JPH0370655B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a seat belt retractor using a motor, and particularly to one that prevents the generation of tension due to winding bias when pulling out the seat belt.

Conventionally, as a seatbelt retractor using a motor, there is one shown in FIGS. 1 and 2, for example (Japanese Utility Model Publication No. 54-3452).

This seatbelt retractor is applied to a passive seatbelt, and as shown in the figure, a seatbelt 101 is attached to a belt 111 supported by a door A.
and a belt 112 connected to the winding device 102. The winding device 102 is composed of an emergency lock device 123, a winding reel 121, and a winding force generating motor 122, and the winding generating motor 122 is connected to a battery 117 via a slack detection device 115. . Slack detection device 115
As shown in FIG. 2, there is a U-shaped actuation lever 152 that is biased upward in the figure, a cylinder body 151 having a spring that applies a biasing force to the actuation lever, and an actuation rod 153a by the actuation lever. It consists of a micro switch 153 that is displaced. According to such a seat belt retractor device,
When the occupant pulls out the seatbelt 101 when wearing the seatbelt, and the tension of the seatbelt 101 exceeds a predetermined value, the actuation lever 152 is displaced to the dotted line position, and the actuation rod 1 of the micro switch 153 is moved.
53a is separated and the micro switch 153 is opened. Therefore, the winding operation of the motor 122 is stopped, and the pulling force is reduced. When the seatbelt 101 is worn and the tension of the seatbelt 101 becomes less than a predetermined value, the microswitch 153 is closed and the motor 122 is energized, so that the seatbelt 101 is wound up and tightly attached to the occupant.

However, with such conventional seatbelt retractors, although the tension at the time of withdrawal is reduced, when the withdrawal is finished and the tongue is inserted into the buckle, the seatbelt retractor immediately starts retracting. However, it was difficult to insert the tongue into the buckle. Further, even if the tongue could be directly inserted into the buckle without stopping the drawer, it was still difficult to insert the tongue because the tension of the belt tension detection spring was applied to the belt.

The present invention has been made to solve this problem, and when normally wearing a seatbelt, that is, when inserting the tongue provided at the end of the seatbelt into the buckle provided on the side of the seat. Focusing on the fact that the belt is pulled out more than a predetermined amount, if the belt is pulled out more than a predetermined amount, it is determined that the belt will be attached next and the belt is prohibited from being retracted. The object of this invention is to solve the above-mentioned problem by preventing tension from being generated in the belt when the buckle is inserted.

That is, the configuration of the seat belt retractor of the present invention includes a seat belt drive device that retracts the seat belt, a withdrawal amount detection device that detects the amount of withdrawal of the seat belt, and a wearing detection device that detects whether the seat belt is being worn. Based on outputs from the attachment detection device and the withdrawal amount detection device, when the seatbelt is pulled out by a preset amount or more and the belt is not worn, retraction of the seatbelt driving device is prohibited for a predetermined period of time. The invention is characterized in that it is provided with a means for doing so, and will be described in detail below with reference to an embodiment shown in the drawings. In FIGS. 3 and 4, 11 is a housing formed in a substantially U-shape;
A winding shaft 2 is rotatably supported by side plates 11a and 11b of the housing, and to which one end of the belt 1 is fixed.

One end of this winding shaft 12 is provided with a winding shaft 1 in case of an emergency.
A known emergency locking mechanism 13 is provided to prevent rotation of the drawer 2 in the withdrawal direction.

A rotation angle detection ratchet wheel 14 is fixed to the protrusion at the other end of the take-up shaft 12, and a worm wheel 16 is loosely fitted around a friction transmission spring 15 so as to be freely rotatable. A snap spring 17 is engaged with the end of the winding shaft 12, and a worm wheel 16 is engaged with the end of the winding shaft 12.
It is prevented from coming off.

18 is a motor fixed to the upper part of the housing 11, and the rotation shaft 18a of this motor 18 is connected to the side plate 11a.
It protrudes further rearward, and a worm 19 is fixed thereto. This worm 19 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. Furthermore, a worm 22 is formed at the end of the shaft 20 and engages with a worm wheel 16 loosely fitted onto the winding shaft 12.

Therefore, when the motor 18 is rotated, its rotation is decelerated via the worm 19, the worm wheel 21, and the worm 22, and the rotation is reduced by the worm wheel 16.
transmitted to. The rotation of the worm wheel 16 is caused by the friction force between the worm wheel 16 and the friction transmission spring 15.
4 to the winding shaft 12.

23 is a displacement detection device using two photocouplers, and is fixed to the side plate 11a of the housing 11.

Next, FIG. 5 shows an embodiment using a microcomputer such as a belt drive device. In the figure, 24 is a CPU of a 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. Reference numeral 27 denotes a transistor bridge circuit for controlling the motor 18 in the forward and reverse directions, and is controlled so that the belt is wound up by reversing the motor 18, and to give an appropriate slack by rotating the motor 18 in the forward direction. Reference numeral 28 is an input port for inputting a signal from the vehicle speed pulse generator 51 for setting a value for giving an appropriate slack to the belt, and 29 is an input port for engaging a tongue sewn to the pulled-out end of the belt with a buckle. an input port to which a signal is input from the attachment detection device 50 that generates a switch signal in which the seatbelt is on (seatbelt fastened state) is "ON" and the non-engaged state (seatbelt not fastened state) is "OFF"; Reference numeral 31 denotes input ports into which signals from the displacement detection device 23 for detecting displacement of the seat belt are respectively input.

As shown in the detailed diagram of FIG. 6, the displacement detection device 23 inputs the pulse signals S ₁ and S ₂ from the two photocouplers to the CPU 24 of the microcomputer through the input ports 30 and 31.
By counting this at step 4 and detecting the rotational direction and rotation angle of the winding shaft 12, it is possible to detect the withdrawal of the seat belt, and it also functions as a withdrawal detection device.

Next, the CPU of the microcomputer incorporates a pull-out amount detection device, an attachment detection device, a means for prohibiting the seat belt retractor from retracting for a predetermined period of time, etc.
The operation of 24 will be explained with reference to the flowchart of the main routine shown in FIG. 7 and the flowchart of the scheduled interrupt routine shown in FIG.

First, the flowchart shown in Figure 7 is executed at the same time as the ignition switch is turned on, and the "buckle SW" is activated when the tongue sewn to the tip of the seatbelt is engaged with the buckle as described above. N for N, FF for not engaged
is input from the input port 29, and in the case of N, the process proceeds to "normal control". This "normal control" consists of "wrapping" which winds up the excess belt after it is worn and brings it into close contact with the body, "belt stop" which stops the belt tightening at a predetermined tightening position, and "belt stop" which stops the belt tightening at a predetermined tightening position. Belt slack adjustment immediately after sitting, consisting of "belt slackening" that loosens the belt;
The purpose of this is to adjust belt slack during driving by "applying belt slack" according to the vehicle speed during subsequent driving. When adjusting the belt slack during driving, as shown in Figure 9, the amount of slack is reduced as the speed increases, reducing the discomfort caused by the pressure of the belt on the body at low speeds, and reducing the amount of belt slack on the body at high speeds. The amount of slack in the belt is adjusted in order to make it fit more closely and protect the body from impact. Furthermore, since it is troublesome for the passengers to frequently adjust the amount of slack in response to minute changes in speed, the amount of slack is set in stages for each speed range. ing. Then go to "JAP START" from the check and select "JAP START".
This flowchart will be repeated from "START", but as long as the tongue remains engaged with the buckle, the process will proceed in the order of check→→.

On the other hand, if "Batsukuru SW" is FF, proceed to "N→FF". This “N→
FF" means FF in which the tongue is not engaged with the buckle.
Even if the belt is in the state of This is a check to determine whether the FF is being installed and requires prohibition of winding.If this is YES, that is, it changes from N to FF, the FF does not require prohibition of winding. If so, proceed to ``FW←1'', set the winding flag FW to start winding after the belt is released, and proceed to ``clear stop timer''. Also, in the case of N, that is, the FF has been previously FF and requires prohibition of winding, the process proceeds to "L-N≧30cm" and the necessity of prohibiting winding is checked again. In other words, in this "L-N≧30cm", the position before the belt is pulled out (target position) is L, the current pulled-out position is N, and when attaching the belt, the length must be at least a certain length (30cm in this example). Assuming that the drawers (above) will be drawn out, it is determined that it is necessary to prohibit winding if there is a drawer that exceeds the above-mentioned certain length, and the process proceeds to "Stop timer set" and If the length is less than a certain length and there is no need to prohibit winding, the process proceeds to "stop timer clear". Therefore, "stop timer clear" is a process to be performed when the belt is pulled out less than 30 cm and when the tongue is released from the buckle. Winding is permitted as Ts←O, and the belt is removed by the winding device. It will be wound up inside the retractor.

On the other hand, if the check determines that the buckle is FF from before, and the check determines that the belt is pulled out more than 30 cm, and the process proceeds to "Stop timer set," it is determined that the passenger is pulling out the belt to put on the belt. Ts is set to ¹⁰⁴ to prohibit winding of the belt for a predetermined period of time (10 seconds in this embodiment). The reason why Ts is set to 10 ⁴ here is that Ts is counted every 1 msec in the interrupt routine shown in Figure ⁸ , which will be described later. This is what I did. And “J.M.P.
"START" returns to "START" and repeats the above process.

Next, the scheduled interrupt routine will be explained with reference to FIG. In this routine, the processes . . . are routines for detecting the belt position, and the processes . . . are routines for controlling the motor drive of the belt winding device.

This periodic interrupt routine is performed as described above.
It interrupts every msec, and first, with "No←N", the belt position N 1 msec ago is
It is stored in the RAM 26 as No. This is for checking whether there is a drawer or not using "N-No?" which will be described later. Next, the "extraction pulse counter" counts the pulses from the signals _S1 and _S2 of the photocoupler of the displacement detection device 23 shown in FIG. The value of N is N+1, and when it is wound, the value of N is N-1, and furthermore, "Tw←Tw
+1", Tw is a timer to confirm that the belt is stopped, and this timer Tw
Count up as Tw+1 and proceed to check. "N-No?" compares the current position of the belt with the position No. 1 msec ago, and if it is not moving, N=No, so the value of N-No is "0"
and check, if it is moving, press N.
= No, it becomes "0" and the process proceeds.

In "Tw≧1 second?", Tw is a timer to confirm that the belt is stopped as described above, and in this embodiment, the time is set to 1 second, and if the same signal continues for 1 second or more, If there is no displacement of the belt for 1 second or more, the result is YES and the process proceeds; if there is any displacement within 1 second, the result is N and the process proceeds to check. Therefore N
If =No and this state continues for 1 second or more, the process will proceed to "L←N". Then, the position N of the belt that has moved forward at "L←N" and remains stationary for more than one second is set to a new target value L, specifically, a value to be compared when the next withdrawal is performed, and further At "Fw←O", the winding flag Fw, which is the winding command signal set at "Fw←1", is determined to be the end of winding and is cleared. On the other hand, if N-No becomes "≠0" in the check and progresses to "Tw←O",
Since it is already obvious that the belt is moving, there is no need to check whether the belt is stationary, and therefore the timer Tw is set to check whether the belt is stationary.
Clear and proceed to check.

As mentioned above, the routine from check to control the motor drive of the belt winding device is first, in "Fw=1?", the winding command flag Fw is checked, and if Fw=1, it is unconditional. The process proceeds directly to "belt winding" and belt winding is performed.

On the other hand, if "Fw=1?" is N,
Proceed to "Ts←Ts-1", count down the timer Ts set to 10 seconds, or ¹⁰⁴ , by "-1" in the "stop tire set", and further, if "Ts≦O", Ts is greater than or equal to O, In other words, if the belt winding prohibition time has not exceeded 10 seconds, proceed to "Motor FF", and then select "Motor FF".
motor FF to prohibit motor drive.
A signal is output from the CPU 24 to continue stopping the winding operation of the motor until 10 seconds have elapsed, so that during these 10 seconds, no tension is applied to the belt due to winding, and the belt can be easily installed. becomes. Particularly in the case of a seatbelt device that controls the position of the seatbelt, such as the seatbelt device of this embodiment, the buckle can be inserted with some slack in advance, which greatly improves operability.

On the other hand, if 10 seconds have passed since "Ts≦O" becomes Ts≦O, the process advances to "L=N?". This “L”
=N? ” is a check for controlling the belt position, L indicates the target position when controlling the belt as described above, and N indicates the current position, L=N? is YES, that is, if the target position and the current position are equal, there is no need to displace the belt, so proceed to "motor FF" and keep the belt stopped. Also L=N? is N, that is, if the target position and current position do not match, proceed to "belt winding" and wind the belt to match the current position with the target position.
Proceed to "O". At "Ts←O", Ts is set to O in preparation for setting the next stop timer, and the process returns to the main routine shown in FIG. 8 through this process and the above process.

As described above, the present invention provides a belt drive device that winds up a seal belt, a pullout amount detection device that detects the amount of pullout of the seatbelt, a wearing detection device that detects whether the seatbelt is being worn, and a belt driving device that winds up a seal belt. means for prohibiting the seat belt drive device from retracting for a predetermined period of time when the seat belt is pulled out by a predetermined amount or more and the belt is not worn, based on outputs from the device and the pull-out amount detection device; Firstly, when an occupant puts on a seatbelt, the passenger pulls out the seatbelt by more than a predetermined amount from the retractor, and before engaging the tongue sewn to the pulled-out end with the buckle. In this case, winding of the belt is prohibited for a predetermined period of time, and therefore no tension is generated on the belt. Therefore, by setting the predetermined time to a sufficient time normally required to put on the belt, the tension that is generated on the belt can be reduced. Therefore, it is possible to easily put on the seat belt without hindering the work of putting on the seat belt. Secondly, whether or not to prohibit the above-mentioned winding is as follows.
Since the determination is made based on whether or not more than a predetermined number of drawers have been pulled out, if the number of drawers is less than a predetermined number, the belt will be retracted immediately. If the seat belt gets caught in the retractor and stops without being completely retracted, by pulling out the belt less than the predetermined amount, the belt will be re-wound immediately and the inconvenience of the seat belt remaining outside the retractor can be prevented. be.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram showing an example of a conventional seat belt retractor, and FIG. 2 is a partially detailed diagram thereof.
FIG. 3 is a front view showing an embodiment of the configuration of the seat belt retractor according to the present invention, FIG. 4 is a side view thereof, and FIG. 5 is a schematic configuration diagram of an embodiment using the microcomputer of the present invention. FIG. 6 is a detailed configuration diagram of the displacement detection device, FIGS. 7 and 8 are flowcharts of the control program, and FIG. 9 is a set slack amount characteristic diagram depending on the vehicle speed. 1...Seat belt, 11...Housing, 1
2... Winding shaft, 14... Rotation angle detection ratchet wheel, 18
...Motor, 23...Displacement detection device, 24...Microcomputer, 25...RAM, 27...
Transistor bridge circuit.

Claims (1)

[Scope of Claims] 1. A belt drive device that winds up a seatbelt, a withdrawal amount detection device that detects the amount of withdrawal of the seatbelt, a wearing detection device that detects whether the seatbelt is being worn, and this wearing detection device. means for prohibiting the belt driving device from retracting for a predetermined period of time when the seat belt is pulled out by a predetermined amount or more and the belt is not attached, based on an output from the withdrawal amount detection device; A seat belt retractor characterized by: