JP2003045274A - Seating sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seating sensor equipped with a high durability enabling to detect load precisely even in a situation of high load for a long period of time. SOLUTION: The seating sensor 6 is structured by polymerizing a pair of elastic sheets 11, 12 through a insulating spacer 13 and an adhesive 14. On the opposing faces 11a, 12a of the elastic sheets 11, 12, an upper electrode 15a and a lower electrode 16a are formed at a position corresponding to a contact part 17. At a position of the insulating spacer 13 corresponding to the contact part 17, an opening 18 with a given diameter is formed, and at same time, an air conduit 19 communicating with the opening 18 and connecting the contact part 17 spatially with another adjacent contact part is formed. When load is applied on each contact part at the same time, an actual load on each contact part 1 to 7 is reduced due to repulsive force of sealed air, and when load is applied on a part of the contact parts 17, the other part of the contact parts swells and the contacts with the load are capable of an on/off switching at low load.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seating sensor for detecting the presence / absence of a load on a seat, and in particular, a seating sensor having stable detection characteristics without losing durability even in a state where a high load is applied for a long time. Regarding

[0002]

2. Description of the Related Art In recent years, seating sensors are often mounted on automobile seats and the like, and have attracted attention as a detecting device for performing various controls. 10 is an exploded perspective view showing the configuration of a seating sensor using a membrane switch, and FIG. 11 is a sectional view taken along the line AA ′ of FIG. As shown in FIGS. 10 and 11, a conventional seating sensor 100 includes a pair of flexible sheets 101 and 102 made of an insulating resin film such as polyethylene terephthalate (PET) or polyethylene naphthalate (PEN) and an insulating spacer. It is constituted by polymerizing via 103. Conductive patterns 104 and 105 made of a conductive material such as Ag (silver) paste are provided on the opposing surfaces of the pair of flexible sheets 101 and 102, respectively.
Are formed by a method such as screen printing. An opening 106 is formed at a predetermined position of the insulating spacer 103, and the conductive patterns 1 above and below the position of the opening 106 are formed.
04 and 105 form the contact portion 107. Contact point 107
When a load in the thickness direction of the flexible sheets 101 and 102 is applied to the upper and lower conductive patterns 1 through the openings 106.
04 and 105 are brought into contact with each other to be electrically conducted, and the current flowing therethrough is detected, whereby the ON / OFF (presence / absence of load) of the switch of the contact portion 107 can be detected.

[0003]

However, in such a seating sensor, when a high load is continuously applied to the contact portion 107 for a long period of time, creep (deformation) occurs in the contact portion 107 and the upper and lower conductive patterns are formed. 10
There is a problem that the contact points are deformed due to the displacement of 4, 105 and the accurate detection cannot be performed.

The present invention has been made in view of the above problems, and provides a seating sensor having high durability that can accurately detect a load even when a high load is applied for a long time. The purpose is to provide.

[0005]

A first seating sensor according to the present invention is a seating sensor for detecting the presence / absence of a load on a seat, in which a pair of flexible sheets are provided as an insulating spacer and both surfaces of the insulating spacer. Is formed by polymerizing via an adhesive material disposed on the contact surfaces of the pair of flexible sheets and the insulating spacer, and the contact surfaces are sealed by the adhesive material. And an opening for forming the contact portion at a predetermined position of the insulating spacer, and an air path for spatially connecting adjacent contact portions communicating with the opening portion with each other. And a membrane switch formed with.

A second seating sensor according to the present invention is a seating sensor for detecting the presence / absence of a load on a seat, in which a pair of flexible sheets are provided as insulating spacers and an adhesive material arranged on both surfaces of the insulating spacers. Is formed by superposing through the above, the contact surfaces of the opposing surfaces of the pair of flexible sheets and the insulating spacers are sealed by the adhesive, and conductive patterns forming a plurality of contact points are formed on the opposing surfaces. At least one of the conductive patterns formed on the contact portion is covered with a pressure sensitive layer whose resistance value decreases as the load applied to the contact portion increases, and the contact portion is provided at a predetermined position of the insulating spacer. And a pressure sensitive switch in which an opening for forming a space and an air passage communicating with the opening and spatially connecting adjacent contact portions are formed. To.

According to the present invention, the opening of the insulating spacer forming the contact portion formed by the upper and lower conductive patterns formed on the opposing surfaces of the pair of flexible sheets is bonded to the pair of flexible sheets and the adhesive. The opening is sealed by a material, and the opening is communicated by an air path that spatially connects the adjacent contact portions. Therefore, when a load is applied to multiple contact points at the same time, the load applied to each contact point can be reduced due to the compression repulsive force of the air that is sealed inside the opening and air passage, and the load on the contact points is reduced. It is possible to reduce the weight so that deformation or the like does not occur. In addition, when a load is applied to a part of the contact points, the sealed air is pushed out through the air passage to the contact points where there is no applied load. It is possible to detect ON / OFF of the contact portion having a load by the dispersion action with a relatively low load, and similarly, it is possible to reduce the load on the contact portion and prevent deformation or the like. Thereby, the durability of the seating sensor can be improved.

It is preferable that the adhesive for adhering the pair of flexible sheets and the insulating spacer to each other is a hot-melt adhesive from the viewpoint of cost and handleability.
Other synthetic resin adhesives and adhesives can also be used.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a side view showing a seat incorporating a seating sensor according to an embodiment of the present invention. As shown in FIG. 1, the seat 1 includes a seat 2, a backrest 3, and a headrest 4. On the surface of the seating portion 2, a skin 5, such as cloth or leather, is formed, and a seating sensor 6 in a sheet shape is embedded and arranged immediately below the skin 5. In addition, a child seat 7 on which a child is placed is installed in the seat 2 so that a load is applied to the entire seat 2. In addition,
The seating sensor 6 may be arranged at any position of the seating portion 2 as long as it can be surely sensed.

FIG. 2 is a sectional view showing a part of the seating sensor 6. The seating sensor 6 is a membrane switch in this example, and is a pair of flexible sheets 11 and 1 made of an insulating resin film such as a polyester film.
2 is polymerized via an insulating spacer 13 which is also made of an insulating resin film and an adhesive material 14 arranged on both surfaces of the insulating spacer 13.
In addition, in this example, the insulating spacer 13 includes two insulating spacers 13a and 13b, which are adhesive members 13 such as double-sided tape.
It has a structure in which it is bonded via c. Conductive patterns 15, 1 made of a conductive material such as silver paste are provided on the facing surfaces 11 a, 12 a of the pair of flexible sheets 11, 12, respectively.
6 is formed by a method such as screen printing. The conductive pattern 15 on the upper side in the drawing includes an upper electrode 15a formed at a position corresponding to the contact portion 17, and a lead portion (not shown) commonly connecting these upper electrodes 15a to, for example, a + side power supply terminal. It is composed of. On the other hand, the conductive pattern 16 on the lower side in the drawing includes lower electrodes 16a formed at positions corresponding to the contact portions 17, and lead portions (not shown) for individually guiding the currents flowing through the lower electrodes 16a to the detection circuit 50. No)) and.

An opening 18 having an opening diameter that allows the upper electrode 15a and the lower electrode 16a to sufficiently contact each other is formed at a position corresponding to the contact portion 17 of the insulating spacer 13 and communicates with this opening 18. An air passage 19 is formed that spatially connects the contact portion 17 to another adjacent contact portion (not shown). The air passage 19 is formed by, for example, the adhesive member 13 arranged between the insulating spacers 13a and 13b.
It is formed by patterning c in advance.
In this seating sensor 6, the seat 1 is provided through the opening 18.
The upper electrode 15a and the lower electrode 16a are in contact with each other when a load is applied to the seat portion 2. At this time,
As shown in, since the upper electrode 15a and the lower electrode 16a of each contact portion 17 to which a load is applied are electrically connected,
The presence or absence of a load can be determined by detecting the current flowing through each contact 17 with the detection circuit 50.

In this seating sensor 6, each contact point 17 (1
7a, 17b, 17c) forming an opening 18 (18
a, 18b, 18c) are adjacent contact points and air paths 19
Since it is sealed by the pair of flexible sheets 11 and 12, the insulating spacer 13 and the adhesive material 14 except that they are spatially connected to each other, as shown in FIG. 4, for example, as shown in FIG. F) is applied to the entire surface of the seating portion 2 and the load F is simultaneously applied to the respective contact portions 17a to 17c of the seating sensor 6, each opening 18
The sealed air in the a to 18c and the air passage 19 is simultaneously compressed. Since the air compressed in the hermetically sealed state produces a repulsive force, a force that pushes each of the contact portions 17a to 17c outward is generated. Therefore, the actual load applied to each of the contact points 17a to 17c is
The load is less than the load F. Therefore, even when the load F is applied for a long time, each contact point 17a ...
Since 17c is less likely to be deformed, it is possible to realize excellent durability while maintaining high detection performance. The contact condition between the upper electrode 15a and the lower electrode 16a at each of the contact portions 17a to 17c can be set in advance in consideration of this repulsive force, and therefore the performance of on / off detection is higher than that of a normal seating sensor. Has no effect on.

On the other hand, as shown in FIG. 5, for example, when a person sits on the seating portion 2 of the seat 1, depending on the seating position of the buttocks 30 of the person, the contact points 17 (17d, 17d) of the seating sensor 6 are provided.
e, 17f, 17g), some contact points 17d, 1
A situation may occur in which the load F is applied to 7e and the load is not applied to the other contact portions 17f and 17g. In this case, the openings 18d, 17d of the contact points 17d, 17e to which the load F is applied,
The air of 18e passes through the air passage 19 to the other contact portions 17f,
Since it is pushed out to each opening 18f, 18g of 17g,
Each opening 1 of the contact points 17f and 17g into which air has flown
In 8f and 18g, the air volume increases and a pressure reducing action occurs, and the contact portions 17f and 17g are expanded outward. Thereby, the contact points 17d and 17e to which the load F is applied
In each of the openings 18d and 18e, the air compression in the same volume is reduced and the air dispersion action occurs, so that the upper electrode 15a and the lower electrode 16a of the contact portions 17d and 17e.
The contact is made with a lower load than that of a normal seating sensor. Therefore, the resistance of the contact portions 17d and 17e to the load F is reduced, so that the contact portions are less likely to be deformed, and similarly excellent durability can be realized.

FIG. 6 is a sectional view showing a seating sensor according to another embodiment of the present invention. It should be noted that in the following, a description that overlaps with the already described portions will be omitted. The seating sensor 8 is composed of a pressure-sensitive switch, and includes a pair of flexible sheets 21 and 22 made of an insulating resin film or the like via an insulating spacer 23 and an adhesive material 14 arranged on both surfaces of the insulating spacer 23. Conductive patterns 25 and 26 are formed on the facing surfaces 21a and 22a of the pair of flexible sheets 21 and 22, respectively, which are formed by superposition. Similar to the insulating spacer 13, the insulating spacer 23 has a structure in which two insulating spacers 23a and 23b are bonded together via an adhesive member 23c such as a double-sided tape. The upper conductive pattern 25 in the drawing is composed of upper electrodes 25a formed at positions corresponding to the contact portions 27, and lead portions (not shown) commonly connecting these upper electrodes 25a to, for example, a Vcc power supply terminal. There is. on the other hand,
The lower conductive pattern 26 in the drawing includes lower electrodes 26a formed at positions corresponding to the contact portions 27, and lead portions (not shown) that ground the lower electrodes 26a via resistors. . In addition, the flexible sheet 2
A pressure sensitive ink (pressure sensitive layer) 30 is formed on the lower electrode 26a of the second conductive pattern 26 so as to cover the lower electrode 26a. The pressure-sensitive ink 30 has a resistance value (contact resistance) that changes according to the applied load (pressure). The pressure-sensitive ink 30 is formed by a method of forming a paste-like material by a method such as screen printing or offset printing, or a method of fixing a preformed film electrode in a predetermined place.

An opening 28 having a predetermined opening diameter is formed in the insulating spacer 23 at a position corresponding to the contact 27, and the contact 27 communicates with the opening 28. An air passage 29 is formed to spatially connect to another adjacent contact portion (not shown). The air passage 29 is formed, for example, by patterning the adhesive member 23c arranged between the insulating spacers 23a and 23b in advance. In this seating sensor 8, the opening 2
The upper electrode 25a and the lower electrode 26a are in contact with each other via the electrode 8.

In this seating sensor 8, the flexible sheet 21
A pressing force (load F) is applied to the lower electrode 26a of the flexible sheet 22 from above the contact portion 27 of the upper electrode 25a, and the flexible sheet 21 bends to contact the upper electrode 25a with the pressure-sensitive ink 30. Then, the load F applied to the pressure-sensitive ink 30
Pressure sensitive ink 30 according to (ie, inversely proportional to) pressure
Changes its resistance value and exhibits the characteristics as shown in FIG. That is, in the state where the load F is not applied to the contact portion 27 of the upper electrode 25a of the flexible sheet 21, the upper electrode 25a and the lower electrode 26a are separated from each other by the insulating spacer 23, so that the resistance value thereof is It is infinity (∞).
On the other hand, a load F is applied from above the upper electrode 25a of the flexible sheet 21 (above the contact portion 27) in the direction of the lower electrode 26a (downward) to bend the flexible sheet 21, and the upper electrode 2
When 5a comes into contact with the pressure-sensitive ink 30 and the load is further applied to the contact portion 27, the load (that is, the pressure value) F applied to the pressure-sensitive ink 30 is F ₁ , F ₂ , F ₃ , ..., F. _As the resistance value R of the pressure-sensitive ink 30 increases to _n , R ₁ , R ₂ , R ₃ , ...,
It gradually decreases with R _n .

In this seating sensor 8, as described above,
Depending on the load value (pressure value) of the contact portion 27, the pressure-sensitive ink 30
Resistance value R changes (when the load value increases, the resistance value R decreases)
Therefore, it can be equivalently regarded as a variable resistance. Therefore, as shown in FIG. 8, the contact portion 2 of the seating sensor 8 is
The upper electrode 25a of the flexible sheet 21 of 7a to 27n is
The lower electrode 26a of the flexible sheet 22 is connected to a constant voltage source (not shown) that outputs a constant voltage Vcc, and the lower electrode 26a of the flexible sheet 22 has a resistor 40a.
It can be configured to be respectively grounded through ~ 40n. Therefore, the constant voltage V is applied to one end of the variable resistor.
cc is supplied, and the other ends of the variable resistors are resistors 40a to 40n.
Can be considered equivalent to being grounded through. Contact portions 27a to 2 of the seating sensor 8 having such a configuration
7n, that is, lower electrode 26a and resistors 40a-40
The potentials of the connection points Xa to Xn with n are set to the connection points Xa to X
n is connected to each of the A / D converters 41a to 41n to convert an analog signal into a digital signal and the detection circuit 5
By detecting 0, it becomes possible to determine the presence or absence of a load, the magnitude of pressure, and the like.

Like the seating sensor 6, the seating sensor 8 has a pair of flexibility except that the opening 28 forming each contact 27 is connected to the adjacent contact by the air passage 19. Since the sheets 21 and 22 are sealed by the insulating spacers 23 and the adhesive material 14, when the load F is applied to each contact portion 27 at the same time, the applied load is reduced and a part of the contact portions 27 is loaded. When F is applied and the load F is not applied to the other contact portions 27, the contacts of the contact portion 27 to which the load F is applied with a low load are turned on / off.
It is possible to suppress deformation of each contact portion 27, and it is possible to achieve high detection performance and excellent durability at the same time.

In the above embodiment, the insulating spacer 13
(23) is replaced by two insulating spacers 13a, 13b (23
a, 23b) and a structure in which the adhesive member 13c (23c) is adhered to the adhesive member 13c (23c).
Although the air passage 19 (29) is formed in advance in the above, as shown in FIG. 9, a concave portion that constitutes the air passage 39 is formed in advance in the insulating spacer 33, and a pair of flexible members are provided via the adhesive material 14. You may make it interpose between the property sheets 31 and 32. In addition to this, as long as the structure is such that the openings can be connected by the air passage, its form is various.

[0020]

As described above, according to the present invention,
The opening of the insulating spacer forming the contact portion formed by the upper and lower conductive patterns formed on the opposing surfaces of the pair of flexible sheets is sealed by the pair of flexible sheets and the adhesive, and the opening is formed. Since the parts are connected by the air path that spatially connects the adjacent contact parts, when a load is applied to multiple contact parts at the same time, the compression repulsive force of the air sealed inside the opening and the air path It is possible to reduce the load applied to each contact portion, reduce the load on the contact portion, and prevent deformation or the like. In addition, when a load is applied to a part of the contact points, the sealed air is pushed out through the air passage to the contact points where there is no applied load. It is possible to detect ON / OFF of the contact portion having a load by the dispersion action with a relatively low load, and similarly, it is possible to reduce the load on the contact portion and prevent deformation or the like. Thereby, there is an effect that the durability of the seating sensor can be improved.

[Brief description of drawings]

FIG. 1 is a side view showing a seat incorporating a seating sensor according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a part of the seating sensor.

FIG. 3 is a diagram showing a circuit configuration of the seating sensor.

FIG. 4 is a cross-sectional view showing how a load is applied to the entire seat sensor.

FIG. 5 is a cross-sectional view showing how a load is applied to a part of the seat sensor.

FIG. 6 is a sectional view showing a seating sensor according to another embodiment of the present invention.

FIG. 7 is a characteristic diagram showing a relationship between load and resistance in the seating sensor.

FIG. 8 is a diagram showing a circuit configuration of the seating sensor.

FIG. 9 is a sectional view showing a seating sensor according to still another embodiment of the present invention.

FIG. 10 is an exploded perspective view showing a configuration of a seating sensor using a membrane switch.

11 is a cross-sectional view taken along the line AA ′ of FIG.

[Explanation of symbols]

1 ... seat, 2 ... seat part, 3 ... backrest part, 4 ... headrest, 5 ... skin, 6,8 ... seating sensor, 7 ... child seat, 11,12,21,22 ... flexible seat, 1
3, 23 ... Insulating spacer, 14 ... Adhesive material, 15, 16,
25, 26 ... Conductive pattern, 17, 27 ... Contact part, 1
8, 28 ... Openings, 19, 29 ... Air passages, 30 ... Pressure sensitive ink, 40 ... Resistors, 41 ... A / D converter, 50 ... Detection circuit.

Claims (3)

[Claims] 1. A seating sensor for detecting the presence / absence of a load on a seat, which is formed by polymerizing a pair of flexible sheets through an insulating spacer and an adhesive material arranged on both sides of the insulating spacer. The contact surfaces between the facing surfaces of the pair of flexible sheets and the insulating spacers are sealed with the adhesive, and conductive patterns forming a plurality of contact portions are formed on the facing surfaces, respectively, and the insulating spacers are formed. A seating characterized by comprising a membrane switch in which an opening for forming the contact portion at a predetermined position and an air path communicating with the opening and spatially connecting adjacent contact portions are formed. Sensor. 2. A seating sensor for detecting the presence or absence of a load on a seat, which is formed by polymerizing a pair of flexible sheets through an insulating spacer and an adhesive material arranged on both sides of the insulating spacer. The contact surfaces between the opposing surfaces of the pair of flexible sheets and the insulating spacer are sealed by the adhesive material, and conductive patterns forming a plurality of contact portions are formed on the opposing surfaces, respectively, and the contact portions are formed. At least one of the conductive patterns in is covered by a pressure-sensitive layer whose resistance value decreases as the load applied to the contact portion increases, and an opening for forming the contact portion at a predetermined position of the insulating spacer, A seating sensor comprising a pressure sensitive switch having an air passage communicating with the opening and spatially connecting adjacent contact portions. 3. The seating sensor according to claim 1, wherein the adhesive material is a hot melt adhesive material.