JP2000275115A - Pressure detector and seating detector for automobile using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure detector capable of accurately detecting at least two kinds of pressures at a low cost and a seating detector for an automobile using the same. SOLUTION: In the pressure detector, a first film 11 obtained by laminating a first conductive layer 12 and a second film 15 obtained by laminating a second conductive layer 16 are laminated and disposed between opposed layers 12 and 16 through a first spacer 14, a third conductive layer 17 is laminated on the film 15 at opposite side to the layer 16, a third film 20 obtained by laminating a fourth conductive layer 21 opposed to the layer 17 on the film 15 through a second spacer 19, and the layers 12, 16 and 17, 21 are brought into contact with or separated from each other by different pressing forces from above and below through openings 14b, 19b formed through the spacers 14, 19.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure detecting device in which a plurality of conductive layers are mechanically brought into contact with and separated from each other by a load force, and more particularly to a seating device which is mounted on an automobile seat (seat) and detects a seated person. For a seating detection device for an automobile.

[0002]

2. Description of the Related Art For example, in a method disclosed in Japanese Patent Application Laid-Open No. 10-188724, a cover film (first film), a spacer, and a support film (second film) are laminated on a sandwich and integrally joined. A pressure-sensitive switch for detecting seating is provided near a surface of a seat of a vehicle seat.

This pressure-sensitive switch is composed of a support film, a cover film facing in parallel with the support film, and a spacer which is an insulator interposed between the support film and the cover film. The support film is made of polyethylene naphthalate, and has a strip-shaped lead, a base, and a branch. A conductive layer formed by printing is provided on the surface of the support film, and the conductive layer integrally has a lead portion and a round electrode portion corresponding to a hole of a spacer to be described later.

The spacer is an insulator made of polyethylene terephthalate, and has a shape in which a strip-shaped lead portion, a trunk and a branch are integrally and continuously distributed in a substantially fork shape.
The backbone has a number of holes aligned in a straight line. At the tip of each branch, a number of holes are also aligned. The backbone is configured such that the area around the hole is easily bent. The cover film has the same shape as that of the support film, and has a strip-shaped lead portion, a base, and a branch. There is a printed conductive layer on the back surface of the cover film, and this electrode layer integrally has a round electrode portion corresponding to each hole of the spacer and a lead portion. The electrode portion of the conductive layer formed on the cover film in this manner is
It is located at a position facing the electrode portion of the support film via each hole of the spacer, and each hole of the spacer is arranged so as to be distributed in a region where the weight of the occupant is added to the seat of the automobile. In this way, the support film, the spacer,
They are superposed in the order of the cover film and joined together.
Therefore, the support film and the cover film are insulated by the spacer.

When this pressure-sensitive switch is mounted on an automobile seat, when a person is not seated, the pressing force is not substantially applied to the switch. The lead between the film and the cover film is in a non-conductive (switch-off) state. When a person sits in the area where the pressure-sensitive switch is provided, the cover film bends due to the load of the occupant, falls into the hole of the spacer, and the conductive layer on the lower surface of the cover film becomes the conductive layer on the upper surface of the support film. Contact.
As a result, conduction (switch-on) is established between the lead portions of the support film and the cover film.

[0006]

By the way, in the pressure detecting device using the above-mentioned pressure-sensitive switch, the pressure-sensitive switch has a structure in which a perforated spacer is interposed between films, and is attached to a seat (seat). The structure is simple because it detects whether or not there is a occupant when it is worn by contacting and separating the conductive layers. However, the pressing force can be detected only in the binary of switch-on / off, in which the conductive layers come into contact with and separate from each other in the hole of the spacer, and it is possible to detect whether a seat is occupied. There is a problem that it cannot be determined that a seated person having a different weight, such as a child, is seated. To make that determination,
A so-called pressure-sensitive resistance element or the like whose conduction resistance changes according to the pressure between the contacts is provided, the pressure is detected as a change in the resistance between the contacts, and a plurality of predetermined thresholds are set to increase the pressure. Although it is conceivable that the detection is performed in stages, there are problems that the pressure-sensitive resistance element itself is expensive, the cost cannot be reduced, and the configuration is complicated. Accordingly, an object of the present invention is to provide an inexpensive pressure detection device capable of detecting two or more types of pressures and an automobile seating detection device using the same.

[0007]

At least one of the above objects is attained.
As a first solution to solve the above problem, a first sheet-like switch having a conductive layer which can be separated and contacted at a plurality of locations, the conductive layer being turned on at a first pressure, And a second sheet-like switch having a conductive layer that can be switched on at a second pressure different from the first pressure.

As a second solution, a first sheet-like switch comprises a first film provided with a first conductive layer,
A second film provided with a second conductive layer on one surface side; and a first spacer interposed between the first film and the second film. A third conductive layer provided on the other surface side, a third film provided with a fourth conductive layer, and a second spacer interposed between the second film and the third film; A sheet-like switch and a second sheet-like switch are sequentially laminated, and one of the first and third films is deformed by the first pressure, and the other of the first and third films is deformed by the second pressure Then, the first and second sheet switches are turned on.

As a third solution, a first film in which a first conductive layer is laminated on one surface and a second film in which a second conductive layer is laminated on one surface are formed by opposing the first and second films. Are stacked and arranged via a first spacer having an opening between the conductive layers of the second film.
A third film, in which a fourth conductive layer is directly or indirectly laminated on the first conductive layer, and a fourth conductive layer disposed to face the third conductive layer is laminated on one surface, and the second film is opposed to the third film. The first and second conductive layers are stacked and arranged via a second spacer having an opening, and the first and the second spacers are formed through the respective openings through the first spacer and the second spacer. And the second conductive layer and the third and fourth conductive layers come and go with different pressing forces applied from above and below (on both sides of the other surface of the first film and the other surface of the third film). is there.

As a fourth solution, the opening of the first spacer and the opening of the second spacer have different sizes from each other.

As a fifth solution, the plate thickness of the first spacer is made different from the plate thickness of the second spacer.

As a sixth solution, the thickness of the first film is made different from the thickness of the third film.

As a seventh solution, the first and the second
The third conductive layer and the third and fourth conductive layers have a layer in which conductive powder is mixed with a binder resin made of a thermosetting resin.

As an eighth solution, a pressure detecting device is provided on a seat of an automobile.

According to a ninth solution, a pressing force for bringing the first and second conductive layers into and out of contact with each other is made larger than a pressing force for bringing the third and fourth conductive layers into contact with each other. It is mounted in an automobile seat such that the second conductive layer is on the lower side.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A pressure detecting device 10 according to one embodiment of the present invention will be described with reference to FIGS. 1 to 7 and FIG. As shown in FIG. 1 and FIG.
No. 1 is made of PEN (polyethylene naphthalate) having a thickness of about 75 μm, and has insulating properties and flexibility. The first film 11 has a rectangular portion 11a having a rectangular shape, and the rectangular portion 1a.
1a, and a band-like portion 11b extending in a band shape. A first conductive layer 12 is laminated on the first film 11, and the first conductive layer 12 includes a plurality of substantially circular electrode portions 12a and lead portions extending from the electrode portions 12a. 12b.

The electrode portion 12a has a silver pattern 1 having a substantially circular diameter of about 12 mm and a thickness of about 10 μm.
On the silver pattern 12c, a carbon paste obtained by mixing a thermosetting binder resin such as a phenol resin and a carbon powder with an organic solvent is printed and formed on the silver pattern 12c, and the organic solvent is formed by firing (heating). It is formed by laminating a first carbon layer 12d having a diameter of about 14 mm and a thickness of about 10 μm. The lead portion 12b has a silver pattern 1 having a line width of about 1 mm and a thickness of about 10 μm.
A second carbon layer 12e formed of a thermoplastic binder resin such as a vinyl resin, which is slightly wider than the line width of the silver pattern 12c and has a thickness of about 10 μm, is formed on the second carbon layer 12e. Further, the electrode portion 12a and the lead portion 12b
Although not shown, a part of the second carbon layer 12e is overlapped on the first carbon layer 12d, although not shown.
That is, part of the electrode portion 12a and the lead portion 12b of the first conductive layer 12 is formed on the surface of the rectangular portion 11a of the first film 11 by the silver pattern 12c, the first carbon layer 12d, and the second carbon layer 12d.
The carbon layers 12e are formed in a laminated manner by printing or the like in this order.
At the same time, a silver pattern 12c and a second carbon layer 12e are sequentially formed on the surface of the band-shaped portion 11b by printing or the like. Each electrode portion 12a is disposed at a predetermined position of the rectangular portion 11a to which a load is applied, and a lead portion 12b connected to each electrode portion 12a is disposed from the rectangular portion 11a to the band portion 11b.

As shown in FIGS. 1 and 3, the first spacer 14 has substantially the same external shape as the first film 11, and the base material 14a serving as a base is made of PET having insulation and flexibility. (Polyethylene terephthalate) or the like, and an adhesive 14f (so-called double-sided tape) is applied to the front and back surfaces of the substrate 14a, respectively, and the first spacer 14 including the thickness of the adhesive 14f is included. Has a thickness of about 100 μm. First
The spacer 14 has a substantially circular first opening 14b.
Are formed in a plurality. Each first opening 14b
Has a diameter of about 8 mm. Also, the first spacer 1
In FIG. 4, a groove-shaped connecting portion 14c connecting the first openings 14b is continuously formed. This connecting portion 14c
At the end of the air escape portion 14 formed in a small substantially circular shape
Although not shown, a filter that allows air to pass through but does not allow moisture to pass through is attached to the air escape portion 14d. The first spacer 14 is disposed on the surface of the first film 11 and on the first conductive layer 12 so that each electrode portion 12a of the first conductive layer 12 is located in each first opening 14b. They are overlapped and positioned so as to coincide with each other, and attached and fixed via the adhesive 14f. Since each electrode portion 12a of the first conductive layer 12 has an area larger than each first opening 14b, the first carbon layer forming a part of the electrode portion 12a is entirely formed on each first opening 14b. 12d is exposed. Thus, the first spacer 14 is formed on the surface of the first film 11.

As shown in FIGS. 1, 4 and 5, the second film 15 has substantially the same appearance as the first film 11 and the first spacer 14, and has a thickness of about 75 μm of PET (polyethylene). It is made of a polyester film such as terephthalate) or PEN (polyethylene naphthalate), and has insulation and flexibility. Second film 15
Is composed of a rectangular portion 15a having a rectangular shape and a belt-like band portion 15b extending from a part of the rectangular portion 15a.

The second conductive layer 16 includes a plurality of substantially circular electrode portions 16a and lead portions 16b extending from the electrode portions 16a. The electrode portions 16a and the lead portions 16b are both thick. Is about 10μm silver pattern 16c
A third layer having a thickness of about 10 μm using a thermosetting binder resin on each of the silver patterns 16c was used as a base.
Carbon 16d is formed by lamination, and a fourth carbon 16e having a thickness of about 10 μm using a thermoplastic binder resin is formed by lamination. Further, the electrode portion 12a and the lead portion 12
Although not shown, a part of the fourth carbon 12e is overlapped on the third carbon 12d at the connecting portion b. The electrode portion 16a includes a silver pattern 16c having a circular diameter of about 12 mm and a third carbon 16d having a diameter of about 14 mm. The lead portion 16b has a silver pattern 16c having a line width of about 1 mm and a silver pattern 16c. 16c and cover about 1
The fourth carbon 16e is slightly wider than the fourth carbon 16e. That is, a part of the electrode portion 16a and a part of the lead portion 16b are formed on the back surface of the rectangular portion 15a of the second film 15 by the silver pattern 16c, the third carbon 16d, and the fourth carbon 16d.
The layers are formed by printing or the like in the order of e. At the same time, the silver pattern 16c and the fourth carbon 16
The layers are formed by printing or the like in the order of e. In this manner, the first sheet-like switch including the first film 11 provided with the first conductive layer 12, the first spacer 14 having the first opening 14b, and the second conductive layer 16 is formed. Be composed.

The third conductive layer 17 has the same structure as the second conductive layer 16 as shown in FIGS. 1, 4 and 5, and comprises an electrode portion 17a and a lead portion 17b. Second
A silver pattern 17c, a third carbon layer 17d, and a fourth carbon layer 17e are sequentially formed on the surface of the film 15 by printing or the like in the same manner as the second conductive layer 16. Then, these electrode portions 17a constituting the third conductive layer 17 are formed.
Are opposed to each other with the second film 15 interposed therebetween at a position corresponding to the electrode portion 16a of the second conductive layer 16, that is, at the same position on the front surface and the back surface. Then, the second conductive layer 16
Each of the electrode portions 16a has a larger area than each of the first openings 14b.
The third carbon layer 17d constituting a part of 7a is exposed. The same is true for the third conductive layer 17a. As described above, the second and third conductive layers 16 and 17 are formed on the front and back surfaces of the second film 15, respectively.

As shown in FIGS. 1 and 6, the second spacer 19 has substantially the same external shape as the first spacer 14, and the base material 19a serving as a base is made of PET having insulation and flexibility. (Polyethylene terephthalate) or the like, and an adhesive 19f is applied to each of the front and back surfaces of the base material 19a. The thickness of the second spacer 19 including the thickness of the adhesive 19f is about 100 μm. The second spacer 19 has a plurality of substantially circular second openings 19b formed therethrough. Each second opening 19b has a diameter of about 10 mm, and has a slightly larger hole diameter than the first opening 14b.
In the second spacer 19, a groove-shaped connecting portion 19c connecting the second openings 19b is formed continuously. At the end of the connecting portion 19c, a small substantially circular air escape portion 19d is formed similarly to the first spacer 14, and a filter (not shown) is provided similarly. As described above, the second spacer 19 is configured such that the size of the hole diameter of the second opening 19 b is the first size of the first spacer 14.
It is the same as the first spacer 14 except that it is slightly larger than that of the opening 14b. The second spacers 19 are disposed on the surface of the second film 15 and on the third conductive layer 17, and each electrode portion 1 of the third conductive layer 17 is provided.
7a are superimposed and positioned so as to coincide with the respective second openings 19b, and are attached and fixed via the adhesive 19f.

As shown in FIGS. 1 and 7, the third film 20 is formed substantially the same as the first film 11, and is made of PEN (polyethylene naphthalate) having a thickness of about 75 μm. It has insulation and flexibility. The third film 20 includes a rectangular portion 20a having a rectangular shape, and a rectangular portion 2a.
0a, and a band-like portion 20b extending in a band shape.

The fourth conductive layer 21 is composed of a plurality of circular electrode portions 21a and lead portions 21b extending from the electrode portions 21a.
1b, a silver pattern 21c having the same thickness as the first conductive layer 12 is used as a base, and a first carbon layer 21d having the same material and the same thickness as the first conductive layer 12 is formed on the silver pattern 21c. It is formed by laminating a carbon layer 21e. Further, at the connecting portion between the electrode portion 21a and the lead portion 21b,
Although not shown, a part of the second carbon layer 21e overlaps the first carbon layer 21d. The electrode section 21
a is a silver pattern 21c having a circular diameter of about 12 mm.
And a first carbon layer 21d of about 14 mm,
The lead portion 21b is formed of a silver pattern 21 having a line width of about 1 mm.
and a second carbon 21e that covers the silver pattern 21c and is slightly wider than about 1 mm. That is, part of the electrode part 21a and the lead part 21b
A silver pattern 21 is formed on the back surface of the rectangular portion 20a of the film 20.
c, the first carbon layer 21d, and the second carbon layer 21e are stacked in this order by printing or the like. At the same time, the strip 20b
Are laminated in the order of silver pattern 21c and second carbon layer 21e by printing or the like. Since each of the electrode portions 21a of the fourth conductive layer 21 has a larger area than each of the second opening portions 19b, the electrode portion 21a is formed over the entirety of each of the second opening portions 19b.
The first carbon layer 21d that constitutes a part of “a” is exposed. Thus, the fourth conductive layer 21 is formed on the rear surface of the third film 20 in a laminated manner. Thus, the third conductive layer 17 provided in the second film 15, the second spacer 19 having the second opening 19 b, and the third film 20 provided with the fourth conductive layer 21 Having the second sheet-like switch.

Next, the assembling of the pressure detecting device 10 thus constructed will be described. The first opening 11 of the first spacer 14 is provided on the first film 11 on which the first conductive layer 12 is laminated. The first spacer 14 is mounted on the first conductive layer 12 by positioning the electrode portion 12a on the first conductive layer 12b.
The first spacer 14 has an adhesive 14f applied to the back surface thereof.
Through the surface of the first film 11 and the first conductive layer 12
Mounted and fixed on top. Further, on the first spacer 14, the electrode portion 16 a of the second conductive layer 16 laminated on the second film 15 is provided with the first opening 14 b of the first spacer 14.
And the second film 15 is placed thereon. The second film 15 and the second conductive layer 16 are
It is mounted and fixed on the first spacer 14 via an adhesive 14f applied to the surface of the spacer 14.

Further, on the second film 15, the second film
Electrode portion 17 of third conductive layer 17 laminated on film 15
The second spacer 19 is placed on the second spacer 19 by positioning so that a is located in the second opening 19b of the second spacer 19. Second
The spacer 19 is attached and fixed on the front surface of the second film 15 and the third conductive layer 17 via an adhesive 19f applied to the back surface. Further, on the second spacer 19, the electrode portion 21a of the fourth conductive layer 21 laminated on the third film 20 is positioned so as to be located in the second opening 19b of the second spacer 19, The third film 20 is placed. The third film 20 and the fourth conductive layer 21 are
It is mounted and fixed on the second spacer 19 via an adhesive 19f applied to the surface of the spacer 19. Each of the lead portions 12b, 16b, 17b, 21b electrically connected to each of the electrode portions 12a, 16a, 17a, 21a is formed into a bundle, and one end thereof is gathered at one place to be a terminal portion of a circuit to be described later. Is configured. Thus, the pressure detection device 10 in which the first opening 14b of the first spacer 14 and the second opening 19b of the second spacer 19 have different hole diameters from each other is completed.

Next, as an example in which such a pressure detecting device 10 is buried between cushion members, a seat 25 of an automobile will be described.
10A to 10 show operation states when used for (seat).
Explanation will be made based on C. First, an automobile seat (seat) 25, a part of which is shown in the figure, includes an upper seat portion 25a and a lower seat portion 25b made of thick foamed polyurethane. The pressure detecting device 10 is arranged at a position where a load is received from a seated person sitting on the seat 25, and is sandwiched between cushion members such as foamed polyurethane of the upper seat portion 25a and the lower seat portion 25b.

FIG. 10A shows that the pressure detecting device 10 is in a non-load state. That is, since no occupant is sitting on the seat 25, the pressure is not substantially applied to the pressure detection device 10 and no detection is performed. As shown in FIG. 10B, when the seated person sits on the seat 25, the load force indicated by the arrow (the pressing force generated by the load) f
1 is applied to the third film 20 side of the pressure detection device 10 via the upper sheet portion 25a. As the load force of f1, for example, a case where a child sits on the seat 25 is considered. When this load force f1 is applied to the sheet 25, substantially the same pressure as f1 is applied also from the lower surface side of the first film 11, so that the upper sheet portion 25a and the lower sheet portion 25b The third film 20, which is formed in a deformed curved surface that gradually bends inward, which is the side, and that is in contact with the upper sheet portion 25a corresponding to the deformed curved surface,
The first film 11 in contact with the lower sheet portion 25b also has a deformed curved surface that is gradually bent inward.

Then, one of the third and fourth conductive layers 1
The electrode portions 17a, 21a of the first and the second contact portions 21a and 21a are brought into contact with each other in the second opening portion 19b at a point contact or a surface contact close to the point contact by dropping of the electrode portion 21a, and are electrically connected at the first pressure. On). On the other hand, when the lower sheet portion 25b is deformed into a curved surface by the load force f1, the electrode portion 12a of the first conductive layer 12 laminated on the first film 11 is formed.
And the electrode portion 16a of the second conductive layer 16 laminated on the second film 15 is closer to the electrode portion 12a by dropping (raising), but does not reach the contact because the load force f1 is weak. Maintain a non-conductive (switch-off) state. This is because the second opening 19b of the second spacer 19 disposed between the third and fourth conductive layers 17 and 21 has the first opening 19b.
Since the first spacer 14 disposed between the second conductive layers 12 and 16 has a larger hole diameter than the first opening 14b, the thickness of the first and second spacers 14 and 19 and the third Load force f1 applied to film 20, and load force f1
Accordingly, even if the reaction forces applied to the first film 11 are substantially the same, the third film 20 can be sufficiently moved at the peripheral portion of the second opening 19b having a large hole diameter against the load force f1. This is because it cannot be supported, and the curved surface is deformed to a greater extent than the first film 11 arranged in the first opening 14b having a small hole diameter. In this way, for example, the fact that a child with a small load force is seated is determined by the third and fourth children.
When the respective electrode portions 17a and 21a of the conductive layers 17 and 21 are switched on, they are detected by a circuit described later.

Next, as shown in FIG. 10C, when a load force f2 (approximately 1.5 times to about 5 times the load force f1) indicated by an arrow is applied to the pressure detecting device 10, the load force becomes greater than the load force f1. To
The upper sheet portion 25a and the lower sheet portion 25b are each formed on a deformed curved surface that gradually bends inward, and the third film 20 and the first film 11 also gradually inward corresponding to the deformed curved surface. A deformed curved surface that bends is formed.
The load force f2 may be larger than the load force f1, for example, when an adult sits on the seat 25. Then, the respective electrode portions 17a, 21a of the third and fourth conductive layers 17, 21 are mutually connected to the second opening 19b.
And contact (switch on) by a wider surface contact in the inside.

On the other hand, when the lower sheet portion 25b is greatly deformed into a curved surface by the reaction force of the load force f2, the respective electrode portions 12a and 16a of the first and second conductive layers 12 and 16 are mutually in the first position. Abuts with the point contact or the surface contact close to the point contact in the opening 14b and conducts with the second pressure (switch on)
I do. In this way, for example, the fact that an adult with a load force is seated is determined by the electrode portions 17a, 21a of the third and fourth conductive layers 17, 21 and the first and second conductive layers 12, 16, respectively.
When both of the electrode portions 12a and 16a are turned on (switched on), they are detected by a circuit described later. FIG.
At 0C, the second film 15 is described as not being deformed at all, but actually, it is slightly bent downward (this point is the same in FIGS. 11C and 12C). Further, in the direction of the load forces f1 and f2 applied to the sheet 25, two electrode portions 17a sandwiching a second spacer 19 having a second opening 19b having a large hole diameter on the pressing side to which the load forces f1 and f2 are directly applied, 21a, and two electrode portions 12a, 16a for holding the first spacer 14 having the first opening 14b having a small hole diameter on the side where a reaction force (reaction) is generated corresponding to the load forces f1, f2. Accordingly, the load force is transmitted to the third film 20 on the pressure side slightly earlier than the first film 11 on the lower side, and the load force can be reliably detected without erroneous operation. The first pressure for switching on between the electrode portions 12a and 16a only with the circular first opening 14b and the second opening 19b, and the second pressure for switching on between the electrode portions 17a and 21a. In the first embodiment, the ratio of the hole diameter of the circular opening is set to 1 /.
By setting the ratio to 1.1 to 1 / 1.5, the first pressure with respect to the second pressure can be given an appropriate difference of 1.5 to 5 times, which is preferable.

Next, as shown in FIG. 8 and FIG. 11, the pressure detecting device 30 according to the second embodiment of the present invention includes the opening portions 14b of the first and second spacers 14 and 19 described above.
The thickness of each of the first and second spacers is different from that of the pressure detection device 10 having a different hole diameter of 19b. Therefore, the first film 1 comprising the first conductive layer 12 which constitutes the pressure detecting device 30
1 and a second laminate of the second and third conductive layers 16 and 17
The film 15 and the third film 20 in which the fourth conductive layer 21 is laminated are the same as those described above, and are denoted by the same reference numerals and will not be described in detail to avoid duplication.

The first spacer 34 is provided on the first film 1.
The base material 34a having substantially the same external shape as that of No. 1 and serving as a base
Is made of a polyester film such as PET (polyethylene terephthalate) having insulation and flexibility, and an adhesive is applied to the front and back surfaces of the base material 34a. The thickness of one spacer 34 is about 150 μm. The first spacer 34 has a plurality of first openings 34b each having a substantially circular shape. Each first opening 34b has a hole diameter of about 10 mm.

The second spacer 39 is formed of the first spacer 3
Substrate 39a which has almost the same external shape as that of No. 4 and serves as a base
Is made of a polyester film, such as PET, having insulation and flexibility. An adhesive is applied to the front and back surfaces of the base material 39a, and the second spacer 39 including the thickness of the adhesive is applied. The plate thickness is about 100 μm. Therefore, the plate thickness of the second spacer 39 is formed to be about 50 μm thinner than the plate thickness of the first spacer 34. The second spacer 39 is also provided with a plurality of substantially circular second openings 39b of the same diameter, that is, about 10 mm, at the same position as the first spacer 34.

Next, the assembling of the pressure detecting device 30 configured as described above will be briefly described. The first film 11 on the side of the first conductive layer 12 is provided with the first spacer 34 of the first spacer 34. The electrode portion 12a of the first conductive layer 12 is formed in the opening 34b.
And the electrode portion 16a of the second conductive layer 16 laminated on the second film 15 are positioned so as to face each other, and the first spacer 34 and the second 2 Attach and fix the film 15. Furthermore, on the surface of the second film 15, the electrode portion 17 a of the third conductive layer 17 laminated on the second film 15 in the second opening 39 b of the second spacer 39 and the third film 20 laminated on the third film 20. The second spacer 39 and the third film 20 are positioned at positions where the electrode portions 21a of the fourth conductive layer 21 face each other and the adhesive applied to both surfaces of the second spacer 39 is interposed therebetween.
And fix it. Thus, the pressure detecting device 30 having the plate thicknesses of the first and second spacers 34 and 39 different from each other is completed.

Next, FIG. 1 shows an operation state when such a pressure detecting device 30 is used for a seat 25 (seat) of an automobile.
This will be described with reference to FIGS. 1A to 11C. First, FIG. 11A
Indicates that the pressure detection device 30 is in a non-load state. That is, since no occupant is sitting on the seat 25, no pressure is substantially applied to the pressure detection device 30 and no detection is performed. As shown in FIG.
When a occupant sits on the third film 20, a load force f1 indicated by an arrow is applied to the third film 20 side of the pressure detection device 30 via the upper seat portion 25a. When this load force f1 is applied to the sheet 25, substantially the same pressure as f1 is applied from the lower surface side of the first film 11, so that the upper sheet portion 2
The third film 20 in contact with 5a and the first film 11 in contact with the lower sheet portion 25b form a deformed curved surface that gradually bends inward.

Then, the third and fourth conductive layers 1
The electrodes 17a and 21a of the electrodes 7 and 21 are brought into contact (switch-on) in the second opening 39b by point contact or surface contact close to the point contact with each other. On the other hand, the respective electrode portions 12a and 16a of the first and second conductive layers 12 and 16 are close to each other, but do not come into contact with each other because the load force f1 is weak. maintain.
This is because the second opening 39b of the second spacer 39 disposed between the third and fourth conductive layers 17 and 21 is disposed between the first and second conductive layers 12 and 16. Since the plate thickness is smaller than the first opening 34b of the spacer 34, each opening 34 of the first and second spacers 34 and 39 is formed.
b, 39b, the load force f1 applied to the third film 20, and the first film 1 corresponding to the load force f1.
Even if the reaction forces applied to 1 are almost the same,
When the thickness of the spacer 39 is smaller than the thickness of the first spacer 34 and the third film 20 is curved,
And the moving distance between the fourth conductive layers 17 and 21 is short,
This is because even a light load force comes into contact immediately.

Next, as shown in FIG. 11C, when a load force f2 indicated by an arrow is applied to the pressure detection device 30, the load force f
1, the third film 20 and the first film 1
1 forms a deformed curved surface that gradually bends inward. Then, the respective electrode portions 17a and 21a of one of the third and fourth conductive layers 17 and 21 are brought into contact with each other in a wide area in the second opening 39b to conduct (switch on). On the other hand, the first
And the respective electrode portions 12a and 16a of the second conductive layers 12 and 16
Are brought into contact with each other in the first opening 34b with point contact or surface contact close to the point contact, and they are turned on (switched on). The second side on the pressurized side to which the load force is directly applied
Since the thickness of the spacer 39 is smaller than the thickness of the other first spacer 34, the load force is transmitted to the third film 20 on the side to which the load is applied slightly earlier than the first film 11 on the tongue side. Thus, the load force can be reliably detected without malfunction. The first spacer 34 and the second spacer 3
In the second embodiment in which there is a difference between the first pressure for switching on between the electrode portions 12a and 16a and the second pressure for switching on between the electrode portions 17a and 21a only with a plate thickness of 9, The thickness ratio of the spacer including the adhesive is 1.5
By setting up to 5 times, the pressure to be detected is also 1.5 to
A moderate difference of five times can be provided.

Next, as shown in FIG. 9 and FIG. 12, the pressure detecting device 40 according to the third embodiment of the present invention includes a hole diameter of each opening 14b, 19b of the first and second spacers 14, 19. Pressure detector 10 having different sizes, and pressure detector 30 having different thicknesses of the spacers 34 and 39.
In contrast, the first film 11 and the third film 20 have different sheet thicknesses (plate thicknesses). The first conductive layer 12 and the second
Film 1 in which and third conductive layers 16 and 17 are laminated
5, the second spacer 19, and the fourth conductive layer 21 are the same as those in the above-described first embodiment, are denoted by the same reference numerals, and detailed descriptions thereof will be omitted to avoid duplication.

The first film 41 has a thickness of about 100 μm
Of PEN (polyethylene naphthalate), and has insulating properties and flexibility. The material and configuration are the same except that the thickness of the first film 11 is increased by about 25 μm. The first spacer 44 is a base material 4 serving as a base.
4a is made of a polyester film such as PET (polyethylene terephthalate) having insulation and flexibility, and an adhesive is applied to the front and back surfaces of the base material 44a, including the thickness of the adhesive. First spacer 44
Has a thickness of about 100 μm. The first spacer 44 has a plurality of substantially circular first openings 44b. Each first opening 44b has a hole diameter of about 10 mm, which is the same as the hole diameter of the second opening 19b of the second spacer 19. The third film 50 is
This is the same as the above-described third film 20 having a thickness of about 75 μm. The method of assembling the pressure detecting device 40 having the above-described configuration is the same as that described above, and a description thereof will be omitted.

Next, as an example in which such a pressure detecting device 40 is buried between cushion members, an operation state when it is used for a seat (seat) 25 of an automobile is shown in FIGS.
This will be briefly described based on C. First, FIG. 12A shows that the pressure detection device 40 is in a non-load state.
In FIG. 12B, when a seated person sits on the seat 25,
The load force f1 indicated by the arrow is applied to the third film 50 side of the pressure detection device 40 via the upper sheet portion 25a. When this load force f1 is applied to the sheet 25, the first film 41
Approximately the same pressure as f1 is also applied from the lower surface side of the third film 5 in contact with the upper sheet portion 25a.
0, the first film 41 in contact with the lower sheet portion 25b forms a deformed curved surface that gradually bends inward.

Then, one of the third and fourth conductive layers 1
The electrodes 17a and 21a of the electrodes 7 and 21 are brought into contact (switch-on) by a point contact or a surface contact close to the point contact in the second opening 19b. On the other hand, the respective electrode portions 12a and 16a of the first and second conductive layers 12 and 16 are close to each other, but do not come into contact with each other because the load force f1 is weak. maintain.
This is because the sheet thickness of the third film 50 is the first film 4
1 is about 25 μm thinner than the sheet thickness of the first and second spacers 44, 19, and the opening portions 44b,
19b have the same hole diameter and the load force f1
, Even if the reaction force applied to the first film 41 is the same, the sheet thickness of the third film 50 is
1 is thinner than that of the first film 41, the flexibility is higher than that of the first film 41, and the curved surface is easily deformed.
This is because 7a and 21a come into immediate contact with each other even with a light load force.

Next, as shown in FIG. 12C, when a load force f2 indicated by an arrow is applied to the pressure detecting device 40, the load force f
1, the third film 50 and the first film 4
1 forms a deformed curved surface that gradually bends inward. Then, the respective electrode portions 21a of the third and fourth conductive layers 17 and 21 are brought into contact with each other in a wider surface contact within the second opening 19b to conduct (switch on). On the other hand, each electrode portion 12a, 16a of the first and second conductive layers 12, 16
Are brought into contact with each other in the first opening portion 44b with point contact or surface contact close to the point contact, so that conduction (switch-on) occurs. Further, in the direction of the load forces f1 and f2 applied to the sheet 25, the third film 50 having a small sheet thickness is placed on the pressurized side where the load forces f1 and f2 are applied, and a side where a reaction force is generated corresponding to the load forces f1 and f2. First film 4 with thick sheet
By setting 1, the load force is transmitted to the third film 50 on the pressure side slightly earlier than the first film 41 on the lower side,
The load force can be reliably detected without malfunction. A first pressure for switching on between the electrode portions 12a and 16a only by the plate thickness of the first and third films 41 and 50;
In the third embodiment in which there is a difference between the second pressure for switching on between the electrode portions 17a and 21a, the plate thickness of the first film 41 with respect to the third film 50 is set to 1.1 to 1.1.
By setting the value to 1.7 times, it is possible to give a moderate difference of 1.5 to 5 times between the second pressure and the first pressure.

Next, a schematic circuit configuration example of a detection circuit capable of easily detecting two-stage pressures of the pressure detection devices 10, 30, and 40 common to the first, second, and third embodiments is shown. 13, one end of the first resistor R1 is connected to the reference voltage Vin applied to the input terminal T0, and one end of the second resistor R2 and the output terminal T1 are connected to the other end. , And one end of the second switch SW2 is connected. A first switch S is connected to the other end of the second resistance element R2.
W1 is connected at one end and the first and second switches S
The other ends of W1 and SW2 are grounded via a ground terminal T2. Here, the first switch SW1 corresponds to the respective electrode portions 17a and 21a of the third and fourth conductive layers 17 and 21, and the second switch SW2 corresponds to the first and second conductive layers 1 and 21.
2 and 16 correspond to the respective electrode portions 12a and 16a.

The load force f is applied to the pressure detectors 10, 30, and 40.
When 1 is added, the first switch SW1 is turned on, and the voltage divided by the first resistance element R1 and the second resistance element R2 is output to the output terminal T1. When the load force f2 is applied, the first and second switches SW
When both of SW1 and SW2 are turned on, a voltage of 0 volt (V) is output to the output terminal T1. When neither the load force f1 nor f2 is applied, the output terminal T
1 outputs the same voltage as the input terminal T0. In this way, by applying different loads to the pressure detection devices 10, 30, and 40, three types of detection signals can be extracted from the output terminal T1.

Although the pressure detecting devices 10, 30, and 40 according to the embodiments of the present invention have been described, the present invention is not necessarily limited to the above-described configuration. Therefore, these may be combined as needed. In addition, the first and second conductive layers 12, 1, 1
6, and the third and fourth conductive layers 17 and 21 are made of a binder resin made of a thermosetting resin mixed with a conductive powder, so that a thermosetting resin is used as compared with a thermoplastic resin. Therefore, even when a heavy load is left on a place exposed to a high temperature, for example, a seat 25 on which a pressure detecting device is mounted in a car for a long time, creep hardly occurs, and the pressure detecting characteristic is poor. It is difficult to change over time, and the durability can be improved. here,
Blend of silver powder and carbon powder (comprising carbon black and graphite, etc.) can be used as the conductive powder, and the electrode portion is made of thermosetting epoxy resin, melamine resin, etc. in addition to the above-mentioned phenol resin. A binder resin made of a conductive resin can be used. In addition, the first and second conductive layers 12 and 16 (electrode portions 12a,
16a) and the third and fourth conductive layers 17, 21 (electrode portions 17a, 21a) are each
Opening 14b and the opening 1 of the second spacer 19
9b, the moving distances between the electrode portions 12a and 16a, and 17a and 21a are accurately determined only by the thickness of the spacers 14 and 19, so that each Since there is no influence of the variation in the film thickness of the electrode portion after printing, the variation in the detected pressure can be reduced and the switching between the electrode portions can be switched on / off. In addition, as described above, the second film 15 having the second conductive layer 16 and the third conductive layer 17 laminated on the front and back surfaces, respectively, and the second film 15 and the third conductive layer 17 only, respectively. The second film 15 may be divided into two parts to have two members. The pressure detector 10,
As an example of the use of 30, 40, an example in which it is embedded in the seat of an automobile has been described. However, the present invention may be any device that is embedded between cushion members and can apply substantially the same pressure from above and below. For example, it can be installed in a bed.

[0047]

As described above, the pressure detecting device of the present invention has a conductive layer which can be brought into contact with and separated from a plurality of places, and the conductive layer has a first sheet-like switch which switches on at a first pressure. The second sheet-like switch, which has a conductive layer that can be contacted and separated at a plurality of places and is switched on at a second pressure different from the first pressure, is formed by laminating, so that it is inexpensive and has a simple structure. Multi-stage pressure can be detected.

A first film provided with a first conductive layer, a second film provided with a second conductive layer on one side and a third conductive layer on the other side, and a fourth A third film provided with a conductive layer, a first spacer and a second
The pressing force for deforming the first and third films so as to contact and separate the first and second conductive layers and the third and fourth conductive layers are formed by sequentially laminating the first and third films via spacers. By making the pressing force to make contact and separation different, multi-stage pressure can be detected with a simple structure, so that the cost can be reduced.

Further, a first film having a first conductive layer on one surface and a second film having a second conductive layer on one surface are formed by forming a first film having an opening between opposing first and second conductive layers. The third conductive layer is directly or indirectly laminated on the other surface of the second film, and the fourth conductive layer is disposed opposite to the third conductive layer. A third film having a conductive layer on one surface thereof, and the second film are stacked and arranged via a second spacer having an opening between the third and fourth conductive layers facing each other; The first and second conductive layers and the third and fourth conductive layers are configured to come into contact with and separate from each other with different pressing forces applied from above and below through the respective openings formed through the second spacer. Multi-stage pressure detection with simple structure Since it is Rukoto, it is possible to reduce the cost down.

Further, since the opening of the first spacer and the opening of the second spacer have different hole diameters, each film deformed into a different curved surface in each opening can be used as a spacer. Since the same plate thickness can be used, a common spacer material may be used, and it is not necessary to prepare a plurality of types of materials, and cost can be reduced. Further, since the hole diameters are different, it is easy to easily distinguish the two types of spacers visually when assembling.

Further, since the thickness of the first spacer and the thickness of the second spacer are made different, spacers having the same hole diameter and outer shape can be used.
These spacers can be punched out by the same mold, so that the cost of the mold can be reduced, and multi-stage pressure can be detected with a simple structure.

Further, since the plate thickness of the first film and the plate thickness of the third film are made different from each other, even if the spacers having openings having the same hole diameter are the same, each film deformed into a curved surface. Because of the different deformation states, the pressure detecting device can be switched on at different required timings with a simple structure. Also, the first spacer and the second spacer
Since the same spacer can be used, the cost can be reduced.

The first and second conductive layers and the third
And the fourth conductive layer has a layer in which a conductive powder is mixed with a binder resin made of a thermosetting resin. Due to the use of the thermosetting resin, the durability is good, so that creep hardly occurs and pressure detection is performed. Characteristics are hardly deteriorated, and changes with time can be reduced.

Further, since the pressure detecting device is provided in the seat of the automobile, a seat (seat) having a seating detecting function capable of detecting two different seating states can be manufactured with a simple structure. By reducing the cost and analyzing the pressure distribution, it is possible to reliably detect, for example, the sitting state of an adult and a child.

The pressing force for bringing the first and second conductive layers into and out of contact with each other is made larger than the pressing force for bringing the third and fourth conductive layers into and out of contact. Is mounted in the seat of the automobile such that the first and second conductive layers are pressed against the pressing force applied between the third and fourth conductive layers due to the viscosity (viscoelasticity) of the cushion member such as urethane foam in the seat. Of the pressing force applied to the conductive layer (delay of transmission of load) can be prevented, and the third and fourth conductive layers can be reliably switched on first.

The first and second conductive layers and the third
And the fourth conductive layer is made by mixing a conductive powder with a binder resin made of a thermosetting resin, so that even when heavy luggage is left on a car seat at a high temperature for a long time. , Creep is less likely to occur, pressure detection characteristics are less likely to degrade, and there is little change over time, and durability can be improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a main part of a first embodiment of a pressure detecting device according to the present invention.

FIG. 2 is a plan view of a first film on which a first conductive layer constituting the pressure detecting device is laminated.

FIG. 3 is a plan view of a first spacer included in the pressure detecting device.

FIG. 4 is a rear (front) plan view of a second film on which a second and a third conductive layer constituting the pressure detecting device are laminated.

FIG. 5 is a sectional view taken along line 5-5 in FIG. 4;

FIG. 6 is a plan view of a second spacer constituting the pressure detecting device.

FIG. 7 is a plan view of a third film constituting the pressure detecting device.

FIG. 8 is a cross-sectional view illustrating a main part of a pressure detecting device according to a second embodiment of the present invention.

FIG. 9 is a sectional view of an essential part for explaining a third embodiment of the pressure detecting device of the present invention.

FIG. 10 is a sectional view of an essential part showing an operating state when the pressure detecting device according to the first embodiment is used for an automobile seat, in a state where the load applied in the order of FIGS. 10A, 10B and 10C is increased; Is shown.

FIG. 11 is a sectional view of an essential part showing an operating state when the pressure detecting device according to the second embodiment is used for an automobile seat, in a state where the load applied in the order of FIGS. 11A, 11B and 11C is increased; Is shown.

FIG. 12 is a cross-sectional view of an essential part showing an operation state when the pressure detection device according to the third embodiment is used for an automobile seat, in a state where the load applied in the order of FIGS. 12A, 12B, and 12C is increased; Is shown.

FIG. 13 is a circuit diagram illustrating a detection unit used in the pressure detection device according to the first, second, and third embodiments of the present invention.

[Explanation of symbols]

 11, 41 1st film 12 1st conductive layer 14, 34, 44 1st spacer 14b, 34b, 44b 1st opening 15 2nd film 16 2nd conductive layer 17 3rd conductive layer 19, 39th 2 spacer 19b, 39b Second opening 20, 50 Third film 21 Fourth conductive layer

Claims (9)

[Claims] 1. A switch comprising: a first sheet-like switch having a conductive layer which can be turned on and off at a plurality of places; a conductive layer which can be turned on and off at a plurality of places; A pressure detecting device, wherein a second sheet-like switch that is turned on at a second pressure different from the first pressure is stacked and formed. 2. The first sheet-like switch comprises a first film provided with a first conductive layer, a second film provided with a second conductive layer on one surface side, and A first spacer interposed between the second films,
The second sheet-like switch includes a third conductive layer provided on the other surface side of the second film, a third film provided with a fourth conductive layer, the second film and the third film. A second spacer interposed therebetween, the first sheet-like switch and the second sheet-like switch are sequentially laminated, and one of the first film and the third film is pressed at the first pressure. The first and second sheet-like switches are turned on by deforming and deforming the other of the first film and the third film by the second pressure. The pressure detection device as described in the above. 3. An opening formed between a first film having a first conductive layer laminated on one surface and a second film having a second conductive layer laminated on one surface between the opposed first and second conductive layers. A third conductive layer is formed directly or indirectly on the other surface of the second film, and is disposed opposite to the third conductive layer. And a third film in which a fourth conductive layer to be formed is laminated on one surface, and the second film are laminated and arranged via a second spacer having an opening between the opposed third and fourth conductive layers. The first spacer through the openings formed through the first spacer and the second spacer, respectively.
And the second conductive layer, and the third and fourth conductive layers come and go with different pressing forces applied from both sides of the other surface of the first film and the other surface of the third film. Pressure detector. 4. The pressure detection device according to claim 3, wherein the opening of the first spacer and the opening of the second spacer have different sizes from each other. 5. The pressure detecting device according to claim 2, wherein the thickness of the first spacer is different from the thickness of the second spacer. 6. The pressure detecting device according to claim 2, wherein the thickness of the first film is different from the thickness of the third film. . 7. The first and second conductive layers, and the third and fourth conductive layers have a layer in which conductive powder is mixed with a binder resin made of a thermosetting resin. The pressure detecting device according to any one of claims 2 to 6. 8. A vehicle seat detecting device, wherein the pressure detecting device according to claim 2 is provided in a vehicle seat. 9. A pressing force for bringing the first and second conductive layers into and out of contact with each other is larger than a pressing force for bringing the third and fourth conductive layers into and out of contact with each other. 9. The vehicle seat detecting device according to claim 8, wherein the conductive layer is mounted in the seat so as to be lower than the third and fourth conductive layers.