JPS5977943A - Seatbelt retractor - Google Patents

Abstract

PURPOSE:To eliminate hunching in the belt retraction drive due to the belt tension by changing the control target of the belt retraction to the withdrawal side after the belt is stopped. CONSTITUTION:A belt wearing sensor device 50, a vehicle speed sensor device 51 and a displacement sensor device consisting of a rachet wheel 14 carried on a retraction shaft 12 and a photocoupler 23 are connected to the CPU24 of a micro computer. When the belt is withdrawn, the CPU counts the number of teeth of the rachet wheel, and retacts it by driving a motor 18 until the number is surpassed. By changing the control target to the withdrawal side after the belt is stopped, there is a belt tension at the time of the belt retraction and the motor 18 is not driven again even if the belt is withdrawn, eliminating hunching.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a seatbelt retractor that uses a motor to unwind and unwind a seatbelt.

Recently, a seatbelt retractor has been proposed that uses a motor to wind up the seatbelt to eliminate the feeling of being restrained by the belt when the seatbelt is worn. Figure 1.2 shows a seatbelt retractor already proposed by the applicant (Japanese Patent Application No. 57-27597). In the figure, reference numeral 11 denotes a housing formed in a substantially U-shape, and reference numeral 12 denotes a winding shaft rotatably supported by side plates 11a and llb of the housing, and to which one end of the belt 1 is fixed.

A known emergency lock mechanism 13 is provided at one end of the winding shaft 12 to prevent rotation of the winding shaft 12 in the pull-out direction in an emergency.

Further, a rotation angle detection ratchet wheel 1 is provided at the other end protrusion of the winding shaft 12.
4 is fixed, further sandwiching the friction transmission spring 15,
A worm wheel 16 is loosely fitted in a rotatable manner. A snap ring 17 is engaged with the end of the winding shaft 12 to prevent the worm wheel 16 from being removed.

A motor 18 is fixed to the upper part of the housing 11, and a rotating shaft 18a of the motor 18 protrudes rearward from the side plate 11a, to which a worm 19 is fixed. This warm 19
The end portion of the shaft 20 is provided with the winding, which is meshed with a worm wheel 21 fixed to a shaft 20 which is disposed perpendicularly to the worm 19 on the side plate 11a and is rotatably supported. The worm 22 meshed with the worm wheel 16 loosely fitted onto the shaft 12 is completely fixed.

Therefore, when the motor 18 is rotated, the rotation is caused by the worm 19. Worm wheel 21. A worm 22 is formed which is decelerated via the worm 22 and meshed with the worm wheel 16.

Therefore, when the motor 18 is rotated, the rotation is caused by the worm 19. Worm wheel 21. Warm 22
It is decelerated and transmitted to the worm wheel 16 via the worm wheel 16. The rotation of the worm wheel 16 is controlled by the friction transmission spring 1.
5 is transmitted to the winding shaft 12 via the windmill 14.

23 is a pulse signal generator fixed to the side plate 11a of the housing 11, and the detector 23 of this signal generator 23
A is brought into contact with the tooth tip of the rotation angle detection ratchet 14, and a pulse is generated when the windmill 14 is rotated and the detector 23a is swung.

In the seatbelt retractor body having the above configuration, the motor 18 is controlled using a predetermined electronic circuit, and when the seatbelt that is pulled out of the retractor body when the seatbelt is not worn is to be completely retracted, the motor 18 rotates when the seatbelt is pulled out. The number of rotation teeth of the rotation angle detection ratchet 14 is determined by the signal generator 2.
By counting the number of retractor teeth and winding up the seat belt until it exceeds the number of rotating teeth at the time of pulling out, it is possible to prevent the seat belt from remaining outside the retractor body.

In addition, if you want to give the seat belt the optimum amount of slack after it has been fitted, tighten the belt by winding it up until the extra belt is pulled out tightly against the passenger, without undoing it. The condition is that the winding is stopped, and then the motor j8 is operated once in order to provide a predetermined amount of slack, and the drawing is performed.

However, with this seat belt retractor,
When winding up all the seat belts, see Figure 3 (
As shown in b), when the buckle switch is OFF, the motor is turned on and the seat belt is wound up, but as mentioned above, in order to complete the front winding, it is wound up with a groove that exceeds the number of rotating teeth when pulled out. In order to do this, seat belt tension near the tank that is sewn to the end of the seat belt and is not stored in the retractor body, and this tension causes the drawer to open after the motor is turned off. The motor is re-driven (c) by counting the number of rotational teeth of the rotating rotation angle detection ratchet, and this tension causes the pull-out and re-driving (c) to be repeated. Therefore, there is a problem that the seat belt and motor are subject to excessive hunting. This problem is similar to the above-mentioned case where the belt is loosened after being attached, and the same phenomenon occurs due to the tension generated by tightening the belt.

The present invention has been made in order to solve the above-mentioned problems of a seatbelt retractor that uses a motor and a control circuit that controls the motor to retract a seatbelt. The purpose of this is to prevent hunting between the seat belt and the motor due to the above-mentioned phenomenon by causing the belt to be drawn out after the belt winding is stopped.

In other words, the configuration of the present invention includes a winding shaft fixed to the end of the seat belt, a motor that rotates the winding shaft in the winding direction or the pulling direction, and a motor that rotates the winding shaft according to the rotation angle of the winding spool. A seatbelt retractor having a signal generator that generates a signal, and a belt control device that rotates the motor in forward and reverse directions based on the output from the signal generator and controls the stop position of the seatbelt to a target position. The present invention is characterized in that it is provided with means for changing the control target position of the belt control device at the time of belt removal to the belt drawer side after the belt has stopped. Describe.

Note that the same components and members as those in the conventional example are given the same reference numerals and redundant explanations will be omitted, and only the different parts and members will be explained.

FIG. 4 shows an embodiment using a microcomputer such as a belt control device.

In the figure, 24 is CP' (J) of the microcomputer, which has an output port and an input port, and is connected to a ROM 25 that stores programs and constant data, and a RAM 26 that temporarily stores input signals, calculation results, etc. 27
is a transistor bridge circuit for controlling the front d-pi motor 18 in the forward and reverse directions, and is controlled so that by reversing the motor 18, the belt is wound up, and by rotating the motor 18 in the forward direction, giving appropriate slack. 28 is an input port for inputting a signal from a vehicle speed pulse generator 51 for setting a value for giving appropriate slack to the belt; 29 is a tank sewn to the belt pull-out end and engaged with a buckle; case (seat belt wearing state) is SS Q
Ntt.

The state of non-engagement pε (seatbelt not worn) is 'O'
Attachment detection device 51 that generates a switch signal that is FF//
1), 31 and 32 are input ports to which signals from the displacement detection device 123 for detecting the displacement of the seat belt are respectively input.

As shown in the 5121st detailed diagram, the displacement detection device 123 receives pulse signals Sl,
It has the function of counting S2 in the microcomputer, detecting the rotation direction and rotation angle of the retractor, and detecting the relative position of the seat belt.

Next, the microcomputer CP [J2
The operation of step 4 will be explained according to the flowcharts shown in FIGS. 6(a) and 6(b).

First, the buckle SWJ is inputted from the input boat 29 with the tangino sewn to the tip of the seatbelt sewn to the tip as ON when it is engaged with the buckle, and OFF when it is not engaged. When ON -2
(4) Proceed to "Normal Control". This q) "Normal control"
After wearing the belt, pull out the excess belt and tighten it tightly to the body with N winding, and stop the belt tightening at IJ with IH, and tighten the belt to a specified length! The contents include belt slack adjustment immediately after seating, which consists of adding belt slack to l+b-a, and belt slack adjustment during driving, which adds one belt slack depending on the medium speed during subsequent driving. After performing this process (4), proceed to C5) "Lo 4-L J. Also, if (1) [buckle SWJ is OFF, ('2') "O
N→OFF? Proceed to J.

This (2,) "ON - + 0FF2" will change from ON to O even if the tank is in the OFF state where it is not engaged with the buckle.
This is a check to determine whether it is OFF, which has changed to FF and requires winding, or OFF, where the belt has been pulled out from the retractor and the belt is still being attached and there is no need to wind it. , If this is yes and changes from ON to OFF, that is, if it is OFF that requires winding, ■ "F1←I
Proceed to step J and open the winding immediately after disassociating the notebook belt.
i, set the winding determination flag F1 and proceed to step φ), and if it is ON, that is, the belt is being operated and has been OFF before and there is no need to perform winding, the flag F1 is set directly to step (5). ).

(j) In "LO←L", L is the belt position measured last time in the next (6) "Pulse count", that is, 1m if this routine is performed at 1m5ec4n.
<r< is the value detected in the previous process of (fj),
This lr4 is stored as the belt position L○ of the 11th turn. Step (6) is to detect the position of the belt as described above. and the displacement detection device 12 shown in FIG.
3-7 Using the signals S1 and S2 from the automatic coupler, the pulses are counted and the belt position is detected. For example, when the belt is being wound, the belt position is Lm-T, -1. . Next (7) rT+←T, +11
In this example, T1 is a timer for determining whether the belt has stopped, and in this embodiment, the time for determining is 1 second, and each time this routine is repeated, it counts up as +1. ? J to grind e y (8
) “In L −LOJ, as mentioned above, L is t
The current position of the belt detected in the process of 6), LO is the previous position (Imm) of the belt in front of the enemy stored in the process of (6), and by comparing these two values, it is determined whether the belt has moved or not. If the belt is stopped, press L.
Since the force = Lo, the value of L - Lo is ant O〃
and check q()), and if it is moving, L
% Lo from all things L -Lo ketao lol 〃
Then, (9) r T+←0-1, the stop determination timer T1 is cleared and the process directly proceeds to step shouting. On the other hand, L
αQrT+ when −L○ is St: Q I/
≧1 second", if the stop determination timer T1 is 1 second or more, the result is Yes and the process proceeds to step 4p; before 1 second has elapsed, the result is No and the process proceeds to check qri1. Therefore, L = Lo and the belt stops)1
When you are in a state and the state continues for more than 1 second (jp "M
We will proceed to 4-LJ. And αν “M 4− T
In front of the current position of the belt as mentioned above in J.
, M is the (new) control target position, where the current position of the belt is gT and the control target position M, and Q4
rF1=1? At J, the winding determination flag F1 is checked, and if Fl=1, the winding is determined to have been completed, and the process advances to step q and step, or to check if F1-0. Step (1
3' 4ψ process is a process to ignore the displacement due to tension after the belt stops, and T2 is a timer that measures the time after the winding stops, and as shown in check knowledge 1, the main In the example, it takes 0.5 seconds, q sword "
Clear this timer T2 with T2←0-J and then q+r
Ft←0", clear all the winding discrimination flags F,
05) Go to "12505 seconds". The routine from check q to processing q is to change the target position of the belt control device to the belt pulling out position after the belt has stopped. This is a timer that measures the time after the stop, and in this example, it is set to ( ) 5 seconds, and since the belt can be pulled out by tension during this 0.5 seconds, the timer is set to 5 seconds. However, in order to prevent this from being determined as a withdrawal, if T2≦0.5 seconds is Yes, that is, before 0.5 seconds have passed, the 1250
If 5 seconds is NO, that is, after 05 seconds have elapsed, the process proceeds to the section check. e "L-M≦3 rm J is for a drawer that is within the amount of door pullout, this is a drawer due to the tension applied to the seat belt, and this is to prevent the drawer due to such tension from being distinguished as an unauthorized drawer. In the process, in this embodiment, this negligible withdrawal amount is reduced to 3on<2
~4(1) is preferable. ). Specifically, from the belt's current position T-, to the main position IF (M is van
However, if LM≦3crn is Yes, that is, the drawer is 3 m or less, the drawer iQ-, which can be ignored, is within 3 cm, so the current position including this ignored 15f drawer meter is set as the target position M. qsrM4-L
Do it with J. In other words, @ “M 47 LJ’s place full!
id, the withdrawal is within 05 seconds after the belt stops ((
This process is performed when the following two conditions are satisfied: 1rl rp2≦o, 5) is within 3rm (Q+>1L -M≦3 secondary), and after the belt stops 0
The current f1′ when the withdrawal amount within 3nn has been added within 5 seconds
11 west ゛L is set as the 11th position IV, and therefore, the belt system fii () Sooka's jljll (All target positions are changed to the drawer side after the belt stops by the drawer amount within 3 (7) above. This is what happens.

The next step Q12rF'l=1? is a routine for driving motor J8. At J, check the winding determination flag F1, and if F1 = 1, proceed to Qu 1 winding unconditionally and wind the belt.
[M-L? J Go forward. This ■lrM-L? J is a position control process to make the difference between the current position and the target control position M Sj Q //, that is, a check to control the seat belt stop position to the control 1-] target position, The control target position M is compared with the current position, and M - L
= In the case of Q, that is, when the current position matches the control eye position fat, there is no need to displace the seat belt.

M-L (If Q, the seat belt is pulled out more than the control target position, so proceed to "winding", and if M-L>00, it is too much to wind up. ``Drawer JK'' progresses, and when L=M due to winding or drawing, respectively, the process proceeds to ``Motor OFF''J as described above, and the notebook belt will stop at the control target position. .

Then, depending on each of the conditions mentioned above, @ "winding", ♀
ν "Motor 0FFj, [Stock]""J' of drawer J"
The process advances to MP 5TARTJ and the above routine is repeated, but these processes may be performed by regular interrupt processing.

In this embodiment, the determination when changing the control position of the belt control device to the belt draw-out side after the belt has stopped is made by checking the time of ``T2≦0.5 seconds'' and checking the time of 0-1ν. Although both length checks are carried out under ``L-M≦3(7)'', it is possible to sufficiently obtain the desired effect by checking either time or length.
Also, in this embodiment, the buckle SW changes from ON to OFF.
The explanation was given only in the case of seatbelt rewinding after release, but in other cases, for example, buckle SW
, the same effect is achieved when the seat belt is tightened in the seatbelt wearing state in the case of OFF→ON.

Next, qle'"M4-M10a" shown in parentheses in the figure shows another embodiment of the present invention, which replaces the routine of step battle .about.O in the previous embodiment. That is, in qp/, M is the control target position, and in the above embodiment, the current position is set as the control eye position #M at (lp l''-11,4←L), and later step aid 1.[
However, in this embodiment, the amount α of withdrawal due to tension is set in advance, and the control target position is changed again in the process of O. By processing Q' instead of Q', you can actively draw 4! without waiting for the actual withdrawal due to tension. At the processing stage of J', the control target position is changed by α to the drawer side. Therefore, according to this embodiment, it is possible to omit the processing of steps .

As explained above, the present invention provides a winding shaft in which a loop portion of a seat belt is identified, a motor that rotates this winding shaft in the winding direction or an unwinding direction, and a signal corresponding to the rotation angle of the winding shaft. and a belt control device that controls the seat belt to a stop position 1θ before the target position by rotating the motor in forward and reverse directions based on the output from the signal generator. Since we have provided means for changing the control target position of the belt control device when retracting the seatbelt to the belt drawer side after the belt has stopped, first, when retracting the entire seatbelt when the belt is not worn, it is necessary to When the seatbelt is sewn to the end of the seatbelt and is not stored in the retractor body, tension is generated in the seatbelt near the tank, and this tension causes the seatbelt to be pulled out after the seatbelt retraction is completed.
In this case, the pulled out position is changed to the control target position, in other words, the pulled out position due to the tension of the seat belt becomes the control target position.
The belt control device does not require the motor to take up the portion of the drawer that is pulled out due to tension, and therefore can prevent winding and hunting due to the 7F reeling of the drawer due to tension. In addition, hunting can be prevented not only when the belt is not worn, but also when the belt is tightened to create slack when the belt is worn, and also against the same phenomenon caused by the tension that occurs when the belt is brought into close contact with the passenger's body. It is something that can be effective.

[Brief explanation of the drawing]

Fig. 1 is a front view showing an example of a conventional seatbelt (IJ) tractor, Fig. 2 is a side view of the same, Fig. 3 is an explanatory diagram showing a hunting state, and Fig. 4 is an illustration of an example of a conventional seatbelt tractor using the microcomputer of the present invention. FIG. 5 is a schematic configuration diagram of an embodiment, FIG. 5 is a detailed configuration diagram of the displacement detection device, and FIGS. 6(a) and 6(b) are flowcharts of the control program. ■...Seat belt, 11...e/X Uzing, 12
... Winding shaft, 14 - Working/rotation angle detection ratchet wheel, 18.
...Motor, 123...Displacement detection device, 24...Microcomputer, 25...ROM, 26...
RAM, 27 fists...transistor bridge circuit O Figure 1 Figure 3 Procedural amendment export) 1. Display of the case 1989 Patent Application No. 189910 2 Name of the invention Seat belt retractor 3 Person making the amendment Relationship to the case Applicant (899) Nissan Motor Co., Ltd. 4 Agent address: Akashi-cho, Chuo-ku, Tokyo 104 No. 1 No. 29 Detailed explanation of the invention in the Risekai Building Specification (11 Specification, page 6, line 5, ``...pre-loading...'' was replaced with ``...winding...'' (2) Page 15, line 13, rrTs≦05 seconds-J
"KrrTs≦0.5 seconds J" is corrected.

Claims (1)

[Claims] (1) A take-up shaft to which the end of the seat belt is fixed, a motor that rotates the take-up shaft in the winding direction or the pull-out direction, and a signal generator that generates a signal according to the rotation angle of the take-up shaft. and a belt control device that controls the stop position of the seat belt to a target position by rotating the motor in forward and reverse directions based on the output from the signal generator, the belt control device when retracting the seat belt. 1. A seatbelt retractor, characterized in that the seatbelt retractor is provided with means for changing the control target position to the belt withdrawal side after the belt is stopped.