JP3937938B2 - Vehicle seat belt device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle seat belt device that controls the tension of a seat belt 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 provides conditions and safety for imparting comfort when controlling the driving of a motor that winds and pulls out a seat belt. The point which changes at least one of conditions is described.
[0003]
Japanese Patent Application Laid-Open No. 2000-52925 describes that the amount of seat belt slack is changed in accordance with the degree of collision risk of a vehicle.
[0004]
[Problems to be solved by the invention]
By the way, when driving the vehicle, in a scene where an obstacle jumps out from the side, a state where the risk of collision is high appears suddenly.
[0005]
In this case, the belt tension changes with respect to the change in the collision risk degree, and the passenger feels uncomfortable.
[0006]
[Means for Solving the Problems]
  In order to achieve the above object, the invention of claim 1 sets two or more target values for the tension of the seat belt, and always uses a low target value when the vehicle travels, while a high target value in an emergency. A tension control means for controlling the tension using a target value, and a target value change detection means for detecting that the target value has been changed from a low value to a high value, respectively. When the value change detecting means detects the change of the target value, the change characteristic of the tension of the seat belt from the low target value to the high target value is obtained.More than the change characteristic of the tension of the seat belt when increasing the tension to the lower target valueGentlyWhen the tension of the seat belt changes from the low target value to the high target value, and the target value needs to be changed to a higher target value than the high target value, the change characteristic to the high target value The change characteristic from the low target value to the high target value, and the change characteristic from the low target value to the high target value, which is steeper than the change characteristic from the point when the change is necessary. Characteristic, and after the tension of the seat belt reaches the high target value due to the intermediate change characteristic, the change characteristic is steeper than the intermediate change characteristic.It is as composition to do.
[0007]
【The invention's effect】
  According to the present invention, when the target value of the seat belt tension is changed from a low value to a high value, the change in the tension when the target value reaches a high value from the low value becomes gentle. It becomes difficult to perceive changes, and the uncomfortable feeling can be reduced.
  In addition, since the belt tension is changing to match the target tension, the tension change characteristics when the target tension is changed to a higher value are provided in the middle of the gradient of the intermediate tension change. The belt tension can be quickly increased with respect to the change in the target tension, and the rapid change in the belt tension accompanying 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 with a higher target value than the high target value is required, the tension change becomes smooth, which makes it difficult for the occupant to sense the tension change and reduce the sense of incongruity.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0009]
FIG. 1 is an exploded perspective view showing a vehicle seat belt apparatus according to a first embodiment of the present invention, and FIG. 2 is a longitudinal sectional view of the assembled state of the apparatus. Here, it is assumed that the seat belt device is provided in each of the driver seat and the passenger seat.
[0010]
As shown in FIG. 1, this seat bell apparatus is roughly divided into a frame 1, a reel 5 for winding up a seat belt 3, and one side (front side in FIG. 1) of the frame 1. A lock mechanism 7 that prevents the rotation of the belt in the belt drawing direction α, a lock operation mechanism 9 that operates the lock mechanism 7 when necessary, an acceleration detection mechanism 11 that detects acceleration during vehicle acceleration / deceleration and left / right turn, A force limiter mechanism (hereinafter also referred to as an EA mechanism) 13 for limiting the load applied to the seat belt 3 when the seat belt 3 is prevented from being pulled out by the operation of the lock mechanism 7 at the time of large deceleration such as a collision, The motor 15 is disposed on the other side (the back side in FIG. 1) and generates belt winding torque, and the torque of the motor 15 is reduced and transmitted to the reel 5. And a speed gear 17 and the planetary gear mechanism 19..
[0011]
The frame 1 includes a pair of side walls 21 and 23 that are parallel to each other and a back plate 25 that connects the side walls 21 and 23 to each other. The reel 5 is accommodated between the side walls 21 and 23 in the frame 1.
[0012]
The reel 5 is provided with a through hole 5a penetrating in the axial direction at the center thereof. The through-hole 5a can be fitted with a cylindrical shaft portion 27a having a regular hexagonal cross section of a shaft gear 27, which will be described later, into which an end of the torsion bar 29 is fitted, at the end portion on the side wall 23 side. 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 that the shaft gear 27 can rotate integrally, and the other end of the torsion bar 29 is fitted to the end on the side wall 21 side. The stopper 31 that can be fitted is formed in a hole having a cross-sectional shape that allows the reel 5 and the stopper 31 to rotate integrally.
[0013]
The locking mechanism 7 includes a locking base 33 and a pawl 35 as shown in an enlarged view in FIG. The locking base 33 rotatably supports the pawl 35 and is formed with an arc-shaped load receiving portion 33a centering on the support point, and receives a load from the pawl 35 via the load transmitting portion 35a. It is like that.
[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. As the pawl 35 rotates, the engaging claw 35 b engages and disengages from the inner teeth 1 a of the frame 1, and when engaged, the reaction force of the pawl 35 is applied to the load transmitting portion of the locking base 33. 33a is supported.
[0015]
The lock operating mechanism 9 includes a lock gear 37, a flywheel 39, and a retainer 41 as shown in an enlarged perspective view of FIG. 4 and a configuration diagram of the assembled state from the right side of FIG. 4 shown in FIG. I have. The lock gear 37 is provided with an arcuate cam hole 37a, 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]
The lock gear 37 supports the flywheel 39 so as to be rotatable. The flywheel 39 is formed with a locking claw 39 a at the tip, and engages and disengages with the internal teeth 41 a of the retainer 41 as the flywheel 39 rotates. Furthermore, a predetermined number of ratchet-shaped external teeth 37 b are formed on the outer peripheral surface of the lock gear 37. The ratchet-like external teeth 37b are engaged with the actuator 43 of the acceleration detection mechanism 11 shown in FIG. 3 to lock the rotation of the lock gear 37 in the belt drawing direction.
[0017]
Reference numeral 45 shown in FIGS. 1 and 4 is a pawl spring that is contracted between the locking base 33 and the lock gear 37. The lock gear 37 is always attached to the locking base 33 in the belt drawing direction α. It is fast. Reference numeral 47 denotes a flywheel spring that is contracted between the lock gear 37 and the flywheel 39 and constantly urges the flywheel 39 in the belt pulling 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 above-described actuator 43 actuated 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 is mounted with an inertial mass 53 and supports the actuator 43 rotatably. The inertial mass 53 normally stands upright as shown in FIG. 6A, but tilts as shown in FIG. 6B when acceleration / deceleration or centripetal acceleration greater than a predetermined value acts on the vehicle. The actuator 43 is rotated.
[0020]
Further, the actuator 43 includes a pressed portion 55 that is pressed by the inertial mass 53 and a locking claw 59 that is provided on the opposite side of the rotating shaft portion 57 and can be locked to the lock gear 37. The actuator 43 is in the lowest position when the inertial mass 53 is in the upright state, and is in a non-engagement position where the locking claw 59 is not engaged with the lock gear 37, and when the inertial mass 53 tilts. By rotating upward, the locking claw 59 is positioned to engage with the external teeth 37b 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 and the actuator 43 rotates, so that the locking claw 59 engages with the external teeth 37b 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 tends 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 pulling direction α, but the locking claw 59 engages with the external teeth 37 b and the lock gear 37 of the lock operating mechanism 9. Therefore, only the reel 5, the torsion bar 29, and the locking base 33 rotate in the same direction α.
[0022]
For this reason, 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 35 b of the pawl 35 engages with the internal teeth 1 a of the frame 1. As a result, the rotation of the reel 5 in the belt withdrawing direction α is stopped and the withdrawal 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 pulling direction α by a predetermined amount.
[0023]
Further, 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 all rotate in the belt pulling direction α, and the flywheel 39 is also moved together with the lock gear 37. The lock gear 37 does not rotate relative to the flywheel 39.
[0024]
However, when the seat belt 3 is pulled out suddenly, the flywheel 39 is delayed in the rotation of the lock gear 37 and rotates relative to the lock gear 37. For this reason, the engaging claw 39a of the flywheel 39 becomes 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 pulling direction α is prevented. When the rotation of the lock gear 37 in the belt pulling direction α is prevented, the rotation of the reel 5 in the belt pulling direction α is also blocked as described above.
[0025]
In FIG. 4, reference numeral 61 denotes a reel rotation volume detection mechanism that detects the rotation of the torsion bar 29, that is, the amount of rotation of the reel 5 as an absolute value, and converts it into an electrical signal. Reference numeral 63 denotes a reel rotation volume. It is a cover that covers the detection mechanism 61. In FIG. 1, reference numeral 64 denotes a cover that covers the side wall 23 side of the frame 1.
[0026]
The EA mechanism 13 includes a torsion bar 29 and a cylindrical stopper 31 that is screwed into the screw shaft portion 33 b of the locking base 33. The torque transmission portion 29a on one end side of the torsion bar 29 shown in FIG. 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 into the screw shaft portion 33 b of the locking base 33. In addition, two convex portions 31b are provided on the outer periphery of the stopper 31, and the rotational torque of the reel 5 is transmitted. By these convex portions 31 b, the stopper 31 rotates integrally with the reel 5 and can move relative to the reel 5 in the axial direction.
[0028]
Therefore, a rotation difference is generated such that the stopper 31 rotates in the belt pulling 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 drawing 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, the torsion bar 29 is twisted while the rotation difference is generated between the stopper 31 and the locking base 33, so that the EA mechanism 13 exhibits an EA function that limits the belt load at the time of a vehicle collision. When the stopper 31 comes into contact with the locking base 33, the EA function ends. In this way, the range for performing the EA function is defined by the stopper 31 and its female screw 31a, the locking base 33 and its screw shaft portion 33b.
[0030]
As shown in FIG. 1, the motor 15 is attached to the frame 1 via a motor bracket 67. The motor torque is transmitted to the reel 5 by the reduction gear 17 and the planetary gear mechanism 19 as shown in FIG. FIG. 7A is a front view, and FIG. 7B is a plan view of FIG.
[0031]
The rotation of the motor 15 decelerated by the reduction gear 17 is input to the sun gear 69 of the planetary gear mechanism 19 and transmitted to the 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, the shaft gear 27 is driven, the reel 5 is rotated, and the seat belt 3 is wound up.
[0032]
As shown in an enlarged view in FIG. 8, one end of an arm 77 is wound around a shaft 81 between the speed 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 up, the lock key 83 is moved by the movement of the arm 77 accompanying the rotation of the reduction gear 17 and is engaged with the ratchet 73a on the outer periphery of the ring gear 73 as shown in FIG. To do. Since the rotation of the ring gear 73 is fixed by the engagement of the lock key 77 and the ratchet 73a of the ring gear 73, the rotation of the motor 15 is transmitted to the reel 5, the seat belt 3 is wound up, and the belt tension is increased. To rise.
[0033]
On the other hand, when the motor 15 is rotated in the reverse direction, the arm 77 tends to move in a direction to return the lock key 83 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. Not come. When the motor 15 is further rotated in the reverse direction, the seat belt 3 is pulled out to lower the belt tension, 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 with respect to the ring gear 73 is unlocked and the ring gear 73 can be freely rotated, torque transmission is not performed between the motor 15 and the reel 5, and the belt tension is lowered.
[0035]
Further, when the belt tension is maintained, it is possible to stop energization of the motor 15 after increasing the tension. This is because the motor 15 to the reel 5 are driven through a gear that amplifies the motor torque and decelerates the rotational speed so that it can be driven by a motor with a small torque. It is necessary to forcibly drive the gear 17 from the opposite side, and a large force is required.
[0036]
Further, even when the current is zero, the motor 15 tries to stay at that position due to the holding torque of the motor itself. Therefore, in order to force the seat belt 3 to be pulled out, 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 about to be pulled out with a larger force, it is necessary to resist the force and prevent the seat belt 3 from being pulled out. In such a case, a belt tension holding mechanism 85 as shown in FIG.
[0038]
The belt tension holding mechanism 85 is provided with a locking claw 91 at the tip of the plunger 89 of the solenoid 87, and the locking claw 91 is always urged downward by a spring 93 in the drawing. 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. The outer teeth 37b of 37 are engaged.
[0039]
Here, after the belt tension is increased by the motor 15, the solenoid 87 is energized, whereby the locking claw 91 is engaged with the external teeth 37b and the rotation of the lock gear 37 in the belt pulling direction is locked. Even if the seat belt 3 is pulled out with a greater force, the seat belt 3 can be prevented from being pulled out and the occupant can be restrained.
[0040]
Next, belt tension control by the tension control means and the target value change detection means will be described.
[0041]
A block diagram of the control system is shown in FIG. The vehicle is provided with a longitudinal acceleration sensor 97 and a lateral acceleration sensor 99 as acceleration detecting means for detecting longitudinal acceleration and lateral acceleration, respectively, and outputs a voltage corresponding to vehicle deceleration and turning centripetal acceleration. To do. The acceleration sensors 97 and 99 correspond to the acceleration detection mechanism 11 shown in FIG. 1, and each voltage signal is input to the controller 101 including a tension control means and a target value change detection means. In addition, a detection signal of the ignition switch 103 is also input to the controller 101 in order to detect the operating state of the engine.
[0042]
In the controller 101, the input voltages from the respective acceleration sensors 97 and 99 are converted into digital values by the I / F circuits 105 and 107, and the detection signal of the ignition switch 103 also passes through the I / F circuit 109 to the CPU 111. Passed. The CPU 111 reads a program stored in the memory 113 and operates according to the program. In addition, data in the calculation process is stored in the temporary memory 113.
[0043]
In the CPU 111, target values of the tensions of the seat belts of the driver seat and the passenger seat (hereinafter referred to as belt tensions) are calculated according to the values of the acceleration sensors 97 and 99, and the respective belt tensions are calculated as target values. The driver seat motor 15d and the passenger seat motor 15a corresponding to the motor 15 and the driver circuits 115, 117, 119 of the driver seat solenoid 87d and the passenger seat solenoid 87a corresponding to the solenoid 87 of FIG. Each of the drive units 121 is controlled.
[0044]
Here, examples of the program stored in the memory 113 include those shown in the flowchart of FIG.
[0045]
When it is detected that the engine has started after the ignition switch 103 is turned on, 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 the current control is being performed (step 1403). If the control is not currently performed, the longitudinal acceleration value: the longitudinal G value is compared with the threshold value Gx1 (step 1405), and the lateral acceleration is determined. Value: The value of the lateral G is compared with the threshold value Gy1 (step 1407).
[0047]
Front and rear G is smaller than Gx1, that is, braking acceleration (deceleration) at the time of braking of the vehicle: When braking G is larger than | Gx1 |, or when the absolute value of lateral G is larger than Gy1, the belt tension A first target tension T1 that is a low value is set as the target value (step 1409), and the current value of the current to be supplied to the motor 15 and the energization time are calculated so that the belt tension becomes the first target tension T1. (Step 1411). When the current value and the energization time are calculated, the motor 15 is energized so as to wind up the seat belt 3 (step 1413). Tension control is not performed when the longitudinal G is Gx1 or more and the absolute value of the lateral G is Gy1 or less.
[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, if the ignition switch 103 is ON, the process returns to step 1401 and signals from the longitudinal acceleration sensor 97 and the lateral acceleration sensor 99 are taken in again.
[0049]
Here, it is again determined whether or not the current control is 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 energization time has not elapsed, do nothing and continue winding.
[0050]
When the energization time has elapsed, the front and rear G are compared with the threshold value Gx2 (step 1419), and the absolute value of the lateral G is compared with the threshold value Gy2 (step 1421). When the front-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 The second target tension T2 that is a high value is set as the target value of the current (step 1423), and the current value of the current that is energized to the motor 15 and the energization time are calculated so that the belt tension becomes the second target tension T2. (Step 1425). When the current value and the energization time are calculated, the motor 15 is energized to wind up the seat belt 3 (step 1427).
[0051]
When the front and rear G is equal to or greater than Gx2 and the absolute value of the lateral G is equal to or less than Gy2, it is determined whether or not the seat belt 3 rewind release condition is satisfied (step 1429). Here, the front-rear G is 0 and the lateral G is 0 as the belt winding release condition. Alternatively, when the longitudinal G is equal to or greater than a predetermined value and the absolute value of the lateral G is equal to or smaller than the predetermined value, the release condition may be set, and the condition may be changed according to a parameter such as a vehicle speed.
[0052]
When the above-described belt winding release condition is satisfied and the time point when both braking and turning are detected is detected, the seat belt 3 is released. On the other hand, if the belt winding release condition is not satisfied, a tension holding operation is performed in order to hold the belt tension in the state where the seat belt 3 is wound up.
[0053]
The belt winding release operation is performed by rotating the motor 15 in the reverse direction as shown in FIG. Further, the belt tension holding operation means that the seat belt 3 is not wound up by continuously applying a certain weak current to the motor 15, but the seat belt 3 is prevented from being pulled out and the belt winding position is maintained. To do.
Even when a constant tension is maintained without changing the target tension by passing a weak current through the motor 15, the winding position of the seat belt 3 is maintained without using the locking mechanism 9 of the seat belt 3. Therefore, it is possible to prevent the seat belt 3 from being pulled out regardless of the lock operation mechanism 9. As a result, it is possible to avoid a change in tension that occurs until the lock actuating mechanism 9 operates, and a change in tension that gives the passenger a feeling of strangeness does not occur.
[0054]
  Here, the tension change characteristics until the first target tension T1 and the second target tension T2 are reached respectively.As a first reference exampleIt is set as shown in FIG. That is, the setting of the current value and the energization time until the first target tension T1 is reached is such that the energization is performed for a certain period of time with a constant current value from the start of energization at time t0 so that the belt tension rises as quickly as possible. Yes. In FIG. 15, an example of front and rear G is shown, but the same setting is made for horizontal G.
[0055]
On the other hand, the current value and energization time from the first target tension T1 to the second target tension T2 are set so 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 time, and the energization time is set as the time required for the belt tension to reach the target tension T2.
[0056]
By setting in this way, 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 changes to the second target tension T2 after reaching the first target tension T1, the tension change becomes gentle, so the belt tension changes unnaturally. It can be suppressed and changes continuously, which makes it difficult for the occupant to perceive a change in tension and reduce the sense of incongruity.
[0057]
  Thus, the first described aboveReference exampleAccording to the above, 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, the change in tension when the low value reaches a high value. Since the occupant becomes gentle, it becomes difficult for the occupant to perceive a change in tension, and the uncomfortable feeling can be reduced.
[0058]
Further, the tension of the seat belt 3 can be accurately controlled by controlling the driving of the motor 15 by the controller 101 that performs tension control. Further, the controller 101 can accurately control the tension of the seat belt 3 according to 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 adjust the seat belt according to the vehicle acceleration detected by the acceleration detection means. It is possible to accurately control the tension.
[0060]
  FIG. 16 shows a second embodiment of the present invention.Reference exampleIndicates. This secondReference exampleThe 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]
  thisReference exampleIn this case, when the belt tension is increased, the characteristic of the belt tension until the first target tension T1 is reached is changed. In FIG. 16, an example of front and rear G is shown, but the same setting is made for horizontal G.
[0062]
That is, the gradient A of the tension change until the first target tension T1 is reached, the gradient B of the longitudinal G at the moment when the longitudinal G becomes smaller than the threshold Gx1 (greater than | Gx1 |), or the lateral The absolute value of G is changed according to the gradient B of the absolute value of the lateral G at the moment when the absolute value of the G exceeds the threshold value Gy1. That is, the tension change characteristic (slope A) reaching the first target tension T1 is a function of the acceleration slope B when the threshold value Gx1 or Gy1 is exceeded.
[0063]
As a result, when the occupant performs an emergency avoidance operation on the vehicle, the front-rear G or the lateral G changes abruptly. Therefore, the gradient A of the tension change until reaching the first target tension T1 is linear. It becomes sudden and the tension rises quickly. In such a case, it is expected that the front-rear G or the lateral G will further increase rapidly thereafter. On the other hand, the occupant's body can be restrained before the occupant's body moves.
[0064]
On the other hand, when the front-rear G or the lateral G gradually changes, the subsequent change of the front-back G or the lateral G is expected to be moderate. In such a case, the belt tension is gradually changed by setting the gradient A of the tension change to be gentle. This prevents the occupant from being aware of unnecessary restraint.
[0065]
  Thus, the secondReference exampleAccording to the above, since the tension change characteristic to reach a low target value is controlled, the rise of the tension of the seat belt 3 can be promptly controlled by controlling the tension to rise quickly at the initial stage of winding of the seat belt 3. Can be achieved. Also, the tension change characteristics that lead to low target values are linearized.TheTherefore, the rise of tension can be made quick.
[0066]
  FIG. 17 shows a third embodiment of the present invention.Reference exampleIndicates. thisReference exampleHowever, 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]
  thisReference exampleThen, the characteristic of the tension until the second target tension T2 is reached from the first target tension T1 is changed. In FIG. 17, an example of front and rear G is shown, but the same setting is made for 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 Gx2 or Gy2. That is, the tension change characteristic (slope 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 and vary depending on 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. Then, as Gx2 and Gy2 are larger, the gradient C of the tension change is abrupt.
[0070]
The reason for reducing Gx2 and Gy2 when the vehicle speed is low is that the vehicle stops before the front and rear G or side G is sufficiently generated, or that the distance from the vehicle surroundings is small enough to make it sufficiently before the collision. This is because the front and rear G or the lateral G does not occur. In addition, when the vehicle speed is low, the energy at the time of collision is low, so the tension change is more gradual than when the vehicle speed is high. Therefore, Gx2 and Gy2 are set low at a low speed, 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 surroundings of the vehicle becomes long. Therefore, 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 higher than those at the low speed. Set. However, since the collision energy is large when a collision occurs, it is desirable to increase the tension as quickly as possible, and the slope of the tension change is abrupt.
[0072]
  From the above, the third described aboveReference exampleAccording to the present invention, it is possible to increase both the tension without causing a sense of incongruity to the occupant in a scene where a sudden increase in tension is not necessary, and to quickly increase the tension in a scene where a rapid increase in tension is necessary. it can. Further, as the belt tension target value (high target value T2) increases, the belt tension rises 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 seat belt 3 is further wound from the state where the tension has risen and reached a low target value, the tension change of the seat belt 3 can be made continuous, so that the occupant senses the tension change. It is difficult to do so, and the uncomfortable feeling can be reduced.
[0073]
  Also thisreferenceAccording to the example, the higher the target value, the more quickly the tension of the seat belt increases. It is possible to make it possible to increase tension without giving a sense of incongruity to an occupant in an unnecessary scene.
[0074]
  FIG. 19 shows a fourth embodiment of the present invention.Reference exampleIndicates. 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]
  thisReference exampleThe gradient D of the tension change from the first target tension T1 to the second target tension T2 is changed according to the difference between the first target tension T1 and the second target tension T2. .
[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. In accordance with this difference, the tension change characteristic (slope D) from the first target value T1 to the second target value T2 is changed.
[0077]
For example, each of the first and second target tensions T1 and T2 is set to a higher value when the rise of the deceleration due to the driver's braking operation is steep, and lower when the rise of the deceleration is gentle. The value of
[0078]
By the way, in a general driving situation, as shown in FIG. 20, the occupant started a braking operation in an attempt to apply a sudden braking when the vehicle travels, but in fact, a scene in which such a sudden braking was not necessary, On the contrary, as shown in FIG. 21, a normal braking operation is performed at the start of braking, but there is a scene where sudden braking is required.
[0079]
In the former case, the first target tension T1 is high, but the second target tension T1 is low. In the latter case, the first target tension T1 is low, but the second target tension T2 is low. Will be higher. Therefore, the former T2-T1 <the latter T2-T1.
[0080]
In addition, when sudden braking is started and braking is continued as it is, the first target tension T1 is increased and the second target tension T1 is also increased, and gentle braking is started and the brake is gradually stepped on as it is. In this case, the first target tension T1 is lower and the second target tension T2 is lower.
[0081]
Thus, since the first target tension T1 and the second target tension T2 change depending on the state of the braking operation, the tension change characteristics from the first target tension T1 to the second target tension T2 are always the same. If this is the case, the increase in tension will be delayed, or the change in tension will be abrupt and the passenger will be unnecessarily aware of the change in tension.
[0082]
However, depending on the difference between the first target tension T1 and the second target tension T2, when this difference is large, the gradient D of the tension change is increased so that the target tension can be reached quickly. When it is small, the inclination D of the tension change is made small so that the occupant is not aware of the tension change.
[0083]
  ThisNoThe fourthReference exampleAccording to the above, since the tension change characteristic is changed according to the difference between the low target value T1 and the high target value T2, the target tension is quickly reached when the difference is large, and conversely when the difference is small. By gradually reaching the target tension, it is possible to prevent the occupant from being aware of the change in tension.
[0084]
  22, 23 and 24 show the fifth aspect of the present invention.Reference exampleIndicates. thisReference exampleHowever, 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]
  thisReference exampleThe target tension is set in three stages, and the flowchart at this time is as shown in FIG. The flowchart of FIG.Reference example14 is compared with the third threshold values Gx3 and Gy3 (step 2201), and a portion for setting the third target tension T3 is added to the flowchart of FIG. It is.
[0086]
The longitudinal G is smaller than Gx3, that is, the braking acceleration (deceleration) at the time of 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 it is larger than (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 energization time are calculated (step 2205). When the current value and the energization time are calculated, the motor 15 is energized so as to wind up the seat belt 3 (step 2207). When the longitudinal G is Gx3 or more and the absolute value of the lateral G is Gy3 or less, the process proceeds to Step 1429 where it is determined whether the seat belt 3 winding release condition is satisfied.
[0087]
Here, as shown in FIG. 23, the tension change characteristic until the second target tension T2 is reached from the first target tension T1, and the tension change until the third target tension T3 is reached from the second target tension T2. The characteristics are changed. 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. The tension change characteristic at that time is indicated by an arrow G in FIG. Overall, it increases exponentially. This is the same for the horizontal G.
[0089]
As a result, while the target tension is low, the change in tension becomes gradual, and when the target tension becomes high, the tension quickly increases. This means that in the event of an emergency where the deceleration and lateral G increase, the tension rises quickly, and then the occupant can be reliably restrained in the event of a collision. This makes it possible to prevent the occupant from feeling the unnaturalness of the tension change, and when the target tension changes from a low target tension to a high target tension, the tension change is smooth and the uncomfortable feeling is surely reduced. Can do.
[0090]
  thisReference exampleThe tension change of the seat belt 3 can be made continuous when the seat belt 3 is further wound from the state where the tension has risen and reached a low target value. It becomes difficult to perceive, and the uncomfortable feeling can be reduced. Also, as the higher target value increases, the tension of the seat belt 3 increases more quickly, so that it is not necessary to increase the tension quickly and to rapidly increase the tension in a scene where a rapid increase in tension is required. It is possible to make it possible to increase the tension without causing the passenger to feel uncomfortable in the scene.
[0091]
  FIG. 25 shows a sixth embodiment of the present invention.Reference exampleIndicates. thisReference exampleHowever, 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]
  This sixthReference exampleThen, the fifth mentioned aboveReference exampleSimilarly, the target tension is set in three stages including the first target tension T1, the second target tension T2, and the third target tension T3.
[0093]
  Here, the change in tension until the lowest first target tension T1 is reached is the fifth change shown in FIG.Reference exampleSimilar to the linear and steep characteristics. On the other hand, the tension change from the first target tension T1 to the second target tension T2 is a combination of the straight line H1 and the exponential curves I1 and I2, and from the second target tension T2. The tension change until reaching the third target tension T3 is a characteristic in which the straight line H2 and exponential curves I3 and I4 are combined.
[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 it is possible to restrain the occupant's body before doing this.
[0095]
On the other hand, it is considered that when the tension becomes higher, the occupant feels the restraining force strongly and the risk of collision becomes higher. For this reason, since it is necessary to raise the tension more quickly, the change in tension becomes abrupt, and the occupant is more likely to feel the restraining force. Therefore, in such a situation, the initial change characteristic of the tension change is made exponential (I1, I3), and then the tension change is increased linearly (H1, H2). Also, immediately before reaching the target tensions T2 and T3, the change characteristics of the tension are made negative exponential (I2, I4) again, thereby making it difficult to sense the change point of the tension change.
[0096]
  Thus, the sixthReference exampleAccording to the above, since the tension change characteristic reaching the target value T2 or T3 having a high belt tension is made to be a geometric series, the tension change becomes continuous, which makes it difficult for the occupant to detect the tension change. , Can surely reduce the sense of incongruity.
[0097]
  26, 27, and 28 show the present invention.1The embodiment of is shown. In this embodimentThe configuration of the seat belt device and the configuration of the control system are shown in FIGS.The
[0098]
  This first1In this embodiment, as shown in FIG. 26, the belt tension starts from time t1.FirstThe tension change characteristic when the target tension is changed to coincide with the third target tension T3 in the middle of changing from the target tension T1 of 1 to coincide with the second target tension T2 (time t2). It corresponds.
[0099]
In such a case, as shown in FIG. 27, the change characteristic (inclination Ka) until the second target value T2 is reached from the first target value T1 and the change until the third target tension T3 is reached. An inclination Kc of an intermediate tension change between the characteristic (inclination Kb) is provided in the middle. The flowchart at this time is as shown in FIG.
[0100]
  This flowchart shows the fifth embodiment shown in FIGS.Reference exampleIs substantially the same as the above, except that when the energization time does not elapse in step 1417, only the portion after the operation of comparing the front and rear G and the lateral G with the threshold values Gx3 and Gy3 is added.
[0101]
  Therefore, this difference will be mainly described. When the second target tension T2 is controlled and the energization time to the motor 15 has not elapsed in step 1417, the absolute values of the front and rear G and the lateral G are respectively set to threshold values Gx3 and Gx.y3(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. Change to time t2.
[0102]
At this time, the tension of the seat belt has not yet reached the second target tension T2, and the occupant may not be able to feel a sufficient sense of restraint unless the tension is increased as quickly as possible. On the other hand, immediately after the start of energization in the control for reaching the second target tension T2, the belt tension changes abruptly when the target tension is immediately changed to the third target tension T3. This makes the passengers strongly aware of changes in tension.
[0103]
Therefore, in order to increase the tension as quickly as possible and to suppress the change in the belt tension, the tension in which the inclination of the tension change is set so as to reach the second target tension T2 from the first target value T1. The change slope Ka and the slope Kc intermediate (average value) between the change change slope Kb set to reach the third target tension T3 from the time of change (time t2). With this inclination Kc, the tension change was set 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 to be supplied to the motor 15 and the current supply time are calculated (step 2805), and the motor 15 is energized to wind up the seat belt 3. (Step 2807).
[0105]
  Thus, the above-mentioned number1According to the embodiment, while the belt tension is changing so as to coincide with the target tension T2, the tension change characteristic when the target tension is further changed to T3 is shown, and the intermediate tension change inclination Kc is shown on the way. To be provided. As a result, the belt tension can be quickly increased with respect to the change in the target tension, and a rapid change in the belt tension accompanying the change in the target tension can be suppressed, so that the passenger is not strongly aware of the change in the tension. In other words, when a belt tension with a higher target value than the high target value is required, the tension change becomes smooth, which makes it difficult for the occupant to sense the tension change and reduce the sense of incongruity.
[0106]
  FIG. 29 shows the first of the present invention.2The embodiment of is shown. 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]
  This first2This embodiment is the same as that shown in FIGS.1In the same way as in the above embodiment, the target tension is further changed while the belt tension is changing so as to coincide with the target tension. The tension change characteristic at this time is as shown in FIG.
[0108]
  That is, when the degree of urgency is low (third target tension T3a),1As in the first embodiment, the change characteristic (slope Ka) until the second target value T2 is reached from the first target value T1 and the change characteristic (slope Kb) until the third target tension T3 is reached. An intermediate tension change gradient Kc is provided in the middle. As a result, a rapid change in tension is suppressed so that the passenger is not strongly aware of the change in tension.
[0109]
On the other hand, when the degree of urgency is high (greater than or equal to a third target tension T3b that is a predetermined value), the above-described intermediate tension change gradient Kc is not provided, and from the point in time when the change becomes necessary (time t2) The tension change characteristic (inclination Kb) with respect to a higher target value (third target tension T3b) is set so as to increase the tension more quickly.
[0110]
  The flowchart1In the embodiment, the urgency level of the vehicle is determined in the tension change characteristic calculation (step 2803). As the vehicle urgency level, for example, when the front and rear G, the lateral G are high or suddenly rise, or the vehicle can be calculated from the inter-vehicle distance and the relative vehicle speed by the inter-vehicle distance sensor using radar, ultrasonic waves, etc. Can be used as the urgency level of the vehicle. If the time to collision is used as the degree of urgency, the gradient of the tension change characteristic can be obtained as shown in FIGS. 30 (a) and 30 (b), for example.
[0111]
That is, the intermediate inclination Kc is expressed by Kc = Ka + (Kb−Ka) × K. As shown in FIG. 30B, K is a coefficient that decreases with the passage of time until the collision.
[0112]
  No. mentioned above2According to the embodiment, when the higher target value T3 is lower than the predetermined value T3b, the tension change becomes smooth and the occupant is less likely to detect the tension change, while the higher target value T3 is equal to or higher than the predetermined value T3b. Sometimes, the change in tension is steep, and the occupant can be restrained quickly.
[0113]
  Each of the above embodiments andReference exampleIn the above example, the control at the time of braking is performed based on the value from the longitudinal acceleration sensor 97 and the control at the time of turning is performed based on the value from the left / right acceleration sensor 99. However, the present invention is not limited to this.
[0114]
As an alternative to the longitudinal acceleration sensor 97, a value corresponding to the longitudinal G at the time of deceleration may be detected. For example, a brake pedal stroke, a brake hydraulic pressure, or the like can be used. As an alternative to the left / right acceleration sensor 99, it is only necessary to be able to detect the turning state. For example, a yaw rate sensor, a steering angle sensor, a left / right wheel speed difference, or the like can be used.
[0115]
  Further, each of the above embodiments andReference exampleShows an example in which control at the time of braking and control at the time of turning are performed simultaneously, but the present invention can also be applied to a system that performs control only during braking or a system that performs control only during turning.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view showing a vehicle seat belt 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.
3 is an exploded perspective view showing a locking mechanism of the seat belt device of FIG. 1. FIG.
4 is an exploded perspective view showing a lock operating mechanism of the seat belt device of FIG. 1. FIG.
FIG. 5 is a configuration diagram of the assembled state from the right side of FIG. 4;
6A and 6B are operation explanatory views showing an acceleration detection mechanism of the seat belt device of FIG. 1, wherein FIG. 6A is a normal time, and FIG. 6B is an acceleration / deceleration / turning.
7A is a front view showing a configuration of a rotational force transmission mechanism portion 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 the arm mounting portion shown in FIG. 7;
9 is an explanatory view showing a belt winding operation by driving the motor of FIG. 7;
10 is an explanatory diagram showing a belt tension releasing operation by driving the motor of FIG. 7;
FIGS. 11A and 11B are explanatory diagrams showing the operation during belt winding and rewinding, where FIG. 11A shows a state in which a frictional force is acting between the ring gear and the lock key, and FIG. 11B shows a decrease in the frictional force. Shows the state.
12A and 12B show a belt tension holding mechanism of the seat belt apparatus of FIG. 1, in which FIG. 12A is a front view showing the overall configuration, and FIG. 12B is a sectional view of a solenoid in FIG.
13 is a block diagram of a control system of the seat belt apparatus of FIG. 1. FIG.
FIG. 14 is a flowchart of a program according to the first embodiment.
FIG. 15 shows the firstReference exampleIt is a tension change characteristic figure until it reaches target tension from the time of exceeding the threshold value of the longitudinal acceleration concerning.
FIG. 16 shows the secondReference exampleIt is a tension change characteristic figure until it reaches target tension from the time of exceeding the threshold value of the longitudinal acceleration concerning.
FIG. 17 shows the thirdReference exampleIt is a tension change characteristic figure until it reaches target tension from the time of exceeding the threshold value of the longitudinal acceleration concerning.
FIG. 18 shows the thirdReference exampleIt is a change characteristic figure of the threshold value by the vehicle speed concerning.
FIG. 19 shows the fourthReference exampleIt is a tension change characteristic figure until it reaches target tension from the time of exceeding the threshold value of the longitudinal acceleration concerning.
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 shows the fifthReference exampleIt is a flowchart of the program concerning.
FIG. 23 shows the fifthReference exampleIt is a tension change characteristic figure until it reaches target tension from the time of exceeding the threshold value of the longitudinal acceleration concerning.
FIG. 24 shows the fifthReference exampleIt is explanatory drawing which shows the tension change characteristic in.
FIG. 25 shows the sixthReference exampleIt is explanatory drawing which shows the tension change characteristic in.
FIG. 261It is a tension change characteristic view from the time of exceeding the threshold value of the longitudinal acceleration according to the embodiment until reaching the target tension.
FIG. 271It is explanatory drawing which shows the tension | tensile_strength change characteristic in embodiment of this.
FIG. 281It is a flowchart of the program concerning the embodiment.
FIG. 292It is explanatory drawing which shows the tension | tensile_strength change characteristic in embodiment of this.
FIG. 30 (a) is the first2(B) is a correlation diagram between the time until the collision and the coefficient K used in the equation for obtaining the tension change characteristic.
[Explanation of symbols]
  3 Seat belt
  5 reels
  15 motor
  97 Longitudinal acceleration sensor (acceleration detection means)
  99 Left / right acceleration sensor (acceleration detection 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)
  T3 Third target value (a higher target value than a higher target value)

Claims (11)

Two or more target values are set for the tension of the seat belt, and when the vehicle is running, a low target value is always used, while a high target value is used in an emergency to control the tension; Target value change detecting means for detecting that the target value has been changed from a low value to a high value, respectively, and the tension control means, when the target value change detecting means detects a change in the target value , the tension of the change characteristics of the seat belt from the lower target value to a higher target value, the more gradual than the change characteristic of the tension of the seat belt when increasing the tension to the lower target value, the tension of the seat belt In the process of changing from the low target value to the high target value, when it is necessary to change the target value to be higher than the high target value, the change characteristic to the high target value is increased from the low target value to the high target value. Eye Between the change characteristic to the value and the change characteristic from the point when the change is necessary to the higher target value, which is steeper than the change characteristic from the low target value to the high target value. The vehicle seat belt device is characterized in that after the tension of the seat belt reaches the high target value due to the intermediate change characteristic, the change characteristic is steeper than the intermediate change characteristic .   2. The vehicle seat belt device according to claim 1, wherein the tension control means controls a change characteristic of the tension of the seat belt when the tension is increased to the low target value.   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 from the low target value to the high target value.   4. The vehicle seat belt device according to claim 3, wherein the tension control means makes the change characteristic of the tension of the seatbelt when the high target value is reached steeper as the high target value is larger.   3. The vehicle seat belt apparatus according to claim 2, wherein the tension control means linearizes a change characteristic of the tension of the seat belt to the low target value.   The tension control means changes a change characteristic of a seat belt tension from the low target value to a high target value according to a difference between the low target value and the high target value. The vehicle seat belt device according to claim 3.   4. The vehicle seat belt device according to claim 3, wherein the tension control means geometrically controls a change characteristic of a seat belt tension from the low target value to the high target value. When the higher target value is equal to or greater than a predetermined value, the tension control means does not set the intermediate change characteristic, and sets the tension as the change characteristic from the time when the change is necessary to the higher target value. The vehicle seat belt device according to any one of claims 1 to 7, wherein the vehicle seat belt device is controlled. A reel for winding the seat belt, the reel is rotated respectively and a motor for adjusting the tension of the seat belt, of claims 1 to 8, characterized in that for controlling the motor is the tension control means vehicle seat belt apparatus according to any one. The vehicle seat belt device according to claim 9 , wherein the tension control unit holds the tension by causing a weak current to flow through the motor. Acceleration detecting means for detecting an acceleration of the vehicle is provided, the tension control means of claims 1 to 10, characterized in that to set the tension of the seat belt in accordance with the acceleration of the vehicle which the acceleration detecting means detects vehicle seat belt apparatus according to any one.

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