JPS6159934B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a switch device for an automobile that can be applied to, for example, commands to set or cancel a constant speed cruise control device.

Generally, in an automobile switch device, only the horn switch is placed on the top of the steering wheel, some of the other switches are mounted on the steering wheel column, and the rest are placed on the instrument panel. However, it is desirable that switches such as a constant speed cruise control device that must be operated while the vehicle is running can be operated while touching the steering wheel, and that they are located at a position where they can be instantly identified.

However, since the steering device is rotatably attached to the vehicle body, it is not easy to attach switches to the steering device. Regarding the above-mentioned horn switch, a direct current path including, for example, a contact ring is provided to electrically connect the horn mounted on the vehicle body and the horn switch on the steering wheel. . However, when installing other switches, providing such a DC current path for each switch leads to the structural complexity of the device, and furthermore, there is a problem of lowering the reliability of the device.

In order to eliminate such problems,
In the switch device described in Publication No. 41527, 1
It has been proposed to use a direct current path to generate different voltage signals when each of a plurality of switches is operated, and to transmit them through this direct current path. However, in this method, there is a risk that disturbances such as voltage fluctuations in the on-vehicle battery or voltage drops occurring in the contact ring or other parts may impede accurate determination of the voltage signal corresponding to each switch.

SUMMARY OF THE INVENTION An object of the present invention is to provide a highly reliable automobile switch device that eliminates the above-mentioned problems.

Another object of the present invention is to provide a switch device for a motor vehicle that has a simple construction, and in particular, can easily supply power to equipment added to a steering system.

The present invention will be described below with reference to an embodiment shown in the accompanying drawings. In the accompanying drawings, a steering device H projects from the front of the vehicle interior toward the interior of the vehicle interior, and is supported by a vehicle body B via a known rotation transmission mechanism R. The steering gear H has an open/close switch 5 including a normally open contact for instructing the activation of a warning horn, and an operating device 1 consisting of a plurality of electric switches 1a, 1b, and 1c, which are operated on the inside of the vehicle. The parts are exposed and are mounted at sufficient intervals on the steering gear. The open/close switch 5 is connected to a horn relay 7 and an on-vehicle battery 8 in the vehicle body B via a DC current path 6 including a known contact ring 6a. When the on-off switch 5 is closed, the horn relay 7 is energized by the DC current flowing from the on-vehicle battery 8 to the body ground via the DC current path 6 and the on-off switch 5, and a horn (not shown) is sounded. Ru.

A transmitting circuit 2 is attached to the steering device H,
This transmitter circuit 2 is operated by being supplied with power from an on-vehicle battery 8 via the DC current path 6, and generates frequency signals corresponding to the open/close signals of the electric switches 1a, 1b, 1c, and superimposes them on the DC current path. It is configured to transmit the information to the electrical device on the vehicle body side. In the transmitting circuit 2, a signal generating circuit 201 generates a frequency code signal corresponding to the electric switches 1a, 1b, 1c when the switches are closed, and a well-known M58480 manufactured by Mitsubishi Electric Corporation is used. This signal generation circuit 201 is a key input terminal
A preprogrammed frequency code signal corresponding to the closing of I ₁ , I ₂ and scan output terminals Φ _C , Φ _D , Φ _E is generated on a carrier wave of several tens of kilohertz three times each at the output terminal OUT. . 202 is an external ceramic resonator circuit that provides a reference clock signal to the signal generating circuit 201, and 203 is an amplifier circuit consisting of an inverter and Darlington connected transistors.

204 is a superimposition circuit, and the transmission drive coil 204
0, Transmission coil 2041, Oscillation capacitor 2
042, is composed of a surge absorbing diode 2043, and when a frequency code signal is passed through the amplifier circuit 203 to the transmitting coil 2041, the transmitting coil 2041 receives a frequency signal synchronized with the frequency code signal by electromagnetic induction. is induced.
The transmitting coil 2041 and the capacitor 2042 form an LC resonant circuit whose resonant frequency is determined to match the carrier wave frequency, and the frequency signal generated in this resonant circuit is transmitted to the vehicle body B via the DC current path 6. be done.

Reference numeral 205 denotes a voltage stabilizing circuit, which accumulates charge from the load side terminal of this switch 5 in a capacitor 2053 via a diode 2050 and a resistor 2051 when the open/close switch 5 is open, and at the same time stores charge in a capacitor 2053 via a diode 2050 and a resistor 2051.
A constant voltage V _T is generated by a constant voltage circuit consisting of a signal generation circuit 201 and an amplifier circuit 203.
supply to. Even if the on-off switch 5 is temporarily closed, the charge accumulated in the capacitor 2053 is discharged, thereby enabling the transmission circuit 2 to operate. The Zener diode 2054 limits the voltage value of the high voltage pulse generated in the transmitting coil 2041. A resistor 206 is a protective resistor for the open/close switch 5.

A receiving circuit 3 is installed in the vehicle body B.
This receiving circuit 3 is operated by being supplied with power from an on-vehicle battery 8, and picks up only the frequency code signal superimposed by the transmitting circuit 2 from the DC current path 6 going from the steering wheel H to the alarm relay 7, and also picks up the frequency code signal superimposed by the transmitting circuit 2. The code signal is decoded to generate an electric signal corresponding to the closing of each of the electric switches 1a, 1b, 1c, and is applied to the electric device 4, for example, a constant speed cruise control device.

In the receiving circuit 3, 301 is a frequency signal extraction circuit, and the frequency code signal applied to the primary coil by the pulse transformer 3010 is transmitted to the secondary coil. The frequency signal induced in the secondary coil has its peak value limited by the Zener diode 3013 and is input to the waveform shaping circuit 302. 30
12 is a smoothing capacitor 3013 that absorbs noise induced from the engine ignition system etc. in the DC current 6;
is also a surge absorption diode. The frequency signal extracted by the frequency signal extraction circuit 301 is waveform-shaped by a known waveform shaping circuit 302,
Signal disconnection circuit 304 via AC coupling circuit 303
is input.

This signal decoding circuit 304 is manufactured by Mitsubishi Electric Corporation.
M58481 is used, and the signal generation circuit 20
1 and generates preprogrammed decoding signals at channel control output terminals P ₀ , P ₁ , and P ₂ . Here, the signal generating circuit 201 and the signal decoding circuit 304 are connected to the operating device 1.
When the electric switch 1a is closed, if the frequency code signals generated from the signal generation circuit are input three times in agreement, the output terminal _P0 becomes high level, and similarly when the electric switch 1b is closed, the output terminal P0 becomes high level. Output terminal P ₁ becomes high level and electric switch 1
The output terminal _P2 is programmed to be at a high level when c is closed.

305 is an external ceramic resonator circuit attached to the signal decoding circuit. CR oscillation circuit 306,
A binary counter 307 used as a delay circuit, a three-input NOR gate 308, and a transistor switch circuit 309 constitute a reset circuit. Then, when any of the output terminals P ₀ , P ₁ , and P ₂ becomes high level, the binary counter 307 is restarted by the 3-input NOR gate 308, and after several hundred milliseconds, the signal decoding circuit is activated by the transistor 309. 304's external control terminals I ₁ and Φ _D are short-circuited. As a result, the signal decoding circuit 305 sets all output terminals P ₀ , P ₁ , and P ₂ to low level. 310 is a transistor switching circuit that amplifies the output signals generated at the output terminals P ₀ , P ₁ , and P ₂ and applies the amplified signals to the electrical device 4 . 311 is an operating switch for the receiving circuit 3; 312
313 is a power-on reset capacitor, and 313 is a known voltage regulator circuit block 3130 (for example, a 3-terminal regulator μ manufactured by Fairchild).
This is a power supply circuit using A78L05). Note that when the electrical device 4 has a switch (ignition switch or independent operating switch) for switching between supplying and stopping power from the on-board battery 8, that switch and the receiving circuit operating switch 311 or the receiving circuit from the on-board battery 8 3 (not shown) can be configured to operate in conjunction with the power supply switch (not shown).

In the above configuration, when the electric switches 1a, 1b, 1c of the operating device 1 are closed, a predetermined frequency signal corresponding to each switch is transmitted to the vehicle body B via the DC current path 6. The vehicle body B decodes the frequency signal and generates electrical signals corresponding to the switches 1a, 1b, 1c, which are applied to the electrical device 4. The electrical device 4 is thus controlled by an electrical switch on the steering gear H. Note that when the on-off switch 5 is closed to activate the alarm, the transmitting circuit 2 cannot transmit a frequency signal through the DC current path 3, but when the on-off switch 5 is closed and then opened, the voltage stabilizes. Due to the charge accumulated in the capacitor 2053 in the conversion circuit 205, the transmitting circuit 2 is immediately activated and signal transmission becomes possible.

As described above, in the present invention, the DC current path for the horn that electrically connects the steering device and the vehicle body is also used to transmit frequency signals corresponding to a plurality of electric switches. Furthermore, since the structure is configured to also feed power to the transmitting circuit added to the steering device, there is an excellent effect that signal transmission is ensured and there is no need to add extra electrical wiring to the vehicle for this purpose.

[Brief explanation of the drawing]

The accompanying drawings are electrical wiring diagrams showing one embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Operating device, 1a, 1b, 1c... Electric switch, 2... Transmission circuit, 201... Signal generation circuit, 204... Superimposition circuit, 205... Voltage stabilization circuit, 3... Receiving circuit, 301 ... Frequency signal extraction circuit, 304 ... Signal decoding circuit, 5 ... Opening/closing switch, 6 ... DC current path, 7 ... Horn relay, B ... Vehicle body, H ... Steering device, R ... Rotation transmission mechanism.

Claims (1)

[Scope of Claims] 1. A steering device that protrudes from the front of the vehicle interior toward the inside of the vehicle interior and is rotatably supported by the vehicle body,
Moreover, this steering device is equipped with an on/off switch for instructing the operation of the horn, and this on/off switch is connected to the power source on the vehicle body side and the horn load by a DC current path. In the automotive switch device configured such that changes in direct current caused by opening and closing of the on/off switch are detected on the vehicle body side, the steering device is configured such that the operated part is exposed on the inside of the vehicle interior. a plurality of electric switches arranged in the electric switch; a signal generating means for generating a frequency signal including information components corresponding to each operation of the electric switch; and a frequency signal generated from the signal generating means to be applied to the DC current path. A superimposing means for superimposing the signal, and a voltage stabilizing means that is supplied with power from the DC current path in parallel with the on-off switch and converts it into a stable DC voltage to operate the signal generating means and the superimposing means, A switch device for an automobile, characterized in that a decoding means for extracting a frequency signal superimposed on the DC current path is provided on the vehicle body side. 2. The signal generating means is configured to continuously generate a frequency signal corresponding to each of the electric switches a plurality of times, and the decoding means is configured to generate a frequency signal that corresponds to each of the electric switches a plurality of times, and the decoding means includes information components that match the frequency signals a predetermined number of times. 2. A motor vehicle switch device as claimed in claim 1, characterized in that it produces an output signal which is valid when the switch is activated.