JPS6248834A - Wiring system for vehicle - Google Patents

Abstract

PURPOSE:To decrease the number of connected optical fibers by connecting control units in a ring form through optical fibers to constitute a data network and outputting only the required signal as an electric signal. CONSTITUTION:In turning on an operation switch in an on-vehicle wiring system 1 to operate a load 16, a command signal is fed to one of parallel electric input terminals 22 of the 1st control unit 2. A CPU 36 reads periodically parallel signal information given in an input buffer 26 via a parallel input/output circuit 30. The parallel signal is converted into a serial signal by a conversion circuit 42 and converted into an optical signal by an electrooptic converter 40 and then sent to an optical fiber 8. The optical signal sent to the 3rd control unit 6 is converted into an electric signal by a photoelectric converter 41. The CPU 36 reads periodically the parallel signal to share the data to a control object load of the unit 6 and the data transferred to the 2nd control unit 4. The signal of the unit 6 to be outputted is outputted to an output buffer 28.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial field of application The present invention is applicable to various devices such as operation switches, lamps, and relays arranged in vehicles such as buses and trucks, which are transmitted via optical fibers. The present invention relates to a vehicle wiring system that is controlled using multiplexed signals.

(B) Prior art and its problems Conventionally, in vehicles such as buses and trucks, the load and the battery that is its power source have been directly connected via an operating switch on the driver's seat. Therefore, it is necessary to use relatively large diameter electric wires for each connection between the variable operation switch and the load, and as a result, the outer diameter of the bundled wiring cable must also be increased.

However, in recent years, the number of various operating switches, lamps, and other devices has increased due to safety requirements. Therefore, in the conventional connection using electric wires, the number of wires increases accordingly. On the other hand, for example, cab-over type buses and trucks do not have an engine compartment in front of the driver's seat, and it is necessary to secure a certain amount of living space around the driver's seat from above. As a result, the allowable space for wiring cables within the instrument panel is extremely limited. For this reason,
If you were using a thick wiring cable as shown above,
Wiring connections between various devices become difficult.

To counter this, in recent years, as shown in Figure 3, instead of directly connecting the operating switch S and the load, a relay box containing relays R is installed between the two, and from the operating switch S to the load. Operate relay R with the signal of
Power from battery B is supplied to the load from the contact on the secondary side of. In this way, the operation switch S and the relay R can be connected using a small-diameter electric wire W, so that it is possible to reduce the diameter of the bundled wiring cable.

However, even in this case, the total number of wires remains the same, and depending on the location of the load and the location of the relay box, the number of wires may increase, so it cannot be a drastic measure.

In order to overcome the above-mentioned difficulties, the use of optical fibers is being considered. In other words, when transmitting multiple channels of signals between two points, the transmitting side serializes parallel electrical signals, converts them into electrical and optical signals, and transmits them through optical fibers.
On the other hand, on the receiving side, the serial power signals from the optical fiber are converted into opto-electrical signals, and then serially-parallel converted to control the respective target loads. As a result, multiple electric wires can be replaced with a single optical fiber, making it possible to further reduce the diameter of the distribution cable. However, conventionally, data is transmitted bidirectionally between two points using two optical fibers, so operation switches, lamps,
When devices such as relay boxes are distributed in various locations, it is necessary to use a large number of control units that control the input and output of signals to these devices, and many optical fibers that connect them. The problem is that it is expensive.

The present invention was made in view of these circumstances, and it reduces the number of control units and optical fibers that connect them, and reduces the number of various devices such as operation switches, lamps, and relay boxes. It is an object of the present invention to provide a wiring system for a vehicle that can be controlled within an allowable space and can be realized at low cost.

(c) Means for Solving the Problems In order to achieve the above-mentioned object, the present invention provides a method for connecting a plurality of control units that control the input and output of signals to various devices such as operation switches, lamps, and relay boxes. are connected in a ring shape via optical fibers to form a data network, the optical signal transmission direction of the data network is unidirectional, and only necessary signals are transmitted from among the control signals sent from each control unit. The control signal is output as an electrical signal, and the remaining control signals are multiplexed with the control signal input from its own control unit and transmitted to the next control unit.

(d) Examples Hereinafter, the present invention will be explained in detail based on examples shown in the drawings.

FIG. 1 is a block diagram of an embodiment in which the vehicle wiring system of the present invention is applied to a truck.

In the figure, numeral l indicates the entire vehicle wiring system, and numeral 2 indicates a first control that is connected to operating switches (not shown) for wipers, headlights, starters, etc. and their display lamps, and controls the input and output of signals to these. Unit 4 is a second control unit which is connected to operation switches (not shown) such as an evaporator, clutch switch, door lock switch, etc. and their indicator lamps, and controls the input/output of signals to these. Further, 6 is a third control unit that controls input and output of control signals to and from a relay box 10, which will be described later. The first control unit 2 is disposed in a combination switch section in front of the driver's seat in the instrument panel, and the second control unit 4 is disposed in a center console section in the instrument panel. Further, the third control unit 6 is arranged under the floor of the driver's seat. And the 11th second and third control unit 2.4.6
They are connected to each other in a ring shape via one optical fiber 8. This constitutes a data network NT that transfers data between the eleventh second and third control units 2.4.6. That is, this data network NT functions as a type of simple local area network (LAN).

10 is a relay box composed of a plurality of relays 12, and the contacts 14 of each relay 12 are turned on and off in response to a control signal from the third control unit 6. 16 is a load such as a starter and a wiper that are individually connected to each relay 12; 18 is a sensor for checking the operation of the load 16; and 20 is a battery that serves as a power source for the load 16.

FIG. 2 shows the 11th second and third control units 2.
4.6, each of these control units has the same configuration.

That is, in the figure, 22 is a parallel electrical input terminal to which signals from the operation switch and sensor 18 are manually input, 24 is an output terminal for outputting signals to the display lamp and relay, 26 is an input buffer, 28 is an output buffer, and 30 .32 is a parallel input/output circuit, and 36 is a CPU1 that controls input/output signals.
38 is a ROM that stores a control program, 40 is an electro-optical converter connected to the optical fiber 8, 41 is an opto-electric converter, and 42 is a conversion circuit that mutually converts input/output signals into parallel/serial/serial/parallel data. .

In the vehicle wiring system 1 having such a configuration, when one operation switch is turned on to operate the load 16, a command signal is sent to, for example, any one of the parallel electrical input terminals 22 of the first control unit 2. Added to the terminal. The CPU 36 inputs the parallel signal information given to the input buffer 26 via the parallel input/output circuit 30.
read periodically. This parallel signal is converted into a serial signal by a conversion circuit 42, and then converted into an optical signal by an electro-optical converter 40, and then transmitted to the optical fiber 8.

The optical signal transmitted to the third control unit 6 is converted into an electrical signal by the opto-electrical converter 41.

The CPU 36 periodically reads the parallel signal converted by the conversion circuit 42 and distributes data to the load to be controlled by the third control unit 6 and data to be transferred to the next second control unit 4. The signal to be output to the load to be controlled by the third control unit 6 is output to the output buffer 28 via the parallel input/output circuit 32.

On the other hand, the data to be transferred to the next second control unit 4 is transferred from the CPt 136 to the conversion circuit 42 as a new parallel signal together with the parallel signal information of the input buffer 26 input from the parallel electrical input terminal 22 of the third control unit 6. The signal is sent and converted into a serial signal, and then converted into an optical signal by an electro-optical converter 40, and then transmitted to the optical fiber 8.

The parallel signal output to the output buffer 28 is sent to and output from a predetermined relay 12 of the relay box 10 via the parallel electrical output terminal 24. As a result, the relay 12 is activated and the contact 14 is turned on, so that the load 1 is transferred from the battery 20 to the load 1.
Power is supplied to 6.

When the operation of the load 16 is detected by the sensor 18, a detection signal is sent to the third control unit 6.廿 lips 1-? -1-i;) The signal is then converted into an optical signal by the third control unit 6 and transmitted over the data network NT.

The signal passes through the second control unit 4 to the first
When the optical signal reaches the control unit 2 and is inputted thereto, the optical signal based on the detection signal of the sensor 18 is converted into an electrical signal and then applied to the indicator lamp of the previously operated switch. This turns on the indicator lamp, allowing you to check the operation of the load.

Although the control units are provided at three locations in this embodiment, the control unit is not limited to this, and may be provided at an even greater number of locations. Further, in this embodiment, a truck has been described, but it goes without saying that the present invention can be applied to other vehicles such as buses.

(E) Effect As described above, according to the present invention, each control unit is connected in a ring shape via an optical fiber to form a data network, and the necessary control signals sent from each control unit are Only the signal is output as an electrical signal, and the remaining control signals are multiplexed with the control signals input from the own control unit and transmitted to the next control unit. The number of points used will decrease. Therefore, even in cases where the engine room is not provided in front of the driver's seat, such as in cab-over type buses and trucks, the allowable space for wiring cables in the instrument panel is extremely limited. Excellent effects such as being able to control various devices such as operation switches, lamps, and relay boxes are exhibited.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a vehicle wiring system showing an embodiment of the present invention, FIG. 2 is a block diagram of the control unit shown in FIG. 1, and FIG. 3 is a block diagram of a conventional wiring system. l... Vehicle wiring system, 2.4.6... Control unit, 8... Optical fiber, NT... Data network.

Claims (1)

[Claims] (1) In a vehicle wiring system in which multiple control units are arranged to control the input and output of signals to various devices such as operation switches, lamps, and relay boxes, a ring is connected between each control unit via an optical fiber. The optical signal transmission direction of the data network is unidirectional, and only necessary signals among the control signals transmitted from each control unit via the optical fiber are converted into electrical signals. A vehicle wiring system characterized in that the remaining control signals are multiplexed together with the control signals input from its own control unit and transmitted to the next stage control unit.