JPS6354576B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a webbing retractor used in a seat belt device for protecting occupants in vehicle emergencies, and particularly relates to a webbing retractor that takes into consideration reducing the retracting force after the webbing is attached. .

The webbing retractor is designed to wind one end of the occupant restraint webbing onto the take-up shaft using the biasing force of an elastic body.The biasing force of the elastic body brings the webbing into close contact with the occupant, and after the occupant releases the webbing. The webbing is wound onto a winding device to prevent it from being scattered inside the car.

However, the biasing force of this elastic body turns into webbing tension and gives a feeling of pressure to the occupant, causing fatigue and resulting in a problem that leads to a decrease in the webbing attachment rate.

For this reason, a webbing retractor has been proposed that automatically reduces the webbing tension after the occupant puts on the webbing. In this webbing take-up device, a pair of elastic bodies are arranged in series, and after the passenger puts on the webbing, the connecting portion of the pair of elastic bodies is fixed, and only the biasing force of one elastic body is applied to the webbing. The control is complicated and the amount of winding force reduction is uniform.

The present invention has been made in consideration of the above-mentioned facts, and an object of the present invention is to provide a webbing take-up device that can reliably obtain an arbitrary reduction state of webbing tension even though a single elastic body is used.

The present invention provides a take-up shaft to which one end of occupant restraint webbing is attached, an elastic body having one end attached to the take-up shaft and biasing the take-up shaft in the webbing winding direction, and the other end of the elastic body. a support means for supporting the webbing; a drive means for moving the elastic body in a loosening direction via the support means to reduce the winding force acting on the webbing when the occupant wears the webbing; a manual adjustment device that is driven to move the elastic body in a loosening direction by an amount corresponding to manual operation; and a manual adjustment device that drives the elastic body in a direction to increase the webbing tension after the occupant releases the webbing, and then drives the driving means to move the elastic body in a direction to increase the webbing tension so that the webbing is fully wrapped. The invention is characterized in that it has a control device for winding up to

Therefore, in the present invention, since the driving means is driven to loosen the elastic body by an amount corresponding to the manual adjustment by the occupant using the manual adjustment device, the occupant can arbitrarily change the tension of the webbing attached. Further, after the occupant releases the webbing, the control device moves the elastic body in the direction of increasing the webbing tension via the drive means, so that the webbing is quickly wound up to a fully wound state.

Embodiments of the present invention will be described below with reference to the drawings.

The webbing retractor 10 shown in FIGS. 1 to 3 has a frame 12 attached to a vehicle body with mounting bolts 14.
It is fixed to 6.

From both sides of the frame 12, a pair of leg plates 18,
20 extend parallel to each other, and the winding shaft 22
The vicinity of both ends are supported pivotably. This winding shaft 22
One end of a webbing 24 for restraining an occupant is attached to the webbing 24, and a tongue plate 26 shown in FIG. 4 is attached to the other end of the webbing 24.
The occupant can attach the intermediate portion of the webbing 24 by engaging the tongue plate 26 with a buckle device 28 attached to the vehicle body. Note that in FIG. 4, the tongue plate engagement structure of the buckle device 28 is omitted from illustration.

The winding shaft 22 is pivotally supported on the leg plate 20 via a cylindrical part 32 protruding from the inner end of a base 30 fixed to the outside of the leg plate 20, and also has a small diameter part connected to the end of the winding shaft 22. The inner end of a mainspring spring 36 is locked to 34. This mainspring spring 36 is housed in a spring case 38, and its outer end is locked to the inner periphery of the spring case 38.

A small diameter portion 38A of the spring case 38 is loosely fitted onto the small diameter portion 34 of the winding shaft 22, so that the spring case 38 is rotatable around the small diameter portion 34 of the winding shaft. Further, the small diameter portion 38A is prevented from moving in the axial direction by a screw 42 that is screwed onto the small diameter portion 34 of the winding shaft. Also mainspring spring 36
A seat 44 is interposed between the main spring 36 and the base 30 to reduce the frictional resistance between the mainspring spring 36 and the seat 44.

The spring case 38 has a gear 46 on its outer periphery, and this gear 46 approaches the inner circumferential surface of a cover 48 that stands up from the periphery of the base 30.

A portion of gear 46 corresponds to solenoid 52 through a notch 50 formed in cover 48 . This solenoid 52 is attached to a support bar 54 fixed to the leg plates 18, 20, and has a pin 56.
passes through the notch 50 and can come into contact with and separate from the gear 46.

In a normal state, the pin 56 meshes with the gear 46 by the biasing force of an elastic body built into the solenoid 52,
The solenoid 52 has the role of a brake to stop the rotation of the gear 46. The solenoid 52 is connected to a microcomputer 58 as a control device shown in FIG. Spring case 38 separated from
The configuration allows rotation of the

Therefore, when the pin 56 is engaged with the gear 46, the spring case 38 supports the reaction force of the biasing force of the mainspring spring 36, and applies a force to the webbing winding direction (direction of arrow A in FIG. 2) on the winding shaft 22. I'm starting to do that.

A pinion 60 is arranged on the outside of the leg plate 20 on the opposite side of the solenoid 52 with respect to the winding shaft 22. This pinion 60 meshes with the gear 46 through a notch 62 formed in the cover 48. Further, this pinion 60 is fixed to an output shaft 66 of a motor 64 as a return device fixed to the leg plate 20 so as to receive the rotational force of the motor 64.

The motor 64 is energized by receiving a signal from the microcomputer 58 by manual operation of the adjusting device 68 after the occupant puts on the webbing. The passenger's webbing attachment status is determined by buckle device 2.
The configuration is such that detection is performed by connecting a buckle switch 70 provided in the microcomputer 58 to the microcomputer 58. In other words, batch switch 7
0 means that the movable contact 72 is connected to the fixed contact 74 when the tongue plate 26 is pulled out, that is, when the passenger is not wearing the webbing, and when the passenger is wearing the webbing, that is, when the tongue plate 26 is unbuckled. When engaged with the device 28, the movable contact 72 contacts the stationary contact 76 to notify the microcomputer 58 of the occupant's webbing non-wearing state and webbing wearing state, respectively.

The manual adjustment device 68 has an operating lever 78 and contacts 80 and 82 with which the lever selectively contacts, the contact 80 being the loosening contact and the contact 82 being the biasing force increasing contact.

Therefore, when the occupant manually operates the operating lever 78 to contact the contact point 80 after wearing the webbing, the microcomputer 58 drives the motor 64 to move the spring case 38 in the loosening direction (arrow A in FIG. 2).
By rotating the webbing by an arbitrary amount in the opposite direction), it is possible to reduce the tension of the webbing that causes a feeling of pressure on the occupant.
When the spring case 38 is brought into contact with the spring case 38, the spring case 38 is driven in the opposite direction and the winding force is increased.

When the passenger is wearing the webbing, the operation lever 7
8 comes into contact with either of the contacts 80, 82, the microcomputer 58 operates the solenoid 52 to extract the pin 56 from between the gears 48, allowing the spring case 38 to rotate.

Further, the microcomputer 58 is connected to a rotation detection device 84 fixed to the outside of the leg plate 20, and this rotation detection device 84 detects the rotational position of the spring case immediately after the webbing is attached, and stores this in the microcomputer 58 as a reference position. Device 58A
It is designed to be memorized.

In detail, the rotation detection device 84 is connected to the spring case 38.
A rotary contact 86, also shown in FIG. 5, is attached to the small diameter protrusion 38A of the rotary contact 86, and around this rotary contact 86, a plurality of mutually electrically conductive strips 88 are arranged parallel to the axis of the winding shaft. There are multiple locations. These strips 88 are arranged at equal intervals on the same radius from the winding shaft axis and correspond to the contacts 90 and 92.
These contacts 90 and 92 are supported by a rotor cover 94 that is fixed to the leg plate 20 across the spring case 38 and are connected to the microcomputer 58, and both the protrusions 96 provided at the tips contact the strip 88. When the protrusion 96 is placed between the strips 88, a signal is sent to the microcomputer 58 indicating a conduction state, and when the protrusion 96 is placed between the strips 88, a signal indicating a cutoff state is sent to the microcomputer 58, and the central processing unit (CPU) 58B in the microcomputer 58 , the conduction state are added, and the number of rotations in the loosening direction of the spring case 38 is stored in the storage device 58A.

Therefore, when the occupant releases the webbing, the microcomputer 58 receives a signal from the buckle switch 70 to rotate the motor 64 in the direction of increasing the biasing force of the mainspring by the number of rotations in the loosening direction, thereby rewinding the webbing to a fully wound state. It's becoming like that.

Note that a ratchet wheel 98 is fixed to the winding shaft 22 as shown in FIG. 1, and corresponds to the pawl 100 pivotally supported on the leg plate 18. This pawl 100 is placed on a pendulum 102, and when the pendulum 102 tilts in the event of a vehicle emergency, it engages with the ratchet wheel 98 and stops the rotation of the webbing pull-out of the take-up shaft 22. Pendulum 102
is placed on a bracket 104 protruding from the leg plate 18.

The operation of this embodiment configured in this way will be explained. After getting on the vehicle, the passenger pulls the webbing 24 onto the winding device 10.
When the tongue plate 26 is pulled out and engaged with the buckle device 28, the webbing is attached.
At this stage, as shown in Fig. 6, the webbing drawer stroke moves from S ₀ (full winding state) to S ₁ ,
The winding force increases from F ₀ to F ₁ . The rotational position of the spring case 38 in this state is stored in the microcomputer 58 as a reference position.

If the occupant wants to reduce the webbing retracting force, he or she can manually operate the control lever 78 of the adjustment device 68.
When the pin 56 is brought into contact with the contact point 80, the solenoid 52, under the command of the microcomputer 58, separates the pin 56 from the gear 46, allowing the spring case 38 to rotate. At the same time, the motor 64 is connected to the spring case 3.
8 in the webbing winding direction, the biasing force of the mainspring spring 36 becomes weaker. At the drawer stroke S _R point shown in FIG.
When the webbing winding force is separated from 0, the webbing winding force is reduced to F _R , and the solenoid 52 causes the pin 56 to protrude and stops the rotation of the spring case 38 again.

Therefore, the occupant can take up the webbing with a pull-out state in which the pull-out stroke is reduced by R compared to when the webbing is attached, and can enter the operating state with a significantly smaller take-up force. Further, if it is desired to increase the webbing winding force, the operating lever 78 may be brought into contact with the contact point 82.

In this way, the winding force during operation can be made weaker than the winding force in the fully wound state. This state of reduced winding force significantly reduces the feeling of pressure on the occupant, and in some cases, the winding force can be completely eliminated, providing a comfortable driving posture.

Webbing 24 when the passenger changes posture while driving.
When the webbing is pulled out from the winding device 10, an increased winding force is applied to the webbing in accordance with the amount of the webbing pulled out.
However, when the occupant returns to the original driving position, the initial winding force reduction state is resumed.

When the vehicle is in an emergency situation such as a collision, the pendulum 102
Since the bowl 100 is engaged with the ratchet wheel 98, the rotation of the take-up shaft 22 in the webbing pull-out direction is stopped, and the occupant is securely restrained by the webbing 24, thereby ensuring safety.

When the passenger pulls out the tongue plate 26 from the buckle device 28 to release the webbing 24, the microcomputer 58 activates the solenoid 52 to separate the pin 56 from the gear 46, allowing the spring case 38 to rotate. At the same time,
The storage device 58A of the microcomputer 58 that stores the reference position of the spring case 38 rotates the motor 64 in the direction of increasing the biasing force via the central processing unit 58B to set the reference position, and then rotates the motor 64 to the reference position.
The pin 56 is projected to stop the rotation of the spring case 38. Therefore, the webbing 24 is wound up to its full length, and the winding force returns to F ₀ .

In order to quickly wind up the webbing after the occupant releases the webbing, the microcomputer 58 may send a signal to the motor 64 to temporarily increase the winding force of the winding shaft 22 beyond the winding force in the fully wound state. can.

Further, in the above embodiment, a solenoid is used to stop the rotation of the spring case in the normal state, but if the motor 64 has a braking force sufficient to prevent the rotation of the spring case when the motor 64 is stopped, the solenoid can be used. There is no need to use it.

In the embodiment described above, the reference position of the spring case 38 was detected by the rotation detection device 84, but the reference position can also be known by detecting the webbing tension immediately after the occupant wears the webbing.

As explained above, the webbing retractor according to the present invention adjusts the amount of loosening of the elastic body by operating the drive means by an arbitrary amount by manual operation by the occupant, so that the webbing retractor according to the present invention can reliably achieve the desired winding force even though it is a single elastic body. It has an excellent effect of being able to obtain a reduced state.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the webbing retractor according to the present invention, FIG. 2 is a right side view with the rotor cover of FIG. 1 removed, and FIG. 3 is a sectional view taken along the line of FIG. FIG. 4 is a wiring diagram showing the connection state of the microcomputer, FIG. 5 is an exploded perspective view showing the rotation detection device, and FIG. 6 is a diagram showing the relationship between the drawer stroke and the webbing take-up force. 10... Webbing take-up device, 22... Take-up shaft, 24... Webbing, 28... Buckle device, 38... Spring case, 52... Solenoid,
58...Microcomputer, 64...Motor, 68...Manual adjustment device, 70...Buckle switch, 78...Operation lever, 84...Rotation detection device.

Claims (1)

[Scope of Claims] 1. A take-up shaft to which one end of the occupant restraint webbing is attached; an elastic body having one end attached to the take-up shaft and urging the take-up shaft in the webbing take-up direction;
a support means for supporting the other end of the elastic body; a drive means for moving the elastic body in a loosening direction via the support means to reduce the winding force acting on the webbing when the occupant wears the webbing; a manual adjustment device that drives the driving means by operation to move the elastic body in the loosening direction by an amount corresponding to the manual operation;
A webbing retractor comprising: a control device that drives the driving means to move the elastic body in a direction of increasing webbing tension after an occupant releases the webbing, and rewinds the webbing to a fully wound state. 2. The webbing according to claim 1, wherein the elastic body is a mainspring spring, and the inner end of the mainspring spring is fixed to a take-up shaft, and the outer end is fixed to a support means. Winding device. 3. The supporting means is a spring case, and the control device returns the spring case to the rotational position before the winding force is reduced after the occupant releases the webbing, and winds up the webbing to a fully wound state. A webbing take-up device according to claim 2. 4. The webbing take-up device according to claim 1 or 2, wherein the driving means moves the elastic body in the return direction using the driving force of a motor. 5. The driving means according to any one of Claims 1 to 4, wherein the driving means is configured to be activated by an occupant engaging a tongue plate at the tip of the webbing with a buckle device. The described webbing retractor.