JP3922171B2 - Vehicle occupant protection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle occupant protection device including an energy absorption mechanism that absorbs collision energy in accordance with displacement of a steering column in a vehicle collision.
[0002]
[Prior art]
Conventionally, as disclosed in, for example, Patent Document 1, an energy absorbing mechanism that displaces a steering column at the time of a vehicle collision and absorbs an impact force accompanying the vehicle collision, and a column pull-in mechanism that pulls the steering column forward at the time of the vehicle collision. A vehicle safety device equipped with the above is known. When the impact force on the steering column exceeds the specified force, the energy absorption mechanism starts to displace the steering column (the outer column and inner column begin to contract), and loads the steering column against the displacement. It absorbs collision energy, and a large load is applied to a driver with a large physique compared to a small driver. The column pull-in mechanism optimizes the space between the steering wheel and the driver so that the back of the airbag does not hit the driver's face or chest when the airbag is deployed or inflated. It works for the driver, but it doesn't work for drivers over the standard physique.
[0003]
[Patent Document 1]
JP 2002-79944 A
[0004]
[Problems to be solved by the invention]
However, in the conventional energy absorbing mechanism, when the driver's chest (or face) collides with the steering pad with a certain degree of impact force after the airbag is expanded and inflated due to a vehicle collision, the steering column is It starts to displace. Therefore, in many cases, the impact that the driver receives on the chest (or face) is increased to some extent regardless of the impact force caused by the vehicle collision (see FIG. 8A).
[0005]
SUMMARY OF THE INVENTION
The present invention has been made to address the above problems, and an object of the present invention is to provide a vehicle occupant protection device that minimizes the impact that the driver receives on the chest (or face) during a vehicle collision. There is to do.
[0006]
  In order to achieve the above object, the present invention is characterized in that, in a vehicle occupant protection device having an energy absorbing mechanism that absorbs collision energy in accordance with displacement of a steering column in the event of a vehicle collision, Displacement restricting device that restricts displacement and is switched to the second state by input of a switching control signal to release the displacement restriction of the steering columnA collision detection means for detecting a vehicle collision, and a means for outputting a switching control signal to the displacement regulating device and switching the displacement regulating device to the second state after the collision detection by the collision detecting means is detected. Predicting the magnitude of the impact force applied to the driver at the time of the vehicle collision, and when the predicted impact force at the time of the vehicle collision is large, the switching control signal Switching control means for delaying the output timingThat is.
[0008]
  According to this,carAfter the two collisions, if the driver is protected by another protective device such as a seat belt or an air bag, the displacement regulating device is switched to the second state and the energy absorbing mechanism is activated at an appropriate timing. The impact that the chest (or face) collides secondarily with the steering wheel can be reduced.When the predicted impact force at the time of the vehicle collision is large, the output timing of the switching control signal is delayed compared to the case when the predicted impact force is small, so the impact force at the time of the vehicle collision is large and early. When the displacement restriction of the steering column is released, even when the steering column reaches the displacement limit (hereinafter referred to as the bottoming of the steering column), the bottoming of the steering column is avoided and the driver is better protected. .
[0010]
Another feature of the present invention is that the energy absorption mechanism has an energy absorption amount variable device that variably sets the absorption amount of collision energy that accompanies displacement of the steering column, and further includes a switching control signal to the displacement restriction device. An energy absorption amount control means for controlling the energy absorption amount variable device is provided so that the amount of collision energy absorption associated with the displacement of the steering column increases as the output timing is delayed. According to this, even when the impact force at the time of the vehicle collision is considerably large, the absorption of the collision energy by the energy absorption mechanism becomes large, so that the bottom of the steering column can be avoided and the driver can be better protected.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a vehicle occupant protection device according to the embodiment. This vehicle occupant protection device includes an airbag device 20 mounted on a steering wheel 11, a column separation mechanism 30 and an energy absorbing mechanism 40 mounted between a steering column 12 and a vehicle body BD, and a seat 50 and a vehicle body. And a seat belt device 60 attached to the vehicle.
[0014]
The steering wheel 11 is assembled to a rear end portion of a steering shaft 13 which is assembled to the steering column 12 so as not to move in the axial direction and to be rotatable. The steering wheel 11 collides with the driver H due to plastic deformation of the steering wheel 11. It is configured to absorb energy. The rear of the steering column 12 is supported by a part of the vehicle body BD via the column detachment mechanism 30, and the front thereof is supported by a part of the vehicle body BD via the energy absorption mechanism 40. The steering shaft 13 is connected to the steering link mechanism 14 at the tip portion. With such a configuration, when the steering wheel 11 is rotated, this rotation is transmitted to the left and right front wheels (not shown) via the steering shaft 13 and the steering link mechanism 14, and the left and right front wheels are steered.
[0015]
The airbag device 20 includes an airbag body folded and housed in a steering pad at the center of the steering wheel 11, and an inflator for supplying gas to the airbag body. When the airbag body inflated and deployed between the driver H and the steering wheel 11 receives the driver H, the collision energy of the driver H is absorbed.
[0016]
As shown in detail in FIG. 2, the column detachment mechanism 30 includes a support member 31 fixed to the vehicle body BD side, and a regulation plate 32 fixed to the steering column 12 via a connecting member 32 a. A pair of the support member 31 and the restriction plate 32 are provided on both the left and right sides of the steering column 12, but only one of them is shown in FIG. The support member 31 is fixed to a bracket 33 fixed to the vehicle body BD by bolts 34a and nuts 34b, and has a slit 31a that supports the restriction plate 32 so as to be movable in the axial direction of the steering column 12.
[0017]
The restriction plate 32 has a through hole 32 b that is continuous with the through hole 31 b provided in the support member 31 in a state where the restriction plate 32 is inserted into the slit 31 a of the support member 31. The regulation pins 35 enter the through holes 31b and 32b so as to be able to advance and retreat. The restriction pin 35 is assembled to an actuator 36 fixed to the support member 31 at the base end portion. The actuator 36 is provided with a spring and an electromagnetic solenoid, and the restriction pin 35 is always urged upward by the spring by the spring, and the restriction pin 35 is pulled downward by energizing the electromagnetic solenoid. This restricting pin 35 restricts the displacement of the steering column 12 in the axial direction when it enters the through hole 32b of the restricting plate 32 shown in the drawing, and is pulled downward by energization of the electromagnetic solenoid of the actuator 36, thereby steering. The restriction on displacement of the column 12 in the axial direction is released. The support member 31, the regulation plate 32, the regulation pin 35, and the actuator 36 that function in this way constitute a displacement regulating device that regulates the displacement of the steering column 12 of the present invention.
[0018]
The energy absorbing mechanism 40 also serves as a supporting mechanism that supports the front of the steering column 12, and as shown in FIG. 3, the supporting bracket 41, the supporting pin 42, the bending plate 43 that is an energy absorbing member, and the shear pin 44 are provided. I have.
[0019]
The support bracket 41 has a gate shape when viewed from the front-rear direction, and is fixed to an upper portion of the outer periphery of the steering column 12 at the lower end of the side wall 41a facing each other. In addition, elongated holes 41b extending diagonally upward from the central portion to the rear are formed in opposite side wall portions 41a of the support bracket 41 so as to face each other. The long hole 41b is formed with a narrow portion 41b1 protruding inward at the front portion. The support pin 42 is fixed to a bracket (not shown) fixed to a part of the vehicle body BD in a state of passing through the long hole 41 b of the support bracket 41. In addition, the support pin 42 is inserted through the front portion of the long hole 41b of the support bracket 41 in the illustrated state, and is moved over the narrow portion 41b1 by the relative movement (relative movement) with the support bracket 41. It can move backward in the hole 41b.
[0020]
As shown in FIGS. 3 to 5, the bending plate 43 is formed in a plate shape with a material having a predetermined width and shearable by the shear pin 44, and extends in the axial direction of the steering column 12. It comprises an installation part 43a and a bent part 43b formed by bending the rear end part side by approximately 360 degrees. The bent plate 43 is welded and fixed to the support bracket 41 in a state where the bent plate 43 is positioned by a plurality of pins 41c implanted in the side wall portion 41a of the support bracket 41 at the front wall of the bent portion 43b. The support pin 42 is enclosed within 41. In the bent plate 43, as shown in FIGS. 4 and 5, upper and lower groove portions 43c1 and 43c2 extending in the length direction are formed at the center portion in the width direction of the extending portion 43a, and both groove portions 43c1 are formed. 43c2 is formed with a circular engagement hole 43c3 at the rear end thereof. In the engagement hole 43c3, a notch 43c4 is formed in order to facilitate the start of shearing of the bending plate 43.
[0021]
The shear pin 44 is formed in a tapered shape that gradually tapers, and enters the engagement hole 43c3 of the bending plate 43, and a large shearing force is required to shear the bending plate 43 as the amount of the penetration increases. It is trying to become. The shear pin 44 is assembled at its proximal end to an actuator 45 fixed to the upper wall portion of the support bracket 41. The actuator 45 includes a small motor and a conversion mechanism that converts the rotation of the small motor into an axial displacement of the shear pin 44, and the amount of penetration of the engagement hole 43c3 of the shear pin 44 is changed.
[0022]
In the energy absorbing mechanism 40 configured as described above, when the steering column 12 is displaced forward, the support pin 42 presses the bent portion 43b of the bent plate 43 together with the support bracket 41 in the right direction in FIG. At this time, the bending plate 43 is stretched while shearing the bending plate 43 along the line L1 of FIG. Since this shearing force is changed by the amount of penetration of the shear pin 44 into the engagement hole 43c3 by the actuator 45, the actuator 45 varies the absorption amount of the collision energy according to the displacement of the steering column 12. Constitutes a variable energy absorption device.
[0023]
The seat 50 can be displaced in the front-rear direction along the seat rail by an electric motor (not shown). The seat belt device 60 includes a seat belt 61, a tongue plate 62, a buckle 63, a shoulder belt anchor 64, and a retractor 65 with a built-in pretensioner mechanism and a force limiter mechanism. The pretensioner mechanism is a mechanism that winds up the seat belt 61 instantaneously at the initial stage of a frontal collision of the vehicle and firmly restrains the driver H's body. The force limiter mechanism is a mechanism capable of slightly reducing the restraining force of the seat belt 61 and reducing the load applied to the chest of the driver H when the driver H moves forward due to the reaction of the impact at the time of a frontal collision of the vehicle. is there.
[0024]
Next, the electric control device 70 that controls the air bag device 20, the column separation mechanism 30, the energy absorption mechanism 40, and the retractor 65 will be described. In addition to the acceleration sensor 71, the seat belt wearing sensor 72, the seat position sensor 73, the load sensor 74, and the vehicle speed sensor 75, the electric control device 70 includes an electric control unit 76 connected to each of these sensors 71 to 75. .
[0025]
The acceleration sensor 71 is assembled to the vehicle body BD, and detects the acceleration G in the front-rear direction of the vehicle body BD in order to detect a vehicle collision. The seat belt wearing sensor 72 is configured by a switch that is incorporated in the buckle 63 and detects the presence or absence of the tongue plate 62, and detects whether the driver H is wearing or not wearing the seat belt. The sheet position sensor 73 is incorporated in a movement mechanism (not shown) of the sheet 50, and detects a forward movement amount as the sheet position SP with reference to the rearmost position of the sheet 50. The load sensor 74 is incorporated in the seat 50 and detects the weight WT of the driver H. The vehicle speed sensor 75 detects the vehicle speed V according to the rotation of the output shaft of the transmission (not shown).
[0026]
The electric control unit 76 includes a microcomputer including a CPU, a ROM, a RAM, a timer, and the like as main components. By executing the program shown in FIG. 6, the airbag device 20, the column separation mechanism 30, the energy absorption mechanism 40, and the like. Control the retractor 65
[0027]
Next, the operation of the embodiment configured as described above will be described. As the vehicle travels, the electric control unit 76 starts the program of FIG. 6 in step S10. After starting the execution of the program, the electric control unit 76 inputs the acceleration G detected by the acceleration sensor 71 in step S12, and the acceleration G is converted into a predetermined acceleration G.₀It is determined whether it is above. In this case, the predetermined acceleration G₀Is set to a large value that is generated when the vehicle collides with a front object. Unless the vehicle collides with a front object, “No” is determined in step S12, and the process proceeds to step S14 and subsequent steps.
[0028]
In step S14, a detection signal from the seat belt wearing sensor 72 is input to determine whether or not the driver H is wearing the seat belt 61. If the driver H is wearing the seat belt 61, “Yes” is determined in step S14, and the delay amount ΔT is determined in step S16.₁Is set to “0”. If the driver H is not wearing the seat belt 61, “No” is determined in step S14, and the delay amount ΔT is determined in step S18.₁Is a predetermined value ΔT_TenSet to. This delay amount ΔT₁Is a delay amount ΔT described later.₂, ΔT_Three, ΔT_FourA variable for controlling the timing at which the steering column 12 is detached from the vehicle body BD after a vehicle collision.
[0029]
After the processes of steps S16 and S18, the electric control unit 76 inputs the detection signal from the sheet position sensor 73 in step S20 and refers to the sheet position-delay amount map to detect the detected sheet position SP. Delay amount ΔT corresponding to₂To decide. As shown in FIG. 7A, the seat position-delay amount map has a delay amount ΔT that increases as the seat position SP increases (as the seat 50 is positioned forward).₂Is remembered.
[0030]
Next, in step S22, the electric control unit 76 inputs the detection signal from the load sensor 74 and refers to the weight-delay amount map, and the delay amount corresponding to the detected weight WT of the driver H is detected. ΔT_ThreeTo decide. As shown in FIG. 7B, the weight-delay amount map shows a delay amount ΔT that increases as the weight WT of the driver H increases._ThreeIs remembered.
[0031]
Next, in step S24, the electric control unit 76 inputs a detection signal from the vehicle speed sensor 75 and refers to the vehicle speed-delay amount map, and the delay amount ΔT corresponding to the detected vehicle speed V._FourTo decide. As shown in FIG. 7C, the vehicle speed-delay amount map has a delay amount ΔT that increases as the vehicle speed V increases._FourIs remembered. In step S26, the determined delay amount ΔT₁, ΔT₂, ΔT_Three, ΔT_FourAre added together to calculate the total delay amount ΔT.
[0032]
Next, in step S28, the column displacement load CP corresponding to the total delay amount ΔT is determined with reference to the delay amount-column displacement load map. As shown in FIG. 7D, the delay amount-column displacement load map stores a column displacement load CP that increases as the total delay amount ΔT increases. In step S30, the actuator 45 is driven and controlled in accordance with the column displacement load CP, and the shear pin 44 is advanced and retracted to a depth position corresponding to the magnitude of the column displacement load CP. In the drive control of the actuator 45, a sensor (not shown) that detects the protruding amount of the shear pin 44 from the actuator 45 is used. In this case, as the column displacement load CP increases, the amount of protrusion of the shear pin 44 from the actuator 45 is controlled, that is, the shear force for the shear pin 44 to shear the bending plate 43 increases. Controlled.
[0033]
After the process of step S30, unless a vehicle collision is detected, the circulation process including steps S12 to S30 is repeatedly executed based on the determination of “No” in step S12.
[0034]
On the other hand, when the vehicle collides with a front object, the electric control unit 76 determines “Yes” in Step S12 and executes the processes after Step S32. In step S32, the pretensioner mechanism and the force limiter mechanism in the retractor 65 are activated. As a result, the seat belt 61 is drawn into the retractor 65, and the driver H is secured to the seat 50 by the seat belt 61 and is protected from jumping forward. Next, in step S34, the inflator in the airbag apparatus 20 is activated to expand and inflate the airbag. Accordingly, it is possible to avoid the airbag from being interposed between the driver H and the steering wheel 11 so that the chest (or face) of the driver H collides with the steering wheel 11.
[0035]
After the processes in steps S32 and S34, the electric control unit 76 starts time measurement by a timer in step S36, and in step S38, the measurement time T is a predetermined value T.₀Is obtained by adding the total delay amount ΔT to the value T₀It is determined whether or not + ΔT or more. The measurement time T is the added value T₀Until it reaches + ΔT, it is determined to be “No” in step S38. On the other hand, the measurement time T is the added value T₀When + ΔT is reached, the electromagnetic solenoid in the actuator 36 is energized in step S40, and the execution of the program is terminated in step S42.
[0036]
By energizing the electromagnetic solenoid, the actuator 36 pulls out the regulation pin 35 from the through hole 32b of the regulation plate 32. Therefore, at this time, displacement of the regulating plate 32, that is, the steering column 12 in the axial direction is allowed. By allowing the displacement of the steering column 12, the steering column 12 moves forward by the impact force of the vehicle collision. In this case, in the energy absorbing mechanism 40, the support pin 42 moves rearward relative to the support bracket 41 and the steering column 12, and the bending plate 43 is stretched while being sheared by the shear pin 44 (see FIG. 3 (see the two-dot chain line). Therefore, the impact force is absorbed by shearing of the bending plate 43 by the shear pin 44.
[0037]
According to the above-described embodiment that operates in this manner, the processing of steps S12 and S32 to S40 allows the driver to satisfactorily use the energy absorbing mechanism 40 in addition to the driver protection of the tightening of the seat belt 61 and the deployment of the airbag. H is protected. In particular, after the vehicle collision, after the seat belt 61 is tightened and the airbag is deployed, the actuator 36 in the column separation mechanism 30 is operated to allow the steering column 12 to be displaced, and the energy absorption mechanism 40 absorbs the impact caused by the vehicle collision. Thus, the impact of the driver H's chest (or face) secondary collision with the steering wheel 11 can be mitigated.
[0038]
That is, even if the driver's chest (or face) does not collide with the steering wheel 11 secondarily after the airbag is expanded and inflated due to a vehicle collision, the displacement of the steering column 12 is allowed. Therefore, when the impact due to the vehicle collision is small, the impact force of the secondary collision is alleviated by the energy absorbing mechanism 40, and the impact force that the driver receives on the chest (or face) is favorably mitigated.
[0039]
In the above embodiment, the processing of steps S14 to S26 takes into account the presence or absence of the driver's seat belt 61, the position of the seat 50, the weight of the driver H, and the vehicle speed V, and the delay amount accordingly. ΔT₁, ΔT₂, ΔT_Three, ΔT_FourAnd the total delay amount ΔT thereof is calculated. In other words, the magnitude of the impact force applied to the driver in the event of a vehicle collision is predicted, and the delay amount ΔT is determined according to the predicted magnitude of the impact force.₁, ΔT₂, ΔT_Three, ΔT_FourAnd a total delay amount ΔT is calculated. And the energy absorption mechanism 40 was made to function at the timing according to the total delay amount ΔT by the processing of steps S38 and S40. More specifically, when the driver does not wear the seat belt 61, when the seat 50 is positioned forward, when the weight of the driver H is large (that is, when the physique of the driver is large), When the vehicle speed V is high, that is, when the predicted impact force is large, the operation timing of the energy absorbing mechanism 40 is delayed.
[0040]
Therefore, even if the steering column 12 reaches the displacement limit (hereinafter referred to as the bottom of the steering column 12) when the displacement restriction of the steering column 12 is released early because the impact force at the time of the vehicle collision is large, the steering column 12 Twelve bottoms are avoided and the driver is better protected.
[0041]
Further, as the predicted impact force is increased by the processing in step S30, the amount of collision energy absorbed by the displacement of the steering column 12 by the energy absorbing mechanism 40 is controlled to increase, so that the impact force at the time of vehicle collision Can be avoided, and the driver can be better protected.
[0042]
Although one embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment and its modifications, and various modifications can be made without departing from the object of the present invention. is there.
[0043]
For example, the weight (or physique) of the driver H is detected (or estimated) by the load sensor 74. Instead of or in addition to this, the driver H is detected according to the seat position SP detected by the seat position sensor 73. The body weight (physique) of H may be estimated. In this case, the estimated weight (physique) of the driver H may be increased as the seat position SP becomes smaller (indicating the rear position).
[0044]
Further, a sensor for detecting the amount of withdrawal of the seat belt 61 may be provided, and the weight (physique) of the driver H may be estimated according to the amount of withdrawal of the seat belt 61 detected by the sensor. In this case, the estimated weight (physique) of the driver H may be increased as the amount of withdrawal of the seat belt 61 increases.
[0045]
Further, in place of or in addition to the presence or absence of the seat belt 61 of the driver H, the position of the seat 50, the weight (physique) of the driver H, and the vehicle speed V in the above embodiment, the impact of the driver H upon a vehicle collision is received. Depending on another physical quantity that directly or indirectly represents the size, the column separation timing by the process of step S38 and the energy absorption quantity by the process of step S30 may be variably controlled. As other physical quantities, the distance between the steering wheel 11 and the driver's H chest (or face), the magnitude of the collision impact force, and the like can be considered.
[0046]
In the case of control according to the distance between the steering wheel 11 and the driver's H chest (or face), a distance sensor for detecting the distance is assembled to the steering wheel 11 and the distance detected by the distance sensor becomes closer. Control may be performed so that the column removal timing is delayed and the energy absorption amount is increased. Further, in the case of control by the magnitude of the collision impact force, as the acceleration detected by the acceleration sensor 71 increases or as the impact force detected by the impact force sensor separately attached to the vehicle body BD increases. Control may be performed so that the column removal timing is delayed and the energy absorption amount is increased.
[Brief description of the drawings]
FIG. 1 is a schematic view of a vehicle occupant protection device according to an embodiment of the present invention.
2 is a cross-sectional view in which the column detachment mechanism of FIG. 1 is broken in a direction perpendicular to the axis of the steering column.
3 is a partially cutaway view of the energy absorbing mechanism of FIG. 1 with a portion broken along the axial direction of the steering column. FIG.
4 is a plan view of the bending plate of FIG. 3;
FIG. 5 is an enlarged longitudinal sectional front view taken along line 5-5 in FIG.
6 is a flowchart of a program executed by the electric control unit of FIG.
7A is a graph showing the relationship between seat position and delay amount, FIG. 7B is a graph showing the relationship between weight and delay amount, and FIG. 7C is the relationship between vehicle speed and delay amount. (D) is a graph showing the relationship between the delay amount and the column contraction load.
FIG. 8A is a graph showing a temporal change characteristic of a load that a driver receives on a chest at the time of a vehicle collision in a conventional occupant protection device, and FIG. 8B is a graph showing a driving operation at the time of a vehicle collision in the occupant protection device of the present invention. It is a graph showing the time change characteristic of the load which a person receives to a chest.
[Explanation of symbols]
BD ... body, 11 ... steering wheel, 12 ... steering column, 13 ... steering shaft, 20 ... airbag device, 30 ... column release mechanism, 32 ... regulating plate, 35 ... regulating pin, 36 ... actuator, 40 ... energy absorbing mechanism , 43 ... bending plate, 44 ... shear pin, 45 ... actuator, 50 ... seat, 60 ... seat belt device, 61 ... seat belt, 65 ... retractor, 70 ... electric control device, 71 ... acceleration sensor, 72 ... wearing seat belt Sensor 73 ... Seat position sensor 74 ... Load sensor 75 ... Vehicle speed sensor 76 ... Electric control unit

Claims (2)

In a vehicle occupant protection device equipped with an energy absorption mechanism that absorbs collision energy in accordance with displacement of a steering column in a vehicle collision,
A displacement regulating device that regulates the displacement of the steering column in the first state and is switched to the second state by the input of a switching control signal to release the displacement restriction of the steering column ;
Collision detection means for detecting a vehicle collision;
After the vehicle collision is detected by the collision detection means, a switching control signal is output to the displacement regulating device to switch the displacement regulating device to the second state, and the magnitude of the impact force applied to the driver at the time of the vehicle collision Switching control means for delaying the output timing of the switching control signal when the predicted impact force at the time of the vehicle collision is larger than when the predicted impact force is small. An occupant protection device for a vehicle. In the vehicle occupant protection device according to claim 1,
The energy absorption mechanism includes an energy absorption amount variable device that variably sets the amount of collision energy absorption associated with the displacement of the steering column,
Energy absorption amount control means is provided for controlling the energy absorption amount variable device so that the amount of collision energy absorption associated with the displacement of the steering column increases as the output timing of the switching control signal to the displacement regulating device is delayed. An occupant protection device for a vehicle.

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