JP2009192353A - Occupant weight detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a weight detector of simple constitution, capable of detecting stably, sensitively and precisely the weight of an occupant seated on a vehicular seat all the time over a wide fluctuation range of an occupant weight. <P>SOLUTION: This occupant weight detector 3 detects the weight of the occupant seated on the vehicular seat A. The occupant weight detector 3 has a support mechanism B for supporting the seat A vertically movably with respect to a seat fixing part 4 of a vehicle, an elastic repulsion imparting mechanism D for imparting an elastic repulsion to the seat A to move the seat A vertically with respect to the seat fixing part 4 by a distance in response to a level of a load applied onto the seat A, a vertical moving distance detecting mechanism E for detecting a vertical moving distance of the seat A with respect to the seat fixing part 4, and a vertical moving range limiting mechanism C for limiting a vertical moving range of the seat A with respect to the seat fixing part 4. The elastic repulsion imparting mechanism D comprises a spring 23. A damper mechanism F is provided to damp the vibration of the spring 23. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an occupant weight detection device that detects the weight of an occupant seated on a vehicle seat.

In order to improve occupant safety, comfort, and the like, it has been proposed to change various settings of the vehicle seat and its peripheral devices according to the weight of the occupant. (For example, Patent Documents 1 and 2). In the occupant weight detection devices described in these documents, a load sensor is installed on a seat rail of a vehicle seat, and the weight of the seat including the occupant's weight is directly measured by the load sensor.
Japanese Patent Laid-Open No. 11-11535 JP-A-11-304579

  However, when the weight of the occupant is directly measured by the load sensor as in the conventional occupant weight detection device, the sensor itself needs to support the load, and the capacity of the sensor (measurable) In other words, there is a problem that it is difficult to measure a slight weight difference between passengers with high sensitivity and accuracy over a wide range of passenger weight fluctuations.

  Therefore, instead of directly measuring the occupant weight with a load sensor, an attempt was made to obtain the load from the vertical movement distance of the seat so that the seat moves up and down according to the load. This eliminates the need for the sensor itself to support the load. As described above, when the load is obtained from the vertical movement distance of the seat, it is required that the seat can be supported stably at all times in order to stabilize the load detection accuracy even though the configuration is simple.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an occupant weight detection device having a simple configuration that can always detect the weight of an occupant seated on a vehicle seat stably and with high sensitivity and accuracy over a wide range of occupant weight fluctuations. Is to provide.

An occupant weight detection device according to the present invention is a device that detects the weight of an occupant seated on a vehicle seat, and a support mechanism that supports the seat in a vertically movable manner with respect to a seat fixing portion of the vehicle; An elastic repulsion force applying mechanism for applying an elastic repulsive force to the sheet so that the sheet moves up and down with respect to the sheet fixing portion by a distance corresponding to a load applied to the sheet; and the sheet with respect to the sheet fixing portion. A vertical movement distance detecting mechanism for detecting the vertical movement distance of the sheet, and a vertical movement range limiting mechanism for limiting a vertical movement range of the sheet with respect to the sheet fixing portion, wherein the elastic repulsion force applying mechanism is a spring. A damper mechanism for damping the vibration of the spring is provided.
According to this configuration, when the occupant is seated on the seat, the seat moves up and down by a distance corresponding to the weight of the occupant by the action of the elastic repulsion force imparting mechanism. The vertical movement distance of the sheet is detected by a vertical movement distance detection mechanism. If the relationship between the vertical movement distance of the seat and the load applied to the seat is obtained in advance, the load applied to the seat, that is, the weight of the occupant, can be obtained from the vertical movement distance of the seat. In this way, the support mechanism and the elastic repulsion force imparting mechanism are provided so that the seat moves up and down by a distance corresponding to the magnitude of the load applied to the seat. The relationship between load and vertical movement distance. Since the occupant weight is detected by measuring the changing vertical movement distance in this way, the occupant weight can be detected with high sensitivity and accuracy over a wide range of occupant weight fluctuations.
Since the elastic repulsive force applying mechanism is made of a spring, the entire structure including the elastic repulsive force applying mechanism can be simplified. When the load changes abruptly, vibration is generated in the spring, but since the damper mechanism for damping the vibration of the spring is provided, the vertical movement distance detection mechanism is less affected by the vibration. For this reason, the detection of the vertical movement distance is stable, and the weight of the occupant can always be stably detected with high sensitivity and accuracy.

The spring may be a non-linear characteristic spring. For example, the non-linear characteristic spring has a non-linear characteristic in which the relationship between the magnitude of the load applied to the seat and the output of the sensor included in the vertical movement distance detection mechanism is substantially linear.
Since the sensor has non-linear characteristics, if the load applied to the seat is proportional to the vertical movement distance of the seat, the relationship between the load applied to the seat and the output of the sensor is not linear. Therefore, the spring of the elastic repulsion force applying mechanism is a non-linear characteristic spring, and the relationship between the load of the non-linear characteristic spring and the deflection is set according to the characteristics of the sensor, so that the relationship between the load applied to the seat and the output of the sensor is obtained. It can be a linear or gentle curve over a wide range of occupant weight changes. In this way, by correcting the sensor characteristics mechanically, it is not necessary to correct the sensor output by a microcomputer or ECU (electric control unit) provided separately from the occupant weight detection device.

In the present invention, the support mechanism and the damper mechanism form a cylinder whose central axis is directed in the vertical direction on one of the seat-side member and the sheet fixing portion-side member provided facing each other in the vertical direction. Preferably, the other member is formed with a piston slidably fitted in the cylinder, and the cylinder is filled with a fluid for buffering the piston operation.
With this configuration, the seat-side member and the seat fixing portion-side member serve both as a support mechanism and a damper mechanism, so that the configuration can be simplified and the number of parts can be reduced.

The vertical movement distance detection mechanism preferably uses a magnetic sensor. As the magnetic sensor, for example, a Hall sensor, an MR sensor (magnetoresistance element sensor), or the like can be used.
If a magnetic sensor is used, a passenger | crew weight detection apparatus can be comprised at low cost compared with another general sensor. For example, Patent Document 2 describes using a strain gauge, a piezoelectric type, a capacitance type, a magnetostrictive type, a pressure-sensitive resistance type, or the like as a load sensor. And a detection circuit are required, and it takes time and effort to assemble them.

The output of the vertical movement distance detection mechanism can be input to a control unit that controls the amount of airbag deployment based on the detection result of the vertical movement distance detection mechanism.
The output of the vertical movement distance detection mechanism is input to control means for controlling the position of one or both of the vertical direction and the front / rear direction of the steering handle based on the detection result of the vertical movement distance detection mechanism. Also good.
Further, the output of the vertical movement distance detection mechanism may be input to a control unit that controls the position of the seat in the front-rear direction based on the detection result of the vertical movement distance detection mechanism.
Further, the output of the vertical movement distance detection mechanism may be input to a control unit that controls the position of the seat back portion in the front-rear direction based on the detection result of the vertical movement distance detection mechanism.
Further, the output of the vertical movement distance detection mechanism may be input to a control unit that controls the position of the headrest of the seat in the front-rear direction based on the detection result of the vertical movement distance detection mechanism.
In either case, the safety and comfort of the occupant can be improved by changing various settings of the seat and its peripheral devices according to the output of the vertical movement distance detection mechanism.

In the vehicle seat device according to the present invention, a vehicle seat having a substantially quadrangular seating shape is supported on the seat fixing portion of the vehicle via the occupant weight detection device at four corners of the seating portion. It is said.
According to this configuration of the vehicle seat device, the weight of the occupant seated on the vehicle seat is detected by each occupant weight detection device that supports the four corners of the seat seating portion. The weight of the occupant is obtained from the sum of the detection values of each occupant weight detection device. Various settings of the seat and its peripheral devices can be changed from the obtained weight of the occupant to improve occupant safety, comfort and the like.
Moreover, the weight distribution in a seating part is known by comparing the detection value of each passenger | crew weight detection apparatus. From this weight distribution, it is possible to estimate the characteristics of the occupant's physique and how to sit down, and to change the various settings based on the estimation results, it is possible to make rational setting changes that are more realistic. Can do.

  An occupant weight detection device of the present invention is a device for detecting the weight of an occupant seated on a vehicle seat, the support mechanism for supporting the seat movably up and down with respect to a seat fixing portion of the vehicle, An elastic repulsive force applying mechanism for applying an elastic repulsive force to the sheet so that the sheet moves up and down with respect to the sheet fixing portion by a distance corresponding to a load applied to the sheet; and A vertical movement distance detecting mechanism for detecting a vertical movement distance; and a vertical movement range limiting mechanism for limiting a vertical movement range of the seat with respect to the seat fixing portion; and the elastic repulsion force applying mechanism is made of a spring, Since the damper mechanism that attenuates the vibration of the spring is provided, the weight of the occupant sitting on the vehicle seat is always stable and sensitive over a wide range of occupant weight fluctuations. Accurately be detected, a simple configuration.

  An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a side view of a vehicle seat device provided with an occupant weight detection device of this embodiment, and FIG. 2 is a plan view thereof. The vehicle seat device includes a vehicle seat A including a seat body 1 and a seat rail 2. The seat body 1 includes a seat portion 1a having a substantially rectangular planar shape, a backrest portion 1b that rises upward from the rear portion of the seat portion 1a, and a headrest 1c provided at the upper end of the backrest portion 1b. The lower surface of the part 1a is supported on a pair of left and right seat rails 2 that are long in the front-rear direction so as to be movable back and forth. The left and right seat rails 2 are installed on the seat fixing portion 4 which is a part of the vehicle body floor portion of the vehicle via the occupant weight detection device 3 at both front and rear ends. Therefore, the seat A is supported by the seat fixing portion 4 via the four occupant weight detection devices 3 at the four corners of the seating portion 1a.

  As shown in FIGS. 3 and 4, the occupant weight detection device 3 includes a seat-side member and a seat fixing portion-side member that are provided facing each other in the vertical direction. A member on the seat side is a seat rail mounting member 5, which is attached to the seat rail 2 of the seat A by mounting screws 10 that protrude upward from the upper end. The mounting screw 10 may be separated from the seat rail mounting member 5. The member on the seat fixing portion side is the seat fixing member 6 and is attached to the seat fixing portion 4 with an attaching screw 13 protruding downward from the lower end. The attachment screw 13 may be separated from the sheet fixing member 6.

  The seat rail mounting member 5 as a whole is a cylinder whose central axis faces the vertical direction. A through hole 5b through which a piston rod 6b, which will be described later, is inserted is formed at the center of the lower end wall 5a. The seat fixing member 6 is provided at the lower end side base plate 6a, the rod base 6b provided on the upper surface of the base plate 6a, the piston rod 6c extending upward from the rod base 6b, and the tip of the piston rod 6c. It consists of a piston 6d. The piston rod 6c is inserted through the through hole 5b, and the piston 6d is slidably fitted to the inner periphery of the seat rail mounting member 5 that is a cylinder. The interior of the seat rail mounting member 5 is a cylinder chamber sealed from the outside, and is filled with a fluid 7 for buffering the piston operation. The fluid is, for example, a liquid. The seat rail mounting member 5 and the seat fixing member 6 serve as a support mechanism B that supports the seat A so as to be movable up and down with respect to a seat fixing portion A of the vehicle, and a damper mechanism F that attenuates vibration of a coil spring 23 described later. ing.

  A coil spring 23 is provided between the lower end wall 5 a of the seat rail mounting member 5 and the base plate 6 a of the seat fixing member 6. The coil spring 23 is a main component of the elastic repulsive force imparting mechanism D, and when the occupant sits on the seat A, the direction opposite to the direction in which the seat rail mounting member 5 moves, that is, the upward elastic repulsive force is applied to the seat rail. The attachment member 5 is provided. As a result, when no load is applied to the sheet A, the sheet A is held at a predetermined no-load position (not shown). When a load is applied to the sheet A, the load is applied to the sheet fixing portion 4 by a distance corresponding to the magnitude of the load. Thus, the sheet A is allowed to descend, and when the load applied to the sheet A disappears, the sheet A is returned to the original no-load position.

  When a load exceeding the weight assumed in advance is applied to the seat A, when the seat A descends to a predetermined height, the lower end wall portion 5a of the seat rail mounting member 5 hits the rod base portion 6b of the seat fixing member 6, and more The lowering of the sheet A is restricted. The lower end wall portion 5 a of the seat rail mounting member 5 and the rod base portion 6 b of the seat fixing member 6 constitute a vertical movement range limiting mechanism C that limits the vertical movement range of the seat A with respect to the seat fixing portion 4.

  The occupant weight detection device 3 includes a magnet 25 and a magnetic sensor 26 as a vertical movement distance detection mechanism E that detects the vertical movement distance of the seat A with respect to the seat fixing portion 4. The magnet 25 is provided on the lower surface of the lower end wall 5 a of the seat rail mounting member 5. The magnetic sensor 26 is provided on the upper surface of the base plate 6 a of the sheet fixing member 6 so as to face the magnet 25. The magnetic sensor 26 is, for example, a Hall sensor, an MR sensor (magnetoresistance element sensor), or the like, and an analog output sensor is used. The positions of the magnet 25 and the magnetic sensor 26 may be reversed.

  As shown in FIG. 5, the magnetic sensors 26 (1) to 26 (4) of the four occupant weight detection devices 3 provided below the four corners of the seat seating portion 1 a are respectively input to the control device 30 of the vehicle. Connected to the side. The control device 30 is, for example, a computer-type ECU (electric control unit). Further, an airbag deployment amount control means 31, a steering handle position control means 32, a seat position control means 33, and a headrest position control means 34 are connected to the output side of the control device 30, respectively. Each control means 31 to 34 may be provided as a part of the control device 30. The operations of the control device 30 and the control units 31 to 34 will be described later.

  When an occupant sits on the seating portion 1a of the seat A, a load is applied to the seat rail mounting member 5, and the seat rail mounting member 5 is lowered (FIG. 4). By the action of the elastic repulsion force applying mechanism D, the seat mounting member 5 is lowered by a distance corresponding to the weight of the occupant. The vertical movement distance of the seat rail mounting member 5 is detected by the magnetic sensor 26 and output in analog form. The relationship between the load applied to the seat rail mounting member 5 and the vertical movement distance of the seat rail mounting member 5 can be adjusted by changing the spring constant of the coil spring 23.

Output signals from the magnetic sensors 26 (1) to 26 (4) are transmitted to the control device 30. The control device 30 sets the first relationship setting in which the relationship between the load applied to the seat A, that is, the weight of the occupant, and the sum of the output values of the magnetic sensors 26 (1) to 26 (4) is set by an arithmetic expression or a table. Means (not shown), and the weight of the occupant is calculated from the sum of the input values using the relationship setting means. The setting contents of the first relationship setting means are obtained in advance through tests and simulations.
Since the seat A is supported so as to move up and down by a distance corresponding to the magnitude of the load applied to the seat A, an appropriate load / up-and-down moving distance is established over a wide range of changes in the occupant weight. When the load suddenly changes, vibration is generated in the coil spring 23. Since the vibration of the coil spring 23 is attenuated by the action of the damper mechanism F, the vertical movement distance detection mechanism E may be affected by the vibration. The detection of the vertical movement distance is small and stable. For this reason, it is possible to always detect the occupant weight stably and with high sensitivity and accuracy over a wide range of fluctuations of the occupant weight.

  In addition, the control device 30 includes second relationship setting means (not shown) that sets the relationship between the output values of the magnetic sensors 26 (1) to 26 (4) and the physique and sitting characteristics of the occupant. The physique and sitting characteristics of the occupant are estimated from the output values of the magnetic sensors 26 (1) to 26 (4). The setting contents of the second relationship setting means are also obtained in advance by tests and simulations.

  An output signal is output to each of the control means 31 to 34 based on the information such as the weight of the occupant, the physique, and the characteristics of the sitting. The airbag deployment amount control means 31 controls the deployment amount of an airbag (not shown) based on the occupant information. The steering handle position control means 32 controls the position of one or both of the vertical direction and the front / rear direction of the steering handle (not shown) based on the occupant information. The seat position control means 33 controls the position of the seat A in the front-rear direction based on the occupant information. The headrest position control means 34 controls the position of the headrest 1c in the front-rear direction based on the occupant information. By performing these controls, it is possible to improve the safety and comfort of the passenger.

  Since this occupant weight detection device 3 does not use a load sensor, it is not necessary for the sensor itself to support the load, and the elastic repulsion force imparting mechanism D is composed of the coil spring 23, so The entire structure including the force applying mechanism D can be simplified. For this reason, it can be manufactured at low cost. Further, the magnitude of the load applied to the seat A is detected as the vertical movement distance of the seat rail mounting member 5 with respect to the seat fixing member 6, and the magnetic sensor 26 is used for the detection. The weight detection device 3 can be configured at low cost because it is unnecessary and does not require much time to assemble them.

  In this embodiment, a plurality of control means 31 to 34 for changing various settings of the vehicle seat and its peripheral devices based on the detection result of the occupant weight detection device 3 are provided, but all these control means 31 to 34 are provided. There is no need to provide a control means, and only an appropriate control means that meets the specifications of the vehicle may be provided.

  6 and 7 each show a different embodiment of the present invention. In these embodiments, the coil spring 23 is a non-linear characteristic spring in which the relationship between load and deflection is not linear. The relationship between the load and deflection of the coil spring 23, which is a non-linear characteristic spring, is set in accordance with the characteristics (FIG. 8) of the magnetic sensor 26 described later. As the nonlinear characteristic spring, a conical coil spring, an unequal pitch coil spring, a taper pitch spring, or the like can be used. The coil spring 23 of the embodiment shown in FIG. 6 is a conical coil spring and an unequal pitch coil spring. Moreover, the coil spring 23 of the embodiment shown in FIG. 7 is a taper pitch spring. Except that the coil spring 23 is the coil spring 23, it is the same as that of the said embodiment.

  FIG. 8 is a diagram illustrating the relationship between the gap g between the magnet 25 and the magnetic sensor 26 and the magnetic flux density applied to the magnet 25. As can be seen, the amount of magnetic density decreases as the magnet 25 moves away from the magnetic sensor 26. The relationship between the gap g and the magnetic flux density is non-linear. The smaller the gap g, the larger the change in magnetic flux density. FIG. 9 is a diagram showing the characteristics of the coil spring 23. The relationship between the load and the deflection is set to a non-linear relationship that matches the characteristics of the magnetic sensor 26 (FIG. 8). Thereby, as shown in FIG. 10, the load applied to the seat A and the sensor output have a linear relationship. For this reason, it is not necessary to correct the sensor output by a microcomputer provided separately from the occupant weight detection device 3 or the vehicle control device 30, and the control can be simplified.

1 is a side view of a vehicle seat device including an occupant weight detection device according to an embodiment of the present invention. It is a top view of the vehicle seat apparatus. It is a fracture | rupture side view of the same passenger | crew weight detection apparatus. It is a fracture | rupture side view which shows the different state of the passenger | crew weight detection apparatus. It is a block diagram of a control system of the vehicle seat device. It is a fracture | rupture side view of the passenger | crew weight detection apparatus which concerns on different embodiment of this invention. It is a fracture side view of an occupant weight detection device according to still another embodiment of the present invention. It is a figure which shows the relationship between the gap between a magnet and a magnetic sensor, and the magnetic flux density provided to a magnet. It is a figure which shows the relationship between the load added to a sheet | seat, and the bending of a coil spring. It is a figure which shows the relationship between the load added to a sheet | seat, and a sensor output.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Seat main body 1a ... Seating part 1b ... Backrest part 1c ... Headrest 2 ... Seat rail 3 ... Passenger weight detection apparatus 4 ... Seat fixing | fixed part 5 ... Seat rail attachment member (cylinder)
6 ... Seat fixing member 6d ... Piston 7 ... Piston motion buffering fluid 23 ... Coil spring 25 ... Magnet 26 ... Magnetic sensor 30 ... Control device A ... Vehicle seat B ... Support mechanism C ... Vertical movement range limiting mechanism D ... Elastic repulsion Force applying mechanism E ... Vertical movement distance detecting mechanism F ... Damper mechanism

Claims (11)

  An occupant weight detection device for detecting the weight of an occupant seated on a vehicle seat, the support mechanism supporting the seat so as to be movable up and down with respect to a seat fixing portion of the vehicle, and a load applied to the seat An elastic repulsion force applying mechanism that applies an elastic repulsive force to the sheet so that the sheet moves up and down with respect to the sheet fixing portion by a distance corresponding to the distance, and a vertical movement distance of the sheet with respect to the sheet fixing portion. It has a vertical movement distance detection mechanism and a vertical movement range limiting mechanism that limits the vertical movement range of the seat with respect to the seat fixing portion, and the elastic repulsion force applying mechanism comprises a spring and damps the vibration of the spring An occupant weight detection device provided with a damper mechanism.   2. The occupant weight detection device according to claim 1, wherein the spring is a non-linear characteristic spring.   3. The occupant weight detection device according to claim 1, wherein the non-linear characteristic spring has a non-linear characteristic in which a relationship between a magnitude of a load applied to the seat and an output of a sensor included in the vertical movement distance detection mechanism is substantially linear. .   4. The support mechanism and the damper mechanism according to claim 1, wherein the support mechanism and the damper mechanism are centered on any one of a member on a sheet side and a member on a sheet fixing portion provided to be opposed to each other in the vertical direction. An occupant having a cylinder whose shaft is directed in the vertical direction, a piston that is slidably fitted in the cylinder is formed on the other member, and a fluid for buffering the piston operation is filled in the cylinder. Weight detection device.   5. The occupant weight detection device according to claim 1, wherein the vertical movement distance detection mechanism uses a magnetic sensor.   6. The occupant according to claim 1, wherein an output of the vertical movement distance detection mechanism is input to a control means for controlling an airbag deployment amount based on a detection result of the vertical movement distance detection mechanism. Weight detection device.   6. The output of the vertical movement distance detection mechanism according to claim 1, wherein the output of the vertical movement distance detection mechanism is based on a detection result of the vertical movement distance detection mechanism. An occupant weight detection device input to a control means for controlling the position.   6. The output of the vertical movement distance detection mechanism according to claim 1, wherein the output of the vertical movement distance detection mechanism is input to a control unit that controls the position of the seat in the front-rear direction based on the detection result of the vertical movement distance detection mechanism. Crew weight detection device.   6. The control means according to claim 1, wherein the output of the vertical movement distance detection mechanism controls the position in the front-rear direction of the seat back portion based on the detection result of the vertical movement distance detection mechanism. Occupant weight detection device input to the.   6. The output of the vertical movement distance detection mechanism according to claim 1, wherein the output of the vertical movement distance detection mechanism is input to a control unit that controls a front-rear direction position of the headrest of the seat based on a detection result of the vertical movement distance detection mechanism. Occupant weight detection device.   11. A vehicle seat having a substantially quadrangular planar shape of a seating portion is supported on the seat fixing portion of the vehicle at the four corners of the seating portion via the occupant weight detection device according to any one of claims 1 to 10. A vehicle seat device.

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