A locking mechanism and a seat belt retractor

Abstract

The present invention discloses a locking mechanism and a seat belt retractor. At least one locking block is provided between the main gear and the clutch fixing piece. At least one track groove is formed on the bottom surface of the guiding chamber where the main gear is located. The number of the track grooves is the same as that of the locking blocks and they are arranged in one-to-one correspondence. One end of the locking block is rotatably connected to the clutch fixing piece, and the other end of the locking block is slidably connected in the track groove. The combination of the main gear and the clutch fixing piece is sleeved on the outer peripheral side of the transmission wheel. When the main gear rotates forward relative to the clutch fixing piece, the locking block slides in the track groove to a state of contacting and engaging with the transmission wheel. When the main gear rotates backward relative to the clutch fixing piece, the locking block slides in the track groove to a state of separating from contact with the transmission wheel. The purpose is to solve the problem of large vibration and noise during the use of the clutch assembly of the seat belt retractor in the prior art. Effect: The vibration and noise generated by the locking mechanism are significantly reduced, and the smoothness during the operation of the locking mechanism is significantly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle seat belts, and in particular to a locking mechanism and a seat belt retractor. Background Art

[0002] Existing seat belt retractors can provide protection for the driver before a collision. An active seat belt retractor driven by an electric motor can drive the seat belt retractor to retract a certain amount of seat belt through the electric motor before a possible collision of the vehicle, achieving the protection effect on the driver.

[0003] The electric motor of the seat belt retractor has a relatively small output torque. The existing clutches for seat belt retractors are mainly tooth-type clutches. Such clutches have problems such as large clutch delay, lack of synchronism between internal and external teeth, and large impact vibration and noise; there is a lack of a clutch locking mechanism with low vibration and noise, simple structure and good stability. Summary of the Invention

[0004] Therefore, the present invention provides a locking mechanism to solve the problem of large vibration and noise during the use of the clutch assembly of the seat belt retractor in the prior art.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] According to the first aspect of the present invention, a locking mechanism includes a main gear, a transmission wheel, a locking block and a clutch fixing piece; a guiding chamber is provided on one end face of the main gear, one end of the clutch fixing piece is embedded in the guiding chamber, at least one locking block is arranged between the main gear and the clutch fixing piece, at least one track groove is provided on the bottom surface of the guiding chamber of the main gear, and the number of the track grooves is the same as and corresponds to the number of the locking blocks one by one; one end of the locking block is rotatably connected to the clutch fixing piece, the other end of the locking block is slidably connected in the track groove, and the combination of the main gear and the clutch fixing piece is sleeved on the outer peripheral side of the transmission wheel; when the main gear rotates forward relative to the clutch fixing piece, the locking block slides in the track groove to a state of contacting and meshing with the transmission wheel; when the main gear rotates backward relative to the clutch fixing piece, the locking block slides in the track groove to a state of disengaging from the transmission wheel.

[0007] Further, when there are multiple locking blocks, the multiple locking blocks are arranged in an annular equidistant array around the axis of the transmission wheel.

[0008] Further, the locking block includes a rotating part, a connecting part, a locking part and a sliding protrusion; the rotating part is connected to the locking part through the connecting part, a sliding protrusion is arranged on the side surface of the connecting part, the sliding protrusion is slidably connected to the track groove, the rotating part is rotatably connected to the clutch fixing piece, and at least one transmission tooth meshing with the transmission wheel is arranged on the locking part.

[0009] Furthermore, a shock-absorbing spring is provided on the main gear, one end of which is fixed to one end of the track groove, the other end of which extends toward the other end of the track groove and tilts toward the inside of the track groove, and the shock-absorbing spring abuts against the sliding protrusion.

[0010] Furthermore, the extension line of the track groove is an arc curve, the curvature center of the arc curve is located at an eccentric position of the center of the main gear, and the shock-absorbing spring is in an arc shape.

[0011] Furthermore, the tooth shape on the outer peripheral side of the transmission wheel is matched with the tooth shape of the transmission teeth of the locking portion.

[0012] Furthermore, the tooth shape on the outer peripheral side of the transmission wheel is an asymmetric trapezoidal tooth, which is inclined toward the side of the locking part away from the rotating part, and the transmission teeth of the locking part are asymmetric trapezoidal teeth adapted to the tooth shape on the outer peripheral side of the transmission wheel.

[0013] Furthermore, a pressure-bearing surface is provided in the guide cavity of the main gear, the pressure-bearing surface abuts against the outer side surface of the locking portion facing away from the connecting portion, and the pressure-bearing surface extends in the radial direction of the transmission wheel.

[0014] Furthermore, a plurality of wedge-shaped blocks are provided on the outer edge of one side of the main gear located in the guide chamber, and the plurality of wedge-shaped blocks are clamped on the end surface of the clutch fixing plate which is away from the main gear.

[0015] Furthermore, at least one limiting protrusion is provided on the end face of the clutch fixing plate located on the inner side of the guide chamber, and a limiting groove with an open end is provided in each limiting protrusion, and the rotating part of the locking block is rotatably connected to the closed end of the limiting groove, and the locking part of the locking block extends out of the open end of the limiting groove, and the limiting groove is a V-shaped groove whose open end has a width greater than that of the closed end.

[0016] According to a second aspect of the present invention, a seat belt retractor comprises the locking mechanism of any one of the first aspect of the present invention.

[0017] The present invention has the following advantages: the locking block provided in the present invention slides in the track groove, so that the locking block gradually stabilizes and engages with the transmission wheel as the main gear rotates relative to the clutch fixing plate during use of the clutch assembly; during use, the vibration noise generated by the locking mechanism is significantly reduced, the stability of the locking mechanism during operation is significantly improved, and the one-way rotation locking function of the main gear is realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a structural diagram of a clutch torque plate of a friction plate clutch assembly according to some embodiments of the present invention.

[0019] Figure 2 The exploded structure diagram of a friction plate clutch assembly according to some embodiments of the present invention.

[0020] Figure 3 This is the front view of a friction plate type clutch assembly according to some embodiments of the present invention.

[0021] Figure 4 This is the sectional view of a friction plate type clutch assembly according to some embodiments of the present invention.

[0022] Figure 5 This is the exploded view of a friction plate type clutch assembly according to some other embodiments of the present invention.

[0023] Figure 6 This is the exploded view of a spring type clutch assembly according to some embodiments of the present invention.

[0024] Figure 7 This is the plan view of a spring type clutch assembly according to some embodiments of the present invention.

[0025] Figure 8 This is the structure diagram of the clutch fixing plate of a spring type clutch assembly according to some embodiments of the present invention.

[0026] Figure 9 This is the structure diagram of the one-way clutch spring of a spring type clutch assembly according to some embodiments of the present invention.

[0027] Figure 10 This is the front structure diagram of a locking mechanism according to the first scheme of some embodiments of the present invention.

[0028] Figure 11 This is the structure diagram of the locking block of a locking mechanism according to the first scheme of some embodiments of the present invention.

[0029] Figure 12 This is the structure diagram of the return spring of a locking mechanism according to the first scheme of some embodiments of the present invention.

[0030] Figure 13 This is the structure diagram of the clutch fixing plate of a locking mechanism according to the first scheme of some embodiments of the present invention.

[0031] Figure 14 This is the structure diagram of the locking fixing plate of a locking mechanism according to the first scheme of some embodiments of the present invention.

[0032] Figure 15 This is the exploded view of a locking mechanism according to the second scheme of some embodiments of the present invention.

[0033] Figure 16 This is the partial front sectional view of a locking mechanism according to the second scheme of some embodiments of the present invention.

[0034] Figure 17 This is the structure diagram of the main gear of a locking mechanism according to the second scheme of some embodiments of the present invention.

[0035] Figure 18 Structural diagram of a locking block of a locking mechanism, which is the second solution of some embodiments of the present invention.

[0036] Figure 19 Overall structural schematic diagram of a motor-driven seat belt retractor according to some embodiments of the present invention;

[0037] Figure 20 Schematic diagram of the transmission structure of a motor-driven structure for a seat belt according to some embodiments of the present invention;

[0038] Figure 21 Schematic diagram of the transmission structure of a motor-driven structure for a seat belt according to some embodiments of the present invention (removing the planet carrier gear);

[0039] Figure 22 Schematic diagram of the transmission structure of a motor-driven structure for a seat belt according to some embodiments of the present invention (with a base);

[0040] Figure 23 Schematic diagram of the structure of a main gear according to some embodiments of the present invention;

[0041] Figure 24 Schematic diagram of the structure of a stepped gear according to some embodiments of the present invention;

[0042] Figure 25 Schematic diagram of the transmission structure of a high-torque motor-driven structure for a seat belt according to some embodiments of the present invention;

[0043] Figure 26 Schematic diagram of a high-torque motor-driven structure for a seat belt according to some embodiments of the present invention;

[0044] Figure 27 Schematic diagram of the structure of a high-torque motor-driven structure for a seat belt according to some embodiments of the present invention (removing the secondary transmission gear);

[0045] Figure 28 Schematic diagram of the structure of an eccentric structure component according to some embodiments of the present invention;

[0046] Figure 29 Exploded structural schematic diagram of a seat belt retractor according to some embodiments of the present invention;

[0047] Figure 30 Schematic diagram of the structure of a seat belt retractor according to some embodiments of the present invention (removing the outer cover);

[0048] Figure 31 Schematic diagram of the structure of a torsion spring cover plate according to some embodiments of the present invention;

[0049] Figure 32Schematic diagram of the trigger structure of the seat belt in the triggered state for some embodiments of the present invention;

[0050] Figure 33 Schematic diagram of the trigger structure of the seat belt in the non-triggered state for some embodiments of the present invention;

[0051] Figure 34 Schematic diagram of the structure of a cutting component for a seat belt in some embodiments of the present invention;

[0052] In the figure: 100, coiled spring assembly; 101, coiled spring; 102, spring; 103, protruding part; 104, pin hole; 200, speed reduction mechanism assembly; 201, planet carrier gear assembly; 2011, common planet gear; 2012, planet gear internal gear; 2013, base; 20131, first groove; 20132, second groove; 2014, planet carrier gear; 2015, spline; 2016, cylinder; 202, stepped gear; 2021, driving external gear; 2022, first-stage driven gear; 203, swing gear assembly; 2031, swing gear; 2032, transmission part; 204, eccentric structure assembly; 2041, eccentric shaft; 2042, first-stage transmission gear; 205, second-stage transmission gear; 2051, through hole; 206, speed reduction internal gear; 300, clutch assembly; 301, transmission wheel; 3011, spline groove; 302, locking block; 3021, sliding protrusion; 3022, rotating part; 3023, connecting part; 3024, locking part; 3025, locking pressure-bearing protrusion; 3026, torsion spring slot; 303, clutch fixing piece; 3031, annular protrusion; 3032, limiting protrusion; 3033, limiting groove; 3034, clutch spring slot; 3035, first limiting pin; 3036, torsion spring fixing groove; 3037, second limiting pin; 3038, torsion spring supporting protrusion; 304, clutch torque piece; 3041, internal friction plate; 3042, external fixing plate; 3043, circular ring plate; 3044, friction protrusion; 305, clutch base; 3051, external fixing groove; 3052, internal fixing groove; 3053, annular friction part; 306, one-way clutch spring; 3061, clutch spring extension end; 307, return spring; 3071, first leg; 3072, second leg; 308, locking fixing piece; 3081, locking fixing hole; 3082, rotating mating groove; 3083, force-applying pressure-bearing surface; 309, clutch support; 3091, first limiting hole; 3092, second limiting hole; 400, control unit; 500, mandrel assembly; 501, pin; 600, motor; 601, driving gear; 700, pretensioner assembly; 800, mechanical end assembly; 900, main gear; 901, track groove; 902, shock-absorbing elastic piece; 903, external gear ring; 904, wedge-shaped block; 905, guiding chamber; 906, pressure-bearing surface; 907, locking trigger protrusion; 908, force-applying guiding surface; 11, outer cover; 12, coiled spring cover plate; 121, spring installation part; 122, magnet installation part; 13, positioning cover plate; 14, Hall sensor; 15, magnet. Detailed implementation mode

[0053] According to an embodiment of the present invention, there is provided a seat belt retractor driven by a motor, as Figures 1 to 34As shown, it includes 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, 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 mandrel assembly 500 through the clutch assembly 300, so as to realize the rotation of the mandrel assembly 500 driven by the motor 600. When in use, 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 mandrel assembly 500 through the clutch assembly 300, so as to realize the rotation of the mandrel assembly 500 driven 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 through the forward and reverse rotation of the motor 600.

[0054] In some alternative embodiments, the seat belt retractor further includes a torsion spring assembly 100. The torsion spring assembly 100 is arranged on one 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 arranged inside the torsion spring cover plate 12, and the torsion spring 101 is connected to the shaft end of the mandrel assembly 500. By arranging 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. It further includes a control unit 400. The control unit 400 is arranged inside the motor-driven seat belt retractor and is used to control the motor 600 and the clutch assembly 300, such as controlling the motor 600 to stop rotating, etc. It further includes a pretensioner assembly 700. The pretensioner assembly 700 is arranged outside the mandrel assembly 500. When an emergency occurs in the vehicle, the mandrel assembly 500 is pretensioned, and the motor 600 can be used to achieve the pretension.

[0055] In some alternative embodiments, the drive structure of the seat belt retractor can be a motor drive structure for a seat belt. The planetary carrier gear type reduction mechanism assembly 200 of the first solution 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 with the first-stage driven gear 2022, and the driving external gear 2021 is connected with 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. 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 through the motor 600; by adopting the motor 600, through the driving gear 601 at the output end of the motor 600, 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. 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 through 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; the planetary carrier gear assembly 201 further includes a common planetary gear 2011, and the common planetary gear 2011 is meshed and connected with the driving external gear 2021. Wherein, 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 carrier gear assembly 201 further includes a planetary gear internal gear 2012, and the planetary gear internal gear 2012 is fixed on the base 2013 of the reduction mechanism assembly 200 and is connected by a spline 2015. When the common planetary gear 2011 rotates, the planetary gear internal gear 2012 is fixed; the planetary carrier gear assembly 201 further includes a planetary carrier gear 2014, and the planetary carrier gear 2014 is arranged on the side of the planetary gear internal gear 2012 axially away from the base 2013 and can be meshed and connected with the main gear 900;On the surface of the planet carrier gear 2014 facing the common planet gear 2011, there is a cylinder 2016. The cylinder 2016 is arranged opposite to the axis of the common planet gear 2011. The cylinder 2016 is inserted at the axis of the common planet gear 2011. When the common planet gear 2011 rotates, the cylinder 2016 rotates synchronously with the common planet gear 2011. Through the rotation of the cylinder 2016, the planet carrier gear 2014 is driven to rotate. Among them, the number of cylinders 2016 is the same as the number of common planet gears 2011, which can be three to five, and the specific position where it is set corresponds to the center of the common planet gear 2011; the motor 600 is a brushed DC motor, with a voltage of 12V / 24V / 36V / 48V and a maximum current of 40A, and has the characteristics of fast startup, timely braking, smooth speed regulation in a large range, and relatively simple control circuit.

[0056] In some alternative embodiments, the drive structure of the seat belt retractor can also be a high-torque motor drive structure for seat belts. The eccentric swing gear structure type reduction mechanism assembly 200 of the second solution 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; 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 core shaft assembly 500 through the clutch assembly 300, so as to realize the rotation of the core shaft assembly 500 driven by the motor 600; 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 core shaft assembly 500 through the clutch assembly 300, so as to realize the rotation of the core shaft assembly 500 driven 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, and it has the characteristics of simple structure and high transmission torque; 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 surface 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 arranged on the surface of the swing gear 2031 facing the secondary transmission gear 205, and the transmission member 2032 is arranged 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, so as to realize 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; wherein, the transmission member 2032 is cylindrical, which can make the whole transmission process stable. 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 transmission parts 2032 can also be less than the number of through holes 2051, and the transmission of rotation can be achieved. During the transmission process, the transmission parts 2032 are inserted into the through holes 2051. During the rotation of the oscillating gear 2031, the transmission parts 2032 are driven to rotate synchronously, thereby driving the secondary transmission gear 205 to rotate. The high-torque motor drive structure for seat belts further includes a reduction internal gear 206. The reduction internal gear 206 is arranged on the outer side of the circumferential direction of the oscillating gear 2031 and is meshed and connected with the oscillating 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 oscillating gear 2031, the reduction of the reduction mechanism assembly 200 is achieved. The number of teeth of the reduction internal gear 206 is greater than the number of teeth of the oscillating gear 2031. Among them, the number of teeth of the reduction internal gear 206 is 36, and the number of teeth of the oscillating gear 2031 is 32 to 35. By setting a tooth number difference between the reduction internal gear 206 and the oscillating gear 2031, the reduction of the reduction mechanism assembly is achieved. The swing amplitude of the oscillating 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 here. In this embodiment, the eccentric structure assembly is used to achieve the transmission of motion, and multi-stage reduction can be achieved during the transmission process.

[0057] In some alternative embodiments, the first solution of the clutch assembly 300 of the seat belt retractor is a friction plate type clutch assembly, which includes a main gear 900, a locking mechanism, a transmission wheel 301, a clutch fixing plate 303, a clutch torque plate 304 and a clutch base 305; a locking mechanism is arranged between the main gear 900 and the clutch fixing plate 303, a clutch torque plate 304 is arranged between the clutch base 305 and the clutch fixing plate 303, one end of the clutch torque plate 304 is connected to the clutch fixing plate 303, and the other end of the clutch torque plate 304 is connected to the clutch base 305; when the main gear 900 rotates forward relative to the clutch fixing plate 303, the locking mechanism is pushed to a state of contacting and engaging with the transmission wheel 301; when the main gear 900 rotates backward relative to the clutch fixing plate 303, the locking mechanism is pushed to a state of disengaging from the transmission wheel 301; the clutch torque plate 304 provides the friction force required for the main gear 900 to rotate relative to the clutch fixing plate 303 by continuously contacting to generate sliding friction; it should be noted that there are two ways for the clutch torque plate 304 to provide relative friction between the clutch fixing plate 303 and the clutch base 305: one is that the clutch torque plate 304 is fixed on the clutch base 305, and there is an interference fit sliding friction between the clutch torque plate 304 and the clutch fixing plate 303; the other is that the clutch torque plate 304 is fixed on the clutch fixing plate 303, and there is an interference fit sliding friction between the clutch torque plate 304 and the clutch base 305; by the way of the clutch torque plate 304 continuously contacting the clutch base 305 or the clutch fixing plate 303 to generate friction force in this embodiment, the one-way locking performance of the main gear 900 driving the locking mechanism to lock the transmission wheel 301 is significantly improved, and the extremely high motion synchronism between the main gear 900 and the clutch fixing plate 303 is achieved. The friction plate type clutch assembly has a simple structure and good stability, and significantly improves the clutch effect of the seat belt retractor; the locking mechanism includes a plurality of locking blocks 302, the plurality of locking blocks 302 are arranged in an annular equidistant array around the axis of the transmission wheel 301, one end of the locking block 302 is rotatably connected to the clutch fixing plate 303, and the other end of the locking block 302 is slidably connected in the main gear 900; the main gear 900 pushes the locking block 302 to engage with the transmission wheel 301 through a track groove or a guiding surface; by arranging a plurality of locking blocks 302, the stability of the main gear 900 driving the transmission wheel 301 to rotate simultaneously is significantly improved, and the vibration and noise are significantly reduced during the locking process; the clutch torque plate 304 includes an annular plate 3043, an inner friction plate 3041 and an outer fixing plate 3042;The annular disc 3043 has an annular sheet-like structure. A plurality of inner friction discs 3041 are fixed to the inner ring of the annular disc 3043, and a plurality of outer fixing discs 3042 are fixed to the outer ring of the annular disc 3043. Each inner friction disc 3041 is inclined towards the side of the outer fixing disc 3042, thereby producing an interference fit. In this embodiment, the annular disc 3043, the inner friction discs 3041, and the outer fixing discs 3042 are integrally formed structures, and their materials are made of wear-resistant materials, such as wear-resistant plastics or wear-resistant metals; each inner friction disc 3041 is provided with friction protrusions 3044, and the friction protrusions 3044 are arranged on the side of the inner friction disc 3041 close to the outer fixing disc 3042. The clutch torque disc 304 generates friction by sliding contact between the friction protrusions 3044 and the clutch base 305 or the clutch fixing disc 303; the friction protrusions 3044 are an integral structure formed by stamping or casting on the inner friction disc 3041. The integrally formed structural form reduces the material manufacturing cost of the friction protrusions 3044, and the service life of the clutch torque disc 304 is significantly extended; the number of inner friction discs 3041 is the same as the number of outer fixing discs 3042. The plurality of inner friction discs 3041 are arranged in a circular and uniform array around the center of the annular disc 3043, and the inner friction discs 3041 and the outer fixing discs 3042 are arranged in one-to-one correspondence. For example, both the inner friction discs 3041 and the outer friction discs are 8. The outer fixing discs 3042 are perpendicular to the annular disc 3043, and the included angle between the inner friction discs 3041 and the annular disc 3043 is an acute angle.;

[0058] In some alternative embodiments, a friction plate type clutch assembly of the first solution of the clutch assembly 300 has a spline groove 3011 formed on the inner side of the drive wheel 301. The drive wheel 301 is fixed on the core shaft assembly 500 through the spline groove 3011. In addition, the drive wheel 301 and the core shaft assembly 500 can also be fixed on the core shaft assembly 500 by means of key connection or the like; an annular protrusion 3031 is provided on the end face of the clutch fixing plate 303 facing away from the main gear 900. A plurality of inner friction plates 3041 are inserted into the inner ring of the annular protrusion 3031, and the friction protrusions 3044 are abutted against the inner ring of the annular protrusion 3031; a plurality of outer fixing grooves 3051 are formed on the side of the clutch base 305 close to the clutch torque plate 304. The number of the outer fixing grooves 3051 is the same as the number of the outer fixing plates 3042 of the clutch torque plate 304. The corresponding outer fixing plates 3042 of the clutch torque plate 304 are inserted and fixed in the outer fixing grooves 3051 of the clutch base 305; an arc-shaped protrusion plate is provided on the inner side of the arc surface between every two adjacent outer fixing grooves 3051, and an inner fixing groove 3052 is formed between every two adjacent arc-shaped protrusion plates. The corresponding inner friction plates 3041 of the clutch torque plate 304 are inserted into the inner fixing grooves 3052. In this embodiment, a plurality of wedge-shaped blocks 904 are formed on the main gear 900, and the plurality of wedge-shaped blocks 904 jointly limit the clutch fixing plate 303 on one side of the main gear 900. During clamping, the clutch fixing plate 303 can rotate relative to the main gear 900; the working principle of this solution is that the main gear 900 rotates relative to the clutch fixing plate 303 under the drive of the motor 600. The locking mechanism contacts and engages with the drive wheel 301 under the action of the main gear 900. The clutch fixing plate 303 and the clutch torque plate 304 are in interference fit and friction is generated between the two. The clutch torque plate 304 is fixed on the clutch base 305, so as to provide a frictional force formed by torque to the clutch fixing plate 303. This frictional force causes the clutch fixing plate 303 to rotate relative to the main gear 900. When the locking is completed, the main gear 900 pushes the clutch fixing plate 303 to break through the frictional force provided by the clutch torque plate 304, so as to realize the continuous rotation of the main gear 900 driving the clutch fixing plate 303.

[0059] In some optional embodiments, the first scheme of the clutch assembly 300 is a friction plate clutch assembly. In another possible form, a plurality of external fixing grooves 3051 are provided on the end surface of the clutch fixing plate 303 facing away from the main gear 900, and the number of the external fixing grooves 3051 is the same as the number of the external fixing plates 3042. The external fixing plates 3042 of the clutch torque plate 304 are correspondingly plugged and fixed in the external fixing grooves 3051 of the clutch fixing plate 303; an annular protrusion 3031 is provided on the side of the clutch base 305 close to the clutch torque plate 304, and a plurality of inner friction plates 3041 are plugged into the inner ring of the annular protrusion 3031, and the friction protrusion 3044 abuts against the inner ring of the annular protrusion 3031. On; the operating principle of this embodiment is that the main gear 900 rotates relative to the clutch fixing plate 303 under the drive of the motor 600, and the locking mechanism contacts and meshes with the transmission wheel 301 under the action of the main gear 900. The clutch fixing plate 303 and the clutch base 305 are interference fit and the two generate friction. The clutch torque plate 304 is fixed on the clutch fixing plate 303, thereby providing a friction force formed by torque to the clutch fixing plate 303, and the friction force causes the clutch fixing plate 303 and the main gear 900 to rotate relative to each other. When the locking is completed, the main gear 900 pushes the clutch fixing plate 303 to break through the friction force provided by the clutch torque plate 304, thereby realizing that the main gear 900 drives the clutch fixing plate 303 to rotate continuously.

[0060] In some alternative embodiments, the second solution of the clutch assembly 300 of the seat belt retractor is a spring-type clutch assembly, including a main gear 900, a locking mechanism, a transmission wheel 301, a clutch fixing plate 303, a one-way clutch spring 306, and a clutch base 305; a locking mechanism is provided between the main gear 900 and the clutch fixing plate 303, and a one-way clutch spring 306 is provided between the clutch base 305 and the clutch fixing plate 303. One end of the one-way clutch spring 306 is connected to the clutch fixing plate 303, and the other end of the one-way clutch spring 306 is connected to the clutch base 305; when the main gear 900 rotates forward relative to the clutch fixing plate 303, the locking mechanism is pushed to a state of contacting and engaging with the transmission wheel 301; when the main gear 900 rotates backward relative to the clutch fixing plate 303, the locking mechanism is pushed to a state of disengaging from the transmission wheel 301; the inner ring of the one-way clutch spring 306 contacts the clutch base 305 to generate a frictional force, providing the frictional force for the clutch fixing plate 303 to rotate relative to the clutch base 305; when the clutch fixing plate 303 drives the one-way clutch spring 306 to rotate forward, the frictional force between the one-way clutch spring 306 and the clutch base 305 gradually increases; when the clutch fixing plate 303 drives the one-way clutch spring 306 to rotate backward, the frictional force between the one-way clutch spring 306 and the clutch base 305 gradually decreases; the working principle is as follows: an external gear ring 903 is provided on the outer peripheral side of the main gear 900, and the motor 600 drives the main gear 900 to rotate through the reduction mechanism assembly 200 meshing with the external gear ring 903. A torque frictional force is generated between the clutch fixing plate 303 and the clutch base 305 under the action of the one-way clutch spring 306. The main gear 900 rotates forward relative to the clutch fixing plate 303. During the rotation of the main gear 900, the locking mechanism is driven to engage with the transmission wheel 301. The main gear 900 continues to rotate, and the clutch fixing plate 303 and the main gear 900 rotate continuously at the same time. The clutch fixing plate 303 and the one-way clutch spring 306 are in continuous contact, and friction is generated between them. This friction is not sufficient to prevent the rotation of the clutch fixing plate 303; when the main gear 900 rotates backward driven by the motor 600, the clutch fixing plate 303 drives the one-way clutch spring 306 to rotate backward, and the frictional force between the one-way clutch spring 306 and the clutch base 305 decreases. The locking mechanism disengages from the transmission wheel 301 under the action of the track groove on the main gear 900 or the return spring 307; it should be noted that a spline groove 3011 is provided inside the transmission wheel 301, and the transmission wheel 301 is fixed on the core shaft assembly 500 through the spline groove 3011; when the return spring 307 is used to reset the locking block 302, a locking fixing plate 308 and a clutch support 309 are also provided on the clutch fixing plate 303;The beneficial effects in this embodiment are as follows: By the way that the inner ring of the one-way clutch spring 306 in this embodiment shrinks and then contacts the clutch base 305 or the clutch fixing piece 303 to generate frictional force, the one-way locking performance of the main gear 900 driving the locking mechanism to lock the transmission wheel 301 is significantly improved, and extremely high motion synchronization between the main gear 900 and the clutch fixing piece 303 is achieved. The spring-type clutch assembly has a simple structure and good stability, and significantly improves the clutch effect of the seat belt retractor.

[0061] In some alternative embodiments, there is a spring - type clutch assembly as the second solution of the clutch assembly 300. The one - way clutch spring 306 is a helical steel wire structure. One end of the helical steel wire forming the one - way clutch spring 306 is provided with a clutch spring extension end 3061. On the side end face of the clutch fixing piece 303 facing away from the locking mechanism, there is an annular protrusion. The one - way clutch spring 306 is embedded in the annular protrusion. An inner ring of the annular protrusion is provided with a clutch spring slot 3034, and the clutch spring extension end 3061 is inserted into the clutch spring slot 3034. Preferably, the one - way clutch spring 306 is integrally formed by bending an elastic steel wire. The number of helical turns of the one - way clutch spring 306 is greater than 2, and the outer diameter of the one - way clutch spring 306 is smaller than the inner diameter of the annular protrusion. By providing the clutch spring slot 3034, relative rotation between the one - way clutch spring 306 and the clutch fixing piece 303 is achieved, avoiding the locking phenomenon caused by excessive frictional force between the one - way clutch spring 306 and the clutch base 305. The width of the clutch spring slot 3034 is greater than the diameter of the clutch spring extension end 3061. The width of the clutch spring slot 3034 refers to the width extending circumferentially. The number of clutch spring slots 3034 is multiple, and the multiple clutch spring slots 3034 are arranged in an annular equidistant array around the axis of the clutch fixing piece 303, and the clutch spring extension end 3061 is inserted into one of the clutch spring slots 3034. The advantage of setting multiple clutch spring slots 3034 is to facilitate the replacement of the one - way clutch spring 306 and avoid the failure of the slots. On the side face of the clutch base 305 close to the clutch fixing piece 303, there is an annular friction part 3053, and the inner ring of the one - way clutch spring 306 is sleeved on the outer peripheral side of the annular friction part 3053. When the clutch fixing piece 303 drives the clutch spring extension end 3061 to rotate forward, the frictional force between the inner ring of the one - way clutch spring 306 and the outer peripheral side of the annular friction part 3053 gradually increases. When the clutch fixing piece 303 drives the clutch spring extension end 3061 to rotate backward, the frictional force between the inner ring of the one - way clutch spring 306 and the outer peripheral side of the annular friction part 3053 gradually decreases. The annular friction part 3053 is sleeved on the outer peripheral side of one end of the core shaft assembly 500 of the seat belt retractor. By providing the annular friction part 3053, a reasonable frictional force between the one - way clutch spring 306 and the clutch base 305 is achieved. In addition, it plays a role of guiding and limiting the one - way clutch spring 306. The inner ring of the one - way clutch spring 306 and the outer peripheral side of the annular friction part 3053 are in interference fit. Specifically, the one - way clutch spring 306 can rotate relative to the annular friction part 3053. The extending direction of the clutch spring extension end 3061 is the radial direction of the one - way clutch spring 306. By setting the clutch spring extension end 3061 to extend along the radial direction of the one - way clutch spring 306, the uniformity of the force on the one - way clutch spring 306 is improved, avoiding the phenomenon of disengagement contact between the one - way clutch spring 306 and the clutch spring slot 3034, and improving the stability of the one - way clutch spring 306 during use.The spiral wire structure of the one-way clutch spring 306 is an equal pitch spiral curve. The pitch size of the one-way clutch spring 306 is equal to the wire diameter size of the one-way clutch spring 306. Through the setting of this embodiment, the one-way clutch spring 306 is not easily deformed, has a long service life, and at the same time, the accuracy of the friction force change is significantly improved; the locking mechanism includes a plurality of locking blocks 302. The plurality of locking blocks 302 are arranged in an annular equidistant array around the axis of the transmission wheel 301. One end of the locking block 302 is rotatably connected to the clutch fixing piece 303, and the other end of the locking block 302 is slidably connected in the main gear 900; when the main gear 900 rotates forward, it pushes the plurality of locking blocks 302 to be in meshing contact with the transmission wheel 301; when the main gear 900 rotates reversely, the plurality of locking blocks 302 are disengaged from the meshing contact with the transmission wheel 301; specifically, the main gear 900 pushes the locking block 302 to be in meshing contact with the transmission wheel 301 through a track groove or a guiding surface; by arranging the plurality of locking blocks 302, the stability of the main gear 900 driving the transmission wheel 301 to rotate simultaneously is significantly improved, and the vibration and noise are significantly reduced during the locking process.;

[0062] In some alternative embodiments, one of a friction plate type clutch assembly or a spring type clutch assembly of the seat belt retractor is selected for use, and the locking mechanisms of the two respectively have the following two different solutions.

[0063] In some alternative embodiments, a locking mechanism of the first solution includes a main gear 900, a transmission wheel 301, a locking block 302, a return spring 307, and a clutch fixing piece 303; a guiding chamber is formed on one end face of the main gear 900, one end of the clutch fixing piece 303 is embedded in the guiding chamber, at least one locking trigger projection 907 is provided on the inner ring of the main gear 900, and a corresponding locking block 302 is provided for each locking trigger projection 907; one end of the locking block 302 is rotatably connected to the clutch fixing piece 303, the other end of the locking block 302 abuts against one end of the return spring 307, and the other end of the return spring 307 abuts against the clutch fixing piece 303. The combination of the main gear 900 and the clutch fixing piece 303 is sleeved on the outer peripheral side of the transmission wheel 301; when the main gear 900 rotates forward relative to the clutch fixing piece 303, the locking trigger projection 907 pushes the locking block 302 to rotate into a state of contacting and engaging with the transmission wheel 301; when the main gear 900 rotates backward relative to the clutch fixing piece 303, the locking block 302 rotates under the action of the return spring 307 to a state of disengaging from the transmission wheel 301; the locking trigger projection 907 is a cubic projection formed by the inner ring of the main gear 900 protruding towards its center. The number of locking blocks 302 is two, and the number of corresponding locking trigger projections 907 is also two. The two locking blocks 302 are symmetrically arranged on the outer peripheral side of the transmission wheel 301. An external gear ring 903 is provided on the outer peripheral side of the main gear 900. During use, the output shaft of the motor 600 is meshed with the external gear ring 903 on the main gear 900 through the reduction mechanism assembly 200. Preferably, the return spring 307 is a torsion spring, which occupies a small space. The external gear ring 903 of the main gear 900 has an involute tooth profile. A spline groove 3011 is formed on the inner side of the transmission wheel 301, and the transmission wheel 301 is fixedly connected to the core shaft assembly 500 through the spline groove 3011. The core shaft assembly 500 is used to realize the retraction of the seat belt; the working principle of this embodiment is that the main gear 900 rotates relative to the clutch fixing piece 303 under the drive of the motor 600, the locking block 302 contacts and engages with the transmission wheel 301 under the push of the locking trigger projection 907, and the clutch fixing piece 303 is in interference fit with the clutch torque piece or the one-way clutch spring 306; when using the clutch torque piece, the clutch torque piece is fixed on the clutch base 305; or, when using the one-way clutch spring 306, one end of the one-way clutch spring 306 is inserted into the clutch fixing piece 303, the inner ring is sleeved on the clutch base 305, and the inner ring gradually shrinks when the one-way clutch spring 306 rotates in one direction to generate friction with the clutch base 305;Both of the above two methods can provide the frictional force formed by torque to the clutch fixing piece 303. This frictional force prompts the clutch fixing piece 303 to rotate relative to the main gear 900. After the locking block 302 completes the locking transmission with the transmission wheel 301, the main gear 900 pushes the clutch fixing piece 303 to break through the frictional force provided by the clutch torque piece or the one-way clutch spring 306, so as to realize the continuous rotation of the main gear 900 driving the clutch fixing piece 303; The beneficial effect of this embodiment is that the locking block 302 provided in this embodiment rotates under the push of the locking trigger protrusion 907, realizing that the locking block 302 gradually stabilizes and meshes with the transmission wheel 301 as the main gear 900 rotates relative to the clutch fixing piece 303 during the use of the clutch assembly 300. During the use process, the vibration noise generated by the locking mechanism is significantly reduced, and the smoothness during the operation of the locking mechanism is significantly improved. By setting the return spring 307, the functions of one-way rotation locking and reverse reset of the main gear 900 are realized.;

[0064] In some optional embodiments, a locking mechanism of the first scheme, the locking block 302 includes a rotating portion 3022 and a locking portion 3024, the rotating portion 3022 is connected to the locking portion 3024, and the locking portion 3024 is provided with at least one transmission tooth meshing with the transmission wheel 301 on the side close to the transmission wheel 301, and a torsion spring slot 3026 is provided on the locking portion 3024, and the end of the return spring 307 that abuts against the locking block 302 is inserted into the torsion spring slot 3026. In this embodiment, preferably, the transmission teeth on the locking block 302 are asymmetric trapezoidal teeth, and the asymmetric trapezoidal teeth are inclined toward the side of the positive rotation of the transmission wheel 301. This method has greater traction; in addition, the transmission teeth can also be special-shaped teeth, serrated teeth, or involute teeth. The locking portion 3024 is also provided with a locking pressure-bearing protrusion 3025, and the locking pressure-bearing protrusion 3025 is located on the side of the torsion spring slot 3026 away from the transmission tooth; when the main gear 900 pushes the locking block 302 to rotate, the locking trigger protrusion 907 abuts against the locking pressure-bearing protrusion 3025, and the force-bearing surface of the locking pressure-bearing protrusion 3025 extends along the radial direction of the transmission wheel 301. At this time, the surface of the locking trigger protrusion 907 in contact with the locking pressure-bearing protrusion 3025 is along the radial direction of the main gear 900. The locking plate 308 is also provided with at least one locking hole 3081, and the clutch fixing plate 303 is provided with at least one first limiting pin 3035 on one side end face of the clutch fixing plate 303 close to the locking block 302, and the locking hole 3081 is correspondingly plugged into the first limiting pin 3035, and the locking fixing plate 308 is in an arc shape, and an arc-shaped rotation matching groove 3082 is provided at one end of the arc-shaped locking fixing plate 308, and the rotating portion 3022 of the locking block 302 is rotatably connected in the rotation matching groove 3082; preferably, the locking fixing hole 3081 is The first limiting pin 3035 is a cylindrical pin. There are two locking fixing holes 3081 on each locking fixing plate 308, which are correspondingly plugged into the two first limiting pins 3035. By setting the locking fixing plate 308, a better supporting effect is played on the locking block 302, avoiding damage to the clutch fixing plate 303 during the movement of the locking block 302, and reducing the difficulty of parts maintenance; a force-bearing surface 3083 is convexly provided on the outer arc surface of the locking fixing plate 308, and a force-bearing guide surface 908 is provided on the inner ring of the main gear 900, and the force-bearing guide surface 908 is located next to the locking trigger protrusion 907; when the main gear 900 pushes the locking block 302 to rotate, the force-bearing guide surface 908 abuts against the force-bearing surface 3083;By providing the force guiding surface 908 and the force bearing surface 3083, the synchronization of the joint rotation of the main gear 900 and the clutch fixing plate 303 is improved, and the reduction in the service life of the locking block 302 caused by excessive force on the locking block 302 is reduced; at least one second limit pin 3037 is also provided on the end surface of the clutch fixing plate 303 close to the locking block 302, and a torsion spring fixing groove 3036 is arranged around the outer side of the second limit pin 3037; the middle part of the reset spring 307 is sleeved on the second limit pin 3037, and the reset spring 307 has a first leg 3071 and a second leg 3072 connected to the middle part of the reset spring 307, the first leg 3071 is inserted into the torsion spring slot 3026 of the locking block 302, and the second leg 3072 abuts against the clutch fixing plate 303. In the torsion spring fixing groove 3036 of the fixing plate 303, preferably, the second limiting pin 3037 is a cylindrical pin. By setting the second limiting pin 3037, the reset spring 307 is effectively limited. A torsion spring supporting protrusion 3038 is set in the torsion spring fixing groove 3036. The torsion spring supporting protrusion 3038 is located on the side of the second limiting pin 3037 away from the first limiting pin 3035. The middle part of the first leg 3071 abuts against the torsion spring supporting protrusion 3038. By setting the torsion spring supporting protrusion 3038, the supporting effect on the first leg 3071 is achieved, the uniformity of the force of the torsion spring is improved, and a fulcrum for the first leg 3071 is formed at the torsion spring supporting protrusion 3038, so that the force generated by the reset of the locking block 302 is more uniform and stable.

[0065] In some optional embodiments, a locking mechanism of the first scheme also includes a clutch support 309, the clutch support 309 is a circular sheet structure, and a first limiting hole 3091 and a second limiting hole 3092 are opened on the clutch support 309, the first limiting hole 3091 is corresponding to the first limiting pin 3035, and the second limiting hole 3092 is corresponding to the second limiting pin 3037; the first limiting pin 3035 is inserted in the first limiting hole 3091, and the second limiting pin 3037 is inserted in the second limiting hole 3092; the locking block 302 and the locking fixing block are both located at the clutch support 309. Preferably, the first limiting hole 3091 and the second limiting hole 3092 are both circular holes between the clutch support 309 and the clutch fixing plate 303. By setting the clutch support 309, a limiting effect is played on the locking block 302, the return spring 307 and the locking fixing plate 308, thereby avoiding axial movement of the three in the axial direction of the transmission wheel 301. When there are multiple locking blocks 302, the multiple locking blocks 302 are arranged in a circular array with equal intervals around the axis of the transmission wheel 301. By setting multiple locking blocks 302, the locking mechanism is more stable during operation and has less impact during use.

[0066] In some alternative embodiments, a locking mechanism of the second solution includes a main gear 900, a transmission wheel 301, a locking block 302, and a clutch fixing plate 303. A guiding chamber 905 is formed on one end face of the main gear 900. One end of the clutch fixing plate 303 is embedded in the guiding chamber 905. At least one locking block 302 is arranged between the main gear 900 and the clutch fixing plate 303. At least one track groove 901 is formed on the bottom surface of the guiding chamber 905 of the main gear 900. The number of the track grooves 901 is the same as and corresponds to that of the locking blocks 302 one by one. One end of the locking block 302 is rotatably connected to the clutch fixing plate 303, and the other end of the locking block 302 is slidably connected in the track groove 901. The combination of the main gear 900 and the clutch fixing plate 303 is sleeved on the outer peripheral side of the transmission wheel 301. When the main gear 900 rotates forward relative to the clutch fixing plate 303, the locking block 302 slides in the track groove 901 to a state of contacting and meshing with the transmission wheel 301. When the main gear 900 rotates backward relative to the clutch fixing plate 303, the locking block 302 slides in the track groove 901 to a state of disengaging from the transmission wheel 301. In a specific embodiment, the number of the locking blocks 302 is two, and the number of the corresponding track grooves 901 is also two. The two locking blocks 302 are symmetrically arranged on the outer peripheral side of the transmission wheel 301. An external gear ring 903 is arranged on the outer peripheral side of the main gear 900. During use, the output shaft of the motor 600 is meshed with the external gear ring 903 on the main gear 900 through the reduction mechanism assembly 200. Preferably, the external gear ring 903 of the main gear 900 has an involute tooth profile. A spline groove 3011 is formed inside the transmission wheel 301. The transmission wheel 301 is fixedly connected to the core shaft assembly 500 through the spline groove 3011. The core shaft assembly 500 is used to realize the retraction of the seat belt. The working principle of this embodiment is that the main gear 900 rotates relative to the clutch fixing plate 303 under the drive of the motor 600. The locking block 302 contacts and meshes with the transmission wheel 301 under the action of the track groove 901. The clutch fixing plate 303 is in interference fit with the clutch torque plate 304. The clutch torque plate 304 is fixed on the clutch base 305, so as to provide a frictional force formed by torque to the clutch fixing plate 303. This frictional force causes the clutch fixing plate 303 to rotate relative to the main gear 900. After locking is completed, the main gear 900 pushes the clutch fixing plate 303 to break through the frictional force provided by the clutch torque plate 304, so as to realize the continuous rotation of the main gear 900 driving the clutch fixing plate 303. By arranging the locking block 302 to slide in the track groove 901, when the clutch assembly 300 rotates relative to the clutch fixing plate 303 along with the main gear 900 during use, the locking block 302 is gradually stabilized and meshed with the transmission wheel 301. During use, the vibration and noise generated by the locking mechanism are significantly reduced, and the smoothness during the operation of the locking mechanism is significantly improved, realizing the one-way rotation locking function of the main gear 900.

[0067] In some optional embodiments, a locking mechanism of the second scheme, when there are multiple locking blocks 302, the multiple locking blocks 302 are arranged in a circular array with equal intervals around the axis of the transmission wheel 301, and there are two locking blocks 302. In addition, the number of locking blocks 302 can also be one, three or even more. The more the number of locking blocks 302, the higher the stability of the transmission; the locking block 302 includes a rotating part 3022, a connecting part 3023, a locking part 3024 and a sliding protrusion 3021; ​​the rotating part 3022 and the locking part 3024 are connected by the connecting part 3023, and the sliding protrusion 3021 is provided on the side of the connecting part 3023, the sliding protrusion 3021 is slidably connected to the track groove 901, and the rotating part 3022 is fixed to the clutch The plate 303 is rotatably connected, and the locking portion 3024 is provided with at least one transmission tooth meshing with the transmission wheel 301. Preferably, the sliding protrusion 3021 is a cylindrical pin structure; a shock-absorbing spring piece 902 is also provided on the main gear 900, and one end of the shock-absorbing spring piece 902 is fixed to one end of the track groove 901, and the other end of the shock-absorbing spring piece 902 extends to the other end of the track groove 901 and is inclined toward the inside of the track groove 901. The shock-absorbing spring piece 902 abuts against the sliding protrusion 3021. Preferably, the shock-absorbing spring piece 902 and the main gear 900 are an integrally formed structure. By providing the shock-absorbing spring piece 902, the noise generated during the working process of the locking block 302 is significantly reduced under the elastic limiting action of the shock-absorbing spring piece 902; the extension line of the track groove 901 is a circle The center of curvature of the arc curve is located at an eccentric position of the center of the main gear 900. The shock-absorbing spring piece 902 is in the shape of an arc. In addition, the track groove 901 can also be in the shape of an involute. By setting the track groove 901 in the shape of an arc curve, the stability of the sliding protrusion 3021 of the locking block 302 moving in the track groove 901 is enhanced, and the impact generated during the movement is reduced; the tooth shape on the outer peripheral side of the transmission wheel 301 is an asymmetric trapezoidal tooth, and the asymmetric trapezoidal tooth shape on the outer peripheral side of the transmission wheel 301 is inclined toward the side of the locking part 3024 away from the rotating part 3022, and the transmission teeth of the locking part 3024 are asymmetric trapezoidal teeth adapted to the tooth shape on the outer peripheral side of the transmission wheel 301; through the structural form of the asymmetric trapezoidal teeth, the locking block 302 and the transmission wheel 301 are in the shape of an arc curve. 01 has a very high meshing force. In addition, the tooth shape on the outer side of the transmission wheel 301 can also be an involute cylindrical tooth shape, a triangular tooth shape, a sawtooth tooth shape, a rectangular tooth shape or other special-shaped teeth; a pressure-bearing surface 906 is arranged in the guide chamber 905 of the main gear 900, and the pressure-bearing surface 906 abuts against the outer side surface of the locking portion 3024 away from the connecting portion 3023, and the pressure-bearing surface 906 extends along the radial direction of the transmission wheel 301. When the pressure-bearing surface 906 extends along the radial direction of the transmission wheel 301, when the locking block 302 is in a locked state, the force direction of the locking block 302 is along the tangent direction of the outer edge of the transmission wheel 301, and the force is most ideal at this time; in addition, the extension direction of the pressure-bearing surface 906 can also be at a certain angle to the radial direction of the transmission wheel 301;On one side outer edge of the main gear 900 located in the guiding chamber 905, a plurality of wedge-shaped blocks 904 are further provided. The plurality of wedge-shaped blocks 904 are clamped on the end surface of the clutch fixing piece 303 facing away from the main gear 900. By providing the wedge-shaped blocks 904, the offset between the clutch fixing piece 303 and the main gear 900 is effectively avoided, and the stability of their contact operation is significantly enhanced; on the end surface of the clutch fixing piece 303 located inside the guiding chamber 905, at least one limiting protrusion 3032 is provided. Each limiting protrusion 3032 is provided with a limiting groove 3033 with one end open. The rotating part 3022 of the locking block 302 is rotatably connected to the closed end of the limiting groove 3033, and the locking part 3024 of the locking block 302 extends out of the open end of the limiting groove 3033. The limiting groove 3033 is a V-shaped groove with the width of its open end greater than that of its closed end. By providing the limiting groove 3033, the excessive deflection angle of the locking block 302 is avoided, and the impact phenomenon generated during the use of the locking block 302 is reduced; on the end surface of the clutch fixing piece 303 facing away from the main gear 900, an annular protruding part 3031 is provided. The annular protruding part 3031 is of a circular ring columnar structure. The annular protruding part 3031 contacts the clutch torque piece 304, and there is a certain frictional force between the two. The clutch torque piece 304 is fixed on the clutch base 305.;

[0068] In a friction plate type clutch assembly of the first solution of the clutch assembly 300 of the seat belt retractor in the above embodiment, the locking mechanism of the first solution or the locking mechanism of the second solution can be provided. Similarly, in a spring type clutch assembly of the second solution of the clutch assembly 300 in the above embodiment, the locking mechanism of the first solution or the locking mechanism of the second solution can be provided.

[0069] In some alternative embodiments, the seatbelt retractor further has a triggering structure for the seatbelt, including a magnet 15 and a Hall sensor 14. The magnet 15 is disposed on the side of the torsion spring cover plate 12 facing the torsion 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 torsion spring 101, the magnet 15 moves along the first groove 20131. When the magnet 15 is opposite to the Hall sensor 14, the magnet 15 triggers the Hall sensor 14. When the magnet 15 moves along the first groove 20131, when reaching the limit position of the torsion spring 101, the magnet 15 is opposite to the Hall sensor 14, thereby triggering the Hall sensor, causing the motor to stop, preventing the torsion spring 101 from being damaged, and avoiding the phenomenon of damaging the torsion spring 101 by exceeding the limit position of the torsion spring 101. A spring mounting portion 121 is further provided on the torsion spring cover plate 12, and the spring mounting portion 121 extends tangentially along the circumference of the torsion 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 closer to the torsion spring cover plate 12 is the large head end. Among them, the spring mounting portion 121 is made of cylindrical or frustum-shaped, which can prevent the spring 102 from being blocked 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. A second groove 20132 is provided on the end surface of the base 2013 opposite to the torsion spring cover plate 12. When the torsion 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 triggering structure for the seatbelt further includes a positioning cover plate 13, and the positioning cover plate 13 is disposed between the torsion spring cover plate 12 and the base 2013. Among them, the positioning cover plate 13 is mainly provided to facilitate the installation of the torsion spring cover plate 12 and the torsion 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 triggering structure for the seatbelt further includes a magnet mounting portion 122. One end of the magnet mounting portion 122 is fixed to the edge of the torsion spring cover plate 12 and extends along the central axis of the torsion 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 triggering 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 at 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 triggering structure failing due to the falling off of the magnet 15 can be avoided; when the spring 102 is in the extreme compressed state, the magnet 15 faces the Hall sensor 14, the Hall sensor 14 is triggered, and 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 clock spring 101, then the clock spring cover plate 12 will rotate reversely under the action of the spring 102, so that the clock spring 101 is opened to a certain extent, and the magnet 15 and the Hall sensor 14 are not opposite, that is, the magnet 15 is in a 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; it further includes an outer cover 11, and the outer cover 11 is used to enclose the speed reduction mechanism assembly 200 and the clock spring cover plate 12.;

[0070] In some alternative embodiments, the seat belt retractor further has a seat belt cutting assembly, including a pin 501 and a pin hole 104. Among them, the pin 501 is arranged at one end of the core shaft assembly 500 close to the shaft head of the torsion spring assembly 100, and the pin hole 104 is arranged on the shaft head of the torsion spring assembly 100; alternatively, the pin 501 is arranged at one end on the shaft head of the torsion 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 torsion spring assembly 100; the pin hole 104 is opposite to the pin 501; when the shaft head of the torsion spring assembly 100 is connected to the core shaft assembly 500, the pin 501 is inserted into the pin hole 104; by providing the pin 501 and the pin hole 104, when the situation of simultaneous fixing and locking at both ends of the core shaft assembly 500 occurs when using the motor structure to drive the seat belt retractor, it can be cut off when the core shaft assembly 500 is locked to a certain force value, so that the core shaft assembly can continue to perform force limiting control to relieve the pressure of the seat belt on the occupant's chest; the number of pins 501 is one or more, and is arranged on the end face of the core shaft assembly 500; the number of pin holes 104 is the same as the number of pins 501, and the position of the pin hole 104 is opposite to the corresponding pin 501. Among them, the number of pins 501 is related to the force value required for cutting. When the force value required for cutting is small, the number of pins 501 can be selected to be less. For example, when it is set that the core shaft assembly 500 is locked to reach 75 N, one pin 501 can be selected. When it is set that the core shaft assembly 500 is locked to reach 150 N and the pin 501 is cut off, two pins 501 can be selected. Among them, the two pins 501 and the center of the end face of the core shaft 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, and the pin hole 104 is arranged on the protrusion 103 of the torsion spring assembly 100. The cross section of the protrusion 103 is arc-shaped, and the pin hole 104 is arranged along the axial direction of the protrusion 103. The pin 501 is cylindrical, the pin hole 104 is circular, and the diameter of the pin hole 104 is adapted to the diameter of the pin 501. Alternatively, the pin 501 is frustum-shaped, its large head end is in contact with the core shaft assembly 500, and the shape and size of the pin hole 104 are adapted to the shape and size of the pin 501. Alternatively, the pin 501 is a rectangular body, the cross section of the pin hole 104 is rectangular, and the size of the pin hole 104 is adapted to the size of the pin 501. Alternatively, 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 pins 501 is one, its central position is arranged at a non-central position on the end face of the core shaft assembly 500.When the number of pins 501 is multiple, the multiple pins 501 are evenly distributed on the end face of the core shaft assembly 500 along the center of the end face of the core shaft assembly 500. Among them, the number of pins 501 is two, and other numbers of pins can be selected for setting according to needs, such as 3 or 4, etc. Among them, the distance between the center position of the pin 501 and the center position of the end face of the core shaft 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 core shaft assembly 500 and obtained by an integral forming process, or different materials can be used and fixed to the end face of the core shaft assembly 500 by welding or bonding.

[0071] In some alternative embodiments, the seat belt retractor further includes a mechanical end assembly 800, and the mechanical end assembly 800 is disposed on one side of the core shaft 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 in the vehicle, trigger the gas generant in time, and the locking mechanism can quickly lock the retractor and can buffer the pressure of the seat belt.

Claims

1. A locking mechanism, It is characterized in that The gear train comprises a main gear, a transmission wheel, a locking block and a clutch fixing plate; a guide chamber is provided on one side end face of the main gear, one end of the clutch fixing plate is embedded in the guide chamber, at least one locking block is arranged between the main gear and the clutch fixing plate, and the main gear is located on the bottom surface of the guide chamber and has at least one track groove, the track grooves are the same in number as the locking blocks and are arranged in a one-to-one correspondence; one end of the locking block is rotatably connected to the clutch fixing plate, and the other end of the locking block is slidably connected in the track groove, and the combination of the main gear and the clutch fixing plate is sleeved on the outer peripheral side of the transmission wheel; when the main gear rotates forwardly relative to the clutch fixing plate, the locking block slides in the track groove to a contact and meshing state with the transmission wheel; when the main gear rotates reversely relative to the clutch fixing plate, the locking block slides in the track groove to a disengagement state with the transmission wheel.

2. A locking mechanism according to claim 1, It is characterized in that When there are multiple locking blocks, the multiple locking blocks are arranged in a circular array with equal intervals around the axis of the transmission wheel.

3. A locking mechanism according to claim 1, It is characterized in that The locking block includes a rotating part, a connecting part, a locking part and a sliding protrusion; the rotating part and the locking part are connected through the connecting part, the sliding protrusion is arranged on the side of the connecting part, the sliding protrusion is slidingly connected to the track groove, the rotating part is rotationally connected to the clutch fixing plate, and the locking part is provided with at least one transmission tooth meshing with the transmission wheel.

4. A locking mechanism according to claim 3, It is characterized in that The main gear is also provided with a shock-absorbing spring sheet, one end of which is fixed to one end of the track groove, the other end of which extends toward the other end of the track groove and tilts toward the inside of the track groove, and the shock-absorbing spring sheet abuts against the sliding protrusion.

5. A locking mechanism according to claim 4, It is characterized in that The extension line of the track groove is an arc curve, the curvature center of the arc curve is located at an eccentric position of the center of the main gear, and the shock-absorbing spring is in an arc shape.

6. A locking mechanism according to claim 3, It is characterized in that The tooth shape of the outer peripheral side of the transmission wheel is matched with the tooth shape of the transmission teeth of the locking part.

7. A locking mechanism according to claim 3, It is characterized in that A pressure-bearing surface is provided in the guide cavity of the main gear, the pressure-bearing surface abuts against an outer side surface of the locking portion facing away from the connecting portion, and the pressure-bearing surface extends along the radial direction of the transmission wheel.

8. A locking mechanism according to claim 7, It is characterized in that The main gear is also provided with a plurality of wedge-shaped blocks on the outer edge of one side of the guide chamber, and the plurality of wedge-shaped blocks are clamped on the end surface of the clutch fixing plate on the side facing away from the main gear.

9. A locking mechanism according to claim 8, It is characterized in that At least one limiting projection is provided on the end surface of the clutch fixing piece located inside the guiding chamber. Each of the limiting projections is provided with a limiting groove with one end open. The rotating part of the locking block is rotatably connected to the closed end of the limiting groove, and the locking part of the locking block extends out of the open end of the limiting groove. The limiting groove is a V-shaped groove with the width of its open end greater than that of its closed end.

10. A seat belt retractor, characterized in that it includes a locking mechanism as described in any one of claims 1 to 9.

Images