JPH02212241A - Cloud preventing device for car - Google Patents

Abstract

PURPOSE:To prevent a dead battery without impairing cloud prevention effect by blowing air inside a window glass for a car after lowering the amount of electrifying a flat heater installed on the window glass for the car, in case that a battery mounted on the car is in the condition of a preset or more discharge. CONSTITUTION:When a front glass 1 is dew-condensed, a power control circuit 8 is controlled by a CPU 10 in accordance with detected signals from a dew- condensation sensor 3 and the power of a battery 6 is therefore supplied to a flat heater 2 via an alternator 5 and the power control circuit 8 to perform the cloud prevention of the front glass 1. In this case, if the battery 6 is in the condition of a preset or more discharge, the power control circuit 8 is controlled by the CPU 10 in accordance with detected signals from a battery voltage detector 7 and the amount of electrifying the flat heater 2 is therefore lowered. At the same time a blowing port control circuit 11 and an inside and outside air control circuit 18 are controlled by the CPU and air is blown inside the front glass 1 to perform the cloud prevention, accordingly.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a control device for preventing fogging of a vehicle window glass due to dew condensation.

[Prior art]

Conventionally, there are two methods for defogging vehicle window glasses: dehumidifying the window glass to lower the absolute temperature, or warming the window glass and keeping it above the dew point temperature.

[Problem to be solved by the invention]

Among the above methods, the former method generally dehumidifies by operating an air conditioner (A/C), but it does not operate when the outside temperature is low (for example, below 0°C), and its range of use is limited. ing. Moreover, the latter is disclosed in Utility Model Application No. 63-7053 and Utility Model Application No. 63-7053.
As disclosed in Japanese Patent No. 7054, there is a method of heating window glass using a sheet heater, but the sheet heater consumes a large amount of power when heating, which worsens the charging and discharging balance of the battery. This was causing the battery to run out. The present invention has been made to solve the above problems, and its purpose is to appropriately control a sheet heater attached to a vehicle window glass and an air conditioner mounted on the vehicle. To provide an anti-fogging device for a vehicle that prevents fogging of a vehicle window glass due to dew condensation while preventing a dead battery.

[Means to solve the problem]

The structure of the invention for solving the above problem is to provide an anti-fogging device for a vehicle that has an air conditioner capable of blowing air to the inside of the vehicle window glass to prevent fogging, and a sheet heater attached to the vehicle window glass. a battery detector that detects the balance of charge and discharge of the battery; a power control circuit that can change the amount of power supplied to the sheet heater; and a power control circuit that controls the timing of energization of the sheet heater, and controls the timing of energization of the sheet heater based on the output of the battery detector. When it is detected that the in-vehicle battery is in a discharged state exceeding a predetermined level,
energization control means for controlling the power control circuit to reduce the amount of current applied to the planar heater, and operating the air conditioner when the amount of electricity applied to the planar heater is reduced by the energization control means; and an anti-fog control means for blowing air to the inside of a vehicle window glass to prevent fogging.

[Effect]

When the vehicle window glass is in a state of condensation, the energization control means controls the timing of energization from the vehicle battery to the sheet heater via the power control circuit in response to a manual operation or in response to the output of the dew condensation sensor. When the battery detector detects that the on-vehicle battery is discharged to a predetermined level or more, the energization control means controls the power control circuit to reduce the amount of energization to the planar heater. In this case, the anti-fog control means also uses an air conditioner to blow air to the inside of the vehicle window glass to perform anti-fog. In this way, when the vehicle battery is about to run out, the power supply to the planar heater is suppressed to increase the amount of charge to the vehicle battery, and the air conditioner mounted on the vehicle is also controlled. Therefore, the balance of charging and discharging the vehicle battery is improved, and fogging caused by dew condensation on the vehicle window glass is quickly removed and prevented.

【Example】

The present invention will be described below based on specific examples. FIG. 1 is an explanatory diagram showing the configuration of a vehicle equipped with an anti-fogging device for a vehicle according to the present invention. 2 is a planar heater, and the planar heater 2 is attached between laminated glasses of a windshield 1, which is a window glass for a vehicle. Reference numeral 3 denotes a dew condensation sensor disposed inside the windshield l, and the dew condensation sensor 3 detects the state of dew condensation on the inner surface side of the windshield 1. 5 is an alternator that supplies power to the planar heater 2 and charges the vehicle battery 6. Reference numeral 7 denotes a battery voltage detector as a battery detector that detects the battery voltage, which is the balance of charging and discharging the on-vehicle battery 6. 10 is a CPU such as a microcomputer, which inputs the output signal of the dew condensation sensor 3 and the output signal of the battery voltage detector 7 that detects the battery voltage, and controls the amount of electricity supplied to the sheet heater 1; A control signal is output to the exit control circuit 11 and the inside/outside air control circuit 18. The blower fan 12 of the air conditioner directs the air in the duct 13 to each outlet 14, 15 provided appropriately at the end of the duct 13.
．． Air is blown in 16 directions. Each air outlet 14, 15, and 16 are DEF and VENT, respectively. Switching dampers 141°151.1 are called HEAT and are opened and closed by control signals from the air outlet control circuit 11.
61, and guides the air blown from the blower fan 12 in the direction in which the switching damper is open. Further, the internal/external air switching damper 19 is opened/closed in response to a control signal from the internal/external air control circuit 18, thereby switching the air in the duct 13 from being circulated inside the vehicle to introducing external air. Next, the processing procedure of the CPU used in the device of this embodiment will be explained based on the flowchart of FIG. First, in step 100, it is determined based on the output signal from the dew condensation sensor 3 whether or not there is dew condensation on the inner surface of the windshield 1 to which the sheet heater 2 is attached. If dew condensation is not detected by the dew condensation sensor 3 in step 100, the process returns to step 100, and the dew condensation sensor 3 in step 100
Repeat dew condensation detection. Then, in step 100, when dew condensation is detected by the dew condensation sensor 3, the determination becomes YES, and the process moves to step 102 to achieve the energization control means, in which energization is performed from the alternator 5 to the sheet heater 2 via the power control circuit 8. Control is started, and anti-fog control for the inner surface of the windshield 1 is implemented. Next, proceeding to step 104, the battery voltage detector 7
Accordingly, it is determined whether the voltage V of the vehicle-mounted battery 6 is lower than a preset limit voltage Vtta+t. That is, it is determined whether or not Vm≦V Llt, and if the above inequality does not hold, the voltage V of the vehicle battery 6 is greater than the limit voltage VLjml&, so the determination is NO, and the process moves to step 100. Anti-fogging control on the inner surface of the windshield 1 is continued by controlling the energization of the planar heater 2 in step 102 until the dew condensation sensor 3 no longer detects dew condensation in step 100 . Then, in step 104, when V≦VLalt, the voltage V of the vehicle battery 6 becomes the limit voltage VL1mll.
Since the voltage has decreased further, the determination is YBS, and the process moves to step 106 to achieve the energization control means. Step 10
6, in order to prevent the vehicle battery 6 from running out of power, the power control circuit 8, which performs transformer switching or switching regulator adjustment, reduces the amount of current flowing from the alternator 5 to the sheet heater 2. As a result, the amount of current flowing from the alternator 5 to The amount of charge to the vehicle battery 6 is increased. Then, the process moves to step 108, and control of the air conditioner is started in order to compensate for the decrease in the anti-fogging ability due to the reduction in the amount of electricity supplied to the sheet heater 1. Note that the anti-fogging control means is achieved by processing steps from step 108 onwards. Next, in step 110, it is determined whether or not the air conditioner is in the indoor air mode for circulating air inside the vehicle. If the shyness mode is determined in step 110, the determination in step 110 is YES, and step 11
2, the inside/outside air control circuit 18 switches the inside/outside air switching damper 19 from the inside air mode to the outside air mode. In other words, the outside air switching damper 19 is opened and the outside air is sent to the duct 1.
It will be introduced within 3. Next, the process moves to step 114, and the air outlet of the air conditioner is
Opening the damper 161 to warm the driver's feet
It is determined whether or not the EAT mode is set. If the HEAT mode is selected in step 114, the determination is YES.
Then, the process moves to step 116, and the air outlet control circuit 11
HAET opens the dampers 161 and 141 to warm the driver's feet and the inner surface of the windshield 1.
After switching to -DEF mode, the process returns to step 100 and the same processing as described above continues. On the other hand, if the air outlet of the air conditioner is not in the HEAT mode at step 114, the determination is NO, and the process proceeds to step 118, where it is determined whether the air outlet is in the HAET-DEF mode. If the HAET-DEF mode is set in step 118, the determination is YES, and the process moves to step 120, where a control signal is output to the air outlet control circuit 11 and only the damper 141 for warming the inner surface of the windshield 1 is opened. After switching to the DEF mode, the process returns to step 100 and the same processing as described above is continued. Furthermore, in step 118, the outlet of the air conditioner is set to HAET-.
If it is not the DEF mode, the determination is NO, and step 12
2, the air outlet of the air conditioner in this case is in a mode other than the above-mentioned mode, that is, the VENT mode in which air conditioning is directed toward the driver's body, so a control signal is sent to the outlet control circuit 11. After outputting and switching to the HEAT mode, the process returns to step 100 and the same processing as described above is continued. Note that if the mode is not in the inside air mode at step 110, that is, if it is in the outside air mode at that point, the determination is No, the process moves to step 114, and the process is performed in the same manner as described above. In this way, anti-fog and anti-fog auxiliary control for the inner surface of the windshield 1 is performed. In the above-mentioned embodiment, the dew sensor 3 that detects the condensation state on the vehicle window glass is used to automatically control the energization timing of the sheet heater 2. Alternatively, the planar heater 2 may be energized. Further, in the above-described embodiment, as a battery detector for detecting the balance status of charging and discharging the vehicle-mounted battery 6,
Although the battery voltage detector 7 is used, the current value from the vehicle battery 6 may also be detected. Furthermore, in the above embodiment, the inside/outside air control circuit 180
There are two control modes: inside air mode and outside air mode, but 1/2 which is other than these two control modes
Control may be performed using an intermediate control mode such as inside air or 1/4 inside air, or a control mode in which the air is continuously changed from inside air to outside air. Further, in the above-described embodiment, as an anti-fog control means, the inside/outside air control circuit 18 switches between inside and outside air, and the air outlet control circuit 11
Although anti-fogging is performed by switching the air outlet as described above, the anti-fogging effect can be further enhanced by controlling the air outlet temperature to be increased. Incidentally, the installation location of the sheet heater used in the vehicle anti-fogging device of the present invention is not limited to the windshield, which is the front part of the vehicle window glass, but can also be installed between the glass at the rear or side part. By controlling these alone or in combination, it is possible to obtain a more appropriate anti-fogging effect. Furthermore, the number of air outlets provided at the end of the duct is not limited to the three locations in the above embodiment.

【Effect of the invention】

In the present invention, the energization control means controls the timing of energizing the sheet heater via the power control circuit, and when the battery detector detects that the vehicle battery is in a discharged state exceeding a predetermined level, the energization to the sheet heater is stopped. After the amount is reduced, the air conditioner is activated by the anti-fog control means to blow air to the inside of the vehicle window glass to prevent fogging, so even if the vehicle window glass becomes foggy due to condensation, the vehicle battery will not be charged. If the balance of discharge deteriorates, the power supply to the planar heater is suppressed and the air conditioner is operated in combination. Therefore, the charging/discharging balance of the vehicle battery is improved, battery exhaustion is prevented, and the anti-fogging effect is not impaired by the auxiliary control of the air conditioner.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the mechanical and electrical configuration of a vehicle defogging device according to a specific embodiment of the present invention. FIG. 2 is a flowchart showing the processing procedure of the CPU used in the device of the embodiment. °Windshield 2゛゛゛゛゛゛゛゛゛゛゛゛゛゛゛゛゛゛゜゛゛゛゛゛゛゛゛゛゛゛゛゛゛゜゛゛゛゛゛) 15. 16-Air outlet 9
Internal/external air switching damper 41.151.161/Switching damper patent applicant Nippondenso Co., Ltd.

Claims (1)

[Scope of Claims] In a vehicle anti-fogging device that includes an air conditioner that blows air to the inside of a vehicle window glass to prevent fogging, and a planar heater attached to the vehicle window glass, the balance of charge and discharge of a vehicle battery is provided. a power control circuit that can change the amount of power supplied to the planar heater; and a power control circuit that controls the timing of energization of the planar heater, and detects when the on-vehicle battery reaches a predetermined level based on the output of the battery detector. energization control means for controlling the power control circuit to reduce the amount of current applied to the planar heater when it is detected that the sheet heater is in a discharging state; An anti-fog device for a vehicle, comprising: an anti-fog control means for activating the air conditioner and blowing air to the inside of a vehicle window glass to perform anti-fog.