A triggering structure for a seat belt and a seat belt retractor having the same

Abstract

The present invention discloses a trigger structure for a seat belt and a seat belt retractor having the same. The trigger structure for the seat belt includes a magnet and a Hall sensor. The magnet is disposed on one side of the spring cover facing the spring, and the Hall sensor is disposed on the base. A first groove is provided on the base. Under the action of the spring, the magnet moves along the first groove. When the magnet is opposite to the Hall sensor, the magnet triggers the Hall sensor. Under the driving action of the motor, when the magnet moves along the first groove, when the limit position of the spring is reached, the magnet is opposite to the Hall sensor, thereby triggering the Hall sensor to stop the motor and prevent the spring from being damaged, and prevent the phenomenon that the spring is damaged due to exceeding the limit position of the spring.

Description

Technical Field

[0001] The present invention relates to the technical field of seat belts, and particularly to a triggering structure for a seat belt and a seat belt retractor having the same. Background Art

[0002] When the seat belt retractor in the prior art is controlled by a motor drive structure, the mandrel assembly may rotate beyond the limit position of the torsion spring during rotation, thereby damaging the torsion spring. Therefore, there is an urgent need for a structure to avoid the situation where the torsion spring is deformed beyond its limit position and the spring is damaged. Summary of the Invention

[0003] Therefore, the present invention provides a triggering structure for a seat belt and a seat belt retractor having the same to solve the problem that when the motor drive structure is used for control, the torsion spring may be deformed beyond its limit position and the spring may be damaged.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] According to the present invention, there is provided a triggering structure for a seat belt, including a magnet and a Hall sensor. The magnet is disposed on one side of the torsion spring cover plate facing the torsion spring, and the Hall sensor is disposed on the base. A first groove is provided on the base. Under the action of the torsion spring, the magnet moves along the first groove. When the magnet is opposite to the Hall sensor, the magnet triggers the Hall sensor.

[0006] Further, a spring mounting portion is further provided on the torsion spring cover plate, and the spring mounting portion extends tangentially along the circumference of the torsion spring cover plate.

[0007] Further, the spring mounting portion is cylindrical or frustoconical. When the spring is frustoconical, the end close to the torsion spring cover plate is the large head end.

[0008] Further, a second groove is provided on the end face of the base opposite to the torsion spring cover plate. When the torsion spring cover plate rotates, the spring mounting portion can move, compress or loosen the spring in the second groove.

[0009] Further, a positioning cover plate is further included, and the positioning cover plate is disposed between the torsion spring cover plate and the base.

[0010] Further, a control unit is further included, and the control unit is connected to the Hall sensor for closing the motor according to the signal sent by the Hall sensor.

[0011] Further, it further includes a magnet mounting portion, one end of which is fixed to the edge of the clock spring cover plate and extends along the central axis of the clock spring cover plate in the direction close to the Hall sensor.

[0012] Further, the magnet mounting portion is in a cylindrical shape, a frustum shape or a rectangular body.

[0013] Further, the magnet is embedded in the end of the magnet mounting portion.

[0014] The present invention also provides a seat belt retractor having the seat belt triggering structure described above.

[0015] The present invention has the following advantages:

[0016] In the triggering structure of the embodiment of the present invention, under the driving action of the motor, when the magnet moves along the first groove and reaches the limit position of the clock spring, the magnet faces the Hall sensor, thereby triggering the Hall sensor to stop the motor and prevent the clock spring from being damaged, and prevent the phenomenon that the clock spring is damaged due to the rotation speed of the motor exceeding the defined rotation speed value and causing the limit position of the clock spring to be exceeded. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only exemplary, and for those of ordinary skill in the art, without creative efforts, other implementation drawings can also be obtained according to the provided drawings.

[0018] The structures, ratios, sizes, etc. shown in this specification are only used to cooperate with the content disclosed in the specification for those familiar with this technology to understand and read, and are not used to limit the limited conditions for the implementation of the present invention. Therefore, they do not have technical essence. Any modification of the structure, change of the proportional relationship or adjustment of the size should still fall within the scope that can be covered by the technical content disclosed in the present invention without affecting the effects that the present invention can produce and the purposes that can be achieved.

[0019] Figure 1 FIG. is a schematic diagram of the overall structure of a motor-driven seat belt retractor shown according to an exemplary embodiment;

[0020] Figure 2 FIG. is a schematic diagram of the transmission structure of a motor drive structure for a seat belt shown according to an exemplary embodiment;

[0021] Figure 3Schematic diagram of the transmission structure of an electric motor drive structure for a seat belt (removing the planet carrier gear) shown according to an exemplary embodiment;

[0022] Figure 4 Schematic diagram of the transmission structure of an electric motor drive structure for a seat belt (with a base) shown according to an exemplary embodiment;

[0023] Figure 5 Schematic diagram of the structure of a stepped gear shown according to an exemplary embodiment;

[0024] Figure 6 Schematic diagram of the structure of a planet carrier gear shown according to an exemplary embodiment;

[0025] Figure 7 Schematic diagram of the transmission structure of a high-torque electric motor drive structure for a seat belt shown according to an exemplary embodiment;

[0026] Figure 8 Schematic diagram of the structure of a high-torque electric motor drive structure for a seat belt shown according to an exemplary embodiment;

[0027] Figure 9 Schematic diagram of the structure of a high-torque electric motor drive structure for a seat belt from another perspective shown according to an exemplary embodiment;

[0028] Figure 10 Schematic diagram of the structure of a high-torque electric motor drive structure for a seat belt (removing the secondary transmission gear) shown according to an exemplary embodiment;

[0029] Figure 11 Schematic diagram of the structure of an eccentric structure assembly shown according to an exemplary embodiment;

[0030] Figure 12 Exploded view schematic diagram of a seat belt retractor shown according to an exemplary embodiment;

[0031] Figure 13 Schematic diagram of the structure of a seat belt retractor (removing the outer cover) shown according to an exemplary embodiment;

[0032] Figure 14 Schematic diagram of the structure of a torsion spring cover plate shown according to an exemplary embodiment;

[0033] Figure 15 Schematic diagram of the trigger structure for a seat belt in a triggered state shown according to an exemplary embodiment;

[0034] Figure 16 Schematic diagram of the trigger structure for a seat belt in a non-triggered state shown according to an exemplary embodiment;

[0035] Figure 17 Schematic structural diagram of a shearing component for a seat belt shown according to an exemplary embodiment;

[0036] Figure 18 Schematic structural diagram of a pin hole shown according to an exemplary embodiment. Detailed implementation manners

[0037] The following specific embodiments illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0038] According to an embodiment of the present invention, a motor-driven safety retractor is provided, as Figures 1 to 18 shown, including a motor 600, a reduction mechanism assembly 200, a main gear 900, a clutch assembly 300, and a core shaft assembly 500. Among them, the output end of the motor 600 is connected to the reduction mechanism assembly 200, the output end of the reduction mechanism assembly 200 is meshed and connected to the main gear 900, the main gear 900 is connected to the core shaft assembly 500 through the clutch assembly 300, and the core shaft assembly 500 is driven to rotate by the motor 600;

[0039] Among them, the output end of the motor 600 is provided with a driving gear 601. The reduction mechanism assembly 200 adopts a planetary carrier gear structure or an eccentric swing gear structure. The motor 600 is decelerated through the reduction mechanism assembly 200, and the motion is transmitted to the main gear 900. The main gear 900 is connected to the core shaft assembly 500 through the clutch assembly 300, so as to realize driving the core shaft assembly 500 to rotate by the motor 600.

[0040] For the motor-driven safety retractor provided by the present invention, the motor 600 is decelerated through the reduction mechanism assembly 200, and the motion is transmitted to the main gear 900. The main gear 900 is connected to the core shaft assembly 500 through the clutch assembly 300, so as to realize driving the core shaft assembly 500 to rotate by the motor 600. When the seat belt is pre-tightened, it can be reused, and the forward and reverse rotation of the core shaft assembly 500 can be realized through the forward and reverse rotation of the motor 600.

[0041] In some alternative embodiments, the motor-driven safety retractor further includes a torsion spring assembly 100, and the torsion spring assembly 100 is disposed on a side of the mandrel assembly 500 close to the clutch assembly 300. The torsion spring assembly 100 includes a torsion spring cover plate 12 and a torsion spring 101. The torsion spring 101 is disposed within the torsion spring cover plate 12, and the torsion spring 101 is connected to an axial end of the mandrel assembly 500. By providing the torsion spring 101, the seat belt wound around the mandrel assembly 500 can be retracted, ensuring that the seat belt always adheres to the human body.

[0042] In some alternative embodiments, the motor-driven safety retractor further includes a control unit 400. The control unit 400 is disposed inside the motor-driven safety retractor and is used to control the motor 600 and the clutch assembly 300, such as controlling the motor 600 to stop rotating.

[0043] In some alternative embodiments, the motor-driven safety retractor further includes a pretensioner assembly 700. The pretensioner assembly 700 is disposed outside the mandrel assembly 500. When an emergency occurs in the vehicle, the mandrel assembly 500 is pretensioned, and the pretension can be achieved by using the motor 600.

[0044] The drive structure in the embodiments of the present invention may adopt a motor drive structure for a seat belt, including a motor 600, a reduction mechanism assembly 200, a main gear 900, a clutch assembly 300, and a mandrel assembly 500. Among them, an output end of the motor 600 is connected to the reduction mechanism assembly 200, an output end of the reduction mechanism assembly 200 is meshed and connected to the main gear 900, the main gear 900 is connected to the mandrel assembly 500 through the clutch assembly 300, and the mandrel assembly 500 is driven to rotate by the motor 600; among them, an output end of the motor 600 is provided with a driving gear 601, the reduction mechanism assembly 200 includes a planetary carrier gear assembly 201 and a stepped gear 202, the stepped gear 202 includes a driving external gear 2021 and a first-stage driven gear 2022, and the driving external gear 2021 and the first-stage driven gear 2022 are coaxially and integrally arranged; the driving gear 601 is meshed and connected to the first-stage driven gear 2022, and the driving external gear 2021 is connected to the planetary carrier gear assembly 201; when the driving gear 601 rotates, the main gear 900 is rotated through the first-stage driven gear 2022, the driving external gear 2021, and the planetary carrier gear assembly 201, and the main gear 900 is connected to the mandrel assembly 500 through the clutch assembly 300, so as to achieve driving the mandrel assembly 500 to rotate by the motor 600.

[0045] The present invention uses a motor 600. Through the driving gear 601 at the output end of the motor 600, the main gear 900 is rotated by the first-stage driven gear 2022, the driving external gear 2021, and the planetary gear assembly 2021. The main gear 900 is connected to the mandrel assembly 500 through the clutch assembly 300, so as to drive the mandrel assembly 500 to rotate through the motor 600. When the seat belt is pre-tightened, it can be reused, and the forward and reverse rotation of the motor 600 can be used to realize the forward and reverse rotation of the mandrel assembly 500.

[0046] In some alternative embodiments, the planetary gear assembly 201 further includes a common planetary gear 2011, which is meshed and connected with the driving external gear 2021. The common planetary gear 2011 is arranged on the circumferential outer side of the driving external gear 2021, and the rotation of the driving external gear 2021 drives the rotation of the common planetary gear 2011. The number of the common planetary gears 2011 is one or more. When the number of the common planetary gears 2011 is multiple, for example, the number of the common planetary gears 2011 can be 3-5, and they are evenly distributed along the circumferential direction of the driving external gear 2021. The number of the common planetary gears 2011 is three. The planetary gear assembly 201 further includes a planetary gear internal gear 2012, which is fixed on the base 2013 of the reduction mechanism assembly 200 and connected by a spline 2015. When the common planetary gear 2011 rotates, the planetary gear internal gear 2012 remains stationary. The planetary gear assembly 201 further includes a planetary carrier gear 2014, which is arranged on the side of the planetary gear internal gear 2012 axially away from the base 2013 and can be meshed with the main gear 900. A cylinder 2016 is provided on the surface of the planetary carrier gear 2014 facing the common planetary gear 2011. The cylinder 2016 is arranged opposite to the axis of the common planetary gear 2011 and is inserted into the axis of the common planetary gear 2011. When the common planetary gear 2011 rotates, the cylinder 2016 rotates synchronously with the common planetary gear 2011, and the rotation of the cylinder 2016 drives the planetary carrier gear 2014 to rotate. The number of the cylinders 2016 is the same as the number of the common planetary gears 2011, which can be three to five, and the specific positions where they are arranged correspond to the centers of the common planetary gears 2011. The motor 600 is a brushed DC motor, with a voltage of 12V / 24V / 36V / 48V and a maximum current of 40A, having the characteristics of fast startup, timely braking, smooth speed regulation in a large range, and relatively simple control circuit.

[0047] The drive structure in the embodiments of the present invention can also be a high-torque motor drive structure for a seat belt, including a motor 600, a reduction mechanism assembly 200, a main gear 900, a clutch assembly 300, and a mandrel assembly 500. Among them, the output end of the motor 600 is connected to the reduction mechanism assembly 200, the output end of the reduction mechanism assembly 200 is meshed and connected to the main gear 900, the main gear 900 is connected to the mandrel assembly 500 through the clutch assembly 300, and the mandrel assembly 500 is driven to rotate by the motor 600. Among them, a driving gear 601 is provided at the output end of the motor 600. The reduction mechanism assembly 200 includes a swing gear assembly 203, an eccentric structure assembly 204, and a secondary transmission gear 205. The eccentric structure assembly 204 includes an eccentric shaft 2041 and a primary transmission gear 2042, and the eccentric shaft 2041 and the primary transmission gear 2042 are integrally provided. The driving gear 601 is meshed and connected to the primary transmission gear 2042, the eccentric shaft 2041 is connected to the swing gear assembly 203, and the swing gear assembly 203 is connected to the secondary transmission gear 205.

[0048] When the driving gear 601 rotates, the main gear 900 is rotated through the primary transmission gear 2042, the swing gear assembly 203, and the secondary transmission gear 205. The main gear 900 is connected to the mandrel assembly 500 through the clutch assembly 300, so as to realize driving the mandrel assembly 500 to rotate by the motor 600.

[0049] In the present invention, when the driving gear 601 rotates, the main gear 900 is rotated through the primary transmission gear 2042, the swing gear assembly 203, and the secondary transmission gear 205. The main gear 900 is connected to the mandrel assembly 500 through the clutch assembly 300, so as to realize driving the mandrel assembly 500 to rotate by the motor 600. When the seat belt is pre-tightened, it can be reused, and the forward and reverse rotation of the mandrel assembly 500 can be realized by the forward and reverse rotation of the motor 600, and it has the characteristics of simple structure and high transmission torque.

[0050] In some alternative embodiments, the eccentric swing gear structure includes a swing gear assembly 203, an eccentric structure assembly 204, and a secondary transmission gear 205. The eccentric structure assembly 204 includes an eccentric shaft 2041 and a primary transmission gear 2042, and the eccentric shaft 2041 and the primary transmission gear 2042 are integrally provided. The driving gear 601 is meshed and connected with the primary transmission gear 2042, the eccentric shaft 2041 is connected with the swing gear assembly 203, and the swing gear assembly 203 is connected with the secondary transmission gear 205. A plurality of through holes 2051 are provided on the end face of the secondary transmission gear 205, and the through holes 2051 are evenly distributed around the axis of the secondary transmission gear 205. The swing gear assembly 203 includes a swing gear 2031 and a transmission member 2032. The transmission member 2032 is provided on the surface of the swing gear 2031 facing the secondary transmission gear 205, and the transmission member 2032 is disposed opposite to the through holes 2051. By providing the transmission member 2032 and the through holes 2051, the rotation of the swing gear 2031 can be transmitted to the rotation of the secondary transmission gear 205, thereby realizing the transmission of motion. The transmission member 2032 is cylindrical, and the diameter of the transmission member 2032 is smaller than the diameter of the through holes 2051. Among them, the use of a cylindrical shape for the transmission member 2032 can make the entire transmission process stable, and compared with using a frustum shape or a prism shape, the contact between the transmission member 2032 and the through holes 2051 can be increased. The number of the through holes 2051 is 6, and the number of the through holes 2051 is the same as the number of the transmission members 2032. Of course, the number of the transmission members 2032 can also be less than the number of the through holes 2051, and the transmission of rotation can be realized. During the transmission process, the transmission member 2032 is inserted into the through holes 2051. During the rotation of the swing gear 2031, the transmission member 2032 is driven to rotate synchronously, thereby driving the secondary transmission gear 205 to rotate. The high-torque motor drive structure for a seat belt further includes a reduction internal gear 206. The reduction internal gear 206 is provided on the outer side of the circumference of the swing gear 2031 and is meshed and connected with the swing gear 2031. The reduction internal gear 206 is fixed to the base of the reduction mechanism assembly 200 by a spline structure. By providing the reduction internal gear 206 and cooperating with the swing gear 2031, the reduction of the reduction mechanism assembly 200 is realized. The number of teeth of the reduction internal gear 206 is greater than the number of teeth of the swing gear 2031. Among them, the number of teeth of the reduction internal gear 206 is 36, and the number of teeth of the swing gear 2031 is 32 to 35. By setting a tooth number difference between the reduction internal gear 206 and the swing gear 2031, the reduction of the reduction mechanism assembly is realized.The swing amplitude of the swing gear assembly 203 is not greater than the eccentricity of the eccentric structure assembly 204. The specific relationship between the eccentricity and the swing amplitude is not limited herein. In the present invention, the eccentric structure assembly is used to achieve the transmission of motion, and multi-stage deceleration can be achieved during the transmission process.

[0051] According to an embodiment of the present invention, a trigger structure for a seat belt is further provided, including a magnet 15 and a Hall sensor 14. The magnet 15 is disposed on one side of the spring cover 12 facing the spring, and the Hall sensor 14 is disposed on the base 2013. A first groove 20131 is provided on the base 2013. Under the action of the spring 101, the magnet 15 moves along the first groove 20131. When the magnet 15 faces the Hall sensor 14, the magnet 15 triggers the Hall sensor 14.

[0052] In the trigger structure of the embodiment of the present invention, when the magnet 15 moves along the first groove 20131 and reaches the limit position of the spring 101, the magnet 15 faces the Hall sensor 14, thereby triggering the Hall sensor, causing the motor to stop, preventing the spring 101 from being damaged, and avoiding the phenomenon that the spring 101 is damaged by exceeding the limit position of the spring 101.

[0053] In some alternative embodiments, a spring mounting portion 121 is further provided on the coil spring cover plate 12, and the spring mounting portion 121 extends tangentially along the circumference of the coil spring cover plate 12. Among them, the number of the spring mounting portions 121 is one, and one end of the spring 102 is fixed to the spring mounting portion 121, and a part of the spring 102 is sleeved on the outer surface of the spring mounting portion 121. The spring mounting portion 121 is cylindrical or frustum-shaped. When the spring mounting portion 121 is frustum-shaped, the end close to the coil spring cover plate 12 is the large-head end. Among them, the spring mounting portion 121 being cylindrical or frustum-shaped can prevent the spring 102 from being obstructed by the side surface of the spring mounting portion 121 during the compression process, making the entire compression and expansion process of the spring 102 smooth and unobstructed. The end face of the base 2013 opposite to the coil spring cover plate 12 is provided with a second groove 20132. When the coil spring cover plate 12 rotates, the spring mounting portion 121 can move in the second groove 20132 to compress or loosen the spring 102. Among them, the space between the second groove 20132 and the spring mounting portion 121 is the moving space of the spring 102. The trigger structure for the seat belt further includes a positioning cover plate 13, and the positioning cover plate 13 is disposed between the coil spring cover plate 12 and the base 2013. Among them, the positioning cover plate 13 is mainly provided to facilitate the installation of the coil spring cover plate 12 and the coil spring 101. The control unit 400 is connected to the Hall sensor 14 and is used to turn off the motor 600 according to the signal sent by the Hall sensor 14. Here, the control unit 400 is used to control the start and stop of the motor 600 and the magnitude of the rotational speed. The trigger structure for the seat belt further includes a magnet mounting portion 122, and one end of the magnet mounting portion 122 is fixed to the edge of the coil spring cover plate 12 and extends along the central axis of the coil spring cover plate 12 in the direction close to the Hall sensor 14. By providing the magnet mounting portion 122, the distance between the magnet 15 and the Hall sensor 14 can be made closer, making the trigger structure more sensitive. Among them, the magnet mounting portion 122 is cylindrical, frustum-shaped or rectangular. In actual use, the magnet mounting portion 122 can also adopt other shapes as long as the distance between the magnet 15 and the Hall sensor 14 can be made closer. The magnet 15 is embedded in the end of the magnet mounting portion 122. By adopting this mounting method, the situation of the magnet 15 falling off can be avoided, and the phenomenon of the trigger structure failing due to the magnet 15 falling off can be avoided.When the spring 102 is in the extreme compressed state, the magnet 15 faces the Hall sensor 14, and the Hall sensor 14 is triggered. The control unit 400 stops the operation of the motor 600 according to the signal of the Hall sensor 14 to avoid exceeding the limit position of the retractable spring 101. Then, the retractable spring cover 12 will rotate reversely under the action of the spring 102, so that the retractable spring 101 is opened to a certain extent, and the magnet 15 and the Hall sensor 14 are not opposite to each other, that is, the magnet 15 is in the non-triggered position. The first groove 20131 and the second groove 20132 are respectively arranged on both sides of the circular ring in the base 2013, and their shapes are both arc-shaped grooves.

[0054] According to an embodiment of the present invention, there is also provided a cutting component for a seat belt, including a pin 501 and a pin hole 104. Wherein, the pin 501 is arranged at one end of the core shaft assembly 500 close to the shaft head of the retractable spring assembly 100, and the pin hole 104 is arranged on the shaft head of the retractable spring assembly 100; alternatively, the pin 501 is arranged at one end on the shaft head of the retractable spring assembly 100, and the pin hole 104 is arranged at one end of the core shaft assembly 500 close to the shaft head of the retractable spring assembly 100; the pin hole 104 is opposite to the pin 501; when the shaft head of the retractable spring assembly 100 is connected to the core shaft assembly 500, the pin 501 is inserted into the pin hole 104.

[0055] By setting the pin 501 and the pin hole 104, when the two ends of the core shaft assembly 500 are simultaneously fixed and locked when using the motor structure to drive the seat belt retractor, it can be cut when the core shaft assembly 500 is locked to reach a certain force value, so that the core shaft assembly can continue to perform force limit control to relieve the pressure of the seat belt on the occupant's chest.

[0056] In some alternative embodiments, the number of the pins 501 is one or more, and they are arranged on the end face of the mandrel assembly 500; the number of the pin holes 104 is the same as that of the pins 501, and the positions of the pin holes 104 are opposite to the corresponding pins 501. Among them, the number of the pins 501 is related to the force value required for shearing. When the force value required for shearing is small, the number of the pins 501 can be selected to be less. For example, when it is set that the mandrel assembly 500 is locked to reach 75 N, one pin 501 can be selected. When it is set that the mandrel assembly 500 is locked to reach 150 N and the pin 501 is sheared, two pins 501 can be selected. Among them, the two pins 501 and the center of the end face of the mandrel assembly 500 are on the same straight line. A protrusion 103 is formed on the inner surface in the axial direction of the torsion spring assembly 100. The pin holes 104 are arranged on the protrusion 103 of the torsion spring assembly 100. The cross section of the protrusion 103 is arc-shaped, and the pin holes 104 are arranged along the axial direction of the protrusion 103. The pin 501 is cylindrical, the pin hole 104 is circular, the diameter of the pin hole 104 is adapted to the diameter of the pin 501, or the pin 501 is frustum-shaped, its large head end is in contact with the mandrel assembly 500, the shape and size of the pin hole 104 are adapted to the shape and size of the pin 501, or the pin 501 is a rectangular body, the cross section of the pin hole 104 is rectangular, the size of the pin hole 104 is adapted to the size of the pin 501, or the pin 501 is pyramid-shaped, and the size of the pin hole 104 is adapted to the shape and size of the pin. When making a selection, the pin 501 can also be of other shapes, as long as it is adapted to the shape of the pin hole 104. Among them, the size of the pin hole 104 is slightly larger than the size of the pin 501, so that the pin 501 can normally enter the pin hole 104. When the number of the pins 501 is one, its central position is set at a non-central position on the end face of the mandrel assembly 500. When the number of the pins 501 is multiple, the multiple pins 501 are evenly distributed on the end face of the mandrel assembly 500 along the center of the end face of the mandrel assembly 500. Among them, the number of the pins 501 is two. Other numbers of pins can be selected for setting according to needs, such as 3 or 4, etc. Among them, the distance between the central position of the pin 501 and the center position of the end face of the mandrel assembly 500 is not specifically limited. The material of the pin 501 is metal or plastic. Among them, when selecting the material of the pin 501, it can be the same as the material of the mandrel assembly 500 and obtained by an integral forming process, or different materials can be used and fixed to the end face of the mandrel assembly 500 by welding or bonding. The seat belt retractor further includes an outer cover 11 for enclosing the deceleration mechanism assembly 200 and the torsion spring cover 12.

[0057] In some alternative embodiments, the motor-driven safety retractor further includes a mechanical end assembly 800 disposed on a side of the mandrel assembly 500 close to the pretensioner assembly 700. The mechanical end assembly 800 includes a sensor assembly and a locking structure. Among them, the sensor assembly includes a vehicle sensor, a belt sensor, and an inclination angle sensor. The sensor assembly can sense an emergency occurring inside the vehicle and trigger the gas generant in a timely manner. The locking mechanism can quickly lock the seat belt retractor and can buffer the pressure of the seat belt.

[0058] Although the present invention has been described in detail above with general descriptions and specific embodiments, on the basis of the present invention, some modifications or improvements can be made, which are obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of the present invention claimed.

Claims

1. A triggering structure for a seat belt, characterized in that, it includes a magnet, a Hall sensor and a control unit. The magnet is arranged on one side of the clock spring cover plate facing the clock spring. The Hall sensor is arranged on the base. There is a first groove on the base. Under the action of the clock spring, the magnet moves along the first groove. When the magnet is opposite to the Hall sensor, the magnet triggers the Hall sensor. The control unit is connected to the Hall sensor and is used to turn off the motor according to the signal sent by the Hall sensor.

2. The triggering structure for a seat belt according to claim 1, characterized in that, the clock spring cover plate is further provided with a spring installation part, and the spring installation part extends along the tangent of the circumference of the clock spring cover plate.

3. The triggering structure for a seat belt according to claim 2, characterized in that, the spring installation part is cylindrical or frustum-shaped. When the spring is frustum-shaped, the end close to the clock spring cover plate is the large head end.

4. The triggering structure for a seat belt according to claim 2, characterized in that, the end face of the base opposite to the clock spring cover plate is provided with a second groove. When the clock spring cover plate rotates, the spring installation part can move in the second groove to compress or loosen the spring.

5. The triggering structure for a seat belt according to claim 2, characterized in that, it further includes a positioning cover plate, and the positioning cover plate is arranged between the clock spring cover plate and the base.

6. The triggering structure for a seat belt according to claim 1, characterized in that, it further includes a magnet installation part, and one end of the magnet installation part is fixed to the edge of the clock spring cover plate and extends along the central axis of the clock spring cover plate in the direction close to the Hall sensor.

7. The triggering structure for a seat belt according to claim 6, characterized in that, the magnet installation part is cylindrical, frustum-shaped or rectangular.

8. The triggering structure for a seat belt according to claim 6, characterized in that, the magnet is embedded in the end of the magnet installation part.

9. A seat belt retractor, characterized in that, the seat belt retractor includes a clock spring, a clock spring cover plate and the triggering structure for a seat belt according to any one of claims 1 to 8.

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