JPH1199909A - Vehicle body acceleration sensor for seat belt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably and surely perceive acceleration by relatively moving a sensor arm when speed change exceeding a fixed value is received, and interlocking a sensor case around a rotary axis, so as to appropriately keep the direction of an inertia body supporting face regardless of the slant state of a seat back. SOLUTION: When an inertia body 33 is loaded on an inertia body supporting face 30b and received speed change exceeding a fixed value, it is relatively moved on the inertia body supporting face 30b and a sensor arm 31 circumscribed to the inertia body 33 is moved to a position operating a lock means. A rotation transmitting means 39 rotationally moves a sensor case 30 around the rotary axis S according to the slant angle of a seat back, so that the direction of the inertia body supporting face 30b is appropriately kept regardless of the slant state of the seat back. Even if the tilting state of the seat back is changed, the sensor case is kept in a favorable state, the inertia body on the sensor case is only moved by inertia force by a shock and the like, and hence blunting of sensibility of the sensor is not generated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle body acceleration sensor for a seatbelt, and more particularly to a seatbelt retractor mounted in a seatback of a reclining type seat of a vehicle or the like to prevent extension of a webbing in an emergency. The present invention relates to an improvement in a vehicle acceleration sensor for a seat belt that operates a locking means.

[0002]

2. Description of the Related Art Conventionally, a seat belt device for safely holding a vehicle occupant or the like in a seat includes an emergency lock that physically locks a retractor by inertial sensing means that responds to sudden acceleration, collision or deceleration. An emergency lock type retractor that has a mechanism to effectively and safely restrain an occupant and reduce the feeling of pressure due to webbing is used.

As an inertia sensing means used in such an emergency lock type retractor, there is a vehicle acceleration sensor for detecting the acceleration of the vehicle. The vehicle body acceleration sensor, for example, when the inertial body moves due to collision or inclination of the vehicle body, swings a sensor arm provided on the upper part of the inertial body, and rotates the take-up shaft on which the webbing is wound in the webbing pull-out direction. This is a configuration for operating locking means for locking.

In recent years, a vehicle acceleration sensor for a seatbelt has been provided in which a retractor as described above is mounted in a seatback (seat backrest) of a reclining type seat of a vehicle or the like, and which can be operated even when the inclination of the seatback is changed. Various proposals have been made. Such a vehicle body acceleration sensor uses a retractor-based sensor case having the inertial body support surface so that the orientation of the inertial body support surface that supports the inertial body is appropriately maintained regardless of the inclination of the seat back. When the tilted state of the seat back is changed, the sensor case is rotated to correct the orientation of the inertial body support surface, and the sensor case is rotated. The mechanism and the equipment form of the sensor arm are devised.

For example, in a vehicle acceleration sensor disclosed in Japanese Patent Application Laid-Open No. 8-80807, a sensor case is mounted on a retractor base so that a rotation axis of the sensor case passes through the center of a ball weight as an inertial body. The position of the center of gravity of the sensor case is set below the rotation axis, so that the sensor case always faces in the vertical direction by its own weight. Also, Japanese Patent Application Laid-Open No. 1-20
No. 2,553,383, US Pat. No. 5,622,383, etc., a rotation transmitting means for rotating the sensor case in conjunction with the change of the tilting state of the seat back when the tilting state of the seat back is changed is combined with the sensor case and the seat. Various arrangements have been proposed in which the sensor case is arranged between a metal fitting and the direction of the sensor case is corrected by the rotation transmitting means when the inclination state of the seat back is changed.

On the other hand, the vehicle acceleration sensor disclosed in US Pat. No. 5,622,383 is a so-called single arm type having a single sensor arm that swings by movement of an inertial body on a sensor case. The arm is rotatably attached to the retractor base,
When the rocker swings, its tip engages with the teeth of the ratchet wheel to activate the locking means of the retractor.
In general, such a single-arm type is widely used. In the vehicle body acceleration sensor disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 1-220253, for example, a first sensor arm that swings by movement of an inertial body, There is also a so-called double arm type that uses two sensor arms having a second sensor arm that is driven by the swinging operation of the first sensor arm to operate the locking means.

[0007]

By the way, in the vehicle acceleration sensor disclosed in Japanese Patent Application Laid-Open No. 8-80807 or the like, which realizes the rotation of the sensor case by its own weight, when the vehicle suddenly decelerates, In the longitudinal direction of the vehicle body in which the sensor case swings, the difference in inertial force between the inertial body and the sensor case becomes small, and the sensor case may move together with the inertial body, causing a decrease in acceleration sensitivity.

On the other hand, Japanese Unexamined Patent Publication No. Hei.
As disclosed in Japanese Unexamined Patent Publication No. 3 and US Pat. No. 5,622,383, a vehicle equipped with a dedicated rotation transmitting means for rotating a sensor case in conjunction with a tilt of a seat back is provided in a vehicle. It is possible to prevent the sensor case itself from rotating due to acceleration acting upon sudden deceleration or the like, and prevent a decrease in acceleration sensitivity due to the swing of the sensor case. However, in the single arm type in which the locking means is operated by a single sensor arm rotatably attached to the retractor base, the ground angle of the sensor arm fluctuates due to a change in the tilting state of the seat back, and the sensor arm has Since the engagement portion is directed upward or downward, the influence of this portion on the acceleration of the inertial mass differs depending on the tilting state of the seat back, which may affect the acceleration sensitivity.

On the other hand, the double arm type disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 1-202553 can avoid the inconvenience that the variation in the angle of the sensor arm with respect to the ground affects the acceleration sensitivity. Although the acceleration sensitivity can be stabilized, there is a problem on the other hand that an increase in the number of parts and an increase in the complexity of the mechanism cause an increase in the manufacturing cost.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned problems, and it is an object of the present invention to provide a vehicle acceleration sensor mounted on a retractor mounted in a seat back, and to stably and surely detect the acceleration of the vehicle. It is an object of the present invention to provide an excellent vehicle body acceleration sensor for a seatbelt, which can reduce the manufacturing cost with a simple mechanism.

[0011]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a retractor for a seat belt retractor provided on a seat back of a reclining type seat of a vehicle or the like so as to be rotatable about a rotation axis of a winding shaft of a winding shaft of a retractor for a seat belt. A sensor case supported by the base, a first position for actuating locking means for locking the take-up shaft of the seat belt retractor in the webbing withdrawal direction, and a second position for not actuating the locking means. And a sensor arm rotatably attached to the sensor case to be located at each of the first and second positions, and when subjected to a speed change of a predetermined value or more, the sensor arm relatively moves on an inertial body supporting surface of the sensor case, and the sensor arm is moved to the first position. The inertia body to be moved to the position and the orientation of the inertia body support surface are appropriately maintained regardless of the inclination state of the seat back. Rotation transmitting means for interlocking the sensor case around the rotation axis of the winding shaft in accordance with the inclination angle of the seat back, wherein the locking means is moved by the inertial body when a predetermined vehicle acceleration is applied. This is achieved by a vehicle acceleration sensor for a seat belt that activates the vehicle.

According to the above configuration, when the tilted state of the seat back is changed, the sensor case is rotated by the rotation transmitting means interlocking with the tilting of the seat back, and the inertial body support surface is maintained in an appropriate state. You. And because the sensor case with the sensor arm rotatably attached is configured to rotate around the rotation axis of the retractor winding shaft,
When the inclination state of the seat back is changed, the sensor case is rotated with respect to the inertia member rotatably disposed around the rotation axis of the winding shaft so as to maintain a constant interval. I do. Therefore, the distance between the engagement portion of the sensor arm and the inertia member does not change, and the angle of the sensor arm to the ground is always kept constant.

[0013]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a vehicle body acceleration sensor for a seat belt according to an embodiment of the present invention. As shown in FIG. 1, the seatbelt retractor 100 including the vehicle body acceleration sensor 32 of the present embodiment is attached to a seatback 62 of a reclining type seat 61 attached to the vehicle body.
The seat back 62 is connected to the seat portion 63 so as to be able to pivot about an adjustment shaft (adjustment axis of the seat back) 71 extending in the width direction of the vehicle body. The tilt state is adjusted.

The seat belt retractor 100
As shown in FIG. 2 and FIG. 3, a substantially cylindrical bobbin 2 around which the webbing 70 is wound, and the bobbin 2 are inserted through the bobbin 2 so as to be rotatably supported by the retractor base 1 and are driven by a ratchet wheel. A take-up shaft 4 provided with a certain latch plate 4a on one end side (right side in FIG. 3);
a) the emergency locking mechanism 300 for preventing rotation of the webbing 70 in the pull-out direction. The webbing 70 extending from the retractor 100 through the slot 64 formed in the seat back 62 restrains the occupant to the seat.

The retractor base 1 fixed to a frame member (not shown) of the seat back 62 is formed by press-forming 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 plates la and 1b. Side plate 1 of the retractor base 1
A known take-up spring device (not shown) that constantly urges the bobbin 2 in the take-up direction of the webbing 70 via the take-up shaft 4 is provided at the other end of the take-up shaft 4 through which the b is inserted. Have been.

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 present embodiment, the ratchet wheel 19, which is an inertia member rotatably disposed around the rotation axis S of the winding shaft 4, causes a rotation delay with respect to the winding shaft 4, thereby causing a latch. The cup 13 engages the pawl 11 with the latch plate 4a to prevent the winding shaft 4 from rotating in the webbing pull-out direction.

Below the ratchet wheel 19,
A vehicle acceleration sensor 32 according to the present invention is provided. Body acceleration sensor 3 for seat belt according to the present embodiment
2 is a sensor arm 3 as shown in FIGS.
1, sensor case 30, inertial body 33, rotation transmitting means 3
9.

The sensor case 30 includes the inertial body 3
3 is provided with a case main body 30a having an inertial body support surface 30b on which is mounted, and a hanger part 30c extending upward from one side of the case main body 30a, and the upper end of the hanger part 30c is a pin. It is rotatably connected to the end of the winding shaft 4 via 35. Here, the center axis of the pin 35 coincides with the rotation axis S of the winding shaft 4, and the rotation axis of the sensor case 30 extends in parallel with the adjustment axis 71 of the seat back 62. Rotation axis S of spindle 4
Has been matched. However, the upper end of the base is tilted in the YY direction based on the base mounting hole 1c in FIG.
The adjustment shaft 71 and the winding shaft 4 may intersect at a predetermined angle and are not parallel. In this case, the sensor 32 may be mounted so as to assume the state shown in FIG. 3 even when the base is inclined at a predetermined angle.

The inertial body support surface 3 of the sensor case 30
Reference numeral 0b denotes a mortar shape depressed toward the center, and a connection hole in which a long hole 50 to be connected to a rotation transmission means 39 described later is formed at the bottom of the case body 30a provided with the inertial body support surface 30b. The part 51 is provided vertically.

The sensor arm 31 has a shaft 31a on the base end side rotatably supported by a column integrally formed with a case body 30a of the sensor case 30, and the sensor case 30 is retracted via a pin 35. When the ratchet wheel 1 is attached to the
The engagement portion 31b is engaged with the teeth 19a from a first position in which the locking means for locking the rotation of the winding shaft 4 in the webbing withdrawing direction is activated by engaging with the teeth 19a.
The shaft 31a can be pivotally displaced about the shaft portion 31a to a second position where the shaft portion 31a is released from the position a. The “lock means” in the present invention means the emergency lock mechanism 300 excluding the vehicle body acceleration sensor 32.

When the engaging portion 31b of the sensor arm 31 engages with the teeth 19a of the ratchet wheel 19, the ratchet wheel 19 causes a rotation delay with respect to the winding shaft 4, and the latch 11 engages with the latch plate 4a to prevent the take-up shaft 4 from rotating in the webbing 70 pull-out direction.

The inertial body 33 has a spherical shape. When the inertial body 33 is placed on the inertial body support surface 30b and undergoes a speed change of a predetermined value or more, the inertial body 33 relatively moves on the inertial body support surface 30b,
The sensor arm 31 circumscribing the inertial body 33 is moved to the first position.

The rotation transmitting means 39 controls the inclination angle of the seat back 62 so that the direction of the inertial body support surface 30b is maintained properly (upward in the vertical direction) regardless of the inclination state of the seat back 62. The sensor case 30 is rotated around its rotation axis S in response to The sensor case 30 connected to the rotation transmitting means 39 does not rotate around the rotation axis S due to the inertial force acting upon a vehicle collision or the like.

As shown in FIG. 1, the rotation transmitting means 39 includes a slide member 53 disposed on a seat seat 63 of a reclining type seat 61 so as to be linearly movable in the longitudinal direction of the vehicle, and an adjusting shaft 71. And the slide member 53 is rotated in accordance with the inclination state of the seat back 62.
And a cam plate 54 for moving the actuator forward and backward only within a predetermined range corresponding to the rotatable range of the sensor case 30, and one end connected to the slide member 53 and the other end connected to the connection 51 of the sensor case 30. And a wire 56 as a flexible transmission member for transmitting the movement of the slide member 53 to the sensor case 30. Note that the wire 56 has a flexible guide tube having one end fixed near the mounting position of the slide member 53 via a fixing portion 55a and the other end fixed to 1 in the seat back 62. 55.

In the above-mentioned rotation transmitting means 39, while the seat back 62 is tilted forward and backward as much as possible within the range of use of the seat belt, the cam plate 54 is integrated with the seat back 62 around the adjustment shaft 71. By rotating the cam plate 54 to rotate the sensor case 30 via the slide member 53 and the wire 56, the inertial body support surface 30 is rotated.
b is vertically upward. When the seat back 62 is further tilted back and forth (that is, when the seat back 62 is out of the usable range of the seat belt), the rotation operation of the sensor case 30 by the rotation transmitting means 39 is not performed.

Therefore, according to the vehicle body acceleration sensor 32 of the present embodiment, when the tilt state of the seat back 62 is changed, the sensor case 30 is rotated by the rotation transmitting means 39 interlocking with the tilt of the seat back 62. Thus, the inertial body support surface 30b is maintained in an appropriate state. Therefore, even if the tilting state of the seat back 62 is changed, the sensor case 30 maintains a good posture, and moves only by the inertial body 33 on the sensor case 30 due to the inertial force due to the impact in the event of a vehicle emergency. Therefore, the sensitivity of the sensor does not decrease and the acceleration of the vehicle body can be stably and reliably detected.

Since the sensor case 30 to which the sensor arm 31 is rotatably mounted is rotated around the rotation axis S of the winding shaft 4, when the inclination of the seat back 62 is changed, The sensor case 30 is rotated around a rotation axis S of the winding shaft 4 with respect to the teeth 19a of the ratchet wheel 19 rotatably disposed so as to maintain a constant interval.

That is, in the vehicle body acceleration sensor 32, the distance between the engaging portion 31b of the sensor arm 31 and the tooth 19a of the ratchet wheel 19 does not change, and the ground angle of the sensor arm 31 is always kept constant. Dripping. Therefore, the acceleration sensitivity is not affected by the tilting state of the seat back 62, even though the sensor arm 31 is of a so-called single arm type which requires only a single arm. Also, a case body 30a and a sensor arm 3 which are assembled as the sensor case 30 are provided.
As the 1 and the inertia body 33, those used for a general vehicle body acceleration sensor in which the retractor is fixed to the vehicle body can be used as they are.

Therefore, the acceleration of the vehicle body can be stably and reliably sensed, and the number of parts and the complexity of the mechanism can be prevented, and the manufacturing cost can be reduced.
Note that the configurations of the lock unit, the sensor arm, the sensor case, the inertial body, and the rotation transmitting unit according to the present invention are not limited to the configurations of the above-described embodiment, and can be appropriately changed based on the gist of the present invention. Needless to say.

[0030]

According to the vehicle body acceleration sensor for a seat belt of the present invention, when the tilted state of the seat back is changed, the sensor case is rotated by the rotation transmitting means interlocking with the tilt of the seat back, and the inertia is reduced. The body support surface is maintained in a proper state. Therefore, even if the tilting state of the seat back is changed, the sensor case maintains a good posture, and only the inertial body on the sensor case moves with the inertial force due to the impact in the event of a vehicle emergency. Sensitivity does not slow down, and the acceleration of the vehicle body can be stably and reliably detected.

Since the sensor case, to which the sensor arm is rotatably mounted, rotates around the rotation axis of the winding shaft, when the tilting state of the seat back is changed, the winding shaft 4 is rotated. The sensor case rotates so as to follow a predetermined interval with respect to an inertial member rotatably disposed around the rotation axis of the sensor case. That is, the distance between the engaging portion of the sensor arm and the inertia member does not change, and the angle of the sensor arm with respect to the ground is always kept constant. Thus, the acceleration sensitivity is not affected by the inclination of the seat back, even though the sensor arm is a so-called single arm type in which a single arm is sufficient. Therefore, the vehicle body acceleration sensor for a seatbelt of the present invention can stably and reliably detect the acceleration of the vehicle body, and further prevents an increase in the number of parts and a complicated mechanism, and reduces the manufacturing cost. Can be.

[Brief description of the drawings]

FIG. 1 is a side view of a reclining type seat equipped with a seat belt retractor having a vehicle body acceleration sensor according to an embodiment of the present invention.

FIG. 2 is a side view of the seat belt retractor shown in FIG.

FIG. 3 is a vertical sectional view of a main part of the seat belt retractor shown in FIG. 2;

FIG. 4 is a side view of the seat belt retractor in a state where the seat back of the reclining type seat shown in FIG. 1 is tilted rearward.

5 is a side view of the seat belt retractor in a state where the seat back of the reclining type seat shown in FIG. 1 is tilted forward.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Retractor base 2 Bobbin 4 Take-up shaft 19 Ratchet wheel 11 Pole 30 Sensor case 30b Inertial body support surface 31 Sensor arm 32 Body acceleration sensor for seat belt 33 Inertial body 39 Rotation transmission means 56 Wire 61 Reclining type seat 62 Seat back 63 Seat seat 70 Webbing 100 Retractor for seat belt

Claims (1)

[Claims] 1. A sensor case supported on a retractor base so as to be rotatable about a rotation axis of a winding shaft of a seat belt retractor provided on a seat back of a reclining type seat of a vehicle or the like; The sensor case is rotated to be located at a first position for activating a locking means for locking the rotation of the winding shaft of the belt retractor in the webbing withdrawing direction and a second position for not operating the locking means. A freely mounted sensor arm, an inertial body that relatively moves on an inertial body support surface of the sensor case when receiving a speed change greater than a predetermined value, and moves the sensor arm to the first position; In accordance with the inclination angle of the seat back, the direction of the support surface is appropriately maintained regardless of the inclination state of the seat back. A vehicle body acceleration sensor for a seatbelt, comprising: a rotation transmitting means for interlocking the sensor case around the rotation axis of the winding shaft; and operating the locking means by a movement operation of the inertial body when a predetermined vehicle body acceleration is applied. .