JP2004268729A - Occupant protection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an occupant protection device capable of disposing a backup capacitor in an ECU case without restricting a component mounting area in a central part on a substrate. <P>SOLUTION: The ECU has a first substrate 10 in the case, and the component mounting area 11 is formed on the first substrate 10 almost over the entire area. A G-sensor 26A for detecting a frontal crash and a G-sensor 26B for detecting a side crash are mounted on the peripheral part of the component mounting area 11, and a second substrate 20 is vertically fixed. The backup capacitor 22 is mounted on the second substrate 20, and a G-sensor 26C for detecting rollover is mounted. The backup capacitor 22 is disposed leaving a space between the first substrate 10 and the backup capacitor. Therefore, a circuit component can be mounted to the area on the first substrate 10 below the backup capacitor 22. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an occupant protection device that protects an occupant when a collision or an accident occurs in a vehicle.
[0002]
[Prior art]
Conventionally, as a device for protecting an occupant in the event of a collision or accident in a vehicle, an airbag device for protecting the occupant's head by deploying an airbag, a pretensioner for winding up a slack in a seat belt, and the like have been used. Are known. Such an occupant protection device includes an ECU that controls the deployment of the airbag and the driving of the pretensioner. The ECU controls a situation in which a vehicle collision or a collision may occur based on a signal from a G sensor or the like. Is detected, and the airbag is deployed or the pretensioner is driven as necessary.
[0003]
The occupant protection device normally operates using a battery mounted on the vehicle as a power supply. It operates using the backup capacitor installed in the power supply.
[0004]
It is necessary that the backup capacitor has a capacity capable of supplying electric power required for operating the ECU to deploy the airbag and drive the pretensioner in the event of a collision. An occupant protection system that detects only frontal collisions and side collisions is equipped with one or two 5600 μF backup capacitors because the deployment of the airbag and the driving of the pretensioner are completed in about 0.1 second after the collision occurs. However, in the occupant protection device that detects the rollover of the vehicle, it takes about one second from the occurrence of the rollover to the end of the deployment of the airbag or the driving of the pretensioner. Needs to be provided.
[0005]
When the number of the backup capacitors increases, the area occupied by the backup capacitors on the board in the ECU increases, and as a result, the area in which the circuit components are mounted becomes narrow. Therefore, it has been proposed to fix the backup capacitor using a fixture on the board, to dispose the backup capacitor away from the board, and to provide a space for mounting circuit components on the board below the backup capacitor. (For example, see Patent Document 1).
[0006]
[Patent Document 1]
JP-A-5-256867
[Problems to be solved by the invention]
However, in the above prior art, a fixture for fixing the backup capacitor is arranged in a central area on the board, and the legs of the fixture are fixed on the board, so this is a main component mounting area on the board. In the central portion, the area where components can be actually mounted is limited.
[0008]
The present invention has been made in view of the above points, and has as its object to provide an occupant protection device in which a backup capacitor can be arranged in an ECU case without limiting a component mounting area in a central portion on a substrate.
[0009]
[Means for Solving the Problems]
To solve the above problem, an occupant protection device according to claim 1 controls a battery mounted on a vehicle, protection means for protecting an occupant in the event of a vehicle collision, and activation of the protection means by electric power supplied from the battery. An occupant protection device comprising: a first board on which circuit components for configuring the control unit are mounted; a backup capacitor used as a power supply when supply of an electrode from a battery is interrupted; A second substrate on which the backup capacitor is mounted, the second substrate being vertically arranged on an edge of the first substrate.
[0010]
As described above, when the second substrate (sub-substrate) is provided on the edge of the first substrate (main substrate) perpendicular to the first substrate, and the backup capacitor is mounted thereon, In the central part, which is the main component mounting area of one board, the backup capacitor can be arranged in the ECU case without limiting the area where components can be actually mounted.
[0011]
In this case, when the backup capacitor is mounted on the second substrate so as to maintain a predetermined distance between the backup capacitor and the first substrate, the first substrate below the backup capacitor may be mounted on the first substrate. It is possible to mount the components also in the area. According to such a configuration, the area where the component cannot be mounted on the first substrate is only the edge portion where the second substrate is fixed, and the other areas include the center area. Therefore, all components can be mounted.
[0012]
Further, when the occupant protection device includes a sensor for detecting a roll state of the vehicle, the sensor may be mounted on the second substrate, for example, on the first substrate. Even when a G sensor for detecting a frontal collision or a side collision is mounted, it is possible to detect the roll state of the vehicle by using a sensor that detects a horizontal acceleration similar to these sensors. .
[0013]
Further, in the occupant protection device that detects the roll state as described above, the backup capacitor needs to have a capacity capable of supplying power for about one second after the power from the battery is cut off, and is therefore mounted. The number of backup capacitors increases. When these backup capacitors are mounted on the first substrate, the component mounting area on the first substrate becomes very narrow. However, as in claim 1, the backup capacitors are vertically arranged on the first substrate. When mounted on the two substrates, the area where the circuit components can be actually mounted in the central portion on the first substrate is not limited.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
The occupant protection device according to one embodiment of the present invention is mounted on a vehicle, detects a frontal collision, a side collision, and a rollover of the vehicle, and if necessary, winds up a slack in a seatbelt by a pretensioner. Deploying the airbag protects occupants against these collisions and accidents. FIG. 1 shows the overall configuration of the occupant protection device 1.
[0015]
The occupant protection device 1 deploys a control device (ECU) 2, an external sensor 3 for detecting a collision or an accident outside the ECU 2, an internal sensor 26 for detecting a collision or an accident inside the ECU 2, and an airbag. The vehicle is provided with an inflator 4 and a pretensioner 5 for winding up a slack in a seat belt, and further includes a warning light 6 for displaying an abnormality of the occupant protection device 1 to an occupant. The ECU 2 includes therein a microcomputer 7 having a CPU, a ROM, a RAM, an I / O port, and the like, which are connected to each other via a bus.
[0016]
The microcomputer 7 receives a signal from the external sensor 3 and the internal sensor 26 at the input port 8 and executes a program stored in the ROM, so that the pretensioner 5 It is determined whether or not it is necessary to drive the airbag and whether or not it is necessary to deploy the airbag. Based on the result of the determination, an ignition signal is output from the output port 9 if necessary. 5 is driven, and the airbag is deployed by the inflator 4. The microcomputer 7 monitors the presence or absence of an abnormality in the entire occupant protection device 1, and notifies the occupant of the abnormality with the warning light 6 when the abnormality is detected.
[0017]
FIG. 2 shows an arrangement of each component of the occupant protection device 1 in a vehicle. The ECU 2 is disposed on a floor panel at the front center of the vehicle compartment. The external sensors 3 include a roll rate sensor 3A and a lateral acceleration sensor 3B for detecting a rollover of the vehicle, a right side sensor 3C and a left side sensor 3D for detecting a side collision, and a frontal collision of the vehicle. Front G sensor 3E and left front G sensor 3F are provided.
[0018]
In the vehicle, the right front airbag 4A and the left front airbag 4B deployed at the time of detecting a frontal collision, the right side airbag 4C and the left side airbag 4D deployed at the time of detecting a side collision, A right curtain airbag 4E and a left curtain airbag 4F that are deployed when rollover is detected are provided. Each of these airbags 4A to 4F is provided with an inflator 4 having an ignition device (squib) for deploying the airbag. Together with the airbag module.
[0019]
As the pretensioner 5, a front seat right pretensioner 5A, a front seat left pretensioner 5B, a rear seat right pretensioner 5C, and a rear seat left pretensioner 5D are provided. These pretensioners 5A to 5D are driven when a frontal collision, a side collision, or a rollover is detected.
[0020]
FIG. 3 is a block diagram showing main functions of the ECU 2. When the ignition switch 50 of the vehicle is turned on, the ECU 2 is supplied with electric power from the battery 51 and operates. The ECU 2 includes a booster circuit 21 and a backup capacitor 22. The booster circuit 21 converts a battery voltage into a predetermined drive voltage and supplies the drive voltage to each part of the occupant protection device 1. The drive voltage from the booster circuit 21 is reduced to 5 V by the regulator 23 and supplied to the microcomputer 7. Further, when the power supply from the battery 51 is cut off, the booster circuit 21 generates a drive voltage by using the power stored in the backup capacitor 22.
[0021]
The ECU 2 includes, as internal sensors 26, a front collision detection G sensor 26A for detecting a front collision, a side collision detection G sensor 26B for detecting a side collision, and a rollover detection G for detecting a rollover. The sensor 26C is provided.
[0022]
The microcomputer 7 executes the ignition determination process to determine whether it is necessary to drive the pretensioner 5 based on the signal from the external sensor 3 and the signal from the internal sensor 26, and to deploy the airbag. It is determined whether or not it is necessary to turn on the power, and if necessary, the power transistor 24 is turned on to ignite the ignition device (squib) 25 of the pretensioner 5 and the inflator 4.
[0023]
Although only one power transistor 24 and one ignition device 25 are shown in FIG. 3, actually, the power transistor 24 and the ignition device 25 correspond to the inflator 4 of each of the airbags 4A to 4F and each of the pretensioners 5A to 5D. An ignition device 25 is provided.
[0024]
In the ignition determination process, a frontal collision, a side collision, and a rollover of the vehicle are respectively performed when a similar collision or accident is detected based on both a signal from the external sensor 3 and a signal from the internal sensor 26. Only it is determined that such a collision or accident has actually occurred. As described above, even if an impact is applied only to the external sensor 3 or only to the ECU 2, the airbag and the pretensioner 5 do not operate, so that malfunction can be prevented.
[0025]
The microcomputer 7 further executes a diagnosis process, thereby monitoring the abnormality of each part of the occupant protection device 1 and, when an abnormality is detected, turning on the warning light 6 to thereby notify the occupant of an abnormality. Is displayed.
[0026]
FIG. 4 is a perspective view showing a schematic configuration inside the ECU 2. The ECU 2 is housed in a case (not shown), and the case is provided with a connector (not shown) for connecting the power supply 51, the external sensor 3, the inflator 4, the pretensioner 5, and the like. A rectangular first substrate 10 is disposed inside the case, and pins of the connector are soldered to the first substrate 10. The size of the first substrate 10 is, for example, about 150 × 105 mm.
[0027]
A component mounting area 11 on which circuit components are mounted is formed over substantially the entire area of the first substrate 10, and a rectangular area along one short side is formed around the component mounting area 11 around the component mounting area 11. The second substrate 20 is fixed vertically. Further, a G sensor 26A for frontal collision detection is soldered along one long side of the first substrate 10, and a G sensor 26B for side collision detection is soldered along the other short side of the first substrate 10. Is attached.
[0028]
At a position on the first substrate 10 where the second substrate 20 is fixed, a connector 14 for attaching the second substrate 20 is provided. The second substrate 20 is inserted into the connector 14 and is made of resin. Fixed. The size of the second substrate 20 is, for example, about 20 × 100 mm.
[0029]
A plurality of backup capacitors 22 are soldered on the second substrate 20, and a G sensor 26C for rollover detection is soldered to an edge of the second substrate 20. In the present embodiment, five capacitors having a capacity of 5600 μF, a diameter of 10 mm, and a height of about 20 mm are attached as the backup capacitors 22.
[0030]
The backup capacitor 22 is arranged at a distance from the first substrate 10, so that circuit components can be mounted in a space on the first substrate 10 below the backup capacitor 22.
[0031]
As in the present embodiment, in an occupant protection device that detects a rollover of a vehicle and operates in response thereto, the backup capacitor needs to have a capacity capable of supplying power for about one second after the occurrence of a collision. Therefore, about 5 to 6 backup capacitors 22 having a capacity of 5600 μF are mounted.
[0032]
When a large number of backup capacitors are mounted on the first substrate (main substrate) in this manner, the circuit mounting area on the main substrate becomes very small. Even if a space for mounting components is secured, the component mounting area is limited in the central portion on the main board by the legs of the fixture.
[0033]
Therefore, as in the present embodiment, the second substrate (sub-substrate) 20 is provided vertically on the edge portion of the first substrate 10, and the backup capacitor 22 is mounted thereon, and the first substrate under the backup capacitor 22 is also provided. When the backup capacitor 22 is arranged on the second substrate 20 at a distance from the first substrate 10 so that circuit components can be mounted on the substrate 10, this is a main component mounting area of the first substrate 10. In the central portion, the backup capacitor 22 can be housed in the ECU case without limiting the area where the circuit components can be actually mounted.
[0034]
Further, when the rollover detection sensor is disposed on the first substrate 10, it is necessary to use a sensor capable of detecting acceleration in a direction perpendicular to the substrate, but as in the present embodiment, When the rollover detection G sensor is arranged on the second substrate 20 perpendicular to the first substrate 10, a sensor for detecting horizontal acceleration similar to the front collision detection G sensor 26A and the side collision detection G sensor 26B is provided. It can be used as a rollover detection sensor 26C.
[0035]
The present invention is not limited to the above embodiment, and various modifications are possible. For example, in the above embodiment, the second substrate 20 is arranged along one short side of the first substrate 10, but along the long side opposite to the side where the frontal collision detection G sensor 26A is arranged. The second substrate 20 may be provided.
[0036]
Further, in the above-described embodiment, when the second board 20 detects that the second board 20 has come off from the connector 14 of the first board 10 and is connected again, a signal indicating this is sent to the first board 20. A detection circuit to be sent to a circuit on the substrate 10 may be mounted.
[0037]
In the above-described embodiment, the present invention is applied to the occupant protection device that protects the occupant not only at the time of a frontal collision or a side collision but also at the time of a rollover, but the occupant is protected only at the time of a frontal collision or a side collision. The present invention can also be applied to an occupant protection device.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram showing an occupant protection device according to an embodiment of the present invention.
FIG. 2 is a diagram showing an arrangement of each component of an occupant protection device in a vehicle.
FIG. 3 is a functional block diagram illustrating main functions of an ECU.
FIG. 4 is a perspective view showing a schematic configuration inside an ECU.
[Explanation of symbols]
1 occupant protection device 2 ECU
REFERENCE SIGNS LIST 3 sensor 4 inflator 5 pretensioner 6 warning light 7 microcomputer 10 first substrate 20 second substrate 22 backup capacitor 26C G sensor for rollover detection (sensor for detecting roll state)
51 Battery

Claims (3)

A battery mounted on the vehicle,
Protection means for protecting an occupant in the event of a collision of the vehicle;
Control means for controlling the activation of the protection means by the power supplied from the battery, an occupant protection device,
A first substrate on which circuit components for constituting the control means are mounted;
A backup capacitor used as a power supply when power supply from the battery is cut off,
An occupant protection device, comprising: a second board on which the backup capacitor is mounted, the second board being disposed perpendicularly to an edge on the first board. The occupant protection device according to claim 1, wherein the backup capacitor is mounted on a second board so as to maintain a predetermined interval between the backup capacitor and the first board. A sensor for detecting a roll state of the vehicle,
The occupant protection device according to claim 1, wherein the sensor is mounted on the second board.

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