JP2001239875A - Seat for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seat for a vehicle capable of improving the reliability in a result of the detection of the seating over-weight. SOLUTION: A front right load sensor 21 and a front left load sensor 22 are mounted on a front part of a seat body 1, and a rear right load sensor 23 and a rear left load sensor 24 are mounted at a rear part of the seat body 1. The right and left front load detection values FR, FL and the right and left rear load detection values RR, RL are operated on the basis of load signals from these load sensors 21-24. An ECU 25 determines a normal traveling condition or a braking condition of the vehicle by comparing a front load addition value SF obtained by adding the right and left front load detection values RF, RL with a rear load addition value SR obtained by adding the right and left rear load detection values RR, RL. When the braking condition of the vehicle is determined, the seating over-load (the total load addition values S obtained by adding the load detection values FR, FL, RR, RL) detected this time is canceled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle seat provided with a seat load detecting device.

[0002]

2. Description of the Related Art Conventionally, for example, when an airbag is provided to protect an occupant of a vehicle seat,
In order to detect whether there is an occupant in the target seat,
Alternatively, in order to appropriately adjust the amount of gas generated for inflating the airbag in accordance with the weight of the occupant, a seating load detecting device is provided on the vehicle seat.

For example, Japanese Patent Application Laid-Open No. H11-1153 discloses rails arranged on both left and right sides of a seat to guide the seat so as to be slidable in the vehicle traveling direction, and each rail is fixedly supported on a vehicle floor. A mode is described in which load sensors are provided between the load sensors and a mountain bracket, and a seat weight (excessive seating) is detected based on load signals from the load sensors.

[0004]

When a vehicle is braked, for example, a deceleration load is applied to the vehicle seat. Therefore, for example, when the seat weight (excessive seating) is detected by the sum of the load signals from the load sensors, the influence of the deceleration load is also included in the load signal.
The weight greater than the original sheet weight is detected. As a result, the reliability of the detection result of the overseat is reduced, and for example, the presence or absence of the occupant of the target seat may be erroneously detected.

It is an object of the present invention to provide a vehicle seat that can improve the reliability of the result of detection of a heavy seat.

[0006]

In order to solve the above-mentioned problems, a first aspect of the present invention provides a front load sensor provided at a front portion of a seat body and a rear load sensor provided at a rear portion of the seat body. A vehicle seat having a sensor for detecting a seat load based on a front load detection value from the front load sensor and a rear load detection value from the rear load sensor. Comparing means for comparing the detected value with the rear load detected value; determining means for determining a braking state of the vehicle based on a comparison result of the comparing means; and The gist of the present invention is to provide an invalidating means for invalidating the excessive seating load detected by the seating load detection device.

According to a second aspect of the present invention, in the vehicle seat according to the first aspect, the comparing means compares the magnitudes of the front load detection value and the rear load detection value. The gist is to judge that the vehicle is in the braking state when the front load detection value is larger than the rear load detection value.

According to a third aspect of the present invention, in the vehicle seat according to the second aspect, the determination unit determines that the state in which the front load detection value is larger than the rear load detection value has continued for a predetermined time. The gist is to determine that the vehicle is in the braking state.

The invention according to claim 4 is the invention according to claim 2 or 3.
The gist of the invention is that, when the state in which the front load detection value is smaller than the rear load detection value continues for a predetermined time, the determination unit determines that the vehicle is not in the braking state.

According to a fifth aspect of the present invention, there is provided the vehicle seat according to any one of the first to fourth aspects, wherein the vehicle seat according to any one of the first to fourth aspects detects the front load detected value based on the front load detection value and the rear load detection value before a predetermined time. It is provided with previous sitting load holding means for holding the sitting load, and when the determining means determines that the vehicle is in the braking state, the previous sitting load held by the last sitting load holding means is set as the current sitting load. Make a summary.

(Operation) When a detected value of a front load from a front load sensor provided at a front portion of a seat body is compared with a detected value of a rear load from a rear load sensor provided at a rear portion of the seat body, It has been confirmed by the applicants that significant differences appear between the normal running state and the braking state of the vehicle.

According to the first and second aspects of the present invention, the front load detection value from the front load sensor is compared with the rear load detection value from the rear load sensor to make it extremely simple and easy. Preferably, the braking state of the vehicle is detected. Then, when it is determined that the vehicle is in the braking state, the reliability of the detection result of the seating overload is improved by invalidating the seating overload detected by the seating load detecting device.

According to the third aspect of the present invention, when the state in which the front load detection value is larger than the rear load detection value continues for a predetermined time, it is determined that the vehicle is in a braking state. Something is more precisely detected.

According to the fourth aspect of the present invention, when the state in which the front load detection value is smaller than the rear load detection value continues for a predetermined time, it is determined that the vehicle is not in the braking state. (The normal running state) is more strictly detected.

According to the fifth aspect of the present invention, when the determination means determines that the vehicle is in the braking state, the previous sitting load held by the previous sitting load holding means is set as the current sitting load. Therefore, even in the braking state of the vehicle, for example, determination of the presence or absence of an occupant is suitably performed based on the seating load set as described above.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a vehicle seat embodying the present invention will be described below with reference to FIGS.

FIG. 1 shows a seat body 1 provided in a vehicle seat.
FIG. In FIG. 1, a pair of left and right support frames 2 are fixed to a vehicle floor (not shown) in the front-rear direction (the X arrow direction in FIG. 1). A pair of front and rear brackets 3 is fixed to the upper surface of each support frame 2, and the lower rail 4
Are supported and fixed along the support frame 2. The pair of left and right lower rails 4 is formed in a U-shaped cross section, and the upper part thereof is open and the opening forms a slide groove 5 extending in the front-rear direction.

A slide groove 5 formed in each lower rail 4
, A pair of left and right upper rails 6 are provided so as to be slidable in the front-rear direction along the slide grooves 5. FIG.
As shown in FIG. 3, a lower arm 16 supporting the seat cushion 9 and the seat back 10 of the seat body 1 at a predetermined interval via a pair of left and right front sensor brackets 7 and a rear sensor bracket 8 is provided on each upper rail 6. Are linked.

As shown in FIG. 3A, the upper and lower ends of the front sensor bracket 7 are formed as an upper fastening portion 7a and a lower fastening portion 7b, and the upper and lower fastening portions 7a and 7b are curved. A bending portion 7c is formed. The front sensor bracket 7 includes the upper and lower fastening portions 7a and 7b.
Are connected to the lower arm 16 and the front side of the upper rail 6, respectively. A front right load sensor 21 and a front left load sensor 22 as front load sensors are respectively attached to the bent portions 7c of the right and left front sensor brackets 7. Each of the front right load sensor 21 and the front left load sensor 22 includes a strain detecting element such as a strain gauge, for example, and electrically measures a bending amount of the bending portion 7c relative to a load applied to the seat cushion 9. It is designed to detect.

As shown in FIG. 3B, the upper and lower ends of the rear sensor bracket 8 are upper and lower fastening portions 8a and 8b, and the upper and lower fastening portions 8a and 8b are curved. The bent portion 8c is formed. The rear sensor bracket 8 includes the upper and lower fastening portions 8a and 8b.
Are connected to the lower arm 16 and the rear side of the upper rail 6, respectively. A rear right-side load sensor 23 and a rear left-side load sensor 24 as rear load sensors are attached to the bent portions 8c of the right and left rear sensor brackets 8, respectively. Like the front right load sensor 21 and the front left load sensor 22, the rear right load sensor 23 and the rear left load sensor 24 include a strain detecting element such as a strain gauge, for example. The amount of flexure of the flexure 8c relative to the flexure 8c is electrically detected.

FIG. 4 is a block diagram showing an electrical configuration of the seat load detecting device 20 provided in the vehicle seat. The seat load detection device 20 includes the load sensors 21 to 24,
An electronic control unit (hereinafter, referred to as “ECU”) 25 is provided.

The ECU 25 includes a central processing unit (hereinafter, referred to as a central processing unit).
A “CPU”) 26 and a sensor signal input circuit 27
And a determination output circuit 28. The sensor signal input circuit 27 includes active filters 27a, 27b, 27c, and 27d provided corresponding to the front right load sensor 21, the front left load sensor 22, the rear right load sensor 23, and the rear left load sensor 24, respectively.
The load signals from the load sensors 21 to 24 are input to the CPU 26 via the active filters 27a to 27d. The active filters 27a to 27d are well-known low-pass filters in which a passive element including, for example, a capacitor and a resistor is combined with an active element such as an amplifier. Therefore, among the load signals from the load sensors 21 to 24, the active filters 27a to 27d pass only low-frequency signals, and lose other signals.

Incidentally, the active filters 27a, 27
The right and left front load detection values FR and FL are calculated based on the load signals from the front right load sensor 21 and the front left load sensor 22 that have passed through the respective sensors 7b. Further, the right and left rear load detection values RR and RL are calculated based on the load signals from the rear right load sensor 23 and the rear left load sensor 24 that have passed through the active filters 27c and 27d, respectively.

The CPU 26 executes various arithmetic processes in accordance with a control program and initial data stored in advance, and outputs the arithmetic results to the determination output circuit 28.
The calculation result is output to, for example, an electronic control unit (hereinafter, referred to as an “airbag ECU”) 30 of the airbag device via the determination output circuit 28, whereby the operation of the airbag device is controlled. I have.

Here, when braking the vehicle, a deceleration load is applied to the vehicle seat. Then, as shown in FIG. 6, the seating obtained by adding the right and left front load detection values and the right and left rear load detection values FR, FL, RR, and RL during normal running and braking of the vehicle. Total load addition value S corresponding to load, right and left front load detection values F
The following characteristics are respectively applied to a front load addition value SF as a front load detection value obtained by adding R and FL, and a rear load addition value SR as a rear load detection value obtained by adding right and left rear load detection values RR and RL. Have been confirmed by the Applicants.

That is, during normal running of the vehicle, the front load addition value SF and the rear load addition value SR are each maintained at stable values, and the front load addition value SF is higher than the rear load addition value SR. It is confirmed that the value is calculated as a small value.

On the other hand, at the time of braking of the vehicle, the front load addition value SF sharply increases and the rear load addition value SR decreases, and the magnitude relation between the front load addition value SF and the rear load addition value SR reverses. are doing. Then, it is confirmed that the total load addition value S is also increased as compared with the normal traveling. Therefore, it can be seen that by comparing the front load addition value SF and the rear load addition value SR, it can be confirmed whether the vehicle is in the normal running state or the braking state. When the vehicle starts to return to the normal running state again from this state, the front load addition value SF sharply decreases, and the rear load addition value SR increases, and the front load addition value SF and the rear load addition value SF increase. The magnitude relationship of SR returns to the original state.

In consideration of such characteristics of the front load addition value SF and the rear load addition value SR, a process for determining the presence or absence of an occupant in the present embodiment will be described with reference to a flowchart of FIG. This processing is performed by a periodic interruption every predetermined time.

When the processing shifts to this routine, first, in step 101, the CPU 26 sets the load detection value F
R, FL, RR, and RL are read, and the process proceeds to step 102.

In step 102, the CPU 26 calculates the front load added value SF obtained by adding the right and left front load detection values FR and FL to the rear load added by the right and left rear load detection values RR and RL. It is determined whether the sum is smaller than the sum SR.

If it is determined that the front load addition value SF is equal to or greater than the rear load addition value SR, the CPU 26 temporarily determines that the current vehicle is in a braking state, and proceeds to step 10.
Move to 3. Then, in step 103, the CPU
26 indicates that the front load addition value SF is equal to the rear load addition value S
It is determined whether the state of R or more has continued for a certain period of time.

If it is determined in step 103 that the front load addition value SF is equal to or greater than the rear load addition value SR for a certain period of time, the CPU 26 determines that the current vehicle is in a braking state. To step 104, and the right and left front load detection values and the right and left rear load detection values FR, FL, R calculated before the time T1.
A total load addition value S_ obtained by adding R and RL is set as data for occupant determination. The total load addition value S_ is sequentially updated as the vehicle continues normal traveling for the time T1 or more, and is data used for occupant determination instead of when the vehicle shifts to the braking state. Therefore, when the vehicle enters the braking state, the occupant determination is performed based on the data during normal traveling before entering the braking state.

The CPU 26, which has set the total load addition value S_ before the time T1 as the data for the occupant determination, proceeds to step 105.
Then, the occupant is determined based on the total load addition value S_, and the subsequent processing is temporarily terminated.

If it is determined in step 103 that the front load addition value SF is not less than the rear load addition value SR for a certain period of time, the CPU 26 determines that the current vehicle is not in the braking state. Step 1
09, the right and left front load detection values and the right and left rear load detection values FR, FL,
The total load addition value S obtained by adding RR and RL is set as it is as data for occupant determination.

The CPU 26, which has set the total load addition value S this time as the data for the occupant determination, proceeds to step 105, performs the occupant determination based on the total load addition value S, and temporarily ends the subsequent processing.

On the other hand, if it is determined in step 102 that the front load added value SF is smaller than the rear load added value SR, the CPU 26 temporarily determines that the current vehicle is in a normal running state, and proceeds to step 106. Move to Then, in step 106, the CPU 26 determines whether or not the state where the front load added value SF is smaller than the rear load added value SR has continued for a certain period of time.

If it is determined in step 106 that the front load addition value SF is smaller than the rear load addition value SR for a certain period of time, the CPU 26 determines that the current vehicle is in a normal running state. Judge and step 10
Move to 7. Then, the CPU 26 determines in step 107
In the above, the front load addition value SF is changed to the rear load addition value SR.
It is determined whether or not the state smaller than the time T1 has continued for a time T1. If the state has continued, the detected value is assumed to be stable, and the process proceeds to step 108 to add the total load value S_ before the time T1. Then, the process proceeds to step 109, and if not continued, the process directly proceeds to step 109.

The CPU 26 that has proceeded to step 109
This time, the total load addition value S obtained by adding the read right and left front load detection values and the right and left rear load detection values FR, FL, RR, and RL is set as the occupant determination data.

The CPU 26, which has set the total load addition value S this time as the data for occupant determination, proceeds to step 105, performs occupant determination based on the total load addition value S, and terminates the subsequent processing once.

If it is determined in step 106 that the state in which the front load addition value SF is smaller than the rear load addition value SR has not continued for a certain period of time, the CPU 26 determines
It is determined that the current vehicle is not in the normal running state, and the process proceeds to step 104, where the right and left front load detection values and the right and left rear load detection values FR, FR calculated before time T1 are calculated. Total load addition value S obtained by adding FL, RR, and RL
Set _ as occupant determination data.

The CPU 26, which has set the total load addition value S_ before the time T1 as the data for determining the occupant, sets
Then, the occupant is determined based on the total load addition value S_, and the subsequent processing is temporarily terminated.

The CPU that has performed the occupant determination as described above
26 outputs the determination result via the determination output circuit 28,
For example, it outputs to the airbag ECU30. Then, the airbag ECU 30 suitably controls the operation of the airbag device based on the above determination results.

As described in detail above, according to the present embodiment, the following effects can be obtained. (1) In the present embodiment, the front load addition value SF can be confirmed to be significantly different depending on whether the vehicle is in the normal running state or the braking state.
And the rear load addition value SR, that is, whether the front load addition value SF is smaller than the rear load addition value SR is extremely simple, and preferably the vehicle is in the normal traveling state. It is possible to detect whether the vehicle is in the braking state. Then, when the braking state of the vehicle is determined, the seating overload detected this time (the total load added value S obtained by adding the load detection values FR, FL, RR, and RL) is invalidated, and the seating overload is detected. Can improve the reliability of the detection result.

(2) In this embodiment, the front load added value S
The state in which F is smaller than the rear load addition value SR continues for a certain period of time, or the state in which the front load addition value SF is greater than or equal to the rear load addition value SR continues for a certain period of time. Alternatively, the braking state of the vehicle is determined. Therefore, it is possible to more strictly detect that the vehicle is in the normal running state or in the braking state.

(3) In this embodiment, when the braking state of the vehicle is determined, the previous data (full load addition value S_)
Based on the above, the occupant determination can be suitably performed. (4) In the present embodiment, when the normal traveling state of the vehicle is determined, based on the present data (full load addition value S),
The occupant determination can be suitably performed.

(5) In the present embodiment, the operation of the airbag device can be suitably controlled based on the determination result of the occupant. (6) In the present embodiment, the active filters 27a, 27
7b, load signals from the front right load sensor 21 and the front left load sensor 22, respectively, and the rear right load sensor 23 that has passed the active filter 27c.
And the right and left front load detection values and the right and left rear load detection values FR, FL, RR, and RL based on the load signal from the rear left load sensor 24 that has passed through the active filter 27d. Each can be operated stably.

The embodiment of the present invention is not limited to the above embodiment, but may be modified as follows. In the above-described embodiment, a pair of right and left front right load sensors 21 and a left front load sensor 22 are provided at the front of the seat body 1 and a pair of right and left rear right load sensors 23 and 24 are provided at the rear. . On the other hand, the number of these overload sensors may be one each at the front part and the rear part of the seat body 1, or may be three or more.

The shapes of the front and rear sensor brackets 7 and 8 employed in the above-described embodiment are merely examples, and any shape may be used as long as bending occurs according to the seat weight (seating load).

The mounting positions (front and rear sensor brackets 7, 8) of the load sensors 21 to 24 employed in the above embodiment are merely examples, and the seat weight (seating load) is detected in the same arrangement. If so, the mounting position is arbitrary.

In the above embodiment, the occupant determination is made based on the total load addition values S and S_. However, the weight of the occupant may be detected based on the total load addition values S and S_, for example. In this case, for example, the amount of gas generated for inflating the airbag may be appropriately adjusted according to the weight of the occupant.

The vehicle seat in the above embodiment may be a driver seat or a passenger seat.

[0052]

As described in detail above, according to the first and second aspects of the present invention, it is possible to improve the reliability of the detection result of the excessive seating.

According to the third aspect of the present invention, it is possible to more strictly detect that the vehicle is in the braking state.
According to the fourth aspect of the present invention, it is possible to more strictly detect that the vehicle is not in the braking state (normal traveling state).

According to the fifth aspect of the present invention, it is possible to suitably determine whether or not an occupant is present even in a braking state of the vehicle.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a vehicle seat according to the present invention.

FIG. 2 is a side view showing the same embodiment.

FIG. 3 is a front view showing front and rear sensor brackets.

FIG. 4 is a block diagram showing an electrical configuration of the embodiment.

FIG. 5 is a flowchart showing an occupant determination mode according to the embodiment;

FIG. 6 is a graph showing characteristics of detection values from each load sensor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Seat main body 20 Seating load detecting device 21 Front right load sensor as front load sensor 22 Front left load sensor as front load sensor 23 Rear right load sensor as rear load sensor 24 Rear left load sensor as rear load sensor 25 ECU

Claims (5)

[Claims] 1. A front load sensor provided at a front portion of a seat body and a rear load sensor provided at a rear portion of the seat body, wherein a front load detection value from the front load sensor and a rear load sensor In a vehicle seat provided with a seating load detection device that detects a seating load based on a rear load detection value, a comparison unit that compares the front load detection value with the rear load detection value, and a comparison result of the comparison unit. Determining means for determining the braking state of the vehicle based on the vehicle, and invalidating means for invalidating the seating load detected by the seating load detecting device when the determining means determines that the vehicle is in the braking state. Features vehicle seats. 2. The vehicle seat according to claim 1, wherein the comparing unit compares the magnitude of the front load detection value with the magnitude of the rear load detection value, and wherein the determination unit includes the front portion. A vehicle seat, wherein when the detected load value is greater than the detected rear load value, it is determined that the vehicle is in a braking state. 3. The vehicle seat according to claim 2, wherein the determination unit determines that the vehicle is in a braking state when a state in which the front load detection value is larger than the rear load detection value has continued for a predetermined time. A vehicle seat characterized in that: 4. The vehicle seat according to claim 2, wherein the determination unit determines that the vehicle is in a braking state when a state in which the front load detection value is smaller than the rear load detection value has continued for a predetermined time. A vehicle seat characterized in that it is determined that the vehicle seat is not the vehicle seat. 5. The vehicle seat according to claim 1, wherein a previous seating load detected based on the front load detection value and the rear load detection value before a predetermined time is retained. A vehicle seat comprising a load holding unit, wherein when the determination unit determines that the vehicle is in a braking state, the last sitting load held by the last sitting load holding unit is set as a current sitting load.