JP2006019079A - Rotating connector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotating connector in which cost reduction can be promoted by shortening a required length of a flat cable in a large scale. <P>SOLUTION: In the rotating connector in which a rotor 2 having an inner cylindrical part 7b is rotatably coupled to a stator 1 having an outer cylindrical part 5a, and in an annular space 9 demarkated between these, a flat cable 3 is housed in an inversed state and a holder 4 is rotatably arranged, a small diameter part 7d is formed that continues to the rotor 2 via the inner cylindrical part 7b and a stage part 7e, a guide wall 4b having an outer peripheral face eccentric against a center penetrating hole 4e is standingly formed on the annular flat plate part 4a of the holder 4, an aperture 15 where the inversed part 3a of the flat cable 3 passes through is installed at the maximum diameter part of this guide wall 4b, and by making tips of a plurality of elastic tongue pieces 4d integrally formed in the annular flat plate part 4a of the holder be elastically contacted with the upper face of a bottom part 6a of the stator 1, the peripheral part of the penetrating hole 4e inserted into the small diameter part 7d is crimped to the stage part 7e. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a rotary connector incorporated in a steering device of an automobile and used as an electrical connection means for an air bag system or the like, and in particular, a flat cable has an inversion portion in an annular space defined between a rotor and a stator. It is related with the rotation connector wound by reverse direction via.

  A rotary connector uses one of a pair of rotatably connected housings as a rotor and the other as a stator, and a flat cable is housed and wound between the rotor and the stator. It is used as an electrical connection means for an airbag system or the like attached to a handle having a limited number of rotations. The flat cable is a belt-shaped body carrying a plurality of conductors, and a spiral type in which the flat cable is wound in a spiral shape and a reverse type in which the flat cable is reversed in the middle and wound in the opposite direction are known. The length of the flat cable required for the inversion type can be shortened.

Conventionally, in such a reversing type rotary connector, a flat cable is housed in an annular space defined between a rotor and a stator in a state where the winding direction is reversed halfway, and a plurality of rollers are placed in the annular space. A holder in which a pivotally supported holder is rotatably arranged and a reversing portion of a flat cable is looped around one roller is known (for example, see Patent Document 1). In the rotary connector configured as described above, when the rotor rotates in either the forward or reverse direction with respect to the stator, the flat cable is drawn out from the outer cylindrical portion of the stator and wound around the inner cylindrical portion of the rotor. On the contrary, the flat cable is drawn out from the inner cylinder portion and is rewound onto the outer cylinder portion. At that time, the reversing part of the flat cable moves in the same direction by a smaller amount of rotation than the rotor, and the holder also moves in the same direction following this reversing part. The flat is about twice as long as the amount of movement. The cable is fed out from the outer cylinder part or the inner cylinder part. Further, since the movement of the flat cable in the radial direction is restricted by the plurality of rollers pivotally supported by the holder, the flat cable can be smoothly fed out in the direction of the reversing portion.
Japanese Patent Laid-Open No. 2001-126836 (page 2-3, FIG. 4)

  In this type of rotary connector, the ratio of the flat cable in the total cost is very high, and the cost can be reduced as the length of the flat cable required becomes shorter. In the reversing type rotary connector, the length of the flat cable can be shortened to about half at most as compared with the spiral type, and this is a major factor that hinders further cost reduction.

  The present invention has been made in view of the actual situation of the prior art, and an object of the present invention is to provide a rotary connector capable of reducing the cost by significantly reducing the length of a required flat cable. It is in.

  In order to achieve the above object, a rotary connector of the present invention includes a stator having a bottom plate portion and an outer cylinder portion, a rotor having a top plate portion and an inner cylinder portion and rotatably connected to the stator, A flat cable which is housed in an annular space defined between the stator and the rotor in a state in which the winding direction is reversed halfway and whose both ends are led out to the outside through the inner cylinder part and the outer cylinder part And a holder that is rotatably disposed in the annular space and has an annular flat plate portion facing the bottom plate portion and a guide wall erected on the annular flat plate portion, and is provided on the guide wall. In the rotary connector in which the inversion portion of the flat cable is disposed in the opening, the inner wall surface of the guide wall is formed concentrically with a circular through hole drilled in the center of the annular flat plate portion, and the rotation of the rotor During ~ A distance from the guide wall to the outer wall of the guide wall is maximized in the vicinity of the opening compared to other portions, and the rotor has a small-diameter portion continuous via the inner cylinder portion and the step portion. An elastic biasing portion that is formed and presses the peripheral portion of the through hole inserted into the small diameter portion against the stepped portion is provided on at least one of the annular flat plate portion and the bottom plate portion.

  In the rotary connector configured as described above, for example, when the rotor is rotated in one of the forward and reverse directions when the flat cable is wound around the outer wall of the inner cylindrical portion, the flat cable is first drawn out from the inner cylindrical portion. After being wound around the inner wall of the outer cylinder, the flat cable wound around the inner wall of the outer cylinder is wound around the outer peripheral surface of the guide wall provided on the holder by further rotating the rotor in the same direction. Turned to rewind. On the other hand, when the rotor is rotated in any direction from the state where the flat cable is rewound on the outer peripheral surface of the guide wall, the flat cable is first unwound from the guide wall and wound around the inner wall of the outer cylinder portion. After that, by further rotating the rotor in the same direction, the flat cable wound around the inner wall side of the outer cylinder part is wound around the outer wall of the inner cylinder part to be tightened. In other words, the flat cable is temporarily wound around the inner wall of the outer cylinder part in the middle from the tightened state to the rewinded state, but in the rewinded state, the flat cable is wound around the guide wall of the holder disposed in the annular space. Since the total length along the circumferential direction of the outer peripheral surface of this guide wall is sufficiently shorter than the total length along the circumferential direction of the inner wall surface of the outer cylinder portion, the required length of the flat cable must be greatly shortened. Can do. In addition, the rotor is formed with a small-diameter portion continuous through the inner cylinder portion and the step portion, and a through-hole drilled in the center of the annular flat plate portion of the holder is inserted into the small-diameter portion, and the peripheral portion of the through-hole is elastically elastic. Since the urging portion is pressed against the stepped portion, even when vibration is applied from the outside in the direction of the rotation axis of the rotor, the movement of the holder to move up and down in the annular space is suppressed, and the holder is Noise generated by colliding with the bottom plate can be reduced.

  In the above configuration, the annular flat plate portion has a substantially same outer diameter as the inner diameter of the outer tube portion, and a plurality of elastic tongues in which the elastic biasing portion is integrally formed in a cantilever shape with the annular flat plate portion. If it is a piece, an elastic biasing part with a simple structure can be realized, which is preferable. In this case, it is preferable that a curved surface portion is formed at the free end of each elastic tongue piece and the curved surface portion is elastically contacted with the bottom plate portion of the stator so that the holder can be smoothly rotated in the annular space. Further, it is preferable that three or more elastic tongue pieces are formed at equal intervals in the circumferential direction of the annular flat plate portion because the holder can be stably supported on the bottom plate portion.

  The rotary connector according to the present invention defines an annular space between the inner cylinder part and the top plate part of the rotor and the outer cylinder part and the bottom plate part of the stator, and is arranged rotatably in the annular space. A guide wall through which the inverted portion of the flat cable passes is erected on the annular flat plate portion of the holder, and the inner wall surface of this guide wall is formed concentrically with a through-hole drilled in the center of the annular flat plate portion, and the rotation of the rotor Since the distance from the center to the outer wall surface of the guide wall is maximized in the vicinity of the opening compared to the other parts, a flat cable is wound around the outer peripheral surface of the guide wall having a smaller diameter than the outer cylindrical portion of the stator. As a result, the length of the flat cable required can be greatly shortened. Further, the rotor is formed with a small diameter portion that is continuous with the inner cylinder portion via the step portion, and a through hole of the holder is inserted into the small diameter portion, and the peripheral portion of the through hole is pressed against the step portion by the elastic biasing portion. Therefore, even when vibration is applied from the outside in the direction of the rotation axis of the rotor, the movement of the holder to move up and down in the annular space is suppressed, and the noise generated by the holder colliding with the top plate and bottom plate Can be reduced.

  An embodiment of the invention will be described with reference to the drawings. FIG. 1 is an exploded perspective view of a rotary connector according to an embodiment of the present invention, FIG. 2 is a sectional view of the rotary connector, and FIG. FIG. 4 is an explanatory view of an engagement portion between the holder and the rotor, and FIG. 5 is an operation explanatory view of the rotary connector.

  As shown in FIGS. 1 to 3, the rotary connector according to this embodiment includes a stator 1, a rotor 2 that is rotatably connected to the stator 1, and an electrical connection between the stator 1 and the rotor 2. A flat cable 3 to be connected and a holder 4 that is rotatably disposed between the stator 1 and the rotor 2 are schematically configured.

  The stator 1 is a fixing member fixed to the steering column, and the stator 1 includes a synthetic resin case 5 and a cover 6. The case 5 has an annular outer cylinder portion 5a and a lid portion 5b protruding outward from the outer wall thereof, and the cover 6 has a bottom plate portion 6a and a lower storage portion 6b protruding downward from the outer edge portion thereof. ing. A circular center hole 6c is formed in the center of the bottom plate portion 6a, and the lower end of the outer cylinder portion 5a is integrated with the bottom plate portion by integrating the lower end of the case 5 and the outer edge portion of the cover 6 by snap coupling. The upper opening end of the lower storage portion 6b is closed by the lid portion 5b.

  The rotor 2 is a movable member connected to the handle side. The rotor 2 includes an upper rotor 7 and a lower rotor 8 made of synthetic resin. The upper rotor 7 has an annular top plate portion 7a and an inner cylinder portion 7b hanging from the center thereof, and an upper storage portion 7c is erected on the upper surface of the top plate portion 7a, and the inner cylinder portion 7b is attached to the steering shaft. It has a hollow structure having an inner diameter dimension that can be inserted. As shown in FIG. 4, the lower end part of the inner cylinder part 7b is the small diameter part 7d, and these inner cylinder part 7b and the small diameter part 7d are continuing via the step part 7e. The outer diameter dimension of the inner cylinder part 7b is set somewhat larger than the center hole 6c of the bottom plate part 6a, but the outer diameter dimension of the small diameter part 7d is set slightly smaller than the center hole 6c. On the other hand, the lower rotor 8 is a cylindrical body having a flange portion 8a. The lower rotor 8 is inserted into the center hole 6c of the cover 6 and snap-coupled to the inner peripheral surface of the inner cylindrical portion 7b, whereby the rotor 2 is The stator 1 is rotatably connected. In this connected state, an annular space 9 having a ring shape in plan view is defined by the outer cylindrical portion 5a and bottom plate portion 6a on the stator 1 side, and the top plate portion 7a and inner cylindrical portion 7b on the rotor 2 side. .

  The flat cable 3 is formed of a strip-like body in which a plurality of conductors parallel to each other are laminated with a pair of insulating films. The flat cable 3 is accommodated in the annular space 9 in the reverse direction via a U-shaped inversion portion 3a. . Lead blocks 10 and 11 are connected to both ends of the flat cable 3, respectively. One lead block 10 is fixed in the lower housing portion 6b of the cover 6, and a lead wire 12 having an external connector 12a at the tip is connected to the lead block 10. The other lead block 11 is fixed in the upper storage portion 7c of the upper rotor 7, and a lead wire 13 having an external connector 13a at the tip is connected to the lead block 11.

  The holder 4 has an annular flat plate portion 4a placed on the bottom plate portion 6a of the cover 6, and a guide wall 4b and a support shaft 4c erected on the annular flat plate portion 4a. These are made of synthetic resin. It is integrally molded. The annular flat plate portion 4a has substantially the same outer diameter as the inner diameter of the outer cylinder portion 5a, and a plurality of elastic tongue pieces 4d are integrally formed in a cantilever shape on the annular flat plate portion 4a. At least three of these elastic tongue pieces 4d are formed at equal intervals in the circumferential direction of the annular flat plate portion 4a. In the present embodiment, three elastic tongue pieces 4d are provided on the annular flat plate portion 4a. The elastic tongue pieces 4d are formed at equal intervals of 120 degrees, and the tips (free ends) of the elastic tongue pieces 4d extend obliquely downward from the annular flat plate portion 4a to form a hemispherical curved surface portion. A circular through hole 4e is formed in the center of the annular flat plate portion 4a. By inserting the through hole 4e into the small diameter portion 7d of the upper rotor 7 and abutting against the stepped portion 7e, the holder 4 is The inside of the annular space 9 can be rotated around the inner cylinder portion 7b. In this case, as shown in FIG. 4, the annular flat plate portion 4a and the bottom plate portion 6a are sandwiched between the step portion 7e of the upper rotor 7 and the flange portion 8a of the lower rotor 8, and the curved portion of each elastic tongue 4d is Since it is in a state of elastic contact with the upper surface of the bottom plate portion 6a by the force of P1, the reaction force P2 from P1 acts upward on the annular flat plate portion 4a, and the peripheral portion of the through hole 4e is P2 on the stepped portion 7e. It is pressed by force.

  The guide wall 4b of the holder 4 is erected on the annular flat plate portion 4a so as to surround most of the through hole 4e, and its inner peripheral surface is substantially concentric with the through hole 4e. It is greatly decentered with respect to 4e. A part of the guide wall 4b is cut out on the annular flat plate portion 4a, and a cylindrical support shaft 4c is erected in the cutout portion. A roller 14 is rotatably supported on the support shaft 4c, and the reversing portion 3a of the flat cable 3 described above is located in an opening 15 between the roller 14 and the side surface of the guide wall 4b facing the roller 14 (FIG. 5). Therefore, the distance from the rotation center of the rotor 2 to the outer peripheral surface of the guide wall 4b is the largest in the vicinity of the opening 15 where the roller 14 is supported, and the portion facing the roller 14 180 degrees is the smallest. A concave cavity 4f is formed between the inner circumferential surface and the outer circumferential surface of the guide wall 4b, and the weight of the entire holder 4 is reduced by the cavity 4f.

  Next, the operation of the thus-configured rotary connector will be described mainly with reference to FIG. In FIG. 5, the stator 1 and the rotor 2 including the outer cylinder part 5a and the inner cylinder part 7b are omitted.

  FIG. 5 (a) shows a tightened state in which most of the flat cable 3 is wound around the outer wall of the inner cylindrical portion 7b, and when the rotor 2 is rotated counterclockwise (arrow A direction) from this wound state, Since the reversing portion 3a of the flat cable 3 moves counterclockwise by a smaller rotation amount than the rotor 2, the roller 14 and the holder 4 also move counterclockwise following this reversing portion 3a, and FIG. As shown in b), the flat cable 3 which is about twice as much as the amount of movement is drawn out from the inner cylinder part 7b side and wound around the inner wall of the outer cylinder part 5a. When the rotor 2 is further rotated in the counterclockwise direction, as shown in FIG. 5C, the flat cable 3 is drawn out from the outer cylinder portion 5a side and wound around the outer peripheral surface of the guide wall 4b of the holder 4, and finally Thus, most of the flat cable 3 is in a rewound state wound around the outer peripheral surface of the guide wall 4b. Contrary to the above, when the rotor 2 is rotated in the clockwise direction (arrow B direction) from the unwinding state shown in FIG. 5 (c), the flat cable 3 is drawn out from the guide wall 4b side and the inner wall of the outer cylinder portion 5a. After being wound around, the rotor 2 is further rotated in the clockwise direction so that most of the flat cable 3 is wound around the outer wall of the inner cylindrical portion 7b as shown in FIG. It becomes.

  As described above, in the rotary connector according to the present embodiment, the flat cable 3 is in the middle of the tightened state shown in FIG. 5A or the unwinded state shown in FIG. As shown in FIG. 1, the flat cable 3 is once wound around the outer cylinder portion 5a located outside the holder 4, and the circumference of the outer peripheral surface of the guide wall 4b is larger than the circumference of the inner wall surface of the outer cylinder portion 5a. Since it is sufficiently short, the required length of the flat cable 3 can be greatly shortened. Further, the rotor 2 is formed with a small-diameter portion 7d continuous through the inner cylindrical portion 7b and the stepped portion 7e, and the tips of the elastic tongue pieces 4d formed integrally with the annular flat plate portion 4a of the holder 4 are formed on the upper surface of the bottom plate portion 6a. By elastic contact, the peripheral portion of the through hole 4e inserted into the small diameter portion 7d was brought into pressure contact with the stepped portion 7e by the reaction force from each elastic tongue piece 4d, so that vibration was applied from the outside in the direction of the rotation axis of the rotor 2. Sometimes, the movement of the holder 4 trying to move up and down in the annular space 9 is suppressed, and noise generated when the holder 4 collides with the top plate portion 7a and the bottom plate portion 6a can be reduced.

The shortening effect of the flat cable 3 described above will be described with reference to FIG. 6. FIG. 6 (a) is a conventional rotary connector in which the flat cable is wound around the outer cylinder portion to be unwound, and FIG. 6 (b). Is a rotary connector according to the present embodiment in which a flat cable is wound around a guide wall of a holder to be in a rewind state. In both rotary connectors, the inner diameter of the path of the flat cable (the diameter dimension in the tightened state) is r. When the outer diameter of the path of the flat cable (the diameter dimension in the rewind state) is R and the finite rotation speed of the rotor is N, the required length L of the flat cable 3 is (L / rπ) + (L / Rπ) = N,
L = rR × Nπ / (r + R) (1)
As given. Here, the inner diameter r corresponds to the outer diameter of the inner cylinder portion of the rotor. Due to the structure in which the inner cylinder portion is inserted into the steering shaft, the inner diameter r is the same as that shown in FIG. The rotary connector shown in FIG. As for the outer diameter R, in the case of the rotary connector shown in FIG. 6 (a), the outer diameter R corresponds to the inner diameter of the outer cylinder portion, but in the case of the rotary connector shown in FIG. The diameter R corresponds to the outer diameter of the guide wall, which is smaller than the inner diameter of the outer cylinder portion. Therefore, as apparent from the above equation (1), the outer diameter R of the present embodiment shown in FIG. 6B is much smaller than that of the conventional example shown in FIG. It is possible to reduce the length L of the flat cable 3 while ensuring a constant finite rotation speed N. For example, when the outer diameter of the inner cylinder part is 50 mm, the inner diameter of the outer cylinder part is 100 mm, the outer diameter of the guide wall is 70 mm, and the finite number of rotations of the rotor is six, Substituting r = 50 mm, R = 100 mm, and N = 6 into the equation results in L = 628 mm. On the other hand, in the case of the rotary connector according to this embodiment, when r = 50 mm, R = 70 mm, and N = 6 are substituted into the above equation (1), L = 549.5 mm is obtained, and the required length of the flat cable 3 The length L can be shortened by 78.5 mm.

  In the above embodiment, the outer wall surface of the guide wall 4b erected on the holder 4 is formed as an annular circumferential surface that is eccentric with respect to the inner circumferential surface, and the outer cylinder portion passes through the opening 15 from the inner cylinder portion 7b. Although the case where the flat cable 3 toward 5a is wound around the outer peripheral surface of the guide wall 4b in an annular shape has been described, the guide wall 4b has a shape other than this, for example, a straight line passing through the center of the through hole 4e and the support shaft 4c. The shape of the shaft may be oval or oval in plan view. In short, the distance from the rotation center of the rotor 2 to the outer wall surface of the guide wall 4b is closer to the opening 15 than the other portions. It suffices if it is formed so as to be maximum.

  In the above embodiment, the rotary connector using one flat cable has been described, but it goes without saying that the present invention can be applied to a double-winding type rotary connector using two flat cables stacked together. Absent.

It is a disassembled perspective view of the rotation connector which concerns on the example of embodiment of this invention. It is sectional drawing of this rotation connector. It is a perspective view of the holder with which this rotation connector is equipped. It is explanatory drawing of the engaging part of this holder and a rotor. It is operation | movement explanatory drawing of this rotation connector. It is explanatory drawing which shows the comparative example of the shortening effect of a flat cable.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Stator 2 Rotor 3 Flat cable 4 Holder 4a Annular flat plate part 4b Guide wall 4c Support shaft 4d Elastic tongue piece 4e Through hole 4f Cavity part 5 Case 5a Outer cylinder part 6 Cover 6a Bottom plate part 6c Center hole 7 Upper rotor 7a Top plate part 7b Inner cylinder part 7d Small diameter part 7e Step part 8 Lower rotor 8a Eave part 9 Annular space 14 Roller 15 Opening

Claims (4)

A stator having a bottom plate portion and an outer cylinder portion, a rotor having a top plate portion and an inner cylinder portion and rotatably connected to the stator, and an annular space defined between the stator and the rotor The bottom plate is housed in a state where the winding direction is reversed in the middle, and both ends of the flat cable are led out to the outside via the inner cylinder part and the outer cylinder part, and are rotatably arranged in the annular space. A rotary connector in which an inversion portion of the flat cable is disposed in an opening provided in the guide wall, and a holder having a guide wall standing on the annular flat plate portion. There,
The inner wall surface of the guide wall is formed concentrically with a circular through-hole drilled in the center of the annular flat plate portion, and the distance from the rotation center of the rotor to the outer wall surface of the guide wall is larger than that of other portions. Forming a maximum diameter in the vicinity of the opening, and forming a small-diameter portion continuous through the inner cylinder portion and the step portion in the rotor, and at least one of the annular flat plate portion and the bottom plate portion, A rotary connector comprising an elastic urging portion that presses a peripheral edge portion of the through hole inserted into the small diameter portion against the stepped portion.   In Claim 1, The said annular flat plate part has the outer diameter dimension substantially the same as the internal diameter of the said outer cylinder part, The said elastic urging | biasing part is integrally formed in this annular flat plate part by the cantilever shape. A rotary connector comprising an elastic tongue piece.   The rotary connector according to claim 2, wherein a curved surface portion is formed at a free end of each elastic tongue piece, and the curved surface portion is elastically contacted with the bottom plate portion. 4. The rotary connector according to claim 2, wherein three or more elastic tongue pieces are formed at equal intervals in the circumferential direction of the annular flat plate portion.

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