JP6533007B2 - Load detection sensor unit - Google Patents

Description

  The present invention relates to a load detection sensor unit, and is suitable for appropriately detecting seating and the like.

  As one of the safety systems in vehicles, an alarm system has been put to practical use to warn that the seat belt is not worn when getting on the vehicle. In this alarm system, a warning is issued when the seat belt is not worn while sensing that a person is seated. As a device for sensing the seating of a person, a seating detection device for sensing a load due to seating may be used.

  As a seating detection device, a spacer having an opening formed therein is disposed between a pair of resin films, and electrodes formed on the respective films face each other at a predetermined interval in the opening of the spacer. It is known that a load detection sensor is used. However, a resin film generally has a tendency to decrease in strength as the temperature rises and to bend with a weak force. Therefore, when placed in a hot environment as in a car under a sun, the strength of the resin film may decrease as described above. In this case, even when a load lighter than the load of a normal person is applied to the seat apparatus, there is a possibility that the seat apparatus may be erroneously detected as being seated.

  The following patent document 1 describes a seating detection device capable of suppressing such erroneous detection. In the load detection sensor used in the seating detection apparatus, a spacer having an opening between a pair of resin films is disposed, and electrodes formed on the respective films have a predetermined interval in the opening of the spacer. A metal plate is disposed on the surface of one of the films opposite to the spacer side so as to cover the opening.

  According to this seating detection device, the metal plate has elasticity, and the elasticity does not change so much with temperature, so the metal plate suppresses deformation of the film during seating detection, but changes due to temperature are suppressed. Ru. Therefore, according to the said load detection sensor, it can suppress that the load which detects seating changes with temperature.

Patent No. 05324548 gazette

  However, when the metal plate as described above is provided, the film is less likely to bend as compared with the case where the metal plate is not provided, and the load detection unit is less likely to be turned on. Therefore, there is a need for a device that can detect a load that can be used for a detection device such as a seating device or the like in which erroneous detection such as seating is suppressed while being able to properly detect seating and the like.

  Then, an object of this invention is to provide the load detection sensor unit which can suppress incorrect detection of seating etc., being able to detect seating etc. appropriately.

  In order to solve the above problems, the present invention is a load detection sensor unit disposed under a seat cushion, comprising: a pair of electrodes facing each other via a predetermined distance; and the seat cushion among the pair of electrodes A load detection sensor having a metal plate covering at least a part of the opposite electrode from the side opposite to the seat cushion, and a portion overlapping the one electrode of the metal plate is pressed from the opposite side to the seat cushion A pressing portion that is harder than the seat cushion, and the pair of electrodes are in contact with each other due to the bending of the metal plate due to the load detection sensor being pressed by the pressing portion. is there.

  In this load detection sensor unit, when a person is seated on the seat cushion, the metal sheet is pressed by the pressing portion by the load detection sensor being pressed by the seat cushion and moved downward. When the metal plate is pressed, the metal plate is bent, and one of the electrodes located on the side opposite to the seat cushion is pushed by the bending of the metal plate to be in contact with the other electrode to turn on the switch. In this way, seating etc. are detected. By the way, the metal does not change its flexibility as described above even when the temperature changes. Therefore, even when the environmental temperature around the load detection sensor unit changes, the deflection of the metal plate pressed by the pressing portion does not change so much. Therefore, according to this load detection sensor unit, even when the environmental temperature changes, it is possible to suppress false detection such as seating. Further, in the load detection sensor unit, the pressing portion that is harder than the seat cushion presses a part of the metal plate, so the metal plate can be appropriately bent, and seating and the like can be appropriately detected. In addition, since metal is less likely to creep compared to resin, even if a part is pressed by the pressing part, it is difficult for the metal plate to be easily cracked. Furthermore, since the pressing portion is on the opposite side to the seat cushion, it is possible to suppress the occurrence of creep in the seat cushion by the pressing portion, and it is difficult for the seat cushion to be wrinkled. In addition, when the pressing portion is disposed between the load detection sensor and the seat cushion, the pressing portion may be unstable and the relative positional relationship between the load detection sensor and the seat cushion may be shifted, but the pressing portion is opposite to the seat cushion. By being located on the side, it is possible to suppress the relative positional relationship between the load detection sensor and the seat cushion from shifting. Therefore, according to the load detection sensor unit of the present invention, it is possible to appropriately detect seating and the like, and to suppress erroneous detection of seating and the like due to a pushing rod and the like. In addition, as detection other than seating in a seat, for example, the load detection sensor unit of the present invention is disposed under a seat cushion such as a bed mattress, and the presence or absence of a person on the bed can be detected.

  Moreover, it is preferable to cover the other electrode in the pair of electrodes from the side of the seat cushion, and to further include a plate-like covering member harder than the seat cushion.

  The pressing force received from the seat cushion is transmitted to the load detection sensor via the plate-like covering member harder than the seat cushion, so that the pressing portion is in a state in which the pair of electrodes is sandwiched between the metal plate and the covering member. Presses the metal plate. Therefore, compared with the case where the seat cushion directly presses the load detection sensor, the pressing force received from the seat cushion can be properly transmitted to the pressing portion.

  It is preferable that the covering member has an area larger than the area of the metal plate.

  Since the covering member has a larger area than the metal plate, the pressing force from the seat cushion can be received in a wider range. Therefore, the pressing force received from the seat cushion can be more appropriately transmitted to the pressing portion.

  Moreover, it is preferable that the said covering member has flexibility.

  When the covering member has flexibility, the part pressed by the pressing portion of the metal plate is further bent while the covering member is bent together with the metal plate. Therefore, while the pair of electrodes is entirely bent, one of the electrodes on the pressing portion side is further pressed by the metal plate and bent more than the other electrode to be turned on. In this case, the amount of bending of one of the electrodes can be reduced as compared with the case where the other electrode does not bend, and the durability can be improved.

  Moreover, it is preferable to further provide the mounting member by which the said load detection sensor is mounted, and the said press part is fixed to the said mounting member.

  By fixing the pressing portion to the mounting member, the pressing portion is stable and stable compared to the case where the pressing portion is disposed between the load detection sensor and the seat cushion, and the pressing portion presses the metal plate more appropriately. can do. In addition, as an example in which a pressing part is fixed to a mounting member, it can mention that a pressing part is adhere | attached on a mounting member, and a pressing part is integrally molded with a mounting member.

  In addition, the load detection sensor further includes a sheet-like spacer having an opening formed therein, and a pair of insulating sheets made of resin provided on both sides of the spacer, and the pair of electrodes are formed of the insulating sheet At least a part of a portion of the pair of insulating sheets on the side of the metal plate, which is provided on the surface on the spacer side and faces each other through the opening, is bonded to the metal plate. Is preferred.

  As described above, when the temperature rises, the strength of the resin decreases and the resin is bent with a weak force, and once it is bent, it tends to be difficult to return to the original state. However, the metal plate can be pulled back to the original state by bonding the metal plate and at least a part of the portion overlapping with the one electrode in the insulating sheet. Therefore, the pressure sore can be suppressed more appropriately, and false detection of seating can be suppressed.

  Moreover, it is preferable that the site | part which overlaps with the said one electrode of the said metal plate is made non-adhesive with the said mounting member.

  As described above, the portion overlapping the one electrode of the metal plate is a portion including the portion pressed by the pressing portion. Therefore, even if the load detection sensor is pressed by the pressing portion from an oblique direction by the portion not being adhered to the mounting member, the metal plate is made to follow it obliquely and the metal plate is appropriately The load detection sensor can be properly turned on.

  As described above, according to the present invention, it is possible to provide a load detection sensor unit capable of appropriately detecting seating and the like and suppressing erroneous detection of seating and the like.

It is an exploded view showing composition of a load detection sensor unit concerning a 1st embodiment of the present invention. It is sectional drawing which shows a mode that the load detection sensor unit of FIG. 1 was attached to S spring. It is a figure which shows the cover of FIG. It is an exploded view which shows the structure of the load detection sensor of FIG. It is a figure which shows the appearance of the load detection sensor unit in the ON state of a load detection sensor. It is an enlarged view of the switch vicinity in the state of FIG. It is sectional drawing which shows the structure of the load detection sensor unit concerning 2nd Embodiment of this invention.

  Hereinafter, preferred embodiments of a load detection sensor unit according to the present invention will be described in detail with reference to the drawings. In addition, the scale of each figure may differ from the scale described in the following description for easy understanding.

First Embodiment
FIG. 1 is an exploded view showing the configuration of a load detection sensor unit of the present embodiment, and FIG. 2 is a cross-sectional view showing the load detection sensor unit attached to an S spring of a seat device. FIG. 2 is a cross-sectional view of the load detection sensor unit on a surface along the left-right direction of the seat device. As shown to FIG. 1, FIG. 2, the load detection sensor unit 1 is equipped with the base 2, the cover 4, and the load detection sensor 5 as a main structure.

  The pedestal 2 has a mounting portion 21 on which a portion including at least a switch of the load detection sensor 5 is mounted, and a pair of hook portions 22 connected to the mounting portion 21. Since the load detection sensor 5 is mounted on the pedestal 2, it can be understood as a mounting member having the mounting portion 21. The upper surface of the placement unit 21 is a placement surface 21S on which the load detection sensor 5 is placed. Further, in the mounting portion 21, a plurality of substantially rectangular through holes 24 are formed to penetrate from the mounting surface 21S to the lower surface (surface opposite to the mounting surface 21S) of the mounting portion 21. . The through hole 24 is a hole for fixing the cover 4. Further, the mounting portion 21 is formed with a plurality of substantially circular through holes 20H. The through hole 20H is a hole that restricts the movement of the cover 4 in the direction along the mounting surface 21S. The pedestal 2 is formed, for example, by molding a metal plate, and in this case, the plate thickness is, for example, 0.8 mm.

  In addition, the pressing unit 25 is fixed to the placement unit 21. Thus, the pedestal 2 as the placement member has the pressing portion. In the present embodiment, the pressing portion 25 has a substantially cylindrical shape and is harder than the seat cushion SC. When the pressing portion 25 is fixed to the placement surface 21S, the pressing portion 25 is protruded with respect to the placement surface 21S. Therefore, as shown in FIG. When placed, the tip of the pressing portion 25 contacts the load detection sensor 5. Specifically, the tip of the pressing portion 25 is in contact with the metal plate 60 of the load detection sensor 5 described later.

  The pair of hook portions 22 are respectively provided at positions facing each other across the placement portion 21 and, as shown in FIG. 2, a plurality of S springs 100 which are stretched across the opening of the frame in the seat apparatus of the vehicle. Are respectively fitted into a pair of adjacent S springs 100. Therefore, each hook portion 22 is a locking portion that locks the pedestal 2 to the S spring 100. In the present embodiment, the pair of hook portions 22 are formed to be aligned in the lateral direction of the seat apparatus and to be fitted into the pair of S springs 100 adjacent in the lateral direction. Further, in a state where the pair of hook portions 22 is thus fitted into the pair of adjacent S springs 100, the placement portion 21 is located below the seat cushion SC placed on the plurality of S springs 100, Furthermore, when the plurality of S springs are viewed from above, the placement portion 21 is disposed between the pair of S springs 100. With the pair of hooks 22 fitted into the pair of S springs 100 as described above, in the present embodiment, the placement surface 21S is positioned below the lower end portions of the respective S springs 100.

  FIG. 3 is a view showing the cover 4. The cover 4 is a cover member that covers a part of the load detection sensor 5 placed on the placement unit 21 and presses the switch of the load detection sensor 5 by being pressed by the seat cushion SC shown in FIG. 2. It is a pressing member. The cover 4 has a top wall 45 and a frame wall 48 which are substantially plate-like. The top wall 45 is a substantially circular plate-like member. The frame wall 48 of the cover 4 is divided into a plurality of pieces and connected to the outer periphery of the top wall 45. A hook piece 47 having a hook formed at its tip is connected to the top wall 45 between the frame walls 48 divided into a plurality of pieces. Each hook piece 47 is configured to be fitted into the through hole 24 formed in the pedestal 2. Each hook piece 47 is fitted in the through hole 24, whereby the hook formed at the tip of the hook piece 47 is prevented from being caught on the pedestal 2 and the cover 4 being pulled out.

  The lower surface 45L of the top wall 45 of the cover 4 facing the pedestal 2 is substantially planar. The top wall 45 of the cover 4 is provided with a plurality of ribs 49 projecting from the lower surface 45L. The ribs 49 are formed at positions overlapping the plurality of through holes 20 H formed in the pedestal 2. These ribs 49 are inserted into the respective through holes 20H in a state where the cover 4 covers a part of the load detection sensor 5 and the respective hook pieces 47 are fitted in the respective through holes 24 of the pedestal 2. As described above, when the cover 4 is attached to the pedestal 2, the lower surface 45 L of the top wall 45 of the cover 4 is in surface contact with the region including the portion including the switch of the load detection sensor 5.

  In the present embodiment, the cover 4 is formed of a material harder than the seat cushion SC, like the pressing portion 25. Since the seat cushion SC is generally made of a foamed urethane resin, the material of such a cover 4 may be polycarbonate (PC), polyamide (PA), polybutylene terephthalate (PBT), phenol resin, epoxy resin, etc. Resin is mentioned. Further, the above-described pressing portion 25 is made of, for example, the same material as the cover 4.

  The upper surface 45U of the top wall 45 of the cover 4 is spaced a predetermined distance from the lower surface of the seat cushion SC in a state where the load detection sensor unit 1 assembled in this manner is disposed below the seat cushion SC of the seat device. opposite. The upper surface 45U is flat. The upper surface 45U is a surface pressed by the seat cushion SC, and can be understood as a pressure receiving surface of the load detection sensor unit 1. The area of the upper surface 45U is larger than the area of the portion of the pressing portion 25 in contact with the load detection sensor 5. It is enlarged.

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

  FIG. 4 is an exploded view showing the load detection sensor 5 of FIG. However, in order to facilitate understanding, the viewing directions in FIGS. 1 and 4 are changed. As shown in FIGS. 1 and 4, the load detection sensor 5 of the present embodiment includes a switch sheet 50 having a switch SW and a metal plate 60.

  As shown in FIG. 1, the switch sheet 50 of this embodiment is a sheet-like membrane switch. The switch sheet 50 has a substantially rectangular main block 50m and a tail block 50t connected to the main block 50m and narrower than the main block 50m. A switch SW is provided on the main block 50m. Further, a wide wing portion 50f is formed on the tail block 50t. Further, through holes 50H are formed in the vicinity of the tops of the main block 50m.

  As shown in FIG. 4, the switch sheet 50 of the present embodiment includes a first electrode sheet 56, a spacer 58, and a second electrode sheet 57.

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

  The first insulating sheet 56s is a flexible insulating sheet, and the main block 56m having the same shape as the main block 50m of the switch sheet 50 and the tail block 50t of the switch sheet 50 connected to the main block 56m are And a tail block 56t of the same shape. The shape of the tail block 56t differs from the shape of the tail block 50t of the switch sheet 50 in that the tip portion opposite to the main block 56m has a narrower width than the other portions of the tail block 56t. Further, in the main block 56m, a through hole 56H is formed at the same position as the through hole 50H of the switch sheet 50. Examples of the material of the first insulating sheet 56s include resins such as polyethylene terephthalate (PET), polyimide (PI), and polyethylene naphthalate (PEN).

  The first electrode 56 e is provided on one surface of the main block 56 m substantially at the center. The first electrode 56 e is made of a layer of a conductor, and is, for example, a substantially circular metal print layer. The first terminal 56c is made of a conductor layer, and is, for example, a substantially rectangular metal layer. The first terminal 56c is provided on the surface of the tail block 56t on the side where the first electrode 56e is provided. In addition, the first electrode 56e and the first terminal 56c are electrically connected to each other through the first wiring 56w.

  The second electrode sheet 57 mainly has a second insulating sheet 57s, a second electrode 57e, and a second terminal 57c.

  The second insulating sheet 57s is an insulating sheet similar to the first insulating sheet 56s. In the case of the present embodiment, the second insulating sheet 57s is connected to the main block 57m having the same shape as the main block 56m of the first insulating sheet 56s and to the main block 57m and other than the tail block 56t of the first insulating sheet 56s and the tip portion And the tail block 57t of the same shape. The tip portion of the tail block 57t is narrower than the other portions of the tail block 57t, and when the first insulating sheet 56s and the second insulating sheet 57s overlap, the tail block 56t of the first insulating sheet 56s And the tip end portion of the tail block 57t of the second insulating sheet 57s do not overlap each other. Further, through holes 57H are formed in the main block 57m at the same positions as the through holes 50H of the switch sheet 50, similarly to the first insulating sheet 56s. As the material of the second insulating sheet 57s, similar to the first insulating sheet 56s, a resin such as PET, PI or PEN can be mentioned, and the material of the second insulating sheet 57s is the same as the material of the first insulating sheet 56s It may be the same or different.

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

  The spacer 58 is a flexible insulating sheet and comprises a main block 58m and a tail block 58t connected to the main block 58m. The outer shape of the main block 58m is the same as the outer shape of the main blocks 56m and 57m of the first insulating sheet 56s and the second insulating sheet 57s. Further, an opening 58c is formed in the center of the main block 58m, and a through hole is formed at the same position as the through hole 50H of the switch sheet 50 in the same manner as the first insulating sheet 56s and the second insulating sheet 57s. 58H is formed. The tail block 58t is shaped so as to exclude tip portions where the width of the tail blocks 56t and 57t of the first insulating sheet 56s and the second insulating sheet 57s is narrow.

  The opening 58c has a substantially circular shape, and has a diameter slightly smaller than the diameters of the first electrode 56e and the second electrode 57e. When the opening 58c overlaps the spacer 58 with the first electrode sheet 56 and the second electrode sheet 57 and the spacer 58 is viewed in plan, the opening 58c is located inside the periphery of the first electrode 56e and the second electrode 57e. It is formed to be located. Further, the spacer 58 is formed with a slit 58 b connecting the space in the opening 58 c and the space outside the switch sheet 50. The slits 58 b are air vented when the first electrode sheet 56, the spacer 58, and the second electrode sheet 57 are respectively stacked.

  As a material of the spacer 58, similar to the first insulating sheet 56s and the second insulating sheet 57s, a resin such as PET, PI or PEN can be mentioned. The material of the spacer 58 may be the same as or different from the material of the first insulating sheet 56s or the second insulating sheet 57s. Further, an adhesive (not shown) for adhering to the first electrode sheet 56 and the second electrode sheet 57 is applied to both surfaces of the spacer 58.

  With the first electrode sheet 56, the spacer 58, and the second electrode sheet 57 attached in this order, the first electrode 56e of the first electrode sheet 56, the first wiring 56w, and the second electrode sheet 57. The second electrode 57e and the second wiring 57w are positioned between the first insulating sheet 56s and the second insulating sheet 57s. Then, the first electrode 56 e and the second electrode 57 e face each other through the opening 58 c to configure the switch SW. The height of the pressing portion 25 is made larger than the distance between the first electrode 56 e and the second electrode 57 e facing each other. The height of the pressing portion 25 is the length of the pressing portion 25 in the direction in which the first electrode 56 e and the second electrode 57 e face each other. Further, in a state where the first electrode sheet 56, the spacer 58, and the second electrode sheet 57 are overlapped, the through holes 56H, 57H, 58H overlap with each other, and become the through holes 50H of the switch sheet 50.

  A signal cable 19 connected to a control device (not shown) is connected to the first terminal 56c and the second terminal 57c of the switch sheet 50, respectively. The first terminals 56c and the second terminals 57c and the respective signal cables 19 are connected by conductive paste, soldering or the like. The end portion of the tail block 50t of the switch sheet 50 including the first terminal 56c and the second terminal 57c to which the signal cable 19 is connected is covered with a terminal sealing resin 18, as shown in FIG. The terminal sealing resin 18 is made of, for example, a hot melt or a light curing resin. Thus, the respective signal cables 19 are prevented from being detached from the respective first terminals 56c and the second terminals 57c, and short circuiting of the first terminals 56c and the second terminals 57c by conductive dust or the like is suppressed. ing.

  The metal plate 60 is made of a flexible metal plate. The material of the metal plate 60 is not particularly limited as long as it is a conductive metal, and examples thereof include copper and stainless steel. The metal plate 60 has substantially the same shape as the main block 50m of the switch sheet 50, and a through hole 60H is formed at the same position as the through hole 50H of the switch sheet 50. Therefore, when the switch sheet 50 and the metal plate 60 are stacked, the through hole 50H of the switch sheet 50 and the through hole 60H of the metal plate 60 overlap each other. When the switch sheet 50 and the metal plate 60 are stacked, the metal plate 60 covers the switch SW of the switch sheet 50. Specifically, as is apparent from FIGS. 1, 2 and 4, the metal plate 60 is provided on the side (the side opposite to the seat cushion SC side) opposite to the spacer 58 of the second insulating sheet 57s. Of the first electrode 56e and the second electrode 57e, the second electrode 57e located on the side of the pedestal 2 is covered from the side of the pedestal 2. In the present embodiment, the metal plate 60 and the second insulating sheet 57s (switch sheet 50) are adhered to each other. Specifically, at least a part of a portion of the second insulating sheet 57s overlapping the second electrode is bonded to the metal plate 60. For example, the entire metal plate 60 may be adhered to the second insulating sheet 57s, and a portion of the metal plate 60 overlapping with the second electrode 57e is adhered and a portion not overlapping with the second electrode 57e is not adhered Alternatively, only a portion of the metal plate 60 overlapping with the center of the second electrode 57e may be adhered.

  The load detection sensor 5 having the above configuration is disposed on the mounting portion 21 of the pedestal 2 as described above. Specifically, the main block 50m of the switch sheet 50 having the metal plate 60 and the switch SW is located on the mounting portion 21, and the tip of the pressing portion 25 contacts the area overlapping the switch SW of the metal plate 60. In the present embodiment, the area where the pressing portion 25 contacts the metal plate 60 is smaller than the area of the second electrode 57 e of the switch SW, and further smaller than the area of the opening 58 c of the spacer 58. Therefore, when the pressing portion 25 and the switch sheet 50 are viewed from the direction perpendicular to the surface direction of the switch sheet 50, the region where the pressing portion 25 contacts the metal plate 60 is within the outer periphery of the second electrode 57e and the opening 58c. To position. In this state, the tail block 50 t of the switch sheet 50, the terminal sealing resin 18, and the pair of signal cables 19 are led out from the pedestal 2. In the present embodiment, the metal plate 60 and the pedestal 2 are not bonded.

  In this state, with the cover 4 covering the main block 50 m including the switch SW of the load detection sensor 5 and the respective hook pieces 47 fitted in the respective through holes 24, the respective ribs 49 are of the metal plate 60. The through holes 60 H and the through holes 50 H of the switch sheet 50 are inserted into the through holes 20 H of the pedestal 2. Thus, the load detection sensor unit 1 is assembled. The top wall 45 of the cover 4 can be understood as a covering member covering the switch SW, and the rib 49 is understood as a movement restricting member which restricts relative movement between the pedestal 2 and the metal plate 60 in the surface direction of the metal plate 60 You can also As described above, since the cover 4 covers the main block 50m of the load detection sensor 5, the area of the upper surface 45U of the top wall 45 of the cover 4 is larger than the areas of the first electrode 56e and the second electrode 57e. Greater than 60 area.

  The lower surface 45L of the top wall 45 of the cover 4 is in contact with the entire main block 50m of the load detection sensor 5 when the load detection sensor unit 1 is assembled in this manner. The area of the top wall 45 in contact with the switch sheet 50 is larger than the area of the pressing portion 25 in contact with the metal plate 60 and larger than the area of the first electrode 56 e of the switch SW.

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

  FIG. 5 is a view showing the load detection sensor unit 1 in the on state of the load detection sensor 5, and FIG. 6 is an enlarged view of the vicinity of the switch SW in the state of FIG. When a person is seated on the seat device or the like, the lower surface of the seat cushion SC moves downward by the load of the person, and the lower surface of the seat cushion SC contacts the upper surface 45U of the cover 4 to press the entire upper surface 45U. When the lower surface of the seat cushion SC further moves downward, the pressing force from the seat cushion SC received on the upper surface 45U is concentrated on the pressing portion 25 and the second insulating sheet 57s is also bent by the bending of the metal plate 60. The second electrode 57e is in contact with the first electrode 56e, and the switch SW of the load detection sensor 5 is turned on. At this time, as described above, since the height of the pressing portion 25 is larger than the distance between the first electrode 56 e and the second electrode 57 e, the switch SW of the load detection sensor 5 is turned on in the present embodiment. It is easy to configure.

  At this time, as shown in FIG. 5 and FIG. 6, it is preferable that the cover 4 has flexibility and is bent. When the cover 4 is bent, the first electrode 56 e and the second electrode 57 e are not in contact with each other only by the bending of the second electrode sheet 57, but the first electrode sheet is in surface contact with the cover 4 together with the second electrode sheet 57. 56 also bends, and the first electrode 56e and the second electrode 57e come in contact with each other. For this reason, the first electrode 56 e and the second electrode 57 e can be easily brought into contact with each other, and concentration of stress on the second electrode 57 e can be suppressed, and the durability of the load detection sensor 5 can be improved.

  Thus, when the switch SW of the load detection sensor 5 is turned on, the vehicle control unit (not shown) connected to the signal cable 19 detects seating. In the present embodiment, since the area of the upper surface 45U is larger than the areas of the first electrode 56e and the second electrode 57e, the upper surface 45U receives and transmits the pressing force transmitted from other than immediately above the switch SW in the seat cushion SC. Can. Therefore, a larger pressing force can be received, the pressing force can be appropriately concentrated on the pressing portion 25, and the metal plate 60 can be bent more appropriately.

  Then, when a person leaves the seat, the lower surface of the seat cushion SC rises, the first electrode 56 e and the second electrode 57 e separate from each other, and the switch SW is turned off. At this time, if the temperature around the load detection sensor 5 is high, the second insulating sheet 57s of the second electrode 57e tends to be easily pressed. However, in the present embodiment, since the second electrode sheet 57 and the metal plate 60 are bonded to each other, the second insulating sheet 57 s is also original together with the metal plate 60 by a force that causes the metal plate 60 to return to the original shape. Return to shape. Therefore, the formation of the pressing wrinkles on the second electrode sheet 57 is suppressed.

  As described above, in the load detection sensor unit 1 of the present embodiment, the metal plate 60 is pressed by the pressing portion 25 and the metal plate 60 is bent, and the second electrode 57 e which is one electrode on the metal plate 60 side is concerned. The switch SW is turned on by being pressed by the metal plate 60 and in contact with the other electrode, the first electrode 56e. By the way, metal does not change so much in flexibility even when the temperature changes. Therefore, even when the environmental temperature around the load detection sensor unit 1 changes, the bending of the metal plate 60 pressed by the pressing portion 25 does not change so much. Therefore, according to this load detection sensor unit 1, even when the environmental temperature changes, erroneous detection of seating can be suppressed. Further, in the load detection sensor unit 1, since the pressing portion 25 harder than the seat cushion SC presses a part of the metal plate 60, the metal plate 60 can be appropriately bent, and the seating is appropriately detected. be able to. Further, since metal is less likely to creep as compared with resin, even if a part is pressed by the pressing part 25, the metal plate 60 is less likely to be wrinkled. Therefore, according to the load detection sensor unit 1 of the present invention, it is possible to appropriately detect seating while suppressing erroneous detection of seating due to a push rod or the like.

  Further, in the present embodiment, when the pressing portion 25 is located on the opposite side to the seat cushion SC, the pressing portion 25 can suppress the occurrence of creep in the seat cushion SC, and the pressing cushion does not easily stick to the seat cushion SC. Moreover, when the pressing portion 25 is disposed between the load detection sensor 5 and the seat cushion SC, there is a possibility that the relative positional relationship between the pressing portion 25 and the load detection sensor 5 and the seat cushion SC may be shifted, Since the pressing portion 25 is on the opposite side to the seat cushion SC, it is possible to suppress the relative positional relationship between the load detection sensor 5 and the seat cushion SC from being shifted.

  Further, in the present embodiment, the pedestal 2 which is the placement member has the pressing portion 25 so that the pressing portion 25 is more than when the pressing portion 25 is disposed between the load detection sensor 5 and the seat cushion SC. Stabilize without flutter.

  Further, in the present embodiment, as described above, the tip end of the pressing portion 25 contacts the metal plate 60 in a state where the upper surface 45U of the cover 4 is not pressed by the seat cushion SC, and the lower surface 45L of the cover 4 detects load. The sensor 5 is in contact with the metal plate 60 side and the opposite side (the seat cushion SC side). Therefore, when the seat cushion SC presses the cover 4 as the pressing member, the pressing portion 25 can quickly press the metal plate 60, and the seating can be detected quickly.

  Further, in the present embodiment, the pressing force received from the seat cushion SC is transmitted to the load detection sensor 5 through the top wall 45 which is a covering member of the cover 4 which is a plate-like covering member harder than the seat cushion SC. The pressing portion 25 presses the metal plate 60 in a state where the first electrode 56 e and the second electrode 57 e are sandwiched between the metal plate 60 and the cover 4. Therefore, compared with the case where the seat cushion SC directly presses the load detection sensor 5, the pressing force received from the seat cushion SC can be properly transmitted to the pressing portion 25, and the seating can be detected more appropriately.

  Further, as described above, since the cover 4 including the top wall 45 which is the covering member has flexibility, the portion pressed by the pressing portion of the metal plate 60 is further bent while the cover 4 is bent together with the metal plate 60 . Therefore, while the first electrode 56 e and the second electrode 57 e are entirely bent, the second electrode 57 e on the pressing portion 25 side is further pressed by the metal plate 60 and bent more than the first electrode 56 e to be turned on. For this reason, compared with the case where the 1st electrode 56e does not bend, the amount of bending of the 2nd electrode 57e can be made small, and durability can be improved.

  Furthermore, in the present embodiment, as described above, the area of the upper surface 45U of the top wall 45 which is the covering member of the cover 4 is larger than the area of the portion of the pressing portion 25 in contact with the load detection sensor 5, The pressing force from the seat cushion SC can be concentrated on the pressing portion 25. Furthermore, in the present embodiment, as described above, the area of the upper surface 45U of the cover 4 is larger than the areas of the first electrode 56e and the second electrode 57e, and further larger than the area of the metal plate 60. Therefore, the pressing force from the seat cushion SC can be received in a wider range, and the pressing force can be transmitted to the pressing portion 25 more appropriately.

  Further, in the present embodiment, the metal plate 60 and the pedestal 2 as the placement member are not bonded. Therefore, when the metal plate 60 bends, the area surrounding the pressing portion 25 of the metal plate 60 can move relative to the pedestal 2 to bend the metal plate 60 appropriately and turn on the load detection sensor 5 appropriately. be able to. In the present embodiment, although the metal plate 60 and the pedestal 2 which is the placement member are not adhered, for example, the edge of the metal plate 60 is adhered to the pedestal 2 and the first electrode 56 e of the metal plate 60 The overlapping portion may be unbonded to the pedestal 2 which is the mounting member. A portion of the metal plate 60 overlapping the first electrode 56 e is a portion including a portion pressed by the pressing portion 25. Therefore, even if the load detection sensor 5 is pressed by the pressing portion 25 from an oblique direction by this portion being not adhered to the pedestal 2, the metal plate 60 follows it and is made oblique. The load detection sensor 5 can be properly turned on by appropriately bending 60.

  Further, in the above embodiment, since the second insulating sheet 57s on the metal plate 60 side in the load detection sensor 5 is bonded to the metal plate 60, as described above, when the environmental temperature is high, the second insulating sheet When the deflection of 57 s is hard to return to the original state, the second insulating sheet 57 s can be pulled back to the original state of the metal plate 60.

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

  FIG. 7 is a cross-sectional view showing the configuration of a load detection sensor unit according to the present embodiment. As shown in FIG. 7, the load detection sensor unit 1 a according to this embodiment does not have the pedestal 2, and further includes a felt sheet 3, and a metallic cover 42 which is a covering member instead of the cover 4. It differs from the load detection sensor unit 1 of the first embodiment in the provision point.

  The felt sheet 3 is, for example, a non-woven fabric made of fibers of resin, cotton or the like. The pressing portion 25 is fixed on the felt sheet 3 by adhesion or the like. Furthermore, the felt sheet 3 is disposed on the side opposite to the switch sheet 50 side of the metal plate 60. In this state, the tip end of the pressing portion 25 is in contact with the area overlapping the switch SW of the metal plate 60 as in the first embodiment. In the present embodiment, the metal plate 60 and the felt sheet 3 may be bonded or may not be bonded. In addition, the pressing portion 25 may be fixed to the metal plate 60 instead of the felt sheet 3.

  Further, a cover 42 is disposed on the opposite side of the main block 50m of the switch sheet 50 to the metal plate 60 side, and the cover 42 is bonded to the main block 50m. This cover 42 can be understood as a covering member that covers the switch SW. In the present embodiment, the cover 42 has the same configuration as the metal plate 60 and is flexible.

  The load detection sensor unit 1 a is fixed to the seat cushion SC by a plurality of fixing tools 31. In the present embodiment, the fixing tool 31 is a rivet, and the fixing tool 31 is inserted into the seat cushion SC through the felt sheet 3, the load detection sensor 5 and the cover 42, and is inserted into the seat cushion SC. It is fixed to SC. Thus, the pressing portion 25 on the felt sheet 3 is fixed below the seat cushion SC. In this state, as shown in FIG. 7, the upper surface of the cover 42 opposite to the load detection sensor 5 is in surface contact with the lower surface of the seat cushion SC.

  The seat cushion SC with the load detection sensor unit 1a fixed to the lower surface in this manner is disposed, for example, on the frame of the vehicle body.

  When a person is seated on the seat cushion SC arranged in this manner, the lower surface of the seat cushion SC presses the entire upper surface of the cover 42 by the load of the person. Then, when the lower surface of the seat cushion SC further moves downward, the pressing force from the seat cushion SC received by the cover 42 is concentrated on the pressing portion 25, and in the same manner as in the first embodiment, The insulating sheet 57s is also bent, and the second electrode 57e contacts the first electrode 56e, and the switch SW of the load detection sensor 5 is turned on.

  At this time, since the cover 42 is flexible, the cover 42 can be bent. By bending the cover 42, the first electrode 56e and the second electrode 57e can be easily brought into contact with each other as in the case where the cover 4 is bent in the first embodiment, and stress is concentrated on the second electrode 57e. Can be suppressed, and the durability of the load detection sensor 5 can be improved.

  According to the load detection sensor unit 1a of the present embodiment, the felt sheet 3 is disposed below the load detection sensor 5, and the load detection sensor 5 can receive an impact between the felt sheet 3 and the seat cushion SC. Because the load detection sensor 5 hits another member, generation of abnormal noise can be suppressed.

  In the present embodiment, the cover 42 has the same structure as the metal plate 60. However, the cover 42 may have a different structure from the metal plate 60, and a resin cover may be used instead of the cover 42. good.

  Further, in the present embodiment, the load detection sensor unit 1a is fixed to the lower surface of the seat cushion SC, and there is no need to provide a mounting table on which the load detection sensor 5 is mounted. It is particularly useful in situations where it is difficult for the frame to function as a mounting table, or when it is necessary to make the thickness of the load detection sensor unit 1a thin and it is difficult to provide a separate mounting table. The load detection sensor unit 1a may be in contact with the frame of the vehicle body in a state where no load is applied, or may have a space between itself and the frame of the vehicle body without being in contact with the frame of the vehicle. good. However, when load is applied to the seat cushion SC, contact between the load detection sensor unit 1a and the frame of the vehicle body is preferable from the viewpoint of facilitating the switch SW being turned on. In this case, the pressing portion in the felt sheet 3 It is preferable from the viewpoint of making it easier to turn on the switch SW that the portion directly below 25 contacts the frame of the vehicle body. When the load detection sensor unit 1a contacts the frame of the vehicle body and is held by the frame of the vehicle body, the vehicle body frame can be understood as a mounting table.

  As mentioned above, although the load detection sensor unit of this invention was demonstrated taking the example of 1st, 2nd embodiment, this invention is not limited to the said embodiment.

  For example, in the first embodiment, the pressing portion 25 is fixed to the pedestal 2 by adhesion. However, the pressing portion 25 may be integrally formed with the pedestal 2. In this case, the pressing portion 25 may be formed by performing processing such as pressing on the metal plate constituting the pedestal 2. In the first and second embodiments, the pressing portion 25 has a substantially cylindrical shape, but the shape of the pressing portion 25 is not particularly limited. For example, the tip of the pressing portion 25 on the metal plate 60 is convex It may be in the shape of a curved surface. Moreover, in the said embodiment, although the height of the press part 25 was made larger than the distance between the 1st electrode 56e and the 2nd electrode 57e, the height of the press part 25 is the 1st electrode 56e and the 2nd electrode It may be equal to or less than the distance between 57e. The height of the pressing portion 25 may be larger than the thickness of the switch sheet 50 or may be larger than the thickness of the load detection sensor 5.

  Moreover, in the said 1st, 2nd embodiment, the metal plate 60 and the 2nd electrode 57e were made into another body. However, the second insulating sheet 57s may be omitted, and the second electrode 57e and the metal plate 60 may be integrated. In this case, it can be understood that the second electrode 57 e is covered with the metal plate 60 from the base 2 side and is integrated with the metal plate 60 as described above. That is, it can be understood that a metal layer of the same material as or a material different from that of the metal plate 60 is disposed as a second electrode 57 e at a portion facing the first electrode 56 e of the metal plate 60. In this case, the first insulating sheet 56s may be made of a non-flexible substrate.

  In the first and second embodiments, the covers 4, 42 as plate-like covering members harder than the seat cushion SC cover the first electrodes 56e of the pair of electrodes from the opposite side to the second electrodes 57e. The However, the covers 4, 42 are not essential components. However, when the load detection sensor unit 1 includes the covers 4 and 42, the pressing force from the seat cushion SC can be transmitted more appropriately. In particular, although it is preferable that the covers 4 and 42 have flexibility as in the above embodiment, the covers 4 and 42 may not have flexibility.

  Moreover, in the said 1st Embodiment, although the metal plate 60 was made into non-adhesion with the base 2, you may adhere | attach the metal plate 60 and the base 2. FIG.

  In the first embodiment, the relative movement between the switch sheet 50 and the metal plate 60 and the relative movement between the metal plate 60 and the cover 4 are restricted by the ribs 49. However, the rib 49 is not essential. In this case, for example, a frame is formed on the base 2, and the movement of the switch sheet 50 and the metal plate 60 in the surface direction is restricted by the frame, whereby relative to the metal plate 60 and the switch sheet 50 in the surface direction. The movement of the metal plate 60 and the cover 4 may be restricted by the hook piece 47.

  Moreover, in the said, 1st, 2nd embodiment, although the metal plate 60 and the switch sheet 50 (2nd insulation sheet 57s) were adhere | attached, the metal plate 60 and the switch sheet 50 may be made into non-adhesion. Even if the metal plate 60 and the second insulating sheet 57 s are not adhered to each other, relative displacement between the switch sheet 50 and the metal plate 60 is suppressed by the rib 49. Therefore, the rib 49 can be understood as a movement restricting member which restricts the relative movement of the switch sheet 50 and the metal plate 60 in the surface direction.

  Further, the load detection sensor unit of the present invention can be used as long as it can be provided at a position where the load should be detected under the seat cushion SC. In the above embodiment, the seat is disposed under the seat cushion SC of the seat of the vehicle and the seating of a person is detected. For example, the load detection sensor unit is disposed under the seat cushion such as a bed for nursing care and the person on the bed etc. The presence or absence of may be detected.

  As described above, according to the present invention, it is possible to provide a load detection sensor unit capable of appropriately detecting seating and the like and suppressing erroneous detection of seating and the like.

Reference Signs List 1 load detection sensor unit 2 pedestal 3 felt sheet 4 cover 5 load detection sensor 25 pressing portion 42 cover 50 switch sheet 56 First electrode sheet 56e First electrode 56s First insulating sheet 57 Second electrode sheet 57e Second electrode 57s Second insulating sheet 58 Spacer 60 ... Metal plate SC ... Seat cushion SW ... Switch

Claims (7)

A load detection sensor unit disposed under a seat cushion, comprising:
Load detection having a pair of electrodes facing each other through a predetermined distance, and a metal plate covering at least a part of one of the pair of electrodes opposite to the seat cushion from the side opposite to the seat cushion Sensor,
A pressing portion that is harder than the seat cushion that presses the portion of the metal plate overlapping the one electrode from the side opposite to the seat cushion;
Equipped with
A load detection sensor unit characterized in that the pair of electrodes contact each other by the bending of the metal plate caused by the load detection sensor being pressed by the pressing portion. The load detection sensor unit according to claim 1, further comprising a plate-like covering member which covers the other of the pair of electrodes from the side of the seat cushion and which is harder than the seat cushion. The load detection sensor unit according to claim 2, wherein the covering member has an area larger than the area of the metal plate. The load detection sensor unit according to claim 2, wherein the covering member has flexibility. It further comprises a mounting member on which the load detection sensor is mounted,
The load detection sensor unit according to any one of claims 1 to 4, wherein the pressing portion is fixed to the mounting member. The load detection sensor further includes a sheet-like spacer in which an opening is formed, and a pair of resin insulating sheets provided on both sides of the spacer.
The pair of electrodes are provided on the surface on the spacer side of the insulating sheet, and face each other through the opening.
6. The metal sheet according to any one of claims 1 to 5, wherein at least a part of a portion of the insulation sheet on the metal plate side overlapping with the one electrode in the pair of insulation sheets is bonded to the metal sheet. The load detection sensor unit according to the above item. The load detection sensor unit according to claim 5, wherein a portion of the metal plate overlapping with the one electrode is not adhered to the mounting member.

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