JP4058010B2 - Occupant detection device - Google Patents

Description

  The present invention relates to an occupant detection device in which a plurality of switch cells that are turned on by the occupant's weight are arranged on a seat cushion in order to detect an occupant seated on a seat.

  An airbag device for a passenger seat of an automobile detects whether or not an occupant is seated on a seat, and if the occupant is seated at the time of a vehicle collision, the airbag is deployed. The bag is controlled so as not to unfold.

As an occupant detection device used for such a purpose, a device described in Patent Document 1 described below is configured such that a plurality of switch cells that are turned on by the occupant's weight are electrically connected in parallel to the upper surface of the seat cushion, and at least When one switch cell is turned on, the seating of the occupant is detected.
Japanese Patent Laid-Open No. 10-39045

  However, the above-described conventional device detects the seating of an occupant when any one of a plurality of switch cells electrically connected in parallel is turned on, so an article such as a handbag is placed on the seat cushion. Even if only one switch cell is turned on, there is a possibility of erroneous detection that a passenger is seated.

  The present invention has been made in view of the above-described circumstances, and when an occupant seated on a seat is detected by a plurality of switch cells provided on the seat cushion, an article placed on the seat cushion is erroneously detected as an occupant. The purpose is to prevent.

In order to achieve the above object, according to the invention described in claim 1, in the occupant detection device in which a plurality of switch cells that are turned on by the occupant's weight are arranged on the seat cushion in order to detect the occupant seated on the seat. A pair of left and right first switch cells disposed at positions corresponding to the left and right buttocks of the occupant seated on the seat; and a pair of left and right second switch cells disposed in front of or behind the pair of left and right first switch cells; Each of the first switch cells includes first and second contacts connected in series between a plus terminal and a minus terminal, and the first and second contacts of both the left and right first switch cells are weights of passengers. An occupant is detected when the plus terminal and the minus terminal are conducted, and each second switch cell has a third and a fourth contact connected to the plus terminal and the minus terminal, respectively. When the third and fourth contacts of at least one of the left and right second switch cells are conducted by the weight of the occupant and the plus terminal and the minus terminal are conducted, the occupant is detected, and the third and third of the second switch cell are detected. An occupant detection device is proposed in which the load at which the four contacts are conducted is set larger than the load at which the first and second contacts of the first switch cell are conducted .

According to a second aspect of the present invention, in addition to the configuration of the first aspect, the first switch cell and the second switch cell have a thickness of a spacer disposed between contacts that can contact each other. An occupant detection device is proposed in which the magnitude of the load with which these contacts come into contact can be adjusted by changing.

According to a third aspect of the present invention, in addition to the configuration of the first aspect, the first switch cell and the second switch cell change the spacing of the spacers arranged between the contacts that can contact each other. Thus, there is proposed an occupant detection device characterized in that the magnitude of the load that these contact points come into contact with can be adjusted.

  According to the configuration of the first aspect, the pair of left and right first switch cells arranged on the seat cushion each include the first and second contacts connected in series between the plus terminal and the minus terminal. When the first and second contacts are conducted by the seated load and the two first switch cells are both turned on, the plus terminal and the minus terminal are conducted and the seating of the occupant can be detected. Since the first switch cell is turned on with a small load, even if the seating position or seating angle of the occupant is slightly shifted, the two first switch cells can be turned on together to reliably detect the occupant's seating. When an article such as a handbag is placed on the seat, only one of the two first switch cells is turned on at most, so there is no possibility that the article is erroneously detected as an occupant.

In addition, each of the pair of left and right second switch cells arranged on the seat cushion includes third and fourth contacts connected to the plus terminal and the minus terminal, so that the third and fourth loads are applied by the load on which the occupant is seated. When the contact is conducted and at least one of the left and right second switch cells is turned on, the plus terminal and the minus terminal are conducted and the seating of the occupant can be detected. Since the second switch cell is turned on with a large load, there is a possibility that only one of the two second switch cells will be turned on if the seating position or seating angle of the occupant is shifted. Even when an article such as a handbag is placed on the seat, the second switch cell does not turn on at such a load, so there is no possibility of erroneously detecting the article as an occupant .

According to the configuration of claim 2 , since the first and second switch cells have the spacers arranged between the contacts that can contact each other, the contacts can be contacted only by changing the thickness of the spacers. The magnitude of the load to be adjusted can be easily adjusted.

According to the third aspect of the present invention, the first and second switch cells have the spacers arranged between the contact points that can contact each other, so that the contact points can be contacted only by changing the interval of the spacers. The magnitude of the load can be easily adjusted.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on examples of the present invention shown in the accompanying drawings.

  1 to 5 show a first embodiment of the present invention. FIG. 1 is a plan view of a seat provided with an occupant detection circuit, FIG. 2 is a view showing an occupant detection circuit, and FIG. FIG. 4 is a sectional view taken along line 4-4 of FIG. 3, and FIG. 5 is an explanatory diagram of the operation of occupant detection.

  As shown in FIGS. 1 and 2, the vehicle seat S includes a seat cushion 11 and a seat back 12, and four switch cells 13 </ b> L having the same structure are disposed on the inner surface of the upper surface of the seat cushion 11. 13R; 14L, 14R are arranged. The two first switch cells 13L and 13R constituting the front switch cell group 13 are disposed in the front portion of the seat cushion 11 so as to be separated from each other in the left-right direction, and two second switches constituting the rear switch cell group 14 The cells 14L and 14R are arranged at the rear part of the seat cushion 11 so as to be separated in the left-right direction. The two first switch cells 13L, 13R are connected in series via harnesses a, b, c, d, e to the plus terminal 15a and minus terminal 15b of the controller 15 housed in the rear part of the seat cushion 11. The The two second switch cells 14L and 14R are connected in parallel to the plus terminal 15a and the minus terminal 15b of the controller 15. That is, the left second switch cell 14L is connected to the plus terminal 15a of the controller 15 via the harnesses a and f, and is connected to the minus terminal 15b of the controller 15 via the harnesses g, d, and e. The second switch cell 14R is connected to the plus terminal 15a of the controller 15 through the harnesses a, b, and h, and is connected to the minus terminal 15b of the controller 15 through the harnesses i and e.

  Next, the structure of the switch cells 13L, 13R; 14L, 14R will be described with reference to FIGS. Since the structures of the four switch cells 13L, 13R; 14L, 14R are all the same, the one first switch cell 13L will be described as a representative.

  The first switch cell 13L is disposed so as to be sandwiched between the lower surface of the skin 21 of the seat cushion 11 and the upper surface of the cushion material 22, and the upper film 23 and the lower film made of an elastic material such as synthetic resin. 24, a spacer 25 having a circular opening 25a and sandwiched between the upper film 23 and the lower film 24, and a first flexible material such as carbon fixed to the lower surface of the upper film 23 so as to face the opening 25a. The second contacts 26a and 27a, and a circular common contact 28 having flexibility such as carbon fixed to the upper surface of the lower film 24 so as to face the opening 25a. The first and second contacts 26a and 27a formed in a comb shape are arranged so as to enter each other, and each is connected in series in a circuit connecting the plus terminal 15a and the minus terminal 15b of the controller 15.

  Therefore, when the weight of the occupant is applied to the skin 21 of the seat cushion 11, the upper film 23 and the lower film 24 of the first switch cell 13L are pushed into the opening 25a of the spacer 25 as shown in FIG. The first and second contacts 26 a and 27 a fixed to the upper film 23 in the opening 25 a come into contact with the common contact 28 fixed to the lower film 24. As a result, the first and second contacts 26 a and 27 a are electrically connected to each other via the common contact 28.

  At this time, if the thickness t of the spacer 25 (see FIG. 3A) is increased, the sensitivity of the first switch cell 13L is decreased, and if the thickness is decreased, the sensitivity of the switch cell 13L is increased. Further, if the width or interval w (see FIG. 4) of the opening 25a of the spacer 25 is reduced, the sensitivity of the first switch cell 13L is reduced, and if it is increased, the sensitivity of the first switch cell 13L is increased. Accordingly, the sensitivity of the first switch cell 13L can be arbitrarily adjusted by changing the thickness t and the interval w of the spacer 25. In this embodiment, when an article such as a handbag is placed on the seat cushion 11. In addition, the sensitivity is adjusted to be high to the extent that the left first switch cell 13L or the right first switch cell 13R may be turned on.

  The other three switch cells 13R, 14L, and 14R have the same structure as the one switch cell 13L described above, but the first and second contacts 26a and 27a of the first switch cells 13L and 13R. The members of the second switch cells 14L and 14R corresponding to are the third and fourth contacts 26b and 27b.

  However, the sensitivity of the two first switch cells 13L and 13R is set to be relatively high, whereas the sensitivity of the two second switch cells 14L and 14R is set to be lower than that. Specifically, the sensitivity is set so as not to be turned on even when an article such as a handbag is placed on the second switch cells 14L and 14R.

  When the occupant is not seated on the seat S, as shown in FIG. 5A, all the four switch cells 13L, 13R; 14L, 14R are off, and the plus terminal 15a and minus of the controller 15 The conduction of the terminal 15b is cut off, and the seating of the passenger is not detected.

  When the occupant sits on the seat S, when the seating posture is shallow, a load from the occupant's buttocks acts mainly on the left and right front portions of the seat cushion 11, and is connected in series as shown in FIG. In addition, both the first switch cells 13L and 13R are turned on, and the plus terminal 15a and the minus terminal 15b of the controller 15 are turned on to detect the seating of the occupant.

  At this time, since the sensitivity of the left and right first switch cells 13L and 13R is set high, both the left and right first switch cells 13L and 13R are turned on even when the seating position of the occupant is slightly shifted in the left and right direction. The seating of the passenger can be detected. When an article such as a handbag is placed on the sheet S, as shown in FIG. 5C, the left and right first switch cells 13L and 13R may be turned on. Since the possibility that both the cells 13L and 13R are turned on is low, the article is not erroneously detected as an occupant.

  Further, when the seating posture of the occupant is deep, the load from the occupant's buttocks acts mainly on the left and right rear portions of the seat cushion 11, and two pieces connected in parallel as shown in FIG. When at least one of the second switch cells 14L and 14R is turned on, the plus terminal 15a and the minus terminal 15b of the controller 15 are brought into conduction, and the seating of the occupant is detected. Of course, even if both of the two second switch cells 14L and 14R are turned on, the seating of the passenger is detected.

  At this time, the sensitivity of the left and right second switch cells 14L and 14R is set to be low. However, if at least one of the left and right second switch cells 14L and 14R is turned on, an occupant can be detected. The probability is very low. Moreover, since the sensitivity of the left and right second switch cells 14L, 14R is set low, the second switch cells 14L, 14R are not turned on only by placing an article such as a handbag, and the article is not erroneously detected as an occupant. .

  As described above, when both of the two first switch cells 13L and 13R of the front switch cell group 13 are turned on, the seating of the occupant is detected regardless of whether the other switch cells are on or off, and the rear switch If either one of the two second switch cells 14L, 14R of the cell group 14 is turned on, the seating of the occupant is detected regardless of whether the other switch cells are on or off, so that the detection accuracy can be improved. Moreover, it is possible to prevent an article such as a handbag placed on the seat S from being erroneously detected as an occupant.

  Next, a second embodiment of the structure of the switch cells 13L, 13R; 14L, 14R will be described with reference to FIGS. The second embodiment is the same as the first embodiment except for the structure of the switch cells 13L, 13R; 14L, 14R, and the four switch cells 13L, 13R; 14L, 14R of the second embodiment are the same. Since all the structures are the same, one switch cell 13L will be described as a representative.

  The switch cell 13L is disposed so as to be sandwiched between the lower surface of the skin 21 of the seat cushion 11 and the upper surface of the cushion material 22, and includes an upper film 23 and a lower film 24 made of an elastic material such as synthetic resin. A first circular contact 29a having flexibility such as carbon fixed to the lower surface of the upper film 23, and a second circular contact 30a having flexibility such as carbon fixed to the upper surface of the lower film 24; The spacer 25 has a circular opening 25a and is sandwiched between the first and second contacts 29a and 30b.

  Therefore, when the weight of the occupant is applied to the skin 21 of the seat cushion 11, the upper film 23 and the lower film 24 of the switch cell 13L are deformed so as to be pushed into the opening 25a of the spacer 25 as shown in FIG. The first contact 29a fixed to the upper film 23 in the opening 25a comes into contact with the second contact 30b fixed to the lower film 24 and is electrically connected to each other.

  Also in the second embodiment, when the thickness t (see FIG. 6A) of the spacer 25 is increased, the sensitivity of the first switch cell 13L is decreased, and when the spacer 25 is decreased, the sensitivity of the switch cell 13L is increased. Further, if the width or interval w (see FIG. 7) of the opening 25a of the spacer 25 is reduced, the sensitivity of the first switch cell 13L is reduced, and if it is increased, the sensitivity of the first switch cell 13L is increased. Therefore, the sensitivity of the first switch cell 13L can be arbitrarily adjusted by changing the thickness t of the spacer 25 and the interval w.

  The other three switch cells 13R, 14L, 14R have the same structure as the one switch cell 13L described above, but the first and second contacts 29a, 30a of the first switch cells 13L, 13R. The members of the second switch cells 14L and 14R corresponding to are the third and fourth contacts 29b and 30b.

Thus, the second embodiment can achieve the same effects as those of the first embodiment described above .

  Although the embodiments of the present invention have been described above, various design changes can be made without departing from the scope of the present invention.

  For example, in the embodiment, the first switch cells 13L and 13R are arranged at the front part of the seat cushion 11, and the second switch cells 14L and 14R are arranged at the rear part of the seat cushion 11, but the positional relationship between them is different. It may be reversed.

  The structure of the first and second switch cells 13L, 13R; 14L, 14R is not limited to the embodiment.

Plan view of a seat provided with an occupant detection circuit according to the first embodiment Diagram showing occupant detection circuit 3-3 enlarged sectional view of FIG. Sectional view taken along line 4-4 in FIG. Action explanation diagram of occupant detection The figure corresponding to the said FIG. 3 which shows the switch cell which concerns on 2nd Example. Sectional view along line 7-7 in FIG.

Explanation of symbols

S seat 11 seat cushion 13L first switch cell 13R first switch cell 14L second switch cell 14R second Tchiseru 15a plus terminal 15b minus terminal 25 spacer 26a first contacts 26b third contact 27a second contact 27b fourth contact point < 29a First contact 29b Third contact 30a Second contact 30b Fourth contact t Spacer thickness w Spacer spacing

Claims (3)

In the occupant detection device in which a plurality of switch cells (13L, 13R; 14L, 14R) that are turned on by the occupant's weight are arranged on the seat cushion (11) in order to detect the occupant seated on the seat (S),
Front or rear of the pair of left and right first switch cells (13L, 13R) and the pair of left and right first switch cells (13L, 13R) disposed at positions corresponding to the left and right buttocks of the occupant seated on the seat (S) A pair of left and right second switch cells (14L, 14R) arranged in
Each first switch cell (13L, 13R) has first and second contacts (26a, 27a; 29a, 30a) connected in series between a plus terminal (15a) and a minus terminal (15b), both left and right When the first and second contacts (26a, 27a; 29a, 30a) of the first switch cell (13L, 13R) are turned on by the weight of the passenger and the positive terminal (15a) and the negative terminal (15b) are turned on. Detect the occupant,
Each of the second switch cells (14L, 14R) includes third and fourth contacts (26b, 27b; 29b, 30b) respectively connected to the plus terminal (15a) and the minus terminal (15b), and at least one of the left and right contacts When the third and fourth contacts (26b, 27b; 29b, 30b) of the second switch cell (14L, 14R) are turned on by the weight of the passenger and the plus terminal (15a) and the minus terminal (15b) are turned on, the passenger Detect
In addition, the load at which the third and fourth contacts (26b, 27b; 29b, 30b) of the second switch cell (14L, 14R) are conducted is applied to the first and second contacts (26a) of the first switch cell (13L, 13R). , 27a; 29a, 30a) is set to be larger than the load at which conduction is established . The first switch cell (13L, 13R) and the second switch cell (14L, 14R) are formed by changing the thickness (t) of the spacer (25) disposed between the contacts that can contact each other. The occupant detection device according to claim 1, wherein the magnitude of the load with which the contact of the vehicle contacts can be adjusted. The first switch cell (13L, 13R) and the second switch cell change the distance (w) between the spacers (25) arranged between the contact points that can contact each other, so that the load with which these contact points contact each other. The occupant detection device according to claim 1, wherein the size of the occupant can be adjusted.

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