 of the spacer 8, and the portion of the metal plate 71 exposed in the opening 81 that faces the first electrode 62 is the second electrode 72. To position. The first electrode 62 and the second electrode 72 having such a positional relationship constitute a switch SW.

  The first electrode 62 and the second electrode 72 are disposed closer to the center of the opening 81 than the protrusion 90 disposed in the opening 81 of the spacer 8, and are positioned inside the plurality of protrusions 90. In other words, each of the plurality of protrusions 90 is disposed in the opening 81 other than the center of the opening 81 of the spacer 8, and is disposed between the inner wall of the opening 81 and the first electrode 62. The tips of the plurality of protrusions 90 are in contact with the substrate 61 of the first electrode sheet 6 exposed in the openings 81 of the spacer 8. The first wirings 65A and 65B disposed on the surface of the substrate 61 are disposed so as to pass between the adjacent projecting portions 90, and are not in contact with the projecting portions 90.

  As shown in FIG. 2, each of the plurality of protrusions 90 is separated from both the inner wall of the opening 81 of the spacer 8 and the first electrode 62, but is in contact with at least one of the inner wall and the first electrode 62. May be. Moreover, although the front-end | tip of the some projection part 90 is each made into the convex curved surface shape, you may be made into the planar shape.

  In addition, the 2nd contact part 73 in 5 A of load detection sensors is in the state which always carried out the plastic deformation with respect to the surface of the direction orthogonal to the thickness direction in the metal plate 71, as mentioned above. Therefore, in a state where the substrate 61 is bonded to one surface of the spacer 8 via the first adhesive layer 9 and the metal plate 71 is bonded to the other surface of the spacer 8 via the second adhesive layer 10, The two contact portions 73 continue to press the first contact portion 63 facing the second contact portion 73 through the contact opening 83. Therefore, as described above, even when no external pressure is applied to the load detection sensor unit 1, the electrical connection state between the first contact portion 63 and the second contact portion 73 is maintained.

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

  FIG. 3 is a diagram illustrating an on state of the load detection sensor according to the first embodiment. As shown in FIG. 3, the pressing portion PP receives a load and moves downward to contact the surface on the opposite side of the spacer 8 side of the metal plate 71 of the second electrode sheet 7. The metal plate 71 is pressed. At this time, since the metal plate 71 is supported by a plurality of protrusions 90 disposed in the openings 81 of the spacer 8, the metal plate 71 is bent so that the inner part of the protrusions 90 in the metal plate 71 enters the openings 81 of the spacer 8. Mu As a result, the second electrode 72 of the metal plate 71 contacts the first electrode 62, and the switch SW of the load detection sensor 5A is turned on.

  As described above, the first electrode 62 is provided on the inner peripheral surface of the pin through hole 64D through the tubular first conductive member provided on the inner peripheral surface of the first sheet through hole 64A and the first wiring 65A. It is electrically connected to the tubular terminal. Further, as described above, the second electrode 72 penetrates the pin through the second contact portion 73, the first contact portion 63, the second conductive member filled in the second sheet through hole 64B, and the first wiring 65B. It is electrically connected to a tubular terminal provided on the inner peripheral surface of the hole 64C. Therefore, when the second electrode 72 of the metal plate 71 comes into contact with the first electrode 62 and the switch SW of the load detection sensor 5A is turned on, through the pin terminals inserted into the pin through holes 64C and 64D, The load can be detected by a vehicle control unit (not shown) that is electrically connected to the pin terminal.

  When the metal plate 71 is bent, the air in the opening 81 of the spacer 8 is discharged through the exhaust path SP provided in the first electrode 62 and the first sheet through hole 64A. Therefore, it is avoided that the bending of the metal plate 71 is suppressed by the air in the opening 81 of the spacer 8, and the switch SW of the load detection sensor 5A is appropriately turned on.

  As described above, the load detection sensor 5 </ b> A of the present embodiment includes the first electrode sheet 6 having the first electrode 62 and the second electrode sheet 7. The second electrode sheet 7 overlaps the first electrode 62 in a direction orthogonal to the sheet surface of the first electrode sheet 6, and the metal plate 71 disposed along the sheet surface, and the metal plate 71 facing the first electrode 62. 2nd electrode 72 arrange | positioned at a part. Further, the load detection sensor 5A of the present embodiment is interposed between the first electrode sheet 6 and the second electrode sheet 7 and includes a spacer 8 having an opening 81 between the first electrode 62 and the second electrode 72. The second adhesive layer 10 is provided between the spacer 8 and the second electrode sheet 7.

  In addition to this, the metal plate 71 has a protruding portion 90 that protrudes toward the first electrode sheet 6, and the protruding portion 90 is disposed in the opening 81 other than the center of the opening 81 of the spacer 8. In addition, at least a part of the first electrode 62 and the second electrode 72 is disposed closer to the center of the opening 81 than the protrusion 90.

  In such a load detection sensor 5 </ b> A, when the second electrode sheet 7 is pressed from a surface opposite to the surface on the spacer 8 side, the metal plate 71 is moved by the protrusion 90 disposed in the opening 81 of the spacer 8. Supported. For this reason, compared with the case where the metal plate 71 is not supported by the protrusion part 90, the 2nd electrode sheet 7 becomes difficult to receive the influence by the temperature change of the 2nd contact bonding layer 10. FIG.

  That is, the second adhesive layer 10 tends to be softened under a high temperature environment and hardened under a low temperature environment. Therefore, when the metal plate 71 is not supported by the protrusion 90, the second adhesive layer 10 at the edge portion of the opening 81 of the spacer 8 changes according to the temperature environment and enters the opening 81 of the spacer 8. The bending method of the two-electrode sheet 7 changes. The load necessary for the first electrode 62 and the second electrode 72 to be in contact with each other is changed by the change in the bending method. On the other hand, in the present embodiment, the metal plate 71 is supported by the protrusion 90. For this reason, the metal plate portion on the center side of the opening 81 is easily bent toward the first electrode sheet 6 with the protrusion 90 as a fulcrum. Since the metal plate portion is located in the opening 81 of the spacer 8 and the second adhesive layer 10 does not exist, the second adhesive layer 10 disposed between the spacer 8 and the second electrode sheet 7 depends on the temperature environment. Even if it changes, the bending method of the metal plate portion does not change substantially. Therefore, it is possible to reduce a change in load necessary for the first electrode 62 and the second electrode 72 to contact each other.

  In addition, since the metal plate 71 is supported by the protrusions 90, it is difficult for a load to be applied to the second adhesive layer 10, and the second adhesive layer 10 is difficult to creep. Even if the load detection sensor 5A is pressed for a long time, even if the second adhesive layer 10 creep-deforms, the distance between the first electrode sheet 6 and the second electrode sheet 7 is substantially constant by the protrusion 90. Retained. As a result, a change in load necessary for the first electrode 62 and the second electrode 72 to come into contact with each other due to creep deformation is reduced.

  As described above, according to the load detection sensor 5A of the present embodiment, it is possible to reduce a change in load necessary for the first electrode 62 and the second electrode 72 to come into contact with a temperature change or an aging change. . In this way, the load detection sensor 5A that can appropriately detect the load is realized.

  Further, the protrusion 90 of the present embodiment is in contact with the first electrode sheet 6. For this reason, compared with the case where the protrusion part 90 is non-contact with the 1st electrode sheet 6, the metal plate 71 can be supported stably, As a result, the 1st electrode 62 and the 2nd electrode 72 contact. Therefore, the change in load necessary for this can be further reduced.

  Note that the height of the protrusion 90 is such that the thickness of the first adhesive layer 9 between the substrate 61 and the spacer 8, the thickness of the second adhesive layer 10 between the metal plate 71 and the spacer 8, It is about the same as the total thickness. For this reason, it can suppress that a stress arises in the direction which peels the spacer 8 and the board | substrate 61, and the direction which peels the spacer 8 and the metal plate 71 under no load in which the load is not added to the load detection sensor 5A. In the present embodiment, the metal plate 71 is directly bonded to the spacer 8 via the second adhesive layer 10. Accordingly, since the metal plate 71 and the spacer 8 are in close contact with each other via the second adhesive layer 10, the load detection sensor 5 </ b> A can be made thinner than when an insulating sheet is interposed between the metal plate 71 and the spacer 8. Can do. Further, since the distance from the metal plate 71 to the first electrode 62 is reduced, the height of the protruding portion 90 protruding from the metal plate 71 can be reduced, and as a result, the durability of the protruding portion 90 is improved. Can be made.

  In addition, the number of the protrusions 90 in the present embodiment is plural. For this reason, compared with the case where the number of the protrusions 90 is one, the metal plate 71 can be supported stably, and as a result, it is necessary for the first electrode 62 and the second electrode 72 to contact each other. The change in load can be further reduced.

  In addition, the first electrode 62 and the second electrode 72 are disposed only on the center side of the opening 81 of the spacer 8 with respect to the protrusion 90. For this reason, compared with the case where the 1st electrode 62 and the 2nd electrode 72 overlap with the projection part 90, it is possible to make the said 1st electrode 62 and the 2nd electrode 72 hard to damage.

  When the protrusion 90 is separated from the inner wall of the opening 81 of the spacer 8, the first adhesive layer 9 and the second adhesive layer 10 are softened by the presence of the load detection sensor 5 </ b> A in a high temperature environment, and the opening 81. Even if it flows, the protrusion 90 and the spacer 8 can be accommodated. Therefore, when the protrusion 90 and the first electrode sheet 6 are not in contact with each other, the softened first adhesive layer 9 and second adhesive layer 10 flow between the protrusion 90 and the first electrode sheet 6. It is avoided.

(2) Second Embodiment Next, a load detection sensor unit will be described as a second embodiment. In addition, the same code | symbol is attached | subjected about the structure similar to the structure demonstrated above, and the overlapping description is abbreviate | omitted except the case where it demonstrates especially.

  FIG. 4 is an exploded view showing the load detection sensor of the second embodiment, and FIG. 5 is a cross-sectional view showing a part of the load detection sensor of FIG. As shown in FIGS. 4 and 5, the load detection sensor 5 </ b> B according to the present embodiment mainly includes the first electrode sheet 60, the second electrode sheet 70, the spacer 80, the first adhesive layer 9, and the second adhesive layer 10. As a major component. In addition, the 1st contact bonding layer 9 and the 2nd contact bonding layer 10 are abbreviate | omitted in FIG.

  The first electrode sheet 60 includes a first insulating sheet 66, a first electrode 67, and a first wiring 68 (FIG. 1). The first insulating sheet 66 is a resin insulating sheet having flexibility. Examples of the material of the first insulating sheet 66 include resins such as PET, PI, and PEN.

  The first insulating sheet 66 of the present embodiment is composed of a main block M1 and a tail block M2. The outer shape of the main block M1 is circular, and the first electrode 67 is disposed on one surface of the main block M1. The tail block M2 is connected to the main block M1, and the outer shape of the tail block M2 is rectangular.

  The first electrode 67 is one switch element constituting the switch SW (FIG. 2) of the load detection sensor 5B, and is, for example, a substantially circular metal print layer. The first electrode 67 is disposed on the surface of the first insulating sheet 66 on the spacer 80 side.

  The first wiring 68 is a wiring that is electrically connected to the first electrode 67 and a terminal (not shown), and is, for example, a metal printing layer.

  The second electrode sheet 70 includes a metal plate 75, a second insulating sheet 76, a second electrode 77, a second wiring 78 (FIG. 1), and a protrusion 90. The second electrode sheet 7 of the first embodiment is composed of one layer of the metal plate 71, whereas the second electrode sheet 70 of the present embodiment is a two-layer of the metal plate 75 and the second insulating sheet 76. It consists of

  Similar to the first embodiment, the metal plate 75 is a thin metal plate having flexibility. The metal plate 75 overlaps the first electrode 67 in a direction orthogonal to the sheet surface of the first insulating sheet 66, and is disposed on the pressing portion PP (FIG. 5) side of the first insulating sheet 66 along the sheet surface. The The metal plate 75 of the present embodiment is approximately the same shape and size as the main block M <b> 1 of the first insulating sheet 66. The material of such a metal plate 75 is not particularly limited as long as it is a metal, but examples thereof include copper and stainless steel as in the first embodiment.

  The second insulating sheet 76 is a flexible resin insulating sheet, and is disposed between the metal plate 75 and the spacer 80. The second insulating sheet 76 has a plurality of through holes 76H penetrating from one surface of the second insulating sheet 76 to the other surface. The protrusions 90 are inserted through the through holes 76H, respectively. As a material of the second insulating sheet 76, a resin such as PET, PI, or PEN can be used as in the first insulating sheet 66. Note that the material of the second insulating sheet 76 may be the same as or different from that of the first insulating sheet 66.

  The second insulating sheet 76 of the present embodiment is composed of a main block M21 and a tail block M22. The main block M21 has substantially the same shape and size as the main block M1 of the first electrode sheet 60, and the second electrode 77 and the through hole 76H are provided on one surface of the main block M31. The tail block M22 is approximately the same shape and size as the tail block M2 of the first electrode sheet 60.

  The second electrode 77 is, for example, a metal printing layer having the same shape and size as the first electrode 67. The second wiring 78 is, for example, a metal printing layer, and electrically connects the second electrode 77 and a terminal (not shown). The second electrode 77 is disposed on the surface of the second insulating sheet 76 on the spacer 80 side.

  The protruding portion 90 is a portion that protrudes from the metal plate 75 to the first electrode sheet 60 side. The shape, arrangement position, and number of the protrusions 90 in the present embodiment are the same as those in the first embodiment. However, the height of the protrusion 90 is determined by the thickness of the first adhesive layer 9 between the first insulating sheet 66 and the spacer 80 and the thickness of the second adhesive layer 10 between the spacer 80 and the second insulating sheet 76. The thickness of the second adhesive layer 10 between the second insulating sheet 76 and the metal plate 75, the thickness of the spacer 80, and the thickness of the second insulating sheet 76 are approximately the same.

  The spacer 80 is interposed between the first electrode sheet 60 and the second electrode sheet 70, and is a flexible resin insulating sheet. Examples of the material of the spacer 80 include resins such as PET, PI, and PEN, as with the first insulating sheet 66 and the second insulating sheet 76. The material of the spacer 80 and the first insulating sheet 66 or the second insulating sheet 76 may be the same or different.

  In addition, the spacer 80 has an opening 80 </ b> H penetrating from one surface side of the spacer 80 to the other surface side. The peripheral shape of the opening 80H is, for example, substantially circular, and the diameter of the opening 80H is larger than the diameter of the first electrode 67.

  Furthermore, the spacer 80 has a slit 80S that communicates the space in the opening 80H and the space outside the load detection sensor 5B. The slit 80 </ b> S becomes an air vent when the spacer 80 is overlapped with the first electrode sheet 60 and the second electrode sheet 70. The air vent means a passage for extracting the air in the opening 80H of the spacer 80 to the outside of the load detection sensor 5B, and corresponds to the exhaust passage SP of the first embodiment.

  The spacer 80 according to this embodiment includes a main block M31 and a tail block M32. The main block M31 is substantially the same shape and size as the main block M1 of the first electrode sheet 6, and an opening 80H and a slit 80S are provided in the main block M31. The tail block M32 is approximately the same shape and size as the tail block M2 of the first electrode sheet 6.

  The spacer 80 is bonded to the one surface side of the second insulating sheet 76 with the second adhesive layer 10. Then, the metal plate 75 is bonded to the other surface side of the second insulating sheet 76 with the second adhesive layer 10 in a state where the protrusions 90 are inserted into the respective through holes 76H of the second insulating sheet 76. . Furthermore, the load detection sensor 5 </ b> B is configured by bonding the first insulating sheet 66 of the first electrode sheet 60 with the first adhesive layer 9 on the side of the spacer 80 opposite to the second electrode sheet 70 side. The

  In the load detection sensor 5B, the first electrode 67 disposed on the surface of the first insulating sheet 66 exposed on one side of the opening 80H of the spacer 80, and the second insulating sheet 76 exposed on the other side of the opening 80H. The second electrodes 77 arranged on the surface of each other face each other. The first electrode 67 and the second electrode 77 facing each other constitute a switch SW.

  Similar to the first embodiment, the first electrode 67 and the second electrode 77 are disposed closer to the center of the opening 80H than the protrusion 90 disposed in the opening 80H of the spacer 80, and a plurality of protrusions 90 are provided. Located inside. That is, the plurality of protrusions 90 are respectively disposed between the inner wall of the opening 80 </ b> H of the spacer 80 and the first electrode 67 and the second electrode 77. The tips of the plurality of protrusions 90 are in contact with the first insulating sheet 66 exposed in the opening 80H of the spacer 80, as in the first embodiment. Note that the first wiring 68 disposed on the surface of the first insulating sheet 66 is disposed so as to pass between the adjacent projecting portions 90 and is not in contact with the projecting portions 90. Similarly, the second wiring 78 disposed on the surface of the second insulating sheet 76 is disposed so as to pass between the protrusions 90 adjacent to each other, and is not in contact with the protrusions 90.

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

  FIG. 6 is a diagram illustrating an on state of the load detection sensor according to the second embodiment. As shown in FIG. 6, the pressing portion PP receives a load and moves downward to contact the surface on the opposite side of the surface on the spacer 80 side of the metal plate 75 of the second electrode sheet 7. The metal plate 75 is pressed. At this time, since the metal plate 75 is supported by a plurality of protrusions 90 disposed in the opening 80H of the spacer 80, the metal plate 75 is bent so that the inner portion of the protrusion 90 in the metal plate 75 enters the opening 80H of the spacer 80. Mu In response to this bending, the second insulating sheet 76 bonded to the metal plate 75 with the second adhesive layer 10 is also bent, so that the second electrode 77 contacts the first electrode 67, and the switch SW of the load detection sensor 5B is Turn on. At this time, the load is detected by a vehicle control unit (not shown) that is electrically connected to the second electrode 77 and the first electrode 67.

  When the metal plate 75 and the second insulating sheet 76 are bent, the air in the opening 80H of the spacer 80 is discharged through the slit 80S. Therefore, it is avoided that the bending of the metal plate 75 and the second insulating sheet 76 is suppressed by the air in the opening 80H of the spacer 80, and the switch SW of the load detection sensor 5B is appropriately turned on.

  As described above, the load detection sensor 5 </ b> B of the present embodiment includes the first electrode sheet 60 having the first electrode 67 and the second electrode sheet 70. The second electrode sheet 70 is overlapped with the first electrode 67 in a direction orthogonal to the sheet surface of the first electrode sheet 60, and is disposed along the sheet surface, and the first electrode sheet than the metal plate 75. It has the 2nd electrode 77 arrange | positioned facing the 1st electrode 67 at 60 side. In addition, the load detection sensor 5B of the present embodiment is interposed between the first electrode sheet 60 and the second electrode sheet 70, and a spacer 80 having an opening 80H between the first electrode 67 and the second electrode 77. The second adhesive layer 10 is provided between the spacer 80 and the second electrode sheet 70.

  In addition to this, the metal plate 75 has a protrusion 90 protruding toward the first electrode sheet 60, and the protrusion 90 is disposed in the opening 80 </ b> H other than the center of the opening 80 </ b> H of the spacer 80. Further, the first electrode 67 and the second electrode 77 are disposed at least on the center side of the opening 80H from the protrusion 90.

  In such a load detection sensor 5B of this embodiment, when the second electrode sheet 70 is pressed from the surface opposite to the surface on the spacer 80 side, the protrusion 90 disposed in the opening 80H of the spacer 80 A metal plate 75 is supported. For this reason, compared with the case where the metal plate 75 is not supported by the protrusion 90, the second electrode sheet 70 is less susceptible to the temperature change of the second adhesive layer 10 as described above in the first embodiment. Become.

  Further, since the metal plate 75 is supported by the protrusions 90, it is difficult for a load to be applied to the second adhesive layer 10, and the second adhesive layer 10 is difficult to creep. Even if the load detecting sensor 5B is pressed for a long time, even if the second adhesive layer 10 creep-deforms, the distance between the first electrode sheet 60 and the second electrode sheet 70 is substantially constant by the protrusion 90. Retained. As a result, a change in load necessary for the first electrode 67 and the second electrode 77 to come into contact with creep deformation is reduced.

  As described above, according to the load detection sensor 5B of the present embodiment, similar to the first embodiment, the first electrode 67 and the second electrode 77 are required to come into contact with a temperature change or a secular change. A change in load can be reduced. In this way, the load detection sensor 5B that can appropriately detect the load is realized.

  Further, the protrusion 90 of the present embodiment is in contact with the first electrode sheet 60 as in the first embodiment. For this reason, compared with the case where the projection part 90 is non-contact with the 1st electrode sheet 60, the metal plate 75 can be supported stably, As a result, the 1st electrode 67 and the 2nd electrode 77 contact. Therefore, the change in load necessary for this can be further reduced.

  The height of the protrusion 90 is determined by the thickness of the first adhesive layer 9 between the substrate 61 and the spacer 80, the thickness of the second adhesive layer 10 between the metal plate 75 and the spacer 80, The thickness is approximately the same as the total thickness of the second insulating sheet 76. For this reason, in the same manner as in the first embodiment, in the direction in which the spacer 80 and the substrate 61 are peeled off and in the direction in which the spacer 80 and the metal plate 75 are peeled off under no load where no load is applied to the load detection sensor 5A. Generation of stress can be suppressed.

  In addition, the number of the protrusions 90 in the present embodiment is plural. Therefore, as in the first embodiment, the metal plate 75 can be supported more stably than in the case where the number of the protrusions 90 is one. As a result, the first electrode 67 and the second electrode can be supported. The load change required for the contact with 77 can be further reduced.

  Further, the first electrode 67 and the second electrode 77 are arranged on the center side of the opening 80H of the spacer 80 with respect to the protrusion 90. For this reason, as in the first embodiment, the first electrode 67 and the second electrode 77 are less likely to be damaged as compared with the case where the first electrode 67 and the second electrode 77 overlap the protrusion 90. Is possible.

  When the protrusion 90 is separated from the inner wall of the opening 80H of the spacer 80, the first adhesive layer 9 and the second adhesive layer 10 are softened by the presence of the load detection sensor 5A in a high temperature environment, and the opening 80H. Even if it flows, the gap between the protrusion 90 and the spacer 80 can be accommodated. Therefore, as in the first embodiment, when the protrusion 90 and the first electrode sheet 60 are not in contact with each other, the softened first adhesive layer 9 and second adhesive layer 10 are not in contact with the protrusion 90 and the first electrode layer 60. Flowing between the electrode sheet 60 is avoided.

  In addition, the second electrode sheet 70 of the present embodiment further includes a second insulating sheet 76 disposed between the metal plate 75 and the spacer 80, and the second electrode 77 has a second insulating sheet. The sheet 76 is disposed on the surface on the spacer 80 side. For this reason, since the insulation of the 2nd electrode 77 is ensured by the 2nd insulating sheet 76, even if static electricity etc. are added to the metal plate 75 from the outside, a load can be detected appropriately, the damage of the 2nd electrode 77, etc. Can also be prevented.

  Further, the second insulating sheet 76 of the present embodiment has a through hole 76H penetrating from one surface of the second insulating sheet 76 to the other surface, and the protrusion 90 is inserted into the through hole 76H. For this reason, the protrusion 90 can not only support the metal plate 75 but also suppress a relative shift in the sheet surface direction between the metal plate 75 and the second insulating sheet 76. Therefore, since it is not necessary to bond the metal plate 75 and the second insulating sheet 76 with the second adhesive layer 10, the second electrode sheet 70 receives the temperature change of the second adhesive layer 10 as described above. The impact can be further reduced.

(3) Modification In the above embodiment, the number of the protrusions 90 is five, but a plurality other than five may be used, or one. However, in order to stably support the metal plate 71 of the first embodiment or the metal plate 75 of the second embodiment, it is preferable that there are three or more.

  In the first embodiment, the tips of the plurality of protrusions 90 are in contact with the substrate 61 of the first electrode sheet 6 exposed in the openings 81 of the spacer 8, but are not in contact with the substrate 61. May be. In the second embodiment, the tips of the plurality of protrusions 90 are in contact with the first insulating sheet 66 of the first electrode sheet 60 exposed at the openings 80H of the spacer 80. However, the first insulating sheet 66 may be non-contact. In order to stably support the metal plate 71 of the first embodiment or the metal plate 75 of the second embodiment, it is preferable that the tips of the plurality of protrusions 90 are in contact with each other.

  Moreover, in the said embodiment, although the shape of the projection part 90 was made into the rod shape, you may make it cyclic | annular. In the case of the projecting portion projecting in a ring shape, the metal plate 71 of the first embodiment or the metal plate 75 of the second embodiment can be stably supported more easily than the projecting portion 90 projecting in a rod shape.

  FIG. 7 is a diagram illustrating a state in which the protrusions of the load detection sensor of the second embodiment are annular and the load detection sensor is viewed in plan from the sheet surface side of the second electrode sheet. As shown in FIG. 7, the annular protrusion 100 has a slit 100 </ b> S for allowing the wiring to pass therethrough. Two slits in the circumferential direction of the annular protrusion 90 are interrupted by the slit 100S. The total length of the interrupted portions along the circumferential direction of the annular protrusion 90 is preferably equal to or less than 1/3 of the entire length of the annular protrusion 90 including the interrupted portion. In addition, the location of the slit 100S may be one location. As described above, the annular protrusion 100 includes a case where the annular protrusion 100 is interrupted at one place or intermittently as long as it extends like a ring.

  Further, in the second embodiment, the first electrode 67 and the second electrode 77 are disposed on the center side of the opening 80H with respect to the protrusion 90 disposed in the opening 80H of the spacer 80, and the plurality of protrusions 90 are formed. Located inside. However, the first electrode 67 and the second electrode 77 may extend from the center side of the opening 80 </ b> H of the spacer 80 to the outside of the protrusion 90.

  FIG. 8 is a cross-sectional view showing the case where the electrode of the load detection sensor of the second embodiment is enlarged from the same viewpoint as FIG. 5, and FIG. 9 shows the sheet surface of the second electrode sheet of the load detection sensor shown in FIG. It is a figure which shows a mode that it planarly viewed from the side. As shown in FIG. 8, the diameters of the first electrode 67 and the second electrode 77 are larger than the diameter of the opening 80H, and the end portions of the first electrode 67 and the second electrode 77 are the spacer 80 and the first insulating sheet 66. It is arranged between. For this reason, the first electrode 67 and the second electrode 77 extend from the center side of the opening 80 </ b> H to the outside of the protrusion 90 with respect to the protrusion 90. The end of the first electrode 67 is disposed between the first insulating sheet 66 of the first electrode sheet 60 and the spacer 80, and the end of the second electrode 77 is the second insulating sheet 76 of the second electrode sheet 7. And the spacer 80. For this reason, even when the thickness of the first electrode 67 or the second electrode 77 varies, the distance between the first electrode 67 and the second electrode 77 can be made substantially constant by the spacer 80.

  Note that the first electrode 67 and the second electrode 77 extend from the center of the opening 80H to the outside of the protrusion 90 with respect to the protrusion 90, but the diameters of the first electrode 67 and the second electrode 77 are It may be smaller than the diameter of the opening 80H. In this way, even if the diameters of the first electrode 67 and the second electrode 77 are large, the protrusion 90 can be brought into contact with the first insulating sheet 66 of the first electrode sheet 60. Accordingly, the metal plate 75 can be stably supported as compared with the case where the protrusion 90 is not in contact with the first electrode sheet 60 as described above. As a result, the first electrode 67 and the second electrode 77 It is possible to further reduce the change in load necessary for the contact.

  By the way, in order to stably support the metal plate 75 as described above, it is preferable that the protrusion 90 be in contact with the first insulating sheet 66. Therefore, when the protrusion 90 is in contact with the first insulating sheet 66 and the diameters of the first electrode 67 and the second electrode 77 are larger than the diameter of the opening 80H, the protrusion 90 has the first electrode 67 and the second electrode 67. Insulated from the electrode 77. For example, as shown in FIGS. 8 and 9, the first electrode 67 and the second electrode 77 are provided with a through hole OP penetrating along the thickness direction, and the protrusion 90 is disposed in the through hole OP. The In this way, even if the diameter of the first electrode 67 is large, the protrusion 90 can be made non-contact with the first electrode 67. Accordingly, it is possible to prevent the first electrode 67 from being damaged due to rubbing or abrasion between the protrusion 90 and the first electrode 67. Further, it is possible to prevent the scraping of the first electrode 67 from being generated due to rubbing between the protrusion 90 and the first electrode 67. Furthermore, it is not necessary to consider the thickness variation of the first electrode 67, and as a result, the change in load necessary for the first electrode 67 and the second electrode 77 to contact each other can be further reduced.

  The load detection sensor of the present invention has applicability as long as the presence / absence of a load on a detection target to be detected is detected. For example, the form which arrange | positions a load detection sensor under the seat cushion of vehicles, such as a motor vehicle, or a bed for nursing care is mentioned. In such a configuration, the load detection sensor can detect a load in response to a pressure from the seat cushion, and information indicating whether a person is present on the seat cushion is obtained based on a detection result of the load detection sensor. Can do. 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 by giving examples and comparative examples related to the above embodiment. However, the present invention is not limited to the following examples and comparative examples.

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

  As a load detection sensor of Comparative Example 1, a load detection sensor having a configuration in which the protrusion 90 and the plurality of through holes 76H of the second insulating sheet 76 are omitted from the load detection sensor 5B in the second embodiment. As a load detection sensor of Example 1, a load detection sensor corresponding to the load detection sensor 5B of the second embodiment was prepared. As a load detection sensor of Example 2, a load detection sensor having different opening diameters of spacers in the load detection sensor of Example 1 was prepared.

  The conditions of the constituent elements of the load detection sensor of Comparative Example 1, the load detection sensor of Example 1, and the load detection sensor of Example 2 were as follows. That is, the first insulating sheet was a 75 μm thick sheet made of PET, and the second insulating sheet was a 50 μm thick sheet made of PET. The spacer was a sheet of 50 μm thickness made of PET, and the metal plate was a sheet of 0.1 mm thickness made of SUS301. The adhesive layer for bonding the first insulating sheet and the spacer is an acrylic adhesive layer having a thickness of 25 μm, the adhesive layer for bonding the second insulating sheet and the spacer is an acrylic adhesive layer having a thickness of 25 μm, and a metal plate The adhesive layer for bonding the second insulating sheet was an acrylic adhesive layer having a thickness of 24 μm.

  Furthermore, the load detection sensor of Comparative Example 1, the load detection sensor of Example 1, the diameter of each spacer of the load detection sensor of Example 2, and the load detection sensor of Example 1 and the load detection sensor of Example 2, respectively. The number of protrusions and the arrangement diameter of the protrusions are shown in FIG. In addition, the arrangement | positioning diameter of a projection part is a diameter of the circle | round | yen which passes along the central axis along the height direction of a rod-shaped projection part, respectively.

(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 in each of the temperature environments of −40 ° C., 25 ° C., and 85 ° C., and the load detection sensor is the second. The load (on load) applied when the electrode sheet was pressed and the pair of electrodes contacted each other was measured. In addition, in FIG. 10, with respect to the on load measured in the temperature environment of 25 degreeC, the increase / decrease of the on load measured in the temperature environment of -40 degreeC and the on load measured in the temperature environment of 85 degreeC in percent. Represents.

  As shown in FIG. 10, compared to Comparative Example 1 having no protrusion, Example 1 and Example 2 provided with the protrusion change to 85 ° C. even when the temperature changes to −40 ° C. on the basis of normal temperature. However, the on-load variation at that temperature is small. That is, it has been found that if there is a protrusion, the load can be detected in the same manner as in the normal temperature environment, 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 in an air temperature environment of 80 ° C., and the load sensor is 144 from the second electrode sheet side at a pressure of 20 N. Pressed for hours. Then, the on load at normal temperature was measured, and the change rate with respect to the on load at normal 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. 10, compared to Comparative Example 1 having no protrusions, Example 1 and Example 2 provided with the protrusions change the on-load even when pressed for a long time in a high temperature environment. The rate is getting smaller. That is, it has been found that if there is a protrusion, a load can be detected in the same manner as in a normal temperature environment even if the projection is kept pressed for a long time in a high temperature environment.

5A, 5B ... load detection sensors 6, 60 ... first electrode sheet 7, 70 ... second electrode sheet 8, 80 ... spacer 9 ... first adhesive layer 10 ... second Adhesive layer 61... Substrate 62, 67... First electrode 66... First insulating sheet 71, 75... Metal plate 72, 77. , 100 ... protrusion

Claims (10)

A first electrode sheet having a first electrode;
A metal plate that overlaps the first electrode in a direction orthogonal to the sheet surface of the first electrode sheet and is disposed along the sheet surface, and is disposed on a part of the metal plate that faces the first electrode, or A second electrode sheet having a second electrode disposed opposite to the first electrode on the first electrode sheet side than the metal plate;
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 adhesive layer disposed between the spacer and the second electrode sheet;
With
The metal plate has a protrusion protruding to the first electrode sheet side,
The protrusion is disposed in a region other than the center of the opening in the opening,
At least a part of the first electrode and the second electrode is disposed closer to the center of the opening than the protrusion. The load detection sensor according to claim 1, wherein the protrusion is in contact with the first electrode sheet. The load detection sensor according to claim 1, wherein the number of the protrusions is plural. The load detection sensor according to claim 1, wherein the protrusion is annular. The load detection sensor according to any one of claims 1 to 4, wherein the metal plate is directly bonded to a spacer through the adhesive layer. The second electrode sheet further includes an insulating sheet disposed between the metal plate and the spacer,
The load detection sensor according to claim 1, wherein the second electrode is disposed on a surface of the insulating sheet on the spacer side. The insulating sheet has a through-hole penetrating from one surface to the other surface of the insulating sheet,
The load detection sensor according to claim 6, wherein the protrusion is inserted through the through hole. The load detection sensor according to any one of claims 1 to 7, wherein the first electrode and the second electrode are disposed only on a center side of the opening with respect to the protrusion. The first electrode and the second electrode extend from the center side of the opening to the outside of the protrusion, rather than the protrusion.
The first electrode and the second electrode are provided with a through hole penetrating along the thickness direction,
The load detection sensor according to claim 1, wherein the protrusion is disposed in the through hole. The load detection sensor according to claim 9, wherein the first electrode and the second electrode are larger than the opening.

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