JPH0420691Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a webbing take-up device used in a seat belt device installed in a vehicle or the like to restrain an occupant in a vehicle emergency or the like.

[Prior Art] There are various types of winding devices of this type, and a type that does not apply webbing tension to the occupant when the webbing is attached has also been proposed.

This type of take-up device is known to use a screw feed mechanism, but the shaft with a male thread extends in the axial direction of the webbing take-up shaft, so the shape is large. It has the disadvantage that it can become

[Problems to be solved by the invention] Taking the above facts into consideration, the present invention provides a webbing retractor for a seat belt device that has a function of not applying webbing tension to the occupant when the webbing is attached, and can be made smaller. The purpose is to obtain.

[Means for Solving the Problems] The webbing retractor for a seat belt device according to the present invention includes a take-up shaft for winding the webbing and a take-up shaft biasing force for urging the take-up shaft in the webbing retracting direction. a rotating body disposed coaxially with the winding shaft and rotatable independently of the winding shaft; and a rotating body supported by the winding shaft and biasing the rotating body in the webbing unwinding direction. a first gear disposed coaxially with the winding shaft and rotated integrally with the winding shaft; and a first gear pivotally supported by the rotating body and meshed with the first gear. A second gear having a different number of teeth is provided on each of the first gear and the second gear, and the first gear and the second gear are in contact with each other.
Webbing take-up amount limiting means that prevents rotation relative to the gear in one direction but allows multiple rotations of the first gear in the opposite direction; and a webbing take-up amount limiting means that engages with the rotating body to prevent rotation of the rotating body. a rotating body rotation preventing means; a rotating body rotation preventing means biasing means for urging the rotating body rotation preventing means in a direction to engage the rotating body; A first rocking body capable of swinging in an angular range, an engagement prevention portion provided on the first rocking body to prevent rotation body rotation prevention means from engaging with the rotation body, and a recessed part from the engagement prevention portion. A first cam means having an engagement permitting portion formed on the outer circumferential surface that allows the rotating body rotation prevention means to engage with the rotating body; a second rocking body that engages with and swings with the first rocking body and includes an engaging part with the rocking body and an engaging part with the first rocking body that swings in the webbing unwinding direction; 2. An engagement prevention part provided on the rocking body to prevent the rotation body rotation prevention means from engaging with the rotation body, and an engagement prevention part recessed from the engagement prevention part to allow the rotation body rotation prevention means to engage with the rotation body. The engagement permitting portion and the outer circumferential surface rising from the engagement permitting portion and protruding toward the engagement preventing portion are brought into contact with the rotating body rotation blocking means, and the webbing is wound up on the second rocking body. A second cam means is provided with a second cam means formed on the outer circumferential surface of the second oscillating body, and a second cam means is formed on the outer peripheral surface of the second oscillating body. Rotating body rotation prevention means that allows the rotating body rotation prevention means to engage with the rotating body and disengages the rotating body rotation prevention means from the rotating body in conjunction with the opening operation of the door or the uninstalling operation of the webbing. means moving means, wherein the first oscillating body and the second oscillating body are such that when the webbing is unwound immediately after the webbing is attached, the engagement permitting portions of the first cam means and the second cam means are connected to the rotating body. The second cam means is arranged to allow engagement of the rotation blocking means with the rotating body, and the second oscillating body swing preventing portion of the second cam means has a second oscillating body on the outer circumferential surface along the swinging direction of the second oscillating body. The rotating body rotation blocking means is arranged so as to come into contact with the moving body when the moving body is swung to the swinging limit in the webbing winding direction to prevent the rotating body rotation blocking means from engaging with the rotating body. It is said to be composed of

[Function] In the webbing retractor for a seat belt device having the above configuration, when the webbing is in a state in which the webbing can be attached, the rotating body rotation preventing means moving means makes the rotating body rotation preventing means in a state in which it can be engaged with the rotating body. In this state, the second rocking body is moved to the rocking limit in the webbing winding direction, so the rotary body rotation blocking means prevents the second rocking body from swinging in the second rocking body rocking blocking portion of the second cam means. It comes into contact with the outer circumferential surface along the direction of movement and is prevented from engaging with the rotating body.

When the take-up shaft is rotated against the biasing force of the take-up shaft biasing means during webbing unwinding for the webbing device, the first gear is rotated. As the first gear rotates, the second gear is moved to the first gear by the webbing take-up amount limiting means.
While being prevented from rotating relative to the gear, it is rotated together with the rotating body urged by the rotating body urging means.

The rotation of the rotating body causes the first swinging body to swing in the webbing unwinding direction, and is moved to the swing limit in this direction. As the first rocking body swings, the second rocking body engages with the first rocking body and swings together in the same direction. In this state, at least one of the engagement preventing portions of the first cam means and the second cam means prevents the rotating body rotation preventing means from engaging with the rotating body.

Webbing unwinding ends when the occupant engages the tongue plate with the buckle device. At this time,
The webbing is pulled out longer than necessary. Therefore, the excess webbing that has been pulled out is wound onto the take-up shaft that is biased by the take-up shaft biasing means.

When the excess webbing that has been pulled out as described above is wound onto the take-up shaft, the first gear is rotated in the webbing take-up direction. When the first gear rotates, the second gear is set to the webbing take-up amount limiting means.
While being prevented from rotating relative to the gear, it is rotated together with the rotating body in the webbing winding direction against the biasing force of the rotating body biasing means.

The rotation of the rotating body causes the first swinging body to swing in the webbing winding direction. During the rocking of the first rocking body, the second rocking body is engaged with the first rocking body, and the second rocking body is also rocked together in the same direction. The second rocking body is the second oscillator of the second cam means.
When the outer circumferential surface rising from the engagement permitting portion of the rocking body rocking prevention portion comes into contact with the rotary body rotation prevention means, rocking is prevented. In this state, the engagement permitting portion of the second cam means allows the rotating body rotation blocking device to engage with the rotating body, but the engagement blocking portion of the first cam device prevents this.

After the excess webbing that has been pulled out is wound around the take-up shaft, the webbing is unwound due to a change in the occupant's upper body posture. When unwinding the webbing, the rotating body is rotated in the webbing unwinding direction in the same manner as described above. When the first rocking body is swung by the rotation of the rotary body, the engagement permitting portion of the first cam means also allows the rotary body rotation blocking means to engage with the rotary body. As a result, the rotating body rotation preventing means biased by the rotating body rotation preventing means biasing means engages with the rotating body and prevents rotation of the rotating body.

In the state where the rotation of the rotating body is blocked, the webbing take-up amount limiting means prevents the first gear from rotating in the webbing take-up direction from the state immediately after the rotation of the rotating body is blocked. . Therefore, the winding shaft integrated with the first gear is also prevented from rotating in the same direction, and the webbing is not further wound up from the state immediately after the rotating body is prevented from rotating.
As a result, the urging force of the take-up shaft urging means does not act on the webbing via the take-up shaft, so
Webbing tension does not act on the occupant.

Since the webbing take-up amount limiting means allows the first gear to rotate in the webbing unwinding direction, the webbing is unwound against the urging force of the take-up shaft urging means, thereby changing the occupant's upper body posture. Nothing can prevent change.
Moreover, since the webbing take-up amount limiting means allows the first gear to rotate multiple times in the webbing unwinding direction, it does not prevent large changes in the occupant's body posture.

When the occupant returns to a normal sitting position from a state in which the body posture has been changed, the take-up shaft is urged by the take-up shaft biasing means and rotated to wind up the webbing. As the take-up shaft rotates, the first gear is rotated in the webbing take-up direction, but is stopped midway by the webbing take-up amount limiting means. When the first gear is stopped,
As described above, this is the same as the state immediately after the rotating body is prevented from rotating, and no webbing tension is applied to the occupant.

In conjunction with the release of the tongue plate from the buckle device or in conjunction with the opening of the door, the rotating body rotation blocking means is activated by the rotating body rotation blocking means moving means. By being moved against the biasing force of the means, the rotating body rotation blocking means is released from engagement with the rotating body. As a result, the webbing is wound onto the take-up shaft biased by the take-up shaft biasing means and placed in the stored state.

The rotation of the winding shaft causes the rotation body to rotate, and the rotation of the rotation body causes the first oscillation body to oscillate. Furthermore, the second rocking body is engaged with the first rocking body by the rocking of the first rocking body, and the second rocking body is also rocked, and the first rocking body and the second rocking body are rocked to the rocking limit in the webbing winding direction. .

From this state, when the rotating body rotation preventing means moving means makes the rotating body rotation preventing means engageable with the rotating body, the rotating body rotation preventing means is biased by the urging means of the rotating body rotation preventing means. Then, the second cam means comes into contact with the outer circumferential surface of the second oscillating body rocking prevention portion of the second cam means along the oscillating direction of the second oscillating body. This state is a state in which the webbing can be attached as described at the beginning.

[Example] Figs. 1 to 9 show an example of a webbing retractor for a seat belt device according to the present invention, and Fig. 10 shows a seat belt device in which this embodiment is used. It is shown.

As shown in FIG. 10, a webbing retractor 12 for retracting the webbing 10 is attached to an intermediate portion of the side wall of the vehicle compartment. Webbing take-up device 1
The tip of the webbing 10 pulled out from the webbing 2 passes through a slip joint 14 attached to the upper part of the side wall of the vehicle interior, passes through a tongue plate 16, and is attached to the lower part of the side wall of the vehicle interior via an anchor plate 18. The tongue plate 16 is arranged upright from the floor tunnel 20 and can be engaged with and disengaged from a buckle device 22 located on the side of the seat 21.

As shown in FIGS. 1 to 4, the webbing take-up device 12 is equipped with a take-up shaft 24 to which the rear end of the webbing 10 is locked. The winding shaft 24 is pivotally supported by side walls 26A and 26B of the frame 26. One end of the take-up shaft 24 is housed in a cover 28 attached to one side wall 26A of the frame 26 so that the webbing 1 can be used in case of a vehicle emergency.
It is linked with an inner lock mechanism that instantly stops the unwinding of the zero.

An adapter 32 is connected to the other end of the winding shaft 24. The adapter 32 projects into a cover 30 attached to the other side wall 26B of the frame 26. The adapter 32 is pivotally supported by a seat 33 and a mainspring spring case 34. The seat 33 and mainspring spring case 34 are attached to the side wall 2
It is fixed to 6B. Mainspring spring case 3
4 includes a large mainspring spring 3 which is a winding shaft biasing means.
6 is accommodated. The large mainspring spring 36 has an outer end locked to the large mainspring spring case 34 and an inner end locked to the adapter 32. The mainspring spring 36 connects the winding shaft 24 to the second
It is designed to be biased clockwise in the figure.

A small mainspring spring case 38, which is a rotating body, is pivotally supported in the adapter 32 at a portion extending from the large mainspring spring case 34 toward the opposite wall 26B. A small mainspring spring 40 is housed in the small mainspring spring case 38. The outer end of the small mainspring spring 40 is locked to the small mainspring spring case 38, and the inner end is locked to the adapter 32. The small mainspring spring 40 urges the small mainspring spring case 38 counterclockwise in FIG. 2 with respect to the adapter 32.

Further, a first gear 42 is coaxially fixed to the adapter 32 through a key 43 at a portion extending from the small mainspring spring case 38 toward the opposite wall 26B. The first gear 42 is meshed with a second gear 44 that is pivotally supported by the small mainspring spring case 38. The second gear 44 has a larger diameter than the first gear 42 and has a greater number of teeth. That is, in this embodiment, the second gear 4 has 25 teeth compared to the 25 teeth of the first gear 42.
4 is said to have 27 teeth.

A first stopper member 46 and a second stopper member 48, which together constitute webbing take-up amount limiting means, are fixed to the first gear 42 and the second gear 44, respectively. The first stopper member 46 and the second stopper member 48 are adapted to meet and abut each other at the position shown in FIG. 2.

When the first gear 42 is rotated counterclockwise from the state shown in FIG. 2, the first stopper member 46 is also moved in the same direction. At this time, the small mainspring spring case 38 is made rotatable and Mainspring spring 40
When the second gear 44 is biased counterclockwise, the second gear 44 revolves counterclockwise without being rotated while the second stopper member 48 remains in contact with the first stopper member 46. .

Further, when the first gear 42 is rotated clockwise from the same state, the second stopper member 48 is pressed by the first stopper member 46, and the second gear 44 is rotated clockwise without being rotated. Ru.

Furthermore, in a state where the small mainspring spring case 38 is prevented from rotating by a mechanism to be described later, when the first gear 42 is about to rotate clockwise from the state shown in FIG. Since the rotation is prevented, the first stopper member 46 is prevented from moving by the second stopper member 48, so the first gear 42 is not rotated.

Furthermore, when the first gear 42 is rotated counterclockwise from the same state, the second gear 44 rotates while being prevented from revolution. As a result, the first stopper member 46 and the second stopper member 48 are separated from each other. Since the first gear 42 and the second gear 44 have different numbers of teeth, even if the first gear 42 makes one rotation counterclockwise from the state shown in FIG. Stopper member 4
I will never meet 8. First stopper member 46
For the second stopper member 48 to meet again, the first gear 42 must rotate a large number of times (13.5 rotations in this embodiment).
Therefore, the winding shaft 24 can rotate many times counterclockwise from the state shown in FIG. 2, that is, in the webbing unwinding direction.

A cam drum 50, which is a first rocking body, is mounted on the opposite side wall 26B of the small mainspring spring case 38. The cam drum 50 has an integrally formed shaft portion 52 attached to the side wall 30A of the cover 30 and the adapter 3.
It is coaxially supported with 2. A cam plate 54, which is a second swinging body, is fitted into the shaft portion 52 so as to be swingable. In addition, a cam drum 50 is attached to the shaft portion 52.
A friction spring 56 is fitted between the cam plate 54 and the cam plate 54 . The friction spring 56 presses the cam drum 50 toward the small mainspring spring case 38, and presses the cam plate 54 toward the side wall 30A.

As a result, the tapered portion 58 of the cam drum 50 is brought into pressure contact with the tapered portion 60 of the small mainspring spring case 38, so that the cam drum 50 can rotate together with the small mainspring spring case 38 by frictional force.

The cam drum 50 has a cam portion 62, which is a first cam means, concentrically protruding from the other general surface on the outer peripheral surface.
are integrally formed. The cam portion 62 is formed with an engagement blocking portion 62A and an engagement allowing portion 62B that is recessed from the engagement blocking portion 62A. In the cam drum 50, both end surfaces 63A and 63B of the cam portion 62 are stopper surfaces 6 formed by the stepped portions of the cover 30.
4 and 66 (see FIG. 3), the rocking movement in the clockwise and counterclockwise directions is restricted.

As shown in FIGS. 3 and 4, the cam plate 54 has an arcuate guide hole 68 formed therein. A guide pin 70 protruding from the cam drum 50 is inserted into the guide hole 68 . Thereby, the cam plate 54 is connected to the cam drum 50.
is swung counterclockwise in FIG. 3 and the guide pin 70
When the end face 68A of the guide hole 68 comes into contact with the guide hole 68, it is swung together with the cam drum 50 in the counterclockwise direction in FIG. When it comes into contact with the other end surface 68B of the cam drum 50, it is swung clockwise in FIG. 3 together with the cam drum 50.

Further, the cam plate 54 is formed with a cam portion 74 which is a second cam means. The cam portion 74 includes an engagement blocking portion 74A, an engagement permitting portion 74B recessed from the engagement blocking portion 74A, and a cam plate rocker rising from the engagement permitting portion 74B and protruding with respect to the engagement blocking portion 74A. A motion blocking portion 74C is formed.

A ratchet wheel 80 is integrally provided on the outer peripheral surface of the small mainspring spring case 38. This ratchet wheel 8
0 can be engaged with a pawl 82 which is a rotating body rotation prevention means.

The pawl 82 is swingably supported at its intermediate portion by a mainspring spring case 34 via a pin 83, and is urged counterclockwise in FIGS. 2 and 3 by a tension coil spring 84. A claw portion 86 that engages with the ratchet wheel 80 to prevent rotation of the ratchet wheel 80 is formed at one end of the pawl 82, and a stopper pin 88 is protruded near the claw portion 86. Stoppin 88
are positioned corresponding to the cam portion 62 and the cam portion 74, and when they come into contact with the outer peripheral surfaces of the respective engagement prevention portions 62A, 74A and cam plate rocking prevention portion 74C along the cam plate rocking direction. , the claw portion 86 of the pawl 82 is not engaged with the ratchet wheel 80. Further, when the stopper pin 88 enters the engagement permitting portions 62B and 74B of the cam portion 62 and the cam portion 74, the claw portion 86 of the pawl 82 is engaged with the ratchet wheel 80.

In addition, when the cam plate 54 is swung to the counterclockwise swing limit, the stopper pin 88 is positioned corresponding to the outer circumferential surface of the cam plate swiveling prevention portion 74C along the cam plate swiveling direction.

A pin 90 is provided protruding from the other end of the pole 82.

This pin 90 is inserted into a guide hole 94 formed in a lever 92 which is a means for moving a rotating body rotation preventing means. The lever 92 is pivotally supported by the side walls 26A and 26B of the frame 26, and is urged counterclockwise in FIGS. 2 and 3 by a torsion coil spring 96. The tip of the lever 92 is the side door 98
(see Fig. 10), and when the side door 98 is opened, it is biased by the torsion coil spring 96 and swung counterclockwise in Fig. 2, and when the side door 98 is closed, the side Pressed by the door 98 and resisting the biasing force of the torsion coil spring 96, the second
Figure 3: It is swung clockwise.

When the side door 98 is closed, the lever 92 has the guide hole 94 aligned with the pin 9 of the pole 82.
However, when the side door 98 is opened, the end wall of the guide hole 94 comes into contact with the pin 90 and pulls the pole 82 against the biasing force of the coil spring 84. It is designed to swing in the direction.

Next, the operation of this embodiment will be explained.

When the occupant 102 gets on board and sits on the seat 21 and the side door 98 is closed, the lever 92 is moved by the torsion coil spring 96 as shown in FIG.
(not shown in FIG. 5) is swung clockwise against a biasing force. As a result, the pole 82
is in a state where it can swing without being restrained by the lever 92.

In this state before the webbing 10 is attached, both the cam drum 50 and the cam plate 54 are swung to their swing limits in the webbing winding direction (counterclockwise in FIG. 5). That is, in the cam drum 50, one end surface 63A of the cam portion 62 is in contact with the stopper surface 64 of the cover 30, and the cam plate 54 has the guide pin 7 in one end surface 68B of the guide hole 68.
0 is in contact. As a result, the stopper pin 88 of the pawl 82 is in contact with the outer circumferential surface of the cam plate rocking prevention portion 74C of the cam portion 74 along the cam plate rocking direction, and further rocking in the counterclockwise direction in FIG. movement is blocked. Therefore, the claw portion 86 of the pawl 82 is not engaged with the ratchet wheel 80 of the small mainspring spring case 38, so that the small mainspring spring case 38 is in a rotatable state.

Since the small mainspring spring case 38 is in a rotatable state, it can be rotated counterclockwise by being biased by the small mainspring spring 40, but as shown in FIG. Since it is in contact with the first stopper member 46, rotation is prevented and stopped. The first stopper member 46 is biased clockwise by the large mainspring spring 36 via the adapter 32, but both stop when the webbing 10 is wound up to its maximum and the rotation of the winding shaft 24 is stopped. are doing.

When the occupant 102 pulls out the webbing 10 against the biasing force of the mainspring spring 36, the adapter 32 is rotated counterclockwise together with the take-up shaft 24.
The first gear 42 is similarly rotated. First gear 42
As the first stopper member 46 rotates, the small mainspring spring case 38 is urged by the small mainspring spring 40 and rotates counterclockwise in FIG. 2. At this time, since the second stopper member 48 follows the first stopper member 46, the relative positions of the first gear 42 and the second gear 44 do not change.

When the small mainspring spring case 38 rotates counterclockwise, the cam drum 50 also swings counterclockwise in FIG. 5 due to the frictional force. While the cam drum 50 starts swinging and the guide pin 70 moves through the guide hole 68, the cam plate 54 remains stationary, but the guide pin 70 comes into contact with the other end surface 68A of the guide hole 68. Then, the cam plate 54 is swung together with the cam drum 50. cam plate 54
When the cam plate swing prevention portion 74C is moved away from the stopper pin 88, the pawl 82 is urged by the tension coil spring 84 and swings counterclockwise in FIG. 5, and the stopper pin 88 is allowed to engage. Part 7
However, in this state, the engagement preventing portion 62A of the cam portion 62 overlaps the engagement allowing portion 74B, so it comes into contact with the engagement preventing portion 62A and prevents further swinging. is prevented.

As shown in FIG. 6, when the other end surface 63B of the cam portion 62 comes into contact with the stopper surface 66 of the cover 30, the cam drum 50 stops rocking even though the small mainspring spring case 38 continues to rotate. The cam plate 54 is also prevented from swinging. In this state, the stopper pin 88 is
The engagement prevention portions 62A and 74A are in contact with both of the engagement prevention portions 62A and 74A.

When the passenger 102 engages the tongue plate 16 with the buckle device 22 and releases his/her hand from the webbing 10, the webbing 10 that has been pulled out excessively is removed.
is urged by the large mainspring spring 36 and wound up. By winding up the webbing 10, the first gear 42 is rotated clockwise in FIG. The rotation of the first gear 42 causes the second gear 44 to revolve clockwise without changing its relative position with respect to the first gear 42 in the same manner as described above, so that the small mainspring spring case 38 is rotated around the small mainspring spring 40. It is rotated clockwise in FIG. 6 against the biasing force.

As the small mainspring spring case 38 rotates clockwise in FIG. 6, the cam drum 50 also swings clockwise in FIG. The cam drum 50 is swung clockwise in FIG.
When it comes into contact with B, the cam plate 54 is also swung clockwise in FIG. As shown in FIG. 7, the cam plate 54 has a cam plate rocking prevention portion 74C.
When the stopper pin 88 comes into contact with the outer peripheral surface rising from the engagement permitting portion 74B, further swinging is prevented, and at the same time, the cam drum 50 is also prevented from swinging. In this state, the stopper pin 88 is positioned corresponding to the engagement permitting portion 74B of the cam portion 74 and is in contact with the engagement preventing portion 62A of the cam portion 62.

After the winding of the webbing 10 is completed, the crew member 10
When the user 2 changes his or her body posture, the webbing 10 is unwound against the biasing force of the mainspring spring 36. As a result, the small mainspring spring case 38 is rotated counterclockwise in FIG. 7, and the cam drum 50 is similarly swung. As the cam drum 50 swings, the engagement permitting portion 62B of the cam portion 62 aligns with the engagement permitting portion 74B of the cam portion 74, and these engagement permitting portions 62
The stopper pin 88 can now enter into B and 74B. As a result, as shown in FIG. 8, the pawl 82 is urged by the tension coil spring 84 and swings, and the claw portion 86 comes into contact with the ratchet wheel 80 of the small mainspring spring case 38. At this time, the claw portion 86 is connected to the ratchet wheel 80.
If the claws are opposed to each other, the claw portion 86 immediately engages with the ratchet wheel 80 and restrains the small mainspring spring case 38 in a non-rotatable state. In addition, if they are not facing each other, a further slight rotation of the small mainspring spring case 38 or a slight rotation in the opposite direction will cause
The claw portion 86 is engaged with the ratchet wheel 80 .

In this state, the first stopper member 46 is prevented from moving by the second stopper member 48, so that the first gear 42 cannot rotate clockwise in FIG. 2. Therefore, the webbing 10 will not be wound up any further. In addition, in this state, the webbing 10 is in a state in which it is slightly pulled out from a state in which it is in close contact with the upper body of the occupant 102, and
Since no tension is applied to 2, there is no feeling of pressure. From this state, the first gear 42 can rotate counterclockwise in FIG. 2, so the webbing 10 can be unwound. Therefore,
The upper body movement of the occupant 102 is not hindered.

When the occupant 102 changes his or her body posture and the webbing 10 is pulled out against the urging force of the mainspring spring 36, the first gear 42 is rotated counterclockwise in FIG. The rotation of the first gear 42 causes the second gear 44 to rotate clockwise. At this time, since the first gear 42 and the second gear 44 have different numbers of teeth, the first stopper member 46 and the second stopper member 48 meet each other many times (in this embodiment). This is after being rotated (13.5 rotations in the example). Therefore, the first gear 42 is connected to the first stopper member 4
6 and the second stopper member 48, the webbing 10 can be unwound by a sufficient amount to follow large changes in the body posture of the occupant 102.

When the occupant 102 returns his or her upper body posture to the original position, the webbing 10 is urged by the mainspring spring 36 and wound up. As the webbing 10 is wound up, the first gear 42 is rotated clockwise, and the rotation of the first gear 42 causes the second gear 44 to rotate counterclockwise. 1st
The gear 42 and the second gear 44 are stopped when the first stopper member 46 and the second stopper member 48 meet, and winding of the webbing 10 is stopped. The length of the webbing 10 unwound at this time is
02 is the same as before changing the body posture.

When the passenger 102 exits the vehicle, the webbing 10
The tongue plate 16 is released from the buckle device 22 in order to release the attachment of the webbing 1.
0 is not wound in this operation. Webbing 1
0, when the occupant 102 opens the side door 98, the lever 92 is biased by the torsion coil spring 96 and swings counterclockwise as shown in FIGS. 9 and 3. . By swinging the lever 92, the end wall of the guide hole 94 is moved to the pin 90 of the pole 82.
to move the pin 90. The movement of the pin 90 causes the pole 82 to swing clockwise against the biasing force of the tension coil spring 84. paul 82
When swung, the claw portion 86 is disengaged from the ratchet wheel 80, and the small mainspring spring case 38 becomes rotatable.

As a result, the first gear 42 can rotate clockwise in FIG. 2, and the small mainspring spring case 38 is rotated by the urging force of the large mainspring spring 36 against the urging force of the small mainspring spring 40 , the webbing 10 is wound up by being rotated clockwise.

At the same time that the small mainspring spring case 38 starts to rotate, it is swung clockwise by the small mainspring spring case 38 of the cam drum 50, and the cam plate 54 is also rotated clockwise by the guide pin 70. The cam drum 50 is prevented from swinging as one end surface 63A of the cam portion 62 comes into contact with the stopper surface 64 of the cover 30, thereby simultaneously preventing the cam plate 54 from swinging.

When the occupant 102 exits the vehicle and closes the side door 98, the lever 92 is swung clockwise in FIG. 9 against the biasing force of the torsion coil spring 96. Lever 9
2, the pin 90 of the pole 82 moves into the guide hole 9.
The tension coil spring 8 is released from the restraint from 4.
However, the stopper pin 88 comes into contact with the outer circumferential surface of the cam plate rocking prevention part 74C of the cam part 74 along the rocking direction, preventing further rocking. is prevented. This state is the state shown in FIG. 5 above.

In FIG. 11, the operating modes are shown by webbing unwinding lengths corresponding to the states shown in FIGS. 5 to 9. In the figure, the symbol S indicates the slack length of the webbing, so-called slack amount, so that the tension of the webbing is not applied to the occupant. Also, the code M
is the so-called memory amount, which is the length of the webbing that can be unwound following changes in the occupant's body posture.

In the above embodiment, the lever 92 is used as the rotating body rotation preventing means moving means, and this lever 92 is operated in conjunction with the opening and closing of the side door 98. However, the buckle device 22 of the tongue plate 16
It is also possible to use a solenoid or the like which is electrically operated by a buckle switch to detect the engagement and disengagement of the rotating body as a moving means for preventing rotation of the rotating body.

FIGS. 12 and 13 show embodiments of the present invention corresponding to FIGS. 1 and 2. This embodiment differs from the previous embodiment in that the second gear 44 is an internal gear, but its function is basically the same as that of the previous embodiment.

In the case of this embodiment, the ratio of the number of teeth between the first gear 42 and the second gear 44 can be set larger than in the case of the previous embodiment, so that the amount by which the webbing 10 can be unwound can be further increased. effective.

[Effects of the invention] As explained above, the webbing retractor for a seat belt device according to the invention has the effect that it has a function of not applying webbing tension to the occupant when the webbing is attached, and can be made smaller. has.

[Brief explanation of the drawing]

FIG. 1 is a partially sectional front view showing an embodiment of a webbing retractor for a seat belt device according to the present invention;
Fig. 2 is a view corresponding to the - line arrow in Fig. 1, Fig. 3 is a view corresponding to - line in Fig. 1, Fig. 4 is an exploded perspective view of main parts of Fig. 1, and Figs. 5 to 9. 10 is a side view of a seat belt device to which this embodiment is applied, and FIG. 11 is an operation mode diagram of this embodiment, corresponding to FIG. 3. ,
FIG. 12 is a sectional front view of a main part of another embodiment of the present invention, and FIG. 13 is a view corresponding to the direction indicated by the - line arrow in FIG. 12. 10... Webbing, 12... Webbing take-up device, 24... Take-up shaft, 26... Frame, 32
...Adapter, 34...Large mainspring spring case,
36...Large mainspring spring (take-up shaft biasing means), 3
8...Small mainspring spring case (rotating body), 40...
Small mainspring spring (rotating body biasing means), 42...first gear, 44...second gear, 46...first stopper member (webbing take-up amount limiting means), 48...
a second stopper member (webbing take-up amount limiting means);
50... Cam drum (first rocking body), 54... Cam plate (second rocking body), 62... Cam portion (first cam means), 62A... Engagement prevention portion, 62B...
...Engagement permitting portion, 68... Guide hole, 70... Guide pin, 74... Cam portion (second cam means), 74
A...Engagement blocking portion, 74B...Engagement allowing portion, 74
C...Cam plate rocking prevention part, 80...Rawl wheel,
82...Pole (rotating body rotation prevention means), 84...
...Tension coil spring (rotating body rotation prevention means urging means), 92... Lever (rotating body rotation prevention means moving means).

Claims (1)

[Scope of utility model registration request] A take-up shaft for winding the webbing, a take-up shaft biasing means for urging the take-up shaft in the webbing winding direction, and a take-up shaft biasing means arranged coaxially with the take-up shaft and capable of rotating independently of the take-up shaft. a rotating body, a rotating body biasing means supported by the take-up shaft and urging the rotating body in the webbing unwinding direction;
The first gear, which is arranged coaxially with the winding shaft and rotates together with the winding shaft, and the first gear, which is pivotally supported by the rotating body and meshes with the first gear, have different numbers of teeth. The second gear is provided on each of the first gear and the second gear and is in contact with each other to prevent relative rotation of the first gear and the second gear in one direction, but the first gear does not rotate in the opposite direction. a webbing take-up amount limiting means that allows multiple rotations of the webbing;
A rotating body rotation blocking means that engages with the rotating body to prevent rotation of the rotating body, and a rotating body rotation blocking means urging device that urges the rotating body rotation blocking means in a direction to engage the rotating body. a first rocking body that is engaged with the rotary body by frictional force so as to be able to swing together with the rotary body within a predetermined angular range; a first cam means formed on the outer circumferential surface thereof, an engagement preventing portion for preventing engagement, and an engagement allowing portion recessed from the engagement preventing portion to permit engagement of the rotating body rotation blocking means with the rotating body; , the first rocking member includes an engaging part with the first rocking body that swings in the webbing winding direction and an engaging part with the first rocking body that swings in the webbing unwinding direction at positions spaced apart from each other. A second rocking body that engages with the moving body and swings; an engagement prevention portion provided on the second rocking body that prevents the rotation body rotation prevention means from engaging with the rotation body; and a recessed part from the engagement prevention portion. An engagement permitting portion that allows engagement of the rotating body rotation blocking means with the rotating body; and an outer circumferential surface that rises from the engagement permitting portion, projects toward the engagement blocking portion, and rises from the engagement permitting portion is the rotating body. a second cam means having a second rocking body rocking prevention part formed on the outer circumferential surface that comes into contact with the rotation prevention means to prevent the second rocking body from rocking in the webbing winding direction; and a second cam means for attaching the webbing. state or in a closed state of a door of a vehicle equipped with a seat belt device, the rotating body rotation prevention means is brought into a state where it can engage with the rotating body, and the rotating body rotates in conjunction with the opening operation of the door or the operation of uninstalling the webbing. rotating body rotation blocking means moving means for releasing the engagement of the blocking means with the rotating body; The engagement permitting portions of the cam means and the second cam means are arranged so as to permit engagement of the rotating body rotation preventing means with the rotating body, and the second oscillating body swing preventing portion of the second cam means When the second rocking body is rocked to the rocking limit in the webbing winding direction, the rotary body rotation prevention means comes into contact with the outer peripheral surface of the second rocking body along the rocking direction, and the rotating body rotates. A webbing retractor for a seat belt device, characterized in that the webbing retractor for a seat belt device is arranged to prevent a blocking means from engaging with a rotating body.