Clutch unit

Abstract

A locking mechanism 12 of this clutch unit comprises a first lock element 27 provided to an output member 22 and a second lock element 28 that engages with the first lock element 27. Together with rotation of an input member, the second lock element 28 of the locking mechanism 12 rotates about a second rotational axis RA2, thereby disengaging from the first lock element 27.

Description

Clutch unit

[0001] The present invention relates to a clutch unit including an input-side clutch portion and an output-side clutch portion.

[0002] In a clutch unit using engaging members such as cylindrical rollers or balls, a clutch portion is disposed between an input member and an output member. The clutch portion is configured to control the transmission and interruption of rotational torque by engaging and disengaging the engaging member between the input member and the output member.

[0003] For example, Patent Document 1 discloses a clutch unit incorporated in an automotive seat lifter portion that vertically adjusts a seat seat by lever operation.

[0004] This clutch unit includes a lever-side clutch portion to which rotational torque is input by lever operation, and a brake-side clutch portion that transmits the rotational torque from the lever-side clutch portion to the output side and blocks the rotational torque (reverse input torque) from the output side.

[0005] The lever-side clutch portion includes an outer ring to which rotational torque is input by lever operation, an inner ring that transmits the rotational torque input from the outer ring to the brake-side clutch portion, and a cylindrical roller that controls the transmission and interruption of the rotational torque from the outer ring by engaging and disengaging the wedge clearance between the outer ring and the inner ring.

[0006] The brake-side clutch portion includes an inner ring to which the rotational torque from the lever-side clutch portion is input, an output shaft to which the rotational torque from the inner ring is output, an outer ring whose rotation is restricted, and a cylindrical roller that controls the blocking of the rotational torque from the output shaft and the transmission of the rotational torque from the inner ring by engaging and disengaging the wedge clearance between the output shaft and the outer ring.

[0007] In the lever-side clutch portion, when rotational torque is input to the outer ring by lever operation, the cylindrical roller engages with the wedge clearance between the outer ring and the inner ring. By this engagement of the cylindrical roller with the wedge clearance, rotational torque is transmitted to the inner ring and the inner ring rotates.

[0008] In the brake-side clutch section, when rotational torque is applied to the output shaft by sitting on the seat, the cylindrical rollers engage with the wedge gap between the output shaft and the outer ring, locking the output shaft against the outer ring. This locking of the output shaft cuts off the rotational torque applied in reverse from the output shaft. As a result, the seat height of the seat is maintained.

[0009] On the other hand, when rotational torque is input from the lever-side clutch to the brake-side clutch, the inner ring presses against the cylindrical roller of the brake-side clutch, causing that cylindrical roller to disengage from the wedge gap between the output shaft and the outer ring. This disengagement of the cylindrical roller from the wedge gap releases the lock on the output shaft, allowing it to rotate.

[0010] As the inner ring rotates further, the rotational torque from the inner ring is transmitted to the output shaft, causing the output shaft to rotate. This rotation of the output shaft allows the seat height of the seat to be adjusted.

[0011] Japanese Patent Publication No. 2009-210117

[0012] As described above, in conventional clutch units, when rotational torque is input to the output shaft by the occupant sitting in the seat, the cylindrical roller of the brake-side clutch engages with the wedge gap between the output shaft and the outer ring, locking the output shaft against the outer ring.

[0013] The rotational torque input in reverse from the output shaft is locked in the brake-side clutch section by the engagement of the cylindrical rollers between the output shaft and the outer ring through a wedge gap, thereby blocking the return flow to the lever-side clutch section. This maintains the seat height of the seat.

[0014] Furthermore, in a clutch unit incorporated into an automobile seat lifter, when vertical vibration occurs while the vehicle is driven on rough roads or similar conditions while the passenger is seated in the seat, forward rotational torque and reverse rotational torque are continuously and alternately input to the output shaft.

[0015] At this time, in the brake-side clutch section, the contact position of the cylindrical rollers up to the wedge gap between the output shaft and the outer ring may be slightly misaligned, or hysteresis due to elastic deformation may exist in the output shaft, outer ring, and cylindrical rollers that are subjected to rotational torque, causing the output shaft to gradually rotate. In addition, deterioration of the brake-side clutch section can also cause misalignment of the cylindrical rollers. As a result, a phenomenon occurs where the seat drops slightly.

[0016] This invention has been made in view of the above circumstances, and its technical objective is to prevent a slight downward movement of the seat.

[0017] The present invention is for solving the above problems and comprises an input-side clutch unit that controls the transmission and interruption of input rotational torque, and an output-side clutch unit that interrupts input reverse input torque, wherein the input-side clutch unit comprises an input member that is rotatable around a first rotation axis when the rotational torque is applied and can return to a neutral position, and the output-side clutch unit comprises a rotatable output member that outputs the rotational torque input to the input member, a stationary member whose rotation is constrained, and an engaging element that, by engagement between the stationary member and the output member, interrupts the reverse input torque input from the output member, wherein the output The device is equipped with a locking mechanism for restricting the rotation of a force member, the locking mechanism comprising a first locking element provided on the output member and a second locking element that engages with the first locking element, the second locking element being configured to be rotatable around a second rotation axis parallel to the first rotation axis, the locking mechanism being configured such that the second locking element engages with the first locking element to restrict the rotation of the output member due to the reverse input torque, and the locking mechanism being configured such that, as the input member rotates, the second locking element rotates around the second rotation axis, releasing the engagement of the second locking element with the first locking element.

[0018] With this configuration, by providing a locking mechanism to the clutch unit which comprises an input clutch section and an output clutch section, even if misalignment occurs in the engaging element such as a cylindrical roller in the output clutch section, rotation of the output shaft due to reverse input torque can be prevented. This prevents a slight downward movement of the seat supported by the automotive seat lifter section into which the clutch unit is incorporated.

[0019] In a clutch unit having the above configuration, the locking mechanism may include a case that covers the input-side clutch portion, and the second locking element may be positioned between the input member and the case. With this configuration, the case can protect the second locking element.

[0020] In the clutch unit having the above configuration, the case may be fixed to the output clutch portion.

[0021] In the clutch unit having the above configuration, the output member may include an output shaft that rotates around the first rotation axis, and the case may have a positioning portion that is positioned by the output shaft. This allows the case to be attached to the clutch unit accurately and easily.

[0022] In the clutch unit having the above configuration, the locking mechanism includes a support member that is positioned around the second rotation axis and rotatably supports the second locking element, and the support member may be positioned between the case and the input member. With this configuration, the support member can be protected by the case.

[0023] In the clutch unit having the above configuration, the first locking element is configured in the shape of a disc and has a plurality of teeth on its outer circumference that engage with the second locking element, the center of the first locking element is positioned to coincide with the first rotation axis, the second locking element has a contact surface that makes surface contact with the teeth of the first locking element, the angle between the contact surface of the second locking element and the teeth of the first locking element is θ1, and when the tip of the contact surface of the second locking element rotates around the second rotation axis, a tangent line is drawn to the rotational orbit circle, and the angle between the tip and the teeth is θ2, then θ1 ≥ θ2.

[0024] With this configuration, when disengaging the second locking element from the first locking element, the contact surface of the second locking element can be easily separated from the teeth of the first locking element.

[0025] In the clutch unit having the above configuration, the second locking element may have a projection that engages with the first locking element and a cam that is operated by the input member. With this configuration, the engagement and disengagement of the second locking element with respect to the first locking element can be performed effectively.

[0026] In a clutch unit having the above configuration, the locking mechanism may include an elastic member that biases the second locking element toward the first locking element. With this configuration, the elastic force of the elastic member can maintain the engagement state of the second locking element with respect to the first locking element.

[0027] In the clutch unit having the above configuration, the input member may be provided with a side plate that is rotatable around the first rotation axis, and the side plate may have an operating part that presses against the second locking element as the side plate rotates. With this configuration, the second locking element can be suitably operated by the operating part of the side plate.

[0028] According to the present invention, it is possible to prevent the seat from sinking slightly.

[0029] This is a perspective view of the clutch unit. This is a front view of the clutch unit. This is a cross-sectional view taken along the line of arrow III-III in Figure 2. This is a perspective view of the clutch unit with the case omitted. This is an exploded perspective view of the locking mechanism in the clutch unit. This is an enlarged front view of the main part of the locking mechanism. This is an enlarged front view of the main part of the locking mechanism. This is an enlarged front view of the main part of the locking mechanism. This is an enlarged front view of the main part of the locking mechanism. This is a configuration diagram showing the seat and seat lifter of an automobile. This is an enlarged front view of the main part showing the operation of the locking mechanism. This is an enlarged front view of the main part showing the operation of the locking mechanism.

[0030] Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. Figures 1 to 12 show one embodiment of the clutch unit according to the present invention. The clutch unit according to this embodiment is incorporated into, for example, an automobile seat lifter, but is not limited to this and can be applied to devices other than automobile seat lifters.

[0031] As shown in Figures 1 and 2, the clutch unit has a structure that integrates a lever-side clutch section 10 as the input-side clutch section and a brake-side clutch section 11 as the output-side clutch section. Furthermore, the clutch unit is equipped with a locking mechanism 12 attached to the lever-side clutch section 10 and the brake-side clutch section 11.

[0032] The lever-side clutch unit 10 controls the transmission and interruption of rotational torque input by lever operation. The brake-side clutch unit 11 transmits rotational torque from the lever-side clutch unit 10 to the output side and also has a reverse input interruption function that interrupts reverse input torque (reverse rotation torque) input in the reverse direction from the output side.

[0033] As shown in Figures 1 to 3, the lever-side clutch section 10 mainly comprises an input member, which is a side plate 13 and an outer ring 14; a connecting member, which is an inner ring 15; a plurality of cylindrical rollers 16, which are engaging elements (torque transmission members); a retainer 17; an inner centering spring 18; and an outer centering spring 19.

[0034] The side plate 13 and outer ring 14, which serve as input members, are configured to be rotatable around the first rotation axis RA1 by applying rotational torque through lever operation. The side plate 13 and outer ring 14 are integrated by fitting a part of the outer peripheral edge (claw portion) of the side plate 13 into a part of the outer peripheral edge (notched recess) of the outer ring 14 and crimping them together. However, the side plate 13 and outer ring 14 may also be connected by welding.

[0035] The side plate 13 has a lever mounting portion 20 to which an operating lever is attached. When the operating lever attached to this lever mounting portion 20 is operated, rotational torque is input to the lever-side clutch portion 10.

[0036] Multiple cam surfaces 14a are formed on the inner circumference of the outer ring 14 at equal intervals in the circumferential direction. The inner ring 15 is a cylindrical member positioned inside the outer ring 14. The output member (output shaft 22) of the brake-side clutch unit 11, which will be described later, is inserted through the inside of the inner ring 15. The inner ring 15 transmits the rotational torque input from the outer ring 14 to the brake-side clutch unit 11.

[0037] A wedge gap is formed between the cylindrical outer surface 15a of the inner ring 15 and the cam surface 14a formed on the inner circumference of the outer ring 14. The cylindrical roller 16 controls the transmission and interruption of rotational torque from the outer ring 14 by engaging and disengaging through the wedge gap.

[0038] The retainer 17 is cylindrical in shape and has a plurality of pockets 17a for housing and holding the cylindrical rollers 16. Each pocket 17a is formed at equal intervals in the circumferential direction of the retainer 17.

[0039] The inner centering spring 18 is a C-shaped elastic member with a circular cross-section, disposed between the retainer 17 and the cover 24 of the brake-side clutch portion 11. The inner centering spring 18 has both ends that are locked to the retainer 17 and a part of the cover 24.

[0040] When a rotational torque is input from the outer ring 14 by a lever operation, the inner centering spring 18 is pushed and expanded along with the rotation of the cage 17 that follows the outer ring 14 with respect to the stationary cover 24, and elastic force is accumulated. When the input of the rotational torque from the outer ring 14 stops, the cage 17 returns to the neutral state by the elastic force of the inner centering spring 18.

[0041] The outer centering spring 19 is located radially outside the inner centering spring 18. The outer centering spring 19 is a C-shaped strip elastic member disposed between the outer ring 14 and the cover 24. Both ends of the outer centering spring 19 are locked to a part of the outer ring 14 and the cover 24.

[0042] When a rotational torque is input from the outer ring 14 by a lever operation, the outer centering spring 19 is pushed and expanded along with the rotation of the outer ring 14 with respect to the stationary cover 24, and elastic force is accumulated. When the input of the rotational torque from the outer ring 14 stops, the outer ring 14 returns to the neutral state by the elastic force of the outer centering spring 19.

[0043] As shown in FIGS. 1 and 3, the brake-side clutch portion 11 mainly includes an inner ring 15 of the lever-side clutch portion 10, an output shaft 22 which is an output member that outputs the torque input to the input member (side plate 13 and outer ring 14), the outer ring 23, the cover 24, and the side plate 25 which are stationary members whose rotation is restricted, and a plurality of pairs of cylindrical rollers 26 which are engaging members.

[0044] The output shaft 22 is configured to rotate around the first rotation axis RA1. That is, the center (axis) of the output shaft 22 coincides with the first rotation axis RA1. The output shaft 22 has a pinion gear portion 22a (see FIGS. 3 and 10) formed coaxially at its output side end. The inner ring 15 is externally inserted into the output shaft 22, and the rotational torque from the lever-side clutch portion 10 is transmitted to the output shaft 22 through this inner ring 15. The pinion gear portion 22a of the output shaft 22 is connected to a seat lifter portion that supports the seat sheet so as to be able to move up and down.

[0045] The output shaft 22 has a disk-shaped large-diameter portion 22b in the middle thereof. The large-diameter portion 22b has a plurality of cam surfaces 22b1 on its outer peripheral surface. Each cam surface 22b1 is formed on the outer peripheral surface of the large-diameter portion 22b at intervals in the circumferential direction thereof. The cam surface 22b1 is configured as a flat surface.

[0046] The outer ring 23 is arranged radially outward of the large-diameter portion 22b of the output shaft 22. A wedge clearance is formed between the cam surface 22b1 of the large-diameter portion 22b of the outer ring 23 and the cylindrical inner peripheral surface 23a of the outer ring 23.

[0047] In this wedge clearance, a pair of cylindrical rollers 26 and a single leaf spring interposed between the cylindrical rollers 26 are respectively arranged. The cylindrical roller 26 controls the interruption of the rotational torque reversely input from the output shaft 22 and the transmission of the rotational torque input from the inner ring 15 by engagement and disengagement with the wedge clearance. The leaf spring biases the cylindrical rollers 26 in the circumferential direction away from each other.

[0048] The large-diameter portion 22b of the output shaft 22 has a plurality of protrusions 22b2 for transmitting the rotational torque from the inner ring 15 to the output shaft 22. The protrusions 22b2 are formed on one surface in the thickness direction (axial direction of the output shaft 22) of the large-diameter portion 22b. The plurality of protrusions 22b2 are formed at predetermined intervals along the circumferential direction of the large-diameter portion 22b.

[0049] On the other hand, a hole 15b into which the protrusion 22b2 of the output shaft 22 is inserted is formed in the inner ring 15. A predetermined clearance is set between the inner peripheral surface of the hole 15b of the inner ring 15 and the protrusion 22b2 of the output shaft 22 inserted into the hole 15b. Further, the inner ring 15 has a diameter-expanded portion 15c at its end. A pocket for holding the cylindrical roller 26 is formed in the diameter-expanded portion 15c. With this configuration, the inner ring 15 also functions as a cage for holding the cylindrical roller 26.

[0050] The outer ring 23, the cover 24, and the side plate 25 are integrated by connecting a part of them to each other by means such as caulking or welding.

[0051] The side plate 25 is fixed to the seat lifter and is a member (fixing member) that supports the entire clutch unit. The side plate 25 has a first fixing part 25a to which a part of the locking mechanism 12 is fixed, and a second fixing part 25b to which the seat lifter is fixed.

[0052] The first fixing portion 25a is configured as a plurality of protrusions that project from the outer circumference of the side plate 25. A pair of claws are formed at the tip of the first fixing portion 25a. The second fixing portion 25b is configured as a plurality of protrusions that project from the outer circumference of the side plate 25. The tip of the second fixing portion 25b is fixed to the seat lifter portion via a fixing member 25c such as a screw member.

[0053] The locking mechanism 12 is for restricting the rotation of the output shaft 22 due to reverse input torque. As shown in Figures 1 to 8, the locking mechanism 12 comprises a first locking element 27 provided on the output shaft 22, a second locking element 28 provided on the side plate 13 side of the lever-side clutch portion 10, support members 29 and 30 that support the second locking element 28, a case 31 that covers the lever-side clutch portion 10, and an operating part 32 that operates the second locking element 28.

[0054] The first locking element 27 is configured in a disc shape and has a hole 27a in its center through which the output shaft 22 is inserted. The first locking element 27 is supported by the output shaft 22 through this hole 27a. The center of the first locking element 27 (the center of the hole 27a) is positioned to coincide with the first rotation axis RA1. That is, the first locking element 27, which is integrally fixed to the output shaft 22, is configured to be rotatable together with the output shaft 22 about the first rotation axis RA1.

[0055] Furthermore, the first locking element 27 has a plurality of teeth 27b on its outer circumference with which the second locking element 28 engages. The plurality of teeth 27b are formed at equal intervals in the outer circumference direction of the second locking element 28.

[0056] The second locking element 28 engages with the first locking element 27 to restrict the rotation of the output shaft 22 due to reverse input torque. The second locking element 28 is configured to be able to change its position between the locked position (restricting position) shown in Figure 6 and the unlocked position (unrestricted position) shown in Figure 7.

[0057] The second locking element 28 is supported by support members 29 and 30 and is configured to rotate around a second rotation axis RA2 which is parallel to the first rotation axis RA1. The second locking element 28 is positioned between the side plate 13 of the lever-side clutch portion 10 and the case 31.

[0058] The second locking element 28 has a main body portion 28a, a projection portion 28b that engages with the teeth portion 27b of the first locking element 27, a support portion 28c supported by a support member 29, and a cam portion 28d operated by an operating portion 32.

[0059] The main body portion 28a is composed of a long, plate-like member, but is not limited to this shape. The projection portion 28b is formed at one end of the main body portion 28a, and the support portion 28c is formed at the other end of the main body portion 28a.

[0060] As shown in Figures 6 to 8, the projection 28b includes a first contact surface 28b1, a second contact surface 28b2, and a top surface 28b3 that can contact the teeth 27b of the first locking element 27. In Figures 6 to 8, the teeth of the teeth 27b of the first locking element 27 that are in contact with the first contact surface 28b1 are called the first teeth 27b1. The teeth facing the second contact surface 28b2 are called the second teeth 27b2. When the first contact surface 28b1 is in contact with the first teeth 27b1, the second teeth 27b2 are not in contact with the second contact surface 28b2 of the second locking element 28 and are located away from the second contact surface 28b2.

[0061] The first tooth portion 27b1 and the second tooth portion 27b2 have first tooth surfaces 27b11 and 27b21 that are in surface contact with the first contact surface 28b1 of the projection portion 28b, and second tooth surfaces 27b12 and 27b22 that are in surface contact with the second contact surface 28b2 of the projection portion 28b.

[0062] The second contact surface 28b2 of the second locking element 28 contacts the second tooth portion 27b2 (second tooth surface 27b22) of the first locking element 27 when the side plate 13 and outer ring 14 move in the second direction DR2, which is opposite to the first direction DR1, due to the operation of the lever-side clutch portion 10.

[0063] Here, the first direction DR1 corresponds to the direction of movement of the operating lever for lowering the seat, and the second direction DR2 corresponds to the direction of movement of the operating lever for raising the seat.

[0064] As shown in Figures 6 and 8, when the first tooth surface 27b11 of the first tooth portion 27b1 related to the first locking element 27 is in surface contact with the first contact surface 28b1 of the projection 28b related to the second locking element 28, the angle that the first contact surface 28b1 makes with respect to the first tooth portion 27b1 is defined as the first angle θ1. This first angle θ1 is the angle made between the first contact surface 28b1 and the center line CL of the first tooth portion 27b1. The center line CL of the first tooth portion 27b1 is a straight line passing through the center of the first locking element 27 (first rotation axis RA1) and the center of the tooth portion 27b1 in the tooth thickness direction.

[0065] As shown in Figures 6 and 8, when the tip portion TP of the first contact surface 28b1 of the second locking element 28 is rotated around the second rotation axis RA2, a tangent line (hereinafter referred to as the "first tangent line") TL1 is drawn to the rotational orbit circle CO at the position of the contact point CP between the tip portion TP and the first tooth portion 27b1. Here, the tip portion TP of the first contact surface 28b1 is the boundary between the first contact surface 28b1 and the top surface 28b3 of the projection portion 28b.

[0066] The second angle θ2 is defined as the angle that the first tangent line TL1 makes with the center line CL of the first tooth portion 27b1. In this case, it is preferable that the first angle θ1 is greater than or equal to the second angle θ2 (θ1 ≥ θ2). This prevents excessive resistance from acting between the first tooth surface 27b11 and the first contact surface 28b1 (interference between the first tooth surface 27b11 and the first contact surface 28b1) when the projection 28b of the second locking element 28 is separated from the first tooth portion 27b1 and the first contact surface 28b1 of the second locking element 28, thereby releasing the face contact between the first tooth surface 27b11 of the first tooth portion 27b1 and the first contact surface 28b1 of the second locking element 28.

[0067] In this embodiment, Figures 6 and 8 show examples of a second locking element 28 in which the first angle θ1 is greater than the second angle θ2 (θ1 > θ2). Also, Figure 9 shows an example of a second locking element 28 in which the first angle θ1 is equal to the second angle θ2 (θ1 = θ2).

[0068] The top surface 28b3 of the projection 28b in the second locking element 28 is formed between the first contact surface 28b1 and the second contact surface 28b2. The width dimension W of the top surface 28b3 is smaller than the distance D between two adjacent teeth 27b in the first locking element 27. The top surface 28b3 functions as a contact surface that contacts the tooth root surface 27c formed between adjacent teeth 27b in the first locking element 27.

[0069] As shown in Figure 8, when a tangent line (hereinafter referred to as the "second tangent line") TL2 is drawn at the contact point between the top surface 28b3 and the tooth root surface 27c of the first locking element 27, it is preferable that the third angle θ3 formed by this second tangent line TL2 and the second contact surface 28b2 is acute. Furthermore, it is preferable that the fourth angle θ4 formed by this second tangent line TL2 and the first contact surface 28b1 is obtuse.

[0070] As shown in Figures 3 and 5, the support portion 28c has a through hole 28c1 that penetrates the main body portion 28a, and a cylindrical portion 28c2 that is concentric with the through hole 28c1. A part of the support member 29 is inserted into the through hole 28c1. The support portion 28c is positioned so that the center of the through hole 28c1 coincides with the second rotation axis RA2. The cylindrical portion 28c2 is formed on one surface in the thickness direction of the second locking element 28. The cylindrical portion 28c2 is positioned so as to face the side plate 13 in the lever-side clutch portion 10. The cylindrical portion 28c2 is configured in a cylindrical shape, but is not limited to this shape.

[0071] As shown in Figures 5 to 7, the cam portion 28d is operated by the operating portion 32 of the lever-side clutch portion 10 when the output shaft 22 rotates due to the lever operation for lowering the seat. The cam portion 28d is a plate-shaped portion that is integrally formed with the support portion 28c. The cam portion 28d is configured as a projection that protrudes radially outward from the through hole 28c1 of the support portion 28c. The cam portion 28d has a cam surface 28d1 that contacts the operating portion 32. The cam surface 28d1 is configured as a curved surface that is arc-shaped.

[0072] The support members 29 and 30 are positioned between the case 31 and the side plate 13 of the lever-side clutch portion 10. The support members 29 and 30 include a first support member 29 and a second support member 30.

[0073] The first support member 29 is positioned with the second rotation axis RA2 as its center and rotatably supports the second locking element 28. The first support member 29 has a shaft portion 29a, a head portion 29b, and an intermediate portion 29c.

[0074] The shaft portion 29a is cylindrical in shape and is positioned so that its axis coincides with the second rotation axis RA2. The shaft portion 29a is positioned between the case 31 and the side plate 13 of the lever-side clutch portion 10. The tip of the shaft portion 29a (the end opposite to the end on which the head portion 29b is provided) is positioned to face the side plate 13.

[0075] The head portion 29b is formed at one end of the shaft portion 29a. The head portion 29b is configured in a disc shape, but is not limited to this shape. The head portion 29b is supported by the case 31 by contacting the outer surface of the case 31.

[0076] The intermediate portion 29c is a cylindrical part formed between the shaft portion 29a and the head portion 29b. The diameter of the intermediate portion 29c is larger than the diameter of the shaft portion 29a and smaller than the diameter of the head portion 29b.

[0077] The second support member 30 is configured as an elastic member that biases the second locking element 28 toward the first locking element 27. The second support member 30 is configured as a torsion spring (coil spring), but is not limited to this configuration. The second support member 30 may be configured as a leaf spring or other elastic member.

[0078] As shown in Figure 5, the second support member 30 has a first end 30a, a second end 30b, and a coil portion 30c formed between the first end 30a and the second end 30b. The first end 30a is in contact with the middle portion of the second locking element 28. As shown in Figures 1 and 2, the second end 30b is supported by the case 31.

[0079] The coil portion 30c is positioned between the second locking element 28 and the side plate 13 of the lever-side clutch portion 10, generating an elastic force that presses the second locking element 28 toward the first locking element 27. The cylindrical portion 28c2 of the support portion 28c of the second locking element 28 is inserted through the inside of the coil portion 30c. The coil portion 30c supports the main body portion 28a of the second locking element 28 by contacting it.

[0080] The case 31 is made of, for example, a steel plate or a resin plate, but the material of the case 31 is not limited to this embodiment. The case 31 has a main body portion 31a and a fixing portion 31b that is fixed to the brake-side clutch portion 11.

[0081] The main body portion 31a is positioned away from the side plate 13 of the lever-side clutch portion 10, so as to face it. This creates a space between the main body portion 31a and the side plate 13 in which the locking mechanism 12 can be housed.

[0082] As shown in Figures 2 and 5, the main body 31a has a positioning portion 31a1 that is positioned by the output shaft 22, a first insertion hole 31a2 through which the intermediate portion 29c of the first support member 29 is inserted, and a second insertion hole 31a3 through which the second end portion 30b of the second support member 30 is inserted.

[0083] The positioning portion 31a1 is composed of a circular hole through which the output shaft 22 can be inserted, but the shape of the positioning portion is not limited to this embodiment. For example, the positioning portion 31a1 may be composed of a recess into which the end of the output shaft 22 can be inserted.

[0084] The first through-hole 31a2 is configured in a circular shape, but is not limited to this shape. The diameter of the first through-hole 31a2 is larger than the diameter of the shaft portion 29a of the first support member 29, and smaller than the diameter of the head portion 29b of the first support member 29. The diameter of the first through-hole 31a2 is slightly smaller than the diameter of the intermediate portion 29c of the first support member 29. The intermediate portion 29c of the first support member 29 is press-fitted into the first through-hole 31a2 by interference fit. However, the intermediate portion 29c may be fixed to the first through-hole 31a2 by welding. As a result, the first through-hole 31a2 functions as a support portion for the first support member 29.

[0085] The second insertion hole 31a3 is configured in a circular shape, but is not limited to this shape. The diameter of the second insertion hole 31a3 is larger than the diameter of the second end portion 30b of the second support member 30. As shown in Figures 1 and 2, when the second end portion 30b of the second support member 30 is inserted into the second insertion hole 31a3, the second insertion hole 31a3 supports the second end portion 30b by a portion of its inner circumferential surface contacting the second end portion 30b.

[0086] The fixing portion 31b is composed of a projection that protrudes from the main body portion 31a. In this embodiment, a case 31 having two fixing portions 31b is illustrated, but the number of fixing portions 31b is not limited to this embodiment. The tip of the fixing portion 31b has a pair of claw portions 31b1 and a recess 31b2 formed between the pair of claw portions 31b1. The fixing portion 31b is fixed to the side plate 25 of the brake-side clutch portion 11 by inserting a first fixing portion 25a formed on the side plate 25 into the recess 31b2 and crimping the first fixing portion 25a. However, the fixing portion 31b may also be fixed to the first fixing portion 25a of the side plate 25 by welding or other means.

[0087] The operating part 32 is formed on the outer circumference of the side plate 13 of the lever-side clutch part 10. The operating part 32 is configured as a projection that protrudes from the side plate 13 along the direction of the second rotation axis RA2. The operating part 32 is configured to reciprocate between a standby position and an operating position that moves the second locking element 28 of the locking mechanism 12 to a position away from the first locking element 27.

[0088] The following describes the operation of the lever-side clutch section 10 and the brake-side clutch section 11, which are the basic components of the clutch unit.

[0089] In the lever-side clutch section 10, when rotational torque is applied to the outer ring 14 by lever operation, the cylindrical roller 16 engages with the wedge gap between the outer ring 14 and the inner ring 15. This engagement of the cylindrical roller 16 with respect to the wedge gap transmits rotational torque to the inner ring 15, causing the inner ring 15 to rotate. At this time, elastic force is accumulated in both centering springs 18 and 19 as the outer ring 14 and the cage 17 rotate.

[0090] When the rotational torque input from the lever operation is removed, the elastic force of the two centering springs 18 and 19 returns the cage 17 and outer ring 14 to the neutral position. Meanwhile, the inner ring 15 maintains its given rotational position. Therefore, the repeated rotation of the outer ring 14 by the pumping action of the operating lever 43 causes the inner ring 15 to rotate in increments.

[0091] In the brake-side clutch section 11, even if rotational torque is reversed on the output shaft 22 when the driver or other occupants are seated in the seat, the cylindrical roller 26 engages with the wedge gap between the output shaft 22 and the outer ring 23, locking the output shaft 22 against the outer ring 23.

[0092] In this way, the rotational torque input in reverse from the output shaft 22 is locked by the brake-side clutch unit 11, blocking the return flow to the lever-side clutch unit 10. As a result, the seat height of the seat is maintained.

[0093] On the other hand, when rotational torque from the lever-side clutch section 10 is input to the inner ring 15 by lever operation, the inner ring 15 presses against the cylindrical roller 26 of the brake-side clutch section 11, which is held in the pocket of the enlarged diameter section 15c. As a result, the cylindrical roller 26 of the brake-side clutch section 11 disengages from the wedge gap between the output shaft 22 and the outer ring 23. This disengagement of the cylindrical roller 26 from the wedge gap releases the locked state of the output shaft 22, allowing the output shaft 22 to rotate.

[0094] As the inner ring 15 rotates further, the clearance between the hole 15b of the inner ring 15 and the projection 22b2 of the output shaft 22 decreases, and the inner surface of the hole 15b comes into contact with the projection 22b2 of the output shaft 22 in the rotational direction.

[0095] As a result, the rotational torque from the lever-side clutch section 10 is transmitted to the output shaft 22 via the inner ring 15, causing the output shaft 22 to rotate. In other words, when the inner ring 15 rotates in increments, the output shaft 22 also rotates in increments. This makes it possible to adjust the seat height of the seat 40.

[0096] Next, the configuration of the seat lifter section into which the clutch unit is incorporated, and the operating mode of the locking mechanism 12 will be described.

[0097] Figure 10 illustrates an automotive seat lifter unit 39 incorporating a clutch unit. The seat lifter unit 39 supports a seat 40 installed in the passenger compartment of an automobile. The seat lifter unit 39 is used to adjust the seat height of the seat 40 by operating a lever.

[0098] As shown in Figure 10, the seat height of the seat 40 in the seat lifter section 39 is adjusted by an operating lever 43 attached to the side plate 13 (lever mounting section 20) of the lever-side clutch section 10 in the clutch unit.

[0099] The seat lifter section 39 comprises a sliding movable member 44, a first link member 45, and a second link member 46. One end of each link member 45, 46 is pivotally attached to the sliding movable member 44. The other end of each link member 45, 46 is pivotally attached to the seat 40. A sector gear 47 is integrally provided at the other end of the first link member 45. The sector gear 47 meshes with the pinion gear section 22a of the output shaft 22 of the clutch unit.

[0100] In this seat lifter section 39, for example, when lowering the seat surface of the seat 40, the brake-side clutch section 11 is released by operating the lever on the lever-side clutch section 10, that is, by swinging the operating lever 43 downwards.

[0101] When the lock is released at the brake-side clutch section 11, the rotational torque transmitted from the lever-side clutch section 10 to the brake-side clutch section 11 causes the pinion gear section 22a of the output shaft 22 of the brake-side clutch section 11 to rotate clockwise (in the direction of the arrow in Figure 10).

[0102] In the seat lifter section 39, the sector gear 47, which meshes with the pinion gear section 22a, swings counterclockwise (in the direction of the arrow in Figure 10), causing both the first link member 45 and the second link member 46 to tilt, lowering the seat surface of the seat 40.

[0103] In this way, after adjusting the seat height of the seat 40, when the operating lever 43 is released, the outer ring 14 of the lever-side clutch part 10 swings upward due to the elastic force of both centering springs 18 and 19 and returns to its original position (neutral state). Along with the movement of the outer ring 14, the operating lever 43 also returns to its original position.

[0104] When the operating lever 43 is swung upward, the seat surface of the seat 40 rises in the opposite direction to the operation described above. After adjusting the seat surface height of the seat 40, when the operating lever 43 is released, the operating lever 43 swings downward and returns to its original position (neutral state).

[0105] Next, the operation of the locking mechanism 12 in conjunction with the operation of the operating lever 43 will be described.

[0106] Before the operating lever 43 is operated, the locking mechanism 12 restricts (locks) the rotation of the output shaft 22 by making surface contact between the projection 28b (first contact surface 28b1) of the second locking element 28 and the first tooth portion 27b1 (first tooth surface 27b11) of the first locking element 27. When the operating lever 43 is operated downward from this state as described above, the outer ring 14 of the lever-side clutch portion 10 rotates clockwise around the first rotation axis RA1. Due to this rotation, the operating portion 32 moves from the standby position along the first direction DR1 in order to operate the second locking element 28 (see Figure 7).

[0107] This movement causes the operating unit 32 to press the cam surface 28d1 of the cam portion 28d of the second locking element 28, thereby moving the second locking element 28. As the second locking element 28 is pressed by the operating unit 32, it rotates clockwise around the second rotation axis RA2, as shown in Figures 6 and 7. This rotation causes the projection 28b of the second locking element 28 to move away from the first tooth portion 27b1 of the first locking element 27. At this time, the first contact surface 28b1 of the projection 28b slides while maintaining contact with the first tooth surface 27b11 of the first tooth portion 27b1. In this case, by defining the relationship between the first angle θ1 and the second angle θ2 (θ1 ≥ θ2) as described above, the first contact surface 28b1 can move smoothly without interference from the first tooth surface 27b11. As shown in Figure 7, the second locking element 28 is in the unlocked position, the engagement between the first locking element 27 and the second locking element 28 is released, and the output shaft 22 becomes rotatable.

[0108] When the operation of the operating lever 43 is completed, the operating unit 32 returns to its original standby position as the outer ring 14 of the lever-side clutch unit 10 returns to the neutral position due to the elastic force of the outer centering spring 19.

[0109] On the other hand, when the operating lever 43 is pulled up to raise the seat 40, the outer ring 14 of the lever-side clutch section 10 rotates counterclockwise around the first rotation axis RA1. Along with this rotation, the output shaft 22 and the first locking element 27 of the locking mechanism 12 rotate counterclockwise around the first rotation axis RA1. That is, the first locking element 27 moves in the second direction DR2, as shown in Figure 11.

[0110] As the first locking element 27 rotates (moves) as described above, the first tooth surface 27b11 of the first tooth portion 27b1 moves away from the first contact surface 28b1 of the second locking element 28. The second tooth portion 27b2 approaches the second contact surface 28b2 of the second locking element 28. Subsequently, the second tooth surface 27b22 of the second tooth portion 27b2 comes into contact with the second contact surface 28b2. Furthermore, the second tooth surface 27b22 continues to move while pressing against the second contact surface 28b2, passing over the projection 28b. While the second tooth portion 27b2 moves toward the second contact surface 28b2 of the second locking element 28, the top surface 28b3 of the second locking element 28 maintains contact with the tooth root surface 27c between the first tooth portion 27b1 and the second tooth portion 27b2.

[0111] The second locking element 28 rotates clockwise around the second rotation axis RA2 as the second contact surface 28b2 of the projection 28b is pressed and pushed away by the second tooth portion 27b2. At this time, the top surface 28b3 of the second locking element 28 separates from the tooth root surface 27c of the first locking element 27. As shown in Figure 12, when the second tooth portion 27b2 passes the projection 28b of the second locking element 28, the top surface 28b3 of the projection 28b comes into contact with the top surface of the second tooth portion 27b2.

[0112] When the second tooth portion 27b2 passes the projection portion 28b, the top surface 28b3 of the projection portion 28b comes into contact with the tooth root surface 27c located behind the second tooth portion 27b2 in the direction of travel, due to the action of the elastic force of the second support member 30. Subsequently, until the operation of the operating lever 43 is completed, the following teeth portions 27b will pass the projection portion 28b in the same way as the second tooth portion 27b2.

[0113] When the operation of the operating lever 43 is completed, the first contact surface 28b1 of the projection 28b comes into contact with the first tooth surface 27b11 of the adjacent first tooth portion 27b1, thereby restricting (locking) the rotation of the first locking element 27.

[0114] According to the embodiment described above, by providing a locking mechanism 12 to a clutch unit comprising a lever-side clutch portion 10 and a brake-side clutch portion 11, it is possible to prevent a slight downward movement of the seat supported by the automobile seat lifter portion.

[0115] In other words, by attaching the locking mechanism 12 to the clutch unit, which is a unitized unit of the lever-side clutch section 10 and the brake-side clutch section 11, it is possible to prevent reverse rotation torque from being input even if the cylindrical roller 26 in the wedge gap between the output shaft 22 and the outer ring 23 of the brake-side clutch section 11 is repelled, or if vertical vibration occurs when the vehicle is driven on rough roads, causing a slight shift in the contact position of the cylindrical roller 26 in the wedge gap between the output shaft 22 and the outer ring 23 of the brake-side clutch section 11, or if the brake-side clutch section 11 deteriorates.

[0116] In this embodiment, the locking mechanism 12 can be easily attached to the clutch unit, which comprises the lever-side clutch section 10 and the brake-side clutch section 11. This allows the user of the clutch unit to choose whether or not to include the locking mechanism 12 depending on the operating environment of the clutch unit.

[0117] Furthermore, in the clutch unit according to this embodiment, there is no need to significantly alter the structure of the lever-side clutch section 10 and the brake-side clutch section 11 in order to assemble the locking mechanism 12. Therefore, the manufacturing equipment for conventional clutch units can be used as is. Consequently, the clutch unit according to this embodiment can be manufactured without increasing the cost of manufacturing equipment.

[0118] Furthermore, the present invention is not limited to the configuration of the above embodiments, nor is it limited to the effects described above. The present invention can be modified in various ways without departing from the spirit of the invention.

[0119] In the above embodiment, the second support member 30 and the case 31 of the locking mechanism 12 were made of separate materials, but the present invention is not limited to this configuration. For example, the second support member 30 and the case 31 may be integrally formed by injection molding or the like.

[0120] 10 Lever-side clutch section (input-side clutch section) 11 Brake-side clutch section (output-side clutch section) 12 Locking mechanism 13 Side plate 14 Outer ring of lever-side clutch section (input member) 22 Output shaft (output member) 23 Outer ring of brake-side clutch section (stationary member) 27 First locking element 27b Teeth 28 Second locking element 28b Projection 28b1 First contact surface 28d Cam 29 First support member 30 Second support member (elastic member) 31 Case 31a1 Positioning section 32 Operating section CO Rotational orbit circle CP Contact point between the tip of the first contact surface and the first teeth RA1 First rotation axis RA2 Second rotation axis TL1 First tangent TP Tip of the first contact surface θ1 First angle (angle made by the first contact surface with respect to the first tangent) θ2 Second angle (the angle the first tangent makes with respect to the first tooth)

Claims

1. A clutch unit comprising: an input-side clutch section for controlling the transmission and interruption of input rotational torque; and an output-side clutch section for interrupting input reverse input torque, wherein the input-side clutch section comprises an input member that is rotatable around a first rotation axis when the rotational torque is applied and can return to a neutral position; the output-side clutch section comprises a rotatable output member that outputs the rotational torque input to the input member; a stationary member whose rotation is constrained; and an engaging element that, by engagement between the stationary member and the output member, interrupts the reverse input torque input from the output member, wherein the clutch unit comprises a locking mechanism for restricting the rotation of the output member, wherein the locking mechanism comprises a first locking element provided on the output member and a second locking element that engages with the first locking element, wherein the second locking element is configured to be rotatable around a second rotation axis parallel to the first rotation axis, and the locking mechanism is configured such that the second locking element engages with the first locking element to restrict the rotation of the output member due to the reverse input torque. The locking mechanism is a clutch unit characterized by rotating the second locking element around the second rotation axis in conjunction with the rotation of the input member, thereby releasing the engagement of the second locking element with respect to the first locking element.

2. The clutch unit according to claim 1, wherein the locking mechanism comprises a case covering the input-side clutch portion, and the second locking element is disposed between the input member and the case.

3. The clutch unit according to claim 2, wherein the case is fixed to the output clutch portion.

4. The clutch unit according to claim 2 or 3, wherein the output member includes an output shaft that rotates around the first rotation axis, and the case has a positioning portion that is positioned by the output shaft.

5. The clutch unit according to claim 2 or 3, wherein the locking mechanism comprises a support member that is arranged around the second rotation axis and rotatably supports the second locking element, and the support member is arranged between the case and the input member.

6. The clutch unit according to any one of claims 1 to 3, wherein the first locking element is configured in the shape of a disc and has a plurality of teeth on its outer circumference that engage with the second locking element, the center of the first locking element is positioned to coincide with the first rotation axis, the second locking element has a contact surface that makes surface contact with the teeth of the first locking element, and when the angle between the contact surface of the second locking element and the teeth of the first locking element is θ1, and a tangent line is drawn at the position of the point of contact between the tip and the teeth of the rotational orbit circle drawn when the tip of the contact surface of the second locking element rotates around the second rotation axis, and the angle between the tangent line and the teeth is θ2, then θ1 ≥ θ2.

7. The clutch unit according to any one of claims 1 to 3, wherein the second locking element has a projection that engages with the first locking element and a cam that is operated by the input member.

8. The clutch unit according to any one of claims 1 to 3, wherein the locking mechanism comprises an elastic member that biases the second locking element toward the first locking element.

9. The clutch unit according to any one of claims 1 to 3, wherein the input member comprises a side plate rotatable about the first rotation axis, and the side plate has an operating part that presses the second locking element as the side plate rotates.

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