Clutching device

Abstract

The present invention relates to a clutch device. The clutch device is used for a seat belt retractor, and includes a first rotary member that is drivable to rotate about its own rotary axis, a second rotary member that is coaxially provided with the first rotary member and is used to be torsionally connected to a spool of the seat belt retractor, and a transmission member that is provided between the first rotary member and the second rotary member and through which the first rotary member can transmit a torque to the second rotary member in a first rotary direction. The transmission member includes a cage and a transmission element provided in the cage. The clutch device further includes a first elastic member that is used to elastically hold the transmission element in a manner of applying a force to the transmission element in a radial direction so as to be away from the first rotary member or the second rotary member, and the first elastic member is integrated on the cage.

Description

Technical Field

[0001] This invention relates to a clutch device for a seat belt retractor. Background Technology

[0002] Existing seatbelt retractors offer features such as pre-collision protection, human-machine interaction during driving, and comfort. Active seatbelt retractors can use a motor to wind up a certain amount of seatbelt before the control unit determines that a collision may occur, gently restraining the occupants; and can allow the seatbelt to be freely pulled out when the control unit determines that the collision risk has disappeared.

[0003] Seatbelt retractors include a clutch mechanism, which mainly comes in two types: cageless and caged. In a cageless clutch, the balls are fixed to the inner or outer ring, and the input and output ends cannot be completely disengaged. When used with seatbelts, motion control can be achieved if a motor is used as the input end. However, because complete disengagement is not possible, jamming can occur when the occupant pulls or unhooks the seatbelt. In a caged clutch, the input and output ends can be isolated from each other; however, this type of clutch either cannot achieve the comfort function requiring low-speed start-up, or it has more parts, a more complex structure, and is more difficult to install.

[0004] Therefore, an improved clutch mechanism for seat belt retractors is desired. Summary of the Invention

[0005] The object of this invention is to provide an improved clutch mechanism for seat belt retractors. Specifically, this clutch mechanism not only enables comfort functions requiring low-speed start-up, but also has fewer parts, a simpler structure, and is easy to install.

[0006] The present invention provides a clutch device for a seat belt retractor, and includes:

[0007] The first rotating component is capable of being driven to rotate about its own axis of rotation;

[0008] A second rotating member, coaxially arranged with the first rotating member, and for torsionally connected to the reel of the seatbelt retractor; and

[0009] A transmission member is disposed between the first rotating member and the second rotating member, and the first rotating member is capable of transmitting torque to the second rotating member via the transmission member along a first rotation direction.

[0010] The transfer member is rotatable relative to the first rotating member between an engaged position and a non-engaged position. When the transfer member is in the engaged position, it engages with both the first and second rotating members, allowing them to rotate together. When the transfer member is in the non-engaged position, it does not engage with either the first or second rotating member, allowing them to rotate freely relative to each other.

[0011] The transfer member includes a cage and a transfer element disposed in the cage, and

[0012] The clutch device further includes a first elastic member for elastically holding the transmission element in such a way as to apply a force in the radial direction to the transmission element to move it away from the first rotating member or the second rotating member, and the first elastic member is integrated on the cage.

[0013] According to an embodiment of the present invention, the retainer is formed in an annular shape and is rotatably fitted onto the second rotating member.

[0014] According to an embodiment of the present invention, the retainer includes a first side ring and a second side ring, and the first elastic member is located between the first side ring and the second side ring.

[0015] According to an embodiment of the present invention, the first elastic component includes a cantilever spring, one end of which is fixed to the cage and the other end extends to the transmission element.

[0016] According to an embodiment of the present invention, the retainer further includes a tab connecting the first side ring and the second side ring, and one end of the first elastic member is fixed to the tab.

[0017] According to an embodiment of the present invention, a plurality of the first elastic members are provided at intervals in the circumferential direction of the cage, and a pair of the first elastic members are provided on both sides of the circumferential direction of the transmission element.

[0018] According to an embodiment of the invention, a base is further included, which forms a receiving cavity to receive the first rotating member and the transmission member.

[0019] According to an embodiment of the invention, a cover plate is also included, which is connected to the base to close the receiving cavity.

[0020] According to an embodiment of the present invention, the clutch device further includes a second elastic member for applying a biasing force to cause the transmission member to abut against the cover plate, and the second elastic member is integrated on the retainer.

[0021] According to an embodiment of the present invention, the second elastic member is disposed on the shaft end face of the retainer opposite to the cover plate.

[0022] According to an embodiment of the invention, the second elastic member extends axially toward the cover plate to extend beyond the retainer by a distance.

[0023] According to an embodiment of the present invention, the second elastic member is configured such that one end is fixed to the retainer and the other end is bent to form a curved portion.

[0024] According to an embodiment of the present invention, the cage includes a first limiting portion located on its axial end face, the first rotating member includes a second limiting portion located on its corresponding axial end face, and the first limiting portion and the second limiting portion can cooperate with each other to limit the rotation angle of the cage relative to the first rotating member.

[0025] According to an embodiment of the present invention, the first limiting portion and the second elastic component are disposed on the same axial end face of the cage. Attached Figure Description

[0026] Figure 1 An exploded view schematically illustrates the clutch mechanism of a seatbelt retractor according to an embodiment of the present invention.

[0027] Figure 2 A perspective view of the retainer of the clutch device according to an embodiment of the present invention is shown.

[0028] Figure 3 A side view of a clutch device according to an embodiment of the present invention is shown.

[0029] Figure 4 A cross-sectional view of a clutch device according to an embodiment of the present invention is shown.

[0030] Figure 5 Show Figure 4 A magnified view of A in the middle.

[0031] Figure 6 A side view of a clutch device according to an embodiment of the present invention is shown. Detailed Implementation

[0032] The following describes specific embodiments of the clutch device according to the present invention in conjunction with the accompanying drawings. The detailed description and drawings below are provided to illustrate the principles of the invention, and the invention is not limited to the described preferred embodiments; the scope of protection of the invention is defined by the claims.

[0033] Furthermore, spatially related terms (such as "up," "down," "left," and "right") are used to describe the relative positional relationship between elements shown in the accompanying drawings and other elements. Therefore, spatially related terms can be applied to directions different from those shown in the accompanying drawings. Clearly, while all these spatially related terms refer to the directions shown in the accompanying drawings for ease of explanation, those skilled in the art will understand that directions different from those shown in the accompanying drawings can be used.

[0034] Figure 1 An exploded view schematically illustrates the clutch mechanism of a seatbelt retractor according to an embodiment of the present invention. Figure 1 As shown, the clutch device may include a first rotating member 10, a second rotating member 20, and a transmission member 30.

[0035] The first rotating member 10 is capable of being driven to rotate about its own axis of rotation. The first rotating member 10 may have a hollow structure so that at least a portion of the second rotating member 20 passes through it. In some embodiments, the first rotating member 10 includes teeth 11 located on its outer peripheral surface. The teeth 11 can engage with the drive mechanism of the seat belt retractor via a gear mechanism, such as a worm gear, rack and pinion, etc.

[0036] According to an embodiment of the invention, the first rotating member 10 includes an engagement portion 12 defined on its radially inner surface. In an exemplary embodiment, the first rotating member 10 defines a plurality of engagement portions 12, for example, four, on its radially inner surface. The engagement portions 12 are for engaging with the transmission member 30.

[0037] The second rotating member 20 is coaxially disposed with the first rotating member 10. The second rotating member 20 may be torsionally connected to the reel of the seatbelt retractor to transmit torque to the reel. In an exemplary embodiment, at least a portion of the radially outer surface of the second rotating member 20 may be used to engage with the transmission member 30.

[0038] A transfer member 30 is disposed between the first rotating member 10 and the second rotating member 20. In an exemplary embodiment, the transfer member 30 may include a cage 31 and a transfer element 32 disposed in the cage 31. The cage 31 is used to hold one or more transfer elements 32. In some embodiments, the number of transfer elements 32 is the same as the number of engagement portions 12. In some embodiments, the transfer element 32 may be formed as a rolling element, such as a roller, needle roller, etc.

[0039] Figure 2 A perspective view of the retainer of the clutch device according to an embodiment of the present invention is shown. Reference is made below. Figure 2 The cage of the clutch device according to an embodiment of the present invention is described.

[0040] like Figure 2 As shown, the retainer 31 is formed in a ring shape and can be rotatably fitted onto the second rotating member 20. Figure 2 In the exemplary embodiment shown, the retainer 31 includes a first side ring 31A and a second side ring 31B. Furthermore, the retainer 31 includes a tab 35 connecting the first side ring 31A and the second side ring 31B. The tab 35 is distributed circumferentially along the retainer 31 and, together with the first side ring 31A and the second side ring 31B, defines a plurality of pockets. A transfer element 32 can be disposed and held in the pockets. The pockets of the retainer 31 can restrict the axial movement of the transfer element 32 relative to the retainer 31, for example, through the first side ring 31A and the second side ring 31B.

[0041] Continue to refer to Figure 2 The clutch mechanism also includes a first elastic member 33. The first elastic member 33 is used to elastically retain the transmission element 32 in such a way that a force is applied radially to the transmission element 32 to move it away from the first rotating member 10 or the second rotating member 20. Furthermore, the first elastic member 33 is integrated into the cage 31.

[0042] In an exemplary embodiment, the first elastic member 33 is located between the first side ring 31A and the second side ring 31B, and one end of the first elastic member 33 is fixed to the tab 35. Specifically, a plurality of first elastic members 33 are spaced apart in the circumferential direction of the retainer 31, and a pair of first elastic members 33 are positioned on both sides of the transmission element 32 in the circumferential direction. Each first elastic member 33 includes a cantilever spring, one end of which is fixed to the retainer 31 and the other end extends to the transmission element 32 (see [link]). Figure 5 ). Figure 2 The first elastic component 33 shown is in its initial, undeformed state; as Figure 5 The first elastic member 33 shown in the figure undergoes radial outward deformation under the action of the transmission element 32. At this time, the first elastic member 33 applies a radial inward biasing force to the transmission element 32 in order to restore the deformation. That is, the first elastic member 33 can be used to elastically hold the transmission element 32 in a way that applies a force to the transmission element 32 in the radial direction to move it away from the second rotating member 20.

[0043] Figure 3 A side view of a clutch device according to an embodiment of the present invention is shown. Figure 4 A cross-sectional view of a clutch device according to an embodiment of the present invention is shown. Figure 3 and Figure 4 As shown, the distance from the joint 12 to the axis of rotation gradually increases along the first rotation direction C1 (counterclockwise). Viewed axially, the joint 12 can have any suitable curved shape, such as an involute. Figure 3 and Figure 4 The clutch is shown in an engaged state, wherein the transmission element 32 of the transmission member 30 and the radial outer surfaces of the first rotating member 10 (joint portion 12) and the second rotating member 20 are both radially engaged without gaps. Figure 5 Show Figure 4 In the enlarged view of A, in an exemplary embodiment, in order to apply a force in the radial direction to the transmission element 32 to move it away from the first rotating member 10 or the second rotating member 20, the diameter d of the transmission element 32 is greater than the distance D between the two opposing end faces of a pair of first elastic members used to apply force to the transmission element 32.

[0044] Figure 6 A side view of a clutch device according to an embodiment of the present invention is shown. Figure 6 As shown, the clutch is in the disengaged state, wherein the transmission element 32 of the transmission member 30 is not engaged with the second rotating member 20.

[0045] The transmission member 30 is rotatable relative to the first rotating member 10 between an engaged position and a non-engaged position.

[0046] exist Figure 3 and Figure 4 In the engagement state shown, the transmission element 32 is radially engaged with both the first rotating member 10 (engagement portion 12) and the second rotating member 20. When the first rotating member 10 rotates along the first rotation direction C1, the first rotating member 10 can transmit torque to the second rotating member 20 via the transmission member 30 (e.g., the transmission element 32), so that the first rotating member 10, the transmission element 32, and the second rotating member 20 can rotate together.

[0047] From the engaged state of the clutch device, when the first rotating member 10 rotates along the second rotating direction C2, which is opposite to the first rotating direction C1, the transmission element 32 of the transmission member 30 can disengage from the second rotating member 20 (e.g., Figure 6 As shown), the first rotating member 10 and the second rotating member 20 can rotate freely relative to each other.

[0048] like Figure 4 As shown, in the engaged state, the transmission element 32 is subjected to a force from the engagement portion 12 and thus overcomes the biasing force of the first elastic member 33. Consequently, the transmission element 32 moves radially inward to engage with the second rotating member 20. Figure 6As shown, in the separated state, the transmission element 32 is subjected to the biasing force of the first elastic member 33 and is radially spaced from the second rotating member 20.

[0049] According to an embodiment of the present invention, the clutch device may further include a base 40 and a cover plate 50, such as Figure 1 As shown. The base 40 forms a receiving cavity to accommodate the first rotating member 10 and the transmission member 30. A cover plate 50 may be attached to the base 40 to close the receiving cavity. In an exemplary embodiment, the cover plate 50 may be fixed to an axial end face of the base 40 by means of, for example, screws. The base 40 and the cover plate 50 may each have a central through hole to allow at least a portion of the second rotating member 20 to pass through.

[0050] The base 40 can serve as a support bearing for the first rotating member 10, allowing the first rotating member 10 to be rotatably supported within the base 40. In some embodiments, the first rotating member 10 includes an axially extending annular groove (not shown), while the base 40 includes an axially extending annular protrusion 41. The annular protrusion 41 of the base 40 can be inserted into the annular groove of the first rotating member 10 to rotatably support the first rotating member 10.

[0051] According to certain embodiments of the present invention, the retainer 31 may further include a first limiting portion 36 located on its axial end face, and the first rotating member 10 may include a second limiting portion 13 located on its corresponding axial end face. The first limiting portion 36 of the retainer 31 and the second limiting portion 13 of the first rotating member 10 may cooperate with each other to limit the rotation angle of the retainer 31 relative to the first rotating member 10. In an exemplary embodiment, the first limiting portion 36 is located on one axial side of the retainer 31 (e.g., the side closer to the cover plate 50), while the second limiting portion 13 is located on the corresponding axial side of the first rotating member 10. Figure 6 As shown, during the operation of the clutch device, when the first limiting part 36 and the second limiting part 13 abut against each other, the first rotating member 10 and the retainer 31 remain relatively stationary.

[0052] In an exemplary embodiment, the joining portion 12 and the limiting portion 13 of the first rotating member 10 can be arranged sequentially along the axial direction, such as... Figure 1 As shown. Furthermore, the first limiting portion 36 of the retainer 31 is axially disposed on the outer side of the joint. In this case, the engagement of the first rotating member 10 and the transmission member 30 is not affected by these limiting portions.

[0053] According to an embodiment of the present invention, the clutch device may further include a second elastic member 34, such as Figure 2As shown, the second elastic member 34 is used to apply a biasing force to cause the transfer member 30 to abut against the cover plate 50, and the second elastic member 34 is integrated into the retainer 31. In an exemplary embodiment, the second elastic member 34 is disposed on the axial end face of the retainer 31 opposite to the cover plate 50. The second elastic member 34 extends axially toward the cover plate 50 beyond the retainer 31 by a certain distance, so that when the transfer member 30 approaches the cover plate 50, the second elastic member 34 can deform in a direction away from the cover plate 50 under the action of the cover plate 50. In order to recover from the deformation, the second elastic member 34 abuts against the cover plate 50, that is, applies a biasing force to cause the transfer member 30 to abut against the cover plate 50. Specifically, as Figure 2 As shown, the second elastic member 34 is configured such that one end is fixed to the retainer 31 and the other end is bent to form a curved portion. Furthermore, the first limiting portion 36 and the second elastic member 34 are disposed on the same axial end face of the retainer 31.

[0054] The second elastic member 34 can generate friction between the transmission member 30 and the cover plate 50 by applying a biasing force to the transmission member 30. When the first rotating member 10 just begins to rotate, the second elastic member 34 can remain stationary due to the frictional force. This facilitates the rapid engagement or disengagement of the transmission member 30 and the second rotating member 20.

[0055] The following describes the operation method of the clutch device according to an embodiment of the present invention.

[0056] In the disengaged state of the clutch, such as Figure 6 As shown, the transmission element 32 is located closer to the teeth 11 of the engagement portion 12 in the circumferential direction, and the transmission element 32 is biased by the first elastic member 33 in the radially outward direction, thereby separating the transmission element 32 from the second rotating member 20 in the radial direction. When transitioning from the separated state to the engaged state, the first rotating member 10 is first driven by the drive device to rotate in the first rotation direction C1. Under the biasing force of the second elastic member 34, the transmission member 30 is subjected to friction with the cover plate 50 and remains stationary in the initial stage. The engagement portion 12 of the first rotating member 10 and the transmission element 32 of the transmission member 30 are engaged radially without gap. As the first rotating member 10 rotates, the engagement portion 12 applies a force to the transmission element 32, causing the transmission element 32 to gradually approach the radial outer surface of the second rotating member 20 in the radial direction. When the transmission element 32 moves to engage with the radial outer surface of the second rotating member 20 without gap, the first rotating member 10 can drive the second rotating member 20 to rotate through the transmission element 32, thereby realizing the engaged state of the clutch device, as shown. Figure 3 and Figure 4 As shown.

[0057] In the engaged state of the clutch, such as Figure 2 and Figure 3 As shown, the transmission element 32 is located circumferentially further away from the teeth 11 of the engagement portion 12. The transmission element 32 engages with the engagement portion 12 and is subjected to the force of the engagement portion 12 in the radially inward direction, thereby overcoming the biasing force of the elastic member 33 and engaging with the second rotating member 20 in the radial direction. When transitioning from the engaged state to the disengaged state, the first rotating member 10 is initially driven by the drive device to rotate in the second rotation direction C2. Under the biasing force of the elastic member 60, the transmission member 30 is subjected to frictional force with the cover plate 50 and remains stationary in the initial stage. As the first rotating member 10 rotates, the elastic member 33 applies a biasing force to the transmission element 32 in the radially outward direction, causing the transmission element 32 to gradually move away from the radially outer surface of the second rotating member 20. When the transmission element 32 moves to disengage from the radially outer surface of the second rotating member 20, the first rotating member 10 and the second rotating member 20 can rotate freely relative to each other, thereby realizing the disengaged state of the clutch device, as shown. Figure 6 As shown.

[0058] According to an embodiment of the present invention, in the disengaged state of the clutch, the transmission element and the second rotating member are radially separated, thereby completely isolating the input and output ends of the clutch. In the initial stage of clutch state transition, due to the friction between the cage and the cover plate, the transmission element can engage the first and second rotating members at a smaller rotation angle. Therefore, the clutch of the present invention can reduce clutch delay, enabling faster seatbelt winding to provide occupant protection. Furthermore, due to the friction between the cage and the cover plate, the clutch can engage or disengage even at low motor speeds, thereby reducing noise and shock. This clutch not only achieves comfort functions requiring low-speed start-up but also has fewer parts, a simpler structure, and is easy to install.

[0059] The transmission element described above is a rolling element. However, the present invention is not limited thereto. According to embodiments of the present invention, the transmission element may also take other forms such as a wedge.

[0060] The above description indicates that when the clutch is in the disengaged state, the transmission element 32 of the transmission member 30 does not engage with the second rotating member 20. However, the present invention is not limited thereto. According to embodiments of the present invention, the clutch can also be configured such that, when in the disengaged state, the transmission element 32 does not engage with the first rotating member 10 (e.g., the engagement portion 12). For example, the elastic member 33 can apply a biasing force to the transmission element 32 in a radially inward direction. When the first rotating member 10 rotates in a second rotation direction, the transmission element 32 gradually moves radially away from the engagement portion 12 of the first rotating member 10, thereby achieving the disengaged state of the clutch.

[0061] As mentioned above, although exemplary embodiments of the present invention have been described with reference to the accompanying drawings, the present invention is not limited to the specific embodiments described above, and the scope of protection of the present invention should be defined by the claims and their equivalents.

Claims

1. A clutch device for a seatbelt retractor, comprising: The first rotating component (10) is capable of being driven to rotate about its own axis of rotation; The second rotating member (20) is coaxially arranged with the first rotating member (10) and is used to be torsionally connected to the reel of the seat belt retractor; A transmission member (30) is disposed between the first rotating member (10) and the second rotating member (20), and the first rotating member (10) is capable of transmitting torque to the second rotating member (20) via the transmission member (30) in a first rotation direction (C1). The base (40) forms a receiving cavity to receive the first rotating member (10) and the transmission member (30). A cover plate (50), which is connected to the base (40) to close the receiving cavity, The transfer member (30) is rotatable relative to the first rotating member (10) between an engaged position and a non-engaged position. When the transfer member (30) is in the engaged position, it engages with both the first rotating member (10) and the second rotating member (20), allowing them to rotate together. When the transfer member (30) is in the non-engaged position, it does not engage with either the first rotating member (10) or the second rotating member (20), allowing them to rotate freely relative to each other. Its features are, The transfer member (30) includes a retainer (31) and a transfer element (32) disposed in the retainer (31), and The clutch device further includes a first elastic member (33) for elastically holding the transmission element (32) in such a way as to apply a force in the radial direction to the transmission element (32) to move it away from the first rotating member (10) or the second rotating member (20), and the first elastic member (33) is integrated on the cage (31). The clutch device further includes a second elastic member (34) for applying a biasing force to cause the transmission member (30) to abut against the cover plate (50), and the second elastic member (34) is integrated on the retainer (31).

2. The clutch device according to claim 1, wherein, The retainer (31) is formed in a ring shape and is rotatably fitted onto the second rotating member (20).

3. The clutch device according to claim 2, wherein, The retainer (31) includes a first side ring (31A) and a second side ring (31B), and the first elastic member (33) is located between the first side ring (31A) and the second side ring (31B).

4. The clutch device according to claim 3, wherein, The first elastic component (33) includes a cantilever spring, one end of which is fixed to the retainer (31) and the other end extends to the transmission element (32).

5. The clutch device according to claim 4, wherein, The retainer (31) further includes a tab (35) connecting the first side ring (31A) and the second side ring (31B), and one end of the first elastic member (33) is fixed to the tab (35).

6. The clutch device according to claim 5, wherein, A plurality of the first elastic members (33) are provided at intervals in the circumferential direction of the retainer (31), and a pair of the first elastic members (33) are provided on both sides of the circumferential direction of the transmission element (32).

7. The clutch device according to claim 1, wherein, The second elastic member (34) is disposed on the shaft end face of the retainer (31) opposite to the cover plate (50).

8. The clutch device according to claim 7, wherein, The second elastic member (34) extends axially toward the cover plate (50) beyond the retainer (31) by a distance.

9. The clutch device according to claim 8, wherein, The second elastic member (34) is configured such that one end is fixed to the retainer (31) and the other end is bent to form a bend.

10. The clutch device according to claim 9, wherein, The cage (31) includes a first limiting portion (36) located on its axial end face, and the first rotating member (10) includes a second limiting portion (13) located on its corresponding axial end face. The first limiting portion (36) and the second limiting portion (13) can cooperate with each other to limit the rotation angle of the cage (31) relative to the first rotating member (10).

11. The clutch device according to claim 10, wherein, The first limiting part (36) and the second elastic member (34) are disposed on the same axial end face of the cage (31).

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