Clutch

Abstract

The clutch comprises a retaining ring, a friction ring, a driving wheel, a ratchet wheel and a pawl, the driving wheel is provided with a first containing groove, a second containing groove and a through hole, the first containing groove and the second containing groove are located in the radial end face of the driving wheel, and the through hole is located in the center. The retaining ring is distributed in the first containing groove and can be positioned or rotated at a preset angle. The friction ring and the retaining ring are in friction connection through a limiting structure, a hook is arranged at a first preset position of the circumferential end face of the inner side of the friction ring, and a guide piece is arranged at a second preset position. The ratchet wheel is distributed in the through hole, is coaxial with the driving wheel and is connected with the mandrel through a shearing structure. The pawl is pivotally mounted in the second accommodating groove, and the free end of the pawl is arranged opposite to the hook; a guide structure is arranged on the radial end face of the pawl, and the free end of the pawl can be clamped with the ratchets distributed on the circumferential end side of the ratchet wheel and the hook under a guide track formed when the guide piece makes contact with the guide structure.

Description

Technical Field

[0001] This application relates to the field of clutch technology, specifically to a clutch. Background Technology

[0002] With the development of vehicle electrification and intelligence, seat belts need to have both passive safety protection and active pretensioning functions. They are usually equipped with an irreversible pyrotechnic pretensioning device (which quickly retracts the webbing to eliminate gaps during a collision) and a reversible active pretensioning device (including a motor and clutch, which pretensions the webbing in danger and unlocks it after the danger is over). The two devices need to work together without interfering with each other.

[0003] The clutch is the core component of the active pre-tensioning device, responsible for power transmission and cut-off functions. It needs to reliably engage during active pre-tensioning, decouple from other functions of the retractor after unlocking, and completely fail during pyrotechnic pre-tensioning activation to avoid affecting the protection effect. Existing clutches have shortcomings in terms of functional coordination, stability, and precise control, making it difficult to meet the requirements of high safety and comfort.

[0004] Therefore, how to improve the clutch in terms of functional coordination, stability, and precise control has become an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0005] This application provides a clutch to address the problems in the prior art regarding how to improve the functional coordination, stability, and precise control of clutches.

[0006] This application provides a clutch, comprising: a retaining ring, a friction ring, a drive wheel, a ratchet, and a pawl, characterized in that, The drive wheel has a first receiving groove, a second receiving groove, and a through hole located at the center on the radial end face of the drive wheel; The retaining ring is distributed in the first receiving groove and can be positioned or rotated at a preset angle; The friction ring and the retaining ring are frictionally connected by a limiting structure, and a hook is provided at a first preset position and a guide is provided at a second preset position on the circumferential end face inside the friction ring. The ratchet is distributed in the through hole and coaxial with the drive wheel; the ratchet is connected to the spindle through a shearing structure. The pawl is pivotally mounted in the second receiving groove via a pivot connection assembly, and the free end of the pawl is positioned relative to the hook. The radial end face of the pawl is provided with a guide structure, and the free end of the pawl can engage with the ratchet teeth distributed on the circumferential end side of the ratchet and the hook under the guide trajectory formed when the guide member contacts the guide structure. The clutch is configured such that: when the drive wheel rotates relative to the friction ring in a first direction, the pawl pivots with the drive wheel to a first pivot position, and the free end of the pawl engages with the ratchet teeth of the ratchet; when the drive wheel rotates relative to the friction ring in a second direction opposite to the first direction, the pawl pivots with the drive wheel to a second pivot position, and the free end of the pawl disengages from the ratchet teeth of the ratchet and resets; and When the pyrotechnic warning is triggered, the ratchet rotates and causes the pawl to rebound. The pawl strikes the hook and the guide, causing the hook to deform and shift, and the guide to bend or break. When the pawl moves to the point of colliding with the friction ring, it rebounds and engages with the hook, so that the clutch is not activated.

[0007] Optionally, the second receiving groove is arranged symmetrically with respect to the center of the drive wheel; The pawl is symmetrically arranged in the second receiving groove with respect to the center of the drive wheel; The hooks and guides are configured in two groups, with each group of hooks and guides abutting against one of the pawls.

[0008] Optionally, the guide member includes an integrally formed connecting portion, a first guide portion, and a second guide portion; The connecting part is connected to the circumferential end face of the inner side of the friction ring; The first guide portion is connected to the connecting portion and faces the center of the friction ring in the radial direction; The second guide portion is connected at the connection between the connecting portion and the first guide portion, and the second guide portion faces the ratchet in the axial direction.

[0009] Optionally, the guide structure is disposed near the pivot end of the pawl, and the guide structure includes a guide groove, a first guide surface, and a second guide surface; The guide groove is recessed on the radial end face of the pawl. The guide groove has a first groove edge and a second groove edge distributed opposite to each other in the radial direction. The first groove edge is away from the circumferential end face of the inner side of the friction ring, and in the axial direction, the depth of the first groove edge is greater than the depth of the second groove edge. The first guide surface is distributed on the circumferential end face inside the first groove edge, and the end of the first guide portion can abut against the first guide surface to form an extended guide trajectory, so as to cause the pawl to pivot to the first pivot position. The second guide surface is distributed on the circumferential end face inside the second groove edge, and the end of the second guide portion can abut against the second guide surface to form a retraction guide trajectory.

[0010] Optionally, the free end of the pawl includes a first boss and a second boss; The first boss and the second boss are set at a preset angle; The first boss can engage with the ratchet teeth of the ratchet; The second protrusion can be attached to the hook.

[0011] Optionally, the circumferential portion of the friction ring is configured as a discontinuous first end and second end, the first end and the second end of the friction ring are connected by a tensioning assembly, and a reset engagement assembly is provided between the friction ring and the drive wheel. The tensioning assembly and the reset engagement assembly are set at a preset angle relative to the center of the friction ring. The tensioning assembly, together with the reset hook assembly and the limiting structure, tightly attaches the friction ring to the retaining ring.

[0012] Optionally, the tensioning assembly includes: a limiting platform, a limiting post, and a tensioning spring; The limiting platform is located at the first end and the second end of the friction ring, respectively, and is located on the circumferential end face inside the friction ring; The limiting posts are respectively disposed on the limiting platform along the axial direction of the friction ring, and do not protrude from the radial end face of the friction ring; The tension spring is connected between the limiting posts, and the tension spring can cause the first end and the second end of the friction ring to come closer to each other.

[0013] Optionally, the reset hook assembly includes: a support post, a reset tension spring, and a hook; The support column is disposed at the radial bottom of the first receiving groove of the drive wheel; The hook is located on the circumferential end face inside the friction ring; The reset spring is connected radially between the support column and the hook.

[0014] Optionally, the limiting structure includes a limiting annular groove and a limiting protrusion / annular groove; The limiting ring groove is formed on the circumferential end face inside the retaining ring, and the groove opening of the limiting ring groove is away from the radial groove bottom of the first receiving groove of the drive wheel. The limiting protrusion / ring groove is formed on the radial end face of the inner side of the friction ring; the limiting protrusion / ring groove can be installed in the limiting ring groove so that the friction ring and the retaining ring are frictionally connected.

[0015] Optionally, the shearing structure includes: a first shearing boss, a second shearing boss, a first limiting groove, a second limiting groove, and a receiving groove; The first limiting groove is disposed on the circumferential end face inside the ratchet; The first shearing boss protrudes from the outer circumferential end face of the mandrel and can be locked in the first limiting groove. The storage groove is disposed on the outer circumferential end face of the mandrel and is connected to the first shearing boss; The second limiting groove is provided on the radial end face of the ratchet, and the second shearing boss is provided on the radial end face of the spindle. The second shearing boss can be engaged in the second limiting groove. The first shearing boss slides into the receiving groove under the action of shearing force, and the second shearing boss is cut off.

[0016] Compared with the prior art, this application has the following advantages: This application provides a clutch, including a retaining ring, a friction ring, a drive wheel, a ratchet, and a pawl. The drive wheel has a first receiving groove, a second receiving groove, and a through hole located at the center on its radial end face. The retaining ring is distributed in the first receiving groove and can be positioned or rotated at a preset angle. The friction ring and the retaining ring are frictionally connected by a limiting structure, and a hook is provided at a first preset position and a guide is provided at a second preset position on the circumferential end face inside the friction ring. The ratchet is distributed in the through hole and coaxial with the drive wheel, and the ratchet is connected to a spindle through a shearing structure. The pawl is pivotally mounted in the second receiving groove, with its free end positioned relative to the hook; the radial end face of the pawl has a guide structure, and the free end of the pawl can engage with the ratchet teeth and hook distributed on the circumferential end face of the ratchet under the guide trajectory formed when the guide and the guide structure contact.

[0017] The clutch is configured such that: when the drive wheel rotates relative to the friction ring in a first direction, the pawl pivots with the drive wheel to a first pivot position, and the free end of the pawl engages with the ratchet teeth of the ratchet; when the drive wheel rotates relative to the friction ring in a second direction opposite to the first direction, the pawl pivots with the drive wheel to a second pivot position, and the free end of the pawl separates from the ratchet teeth of the ratchet and resets; and when a pyrotechnic warning is triggered, the ratchet rotates and causes the pawl to rebound, the pawl strikes the hook and the guide, causing the hook to deform and shift, and the guide to bend or break; when the pawl moves to the point of colliding with the friction ring, it rebounds and engages with the hook, so that the clutch is not activated.

[0018] This application describes a clutch that, upon collision with the friction ring, rebounds and engages with the hook, thus disconnecting the power transmission between the motor and the ratchet. The pawl can also be disengaged by reversing the motor. Furthermore, the free end of the pawl can engage with the ratchet teeth and hook distributed on the circumferential side of the ratchet along the guide trajectory formed when the guide member contacts the guide structure, thereby making the pawl's movement trajectory more defined. Additionally, the ratchet is connected to the spindle via a shearing structure, allowing the connection between the ratchet and the spindle to be disconnected without affecting the normal operation of the retractor. This application improves the clutch's functional coordination, stability, and precise control. Attached Figure Description

[0019] Figure 1 This is a structural diagram of a clutch provided in an embodiment of this application.

[0020] Figure 2 This is a schematic diagram of a portion of the clutch structure provided in an embodiment of this application.

[0021] Figure 3 This is a schematic diagram of the drive wheel provided in an embodiment of this application.

[0022] Figure 4 This is a schematic diagram of the retaining ring provided in an embodiment of this application.

[0023] Figure 5 This is a schematic diagram of the friction ring provided in this application at one angle.

[0024] Figure 6 This is a schematic diagram of the friction ring provided in an embodiment of this application from another angle.

[0025] Figure 7 This is a schematic diagram of the pawl structure provided in the embodiments of this application.

[0026] Figure 8 This is a schematic diagram of the ratchet assembly on the spindle provided in the embodiment of this application.

[0027] Figure 9 This is a schematic diagram of the shearing structure on the mandrel provided in the embodiments of this application.

[0028] Figure 10 This is a schematic diagram of the shearing structure on the ratchet provided in an embodiment of this application.

[0029] Figure label: Drive wheel 1, first receiving groove 10, second receiving groove 11, through hole 12, first limiting connector 13, second limiting connector 14, third limiting connector 15, anti-sway plate 16, encapsulation plate 17, retaining ring 2, mounting groove 20, limiting structure 21, limiting ring groove 211, limiting protrusion / ring groove 212, friction ring 3, first preset position 30, second preset position 31, hook 32, guide 33, connecting part 330, first guide part 331, second guide part 332, first end 34, second end 35, tensioning assembly 4, limiting platform 40, limiting post 41, tension spring 42, reset hook Component 5, support column 50, reset spring 51, hook 52, ratchet 6, shearing structure 60, first shearing boss 601, second shearing boss 602, first limiting groove 603, second limiting groove 604, storage groove 605, ratchet part 61, connecting platform 62, pawl 7, pivot connection component 70, first pivot hole 701, second pivot hole 702, pivot shaft 703, free end 71, first boss 710, second boss 711, pivot end 72, guide structure 73, guide groove 730, first groove edge 731, second groove edge 732, first guide surface 733, second guide surface 734, spindle 8. Detailed Implementation

[0030] Many specific details are set forth in the following description to provide a full understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of this application; therefore, this application is not limited to the specific embodiments disclosed below.

[0031] In the description of this application, it should be understood that the terms "upper", "lower", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0032] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0033] With the development of vehicle electrification and intelligence, seat belts need to have both passive safety protection and active pretensioning functions. They are usually equipped with an irreversible pyrotechnic pretensioning device (which quickly retracts the webbing to eliminate gaps during a collision) and a reversible active pretensioning device (including a motor and clutch, which pretensions the webbing in danger and unlocks it after the danger is over). The two devices need to work together without interfering with each other.

[0034] The clutch is the core component of the active pre-tensioning device, responsible for power transmission and cut-off functions. It needs to reliably engage during active pre-tensioning, decouple from other functions of the retractor after unlocking, and completely fail during pyrotechnic pre-tensioning activation to avoid affecting the protection effect. Existing clutches have shortcomings in terms of functional coordination, stability, and precise control, making it difficult to meet the requirements of high safety and comfort.

[0035] Accordingly, this application provides a clutch, including a retaining ring, a friction ring, a drive wheel, a ratchet, and a pawl. The drive wheel has a first receiving groove, a second receiving groove, and a centrally located through hole on its radial end face. The retaining ring is distributed in the first receiving groove and can be positioned or rotated at a preset angle. The friction ring and the retaining ring are frictionally connected by a limiting structure, and a hook is provided at a first preset position and a guide is provided at a second preset position on the circumferential end face inside the friction ring. The ratchet is distributed in the through hole and coaxial with the drive wheel, and is connected to a spindle via a shearing structure. The pawl is pivotally mounted in the second receiving groove, with its free end positioned relative to the hook; the radial end face of the pawl has a guide structure, and the free end of the pawl can engage with the ratchet teeth and hook distributed on the circumferential end face of the ratchet under the guide trajectory formed when the guide and the guide structure contact.

[0036] The clutch is configured such that: when the drive wheel rotates relative to the friction ring in a first direction, the pawl pivots with the drive wheel to a first pivot position, and the free end of the pawl engages with the ratchet teeth of the ratchet; when the drive wheel rotates relative to the friction ring in a second direction opposite to the first direction, the pawl pivots with the drive wheel to a second pivot position, and the free end of the pawl separates from the ratchet teeth of the ratchet and resets; and when a pyrotechnic warning is triggered, the ratchet rotates and causes the pawl to rebound, the pawl strikes the hook and the guide, causing the hook to deform and shift, and the guide to bend or break; when the pawl moves to the point of colliding with the friction ring, it rebounds and engages with the hook, so that the clutch is not activated.

[0037] This application describes a clutch that, upon collision with the friction ring, rebounds and engages with the hook, thus disconnecting the power transmission between the motor and the ratchet. The pawl can also be disengaged by reversing the motor. Furthermore, the free end of the pawl can engage with the ratchet teeth and hook distributed on the circumferential side of the ratchet along the guide trajectory formed when the guide member contacts the guide structure, thereby making the pawl's movement trajectory more defined. Additionally, the ratchet is connected to the spindle via a shearing structure, allowing the connection between the ratchet and the spindle to be disconnected without affecting the normal operation of the retractor. This application improves the clutch's functional coordination, stability, and precise control.

[0038] The clutch provided in this application will now be described in detail with reference to the accompanying drawings. Figure 1 This is a structural diagram of a clutch provided in an embodiment of this application. Figure 2 This is a schematic diagram of a portion of the clutch structure provided in an embodiment of this application. Figure 3 This is a schematic diagram of the drive wheel provided in an embodiment of this application. Figure 4 This is a schematic diagram of the retaining ring provided in an embodiment of this application. Figure 5 This is a schematic diagram of the friction ring provided in this application at one angle. Figure 6 This is a schematic diagram of the friction ring provided in this application embodiment from another angle. Figure 7 This is a schematic diagram of the pawl structure provided in the embodiments of this application. Figure 8 This is a schematic diagram of the ratchet assembly on the spindle provided in the embodiment of this application. Figure 9 This is a schematic diagram of the shearing structure on the mandrel provided in the embodiments of this application. Figure 10 This is a schematic diagram of the shearing structure on the ratchet provided in an embodiment of this application.

[0039] like Figures 1 to 10As shown, this application provides a clutch, including a retaining ring 2, a friction ring 3, a drive wheel 1, a ratchet 6, and a pawl 7. The drive wheel 1 has a first receiving groove 10, a second receiving groove 11, and a through hole 12 located at the center of its radial end face. The retaining ring 2 is distributed in the first receiving groove 10 and can be positioned or rotated at a preset angle. The friction ring 3 is frictionally connected to the retaining ring 2 via a limiting structure 21, and a hook 32 is provided at a first preset position 30 and a guide 33 is provided at a second preset position 31 on the circumferential end face inside the friction ring 3. The ratchet 6 is distributed in the through hole 12 and coaxial with the drive wheel 1, and is connected to a spindle 8 via a shearing structure 60. The pawl 7 is pivotally mounted in the second receiving groove 11, and its free end 71 is positioned relative to the hook 32. The radial end face of the pawl 7 is provided with a guide structure 73. The free end 71 of the pawl 7 can engage with the ratchet teeth and hook 32 distributed on the circumferential end side of the ratchet 6 under the guide trajectory formed when the guide member 33 contacts the guide structure 73. The clutch is configured such that: when the drive wheel 1 rotates relative to the friction ring 3 in a first direction, the pawl 7 pivots with the drive wheel 1 to a first pivot position, and the free end 71 of the pawl 7 engages with the ratchet teeth of the ratchet 6; when the drive wheel 1 rotates relative to the friction ring 3 in a second direction opposite to the first direction, the pawl 7 pivots with the drive wheel 1 to a second pivot position, and the free end 71 of the pawl 7 separates from the ratchet teeth of the ratchet 6 and resets. Furthermore, when a pyrotechnic warning is triggered, the ratchet 6 rotates and causes the pawl 7 to rebound. The pawl 7 strikes the hook 32 and the guide member 33, causing the hook 32 to deform and shift, and the guide member 33 to bend or break; when the pawl 7 moves to the point of colliding with the friction ring 3, it rebounds and engages with the hook 32, thereby disengaging the clutch.

[0040] Specifically, in this embodiment, the drive wheel 1 has a first receiving groove 10, a second receiving groove 11, and a through hole 12 located on the radial end face of the drive wheel 1. The circumferential end face of the drive wheel 1 is provided with meshing teeth, and one radial end face of the drive wheel 1 is configured as a groove, i.e., a first receiving groove 10 is formed on the radial end face of the drive wheel 1, allowing the retaining ring 2, friction ring 3, pawl 7, and a portion of the ratchet 6 to be accommodated in the first receiving groove 10. Further, to make the pawl 7 and ratchet 6 more stably installed on the drive wheel 1, a second receiving groove 11 is provided at the radial bottom of the first receiving groove 10, and the depth of the second receiving groove 11 is greater than the depth of the first receiving groove 10. In one example, the second receiving groove 11 has a shape that accommodates and allows the pawl 7 to move. In one example, the second receiving grooves 11 are arranged symmetrically about the center of the drive wheel 1, and the number of second receiving grooves 11 is set to two.

[0041] In one example, a limiting connector is provided on the radial end face of the drive wheel 1, and the insertion pin on the encapsulation plate 17 can be inserted into the limiting connector to realize the encapsulation plate 17 encapsulating the first receiving groove 10 on the radial end face of the drive wheel 1. The limiting connector also functions as a limiting friction ring 3, as detailed below.

[0042] In this embodiment, the drive wheel 1 has a through hole 12 in the middle, and the ratchet 6 is installed in the through hole 12.

[0043] The retaining ring 2 is distributed in the first receiving groove 10 and can be positioned or rotated at a preset angle. In one example, the retaining ring 2 is a closed ring. In one example, positioning the retaining ring 2 at the preset angle means that the retaining ring 2 does not rotate. In one example, the outer circumferential end face of the retaining ring 2 is provided with multiple mounting grooves 20. The multiple mounting grooves 20 facilitate the installation of the clutch housing and can limit the rotation of the retaining ring to a certain extent.

[0044] Friction ring 3 and retaining ring 2 are frictionally connected by limiting structure 21. Specifically, in this embodiment, limiting structure 21 includes limiting ring groove 211 and limiting protrusion / ring groove 212. The limiting ring groove 211 is formed on the circumferential end face inside the retaining ring 2, and the opening of the limiting ring groove 211 is away from the radial bottom of the first receiving groove 10 of the drive wheel 1. In one example, the opposite annular groove edges of the limiting ring groove 211 are set with a stepped height, and the lower annular groove edge is located near the center of the retaining ring 2. The limiting protrusion / ring groove 212 is formed on the radial end face inside the friction ring 3. In one example, the limiting protrusion / ring groove 212 includes an integrally formed protrusion portion and an annular groove portion, with the annular groove portion located near the center of the friction ring 3. When the friction ring 3 is installed on the retaining ring 2, the protruding part can be locked in the groove of the limiting ring groove 211. The groove part can accommodate the lower annular groove edge of the limiting ring groove 211, thereby restricting the movement of the friction ring 3 relative to the retaining ring 2 in the radial direction, while making the friction ring 3 and the retaining ring 2 frictionally connected.

[0045] In this embodiment, the circumferential portion of the friction ring 3 is set as a discontinuous first end 34 and second end 35. The first end 34 and second end 35 of the friction ring 3 are connected by a tensioning assembly 4. A reset hook assembly 5 is provided between the friction ring 3 and the drive wheel 1. The tensioning assembly 4 and the reset hook assembly 5 are set at a preset angle relative to the center of the friction ring 3. The tensioning assembly 4, the reset hook assembly 5, and the limiting structure 21 cooperate to tightly attach the friction ring 3 to the retaining ring 2.

[0046] In this embodiment, the tensioning assembly 4 includes a limiting platform 40, limiting posts 41, and a tension spring 42. Specifically, the limiting platform 40 is located at the first end 34 and the second end 35 of the friction ring 3, respectively, and is located on the circumferential end face inside the friction ring 3. The limiting posts 41 are respectively disposed on the limiting platform 40 along the axial direction of the friction ring 3, and do not protrude from the radial end face of the friction ring 3. The tension spring 42 is connected between the limiting posts 41, and the tension spring 42 can bring the first end 34 and the second end 35 of the friction ring 3 relatively close. In one example, to prevent the tension spring 42 from falling off the two limiting posts 41, a hook is provided at the top end of the limiting post 41, and the extension direction of the hook is in the radial direction.

[0047] In this embodiment, to prevent the friction ring 3 from rotating relative to the retaining ring 2, a reset hook assembly 5 is provided between the friction ring 3 and the drive wheel 1. The reset hook assembly 5 includes a support post 50, a reset spring 51, and a hook 52. Specifically, the support post 50 is located at the radial bottom of the first receiving groove 10 of the drive wheel 1, the hook 52 is located on the circumferential end face inside the friction ring 3, and the reset spring 51 is connected radially between the support post 50 and the hook 52. In one example, to prevent the reset spring 51 from falling off the hook 52 and the support post 50, a latch is provided at the top of the hook 52 and the support post 50, the latch extending in the radial direction.

[0048] This embodiment employs a double tension spring structure consisting of a reset tension spring 51 and a tension spring 42 to provide stable tension, which can further increase the friction between the friction ring 3 and the retaining ring 2, ensuring that the friction components fit tightly together and reducing friction fluctuations.

[0049] It should be further explained that, in one example, to further limit the rotation of the friction ring 3 relative to the retaining ring 2, a limiting connector is needed to play a limiting role. Specifically, the limiting connector includes a first limiting connector 13, a second limiting connector 14, and a third limiting connector 15. The first limiting connector 13 is disposed at the bottom of the first receiving groove 10 of the drive wheel 1 and is fitted against the limiting platform 40. The first limiting connector 13 is cylindrical, and a portion of its circumferential end face is engaged with one end face of the limiting platform 40 to limit the rotation of the limiting platform 40. A portion of the circumferential end face of the first limiting connector 13 abuts against the inner circumferential end face of the friction ring 3 to limit the radial movement of the friction ring 3. In one example, a first positioning connection hole is provided at the axial center of the first limiting connector 13, and a first insertion pin on the encapsulation plate 17 can be inserted into the first positioning connection hole. The second limiting connector 14 is disposed at the bottom of the first receiving groove 10 of the drive wheel 1 and close to the hook 32. The second limiting connector 14 is an irregular column. The end face of the second limiting connector 14 close to the hook 32 has a first arc that matches the hook 32, and the end face of the second limiting connector 14 close to the inner circumferential end face of the friction ring 3 has a second arc that matches the inner circumferential end face of the friction ring 3. The end face with the second arc can be engaged with the inner circumferential end face of the friction ring 3, thereby restricting the radial movement of the friction ring 3. In one example, the second limiting connector 14 has a second positioning connection hole at its axial center, and the second insertion pin on the encapsulation plate 17 can be inserted into the second positioning connection hole. The third limiting connector 15 is disposed at the bottom of the first receiving groove 10 of the drive wheel 1 and close to the circumferential end face of the inner side of the friction ring 3. Multiple third limiting connectors 15 are provided, wherein each third limiting connector 15 is configured as a plate with an arc, the arc being adapted to the circumferential end face of the inner side of the friction ring 3.

[0050] In this embodiment, a hook 32 is provided at a first preset position 30 and a guide 33 is provided at a second preset position 31 on the circumferential end face inside the friction ring 3. The first preset position 30 and the second preset position 31 on the circumferential end face inside the friction ring 3 are determined based on the swing displacement of the pawl 7. That is, the hook 32 at the first preset position 30 and the guide 33 at the second preset position 31 on the circumferential end face inside the friction ring 3 allow the pawl 7 to engage with the ratchet teeth of the ratchet wheel 6 when it pivots to the first pivot position. Furthermore, when a pyrotechnic warning is triggered, the ratchet wheel 6 rotates, causing the pawl 7 to rebound. The pawl 7 strikes the hook 32 and the guide 33, causing the hook 32 to deform and shift, and the guide 33 to bend or break. When the pawl 7 moves to the point of colliding with the friction ring 3, it rebounds and engages with the hook 32, thus disengaging the clutch. In this embodiment, the power transmission between the motor and the ratchet wheel 6 can be disconnected via the hook 32. Alternatively, the pawl 7 can be disengaged by reversing the motor. That is, the clutch of this application can quickly change and remain in a failed state for a long time, and has a backup failure mechanism to ensure that the irreversible pre-tightening function is not affected; the pawl 7 can be reset by reversing the motor when it is accidentally engaged.

[0051] Furthermore, in this embodiment, the guide member 33 includes an integrally formed connecting portion 330, a first guide portion 331, and a second guide portion 332. The connecting portion 330 is connected to the circumferential end face inside the friction ring 3. The first guide portion 331 is connected to the connecting portion 330 and faces radially toward the center of the friction ring 3. The second guide portion 332 is connected at the junction of the connecting portion 330 and the first guide portion 331, and faces axially toward the ratchet 6. In one example, the first guide portion 331 and the second guide portion 332 are arranged perpendicularly. In another example, the contact portions of the first guide portion 331 and the second guide portion 332 with the guide structure 73 on the radial end face of the pawl 7 are respectively designed as arc-shaped. This arc shape of the contact portions allows the first guide portion 331 and the second guide portion 332 to move more easily when in contact with the guide structure 73, and the applied force is more effective.

[0052] In this embodiment, the pawl 7 is pivotally mounted on the second receiving groove 11 via a pivot connection assembly 70. The pivot connection assembly 70 includes a first pivot hole 701, a second pivot hole 702, and a pivot shaft 703. The first pivot hole 701 extends through the second receiving groove 11, and the second pivot hole 702 extends through the pivot end 72 of the pawl 7. The pivot end 72 and the free end 71 of the pawl 7 are opposite each other. The pivot shaft 703 is connected to the first pivot hole 701 and the second pivot hole 702. When the pivot shaft 703 is fitted into the second pivot hole 702, the pawl 7 can only rotate relative to the pivot shaft 703 under the action of an external force.

[0053] In one example, the encapsulation plate 17 is fixed by a metal pin fixed to the first pivot hole 701 (the drive wheel 1 is injection molded, and the metal pin is fixed to the drive wheel by injection molding). That is, the metal pin is first fixed to the drive wheel 1, and then the pawl 7 and the encapsulation plate 17 are fixed by the metal pin.

[0054] In one example, the pivot connection assembly 70 further includes a limiting platform 40 post and a locating pin hole, wherein the limiting platform 40 post is coaxially arranged with the pivot shaft 703 and protrudes from the radial end face of the pivot shaft 703. The locating pin hole is located at the center of the axis of the limiting platform 40 post. The limiting platform 40 post is engaged in the connection assembly hole of the encapsulation plate 17.

[0055] The free end 71 of the pawl 7 is positioned relative to the hook 32. In this embodiment, the free end 71 of the pawl 7 includes a first boss 710 and a second boss 711. The first boss 710 and the second boss 711 are positioned at a preset angle, which allows the free end 71 of the pawl 7 to fully engage with the ratchet teeth of the ratchet 6. The first boss 710 can engage with the ratchet teeth of the ratchet 6, and the second boss 711 can engage with the hook 32.

[0056] The radial end face of the pawl 7 is provided with a guide structure 73. The free end 71 of the pawl 7 can engage with the ratchet teeth and hooks 32 distributed on the circumferential end side of the ratchet 6 under the guide trajectory formed when the guide member 33 contacts the guide structure 73.

[0057] Specifically, in this embodiment, the guide structure 73 is disposed near the pivot end 72 of the pawl 7. The guide structure 73 includes a guide groove 730, a first guide surface 733, and a second guide surface 734. The guide groove 730 is recessed into the radial end face of the ratchet 6. The guide groove 730 has a first groove edge 731 and a second groove edge 732 distributed radially opposite to each other. The first groove edge 731 is located away from the inner circumferential end face of the friction ring 3, and in the axial direction, the depth of the first groove edge 731 is greater than the depth of the second groove edge 732. The first guide portion 331 and the second guide portion 332 can be accommodated in the guide groove 730. The first guide surface 733 is distributed on the inner circumferential end face of the first groove edge 731. The end (contact portion) of the first guide portion 331 can abut against the first guide surface 733 to form an extension guide trajectory, thereby causing the pawl 7 to pivot to a first pivot position. The second guide surface 734 is distributed on the circumferential end face inside the second groove edge 732. The end (contact part) of the second guide portion 332 can abut against the second guide surface 734 to form a retraction guide trajectory. In this embodiment, the extension guide trajectory and retraction guide trajectory of the pawl 7 are designed separately, making the movement trajectory of the pawl 7 clearer and avoiding defects such as jamming and incomplete unlocking.

[0058] When the ratchet 6 is installed in the through hole 12 and the pawl 7 is arranged in the second receiving groove 11, the free end 71 of the ratchet 6 and the ratchet teeth on the circumferential end side of the ratchet 6 are in the same movable surface, and the free end 71 of the ratchet 6 and the ratchet teeth on the circumferential end side of the ratchet 6 can engage. In one example, in the axial direction, the width of the free end 71 of the ratchet 6 is the same as the width of the ratchet teeth of the ratchet 6.

[0059] In this embodiment, the ratchet 6 is arranged symmetrically with respect to the center of the drive wheel 1, that is, there are two ratchet 6s, and two corresponding pivot connection components 70. Correspondingly, the hooks 32 and guides 33 are arranged in two sets, with each set of hooks 32 and guides 33 abutting against one pawl 7.

[0060] The ratchet 6 is distributed in the through hole 12 and is coaxial with the drive wheel 1. In one example, to ensure that the ratchet 6 swings out when it is distributed in the through hole 12, an anti-sway plate 16 is provided around the through hole 12. The anti-sway plate 16 is provided to protrude from the radial end face of the drive wheel 1.

[0061] The ratchet 6 is connected to the spindle 8 via a shearing structure 60. In this embodiment, the shearing structure 60 includes: a first shearing boss 601, a second shearing boss 602, a first limiting groove 603, a second limiting groove 604, and a receiving groove 605. The first limiting groove 603 is located on the inner circumferential end face of the ratchet 6, and the first shearing boss 601 protrudes from the outer circumferential end face of the spindle 8, and can be engaged in the first limiting groove 603. The receiving groove 605 is located on the outer circumferential end face of the spindle 8 and is connected to the first shearing boss 601. The second limiting groove 604 is located on the radial end face of the ratchet 6, and the second shearing boss 602 is located on the radial end face of the spindle 8, and can be engaged in the second limiting groove 604. Under the action of shearing force, the first shearing boss 601 slides into the receiving groove 605, and the second shearing boss 602 is sheared off.

[0062] Furthermore, in one example, the raised surface of the first shearing boss 601 is a semi-circular arc surface. The first shearing boss 601 is distributed along the axial direction of the mandrel 8 on the outer circumferential end face of the mandrel 8.

[0063] In one example, the second shear boss 602 has a right trapezoidal or right triangle cross section in the circumferential section of the mandrel 8.

[0064] In one example, the ratchet 6 includes an integrally formed ratchet portion 61 and a connecting platform 62. The ratchet portion 61 and the connecting platform 62 are coaxially arranged. The connecting platform 62 is located on one side near the main body of the spindle 8, and a second limiting groove 604 is provided on the radial end face of the connecting platform 62. In one example, the ratchet portion 61 is generally cylindrical, with ratchet teeth distributed on the circumferential end face of the ratchet portion 61. The connecting platform 62 is also cylindrical.

[0065] In one example, the first shearing boss 601 and the second shearing boss 602 are equally spaced around the ratchet 6, and correspondingly, the first limiting groove 603, the second limiting groove 604, and the receiving groove 605 are equally spaced. In another example, three of the first shearing bosses 601 and the second shearing bosses 602 are equally spaced around the ratchet 6.

[0066] This application provides a clutch, including a retaining ring 2, a friction ring 3, a drive wheel 1, a ratchet 6, and a pawl 7. The drive wheel 1 has a first receiving groove 10, a second receiving groove 11 located on its radial end face, and a through hole 12 located at its center. The retaining ring 2 is distributed in the first receiving groove 10 and can be positioned or rotated at a preset angle. The friction ring 3 is frictionally connected to the retaining ring 2 via a limiting structure 21, and a hook 32 is provided at a first preset position 30 and a guide 33 is provided at a second preset position 31 on the circumferential end face inside the friction ring 3. The ratchet 6 is distributed in the through hole 12 and coaxial with the drive wheel 1, and the ratchet 6 is connected to a spindle 8 via a shearing structure 60. The pawl 7 is pivotally mounted in the second receiving groove 11, and the free end 71 of the pawl 7 is positioned relative to the hook 32. The radial end face of the pawl 7 is provided with a guide structure 73, and the free end 71 of the pawl 7 can engage with the ratchet teeth and hook 32 distributed on the circumferential end side of the ratchet 6 under the guide trajectory formed when the guide member 33 contacts the guide structure 73.

[0067] The clutch is configured such that: when the drive wheel 1 rotates relative to the friction ring 3 in a first direction, the pawl 7 pivots with the drive wheel 1 to a first pivot position, and the free end 71 of the pawl 7 engages with the ratchet teeth of the ratchet wheel 6; when the drive wheel 1 rotates relative to the friction ring 3 in a second direction opposite to the first direction, the pawl 7 pivots with the drive wheel 1 to a second pivot position, and the free end 71 of the pawl 7 separates from the ratchet teeth of the ratchet wheel 6 and resets; and when a pyrotechnic warning is triggered, the ratchet wheel 6 rotates and causes the pawl 7 to rebound, the pawl 7 strikes the hook 32 and the guide member 33, causing the hook 32 to deform and shift, and the guide member 33 to bend or break; when the pawl 7 moves to the point of colliding with the friction ring 3, it rebounds and engages with the hook 32, so that the clutch is not activated.

[0068] This application describes a clutch where the pawl 7 rebounds and engages with the hook 32 upon collision with the friction ring 3, thus disconnecting the power transmission between the motor and the ratchet 6. The pawl 7 can also be disengaged by reversing the motor. Furthermore, the free end 71 of the pawl 7 can engage with the ratchet teeth and hook 32 distributed on the circumferential side of the ratchet 6 along the guide trajectory formed when the guide member 33 contacts the guide structure 73, thereby making the movement trajectory of the pawl 7 more defined. Additionally, the ratchet 6 is connected to the spindle 8 via the shearing structure 60, which can disconnect the connection between the ratchet 6 and the spindle 8, thus not affecting the normal operation of the retractor. This application improves the functional coordination, stability, and precise control of the clutch.

[0069] It should be noted that although several structures, components, or units for implementing the relevant functions have been mentioned in the detailed description above, this division is not mandatory. In fact, according to the specific embodiments of this application, the features and functions of two or more structures, components, or units described above can be embodied in one structure, component, or unit. Conversely, the features and functions of one structure, component, or unit described above can be further divided and embodied by multiple components, structures, or units.

[0070] Furthermore, although the various components of the components or apparatus in this application and the mounting arrangements between them are described in a specific order in the accompanying drawings, this does not require or imply that the components or apparatus must be designed according to that specific component or mounting arrangement, or that all the components shown must be included to achieve the desired result. Additional or alternative components may be omitted, multiple components may be combined into one component to achieve the corresponding function, and / or a component may be decomposed into multiple components to achieve the corresponding function, etc.

[0071] Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any person skilled in the art can make possible changes and modifications without departing from the spirit and scope of this application. Therefore, the scope of protection of this application should be determined by the scope defined in the claims of this application.

Claims

1. A clutch comprising a retaining ring, a friction ring, a driving wheel, a ratchet wheel and a pawl, characterized in that, the driving wheel has a first accommodating groove and a second accommodating groove on the radial end face of the driving wheel, and a through hole in the center; the retaining ring is distributed in the first accommodating groove and can be positioned or rotated at a preset angle; the friction ring is frictionally coupled with the retaining ring through a limiting structure, and a hook is arranged at a first preset position on the circumferential end face inside the friction ring, and a guide is arranged at a second preset position; the ratchet wheel is distributed in the through hole and coaxial with the driving wheel, and the ratchet wheel is connected with a mandrel through a shearing structure; the pawl is pivotally installed in the second accommodating groove through a pivoting connection assembly, and the free end of the pawl is arranged opposite the hook; the radial end face of the pawl is provided with a guide structure, and the free end of the pawl can be clamped with the ratchet teeth distributed on the circumferential end side of the ratchet wheel and the hook when the guide formed by the contact between the guide and the guide structure; the clutch is configured such that when the driving wheel rotates relative to the friction ring in a first direction, the pawl pivots with the driving wheel to a first pivoting position, and the free end of the pawl is clamped with the ratchet teeth of the ratchet wheel; when the driving wheel rotates relative to the friction ring in a second direction opposite to the first direction, the pawl pivots with the driving wheel to a second pivoting position, and the free end of the pawl is separated from the ratchet teeth of the ratchet wheel and then resets; and when the pyrotechnic warning is triggered, the ratchet wheel rotates and causes the pawl to rebound, the pawl strikes the hook and the guide, the hook is deformed and offset, the guide is bent or broken; the pawl moves to collide with the friction ring and rebounds and hooks to the hook, so that the clutch does not work.

2. The clutch of claim 1, wherein the second accommodating groove is symmetrically arranged with the center of the driving wheel; the pawl is symmetrically arranged in the second accommodating groove with the center of the driving wheel; the hook and the guide are arranged as two groups, and each group of the hook and the guide is arranged close to one pawl.

3. The clutch of claim 1, wherein the guide comprises an integral connecting part, a first guide part and a second guide part; the connecting part is connected to the circumferential end face inside the friction ring; the first guide part is connected to the connecting part and faces the center of the friction ring in the radial direction; the second guide part is connected at the connection between the connecting part and the first guide part, and the second guide part faces the ratchet wheel in the axial direction.

4. The clutch of claim 3, wherein the guide structure is arranged close to the pivoting end of the pawl, and the guide structure comprises a guide groove, a first guide surface and a second guide surface; the guide groove is recessed on the radial end face of the pawl, and the guide groove has a first groove side and a second groove side arranged opposite in the radial direction, the first groove side is away from the circumferential end face inside the friction ring, and in the axial direction, the depth of the first groove side is greater than the depth of the second groove side; The first guide surface is distributed on the circumferential end surface of the inner side of the first groove, and the end of the first guide part can abut against the first guide surface to form an extension guide track to facilitate the pawl to pivot to a first pivot position. The second guide surface is distributed on the circumferential end surface of the inner side of the second groove, and the end of the second guide part can abut against the second guide surface to form a retraction guide track.

5. The clutch of claim 1, wherein, The free end of the pawl comprises a first boss and a second boss; The first boss and the second boss are arranged at a preset angle; The first boss can be clamped with the teeth of the ratchet wheel; The second boss can be hung with the hook.

6. The clutch of claim 1, wherein, The circumferential part of the friction ring is provided with a discontinuous first end and a second end, the first end and the second end of the friction ring are connected through a tensioning assembly, a reset hooking assembly is arranged between the friction ring and the drive wheel, and the tensioning assembly and the reset hooking assembly are arranged at a preset angle relative to the center of the friction ring. The tensioning assembly cooperates with the reset hooking assembly and the limiting structure to tightly attach the friction ring to the retaining ring.

7. The clutch of claim 6, wherein The tensioning assembly comprises a limiting table, a limiting column and a tensioning spring. The limiting table is respectively arranged at the first end and the second end of the friction ring and on the circumferential end surface of the inner side of the friction ring. The limiting column is arranged on the limiting table along the axial direction of the friction ring and does not protrude from the radial end surface of the friction ring. The tensioning spring is connected between the limiting columns, and the tensioning spring can facilitate the first end and the second end of the friction ring to approach each other.

8. The clutch of claim 6, wherein, The reset hooking assembly comprises a supporting column, a reset tension spring and a hooking hook. The supporting column is arranged on the radial groove bottom of the first accommodating groove of the drive wheel. The hooking hook is arranged on the circumferential end surface of the inner side of the friction ring. The reset tension spring is connected between the supporting column and the hooking hook in the radial direction.

9. The clutch of claim 1, wherein, The limiting structure comprises a limiting ring groove and a limiting protrusion / annular groove. The limiting ring groove is formed on the circumferential end surface of the inner side of the retaining ring, and the groove opening of the limiting ring groove faces away from the radial groove bottom of the first accommodating groove of the drive wheel. The limiting protrusion / annular groove is formed on the radial end surface of the inner side of the friction ring, and the limiting protrusion / annular groove can be installed in the limiting ring groove to enable the friction ring to be frictionally coupled with the retaining ring.

10. The clutch of claim 1, wherein, The shearing structure comprises a first shearing boss, a second shearing boss, a first limiting groove, a second limiting groove and a receiving groove. The first limiting groove is arranged on the circumferential end surface of the inner side of the ratchet wheel. The first shearing boss is protrusively arranged on the outer circumferential end surface of the mandrel, and the first shearing boss can be clamped in the first limiting groove. The receiving groove is arranged on the outer circumferential end surface of the mandrel and is connected in conjunction with the first shearing boss. The second limiting groove is arranged on the radial end surface of the ratchet wheel, and the second shearing boss is arranged on the radial end surface of the mandrel, and the second shearing boss can be clamped in the second limiting groove. The first shearing boss slides into the receiving groove under the action of shearing force, and the second shearing boss is sheared off.

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