JP2019186081A - Load detection sensor - Google Patents

Abstract

To provide a load detection sensor capable of detecting appropriately a load.SOLUTION: A load detection sensor 30 comprises: a first insulation sheet 41 in which a first electrode 50 is provided; a second insulation sheet 61 in which a second electrode 70 opposite to the first electrode 50 is provided; a spacer 80 interposed between the first insulation sheet 41 and the second insulation sheet 61, and in which an opening 80H is formed between the first electrode 50 and the second electrode 70; a metal plate 100 that is arranged at a surface side inverted from a surface at a spacer 80 side in the first insulation sheet 41, and overlaps with the first electrode 50 and the second electrode 70; and a metal adhesion layer 90 of which at least a part is arranged so as to overlap with the first electrode 50 between the metal plate 100 and the first insulation sheet 41, and in which the metal plate 100 is brough into contact with the first insulation sheet 41. In the first insulation sheet 41, a penetration hole 41H overlapping with a part of the opening 80H of the spacer 80 is formed.SELECTED DRAWING: Figure 3

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 in Patent Document 1 below. A pair of films of the load detection sensor described in the following Patent Document 1 are bonded together with an adhesive disposed other than between the electrodes facing each other.

JP 09-315199 A

  However, a resin film generally tends to bend with a weak force due to a decrease in strength when the temperature rises. Therefore, when the load detection sensor described in Patent Document 1 is placed in an environment where the temperature is high, such as in a car of a car under hot weather, the strength of the resin film may be reduced. In this case, even when a load that is lighter than a normal human load is applied to the seat cushion, there is a possibility of erroneous detection as a load caused by the seating.

  In order to suppress the erroneous detection as described above, a metal plate may be attached so as to overlap the pair of electrodes on the surface of the one resin film opposite to the electrode side. Since the elasticity of the metal plate does not change so much in the temperature environment inside the vehicle, it is possible to suppress the bending of one resin film at the time of load detection by the metal plate according to the environmental temperature.

  However, the adhesive layer for adhering the metal plate generally tends to soften in a high temperature environment and harden in a low temperature environment. For this reason, in a high temperature environment, there is a concern that the load necessary for the electrodes provided on the respective films to come into contact with each other is reduced due to the softening of the adhesive layer. On the other hand, in a low temperature environment, there is a concern that the load necessary for the electrodes provided on the respective films to be in contact with each other is increased due to the hardening of the adhesive layer. That is, there is a concern that an error may occur in the load when the load detection sensor is turned on according to the environmental temperature where the load detection sensor is placed.

  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 according to the present invention includes a first insulating sheet on which a first electrode is provided, a second insulating sheet on which a second electrode facing the first electrode is provided, and the first insulation. A spacer interposed between the sheet and the second insulating sheet and having an opening formed between the first electrode and the second electrode; and a surface opposite to the spacer side surface of the first insulating sheet A metal plate disposed on a surface side and overlapping the first electrode and the second electrode; and at least a portion overlapping the first electrode between the metal plate and the first insulating sheet; And an adhesive layer for adhering the plate to the first insulating sheet, wherein the first insulating sheet is formed with a through hole that overlaps a part of the opening of the spacer.

  In such a load detection sensor, when the metal plate is pressed, the metal plate is bent, and the first insulating sheet bonded to the metal plate is bent according to the bending so as to enter the opening of the spacer. As a result, the first electrode and the second electrode come into contact with each other, or the resistance value or capacitance value between the electrodes changes, and the load detection sensor is turned on to detect the load.

  The insulating sheet is generally a resin sheet, and the resin sheet tends to bend with a weak force due to a decrease in strength under a high temperature environment as described above. In the load detection sensor of the present invention, as described above, at least a part of the adhesive layer that adheres the metal plate to the first insulating sheet is disposed so as to overlap the first electrode. At least a part of the portion to be provided is bonded to the metal plate. For this reason, when the metal plate is pressed, the portion where the first electrode is provided can bend following the metal plate. Further, when the metal plate returns to the position when the metal plate is not pressed and is not pressed, the metal plate can return to the position where the first electrode in the first insulating sheet is provided. Here, since the elasticity of the metal plate is less likely to change according to the environmental temperature than the insulating sheet, it is possible to suppress the bending of the first insulating sheet during load detection from changing according to the environmental temperature.

  Further, as described above, the adhesive layer tends to be softened under a high temperature environment and hardened under a low temperature environment. In the load detection sensor of the present invention, as described above, the first insulating sheet is formed with a through hole that overlaps a part of the opening of the spacer. For this reason, the 1st insulating sheet and adhesive layer located inside the opening of a spacer can be reduced compared with the case where the through-hole which overlaps with a part of opening of a spacer is not formed in a 1st insulating sheet. Therefore, it is possible to suppress a change in the load necessary for the first electrode and the second electrode to contact each other due to the strength change of the first insulating sheet and the adhesive layer due to the change of the environmental temperature. Thus, the load detection sensor of the present invention can detect the load appropriately.

  The through hole of the first insulating sheet is formed in a region other than the center of the opening of the spacer, and the first electrode includes a central electrode portion located inside the opening of the spacer, the central electrode portion and the It is preferable that the second electrode overlaps the center of the opening of the spacer, and at least a part of the adhesive layer is overlapped with the central electrode portion.

  In this load detection sensor, as described above, the center electrode portion and the second electrode overlap each other with the center of the opening of the spacer, and at least a part of the adhesive layer overlaps with the center electrode portion. For this reason, at least a part of the portion where the central electrode portion is provided in the first insulating sheet is bonded to the metal plate, and the portion where the central electrode portion is provided can bend following the metal plate. By the way, the amount of deformation of the first insulating sheet that is bent so as to enter the opening of the spacer according to the bending of the metal plate is likely to increase as it is closer to the center of the opening. For this reason, a 1st insulating sheet tends to approach a 2nd insulating sheet from the site | part close | similar to the center of the opening of a spacer. Therefore, compared with the case where the center electrode portion and the second electrode of the first electrode do not overlap with the center of the opening of the spacer, the first electrode and the second electrode can be properly contacted, and the load is detected appropriately. Can do.

  When the central electrode portion is located inside the opening of the spacer, it is preferable that the through hole of the first insulating sheet surrounds at least a part of the outer periphery of the central electrode portion inside the opening of the spacer.

  With such a configuration, at least a part of the outer periphery of the central electrode portion is surrounded by a region where the first insulating sheet and the metal plate are not bonded inside the opening of the spacer. For this reason, when the 1st insulating sheet bends so that a center electrode part may approach the 2nd electrode compared with the case where the perimeter of a center electrode part is surrounded by the field where the 1st insulating sheet and a metal plate are pasted up. Further, it is possible to suppress the influence of the strength change of the adhesive layer due to the change of the environmental temperature. Therefore, it is possible to suppress a change in load necessary for the first electrode and the second electrode to contact with each other according to a change in the environmental temperature.

  When the central electrode part is positioned inside the opening of the spacer, the first electrode further includes an outer electrode part surrounding at least a part of the outer periphery of the central electrode part, and at least a part of the outer electrode part is It is preferable to be located outside the opening of the spacer.

  The electrode provided on the insulating sheet may be formed of a metal printing layer, and the thickness of the metal printing layer may vary depending on manufacturing reasons. For this reason, when the 1st electrode is located inside the opening of a spacer, the distance between the 1st electrode and the 2nd electrode tends to change according to the variation in the thickness of a metal printing layer. However, in this load detection sensor, as described above, at least a part of the outer electrode portion of the first electrode is located outside the opening of the spacer. For this reason, at least a part of the outer electrode portion is in contact with the surface on the first insulating sheet side of the spacer, and the surface on the second electrode side of the first electrode is generally located on the surface on the first insulating sheet side of the spacer. become. For this reason, it can suppress that the distance between the center electrode part of a 1st electrode and a 2nd electrode changes according to the dispersion | variation in the thickness of a metal printing layer, and the distance between a center electrode part and a 2nd electrode Can be kept substantially constant. Therefore, it can suppress that a load required in order for a 1st electrode and a 2nd electrode to contact changes.

  When the central electrode portion is located inside the opening of the spacer, the second electrode may not overlap the first electrode other than the central electrode portion inside the opening of the spacer.

  As described above, since the strength of the first insulating sheet tends to decrease in a high temperature environment, the portion of the first insulating sheet that is not bonded to the metal plate is subject to creep deformation or slack to the metal plate. May be bent toward the second insulating sheet. However, as described above, at least a part of the portion of the first insulating sheet where the central electrode portion is provided is bonded to the metal plate. Furthermore, in this load detection sensor, as described above, the second electrode does not overlap the first electrode other than the central electrode portion inside the opening of the spacer. For this reason, even if the portion of the first insulating sheet that is not bonded to the metal plate is bent toward the second insulating sheet, the portion where the central electrode portion is provided is suppressed from approaching the second electrode. It can suppress that parts other than the center electrode part in a 1st electrode contact a 2nd electrode. Therefore, erroneous detection of a load due to creep deformation of the first insulating sheet, loosening of the first insulating sheet with respect to the metal plate, or the like can be suppressed.

  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 unit of 1st Embodiment. It is sectional drawing which shows a mode that the load detection sensor unit was attached to S spring of a seat apparatus. It is an exploded view which shows the structure of a load detection sensor. It is a figure which shows the cross section of the load detection sensor in IV-IV of FIG. It is a figure which shows the state with which the 1st insulating sheet and the spacer were overlaid. It is a figure which shows the state with which the 2nd insulating sheet and the spacer were overlaid. It is a figure which shows the ON state of a load detection sensor unit. It is an exploded view which shows the structure of the load detection sensor of 2nd Embodiment.

  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.

(First embodiment)
FIG. 1 is an exploded view showing a configuration of a load detection sensor unit of the present embodiment, and FIG. 2 is a cross-sectional view showing a state in which the load detection sensor unit is attached to an S spring of a seat device. In FIG. 2, the description of the inside of the load detection sensor 30 is omitted in order to avoid complication of the drawing. As shown in FIGS. 1 and 2, the load detection sensor unit 1 includes a support plate 10, an upper case 20, and a load detection sensor 30 as main components.

  The support plate 10 includes a placement portion 11 on which the load detection sensor 30 is placed, and a pair of hook portions 12 coupled to the placement portion 11. The mounting unit 11 includes a wide main block mounting unit 11m and a tail block mounting unit 11t extending from the main block mounting unit 11m and having a width narrower than the main block mounting unit 11m. In the present embodiment, the hook portion 12 is connected to the main block placement portion 11m. Moreover, in this embodiment, the mounting part 11 and a pair of hook part 12 are integrally shape | molded by bending a metal plate. In addition, the plate | board thickness of the support plate 10 shall be 0.8 mm, for example.

  The main block 30m of the load detection sensor 30 is disposed on the surface of the main block placement portion 11m facing the seat cushion SC. Further, as shown in FIG. 1, a plurality of circular through holes 13 penetrating the support plate 10 are formed in the main block mounting portion 11 m, and a plurality of generally rectangular case stop openings 14 are formed. Yes.

  In addition, as shown in FIG. 2, the main block mounting portion 11m is provided between two S springs BN facing each other among a plurality of S springs BN stretched side by side in the opening of the seat frame in the vehicle seat device. The size is such that it can be placed. The S spring BN is a spring meandering in an S shape.

  The tail block placement portion 11t has a substantially rectangular shape, and extends in a direction substantially perpendicular to the direction connecting the pair of hook portions 12 when the main block placement portion 11m is viewed in plan. The tail block 30t of the load detection sensor 30 is disposed on the surface of the tail block placement portion 11t that faces the seat cushion SC. In the present embodiment, the width in the direction perpendicular to the extending direction of the tail block mounting portion 11t is smaller than the width of the tail block 30t of the load detection sensor 30, and the extending direction of the tail block mounting portion 11t. Is made smaller than the length of the tail block 30 t of the load detection sensor 30.

  The upper case 20 is a member that covers the main block 30m placed on the main block placement portion 11m of the placement portion 11 and protects the switch SW and the like of the main block 30m. Further, as shown in FIG. 2, the upper case 20 is also a pressing member that presses the switch SW of the load detection sensor 30 when pressed by the seat cushion SC.

  The upper case 20 has a top wall 21 and a frame wall 24. In the present embodiment, the top wall 21 is a plate-like member that is generally circular. The frame wall 24 of the upper case 20 is divided into a plurality of parts and connected to the top wall 21 along the outer periphery of the top wall 21. A hook piece 23 is connected to the top wall 21 between each of the frame walls 24 divided into a plurality of parts. Each hook piece 23 is configured to be fitted into the case stop opening 14 in the main block placement portion 11 m of the support plate 10. As each hook piece 23 is fitted in each case stop opening 14, the relative movement of the support plate 10 and the upper case 20 in the mounting surface direction of the main block mounting portion 11 m is restricted.

  The top wall 21 of the upper case 20 is provided with a pressing portion 22 that protrudes from the bottom surface on the side facing the mounting portion 11 of the support plate 10. The front end of the pressing portion 22 has a planar shape. In addition, the front-end | tip of the press part 22 may be made into a convex curved surface shape. In the case of the present embodiment, when the upper case 20 covers the load detection sensor 30 placed on the placement unit 11 and each hook piece 23 is fitted in each case stop opening 14, the tip of the pressing unit 22. Is in contact with the load detection sensor 30, but may not be in contact.

  As shown in FIG. 2, the upper surface 21S of the top wall 21 of the upper case 20 is separated from the lower surface of the seat cushion SC when the load detection sensor unit 1 is attached to the pair of S springs BN. You may do it. The upper surface 21S has a planar shape. The upper surface 21S is a pressure receiving surface that receives pressure from the seat cushion SC, and the area of the upper surface 21S is larger than the area of the portion of the pressing portion 22 that contacts the load detection sensor 30.

  The upper case 20 is formed of a material harder than the seat cushion SC. Therefore, the pressing part 22 which is a part of the upper case 20 is also formed of a material harder than the seat cushion SC. Since the seat cushion SC is generally made of a foamed urethane resin, examples of the material of the upper case 20 include polycarbonate (PC), polybutylene terephthalate (PBT), polyamide (PA), phenol resin, and epoxy resin. And the like.

  The load detection sensor 30 includes a substantially rectangular main block 30m and a tail block 30t connected to the main block 30m and narrower than the main block 30m. A switch SW is provided in the main block 30m. A through hole 36 is formed near each vertex of the main block 30m. These through holes 36 are formed in a positional relationship overlapping with the plurality of through holes 13 formed in the mounting portion 11 of the support plate 10. The tail block 30t is connected to the main block 30m and extends away from the main block 30m.

  FIG. 3 is an exploded view showing the configuration of the load detection sensor. As shown in FIG. 3, the load detection sensor 30 according to the present embodiment includes a first electrode sheet 40, a second electrode sheet 60, a spacer 80, a metal plate 100, and a metal adhesive layer 90 as main components.

  The first electrode sheet 40 includes a first insulating sheet 41 and a first conductive layer 42.

  The first insulating sheet 41 is a flexible resin insulating sheet. The first insulating sheet 41 includes a main block 41m and a tail block 41t connected to the main block 41m. The main block 41m includes a substantially circular central block 43, an annular outer block 44 surrounding the outer periphery of the central block 43, and the central block 43 provided between the central block 43 and the outer block 44. The connecting block portion 45 is connected to the outer block portion 44. The outer block 44 is formed in an annular shape having an outer peripheral edge that is substantially square and an inner peripheral edge that is substantially circular. A through hole 41H is formed between the central block portion 43 and the outer block portion 44. The through hole 41H substantially surrounds the outer periphery of the central block portion 43 in plan view. Further, a through hole 46 is formed in the outer block portion 44. The through hole 46 is a part of the through hole 36 of the load detection sensor 30. The tail block 41t has a shape in which the tip portion opposite to the main block 41m is narrower than other portions of the tail block 41t. Examples of the material of the first insulating sheet 41 include resins such as polyethylene terephthalate (PET), polyimide (PI), and polyethylene naphthalate (PEN).

  The first conductive layer 42 includes a first electrode 50, a first terminal 51, and a first wiring 52, and is provided on one surface of the first insulating sheet 41. In FIG. 3, for easy understanding, the first conductive layer 42 and the first insulating sheet 41 are described in an exploded manner, and the arrangement position of the first conductive layer 42 is indicated by a broken line on the first insulating sheet 41. .

  The first electrode 50 is provided approximately at the center of the main block 41m. The first electrode 50 is made of a conductor layer, for example, a metal printing layer. The first electrode 50 of the present embodiment includes a substantially circular central electrode portion 53, an outer electrode portion 54 that surrounds the outer periphery of the central electrode portion 53, and a generally circular annular outer electrode portion 54, and the central electrode portion 53 and the outer electrode portion 54. And a connecting electrode portion 55 connected to the central electrode portion 53 and the outer electrode portion 54. An opening 50 </ b> H is formed between the central electrode portion 53 and the outer electrode portion 54. The opening 50H substantially surrounds the outer periphery of the central electrode portion 53 in plan view, and the shape of the edge of the opening 50H is the same as the shape of the edge of the through hole 41H of the first insulating sheet 41.

  As shown by a broken line in FIG. 3, the central electrode portion 53 of the first electrode 50 is a central block of the first insulating sheet 41 in a state where the first conductive layer 42 is disposed on one surface of the first insulating sheet 41. Located on part 43. Further, the outer electrode portion 54 of the first electrode 50 is located on the outer block portion 44 of the first insulating sheet 41, and the connecting electrode portion 55 of the first electrode 50 is located on the connecting block portion 45 of the first insulating sheet 41. To do. The edge of the opening 50 </ b> H of the first electrode 50 and the edge of the through hole 41 </ b> H of the first insulating sheet 41 substantially coincide with each other. That is, the edge of the central electrode part 53 substantially coincides with the edge of the central block part 43 of the first insulating sheet 41, the edge of the connection electrode part 55 substantially coincides with the edge of the connection block part 45 of the first insulation sheet 41, The inner peripheral edge of the outer electrode portion 54 substantially coincides with the outer peripheral edge of the outer block portion 44 of the first insulating sheet 41. As described above, the opening 50H of the first electrode 50 substantially surrounds the outer periphery of the central electrode portion 53 in plan view. For this reason, the through hole 41 </ b> H of the first insulating sheet 41 substantially surrounds the outer periphery of the central electrode portion 53 in a plan view. The first electrode 50 does not overlap with the through hole 41H of the first insulating sheet 41 in plan view. Note that the outer electrode portion 54 of the first electrode 50 only needs to surround at least a part of the outer periphery of the central electrode portion 53, and the outer electrode portion 54 may be formed discontinuously in the circumferential direction.

  The first terminal 51 is made of a conductor layer, for example, a substantially rectangular metal printing layer. The first terminal 51 is provided at the tip portion of the tail block 41t. The first electrode 50 and the first terminal 51 are electrically connected to each other via the first wiring 52.

  The second electrode sheet 60 includes a second insulating sheet 61 and a second conductive layer 62.

  Similar to the first insulating sheet 41, the second insulating sheet 61 is a resin insulating sheet. The second insulating sheet 61 has the same outer shape as that of the main block 61m of the first insulating sheet 41 and the same shape as the tail block 41t of the first insulating sheet 41 connected to the main block 61m. The tail block 61t. However, when the first insulating sheet 41 and the second insulating sheet 61 are overlapped, the tip portion of the tail block 41t of the first insulating sheet 41 and the tip portion of the tail block 61t of the second insulating sheet 61 overlap each other. It is made not to become. A through hole 66 is formed in the main block 61m. The through hole 66 is a part of the through hole 36 of the load detection sensor 30, similarly to the through hole 46 of the first insulating sheet 41. An air vent 63 is formed near the center of the tail block 61t. In the present embodiment, the thickness of the second insulating sheet 61 is larger than the thickness of the first insulating sheet 41. Examples of the material of the second insulating sheet 61 include the same material as the material of the first insulating sheet 41. The material of the second insulating sheet 61 and the material of the first insulating sheet 41 are different even if they are the same. May be.

  The second conductive layer 62 includes the second electrode 70, the second terminal 71, and the second wiring 72, and is provided on one surface of the second insulating sheet 61. One surface of the second insulating sheet 61 is a surface facing one surface of the first insulating sheet 41 on which the first conductive layer 42 is provided. In FIG. 3, for easy understanding, the second conductive layer 62 and the second insulating sheet 61 are disassembled and described, and the arrangement position of the second conductive layer 62 is indicated by a broken line on the second insulating sheet 61. .

  The second electrode 70 is provided approximately at the center of the main block 61 m of the second insulating sheet 61. Similar to the first electrode 50, the second electrode 70 is composed of a conductor layer, for example, a substantially circular metal printing layer. The second terminal 71 is made of a conductor layer, for example, a substantially rectangular metal printing layer. The second terminal 71 is provided at the tip portion of the tail block 61t. The second electrode 70 and the second terminal 71 are electrically connected to each other via the second wiring 72. In addition, as mentioned above, when the 1st insulating sheet 41 and the 2nd insulating sheet 61 are piled up, the front-end | tip part of each insulating sheet does not mutually overlap. For this reason, the first terminal 51 and the second terminal 71 are exposed without being positioned between the first insulating sheet 41 and the second insulating sheet 61.

  The spacer 80 is disposed between the first insulating sheet 41 and the second insulating sheet 61 and is a flexible resin insulating sheet. The spacer 80 includes a main block 80m and a tail block 80t connected to the main block 80m. The outer shape of the main block 80m is the same as the outer shape of the main blocks 41m and 61m of the first insulating sheet 41 and the second insulating sheet 61. A through hole 86 is formed in the main block 80 m of the spacer 80 in the same manner as the main block 41 m of the first insulating sheet 41 and the main block 61 m of the second insulating sheet 61. The through hole 86 is a part of the through hole 36 of the load detection sensor 30. As a material of such a spacer 80, the same material as the 1st insulating sheet 41 and the 2nd insulating sheet 61 can be mentioned. The material of the spacer 80 may be the same as or different from the material of the first insulating sheet 41 or the second insulating sheet 61.

  A substantially circular opening 80H is formed near the center of the main block 80m of the spacer 80. In addition, a slit 81 is formed in the spacer 80. The slit 81 extends from the opposite side of the tail block 70t to the main block 80m side to the opening 80H. Accordingly, the slit 81 communicates with the opening 80H.

  FIG. 4 is a cross-sectional view of the load detection sensor taken along line IV-IV in FIG. 3, and is a cross-sectional view across the opening 80 </ b> H of the spacer 80. As shown in FIG. 4, resin adhesive layers 89 that are bonded to the first insulating sheet 41 and the second insulating sheet 61 are disposed on both surfaces of the spacer 80. This resin adhesive layer 89 is omitted in FIG. 3 in order to avoid complication of the drawing. The resin adhesive layer 89 is not particularly limited as long as the first insulating sheet 41 and the spacer 80 and the second insulating sheet 61 and the spacer 80 are bonded together. Further, the resin adhesive layer 89 may be disposed on the entire surface of the first insulating sheet 41 and the entire surface of the second insulating sheet 61, or may be disposed on a part of these surfaces. The material of the resin adhesive layer 89 may be the same as the material of the metal adhesive layer 90 described later. The resin adhesive layer 89 is provided with a through hole similar to the through hole 86 of the spacer 80.

  FIG. 5 is a view showing a state in which the first insulating sheet and the spacer are overlapped, and is a plan view seen from the spacer 80 side. As shown in FIG. 5, when the first insulating sheet 41 and the spacer 80 are overlapped and the first insulating sheet 41 is viewed in plan, the central electrode portion 53 of the first electrode 50 and a part of the connecting electrode portion 55 are spacers. The outer electrode portion 54 is located outside the opening 80 </ b> H of the spacer 80. Further, as described above, the edge of the opening 50H of the first electrode 50 and the edge of the through hole 41H of the first insulating sheet 41 substantially coincide with each other. For this reason, the through hole 41H of the first insulating sheet 41 overlaps a part of the opening 80H of the spacer 80 in a plan view. That is, the first insulating sheet 41 is formed with a through hole 41H that overlaps a part of the opening 80H of the spacer 80 in plan view. Further, the through hole 41H of the first insulating sheet 41 is formed in a region other than the center 80c of the opening 80H of the spacer 80 in a plan view, and the central electrode portion 53 of the first electrode 50 is formed of the opening 80H of the spacer 80. It overlaps the center 80c. Further, as described above, the through hole 41 </ b> H of the first insulating sheet 41 substantially surrounds the outer periphery of the central electrode portion 53. For this reason, the through hole 41H of the first insulating sheet 41 substantially surrounds the outer periphery of the central electrode portion 53 inside the opening 80H of the spacer 80 in plan view.

  FIG. 6 is a view showing a state in which the second insulating sheet and the spacer are overlapped, and is a plan view seen from the spacer 80 side. As shown in FIG. 6, the second insulating sheet 61 and the spacer 80 are overlapped, and when the second insulating sheet 61 is viewed in plan, the edge of the second electrode 70 is located outside the opening 80 </ b> H of the spacer 80. That is, the second insulating sheet 61 side of the opening 80H of the spacer 80 is covered with the second electrode 70, and a part of the second electrode 70 is located outside the opening 80H of the spacer 80. Further, the second electrode 70 overlaps the center 80c of the opening 80H of the spacer 80. Further, the air vent 63 of the second insulating sheet 61 overlaps the slit 81 of the spacer 80.

  As shown in FIG. 3, the metal plate 100 is disposed on the surface side of the first insulating sheet 41 opposite to the surface on the spacer 80 side. The outer shape of the metal plate 100 is the same as the outer shape of the outer block portion 44 of the first insulating sheet 41. A through hole 106 is formed in the metal plate 100. The through hole 106 is a part of the through hole 36 of the load detection sensor 30. Examples of the material of the metal plate 100 include copper and stainless steel.

  The metal plate 100 is bonded to the first insulating sheet 41. Specifically, the metal plate 100 has a spacer 80 in the main block 41m of the first insulating sheet 41 by the metal adhesive layer 90 disposed between the metal plate 100 and the main block 41m of the first insulating sheet 41. Bonded to the opposite surface to the side surface. That is, the metal adhesive layer 90 is an adhesive layer that bonds the first insulating sheet 41 and the metal plate 100 together. Examples of the metal adhesive layer 90 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 for the metal adhesive layer 90 include thermoplastic resins, thermosetting resins, and photo-curing resins. In addition, as said adhesive, a silicon-type adhesive, a urethane type adhesive, an acrylic adhesive, etc. are mentioned, for example. Here, it is preferable that the glass transition point Tg of the adhesive layer 90 for metals is 85 degreeC or more. When the glass transition point Tg is 85 ° C. or more, the metal adhesive layer 90 is less likely to flow even in an environment where the temperature is high, such as in a car under hot weather. For this reason, erroneous detection of the load due to the flow of the metal adhesive layer 90 can be suppressed.

  The shape of the metal adhesive layer 90 according to this embodiment in plan view is the same as the shape of the main block 41 m of the first insulating sheet 41. Specifically, the metal adhesive layer 90 includes a substantially circular central adhesive portion 93, an annular outer adhesive portion 94 that surrounds the outer periphery of the central adhesive portion 93, and the central adhesive portion 93 and the outer adhesive portion 94. It comprises a connecting adhesive portion 95 provided and connected to the central adhesive portion 93 and the outer adhesive portion 94. An opening 90H is formed between the center adhesive portion 93 and the outer adhesive portion 94. The opening 90H substantially surrounds the outer periphery of the central adhesive portion 93 in plan view, and the shape of the edge of the opening 90H is the same as the shape of the edge of the through hole 41H of the first insulating sheet 41. A through hole 96 is formed in the outer adhesive portion 94. The through hole 96 is a part of the through hole 36 of the load detection sensor 30.

  The main block 41 m of the first insulating sheet 41 is covered with the metal plate 100 in a state where the metal plate 100 is bonded to the first insulating sheet 41 by the metal adhesive layer 90. For this reason, the metal plate 100 side of the through hole 41 </ b> H of the first insulating sheet 41 is covered with the metal plate 100.

  When the metal adhesive layer 90 is viewed in plan, the central adhesive portion 93 and the central block portion 43 of the first insulating sheet 41 overlap each other, the outer adhesive portion 94 and the outer block portion 44 of the first insulating sheet 41 overlap each other, The connection adhesive part 95 and the connection block part 45 of the first insulating sheet 41 overlap each other. Then, the central block portion 43, the outer block portion 44, and the connection block portion 45 in the first insulating sheet 41 are bonded to the metal plate 100. For this reason, a part of the metal adhesive layer 90 overlaps the first electrode 50 in a plan view, and the outer periphery of the center electrode portion 53 is formed by the first insulating sheet 41 and the metal plate 100 inside the opening 80H of the spacer 80. It is generally surrounded by a non-bonded area. It should be noted that at least a part of the metal adhesive layer 90 only has to overlap the first electrode 50 in plan view. Further, the metal adhesive layer 90 is preferably not located inside the through hole 41H of the first insulating sheet 41 when viewed in plan.

  As described above, the first insulating sheet 41 and the metal plate 100 are bonded by the metal adhesive layer 90, and the first insulating sheet 41 is bonded to one surface side of the spacer 80 by the resin adhesive layer 89. Further, the load detection sensor 30 is configured by adhering the second insulating sheet 61 to the other surface side of the spacer 80 by the adhesive layer 89 for resin.

  Therefore, in this load detection sensor 30, the respective through holes 46, 66, 86, 96, 106 overlap each other to form the through hole 36. In addition, as described above, the central electrode portion 53 of the first electrode 50 and a part of the connection electrode portion 55 are located inside the opening 80H of the spacer 80, and the second insulating sheet 61 side of the opening 80H of the spacer 80 is Covered by the second electrode 70. Therefore, the central electrode portion 53 of the first electrode 50 and the second electrode 70 face each other through the opening 80H of the spacer 80. That is, the spacer opening 80 </ b> H is formed between the first electrode 50 and the second electrode 70. The center electrode portion 53 and the second electrode 70 of the first electrode 50 constitute a switch SW. Further, since the metal plate 100 covers the main block 41m of the first insulating sheet 41 as described above, the metal plate 100 overlaps the first electrode 50 and the second electrode 70 in a plan view, and the first insulating sheet 41 The through hole 41H is covered. Further, as described above, the outer electrode portion 54 of the first electrode 50 located outside the opening 80 </ b> H of the spacer 80 is located on the outer block portion 44 of the first insulating sheet 41. The outer block portion 44, the central block portion 43, and the connecting block portion 45 are bonded to the metal plate 100 by a metal adhesive layer 90. Therefore, the metal plate 100 is bonded to the first insulating sheet 41 inside the opening 80H of the spacer 80 in a plan view, and is also bonded to the first insulating sheet 41 outside the opening 80H.

  Further, the slit 81 of the spacer 80 is a ventilation path. As described above, the slit 81 communicates with the opening 80 </ b> H, and the air vent 63 of the second insulating sheet 61 overlaps the slit 81 of the spacer 80. Therefore, the opening 80H of the spacer 80 and the air vent 63 communicate with each other through the ventilation path.

  A signal cable 19 connected to a control device (not shown) is connected to the first terminal 51 and the second terminal 71 of the load detection sensor 30. The first terminal 51 and the second terminal 71 are connected to the respective signal cables 19 by conductive paste, soldering, or the like.

  The load detection sensor 30 having the above configuration is disposed on the support plate 10 as shown in FIG. Specifically, the main block 30m of the load detection sensor 30 having the switch SW is disposed on the main block mounting portion 11m of the support plate 10, and the tail block 30t of the load detection sensor 30 is mounted on the tail block of the support plate 10. It arrange | positions on the part 11t. Further, the first terminal 51, the second terminal 71, and the air vent 63 provided in the tail block 30t are in a state of protruding from the tail block mounting portion 11t. Therefore, the first terminal 51, the second terminal 71, and the air vent 63 are located in a region that does not overlap the support plate 10. Each signal cable 19 connected to the first terminal 51 and the second terminal 71 of the load detection sensor 30 is led out from the support plate 10.

  As described above, in the state where the load detection sensor 30 is disposed on the support plate 10, the end portion of the tail block 30 t including the first terminal 51 and the second terminal 71 to which the signal cable 19 is connected is protected by the protective resin 18. It is covered. The air vent 63 is not covered with the protective resin 18. Examples of the material of the protective resin 18 include polyamide-based, polyimide-based, olefin-based, urethane-based, acrylic-based thermoplastic resins, and resins such as photo-curing resins.

  As described above, in the state where the upper case 20 covers the load detection sensor 30 placed on the support plate 10 and each hook piece 23 is fitted in each case stop opening 14, the pressing portion 22 is The tip of the metal plate 100 of the load detection sensor 30 contacts the position overlapping the switch SW. Further, in this state, each rib 25 is inserted through the through hole 36 of the load detection sensor 30 and the through hole 13 of the support plate 10. Therefore, even when the support plate 10 and the first insulating sheet 41 are not bonded, the relative movement between the switch SW of the load detection sensor 30 and the pressing portion 22 of the upper case 20 is restricted. That is, the rib 25 can be understood as a movement restricting member that restricts relative movement between the load detection sensor 30 and the support plate 10 in the surface direction of the support plate 10.

  Next, load detection by the load detection sensor unit 1 of the present embodiment will be described.

  FIG. 7 is a diagram illustrating 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 21S of the upper case 20 and presses the upper surface 21S. When the lower surface of the seat cushion SC further moves downward, as shown in FIG. 7, the tip of the pressing portion 22 presses the metal plate 100 in the load detection sensor 30, and the metal plate 100 bends. When the metal plate 100 is bent, the first insulating sheet 41 to which the metal plate 100 is bonded follows the metal plate 100 and bends. More specifically, the main block 41 m of the first insulating sheet 41 is bent so as to enter the opening 80 </ b> H of the spacer 80, and the central electrode portion 53 of the first electrode 50 approaches the second electrode 70. When the central electrode portion 53 contacts the second electrode 70, the switch SW of the load detection sensor 30 is turned on. Then, seating is detected by a vehicle control unit (not shown) connected to the signal cable 19. At this time, in this embodiment, the surface on the support plate 10 side of the main block 61 m of the second insulating sheet 61 is not bonded to the support plate 10. For this reason, at least the first insulating sheet 41 in the peripheral portion of the switch SW can be deformed so as to follow the way the metal plate 100 bends, so that the switch SW is easily turned on.

  In addition, when the 1st insulating sheet 41 bends, the air in the opening 80H of the spacer 80 is discharged | emitted from the air vent 63 through the slit 81 of the spacer 80 used as a ventilation path. Therefore, it can be avoided that the bending of the metal plate 100 and the first insulating sheet 41 is suppressed by the air in the opening 80H of the spacer 80, and the switch SW of the load detection sensor 30 can be appropriately turned on.

  On the other hand, when a person leaves the seat device, the lower surface of the seat cushion SC moves upward, the upper surface 21S of the upper case 20 is released, and the pressure on the metal plate 100 by the tip of the pressing portion 22 is released. When the pressure on the metal plate 100 is released, the metal plate 100 returns to the non-pressed position due to the elasticity of the metal plate 100. At this time, the first insulating sheet 41 to which the metal plate 100 is bonded follows the metal plate 100 and returns to the non-pressed position.

  As described above, the load detection sensor 30 of the present embodiment includes the first insulating sheet 41, the second insulating sheet 61, the spacer 80, the metal plate 100, and the metal adhesive layer 90. The first insulating sheet 41 is provided with a first electrode 50, and the second insulating sheet 61 is provided with a second electrode 70 facing the first electrode 50. The spacer 80 is interposed between the first insulating sheet 41 and the second insulating sheet 61, and an opening 80 </ b> H is formed in the spacer 80 between the first electrode 50 and the second electrode 70. The metal plate 100 is disposed on the side of the first insulating sheet 41 opposite to the surface on the spacer 80 side, and overlaps the first electrode 50 and the second electrode 70. The metal adhesive layer 90 is disposed so as to partially overlap the first electrode 50 between the metal plate 100 and the first insulating sheet 41, and adheres the metal plate 100 to the first insulating sheet 41. The first insulating sheet 41 is formed with a through hole 41H that overlaps a part of the opening 80H of the spacer 80.

  In such a load detection sensor 30, the metal plate 100 is bent when the metal plate 100 is pressed, and the first insulating sheet 41 bonded to the metal plate 100 enters the opening 80 </ b> H of the spacer 80 according to the bending. Bend. As a result, the first electrode 50 and the second electrode 70 come into contact with each other, the load detection sensor 30 is turned on, and the load is detected. When the first insulating sheet 41 is deformed so as to enter the opening 80H according to the bending of the metal plate 100, the resistance value and the capacitance value between the first electrode 50 and the second electrode 70 change. Thus, the load detection sensor may be turned on.

  The insulating sheet is generally a resin sheet, and the resin sheet tends to bend with a weak force due to a decrease in strength under a high temperature environment as described above. In the load detection sensor 30 of the present embodiment, as described above, a part of the metal adhesive layer 90 that bonds the metal plate 100 to the first insulating sheet 41 is disposed so as to overlap the first electrode 50. A part of the portion of the one insulating sheet 41 where the first electrode 50 is provided is bonded to the metal plate 100. For this reason, when the metal plate 100 is pressed, the portion where the first electrode 50 is provided can bend following the metal plate 100. Further, when the metal plate 100 returns to the position when the metal plate 100 is not pressed and is not pressed, the metal plate 100 can return to the position where the first electrode 50 is provided in the first insulating sheet 41. Here, since the elasticity of the metal plate 100 is less likely to change according to the environmental temperature than the insulating sheet, it is possible to suppress the bending of the first insulating sheet 41 during load detection from changing according to the environmental temperature.

  Further, as described above, the adhesive layer tends to be softened under a high temperature environment and hardened under a low temperature environment. In the load detection sensor 30 of the present embodiment, as described above, the first insulating sheet 41 is formed with the through hole 41H that overlaps a part of the opening 80H of the spacer 80. Therefore, the first insulating sheet 41 and the metal adhesive layer located inside the opening 80H of the spacer 80 are compared with the case where the first insulating sheet 41 is not formed with the through hole 41H that overlaps a part of the opening 80H of the spacer 80. 90 can be reduced. Therefore, it is possible to suppress a change in the load required for the first electrode 50 and the second electrode 70 to contact each other due to the strength change of the first insulating sheet 41 and the metal adhesive layer 90 due to the change of the environmental temperature. . Thus, the load detection sensor 30 of the present embodiment can appropriately detect the load.

  In the present embodiment, the through hole 41H of the first insulating sheet 41 is formed in a region other than the center 80c of the opening 80H of the spacer 80, and the first electrode 50 is a central electrode portion located inside the opening 80H of the spacer 80. 53. Further, the central electrode portion 53 and the second electrode 70 overlap with the center 80c of the opening 80H of the spacer 80, respectively, and a part of the metal adhesive layer 90 overlaps with the central electrode portion 53. For this reason, a part of the site | part in which the center electrode part 53 in the 1st insulating sheet 41 is provided is adhere | attached on the metal plate 100, and the site | part in which this center electrode part 53 is provided can follow the metal plate 100 and bend. By the way, the amount of deformation of the first insulating sheet 41 that is bent so as to enter the opening 80H of the spacer 80 according to the bending of the metal plate 100 tends to increase as the distance from the center 80c of the opening 80H increases. For this reason, the first insulating sheet 41 is likely to approach the second insulating sheet 61 from a portion close to the center 80c of the opening 80H of the spacer 80. Accordingly, the first electrode 50 and the second electrode 70 are appropriately brought into contact with each other as compared with the case where the central electrode portion 53 and the second electrode 70 of the first electrode 50 do not overlap the center 80c of the opening 80H of the spacer 80, respectively. The load can be detected appropriately.

  In the present embodiment, the through hole 41 </ b> H of the first insulating sheet 41 substantially surrounds the outer periphery of the central electrode portion 53 inside the opening 80 </ b> H of the spacer 80. For this reason, the outer periphery of the central electrode portion 53 is generally surrounded by a region where the first insulating sheet 41 and the metal plate 100 are not bonded inside the opening 80H of the spacer 80. For this reason, compared with the case where the outer periphery of the center electrode part 53 is surrounded by the area | region where the 1st insulating sheet 41 and the metal plate 100 are adhere | attached, the 1st insulating sheet so that the center electrode part 53 may approach the 2nd electrode 70 When 41 is bent, it is possible to suppress the influence of the strength change of the metal adhesive layer 90 due to the change of the environmental temperature. Therefore, it is possible to suppress a change in load necessary for the first electrode 50 and the second electrode 70 to contact with each other in accordance with a change in environmental temperature. The through hole 41H of the first insulating sheet 41 only needs to surround at least a part of the outer periphery of the central electrode portion 53 inside the opening 80H of the spacer 80. However, the through hole 41H of the first insulating sheet 41 is a central electrode from the viewpoint of suppressing a change in load necessary for the first electrode 50 and the second electrode 70 to contact with each other according to a change in environmental temperature. It is preferable to enclose 1/2 or more of the outer periphery of the portion 53. For example, the through hole 41 </ b> H may surround the entire outer periphery of the central electrode portion 53. When the through hole 41H surrounds the entire outer periphery of the central electrode portion 53, for example, the connecting electrode portion 55 may be made of a thin metal in order to connect the central electrode portion 53 and the outer electrode portion 54 to each other.

  In the present embodiment, the first electrode 50 further includes an outer electrode portion 54 that surrounds the outer periphery of the central electrode portion 53, and the outer electrode portion 54 is located outside the opening 80 </ b> H of the spacer 80. The electrode provided on the insulating sheet may be formed of a metal printing layer, and the thickness of the metal printing layer may vary depending on manufacturing reasons. For this reason, when the 1st electrode 50 is located inside the opening 80H of the spacer 80, the distance between a 1st electrode and a 2nd electrode is easy to change according to the dispersion | variation in the thickness of a metal printing layer. However, in the load detection sensor 30, the outer electrode portion 54 of the first electrode 50 is located outside the opening 80 </ b> H of the spacer 80 as described above. Therefore, the outer electrode portion 54 contacts the surface of the spacer 80 on the first insulating sheet 41 side, and the surface of the first electrode 50 on the second electrode 70 side is substantially on the surface of the spacer 80 on the first insulating sheet 41 side. Will be located. For this reason, it can suppress that the distance between the center electrode part 53 of the 1st electrode 50 and the 2nd electrode 70 changes according to the dispersion | variation in the thickness of a metal printing layer, and the center electrode part 53 and the 2nd electrode 70 can be suppressed. Can be kept substantially constant. Therefore, it is possible to suppress a change in load necessary for the first electrode 50 and the second electrode 70 to contact each other. In addition, from the viewpoint of keeping the distance between the central electrode portion 53 and the second electrode 70 substantially constant, the outer electrode portion 54 surrounds ½ or more of the outer periphery of the central electrode portion 53, and the portion is seen in plan view. It is preferable to be located outside the opening 80H of the spacer 80.

  In the present embodiment, a part of the second electrode 70 is located outside the opening 80 </ b> H of the spacer 80. Therefore, a part of the second electrode 70 abuts on the surface of the spacer 80 on the second insulating sheet 61 side, and the surface of the second electrode 70 on the first electrode 50 side is substantially on the second insulating sheet 61 side of the spacer 80. It will be located on the surface. For this reason, it can suppress that the distance between the 1st electrode 50 and the 2nd electrode 70 changes according to the dispersion | variation in the thickness of a metal printing layer, and the center electrode part 53 and the 2nd electrode 70 in the 1st electrode 50 can be suppressed. Can be kept substantially constant. The second electrode 70 may be located outside the opening 80H of the spacer 80.

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

  FIG. 8 is an exploded view showing the configuration of the load detection sensor of the second embodiment. As shown in FIG. 8, in the load detection sensor 30 of the present embodiment, the second electrode 70 includes a central electrode portion 73, an outer electrode portion 74, and a connection electrode portion 75, and the metal adhesive layer 90 is connected and bonded. The point which does not have the part 95 differs from the load detection sensor 30 of 1st Embodiment.

  Similar to the first electrode 50 of the first embodiment, the second electrode 70 of the present embodiment includes a substantially circular central electrode portion 73 and a substantially circular annular outer electrode portion 74 that surrounds the outer periphery of the central electrode portion 73. It includes a connecting electrode portion 75 provided between the central electrode portion 73 and the outer electrode portion 74 and connected to the central electrode portion 73 and the outer electrode portion 74. An opening 70 </ b> H is formed between the central electrode portion 73 and the outer electrode portion 74. The opening 70H substantially surrounds the outer periphery of the central electrode portion 73 in plan view.

  When the first insulating sheet 41, the spacer 80, and the second insulating sheet 61 are overlapped and the second insulating sheet 61 is viewed in plan, the central electrode portion 73 of the second electrode 70 and a part of the connecting electrode portion 75 are separated from the spacer 80. The outer electrode portion 74 is located outside the opening 80H of the spacer 80. Further, the central electrode portion 73 of the second electrode 70 overlaps with the central electrode portion 53 of the first electrode 50, but does not overlap with the connection electrode portion 55 of the first electrode 50. Further, the connection electrode portion 75 of the second electrode 70 does not overlap the connection electrode portion 55 of the first electrode 50 in plan view. That is, the second electrode 70 does not overlap the first electrode 50 other than the central electrode portion 53 inside the opening 80H of the spacer 80 in plan view.

  The metal adhesive layer 90 of the present embodiment has the central adhesive portion 93 and the outer adhesive portion 94, but does not have the connecting adhesive portion 95. For this reason, although the center block part 43 and the outer side block part 44 in the 1st insulating sheet 41 are adhere | attached on the metal plate 100, the connection block part 45 is not adhere | attached on the metal plate 100. FIG. The metal adhesive layer 90 only needs to be able to bond at least a portion of the first insulating sheet 41 where the central electrode portion 53 is provided to the metal plate 100, and at least a part of the metal adhesive layer 90 is first in plan view. It only needs to overlap with the central electrode portion 53 of one electrode 50. For example, the metal adhesive layer 90 may not further include the outer adhesive portion 94.

  In the load detection sensor 30, as in the first embodiment, the through hole 41H of the first insulating sheet 41 is formed in a region other than the center 80c of the opening 80H of the spacer 80, and the first electrode 50 is formed of the spacer 80. The center electrode part 53 located inside the opening 80H is included. Further, the central electrode portion 53 and the second electrode 70 overlap with the center 80c of the opening 80H of the spacer 80, respectively, and a part of the metal adhesive layer 90 overlaps with the central electrode portion 53. In the load detection sensor 30, as described above, the second electrode 70 does not overlap the first electrode 50 other than the central electrode portion 53 inside the opening 80 </ b> H of the spacer 80. Incidentally, as described above, since the first insulating sheet 41 tends to decrease in strength under a high temperature environment, the portion of the first insulating sheet 41 that is not bonded to the metal plate 100 is subjected to creep deformation or metal plate. In some cases, slack or the like with respect to 100 may occur and bend toward the second insulating sheet 61 side. However, as described above, a portion of the first insulating sheet 41 where the central electrode portion 53 is provided is bonded to the metal plate 100. Further, in the load detection sensor 30, as described above, the second electrode 70 does not overlap the first electrode 50 other than the central electrode portion 53 inside the opening 80 </ b> H of the spacer 80. For this reason, even if the portion of the first insulating sheet 41 that is not bonded to the metal plate 100 is bent toward the second insulating sheet 61, the portion where the central electrode portion 53 is provided may approach the second electrode. It is suppressed. Moreover, it can suppress that parts other than the center electrode part 53 in the 1st electrode 50 contact the 2nd electrode 70. FIG. Therefore, erroneous detection of a load due to creep deformation of the first insulating sheet 41 or loosening of the first insulating sheet 41 with respect to the metal plate can be suppressed.

  As mentioned above, although the said embodiment was demonstrated to the example about the load detection sensor of this invention, this invention is not limited to the said embodiment.

  For example, in the above embodiment, the outer electrode portion 54 of the first electrode 50 is located outside the opening 80H of the spacer 80 in plan view. However, a part of the outer electrode portion 54 may be located inside the opening 80H of the spacer 80 in plan view. Even with such a configuration, it is possible to suppress a change in the distance between the first electrode 50 and the second electrode 70 in accordance with variations in the thickness of the metal print layer.

  In the above-described embodiment, the first electrode 50 and the second electrode 70 overlap with the center 80c of the opening 80H of the spacer 80 in plan view, but may not overlap with the center 80c of the opening 80H of the spacer 80. good. However, from the viewpoint of appropriately bringing the first electrode 50 and the second electrode 70 into contact, the first electrode 50 and the second electrode 70 preferably overlap with the center 80c of the opening 80H of the spacer 80 in plan view. .

  In the first embodiment, the shape of the first electrode 50 is different from the shape of the second electrode 70 inside the opening 80 </ b> H of the spacer 80. However, when the entire first electrode 50 overlaps the metal adhesive layer 90 inside the opening 80H of the spacer 80, the shape of the first electrode 50 is the shape of the second electrode 70 inside the opening 80H of the spacer 80. May match. With such a configuration, a wide area where the first electrode 50 and the second electrode 70 are in contact can be ensured, and the first electrode 50 and the second electrode 70 can be appropriately brought into contact with each other.

  The first electrode 50 and the second electrode 70 are not particularly limited as long as they face each other through the opening 80H of the spacer 80. For example, the first electrode 50 may not include the outer electrode portion 54.

  In the above embodiment, one through hole 41H is formed in the first insulating sheet 41, but a plurality of through holes 41H may be formed in the first insulating sheet 41.

  In the above embodiment, the adhesive layer 89 for resin is disposed between the first insulating sheet 41 and the spacer 80 and between the second insulating sheet 61 and the spacer 80. However, only one of them is disposed. May be arranged. When the resin adhesive layer 89 is not disposed on one of the first insulating sheet 41 or the second insulating sheet 61 and the spacer 80, for example, a curable resin is applied to the first insulating sheet 41 or the second insulating sheet 61. The spacer 80 can be formed by being provided and cured, and the spacer 80 can be directly bonded to the first insulating sheet 41 or the second insulating sheet 61.

  Moreover, in the said embodiment, although the 2nd insulating sheet 61 was made into the insulating sheet which has flexibility, it may be set as the board | substrate which does not have flexibility, for example, may be used as the metal sheet, You may be comprised by two layers of an insulating sheet and a metal sheet.

  Moreover, in the said embodiment, although the through-hole 36 was provided in the load detection sensor 30, and the rib 25 was penetrated by the through-hole 36, the said through-hole 36 and the rib 25 may be abbreviate | omitted.

  In addition, the load detection sensor of the present invention has applicability as long as it detects the presence or absence of a load on the detection target to be detected. For example, the form which arrange | positions a load detection sensor under the seat cushion of the bed for care is mentioned. Even in such a form, the load detection sensor can detect the load, and information indicating whether a person is present on the seat cushion can be obtained based on the detection result of the load detection sensor. Moreover, it may be used as a switch of an electronic device, and the presence or absence of a load may be detected.

  As described above, according to the present invention, a load detection sensor capable of appropriately detecting a load is provided, and can be used in technical fields such as a seat device and a care bed.

30 ... Load detection sensor 40 ... 1st electrode sheet 41 ... 1st insulating sheet 42 ... 1st conductive layer 41H ... Through-hole 50 ... 1st electrode 53 ... Center electrode Part 54 ... outer electrode part 55 ... connecting electrode part 60 ... second electrode sheet 61 ... second insulating sheet 62 ... second conductive layer 70 ... second electrode 80 ... Spacer 80H ... Opening 80c ... Center 90 ... Metal adhesive layer (adhesive layer)
100 ... Metal plate SW ... Switch

Claims (5)

A first insulating sheet provided with a first electrode;
A second insulating sheet provided with a second electrode facing the first electrode;
A spacer interposed between the first insulating sheet and the second insulating sheet and having an opening formed between the first electrode and the second electrode;
A metal plate disposed on a surface opposite to the spacer-side surface of the first insulating sheet, and overlapping the first electrode and the second electrode;
An adhesive layer disposed between the metal plate and the first insulating sheet so as to at least partially overlap the first electrode, and bonding the metal plate to the first insulating sheet;
With
The first insulating sheet is formed with a through hole that overlaps a part of the opening of the spacer. The through hole of the first insulating sheet is formed in a region other than the center of the opening of the spacer,
The first electrode includes a central electrode portion located inside the opening of the spacer,
The center electrode portion and the second electrode respectively overlap with the center of the opening of the spacer,
The load detection sensor according to claim 1, wherein at least a part of the adhesive layer is disposed so as to overlap the central electrode portion. 3. The load detection sensor according to claim 2, wherein the through hole of the first insulating sheet surrounds at least a part of the outer periphery of the central electrode portion inside the opening of the spacer. The first electrode further includes an outer electrode portion surrounding at least a part of the outer periphery of the central electrode portion,
The load detection sensor according to claim 3, wherein at least a part of the outer electrode portion is located outside the opening of the spacer. 5. The load detection sensor according to claim 2, wherein the second electrode does not overlap with the first electrode other than the central electrode portion inside the opening of the spacer. 6.

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