CN104890612A - Automobile seatbelt retractor - Google Patents

Abstract

The invention provides an automobile safety belt retracting device, which belongs to the technical field of automobile parts. The utility model solves the problems that the existing safety belt retracting device with adjustable rewinding force requires large changes to the retractor and has a complex structure. The device includes a retractor frame, a retractor mandrel, a locking pawl, a coil spring base, a coil spring mandrel, a coil spring and a coil spring cover, a transmission mechanism, a motor and an electric control system. On the side of the frame, the coil spring mandrel is installed on the coil spring base and can rotate freely. The coil spring mandrel and the retractor mandrel are coaxially connected and linked. The inner end of the coil spring is installed on the coil spring mandrel. The end is installed on the inner side of the coil spring cover, the motor is connected with the outside of the coil spring cover through the transmission mechanism and drives the coil spring cover to rotate, and the electric control system is electrically connected with the motor and controls the rotation of the motor. The device can intelligently adjust the retracting force of the seat belt coil spring, provides comfortable use experience, has simple structure and low cost.

Description

An automobile safety belt retracting device

technical field

The invention belongs to the technical field of automobile parts, and relates to an automobile safety belt retracting device.

Background technique

The seat belt retractor is one of the most important functional components in the seat belt system, and is the core of the seat belt system. The main function of an ordinary three-point seat belt retractor is to realize the seat belt sensor lock, belt sensor lock, webbing Functions such as rewinding, in which the rewinding function of the webbing is usually realized by the coil spring inside the retractor. By increasing the stiffness of the coil spring, the webbing rewinding force of the seat belt can be increased, making the webbing rewinding smoother, but The increase of the rewinding force often affects the wearing comfort of the occupant. After wearing the seat belt, the pressure force of the webbing on the occupant's shoulders and chest increases, which makes the occupant feel uncomfortable wearing it for a long time. If the stiffness of the coil spring is reduced, it is often It will also affect the rewinding of the seat belt webbing.

Therefore, in order to make the safety belt more comfortable when fastened, people have carried out a lot of research, such as a practical seat belt winding device [Special Publication No. 60-30576], in the series combination of the device, there are two seat belts with different elastic forces. coil spring, so that when the coil spring is pulled out of the seat belt and retracted into the seat belt, the elastic forces of the above two coil springs are respectively different in strength. Weak coil springs play a role in order to reduce the winding force; another example is a winding device for a seat belt for automobiles published by a Chinese patent [application number 00137797.3], which includes applying a force to the winding shaft to press the winding shaft to the winding direction. The main coil spring with elastic force, the spool linked with the seat belt take-up shaft, the clutch spring and the ring embedded on the spool, transmit the rotation of the spool toward the pull-out direction of the seat belt to the spring pressure of the ring. Tight clutch; one end is fixed on the ring and can generate a rotating elastic force opposite to the above-mentioned main coil spring. Although the above two schemes can solve the winding force when the safety belt is fastened, in the above schemes, two coil springs are used. The former requires the use of two coil springs with different elastic forces. The requirements of the latter are relatively high, and it needs to be matched, which is very cumbersome, the structure is also complicated, and the production cost is high; although the latter does not require the elasticity of the main and secondary coil springs to be different, it increases the clutch structure, the structure is more complicated, and the installation is inconvenient. higher cost.

Contents of the invention

The purpose of the present invention is to solve the above-mentioned problems in the existing technology, and proposes a car safety belt retracting device, which automatically adjusts the retracting force of the retracting device according to different situations, so that the occupant can use the safety belt in the fastened state. It feels comfortable, can ensure the normal recovery of the safety belt in the unfastened state, and has a simple structure and convenient installation.

The purpose of the present invention can be achieved through the following technical solutions: an automobile safety belt retracting device, which includes a retractor frame, a retractor mandrel and a locking pawl, the retractor mandrel is installed on the retractor Inside the retractor frame and one end protrudes from the retractor frame, the locking pawl is installed on the retractor frame for locking the retractor mandrel, the feature is that the device also includes a coil spring base, Coil spring mandrel, coil spring and coil spring cover, transmission mechanism, motor and electric control system, the coil spring base is installed on the side of the retractor frame, and the coil spring mandrel is installed on the coil spring base and can rotate freely , the coil spring mandrel is coaxially connected and linked with the end of the retractor mandrel protruding from the retractor frame, the inner end of the coil spring is installed on the coil spring mandrel, and the outer end of the coil spring is installed on the coil The inner edge of the spring cover, the motor is connected to the outside of the coil spring cover through a transmission mechanism and drives the coil spring cover to rotate, and the electric control system is electrically connected to the motor and controls the rotation of the motor.

The car safety belt retracting device controls the motor to rotate forward or reverse through the electronic control system, and the motor drives the coil spring cover to rotate forward or reverse through the transmission mechanism. Since the outer end of the coil spring is installed inside the coil spring cover, when the coil spring When the cover rotates, the outer end of the coil spring is tightened or loosened relative to its inner end, so as to realize the adjustment of the retracting force of the coil spring; the rotation of the motor is controlled through control, so intelligent control can be realized. When in use, reduce the rewinding force of the coil spring to make the occupant feel comfortable; when the seat belt is not fastened, increase the rewinding force to ensure that the seat belt is retracted.

In the above-mentioned automobile safety belt retracting device, the middle part of the coil spring base is provided with a step hole matched with the coil spring mandrel, and the coil spring mandrel can rotate in the step hole, and the coil spring base It also has a screw hole one, and the coil spring base is fixed on the retractor frame through the screw hole one. By providing a stepped hole in the middle of the coil spring base, the retractor mandrel and the coil spring mandrel can be installed more conveniently and quickly to achieve coaxial connection, and when the retractor mandrel rotates, the coil spring mandrel can be driven to rotate.

In the above-mentioned automobile safety belt retracting device, the front of the coil spring mandrel is provided with a slot 1 for installing the inner end of the coil spring, and the inner edge of the coil spring cover has a slot 2 for installing the outer end of the coil spring. A boss is provided on the reverse side of the coil spring mandrel, and the boss is matched with the stepped hole of the coil spring base. The first slot and the second slot are set, which can easily connect the coil spring mandrel and the coil spring cover through the coil spring, and facilitate the installation of the coil spring; the design of the boss makes the coil spring mandrel and the coil spring base more Good cooperation, and at the same time ensure that the coil spring mandrel rotates more stably. When the seat belt is pulled out or retracted, the coil spring mandrel rotates, but the coil spring cover does not move, so the coil spring is deformed by force and generates a corresponding retracting force.

In the above automotive safety belt retracting device, the coil spring mandrel is provided with a mounting hole that cooperates with one end of the retractor mandrel so that the coil spring mandrel and the retractor mandrel are coaxially connected. By providing the installation hole, the retractor mandrel can be directly inserted into the installation hole to cooperate with the coil spring mandrel, which facilitates the connection and cooperation between the retractor mandrel and the coil spring mandrel.

In the above automotive safety belt retracting device, the transmission mechanism includes a worm wheel arranged outside the spring cover and fixedly connected with the spring cover, and a worm arranged on the power output shaft of the motor, and the worm wheel cooperates with the worm. The motor realizes power transmission through the worm gear mechanism. When the motor rotates, it drives the coil spring cover to rotate, thereby causing the outer end of the coil spring to displace and changing the coil spring’s rewinding force. In addition, the worm gear has a self-locking feature, which means that the motor does not move , the coil spring cover will not move, which ensures the stability of the coil spring rewinding force. In addition to using the above-mentioned worm gear as the transmission mechanism, a gear set or a gear with a rack can also be used to realize the motor and coil. Power transmission between reeds.

In the above-mentioned automobile safety belt retracting device, the device also includes an outer cover arranged on the outside of the coil spring cover, the central axis of the outer cover is provided with a cylindrical protrusion, and the outer center of the coil spring cover is provided with a The rotation hole matched with the projection, the lower part of the outer cover is provided with a worm hole for the worm to pass through, and the outer cover also has a second screw hole. Through the cooperation between the protrusion and the rotation hole, the coil spring cover can rotate around the protrusion under the drive of the motor to ensure the stability of the coil spring cover rotation, and the outer cover is fixed on the outside of the retractor through screw holes and screws or rivets.

In the above-mentioned automotive safety belt retracting device, the electronic control system includes an ECU, control buttons all connected to the ECU, a multi-channel early warning sensor, a touch sensor and a motor driver, the collision sensor is arranged around the car, and the The touch sensor is arranged in the seat belt slot of the car, and the signal of the multi-channel early warning sensor is transmitted to the input port of the ECU, and the output port of the ECU is connected with the motor driver. Setting the control button can realize artificial active control, and the occupant can set the most suitable coil spring retraction force to ensure comfort; in addition, the ECU can judge whether the seat belt is inserted into the seat belt slot by receiving the detection signal of the touch sensor, so as to output control The command controls the forward and reverse rotation of the motor, and the adjustment of the rewinding force of the coil spring is realized through the transmission mechanism; the multi-channel early warning sensor can enable the ECU to predict the road conditions, make the seat belt webbing more suitable for the occupant, and improve the protection of the occupant by the seat belt Effect.

In the above automotive safety belt retracting device, the multi-channel early warning sensor includes: a center-of-mass acceleration sensor; a collision avoidance radar sensor; a yaw rate sensor; a steering wheel angle sensor and a brake pedal displacement sensor. Through the detection of multi-channel early warning sensors, the ECU can predict the road conditions in advance, drive the coil spring cover to rotate through the motor in time, adjust the coil spring retraction force, and realize the early warning function.

In the above-mentioned retracting device for the automobile safety belt, a plurality of process holes are opened on the coil spring mandrel and on the outside of the coil spring cover. As a preference, the number of process holes on the coil spring mandrel is 2-4, and the number of process holes on the outside of the coil spring cover is 4-8. By setting the process holes on the coil spring mandrel, the uniform thickness of the material is guaranteed. , Reduce product injection shrinkage.

Compared with the prior art, this automobile safety belt retracting device has the following advantages:

1. The electric control system controls the motor to directly change the rewinding force of the coil spring to realize the intelligent adjustment of the rewinding force of the coil spring.

2. Set the button that can be manually controlled actively to satisfy the occupants to choose the appropriate rewinding force, meet the most comfortable requirements of each user, and realize humanized settings.

3. The internal structure of the traditional retractor is not changed, the modification range is small, and the cost is low.

4. The multi-channel sensor is used to predict the road conditions, so that the seat belt webbing is more suitable for the occupant, which increases the comfort and improves the protection effect of the seat belt on the occupant.

Description of drawings

Fig. 1 is a schematic exploded view of the structure of the automotive safety belt retracting device.

Fig. 2 is a structural schematic diagram of the coil spring adjusting mechanism of the automobile safety belt retracting device.

Fig. 3 is a structural schematic diagram of the coil spring base of the vehicle safety belt retracting device.

Fig. 4 is a structural schematic view of the front of the coil spring mandrel of the automobile safety belt retracting device.

Fig. 5 is a structural schematic diagram of the reverse side of the coil spring mandrel of the automobile safety belt retracting device.

Fig. 6 is a structural schematic diagram of the cooperation between the inner surface of the coil spring cover and the coil spring of the automobile safety belt retracting device.

Fig. 7 is a structural schematic diagram of cooperation between the outer surface of the coil spring cover and the motor of the automobile safety belt retracting device.

Fig. 8 is a schematic diagram of the structure of the outer cover of the vehicle safety belt retracting device.

Fig. 9 is a schematic diagram of the electronic control system of the automobile safety belt retracting device.

Fig. 10 is a flow chart of the control principle of the vehicle safety belt retracting device.

Fig. 11 is a schematic diagram of a characteristic curve of a retracting force of a conventional safety belt retracting device.

Fig. 12 is a schematic diagram of the characteristic curve of the rewinding force of the automobile safety belt retracting device.

In the figure, 11, retractor frame; 12, retractor mandrel; 13, locking claw; 21, coil spring base; 21a, step hole; 21b, screw hole one; 22, coil spring mandrel; 22a, Card slot one; 22b, installation hole; 22c, process hole one; 22d, boss; 23, coil spring; 23a, coil spring inner end; 23b, coil spring outer end; 24, coil spring cover; 24a, card slot two ; 24b, worm wheel; 24c, process hole two; 24d, rotation hole; 25, outer cover; 25a, bump; 25b, worm hole; 25c, screw hole two; 26, motor; 26a, motor shaft; 26b, worm; , Electronic control system.

Detailed ways

The following are specific embodiments of the present invention and in conjunction with the accompanying drawings, the technical solutions of the present invention are further described, but the present invention is not limited to these embodiments.

As shown in Fig. 1 and Fig. 2, the automobile safety belt retracting device includes a retractor frame 11, a retractor mandrel 12 and a locking pawl 13, and the retractor mandrel 12 is installed in the retractor frame 11 and One end protrudes from the retractor frame 11, and the locking claw 13 is installed on the retractor frame 11 for locking the retractor mandrel 12; One end of the retractor frame 11 includes a coil spring base 21, a coil spring mandrel 22, a coil spring 23, a coil spring cover 24, a transmission mechanism, a motor 26 and an electric control system 27, and the coil spring base 21 is installed on the retractor frame 11 side, the coil spring mandrel 22 is installed on the coil spring base 21 and can rotate freely, the coil spring mandrel 22 is coaxially connected with the retractor mandrel 12 and realizes linkage, and the inner end 23a of the coil spring is installed on the coil spring mandrel 22, the coil spring outer end 23b is installed on the inner edge of the coil spring cover 24, the motor 26 is connected with the coil spring cover 24 outside through the transmission mechanism and drives the coil spring cover 24 to rotate, the electric control system 27 is electrically connected with the motor 26 and controls the motor 26 turn.

Specifically, as shown in Figure 3, the middle part of the coil spring base 21 has a stepped hole 21a that matches the coil spring mandrel 22, and the coil spring mandrel 22 can rotate in the stepped hole 21a, and the coil spring base 21 also has a screw. Hole one 21b, the coil spring base 21 is fixed on the frame by the interference fit of the riveting pin through the screw hole one 21b, of course, it can also be fixed by screws.

As shown in Fig. 4 and Fig. 5, the front of the coil spring mandrel 22 is provided with a draw-in groove 22a for installing the inner end 23a of the coil spring. The spring mandrel 22 is coaxially connected to the mounting hole 22b of the retractor mandrel 12 . The reverse side of the coil spring mandrel 22 is provided with a boss 22d , and the boss 22d matches the step hole 21a of the coil spring base 21 . Further, three process holes 22c are provided around the installation hole 22b on the coil spring mandrel 22, through which the thickness of the material can be kept uniform and the injection shrinkage of the product can be reduced. It should be noted that the number of process holes 1 22c can be set according to actual needs.

As shown in Figure 6, the inner side of the coil spring cover 24 is the main cavity for accommodating the coil spring 23, and the edge of the cavity is provided with a slot 2 24a for the installation of the coil spring outer end 23b, and the coil spring outer end 23b can be effectively stuck in the card. In slot two 24a, when the coil spring cover 24 is fixed and the webbing mandrel rotates, the coil spring 23 is pre-tightened thereupon, and this pre-tightening force is the initial force source of the webbing rewinding force.

As shown in Figure 7, a worm gear 24b is arranged on the outside of the coil spring cover 24, and the worm gear 24b is fixedly connected with the coil spring cover 24, and can also be integrally formed directly, and it cooperates with the worm screw 26b to form a worm gear mechanism, and the worm screw 26b and the motor 26 are powered The output shafts are fixed together. When the motor 26 rotates to drive the worm 26b to rotate, the worm 26b drives the worm wheel 24b to rotate, thereby controlling the tightness of the coil spring 23 and realizing the adjustment of the rewinding force of the coil spring 23 . In addition, the worm gear 24b and the worm 26b have a self-locking feature, that is to say, the motor 26 does not move, and the coil spring cover 24 also does not move, which ensures the stability of the rewinding force of the coil spring 23 . On the above-mentioned worm wheel 24b, that is, the outer middle part of the coil spring cover 24, a rotating hole 24d is provided, and around the rotating hole 24d, there are 6 process holes 24c that are evenly and symmetrically offered. Similarly, the process hole 2 24c here is used to maintain The uniform thickness of the material reduces the shrinkage of the product injection molding. It should be noted that the number of process holes 24c can be set according to actual needs, such as 4, 8 or other numbers. It should be noted that the process holes 24c here should preferably be arranged uniformly and symmetrically to ensure that the coil spring cover 24 balance when turning.

As a preferred solution, in addition to using the above-mentioned worm gear as the transmission mechanism, a gear set or a gear with a rack can also be used to realize the power transmission between the motor 26 and the coil spring cover 24 .

As shown in Figure 8, the vehicle safety belt retracting device also includes an outer cover 25 arranged on the outside of the coil spring cover 24, and the central axis of the outer cover 25 is provided with a cylindrical protrusion 25a, and the protrusion 25a can be connected to the coil spring cover 24. The rotation hole 24d on the outer side cooperates, so that the coil spring cover 24 can rotate around the protrusion 25a under the drive of the motor 26, so as to ensure the stability of the coil spring cover 24 rotation. The lower part of the spring cover 24 is provided with a worm hole 25b, so that the worm 26b passes through the worm hole 25b and cooperates with the worm wheel 24b. In addition, the outer cover 25 also has a second screw hole 25c, and the outer cover 25 is fixed on the frame through the second screw hole 25c by the interference fit of the riveting pin, and it can also be fixed by screws here.

As shown in Figure 9, the electric control system 27 of this automobile safety belt retracting device comprises ECU, the control button that is all connected with ECU, multi-channel early-warning sensor, touch sensor and motor driver, wherein, multi-channel early-warning sensor comprises: centroid Acceleration sensor; anti-collision radar sensor; yaw rate sensor; steering wheel angle sensor and brake pedal displacement sensor. Among them, the longitudinal component of the center-of-mass acceleration signal and the signal of the brake pedal displacement sensor can be used to comprehensively judge the car's sudden braking and rapid acceleration conditions, and the transverse component of the center-of-mass acceleration signal and the yaw rate signal can be used to judge the stability of the car on a curve. The anti-collision radar sensor can be used to judge the relative distance between the vehicle and the front and rear vehicles. On the one hand, the steering wheel speed sensor can assist the on-board electronic control unit to identify the driver's steering intention, and on the other hand, it can also reflect whether the driver is avoiding Therefore, the steering wheel rotation angular velocity signal combined with the yaw angular velocity signal can also determine whether the turning of the car is caused by an urgent dangerous situation. In the implementation process, the multi-channel early warning sensor is set at each corresponding position on the car, the touch sensor is set in the seat belt slot of the car, the signal of the multi-channel early warning sensor is transmitted to the input port of the ECU, and the output port of the ECU is connected to the motor Drive connection.

In this embodiment, setting the control button can realize artificial active control, and the occupant can set the most suitable winding force of the coil spring 23 to ensure comfort; in addition, the ECU can judge whether the seat belt is inserted by receiving the detection signal of the touch sensor Seat belt slot, so that the output control command controls the forward and reverse rotation of the motor 26, and realizes the adjustment of the rewinding force of the coil spring 23 through the transmission mechanism; The spring cover 24 rotates to adjust the rewinding force of the coil spring 23 to realize the early warning function.

Working principle of the present invention is as shown in Figure 10:

When the occupant puts on the seat belt and is in the stage of pulling out the seat belt, the touch sensor does not detect that the plug of the seat belt is inserted into the slot. At this time, the ECU controls the motor 26 to rotate forward n circles (where n is a natural number) through the motor driver. 26 rotates to drive the coil spring cover 24 to rotate, so that the coil spring outer end 23b is displaced, the coil spring 23 is released, and the retracting force of the coil spring 23 is reduced to facilitate the pulling out of the seat belt, and when the touch sensor detects the seat belt plug After being inserted into the slot, keep the motor 26 still, so that the rewinding force of the coil spring 23 is in a relatively loose state, increasing the comfort of the occupants.

After the occupant untied the seat belt, the ECU detected that the seat belt plug was pulled out from the slot by the touch sensor. At this time, the ECU controlled the motor 26 to reverse m circles (here m is a natural number) through the motor driver, and the motor 26 rotated to drive The coil spring cover 24 rotates, causing the coil spring outer end 23b to be displaced, pre-tightening the coil spring 23, increasing the rewinding force of the coil spring 23, and facilitating the recovery of the safety belt.

In addition, when the occupant thinks that the rewinding force of the coil spring 23 intelligently set by the ECU is not suitable, the number of rotations of the motor 26 can be adjusted manually through the control button to ensure that the rewinding force of the coil spring 23 satisfies the maximum value of each occupant. comfort needs.

As shown in Figure 11 and Figure 12, through the automobile seat belt retracting device of the present invention, it can be found by comparison that ordinary seat belts are realized only by coil spring components, and the coil spring components are generally integral. The retractor 1 assembly is fixed on the retractor frame 11 after being pre-tightened with an appropriate number of turns, so far the safety belt webbing is pulled out and rolled back, and the characteristics are determined (Fig. 9). And the automobile safety belt retracting device of the present invention relies on after the coil spring 23 is intelligently adjusted, and the safety belt webbing is pulled out and rolled back characteristic is variable (Fig. 10), when pulling out, along with the rotation of motor 26, required The power of the machine is significantly reduced, and after the motor 26 stops working, the pulling force remains at a low level, thereby increasing the comfort; when rewinding, with the rotation of the motor 26, the rewinding force increases significantly until the motor 26 stops working, This allows for a smooth retraction of the seat belt.

The present invention can be implemented alone or integrated into the position memory system of the vehicle. According to different people's figures and perceptions of the degree of tightness, the tightness information of the coil spring 23 is stored in groups. When the corresponding occupant presses the corresponding position Press the memory recovery button, and the motor 26 will rotate according to the stored memory information, so as to meet the differentiated requirements.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which the present invention belongs can make various modifications or supplements to the described specific embodiments or adopt similar methods to replace them, but they will not deviate from the spirit of the present invention or go beyond the definition of the appended claims range.

Claims (9)

1. a car belt retracting device, this device comprises retractor frame (11), taking-up device mandrel (12) and locking pawl (13), described taking-up device mandrel (12) is arranged in retractor frame (11) and retractor frame (11) is stretched out in one end, described locking pawl (13) is arranged on retractor frame (11) for carrying out locking to described taking-up device mandrel (12), it is characterized in that, this device also comprises wind spring base (21), wind spring mandrel (22), wind spring (23) and wind spring cover (24), transmission device, motor (26) and electric-control system (27), described wind spring base (21) is arranged on retractor frame (11) side, described wind spring mandrel (22) is installed on wind spring base (21) and goes up and can freely rotate, one end that described wind spring mandrel (22) stretches out retractor frame (11) with described taking-up device mandrel (12) is coaxially connected linkage, described wind spring the inner (23a) is installed on wind spring mandrel (22), wind spring outer end (23b) is installed on wind spring cover (24) inside edge, described motor (26) is connected by transmission device with described wind spring cover (24) outside and drives wind spring cover (24) to rotate, described electric-control system (27) is electrically connected with motor (26) and controls motor (26) and rotates.

2. car belt retracting device according to claim 1, it is characterized in that, described wind spring base (21) middle part has the stepped hole (21a) coordinated with described wind spring mandrel (22), described wind spring mandrel (22) can be rotated in this stepped hole (21a), described wind spring base (21) also has screw one (21b), and described wind spring base (21) is by the fixing retractor frame (11) of screw one (21b).

3. car belt retracting device according to claim 2, it is characterized in that, described wind spring mandrel (22) front is provided with the draw-in groove one (22a) installed for wind spring the inner (23a), described wind spring cover (24) inside edge has the draw-in groove two (24a) installed for wind spring outer end (23b), described wind spring mandrel (22) reverse side is provided with a boss (22d), and described boss (22d) coordinates with the stepped hole (21a) of wind spring base (21).

4. car belt retracting device according to claim 3, it is characterized in that, described wind spring mandrel (22) offers the mounting hole (22b) wind spring mandrel (22) and taking-up device mandrel (12) can being coaxially connected with taking-up device mandrel (12) one end fits.

5. car belt retracting device according to claim 4, it is characterized in that, described transmission device comprises and is arranged at wind spring cover (24) outside and the worm gear (24b) be connected with wind spring cover (24) and the worm screw (26b) be arranged on motor (26) power take-off shaft, and described worm gear (24b) coordinates with worm screw (26b).

6. the car belt retracting device according to claim 1-6 any one, it is characterized in that, this device also comprises the outer cover (25) being arranged at wind spring cover (24) outside, described outer cover (25) central axis is provided with cylindric projection (25a), described wind spring cover (24) outer side center place is provided with the rotating hole (24d) matched with described projection (25a), described outer cover (25) bottom offers the worm hole (25b) passed for worm screw (26b), and described outer cover (25) also has screw two (25c).

7. car belt retracting device according to claim 6, it is characterized in that, described electric-control system (27) comprises ECU, the control button be all connected with ECU, multichannel early warning sensor, touch sensor and motor driver, described crash sensor is arranged at automobile surrounding, and described touch sensor is arranged in the safety strap slot of automobile, described in, the Signal transmissions of multichannel early warning sensor is to the input port of ECU, and the output port of ECU is connected with motor driver.

8. car belt retracting device according to claim 7, is characterized in that, described multichannel early warning sensor comprises: automobile longitudinal, lateral acceleration sensor; Forward and backward collision avoidance radar sensor; Automobile yaw-rate sensor; Steering wheel angle sensor and brake pedal displacement pickup.

9. car belt retracting device according to claim 1, is characterized in that, described wind spring mandrel (22) above and outside wind spring cover (24) all offers some auxiliary holes.