JPH10157567A - Retractor for seat belt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably and surely sense the acceleration of a vehicle body by providing a plurality of rollers which are engaged with a sensor case and arranged in a track so as to urge the sensor case in the perpendicular direction. SOLUTION: A sensor case 27 tries to move together with a ball weight 29 by the inertia, but it is difficult to move together with the ball weight 29 because a ball 5 gives the resistance force to the sensor case 27 to be turned from the perpendicular position, and the ball weight 29 is surely and relatively moved to the sensor case 27. A vehicle body sensing means 32 can surely sense the change in the acceleration of the vehicle body irrespective of the tilted position of a seat back even when the differential inertia between an oscillation plate 23 to which the sensor case 27 is fixed and a ball weight 29 is small.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seat belt retractor, and more particularly to an improvement in a seat belt retractor having an emergency lock mechanism.

[0002]

2. Description of the Related Art Conventionally, a seat belt device for safely holding a vehicle occupant or the like in a seat is composed of a webbing, a buckle, a mounting device, and a retractor (winding device). The retractor is a device that automatically retracts the webbing when the seatbelt is not used, and is a winding device that can freely change the length of the webbing when the seatbelt is used.

[0003] Such retractors include automatic locking retractors and emergency locking retractors. However, in general, in order to solve the problem that the occupant is excessively restrained and the wearer feels oppression. In addition, an emergency lock mechanism that effectively and safely restrains an occupant and reduces the feeling of pressure due to webbing is provided with an emergency lock mechanism that physically locks the retractor by inertial sensing means that responds to sudden acceleration, collision or deceleration. Retractors are used.

Further, as an inertia sensing means used in such an emergency lock type retractor, there is a vehicle body sensing means for sensing the acceleration of the vehicle body. For example, when the inertial body moves due to a collision or inclination of the vehicle body, the vehicle body sensing means swings an arm provided above the inertial body, and locks the rotation of the winding shaft on which the webbing is wound in the webbing withdrawing direction. It is the structure which operates the lock means which performs.

On the other hand, the retractor as described above is mounted in a reclining type seat back of a vehicle or the like, and a seat belt provided with a vehicle body detecting means operable when the seat back (seat backrest) is inclined at different positions. An apparatus is disclosed in JP-A-8-80807 and the like. Such a vehicle body sensing means includes a first inertia member (inertial body) movably supported on a second inertia member (sensor case), and a first inertia member supported on the second inertia member. A sensor lever (sensor arm) that is swung by a member. The second inertia member is pivotally supported about an axis extending parallel to the adjustment axis of the seatback to which the retractor is mounted. The first inertial member prevents the take-up shaft from rotating in the webbing pull-out direction by moving the sensor lever to engage the auxiliary teeth with the ratchet rotatable about the first axis.

Therefore, when the angle of the seat back is adjusted to different tilt positions, the retractor body attached to the seat back also has a different tilt direction, but the second inertia member is pivotably supported. Therefore, the first and second inertia members can always stay in the vertical direction.
Then, at the time of rapid deceleration such as at the time of a vehicle collision, the first inertia member vertically above the center mass of the pivotally supported second inertia member moves faster than the second inertia member. The first inertia member can engage the auxiliary pawl with the ratchet via the sensor lever. As a result, the rotation of the winding shaft in the webbing pull-out direction is hindered,
The crew is restrained.

[0007]

However, the vehicle body sensing means disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 8-80807,
The acceleration of the vehicle body is sensed when the inertial force acting on the first inertial member during the rapid deceleration of the vehicle moves faster than the second inertial member by a difference smaller than the inertial force acting on the second inertial member. is there.

Therefore, depending on the layout of the second inertial member with respect to the retractor, etc., the difference in the inertial force between the first inertial member and the second inertial member becomes small, and the second inertial member becomes the first inertial member. In some cases, it may be difficult to detect the acceleration due to movement with the member. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned problem, and to stabilize the acceleration of a vehicle body even though a retractor is mounted in a seatback and can be operated when the seatback is in a different tilt position. It is an object of the present invention to provide a seat belt retractor provided with a highly reliable vehicle body sensing means capable of reliably sensing the vehicle.

[0009]

SUMMARY OF THE INVENTION The object of the present invention is to provide a winding shaft of a retractor on which a webbing is wound, a locking means for locking the winding shaft from rotating in a webbing pull-out direction, and a predetermined vehicle body acceleration. A seat belt retractor comprising: a vehicle body detecting means for detecting the state of the vehicle and operating the locking means, wherein the vehicle body detecting means operates a sensor case, a first position for operating the locking means, and operates the locking means. A sensor arm attached to the sensor case to be located at each of the second positions not to be moved; and a relative movement on the sensor case upon receiving a change in acceleration equal to or more than a predetermined value, and moving the sensor arm to the first position. And a plurality of rolling elements arranged in the track to engage with the sensor case and urge the sensor case in a vertical direction. Is achieved by a seat belt retractor, characterized in that it comprises a body.

According to the above configuration of the present invention, the rolling element constantly urges the sensor case in the vertical direction, and when the seat back is adjusted to a different tilt position, the rolling element rotates with respect to the retractor base. The movable sensor case is rotated to a vertical position. On the other hand, when the acceleration changes suddenly, such as during a vehicle collision, the rolling element gives resistance to the sensor case that is about to rotate from the vertical position, so that the sensor case rotates with respect to the retractor base. This makes it difficult to move the inertial body relative to the sensor case.

[0011] Preferably, the rolling element comprises a mass disposed in an arc-shaped orbit. Preferably, the center of the circular orbit is concentric with the rotation center axis of the sensor case and the rotation center axis of the winding shaft.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the accompanying drawings. 1 and 2 show a seat belt retractor 1 according to a first embodiment of the present invention.
3 is a partial schematic side view of a vehicle body in which the seat belt retractor 100 shown in FIG. 1 is attached to a reclining type seat back.

As shown in FIG. 3, the seat belt retractor 100 of the first embodiment is disposed in a reclining type seat back 42 of a seat 41 attached to a vehicle body 40. The seat back 42 has an adjustment axis 5
It is connected to the bottom cushion of the seat so as to be able to pivot about 1, and is adjusted to a tilting position at different angles depending on the physique and the like of the occupant.

The seat belt retractor 100
As shown in FIG. 2, a substantially cylindrical bobbin 2 around which a webbing 50 is wound, a rotatably supported by the retractor base 1 through the bobbin 2, and a latch plate which is a ratchet wheel. A take-up shaft 4 having one end 4a (right side in FIG. 2) and an emergency lock mechanism 30 for preventing the latch plate 4a from rotating in the webbing withdrawal direction in the event of a vehicle emergency.
0. The webbing 50 extending from the retractor 100 through the slot 43 formed in the seat back 42 restrains the occupant to the seat 41.

The retractor base 1 fixed to a frame member (not shown) of the seat back 42 is formed by press-molding a metal plate so that most of the retractor base 1 has a U-shaped cross section. A winding shaft 4 combined with the bobbin 2 is rotatably bridged at a position facing the side plate 1a. A known take-up spring device that constantly urges the bobbin 2 in the webbing take-up direction through the take-up shaft 4 is provided at the other end of the take-up shaft 4 through which the side plate 1a of the retractor base 1 is inserted. (Not shown).

In the present invention, various known structures can be adopted as the specific structure of the emergency lock mechanism 300 for restraining the take-up shaft 4 from rotating in the webbing withdrawing direction in the event of a vehicle emergency. For example, in the case of the first embodiment,
As shown in FIG. 2, a part of the take-up shaft 4 projects outside the latch plate 4a, and the tension plate 9 and the latch cup 13 which is a latch member having internal teeth 13a play there. It is fitted. Note that the latch cup 1
3 return spring 12 is mounted on the spring hanger 13b and formed with a spring hanger 9a formed on the tension plate 9, the latch cup 13 biasing force to rotate in the arrow direction X ₂ is operatively. Furthermore,
A flange 14 that holds a lock member 15 that can be engaged with the internal teeth 13a is fixed to the winding shaft 4 located outside the latch cup 13.

Further, a ratchet wheel 19 which is an inertia member loosely fitted to a tapping screw 20 screwed to the winding shaft 4 is provided outside the lock member 15, and an outer peripheral surface thereof is provided with: A plurality of teeth 19a oriented in a belt pull-out direction for engaging with a sensor arm 28 of a vehicle body sensing means 32 described later are formed. Also, the mounting portion provided inside the ratchet wheel 19 includes:
Since the friction spring 18 is slidably mounted and the friction spring 18 is engaged with the lock member 15, the ratchet wheel 19 rotates integrally with the winding shaft 4, and Relative displacement is possible.

[0018] Then, as shown in FIG. 1, the pole 11 is a claw member to prevent the rotation of the webbing pull-out direction of the latch plate 4a by engaging the latch plate 4a (direction of arrow X ₁₎ is, pawl pin 10 Is supported on the outside of the side plate 1a so as to be disengageable from the latch plate 4a. The pole 11 is provided with a pole guide protrusion 11b, and the pole guide protrusion 11b is inserted into a pole guide hole 13c formed on the outer periphery of the latch cup 13.

That is, the emergency lock mechanism 300 is configured such that the rotation of the ratchet wheel 19 as a lock operating means with respect to the winding shaft 4 causes a delay in the rotation of the lock member 1.
5 engages with the internal teeth 13 a of the latch cup 13 against the urging force of the sensor spring 16, and engages with the engaging portion 11 of the pawl 11 serving as a locking means through the latch cup 13.
By engaging a with the latch plate 4a, the rotation of the winding shaft 4 in the webbing withdrawing direction is prevented.

Further, below the ratchet wheel 19, a tooth 19 which is an engaging portion of the ratchet wheel 19 is provided.
The sensor case 27 constituting the vehicle body sensing means 32 is arranged so as to be rotatable with respect to the retractor base 1 about a rotation axis extending parallel to the adjustment axis 51 of the seat back 42 along the axis a. Has been established. The "lock means" in the present invention is the emergency lock mechanism 30.
0 means the vehicle body sensing means 32 is excluded.

The vehicle body sensing means 32 is attached to the sensor case 27 so as to be located at a first position engaging the teeth 19a of the ratchet wheel 19 and a second position not engaging the teeth 19a. And a ball weight 29 that is an inertial body that moves relative to the sensor case 27 when the acceleration changes by a predetermined amount or more and moves the sensor arm 28 to the first position.

The sensor case 27 has a concave conical surface 27a for receiving the ball weight 29, and is provided with a swing plate 23 pivotally supported by a support member 21 mounted on the outer surface of the side plate 1a. It is fixed to the swing end. The oscillating plate 23 is pivotally supported on a pivot pin 30 fixed to the support member 21 by a nut 31 so as to be pivotable. The rotation center axis is configured to coincide with the rotation center axis.
Therefore, the sensor case 27 has the ratchet wheel 1
It is possible to rotate with respect to the retractor base 1 so as to keep a constant interval with respect to the nine teeth 19a.

A guide member 3 which forms an arc trajectory concentric with the center axis of rotation of the sensor case 27 is fixed below the side plate 1a.
A plurality of balls 5 as rolling elements are provided on the upper side.
Further, an engagement protrusion 24 which protrudes into the circular orbit of the guide member 3 and engages with the ball 5 is provided on the swing end side of the swing plate 23, and the sensor case 27 is engaged with the engagement case 24. The balls 5 are urged in the vertical direction through the projections 24. Further, a sensor cover (not shown) is provided outside the side plate 1a covering the emergency lock mechanism 300.

Incidentally, the engaging projection 24 protruding into the circular orbit.
Are sandwiched between the same number of balls 5 (four each in the first embodiment). Further, these balls 5 as a mass body are made of metal or high specific gravity resin or the like. For example, metal and resin balls are alternately arranged, or only the outermost metal is used and the remaining resin balls are arranged. By doing so, it is possible to prevent hitting sound due to vibration. Further, all the balls may be made of metal by sandwiching a silencer between the balls 5.

Therefore, the ball 5 rolling on the arc-shaped orbital surface 6 constantly urges the sensor case 27 in the vertical direction, and when the retractor base 1 is tilted, the sensor case 27 is moved relative to the retractor base 1. Rotatable sensor case 27
Is rotated in the vertical direction, and is always maintained at a fixed ground angle. Thus, as shown in FIG. 1, the ball weight 29 remains at the normal position where the sensor arm 28 is located at the second position.

On the other hand, when vehicle body acceleration is applied to the seat belt retractor 100 due to collision or inclination of the vehicle body in a vehicle emergency, the swing plate 23 and the ball weight 29
And the ball 5 tends to move rapidly due to inertia. However, each ball 5 that rolls rapidly in the guide member 3 is given viscous resistance due to the frictional resistance of the contact portion. Each ball 5 can roll only along the arc-shaped orbital surface 6, and the traveling direction of each ball 5 is different from the direction of acceleration. Therefore, these balls 5 are harder to move than the swing plate 23, and as a result, give a resistance force to the swing plate 23 which is about to rotate from the vertical position.

Therefore, the swing plate 23 to which the sensor case 27 is fixed is hard to move together with the ball weight 29 placed on the sensor case 27 even when a sudden acceleration is applied. Therefore, the ball weight 29 that has undergone the acceleration change of a predetermined value or more rolls along the concave conical surface 27a, and the sensor arm 28 can be reliably positioned at the first position.

Next, the seat belt retractor 1
The operation of 00 will be described. First, as shown in FIG. 3, the seat back 42 of the seat 41 is inclined with respect to the bottom cushion of the seat about the adjustment axis 51,
The retractor 100 can be arranged at a plurality of different tilt positions. FIG. 1 shows the retractor 100 at a position shown by a solid line in FIG.
Part 00 indicates that the vehicle body 40 moves forward in the direction of arrow A at a constant speed.

The sensor case 27 is in a vertical direction which is a predetermined direction with respect to the other parts of the retractor 100, and the ball weight 29 has a concave conical surface 27a.
At the normal position. Therefore, the engaging portion 28a of the sensor arm 28 is separated from the teeth 19a of the ratchet wheel 19, and is located at the first position where it is not engaged.
It does not engage with a. Further, in a normal use state, the latch cup 13 is urged in the webbing winding direction (direction of arrow X ₂₎ by the urging force of the spring hanger 13b and the spring hanger 9a and the return spring 12 attached to the tension plate 9 cage, pole 11 pole guide protrusion 11b to the pole guide hole 13c is engaged is biased latch plate 4a and a disengaged arrow Z ₂ direction and the locking member 15 is latched by the urging force of the sensor spring 16 Internal teeth 13 of cup 13
It is urged to a position that is not meshed with d. Therefore, the vehicle body sensing means 32 is in a non-operating state, and the webbing 50 can be pulled out freely.

On the other hand, the seat back 42 is
FIG. 4 shows the retractor 100 tilted with respect to the bottom cushion of the seat about 1 and disposed in a tilted position shown by imaginary lines in FIG. As described above, when the retractor base 1 fixed to the seat back 42 is tilted clockwise in FIG. 4, each ball 5 rolls on the arc-shaped orbital surface 6 and moves in the direction of gravity to engage. Since the oscillating plate 23 is urged in the vertical direction via the projection 24, the oscillating plate 23 rotates counterclockwise in FIG. 4 to keep the sensor case 27 at a constant ground angle. Therefore, as shown in FIG. 4, the ball weight 29 remains at the normal position where the sensor arm 28 is located at the second position.

At this time, since the center axis of rotation of the swinging plate 23 is configured to coincide with the center axis of rotation of the winding shaft 4, the sensor case 27 is connected to the ratchet wheel 1.
The sensor arm 2 rotates with respect to the retractor base 1 so as to maintain a certain interval with respect to the teeth 19a of the
8 and the teeth 19a of the ratchet wheel 19
Does not change depending on the tilting position of the seat back 42. Therefore, even when the sensor case 27 is at a different tilt position with respect to the retractor base 1, the sensitivity of the vehicle body sensing means 32 does not change.

When the vehicle body acceleration is applied to the seat belt retractor 100 in the event of a vehicle emergency such as a collision, and the vehicle body sensing means 32 undergoes a speed change of a predetermined value or more, the ball weight 29 moves to the concave conical surface 27a as described above. Rolling along to assure that the sensor arm 28 is in the first position. At this time, the sensor case 27 tends to move with the ball weight 29 due to inertia.
Since the ball 5 applies a resistance to the sensor case 27 that is about to rotate from the vertical position, it is difficult to move with the ball weight 29, and the ball weight 29 can move relative to the sensor case 27 without fail. it can.

Therefore, as shown in FIG. 5, the engaging portion 28a of the sensor arm 28 is
The rotation of the ratchet wheel 19 in the belt pull-out direction is reliably prevented. When the webbing 50 is further pulled out in a state where the rotation of the ratchet wheel 19 is stopped, the ratchet wheel 19 is rotated.
Causes a rotation delay with respect to the rotation of the winding shaft 4 in the webbing pull-out direction. Then, the lock member 15 is pressed against the biasing force of the sensor spring 16 to prevent the latch cup 1 from moving.
3, the engaging portion 11a of the pawl 11 is engaged with the latch plate 4a through the latch cup 13.
, The rotation of the winding shaft 4 in the webbing pull-out direction is prevented, and the pull-out of the webbing 50 is locked.

That is, the vehicle body sensing means 32 of the first embodiment
Is a swing plate 23 on which a sensor case 27 is fixed.
Even when the difference in the inertial force between the seat back 42 and the ball weight 29 is small, the change in the vehicle body acceleration can be reliably detected regardless of the tilt position of the seat back 42. Further, the emergency locking mechanism 300 of the present first embodiment, the tension to the webbing 50 takes, rotational force of the winding to the shaft 4 over a predetermined stunning webbing pullout direction (the direction of arrow X ₁₎ is applied to a vehicle emergency The ratchet wheel 1
9 receives the inertial force and causes a rotation delay with respect to the rotation of the take-up shaft 4 in the webbing pull-out direction. Therefore, the engaging portion 11a of the pawl 11 is engaged with the latch plate 4a as described above, and the webbing 50 is pulled out. Locked.

FIG. 6 is a cutaway side view of a main part of a seat belt retractor 200 according to a second embodiment of the present invention. Seat belt retractor 20 of the second embodiment
The first reference numeral 0 is different from the first reference except that the support means for supporting the sensor case 67 so as to be rotatable with respect to the retractor base 1 around a rotation axis extending parallel to the adjustment axis 51 of the seat back 42 is different. It has the same configuration as the seat belt retractor 100 of the embodiment. Therefore, the same components as those of the seat belt retractor 100 of the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

The vehicle body sensing means 13 in the second embodiment
As shown in FIG. 7, the second sensor case 67 has a pillar-shaped sliding member 7 on the side wall surface on the side of the side plate 1a via the connecting portion 71.
0 is provided. The sliding member 70 is a cylindrical member curved so as to have the same curvature as the circular orbit of the guide member 3, and is slidable along the circular orbit of the guide member 3.

Therefore, the sensor case 67 in which the sliding member 70 is slidably disposed in the circular orbit of the guide member 3.
Can rotate with respect to the retractor base 1 so as to follow the teeth 19a of the ratchet wheel 19 at a constant interval. Further, the sliding members 70 disposed in the arc-shaped track are sandwiched between the same number of balls 5 (three each in the second embodiment), and the sensor case 67 connects the sliding members 70 to each other. The ball 5 urges the ball 5 in the vertical direction.

When the retractor base 1 is tilted, the ball 5 rolls on the arc-shaped orbital surface 6 and moves in the direction of gravity to urge the sliding member 70 in the vertical direction.
The sliding member 70 slides along the circular orbit of the guide member 3 to keep the sensor case 67 at a constant ground angle.
Thus, as shown in FIG. 6, the ball weight 29 remains at the normal position where the sensor arm 28 is located at the second position.

On the other hand, when vehicle body acceleration is applied to the seat belt retractor 200 due to collision or inclination of the vehicle body in the event of a vehicle emergency, the sensor case 67, the ball weight 2
The ball 9 and the ball 5 tend to move rapidly due to inertia. However, each ball 5 that rolls rapidly in the guide member 3 is given viscous resistance due to the frictional resistance of the contact portion. Further, each ball 5 and sliding member 70 can move only along the arc-shaped orbital surface 6, respectively, and the traveling direction of each ball 5 and sliding member 70 is different from the acceleration direction. Therefore, the ball 5 and the sliding member 70 provide a resistance to the sensor case 67 which is about to rotate from the vertical direction.

Therefore, the sensor case 67 does not easily move with the ball weight 29 placed on the sensor case 67 even when a sudden acceleration is applied. Therefore, the ball weight 29 having undergone a change in acceleration equal to or greater than a predetermined
Rolls along the concave conical surface 67a, so that the sensor arm 28 can be reliably positioned at the first position.

Accordingly, the vehicle body sensing means 1 of the second embodiment
32 can reliably detect a change in vehicle body acceleration regardless of the tilting position of the seat back 42 even when the difference in inertial force between the sensor case 67 and the ball weight 29 is small. In each of the above embodiments, the rolling element disposed in the track to engage with the sensor case and urge the sensor case in the vertical direction is formed by the ball 5. The present invention is not limited to this, and may be formed, for example, in a cylindrical roller shape.

Further, the configuration of the lock means, the lock actuation means, the vehicle body detection means and the like in the present invention is not limited to the configuration of each of the above embodiments, but can be appropriately changed based on the gist of the present invention. Of course.

[0043]

That is, according to the present invention, the rolling element constantly urges the sensor case in the vertical direction, and when the seat back is adjusted to a different tilting position, the rolling element biases the sensor case with respect to the retractor base. The rotatable sensor case is rotated to a vertical position. On the other hand, when the acceleration changes suddenly, such as during a vehicle collision, the rolling element gives resistance to the sensor case that is about to rotate from the vertical position, so that the sensor case rotates with respect to the retractor base. This makes it difficult to move the inertial body relative to the sensor case. Therefore, even when the difference in the inertial force between the sensor case and the inertial body is small, the change in the vehicle body acceleration can be reliably detected regardless of the tilt position of the seat back.

Therefore, even though the retractor is mounted in the seat back and can be operated when the seat back is in a different tilt position, the reliability of the vehicle body can be detected stably and reliably. A seat belt retractor provided with a vehicle body sensing means having a high height can be provided.

[Brief description of the drawings]

FIG. 1 is a fragmentary side view of a main part of a seat belt retractor according to a first embodiment of the present invention.

FIG. 2 is a front vertical sectional view of a main part of the seat belt retractor shown in FIG.

FIG. 3 is a partial schematic side view of a vehicle body in which the seat belt retractor shown in FIG. 1 is attached to a reclining type seat back.

FIG. 4 is a fragmentary side elevational view showing a state where the seat belt retractor shown in FIG. 1 is disposed at different tilt positions.

FIG. 5 is a fragmentary side view showing a state where the vehicle body sensing means shown in FIG. 4 has undergone a speed change of a predetermined value or more.

FIG. 6 is a partial cutaway side view of a seatbelt retractor according to a second embodiment of the present invention.

7 is an overall perspective view of the vehicle body sensing means shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Retractor base 2 Bobbin 3 Guide member 4 Take-up shaft 4a Latch plate 5 Ball 6 Arc-shaped raceway surface 9 Tension plate 10 Pole pin 11 Pole 13 Latch cup 19 Ratchet wheel 21 Support member 23 Swing plate 24 Engagement projection 27 Sensor case 28 Sensor Arm 29 Ball Weight 32 Body Sensing Means 50 Webbing 100 Seat Belt Retractor

Claims (1)

[Claims] 1. A winding shaft of a retractor on which a webbing is wound, a lock means for locking rotation of the winding shaft in a webbing pulling-out direction, and a vehicle body for sensing a predetermined vehicle acceleration and operating the locking means. In the seat belt retractor provided with a sensing means, the vehicle body sensing means is located in a sensor case, a first position for operating the locking means, and a second position for not operating the locking means. A sensor arm attached to the sensor case, an inertial body that relatively moves on the sensor case when receiving a change in acceleration equal to or more than a predetermined value and moves the sensor arm to the first position, and engages with the sensor case; And a plurality of rolling elements disposed in the track to urge the sensor case in a vertical direction. Retractor belt.