One-way joint

Abstract

To disclose one embodiment of a one-way joint using a wedge member which is constituted of non-rolling bodies.SOLUTION: A one-way joint comprises a wedge member 15 having a pressure-contact part 15A pressure-contacting with an internal peripheral face 14A of an immovable ring, and the wedge member 15 comprises: a first follower part 15B for receiving a pressing force from a release cam 16A when a drive force is inputted into an input-side protrusion 11B, and displacing the wedge member 15 to a non-lock position; and a second follower part 15C for receiving a pressing force from a pressure-contact cam 12C when the drive force is inputted into an output-side rotation part 12, and displacing the wedge member 15 to a lock position, where a second follower part 15C is arranged at a position which is displaced from the first follower part 15B.SELECTED DRAWING: Figure 11

Description

[Technical field]

[0001] The present disclosure relates to a one-way joint capable of preventing a driving force input to an output shaft from being transmitted to an input shaft. [Background technology]

[0002] For example, Patent Document 1 describes a clutch using steel balls as a one-way joint. Specifically, in this clutch, when a driving force is input to a worm shaft, the steel balls are pressed against a cylindrical clutch housing to stop the rotation of the worm shaft, thereby blocking the transmission of the driving force from the worm shaft to the rotating shaft. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2001-28863 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the invention described in Patent Document 1, the steel balls are pressed against the clutch housing, making it difficult to change the contact surface pressure according to specifications.

[0005] In view of the above, the present disclosure discloses an example of a one-way joint that uses a wedge member that is configured with a non-rolling element. [Means for solving the problem]

[0006] A one-way joint that has an input side rotating part (11) to which a driving force is input and an output side rotating part (12) that outputs the driving force, transmits the driving force from the input side rotating part (11) to the output side rotating part (12) and prevents the driving force input to the output side rotating part (12) from being transmitted to the input side rotating part (11), desirably has at least one of the following constituent features, for example.

[0007] That is, the constituent features include a transmission section (13) having an input side projection (11B) that rotates integrally with the input side rotating section (11) and an output side projection (12B) that rotates integrally with the output side rotating section (12), and when a driving force is input to the input side rotating section (11), the input side projection (11B) and the output side projection (12B) engage with each other, thereby transmitting the driving force from the input side rotating section (11) to the output side rotating section (12); a stationary ring (14) that is held in an unrotatable state; and a wedge member (15) having a pressure contact section (15A) that is in pressure contact with the circumferential surface of the stationary ring (14) and that is constituted by a non-rolling body, and which is displaceable between a locked position where the pressure contact section (15A) is in pressure contact with the circumferential surface and an unlocked position where the pressure contact is released. the wedge member (15) being capable of being locked and unlocked, an opening cam (16A) rotating integrally with the input side rotating portion (11), a first follower portion (15B) provided on the wedge member (15), the first follower portion (15B) receiving a pressing force from the opening cam (16A) when a driving force is input to the input side rotating portion (11) and displacing the wedge member (15) to an unlocked position, a pressure cam (12C) rotating integrally with the output side rotating portion (12), and a second follower portion (15C) provided on the wedge member (15) at a position offset from the first follower portion (15B), the second follower portion (15C) receiving a pressing force from the pressure cam (12C) when a driving force is input to the output side rotating portion (12) and displacing the wedge member (15) to a locked position.

[0008] As a result, in this one-way joint, when a driving force is input to the input side rotating part (11), the wedge member (15) is in the locked position and the wedge member (15) is pressed against the stationary ring (14), thereby cutting off the transmission of the driving force from the output side rotating part (12) to the input side rotating part (11).

[0009] The wedge member (15) is provided with a first follower portion (15B) that displaces the wedge member (15) to the unlocked position, and a second follower portion (15C) that displaces the wedge member (15) to the locked position. This allows the first follower portion (15B) and the second follower portion (15C) to have shapes suited to each other in the one-way joint.

[0010] The one-way joint may have the following configuration, for example.

[0011] That is, when the diameter direction of the stationary ring 14 is taken as the radial direction, the pressure contact portion 15A is deviated from the second follower portion 15C in the radial direction, and further, it is desirable that the radius of curvature of the pressure contact portion 15A is larger than the radius of curvature of the second follower portion 15C. This prevents the contact surface pressure of the pressure contact portion 15A from becoming excessively large.

[0012] It is desirable to provide a retainer 16 having holding portions 16B that hold the wedge member 15 in position when the circumferential direction of the stationary ring 14 is taken as the circumferential direction. This can prevent the wedge member 15 from being in an inappropriate position when it is pressed against the stationary ring 14.

[0013] It is preferable that the opening cam (16A) is provided on the retainer (16), and further, when a driving force is input to the input side rotating part (11), the retainer (16) is pressed by the input side protrusion (11B), so that the opening cam (16A) presses the first follower part (15B). Further, it is preferable that the output side protrusion (12B) and the pressure contact cam (12C) are integrated with the output side rotating part (12).

[0014] Incidentally, the symbols in the above parentheses are examples showing the corresponding relationship with the specific configurations etc. described in the embodiments described below, and the present disclosure is not limited to the specific configurations etc. shown by the symbols in the above parentheses. [Brief description of the drawings]

[0015] [Figure 1] FIG. 2 is a diagram showing an actuator according to the first embodiment. [Diagram 2] FIG. 2 is an exploded view of the actuator according to the first embodiment. [Diagram 3] FIG. 2 is a diagram showing an input side rotating portion according to the first embodiment. [Figure 4] FIG. 2 is a diagram showing an output side rotating portion according to the first embodiment. [Diagram 5] FIG. 1 is a diagram showing a one-way joint according to a first embodiment. [Figure 6] 4A and 4B are diagrams illustrating an output side rotating portion and a wedge member according to the first embodiment. [Figure 7] 3A and 3B are diagrams showing a wedge member according to the first embodiment. [Figure 8] FIG. 2 is a diagram showing the structure of the one-way joint according to the first embodiment, illustrating a state in which a driving force is input to an input side rotating part. [Figure 9] FIG. 2 is a diagram showing the structure of the one-way joint according to the first embodiment, illustrating a state in which a reverse rotation force is input to an output side rotating part. [Figure 10] FIG. 2 is a diagram showing a retainer according to the first embodiment. [Figure 11] FIG. 2 is a diagram showing the structure of the one-way joint according to the first embodiment, illustrating a state in which a driving force is input to an input side rotating part. [Figure 12] 1A and 1B are diagrams showing a structure of a one-way joint according to a first embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] The following "embodiment of the invention" shows an example of an embodiment that falls within the technical scope of the present disclosure. In other words, the invention-specific matters described in the claims are not limited to the specific configurations and structures shown in the following embodiment.

[0017] This embodiment is an example in which a one-way joint according to the present disclosure is applied to a seat (hereinafter referred to as a vehicle seat) mounted on a vehicle such as a car. Arrows and diagonal lines indicating directions are provided in each figure to facilitate understanding of the relationships between the figures and the shapes of components or parts.

[0018] Therefore, the one-way joint is not limited to the directions shown in the drawings. The directions shown in the drawings are directions in a state in which the vehicle seat according to the present embodiment is assembled to a vehicle. The drawings with diagonal lines do not necessarily show cross-sectional views.

[0019] At least one of each of the members or parts described with a reference number is provided, unless otherwise specified by "one". In other words, unless otherwise specified by "one", two or more of the member may be provided. The one-way joint shown in the present disclosure includes at least the components such as the members or parts described with a reference number, as well as the structural parts shown in the drawings.

[0020] (First embodiment) <1. Overview of one-way joints> This embodiment is an example in which a one-way joint 10 (see FIG. 2) according to this embodiment is applied to an actuator 1 (see FIG. 1) used in a vehicle seat. The actuator 1 generates a driving force that displaces a movable part of the vehicle seat.

[0021] The movable parts of a vehicle seat include, for example, a lifter arm that moves the seat cushion up and down, a tilt arm that moves the front end of the seat cushion up and down, and a recliner that displaces the seat back.

[0022] <1.1 Schematic configuration of the actuator> 2, the actuator 1 includes an electric motor 3, a one-way joint 10, and a housing 5. The electric motor 3 generates a driving force. The housing 5 accommodates the electric motor 3 and the one-way joint 10.

[0023] 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 by sandwiching the electric motor 3. The first housing 5A and the second housing 5B are fastened to each other by fasteners (not shown) such as screws.

[0024] The first housing 5A is provided with at least one (in this embodiment, a plurality of) fixing portions 5C. Each fixing portion 5C is a portion for fixing the actuator 1 to a non-movable portion such as a seat frame (not shown).

[0025] <1.2 Details of one-way joints> The one-way joint 10 is a joint that can perform a transmission function of transmitting the driving force of the electric motor 3 (hereinafter simply referred to as the driving force) to a movable part of the vehicle seat (hereinafter simply referred to as the movable part), and a blocking function of blocking the transmission of rotational force (hereinafter referred to as the reverse force) from the movable part to the electric motor 3.

[0026] 2, the one-way joint 10 at least includes an input side rotating portion 11, an output side rotating portion 12, a transmission portion 13, a stationary ring 14, a wedge member 15, and a retainer 16. In this embodiment, the stationary ring 14 is integrated with the first housing 5A.

[0027] <Input side rotating part> The input side rotating part 11 is a member to which the driving force of the electric motor 3 is input. As shown in Fig. 3, the input side rotating part 11 is a drive ring having a joint part 11A and at least one (in this embodiment, multiple) input side protrusion part 11B.

[0028] The joint portion 11A is a portion that is connected to a rotor shaft 3A (see FIG. 2) of the electric motor 3 and rotates integrally with the rotor shaft 3A. Specifically, the joint portion 11A is provided with an engagement hole 11C into which the rotor shaft 3A is inserted.

[0029] An engagement surface 11D that engages with an engagement surface (not shown) provided on the rotor shaft 3A is provided on the inner circumferential surface of the engagement hole 11C. Therefore, the engagement hole 11C according to this embodiment has a substantially D-shaped hole shape.

[0030] Each input-side protrusion 11B is a protrusion that revolves around the rotor shaft 3A as the center of revolution. Specifically, each input-side protrusion 11B is provided on the outer periphery of the joint portion 11A that is configured in a substantially disk shape, and is a portion that protrudes from the joint portion 11A in a direction parallel to the rotor shaft 3A.

[0031] Each input side protrusion 11B is configured as an integral part of the joint portion 11A. Therefore, each input side protrusion 11B revolves integrally with the rotor shaft 3A around the rotor shaft 3A as the center of revolution.

[0032] <Output rotating part> The output side rotating part 12 is a member that transmits the driving force input to the input side rotating part 11 to a movable part. As shown in Fig. 4, the output side rotating part 12 has an output shaft 12A, at least one (in this embodiment, multiple) output side protrusions 12B, and a pressure cam 12C.

[0033] The output shaft 12A engages with the movable portion to supply a driving force to the movable portion. Each output side protrusion 12B revolves around the output shaft 12A as the center of revolution, and protrudes toward the input side protrusion 11B in parallel with the axial direction of the output shaft 12A.

[0034] The pressure cam 12C is a part that constitutes a pressing portion for pressing the wedge member 15. The output shaft 12A, each output side protrusion 12B, and the pressure cam 12C are integrated together. Therefore, when each output side protrusion 12B revolves, the output shaft 12A rotates. Conversely, when the output shaft 12A rotates, the pressure cam 12C rotates around the output shaft 12A.

[0035] The rotor shaft 3A, the input side rotating part 11, and the output side rotating part 12 are arranged coaxially so that their respective rotation central axes Lo coincide with each other (see FIG. 2). Incidentally, the output side rotating part 12 is provided with an insertion hole 12D (see FIG. 4) into which the rotor shaft 3A is inserted.

[0036] The insertion hole 12D is not provided with an engagement surface that engages with the engagement surface of the rotor shaft 3A, so that the driving force is not directly transmitted between the rotor shaft 3A and the output side rotating portion 12.

[0037] <Transmission section> The transmission part 13 is configured to have an input side protrusion 11B and an output side protrusion 12B, etc. When a driving force is input to the input side rotating part 11, the input side protrusion 11B and the output side protrusion 12B come into contact with each other and engage with each other (see FIG. 8). Therefore, the driving force input to the input side rotating part 11 is transmitted from the input side rotating part 11 to the output side rotating part 12.

[0038] In this embodiment, the contact surfaces of the input side protrusion 11B and the output side protrusion 12B are set so that a virtual tangent L1 (see Figure 8) at the contact point between the input side protrusion 11B and the output side protrusion 12B passes through the rotational center axis Lo of the rotor shaft 3A.

[0039] <Immovable ring> The stationary ring 14 is an annular member that is held in a non-rotatable state (see FIG. 2). In this embodiment, the input side protrusion 11B, the output side protrusion 12B, the wedge member 15, and the retainer 16 are housed in the stationary ring 14 (see FIG. 5).

[0040] <Wedge members and retainers, etc.> As shown in Fig. 6, the one-way joint 10 according to this embodiment includes a plurality of wedge members 15. Each wedge member 15 has a congruent shape. The first wedge member 15 and the second wedge member 15 are disposed at positions rotationally symmetrical with respect to the central axis of rotation Lo.

[0041] 7, each wedge member 15 is a non-rolling body having at least a pressure contact portion 15A, a first follower portion 15B, a second follower portion 15C, etc. In other words, each wedge member 15 is made of a non-spherical or non-cylindrical member.

[0042] Each of the pressure contact portions 15A is a curved surface that is in pressure contact with the circumferential surface of the stationary ring 14 when the blocking function is performed. Note that the pressure contact portions 15A according to this embodiment are in pressure contact with the inner circumferential surface 14A (see FIG. 5). Each of the wedge members 15 is displaced between a locked position (see FIG. 9) where the pressure contact portion 15A is in pressure contact with the inner circumferential surface 14A and an unlocked position (see FIG. 8) where the pressure contact is released.

[0043] In addition, "pressure is released" refers to, for example, a state in which pressurized portion 15A and inner surface 14A are not in contact with each other, or a state in which pressurized portion 15A and inner surface 14A are in contact with each other to such an extent that the contact surface pressure between pressurized portion 15A and inner surface 14A can be regarded as zero.

[0044] The two inclined surfaces constituting the first follower part 15B are plane or curved surfaces inclined with respect to the radial direction, as shown in Fig. 11, so that the gap between the two inclined surfaces becomes smaller as they approach the inner peripheral surface 14A. Note that the radial direction refers to a direction parallel to the diameter direction of the stationary ring 14.

[0045] As shown in Fig. 10, the retainer 16 is provided with the same number of releasing cams 16A (hatched areas in Fig. 10) as the first follower portions 15B. As shown in Fig. 11, each releasing cam 16A is composed of two inclined surfaces that sandwich the first follower portion 15B in the circumferential direction. The circumferential direction is a direction parallel to the circumferential direction of the stationary ring 14.

[0046] The retainer 16 is rotatable within a predetermined angle range around the rotation center axis Lo relative to the input side rotating portion 11 and the output side rotating portion 12. Therefore, when a driving force acts on the input side rotating portion 11, the retainer 16 receives the driving force from the input side protrusion 11B and rotates in the direction of the driving force.

[0047] Then, when the opening cam 16A rotates integrally with the input side protrusion 11B and the opening cam 16A comes into contact with the first follower portion 15B, the first follower portion 15B receives a pressing force F1 from the opening cam 16A and generates a force F2 that displaces the wedge member 15 to the unlocked position, i.e., in a direction away from the inner surface 14A.

[0048] In other words, the first follower portion 15B is configured with a surface inclined in the circumferential direction so as to generate a force F2 that displaces the pressure contact portion 15A to the unlocked position when it receives a pressing force F1 from the opening cam 16A.

[0049] The second follower portion 15C is provided at a position shifted from the first follower portion 15B as shown in Fig. 7. When a reverse force is input to the output side rotation portion 12, the second follower portion 15C receives a pressing force F3 from the pressing cam 12C and displaces the wedge member 15 to the lock position as shown in Fig. 9.

[0050] In this embodiment, the radius of curvature R1 of the pressure contact portion 15A is larger than the radius of curvature R2 of the second follower portion 15C as shown in Fig. 7. Also, the retainer 16 is provided with the same number of holding portions 16B as the wedge members 15 as shown in Fig. 12.

[0051] Holding portion 16B is a portion for holding the position of wedge member 15. Specifically, holding portion 16B is configured by flat surfaces provided on both radial sides of wedge member 15. These flat surfaces are parallel to the radial direction and come into sliding contact with flat surface 15D (see FIG. 7) provided on wedge member 15.

[0052] <2. Operation and features of one-way joints> 8, the input side protrusions 11B and the output side protrusions 12B engage with each other, and the first follower portions 15B receive a pressing force F1 from the release cams 16A, displacing the wedge members 15 to the unlocked position. This transmits the driving force from the input side rotation portion 11 to the output side rotation portion 12.

[0053] 9, for example, when a reverse rotation force in the counterclockwise direction on the page is input to the output side rotation part 12, each second follower part 15C receives a pressing force F3 from each pressure contact cam 12C and displaces each wedge member 15 to the lock position. As a result, the friction force between the inner circumferential surface 14A and each pressure contact part 15A and each pressure contact part 15A bites into the inner circumferential surface 14A prevent the reverse rotation force from being transmitted to the input side rotation part 11.

[0054] The wedge member 15 is provided with a first follower portion 15B that displaces the wedge member 15 to the unlocked position, and a second follower portion 15C that displaces the wedge member 15 to the locked position. This allows the first follower portion 15B and the second follower portion 15C in the one-way joint 10 to have shapes suited to each of them.

[0055] In the one-way joint 10, the position of the wedge member 15 is held by the holding portion 16B. This prevents each wedge member 15 from rotating on its axis even if the reversing force becomes large. This ensures a frictional force between the inner circumferential surface 14A and each of the pressure contact portions 15A, and also allows each of the pressure contact portions 15A to be securely engaged with the inner circumferential surface 14A.

[0056] (Other embodiments) The output side rotating portion 12 according to the embodiment described above is provided with the insertion hole 12D into which the rotor shaft 3A is inserted. However, the present disclosure is not limited to this. That is, in the present disclosure, for example, when the rotor shaft 3A is short, the insertion hole 12D is not necessary.

[0057] In the above embodiment, the radius of curvature R1 of the pressure-contact portion 15A is larger than the radius of curvature R2 of the second follower portion 15C. However, the present disclosure is not limited to this. That is, the present disclosure may be, for example, a configuration in which the radius of curvature R1 of the pressure-contact portion 15A and the radius of curvature R2 of the second follower portion 15C are the same, or a configuration in which the radius of curvature R1 of the pressure-contact portion 15A is smaller than the radius of curvature R2 of the second follower portion 15C.

[0058] In the above embodiment, the vehicle seat according to the present disclosure is applied to a vehicle. However, the application of the invention disclosed in this specification is not limited thereto. That is, the disclosure can be applied to, for example, seats used in vehicles such as railroad cars, ships, and aircraft, as well as stationary seats used in theaters, homes, and the like.

[0059] Furthermore, the present disclosure is not limited to the above-mentioned embodiments as long as it is consistent with the gist of the disclosure described in the above-mentioned embodiments. Therefore, the present disclosure may be a configuration in which at least two of the above-mentioned embodiments are combined, or a configuration in which any of the components illustrated or the components described with reference numerals in the above-mentioned embodiments are eliminated. [Explanation of symbols]

[0060] 1... Actuator 3... Electric motor 3A... Rotor shaft 5... Housing 5C... Fixing part 10... One-way joint 11... Input side rotating portion 11A... Joint portion 11C... Engagement hole 11D: Engagement surface 11B: Input side protrusion 12: Output side rotation portion 12A... Output shaft 12B... Output side protrusion 12C... Pressure cam 12D... Insertion hole 13... Transmission part 14... Fixed ring 14A: Inner peripheral surface 15: Wedge member 15A: Pressure-welded portion 15B… First follower part 15C… Second follower part 16... Retainer 16A... Release cam 16B... Holding portion

Claims

1. A one-way joint including an input side rotating part to which a driving force is input and an output side rotating part to which the driving force is output, the one-way joint transmitting a driving force from the input side rotating part to the output side rotating part and preventing the driving force input to the output side rotating part from being transmitted to the input side rotating part, a transmission section having an input side protrusion which rotates integrally with the input side rotating section and an output side protrusion which rotates integrally with the output side rotating section, and which transmits the driving force from the input side rotating section to the output side rotating section when a driving force is input to the input side rotating section by engaging the input side protrusion with the output side protrusion; a stationary ring that is held in a non-rotatable state; a wedge member having a pressure contact portion that is in pressure contact with a circumferential surface of the stationary ring and that is constituted by a non-rolling body, the wedge member being displaceable between a locked position where the pressure contact portion is in pressure contact with the circumferential surface and an unlocked position where the pressure contact is released; an opening cam that rotates integrally with the input side rotating portion; a first follower portion provided on the wedge member, the first follower portion receiving a pressing force from the opening cam when a driving force is input to the input side rotating portion to displace the wedge member to the unlocked position; a pressure contact cam that rotates integrally with the output side rotating portion; a second follower portion provided in the wedge member at a position offset from the first follower portion, the second follower portion receiving a pressing force from the pressure cam when a driving force is input to the output side rotating portion to displace the wedge member to the lock position, When a diameter direction of the stationary ring is defined as a radial direction, the pressure contact portion is shifted in the radial direction with respect to the second follower portion, a radius of curvature of the pressure contact portion is larger than a radius of curvature of the second follower portion, and a retainer having holding portions that hold the wedge member from both sides in the circumferential direction when the circumferential direction of the stationary ring is defined as the circumferential direction, and The opening cam is provided on the retainer, Furthermore, when a driving force is input to the input side rotation portion, the retainer is pressed by the input side protrusion, causing the opening cam to press the first follower portion.

2. 2. A one-way joint according to claim 1, wherein the output side projection and the pressure cam are integrated with the output side rotating portion.

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