Special Issue

Automobile Electronics

RelatedRelated productproduct

Steering Roll Connector

1.

INTRODUCTION

The Steering Roll Connector (SRC) is a rotatable connector which electrically connects the steering wheel and thecolumn with the vehicle body, and then transmits signals
and supplies power from the vehicle body to the various
switches within the steering wheel and the column.
The SRC consists of flat cables with high-flexibility aselectrical wiring materials and achieves a high rotation
durability and quietness.
In the case of a vehicle accident, the SRC transmits atrigger signal to an air-bag inflator (gas generator) within
the steering and the column to activate an air-bag, andalso transmits signals to the various switches, such ashorn switches, which are attached to the steering wheel
and the column.
Some vehicles have a steering wheel heater which
offers comfortable driving without feeling coldness of thesteering on cold days, thus the SRC supplies high current
for heating up the steering wheel.
Furukawa Automotive Systems Inc. (Furukawa AS) is
the world-leading SRC manufacturer and we use proprietary Multi-Tape U-Turn Method which is the mainstream of
our new products in recent years.

2.

STRUCTURE OF
THE MULTI-TAPE U-TURN TYPE

The feature of this method is that 4 flat cables are woundin spirals with a “u-turn” shape inside the housing (theouter case). The repulsion force of the cables enables thesteady rotation without a cable loosening. (Figure 1)(Figure 2)
Flat cables

Figure 1 Internal structure of the Multi-Tape U-Turn Type.

Rotatable housing

Fixed housing

Flat Cable

Fixed housing
Rotatable
housing

Figure 2 Parts composition of the Multi-Tape U-Turn Type.

3.

FEATURE OF
THE MULTI-TAPE U-TURN TYPE

By packaging multiple, 4 or more, flat cables within theconventional case, the Multi-Tape U-Turn Type can provide
a small and light product without an increase in the product’s height and can be applicable to a multi-circuit and ahigh current.
Reduction in the part count (light weight, low cost)· No need for auxiliary parts of rotation for winding/unwinding cables.
· No need for auxiliary parts to keep quietness.
Applied to multi-circuit in thin thickness· Although the required number of the conductors increases
as the number of circuit increases, it can be easily
achieved without changing the product’s height by using
multiple flat cables internally installed.
Applied to high current in thin thickness· Although the wider conductor width are required as conducting current increases, it can be easily achieved without changing the product’s height by using multiple flat
cables internally installed.
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2013

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Steering Roll Connector

Optimized design for CAN communication circuitapplication· Although the characteristic impedance varies as thewinding status of the flat cables varies, the cables areclosely-located to each other and the winding status issteady in the Multi-Tape U-Turn Type. Therefore, by considering conductor placement, it is possible to optimize
the impedance design for CAN communication circuit
application.

4.

MANUFACTURING AND EVALUATIONOF SRC

Furukawa AS has been manufacturing SRC since 1990.
At present the company has established global supply
system holding 9 plants all over the world. An integrated
manufacturing from the flat-cables to SRC assembling is
the feature of our manufacturing technology. As the flatcable and a wire end connection technology, the metal
jointing by the ultrasonic welding is applied between bothof the flat-cable and a bus bar, the wire and the bus bar,
also jointing parameters are monitored and the jointing
condition is checked, thus the jointing reliability isensured.

The company implements the durability evaluation inconsideration of the market environment by using therotation type durability test equipment which can set thevarious conditions such as rotation pattern, rotational
speed, temperature etc. Rotation noise measurement andfrequency analysis simulating the equipped environmentof the vehicle are available.

5.

CONCLUSION

Besides Multi-Tape U-Turn Method, we provide the technologies of Roller U-Turn Method and Spiral Method
according to types of winding/unwinding flat cables.
We can propose the optimized methods and put theminto production for diversified requirements of customers
with mounting space, variation in the number of circuitand conducting current.
For more information, please contact:
SRC Department,
Electrical/Electronic Components Department,
Production Division
Furukawa Automotive Systems Inc.
Tel: +81-595-85-1526 Fax: +81-595-85-2310

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