Rotary connector device

Abstract

To provide a rotary connector device capable of suppressing floating of a flat cable while achieving compactification.SOLUTION: A rotary connector device 1 comprises: a rotator 2 that includes a cylinder part 21 and can be rotated; a stator 3 that includes an outer wall part 31 and a narrowing outer wall part 32 oppositely arranged on an outer surface of the cylinder part, and of which an opposite distance between the cylinder part and the narrowing outer wall part is shorter than an opposite distance between the cylinder part and the outer wall part; one or more flat cables that are housed in a housing space between the rotator and the stator, are wound in one direction to the cylinder part of the rotator and wound in the other direction to the outer wall part of the stator, and include an inversion part in which a rotational direction that it is wound in one direction and a rotational direction that it is wound in the other direction are inverted; and a cable pressing body 5 that includes one moving pressing part provided to be movable on the inner side of the inversion part of the flat cable, in which the moving pressing part moves in the housing space while pressing, to the cylinder part, a portion in the flat cable that is wound in one direction to the cylinder part of the rotator in accordance with rotation of the rotator.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a rotary connector device. [Background technology]

[0002] Steering wheels mounted on automobiles have traditionally been required to rotate approximately 2.5 times clockwise and 2.5 times counterclockwise from a neutral position, and accordingly, the rotary connector device connecting the steering wheel to the vehicle has also been required to rotate approximately 2.5 times clockwise and 2.5 times counterclockwise from a neutral position.

[0003] Meanwhile, steer-by-wire, a system that controls tire angle using electrical signals without mechanically connecting the steering wheel and tires, has been attracting attention in recent years. In steer-by-wire, the number of rotations required for the steering wheel is approximately 0.5 to 0.8 rotations clockwise and counterclockwise from the neutral position. Therefore, unlike rotary connector devices used in systems that mechanically connect the steering wheel and tires, a rotary connector device that can accommodate the reduced number of steering rotations required for steer-by-wire is required.

[0004] For example, Patent Document 1 describes a relay device that includes a first flat cable, a second flat cable, a moving member, a first contact member, and a second contact member, which are arranged in a space formed between a fixed member and a rotating member. In the relay device of Patent Document 1, the first flat cable is wound from the inner periphery of the forward-direction space to the outer periphery of the reverse-direction space, with a first reversal section where the winding direction is reversed as a boundary, and the second flat cable is wound from the inner periphery of the reverse-direction space to the outer periphery of the forward-direction space, with a second reversal section where the winding direction is reversed as a boundary. In addition, the moving member moves through the space in response to rotation of the rotating member. The first contact member is arranged on the moving member, and when the rotating member rotates in the reverse direction, the first flat cable is wound around the inner periphery, causing contact with the first reversal section, thereby moving the moving member in the reverse direction. In addition, the second contact member is disposed on the moving member, and when the rotating member rotates in the forward direction, the second flat cable is wound around the inner circumference, causing contact with the second inverted portion, thereby moving the moving member in the forward direction.

[0005] However, in the above-mentioned prior art, including Patent Document 1, the width of the annular storage space for storing the flat cable inside the housing of the rotary connector is uniform or approximately uniform around the entire circumference, allowing the flat cable to rotate around the entire circumference. Therefore, a certain outer diameter space is required for the rotation axis of the rotor that constitutes the rotary connector, and the design flexibility of the rotary connector is low. Furthermore, if the design of the configuration related to the storage space is changed, it is also necessary to consider a mechanism to prevent the portion of the flat cable wound around the rotor from floating up from the rotor (hereinafter referred to as flat cable floating). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent Publication No. 2021-190324 Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present disclosure is to provide a rotary connector device that can be made compact and that can prevent the flat cable from floating. [Means for solving the problem]

[0008] [1] A rotary connector device comprising: a rotating body having a cylindrical portion and being rotatable; a fixed body having an outer wall portion and a narrowed outer wall portion arranged opposite the outer surface of the cylindrical portion, the facing distance between the cylindrical portion and the narrowed outer wall portion being shorter than the facing distance between the cylindrical portion and the outer wall portion; one or more flat cables accommodated in an accommodation space between the rotating body and the fixed body, wound in one direction around the cylindrical portion of the rotating body and in the other direction around the outer wall portion of the fixed body, and having a reversing portion where the rotation direction of the flat cable is reversed from the rotation direction of the flat cable in one direction; and a cable retainer having a movable retainer provided inside the reversing portion of the flat cable, which moves within the accommodation space while pressing the portion of the flat cable wound in one direction around the cylindrical portion of the rotating body against the cylindrical portion of the rotating body in accordance with the rotation of the rotating body. [2] The rotating body further has a plurality of inner teeth provided around the circumferential direction of the cylindrical portion on one end side of the cylindrical portion, the fixed body further has a plurality of outer teeth provided around the circumferential direction of the outer wall portion on one end side of the outer wall portion, and the cable holder further has a plurality of teeth provided around the circumferential direction of the moving holder on one end side of the moving holder, and as the rotating body rotates, the teeth of the cable holder rotate while meshing with the inner teeth of the rotating body and the outer teeth of the fixed body, thereby moving the moving holder of the cable holder. A rotary connector device as described in [1] above. [3] The cable holder further has a ring portion that supports the moving holder, abuts at least a portion of which is against the edge of the flat cable, and rotates in response to the rotation of the rotating body, and in response to the rotation of the rotating body, the ring portion of the cable holder rotates and the moving holder of the cable holder moves, as described in [1] above. [4] A rotary connector device according to any one of [1] to [3] above, wherein the inversion portion moves in a moving space where the cylindrical portion of the rotating body and the outer wall portion of the fixed body face each other in response to the rotation of the rotating body, and does not move in a narrowed space where the cylindrical portion of the rotating body and the narrowed outer wall portion of the fixed body face each other. [5] The rotary connector device according to any one of the above [1] to [4], wherein the flat cable is not wound around the narrow outer wall portion. [6] A rotary connector device described in any one of [1] to [5] above, wherein the moving holding portion of the cable holding body does not move in a confined space where the cylindrical portion of the rotating body and the confined outer wall portion of the fixed body face each other. [7] A rotary connector device according to any one of [1] to [6] above, further comprising a dummy cable accommodated in the accommodation space between the rotating body and the fixed body, wound in one direction around the cylindrical portion of the rotating body from the outside of the flat cable, and wound in the other direction around the outer wall portion of the fixed body. [Effects of the Invention]

[0009] According to the present disclosure, it is possible to provide a rotary connector device that can be made compact and that can prevent the flat cable from floating. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a partially transparent plan view showing an example of a rotary connector device according to a first embodiment, as viewed from one side. [Figure 2] FIG. 2 is a partially see-through plan view showing an example of the rotary connector device of the first embodiment as seen from the other side. [Figure 3] FIG. 3 is a partially transparent plan view showing the state of the rotary connector device of FIG. 2 when the steering wheel is rotated 250 degrees counterclockwise. [Figure 4] FIG. 4 is a partially transparent plan view showing the state of the rotary connector device of FIG. 2 when the steering wheel is rotated 250 degrees clockwise. [Figure 5] FIG. 5 is a partially transparent plan view showing an example of a rotary connector device according to the second embodiment as viewed from one side. [Figure 6] FIG. 6 is a partially see-through plan view showing an example of the rotary connector device of the second embodiment as seen from the other side. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, a detailed description will be given based on an embodiment.

[0012] As a result of extensive research, the inventors discovered that by making part of the storage space that houses the flat cable a narrow space and arranging the moving holding portion of the cable holder at a predetermined position relative to the flat cable, the rotary connector device can be made more compact and the floating of the flat cable within the rotary connector device can be suppressed, and the present disclosure was completed based on this finding.

[0013] The rotary connector device of the embodiment comprises a rotating body having a cylindrical portion and being rotatable; a fixed body having an outer wall portion and a narrowing outer wall portion arranged opposite the outer surface of the cylindrical portion, with the opposing distance between the cylindrical portion and the narrowing outer wall portion being shorter than the opposing distance between the cylindrical portion and the outer wall portion; one or more flat cables accommodated in the accommodation space between the rotating bodies and the fixed body, wound in one direction around the cylindrical portion of the rotating body and in the other direction around the outer wall portion of the fixed body, with an inversion portion where the rotation direction of the flat cable wound in one direction and the rotation direction of the flat cable wound in the other direction are reversed; and a cable holder having one movable holder arranged inside the inversion portion of the flat cable, which moves within the accommodation space while pressing the portion of the flat cable wound in one direction around the cylindrical portion of the rotating body against the cylindrical portion of the rotating body in accordance with the rotation of the rotating body.

[0014] (First embodiment) Fig. 1 is a partially transparent plan view showing an example of a rotary connector device according to a first embodiment as viewed from one side. Fig. 2 is a partially transparent plan view showing an example of a rotary connector device according to a first embodiment as viewed from the other side, in a neutral position. Fig. 3 is a partially transparent plan view showing a state of the rotary connector device of Fig. 2 when a steering wheel (not shown) has been rotated 250 degrees counterclockwise. Fig. 4 is a partially transparent plan view showing a state of the rotary connector device of Fig. 2 when the steering wheel has been rotated 250 degrees clockwise.

[0015] For convenience, Figures 1 to 4 and the following figures show the top and bottom plates, which are connected perpendicularly to the cylindrical portion 21 of the rotating body 2 and the outer wall portion 31 and narrowed outer wall portion 32 of the fixed body 3, respectively, and which form the storage space S together with the rotating body 2 and the fixed body 3, in a transparent state.

[0016] As shown in Figures 1 and 2, the rotary connector device 1 of the first embodiment includes a rotating body 2, a fixed body 3, one or more flat cables 4, and a cable presser 5. The rotary connector device 1 is mounted on an automobile and electrically connects an electronic device (not shown) provided on the rotating body 2 side with an electronic device (not shown) provided on the fixed body 3 side. The rotating body 2 rotates in response to rotation of a steering wheel (not shown), while the fixed body 3 does not rotate in response to rotation of the steering wheel. The steering wheel is mounted rotatably relative to the vehicle (not shown).

[0017] The rotating body 2 constituting the rotary connector device 1 has a cylindrical portion 21, and is rotatably attached inside the fixed body 3. The cylindrical portion 21 forms the inner side wall of the rotary connector device 1.

[0018] A steering shaft (not shown) connected to a steering wheel (not shown) is inserted inside the cylindrical portion 21. As the steering wheel rotates, the steering shaft rotates around a rotation axis O, and as the steering shaft rotates, the rotating body 2 rotates around the rotation axis O relative to the fixed body 3. The rotating body 2 rotates less than one rotation, preferably about 0.5 to 0.8 rotations, clockwise and counterclockwise from the neutral position. Even when the steering shaft rotates, the fixed body 3 does not rotate.

[0019] 1 , the rotating body 2 further has a plurality of internal teeth 22 provided on one end side of the cylindrical portion 21 around the entire circumferential direction of the cylindrical portion 21. The internal teeth 22 are provided on the outer peripheral surface side of the cylindrical portion 21. The manner in which the internal teeth 22 provided on one end side of the cylindrical portion 21 are installed on the cylindrical portion 21 is not particularly limited, and the internal teeth 22 may be provided directly on the outer peripheral surface of one end of the cylindrical portion 21, or may be provided by connecting a cylindrical connecting portion (not shown) having the internal teeth 22 on its outer peripheral surface to one end of the cylindrical portion 21.

[0020] The fixed body 3 has an outer wall portion 31 and a narrowed outer wall portion 32. The outer wall portion 31 and the narrowed outer wall portion 32 each extend circumferentially around the cylindrical portion 21 of the rotating body 2 and are disposed opposite to the outer surface of the cylindrical portion 21. The outer wall portion 31 and the narrowed outer wall portion 32 form outer side walls of the rotary connector device 1.

[0021] As shown in FIG. 2, the opposing distance L2 between the outer surface of the cylindrical portion 21 and the inner surface of the narrowed outer wall portion 32 (hereinafter also referred to as the second opposing distance L2) is shorter than the opposing distance L1 between the outer surface of the cylindrical portion 21 and the inner surface of the outer wall portion 31 (hereinafter also referred to as the first opposing distance L1). In the storage space S, the region where the outer surface of the cylindrical portion 21 and the inner surface of the outer wall portion 31 oppose each other is a non-annular movement space S1, and the region where the outer surface of the cylindrical portion 21 and the inner surface of the narrowed outer wall portion 32 oppose each other is a non-annular narrowed space S2. For example, as shown in FIG. 2, the movement space S1 is arc-shaped, and the narrowed space S2 is arc-shaped. Because the second opposing distance L2 is shorter than the first opposing distance L1, the radial length of the narrowed space S2 about the central axis O is shorter than the radial length of the movement space S1. In other words, the width of the narrowed space S2 is smaller than the width of the movement space S1.

[0022] Here, an example is shown in which the outer wall portion 31 and the narrowed outer wall portion 32 are connected via two flat-plate-shaped connecting portions 33, but the connecting state between the outer wall portion 31 and the narrowed outer wall portion 32 is not particularly limited. For example, the connecting portions 33 may be curved plates, or the outer wall portion 31 and the narrowed outer wall portion 32 may be directly connected without the connecting portions 33.

[0023] Furthermore, in conventional rotary connector devices, the rotor rotates at least one revolution in both the clockwise and counterclockwise directions, requiring the width of the annular housing space to be uniform or approximately uniform around the entire circumference to allow components such as the inverted portion of the flat cable to move around the entire circumference of the housing space. In contrast, in the rotary connector device 1, the rotor 2 rotates less than one revolution in both the clockwise and counterclockwise directions, i.e., not more than one revolution. Therefore, components such as the inverted portion 41 of the flat cable 4 do not move around the entire circumference of the housing space S, but move within a portion of the housing space S, i.e., the movement space S1. In the region of the housing space S where components such as the inverted portion 41 of the flat cable 4 do not move, a width equivalent to the movement space S1 is not required. Therefore, the fixed body 3 can have a narrow outer wall portion 32 for forming a narrow space S2 narrower than the movement space S1. As a result, the rotary connector device 1 can be made more compact than conventional rotary connector devices. When a conventional rotary connector device is mounted on an automobile, a certain amount of space is required around the entire circumference of the center of rotation of the rotor, but the rotary connector device 1 can be mounted even if there is no space in a certain direction, for example, above the center of rotation. In this way, the degree of freedom in designing the rotary connector device 1 is improved.

[0024] 1 , the fixed body 3 further has a plurality of outer teeth 34 provided on one end side of the outer wall portion 31 along the extension direction of the outer wall portion 31. The outer teeth 34 are provided on the inner surface side of the outer wall portion 31. The manner in which the outer teeth 34 provided on one end side of the outer wall portion 31 are attached to the outer wall portion 31 is not particularly limited, and the outer teeth 34 may be provided directly on the inner surface of one end of the outer wall portion 31, or may be provided by connecting an arc-shaped connecting portion (not shown) having the outer teeth 34 on its inner surface to one end of the outer wall portion 31.

[0025] One or more flat cables 4 are accommodated in the accommodation space S between the rotating body 2 and the fixed body 3. Here, two flat cables 4a and 4b are accommodated, but the number of flat cables is not particularly limited.

[0026] The flat cable 4 is wound in one direction around the outer surface of the cylindrical portion 21 and in the other direction around the inner surface of the outer wall portion 31. Here, as shown in Fig. 2, the flat cable 4 is wound clockwise around the outer surface of the cylindrical portion 21 and counterclockwise around the inner surface of the outer wall portion 31. In addition, the flat cable 4 is not wound around the inner surface of the narrowed outer wall portion 32.

[0027] The outer wall portion 31 of the fixed body 3 is a portion around which the flat cable 4, which is wound in one direction around the cylindrical portion 21 of the rotating body 2, is wound in the other direction. The narrowed outer wall portion 32 of the fixed body 3 is a portion around which the flat cable 4, which is wound in one direction around the cylindrical portion 21 of the rotating body 2, is not wound in the other direction. In this way, the flat cable 4, which is wound in one direction around the cylindrical portion 21 of the rotating body 2, is wound around the outer wall portion 31, but is not wound around the narrowed outer wall portion 32.

[0028] Furthermore, the outer wall portion 31 is not disposed opposite the entire circumference of the cylindrical portion 21 of the rotating body 2 in the circumferential direction, but is arc-shaped and disposed opposite only a portion of the cylindrical portion 21 in the circumferential direction. Furthermore, the narrowed outer wall portion 32 is not disposed opposite the entire circumference of the cylindrical portion 21 in the circumferential direction, but is arc-shaped and disposed opposite only a portion of the cylindrical portion 21, i.e., at least a portion of the cylindrical portion 21 excluding the portion facing the outer wall portion 31. The radial length of the narrowed outer wall portion 32 about the central axis O is smaller than the radial length of the outer wall portion 31.

[0029] The flat cable 4 also has a reversing section 41 where the direction of rotation of the flat cable 4 is reversed between when it is wound in one direction and when it is wound in the other direction. The reversing section 41 is a so-called U-turn section. In response to the rotation of the rotor 2, the reversing section 41 of the flat cable 4 moves clockwise and counterclockwise in the moving space S1 where the cylindrical section 21 of the rotor 2 faces the outer wall section 31 of the fixed body 3, but does not move in the narrowed space S2 where the cylindrical section 21 of the rotor 2 faces the narrowed outer wall section 32 of the fixed body 3. In this way, the reversing section 41 of the flat cable 4 is accommodated in the moving space S1 in the accommodation space S.

[0030] If the inverting portion 41 moves through the narrow space S2, the curvature of the inverting portion 41 while moving through the narrow space S2 becomes larger than the curvature of the inverting portion 41 while moving through the movement space S1. Therefore, the durability of the flat cable 4 decreases as the curvature of the inverting portion 41 increases, making it difficult to use the rotary connector device 1 for a long period of time.

[0031] One end of the flat cable 4, i.e., the inner end, is equipped with a connector (not shown) and is connected to the rotor connection portion 23 of the rotor 2. For example, the first flat cable 4a is connected to the rotor connection portion 23a, and the second flat cable 4b is connected to the rotor connection portion 23b, with the rotor connection portion 23a and the rotor connection portion 23b being arranged at a predetermined interval in the circumferential direction. The other end of the flat cable 4, i.e., the outer end, is equipped with a connector (not shown) and is connected to the fixed body connection portion 35 of the fixed body 3. For example, the first flat cable 4a is connected to the fixed body connection portion 35a, and the second flat cable 4b is connected to the fixed body connection portion 35b, with the fixed body connection portion 35a and the fixed body connection portion 35b being arranged at approximately the same position or the same position in the circumferential direction. For example, the fixed body connection portion 35 is provided within the moving space S1. With this configuration, the rotating body connection portion 23 moves relative to the fixed body connection portion 35 in accordance with the rotation of the rotating body 2, and the flat cable 4 is wound onto or unwound from the cylindrical portion 21 of the rotating body 2, so that the inversion portion 41 of the flat cable 4 moves in accordance with the rotation of the rotating body 2.

[0032] A connector (not shown) provided at the end of the flat cable 4 connected to the rotating body connecting portion 23 is electrically connected to various electronic devices such as an airbag device mounted on the steering side. Also, a connector (not shown) provided at the end of the flat cable 4 connected to the fixed body connecting portion 35 is electrically connected to various electronic devices such as a vehicle control device mounted on the vehicle side. The various electronic devices on the vehicle side and the various electronic devices on the steering side are electrically connected to each other via the flat cable 4 of the rotary connector device 1.

[0033] The cable retainer 5, which prevents the flat cable 4 from floating, has one moving retainer 51. The moving retainer 51 is movable clockwise and counterclockwise within the moving space S1 and is provided movably inside the inverted portion 41 of the flat cable 4. When there are multiple flat cables 4, the moving retainer 51 is disposed inside the inverted portion of the flat cable that is disposed at the outermost periphery of the multiple flat cables wound around the cylindrical portion 21 of the rotating body 2 (here, inside the inverted portion 41b of the second flat cable 4b). The moving retainer 51 is, for example, columnar or cylindrical. The moving retainer 51 may be made of an elastic or rigid body.

[0034] 1, the cable presser 5 further has a plurality of teeth 52 provided on one end side of the moving presser 51 around the entire circumferential direction of the moving presser 51. The manner in which the teeth 52 provided on one end side of the moving presser 51 are attached to the moving presser 51 is not particularly limited, and they may be provided directly on the outer circumferential surface of one end of the moving presser 51, or they may be provided by connecting a columnar or cylindrical connecting part (not shown) having teeth 52 on its outer circumferential surface to one end of the moving presser 51.

[0035] In response to the rotation of the rotor 2, the moving retainer 51 moves through the moving space S1 of the accommodation space S while pressing the portion of the flat cable 4 that is wound in one direction around the cylindrical portion 21 of the rotor 2 against the cylindrical portion 21 of the rotor 2. Specifically, in response to the rotation of the rotor 2, the teeth 52 of the cable retainer 5 rotate while meshing with the inner teeth 22 of the rotor 2 and the outer teeth 34 of the fixed body 3, and the moving retainer 51 of the cable retainer 5 moves through the moving space S1. In other words, the moving retainer 51 moves due to the rotation of the rotor 2, without the flat cable 4 being involved. In this way, the movement mechanism of the moving retainer 51 differs from the movement mechanism of the inverting portion 41 of the flat cable 4. For example, the movement speed of the moving retainer 51 is the same as the movement speed of the inverting portion 41.

[0036] The moving retainer 51, which is disposed inside the inverted portion 41 of the flat cable 4, is provided at a predetermined interval in the circumferential direction from the inverted portion 41. Furthermore, even when the moving retainer 51 moves clockwise and counterclockwise in response to the rotation of the rotor 2, the moving mechanism of the moving retainer 51 and the moving mechanism of the inverted portion 41 are different, so the moving retainer 51 moves at a predetermined interval in the circumferential direction from the inverted portion 41. Like the inverted portion 41, the moving retainer 51 moves in the moving space S1 but does not move in the narrow space S2.

[0037] In this way, when the rotating body 2 moves clockwise, the moving retainer 51 does not move while pressing the inside of the inverted portion 41. Also, when the rotating body 2 moves counterclockwise, the inverted portion 41 does not move while pressing the moving retainer 51. Therefore, a decrease in the durability of the flat cable 4 due to the moving retainer 51 coming into contact with the inverted portion 41 can be avoided.

[0038] When the moving retainer 51, which moves inside the inverting portion 41 at a predetermined distance from the inverting portion 41, moves in the moving space S1, the moving retainer 51 moves in the moving space S1 while pressing the portion of the flat cable wound in one direction around the cylindrical portion 21 against the cylindrical portion 21. In this way, loosening of the winding of the portion of the flat cable 4 wound around the cylindrical portion 21 is suppressed, thereby preventing the flat cable 4 from floating.

[0039] Furthermore, by deforming the elastic moving retainer 51 in advance and installing it on the rotary connector device 1, the elastic force of the moving retainer 51 can further press the portion of the flat cable wound in one direction around the cylindrical portion 21 against the cylindrical portion 21. This further prevents the flat cable 4 from floating.

[0040] Furthermore, in a conventional rotary connector device in which the width of the annular accommodating space is uniform or approximately uniform around the entire circumference to allow components such as the inverted portion of the flat cable to move around the entire circumference of the accommodating space, a sheet member that does not include electric wires, a so-called dummy cable, is used to prevent the flat cable from floating. However, the rotary connector device 1 is provided with a narrow outer wall portion 32 for compactness, and therefore the accommodating space S has a narrow space S2 that is narrower than the movement space S1. As described above, the inverted portion 41 of the flat cable 4 does not move through the narrow space S2, and furthermore, the inverted portion of the dummy cable does not move through the narrow space S2 either. Therefore, even if a dummy cable is used in the rotary connector device 1 as in the conventional case, it is not possible to sufficiently prevent the cable from floating in the rotary connector device 1.

[0041] Furthermore, since the rotary connector device 1 is provided with the narrow outer wall portion 32 that does not move in the narrow space S2, the floating of the flat cable can be efficiently suppressed by a single movement restraining portion.

[0042] The rotary connector device 1 may further include a dummy cable 6 accommodated in the accommodation space S between the rotating body 2 and the fixed body 3. The dummy cable 6 is a sheet-like member that does not include electric wires. When the rotary connector device 1 includes the dummy cable 6, the movable holding portion 51 of the cable holding body 5 is movably provided inside an inverted portion 61 of the dummy cable 6, which will be described later.

[0043] The dummy cable 6 is wound in one direction around the outer surface of the cylindrical portion 21 of the rotating body 2 from the outside of the flat cable 4, and in the other direction around the inner surface of the outer wall portion 31 of the fixed body 3. When there are multiple flat cables 4, the dummy cable 6 is wound in one direction around the outer surface of the cylindrical portion 21 of the rotating body 2 from the outside of the flat cable (here, the second flat cable 4b) that is arranged at the outermost periphery of the multiple flat cables wound around the cylindrical portion 21 of the rotating body 2, and in the other direction around the inner surface of the outer wall portion 31 of the fixed body 3. Furthermore, the dummy cable 6 is not wound around the inner surface of the narrowed outer wall portion 32.

[0044] Similar to the flat cable 4, the dummy cable 6 has an inverted portion 61 where the direction of rotation of the dummy cable 6 when wound in one direction is reversed to the direction of rotation of the dummy cable 6 when wound in the other direction. The inverted portion 61 of the dummy cable 6 moves clockwise and counterclockwise in the movement space S1 in response to the rotation of the rotating body 2, but does not move in the confined space S2.

[0045] The dummy cable 6 presses the flat cable portion wound around the cylindrical portion 21 from the outside against the cylindrical portion 21 of the rotating body 2, with the inverted portion 61 as a boundary, and also presses the flat cable portion wound around the outer wall portion 31 against the outer wall portion 31 of the fixed body 3 from the outside.

[0046] One end of the dummy cable 6, i.e., the inner end, is connected to the rotor connection portion 23c of the rotor 2. For example, the rotor connection portion 23c connected to the dummy cable 6 and the rotor connection portions 23 (23a, 23b) connected to the flat cable 4 are arranged at a predetermined interval in the circumferential direction. The other end of the dummy cable 6, i.e., the outer end, is connected to the fixed body connection portion 35c of the fixed body 3. For example, the fixed body connection portion 35c and the fixed body connection portions 35 (35a, 35b) are arranged at approximately the same position or the same position in the circumferential direction. With this configuration, the rotor connection portion 23c moves relative to the fixed body connection portion 35c in response to the rotation of the rotor 2, and the dummy cable 6 is wound onto or unwound from the cylindrical portion 21 of the rotor 2, so that the reversal portion 61 of the dummy cable 6 moves in response to the rotation of the rotor 2.

[0047] The inverted portion 61 of the dummy cable 6 is provided at a predetermined interval in the circumferential direction relative to the moving retainer 51, similar to the flat cable 4. Furthermore, even when the moving retainer 51 moves clockwise and counterclockwise in response to the rotation of the rotating body 2, the moving mechanism of the moving retainer 51 and the moving mechanism of the inverted portion 61 of the dummy cable 6 are different, so the moving retainer 51 moves at a predetermined interval in the circumferential direction relative to the inverted portion 61.

[0048] As described above, in the rotary connector device 1, the fixed body 3 has the narrow outer wall portion 32 to form the narrow space S2, where the width of the accommodation space S is narrow, within the rotary connector device 1. This allows the flattening of the cross-sectional shape of the steering column used in the rotary connector device 1 to be increased. A steering column with such a flat shape is suitable for use with irregular-shaped steering wheels, making the rotary connector device 1 suitable for use in steer-by-wire systems. Such a steering wheel is suitable for a retractable steering wheel that can be stored in the dashboard. Furthermore, a flat steering column has the advantages of making it easier to see the instrument panel located above the steering column while driving and increasing the space below the steering column, thereby increasing the legroom for the driver. This further improves the design flexibility of the vehicle, including the rotary connector device 1.

[0049] According to the first embodiment described above, by making a portion of the accommodation space that accommodates the flat cable a narrow space and providing a movable holding portion of the cable holder at a predetermined position relative to the flat cable, the rotary connector device can be made compact and the floating of the flat cable can be suppressed.

[0050] In the above, as shown in Figures 1 and 2, the inner tooth portion 22, the outer tooth portion 34, and the tooth portion 52 are provided only on one side of the rotary connector device 1, but these tooth portions may also be provided on the other side of the rotary connector device 1, i.e., the side shown in Figure 2, in addition to the one side of the rotary connector device 1.

[0051] (Second embodiment) Fig. 5 is a partially transparent plan view showing an example of the rotary connector device of the second embodiment as seen from one side, and Fig. 6 is a partially transparent plan view showing an example of the rotary connector device of the second embodiment as seen from the other side.

[0052] In the following embodiments, the same components as those of the rotary connector device 1 of the first embodiment are denoted by the same reference numerals, and redundant explanations will be omitted or simplified.

[0053] The rotary connector device 1a of the second embodiment is basically the same in configuration as the rotary connector device 1 of the first embodiment, except that it does not have the inner tooth portion 22, the outer tooth portion 34, or the tooth portion 52, and the cable presser body 5 has a ring portion 53. Therefore, the different configuration will be mainly described here.

[0054] 5 and 6, in the rotary connector device 1a of the second embodiment, the cable presser 5 further includes a ring portion 53. The ring portion 53 is accommodated in the accommodation space S and supports the moving presser portion 51. The ring portion 53 is, for example, in the shape of a flat plate.

[0055] The ring portion 53 is connected to one end of the cylindrical portion 21 of the rotating body 2 and extends radially outward around the central axis O, i.e., toward the fixed body 3. An edge of the flat cable 4 abuts against at least a portion of the ring portion 53, for example, against the main surface of the ring portion 53.

[0056] The portion of the ring portion 53 that supports the movement retainer 51 extends partially outward in the radial direction around the central axis O. The movement retainer 51 stands on the ring portion 53.

[0057] The ring portion 53 rotates around the central axis O in response to the rotation of the rotor 2. The rotation mechanism of the ring portion 53 is different from the movement mechanism of the inverted portion 41 of the flat cable 4, and therefore the ring portion 53 rotates due to the rotation of the rotor 2, without passing through the flat cable 4. The rotation speed of the ring portion 53, which rotates in response to the rotation of the rotor 2, is slower than the rotation speed of the rotor 2, for example, about one-third slower than the rotation speed of the rotor 2.

[0058] As the rotating body 2 rotates, the ring portion 53 of the cable presser 5 rotates, causing the moving presser 51 provided on the ring portion 53 of the cable presser 5 to move in the moving space S1. Furthermore, since the rotational speed of the ring portion 53, which rotates in accordance with the rotation of the rotating body 2, is slower than the rotational speed of the rotating body 2, the moving presser 51 moves while maintaining a predetermined gap in the circumferential direction relative to the inverting portion 41. As with the rotary connector device 1 of the first embodiment, the moving presser 51 moves in the moving space S1 of the accommodating space S in accordance with the rotation of the rotating body 2 while pressing the portion of the flat cable wound in one direction around the cylindrical portion 21 against the cylindrical portion 21. Therefore, the rotary connector device 1a can suppress floating of the flat cable.

[0059] According to the second embodiment described above, even if the rotary connector device has a ring portion that supports the moving retainer portion instead of the inner tooth portion, outer tooth portion, and tooth portion configuration, it is possible to make the rotary connector device compact and prevent the flat cable from floating.

[0060] In the above, as shown in Figures 5 and 6, the ring portion 53 is provided only on one side of the rotary connector device 1a, but the ring portion 53 may also be provided on the other side of the rotary connector device 1a, or the inner tooth portion 22, the outer tooth portion 34, and the tooth portion 52 may be provided on the other side of the rotary connector device 1a.

[0061] Although the embodiments have been described above, the present invention is not limited to the above embodiments, but includes all aspects encompassed by the concept and scope of the claims of the present disclosure, and can be modified in various ways within the scope of the present disclosure. [Explanation of symbols]

[0062] 1, 1a Rotating connector device 2 Rotating bodies 21 Cylindrical part 22 inner teeth 23, 23a, 23b, 23c Rotating body connection part 3 Fixed body 31 Exterior wall 32 Stenosis outer wall 33 Connecting part 34 Outer teeth 35, 35a, 35b, 35c Fixed body connection part 4 flat cables 4a 1st flat cable 4b Second flat cable 41 Reversal section 41a Inverted part of the first flat cable 41b Reversed part of second flat cable 5 Cable holder 51 Moving retainer 52 Tooth 53 Ring section 6 dummy cables 61 Dummy cable inversion O Rotation axis L1 opposing distance (first opposing distance) L2 opposing distance (second opposing distance) S Storage space S1 Moving space S2 Constriction space

Claims

1. A rotor having a cylindrical portion and capable of rotating; a fixed body having an outer wall portion and a narrowed outer wall portion disposed opposite to an outer surface of the cylindrical portion, the distance between the cylindrical portion and the narrowed outer wall portion being shorter than the distance between the cylindrical portion and the outer wall portion; one or more flat cables that are accommodated in an accommodation space between the rotating body and the fixed body, that are wound in one direction around the cylindrical portion of the rotating body and in the other direction around the outer wall portion of the fixed body, and that have a reversal portion where the rotation direction of the flat cables wound in one direction and the rotation direction of the flat cables wound in the other direction are reversed; a cable holder having one movable holding portion movably provided inside the inverted portion of the flat cable, the movable holding portion moving within the accommodating space while holding a portion of the flat cable that is wound in one direction around the cylindrical portion of the rotating body against the cylindrical portion of the rotating body in response to rotation of the rotating body; A rotating connector device comprising:

2. The rotating body further includes a plurality of inner teeth provided around a circumferential direction of the cylindrical portion on one end side of the cylindrical portion, The stationary body further includes a plurality of outer teeth provided on one end side of the outer wall portion along an extension direction of the outer wall portion, The cable holder further includes a plurality of teeth provided around one end of the moving retainer, the teeth being arranged in a circumferential direction of the moving retainer.

2. The rotary connector device according to claim 1, wherein the tooth portion of the cable holder rotates while meshing with the inner tooth portion of the rotating body and the outer tooth portion of the fixed body in response to rotation of the rotating body, thereby moving the moving holder of the cable holder.

3. the cable pressing body further includes a ring portion that supports the moving pressing portion, at least a portion of which abuts against an edge of the flat cable, and rotates in response to rotation of the rotating body; 2. The rotary connector device according to claim 1, wherein the ring portion of the cable presser rotates in response to rotation of the rotating body, and the movable presser portion of the cable presser moves.

4. The rotary connector device according to any one of claims 1 to 3, wherein the inversion portion moves through a moving space in which the cylindrical portion of the rotating body and the outer wall portion of the fixed body face each other in response to the rotation of the rotating body, and does not move through a narrowed space in which the cylindrical portion of the rotating body and the narrowed outer wall portion of the fixed body face each other.

5. 4. The rotary connector device according to claim 1, wherein the flat cable is not wound around the narrowed outer wall portion.

6. A rotary connector device as described in any one of claims 1 to 3, wherein the moving holding portion of the cable holding body does not move through a confined space in which the cylindrical portion of the rotating body and the confined outer wall portion of the fixed body face each other.

7. The rotary connector device according to any one of claims 1 to 3, further comprising a dummy cable that is accommodated in the accommodation space between the rotating body and the fixed body, and is wound in one direction from the outside of the flat cable around the cylindrical portion of the rotating body and in the other direction around the outer wall portion of the fixed body.

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