JP2002220028A - Seatbelt retractor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To rapidly and securely lock, if necessary, the rotation of a spool in the direction to unwind webbing, while also preventing a lock means from being actuated when the webbing is abruptly unwound. SOLUTION: At the occurrence of vehicle deceleration equal to or greater than a predetermined deceleration, the rotation of the spool 4 in the direction αto unwind the webbing is locked by a first lock means 5 using a solenoid 19, independently of the rotational movement of the spool 4. Then the rotation of the spool 4 in the direction α to unwind the webbing is rapidly locked and the amount of rotation of the spool 4 before actuation of the first lock means 5 decreases, reducing the amount by which the webbing 3 is unwound. If the solenoid 19 is not powered when necessary and the rotation of the spool 4 is not locked by the first lock means 5, then the electromagnet 34 is made to carry no current and a second lock means 6 locks the rotation of the spool 4 in the direction α to unwind the webbing. Thus, even if the first lock means 5 is not actuated, the rotation of the spool 4 in the direction α to unwind the webbing is securely locked.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of a seatbelt device mounted on a vehicle such as an automobile and protecting an occupant, and particularly when the vehicle has a vehicle deceleration exceeding a predetermined value. The present invention belongs to the technical field of a seat belt retractor in which the deceleration sensing means operates by detecting the vehicle deceleration to prevent the webbing from being pulled out due to the inertial movement of the occupant.

[0002]

2. Description of the Related Art A seatbelt device, which is mounted on a vehicle such as an automobile and protects an occupant, is provided with a deceleration called a vehicle sensor in an emergency when the vehicle is decelerated to a predetermined value or more due to a vehicle collision or the like. When the detecting means operates by detecting the vehicle deceleration, the lock operating means operates to operate the locking means, and the lock operating means prevents the spool in which the webbing is wound up from rotating in the webbing pulling-out direction, thereby preventing the webbing from rotating. When the webbing is rapidly pulled out due to the occupant trying to move forward rapidly due to inertia or the like due to a vehicle collision, an inertial body called a webbing sensor (usually called a flywheel) ) Senses this sudden withdrawal of the webbing and activates it, similarly operating the lock operating means and activating the locking means. , There is a lock actuating means comprising a seat belt retractor to prevent rotation of the webbing pull-out direction of the spool for winding the webbing is adapted to prevent withdrawal of the webbing. As such a seat belt retractor, for example, Japanese Unexamined Patent Publication No. Hei.
There is a seat belt retractor such as that disclosed in Japanese Patent Publication No. 6 and the like.

[0003] In the seat belt retractor disclosed in this publication, the locking means does not normally operate, so that the spool is freely rotatable, the webbing can be freely pulled out, and the occupant is disengaged. You can freely move forward. In addition, in the event of a large vehicle deceleration occurring in the vehicle or in the event of rapid withdrawal of the webbing, the vehicle sensor or the webbing sensor operates as described above, respectively.
Normally, rotation of the lock gear of the lock operating means, which rotates integrally with the spool, in the webbing pull-out direction is prevented. However, when the occupant tries to move forward due to inertia or when the webbing is rapidly pulled out, the rotational force in the webbing pulling-out direction is continuously applied from the webbing to the spool, so that the spool rotates relative to the lock gear in the webbing pulling-out direction. . Then, the pawl of the lock means rotatably supported by the spool rotates and engages with the teeth of the frame, and the rotation of the spool in the webbing pull-out direction is locked. As a result, the webbing is prevented from being pulled out, the occupant is restrained by the webbing, and the occupant is protected from moving forward due to its inertia.

[0004]

In such a conventional seat belt retractor, the locking means is operated by the rotation of the spool in the webbing withdrawing direction, so that the vehicle sensor provides a large vehicle deceleration. The spool is rotated in the webbing withdrawing direction by a predetermined amount of rotation in the webbing withdrawing direction from when the locking means is actuated after the sensing, or when the webbing sensor senses sudden withdrawal of the webbing and before the locking means is actuated. Of course, even if the spool rotates by a predetermined amount of rotation before the locking means is activated, the seat belt device can surely fulfill the function of restraining the occupant, but the spool is not operated until the locking means is activated. It is desirable that the predetermined rotation amount be as small as possible in order to more effectively restrain and protect the occupant.

[0005] Further, when the webbing is rapidly pulled out due to a sudden movement of the occupant or the like, the webbing sensor similarly operates even when the occupant moves abruptly when the seatbelt is worn, even if the above-mentioned large vehicle deceleration does not occur. The locking means is activated. Therefore, the occupant may feel uncomfortable or uncomfortable.

For this reason, the present applicant does not provide a vehicle sensor or a webbing sensor as in the prior art, and uses the locking means to rotate the spool in an emergency when an extremely large vehicle deceleration such as a vehicle collision occurs. By operating independently of the above, the amount of rotation of the spool in the webbing withdrawal direction from the occurrence of vehicle deceleration to the activation of the locking means can be further reduced, and
A seat belt rewinding device has been proposed which does not use a webbing sensor to prevent a passenger from feeling uncomfortable or uncomfortable, and a patent application has been filed (Japanese Patent Application No. 2000-36).
8006).

In this seat belt retractor, as an example, the locking means is operated by a motor or a solenoid which is operated by a webbing pull-out lock signal such as a vehicle collision prediction signal without depending on the rotation of the spool. According to this seat belt retractor, the motor or the solenoid directly operates the locking means in response to the webbing pull-out lock signal, so that when the webbing pull-out lock condition is reached, the spool is more rapidly rotated in the webbing pull-out direction. And the amount of rotation of the spool until the rotation of the spool is locked by the locking means is significantly reduced. Accordingly, the seat belt device can more effectively restrain and protect the occupant. Further, since the locking means does not operate even if the webbing is suddenly pulled out, the occupant does not feel uncomfortable or uncomfortable.

However, when the motor or the solenoid is used as described above, if the motor or the solenoid is not energized for some reason, the motor or the solenoid may not operate and the locking means may not operate. Therefore, even if the seat belt retractor operates the locking means independently of the rotation of the spool and uses an electrically driven locking means such as a motor or a solenoid, the rotation of the spool in the webbing pull-out direction can be ensured when necessary. It is required to lock.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to quickly lock the rotation of the spool in the webbing withdrawal direction when necessary, and to operate the lock means by suddenly withdrawing the webbing. An object of the present invention is to provide a seat belt retractor that can prevent the rotation of the spool in the webbing pull-out direction when necessary even when the electric drive locking means is used, while preventing the occurrence of the rotation.

[0010]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a first aspect of the present invention provides a spool for winding a webbing and a rotation of the spool at a normal time, and a rotation of the spool when necessary. A first lock unit that is independently operated by an electric drive unit to lock the rotation of the spool in the webbing withdrawal direction, and when the lock of the spool is not performed by the first lock unit when necessary, And a second locking means for locking rotation of the spool in the webbing withdrawal direction.

Further, the invention according to claim 2 is characterized in that the electric driving means is a solenoid or a motor. Further, the invention according to claim 3 is characterized in that the second lock means operates by detecting a predetermined deceleration of the vehicle deceleration, and the spool is rotated by the operation of the inertia mass to rotate the spool. An actuator for locking rotation in the webbing withdrawal direction is provided at least.

Further, the invention according to claim 4 is characterized in that the inertial mass is formed of a magnetic material such as iron, and the inertial mass is attracted and held by an electromagnetic force generated by being energized in a normal state. When the operation of the mass is locked and the lock of the rotation of the spool by the first lock means is not performed when necessary, the suction and holding of the inertial mass can be released and the inertial mass can be operated by not being energized. It is characterized by having an electromagnet. Further, claim 5
The invention is characterized in that a load limiting mechanism for limiting a webbing load is provided at least when rotation of the spool in the webbing withdrawal direction is locked by operation of the first locking means.

[0013]

In the seat belt retractor according to the present invention, the first lock means operates independently of the rotation of the spool by the electric drive means when necessary, and the rotation of the spool in the webbing withdrawing direction is directly performed. Locked. As a result, when necessary, the rotation of the spool in the webbing pull-out direction is quickly locked. Therefore, when necessary, the amount of rotation of the spool until the first lock means operates is reduced, and the amount of withdrawal of the webbing is suppressed, the occupant is restrained quickly by the webbing, and the occupant is more effectively protected when necessary. Will be done. Further, even if the webbing is suddenly pulled out, the first locking means does not operate, so that the occupant does not feel uncomfortable or uncomfortable. Further, when the electric drive means of the first lock means is not energized for some reason when necessary, and the lock of the rotation of the spool by the first lock means is not performed, the second lock means sets the spool in the webbing withdrawal direction. Locks rotation. Therefore, even when the first locking means is not operated, the rotation of the spool in the webbing withdrawing direction is reliably locked.

In particular, according to the second aspect of the present invention, since a solenoid or a motor is used as the electric driving means, each locking means is formed at low cost and the structure is simplified.

Further, according to the third aspect of the present invention, since a conventional vehicle sensor can be used, no significant design change is required, and an increase in cost is suppressed. Further, in the invention of claim 4, the second lock means does not operate unnecessarily, and unnecessary lock of rotation of the spool in the webbing pull-out direction by the second lock means is prevented. Further, in the invention of claim 5, at least the first
When the rotation of the spool in the webbing pull-out direction is locked by the operation of the locking means, the webbing load is limited by the load limiting mechanism, and the impact of the occupant is reduced.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an exploded perspective view showing an example of an embodiment of a seat belt retractor according to the present invention.

As shown in FIG. 1, a seat belt retractor 1 of this embodiment is roughly divided into
And a spool 4 for winding the webbing 3 and a frame 2
The first locking means 5 is disposed on one side of the frame 2 and prevents rotation of the spool 4 in the webbing pull-out direction α during operation, and is disposed on the other side of the frame 2 and rotates in the webbing pull-out direction α during operation. Locking means 6, which prevents the second locking means 6 from operating, and a second locking means operating mechanism 7 which operates the second locking means 6 when necessary. The operation of the second locking means 6 during a large deceleration such as a collision prevents the webbing from being pulled out. A force limiter mechanism (hereinafter also referred to as an EA mechanism) 8 for limiting the load of the webbing 3, a deceleration detecting means 9 for detecting a vehicle deceleration, and a motor 10 for generating a rotational torque.
A power transmission gear mechanism 11 for transmitting the rotation torque of the motor 10, a speed reduction mechanism 12 for reducing the rotation torque of the motor 10 transmitted from the power transmission gear mechanism 11 and transmitting the torque to the spool 4, and a rotation torque of the motor 10. And a power transmission path switching mechanism 13 for selectively switching and setting the rotation of the spool 4 to one of a state where the rotation of the spool 4 is not transmitted to the motor 10 and a state where the rotation of the spool 4 is not transmitted. And biasing spring means 14. Note that, in the exploded perspective view of FIG. 1, each component of the seat belt retractor 1 is incorporated along a corresponding one-dot chain line.

A pair of parallel side walls 15, 16 of the frame 2
Large holes 17 and 18 are formed concentrically between them, and a predetermined number of ratchet-like internal teeth 16 a are formed on the inner peripheral surface of the large hole 18 of the side wall 16. A spool 4 for winding the webbing 3 is disposed between the side walls 15 and 16.

An axially penetrating through hole 4a is formed in the center of the spool 4, and the through hole 4a is formed in a hole having a hexagonal cross section at the end on the side wall 15 side. The end on the side wall 16 side is formed as a hole having a cross-sectional shape in which a stopper 29 described later can be fitted and the spool 4 and the stopper 29 can rotate integrally.

As shown in an enlarged view in FIG. 2A, the first locking means 5 is provided with external teeth 43a of a first carrier 43 described later.
And a first lock coil 19a that generates an electromagnetic force when energized.
(Shown in FIG. 4) and a solenoid (corresponding to an electric drive means of the present invention) 19 having a plunger 19b operated by the electromagnetic force of the first lock coil 19a, and detachably connected to the plunger 19b of the solenoid 19. The operation member 20 is pivotably supported by the pivot pin 35a of the second retainer 35, and is set to a position where it can be rotated by the operation of the operation member 20 to engage with the external teeth 43a of the first carrier 43. And a spring 22 that constantly urges the first pawl 21 to a position where the first pawl 21 cannot be engaged with the external teeth 43 a of the first carrier 43 when the operating member 20 is not operated. .

The first pawl 21 has a long hole 21a, and the shaft pin 35 of the second retainer 35 is inserted into the long hole 21a.
a is inserted, the first pawl 21 becomes a pivot pin 35a.
And can be relatively moved with respect to the pivot pin 35a along the longitudinal direction of the long hole 21a. In addition, the first pawl 21 has the external teeth 43 during operation.
and a locking claw 21b that can be engaged with a.

When the first lock coil 19a of the solenoid 19 is not energized, the plunger 19b projects by the spring force of the spring 22 as shown in FIG. Set to position. As a result, the first pawl 21 has its long hole 2
The right end position of 1a is located at the support pin 35a, and the locking claw 21b is set to a non-operating position shown in the drawing, which is a position where it cannot engage with the external teeth 43a.

The first lock coil 19a of the solenoid 19
Is energized, the plunger 19b is attracted by the electromagnetic force of the first lock coil 19a and rises against the spring force of the spring 22, as shown in FIG. Is set to the operation position. As a result, the first pawl 21 rotates counterclockwise in the drawing with the right end position of the long hole 21a positioned on the support pin 35a and around the support pin 35a. The pawl 21b is set at a position where it can engage with the external teeth 43a. In this state of the first pawl 21, when the first carrier 43 rotates clockwise in the drawing, that is, in the webbing withdrawing direction α, the external teeth 43a engage with the locking claws 21b,
The rotation of the first carrier 43 in the webbing withdrawing direction is locked.

External teeth 43a and locking claws 21 shown in FIG.
When the first carrier 43 rotates in the counterclockwise direction in the drawing, that is, in the webbing winding direction β from the engagement state with the b, the ratchet-shaped external teeth 43a press the locking claws 21b obliquely to the upper right in the drawing. The first pawl 21 rotates clockwise and is guided by the long hole 21a, moves diagonally rightward in the figure, and the left end position of the long hole 21a is positioned on the support pin 35a. In this state, it rotates clockwise around the support pin 35a in the figure. As a result, as shown in FIG.
In this state, the engagement between the first carrier 43 and the external teeth 43a of the first carrier 43 is released. By moving the first pawl 21 obliquely to the upper right while rotating clockwise in this manner, the engagement between the locking claw 21b and the external teeth 43a is smoothly and reliably released. The first pawl 2
The first pawl operating section 20 of the operating member 20
a, the first pawl 21 is prevented from rotating clockwise, and the engagement between the locking pawl 21b and the external teeth 43a shown in FIG. 2C is maintained.

Further, when the solenoid 19 is de-energized from the state shown in FIG. 2C of the first lock means 5, the first pawl 21, the operating member 20,
The plunger 19b of the solenoid 19 is lowered in the figure. At this time, the first pawl 21
Is moved obliquely to the lower left in the figure while being guided by the long holes 21a, so that the groove wall 21 of the first pawl 21
c is separated from the first pawl operating portion 20 a of the operating member 20, and the first pawl 21 is rotated clockwise by the spring force of the spring 22. Therefore, the first pawl 21 moves obliquely to the lower left while rotating clockwise, and returns to the initial inoperative position shown in FIG. 2A.

The second locking means 6 includes the locking base 2
3, the second pawl 24, and the internal teeth 16 a of the side wall 16 of the frame 2. Locking base 23
Has a disc portion 23a and a screw shaft portion 23b, and a through hole 23c penetrating in the axial direction is formed at the center thereof. Although not shown, a portion of the through hole 23c corresponding to the disk portion 23a is a hole having a regular hexagonal cross section.
One end of a second pawl 24 is rotatably supported by the disk portion 23a.
A locking claw 24a that can be engaged with the internal teeth 16a is formed at the distal end of 4.

The second locking means operating mechanism 7 includes a lock gear 25, a first retainer 26 detachably fixed to the side wall 16 of the frame 2, and a pawl spring contracted between the locking base 23 and the lock gear 25. 27. A predetermined number of ratchet teeth 25a are formed on the outer peripheral surface of the lock gear 25.

At the center of the first retainer 26, a through hole 26a is formed, through which a first extension shaft 28d of the torsion bar 28 described later penetrates. The pawl spring 27 is contracted between the lock gear 25 and the locking base 23, and the lock gear 25 is constantly urged against the locking base 23 in the webbing pull-out direction α by the spring force of the pawl spring 27.

When the locking base 23 and the lock gear 25 do not rotate relative to each other, the second pawl 24 is set to a non-operating position where it cannot be engaged with the internal teeth 16a of the frame 2, and the locking base 23 is locked. 25
Relative to the webbing withdrawal direction α
The second pawl 24 rotates according to the relative rotation, and is set to an operation position where the second pawl 24 can engage with the internal teeth 16a when the relative rotation amount reaches a predetermined amount. When the locking base 23 rotates in the webbing withdrawing direction α in a state where the second pawl 24 is set to the operating position, the second pawl 24 immediately locks the rotation of the locking base 23 in the webbing withdrawing direction α. Has become.

The EA mechanism 8 includes a torsion bar 28, a screw shaft 23b of the locking base 23, and a screw shaft 23b.
And a cylindrical stopper 29 fitted so as to be rotatable integrally with the spool 4 and relatively movable in the axial direction with respect to the spool 4.

The torsion bar 28 includes a torsion bar portion 28a and a lock gear 2 of the torsion bar portion 28a.
5, the through hole 23 c of the locking base 23.
A first torque transmitting portion 28b having a regular hexagonal cross-section that fits into a hole having a regular hexagonal cross-section and a torsion bar portion 28a opposite to the first torque transmitting portion 28b. A hexagonal second torque transmitting portion 28c, a first extension shaft 28d concentrically protruding from the first torque transmitting portion 28b, and a second extension shaft 28e concentrically protruding from the second torque transmitting portion 28c. Consists of

The cylindrical stopper 29 is provided on the locking base 2.
The screw shaft 23b is rotated relative to the locking base 23 together with the spool 4 in the webbing pull-out direction α while being screwed to the screw shaft portion 23b. . When the stopper 29 rotates relative to the locking base 23 by a predetermined amount in the webbing withdrawing direction α, the locking base 2 is rotated.
The third disk portion 23a abuts on the disk portion 23a to stop its axial movement, and cannot rotate relative to the locking base 23.

Therefore, as described later, the stopper 29
That is, the torsion bar portion 28a is twisted while the rotation difference occurs between the spool 4 and the locking base 23, so that the EA mechanism 8 exerts an EA effect of limiting the webbing load at the time of a vehicle collision. When there is no rotation difference between the stopper 29 and the locking base 23, the torsion bar 28a is no longer twisted and EA
The action ends. As described above, the range in which the EA action is performed is defined by the relative movement amount of the stopper 29 in the axial direction with respect to the spool 4 and the locking base 23. This EA action reduces the impact of the occupant.
The effect is obtained.

The deceleration detecting means 9 includes a housing 30 mounted on the side wall 16, a sensor case 31 mounted on the housing 30, and a spherical inertial mass made of a magnetic material such as iron mounted on the sensor case 31. 32 and the external teeth 2 of the lock gear 25 when rotatably supported by the sensor case 31 and actuated by the inertial mass 32.
5a and the first retainer 2
A housing part 26b provided on the housing 6 to cover the sensor case 31 from the side opposite to the housing 30;
, And an electromagnet 34 that attracts and holds the inertial mass 32 by a magnetic force generated upon energization. In this case, portions other than the electromagnet 34 of the deceleration detecting means 9 are the same as the conventional vehicle sensor.

As shown in FIG. 3 (a), the electromagnet 34 generates a magnetic force when energized and does not generate a magnetic force when not energized.
and an electromagnet member 34b for attracting and holding the inertial mass 32 by the magnetic force generated in step (a). In a normal state, the second lock coil 34a is energized, and the electromagnet member 34
In FIG. 3B, the inertial mass 32 is suction-held and set to the inoperative position shown in FIG. The inertial mass 32 is an electromagnet member 34
In the state of being suction-held in b, even if a large vehicle deceleration such as a collision occurs, the inertial mass 32 does not move (activate) and stops at the inactive position. In the inactive position of the inertial mass 32, the actuator 33 has its pawl 33
a is set to a non-operating position where it cannot engage with the external teeth 25a of the lock gear 25 shown in FIG.

When the second lock coil 34a is not energized, the electromagnet member 34b does not attract and hold the inertial mass 32, so that the inertial mass 32 is set in a movable state. In the movable state of the inertial mass 32, when a large vehicle deceleration such as a collision occurs, the inertial mass 32
Moves leftward and upward along the curved guide surface of the sensor case 31 from the non-operation position indicated by the two-dot line in FIG. 3B, and is set to the operation position indicated by the solid line in FIG. 3B. It is supposed to be. At this time, since the inertial mass 32 operates the actuator 33, the actuator 33 is set from the non-operation position indicated by the two-dot line in FIG. 3B to the operation position engageable with the external teeth 25a indicated by the solid line. You. When the lock gear 25 rotates in the webbing withdrawing direction α in a state where the actuator 33 is set to the operating position, the external teeth 25a are immediately
The actuator 33 locks the rotation of the lock gear 25 in the webbing pull-out direction α.

By the way, as shown in FIG. 4A, the first and second lock coils 19a and 34a are respectively arranged in parallel, and both are connected to a power supply 38 via connection terminals 36 and 37. Also, the first lock coil 19
The circuit a only includes a first lock coil switch means 40 such as a normally open relay switch. The first lock coil switch means 40 is normally opened and turned off, and closed and turned on by a control signal from a control device (not shown) such as a CPU for controlling the driving of the motor 10. Has become.
Therefore, the first lock coil 19a is not energized at normal times, and is energized when the first lock coil switch means 40 is turned on, while the second lock coil 34a is always energized.

The motor 10 is mounted on a second retainer 35 mounted on the left side wall 15 of the frame 2, and the rotating shaft 10 a of the motor 10 is connected to the second retainer 35.
And protrudes to the opposite side of the second retainer 35 through a through-hole (not shown) formed in the hole. The drive of the motor 10 is controlled by the CPU based on various information of the vehicle such as information on a vehicle running state such as a vehicle speed and a vehicle acceleration or information on a vehicle driving state such as a brake pedal depressing speed and an accelerator pedal depressing speed. It has become.

The power transmission gear mechanism 11 has a motor gear 41 composed of a helical gear attached to the rotating shaft 10a of the motor 10 so as to be integrally rotatable, and a large diameter helical gear constantly meshed with the motor gear 41. Connect gear 42
and a connect gear 42 formed concentrically and integrally with the large-diameter connect gear 42a, the small-diameter connect gear 42b having a smaller diameter than the large-diameter connect gear 42a.

The speed reduction mechanism 12 includes a first carrier 43 formed of an annular disk and a ring-shaped internal gear 44.
, Four planetary gears 45, 46, 47, 48, a sun gear 49, and a reduction gear 50. The first carrier 43 has ratchet-shaped external teeth 43a formed on the outer periphery, and the second carrier 43 of the torsion bar 28 is formed at the center.
A through hole 43b through which the extension shaft 28e penetrates is formed. The internal gear 44 has internal teeth 44a on the inner periphery,
And it has ratchet teeth 44b on the outer periphery.

Four planetary gears 45, 46, 47, 4
8 are supported by the first carrier 43 so as to be able to rotate. In that case, these planetary gears 45, 4
Reference numerals 6, 47 and 48 respectively connect the reduction pins 52, 53, 54 and 55 via the reduction plate 51 to the four support holes 43c, 43d, 43e and 43f of the first carrier 43.
It is supported by attaching to. The four planetary gears 45, 46, 47, and 48 are all composed of the same planetary gear, and each of these planetary gears 45, 46, 47, and 48 has the internal gear 44a of the sun gear 49 and the internal gear 44. Both are always meshed. Sun gear 49 is torsion bar 2
8 is supported so as to be rotatable relative to the second extension shaft 28e.

Further, the reduction gear 50 has internal teeth 45a on the inner periphery and external teeth 45b on the outer periphery. The internal teeth 45a of the reduction gear 50 are always screwed with the sun gear 49, so that the reduction gear 50 always rotates integrally with the sun gear 49. Further, the external teeth 50 b of the reduction gear 50 always mesh with the small diameter connect gear 42 b of the connect gear 42.

The power transmission path switching mechanism 13 is integrally and coaxially assembled with the locking lever 56 and the connect gear 42 rotatably supported by the second retainer 35, and is a spring that can rotate integrally with the connect gear 42. A holding member 57 and a lever having predetermined elasticity, one end of which is integrally assembled with the spring holding member 57 and which is rotatable integrally with the spring holding member 57 and the other end of which is connected to the locking lever 56; And a spring 58.

The locking lever 56 is moved to the second retainer 35 by the parallel movement so that the ratchet teeth 44 of the internal gear 44 are moved.
b. When the motor 10 is not driven in the normal state, the connection gear 42 is not rotated and is in an inoperative state, and the locking claw 56a of the locking lever 56 is set at a position where it does not engage with the ratchet teeth 44b. I have. In this state, the spool 4 and the motor 10 are free from being rotationally connected to each other.

When the motor 10 rotates so that the spool 4 rotates in the webbing winding direction β, the connect gear 42
Also, the spool 4 rotates from the non-operating state in the normal state so that the spool 4 rotates in the webbing winding direction β. Then, the rotation of the connect gear 42 is transmitted to the lever spring 58 via the spring holding member 57, and the lever spring 58 similarly rotates so that the spool 4 rotates in the webbing winding direction β. By rotation, the locking lever 56 moves parallel to the direction approaching the internal gear 44, and the locking claw 56 a is set at a position where it can be engaged with the ratchet teeth 44 b of the internal gear 44. . In this state, the spool 4 and the motor 10 are rotationally connected to each other, and the driving torque of the motor 10 is transmitted to the spool 4.

The locking pawl 56a is connected to the ratchet teeth 44b.
When the motor 10 rotates so that the spool 4 rotates in the webbing withdrawing direction α from the state where the connection gear 42 is engaged, the connect gear 42 also rotates so that the spool 4 rotates in the webbing withdrawing direction α. Then, the rotation of the connect gear 42 is transmitted to the locking lever 56 via the spring holding member 57 and the lever spring 58, so that
The locking lever 56 moves parallel to the direction away from the internal gear 44 so that the locking claw 56a is set at a position where it does not engage with the ratchet teeth 44b. In this state, the spool 4 and the motor 10 are free from being rotationally connected to each other.

By the power transmission path switching mechanism 13 configured as described above, the power transmission gear mechanism 11 and the reduction mechanism 1
2, the power transmission path between the spool 4 and the motor 10 is turned off when the motor 10 is not driven, so that the spool 4 and the motor 10 are rotatably free from each other. At times, it is set to ON so that the spool 4 and the motor 10 are rotationally connected. The first cover 59 is attached to the second retainer 35 so as to cover the power transmission gear mechanism 11, the speed reduction mechanism 12, and the power transmission path switching mechanism 13.

Between the first carrier 43 and the spool 4,
A second carrier 60 is provided. The second carrier 60 includes a cylindrical shaft portion 60a having a regular hexagonal cross section and a connecting portion 60b integrally formed with the shaft portion 60a.

The end of the through hole 4a of the spool 4 on the side wall 15 side is fitted into the outer periphery of the shaft portion 60a so as to be relatively non-rotatable.
8, the second torque transmitting portion 28c of the torsion bar 28 is rotated integrally with the spool 4, the second carrier 60, and the second torque transmitting portion 28c of the torsion bar 28. . Also, four connecting pins 60c, 60d, 60e, 60f formed on the connecting portion 60b.
However, the through holes 43g, 43h,
The first and second carriers 43, 56 are integrally rotated by being fitted to 43i, 43j.

The second carrier 60 includes an E-ring 61 attached to the second extension shaft 28 e of the torsion bar 28.
As a result, it is axially fixed to the second torque transmitting portion 28c. Then, the motor 10, the power transmission gear mechanism 1
1, speed reduction mechanism 12, power transmission path switching mechanism 13 and C
The PU constitutes a belt tension control mechanism for controlling the belt tension of the webbing 3.

The spring means 14 includes a bush 62,
A return spring 63 and a spring cover 64 are provided. The bush 62 is the first of the torsion bars 28.
The first extension shaft 2 is always spline-fitted to the extension shaft 28d.
8d and can rotate together. In that case, the bush 62 is rotatably supported by the spring cover 64.

The return spring 63 is formed of a mainspring, and its outer peripheral end 63 a is connected to the first cover 59, and its inner peripheral end 63 b is connected to the outer peripheral surface of the bush 62. The spool 4 is constantly urged in the webbing winding direction β via the bush 62 and the torsion bar 28 by the spring force of the return spring 63.

Next, the operation of the belt tension control mechanism configured as described above will be described. (1) Inactive state of seat belt retractor (webbing retracted state) In the inactive state of seat belt retractor 1, webbing 3 is wound around spool 4 by the spring force of return spring 63 of spring means 14. Also,
The motor 10 is not operating. In this non-operating state, the motor gear 41 and the connect gear 42 do not rotate, so that the power transmission path switching mechanism 13 does not operate as described above, and the power transmission path between the spool 4 and the motor 10 is turned off. Thereby, the internal gear 4
4 is a webbing take-out direction α and a webbing take-up direction β
It is free to rotate in any direction. Therefore, the belt tension control mechanism is in an inactive state. At this time, the power transmission path of the motor gear 41, the connect gear 42, and the reduction gear 50 needs a certain or more force (torque) to rotate these gears due to the holding torque of the motor 10 when not operating. Has become. Further, the first lock coil switch means 40 is set to OFF, the first lock coil 19a is not energized, the first lock means 5 is not operated, and the second lock coil 19a is not operated.
When the lock coil 34 a is energized, the inertial mass 32 is fixed by the electromagnet 34.

(2) Webbing Withdrawal Operation When the webbing 3 is withdrawn from the above-mentioned non-operating state of the seat belt retractor 1, the spool 4 rotates in the webbing withdrawal direction α, so that the second torque transmitting portion 28c of the torsion bar 28 and Both the second carriers 60 rotate in the webbing withdrawing direction α. Then, the first carrier 43
Rotate in the same direction α, so that each planetary gear 45, 4
6, 47, 48 attempt to revolve around sun gear 49 in the same direction α. At this time, the sun gear 49 has the reduction gear 5
0 always meshes, and this reduction gear 50 has an intermediate reduction gear 5
8, the small-diameter intermediate reduction gear 58b always meshes and the intermediate reduction gear 58 requires a predetermined force to rotate as described above. Thus, the internal gear 44 is freely rotatable as described above, the internal gear 44 rotates freely, and the sun gear 49 does not rotate. Therefore,
Each of the planetary gears 45, 46, 47, 48 rotates in the webbing withdrawing direction α.

Since the sun gear 49 does not rotate, the rotation of the spool 4 in the webbing withdrawing direction α when the webbing 3 is withdrawn is not transmitted to the connect gear 42, so that the lever spring 58 does not operate and the locking lever 5 does not operate.
6 also does not move. Therefore, the power transmission path switching mechanism 1
3 does not operate, the power transmission path between the spool 4 and the motor 10 is kept off, the rotation of the spool 4 is not transmitted to the motor 10, and the motor 10 I will not receive it. At this time, the motor 10 is not driven, and the belt tension control mechanism is kept in the non-operating state.

When the webbing is withdrawn, the torsion bar 28, the stopper 29, the locking base 23, and the lock gear 25 rotate integrally with the spool 4 as the spool 4 rotates in the webbing withdrawing direction α. Also, when pulling out the webbing, the first torsion bar 28
When the extension shaft 28d rotates in the webbing withdrawing direction α, the return spring 63 is tightened through the bush 62 of the spring means 14, and the spring force gradually increases in accordance with the webbing withdrawal amount.

(3) Webbing Winding Operation by Motor Driving Torque When the seat belt retractor 1 is not operated, the motor 10 is rotated so that the spool 4 rotates in the webbing winding direction β.
Is driven, the motor gear 41 rotates, and the connect gear 42 rotates at a reduced speed such that the rotation of the spool 4 is in the webbing winding direction β. Then, the power transmission path switching mechanism 13 operates as described above, and the spool 4
The power transmission path between the motor and the motor 10 is set to ON, and the spool 4 and the motor 10 are rotationally connected. That is,
The belt tension mechanism is set to the operating state.

Then, the rotation of the connect gear 42 is transmitted to the reduction gear 50, and the rotation reduction gear 50 rotates at a reduced speed, so that the sun gear 49 rotates at the same speed as the reduction gear 50. The rotation of the sun gear 49 causes each planetary gear 3
9, 40, 59 are further decelerated in the webbing withdrawing direction α and rotate. When the rotation of the internal gear 44 is stopped by the operation of the power transmission path switching mechanism 13, each planetary gear 3
9, 40, 59 are revolved around the sun gear 49 along the internal teeth 44a of the internal gear 44 and revolved. Therefore, since the first carrier 43 rotates at the revolution speed of each of the planetary gears 39, 40, and 59, the spool 4 rotates in the webbing winding direction β at the same speed as the rotation speed of the first carrier 43. In this way, the spool 4 rotates in the webbing winding direction β by transmitting the rotation of the motor 10 in the webbing withdrawing direction α at a predetermined reduction ratio by the reduction mechanism 12.

By the rotation of the spool 4 in the webbing winding direction β, the webbing 3 is forcibly wound on the spool 4 in accordance with the rotation torque of the motor 10, and the belt tension is controlled. The belt tension is controlled to a desired value by controlling the drive of the motor 10 based on the vehicle running state and the vehicle driving state to control the winding amount of the webbing 3 to a desired amount as described above. . In this case, since the first extension shaft 28d rotates in the webbing winding direction β, the return spring 63 is loosened, so that the spring force of the return spring 63 is reduced.

The spool 4 is rotated in the webbing winding direction β to wind up the webbing 3 in a state where the power transmission path switching mechanism 13 is operated and the external teeth 43a and the locking claws 21 are engaged in this manner. Then, the first carrier 43 also rotates in the webbing winding direction β, so that the external teeth 4
The engagement between the hook 3a and the locking claw 21 is released, and the webbing 3 is smoothly and reliably wound up.

(4) Operation for Canceling Webbing Forced Winding Operation When the motor 10 is rotationally driven in the reverse rotation direction to the above (3) in the above-described webbing forced winding state,
Each gear 41, 42, 50, 45, 46, 47, 48 and the first
The spool 4 rotates in the webbing withdrawing direction α via the carrier 43, and the forced winding of the webbing 3 is relaxed. The rotation of the connect gear 42 in the webbing pull-out direction α also rotates the lever spring 58 in the webbing pull-out direction α, so that the locking lever 56 moves parallel to the direction away from the internal gear 44, and the locking claw 56a This is a non-engagement position where the null gear 44 does not engage with the ratchet teeth 44b. As a result, the internal gear 44 is freely rotatable, and the spool 4 and the motor 10 are freely rotatable with respect to each other.

In the seat belt retractor 1 of this embodiment, the rotational torque of the motor 10 of the belt tension mechanism controlled by the CPU is used in accordance with the condition of the occupant in the vehicle, the driving condition outside the vehicle, or the operating condition of the webbing 3. Thus, the belt tension of the webbing 3 is controlled.

(5) When a vehicle deceleration exceeding a predetermined deceleration is applied to the vehicle in a state where the seat belt is fastened When a vehicle deceleration exceeding the predetermined deceleration is applied to the vehicle due to a vehicle collision or the like in a state where the seat belt is worn The CPU outputs an ON signal to the first lock coil switch means 40 based on a vehicle deceleration detection signal detected by a vehicle deceleration detection sensor (not shown).
Turns on. Then, the first lock coil 19a is energized, the first lock means 5 is operated, and the locking pawl 21b of the first pawl 21 is set to a position where it can be engaged with the external teeth 43a of the first carrier 43. On the other hand, the spool 4 and the first carrier 43 rotate in the webbing withdrawing direction α because the occupant tries to move forward at this vehicle deceleration and the webbing 3 is withdrawn. However, this first carrier 43
, The external teeth 43a are immediately engaged with the locking claws 21b, so that the rotation of the first carrier 43 and the spool 4 in the webbing withdrawing direction α is locked. At this time, since the rotation of the spool 4 is locked independently of the rotation of the spool 4, the rotation is locked more quickly than in the conventional case where the rotation is locked with the rotation of the spool 4. Therefore, the webbing 3 is quickly prevented from being pulled out, and the occupant is restrained quickly by the webbing. On the other hand, at this time, the inertia mass 32
Is fixed, the second locking means 6 does not operate.

As described above, in the seat belt retractor 1 of this embodiment, when the vehicle is decelerated at a predetermined deceleration or more, the first locking means 5 prevents the occupant from moving forward more quickly. The occupants will be more effectively protected.

(6) A first terminal caused by disconnection of a terminal, breakage of a common circuit portion of the first and second lock coils 19a and 34a, and the like.
When the vehicle is subjected to the vehicle deceleration described in (5) in a state in which the lock coil is not energized, the connection terminals 36 and 37 are disconnected, and the common circuit portion of the first and second lock coils 19a and 34a is broken. When a vehicle deceleration equal to or more than a predetermined deceleration is applied to the vehicle due to a vehicle collision or the like in a state where the seat belt is worn while the seat belt is being worn, the CPU sends an ON signal to the first lock coil switch means 40 as described above. Output. However, due to the disconnection of the terminal, the first lock coil 19a is not energized, and the first lock means 5 does not operate. For this reason,
The rotation lock of the spool 4 in the webbing withdrawing direction α by the first lock unit 5 is not performed.

However, since the second lock coil 34a is not energized due to the above-mentioned disconnection of the terminal or breakage of the circuit portion, the inertial mass 32 can move as described above. Therefore, the inertia mass 3
2 moves to bring the actuator 33 into the operating position. When the webbing 3 is pulled out by the occupant moving forward, the spool 4, the torsion bar 28, the stopper 29, the locking base 23, and the lock gear 25 rotate integrally in the webbing pulling-out direction α.
Immediately engages with the locking claw 33a of the actuator 33. Thus, the rotation of the lock gear 25 in the webbing withdrawing direction α is locked. On the other hand, since the webbing 3 is about to be further pulled out, the spool 4, the torsion bar 28, the stopper 29, and the locking base 2
3 continuously rotates in the webbing pull-out direction α, so that the locking base 23 rotates relative to the lock gear 25 in the webbing pull-out direction α.

Then, the second lock pawl 24 rotates to the operating position with the relative rotation of the locking base 23 (that is, the relative rotation of the spool 4). Since the locking base 23 continues to rotate in the webbing withdrawing direction α, the locking claw 24a of the second lock pawl 24 immediately engages with the internal teeth 16a of the frame 2. As a result, the rotation of the locking base 23 in the webbing withdrawing direction α is locked. On the other hand, since the webbing 3 is about to be further pulled out, the spool 4 continuously rotates in the webbing pulling-out direction α while torsionally deforming the torsion bar 28 with respect to the locking base 23, and the stopper 29 is also integrated with the spool 4. Rotate. That is, the EA mechanism 8
EA action is performed, the load applied to the webbing 3 is limited, and the impact on the occupant is reduced.

When the stopper 29 rotates relative to the locking base 23 in the webbing pull-out direction α, the stopper 29 moves toward the disk portion 23a in the axial direction of the locking base 23. Then, when the stopper 29 comes into contact with the disk portion 23a, the relative rotation of the stopper 29 with respect to the locking base 23 stops. Thereby, the rotation of the spool 4 in the webbing pull-out direction α is locked. That is, the rotation of the spool 4 in the webbing withdrawing direction α by the operation of the second locking means 6 is locked in the same manner as in the related art, so that the webbing 3 is prevented from being pulled out.
The occupant is restrained by the webbing and is prevented from moving forward.

As described above, in the seatbelt retractor 1 of this example, when the vehicle is decelerated at a predetermined deceleration or more, the electromagnetic force of the solenoid 19 generated when the first lock coil 19a is energized. Since the first locking means 6 operates independently of the rotation of the spool 4, the rotation of the spool 4 in the webbing withdrawing direction α is directly locked. Thus, when the above-described vehicle deceleration occurs, the rotation of the spool 4 in the webbing withdrawing direction α is quickly locked. Therefore, the rotation amount of the spool 4 from the occurrence of the vehicle deceleration to the activation of the first lock means 5 is reduced, and the amount of the webbing 3 pulled out is restrained. Thus, the occupant is more effectively protected when the aforementioned vehicle deceleration occurs.

Also, even if the webbing 3 is suddenly pulled out, the first locking means 5 does not operate, so that the occupant does not feel uncomfortable or uncomfortable. Further, even if the first lock coil 19a is not energized and the first lock means 5 does not operate due to the above-mentioned disconnection of the terminal or the determination of the circuit, the second lock is not applied when the vehicle is decelerated at a predetermined deceleration or more. Since the occupant is prevented from moving forward by the operation of the lock means 6, the occupant is reliably restrained and protected. In this case, the webbing withdrawal amount until the occupant is restrained and protected is larger than when the first locking means 5 is operated, but the same occupant restraining protection effect as in the related art can be obtained.

Further, since the first and second locking means 5 and 6 use solenoids (of course, solenoids are also used for the electromagnets), each locking means 5 and 6 can be formed at low cost. In addition, the structure is simplified. Further, since the second locking means 6 is operated by the electromagnet 34, the rotation of the spool 4 in the webbing withdrawing direction α is quickly locked.

Further, since the above-described conventional vehicle sensor can be used as the deceleration sensing means 9 for operating the second lock means 6, a significant design change is not required, and a cost increase is suppressed. Further, the inertial mass 32 is
Is fixedly held, so that the second lock means 6 does not operate unnecessarily, and unnecessary rotation of the rotation of the spool 4 in the webbing pull-out direction α by the second lock means 6 is prevented.

The seat belt retractor 1 of this example
In the first locking means 5 and the deceleration sensing means 9, the components other than the electromagnet 34, the operation of these components, and the details of the operation and effect of these components have already been filed by the present applicant as a patent application. Japanese Patent Application 2000-23873
5, the description will be limited to the above description.

FIG. 4B is a view similar to FIG. 4A showing another example of the embodiment of the present invention. FIG. 4 described above.
In the example shown in (a), when both the first and second lock coils 19a and 34a are not energized due to a missing terminal or breakage of a common circuit portion of the first and second lock coils 19a and 34a, the second lock is performed. Although the means 6 is operated, in the seat belt retractor 1 of this example, when only the first lock coil 19a is not energized due to breakage of the first lock coil 19a itself or a circuit portion of only the first lock coil 19a. Also, the second lock means 6 is operated.

That is, as shown in FIG.
A current detection means 65 for detecting a current flowing through the first lock coil 19a is provided in a circuit portion including only the lock coil 19a, and the current detection means 65 supplies a detection signal of the current of the first lock coil 19a to the CPU. It is supposed to be. In addition, a circuit portion including only the second lock coil 34a includes a second switch such as a normally closed relay switch.
Lock coil switch means 66 is provided. The second lock coil switch means 66 is normally closed and turned on, and is opened and turned off by a control signal from the CPU. Therefore, the second lock coil 34a is not energized at normal times, and is not energized when the second lock coil switch means 66 is off. Other configurations of the seat belt retractor 1 of this example are the same as those of the above-described example.

In the seat belt retractor 1 of this embodiment thus configured, the first lock coil 19a itself, the first lock coil switch means 40, or the circuit portion of the first lock coil 19a alone is broken to break the first lock coil 19a. When the case where only the one lock coil 19a is not energized occurs, the above-described vehicle deceleration occurs, and the first lock means 5 does not operate even if an operation signal is output from the CPU to the first lock coil switch means 40.

At this time, in the above-mentioned example, since the second lock coil 34a is maintained in the energized state, the second lock means 6 does not operate, but in this example, the second lock means 6a does not operate.
Will work. That is, when an operation signal is output from the CPU to the first lock coil switch means 40, if the current detection means 65 does not detect a current flowing through the first lock coil 19a, the CPU sends a signal to the second lock coil switch means 66. A control signal is output, and the second lock coil switch means 66 is turned off. As a result, the second lock coil 34a is also de-energized, and the second lock means 6 is operated in the same manner as described above to lock the rotation of the spool 4 in the webbing withdrawing direction α, thereby preventing the webbing 3 from being withdrawn.

As described above, according to the seat belt retractor 1 of this embodiment, the second locking means 6 can be reliably operated even when only the first lock coil 19a is not energized, and the webbing 3 is pulled out. Can be more reliably prevented. Other operations and other effects of the seat belt retractor 1 of this example are the same as those of the above-described example.

In each of the above examples, the first locking means 5
The first pawl 21 locks the rotation of the first carrier 43 in the webbing withdrawing direction α, but in addition to the first carrier 43, the spool 4 and the torsion bar 2
8, the second carrier 60 or the locking base 23
Any component that can lock the rotation of the spool 4 independently of the rotation of the spool 4 can be locked. In that case, the first of the locking base 23 or the torsion bar 28
The rotation of the components of the torsion bar 28 on the first torque transmitting portion 28b side, such as the torque transmitting portion 28b, is controlled by the first locking means 5.
To lock the torsion bar 28
An EA effect due to the torsional deformation can be obtained.

In each of the above examples, the first locking means 5
Although the electromagnet 34 is provided to make the inertial mass 32 immovable when can be operated, the electromagnet 34 is not necessarily provided, and the inertial mass 32 can always be set to be movable as in the related art. In this way, no matter what causes the first locking means 5 to become inoperable, the second locking means 6 is reliably operated when the above-described vehicle deceleration occurs, and the webbing 3 is pulled out. In addition to reliable prevention, components such as the electromagnet 34 are not required, so that the number of components can be reduced, and the structure becomes simpler.

Further, in each of the above-mentioned examples, the first locking means 5
The first pawl 21 is operated by the electromagnetic force of the solenoid 19, but other electric drive means such as an electric motor may be used for the first pawl 21.

Further, in each of the above examples, the deceleration sensing means 9
Locks the rotation of the lock gear 25,
Although the locking means 6 locks the rotation of the spool 4 in the webbing pull-out direction α by the rotation of the spool 4,
When the deceleration sensing means 9 locks, for example, the rotation of the locking base 23, the second locking means 6 can also lock the rotation of the spool 4 in the webbing pull-out direction α independently of the rotation of the spool 4. Further, instead of the deceleration sensing means 9, the rotation of the lock gear 25 or the locking base or the like may be locked by operating a pawl by a solenoid or an electric motor, for example, similarly to the first locking means 5. it can. Further, an EA such as a torsion bar 28 or a stopper 29 is used.
The mechanism is not necessarily provided, and can be omitted.

FIG. 5 is an exploded perspective view similar to a corresponding portion in FIG. 1 and partially showing a seat belt retractor according to another embodiment of the present invention. In the example shown in FIG. 1 described above, when the first locking means 5 is operated, the torsion bar 28 is not torsionally deformed, so that the EA effect cannot be obtained.
When the first locking means 5 is activated, the torsion bar 28
Are torsionally deformed to obtain an EA effect.

That is, as shown in FIG. 5, in the seat belt retractor 1 of this embodiment, the second carrier 60 is formed of a cylindrical shaft portion 60a having a regular hexagonal cross section and four connecting pins 60c, 60d, It does not have 60e, 60f, but instead has a connecting portion 60b, a cylindrical screw shaft 60g, and a disk portion 60h, and a through hole 60i penetrating in the axial direction at the center thereof. I have. Although not shown, a portion of the through hole 60i corresponding to the disk portion 60h is a hole having a regular hexagonal cross section. This cross section 6
The second torque transmitting portion 28c of the torsion bar 28 is fitted into the rectangular hole so as not to rotate relatively. In this case, in this example, the second carrier 60 and the second torque transmitting unit 28
c is provided so as to be rotatable relative to the spool 4.

Further, the connecting part 60b is provided with a connecting shaft 60j having a regular hexagonal cross section. And this connecting shaft 6
5, the first and second carriers 43 and 60 are rotated relative to each other by fitting into a through hole 43b (not shown in FIG. 5) having a regular hexagonal cross section formed at the center of the first carrier 43. Disabled. Further, a stopper 29 provided so as to be able to rotate integrally with the spool 4 and to be relatively movable in the axial direction with the spool 4 is screwed into the screw shaft portion 60g.

On the other hand, the locking base 23 does not have the screw shaft 23b of the above-described example, but instead has a cylindrical shaft 23d having a regular hexagonal cross section. The first torque transmitting portion 28b of the torsion bar 28 is provided inside the cylindrical shaft 23d.
Are fitted so that they cannot rotate relative to each other, and the cylindrical shaft 23
d is fitted to the end of the spool 4 on the side wall 16 side of the through hole 4a so as to be relatively non-rotatable.
The spool 4, the locking base 23, and the first torque transmitting portion 28b are all unable to rotate relative to each other. The other configuration of the seat belt retractor 1 of this example is the same as the seat belt retractor 1 of the example shown in FIG.

In the seat belt retractor 1 of this embodiment thus configured, the first
When the locking means 5 of the first carrier 43 is operated to lock the rotation of the first carrier 43 in the webbing withdrawing direction, the second carrier 60 is locked.
The rotation of the second torque transmitting portion 28c of the torsion bar 28 is also locked. Then, the spool 4 rotates in the webbing pull-out direction in the same manner as in the above-described example.
Both the torque transmitting portion 28b and the locking base 23 rotate in the webbing pull-out direction. As a result, the torsion bar 28 is torsionally deformed.
The effect is obtained. At this time, the spool 29 rotates relative to the second torque transmitting portion 28c, so that the stopper 29 faces the disk portion 60h of the second carrier 60 in the axial direction with respect to the spool 4 and the second torque transmitting portion 28c. Relative movement. When the stopper 29 comes into contact with the disk portion 60h, the rotation of the stopper 29 is locked in the same manner as in the above-described example. Therefore, the rotation of the spool 4 is locked, the EA action by the torsion bar 28 ends, and the webbing 3 is pulled out. No longer. Thus, according to the seat belt retractor 1 of this example, when the locking operation by the first locking means 5 is performed, the EA effect by the torsion bar 28 can be obtained.

In the seat belt retractor of this example, the second locking means 6 is locked, and the second pawl 24 is engaged with the internal teeth 16a as described above, and the rotation of the locking base 23 in the webbing withdrawing direction is performed. When locked, the rotation of the spool 4 in the webbing pull-out direction is directly locked via the first torque transmitting portion 28b, so that the torsion bar 28 is not torsionally deformed and the torsion bar 28 is not deformed.
No EA action is performed.

[0089]

As is apparent from the above description, according to the seat belt retractor of the present invention, the first locking means operates independently of the rotation of the spool when necessary.
The rotation of the spool in the webbing pull-out direction can be directly locked, and the rotation of the spool in the webbing pull-out direction can be quickly locked when necessary. Therefore, when necessary, the amount of rotation of the spool until the first locking means is activated can be reduced, so that the amount of webbing pulled out can be suppressed, and the occupant can be quickly restrained by the webbing. Thereby, the occupant can be more effectively protected when necessary.

Further, even if the webbing is suddenly pulled out, the first locking means does not operate, so that the occupant can be prevented from feeling uncomfortable or uncomfortable. Further, even when the rotation of the spool is not locked by the first locking means for some reason when necessary, the rotation of the spool in the webbing pull-out direction can be locked by the second locking means. Therefore, even when the first locking means is not operated, the webbing can be prevented from being pulled out, and the webbing can reliably protect the occupant.

In particular, according to the second aspect of the present invention, since the solenoid or the motor is used as the electric driving means,
Each locking means can be formed at low cost and the structure can be simplified. Furthermore, according to the third aspect of the present invention, since a conventional vehicle sensor can be used, a significant design change is not required, and an increase in cost can be suppressed. Furthermore, according to the invention of claim 4, unnecessary operation of the second lock means can be suppressed, and unnecessary lock of rotation of the spool in the webbing pull-out direction by the second lock means can be prevented. Further, according to the invention of claim 5, when the rotation of the spool in the webbing withdrawing direction is locked by the operation of the first locking means, the webbing load is limited by the load limiting mechanism, so that the impact of the occupant can be reduced. Become like

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a seat belt retractor according to an example of an embodiment of the present invention.

FIG. 2 shows a first locking means of the example shown in FIG. 1,
(A) is a figure which shows the inoperative state of a 1st lock means, (b)
FIG. 4 is a diagram illustrating an operation state of a first lock unit, and FIG. 4C is a diagram illustrating a case where webbing is wound in an operation state of the first lock unit.

FIG. 3 shows a second locking means of the example shown in FIG. 1,
(A) is a figure which shows the non-operation state of a 2nd lock means, (b)
FIG. 7 is a view showing an operation state of a second lock unit.

4A is a diagram showing an example of an electric circuit in the first and second locking means of the example shown in FIG. 1, and FIG.
FIG. 9 is a diagram showing another example of the electric circuit in the first and second locking means of the example shown in FIG.

FIG. 5 is an exploded perspective view similar to a corresponding portion in FIG. 1, partially showing a seatbelt retractor according to another embodiment of the present invention;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Seat belt retractor, 2 ... Frame, 3 ... Webbing, 4 ... Spool, 5 ... First locking means, 6 ... Second
Locking means, 7: second locking means operating mechanism, 8: force limiter mechanism (EA mechanism), 9: deceleration detecting means, 1
0 ... motor, 11 ... power transmission gear mechanism, 12 ... reduction mechanism, 13 ... power transmission path switching mechanism, 14 ... spring means, 16a ... internal teeth, 19 ... solenoid, 19a ... first lock coil, 21 ... first pawl , 23: locking base, 23a: disk part, 23b: screw shaft, 24: second
Paul, 25: Lock gear, 28: Torsion bar, 2
9: stopper, 32: inertial mass, 33: actuator, 34: electromagnet, 34a: second lock coil, 36,
37 connection terminal, 38 power supply, 40 switch means for first lock coil, 41 motor gear, 42 connect gear, 43 first carrier, 44 internal gear, 4
5, 46, 47, 48 planetary gear, 49 sun gear, 50 reduction gear, 56 locking lever, 60 second carrier, 60h disk part, 60g screw shaft, 63
Return spring, 65 ... Current detecting means, 66 ... Second
Switch means for lock coil

Continued on the front page (72) Inventor Koji Tanaka 1-4-3 Roppongi, Minato-ku, Tokyo Takata F-term (reference) 3D018 DA07 HA02 HB03 HC01 HD03 HE00

Claims (5)

[Claims] 1. A spool for winding a webbing, and the rotation of the spool is normally permitted, and the rotation of the spool in the webbing pull-out direction is locked by operating by an electric driving means independently of the rotation of the spool when necessary. First
Locking means, when the lock of the rotation of the spool by the first locking means is not performed when necessary,
A second locking means for locking rotation of the spool in the webbing withdrawal direction, the seat belt retractor comprising: 2. The seat belt retractor according to claim 1, wherein said electric drive means is a solenoid or a motor. 3. The second locking means includes an inertial mass that operates by sensing a predetermined deceleration of a vehicle deceleration, and an inertial mass that is activated by the operation of the inertial mass to rotate the spool in a webbing withdrawal direction of the spool. The seat belt retractor according to claim 1 or 2, further comprising at least an actuator for locking rotation. 4. The inertial mass is formed of a magnetic material such as iron, and locks the operation of the inertial mass by attracting and holding the inertial mass with an electromagnetic force generated by being normally energized; When the lock of the rotation of the spool by the first lock means is not performed at the time of the necessity, an electromagnet is provided which cancels the suction and hold of the inertial mass by not being energized to enable the inertial mass to operate. The seat belt retractor according to claim 3, wherein: 5. A load limiting mechanism for limiting a webbing load when at least the rotation of the spool in the webbing withdrawal direction is locked by the operation of the first locking means. 4
The seatbelt retractor according to any one of the preceding claims.