JP2005228561A - Rotating connector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotating connector in which cost is reduced drastically by shortening the required length of a flat cable. <P>SOLUTION: This is the rotating connector in which a rotor 2 having an inner tube part 7b is connected rotatably to a starter 1 having an outer tube part 5a, and a flat cable 3 is housed in a reversed state in an annular space 9 demarcated between these outer tube part 5a and the inner tube part 7b and the reversed portion 3a of the flat cable 3 is made to pass through the aperture 14 of a holder 4 arranged rotatably in the annular space 9. A guide wall 4b having an outer circumference face which is offset to the center of rotation of the rotor 2 is installed on an annular flat plate part 4a of the holder 4, and the flat cable 3 is wound around the outer circumference face of this guide wall 4b and is made in a rewound state. <P>COPYRIGHT: (C)2005,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 band-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 other hand, the flat cable is drawn out from the inner cylinder portion and 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 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 flat cable can be smoothly fed out in the direction of the reversal part.
Japanese Patent Laying-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 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 flat cable in which both ends thereof are led out to the outside through the inner cylinder part and the outer cylinder part, and the annular ring. A holder that is rotatably disposed in the space and has an opening through which the reversing portion of the flat cable passes, and is provided with a guide wall that extends to surround the inner tube portion with the opening as a base end The distance from the rotation center of the rotor to the outer wall surface of the guide wall is set to be maximum in the vicinity of the opening compared to other portions.

  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. The flat cable wound around the inner wall side of the outer cylinder part is wound around the outer wall surface of the guide wall provided in the holder by further rotating the rotor in the same direction after being wound around the inner wall of the outer cylinder part. Turned to rewind. On the contrary, when the rotor is rotated in any other direction from the state where the flat cable is rewound on the outer wall 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 once 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. The overall length along the circumferential direction of the outer wall surface of this guide wall is sufficiently shorter than the overall length along the circumferential direction of the inner wall surface of the outer cylinder portion, so that the length of the required flat cable should be significantly shortened. Can do.

  In the above configuration, the guide wall has a cylindrical outer peripheral surface, and the flat cable that goes through the opening toward the outer cylinder portion is eccentric with respect to the rotation center of the rotor. It is preferable to configure as described above. Alternatively, the guide wall has a restricting portion located in the vicinity of the opening and an annular portion surrounding most of the inner cylindrical portion, and a flat cable extending through the opening toward the outer cylindrical portion has a noncircular shape on the guide wall. It is preferable to be constituted so as to be wound around.

  Further, in the above configuration, it is preferable that the roller is supported in the vicinity of the opening of the holder, and the flat cable that goes through the opening toward the outer cylinder portion is wound around the roller and the guide wall. In this case, it is preferable that the holder has an annular flat plate portion having substantially the same outer diameter as the inner diameter of the outer cylinder portion, and a roller is pivotally supported on the annular flat plate portion and a guide wall is provided upright.

  The rotary connector according to the present invention has an opening through which a reversing portion of a flat cable passes 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. A guide wall extending so as to surround the cylinder portion is provided, and the distance from the rotation center of the rotor to the outer wall surface of the guide wall is set to be maximum in the vicinity of the opening as compared with other portions. Thus, the flat cable is wound around the small-diameter guide wall so as to be rewound, and the required length of the flat cable can be greatly shortened accordingly.

  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. 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 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 center hole 6c is formed at the center 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 snap coupling, the lower opening end of the outer cylinder portion 5a is formed by the bottom plate portion 6a. While being closed, 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 portion 8a. The lower rotor 8 is inserted into the center hole 6c of the cover 6 and snap-coupled to the inner cylinder portion 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 the bottom plate portion 6a on the stator 1 side, and the top plate portion 7a and the 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 9, 10 are connected to both ends of the flat cable 3, respectively. One lead block 9 is fixed in the lower housing portion 6b of the cover 6, and a lead wire 11 having an external connector 11a at the tip is connected to the lead block 9. The other lead block 10 is fixed in the upper storage portion 7c of the upper rotor 7, and a lead wire 12 having an external connector 12a at the tip is connected to the lead block 10.

  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, which 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 guide hole 4d is formed at the center thereof. The center hole 4d is inserted in 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. A protrusion 4e is formed on the lower surface of the annular flat plate portion 4a to reduce sliding resistance with the bottom plate portion 6a. The guide wall 4b is erected on the annular flat plate portion 4a so as to surround most of the center hole 4d, and its inner peripheral surface is substantially concentric with the center hole 4d. Is very eccentric. 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 13 is rotatably supported on the support shaft 4c, and the reversing portion 3a of the flat cable 3 described above is located in the opening 14 between the roller 13 and the side surface of the guide wall 4b facing the roller 13 (see FIG. 4). Therefore, the distance from the rotation center of the rotor 2 to the outer wall surface of the guide wall 4b is the largest at the part facing the opening 14 through the opening 14, and the part facing the roller 14 at 180 degrees is the smallest.

  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. 4 (a) shows a tightening state in which most of the flat cable 3 is wound around the outer wall of the inner cylindrical portion 7b. When the rotor 2 is rotated counterclockwise (arrow A direction) from this tightening state, Since the reversing portion 3a of the flat cable 3 moves counterclockwise by a smaller rotation amount than the rotor 2, the roller 13 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. 4C, the flat cable 3 is drawn out from the outer tube portion 5a side and wound around the outer wall surface of the guide wall 4b of the holder 4, Thus, most of the flat cable 3 is in a rewind state 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 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 this embodiment, the flat cable 3 is 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 FIG. 4, the flat cable 3 is once wound around the outer cylinder portion 5a located outside the holder 4, and the circumference of the outer wall surface of the guide wall 4b is smaller 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.

The shortening effect of the flat cable 3 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, and FIG. The rotary connector according to the present embodiment in which the flat cable is wound around the guide wall of the holder to be unwound, and in both the rotary connectors, the inner diameter (diameter dimension of the tightened state) of the path of the flat cable is r, If the outer diameter of the path of the flat cable (the diameter dimension in the rewind state) is R, and the finite number of rotations of the rotor is N, the required length L of the flat cable 3 is (L / rπ) + (L / From 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 of the rotary connector 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. 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. 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. 5B 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 inner diameter of the outer cylinder part is 50 mm, the outer diameter of the inner 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-described embodiment, the case where the guide wall 4b continuous in the circumferential direction is erected on the annular flat plate portion 4a of the holder 4 has been described. However, as shown in FIG. 6, the guide wall 4b is scattered in the circumferential direction. Can be used as the guide wall 4b. In this case, the flat cable 3 can be wound around the outer peripheral surface of the guide wall 4b and the roller 13 in a circular shape. Further, the shape of the outer wall of the guide wall 4b plotted is not limited to a cylindrical shape, and as shown in FIG. 7, a non-circular guide wall 4b composed of an annular portion 4b1 and a restricting portion 4b2 is used. The portion may be surrounded by the annular portion 4b1 and the restricting portion 4b2 may be protruded from both ends of the annular portion 4b1 toward both sides of the roller 13. In this case, the flat cable 3 is wound around the annular portion 4b1, the restricting portion 4b2, and the roller 13 of the guide wall 4b in an egg shape.

  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 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. It is a top view of the holder which shows the modification of a guide wall. It is a top view of the holder which shows the modification of a guide wall.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Stator 2 Rotor 3 Flat cable 4 Holder 4a Annular flat plate part 4b Guide wall 4b1 Annular part 4b2 Restriction part 4c Support shaft 5 Case 5a Outer cylinder part 6 Cover 6a Bottom plate part 7 Upper rotor 7a Top plate part 7b Inner cylinder part 8 Lower rotor 9 Annular space 13 Roller

Claims (5)

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 flat cable in which both ends thereof are led out to the outside via the inner cylinder part and the outer cylinder part, and a reversing part of the flat cable, which is rotatably arranged in the annular space. A holder having an opening through which
The holder is provided with a guide wall extending so as to surround the inner cylinder portion with the opening as a base end, and the distance from the rotation center of the rotor to the outer wall surface of the guide wall is closer to the opening than other portions. A rotary connector characterized by being set to the maximum. 2. The guide wall according to claim 1, wherein the guide wall has a cylindrical outer peripheral surface, and the flat cable extending toward the outer tube portion through the opening is eccentric with respect to the rotation center of the rotor. A rotary connector characterized by being wound in a circular shape.
A rotary connector characterized by that.   The said guide wall has a control part located in the vicinity of the said opening, and the cyclic | annular part which surrounds most of the said inner cylinder part, The said heading to the said outer cylinder part through the said opening A rotary connector configured such that a flat cable is wound around the guide wall in a non-circular shape.   4. The roller according to claim 2, wherein a roller is pivotally supported in the vicinity of the opening of the holder, and the flat cable going through the opening toward the outer tube portion is wound around the roller and the guide wall. A rotary connector characterized by comprising. 5. The holder according to claim 4, wherein the holder has an annular flat plate portion having an outer diameter that is substantially the same as the inner diameter of the outer cylinder portion, the roller is pivotally supported on the annular flat plate portion, and the guide wall is erected. A rotary connector characterized by that.

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