Patent Description:
In general, a vehicle is equipped with a seat belt safety device in a seat to ensure the safety of an occupant. The seat belt safety device includes a retractor configured to wind a strip-shaped seat belt on a spool or to withdraw the seat belt for restraining the occupant, and a buckle into which a tongue fixed at one end of the seat belt is detachably inserted.

The retractor prevents the occupant wearing the seat belt from being bounced forward or moved away from a seat due to driving inertia during sudden stop or rapid acceleration caused by a vehicle accident. Such a retractor includes a locking device that permits the withdrawal of the seat belt in a normal state when the occupant wears the seat belt, but suppresses further withdrawal of the seat belt when the withdrawal acceleration of the seat belt is detected due to a vehicle collision or the like.

For example, in Patent Document <NUM> and Patent Document <NUM> below, a retractor technique for controlling winding and unwinding operations of the seat belt is disclosed.

Meanwhile, when an acceleration exceeding a predetermined value is applied to the retractor in the horizontal direction, such as when the vehicle collision occurs, a vehicle sensor that detects the acceleration is operated to prevent the seat belt from being withdrawn by operating a locking device of the seat belt.

A vehicle sensor using a ball as an inertial member or an independent inertial member is generally known in the art.

The vehicle sensor includes an inertial member that moves in a dangerous situation where a deceleration higher than a normal deceleration of the vehicle is applied to the vehicle, and a sensor lever that interworks with external teeth of a control disc which is moved by the inertia member and rotates together with a spool of a seat belt retractor.

Such a seat belt retractor may be mounted on a vehicle body, such as a center pillar of the vehicle, a backrest of a seat, a rear pillar, etc. Accordingly, the mounting posture of the seat belt retractor may be variously changed according to structures of the center pillar, the seat back, the rear pillar, etc. That is, the seat belt retractor is not always mounted in a horizontal state, but may be mounted in a state inclined at a predetermined angle from the horizontal state to the left-right direction or the front-rear direction.

If the posture of the seat belt retractor is changed over a certain range as described above, the acceleration cannot be properly detected.

For example, when a retractor having a vehicle sensor has a posture that is inclined over a certain range from a horizontal state, the distance between a control disc and a sensor lever of a vehicle sensor becomes too close, so the sensor lever operates sensitively, so that the locking operation cannot be property performed.

In addition, for example, when a retractor having a vehicle sensor is mounted on a backrest of a seat, and the backrest of the seat is inclined forward of the vehicle, the sensor lever of the vehicle sensor is caught by the external teeth of the control disc, thereby restricting the rotation of the spool.

For this reason, when an occupant wants to wear a seat belt, it may not be possible to wear the seat belt because the rotation of the spool is restricted.

In order to solve the above problem, the applicant of the present invention has filed a patent application that discloses a seat belt retractor having a vehicle sensor with an improved fixing structure in Patent Document <NUM> below, which is now registered. From the patent document <NUM> it is known further a seat belt retractor comprising all features of the preamble of claim <NUM>.

Meanwhile, various vibrations are generated from a road surface or an engine while the vehicle is running.

When the vibration generated in the vehicle is transmitted to the seat belt retractor as described above, it is difficult for the vehicle sensor to accurately measure the acceleration.

In addition, among various parts applied to the seat belt retractor, the parts manufactured by using synthetic resin materials such as plastics amplify the vibration when the vibration is transmitted thereto, thereby generating noise upon operation.

An object of the present invention is to solve the above-described problems and to provide a seat belt retractor having a vehicle sensor capable of preventing vibration generated in a vehicle from being transmitted to the vehicle sensor.

Another object of the present invention is to provide a seat belt retractor having a vehicle sensor capable of simplifying the fixing structure of the vehicle sensor, thereby improving workability during assembly work and reducing manufacturing cost.

In order to accomplish the above objects, a seat belt retractor having a vehicle sensor of the present invention includes: a fixed frame connected to a vehicle body; a spool mounted on the fixed frame so as to be rotatable about a shaft arranged in a predetermined direction, in which a seat belt is wound around the spool; a control disc connected to the shaft about which the spool rotates to rotate together with the spool, and having external teeth; a vehicle sensor unit for detecting a change in acceleration of a vehicle by a fluctuation of an inertial member to prevent the control disc from rotating; and an installation member coupled to a housing which is coupled to one sidewall of the fixed frame; and a cover for shielding an outer surface of the installation member; wherein the vehicle sensor unit is directly and rotatably coupled to the installation member wherein the cover is coupled to the housing by a fixing protrusion which protrudes from an outer surface of the housing or passes through the housing; wherein the installation member is coupled to the housing by a separate fixing protrusion other than a fixing protrusion for coupling the cover to the housing to prevent a vibration generated from the vehicle from being transmitted to the vehicle sensor unit through the cover.

As described above, according to the seat belt retractor having the vehicle sensor of the present invention, the vehicle sensor unit is directly coupled to the installation member to remove a conventional sensor adapter, so that the number of parts for installing the vehicle sensor unit can be reduced, thereby improving workability during assembly work and reducing the manufacturing cost.

In addition, according to the present invention, the installation member provided with the vehicle sensor unit can be installed by rotating the installation member according to the installation angle of the housing by using the fixing flange formed on the outer peripheral surface of the installation member at predetermined angles.

Therefore, according to the present invention, there is an effect that it is not necessary to perform the work for forming teeth on the outer peripheral surface of the cover and the inner peripheral surface of the installation member.

In addition, according to the present invention, since the vehicle sensor unit is directly coupled to the housing through the installation member, the vibration generated in the vehicle can be prevented from being amplified through the parts formed of synthetic resin materials, so that the vibration and operation noise can be minimized.

Hereinafter, a seat belt retractor having a vehicle sensor according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

In the following description, terms indicating directions such as 'left', 'right', 'front', 'rear', 'upward', and 'downward' refer to directions corresponding to the left, right, front, rear, upward and downward directions of a vehicle.

First, an overall configuration of a seat belt retractor having a vehicle sensor will be briefly described with reference to <FIG>.

<FIG> is a perspective view of the seat belt retractor having a vehicle sensor, <FIG> is an exploded perspective view of the retractor shown in <FIG> and <FIG> is an enlarged perspective view of a vehicle sensor unit.

As shown in <FIG> and <FIG>, the seat belt retractor <NUM> having the vehicle sensor may include a fixed frame <NUM>, a spool <NUM>, a winding spring unit <NUM>, a locking unit <NUM>, a vehicle sensor unit <NUM>, an anti-locking unit <NUM>, and left and right housings <NUM> and <NUM>.

The fixed frame <NUM> may be a part on which the spool <NUM>, the winding spring unit <NUM>, the locking unit <NUM>, the vehicle sensor unit <NUM>, the anti-locking unit <NUM>, and the left and right housings <NUM> and <NUM> are mounted. This is where the back is mounted. The fixed frame <NUM> may include a base wall <NUM> mounted on a vehicle body, such as a center pillar, a rear pillar, and a backrest of a seat, and both side walls <NUM> and <NUM> through which the spool <NUM> is rotatably installed.

The spool <NUM> may be a part where the seat belt is wound. The spool <NUM> may include a cylindrical body <NUM> rotatably operated with respect to the fixed frame <NUM> and spool shafts <NUM> and <NUM> protruding from centers of both sides of the cylindrical body <NUM>. The two spool shafts <NUM> and <NUM> may be rotatably coupled directly or indirectly to centers of housings <NUM> and <NUM> fixed to both side walls <NUM> and <NUM> of the fixed frame <NUM>.

The winding spring unit <NUM> may include a torsion spring <NUM> accommodated in the left housing <NUM> and a spring seat <NUM> making contact with a side <NUM> of the fixed frame <NUM> so as to generate a restoring force for winding up the withdrawn seat belt.

The locking unit <NUM> may stop the rotation of the spool <NUM> when the withdrawal acceleration of the seat belt has a value greater than or equal to a predetermined value. The locking unit <NUM> may include a control disc <NUM>, a latch <NUM>, and a locking arm <NUM>.

The control disc <NUM> may be coupled to a spool shaft <NUM> of the spool <NUM> via a bush <NUM> and may rotate together with the spool <NUM>, and external teeth <NUM> may be formed on an outer peripheral surface of the control disc <NUM>.

The latch <NUM> may be pivotally installed between the spool <NUM> and the control disc <NUM>, and may rotate together with the spool <NUM> and the control disc <NUM> in a normal state. The latch <NUM> may include a latch tooth portion <NUM> that pivots upon rapid deceleration of the vehicle and is caught by a tooth portion <NUM> formed on the fixed frame <NUM>.

The locking arm <NUM> may be installed on the other side of the control disc <NUM> so as to rotate together with the control disc <NUM>, and may serve as an inertial mass upon rapid deceleration of the vehicle so that the locking arm <NUM> may be locked with a locking column <NUM> formed inside the housing <NUM>.

The vehicle sensor unit <NUM> may have a function of preventing the rotation of the spool <NUM> by restraining the control disc <NUM> while being operated upon rapid deceleration of the vehicle.

For this purpose, the vehicle sensor unit <NUM> may include a carrier part <NUM>, an inertial member <NUM> and a sensor lever <NUM> as shown in <FIG> and <FIG>.

The inertial member <NUM> may be arranged upright on a contact surface of the carrier part <NUM> and may be tilted within the carrier part <NUM> upon rapid deceleration of the vehicle.

The sensor lever <NUM> may be coupled to the inertial member <NUM> in a form-fit manner, and may have a locking tip <NUM> that is caught by the outer teeth <NUM> of the control disc <NUM>. The carrier part <NUM> may be coupled to the inside of the housing <NUM> through a sensor adapter <NUM>.

That is, the vehicle sensor unit <NUM> may be fixedly coupled to a predetermined position of the right housing (hereinafter referred to as 'housing') <NUM> through the sensor adapter <NUM>.

For example, as shown in <FIG>, the sensor adapter <NUM> may include a coupling member <NUM> to which the vehicle sensor unit <NUM> is coupled and a weight member <NUM> coupled to the coupling member <NUM> to apply a load to the coupling member <NUM>. The sensor adapter <NUM> may be fixedly coupled between a coupler <NUM> coupled to the outer surface of the housing <NUM> and a cover <NUM> for shielding the outer surface of the coupler <NUM>.

Thus, the sensor adapter <NUM> may be inserted into an installation space defined by inner side walls of the cover <NUM> and fixed inside the cover <NUM>. As the coupler <NUM> and the housing <NUM> are coupled to each other in a state in which the cover <NUM> and the coupler <NUM> are coupled to each other, the sensor adapter <NUM> may be disposed outside the housing <NUM>.

The vehicle sensor unit <NUM> may be coupled to the sensor adapter <NUM> as a coupling protrusion formed at the rear end of the carrier part <NUM> is coupled to a coupling hole formed in the coupling member <NUM>, and the installation angle of the vehicle sensor unit <NUM> may be adjusted by rotating about the coupling protrusion.

The coupling member <NUM> may be formed of a synthetic resin material such as plastic, and the weight member <NUM> may be formed of a metal material having a predetermined weight to reduce the influence by the vibration generated in the vehicle.

That is, conventionally, the influence of the vibration generated in the vehicle is reduced by providing the weight member <NUM> to the sensor adapter <NUM> to apply a constant load to the vehicle sensor unit <NUM>.

As described above, in the seat belt retractor according to the prior art, a sensor adapter including a coupling member made of synthetic resin and a weight member made of metal is coupled to the outside of the housing in order to reduce the effect of vibration generated in the vehicle. It is attached to the cover and installation member.

Therefore, the seat belt retractor according to the related art has a problem that the number of parts is unnecessarily increased so that the manufacturing cost is increased and workability is deteriorated during assembly work.

In addition, the seat valve retractor according to the related art has a limitation for removing the influence of vibration generated in the vehicle because it uses only the load of the weight member to remove the influence of vibration.

In order to solve the above problem, according to the present invention, the sensor adapter is removed and the vehicle sensor unit is directly coupled to the housing separately from the cover installed on the outer surface of the housing, thereby minimizing the influence of vibration generated in the vehicle.

Hereinafter, the configuration of the seat belt retractor, to which the vehicle sensor is applied, according to the present invention will be described in detail with reference to <FIG>.

<FIG> is an exploded perspective view showing an assembly structure of a vehicle sensor unit applied to a seat belt retractor according to a first embodiment of the present invention.

As shown in <FIG>, the vehicle sensor unit <NUM> may be coupled to the installation member <NUM> installed on the outer surface of the housing <NUM>, the installation member <NUM> may be formed in a substantially ring shape.

That is, according to the present embodiment, the conventional sensor adapter <NUM> may be removed, and the ring-shaped installation member <NUM> may be coupled to the housing <NUM> to simplify the assembly structure of the vehicle sensor unit <NUM>.

For this purpose, an installation wall <NUM> may protrude from the outer surface of the installation member <NUM>, and the vehicle sensor unit <NUM> may be fixedly coupled to the installation member <NUM> by coupling the coupling protrusion <NUM> formed at one end of the carrier part into an installation hole <NUM> formed in the installation wall <NUM>.

Fixing flanges <NUM> may be formed on the outer peripheral surface of the installation member <NUM> at preset angles, concave grooves <NUM> may be formed in the fixing flanges <NUM> respectively, and fixing protrusions <NUM> protruding from the outer surface of the housing <NUM> or penetrating through the outer surface of the housing <NUM> may be disposed in the concave grooves <NUM>.

The preset angle may be set to rotate and install the vehicle sensor unit <NUM> so that the vehicle sensor unit <NUM> maintains the horizontal state according to the installation angle of the fixed frame <NUM> and the housing <NUM>.

For example, the preset angle may be set to about <NUM>° or <NUM>°.

<FIG> and <FIG> are views showing a state in which the vehicle sensor unit is installed according to the installation angle of the fixed frame.

<FIG> shows a state in which a base wall <NUM> of the fixed frame <NUM> is vertically installed, and <FIG> shows a state in which the base wall <NUM> is rotated by about <NUM>° in the counterclockwise direction so that the base wall <NUM> is horizontally installed.

As shown in <FIG> and <FIG>, when the preset angle is set to <NUM>°, the present invention can horizontally maintain the vehicle sensor unit by rotating the installation member according to the installation angle of the fixed frame.

However, the present invention is not necessarily limited thereto, and the preset angle may be set to <NUM>° or <NUM>°, or may be subdivided such as <NUM>° or <NUM>° according to the installation angle of the fixed frame.

Referring again to <FIG>, the cover <NUM> may have a substantially cylindrical shape with an open inner surface in contact with the installation member <NUM>, a flange portion <NUM> having a substantially circular shape may be formed on the outer peripheral surface of the cover <NUM>, and a plurality of coupling holes <NUM> coupled with the fixing protrusions <NUM> may be formed in the flange portion <NUM> at preset angles.

However, the present invention is not necessarily limited thereto. For instance, the front end of the fixing protrusion <NUM> may be integrally formed with the flange portion <NUM>, and the rear end of the fixing protrusion <NUM> may have a hook shape coupled to the housing <NUM>.

As described above, according to the present invention, the structure of the installation member may be simply changed and the conventional sensor adapter may be removed by directly coupling the vehicle sensor unit to the installation member, so that the number of parts for installing the vehicle sensor unit can be reduced, thereby improving the workability and reducing the manufacturing cost.

In addition, according to the present invention, the installation member provided with the vehicle sensor unit may be installed by rotating the installation member according to the installation angle of the housing by using the fixing flanges formed on the outer peripheral surface of the installation member at preset angles.

Thus, according to the present invention, it is not necessary to perform the conventional work for forming teeth on the outer peripheral surface of the cover and the inner peripheral surface of the installation member.

In addition, according to the present invention, the vehicle sensor unit can be directly installed on the housing through the installation member so that the vibration generated in the vehicle can be prevented from being amplified when transmitted through the parts formed of synthetic resin materials, thereby minimizing the vibration and operation noise.

Meanwhile, although the installation member has been explained as to have a ring shape in the first embodiment, the present invention is not limited thereto.

<FIG> is an exploded perspective view showing an assembly structure of a vehicle sensor unit applied to a seat belt retractor according to a second embodiment of the present invention.

In the second embodiment of the present invention, as shown in <FIG>, the installation member <NUM> may be formed in an arc shape corresponding to a part of a ring shape.

That is, in the present embodiment, the installation member <NUM> is formed in an arc shape, and a through hole <NUM> into which the fixing protrusion <NUM> is coupled is formed in the installation member <NUM>, so that the installation member <NUM> can be fixed to the housing <NUM>.

As described above, according to the present invention, the assembly structure of the installation member and the vehicle sensor unit can be simplified by installing the vehicle sensor unit on the installation member having the arc shape, thereby improving workability during the assembly work for the retractor, and reducing the manufacturing cost by reducing the number of parts.

Meanwhile, although it has been described in the first embodiment that the installation member <NUM> and the cover <NUM> are formed in the housing <NUM> or fixed together by the fixing protrusion <NUM> coupled through the housing <NUM>, the present invention is not necessarily limited thereto.

According to the present embodiment, the cover <NUM> is coupled to the housing <NUM> by coupling the fixing protrusion <NUM> into the coupling hole <NUM> formed in a plurality of flange portions <NUM> in a state in which the cover <NUM> is separated from the installation member <NUM>.

For example, vibration may be generated from the engine and road surface when driving the vehicle on a road, particularly, on rough roads with gravels or unpaved roads, and parts formed of synthetic resin materials may be severely deformed due to external conditions such as the temperature, etc., so that the vibration may be amplified.

However, according to the present embodiment, the arc-shaped mounting member <NUM> provided with the vehicle sensor unit <NUM> and the cover <NUM> formed of the synthetic resin material are separately installed on the housing <NUM>, so that the vibration generated in the vehicle may be perfectly blocked from being amplified through the cover <NUM> and transmitted to the vehicle sensor unit <NUM>.

Accordingly, the present invention can prevent a malfunction of the vehicle sensor due to the vibration by blocking the transmission of vibration generated in the vehicle to the vehicle sensor, and can minimize the operation noise.

Although the present invention made by the present inventor has been described in detail with reference to the above embodiments, the present invention is not limited to the above embodiments, but may be variously modified within the scope of the present invention.

The present invention can be applied to a technique for a seat belt retractor having a vehicle sensor that reduces the number of parts for installing a vehicle sensor in a seat belt retractor, thereby improving workability during assembly work and reducing manufacturing costs.

Claim 1:
A seat belt retractor (<NUM>) having a vehicle sensor (<NUM>), the seat belt retractor (<NUM>) comprising:
a fixed frame (<NUM>) connected to a vehicle body;
a spool (<NUM>) mounted on the fixed frame (<NUM>) so as to be rotatable about a shaft arranged in a predetermined direction, in which a seat belt is wound around the spool (<NUM>);
a control disc (<NUM>) connected to the shaft about which the spool (<NUM>) rotates to rotate together with the spool (<NUM>), and having external teeth (<NUM>);
a vehicle sensor unit (<NUM>) for detecting a change in acceleration of a vehicle by a fluctuation of an inertial member (<NUM>) to prevent the control disc (<NUM>) from rotating;
an installation member (<NUM>) coupled to a housing which is coupled to one sidewall (<NUM>,<NUM>) of the fixed frame (<NUM>); characterized by
a cover (<NUM>) for shielding an outer surface of the installation member (<NUM>),
wherein the vehicle sensor unit (<NUM>) is directly and rotatably coupled to the installation member (<NUM>),
wherein the cover (<NUM>) is coupled to the housing by a fixing protrusion (<NUM>) which protrudes from an outer surface of the housing or passes through the housing,
wherein the installation member (<NUM>) is coupled to the housing by a separate fixing protrusion (<NUM>) other than a fixing protrusion (<NUM>) for coupling the cover to the housing to prevent a vibration generated from the vehicle from being transmitted to the vehicle sensor unit (<NUM>) through the cover (<NUM>).