One-way joint

Abstract

The present disclosure relates to a one-way joint having a wedge-shaped member having a pressing portion configured to press against an inner peripheral surface of a fixing ring, and the wedge-shaped member having a first follower portion and a second follower portion, wherein the first follower portion is pressed by a pressing force from an open cam when a driving force is input to an input-side protruding portion, thereby displacing the wedge-shaped member to a non-locking position; and the second follower portion is pressed by a pressing force from a pressing cam when a driving force is input to an output-side rotating portion, thereby displacing the wedge-shaped member to a locking position.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a one-way clutch that is capable of preventing a driving force that has been input to an output shaft from being transmitted to an input shaft. BACKGROUND

[0002] For example, Japanese Patent Application Publication No. 2001-28863 (hereinafter referred to as "Patent Document 1") discloses a clutch using a steel ball as a one-way clutch. Specifically, in this clutch, when a driving force has been input to a worm shaft, rotation of the worm shaft is stopped by pressing the steel ball against a cylindrical clutch housing, thereby cutting off transmission of the driving force from the worm shaft to a rotation shaft. SUMMARY

[0003] In the invention disclosed in Patent Document 1, since it is a structure in which the steel ball is pressed against the clutch housing, it is difficult to change the contact surface pressure in accordance with the specifications.

[0004] In view of the above-described problems, the present disclosure discloses a one-way clutch using a wedge-shaped member composed of a non-rotating body.

[0005] The one-way clutch of one aspect of the present disclosure has an input-side rotating portion configured to be input with a driving force and an output-side rotating portion configured to output the driving force, the one-way clutch transmits the driving force from the input-side rotating portion to the output-side rotating portion, and prevents the driving force that has been input to the output-side rotating portion from being transmitted to the input-side rotating portion, and the one-way clutch of one aspect of the present disclosure preferably has at least one of the following configuration elements.

[0006] That is, the configuration requirements are: a transmission portion including an input-side protrusion portion that rotates integrally with the input-side rotating portion and an output-side protrusion portion that rotates integrally with the output-side rotating portion, and configured to transmit the driving force from the input-side rotating portion to the output-side rotating portion by engagement of the input-side protrusion portion with the output-side protrusion portion when the driving force has been input to the input-side rotating portion; a fixed ring held in a state of being unable to rotate; a wedge-shaped member having a pressing portion configured to press against a circumferential surface of the fixed ring, and configured from a non-rotating body, and capable of displacing between a locked position when the pressing portion presses against the circumferential surface and an unlocked position when the pressing is released; an open cam capable of rotating integrally with the input-side rotating portion; a first follower provided on the wedge-shaped member and subjected to a pressing force from the open cam to displace the wedge-shaped member to the unlocked position when the driving force has been input to the input-side rotating portion; a pressing cam capable of rotating integrally with the output-side rotating portion; and a second follower provided at a position on the wedge-shaped member that is offset from the first follower and subjected to a pressing force from the pressing cam to displace the wedge-shaped member to the locked position when the driving force has been input to the output-side rotating portion.

[0007] Thus, in the one-way clutch, when the driving force has been input to the input-side rotating portion, the transmission of the driving force from the output-side rotating portion to the input-side rotating portion is cut off because the wedge-shaped member is in the locked position and the wedge-shaped member presses against the fixed ring.

[0008] The first follower that displaces the wedge-shaped member to the unlocked position and the second follower that displaces the wedge-shaped member to the locked position are provided on the wedge-shaped member. Thus, in the one-way clutch, the first follower and the second follower can each have an appropriate shape.

[0009] Further, when the diameter direction of the fixed ring is set as the radial direction, the pressing portion is offset in the radial direction with respect to the second follower, and the radius of curvature of the pressing portion is greater than the radius of curvature of the second follower. Thus, the contact surface pressure of the pressing portion can be inhibited from increasing excessively.

[0010] The one-way clutch has a holder having a holding portion that holds the posture of the wedge-shaped member by sandwiching the wedge-shaped member from both sides in the circumferential direction when the circumferential direction of the fixed ring is set as the circumferential direction. Thus, the posture of the wedge-shaped member when pressing against the fixed ring can be inhibited from becoming an inappropriate posture.

[0011] The open cam is provided on the holder, and when the driving force has been input to the input-side rotating portion, the holder is pressed by the input-side protrusion portion, whereby the open cam presses the first follower.

[0012] The one-way clutch can be configured as follows, for example.

[0013] The output-side protrusion and the pressing cam are preferably formed integrally with the output-side rotary portion. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 FIG. 1 is a diagram showing an actuator of a first embodiment.

[0015] Figure 2 FIG. 2 is an exploded view of the actuator of the first embodiment.

[0016] Figure 3 FIG. 3 is a diagram showing an input-side rotary portion of the first embodiment.

[0017] Figure 4 FIG. 4 is a diagram showing an output-side rotary portion of the first embodiment.

[0018] Figure 5 FIG. 5 is a diagram showing a one-way clutch of the first embodiment.

[0019] Figure 6 FIG. 6 is a diagram showing the output-side rotary portion and a wedge-shaped member of the first embodiment.

[0020] Figure 7 FIG. 7 is a diagram showing the wedge-shaped member of the first embodiment.

[0021] Figure 8 FIG. 8 is a diagram showing a structure of the one-way clutch of the first embodiment, and is a diagram showing a state in which a driving force has been input to the input-side rotary portion.

[0022] Figure 9 FIG. 9 is a diagram showing a structure of the one-way clutch of the first embodiment, and is a diagram showing a state in which a reverse rotation force has been input to the output-side rotary portion.

[0023] Figure 10 FIG. 10 is a diagram showing a retainer of the first embodiment.

[0024] Figure 11 FIG. 11 is a diagram showing a structure of the one-way clutch of the first embodiment, and is a diagram showing a state in which a driving force has been input to the input-side rotary portion.

[0025] Figure 12 FIG. 12 is a diagram showing a structure of the one-way clutch of the first embodiment. DETAILED DESCRIPTION

[0026] Embodiments of the present disclosure will be described below with reference to the accompanying drawings.

[0027] The following embodiments show examples of embodiments within the technical scope of the present disclosure. That is, the technical solutions recited in the claims and the like are not limited to the specific structures or configurations and the like shown in the following embodiments.

[0028] This embodiment is an example in which the one-way clutch of the present disclosure is applied to a seat (hereinafter also referred to as "vehicle seat") that can be installed in a vehicle or the like. The arrows and the like that indicate directions in each drawing are symbols that are labeled for the purpose of facilitating understanding of the mutual relationships of the drawings and the shapes and the like of the components or parts.

[0029] Therefore, the one-way clutch is not limited to the directions indicated in each drawing. The directions shown in each drawing are directions in a state in which the vehicle seat of this embodiment is assembled in a vehicle. The drawing in which the diagonal line is indicated is not necessarily a cross-sectional view.

[0030] For the components or parts for which at least the symbols are indicated, at least one is provided, except in the case where it is stated in advance that "only one" or the like. That is, in the case where it is not stated in advance that "only one" or the like, the component can be provided with two or more.

[0031] (First Embodiment)

[0032] <1. Outline of One-Way Clutch>

[0033] This embodiment is an example in which the one-way clutch 10 (refer to Figure 2 ) of this embodiment is applied to an actuator 1 (refer to Figure 1 ) for a vehicle seat. The actuator 1 generates a driving force that causes a movable portion of the vehicle seat to displace.

[0034] The movable portion of the vehicle seat can be exemplified by a lifting arm that moves a seat cushion up and down, a reclining arm that moves a front end side of the seat cushion up and down, and a reclining angle adjuster that displaces a seat back, and the like.

[0035] <1.1 Outline of Actuator>

[0036] As shown in Figure 2 , the actuator 1 is provided with an electric motor 3, a one-way clutch 10, and a housing 5, and the like. The electric motor 3 generates a driving force. The housing 5 houses the electric motor 3 and the one-way clutch 10.

[0037] The housing 5 has a first housing 5A and a second housing 5B. The first housing 5A and the second housing 5B hold the electric motor 3 in such a manner that the electric motor 3 is sandwiched therebetween. The first housing 5A and the second housing 5B are fastened to each other by a fastener (not shown) such as a screw.

[0038] At least one (in the present embodiment, a plurality of) fixing portions 5C are provided on the first housing 5A. Each fixing portion 5C is a site for fixing the actuator 1 to a non-movable portion of a seat frame (not shown) or the like.

[0039] <1.2 Details of the one-way clutch>

[0040] The one-way clutch 10 is a clutch capable of functioning as a transmission function and a cut-off function. The transmission function is a function of transmitting a driving force (hereinafter, simply referred to as "driving force") of the electric motor 3 to a movable portion (hereinafter, simply referred to as "movable portion") of a seat for a vehicle. The cut-off function is a function of cutting off a rotational force (hereinafter, referred to as "reverse rotational force") transmitted from the movable portion to the electric motor 3.

[0041] As shown in Figure 2 , the one-way clutch 10 includes at least an input-side rotating portion 11, an output-side rotating portion 12, a transmission portion 13, a fixing ring 14, a wedge-shaped member 15, and a retainer 16. In the present embodiment, the fixing ring 14 is integrated with the first housing 5A.

[0042] <INPUT-SIDE ROTATING PORTION>

[0043] The input-side rotating portion 11 is a member to which the driving force of the electric motor 3 is input. As shown in Figure 3 , the input-side rotating portion 11 is a driving ring having a connecting portion 11A and at least one (in the present embodiment, a plurality of) input-side protruding portions 11B.

[0044] The connecting portion 11A is a site that is linked to the rotor shaft 3A of the electric motor 3 and rotates integrally with the rotor shaft 3A. Specifically, the connecting portion 11A is provided with an engagement hole 11C into which the rotor shaft 3A is inserted. Figure 2

[0045] An engagement surface 11D that engages with an engagement surface (not shown) provided on the rotor shaft 3A is provided on an inner peripheral surface of the engagement hole 11C. Thus, the engagement hole 11C of the present embodiment is a substantially D-shaped hole.

[0046] Each input-side protruding portion 11B is a protruding portion that revolves around the rotor shaft 3A as a center of revolution. Specifically, each input-side protruding portion 11B is provided on an outer peripheral side of the connecting portion 11A formed in a substantially disc shape and is a site that protrudes from the connecting portion 11A toward a direction parallel to the rotor shaft 3A.

[0047] Each input-side protruding portion 11B is configured as a member integral with the connecting portion 11A. Thus, each input-side protruding portion 11B revolves integrally with the rotor shaft 3A around the rotor shaft 3A as a center of revolution.

[0048] <OUTPUT-SIDE ROTATING PORTION>​

[0049] The output-side rotating portion 12 is a member that transmits the driving force that has been input to the input-side rotating portion 11 to the movable portion. As shown in the figure, the output-side rotating portion 12 has an output shaft 12A, at least one (in this embodiment, a plurality of) output-side protruding portion 12B, and a press cam 12C, and the like. Figure 4

[0050] The output shaft 12A is engaged with the movable portion and supplies the driving force to the movable portion. Each output-side protruding portion 12B is a protruding portion that performs revolution with the output shaft 12A as the center of revolution, and protrudes toward the input-side protruding portion 11B side in parallel with the axis direction of the output shaft 12A.

[0051] The press cam 12C is a portion that constitutes a press portion for pressing the wedge-shaped member 15. The output shaft 12A, each output-side protruding portion 12B, and the press cam 12C are formed in one body. Therefore, if each output-side protruding portion 12B performs revolution, the output shaft 12A performs rotation. Conversely, if the output shaft 12A performs rotation, the press cam 12C performs rotation around the output shaft 12A.

[0052] The rotor shaft 3A, the input-side rotating portion 11, and the output-side rotating portion 12 are arranged on the same axis in such a manner that the respective center axes of rotation Lo coincide (refer to Figure 2 ) with each other. The output-side rotating portion 12 is provided with an insertion hole 12D into which the rotor shaft 3A is inserted (refer to Figure 4 ).

[0053] The insertion hole 12D is not provided with an engagement surface that engages with the engagement surface of the rotor shaft 3A. Therefore, the driving force is not directly transmitted between the rotor shaft 3A and the output-side rotating portion 12.

[0054] <Transmission portion>

[0055] The transmission portion 13 includes the input-side protruding portion 11B and the output-side protruding portion 12B, and the like. When the driving force is input to the input-side rotating portion 11, the input-side protruding portion 11B comes into contact with and engages with the output-side protruding portion 12B (refer to Figure 8 ). Therefore, the driving force that is input to the input-side rotating portion 11 is transmitted from the input-side rotating portion 11 to the output-side rotating portion 12.

[0056] In this embodiment, the contact surfaces of the input-side protruding portion 11B and the output-side protruding portion 12B are set so that a virtual tangent line LI (refer to Figure 8 ) at a contact portion at which the input-side protruding portion 11B and the output-side protruding portion 12B come into contact passes through the center axis of rotation Lo of the rotor shaft 3A.

[0057] <Fixed ring>

[0058] ​The stationary ring 14 is a ring-shaped member that is held in a state in which rotation is not possible (see Figure 2 ). Also, in the present embodiment, the stationary ring 14 houses therein the input-side protruding portion 1 IB, the output-side protruding portion 12B, the wedge-shaped member 15, and the holding member 16 (see Figure 5 ).

[0059] < Wedge-shaped member and holding member, etc. >

[0060] As shown in Figure 6 , the one-way joint 10 of the present embodiment is provided with a plurality of wedge-shaped members 15. Each wedge-shaped member 15 is a shape that is congruent. Also, the first wedge-shaped member 15 and the second wedge-shaped member 15 are disposed at positions that are rotationally symmetrical with respect to the rotational center axis Lo.

[0061] As shown in Figure 7 , the wedge-shaped member 15 is a non-rotating body that has at least a pressing portion 15A, a first follower portion 15B, and a second follower portion 15C. That is, each wedge-shaped member 15 is composed of a non-spherical or non-cylindrical member.

[0062] Each pressing portion 15A is a curved surface that presses against the circumferential surface of the stationary ring 14 when the cutting function is performed. The pressing portion 15A of the present embodiment presses against the inner circumferential surface 14A (see Figure 5 ). Each wedge-shaped member 15 displaces between a locked position (see Figure 9 ) at which the pressing portion 15A presses against the inner circumferential surface 14A and an unlocked position (see Figure 8 ) at which the pressing is released.

[0063] "Pressing is released" means, for example, a state in which the pressing portion 15A and the inner circumferential surface 14A are in non-contact, or a state in which the pressing portion 15A and the inner circumferential surface 14A are in contact in such a manner that the contact pressure of the pressing portion 15A and the inner circumferential surface 14A can be considered to be 0.

[0064] As shown in Figure 11 , the two inclined surfaces that constitute the first follower portion 15B are surfaces that are inclined with respect to the radial direction, and are planar surfaces or curved surfaces that are inclined in such a manner that the smaller the gap between the two inclined surfaces becomes, the closer the gap becomes to the inner circumferential surface 14A. The radial direction refers to a direction that is parallel to the diameter direction of the stationary ring 14. Also, as shown in Figure 6 , Figure 7 , the pressing portion 15A is offset in the radial direction with respect to the second follower portion 15C.

[0065] As shown in Figure 10 , the holding member 16 is provided with the same number of open cams 16A (the oblique portions of Figure 10 ) as the first follower portion 15B. As shown in Figure 11 , the open cams 16A are inclined surfaces that are inclined with respect to the radial direction.As shown, each open cam 16A is composed of two inclined surfaces that clamp the first follower 15B in the circumferential direction. The circumferential direction refers to the direction along the circumference of the fixed ring 14.

[0066] The retaining member 16 is capable of rotating about the rotation center axis Lo within a predetermined angle range relative to the input-side rotating part 11 and the output-side rotating part 12. Therefore, if a driving force is applied to the input-side rotating part 11, the retaining member 16 is subjected to a driving force from the input-side protrusion 11B and rotates in the direction of that driving force.

[0067] If the open cam 16A rotates integrally with the input side protrusion 11B, and the open cam 16A contacts the first follower 15B, then the first follower 15B is subjected to a pressing force F1 from the open cam 16A and generates a force F2 that causes the wedge member 15 to move toward the unlocked position, that is, in the direction away from the inner peripheral surface 14A.

[0068] That is, the first follower 15B is formed as a surface inclined along the circumferential direction, so that when the first follower 15B is subjected to the pressing force F1 from the open cam 16A, it generates a force F2 that displaces the pressing part 15A to the unlocked position.

[0069] like Figure 7 As shown, the second follower 15C is positioned offset from the first follower 15B. Figure 9 As shown, when the reverse rotational force has been input to the output side rotating part 12, the second follower part 15C is subjected to the pressing force F3 from the pressing cam 12C, causing the wedge-shaped part 15 to be displaced to the locked position.

[0070] In addition, such as Figure 7 As shown, in this embodiment, the radius of curvature R1 of the pressing part 15A is greater than the radius of curvature R2 of the second follower part 15C. Furthermore, as... Figure 12 As shown, the retainer 16 has the same number of retaining portions 16B as the wedge-shaped members 15.

[0071] The retaining portion 16B is a part used to maintain the posture of the wedge-shaped member 15. Specifically, the retaining portion 16B is composed of planes provided on both radially sides that clamp the wedge-shaped member 15. These planes are parallel to the radial direction and are parallel to the plane 15D (see reference) provided on the wedge-shaped member 15. Figure 7 The sliding contact surface. In addition, viewed from the circumferential direction, the retaining part 16B clamps the wedge-shaped part 15 from both sides in the circumferential direction.

[0072] <2. Operation and Characteristics of One-Way Couplers>

[0073] For example Figure 8As shown, if a driving force in a rightward direction on paper is input to the input-side rotary portion 11, each input-side protruding portion 11B engages with each output-side protruding portion 12B, and each first follower portion 15B receives a pressing force Fl from each open cam 16A, thereby causing each wedge member 15 to move to the non-locking position. Thus, the driving force is transmitted from the input-side rotary portion 11 to the output-side rotary portion 12.

[0074] Further, for example Figure 9 As shown, if a reverse rotation force in a leftward direction on paper is input to the output-side rotary portion 12, each second follower portion 15C receives a pressing force F3 from each abutting cam 12C, thereby causing each wedge member 15 to move to the locking position. Thus, a frictional force is generated between the inner peripheral surface 14A and each abutting portion 15A, and each abutting portion 15A is pressed into the inner peripheral surface 14A, thereby preventing the reverse rotation force from being transmitted to the input-side rotary portion 11.

[0075] The wedge members 15 are each provided with the first follower portion 15B that causes the wedge member 15 to move to the non-locking position, and the second follower portion 15C that causes the wedge member 15 to move to the locking position. Thus, in the one-way clutch 10, the first follower portion 15B and the second follower portion 15C can each have an appropriate shape.

[0076] In the one-way clutch 10, the posture of the wedge member 15 is held by the holding portion 16B. Thus, even if the reverse rotation force increases, the self-rotation of each wedge member 15 can be suppressed. Thus, the frictional force between the inner peripheral surface 14A and each abutting portion 15A can be reliably ensured, and each abutting portion 15A can be reliably pressed into the inner peripheral surface 14A.

[0077] (Other Embodiments)

[0078] The output-side rotary portion 12 of the above-described embodiment is provided with the insertion hole 12D into which the rotor shaft 3A is inserted. However, the present disclosure is not limited thereto. That is, in the present disclosure, for example, in the case where the rotor shaft 3A is short, the insertion hole 12D is not required.

[0079] In the above-described embodiment, the curvature radius Rl of the abutting portion 15A is larger than the curvature radius R2 of the second follower portion 15C. However, the present disclosure is not limited thereto. That is, the present disclosure can be, for example, a structure in which the curvature radius Rl of the abutting portion 15A and the curvature radius R2 of the second follower portion 15C are the same, or a structure in which the curvature radius Rl of the abutting portion 15A is smaller than the curvature radius R2 of the second follower portion 15C.

[0080] In the above-described embodiments, the technical solution of the present disclosure is applied to a seat for a vehicle or the like. However, the range of application of the technical solution disclosed in the present specification is not limited thereto. That is, the present disclosure can also be applied to a seat used in a vehicle such as a railway vehicle, a ship, and an aircraft, and a fixed seat used in a theater or a home or the like.

[0081] Further, the present disclosure is not limited to the above-described embodiments as long as the gist of the invention described in the above-described embodiments is satisfied. Therefore, it can be a structure in which at least two of the above-described embodiments are combined, or a structure in which any one of the constituent elements illustrated in the above-described embodiments is omitted, or a structure in which any one of the constituent elements described with reference to the reference numerals in the above-described embodiments is omitted.

Claims

1. A one-way clutch having an input-side rotary member configured to be inputted with a driving force and an output-side rotary member configured to output the driving force, the one-way clutch transmitting the driving force from the input-side rotary member to the output-side rotary member and preventing the driving force that has been inputted to the output-side rotary member from being transmitted to the input-side rotary member, the one-way clutch characterized by comprising: a transmission portion including an input-side protrusion portion that rotates integrally with the input-side rotary member and an output-side protrusion portion that rotates integrally with the output-side rotary member, the transmission portion being configured to transmit the driving force from the input-side rotary member to the output-side rotary member by engagement of the input-side protrusion portion with the output-side protrusion portion when the driving force has been inputted to the input-side rotary member; a fixed ring held in a state of being unable to rotate; a wedge-shaped member having a pressing portion configured to press against a circumferential surface of the fixed ring and being composed of a non-rotating body, the wedge-shaped member being displaceable between a locked position at which the pressing portion presses against the circumferential surface and an unlocked position at which the pressing is released; an open cam integrally rotatable with the input-side rotary member; a first follower provided on the wedge-shaped member and pressed by the open cam to displace the wedge-shaped member to the unlocked position when the driving force has been inputted to the input-side rotary member; a pressing cam integrally rotatable with the output-side rotary member; and a second follower provided at a position of the wedge-shaped member that is offset from the first follower and pressed by the pressing cam to displace the wedge-shaped member to the locked position when the driving force has been inputted to the output-side rotary member, wherein, when a diameter direction of the fixed ring is taken as a radial direction, the pressing portion is offset in the radial direction with respect to the second follower, and a radius of curvature of the pressing portion is larger than a radius of curvature of the second follower, the one-way clutch comprises a holder having a holding portion that holds a posture of the wedge-shaped member by sandwiching the wedge-shaped member from both sides in a circumferential direction of the fixed ring when the circumferential direction of the fixed ring is taken as a circumferential direction, the open cam is provided on the holder, and the holder is pressed by the input-side protrusion portion when the driving force has been inputted to the input-side rotary member, whereby the open cam presses the first follower.

2. The one-way clutch according to claim 1, wherein the output-side protrusion portion and the pressing cam are formed integrally with the output-side rotary member. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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