JP2840968B2 - Starting devices for acceleration switches and occupant protection devices - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an acceleration switch operated by acceleration and a starter for an occupant protection device including the acceleration switch.

[Description of the Related Art] As an acceleration switch, a permanent magnet that moves against the urging force of a spring when an acceleration equal to or more than a predetermined value acts, and the permanent magnet comes close to the reed contact so that the permanent magnet A reed switch that is closed by a magnetic force is known. This type of acceleration switch is used for a starter for an occupant protection device such as an airbag for protecting an occupant in the event of a vehicle collision, and is described in, for example, JP-A-58-152645. A starting device for a passenger protection device is one example.

[Problems to be Solved by the Invention] However, once mounted on a vehicle, this type of acceleration switch does not operate unless an acceleration at which the acceleration switch operates is given. There was a problem that it was not possible. For this reason, the conventional starting device having this type of acceleration switch cannot arbitrarily check whether or not the acceleration switch operates normally. Was likely to occur.

An object of the present invention is to provide an acceleration switch capable of performing an operation check without applying an acceleration, and an occupant protection device having an operation check function of the acceleration switch. It is to provide a starting device.

[Means for Solving the Problems] In the present invention, a reed switch fixedly disposed inside a cylindrical case and having a reed contact operated by magnetic force, and a ring-shaped electromagnetic switch fixedly disposed on the outer periphery on one end side of the cylindrical case. Means, an annular permanent magnet provided on the outer periphery of the cylindrical case, so as to be slidable between the electromagnetic means and the other end of the cylindrical case, and the other end of the cylindrical case and the A spring provided on the outer periphery of the cylindrical case between the permanent magnet and the spring for biasing the permanent magnet toward the electromagnetic means, wherein the urging force of the spring is applied when an acceleration of a predetermined value or more is applied. The permanent magnet is moved to the vicinity of the reed contact of the reed switch to actuate the reed switch, and a repulsive force is generated between the electromagnetic means and the permanent magnet. When the electromagnetic means is excited as described above, the acceleration causes the permanent magnet to move to the vicinity of the reed contact of the reed switch against the urging force of the spring, and to operate the reed switch. The above object is achieved by a switch.

Further, in the present invention, the starting device includes an acceleration switch that operates when an acceleration equal to or more than a predetermined value acts, and starts the occupant protection device with the operation of the acceleration switch as at least one condition. Vessel
A reed switch having a reed contact operated by magnetic force, an annular electromagnetic means fixedly arranged on the outer periphery of one end of the cylindrical case, and slidable between the electromagnetic means and the other end of the cylindrical case. As described above, an annular permanent magnet provided on the outer periphery of the cylindrical case, and provided on the outer periphery of the cylindrical case between the other end side of the cylindrical case and the permanent magnet, and the permanent magnet A spring that biases the permanent magnet toward the lead contact of the reed switch against an urging force of the spring when an acceleration equal to or greater than a predetermined value acts on the reed switch, The permanent magnet is energized so that a repulsive force is generated between the electromagnetic means and the permanent magnet. The reed switch is configured to move in the vicinity of the reed switch and actuate the reed switch, and further repels the permanent magnet of the acceleration switch in a state where no acceleration acts on the vehicle. The above object is achieved by a starting device for an occupant protection device provided with operation check means for driving the electromagnetic means so as to check whether or not the reed switch of the acceleration switch is operated.

[Operation] In the acceleration switch according to the present invention, the permanent magnet can be moved against the urging force of the spring by the electromagnetic means, so that the switch can be operated without applying acceleration, and an operation check is performed. Becomes possible.

In the starting device for the occupant protection device according to the present invention, the operation check means drives the electromagnetic means of the acceleration switch to detect whether the switch of the acceleration switch is operated.

[Embodiment of the Invention] Fig. 2 is a configuration diagram showing an embodiment of an acceleration switch according to the present invention.

An acceleration switch 1 includes a reed switch 3 and a permanent magnet 4 in a housing 2 including an upper case 2a and a lower case 2b.
And the electromagnetic winding 5.

The reed switch 3 has reed contacts 7 and 8 made of a ferromagnetic material in a sealed tube 6 and these reed contacts 7 and 8 are connected to reeds 7 a and 8.
It is drawn out of the housing 2 through a and the terminals 9 and 10. Such a reed switch 3 is a cylindrical case
11 is fixedly disposed inside by resin filling. One end of the cylindrical case 11 is engaged with a holding wall 2-1 erected from the lower case 2b toward the upper case 2a, and the other end is extended to one side wall 2-2 of the housing 2. .

The permanent magnet 4 is annular and is slidably provided on the outer periphery of the cylindrical case 11. In this example, the side facing the holding wall 2-1 is magnetized to the N pole and the opposite side is magnetized to the S pole. The permanent magnet 4 is provided between the permanent magnet 4 and the holding wall 2-1 by the side wall 2-2.
The permanent magnet 4 is normally held on the side of the side wall 2-2 by the spring 12, and the reed contacts 7, 8 of the reed switch 3 are attracted and closed by the magnetic field of the permanent magnet 4. Is not done. When a negative acceleration acts on the spring 12 in the direction indicated by the arrow due to a collision of the vehicle, when the acceleration becomes a predetermined value or more, the permanent magnet 4 resists the urging force of the spring 12 and the holding wall 2-1 side. , Whereby the reed contacts 7, 8 of the reed switch 3 are closed.

The electromagnetic winding 5 is provided on the outer periphery of the cylindrical case 11 between the permanent magnet 4 and the side wall 2-2 via a non-magnetic annular spacer 13. The electromagnetic winding 5 is wound around a bobbin 14 fitted on the outer periphery of the cylindrical case 11 via an annular yoke 15,
It is drawn out of the housing 2 via the terminals 16 and 17. The electromagnetic winding 5 is excited so that the side facing the permanent magnet 4 via the annular spacer 13 has the same polarity as the permanent magnet 4, and resists the permanent magnet 4 against the urging force of the spring 12 when no acceleration is applied. The reed switch 3 is moved to the holding wall 2-1 side to close the reed contacts 7 and 8 of the reed switch 3.

According to the above configuration, the permanent magnet 4 is excited so as to generate a repulsive force between the permanent magnet 4 and the reed contacts 7 and 8 against the biasing force of the spring 12.
, And the reed contacts 7, 8 can be closed.

FIG. 3 is a block diagram showing an embodiment of a starting device for an occupant protection device using the acceleration switch of FIG. The second
Those having the same reference numerals as those in the drawings indicate the same components.

One reed contact 7 of the reed switch 3 is connected to an ON / OFF confirming terminal a of the microcomputer 20, and one end of a squib 21 for igniting a starting powder for an occupant protection device such as an airbag (not shown). It is connected to the. The other end of the squib 21 is grounded via the collector-emitter circuit of the ignition transistor 22. The base of the ignition transistor 22 is connected to an ignition signal output terminal b of the microcomputer 20. Reed switch 3
The other reed contact 8 is connected to an ignition power source 23. One end of the electromagnetic winding 5 is connected to the control power supply, and the other end is grounded via the collector-emitter circuit of the test transistor 24. The base of the test transistor 24 is connected to the output terminal of the NOR circuit 25. The NOR circuit 25 has one input terminal connected to the test signal output terminal c of the microcomputer 20 and the other input terminal connected to the ignition signal output terminal b of the microcomputer 20. The ON / OFF confirmation terminal a of the microcomputer 20 is
When the reed switch 3 is off, it is at the L level, and when it is on, it is at the H level. An ignition signal at H level is output from the ignition signal output terminal b, and is held at L level when the ignition signal is not output. L from the test signal output terminal c
A level test signal is output, and is held at the H level when the test signal is not output.

Reference numeral 26 denotes an acceleration sensor having an acceleration limit value higher than that of the acceleration switch 1 and configured to be turned on at an acceleration higher than the acceleration at which the acceleration switch 1 turns on when a negative acceleration is applied. A voltage signal is given to the micro computer 20 when it is turned on. 27 is an alarm
It is driven by the micro computer 20.

The micro computer 20 receives a voltage signal from the acceleration sensor 26, integrates the signal, determines that a collision has occurred when the integrated value exceeds a predetermined threshold level, and provides an ignition signal to the ignition transistor 22. And a function of checking the operation of the acceleration switch 1 according to the flowchart of FIG.

FIG. 4 is a flowchart for checking the operation of the acceleration switch 1, and the operation of the configuration of FIG. 3 for checking the operation of the acceleration switch 1 will be described below.

When the key switch of the vehicle is turned on and a key-on signal is given to the microcomputer 20, the operation check of the acceleration switch 1 is started. First, in step 30, it is determined whether or not the reed switch 3 is off by determining the level of the ON / OFF confirmation terminal a. When the key switch is turned on, the vehicle is normally in a stopped state and no acceleration is applied. Therefore, if the acceleration switch 1 is normal, the reed switch 3 is in an off state. In step 30, if the reed switch 3 is not turned off, it is determined that the reed switch 3 is in the closed state and a failure is detected.
Drive 27. If the reed switch 3 is off, the process proceeds from step 30 to step 32, where a test signal (L level pulse signal) is output from the test signal output terminal c. When the key switch is turned on, the vehicle is normally stopped and no acceleration is applied.
Is at the L level, and the output of the NOR circuit 25 is at the H level. As a result, the test transistor 24 is turned on,
The electromagnetic winding 5 is excited, and due to the magnetic repulsion, the permanent magnet 4 moves in a direction to close the reed contacts 7 and 8 of the reed switch 3 against the urging force of the spring 12. Then step 3
In step 3, it is determined whether or not the reed switch 3 is on by determining the level of the ON / OFF confirmation terminal a. If the reed switch 3 is not turned on, it is determined that a failure has occurred. If the reed switch 3 is turned on, it is determined to be normal, and the operation check of the acceleration switch 1 is ended.

When an ignition signal of H level is output from the ignition signal output terminal b due to a failure of the acceleration sensor 26 or the like at the time of checking the operation of the acceleration switch 1, the output of the NOR circuit 25 becomes L level, and the test transistor 24 is turned off. The permanent magnet 4 is returned by the biasing force of the spring 12, and the reed switch 3
The reed contacts 7, 8 are opened to prevent erroneous ignition.

In the above embodiment, turning on the key switch is a condition for starting the operation check of the acceleration switch 1. However, the present invention is not limited to this, and it may be performed in a state where no acceleration acts on the vehicle. It can be performed when the key switch is turned off, or the vehicle speed can be set to 0 in addition to turning the key switch on and off in consideration of the case where the key switch is turned on / off while the vehicle is running. is there.

[Effects of the Invention] As described above, according to the present invention, the permanent magnet can be moved by the electromagnetic means against the urging force of the spring, so that the switch can be operated without applying acceleration. Thus, it is possible to provide an acceleration switch capable of arbitrarily performing an operation check. The operation check means drives the electromagnetic means of the acceleration switch to detect whether or not the switch of the acceleration switch is operated. Therefore, the starting for the occupant protection device capable of checking the operation of the acceleration switch. An apparatus can be provided.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a starting device for an occupant protection device of the present invention, FIG. 2 is a configuration diagram showing an embodiment of an acceleration switch according to the present invention, and FIG. 3 uses the acceleration switch of FIG. FIG. 4 is a block diagram showing an embodiment of the starting device for the occupant protection device. FIG. 4 is a flowchart for checking the operation of the acceleration switch in the configuration of FIG. 1 ... Acceleration switch, 3 ... Reed switch, 4 ... Permanent magnet, 5 ... Electromagnetic winding, 7,8 ... Reed contact, 12 ... Spring, 20 ... Microcomputer

Claims (6)

(57) [Claims] A reed switch fixedly disposed inside a cylindrical case and having a reed contact operated by a magnetic force; an annular electromagnetic means fixedly disposed on the outer periphery of one end of the cylindrical case; an electromagnet means and the cylinder; An annular permanent magnet provided on the outer periphery of the cylindrical case so as to be slidable with the other end of the case; and the cylindrical case between the other end of the cylindrical case and the permanent magnet. A spring provided on the outer periphery of the permanent magnet, for urging the permanent magnet toward the electromagnetic means. When an acceleration of a predetermined value or more is applied, the permanent magnet is opposed to the urging force of the spring. The reed switch is moved to the vicinity of the reed switch to operate the reed switch, and the electromagnetic means is excited so that a repulsive force is generated between the electromagnetic means and the permanent magnet. In Rukoto, the against permanent magnets the biasing force of the spring to move the reed contacts vicinity of the reed switch, the acceleration switch which is to be able to operate the reed switch. 2. A starting device for starting an occupant protection device under the condition that at least one operation of the acceleration switch is performed, the acceleration switch including an acceleration switch that operates when an acceleration equal to or more than a predetermined value acts. A reed switch fixedly arranged inside the cylindrical case and having a reed contact operated by magnetic force; an annular electromagnetic means fixedly arranged on the outer periphery of one end of the cylindrical case; an electromagnet means and the other end of the cylindrical case An annular permanent magnet provided on the outer periphery of the cylindrical case so as to be slidable between the permanent magnet and the outer periphery of the cylindrical case between the other end of the cylindrical case and the permanent magnet. A spring for urging the permanent magnet toward the electromagnetic means, wherein when an acceleration equal to or more than a predetermined value is applied, the permanent magnet opposes the urging force of the spring. A stone moves near the reed contact of the reed switch, the reed switch is configured to operate, and the electromagnetic means is excited so that a repulsive force is generated between the electromagnetic means and the permanent magnet. Thereby, the permanent magnet moves to the vicinity of the reed contact of the reed switch against the urging force of the spring, and the reed switch can be actuated. Further, a state in which no acceleration acts on the vehicle In the following, for an occupant protection device provided with operation check means for driving the electromagnetic means so as to repel the permanent magnet of the acceleration switch and checking whether the reed switch of the acceleration switch operates. Starting device. 3. An acceleration sensor having an acceleration limit value different from that of the acceleration switch and operated by applying an acceleration equal to or higher than the acceleration limit value, and an operation of both the acceleration switch and the acceleration sensor. Starting means for starting the occupant protection device based on the operation of the occupant protection device, wherein when the reed switch of the acceleration switch is operated by the operation checking means, the starting of the starting means is prevented even if the acceleration sensor is operated. 3. The starting device for an occupant protection device according to claim 2, further comprising blocking means. 4. The starting device for an occupant protection device according to claim 2, wherein said operation check means is driven in response to an ON operation or an OFF operation of a key switch of the vehicle. 5. The system according to claim 1, wherein the operation check means responds to an ON operation or an OFF operation of a key switch of the vehicle and a vehicle speed of zero,
The starting device for an occupant protection device according to claim 2, which is driven. 6. The operation check means, comprising: a determination means for determining whether the reed switch is in an operation state or a non-operation state; and responding to the determination means; A driving unit that drives the electromagnetic unit so as to repel the magnet, a detection unit that responds to the driving unit, and detects whether the reed switch is operated, and responds to the determination unit and the detection unit; 3. The warning device according to claim 2, further comprising: a warning unit that is driven when the determination unit determines that the reed switch is in an operating state, and when the detection unit detects that the reed switch does not operate. Starting device for occupant protection device.