JPH0644052Y2 - Brushless electrical signal transmitter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to transmission and reception of electric signals such as power and signals between a rotating body and a fixed body having a finite number of rotations such as a steering device of an automobile. The present invention relates to a brushless electric signal transmission device used when performing.

[Prior Art] In a conventional brushless electric signal transmission device of this type, as shown in FIG. 4, a substantially cylindrical first housing 1 and a second housing 2 are concentric with each other and relatively. Although not shown, the flat cable is housed in a spiral shape in a ring-shaped chamber formed by the housings 1 and 2 which are rotatably combined.
One end (outer end) of the flat cable is fixed to the first housing 1, the other end (inner end) is fixed to the second housing 2, and both ends of the flat cable are connected to each other via connecting portions (not shown). The structure was such that the other conductors 4 such as the wire 3 were connected to each other.

In such a brushless electric signal transmitting device, either one of the housings can rotate to the same extent in both forward and reverse directions at the neutral position of the steering device of the automobile.
However, if the steering device is assembled in a state in which it is displaced from the neutral position, there is a difference in the number of rotations in both the forward and reverse directions, and in the direction in which the number of rotations decreases, it is dangerous that the steering device cannot rotate any further.

In order to improve this, there has been proposed a brushless electric signal transmission device having a structure in which a flat cable is fixed to a housing by a cutter and the flat cable is cut when the flat cable is rotated more than a predetermined amount (Japanese Utility Model Publication No. 63-188886).

[Problems to be solved by the invention] However, in such a structure in which the flat cable is cut by the cutter, it is necessary to provide an extra space in the housing, the housing becomes large, and the housing is installed in a limited space in the vehicle. There is an unfavorable problem as a brushless electric signal transmission device that must be performed.

It is an object of the present invention to provide a brushless electric signal transmission device capable of disconnecting a flat cable without increasing the size of the housing.

[Means for Solving the Problems] The structure of the present invention for achieving the above object will be described. In the present invention, the first housing and the second housing are concentrically and relatively rotatably combined. A flat cable is housed in a spiral shape in a ring-shaped chamber formed by the two housings, one end of which is fixed to the first housing and the other end of which is fixed to the second housing. In a brushless electric signal transmission device in which another conductor is connected to at least one end through a connecting portion, the connecting portion has a breaking tension smaller than a breaking tension of the flat cable. To do.

[Operation] With such a structure, when the steering device rotates more than a predetermined amount, the connecting portion is a mechanical weak point, so the connecting portion is broken, and it is impossible to prevent the steering device from rotating more than the predetermined amount. If the connecting portion is a mechanical weak point, a cutter or the like is not needed, and the housing can be prevented from increasing in size.

Embodiments Embodiments of the present invention will be described in detail below with reference to the drawings.

1 and 2 show a first embodiment of the present invention. In the brushless electric signal transmission device according to the present embodiment, the flat cable 5 and the other conductor 4 are connected to each other by the conductor connecting portion 7 such as ultrasonic welding that connects the conductor 6 of the flat cable 5 and the other conductor 4 to each other. The periphery is connected by a connecting portion 9 having a structure molded with the molding resin 8. In this case, at least the insulating coating 10 of the flat cable 5 and the conductor 6 are not adhered to the molding resin 8 at the connection portion 9, and when tension acts on the flat cable 5 side, the tension reaches a predetermined value or more. At this time, the conductor connecting portion 7 is disconnected, and the flat cable 5 can be pulled out from the molding resin 8. Therefore, the connection portion 9 has a structure having a breaking tension smaller than that of the flat cable 5. The mold resin 8 is adapted to be fixed to the connection portion storage portion 2A within the connection portion storage portion 2A (see FIG. 4) of the second housing 2, for example.

FIG. 3 shows a second embodiment of the present invention. In the brushless electric signal transmission device of the present embodiment, the molding resin 8 in the connecting portion 9 between the flat cable 5 and another conductor (not shown in FIG. 3) is thinner than the other portion in the central portion in the longitudinal direction. The thin wall portion 8A is provided, and the cut portions 11 are intermittently formed in the thin wall portion 8A. In this case, the molding resin 8 on the side of the conductor 4 (not shown) is fixed to the storage portion 2A for the connecting portion by using the thin portion 8A as a sakai.

The connecting portion 9 having such a structure also has a breaking tension smaller than the breaking tension of the flat cable 5 due to the presence of the thin portion 8A and the cut portion 11.

In the brushless electric signal transmission device having the connecting portion 9 of the first and second embodiments, when the steering device rotates more than a predetermined amount, the connecting portion 9 becomes a mechanical weak point and is broken, so that the steering device is kept above the predetermined amount. Does not interfere with rotation.

[Effects of the Invention] As described above, in the brushless electric signal transmission device according to the present invention, since the connecting portion itself between the flat cable and the other conductor is a mechanical weak point, the steering device is rotated more than a predetermined amount. At times, the connection portion is broken, and it is impossible to prevent the steering device from rotating more than a predetermined amount.
In particular, if the connecting portion itself has such a mechanical weakness as described above, it is not necessary to incorporate another member such as a cutter for breaking, and the connecting portion is not increased in size. Therefore, the housing is increased in size. First, there is an advantage that it does not hinder the installation in the limited space in the automobile.

[Brief description of drawings]

1 and 2 are a longitudinal sectional view and a partially broken perspective view of a connecting portion in a first embodiment of a brushless electric signal transmission device according to the present invention, and FIG. 3 is a brushless electric signal transmission device according to the present invention. FIG. 4 is a partially cutaway perspective view of a connecting portion in the second embodiment, and FIG. 4 is a perspective view showing an example of a brushless electric signal transmission device. 1 ... first housing, 2 ... second housing, 3
...... Lead wire, 4 ... Outer conductor, 5 ... Flat cable, 6 ... Conductor, 7 ... Conductor connection part, 8 ... Mold resin, 8A ... Thin wall part, 9 ... Connection part, 10 ... … Insulation, 11
...... Notch.

Claims (1)

[Scope of utility model registration request] 1. A first housing and a second housing are concentrically and rotatably combined with each other, and a flat cable is housed in a spiral shape in a ring-shaped chamber formed by the both housings. In the brushless electric signal transmission device, one end is fixed to the first housing, the other end is fixed to the second housing, and another conductor is connected to at least one end of the flat cable through a connecting portion. The brushless electric signal transmission device, wherein the connection portion has a structure having a breaking tension smaller than a breaking tension of the flat cable.