JP2008265376A - Airbag control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an airbag control device capable of enhancing the degree of versatility of arrangement of a sensor while adequately deploying an airbag and reducing the number of components at low cost. <P>SOLUTION: An airbag mechanism 100 is provided on a lower part of a glove box 3 and stores an electrostatic capacity sensor 10, an airbag device 20 and an angle adjusting motor 30 in a storage part 37. A detection electrode 12 of the electrostatic capacity sensor 10 detects the electrostatic capacity C which is changed by the interposition of a part of a human body 49 between the storage part 37 and at least a fore end of a front passenger seat 40. Whether or not the electrostatic capacity C is within a workable range is determined by a detection circuit 13, and various kinds of states of the front passenger seat 40 can be recognized thereby. The detection circuit 13 outputs the work permitting signal or the work non-permitting signal based on the result of determination. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an airbag control device that controls the operation of an airbag that protects an occupant of a vehicle such as an automobile, and more particularly to an airbag control device that controls the operation of an airbag on the passenger seat side of the vehicle.

  2. Description of the Related Art Conventionally, for example, an operation determination system disclosed in Patent Document 1 has been known as one that controls the operation of an airbag provided on an instrument panel of an automobile. The operation determination system disclosed in Patent Document 1 detects the presence or absence of a passenger in a passenger seat, the installation state of a child seat, and the like by a distance sensor composed of an ultrasonic sensor and an infrared sensor, a heat source sensor composed of an infrared sensor with a chopper, and the like. The airbag is deployed in an appropriate state based on the result.

Japanese Patent No. 2846960

  However, in the conventional operation determination system disclosed in Patent Document 1 described above, for example, when an object other than a human body such as a warm plastic bottle or a stuffed animal exposed to direct sunlight is placed on the passenger seat, or the passenger seat itself For example, when the car gets hot, it is determined that the passenger is seated in the passenger seat. For this reason, it is assumed that the airbag can be deployed even though deployment (operation) of the airbag is unnecessary, and there is a problem that the airbag cannot be deployed in an appropriate state.

  In addition, in this operation determination system, for example, when a child seat is installed in the passenger seat, due to the characteristics of the distance sensor composed of an ultrasonic sensor, a passenger is still seated in the passenger seat even when no human body is present in the child seat. It may be judged that there is. This is also referred to in Patent Document 1, and it is assumed that the airbag can be deployed even though it is not necessary to deploy the airbag. Similarly, the airbag cannot be deployed in an appropriate state. There's a problem.

  Furthermore, since this operation determination system requires a plurality of sensors of different types and shapes and a lot of determination criteria, the system configuration is complicated and the position of the sensor is restricted, so that the occupant is protected by an airbag. There is a problem that it is difficult to reduce the cost.

  In addition, since the occupant's physique cannot be detected with this operation determination system, the occupant can be more comprehensively able to protect the leg by changing the airbag deployment angle according to the difference in physique, for example. There is a problem that an airbag device that can protect the vehicle cannot be realized.

  The present invention has been made in view of such problems, and the airbag can be appropriately deployed under various conditions such as the presence of an occupant and a difference in physique, while reducing the number of parts. An object of the present invention is to provide an airbag control device that can be realized at low cost by improving the degree of freedom of sensor placement.

  An airbag control device according to the present invention is provided in an airbag housing portion in which an airbag disposed on an instrument panel in front of a passenger seat of a vehicle is housed, and the airbag housing portion and at least a front end of the passenger seat A detection electrode that detects a capacitance that changes due to a part of the human body interposed between the detection electrode and a control circuit that controls the operation of the airbag based on a detection signal from the detection electrode. Features.

  By configuring the airbag control device according to the present invention as described above, various states such as the presence or absence of a human body in a passenger seat of a vehicle are detected by electrostatic capacitance, and the airbag is detected by a detection signal from a detection electrode. The operation can be appropriately controlled. For this reason, the airbag can be appropriately deployed even under various conditions, and the degree of freedom in arranging the sensors can be improved while reducing the number of components, which can be realized at low cost.

  The control circuit determines, for example, whether or not the capacitance indicated by the detection signal from the detection electrode is within a range of preset lower and upper thresholds, and based on the determination result, the airbag It may be configured to perform control for determining whether or not the operation is possible.

  In addition, the airbag accommodating portion is provided, for example, in a lower portion of a glove box in the instrument panel, and the detection electrode is, for example, the electrostatic region in a region from a lower portion of the glove box to an upper portion of a seating portion of the passenger seat. You may be set as the structure provided along the external shape of the said airbag accommodating part so that a capacity | capacitance can be detected.

  For example, the detection electrode and the control circuit may be formed on the same substrate. In this case, the said board | substrate consists of a flexible printed circuit board, a rigid board | substrate, or a rigid flexible board | substrate, for example.

  In addition, the detection electrode may be configured such that, for example, when a human body is seated on the seating portion of the passenger seat, the outer shape of the airbag housing portion can be detected at least at the position of the leg portion of the human body below the glove box. A configuration may be adopted in which a plurality of arrangements are provided along the line.

  And it may be set as the structure further equipped with the angle adjustment means which adjusts the operating angle of the said airbag by control of the said control circuit based on the detection signal detected by the said detection electrode.

  According to this invention, various states such as the presence or absence of the human body in the passenger seat of the vehicle can be detected by capacitance, and the operation of the airbag can be appropriately controlled by the detection signal from the detection electrode. It is possible to achieve appropriate development under various conditions and at a low cost by improving the degree of freedom of sensor placement while reducing the number of parts.

  Preferred embodiments of an airbag control device according to the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a schematic view showing an example of the vicinity of a passenger seat of a vehicle in which an airbag mechanism including an airbag control device according to an embodiment of the present invention is arranged, and FIG. 2 shows an example of the appearance of the airbag control device. FIG. 3 is a block diagram showing an example of a circuit configuration of an airbag mechanism including the airbag control device, and FIG. 4 is an explanatory diagram for explaining the operation of the airbag mechanism including the airbag control device. .

  As shown in FIG. 1, the airbag mechanism 100 is arrange | positioned at the instrument panel 2 ahead of the passenger seat 40 in the vehicle interior of the motor vehicle 1, for example. The passenger seat 40 includes a backrest portion 41, a seating portion 42, and a headrest 43, and is provided so as to be movable in the front-rear direction with respect to the floor 1 a of the automobile 1 via the seat rail 44.

  Specifically, the airbag mechanism 100 is provided in the lower part of the glove box 3 provided in the instrument panel 2, and includes a capacitance sensor 10, an airbag device 20, and an angle adjustment motor 30, and these Is housed in a box-shaped housing portion 37 that houses the housing at a predetermined position inside. Further, the capacitance sensor 10 and the airbag device 20 are electrically connected to a control unit (not shown) such as an ECU (Electric Control Unit), respectively.

  As shown in FIG. 2, the capacitance sensor 10 includes a detection electrode 12 formed on one surface side of the substrate 11 and a detection circuit 13 formed on the other surface side. It is provided inside the upper lid 38 of the portion 37. The board | substrate 11 consists of a flexible printed circuit board, a rigid board | substrate, or a rigid flexible board | substrate, for example, and is formed in the rounded rectangle shape in this example.

  The detection electrode 12 is made of a conductive material such as a copper foil, and is changed by a part of the human body 49 (see FIG. 1) interposed between the upper lid 38 of the accommodating portion 37 and at least the front end of the passenger seat 40. The electric capacity C is detected. The detection circuit 13 controls the operation of the airbag device 20 based on the detection signal from the detection electrode 12. Since the detection electrode 12 and the detection circuit 13 are formed on the same substrate 11, harnesses that electrically connect the detection electrode 12 and the detection circuit 13 can be eliminated. Further, the detection electrode 12 and the detection circuit 13 may be formed on the same surface of the substrate 11.

  In this example, the detection electrode 12 is, for example, inside the upper lid 38 so as to detect the capacitance C in the region from the lower side of the glove box 3 to the upper side of the seating part 42 of the passenger seat 40. It is provided in a state along the outer shape. In addition, although illustration is abbreviate | omitted, the detection electrode 12 may be arrange | positioned so that the electrostatic capacitance C of the said area | region can be detected in the predetermined position of the instrument panel 2. FIG.

  In the detection circuit 13, the capacitance C indicated by the detection signal from the detection electrode 12 provided in this way is, for example, a range of preset lower and upper thresholds (hereinafter referred to as “operational range”). .), And whether or not the airbag device 20 is operable is determined based on the determination result, and the operation of the airbag device 20 is controlled.

  That is, as shown in FIG. 3, when the detection circuit 13 determines that the capacitance C from the detection electrode 12 is within the operable range, an operation permission signal is sent to the AND circuit 27 of the control unit. Output. When the detection circuit 13 determines that the capacitance C from the detection electrode 12 is outside the operable range because it is below the lower threshold or exceeds the upper threshold, the AND circuit 27 of the control unit In response to this, an operation non-permission signal is output. Further, the detection circuit 13 outputs an adjustment control signal for adjusting the operating angle of the airbag device 20 to the angle adjustment motor 30 based on the electrostatic capacitance C from the detection electrode 12 as described later.

  On the other hand, when the acceleration sensor 29 installed in the automobile 1 detects a collision of the automobile 1, an operation permission signal is similarly output from the collision detection circuit 28 to the AND circuit 27. The AND circuit 27 outputs a deployment control signal for deploying the airbag to the airbag device 20 only when the operation permission signals are obtained from the detection circuit 13 and the collision detection circuit 28, respectively.

  The airbag device 20 is normally stored compactly, but includes a bag 21 that is inflated so as to receive the human body 49 when inflated, and an inflator that supplies inflation gas and the like to the bag 21. 22. Based on the adjustment control signal from the detection circuit 13, the angle adjustment motor 30 moves the arrangement position of the airbag device 20 in the direction indicated by the arrow in the drawing as shown in FIG. (Operating) Adjust the angle.

  That is, the angle adjustment motor 30 is in an optimal state (for example, a state in which the leg portion 48 is not inadvertently injured due to the expansion of the bag 21) according to the position of the leg portion 48 of the human body 49 seated on the passenger seat 40. ) To adjust the position of the airbag device 20 so that the bag 21 can be deployed. When the airbag apparatus 20 adjusted in position as described above receives the control signal from the AND circuit 27, the airbag apparatus 20 pushes the upper lid 38 and the lower lid 39 of the accommodating portion 37 as shown in FIG. The bag 21 is inflated to open.

  As described above, the airbag mechanism 100 can detect various states of the passenger seat 40 by the capacitance C and can appropriately control the operation of the airbag 21 by the detection signal from the detection electrode 12. As a result, the airbag 21 can be appropriately deployed even under various conditions, and the degree of freedom of arrangement of the capacitance sensor 10 is improved while reducing the number of parts constituting the airbag mechanism 100 and realized at low cost. can do.

  FIG. 5 is a schematic view showing another example below a glove box in which an airbag mechanism including an airbag control device according to an embodiment of the present invention is arranged. FIGS. 6 and 7 are static views of the airbag control device. FIG. 8 is an explanatory diagram showing an example of the distribution of capacitance detected by the capacitance sensor, FIG. 8 is an explanatory diagram showing an example of the distribution of capacitance according to the state of the passenger seat by the airbag control device, and FIG. FIG. 8 is a schematic diagram illustrating an example of the vicinity of a passenger seat corresponding to a capacitance distribution of 8; In the following description, the same parts as those already described are denoted by the same reference numerals and description thereof is omitted.

  The airbag mechanism 100 of the present example is configured such that the position of the leg portion 48 of the human body 49 at least below the glove box 3 when the human body 49 is seated on the seat portion 42 of the passenger seat 40 with the detection electrode 12 of the capacitance sensor 10. Are provided so as to be detectable. That is, the airbag mechanism 100 is provided in a state in which a plurality of detection electrodes 12 are arranged, for example, along the upper lid 38 and the lower lid 39 of the housing portion 37, and as shown in FIG. 5, the right leg portion 48a and the left leg portion 48b. This position can be accurately recognized by the distribution of capacitance from the plurality of detection electrodes 12.

  The plurality of detection electrodes 12 may be formed on the substrate 11 formed in a sheet shape, for example, or may be formed separately. In the airbag mechanism 100 of the present example, the arrows in the figure are used. For example, six arrays are formed along the X-axis direction indicated by X and the Y-axis direction indicated by arrow Y in the drawing. In FIG. 5, the arrangement of the detection electrodes 12 is simply illustrated with numbers 1 to 6 on the X axis and the Y axis, respectively.

  Here, as shown in FIG. 5, when the right leg portion 48a and the left leg portion 48b are detected by the detection electrode 12 at the positions shown by the broken lines in the figure, the electrostatic capacity distribution on the X axis is shown in FIG. 6 and the distribution of capacitance on the Y-axis is as shown in FIG. That is, the electrostatic capacity on the X axis shows a low value for the detection electrodes 12 of numbers 1 to 3 depending on the position of the leg portion 48, but shows a rapidly high value for the numbers 3 to 4, and the numbers 5 to 6 The distribution is maintained while maintaining almost the same value until.

  On the other hand, the electrostatic capacitance on the Y axis shows a distribution from a low value to a high value over the numbers 1-2 depending on the position of the right leg portion 48a, and from a high value to a low value over the numbers 2-3. Further, according to the position of the left leg portion 48b, a distribution from a low value to a high value is again obtained from numbers 4 to 5, and from a high value to a low value from numbers 5 to 6.

  The position information of the leg portions 48a and 48b detected in this way is recognized by the detection circuit 13 and stored in the control unit. The detection circuit 13 outputs an adjustment control signal to the angle adjustment motor 30 based on this position information, and the airbag device 20 is optimal so as not to injure each leg 48a, 48b. The angle is adjusted so that it can be deployed in the state. In this case, the opening angle of the upper lid 38 and the lower lid 39 may be further adjusted by a motor (not shown) to further protect the legs 48a and 48b.

  Since the airbag mechanism 100 of the present example is configured so that the position of the human body 49 can be recognized by the plurality of detection electrodes 12, it can exert a particularly effective effect on the protection of the leg portion 48 of the human body 49. It becomes possible to operate the bag 21 of the airbag device 20 in an optimum state in accordance with 49 different physique differences.

  Further, the airbag device 20 detects an electrostatic capacity that changes due to the leg portion 48 of the human body 49 being interposed between the accommodating portion 37 provided in the instrument panel 2 and at least the front end of the passenger seat 40. Therefore, it is possible to control the operation of the airbag device 20 according to various situations of the passenger seat 40. Therefore, the airbag mechanism 100 can control the operation of the airbag device 20 in an appropriate state even in each of the situations a to e as shown in FIGS. 8 and 9, for example.

  That is, the electrostatic capacity a in FIG. 8 indicates the electrostatic capacity when there is nothing on the passenger seat 40 as shown in FIG. Since the human body 49 is not interposed between the distal end and the value is lower than the lower limit threshold, the detection circuit 13 outputs an operation non-permission signal. The electrostatic capacity b in FIG. 8 indicates the electrostatic capacity when the child seat 47 is mounted rearward on the passenger seat 40 as shown in FIG. 9B. Since the human body 49 is not interposed between the front end of the passenger seat 40 and indicates a value lower than the lower limit threshold value, an operation non-permission signal is output from the detection circuit 13.

  In the conventional operation determination system, in the case of a, the operation is permitted depending on the situation, and in the case of b, the child seat 47 on the passenger seat 40 is detected and the operation is permitted. Since the airbag mechanism 100 of this example does not permit the operation in the case of a and b, it is possible to suppress unnecessary operation of the airbag device 20 while improving safety.

  Further, the capacitance c in FIG. 8 indicates the capacitance when the child seat 47 with the child 46 on the passenger seat 40 is attached backward as shown in FIG. 9C. The child 46 is not interposed between the accommodating portion 37 and the front end of the passenger seat 40, but the rearwardly facing child 46 is detected. A permission signal is output.

  The capacitance d in FIG. 8 indicates the capacitance when the child seat 47 with the child 46 on the front passenger seat 40 is attached forward as shown in FIG. 9D. The electrostatic capacity e in FIG. 8 indicates the electrostatic capacity when the human body 49 is on the passenger seat 40 as shown in FIG. 9 (e). In this case, since a part of the child 46 and the human body 49 is interposed between the accommodating portion 37 and the front end of the passenger seat 40, the capacitance that changes due to them, that is, higher than the lower limit threshold and lower than the upper limit threshold. The capacitance having a value within the operable range is detected, and an operation permission signal is output from the detection circuit 13.

  As described above, according to the airbag mechanism 100 according to the present embodiment, various states such as the presence or absence of the human body 49 in the passenger seat 40 of the automobile 1 are detected by the capacitance, and the detection signal from the detection electrode 12 is detected. Thus, the operation of the airbag device 20 can be appropriately controlled, the bag 21 can be appropriately deployed even under various conditions, and, for example, the capacitance sensor 10 can reduce the number of components constituting the capacitance sensor 10. It is possible to improve the arrangement flexibility of 10 and realize it at low cost as a whole.

  That is, according to the airbag mechanism 100 of the present example, by using the capacitance sensor 10, for example, even when the passenger seat 40 itself has heat, the human body 49 on the passenger seat 40 is erroneously detected. The airbag device 20 can be activated in an appropriate state.

  Further, even when a child seat 47 or the like is placed on the passenger seat 40, the placement state of the child seat 47 or the presence or absence of the child 46 on the child seat 47 can be detected. The airbag device 20 can be operated in the state.

  In addition, since the detection electrode 12 and the detection circuit 13 of the capacitance sensor 10 are formed on the same substrate 11, the airbag mechanism 100 can be manufactured at low cost, and the detection electrode 12 can be made transparent or flexible. Since it can also be configured by a printed circuit board or conductive patterning, it is possible to reduce the number of parts while reducing the number of harnesses and improving the degree of freedom of arrangement.

  Furthermore, since the operating angle of the airbag device 20 can be adjusted by the angle adjustment motor 30 and a plurality of detection electrodes 12 of the capacitance sensor 10 can be provided, the physique and boarding position of the human body 49 on the passenger seat 40 are recognized. Thus, the airbag device 20 can be operated in an optimum state according to these conditions.

  INDUSTRIAL APPLICABILITY According to the present invention, in an airbag mechanism of an automobile or the like, it is particularly useful for improving safety and making it inexpensive.

It is the schematic which shows the example of the passenger seat vicinity of the vehicle which has arrange | positioned the airbag mechanism containing the airbag control apparatus which concerns on this invention. It is the schematic which shows the example of the external appearance of the airbag control apparatus. It is a block diagram which shows the example of a circuit structure of the airbag mechanism containing the airbag control apparatus. It is explanatory drawing for demonstrating operation | movement of the airbag mechanism containing the airbag control apparatus. It is the schematic which shows the other example of the downward direction of the glove box which has arrange | positioned the airbag mechanism containing the airbag control apparatus. It is explanatory drawing which shows the example of distribution of the electrostatic capacitance detected with the electrostatic capacitance sensor of the airbag control apparatus. It is explanatory drawing which shows the example of distribution of the electrostatic capacitance detected with the electrostatic capacitance sensor of the airbag control apparatus. It is explanatory drawing which shows the example of distribution of the electrostatic capacitance according to the state of the passenger seat by the airbag control apparatus. It is the schematic which shows the example of the passenger seat vicinity corresponding to distribution of the electrostatic capacitance of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Automobile, 1a ... Floor, 2 ... Instrument panel, 3 ... Glove box, 10 ... Capacitance sensor, 11 ... Board | substrate, 12 ... Detection electrode, 13 ... Detection circuit, 20 ... Air bag apparatus, 21 ... Bag, DESCRIPTION OF SYMBOLS 22 ... Device base part, 27 ... AND circuit, 28 ... Collision detection circuit, 29 ... Acceleration sensor, 30 ... Angle adjustment motor, 37 ... Housing part, 38 ... Upper lid, 39 ... Lower lid, 40 ... Passenger seat, 41 ... backrest part, 42 ... seating part, 43 ... headrest, 44 ... seat rail, 46 ... child, 47 ... child seat, 48 ... leg part, 48a ... right leg part, 48b ... left leg part, 49 ... human body.

Claims (7)

A part of the human body is interposed between the airbag housing portion and at least the front end of the passenger seat, which is provided in an airbag housing portion that houses an airbag disposed on an instrument panel in front of the passenger seat of the vehicle. A sensing electrode for detecting the capacitance that changes depending on the situation,
An airbag control device comprising: a control circuit that controls the operation of the airbag based on a detection signal from the detection electrode.   The control circuit determines whether or not a capacitance indicated by a detection signal from the detection electrode is within a range of preset lower and upper thresholds, and based on the determination result, the airbag 2. The airbag control device according to claim 1, wherein control for determining whether or not to operate is performed. The airbag accommodating portion is provided at a lower portion of a glove box in the instrument panel,
The detection electrode is provided along the outer shape of the airbag housing portion so as to be able to detect the capacitance in a region from the lower side of the glove box to the upper side of the seating portion of the passenger seat. The airbag control device according to claim 1 or 2, characterized in that.   The airbag control device according to any one of claims 1 to 3, wherein the detection electrode and the control circuit are formed on the same substrate.   The airbag control device according to claim 4, wherein the substrate is a flexible printed circuit board, a rigid circuit board, or a rigid flexible circuit board.   The detection electrode is arranged along the outer shape of the airbag housing portion so that, when a human body is seated on the seating portion of the passenger seat, the leg position of the human body at least below the glove box can be detected. The airbag control device according to claim 3, wherein the airbag control device is provided in a plurality of arrayed states.   The angle adjustment means which adjusts the operating angle of the said airbag by control of the said control circuit based on the detection signal detected by the said detection electrode further is provided, The Claim 1 characterized by the above-mentioned. Airbag control device.

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