JP2006032012A - Rotating connector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotating connector in which the length of the flat cables required is drastically made short and cost reduction can be realized. <P>SOLUTION: The rotating connector connects a rotor 2 having an inner cylinder 7b rotatably to a stator 1 having an outer cylinder 5a and houses two sheets of overlapped flat cables 3A, 3B in reversed state in an annular space 9 demarcated between these outer cylinder 5a and the inner cylinder 7b, and has a holder 4 arranged rotatably in the annular space 9. A guide wall 4b having an opening passage 15 is provided on the annular flat plate 4a of the holder 4, and the inner wall face of this guide wall 4b is formed in cylindrical shape so as to surround the inner cylinder 7b, and the distance from the rotation center of the rotor 2 to the outer wall face of the guide wall 4b is established to become larger at the vicinity of the opening passage 15 compared with other portions, and the reversed portions 3a, 3b of both flat cables 3A, 3B are arranged in the opening passage 15. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a rotary connector incorporated in a steering apparatus of an automobile and used as an electrical connection means for an air bag system or the like, and in particular, a plurality of flat cables in an annular space defined between a rotor and a stator. Relates to a rotary connector wound in a reverse direction via an inversion portion.

  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 plurality of flat cables are 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 flat cables are accommodated in the annular space. It is known that a holder that pivotally supports this roller is rotatably arranged, and a reversing portion of each flat cable is looped on one roller (for example, see Patent Document 1). In the rotary connector configured in this way, when the rotor rotates in either the forward or reverse direction with respect to the stator, each flat cable is drawn out from the outer cylinder part of the stator and wound around the inner cylinder part of the rotor, On the contrary, each flat cable is unwound from the inner tube portion and is rewound onto the outer tube portion. At that time, the reversing portions of the plurality of flat cables move in the same direction by a smaller rotation amount than the rotor, and the holder also moves in the same direction following this reversing portion, which is about twice as long as these moving amounts. The flat cable is fed out from the outer tube portion or the inner tube portion. 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 plurality of flat cables can be smoothly fed out in the direction of the reversing portion.
JP 2000-150098 (page 4-5, FIG. 1)

  By the way, in the rotary connector using multiple flat cables of this kind, the ratio of the flat cable in the total cost is very high, and the cost is reduced as the required length of the flat cable is shortened. can do. However, in the conventional reversing type rotary connector described above, the length of one flat cable can be shortened to about half at most compared to the spiral type. This is a major factor that hinders further cost reduction. It was.

  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 according to the present invention includes a stator having an outer cylindrical portion, and an inner cylindrical portion that is rotatably connected to the stator and defines an annular space between the stator and the outer cylindrical portion. And a plurality of flat cables whose both ends are led out to the outside through the inner cylinder part and the outer cylinder part. And a holder rotatably disposed in the annular space, a guide wall having one opening passage is provided in the holder, and a cylindrical shape is provided so that the inner wall surface of the guide wall surrounds the inner cylinder portion. And the distance from the rotation center of the rotor to the outer wall surface of the guide wall is set to be larger in the vicinity of the opening passage than other portions, and all the reversing portions of the flat cables are formed. In the open passage It was location.

  In the rotary connector configured in this manner, for example, when a plurality of flat cables are wound around the outer peripheral surface of the inner cylinder portion, when the rotor is rotated in either the forward or reverse direction, each flat cable is Each flat cable wound on the inner peripheral surface side of the outer cylinder portion is held by rotating the rotor in the same direction after being drawn out from the cylindrical portion and wound on the inner peripheral surface side of the outer cylindrical portion. It is wound around the outer wall surface of the guide wall provided in the rewound state. On the other hand, when the rotor is rotated in any direction from the state in which a plurality of flat cables are rewound on the outer wall surface of the guide wall, each flat cable is first fed out from the guide wall to be moved inside the outer cylinder portion. After being wound around the peripheral surface, the flat cable wound around the inner peripheral surface side of the outer cylindrical portion is wound around the outer peripheral surface of the inner cylindrical portion by further rotating the rotor in the same direction. It becomes a state. That is, a plurality of flat cables are once wound on the inner peripheral surface side of the outer cylinder part in the middle from the tightened state to the unwinded state, but each flat cable is disposed in the annular space in the unwinded state. Each of the required flats is wound around the guide wall of the holder, and the total length along the circumferential direction of the outer wall surface of the guide wall is sufficiently shorter than the total length along the circumferential direction of the inner circumferential surface of the outer cylinder portion. The length of the cable can be greatly shortened, and a rotary connector suitable for a multi-circuit and low cost can be realized.

  In the above configuration, both ends of the plurality of flat cables are respectively connected to the common inner lead block and the outer lead block, the inner lead block is fixed to the inner cylinder portion of the rotor, and the outer lead block is fixed to the stator. It is preferable to fix to an outer cylinder part, and if such a structure is employ | adopted, a several flat cable can be integrated collectively and it becomes possible to improve assembly workability | operativity. Further, it is preferable that the holder is provided with an annular flat plate portion having an outer diameter that is substantially the same as the inner diameter of the outer cylinder portion, and a guide wall is erected on the annular flat plate portion because the holder can be smoothly rotated in the annular space.

  In the rotary connector of the present invention, a guide wall having one open passage is provided in a holder rotatably disposed in an annular space between an inner cylinder portion of a rotor and an outer cylinder portion of a stator. The inner wall surface is formed in an annular shape so as to surround the inner cylinder portion, and the distance from the rotation center of the rotor to the outer wall surface of the guide wall is set to be larger in the vicinity of the opening passage than other portions, Since each reversing part of the plurality of flat cables is arranged in the opening passage, the flat cable is wound around the outer wall surface of the guide wall having a smaller diameter than the outer cylindrical part of the stator to be in a rewinding state. The required length of each flat cable can be greatly shortened, and a multi-circuit and cost reduction can be realized.

  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 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. The two flat cables 3 </ b> A and 3 </ b> B to be connected and a holder 4 disposed between the stator 1 and the rotor 2 so as to be rotatable 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 outer cylinder part 5a and a lid part 5b protruding from its outer wall, and the cover 6 has a bottom plate part 6a and a lower storage part 6b protruding from its outer edge. A guide hole 6c is formed in the center portion of the bottom plate portion 6a. By integrating the lower end of the case 5 and the outer edge portion of the cover 6 by a snap connection, the lower opening end of the outer cylinder portion 5a becomes the bottom plate portion 6a. And 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 top surface of the top plate portion 7a. The inner cylinder portion 7b has an inner diameter that can be inserted into the steering shaft, and the lower rotor 8 is integrated with the inner peripheral surface of the inner cylinder portion 7b. The lower rotor 8 is a cylindrical body having a flange 8a. The lower rotor 8 is inserted into the guide hole 6c of the cover 6 and snap-coupled to the inner cylinder 7b, whereby the rotor 2 rotates with respect to the stator 1. It is designed to be freely 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. .

  Each of the two flat cables 3A and 3B is formed of a belt-like body in which a plurality of conductors parallel to each other are laminated with a pair of insulating films. Are housed in opposite directions via the inverted parts 3a, 3a. A pair of lead wires 11 and 11 are connected to one end portions of both flat cables 3A and 3B via a common outer lead block 10, and the outer lead block 10 is fixed in the lower storage portion 6b of the cover 6. Has been. Both lead wires 11 and 11 have external connectors 11a and 11a at their tips, and these external connectors 11a and 11a are connected to a control unit on the vehicle body side. A pair of lead wires 13 and 13 are connected to the other ends of the flat cables 3A and 3B via a common inner lead block 12, and the inner lead block 12 is connected to the upper storage portion 7c of the upper rotor 7. It is fixed inside. Both lead wires 13 and 13 have external connectors 13a and 13a at their tips, and these external connectors 13a and 13a are connected to an airbag circuit or a horn circuit on the handle side. Here, the total length from the outer lead block 10 to the inner lead block 12 of both the flat cables 3A and 3B is slightly different. In this embodiment, the flat cable 3A having the shorter total length is connected to the conductor for the airbag circuit. Is supported, and another conductor such as a horn circuit is supported on the flat cable 3B having the longer overall length.

  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 cylindrical portion 5a, and a circular through hole 4d is formed at the center of the annular flat plate portion 4a. The through hole 4d is inserted into the lower outer peripheral surface of the inner cylinder portion 7b, and the holder 4 can rotate in the annular space 9 while slidingly contacting the inner cylinder portion 7b. On the other hand, the guide wall 4b is erected on the annular flat plate portion 4a so as to surround the inner cylinder portion 7b, and its inner wall surface is formed in a cylindrical shape substantially concentric with the through hole 4d. It is formed in a cylindrical shape greatly decentered with respect to the through hole 4d. Further, a part of the guide wall 4b is cut out on the annular flat plate portion 4a, and the roller 14 is rotatably supported by a cylindrical support shaft 4c erected in the cutout portion. One opening passage 15 is formed between the roller 14 and the side surface of the guide wall 4b facing the roller 14, and the reversing portions 3a and 3a of the flat cables 3A and 3B are located in the opening passage 15. (See FIG. 4). 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 passage 15 where the roller 14 is supported, and the portion facing the roller 14 180 degrees is the smallest. A projecting portion 4e for reducing sliding resistance with the bottom plate portion 6a is formed on the lower surface of the annular flat plate portion 4a, and a holder is provided between the inner peripheral surface and the outer peripheral surface of the guide wall 4b. A concave cavity 4f for reducing the weight of the entire 4 is formed.

  Next, the operation of the rotary connector configured as described above will be described mainly with reference to FIG. In FIG. 4, the stator 1 and the rotor 2 including the outer cylinder portion 5a and the inner cylinder portion 7b are omitted.

  FIG. 4A shows a winding state in which most of both flat cables 3A and 3B are wound around the outer peripheral surface of the inner cylindrical portion 7b, and the rotor 2 is rotated counterclockwise (in the direction of arrow A) from this winding state. , The reversing portions 3a, 3a of the flat cables 3A, 3B move counterclockwise by a smaller amount of rotation than the rotor 2, so that the roller 14 and the holder 4 also follow the reversing portions 3a, 3a. As shown in FIG. 4 (b), the flat cables 3A and 3B, which are about twice as much as these movement amounts, are drawn out from the inner cylindrical portion 7b to the inner peripheral surface side of the outer cylindrical portion 5a. . When the rotor 2 is further rotated in the counterclockwise direction, as shown in FIG. 4C, the flat cables 3A and 3B are drawn out from the outer cylindrical portion 5a side and wound around the outer wall surface of the guide wall 4b of the holder 4. Finally, most of the flat cables 3A and 3B are in a rewound state in which they are wound around the outer wall 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. 4C, the flat cables 3A and 3B are moved from the outer wall surface of the guide wall 4b to the outer cylinder portion 5a. After being fed out to the inner peripheral surface side, the rotor 2 is further rotated in the clockwise direction, so that most of the flat cables 3A and 3B are wound around the outer peripheral surface of the inner cylindrical portion 7b as shown in FIG. Turned into a tightened state.

  As described above, in the rotary connector according to this embodiment, both flat cables 3A and 3B are in the middle of being in the tightened state shown in FIG. 4 (a) or in the unwinded state shown in FIG. 4 (c). As shown in (b), the flat cables 3A and 3B are once wound around the outer cylindrical portion 5a positioned outside the guide wall 4b of the holder 4, and the circumferential length of the inner peripheral surface of the outer cylindrical portion 5a is increased. In comparison, since the circumferential length of the outer wall surface of the guide wall 4b is sufficiently short, the required length of both flat cables 3A and 3B can be greatly reduced, and a rotary connector suitable for multi-circuits can be reduced. It can be realized at a cost. Further, both ends of the flat cables 3A and 3B are connected to the common outer lead block 10 and the inner lead block 12, and the outer lead block 10 and the inner lead block 12 are fixed to predetermined positions of the stator 1 and the rotor 2, respectively. Therefore, the two flat cables 3A and 3B can be easily assembled together at the time of the assembly process of the rotary connector. Furthermore, since the total length from the outer lead block 10 to the inner lead block 12 of both flat cables 3A and 3B is slightly different and the conductor for the airbag circuit is carried by the flat cable 3A having the shorter total length, When the rotary connector is erroneously assembled to the steering device, the shorter flat cable 3A is preferentially cut. Accordingly, it is possible to quickly and surely know the disconnection or connection failure of the air bag circuit due to the incorrect assembly, and it is possible to prevent the automobile equipped with the illegal air bag circuit from being supplied to the market.

The shortening effect of the above-described flat cables 3A and 3B will be described with reference to FIG. 5. FIG. 5 (a) shows a conventional rotary connector in which the flat cable is wound around the outer cylinder portion to be rewound. (B) is a rotary connector according to the present embodiment in which the flat cable is wound around the outer wall surface side of the guide wall of the holder so as to be rewound, and only one flat cable is shown for convenience. In these two rotary connectors, when the inner diameter (diameter dimension in the tightened state) of the flat cable path is r, the outer diameter (diameter dimension in the unwinded state) of the flat cable path is R, and the finite rotation speed of the rotor is N. The required length L of the flat cable is (L / rπ) + (L / Rπ) = N,
L = rR × Nπ / (r + R) (1)
As given. Here, the inner diameter r corresponds to the outer diameter dimension of the inner cylinder portion of the rotor, and the inner cylinder portion is inserted into the steering shaft, and therefore, for the inner diameter r, the rotary connector shown in FIG. The rotary connector shown in (b) is the same. As for the outer diameter R, in the case of the rotary connector shown in FIG. 5 (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. 5 (b), The outer diameter R corresponds to the outer diameter dimension of the guide wall, which is smaller than the inner diameter dimension of the outer cylinder portion. Therefore, as apparent from the above equation (1), the outer diameter R of the present embodiment shown in FIG. 5B is much smaller than that of the conventional example shown in FIG. The length L of the flat cables 3A and 3B can be shortened while ensuring the finite rotation speed N of the constant. For example, when the outer diameter of the inner cylinder is 50 mm, the inner diameter of the outer cylinder is 100 mm, the outer diameter of the guide wall is 70 mm, and the rotor has a finite number of rotations of six, Substituting r = 50 mm, R = 100 mm, and N = 6 into equation (1) 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 flat cables 3A and 3B. Can be shortened by 78.5 mm.

  In the above embodiment, the outer lead block 10 and the inner lead block 12 are fixed to predetermined positions of the stator 1 and the rotor 2, respectively, and two flat cables 3A and 3B are connected to the outer lead block 10 and the inner lead block 12, respectively. In the above description, the outer lead blocks 10 fixed to the stator 1 having a relatively large space are connected to each of the two flat cables 3A and 3B. You may do it.

  In the above embodiment, the rotary connector using two flat cables 3A and 3B are described. However, the present invention is applied to a multi-turn rotary connector using three or more flat cables. Needless to say, it can be done.

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 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 3A, 3B Flat cable 3a Inversion part 4 Holder 4a Annular flat plate part 4b Guide wall 4c Support shaft 4d Through-hole 5 Case 5a Outer cylinder part 6 Cover 6a Bottom plate part 6b Lower storage part 7 Upper rotor 7a Top plate part 7b Inner cylinder part 7c Upper storage part 8 Lower rotor 9 Annular space 10 Outer lead block 11, 13 Lead wire 11a, 13a External connector 12 Inner lead block 14 Roller 15 Open passage

Claims (3)

A stator having an outer cylindrical portion, a rotor rotatably connected to the stator and provided with an inner cylindrical portion that defines an annular space with the outer cylindrical portion, and a winding direction in the middle of the annular space And a plurality of flat cables whose both ends are led out to the outside via the inner cylinder part and the outer cylinder part, and a holder rotatably arranged in the annular space, With
A guide wall having one opening passage is provided in the holder, and the inner wall surface of the guide wall is formed in a cylindrical shape so as to surround the inner cylinder portion, and from the rotation center of the rotor to the outer wall surface of the guide wall. The rotary connector is characterized in that the distance is set to be larger in the vicinity of the opening passage than in other portions, and all the reversing portions of the flat cables are arranged in the opening passage.   In Claim 1, The both ends of each said flat cable are each connected to a common inner lead block and an outer lead block, The said inner lead block is fixed to the said inner cylinder part, A rotary connector characterized by being fixed to an outer cylinder part. The rotation according to claim 1 or 2, wherein the holder is provided with an annular flat plate portion having an outer diameter that is substantially the same as the inner diameter of the outer cylinder portion, and the guide wall is erected on the annular flat plate portion. connector.

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