JPS6216376Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a device for recording the causes of operation of an airbag device installed for vehicle safety measures, which records the causes of operation of an airbag device and enables later checking. be.

Nowadays, in view of the current situation where the occurrence of traffic accidents is significantly increasing, airbag devices have been installed as a safety system in vehicles such as passenger cars and trucks from the standpoint of personal protection. This air bag device rapidly inflates between the occupant and the vehicle body, for example, when the vehicle is in an accident and receives an excessive impact. As a result, this airbag device acts as a buffer between the occupant and the vehicle body, protecting the occupant from excessive impact during a collision. However, it is necessary to determine whether the airbag device was operating normally at the time of the accident, or whether it had already malfunctioned before the accident and was not operating normally at the time of the accident, and to notify the user of the occurrence of a malfunction when such a malfunction occurs. It is necessary to check whether the operation was performed normally or whether an accident occurred after this alarm was generated and the airbag device was activated. Alternatively, it is necessary to confirm whether the accident was caused by a malfunction in the airbag system.

The present invention was developed in view of the above points, and its purpose is to detect and record the causes of system operation, so that the causes of operation can be confirmed later. The purpose is to provide a recording device.

Hereinafter, an embodiment based on the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a circuit diagram of an embodiment in which the system operation cause recording device according to the present invention is applied to an air bag device.

In FIG. 1, 10 is an equivalent circuit of an air bag device. Here, one end of the front switch _S1 that detects an impact in front of the vehicle is connected to the power supply 11.
connected to one side of the The other end of the switch _S1 is connected to one end of a rear switch _S2 , which detects an impact at the rear of the vehicle, through a junction A, a resistor _R3 , and a junction B, respectively. The other end of the switch _S2 is connected to the other side of the power source 11. Additionally, switch S ₁ has a resistor R ₁ in parallel.
is connected, and a resistor _R2 is also connected in parallel to the switch _S2 . In addition, each resistor is R ₁ ≫
It is assumed that the relationship R ₃ , R ₂ ≫R ₃ exists. The resistor _R3 is commonly called a squib, and when an excessive current is passed through it, it becomes red hot, operating the airbag device and opening. Reference numeral 12 denotes a comparison circuit means, a junction point A of which is connected to the input terminals of a comparator 13 and a comparator 14, respectively, and a junction point B connected to the input terminals of a comparator 15 and a comparator 16, respectively. The output terminals of comparator 13 and comparator 14 are connected to comparator 1 through OR gate C.
5. Each output terminal of the comparator 16 is connected to the input terminal of an OR gate 17 via an OR gate d. Here, if the input voltage from the junction A of the air bag device 10 becomes higher or lower than two predetermined reference values determined by the comparators 13 and 14, in other words, Once out of the reference band, one of these comparators
The two outputs are set to go from low to high level. Similarly, when the input voltage from junction B becomes higher or lower than two predetermined reference values determined by comparator 15 and comparator 16, the output is set to a high level. 18 is a NAND gate, the input terminals of which are connected to the output terminals of comparators 13 and 16, respectively. An output terminal of the NAND gate 18 is connected to an input terminal of an inverter 19 and also to one input terminal of an AND gate 20. The output terminal of the OR gate 17 is connected to the other input terminal of the AND gate 20. The output terminal of the AND gate 20 is connected to the input terminal of a delay circuit 21 consisting of a resistor _R4 and a capacitor _C1 . The output terminal of the delay circuit 21 is connected to the base of the transistor 22 via a resistor _R5 , and is also grounded via a resistor _R6 . The emitter of transistor 22 is grounded, and its collector is connected to latching relay 23. This latching relay 23 is a wire ring.
l ₁ , has contacts G and H, and when not energized, the movable piece 24 is at the contact H position, and the transistor 2
When energized by turning on the movable piece 24, the movable piece 24 contacts the contact G.
come into contact with. On the other hand, the output terminal of the inverter 19 is connected to one end of the resistor _R7 , and the other end of the resistor _R7 is connected to the base of the transistor 25 and grounded via the resistor _R8 . The emitter of transistor 25 is grounded, and its collector is connected to power supply 27 via wire _l2 of relay 26.
This relay 26 has contacts I and J, and the movable piece 28 is at the contact J position when not energized. When the relay 26 is excited by turning on the transistor 25, the movable piece 28 is switched to the contact I side. still,
Contact J of relay 26 is connected to the wire of latching relay 23 and also to check terminal 29. On the other hand, the power terminal 27 is connected to the check terminal 3.
Connected to 0. In addition, latching relay 23
Contacts G and H are check terminals 31 and 32, respectively.
is connected to. A storage section is constituted by these relays. Here, check terminal 2
9, 30, 31, and 32 constitute a recording display section.
Note that the latching relays 23 and 26 move when the movable pieces 24 and 28 move, respectively.
Return wire 3 to enable return of 8 to the original position
It has 3,34.

The operation of the above circuit configuration will be explained. Here, for example, equivalent circuit 1 of an airbag device
0, both switches S ₁ and S ₂ are in the OFF state during normal operation without an accident occurring. During abnormal operation, that is, when the airbag device itself is malfunctioning, one of the switches S ₁ and S ₂ may be turned on, and during normal operation when a car accident occurs, both switches S ₁ and S ₂ are turned on. It has a form of being in an on state. Switch S ₁ , S ₂
An acceleration sensor or G sensor may be used.

When the air bag device 10 is operating normally without any accident, that is, when the switches S ₁ and S ₂ are both in the OFF state, the voltages V _A and V B at the junctions A and _B are the same as the power supply 11. The voltage of resistors R ₁ , R ₂ , R ₃
It is given by the partial pressure value divided by . At this time, the reference voltage of the comparator 13 is set higher than the voltage V _A and the reference voltage of the comparator 15 is set higher than the voltage V _B in consideration of the relationship between the resistors R ₁ to R ₃ . The reference voltage of the comparator 14 is set lower than the voltage V _A , and the reference voltage of the comparator 16 is set lower than the voltage V _B. Therefore, at this time, each comparator 13, 14, 1
Outputs 5 and 16 are both at low level. Therefore, the output of OR gate C becomes low level.
Similarly, the output of OR gate d is also at low level.
At this time, the output of the OR gate 17 is at a low level, and the output of the NAND gate 18 is at a high level.
Therefore, the output of inverter 19 becomes low level, and transistor 25 is placed in an off state.
Therefore, since the relay 26 is not energized, its movable piece 28 remains held on the contact J side, and the check terminals 29 and 30 are in a closed state. Further, the output of the AND gate 20 is also at a low level, and the transistor 22 is also turned off. Therefore, since the latching relay 23 is not energized, its movable piece 2
4 remains held on the contact H side, and the check terminals 31 and 32 are also in an open state. That is,
In this state, check terminals 29, 30, 3
1 and 32, nothing is recorded or displayed, indicating that normal operation is occurring without any accidents occurring.

Next, a case will be considered in which one of the switches S ₁ and S ₂ is turned on due to a malfunction of the air bag device 10. If the switch S ₁ is turned on, considering the resistors R ₁ to R ₃ mentioned above, the voltage V _A at the junction A becomes almost the same as the power supply voltage and becomes higher than in the normal case. , the voltage V _B at junction B also increases. At this time, the voltages V _A and V _B at the junctions A and B exceed their respective reference voltages, and the outputs of the comparators 13 and 15 become high level, while the outputs of the comparators 14 and 16 remain low level. . Therefore, the outputs of OR gates C and d are at high level, and the output of OR gate 17 is at high level. Also, Nand Gate 1
The output of inverter 8 remains at high level, so the output of inverter 19 remains at low level. As a result, the output of the AND gate 20 becomes high level, and the transistor 22 is turned on. On the other hand, since the transistor 25 is off, the movable piece 28 of the latching relay 26 is in contact with the contact J side, and an excitation current flows through the set wire _l1 of the latching relay 23 due to the on operation of the transistor 22. As a result, the movable piece 24 is switched from contact H to contact G and is held there. Therefore, lamp L ₁ goes out and lamp L ₂ lights up. If this occurs while the vehicle is in operation, it indicates that a malfunction has occurred in the airbag device 10. It is convenient to use a warning buzzer instead of the lamp _L2 , as it will make it easier to notice and prevent the development of an accident.

Furthermore, when only switch _S2 is turned on, the voltage V _A at junction A becomes lower than the voltage that was flowing up to that point. The voltage V _B at junction B is similarly low. At this time, the voltage V at each junction point A, B
Since _A and _VB are lower than the predetermined reference voltage, the outputs of the comparators 14 and 16 become high level. On the other hand, at this time, the outputs of the comparators 13 and 15 are at low level. Therefore, orgate C,
The outputs of d and 17 are each at high level, and the output of NAND gate 18 is also at high level. The subsequent operations are similar to those described above when only switch _S1 is turned on.

This time, if both switches S ₁ and S ₂ are turned on at the same time, that is, when the air bag device 10
Let us consider the case where the system operates due to a vehicle collision.
At this time, the squib resistor _R3 is connected to the switch.
Both S ₁ and S ₂ close, and the excessive current that flows at this time triggers the expansion of the air bag after a certain period of time, and then opens. First, junction A
and the voltages V _A and V _B of B are the comparator 1
The value is such that the outputs of 3 and 16 are both high level. Therefore, or gates C, d and 1
The output of No. 7 becomes high level. At this time, the output of the NAND gate 18 is at a low level. Therefore, the output of the inverter 19 becomes high level,
Transistor 25 is turned on. Therefore, the relay 26 is energized by the current flowing through the set wire _l2 , and the movable piece 28 moves toward the contact point I and is held in contact with it. This holding state continues even after the current in the set wire _l2 is cut off, unless a reset current is applied to the reset wire 34 side. Therefore, the check terminals 29 and 30 are kept open. At this time, the transistor 22 is turned off by the low level output of the AND gate 20. Also, the contact I of the movable piece 28 due to the excitation of the relay 26
Since the power supply 27 is cut off by contact with the side, the latching relay 23 does not operate and the movable piece 24 remains at the contact point H. Therefore, the check terminals 31 and 32 are kept open. In this state, check terminals 29, 30, 31, 3
2, it can be seen that the air bag device 10 was operating normally when the vehicle accident occurred. Note that when a vehicle collides, that is, when switches S ₁ and S ₂ are turned on, there is a slight time difference, but in that case, a delay circuit 21 is arranged to determine the order of operation of the latching relay 23 and relay 26. It is set up. That is, in the event of a vehicle collision, the delay circuit 21 operates the relay 26 before the latching relay 23 operates to reliably record the collision operation of the airbag device 10.

As explained above, the present invention distinguishes between the normal state of the air bag device, the malfunction of the device itself, and the normal operation of the device due to a vehicle accident, and records the state so that it can be checked later. Also,
The present invention uses a latching relay to perform the recording function, making it possible to maintain the recorded state even if the power is cut off when a vehicle accident occurs.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of an embodiment of an operation cause recording device for an air bag device according to the present invention. 10... Equivalent circuit of air bag device, R ₃ ...
Resistor for squib, R ₁ , R ₂ ... Resistor, S ₁ , S ₂ ...
...Switch, 12... Comparison circuit means, C, d, 1
7, 18, 19, 20...Logic circuit network, 25, 2
2...first and second switching circuits, 26,2
3...First and second latching relays.

Claims (1)

[Claims for Utility Model Registration] A series circuit in which a pair of switches that close in response to impact are arranged at both ends of a squib resistor is connected to a DC power source, and has a value sufficiently larger than that of the squib resistor. A circuit arrangement applied to an airbag device having an equivalent circuit in which each of a pair of resistors is connected in parallel to each of the switches, and the potential at each end of the squib resistor is within upper and lower reference voltage values. respective comparator circuit means for determining whether the voltage at each end thereof is the same and inverting the output when the potential at each end takes a value outside the upper and lower reference voltage values;
a logic circuitry for obtaining a first output indicating that both of the switches are closed and a second output indicating that one of the switches is closed; and each of the first and second outputs. The first and second switching circuits each have a set wire ring and a reset wire ring, which perform a switching operation in response to It has a first latching relay that is latched, a set wire ring, and a reset wire ring, and the set wire is connected only when the second switching circuit performs a switching operation in the reset state of the first latching relay. 1. A device for recording the cause of operation of an airbag device, comprising a second latching relay whose ring is energized and whose contacts are switched and latched.