JP3795231B2 - Vehicle occupant protection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle occupant protection device that is mounted on a vehicle such as an automobile and protects the occupant.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as this type of vehicle occupant protection device, the one described in Japanese Patent No. 2706965 is known. This vehicle occupant protection device is an occupant detection switch composed of a first switch and a second switch that are turned on when a seat belt is worn and the occupant is on the vehicle, and turned off when the seat belt is not worn. When only one of them is on or off, it is determined that a failure has occurred and an alarm is issued. In other words, it is abnormal when one of the passengers is seated with the seat belt on and the other is off due to a malfunction or the other is on due to welding or the like despite the removal of the seat belt. It judges that it is and issues an alarm.
[0003]
[Problems to be solved by the invention]
However, in the above conventional vehicle occupant protection device, if only one switch fails, it can be determined to be abnormal, but if both the first and second switches fail in the same failure mode, it is abnormal. Could not be judged. That is, if both the first and second switches remain on due to welding or the like, or if they remain off due to other failures, both the first and second switches remain on or off. Therefore, it was indistinguishable from the normal case.
[0004]
Therefore, according to the present invention, even when both the first and second switches fail in the same failure mode, it can be determined that there is an abnormality, and the reliability of occupant detection by the occupant detection switch can be improved. An object is to provide a vehicle occupant protection device.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, an occupant protection device for a vehicle according to claim 1 of the present invention has an occupant detection switch attached to an occupant restraint device for restraining the occupant, and the occupant according to the switch state of the occupant detection switch. In the vehicle occupant protection device that operates the restraint device, the occupant detection switch can be individually actuated to perform an on / off operation exclusively depending on whether or not the occupant restrained by the occupant restraint device is on board. An exclusive OR circuit to which the logical values of the first switch and the second switch are input; an output of the exclusive OR circuit; and A first logical product circuit to which a logical value of one switch is input, and a second logical product circuit to which an output of the exclusive OR circuit and a logical value of the second switch are input If, based on the output of the exclusive OR circuit when said first and second switch is determined to be both on or off, and abnormality judgment means for the occupant detection switch is determined to be abnormal, When it is determined that the first switch is on and the second switch is off based on the outputs of the first AND circuit and the second AND circuit, passenger boarding is detected. On the other hand, when it is determined that the first switch is off and the second switch is on, occupant detection means for detecting occupant non-boarding is provided .
Further, the vehicle occupant protection apparatus according to claim 2, in vehicle occupant protection apparatus according to claim 1 Symbol placement, the occupant detection switch is incorporated in the buckle portion of the seat belt device the a passenger constraining apparatus, The first and second switches are exclusively turned on and off according to whether a tongue plate is engaged with the buckle portion.
[0006]
When the occupant is on board, the first switch is on and the second switch is off, and when the occupant is not on board, the first switch is off and the second switch is on. If the first switch remains off due to a failure or the like despite being mounted, the first switch and the second switch are both turned off, and it is determined that the occupant detection switch is abnormal.
[0007]
In addition, when the first switch remains on due to welding or the like even though the seat belt is removed and the vehicle is not on board, both the first and second switches are on and the occupant detection switch is abnormal. It is determined that there is.
[0008]
Further, in the case of a failure in which both the first and second switches remain on or off, it is determined that the occupant detection switch is abnormal.
[0009]
Thus, even when both the first and second switches fail in the same failure mode, it can be determined that there is an abnormality, and the reliability of passenger detection by the passenger detection switch can be improved.
[0010]
The first and second switches are not limited to mechanical switches whose contacts open and close, but include optical switches including slits and photointerrupters, magnetic switches such as proximity sensors, and the like.
[0011]
Moreover, when it is determined by the abnormality determination means that the occupant detection switch is abnormal, it is preferable that the occupant restraint device is deactivated or notified to the occupant using a display or a speaker.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of a vehicle occupant protection device of the present invention will be described. The vehicle occupant protection device according to the present embodiment increases or decreases the tension of the seat belt at the time of a collision risk and issues an alarm by vibration due to compression / release to the occupant. The present invention is applied to a vehicle occupant restraint protection device that restrains the vehicle.
[0013]
[First Embodiment]
FIG. 2 is a diagram showing a configuration of a vehicle occupant restraint protection device to which an occupant detection circuit is attached. This vehicle occupant restraint protection device includes a relative distance sensor 11, an occupant detection circuit 12, an interface (I / F) 13, a microcomputer unit (MCU) 14, switches SW 1 to SW 3, a DC power supply 21, an oscillator 22, and a motor 23. Composed.
[0014]
The relative distance sensor 11 outputs a voltage corresponding to the distance between the object and the host vehicle, and the output signal is input to the MCU 14 via the interface 13.
[0015]
The microcomputer unit (MCU) 14 outputs a collision risk signal and a collision unavoidable signal to the switches SW1, SW2, and SW3 based on the output signal of the relative distance sensor 11 input through the interface 13.
[0016]
The switches SW1, SW2, and SW3 are used to switch the power source connected to the motor 23. When a collision danger signal is output from the MCU 14, the switch SW1 is closed and the switches SW2 and SW3 are connected to the A-side contacts. As a result, an output signal from the oscillator 22 is supplied to the motor 23. In this embodiment, the oscillation frequency of the oscillator 22 is 20 Hz.
[0017]
When a collision inevitable signal is output from the MCU 14, the switch SW1 is closed and the switches SW2 and SW3 are connected to the B-side contact. As a result, the output voltage of the DC power supply 21 is applied to the motor 23.
[0018]
The motor 23 is attached to an electric retractor of a seat belt device (not shown). In the seat belt device, a seat belt starting from a fixed portion is wound around a retractor portion through a buckle portion and a shoulder portion. The seat belt is wound and pulled out by driving the motor 23 directly connected to the retractor.
[0019]
FIG. 1 is a circuit diagram showing the configuration of the occupant detection circuit 12. The occupant detection circuit 12 mainly includes a microprocessor unit (MPU) 31 and an occupant detection switch 33. The occupant detection switch 33 is built in a buckle portion (not shown) of the seat belt device, and is turned on / off according to whether or not the tongue plate is engaged with the buckle portion, that is, depending on whether the seat belt is attached or not. The first switch 34 and the second switch 35 are turned off. That is, normally, the first switch 34 is turned off and the second switch 35 is turned on when the seat belt is not worn, that is, the occupant is not boarded, and the first switch 34 is turned on when the seat belt is worn, that is, the occupant is boarded. The second switch 35 is turned off.
[0020]
One contact of the first switch 34 is connected to the + 5V power supply line via a resistor, and the other contact is connected to the P1 terminal of the MPU 31. Similarly, one contact of the second switch 35 is connected to the + 5V power supply line via a resistor, and the other contact is connected to the P2 terminal of the MPU 31.
[0021]
The MPU 31 detects these on / off by a high (H) / low (L) signal of a voltage (H signal is 5V, L signal is 0V), and the first switch 34 is on and the second switch 35 is off. When the first switch 34 is off and the second switch 35 is on, the occupant detection signal is output to the terminal P3 as a signal indicating non-occupation. To do. Further, an alarm signal indicating that both the first switch 34 and the second switch 35 are normal is output to the terminal P4.
[0022]
Further, when both the first switch 34 and the second switch 35 are on, or when both the first switch 34 and the second switch 35 are off, it is determined that the occupant detection switch 33 is abnormal and is abnormal. An alarm signal indicating this is output to the terminal P4.
[0023]
On the other hand, the MCU 14 performs an operation according to an occupant detection signal and an alarm signal received from the occupant detection circuit 12 via the interface 13. That is, when an occupant detection signal is received as a signal indicating occupant boarding, the alarm operation by the seat belt device described above is enabled, and when an occupant detection signal is received as a signal indicating non-passenger occupancy, an alarm is generated by the seat belt device. In order to make the occupant confirm that the occupant detection switch 33 is abnormal when the operation is rendered inoperable and an alarm signal indicating an abnormality is received, the seat belt device operates differently than when the vehicle is in danger of collision. Drive.
[0024]
In the diagnosis of the occupant detection switch 33, if one of the first switch 34 and the second switch 35 breaks down while it is on or off, it turns on or off when the seat belt is worn or not worn. Is output to determine whether the occupant detection switch 33 is abnormal.
[0025]
In addition, when the first switch 34 and the second switch 35 are both turned on or off and a failure occurs, an alarm signal is output to indicate an abnormality regardless of whether the seat belt is worn or not, and the occupant detection switch 33 abnormalities are determined.
[0026]
Thus, in the first embodiment, it is possible to appropriately perform occupant detection and failure diagnosis of the occupant detection switch. In addition, the function can be easily expanded by changing the contents of the processing executed by the MPU 31. Therefore, the reliability of occupant detection by the occupant detection switch can be improved.
[0027]
[Second Embodiment]
A vehicle occupant restraint protection apparatus according to a second embodiment will be described. The vehicle occupant restraint protection device according to the second embodiment is the same as the first embodiment except for the configuration of the occupant detection circuit as compared with the first embodiment. Only the circuit configuration will be described.
[0028]
FIG. 3 is a diagram illustrating a configuration of an occupant detection circuit according to the second embodiment. The occupant detection circuit 42 is configured using a logic circuit instead of the MPU. An exclusive OR circuit 46 and two AND circuits 47 and 48 are connected to the occupant detection switch 43 including the first switch 44 and the second switch 45.
[0029]
The signals output from the logic circuit in accordance with the switch state of the occupant detection switch 43 are as shown in FIG. FIG. 4 is a diagram showing an output pattern of a logic circuit that changes depending on the switch state of the occupant detection switch 43 when the occupant is on board, the occupant is not on board, and the occupant detection switch is abnormal.
[0030]
When the seat belt is attached and the passenger is on board, that is, when the first switch 44 is on and the second switch 45 is off, the output (1) of the AND circuit 47 and the output (2) of the exclusive OR circuit 46 The output {circle over (3)} of the AND circuit 48 becomes H, H, and L signals, respectively.
[0031]
On the other hand, when the seat belt is not worn and the occupant is not on board, that is, when the first switch 44 is off and the second switch 45 is on, the output (1) of the AND circuit 47, the exclusive OR circuit 46 The output {circle over (2)} and the output {circle over (3)} of the AND circuit 48 are L, H and H signals, respectively.
[0032]
When both the first switch 44 and the second switch 45 are on or off, the output (1) of the AND circuit 47, the output (2) of the exclusive OR circuit 46, and the output (3) of the AND circuit 48 All ▼ are L signals.
[0033]
Upon receiving these output signals from the logic circuit, the interface 13 determines that the occupant is on board, the passenger is not on board, or the occupant detection switch is abnormal, and performs a process according to each determination.
[0034]
As described above, in the second embodiment, it is possible to perform the passenger detection and the failure diagnosis of the passenger detection switch with a simple configuration including two AND circuits and one exclusive OR circuit.
[0035]
Further, in the above embodiment, when an alarm signal is received, the operation of the seat belt device is changed to an operation different from that at the time of the collision danger of the vehicle to notify the abnormality of the occupant detection switch. Instead, for example, a display unit may be provided, and the MCU 14 may output the fact to the display unit and notify the occupant. Furthermore, you may make it notify using a speaker.
[0036]
Further, in the above embodiment, the seat belt tension is increased / decreased at the time of a collision risk, and an alarm is issued by vibration caused by compression / release to the occupant. Although the case where the present invention is applied to the belt device has been shown, the present invention is not limited to this, and the present invention can also be applied to a seat belt device in which a pretensioner for winding a seat belt is operated by ignition of a gas generator, an air bag device, or the like.
[0037]
Further, the seat belt device with the occupant detection switch may be provided in both the driver seat and the passenger seat.
[0038]
Furthermore, although the MPU 31 is provided separately from the MCU 14 in the first embodiment, the MCU may have an MPU function, thereby simplifying the electrical configuration.
[0039]
Moreover, in the said embodiment, although a pair of 1st and 2nd switch which opens and closes by a tongue plate engaging with the buckle part of a seatbelt was shown, as a 1st and 2nd switch, the mechanical type which a contact opens and closes Not only the switch but also an optical switch composed of a slit and a photo interrupter, a magnetic switch such as a proximity sensor, and the like can be used.
[0040]
【The invention's effect】
According to the vehicle occupant protection device of the first aspect of the present invention, when an occupant detection switch is attached to the occupant restraint device that restrains the occupant, and the occupant restraint device is operated according to the switch state of the occupant detection switch. The occupant detection switch includes a first switch and a second switch that perform an on / off operation exclusively depending on whether or not the occupant is restrained by the occupant restraint device, and the first and second switches When both switches are on or off, the occupant detection switch is determined to be abnormal by the abnormality determination means, so that it is abnormal even when both the first and second switches fail in the same failure mode. Therefore, the reliability of occupant detection by the occupant detection switch can be improved.
[Brief description of the drawings]
FIG. 1 is a circuit diagram showing a configuration of an occupant detection circuit 12;
FIG. 2 is a diagram showing a configuration of a vehicle occupant restraint protection device to which an occupant detection circuit is attached.
FIG. 3 is a diagram illustrating a configuration of an occupant detection circuit according to a second embodiment.
FIG. 4 is a diagram illustrating an output pattern of a logic circuit that changes depending on a switch state of an occupant detection switch 43 when the occupant is on board, the occupant is not on board, and the occupant detection switch is abnormal.
[Explanation of symbols]
12, 42 Occupant detection circuit 31 Microprocessor unit (MPU)
33, 43 Occupant detection switch 34, 44 First switch 35, 45 Second switch 46 Exclusive OR circuit 47, 48 AND circuit

Claims (2)

Attach an occupant detection switch to the occupant restraint device that restrains the occupant,
In the vehicle occupant protection device for operating the occupant restraint device according to the switch state of the occupant detection switch,
The occupant detection switch has two switches composed of a first switch and a second switch that can be individually operated and perform on / off operations exclusively according to whether or not the occupant restrained by the occupant restraint device is on board. Have
An exclusive OR circuit to which the logical values of the first switch and the second switch are input;
A first AND circuit to which an output of the exclusive OR circuit and a logic value of the first switch are input;
A second AND circuit to which an output of the exclusive OR circuit and a logic value of the second switch are input;
Based on the output of the exclusive OR circuit when said first and second switch is determined to be both on or off, and abnormality judgment means for the occupant detection switch is determined to be abnormal,
When it is determined that the first switch is on and the second switch is off based on the outputs of the first AND circuit and the second AND circuit, passenger boarding is detected. On the other hand, an occupant protection device for a vehicle, comprising: occupant detection means for detecting occupant non-boarding when it is determined that the first switch is off and the second switch is on. . The occupant detection switch is incorporated in a buckle portion of a seat belt device which is the occupant restraint device, and the first and second switches are exclusively turned on depending on whether or not a tongue plate is engaged with the buckle portion. off operation vehicle occupant protection apparatus according to claim 1 Symbol placement and performing.

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