JP2004017765A - Seat belt device for vehicles - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To precisely control the tension of a seat belt without providing a driver with a feeling of physical disorder. <P>SOLUTION: Two or more target values are set for the tension of a seat belt, and during running of a vehicle, a first target value T1 is usually used and meanwhile, the tension of the seat belt is controlled by using a second target value T1 higher than the first target value T1 during emergency. When, during braking and turning of the vehicle, it is detected that the target value of the tension is varied from the first target value T1 to the second target value T2, tension change characteristics from the first target value T1 to the second target value T2 are moderated. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a vehicle seat belt device that controls a seat belt tension with respect to a preset target tension.
[0002]
[Prior art]
As a conventional vehicle seat belt device, for example, Japanese Patent Application Laid-Open No. 2000-127896 discloses a condition for providing comfort and a safety when controlling the driving of a motor for winding and pulling out a seat belt. It is described that at least one of the conditions is changed.
[0003]
Japanese Patent Application Laid-Open No. 2000-52925 describes that the amount of slack in a seat belt is changed according to the degree of collision risk of a vehicle.
[0004]
[Problems to be solved by the invention]
By the way, in a situation where an obstacle jumps out from the side while driving a vehicle, a state where the risk of collision is high suddenly appears.
[0005]
In this case, the belt tension changes with the change in the collision risk degree, and the occupant feels uncomfortable.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 sets two or more target values for the tension of the seat belt, and uses a low target value at all times while the vehicle is running, and sets a high target value in an emergency. And tension value control means for controlling the tension using, and target value change detection means for detecting that the target value has changed from a low value to a high value. When the value change detecting means detects the change in the target value, the change characteristic of the tension of the seat belt from a low target value to a high target value is moderated.
[0007]
【The invention's effect】
According to the present invention, when the target value of the tension of the seat belt is changed from a low value to a high value, the change in the tension when the target value is increased from the low value to the high value becomes gentle, so that the occupant can adjust the tension. It becomes difficult to sense the change, and the sense of discomfort can be reduced.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0009]
FIG. 1 is an exploded perspective view showing a vehicle seat belt device according to a first embodiment of the present invention, and FIG. 2 is a longitudinal sectional view of the vehicle seat belt device in an assembled state. Here, it is assumed that the seat belt devices are provided in the driver's seat and the passenger seat, respectively.
[0010]
As shown in FIG. 1, the seat bell device is roughly divided into a frame 1, a reel 5 for winding up a seat belt 3, and a reel 1 on one side (a front side in FIG. 1) of the frame 1. A lock mechanism 7 for preventing rotation of the belt in the belt withdrawal direction α, a lock operating mechanism 9 for operating the lock mechanism 7 when necessary, an acceleration detecting mechanism 11 for detecting acceleration during vehicle acceleration / deceleration and right / left turning, and a vehicle. A force limiter mechanism (hereinafter, also referred to as an EA mechanism) 13 for limiting a load applied to the seat belt 3 when the pull-out of the seat belt 3 is prevented by the operation of the lock mechanism 7 during a large deceleration such as a collision, and a frame 1 A motor 15 that is disposed on the other side (the back side in FIG. 1) and generates a belt winding torque, and reduces the torque of the motor 15 and transmits the torque to the reel 5. And a speed gear 17 and the planetary gear mechanism 19..
[0011]
The frame 1 includes a pair of parallel side walls 21 and 23 and a back plate 25 connecting the side walls 21 and 23 to each other. The reel 5 described above is accommodated between the side walls 21 and 23 in the frame 1.
[0012]
The reel 5 has a through hole 5a at the center thereof, which penetrates in the axial direction. The through-hole 5a is capable of fitting a cylindrical shaft portion 27a having a regular hexagonal cross section of a shaft gear 27, which will be described later, into which one end of the torsion bar 29 is fitted, at the end on the side wall 23 side, and The shaft gear 27 and one end of a torsion bar 29 to be described later are formed in a hole having a regular hexagonal cross section so as to be integrally rotatable, and the other end of the torsion bar 29 is fitted to the end on the side wall 21 side. The stopper 31 is formed in a hole having a cross-sectional shape that allows the reel 5 and the stopper 31 to rotate together.
[0013]
The lock mechanism 7 includes a locking base 33 and a pawl 35 as shown in an enlarged manner in FIG. The locking base 33 rotatably supports the pawl 35, and has an arcuate load transmitted portion 33a formed around the support point, and receives a load from the pawl 35 via the load transmitting portion 35a. It has become.
[0014]
A locking claw 35b is formed at the lower end of the pawl 35 in the drawing, and a cam follower 35c having a protruding shaft is provided. The locking claw 35b engages with and disengages from the internal teeth 1a of the frame 1 with the rotation of the pawl 35. When the pawl 35b engages, the reaction force of the pawl 35 is applied to the load transmitting portion of the locking base 33. 33a.
[0015]
The lock operating mechanism 9 includes a lock gear 37, a flywheel 39, and a retainer 41, as shown in the perspective view enlarged in FIG. 4 and the assembled state from the right side in FIG. Have. An arcuate cam hole 37a is provided in the lock gear 37, and a cam follower 35c of the pawl 35 is inserted into the cam hole 37a.
Therefore, when the lock gear 37 rotates relative to the locking base 33, the cam follower 35c is guided by the cam hole 37a, and the pawl 35 rotates.
[0016]
Further, the lock gear 37 rotatably supports the flywheel 39. The flywheel 39 has a locking claw 39a formed at the tip, and engages and disengages with the internal teeth 41a of the retainer 41 as the flywheel 39 rotates. Further, a predetermined number of ratchet teeth 37b are formed on the outer peripheral surface of the lock gear 37. An actuator 43 of the acceleration detecting mechanism 11 shown in FIG. 3 is engaged with the ratchet-shaped external teeth 37b to lock the rotation of the lock gear 37 in the belt withdrawing direction.
[0017]
Reference numeral 45 shown in FIGS. 1 and 4 denotes a pawl spring contracted between the locking base 33 and the lock gear 37, and the lock spring 37 is always attached to the locking base 33 in the belt withdrawing direction α. I'm going. Reference numeral 47 denotes a flywheel spring contracted between the lock gear 37 and the flywheel 39, which constantly urges the flywheel 39 in the belt withdrawing direction α with respect to the lock gear 37.
[0018]
As shown in FIG. 3, the acceleration detection mechanism 11 includes a housing 49 attached to the side wall 21 of the frame 1, a sensor case 51 attached to the housing 49, an inertial mass 53 mounted on the sensor case 51, And the actuator 43 described above, which is operated by the inertial mass 53.
[0019]
The housing 49 supports the sensor case 51 and is fitted and attached to the side wall 21 of the frame 1. The sensor case 51 has the inertial mass 53 mounted thereon and rotatably supports the actuator 43. The inertial mass 53 is normally upright as shown in FIG. 6A, but tilts as shown in FIG. 6B when an acceleration / deceleration or a centripetal acceleration of a predetermined value or more acts on the vehicle. , The actuator 43 is rotated.
[0020]
Further, the actuator 43 includes a pressed portion 55 pressed by the inertial mass 53, and a locking claw 59 provided on a side opposite to the rotating shaft portion 57 and lockable with the lock gear 37. When the inertia mass 53 is in the upright state, the actuator 43 is at the lowermost position, and is in a non-engagement position where the locking claw 59 is not engaged with the lock gear 37, and when the inertia mass 53 is tilted. By rotating upward, the locking claw 59 is set to a position where it engages with the external teeth 37 b of the lock gear 37.
[0021]
When a predetermined deceleration acts on the vehicle, the inertial mass 53 of the acceleration detection mechanism 11 tilts forward of the vehicle, the actuator 43 rotates, and the locking claw 59 is brought into a position where it engages with the external teeth 37 b of the lock gear 37. Become. However, at this time, the occupant moves forward due to the inertial force due to deceleration, and the seat belt 3 is about to be pulled out. Then, the reel 5, the torsion bar 29, the locking base 33, and the lock gear 37 all try to rotate in the belt withdrawing direction α, but the locking claws 59 are engaged with the external teeth 37b, and the lock gear 37 of the lock operation mechanism 9 is engaged. Is prevented from rotating in the belt withdrawing direction α, so that only the reel 5, the torsion bar 29 and the locking base 33 rotate in the same direction α.
[0022]
Therefore, relative rotation occurs between the locking base 33 and the lock gear 37, the pawl 35 of the lock mechanism 7 rotates, and the locking claw 35b of the pawl 35 engages with the internal teeth 1a of the frame 1. Thus, the rotation of the reel 5 in the belt withdrawing direction α is stopped, and the pulling out of the seat belt 3 is prevented. When the seat belt 3 is further pulled out, the torsion bar 29 is twisted, and only the reel 5 rotates in the belt withdrawing direction α by a predetermined amount.
[0023]
When the seat belt 3 is pulled out at a normal speed, the reel 5, the torsion bar 29, the locking base 33, and the lock gear 37 rotate in the belt pulling-out direction α, and the flywheel 39 moves together with the lock gear 37. The lock gear 37 rotates and does not rotate relative to the flywheel 39.
[0024]
However, when the seat belt 3 is suddenly pulled out, the flywheel 39 delays the rotation of the lock gear 37 and rotates relatively to the lock gear 37. For this reason, the locking claw 39a of the flywheel 39 is at a position where it engages with the internal teeth 41a of the retainer 41, and further rotation of the lock gear 37 in the belt withdrawing direction α is prevented. When the rotation of the lock gear 37 in the belt withdrawing direction α is blocked, the rotation of the reel 5 in the belt withdrawing direction α is also blocked as described above.
[0025]
Reference numeral 61 in FIG. 4 denotes a reel rotation volume detection mechanism that detects the rotation of the torsion bar 29, that is, the rotation amount of the reel 5 as an absolute value, and converts this into an electric signal. A cover that covers the detection mechanism 61. Reference numeral 64 in FIG. 1 denotes a cover that covers the side wall 23 of the frame 1.
[0026]
The EA mechanism 13 includes a torsion bar 29 and a cylindrical stopper 31 screwed to the screw shaft portion 33b of the locking base 33. The torque transmitting portion 29a at one end of the torsion bar 29 shown in FIG. 3 is fitted into the regular hexagonal hole 33c of the locking base 33 so as not to rotate relative to the locking base 33, and the torque transmitting portion 29b at the other end is provided. Is fitted to the shaft gear 27.
[0027]
As shown in FIG. 3, the cylindrical stopper 31 has a female screw 31 a formed on the inner periphery thereof, and is screwed to the screw shaft 33 b of the locking base 33. Further, two protrusions 31b are provided on the outer periphery of the stopper 31, and the rotation torque of the reel 5 is transmitted. The protrusions 31b allow the stopper 31 to rotate integrally with the reel 5 and to move relative to the reel 5 in the axial direction.
[0028]
Therefore, a rotation difference occurs such that the stopper 31 rotates in the belt withdrawing direction α with respect to the locking base 33. In other words, when a rotation difference occurs such that the reel 5 rotates in the belt withdrawing direction α with respect to the locking base 33, the stopper 31 moves in the axial direction and comes into contact with the disk portion 33d of the locking base 33. ing. Further, when the stopper 31 comes into contact with the locking base 33, the stopper 31 stops moving in the axial direction, and rotates integrally with the locking base 33.
[0029]
Therefore, while the rotation difference is generated between the stopper 31 and the locking base 33, the torsion bar 29 is twisted, so that the EA mechanism 13 exhibits the EA function of limiting the belt load at the time of a vehicle collision. When the stopper 31 contacts the locking base 33, the EA function ends. As described above, the range in which the EA function is performed is defined by the stopper 31 and its female screw 31a, the locking base 33, and its screw shaft 33b.
[0030]
The motor 15 is mounted on the frame 1 via a motor bracket 67 as shown in FIG. The motor torque is transmitted to the reel 5 by the reduction gear 17 and the planetary gear mechanism 19, as shown in FIG. 7A is a front view, and FIG. 7B is a plan view of FIG.
[0031]
The rotation of the motor 15 reduced by the reduction gear 17 is input to the sun gear 69 of the planetary gear mechanism 19 and transmitted to four planetary gears 71. Here, if the rotation of the ring gear 73 is fixed, the rotation is transmitted to the carrier 75 that supports the planetary gear 71, drives the shaft gear 27, rotates the reel 5, and winds up the seat belt 3.
[0032]
As shown in the enlarged view of FIG. 8, one end of an arm 77 is swingably wound around a shaft 81 between the reduction gear 17 and a flange 79, and the other end is a lock key 83 as a lock piece. Is engaged. When the motor 15 is driven in the direction in which the seat belt 3 is wound, the lock key 83 is moved by the movement of the arm 77 accompanying the rotation of the reduction gear 17 and engages with the ratchet 73 a on the outer periphery of the ring gear 73 as shown in FIG. I do. The rotation of the ring gear 73 is fixed by the engagement between the lock key 77 and the ratchet 73a of the ring gear 73, so that the rotation of the motor 15 is transmitted to the reel 5, the seat belt 3 is wound up, and the belt tension is reduced. To rise.
[0033]
On the other hand, when the motor 15 is rotated in the reverse direction, the arm 77 attempts to move the lock key 83 in the direction of returning to the original position as shown in FIG. However, when the belt tension is applied, a frictional force acts between the ratchet 73a on the outer periphery of the ring gear 73 and the lock key 83 as shown in FIG. 11A, so that the lock key 83 returns to the original position. I don't come. When the motor 15 is further rotated in the reverse direction, the seat belt 3 is pulled out and the belt tension is reduced, and the friction between the ratchet 73b on the outer periphery of the ring gear 73 and the lock key 83 as shown in FIG. The force decreases, and the lock key 83 returns to the original position.
[0034]
When the lock key 83 is unlocked from the ring gear 73 and the ring gear 73 can rotate freely, torque transmission between the motor 15 and the reel 5 is stopped, and the belt tension decreases.
[0035]
In addition, when the belt tension is maintained, it is possible to stop the energization to the motor 15 after increasing the tension. This is because the motor from the motor 15 to the reel 5 is driven by a gear that amplifies the motor torque and reduces the number of revolutions so that the motor with a small torque can be driven. It is necessary to forcibly drive the gear 17 from the opposite side, which requires a large force.
[0036]
Furthermore, even when the current is 0, the motor 15 tries to stay at that position by the holding torque of the motor itself. Therefore, in order to forcibly pull out the seat belt 3, a force obtained by amplifying the holding torque of the motor 15 by the reciprocal of the gear ratio of the reduction gear 17 is required, and the belt tension can be held by this force.
[0037]
Furthermore, when the seat belt 3 is pulled out with a larger force, it is necessary to resist the force and prevent the seat belt 3 from being pulled out. To prepare for such a case, a belt tension holding mechanism 85 as shown in FIG.
[0038]
The belt tension holding mechanism 85 has a locking claw 91 at the tip of a plunger 89 of the solenoid 87, and the locking claw 91 is constantly urged downward in the figure by a spring 93. When a current flows through the coil 95 of the solenoid 87 shown in FIG. 12B, the plunger 89 rises against the elastic force of the spring 93, the holding claw 91 rotates around the support pin 92, and the lock gear 37 engages with the external teeth 37b.
[0039]
Here, after the belt tension is increased by the motor 15, by energizing the solenoid 87, the locking claw 91 is engaged with the external teeth 37b, and the rotation of the lock gear 37 in the belt pull-out direction is locked. Even if the seat belt 3 is pulled out with a larger force, the seat belt 3 can be prevented from being pulled out and the occupant can be restrained.
[0040]
Next, control of the belt tension by the tension control means and the target value change detection means will be described.
[0041]
FIG. 13 shows a block diagram of the control system. The vehicle is provided with a longitudinal acceleration sensor 97 and a lateral acceleration sensor 99 as acceleration detecting means for detecting longitudinal and lateral acceleration, respectively, and outputs a voltage corresponding to the deceleration of the vehicle and the centripetal acceleration at the time of turning. I do. Each of the acceleration sensors 97 and 99 corresponds to the acceleration detection mechanism 11 of FIG. 1, and each voltage signal is input to a controller 101 including a tension control unit and a target value change detection unit. Further, a detection signal of an ignition switch 103 is also input to the controller 101 in order to detect an operation state of the engine.
[0042]
In the controller 101, input voltages from the respective acceleration sensors 97 and 99 are converted into digital values by I / F circuits 105 and 107, and a detection signal of an ignition switch 103 is also sent to a CPU 111 via an I / F circuit 109. Passed. The CPU 111 reads out the program stored in the memory 113 and operates according to the program. Further, the data in the calculation process is stored in the temporary memory 113.
[0043]
Inside the CPU 111, a target value of the tension of each of the driver's seat and the passenger's seat belt (hereinafter, referred to as belt tension) is calculated in accordance with the values of the acceleration sensors 97 and 99, and the respective belt tensions are set to the target values. 12, the driver circuits 115, 117, 119 of the driver seat motor 15d and the passenger seat motor 15a corresponding to the motor 15 and the driver seat solenoid 87d and the passenger seat solenoid 87a corresponding to the solenoid 87 of FIG. The drive control of each of them is performed.
[0044]
Here, as the program stored in the memory 113, for example, there is a program as shown in the flowchart of FIG.
[0045]
After the ignition switch 103 is turned on, when the start of the engine is detected, the program starts. First, a signal from the longitudinal acceleration (G) sensor 97 and a signal from the lateral acceleration (lateral G) sensor 99 are A / D converted and input (step 1401).
[0046]
Next, it is determined whether or not control is currently being performed (step 1403). If the control is not being performed, the value of the longitudinal acceleration: the value of longitudinal G is compared with a threshold value Gx1 (step 1405), and the lateral acceleration is determined. Is compared with the threshold value Gy1 (step 1407).
[0047]
When the front and rear G is smaller than Gx1, that is, the braking acceleration (deceleration) at the time of braking the vehicle: When the braking G is larger than | Gx1 |, or when the absolute value of the lateral G is larger than Gy1, A first target tension T1 that is a low target value is set (step 1409), and a current value of a current to be supplied to the motor 15 and a conduction time are calculated so that the belt tension becomes the first target tension T1. (Step 1411). When the current value and the energizing time are calculated, the motor 15 is energized so as to wind up the seat belt 3 (step 1413). When the front and rear G is equal to or greater than Gx1 and the absolute value of the lateral G is equal to or less than Gy1, the tension control is not performed.
[0048]
Next, it is determined whether the ignition switch 103 is ON or OFF (step 1415). If it is OFF, the program is terminated as it is. On the other hand, when the ignition switch 103 is ON, the process returns to the step 1401 to fetch signals from the longitudinal acceleration sensor 97 and the lateral acceleration sensor 99 again.
[0049]
Here, it is determined again whether or not the control is currently being performed (step 1403). If the control is being performed, it is determined whether or not the energization time set at the start of the control has elapsed (step 1417). If the energizing time has not elapsed, the winding is continued without doing anything.
[0050]
If the energization time has elapsed, the front and rear G are compared with a threshold Gx2 (step 1419), and the absolute value of the lateral G is compared with the threshold Gy2 (step 1421). When the front and rear G is smaller than Gx2, that is, when the braking G is larger than | Gx2 | (| Gx1 | <| Gx2 |), or when the absolute value of the lateral G is larger than Gy2 (Gy1 <Gy2), the belt tension is increased. A second target tension T2 which is a high target value is set (step 1423), and a current value of a current to be supplied to the motor 15 and a conduction time are calculated so that the belt tension becomes the second target tension T2. (Step 1425). When the current value and the energizing time are calculated, the motor 15 is energized so as to wind up the seat belt 3 (step 1427).
[0051]
If the front and rear G is greater than or equal to Gx2, and if the absolute value of the lateral G is less than or equal to Gy2, it is determined whether the condition for canceling the winding of the seat belt 3 is satisfied (step 1429). Here, the front and rear G was set to 0 and the horizontal G was set to 0, which was the belt winding release condition. Alternatively, when the front and rear G is equal to or more than a predetermined value and the absolute value of the lateral G is equal to or less than a predetermined value, the cancellation condition may be set as the cancellation condition.
[0052]
At the point in time when the above-mentioned belt take-up release condition is satisfied and both the braking and turning ends, the take-up of the seat belt 3 is released. On the other hand, if the belt take-up release condition is not satisfied, a tension holding operation is performed to maintain the belt tension in a state where the seat belt 3 has been taken up.
[0053]
The belt take-up release operation is performed by rotating the motor 15 in the reverse direction as shown in FIG. The belt tension holding operation is such that the seat belt 3 is not wound up by continuously supplying a constant weak current to the motor 15, but the seat belt 3 is prevented from being pulled out and the belt winding position is maintained. I do.
[0054]
Here, the tension change characteristics until reaching the first target tension T1 and the second target tension T2, respectively, are set as shown in FIG. That is, the current value and the energizing time until the first target tension T1 is reached are set such that energizing is started at a constant current value from the start of energizing at time t0 for a certain time and the belt tension rises as quickly as possible. I have. Although FIG. 15 shows an example of the front and back G, the same setting is applied to the horizontal G.
[0055]
On the other hand, the setting of the current value and the energizing time from when the first target tension T1 reaches the second target tension T2 is such that the belt tension gradually increases from the start of energization at time t1 to reach the target tension T2. To Therefore, the current value for the second target tension T2 increases with the passage of time, and the energizing time is set as the time required for the belt tension to reach the target tension T2.
[0056]
With this setting, the belt tension quickly reaches the first target tension T1, and the occupant is restrained before the body starts moving. Further, when the belt tension reaches the first target tension T1 and then changes to the second target tension T2, the change in the tension becomes gentle, so that the belt tension changes unnaturally. It can be suppressed and changes continuously, which makes it difficult for the occupant to perceive the change in tension, and can reduce a sense of discomfort.
[0057]
As described above, according to the first embodiment, when the target value of the tension of the seat belt 3 is changed from a low value to a high value by the tension control means and the target value change detection means, this low Since the change in the tension when the value increases from the value to the high value becomes gentle, it becomes difficult for the occupant to perceive the change in the tension and the discomfort can be reduced.
[0058]
Further, by controlling the driving of the motor 15 by the controller 101 that performs the tension control, the tension of the seat belt 3 can be accurately controlled. Further, the controller 101 can accurately control the tension of the seat belt 3 in accordance with the vehicle acceleration detected by the longitudinal acceleration sensor 97 and the lateral acceleration sensor 99.
[0059]
Further, by controlling the driving of the motor by the tension control means, the tension of the seat belt can be accurately controlled, and the tension control means can control the seat belt in accordance with the acceleration of the vehicle detected by the acceleration detection means. Can be accurately controlled.
[0060]
FIG. 16 shows a second embodiment of the present invention. In the second embodiment, the configuration of the seat belt device and the configuration of the control system are the same as those in FIGS. 1 to 13 in the first embodiment.
[0061]
In this embodiment, when increasing the belt tension, the characteristic of the belt tension until the first target tension T1 is reached is changed. Although FIG. 16 shows an example of the front and rear G, the same setting is applied to the horizontal G.
[0062]
That is, the gradient A of the tension change until the first target tension T1 is reached is determined by the gradient B of the front and rear G at the moment when the front and rear G becomes smaller than the threshold value Gx1 (greater than | Gx1 |), or the horizontal. The value is changed according to the gradient B of the absolute value of the lateral G at the moment when the absolute value of G exceeds the threshold value Gy1. That is, the tension change characteristic (slope A) that reaches the first target tension T1 is a function of the acceleration slope B when exceeding the threshold value Gx1 or Gy1.
[0063]
Accordingly, when the occupant performs an emergency avoidance operation on the vehicle, the front-back G or the side G changes abruptly, so that the gradient A of the tension change until reaching the first target tension T1 is linear. And the tension rises quickly. In such a case, it is expected that the front and rear G or the lateral G will further rise sharply thereafter, so that the occupant's body can be restrained before the occupant's body moves.
[0064]
On the other hand, when the front-back G or the lateral G gradually changes, it is expected that the subsequent front-back G or the lateral G changes gradually. In such a case, the slope A of the tension change is made gentle, and the belt tension is changed slowly. Thereby, the occupant does not become conscious of unnecessary restraint.
[0065]
As described above, according to the second embodiment, the tension change characteristic that reaches a low target value is controlled. Therefore, by controlling the tension to quickly rise at the beginning of winding the seat belt 3, the seat is controlled. Speeding up of the rising timing of the tension of the belt 3 can be achieved. Further, since the tension change characteristic reaching a low target value is made linear, the rise of the tension can be made quick.
[0066]
FIG. 17 shows a third embodiment of the present invention. Also in this embodiment, the configuration of the seat belt device and the configuration of the control system are the same as those in FIGS. 1 to 13 in the first embodiment.
[0067]
In this embodiment, the characteristic of the tension from the first target tension T1 to the second target tension T2 is changed. Although FIG. 17 shows an example of the front and back G, the same setting is applied to the horizontal G.
[0068]
That is, the gradient C of the tension change from the first target tension T1 to the second target tension T2 is changed according to the threshold value Gx2 or Gy2. That is, the tension change characteristic (gradient C) from the first target tension T1 to the second target tension T2 is a function of the threshold value Gx2 or Gy2.
[0069]
In this case, the threshold values Gx2 and Gy2 are not constant, but change according to other parameters. For example, as shown in FIG. 18, when the vehicle speed is low and when the vehicle speed is high, Gx2 and Gy2 are set to larger values when the vehicle speed is high. And the gradient C of the tension change is set to a sharp change as Gx2 and Gy2 are larger.
[0070]
The reason for reducing Gx2 and Gy2 when the vehicle speed is low is that the vehicle stops before the front / rear G or the lateral G is sufficiently generated, or that the distance to the periphery of the vehicle is short, so that the vehicle is sufficiently stopped before the collision. This is because no front-back G or side G occurs. Further, when the vehicle speed is low, the energy at the time of the collision is low, so that the tension change is made gentler than when the vehicle speed is high. Therefore, at low speeds, Gx2 and Gy2 are set low, and the gradient of the tension change at that time is set to be gentle.
[0071]
On the other hand, when the vehicle speed is high, the distance to the periphery of the vehicle is long, and the front and rear G and the side G are sufficiently increased before the vehicle stops or collides. Therefore, the threshold values Gx2 and Gy2 are set to values higher than those at low speed. Set. However, since the collision energy at the time of collision is large, it is desirable to increase the tension as quickly as possible, and the inclination of the tension change is set to a steep change.
[0072]
As described above, according to the above-described third embodiment, it is possible to increase the tension without giving the occupant a sense of discomfort in a situation where a sudden increase in tension is not required, and to quickly increase the tension in a situation where a rapid increase in tension is necessary. Lifting can be compatible. Further, as the belt tension target value (high target value T2) increases, the belt tension increases more quickly, so that an accurate tension change corresponding to the target value (high target value T2) is obtained. be able to. Furthermore, when the tension once rises and reaches a low target value, when the seat belt 3 is further wound up, the tension change of the seat belt 3 can be made continuous, whereby the occupant senses the tension change. And it is possible to reduce discomfort.
[0073]
Further, according to this embodiment, the higher the high target value, the more quickly the tension of the seatbelt increases. Therefore, when the tension is required to be increased quickly, It is possible to achieve both increasing the tension without giving the occupant a sense of incongruity when the tension does not need to be increased.
[0074]
FIG. 19 shows a fourth embodiment of the present invention. Also in this embodiment, the configuration of the seat belt device and the configuration of the control system are the same as those in FIGS. 1 to 13 in the first embodiment.
[0075]
In this embodiment, the gradient D of the tension change from when the first target tension T1 reaches the second target tension T2 is changed according to the difference between the first target tension T1 and the second target tension T2. I did it.
[0076]
That is, the first target value T1 and the second target value T2 change depending on the conditions, and the difference between the first target value T1 and the second target value T2 also changes with the change. According to this difference, the characteristic of the tension change (gradient D) from the first target value T1 to the second target value T2 is changed.
[0077]
For example, the first and second target tensions T1 and T2 are set to high values when the rising of the deceleration due to the driver's braking operation is steep, and low when the rising of the deceleration is gentle. Value.
[0078]
By the way, in a general driving situation, as shown in FIG. 20, the occupant started the braking operation in an attempt to apply the sudden braking while the vehicle was running, Conversely, as shown in FIG. 21, there is a situation in which a normal braking operation was performed at the start of braking, but sudden braking was required from there.
[0079]
In the former case, the first target tension T1 is higher but the second target tension T1 is lower. In the latter case, the first target tension T1 is lower but the second target tension T2 is lower. Is higher. Therefore, the former T2-T1 <the latter T2-T1.
[0080]
In the case where the rapid braking is started and the braking is continued as it is, the first target tension T1 is increased and the second target tension T1 is also increased, the gentle braking is started, and the brake is gradually increased as it is. In this case, the first target tension T1 is lower and the second target tension T2 is lower.
[0081]
As described above, the first target tension T1 and the second target tension T2 change depending on the state of the braking operation, so that the tension change characteristics from the first target tension T1 to the second target tension T2 are always the same. In this case, the rise in tension is delayed, or the change in tension is so rapid that the occupant becomes unnecessarily aware of the change in tension.
[0082]
However, in accordance with the difference between the first target tension T1 and the second target tension T2, when the difference is large, the gradient D of the tension change is increased so as to reach the target tension quickly, and conversely, the difference becomes large. When it is small, the gradient D of the tension change is made small so that the occupant is not conscious of the tension change.
[0083]
As described above, according to the fourth embodiment, the tension change characteristic is changed according to the difference between the low target value T1 and the high target value T2. Therefore, when the difference is large, the target tension is quickly changed to the target tension. In contrast, when the difference is small, the target tension is gradually reached so that the occupant is not conscious of the tension change.
[0084]
FIGS. 22, 23, and 24 show a fifth embodiment of the present invention. Also in this embodiment, the configuration of the seat belt device and the configuration of the control system are the same as those in FIGS. 1 to 13 in the first embodiment.
[0085]
In this embodiment, the target tension is set in three stages, and the flowchart at this time is as shown in FIG. The flowchart of FIG. 22 differs from the flowchart of FIG. 14 in the first embodiment in that the absolute values of the front and rear G and the lateral G are respectively compared with third threshold values Gx3 and Gy3 (step 2201). A part for setting the third target tension T3 is added.
[0086]
The front-back G is smaller than Gx3, that is, the braking acceleration (deceleration) during braking of the vehicle: when the braking G is larger than | Gx3 | (| Gx2 | <| Gx3 |), or the absolute value of the lateral G is Gy3. If (Gy2 <Gy3), the third target tension T3 is set as the target value of the belt tension (step 2203), and the motor 15 is energized so that the belt tension becomes the third target tension T3. The current value of the current and the conduction time are calculated (step 2205). When the current value and the energizing time are calculated, the motor 15 is energized so as to wind up the seat belt 3 (step 2207). If the front and rear G is greater than or equal to Gx3 and the absolute value of the lateral G is less than or equal to Gy3, the process shifts to step 1429 to determine whether the condition for canceling the retraction of the seat belt 3 is satisfied.
[0087]
Here, as shown in FIG. 23, a tension change characteristic from the first target tension T1 to the second target tension T2 and a tension change characteristic from the second target tension T2 to the third target tension T3. The characteristics are changing. That is, the gradient E of the tension change until reaching the higher target tension T3 is made larger than the gradient F until reaching the lower target tension T2.
[0088]
As a result, when the deceleration gradually increases as shown in FIG. 23, the target tension increases one after another, and the tension change characteristic at that time is as shown by an arrow G in FIG. As a whole, it increases exponentially. The same applies to the horizontal G.
[0089]
As a result, while the target tension is low, the tension change becomes gentle, and when the target tension becomes high, the tension quickly rises. This is because, in an emergency, when the deceleration and the lateral G increase, the tension rises quickly and the occupant can be restrained reliably in the event of a collision, and if the emergency is not so high, the tension changes slowly. This makes it possible for the occupant not to feel the unnaturalness of the tension change, and furthermore, when the target tension changes from a low target tension to a high target tension, the tension change becomes smooth and the feeling of discomfort is reliably reduced. Can be.
[0090]
Also in this embodiment, the tension of the seat belt 3 can be continuously changed when the seat belt 3 is further wound up from the state where the tension has risen once and reached the low target value. It is difficult to sense a change in tension, and it is possible to reduce a sense of discomfort. In addition, as the higher target value increases, the tension of the seat belt 3 increases more quickly, so that the tension is quickly increased in a situation where a quick increase in the tension is required, and a sharp increase in the tension is not required. It is possible to simultaneously increase the tension without giving the occupant a sense of discomfort in the scene.
[0091]
FIG. 25 shows a sixth embodiment of the present invention. Also in this embodiment, the configuration of the seat belt device and the configuration of the control system are the same as those in FIGS. 1 to 13 in the first embodiment.
[0092]
In the sixth embodiment, similarly to the fifth embodiment, the target tension is set to three stages including a first target tension T1, a second target tension T2, and a third target tension T3. I have.
[0093]
Here, the change in tension until reaching the lowest first target tension T1 has a linear and steep characteristic as in the fifth embodiment shown in FIG. On the other hand, the change in the tension from the first target tension T1 to the second target tension T2 has a characteristic obtained by combining the straight line H1 and the exponential curves I1 and I2. The tension change until reaching the third target tension T3 is a characteristic obtained by combining the straight line H2 and the exponential curves I3 and I4.
[0094]
This is because the low target tension T1 is low in tension itself, so that it is difficult to cause discomfort even if the tension is increased linearly, and the occupant's body moves by quickly raising the tension even if the tension is low. This is because the body of the occupant can be restrained before performing the operation.
[0095]
On the other hand, when the tension increases, it is considered that the occupant more strongly feels the restraining force and the risk of collision increases. For this reason, it is necessary to increase the tension more quickly, so that the change in the tension becomes steep, and the occupant becomes more likely to feel the restraining force. Therefore, in such a situation, the tension change is increased linearly (H1, H2) after the initial characteristic of the tension change is exponential (I1, I3). Immediately before reaching the target tensions T2 and T3, the change characteristic of the tension is again made to be a negative exponential function (I2, I4), so that the change point of the tension change is hardly perceived.
[0096]
As described above, according to the sixth embodiment, the tension change characteristic that reaches the target value T2 or T3 of the high belt tension is set to be exponential, so that the tension change is continuous, and thereby the occupant can take a seat. In addition, it becomes more difficult to sense a change in tension, and the sense of discomfort can be reliably reduced.
[0097]
26, 27, and 28 show a seventh embodiment of the present invention. Also in this embodiment, the configuration of the seat belt device and the configuration of the control system are the same as those in FIGS. 1 to 13 in the first embodiment.
[0098]
In the seventh embodiment, as shown in FIG. 26, the belt tension is changing from the first target tension T1 to the second target tension T2 starting at time t1 (time t2), as shown in FIG. This corresponds to the tension change characteristic when the target tension is changed to match the third target tension T3.
[0099]
In such a case, as shown in FIG. 27, a change characteristic (slope Ka) from the first target value T1 to the second target value T2 and a change characteristic until the third target tension T3 is reached. An intermediate gradient Kc of the tension change between the characteristic (gradient Kb) and the characteristic (gradient Kb) is provided in the middle. The flowchart at this time is as shown in FIG.
[0100]
This flowchart is almost the same as the fifth embodiment shown in FIGS. 22 to 24, except that if the energizing time has not elapsed in step 1417, the front and rear G and the horizontal G are respectively set to a threshold value Gx3, The difference is only the part where the operation after the comparison with Gy3 is added.
[0101]
Therefore, the description will focus on these different parts. Control is performed on the second target tension T2, and if the energization time to the motor 15 has not elapsed in step 1417, the absolute values of the front and rear G and the horizontal G are compared with threshold values Gx3 and Gy23, respectively. (Step 2801). When the longitudinal G is smaller than Gx3, that is, when the deceleration is larger than | Gx3 |, or when the absolute value of the lateral G is larger than Gy3, the target tension is set to a higher value, that is, the third target tension T3. At time t2.
[0102]
At this time, the tension of the seat belt has not yet reached the second target tension T2, and unless the tension is increased as quickly as possible, the occupant may not be able to experience a sufficient sense of restraint. On the other hand, if the power is immediately started in the control to reach the second target tension T2, if the target tension is immediately changed to the third target tension T3, the belt tension will suddenly change. This makes the occupant strongly aware of the change in tension.
[0103]
Therefore, in order to increase the tension as quickly as possible and to suppress the change in the belt tension, the gradient of the change in the tension is set so as to reach the second target tension T2 from the first target value T1. The change slope Ka and the middle (average) slope Kc of the change Kb of the tension change set so as to reach the third target tension T3 from the time of the change (time t2). The change in the tension is set based on the slope Kc so as to reach the second target value T2.
[0104]
In this way, the tension change characteristic is calculated (step 2803), and thereafter, the current value of the current supplied to the motor 15 and the current supply time are calculated (step 2805), and the current is supplied to the motor 15 for winding up the seat belt 3. (Step 2807).
[0105]
As described above, according to the above-described seventh embodiment, while the belt tension is changing so as to match the target tension T2, the tension change characteristic when the target tension is further changed to T3 is intermediate. The inclination Kc of the tension change is provided in the middle. As a result, the belt tension can be quickly increased in response to the change in the target tension, and a sudden change in the belt tension due to the change in the target tension can be suppressed, so that the occupant is not strongly aware of the change in the tension. In other words, when a belt tension having a higher target value than the high target value is required, the change in the tension becomes smooth, whereby the occupant becomes more difficult to perceive the change in the tension, and the discomfort can be reduced.
[0106]
FIG. 29 shows an eighth embodiment of the present invention. Also in this embodiment, the configuration of the seat belt device and the configuration of the control system are the same as those in FIGS. 1 to 13 in the first embodiment.
[0107]
In the eighth embodiment, similar to the seventh embodiment shown in FIGS. 26 to 28, when the belt tension is changing to match the target tension, and the target tension further changes. However, the tension change characteristics at this time are as shown in FIG.
[0108]
That is, when the degree of urgency is low (third target tension T3a), similarly to the seventh embodiment, the change characteristic (slope Ka) from the first target value T1 to the second target value T2. An intermediate gradient Kc of the change in tension between the change characteristic and the change characteristic (gradient Kb) until reaching the third target tension T3 is provided in the middle. As a result, a sudden change in the tension is suppressed, so that the occupant is not strongly aware of the change in the tension.
[0109]
On the other hand, when the degree of urgency is high (not less than the third target tension T3b, which is the predetermined value), the above-mentioned intermediate tension change gradient Kc is not provided, and the change becomes necessary (time t2). In addition, a tension change characteristic (slope Kb) with respect to a higher target value (third target tension T3b) is used to increase the tension more quickly.
[0110]
The flowchart is the same as FIG. 28 in the seventh embodiment, but the urgency of the vehicle is determined in the tension change characteristic calculation (step 2803). As the urgency of the vehicle, for example, when the front and rear G, the lateral G is high or suddenly rises, or until the collision, which can be calculated from the inter-vehicle distance and the relative vehicle speed by the inter-vehicle distance sensor using radar or ultrasonic waves Can be used as the urgency of the vehicle. When the time until the collision is used as the degree of urgency, the slope of the tension change characteristic can be obtained, for example, as shown in FIGS.
[0111]
That is, the intermediate slope Kc is represented by Kc = Ka + (Kb−Ka) × K. K is a coefficient that decreases as time elapses until the collision, as shown in FIG.
[0112]
According to the above-described eighth embodiment, when the higher target value T3 is lower than the predetermined value T3b, the tension change becomes smooth and the occupant becomes less likely to sense the tension change, while the higher target value T3 becomes the predetermined value. When the value is equal to or more than the value T3b, the change in the tension is sharp, and the occupant can be quickly restrained.
[0113]
In each of the above-described embodiments, an example in which control during braking is performed based on the value from the longitudinal acceleration sensor 97 and control during turning is performed based on the value from the left and right acceleration sensor 99 has been described. It is not limited to.
[0114]
Instead of the longitudinal acceleration sensor 97, a value corresponding to the longitudinal G during deceleration may be detected, and for example, a brake pedal stroke, a brake fluid pressure, or the like may be used. Instead of the left and right acceleration sensor 99, any device capable of detecting a turning state may be used, and for example, a yaw rate sensor, a steering angle sensor, a difference between left and right wheel speeds, and the like can be used.
[0115]
Furthermore, in each of the above-described embodiments, an example is shown in which control during braking and control during turning are performed simultaneously. However, the present invention is also applicable to a system that performs control only during braking and a system that performs control only during turning. it can.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view showing a vehicle seatbelt device according to a first embodiment of the present invention.
FIG. 2 is a longitudinal sectional view of the seat belt device of FIG. 1 in an assembled state.
FIG. 3 is an exploded perspective view showing a lock mechanism of the seat belt device of FIG.
FIG. 4 is an exploded perspective view showing a lock operation mechanism of the seat belt device of FIG. 1;
FIG. 5 is a configuration diagram of an assembled state from the right side of FIG. 4;
FIGS. 6A and 6B are explanatory diagrams illustrating an operation of the acceleration detecting mechanism of the seat belt device of FIG. 1, in which FIG. 6A shows a normal state, and FIG.
7A is a front view showing a configuration of a rotational force transmission mechanism of a motor in the seat belt device of FIG. 1, and FIG. 7B is a plan view of FIG.
FIG. 8 is an enlarged view showing details of an arm mounting section shown in FIG. 7;
FIG. 9 is an explanatory diagram showing a belt winding operation by the motor drive of FIG. 7;
FIG. 10 is an explanatory diagram showing a belt tension releasing operation by driving the motor shown in FIG. 7;
FIGS. 11A and 11B are explanatory diagrams showing the operation at the time of belt winding and rewinding, where FIG. 11A shows a state in which a frictional force is acting between a ring gear and a lock key, and FIG. It shows the state where it was done.
FIGS. 12A and 12B show a belt tension holding mechanism of the seat belt device of FIG. 1, wherein FIG. 12A is a front view showing the entire configuration, and FIG. 12B is a sectional view of the solenoid in FIG.
13 is a block diagram of a control system of the seat belt device of FIG.
FIG. 14 is a flowchart of a program according to the first embodiment.
FIG. 15 is a tension change characteristic diagram from when a threshold value of the longitudinal acceleration is exceeded to when a target tension is reached according to the first embodiment.
FIG. 16 is a tension change characteristic diagram from when the longitudinal acceleration exceeds a threshold value to when the target tension is reached according to the second embodiment.
FIG. 17 is a tension change characteristic diagram from when the longitudinal acceleration exceeds a threshold value to when the target tension is reached according to the third embodiment.
FIG. 18 is a graph showing a change characteristic of a threshold value according to a vehicle speed according to the third embodiment.
FIG. 19 is a tension change characteristic diagram from when the longitudinal acceleration exceeds a threshold value to when the target tension is reached according to the fourth embodiment.
FIG. 20 is an explanatory diagram showing a change in target tension during vehicle braking.
FIG. 21 is an explanatory diagram showing a change in target tension during vehicle braking.
FIG. 22 is a flowchart of a program according to the fifth embodiment.
FIG. 23 is a tension change characteristic diagram from when the longitudinal acceleration threshold value is exceeded to when the target tension is reached according to the fifth embodiment.
FIG. 24 is an explanatory diagram showing a tension change characteristic in the fifth embodiment.
FIG. 25 is an explanatory diagram showing a tension change characteristic in the sixth embodiment.
FIG. 26 is a tension change characteristic diagram from when the longitudinal acceleration exceeds a threshold value to when the target tension is reached according to the seventh embodiment.
FIG. 27 is an explanatory diagram showing a tension change characteristic in the seventh embodiment.
FIG. 28 is a flowchart of a program according to a seventh embodiment.
FIG. 29 is an explanatory diagram showing a tension change characteristic in the eighth embodiment.
FIG. 30 (a) is a diagram of a tension change characteristic in the eighth embodiment, and FIG. 30 (b) is a correlation diagram between a time until a collision and a coefficient K used in an equation for obtaining the tension change characteristic.
[Explanation of symbols]
3 Seat belt
5 reel
15 Motor
97 longitudinal acceleration sensor (acceleration detection means)
99 Left and right acceleration sensor (acceleration detecting means)
101 controller (tension control means, target value change detection means)
T1 First target value (low target value)
T2 Second target value (high target value)

Claims (11)

Tension control means for setting two or more target values for the tension of the seat belt and using a low target value at all times during traveling of the vehicle, while controlling the tension using a high target value in an emergency, Target value change detection means for detecting that the target value has changed from a low value to a high value, wherein the tension control means detects that the target value change detection means has changed the target value. A seat belt device for a vehicle, wherein a change characteristic of a tension of the seat belt from a low target value to a high target value is moderated. 2. The vehicle seat belt device according to claim 1, wherein the tension control unit controls a change characteristic of the tension of the seat belt when increasing the tension to the low target value. 3. 2. The vehicle seat belt device according to claim 1, wherein the tension control unit controls a change characteristic of a tension of the seat belt from the low target value to the high target value. 3. 4. The vehicle seat belt device according to claim 3, wherein the tension control means makes the change characteristic of the tension of the seat belt steeper when the higher target value is reached, the steeper as the higher target value is reached. 3. The vehicle seatbelt device according to claim 2, wherein the tension control unit makes the change characteristic of the tension of the seatbelt to the low target value linear. The said tension control means changes the change characteristic of the tension of the seatbelt from the low target value to the high target value according to the difference between the low target value and the high target value. 4. The vehicle seat belt device according to 3. 4. The vehicle seat belt device according to claim 3, wherein the tension control unit geometrically controls the change characteristic of the tension of the seat belt from the low target value to the high target value. The tension controller controls the seat belt tension to change to a higher target value when it is necessary to change the seat belt tension from the lower target value to a higher target value. The change characteristic of the change from the low target value to the high target value and the change characteristic from the time when the change becomes necessary to the higher target value. A vehicle seat belt device according to any one of claims 1 to 7. When the higher target value is equal to or more than a predetermined value, the tension control means does not set the intermediate change characteristic and sets the tension as a change characteristic to the higher target value from the time when the change becomes necessary. The vehicle seat belt device according to claim 8, wherein the control is performed. 10. The reel according to claim 1, wherein a reel for winding the seat belt and a motor for rotating the reel to adjust the tension of the seat belt are provided, and the motor is controlled by the tension control unit. The vehicle seat belt device according to any one of the above. 11. The vehicle according to claim 1, further comprising acceleration detection means for detecting acceleration of the vehicle, wherein the tension control means sets the tension of the seat belt in accordance with the acceleration of the vehicle detected by the acceleration detection means. The vehicle seat belt device according to any one of the above.

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