JPS647333Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vehicle sensor for sensing acceleration, deceleration and inclination of a vehicle, and particularly to a vehicle sensor for a belt lock mechanism of a seat belt retractor.

The seat belt is wound around the shaft of a belt retractor which is biased by a spring in the winding direction and is normally freely retractable from the belt retractor. When the brakes are applied or the vehicle tilts, the vehicle sensor activates the belt lock mechanism to prevent the seat belt from being pulled out.
Capable of holding passengers. In this case, a belt lock mechanism or vehicle sensor is installed to prevent the seat belt from being pulled out only when large accelerations and decelerations occur, such as in sudden braking or a collision, or when the vehicle tilts significantly, such as in a rollover. It is desirable to design. This is because when a seatbelt is locked at a small acceleration/deceleration or inclination angle, the person wearing the seatbelt often feels uncomfortable because their body movements are restricted, and it is also difficult to park on a slope. This is because you cannot fasten your seatbelt when you are in the car.

As a vehicle sensor for a belt lock mechanism, a so-called rolling type sensor is known, which consists of a casing having a hemispherical recess and a ball rotatably housed in the casing.
In this case, the ball always rolls within the casing when acceleration/deceleration occurs or when the vehicle tilts. Therefore, in order to be able to freely pull out the seatbelt when the acceleration/deceleration or inclination angle is small, it is necessary to prevent the belt lock mechanism from being operated even if the ball rolls. This is accomplished by arranging the pawl of the belt lock mechanism such that the rolling ball does not come into contact with the pawl of the belt lock mechanism below a predetermined acceleration/deceleration or tilt angle. However, with this structure, when a predetermined acceleration/deceleration or inclination angle that should prevent the seat belt from being pulled out occurs, the operating stroke of the pawl by the ball is very short, making it difficult to fully operate the pawl. This has the disadvantage that the belt lock mechanism may not work properly. Furthermore, in the case of this rolling type vehicle sensor, the ball constantly rolls depending on the acceleration, deceleration, or inclination of the vehicle, resulting in a large amount of noise.

Furthermore, a so-called pendulum type vehicle sensor is known in which a cam is fixed to the upper end of the arm and a weight is fixed to the lower end, and the cam is suspended and supported on a receiver of a support plate. This vehicle sensor also has the same drawbacks as the aforementioned rolling type vehicle sensor. That is, since the weight constantly swings from side to side, it is necessary to prevent the belt lock mechanism from operating while the acceleration/deceleration or inclination angle is small, and it is necessary to prevent the belt lock mechanism from operating while the acceleration/deceleration or inclination angle reaches a value that should prevent the seat belt from being pulled out. In this case, the pawl of the belt lock mechanism cannot be operated sufficiently, and the operation of the belt lock mechanism becomes incomplete. Further, this vehicle sensor has the disadvantage that it has a complicated structure and requires a large casing to allow the weight to swing from side to side.

Furthermore, in the case of the acceleration sensing device known from JP-A-49-134380, the pendulum is supported by an elastic upper electrode, and resists this upper electrode when a predetermined acceleration/deceleration is exceeded. and tilt to cut off the current. In this case, the elastic upper electrode is constantly acting on the pendulum, reducing the response sensitivity of the pendulum. When the acceleration/deceleration falls below a predetermined acceleration/deceleration rate, this elastic upper electrode acts as a return means for the pendulum and returns it to its original position.

Furthermore, Japanese Patent Laid-Open No. 49-25979 discloses an acceleration detection device having a structure in which a conductive ball is supported by a conductive support ring and a contact rod. This device cuts off the electric current and cannot operate the claw as an actuator of the seat belt retractor. This is because it does not have a mechanism to operate the claw or return the ball to its original position.

The aim of the invention is to provide a new vehicle sensor that does not have the above-mentioned drawbacks.

According to the present invention, a spherical protrusion is formed on either the upper part of the sensor body which is approximately spherical and the lower surface of the claw which is provided above the sensor body and is swingable by the sensor body. forming a recess on the other side that cooperates with the protrusion;
A ring-shaped recess is provided in the lower part of the sensor body, a ring-shaped protrusion that loosely fits into the recess is formed at the bottom of the cup-shaped casing that accommodates the sensor body, and the sensor body is supported by the protrusion, The inner diameter of the casing, the diameter of the sensor body, and the ring-shaped protrusion are selected so that when the sensor body tilts and hits the inner wall of the casing, the center of gravity of the sensor body is located within the ring-shaped protrusion when viewed from above. The diameter is determined.

In the case of the vehicle sensor according to the present invention, the sensor body or the claw has a spherical recess or protrusion,
Since the sensor body is supported by a ring-shaped protrusion, it does not operate below a predetermined acceleration/deceleration or inclination angle. When the acceleration/deceleration or inclination angle exceeds a predetermined value, the force that attempts to move the sensor body becomes greater than the supporting force of the protrusion, causing an imbalance, causing the sensor body to tilt. Therefore, the operation stroke of the claw by the sensor body is long, and the response speed of the sensor body is also fast. Furthermore, the vehicle sensor of the present invention is designed such that when the sensor body tilts and hits the inner wall of the casing, the center of gravity of the sensor body is located within the ring-shaped protrusion when viewed from above. Since the diameter of the main body and the diameter of the ring-shaped protrusion are determined, when the acceleration/deceleration or inclination becomes less than a predetermined value, the sensor main body automatically returns to its original position due to its own weight. Therefore, there is no need for any special means for returning the sensor body to its original position, resulting in a simple and compact structure.

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

In FIG. 1, reference numeral 1 denotes a cup-shaped casing fixed to a vehicle, and a claw 2 is swingably supported on the upper part of the cup-shaped casing. This pawl 2 can engage with a ratchet of a belt lock mechanism, not shown.
A ring-shaped projection 3 is formed at the bottom of the casing 1. Reference numeral 4 denotes a substantially spherical sensor body, which is composed of a metal ball 4' and a covering part 4'' made of synthetic resin or the like.In the upper part of this sensor body 4, there is a recess 6 that cooperates with the protruding part 5 of the claw 2. is formed, and a ring-shaped protrusion 7 and another protrusion 8 concentric with this protrusion 7 are formed at the lower part.In the recess 9 between the protrusions 7 and 8, The protrusion 3 at the bottom is loosely fitted, and the protrusion 8 is loosely fitted into the recess 10 inside the ring-shaped protrusion 3.

For a vehicle sensor configured as above,
Since the sensor main body 4 is supported by the ring-shaped protrusion 3 of the casing 1, the sensor main body 4 has a predetermined inclination angle, e.g.
At 15 degrees or a predetermined acceleration/deceleration, for example 0.5g or less,
It doesn't work. Therefore, since the belt lock mechanism 2 is operated only when necessary, unnecessary restraint of the occupant by the seat belt is avoided, the seat belt can be fastened even on slopes, and it is not noisy like conventional vehicle sensors. never occurs.

If the acceleration/deceleration or inclination angle exceeds a predetermined value due to a collision or rollover of the vehicle, the force that attempts to move the sensor body 4 becomes greater than the supporting force of the ring-shaped protrusion 3 and the balance is lost.
The sensor main body 4 is tilted using the protrusion 3 as a fulcrum and comes into contact with the inner wall of the casing 1. As a result, the recess 6 of the sensor body 4 swings the pawl 2 of the belt locking mechanism upward via the protrusion 5 (see FIG. 2), making it impossible to pull out the seat belt.
Since the sensor body 4 is tilted in this way, the claw 2
The operating stroke is long and the sensor response speed is fast. Further, since the sensor body 4 is coated with synthetic resin or the like, the sound generated when it comes into contact with the inner wall of the casing 1 is relatively small.

In the state shown in FIG. 2, when the acceleration/deceleration or inclination angle of the vehicle becomes less than a predetermined value, the sensor body 4 returns to the state shown in FIG. 1 due to its own weight.
At the same time, the claw 2 of the belt lock mechanism also swings downward automatically. When the sensor main body 4 returns to the state shown in FIG. 1, the projections 7 and 8 act as guide members, so that the sensor main body 4 returns reliably and quickly.

The embodiment shown in FIG. 3 differs from the embodiments shown in FIGS. 1 and 2 in that a protrusion 5' is formed on the upper part of the sensor body 4 and a recess 6' is formed on the lower surface of the claw 2.

In both of the above embodiments, the sensitivity of the vehicle sensor can be easily adjusted by changing the diameter of the ring-shaped projection 3.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of a vehicle sensor according to a first embodiment of the present invention, FIG. 2 is a vertical cross-sectional view showing the operating state of the vehicle sensor of FIG. 1, and FIG. FIG. 1 is a longitudinal cross-sectional view of a vehicle sensor according to an embodiment. Codes in the figure: 1...Casing, 3...Protrusion, 4
...Sensor body, 4'...Ball, 4''...Coating part,
9... Concavity.

Claims (1)

[Claims for Utility Model Registration] 1. Either the upper part of the substantially spherical sensor body 4 and the lower surface of the claw 2 provided above the sensor body and swingable by the sensor body have a spherical shape. A ring-shaped recess 9 is provided in the lower part of the sensor body 4, and a cup-shaped recess 9 is provided in the lower part of the sensor body 4. A ring-shaped protrusion 3 that fits loosely into the recess 9 is formed on the bottom of the casing 1, and the sensor body 4 is supported by the protrusion 3, so that the sensor body 4 tilts and hits the inner wall of the casing 1. The inner diameter of the casing 1, the diameter of the sensor body 4, and the diameter of the ring-shaped protrusion 3 are determined so that the center of gravity of the sensor body 4 is located within the ring-shaped protrusion 3 when viewed from above. A vehicle sensor for sensing acceleration, deceleration, and inclination of a vehicle. 2. Sensing the acceleration/deceleration and inclination of a vehicle as set forth in claim 1 of the utility model registration, characterized in that the sensor body 4 is composed of a metal ball 4' and a covering part 4'' made of synthetic resin or the like. Vehicle sensor for.