JPH0531583Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a rear warning device for a vehicle that issues an alarm if there is an obstacle behind the vehicle when the vehicle is reversing.

Conventionally, a rear warning device for a vehicle as shown in FIGS. 1 to 3 has been known, and in order to detect an obstacle B in a rectangular area behind a vehicle that is retreating, a vehicle rear warning device is installed on the rear bumper 17 of the vehicle. Signals such as ultrasonic waves and light emitted from spatial wave transmitters (hereinafter sometimes simply referred to as "transmitters") S1 and S2 installed in Transducer (hereinafter sometimes simply referred to as "receiver") S
3. It is designed to receive waves at S4.

Upon receiving the received signal, the distance discriminator circuit (distance discriminator) 11 calculates the time from transmission to reception, and measures the distance between the vehicle and the obstacle B. Then, when the distance is less than a predetermined value, the alarm sound generation circuit 12 operates, thereby
An alarm sound is emitted from the speaker 109 inside the vehicle,
This notifies the driver of the presence of obstacle B.

In addition, the reference numeral 100 in FIGS. 1 and 2 indicates a control unit, and this control unit 100 includes a back-up lamp switch 102 and an ignition switch in addition to the above-mentioned distance discrimination circuit 11 and alarm sound generation circuit 12. key switch 1
04 is closed, a power supply circuit 1, a clock generation circuit 2 for transmission, a timing generation circuit 3,
It includes a transmission oscillation circuit 4 and a transmission amplifier (transmission amplifier) 5, as well as a reception amplifier (reception amplifier) 8, which also functions as an adder, a filter circuit 9, and a detection circuit 10.

The control unit 100 is also connected to the alarm sound generation circuit 12 via a volume (variable resistor) 16 and a power amplifier 13, and is connected to a radio 1.
A speaker switching circuit 14 for switching between inputting the signal from 08 to the speaker 109 and inputting the signal from the power amplifier 13 to the speaker 109.
and a failure detection circuit 1 for detecting failures in the transmitters S1, S2 and the receivers S3, S4.
It has 5.

Further, in FIGS. 2 and 3, reference numeral 101 indicates a back-up lamp, 103 indicates a fuse, and 105 indicates a battery.

Further, as shown in FIG. 3, the transmitting amplifier 5 includes a transformer T1, transistors Tr1, Tr2, resistors R1, R2, R3, R4, R5, R17, and capacitors C1, C2.
The receiving amplifier 8 is an operational amplifier (OP amplifier) IC1,
IC2, resistors R10, R11, R12, R13,
R14, R15, R16 and capacitor C3,
It is composed of C4 and C5.

Note that the symbols R6, R7, R8, and R9 in FIG.
1 shows resistors provided in the transmitters S1 and S2 and the receivers S3 and S4.

By the way, in such a conventional vehicle rear warning device, in order to detect a small obstacle B, the transmission power of the transmitters S1 and S2 or the transmitter power of the wave receivers S3 and S
If you increase the sensitivity to 4, even raindrops (especially large raindrops) will be detected as obstacles when it rains, so
There was a limit to increasing the transmitting power and receiving sensitivity.

The present invention attempts to solve these problems by reducing either the transmitting power or the receiving sensitivity depending on the operation of the wiper switch, thereby reducing the ability to detect rain and detecting raindrops as obstacles. A rear warning system for vehicles that prevents erroneous detection and detects rear obstacles even during rainy weather when it is difficult to see the rear, ensuring rearward visibility at all times regardless of weather conditions. The purpose is to provide equipment.

For this reason, the rear warning device for vehicles of the present invention uses a spatial wave transmitter and a spatial wave receiver provided at the rear end of a vehicle equipped with a wiper that operates when a wiper switch is operated. a distance discriminator connected to the wave transmitter and the spatial wave receiver, an alarm generator connected to the distance discriminator, and a distance discriminator interposed between the spatial wave transmitter and the distance discriminator. a transmitting amplifier having a first transmitting amplifier section; a receiving amplifier interposed between the spatial wave receiver and the distance discriminator and having a first receiving amplifier section; a second transmission amplifier section that is provided in parallel with the amplifier section and has a lower transmission power than the first transmission amplifier section, or
The first receiving amplifier is provided in parallel with the first receiving amplifier.
the second reception amplifier section having a lower sensitivity than the reception amplifier section of the second reception amplifier section;
The present invention is characterized in that it is equipped with a changeover switch for switching the connection to either the transmitting amplifier section or the second receiving amplifier section.

Hereinafter, an embodiment of the present invention will be explained with reference to the drawings. Figs. 4 and 5 show a vehicle rear warning device as the first embodiment, Fig. 4 is a block diagram of the main part thereof, and Fig. 5 is a 4 and 5, the same reference numerals as in FIGS. 1 to 3 indicate substantially the same parts.

Now, in the case of this first embodiment, the configuration inside the control unit 100' is almost the same as the configuration inside the conventional control unit 100 shown in FIGS. 2 and 3, except for the transmitting amplifier 51 as a rain regulator. It's the same.

Further, this vehicle (automobile) is equipped with a wiper, and the operation of the wiper is controlled by the wiper motor M by turning on and off a wiper switch 106 provided in parallel with the ignition key switch 104.
This is done by controlling the

The wiping speed of this wiper can be changed by switching the wiper wiping speed changeover switch 107 to the H terminal side or the L terminal side.

In addition, transmitters S1, S2 and receivers S3, S
4 is disposed on the rear bumper 17 provided at the rear end of the vehicle, as described above.

Furthermore, the transmitter S1. Immediately before S2, a transmission amplifier 51 amplifies the signal from the transmission oscillation circuit 4.
Immediately after the wave receivers S3 and S4, a receiving amplifier 8 is connected which adds and amplifies the signals from the wave receivers S3 and S4 and sends the signals to the detection circuit 10 via the filter circuit 9. ing.

The transmission amplifier 51 includes two transmission amplifier sections 51a and 51b having different transmission powers, and a relay type changeover switch RL1 for switching the outputs from these transmission amplifier sections 51a and 51b.

This changeover switch RL1 is connected to the excitation coil 5.
1c is excited, the low output transmission amplifier section 51
When the excitation coil 51c is demagnetized, the switch is set so that the output from the high-output transmitting amplifier section 51a is supplied to the transmitters S1 and S2. The piece 51d is configured as a switch.

Here, the excitation coil 51 of the changeover switch RL1
C has one end grounded and the other end connected between the wiper switch 106 and the wiper motor M. Therefore, when the wiper switch 106 is closed and the wiper motor M is in the on state, the excitation coil 51c is in the ON state, that is, when the wiper is When the wiper is in operation, it is in an energized state, and when the wiper switch 106 is open, that is, when the wiper is stopped, it is in a demagnetized state.

Note that signals such as ultrasonic waves and light emitted from the transmitters S1 and S2 provided on the rear bumper 17 of the vehicle are applied to the obstacle B, and the reflected signals are transmitted to the receivers S3 and S2.
After receiving the signal at S4, the distance discriminating circuit (distance discriminator) 11 calculates the time from transmitting to receiving the received signal as shown in FIG. The distance to obstacle B is now measured. Then, when the distance is less than a predetermined value,
When the alarm sound generating circuit 12 operates, an alarm sound is emitted from a speaker (alarm generator) 109 in the vehicle interior, thereby informing the driver of the presence of the obstacle B.

With the above configuration, if it is not raining,
Since the wiper switch 106 is normally off (open), the excitation coil 51c of the changeover switch RL1 is in a demagnetized state, so that the transmission amplifier 51 drives the transmitters S1 and S2 with high power. Therefore, at this time, even a small obstacle B can be sufficiently detected.

When it rains, the wiper switch 106 is normally turned on (closed), so the excitation coil 51c of the changeover switch RL1 becomes excited, thereby reducing the output of the transmission amplifier 51. Therefore, during such rainfall, raindrops are not detected as obstacles.

In this way, even small obstacles can be reliably detected when it is not raining, so the reliability of rear warning is greatly improved, and on the other hand, when it is raining, false detection due to raindrops can be sufficiently prevented.

6 and 7 show a rear warning device for a vehicle as a second embodiment of the present invention, FIG. 6 is a block diagram of its main parts, and FIG. 7 is an electrical circuit diagram of its main parts. 6 and 7, the same reference numerals as in FIGS. 1 to 5 indicate substantially the same parts.

In the case of this second embodiment, the reception sensitivity can be lowered in accordance with the ON operation of the wiper switch 106, and the configuration inside the control unit 100 includes a reception amplifier 81 as a rain adjuster. Except for this, the configuration inside the conventional control unit 100 shown in FIGS. 2 and 3 is almost the same.

A transmitting amplifier 5 for amplifying the signal from the transmitting oscillation circuit 4 is connected immediately before the transmitters S1 and S2, and a transmitting amplifier 5 for amplifying the signal from the transmitting oscillation circuit 4 is connected immediately after the transmitters S3 and S4. A receiving amplifier 81 is connected which adds and amplifies the signals and sends the signals to the detection circuit 10 via the filter circuit 9.

The reception amplifier 81 includes two reception amplifier sections 81a and 81b with different reception sensitivities, and
A relay type changeover switch RL2 is provided to switch the input to these receiving amplifier sections 81a and 81b.

This changeover switch RL2 is connected to the excitation coil 8.
When 1c is excited, the low sensitivity receiving amplifier section 81
When the excitation coil 81c is demagnetized, the switch piece 81d is switched so that the output from the highly sensitive reception amplifier section 81b is supplied to the filter circuit 9. It is configured as.

Here, the excitation coil 81 of the changeover switch RL2
C has one end grounded and the other end connected between the wiper switch 106 and the wiper motor M. Therefore, when the wiper switch 106 is closed and the wiper motor M is in the ON state, the excitation coil 81c is turned on when the wiper switch 106 is closed. When the wiper is in operation, it is in an energized state, and when the wiper switch 106 is open, that is, when the wiper is stopped, it is in a demagnetized state.

Therefore, when it is not raining, the wiper switch 106 is normally off (open), so the excitation coil 81c of the changeover switch RL2 is in a demagnetized state, which causes the receiving amplifier 81 to operate the receiver S3 with high sensitivity. , S4 are amplified.
As a result, at this time, even a small obstacle B can be detected.

When it rains, the wiper switch 106 is normally turned on (closed), so the excitation coil 81c of the changeover switch RL2 becomes excited, thereby reducing the sensitivity of the receiving amplifier 81. Therefore, during such rainfall, raindrops are not detected as obstacles.

In this way, even in the case of the second embodiment, even small obstacles can be reliably detected except when it is raining, so the reliability of rear warning is greatly improved, and when it is raining, false detection due to raindrops is sufficiently prevented. can do.

FIG. 8 is an electrical circuit diagram of the main parts of a rear warning system for a vehicle as a third embodiment of the present invention, and in FIG. 8, the same reference numerals as in FIGS. 1 to 7 indicate almost the same parts. .

In this third embodiment, the transmission power can be lowered especially when the wiper is wiping at high speed, and for this purpose the changeover switch RL
A switch 107' is interposed between the excitation coil 51c of No. 1 and the wiper switch 106 in conjunction with the wiper wiping high speed changeover switch 107, and becomes the H' terminal side when the switch 107 is on the H terminal side.

Note that when the switch 107 is on the L terminal side, the switch 107' is on the L' terminal side.

Therefore, in the third embodiment, in the case of light rain, the transmission power is still high and obstacle detection can be performed with high sensitivity. Normally, the wiper's wiping speed is increased, so the transmission power is lowered at this time to prevent false detection due to rain.

Note that when the wiper is wiping at high speed, the reception sensitivity may be lowered.

In addition, amplifier sections 51a with different powers and sensitivities,
51b, 81a, 81b can share most of the components.
It is also possible to configure 81a and 81b completely separately.

Furthermore, if the wiping speed of the wiper can be changed continuously, the power and sensitivity can also be adjusted continuously accordingly.

As described in detail above, according to the rear warning device for a vehicle of the present invention, in a vehicle equipped with a wiper that is activated by operating a wiper switch, the spatial wave transmitter and the spatial wave receiver provided at the rear end of the vehicle are equipped with , a distance discriminator connected to these spatial wave transmitter and spatial wave receiver, an alarm generator connected to this distance discriminator, and a distance discriminator between the spatial wave transmitter and the distance discriminator. a transmitting amplifier having a first transmitting amplifier interposed therebetween; and a receiving amplifier having a first receiving amplifier interposed between the spatial wave receiver and the distance discriminator. , provided in parallel with the first transmission amplifier section,
at least one of a second transmitting amplifier section having a lower transmission power than the transmitting amplifier section, or a second receiving amplifier section provided in parallel with the first receiving amplifier and having lower sensitivity than the first receiving amplifier section. It has a simple configuration in which it has either one of the above wiper switches and a changeover switch that switches the connection to the second transmitting amplifier section or the second receiving amplifier section according to the operation of the wiper switch. Alternatively, it is possible to reduce one of the reception sensitivities to reduce the detection ability during rain, preventing erroneously detecting raindrops as obstacles, and detecting obstacles behind when it is difficult to see behind. This has the effect of ensuring rearward visibility at all times regardless of weather conditions.

[Brief explanation of the drawing]

Figures 1 to 3 show a conventional vehicle rear warning device. Figure 1 is a schematic perspective view of a vehicle equipped with this device from the rear, Figure 2 is its overall configuration, and Figure 3 is a diagram showing the overall configuration of the vehicle. The figure is an electrical circuit diagram of the main part.
FIG. 5 shows a rear warning system for a vehicle as a first embodiment of the present invention, FIG. 4 is a block diagram of its main parts, FIG. 5 is an electric circuit diagram of its main parts, and FIG.
Fig. 7 shows a vehicle rear warning system as a second embodiment of the present invention, Fig. 6 is a block diagram of its main parts, Fig. 7 is an electric circuit diagram of its main parts, and Fig. 8 is a diagram of its main parts. FIG. 7 is an electrical circuit diagram of a main part of a rear warning device for a vehicle as a third embodiment of the invention. 11... Distance discriminator circuit as a distance discriminator, 5
1... Transmission amplifier as a rain regulator, 51
a, 51b...Transmission amplifier section, 51c...Excitation coil, 51d...Switch piece, 81...Reception amplifier as a rain regulator, 81a, 81b...
Receiving amplifier section, 81c... Excitation coil, 81d...
...Switch piece, 100', 100...Control unit, 101...Backup lamp,
102... Back-up Plump Switch, 103
... Fuse, 104 ... Ignition key switch, 105 ... Battery, 106 ... Wiper switch, 107 ... Wiper wiping speed changeover switch, 107' ... Switch, 109 ... Speaker as alarm generator, M ... ...wiper motor, S
1, S2... Spatial wave transmitter, S3, S4... Spatial wave receiver, RL1, RL2... Changeover switch.

Claims (1)

[Scope of utility model registration request] In a vehicle equipped with a wiper operated by the operation of a wiper switch, a space wave transmitter and a space wave receiver provided at the rear end, and a wire connected to the space wave transmitter and space wave receiver. a distance discriminator, an alarm generator connected to the distance discriminator, a transmission amplifier interposed between the spatial wave transmitter and the distance discriminator and having a first transmission amplifier section; a receiving amplifier interposed between the spatial wave receiver and the distance discriminator and having a first receiving amplifier section; the first transmitting amplifier provided in parallel with the first transmitting amplifier section; at least one of a second transmitting amplifier section having a lower transmission power than the first receiving amplifier section or a second receiving amplifier section provided in parallel with the first receiving amplifier section and having lower sensitivity than the first receiving amplifier section. A rear warning device for a vehicle, further comprising a changeover switch that switches connection to the second transmitting amplifier section or the second receiving amplifier section according to the operation of the wiper switch.