JPH11334521A - Airbag device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To detect the presence or absence of an approaching occupant when an airbag is deployed, and to accurately control the internal pressure of the airbag according to the detection result. SOLUTION: An inflator 20 of an airbag device Rd.
A retainer 19 supporting the airbag 21 is provided with a control valve 30 in which a plate-like piezoelectric element 31 is bonded to a metal protector 32, and a vent hole 29 opened and closed by the control valve 30. The internal pressure of the airbag 21 at the initial stage of deployment is detected by the internal pressure detecting means 35b, and when the internal pressure is higher than normal, it is determined that there is a nearby occupant, and the piezoelectric element 31 is bent by energization to open the vent hole 29. The airbag 21 is opened to discharge the gas in the airbag 21 to the outside. By reducing the internal pressure of the airbag when there is a nearby occupant, the occupant can be restrained with an appropriate restraining force.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an airbag in which an inflator is housed inside a retainer to which the periphery of an opening of a folded airbag is fixed, and which is inflated by gas generated by the inflator upon collision of a vehicle. The present invention relates to an airbag device for restraining an occupant.

[0002]

2. Description of the Related Art In a conventional airbag apparatus, a vent hole is provided in an airbag inflated by gas generated by an inflator, and a part of the gas is discharged from the vent hole to control the internal pressure of the airbag. In such an airbag device, by closing the vent hole with a thin film, the airbag is quickly inflated in the early stage of deployment, and when the deployment is completed and the internal pressure of the airbag increases, the thin film is broken, and the vent hole is broken. That exhaust gas from the vehicle and restrain the occupant softly (Japanese Utility Model 5-62)
No. 06).

Further, two inflators are provided in the airbag device, and when no occupant is present near the airbag device, both of the two inflators are ignited, and the occupant is present near the airbag device. In such a case, a method has been proposed in which the deployment speed and the internal pressure of the airbag are controlled in accordance with the position of the occupant by igniting only one inflator (see JP-A-9-301115).

[0004]

However, the structure disclosed in Japanese Utility Model Publication No. 5-6206 is liable to cause variation in the pressure at which the thin film breaks, so that when the internal pressure of the airbag reaches a predetermined value. In addition, it is difficult to precisely open the vent hole, and it is difficult to precisely control the internal pressure because the vent hole once opened cannot be closed again. In addition, Japanese Patent Application Laid-Open No. 9-301115
Japanese Patent Application Laid-Open Publication No. H11-146556 requires not only two inflators but also an increase in the number of parts, which causes a cost increase. There was a problem that control was difficult.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to accurately control the internal pressure of an airbag in accordance with whether or not an occupant is present near an airbag device. I do.

[0006]

According to one aspect of the present invention, an inflator is housed inside a retainer to which a periphery of an opening of a folded airbag is fixed. In an airbag device that expands an airbag inflated by gas generated by the inflator at the time of collision and restrains an occupant, a vent hole formed in the retainer, and a control valve that is operated by an actuator to open and close the vent hole. An internal pressure detecting means for detecting an internal pressure of the airbag, and determining presence / absence of a nearby occupant based on the internal pressure of the airbag in an initial stage of deployment of the airbag, and determining whether there is a nearby occupant, and detecting the presence of the vent hole. And control means for increasing the opening degree.

According to the above configuration, when it is determined at the early stage of the deployment of the airbag that there is an approaching occupant based on the internal pressure of the airbag, the control means drives the control valve with the actuator to increase the opening of the vent hole. By increasing the amount of gas discharged from the vent hole, the internal pressure of the airbag can be reduced to an arbitrary size suitable for the occupant, and a sufficient and sufficient restraining force can be generated for the occupant. In addition, since it is possible to cope with the restraint of a nearby occupant without needing a plurality of inflators, there is no problem that the cost is increased.

According to a second aspect of the present invention, in addition to the first aspect, the actuator is a piezoelectric element.

[0009] According to the above configuration, by forming the actuator with a piezoelectric element, the vent hole can be opened and closed at a low cost with a simple structure having a smaller number of parts than other actuators such as a motor and a solenoid. Can be.

According to a third aspect of the present invention, in addition to the configuration of the second aspect, the actuator is a plate-shaped piezoelectric element disposed to cover the vent hole and one end of which is fixed to the retainer. There is a feature.

[0011] According to the above configuration, by forming the actuator with the plate-like piezoelectric element, not only the structure of the actuator is extremely simplified, but also the piezoelectric element itself can be used as a valve body, and the number of parts can be reduced. And cost can be further reduced.

According to a fourth aspect of the present invention, in addition to the configuration of the first aspect, the retainer has a plurality of vent holes, and the control valve has a plurality of openings respectively corresponding to the plurality of vent holes. A valve plate is formed, and the actuator slides the valve plate along the retainer so that the plurality of openings face the plurality of vent holes.

According to the above construction, by combining a plurality of vent holes formed in the retainer and a plurality of openings formed in the valve plate, the opening degree of the vent hole can be fully closed by only slightly moving the valve plate. It is possible to change from the state to the fully open state, so that downsizing of the actuator and improvement of responsiveness are achieved at the same time.

According to a fifth aspect of the present invention, in addition to the configuration of the fourth aspect, the plurality of vent holes are arranged in a circumferential direction, and the valve plate is driven to reciprocate by the actuator. It is characterized by the following.

According to the above configuration, a plurality of vent holes arranged in the circumferential direction are opened and closed by the valve plate reciprocally driven by the actuator, so that an actuator having a rotational output such as a motor can be easily applied. it can.

According to a sixth aspect of the present invention, in addition to the configuration of the fourth aspect, the plurality of vent holes are arranged in a linear direction, and the valve plate is reciprocated linearly driven by the actuator. It is characterized by.

According to the above construction, a plurality of vent holes arranged in the linear direction are opened and closed by the valve plate which is linearly driven by the actuator in a reciprocating manner, so that a linear output actuator such as a linear solenoid or a laminated piezoelectric element can be used. Can be easily applied.

According to a seventh aspect of the present invention, in addition to the configuration of the second aspect, the piezoelectric element constituting the actuator also serves as the internal pressure detecting means.

According to the above configuration, the number of components can be reduced by using the common piezoelectric element for both the actuator and the internal pressure detecting means.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described based on embodiments of the present invention shown in the accompanying drawings.

FIGS. 1 to 25 show an embodiment of the present invention. FIG. 1 is a perspective view of a front portion of a passenger compartment of an automobile, FIG. 2 is an enlarged sectional view taken along line 2-2 of FIG. 1, and FIG. FIG. 4 is an enlarged sectional view taken along line 4-4 of FIG. 3, FIG. 5 is an exploded perspective view of the driver airbag device, and FIG. 6 is a modified example of the driver airbag device. FIG. 7 is an enlarged sectional view taken along line 7-7 of FIG. 6, FIG. 8 is an enlarged sectional view taken along line 8-8 of FIG. 1, and FIG. 9 is a sectional view taken along line 9-9 of FIG. FIG. 10 and FIG.
FIG. 11 is an exploded perspective view of the passenger airbag device, FIG. 12 is a view corresponding to FIG. 9, and FIG. 13 is a first modified example of the passenger airbag device. 12 of 1
FIG. 14 is a sectional view taken along line 3-13, FIG. 14 is a sectional view taken along line 14-14 in FIG. 12, FIG. 15 shows a second modification of the airbag device for the passenger seat, and corresponds to FIG. 16-1
6, FIG. 17 is a sectional view taken along line 17-17 of FIG. 15, FIG. 18 is an enlarged sectional view taken along line 18-18 of FIG. 1, and FIG.
FIG. 20 is a sectional view taken along line 20-20 of FIG. 19, FIG. 21 is a sectional view taken along line 21-21 of FIG. 19, FIG. 22 is a sectional view taken along line 22-22 of FIG. FIG. 24 is a block diagram showing a control system of a hole opening degree, FIG. 24 is a diagram showing an example of a change in a vent hole opening degree and an airbag internal pressure depending on the presence or absence of a nearby occupant, and FIG. It is.

As shown in FIG. 1, a driver airbag device Rd is provided at the center of a steering wheel 2 disposed in front of a driver seat 1, and a dashboard disposed in front of a passenger seat 3. An airbag device Rp for a passenger seat is provided on the upper part of the vehicle seat 4, and side collision airbag devices Rs, Rs are provided inside the driver seat 1 and the seatbacks 5, 5 of the passenger seat.

Next, the structure of the driver's seat airbag device Rd will be described with reference to FIGS.

The steering wheel 2 is fitted to the rear end of the steering shaft 11 so as not to rotate relative to each other.
2, a steering boss 13 fixed at 2, an annular wheel rim 14 arranged so as to surround the steering boss 13, a front cover 15 fixed to the steering boss 13, and connected to the front cover 15. A rear cover 16 and a plurality of spokes 17 for connecting the front cover 15 to the wheel rim 14 are provided.
The airbag module 18 is housed in the space defined by.

The airbag module 18 includes a retainer 19 for supporting the airbag module on the inner surface of the rear cover 16, an inflator 20 for generating high-pressure gas, and an inflator
The airbag 21 is inflated by the generated high-pressure gas. Rivet outer periphery of the plurality of the mounting flange 16 ₁ formed integrally on the inner periphery of the mounting flange 19 ₁ rear cover 16 which is formed integrally of the retainer 19 22
, And the peripheral edge of the opening of the airbag 21 and the ring-shaped holder 23 are overlapped and fastened together to the retainer 19 with a plurality of bolts 24. The inflator 20 filled with the granular gas generating agents 25.
1 and is retained by a plurality of bolts 26.
9 is fixed. The igniting agent 2 is provided inside the inflator 20.
7 is disposed, and the tip of an igniter 28 extending inside the inflator 20 faces the igniting agent 27.

The retainer 19 facing the inside of the airbag 21
Are formed in series. The control valve 30 for controlling the opening degree of the vent holes 29 is formed by bonding a strip-shaped piezoelectric element 31 to a protector 32 of the same shape made of a metal plate, and one side surface covers the vent holes 29. As shown in FIG.
At 33, it is fixed to the retainer 19. The fragile and easily breakable piezoelectric element 31 is reinforced by being bonded to the protector 32. The piezoelectric element 31 constitutes the actuator of the present invention.

As shown in FIG. 23, the airbag deployment control device 34 constituting the control means of the present invention includes an acceleration detection means 35a for detecting an acceleration at the time of a vehicle collision, and an internal pressure of the airbag 21. The internal pressure detection means 35b is connected. The internal pressure detecting means 35b is constituted by a normal pressure sensor, and is provided in the retainer 19 so that the detecting portion faces the internal space of the airbag 21.

When the acceleration detecting means 35a detects an acceleration equal to or more than a predetermined value at the time of a vehicle collision, the airbag deployment control device 34 energizes the igniter 28 to ignite the inflator 20 and inflates with the gas generated by the inflator 20. airbag 21 is deployed into the passenger compartment by breaking a thin tear line 16 ₂ formed H-shaped in the rear cover 16. At this time, the airbag deployment control device 34 controls the internal pressure detecting means 35b.
, The energization of the control valve 30 to the piezoelectric element 31 is controlled to change the opening of the vent holes 29. That is, when the piezoelectric element 31 is de-energized,
As shown in FIG. 4, the control valve 30 extends linearly to close the vent holes 29.
As shown in (B), the control valve 30 bends in accordance with the amount of current to open the vent holes 29. In this way, the vent hole 2 is formed by a very simple structure in which the plate-shaped piezoelectric element 31 covering the vent holes 29.
9 can be controlled precisely and steplessly. The specific contents of the opening control of the control valve 30 will be described later in detail.

FIGS. 6 and 7 show a modification of the driver's seat airbag device Rd. The structure of the control valve 30 is different from that described with reference to FIGS.

The control valve 30 of this modification opens and closes the vent holes 29 arranged annularly in the retainer 19, and has the same number and the same number of openings 36 _{1 as the} vent holes 29.
, And an ultrasonic motor 37 that rotationally drives the valve plate 36. When the valve plate 36 is at the position shown in FIG. 7A, the vent holes 29 are closed by the valve plate 36, and when the valve plate 36 is at the position shown in FIG. _The vent holes 29 are opened by ₁ .

As described above, the opening degree of the plurality of annularly arranged vent holes 29 is controlled by rotating the valve plate 36 having the plurality of openings 36 ₁ by the motor 37.
Can be changed from the fully closed state to the fully open state by simply rotating the vent hole 29 by a slight angle corresponding to the central angle of one vent hole 29, and the motor 37 can be reduced in size and responding. Simultaneous improvement is achieved.

Next, the structure of the passenger seat airbag device Rp will be described with reference to FIGS.

The support portion 4 extending from the lid 41 fixed to the opening 4 ₁ formed in the upper surface of the dashboard 4 downward
1 ₁ ..., retainer 43 of the airbag module 42 is fixed. The retainer 43 includes an upper retainer 45 and a lower retainer 46 fixed by a plurality of bolts 44.
The upper retainer 44 is fixed to the support portions 41 _{1 of the} lid 41 by a plurality of bolts 47. Upper retainer 45 and lower retainer 46
Of the airbag 48 is sandwiched by the joints of the airbags 48 and fastened together by the bolts 47. The lid 41 has a thin tear line 4 that breaks when the airbag 48 is inflated.
1 ₂ is formed. A cylindrical inflator 50 is supported on the bottom of the lower retainer 46 via a pair of mounting brackets 49, 49. Further, in order to open and close four vent holes 29 formed at the bottom of the lower retainer 46, the control valve 3 having the same structure as that of the airbag device Rd for the driver's seat is used.
0 is attached. The internal pressure of the airbag 48 is detected by an internal pressure detecting means 35b provided in the lower retainer 46.

The energization of the inflator 50 and the control valve 30 is controlled by the airbag deployment control device 34 to which signals from the acceleration detecting means 35a and the internal pressure detecting means 35b are input. That is, when the acceleration detecting means 35a detects an acceleration equal to or more than a predetermined value at the time of a vehicle collision, the inflator 50 is ignited by a command from the airbag deployment control device 34 to generate high-pressure gas, and the airbag 48 inflated by the pressure. It is to expand into the passenger compartment to rupture the tear line 41 ₂ of the lid 41. At this time, the opening of the control valve 30 is controlled by a signal from the internal pressure detecting means 35b.

FIGS. 12 to 14 show a first modification of the airbag device Rp for a passenger's seat. The structure of the control valve 30 is different from that described with reference to FIGS.

The control valve 30 according to the present modification includes an inflator 5
0 is a cross-sectionally arc-shaped valve plate 5 rotatably supported on the outer periphery
1 and a motor 37 as an actuator for rotating the valve plate 51. When the rotating valve plate 51 slides along the inner surface of the retainer 43, two slit-shaped vent holes 29, 29 formed in the retainer 43 are formed.
Have two corresponding slit-shaped openings 51 ₁ ,
It is opened and closed by a valve plate 51 having 51 ₁ .

As described above, the plurality of vent holes 29, 2
9 with a plurality of openings 51₁, 51 ₁Valve plate 51 having
Is controlled by the motor 37 being rotated by the motor 37, so that the valve plate 51 is
A slight angle turn corresponding to the central angle of the vent holes 29
Turn the vent holes 29 and 29 fully closed
It is possible to change from the
Responsiveness is enhanced.

FIGS. 15 to 17 show a second modification of the passenger seat airbag device Rp, in which the structure of the control valve 30 is different from that described with reference to FIGS.

The control valve 30 of the present modification has a valve plate 52 slidably supported by a pair of guide rails 43 ₁ , 43 ₁ provided on the bottom surface of a retainer 43, and this valve plate 52 is connected to the guide rail 43 _1. , and a linear solenoid 53 as an actuator which reciprocates along a 43 _1. Valve plate 52
The are formed four vent holes 29 ... and the same shape and the same number of openings 52 ₁ ... arranged on a straight line is, the opening 52 of the valve plate 52 which is driven by a linear solenoid 53 ₁ ... vent hole 29 ... , The vent holes 29 ...
Is released.

As described above, the opening degree of the plurality of vent holes 29 arranged on a straight line is controlled by reciprocating the valve plate 52 having the plurality of openings 52 ₁ . Can be changed from the fully closed state to the fully open state by moving the vent holes 29 by a small distance corresponding to the length of one vent hole 29, thereby improving the responsiveness. . Note that, instead of the linear solenoid 53, it is also possible to employ an actuator in which a large number of piezoelectric elements are stacked.

Next, the structure of the side collision airbag device Rs will be described with reference to FIGS.

A metal mounting bracket 62 extending forward of the vehicle body is fixed to a pipe frame 61 extending vertically along the right edge of the seat back 5 by welding, and an airbag module 63 is mounted on the right side of the mounting bracket 62. Are fixed with bolts 64, 64. A shape-retaining material 65 made of a coarse blanket extends from the front surface of the airbag module 63 to an intermediate portion in the thickness direction of the seat back 5 to the left side of the vehicle body, and is connected to a pipe frame (not shown) on the left side of the vehicle body. A mesh-shaped spring 66 is stretched around the inner periphery of the pipe frame 61.
A pad 67 made of sponge is mounted on a portion surrounded by the rear surface of the mounting bracket 62 and the rear surface of the mounting bracket 62. A pad 68 made of sponge is also provided on the front surface of the shape-retaining material 65.
Is attached.

The central portion of the front surface of the seat back 5 is covered with a first covering material 69, and both left and right sides and the upper portion of the first covering material 69 are covered with a second covering material 70. The left and right sides and the upper surface of the continuous seatback 5 are covered with a third covering material 71, and the rear surface of the seatback 5 is covered with a fourth covering material 72. First
The covering material 69 and the second covering material 70 are sewn at a sewing portion 73, and the second covering material 70 and the third covering material 71 are sewn at a sewing portion 74.

The airbag module 63 is made of synthetic resin.
A retainer 75 formed integrally with the retainer 75,
Holder 77 and retainer 75 and
And the holder 77 are mounted with the bolts 64, 64.
It is fastened to the socket 62 together. Retainer 75 faces right
Tray-shaped main body part 75₁And this body 7
5₁Hinge 75 on the rear edge_Two7 connected via
5_ThreeAnd the main body 75₁Top edge, leading edge and
Five locking claws 75 provided on the lower edge_Four... the lid part 75 _Threeupon
Five locking holes 75 provided at the edge, front edge and lower edge_Five... for
By stopping, the main body 75₁Cover to cover the opening of
Part 75_ThreeIs fixed.

The folded airbag 78 is packaged by the protection cover 79. The periphery of the opening of the airbag 78 and both ends of the protect cover 79 are sandwiched and fixed between the retainer 75 and the holder 77, whereby the inflator 80 fixed to the holder 77 is moved to the airbag 78.
Is stored inside. When the airbag 78 is inflated, the protect cover 79 is easily broken, and does not hinder the inflation.

Opening 77 formed in holder 77₁When,
Main body 75 of retainer 75₁Four vents formed in
Holes 29 and openings formed in the mounting bracket 62
62 ₁And a gas passage 68 formed in the pad 68₁When,
Through a space 81 formed on the rear side of the seat back 5.
The inside of the airbag 78 is connected to the outside of the seat back 5.
Pass. The opening of the four vent holes 29 is controlled.
The driver's seat airbag device Rd and the
Control valve having the same structure as that of the passenger seat airbag device Rp
30 is mounted inside the retainer 75.

The energization of the inflator 80 and the control valve 30 is controlled by the airbag deployment control device 34 to which signals from the acceleration detecting means 35a and the internal pressure detecting means 35b are input. Thus, when the inflator 80 generates gas at the time of a vehicle collision, the airbag 78 is inflated inside the retainer 75. When the pressure of the air bag 78 is inflated acts on the lid portion 75 ₃ of the retainer 75, the locking claw 7
5 ₄ ... rotates lid 75 ₃ deviates from the locking hole 75 ₅ ... is the hinge portion 75 ₂ around the body portion 75 ₁ is opened. The pressure lid 75 ₃ opens the seat back 3 dressing 71
Is transmitted to the sewn portion 74 and the second covering material 70
And the third covering material 71 are separated, and the airbag 78 that has passed through the gap is deployed forward along the inner surface of the front door.

Next, the driver-side airbag device Rd, the passenger-side airbag device Rp, and the side-impact airbag device R
The contents of the opening / closing control of the vent holes 29 of s, Rs will be specifically described with reference to FIGS.

The horizontal axis in FIG. 24A is the inflator 20,
The time since ignition of 50, 80 is shown, and the vertical axis shows the internal pressure of the airbags 21, 48, 78. Immediately after the inflators 20, 50 and 80 are ignited, the tear line 16 of the rear cover 16 is provided in the driver airbag device Rd.
Until ₂ (see FIG. 5) breaks, the tear line 41 _{2 of the} lid 41 is used in the passenger airbag device Rp (FIG. 1).
1) until the airbag device R breaks.
In s and Rs, until the sewing portion 74 (see FIG. 18) is broken, the inflation of the airbags 21, 48, and 78 is suppressed, and the internal pressure of the airbag rapidly increases. Subsequently, when the rear cover 16, the lid 41, or the sewn portion 74 is broken and the airbags 21, 48, 78 jump out into the vehicle interior, the inertia increases the volume of the airbags 21, 48, 78. The internal pressure of the airbag suddenly drops and temporarily becomes negative pressure. After that, the inflators 20, 50, 80
Is supplied to the airbags 21, 48, 78, the internal pressure changes from a negative value to a positive value, and the airbag 2
1,48,78 expand and deploy in the vehicle interior.

By the way, for example, when the airbag 48 of the passenger airbag device Rp breaks the lid 41 and deploys in the passenger compartment, when the adult is seated in the passenger seat 3 in a correct posture, The appropriate airbag internal pressure differs between when the child is standing in front of the seat 3. That is, when the position of the occupant is close to the passenger seat airbag device Rp, the internal pressure of the airbag 48 is controlled to be lower, and when the occupant is far from the passenger seat airbag device Rp, the airbag 48 is controlled. If the internal pressure is controlled to be higher, the occupant can be restrained with an appropriate restraining force in any case.

Therefore, as shown in FIGS. 24A and 24B, in this embodiment, the presence or absence of a nearby occupant is determined in accordance with the internal pressure of the airbags 21, 48, 78 detected by the internal pressure detecting means 35b at the initial stage of deployment. When an occupant is present, the vent hole opening is immediately increased to 100%, so that the internal pressure of the airbags 21, 48, 78 is suppressed to a low level so that the occupant can be restrained softly. On the other hand, when there is no nearby occupant, the vent holes 29 are opened at an appropriate timing to an intermediate opening (for example, 50%) so that the occupant seated in the normal posture can be restrained with an appropriate restraining force. High airbag pressure.

FIG. 25 shows a method of judging the presence or absence of a nearby occupant based on the airbag internal pressure detected by the internal pressure detecting means 35b.

At the beginning of the deployment of the airbags 21, 48, 78,
That is, the airbags 21, 48, 78 are
When the lid 41 or the sewn portion 74 is broken and jumps out into the passenger compartment vigorously, the increase in the volume of the airbags 21, 48, 78 due to inertia is not hindered unless there is an in-coming occupant. A large negative pressure. Conversely, if there is an approaching occupant, it will collide with the approaching occupant and inhibit an increase in the volume of the airbags 21, 48, 78 due to inertia, and the detected airbag internal pressure will exhibit a relatively small negative pressure. become. In this manner, the presence or absence of a nearby occupant can be accurately determined only by monitoring the internal pressure of the airbags 21, 48, 78 at the initial stage of deployment. It can contribute to cost reduction as compared with the one.

In the above embodiment, a commercially available pressure sensor is used as the internal pressure detecting means 35b, but other than that, the following internal pressure detecting means 35b can be used.

In the embodiment shown in FIG. 26, the internal pressure detecting means 35 is formed by bonding a piezoelectric element 83 to a metal protector 84.
b is fixed with bolts 86 so as to cover the opening 85 formed in the retainer 19 from the outside. When the internal pressure of the airbag increases and the amount of gas discharged from the opening 85 increases, the piezoelectric element 83 of the internal pressure detecting means 35b is deformed outward, and a potential difference corresponding to the deformation is generated. Therefore, the pressure inside the airbag can be detected by monitoring the potential difference.

The embodiment shown in FIG.
The strain gauge 87 is attached to the inner wall surface of the air bag. When the retainer 19 is deformed according to the change in the air bag internal pressure, the resistance value of the strain gauge 87 changes, so that the air bag internal pressure can be detected.

In the embodiment shown in FIG. 28, the control valve 30 and the internal pressure detecting means 35b are integrated. Control valve 3
No. 0 is obtained by laminating the internal pressure detecting means 35b composed of another piezoelectric element 88 between the protector 32 and the piezoelectric element 31,
It is fixed with bolts 33 so as to cover the vent holes 29 from the outer surface side of the retainer 19. When the internal pressure of the airbag increases in the initial stage of deployment, the control valve 30 bends to the dashed line position, and the internal pressure detecting means 35b composed of the piezoelectric element 88 deforms outward to generate a potential difference according to the amount of deformation, so that the potential difference is monitored. Thus, the internal pressure of the airbag can be detected. After the internal pressure detecting means 35b detects the internal pressure of the airbag, the opening of the vent holes 29 can be changed by controlling the power supply to the piezoelectric element 31 of the control valve 30.

Since the detection of the internal pressure by the internal pressure detecting means 35b and the control of the opening of the vent holes 29 by the control valve 30 are not performed simultaneously, the piezoelectric element 31 of the control valve 30 in the embodiment of FIG. Internal pressure detecting means 35b
Function can be provided. Specifically, in the initial stage of deployment, the piezoelectric element 31 of the control valve 30 functions as the internal pressure detecting means 35b to detect the internal pressure of the airbag, and thereafter, the piezoelectric element 31 functions as an actuator to open the vent holes 29. Can be controlled. This eliminates the need for the special internal pressure detecting means 35b (that is, the piezoelectric element 88), thereby further reducing the number of components.

Also, in the embodiment shown in FIG. 29, the control valve 30 and the internal pressure detecting means 35b are integrated, and the protector 32 formed larger than the piezoelectric element 31 is mounted on the protector 32 formed by the strain gauge 87. Are adhered. When the internal pressure of the airbag increases in the initial stage of deployment, the protector 32 of the control valve 30 bends in the direction of the arrow, and the internal pressure detecting means 35b composed of the strain gauge 87 is deformed to change the electric resistance. Therefore, the electric resistance is monitored. The airbag internal pressure can be detected. Note that the same effect can be obtained even if a piezoelectric element 88 is employed instead of the strain gauge 87.

Although the embodiments of the present invention have been described in detail, various design changes can be made in the present invention without departing from the gist thereof.

[0061]

As described above, according to the first aspect of the present invention, when it is determined at the initial stage of deployment of the airbag that there is a nearby occupant based on the internal pressure of the airbag, the control means controls the control valve with the actuator. Since the opening degree of the vent hole is increased by driving, the amount of gas discharged from the vent hole is increased, the internal pressure of the airbag is reduced to an arbitrary size suitable for the close occupant, and excessive A sufficient binding force can be generated. In addition, since it is possible to cope with the restraint of a nearby occupant without needing a plurality of inflators, there is no problem that the cost is increased.

According to the second aspect of the present invention,
By forming the actuator with a piezoelectric element, the vent hole can be opened and closed at a low cost with a simple structure having a smaller number of parts than other actuators such as a motor and a solenoid.

According to the third aspect of the present invention,
By forming the actuator with a plate-shaped piezoelectric element, not only the structure of the actuator becomes extremely simple, but also the piezoelectric element itself can be used as a valve body, thereby further reducing the number of parts and increasing the cost. Reduction is possible.

According to the fourth aspect of the present invention,
By combining a plurality of vent holes formed in the retainer and a plurality of openings formed in the valve plate, the degree of opening of the vent hole can be changed from the fully closed state to the fully open state with a slight stroke movement of the valve plate. Becomes possible,
The miniaturization of the actuator and the improvement of the responsiveness are simultaneously achieved.

According to the fifth aspect of the present invention,
Since a plurality of vent holes arranged in the circumferential direction are opened and closed by a valve plate that is reciprocally driven by an actuator, a rotary output actuator such as a motor can be easily applied.

According to the invention described in claim 6,
Since a plurality of vent holes arranged in a linear direction are opened and closed by a valve plate which is reciprocally driven linearly by an actuator, a linear output actuator such as a linear solenoid or a laminated piezoelectric element can be easily applied.

According to the invention described in claim 7,
By using the common piezoelectric element for both the actuator and the internal pressure detecting means, the number of components can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view of a front part of a cabin of an automobile.

FIG. 2 is an enlarged sectional view taken along line 2-2 of FIG. 1;

FIG. 3 is a sectional view taken along line 3-3 in FIG. 2;

FIG. 4 is an enlarged sectional view taken along line 4-4 in FIG. 3;

FIG. 5 is an exploded perspective view of an airbag device for a driver's seat.

FIG. 6 is a view corresponding to FIG. 3 and showing a modification of the airbag device for the driver's seat;

FIG. 7 is an enlarged sectional view taken along line 7-7 of FIG. 6;

FIG. 8 is an enlarged sectional view taken along line 8-8 of FIG. 1;

9 is a sectional view taken along line 9-9 in FIG.

FIG. 10 is a view taken along line 10-10 of FIG. 9;

FIG. 11 is an exploded perspective view of an airbag device for a passenger seat.

FIG. 12 is a view showing a first modification of the airbag device for the passenger seat, corresponding to FIG. 9;

13 is a sectional view taken along line 13-13 of FIG.

FIG. 14 is a sectional view taken along line 14-14 of FIG. 12;

FIG. 15 is a view showing a second modification of the airbag device for the passenger seat, corresponding to FIG. 9;

16 is a sectional view taken along line 16-16 of FIG.

17 is a sectional view taken along line 17-17 in FIG.

FIG. 18 is an enlarged sectional view taken along line 18-18 of FIG. 1;

19 is a view in the direction of arrow 19 in FIG. 18;

20 is a sectional view taken along line 20-20 in FIG. 19;

FIG. 21 is a sectional view taken along line 21-21 of FIG. 19;

FIG. 22 is a sectional view taken along line 22-22 in FIG. 19;

FIG. 23 is a block diagram showing a control system for a vent hole opening degree;

FIG. 24 is a diagram showing an example of changes in the opening degree of the vent hole and the internal pressure of the airbag depending on the presence or absence of a nearby occupant.

FIG. 25 is a diagram for explaining a method for determining the presence or absence of a nearby occupant;

FIG. 26 is a diagram showing a second embodiment of the internal pressure detecting means.

FIG. 27 shows a third embodiment of the internal pressure detecting means.

FIG. 28 is a diagram showing a fourth embodiment of the internal pressure detecting means.

FIG. 29 is a diagram showing a fifth embodiment of the internal pressure detecting means.

[Explanation of symbols]

Reference Signs List 19 retainer 20 inflator 21 airbag 29 vent hole 30 control valve 31 piezoelectric element (actuator) 34 airbag deployment control device (control means) 35b internal pressure detecting means 36 valve plate 36 ₁ opening 37 motor (actuator) 43 retainer 48 airbag 50 Inflator 51 Valve plate 51 ₁ opening 52 Valve plate 52 ₁ opening 53 Linear solenoid (actuator) 75 Retainer 78 Airbag 80 Inflator

Claims (7)

[Claims] 1. A folded airbag (21, 48, 7)
8) A retainer (19, 43,
75), the inflator (20, 50, 80) is housed inside the inflator (20, 50, 80) in the event of a vehicle collision.
80), the airbag (21, 4) inflated with the gas generated.
8, 78) to deploy an airbag device for restraining an occupant. The airbag device operates by a vent hole (29) formed in the retainer (19, 43, 75) and an actuator (31, 37, 53). A control valve (30) for opening and closing a vent hole (29); an internal pressure detecting means (35b) for detecting an internal pressure of the airbag (21, 48, 78); and deployment of the airbag (21, 48, 78). A control means for initially determining the presence or absence of a nearby occupant based on the internal pressure of the airbag (21, 48, 78) and increasing the opening of the vent hole (29) when it is determined that there is a nearby occupant ( 34), an airbag device comprising: 2. The airbag device according to claim 1, wherein the actuator (31) is a piezoelectric element. 3. The piezoelectric element according to claim 2, wherein the actuator is a plate-shaped piezoelectric element arranged to cover the vent hole and one end of which is fixed to the retainer. The airbag device according to claim 2, wherein: 4. The retainer (19, 43) includes a plurality of vent holes (29) and the control valve (3).
0) is provided with a valve plate (36, 51, 52) in which a plurality of openings (36 ₁ , 51 ₁ , 52 ₁ ) respectively corresponding to the plurality of vent holes (29) are formed, and the actuator (37) is provided. , 53) are the valve plates (36, 51, 5).
2) sliding the plurality of openings (36 ₁ , 51 ₁ , 52 ₁ ) along the retainers (19, 43) to face the plurality of vent holes (29). Item 2. The airbag device according to item 1. 5. The plurality of vent holes (29) are arranged in a circumferential direction, and the valve plates (36, 51) are reciprocally driven by the actuator (37). Item 5. The airbag device according to item 4. 6. The method according to claim 4, wherein the plurality of vent holes are arranged in a straight line, and the valve plate is reciprocally driven linearly by the actuator. The airbag device as described in the above. 7. The airbag device according to claim 2, wherein the piezoelectric element (31) constituting the actuator also serves as the internal pressure detecting means (35b).