JPH0134604Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field of the Invention The present invention is a so-called rear defogger device that removes fog from a vehicle window glass using a heater fixed to the window glass, and the invention controls the electric power supplied to the heater. The present invention relates to an anti-fog device equipped with a power control means that can perform an appropriate anti-fog effect.

Conventional technology and its problems Conventionally, in this type of anti-fogging device, for example, in the well-known technology disclosed in Japanese Utility Model Application Publication No. 49-140831, a sensor for detecting dew droplets is installed on the glass surface as shown in Fig. 1. 6 is installed, and the timer device 4 is connected to the control device A consisting of the detection device 3 and the timer device 4.
When the defogger switch B is set to the auto position O, the sensor 6 detects dewdrops adhered to the glass surface and energizes the heater 7 to prevent fogging. the defogger switch B to the timer position t.
A glass anti-fog device has been proposed in which the heater 7 is energized for a predetermined period of time to perform the anti-fog action.

However, installing the sensor 6 on the glass surface or installing the detection device 3 for detecting dew droplets attached to the sensor 6 requires multiple devices and is expensive because the detection accuracy is delicate. Unless the dew droplets adhering to the surface increase to the point where they bridge between the two electrodes of the sensor 6, dew drop detection cannot be performed. Therefore, until the sensor 6 detects dewdrops, a cloudy state has occurred. or,
Even if the defogger switch B was set to the timer position t, the power to the heater 7 would stop after a predetermined period of time and the glass would fog up again, so it was necessary to set the defogger switch B to the timer position t again. . In this way, in conventional anti-fogging devices, when the defogger switch B is set to the auto position O, the time it takes for the dew droplets existing between the two electrodes of the sensor 6 to bridge, and the timer for the defogger switch B to be set. When the heater 7 was set at position t, the glass became foggy when the power supply to the heater 7 was stopped after a predetermined period of time had elapsed, and an appropriate anti-fogging effect could not be achieved.

In order to prevent such an inappropriate anti-fogging effect, the heater 7 can be energized continuously, but since the heater 7 normally consumes about 100 to 150 watts of power, it causes wasted battery power. It wasn't realistic.

Purpose of the present invention The present invention was devised in order to eliminate these drawbacks. In order to perform an appropriate anti-fog effect, the defogger switch must be turned on to quickly remove the fog and then continue to operate properly. It is sufficient to use a small amount of electricity to prevent the recurrence of fogging. Therefore, after the defogger switch is turned on, electricity is applied continuously for a predetermined period of time sufficient to quickly clear the fogging or freezing of the window glass, and then to prevent the recurrence of fogging or freezing. By controlling the power supplied to the heater in cooperation with the control means and the power supply means so as to continue the intermittent energization sufficient to prevent It is an object of the present invention to provide an anti-fog device equipped with a power control means that can perform an effective anti-fog effect.

Structure of the present invention Hereinafter, a preferred embodiment of the present invention will be described based on FIGS. 2a to 4b.

In FIG. 2a, 11 is a defogger switch, with a movable contact 11a, a first fixed contact 11b,
It has a second fixed contact 11c and a neutral point 11d.

The movable contact 11a is connected to a DC power source 14 via an ignition switch 12 and a fuse or fusible link 13, and is also connected to a heater 16 and a monitor lamp 17 via a contact 15a of a relay 15, which is a power supply means. has been done.

Further, the first fixed contact 11b is connected to the input section 18a of the control means 18, and is also connected to the output section 18b of the control means 18 via the coil 15b of the relay 15, respectively.

2b to 2d are electrical block diagrams showing a specific embodiment of the control means 18 shown in FIG. 2a.

First, a second example showing a first embodiment of the control means 18I will be explained.
In Figure b, the input section 18Ia is the timer circuit 18
0 and an astable multivibrator circuit 181 to the OR circuit 182.
is connected to the output section 18Ib via the amplification circuit 183, and is further connected to the astable multivibrator circuit 18.
1 is connected to a variable resistor VR1. next,
In FIG. 2c showing a second embodiment of the control means 18J, 184 is a counter circuit such as a so-called binary counter, an input section 184a is connected to a digital oscillation source Qu such as a quartz watch, and a reset input section 184b is connected to a digital oscillation source Qu such as a quartz watch. is connected to the output section of the differentiating circuit 185 and the reset input section 186a of the detection circuit 186, and is connected to the first output section 184c and the second output section 184d.
is connected to the normally open section 188a of the analog switch circuit 188 via the AND circuit 187, and the third output section 184e is connected to the detection input section 186 of the detection circuit 186.
b and the normally closed part 18 of the analog switch circuit 188
8b, respectively.

The third output section 184e is an output stage that divides the oscillation pulse of the digital oscillation source Qu into pulses with a period of about 20 minutes, and the first output section 184c and the second output section 184d are the third output section. Section 184e
This is an output stage connected to output from the output section of the AND circuit 187 a pulse having a shorter period than the pulse output from the AND circuit 187.

Further, the output section 186c of the detection circuit 186 is connected to the input section 188c of the analog switch circuit 188, and the common section 188d of the analog switch circuit 188 is connected to the output section 18b via the amplifier circuit 184.
It is connected to the. Further, the input section 18Ja is connected to the power input section 184f of the counter circuit 184 and the input section of the differentiating circuit 185, respectively.

Furthermore, in FIG. 2d showing a third embodiment of the control means 18K, 189 is an astable multivibrator circuit whose oscillation period or duty ratio can be varied, and the first input section 189a is connected to the normally closed state of the analog switch 188. The second input section 189b is connected to the normally open section 188a, and the second input section 189b is connected to the normally open section 188a.
89c is the amplifier circuit 184, the detection input section 186b of the detection circuit 186, and the analog switch circuit 188.
It is connected to the common part 188d of.

The output section of the amplifier circuit 184 is connected to the output section 18Kb of the control means 18K, and the input section 18Ka is connected to the power supply input section 1 of the astable multivibrator circuit 189.
89d and the detection circuit 1 via the differentiation circuit 185.
The output section 186c of the detection circuit 186 is connected to the input section 188c of the analog switch circuit 188, respectively.

Further, FIG. 3a is an electric circuit diagram showing a specific example of the detection circuit 186, and FIG. 3b is an electric circuit diagram showing a specific example of the astable multivibrator circuit 189.

In FIG. 3a, the reset input section 186a of the detection circuit 186 is connected to the RS flip-flop circuit Q1.
The detection input section 186b is connected to the S terminal via the first knot circuit Q2, and the output section 186c is connected to the Q terminal.

In FIG. 3b, the first input section 189a of the astable multivibrator circuit 189 is connected to the cathode of the diode D1 and the diode D2 through the resistor R1.
The second input section 189b is connected to the anode of the diode D1 via the resistor R2, and is connected to the second knot circuit Q3 and one end of the capacitor C1.
It is connected to the cathode of the diode D2 via the resistor R3, and the output part of the second knot circuit Q3 is connected to the cathode of the diode D2.
It is connected to the output section 189c via the knot circuit Q4 and the fourth knot circuit Q5, and the third knot circuit Q4
is further connected to the other end of the capacitor C1.

Function of the present invention Next, the function of the anti-fogging device equipped with the power control means according to the present invention having the above-mentioned configuration will be explained.

For example, in winter, when there is a temperature difference between the inside of the vehicle and the outside air, and dew droplets adhere to the glass surface inside the vehicle, when the occupant turns on the defogger switch 11 to the first fixed contact 11b, as shown in FIG. A voltage is applied to the input section 18a of the control means 18 shown in FIG. 4A, and the control signal shown in FIG.

Here, the control mode of the heater 16 will be explained in detail using the first embodiment of the control means 18I shown in FIG. 2b. First, at time To, turn on the defogger switch 11.
is turned on and a voltage is applied to the input section 18a of the control means 18, both the timer circuit 180 and the astable multivibrator circuit 181 start operating, the heater 16 is energized via the relay 15, and the glass surface is heated. The fogging action is quickly performed.

Then, the output signal of the timer circuit 180 stops after the time Ta when the fog has cleared, and from then on, only the output signal of the astable multivibrator circuit 181 is transmitted to the output section of the control means 18 until the defogger switch 11 is turned off. Output from 18b,
The heater 16 is energized intermittently, and the operation of eliminating fogging on the glass surface is continued with a small amount of electric power sufficient to prevent recurrence of fogging. At this time, variable resistance
By adjusting VR1, the period Tb or on-time Tc can be varied, and the amount of heat emitted from the heater 16 can be varied.

Hereinafter, another embodiment of the present invention that performs a similar action of eliminating fogging on a glass surface will be described.

A second embodiment of the control means 18J shown in FIG.
The output mode of the control signal shown in FIG. 4a is obtained. In this control means 18J, the counter circuit 184 and the detection circuit 186 are reset at the same time as a voltage is applied to the input section 18Ja, and the counter circuit 184 starts counting the output signal of the digital oscillation source Qu.

Then, the counter circuit 184 is connected to the third output stage 18
From 4e, a rising pulse signal is output at time To, and a falling pulse signal is output after time Ta.

Then, the Q terminal of the RS flip-flop circuit Q1 of the detection circuit 186 becomes a high potential, and the signal path of the analog switch circuit 188 is switched from the normally closed part 188b to the normally open part 188a, and from then on, the passenger turns off the defogger switch 11. The control circuit 18J repeatedly outputs the ON action signal for the ON time Tc every cycle Tb until the ON action is activated. The output mode of the control signal shown in FIG.
This can be obtained by connecting to the first output section 184c of 84.

Further, a third embodiment of the control means 18K shown in FIG. 2d provides the control signal output mode shown in FIG. 4a without using a timer circuit.

This control means 18K controls the input section 1 at time To.
When a voltage of 8Ka is applied, the astable multivibrator 189 starts oscillating, and at the same time the detection circuit 186 is reset. After a time Ta, the output section 18 of the astable multivibrator 189
When 9c falls for the first time, the detection circuit 1
86 leads an output to an analog switch circuit 188, and the signal path of the analog switch circuit 188 is switched from the normally closed part 188b to the normally open part 188a, and from then on, the control means 18K remains in operation until the passenger turns off the defogger switch 11. The output section 18Kb repeatedly outputs a signal for the ON action during the ON time Tc every cycle Tb.

The electric circuit diagram shown in FIG _. 3b shows a specific embodiment of the astable multivibrator circuit ₁₈₉ shown in FIG. is varied, and the power consumption of the heater 16 is adjusted.

Note that the relay can of course be replaced with a high-power semiconductor element such as a power MOS FET transistor, and it is also possible to perform power control by dividing the heater into at least two systems and controlling each system separately.

Further, the control means is not limited to the embodiment, and the control means shown in FIG.
Alternatively, any material that can obtain the electrical characteristics shown in FIG. 4b may be used.

Effects of the present invention The present invention has the following effects due to the above-mentioned structural action.

(a) There is no need to install a sensor on the glass surface.

(b) There is no need for a complicated detection device to detect dew droplets attached to the sensor.

(c) A certain level of anti-fogging effect can always be achieved before the dew droplets adhering to the glass surface increase in size.

(d) Even if the passenger leaves the defogger switch on, the anti-fogging action is always performed using appropriate power, so there is no wastage of battery.

(e) It is composed of a combination of existing circuits and has a simple structure, making it inexpensive and practical.

[Brief explanation of the drawing]

FIG. 1 is an electrical block diagram illustrating the prior art. FIG. 2a is an electrical block diagram showing a preferred embodiment of the present invention. FIGS. 2b to 2d are electrical block diagrams showing specific embodiments of the control means. FIG. 3a is an electrical circuit diagram showing a specific embodiment of the detection circuit. FIG. 3b is an electrical circuit diagram showing a specific embodiment of the astable multi-circuit. 4a and 4b are output electrical characteristic diagrams of the control means of the present invention. 11... Defogger switch, 12... Ignition switch, 13... Fuse or fusible link, 14... Direct current, 15... Relay, 16... Heater, 17... Monitor lamp, 18... Control means.

Claims (1)

[Scope of utility model registration request] A defogger device for defogging a vehicle window glass includes a heater fixed to the vehicle window glass, a power supply means connected to the heater,
A control means connected to the power supply means so as to continuously energize the heater for a predetermined time and then intermittently energize the heater by the on action of the defogger switch, and a control means connected to the control means so as to operate the control means. An anti-fog device equipped with a power control means, characterized in that it is equipped with a defogger switch.