JPH07291061A - Transmitting device between rotating body and fixed body - Google Patents

Abstract

PURPOSE:To mitigate the bending stress to be applied to a flat cable in both sides of a reinforcing layer so as to prevent buckling of the flat cable by gradually reducing the bending rigidity of the reinforcing layer from a central part thereof toward both ends. CONSTITUTION:A transmitting device between a rotating body and a fixed body has an outer periphery side case 23 and an inner periphery side case 22, which can be relatively rotated in relation to the outer periphery side case 23. A casing of the transmitting device between the rotating body and the fixed body is formed by combining both the cases. A reinforcing layer 11 has the bending elasticity of such a degree as not to be buckled when a flat cable 10 is tightened or loosened in winding, and it is made of the insulating resin and rubber or the metal coated with them. Bending elasticity of the reinforcing layer 11 is gradually reduced from a central part 11b toward both ends 11a in the longitudinal direction of the flat cable 10, and the reinforcing layer 11 is attached to the predetermined position of the flat cable 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission device used for transmitting electric signals, optical signals, etc. between a rotating body and a fixed body.

[0002]

2. Description of the Related Art Recently, some automobiles are equipped with an air bag system as an auxiliary device for mitigating the impact on the passenger's face in the event of a collision. In an airbag system for a driver's seat, an airbag module is housed in a steering wheel, and a control unit that detects a collision of a vehicle and operates the airbag module is fixed to the vehicle body side. In some automobiles, an operation switch for activating an audio device fixed to the vehicle body side is arranged on the steering wheel. As described above, a transmission device between a rotating body and a fixed body is used to transmit an electric signal or the like between the steering wheel rotated by the occupant and the control unit or the audio device fixed to the vehicle side. There is.

Conventionally, in a transmission device between a rotating body and a fixed body, a flat conductor is covered with an insulator and a flat cable having a constant thickness is formed by an inner case and an outer case. The flat cables are housed by being wound in an annular space, and one end of each of these flat cables is fixed to the circumferential side case and the other end is fixed to the outer circumferential side case. The fixed end consists of a molded part in which one end of the flat conductor of the flat cable is electrically connected and fixed to the terminal, and the connecting part is mechanically fixed by resin molding. Connection is fixed.

Further, as shown in Japanese Utility Model Publication No. 62-1114, a winding stop portion of a flat cable spirally loaded in a case mounted so as to be rotatable relative to a shaft is fixed to the outer circumference of the inner circumference side case. A buckling prevention member of a predetermined length is provided on the upper surface of the winding stopper along the winding direction to prevent the buckling. The buckling prevention member has a larger thickness at the base end portion, and becomes thinner toward the tip end portion (the end on the opposite side of the base end portion) of the member, and the base end portion Is fixed to the inner case.

[0005]

However, in the conventional transmission device between the rotating body and the fixed body, a buckling prevention member for preventing the buckling of the flat cable is attached to the outer circumference of the inner peripheral side case as a separate member. However, there is a problem that an increase in the number of parts causes an increase in the number of assembling steps and an increase in cost. As a countermeasure for this, it is conceivable to use a flat cable having a high rigidity as a whole, but when installing in a vibrating environment such as in an automobile, the contact noise between the flat cable and the case becomes large, which becomes a problem. It is also conceivable to provide a reinforcing layer with a thin wall thickness at the tip as shown in JP-B-62-1114 at a portion of the flat cable where bending is easy, but when bending stress is applied, the wall thickness is reduced. Since stress concentrates on the corner of one end of the thick reinforcement layer on the opposite side, there is a problem that bending occurs at that portion and partial fatigue fracture progresses.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and it is possible to prevent partial fatigue damage due to repeated bending and bending operations of a flat cable without increasing the number of parts and the number of assembling steps. By providing a transmission device between the rotating body and the fixed body, the durability is improved and noise is less likely to occur.

[0007]

In order to achieve the above object, the present invention has an annular shape which is formed by an inner peripheral case and an outer peripheral case which are relatively rotatable and are coaxially combined. The flat cables are wound and stored in the space of the flat cable between the rotating body and the fixed body, one end of which is fixed to the inner case and the other end of which is fixed to the outer case. In the transmission device, a reinforcing layer integrally formed with the flat cable is provided near one end of the flat cable connected to the inner case,
The bending rigidity of the reinforcing layer gradually increases from the central portion of the reinforcing layer toward both end portions in the length direction of the flat cable.

[0008]

According to the transmission device between the rotating body and the fixed body of the present invention, since the reinforcing layer is integrally provided at a specific position on the flat cable where bending operation is likely to occur repeatedly, the assembling property is improved. Further, since the bending rigidity of the reinforcing layer is gradually reduced from the central portion toward both ends, the bending stress applied to the flat cable is relieved on both sides of the reinforcing layer, so that the buckling of the flat cable can be prevented. it can.

[0009]

The present invention will be described in detail below with reference to the drawings. 1 to 3 are explanatory views showing an embodiment of the present invention. The transmission device between the rotating body and the fixed body is the outer case.
23 and an inner peripheral side case 22 that is relatively rotatable with respect to the outer peripheral side case 23. By combining these two cases, the casing of the transmission device between the rotating body and the fixed body is formed. Taking the case where the transmission device between the rotating body and the fixed body is incorporated in an automobile as an example, the outer peripheral side case 23 is
The inner case 22 is fixed to the vehicle body side, is inserted through a steering shaft (not shown), and rotates in conjunction with the steering wheel.

The outer case 23 has a substantially tubular outer body portion 23a.
And a ring plate-shaped upper flange portion (not shown) that closes the upper opening of the outer body portion 23a. Inner case
22 has an inner barrel portion 22a and a lower flange portion (not shown). A central hole through which a steering shaft (not shown) is inserted is formed in the inner trunk portion 22a. The outer peripheral surface of the inner body portion 22a has a molded portion 25 of the flat cable 10 described later.
A storage chamber 26 for storing the is formed. Also, the inner trunk portion 22a
Has a slit 22b for guiding the flat cable 10 from the housing chamber 26 in the direction of winding the flat cable 10 around the outer peripheral surface of the inner barrel portion 22a. The lower flange part (not shown) is the inner body part 22a.
Is integrally formed at the lower end of the.

The inner case 22 is placed in the outer case 23, the upper flange portion (not shown) is butted against the outer body portion 23a to close the upper opening, and the outer body portion 23a and the flange portion are closed. A plurality of outer peripheral positions (not shown) are fastened with screws or the like. An accommodation space for accommodating a flat cable 10, which will be described later, is formed between both cases. Further, the inner peripheral edge of the lower body portion 23a of the outer peripheral side case 23, the inner peripheral edge of the upper flange portion (not shown), the outer peripheral edge of the lower flange portion (not shown) and the upper inner peripheral edge of the inner body portion 22a are , Each has a stepped portion.

[0012] Both cases relatively rotate while a step portion (not shown) is in sliding contact. Such a case is made of synthetic resin or the like. The outer peripheral end of the flexible tape-shaped flat cable 10 is connected to the inner peripheral surface of the outer body portion 23a, and the inner peripheral end is connected to the outer peripheral surface of the inner body portion 22a. Further, as shown in FIG. 2, the slit 22 of the inner body portion 22a is
A reinforcing layer 11 is provided on the flat cable 10 near the tip of b. A housing chamber 27 for housing and fixing the outer peripheral end of the flat cable 10 is formed in the outer body portion 23a. In this accommodation chamber 27, the outer peripheral end of the flat cable 10 is
It is connected to a lead wire (not shown) connected to the electric component on the vehicle body side and electrically connected to the electric component on the vehicle body side.

Further, by inserting a terminal (not shown) electrically connected to the inner end of the flat cable 10 into a lower flange portion (not shown) of the inner case 22 of the flat cable 10, The inner end is electrically connected to electrical components on the steering wheel side.

FIG. 3 is a partial perspective view of a reinforcing layer showing an embodiment of the present invention. The reinforcing layer 11 is a flat cable.
10 has a bending elasticity that does not buckle when it is wound tightly and unrolled, and may be, for example, an insulating resin and rubber, or a metal covered with them. Further, the bending elasticity of the reinforcing layer 11 is gradually reduced from the central portion 11b toward both end portions 11a in the length direction of the flat cable 10, and the reinforcing layer 11 is located at a predetermined position of the flat cable 10. It is pasted. Note that the attaching method is not particularly limited, such as adhesion and thermocompression bonding. The attachment position is also not particularly limited. In addition, as described above, in order to gradually change the bending elasticity of the reinforcing layer 11, the following several examples can be considered. Example 1. The cross-sectional shape of the reinforcing layer 11 spreads at the hem like a trapezoid,
In addition, it has an arc shape in which the upper surface of the skirt spreading is concave. Example 2. The width of both ends of the reinforcing layer 11 is gradually narrowed. Example 3. Both ends of the reinforcing layer 11 are partially formed with irregularities or the thickness is changed. Example 4. The reinforcing layer 11 is not made of a single material, but is formed of a composite material in which elasticity is gradually changed by combining a plurality of materials having different rigidity.

FIG. 4 is an explanatory view showing another embodiment of the present invention, and FIG. 5 is a partial perspective view of a reinforcing layer showing another embodiment of the present invention. Note that the description of the same drawing number portion shown in FIGS. 1 to 3 is omitted here. The inner case 32 has an inner body portion 32a and a lower flange (not shown), and is placed in the outer case 23. The inner body 32a has
A central hole through which a steering shaft (not shown) is inserted is formed. A flat portion is provided on the outer peripheral surface of the inner body portion 32a for mounting the mold portion 36 of the flat cable 10. Further, the post 34 is provided near the mold portion 36.
The post 34 has a columnar shape having a surface along the outer peripheral surface of the inner trunk portion 32a. As shown in FIG. 5, the reinforcing layer 11 is housed between the post 34 and the inner body portion 32a.

FIG. 6 is a partial perspective view of a reinforcing layer according to another embodiment of the present invention. As shown in FIG. 6, the reinforcing layer 11 ′ is an insulating layer 10 b covering the conductive material 10 a of the flat cable 10.
Are integrally formed by partially increasing the thickness of the.

[0017]

As described above, according to the present invention, partial bending or buckling of the flat cable is caused in the lengthwise direction of the flat cable by an external force generated by tightening or unfolding the flat cable. Since a reinforcing layer whose bending rigidity is gradually reduced from the center to both ends is integrally provided at a specific portion of the flat cable (where bending or buckling is likely to occur), the bending stress applied to the flat cable is reduced. Since it is relaxed on both sides, buckling of the flat cable can be prevented, the number of parts is reduced, and the assemblability is improved. Further, it has remarkable effects such as cost reduction. Further, as compared with the case of similarly increasing the rigidity of the entire flat cable for the purpose of improving durability, it also has remarkable effects such as preventing a problem of noise generation during vibration.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an embodiment of the present invention.

FIG. 2 is a partial perspective view of a reinforcing layer showing an embodiment of the present invention.

FIG. 3 is a partial perspective view showing an embodiment of the present invention.

FIG. 4 is an explanatory view showing another embodiment of the present invention.

FIG. 5 is a partial perspective view of a reinforcing layer showing another embodiment of the present invention.

FIG. 6 is a partial perspective view of a reinforcing layer showing another embodiment of the present invention.

[Explanation of symbols]

 10 ... Flat cable 11 ... Reinforcing layer 11a ... End 11b ... Center 22 ... Inner case 23 ... Outer case

Claims (1)

[Claims] 1. An inner peripheral case (22) and an outer peripheral case (23) which are relatively rotatable and are coaxially combined.
A flat cable (10) is wound and housed in an annular space formed by and. These flat cables have one end on the inner case (22) and the other end on the outer case. In the transmission device between the rotating body and the fixed body, which are respectively fixed to (23), formed integrally with the flat cable (10) near one end of the flat cable (10) connected to the inner case (22). The reinforcing layer (11) is provided such that the bending rigidity of the reinforcing layer (11) is in the longitudinal direction of the flat cable (10) from the central part (11b) of the reinforcing layer (11) to both end parts (11b). 11a) A transmission device between a rotating body and a fixed body, which gradually decreases toward 11a).