JPH0412841Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention is used in a seat belt device for protecting occupants in vehicle emergencies, and relates to a webbing retractor for retracting webbing for restraining occupants. The present invention relates to an adjustable webbing take-up device.

[Background Art and Issues to be Solved] In a webbing retractor used in a seat belt device, one end of the occupant restraint webbing is attached to a retracting shaft, and the webbing is rotated by the urging force of a mainspring spring. It is designed to be rolled up in layers.

The biasing force of this mainspring spring is set to a predetermined value or more in order to reliably wind up the webbing after the occupant releases the webbing, and it is necessary for the occupant to pull out the webbing with a relatively large force when attaching the webbing. In addition, a relatively large resistance force is felt when driving after wearing the webbing or when the occupant moves inside the vehicle.

Therefore, by making the winding force of the mainspring spring adjustable, it is possible to maintain the webbing tension at an arbitrary value (for example,
75129).

However, with such a winding device, in order for the occupant to always obtain an appropriate and comfortable webbing tension, the motor control circuit that controls the biasing force of the mainspring spring must be turned on at all times, which consumes a large amount of power. . It is also possible to prevent the control device from operating if the vehicle's ignition key is not activated, but if the webbing tension is weak or strong and the control device stops, the webbing tension will remain as it is. Since the webbing is maintained in this state, defects in winding the webbing, excessive winding force, etc. occur.

The present invention takes the above facts into consideration and aims to provide a seat belt device that can reduce power consumption.

[Summary and operation of the invention] The seat belt device according to the invention includes an actuator that operates when electric power is supplied to change the winding force applied to the webbing, and an actuator that operates when electric power is supplied. and a control circuit for controlling power to be supplied to the actuator, a winding detection means for detecting a state in which the webbing is completely wound up, and a winding detection means for detecting a state in which the webbing is completely wound up. power supply means that supplies power to the control circuit when the coil is not wound up, and stops supplying power to the control circuit when a completely wound state is detected.

In the present invention, when it is detected that the webbing is completely wound up, power supply to the control circuit is stopped. Along with this, the supply of power to the actuator is also stopped. Therefore, since the control circuit and the actuator do not consume power when the webbing is completely wound up, power consumption can be reduced and the battery of the vehicle can be protected. Furthermore, the webbing winding force can be reliably controlled until the webbing is wound up.

[Embodiment] FIGS. 1 and 2 show a webbing retractor 10 according to a first embodiment of the present invention. In this webbing retractor 10, a frame 12 is fixed to a vehicle body 16 with mounting bolts 14.

From both sides of the frame 12, a pair of leg plates 18,
20 are extended parallel to each other. Both end portions of a winding shaft 22 are pivotally supported on these leg plates 18 and 20, and one end of an occupant restraining webbing 24 is locked to the center of the winding shaft 22, and is wound in layers. It is being

The other end of this webbing 24 is the tongue plate 2.
5 is attached and is engageable with a buckling device 26 as shown in FIG. This buckle device 26 is attached to other parts of the vehicle body, and the middle portion of the webbing 24 is used for attachment by an occupant.

An inertia lock mechanism 27 is attached to the outside of the leg plate 20 between it and the winding shaft 22. This inertia lock mechanism 27 has a generally used structure, and it is
Detects the pull-out acceleration of the winding shaft 22 in case of vehicle emergency.
The rotation of the webbing drawer is suddenly stopped.

A base plate 28 is attached to the outside of the leg plate 18, and a screw 3 is attached to this base plate 28.
A worm wheel 34 is pivotally supported by the shaft support plate 32 and the leg plate 18, which are attached at 0. The outer end of the mainspring spring 36 is fixed to the inside of the worm wheel 34, and the inner end of the mainspring spring 36 is fixed to the winding shaft 22. Therefore, the mainspring spring 36 generates a biasing force against the worm wheel 34 to rotate the winding shaft 22 in the direction in which the webbing 24 is wound up.

A pinion 38 coaxially protrudes from the worm wheel 34 and meshes with a pinion 42 that is pivotally supported by a pin 40 that protrudes from the shaft support plate 32. This pinion 42 meshes with an internal gear 44 that is pivotally supported on the shaft support plate 32. As a result, the internal gear 4
4 is adapted to transmit the rotation of the winding shaft 22 at a reduced speed, and a striker 46 protruding from a part of the internal gear 44 corresponds to a limit switch 48 attached to the shaft support plate 32. The limit switch 48 is turned off when the occupant releases the webbing 24 and the maximum amount of the webbing 24 is wound onto the take-up shaft 22.
When the striker 46 is pulled out, the striker 46 is separated and turned on.

A worm gear 5 is provided on the outer periphery of the worm wheel 34.
This worm gear 50 is attached to a worm gear shaft 52 as shown in FIG. To explain this in detail, the worm gear shaft 52 has a rectangular portion 52A that penetrates the worm gear 50, and is inserted into a rectangular hole 52A formed in the axial center of the worm gear 50. Therefore, the worm gear 50 rotates together with the worm gear shaft 52, but is slidable in the axial direction of the worm gear shaft 52.

Both ends of the worm gear shaft 52 are pivotally supported on the base plate 28 via brackets 54 and 56, and a striker 58 is pivotally supported on a circular portion formed adjacent to the rectangular portion 52A. This striker 58 has a circular penetrating portion through the worm gear shaft 52, allowing the striker 58 to rotate relative to the worm gear shaft 52 and also to move in the axial direction. The striker 58 is prevented from rotating by coming into contact with the side surface of the base plate 28, and is movable in the axial direction of the worm gear shaft 52. Also this striker 58
A compression coil spring 60 is interposed between the bracket 54 and the worm gear 54, and is urged toward the worm gear 50 and abuts against one end of the worm gear 50 in the axial direction.

Therefore, as shown in FIG.
receives the tension of the webbing 24 via the worm wheel 34, and when the tension of the webbing 24 is weak, the striker 58 presses the worm gear 50 against the bracket 56 due to the biasing force of the compression coil spring 60. In this state, as shown in FIG. 4A, the striker 58 turns on only the switch 64 of the switches 62 and 64 attached to the base plate 28.

Further, when the tension of the webbing 24 is medium, the striker 58 which receives the webbing tension via the worm gear 50 is arranged to turn on both switches 62 and 64 as shown in FIG. 4B, and the tension of the webbing 24 is If strong, Figure 4C
The compression coil spring 60 is compressed to the maximum amount, and only the switch 62 is turned on.

A small gear 66 is fixed to the end of the worm gear shaft 52 protruding from the bracket 56, and meshes with a large gear 68 via an intermediate gear 67. This large gear 68 is fixed to the output shaft of a motor 70, and the motor 70 is attached to the base plate 28.

FIG. 5 shows a control circuit diagram of this embodiment, in which the microcomputer 72 controls the switch 6.
2 and 64 are input, and the output of a buckle switch 74, which is disposed within the buckle device 26 and can detect the insertion state of the tongue plate 25 as shown in FIG. 2, is also transmitted.

This microcomputer 72 has a relay 76,
The motor 70 can be rotated in forward and reverse directions via a motor 78.

Also, the limit switch 48 is connected to the diode 7.
9. Connected to the base side of the transistor 81 via the inverting element 80 and the diode 7
It is connected to the microcomputer 72 via 9 and 82. The emitter side of the transistor 81 is connected to the vehicle power supply, and the collector side is connected to the microcomputer 72 via a 5-volt regulator 90.

Next, the operation of this embodiment will be explained with reference to the flowchart of FIG. When the maximum amount of webbing 24 is wound onto the webbing take-up device 10, power to the microcomputer 72 is cut off, and no power is consumed.

When the occupant pulls out the webbing 24 from the webbing retractor 10 to put on the webbing 24, the limit switch 48 shown in FIGS. The input becomes low level and the microcomputer 72 is energized. Now the program is executed, while the diode 82
The output from the microcomputer 72 becomes high level, and the power supply to the microcomputer 72 is latched (step 92 in FIG. 6).

When the microcomputer 72 is power latched, the buckle flag is set to 0 in step 94. This battle flag is battle switch 74
is turned on, that is, tongue plate 2
5 is inserted into the buckle device 26, and even if the buckle switch 74 is turned off, it remains 1 until it is forcibly set to 0.

Next, in step 95, after the 10 seconds elapsed flag is set to 0, in step 96, it is determined whether the buckle switch 26 is on or off, that is, whether the occupant has turned the webbing 24 on or off.
It is determined whether or not the device is attached. Even if the occupant pulls out the webbing 24, the buckle switch 26 remains off until the passenger pulls out the webbing 24, so the process proceeds to step 98. At step 98, it is determined whether or not the winding of the webbing 24 has been completed. However, since the occupant has pulled out the webbing, the limit switch 48 is on, and winding is not completed, and the process proceeds to step 100. move on.

In step 100, it is determined whether the buckle flag is 1 or not, but since the buckle flag has already been set to 0 in step 94, the process proceeds to step 102.

In step 102, it is determined whether the 10 seconds elapsed flag is 1, but it has already been determined in step 95 that it is 0.
Therefore, proceed to step 104. In step 104, control is performed to stop the motor 70, but since the motor 70 has already been stopped in this case, the motor 70 remains stopped.

Next, in step 106, it is determined whether 10 seconds have elapsed since the start of counting in the next step 107. In other words, after pulling out the webbing 24,
If the second has not elapsed, the process waits for 10 milliseconds in step 108, returns to step 96, and repeats the above operation, and if 10 seconds have elapsed, the 10 second elapsed flag is set to 1 in step 110. After that, return to step 96.

Therefore, after the passenger pulls out the webbing 24,
If the tongue plate 25 is not engaged with the buckle device 26 even after 10 seconds have elapsed, it is determined that the webbing 24 has simply been pulled out and there is no intention to wear the webbing, or that the webbing has been discontinued. Step 102 leads to step 112.

In step 112, it is determined whether the tension of the webbing 24 is strong, that is, whether the worm gear 50 is in the state shown in FIG. 4C. If the webbing tension is not strong, the motor 70 is
is wound up, and if it is strong, the motor 70 is stopped in step 116, respectively leading to step 118 and, after waiting 10 milliseconds, returning to step 96.

If the tongue plate 25 is engaged with the buckle device 26 within 10 seconds after the occupant pulls out the webbing 24, this is determined in step 96, and the process proceeds to step 96.
At step 120, the buckle flag is set to 1, and the process proceeds to step 122. In step 122, the timer count started in step 107 is cleared.

Next, the process proceeds to step 124, where it is determined whether the tension of the webbing 24 is in the medium state, that is, whether the worm gear 50 is in the state shown in FIG. 4B. If the tension in the webbing 24 is medium, the motor 70 is stopped in step 126, and it is determined in step 128 whether webbing winding is complete. If the occupant is wearing the webbing 24, the limit switch 48 shown in FIG. 2 is on, so after waiting 10 milliseconds at step 130, the process returns to step 96.

Also, if the webbing tension is not medium,
The process proceeds from step 124 to step 132, where it is determined whether the webbing tension is in a weak state, that is, whether the worm gear 50 is in the state shown in FIG.
At 134, the motor 70 rotates in the webbing winding direction.
After waiting 10 milliseconds at step 136, the process goes to step 96. If the webbing tension is not weak, the motor 70 moves the webbing 2 in step 138.
4, and after waiting 10 milliseconds at step 140, proceed to step 96.

Therefore, after the occupant wears the webbing 24, the webbing tension is always controlled to be in a medium state, resulting in a comfortable riding condition. If the passenger changes his or her driving position while riding the vehicle and moves forward significantly, for example to operate a switch, steps 124, 132, etc.
The webbing take-up force is reduced in accordance with the movement of the occupant in step 138, and when the vehicle returns to its original driving position, the take-up shaft receives a large biasing force in the take-up direction in steps 124, 132, and 134. The webbing is immediately wound up, and then the webbing tension returns to the medium state again.

When the passenger pulls out the tongue plate 25 from the buckle device 26 to exit the vehicle, the buckle switch 74 is turned off, and the process proceeds from steps 96, 98, and 109 to steps 112 and 114, where the motor 70 winds up the mainspring spring 36. The webbing 24 is wound up with a large winding force. When the maximum amount of webbing 24 is wound up, the limit switch 48 is turned off, so the process proceeds from step 98 to step 142, where the buckle flag is set to 0, and in step 144,
After the 10 second flag is also set to 0, the process proceeds to step 122. When winding of the webbing 24 is completed, the tension of the webbing 24 is controlled to a medium state, and the step
After going through steps 124, 126, and 128, it reaches step 146.
The microcomputer 72 is powered off and control is stopped.

In order to power off the microcomputer 72, the limit switch 48 shown in _FIG . This is done by being blocked. Therefore, unnecessary power consumption can be avoided. Furthermore, after the winding force of the webbing 24 is set to a medium state, the microcomputer 72 is powered off and the control is stopped. For example, when the winding force is excessive, the control is stopped and this state is maintained. Inconveniences such as damage to the spring 36 will not occur.

In the above embodiment, the worm gear 50 is moved from the worm gear shaft 5 depending on the tension of the webbing 24.
2, the present invention has a structure that detects the relative rotation between the worm wheel 34 and the winding shaft 22 by changes in capacitance, etc. Various detection structures such as a structure that determines the rotational position of the worm wheel 34 by turning it on or off are applicable.

[Effects of the invention] As explained above, in the seat belt device according to the invention, when it is detected that the webbing is completely wound up, the power supply to the control circuit is stopped. This has excellent effects in that power consumption can be reduced and the webbing winding force can be reliably controlled until the webbing is completely wound up.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view showing an embodiment of the seat belt device according to the present invention, FIG. 2 is a side view of FIG. 1,
Fig. 3 is an exploded perspective view showing the positional relationship between the worm gear and the striker, Fig. 4 is a side view showing the movement of the striker according to the tension state of the webbing, and Fig. 5
The figure is a circuit diagram of this embodiment, and FIG. 6 is a flowchart of this embodiment. DESCRIPTION OF SYMBOLS 10... Webbing winding device, 22... Winding shaft, 24... Webbing, 26... Buckling device, 34... Worm foil, 48... Limit switch, 50... Worm gear, 70... Motor, 72... microcomputer.

Claims (1)

[Scope of utility model registration request] an actuator that operates when electric power is supplied to change the winding force applied to the webbing; and a control circuit that operates when electric power is supplied and controls the actuator so that electric power is supplied to the actuator. , winding detection means for detecting a state in which the webbing is completely wound up; and when the winding detection means does not detect a state in which the webbing is completely wound up, power is supplied to the control circuit and the webbing is completely wound up; A seat belt device comprising: power supply means that stops supplying power to a control circuit when a state in which the seat belt is wound is detected.