JPH07165020A - Heating device for melting snow on vehicle panel - Google Patents

Abstract

PURPOSE:To restrict unnecessary power consumption in a snow/ice heating device for melting snow/ice, which heats up the ice or snow sticking to a wind- shield, etc., to melt them, by providing a power source cutoff means, which shuts off a current to an electric heating elements when a prescribed period of time elapses after a heating switch is turned ON. CONSTITUTION:A heating switch 31 consists of an ignition switch, a dedicated switch, an outside air temperature sensor, etc. When this heating switch 31 is turned ON, electrifying an electric heating element 22 is started, a timer circuit 32 is started, and a time elapsed after the heating switch 31 is turned ON is measured. When a prescribed time, e.g. 10 minutes, elapses after the switch 31 is turned ON, power supply to the electric heating element 22 is cut off by an electric power source cutoff circuit 34. This power source cutoff time i.e., the working time of the timer 32 is changed, based on the output from, for example, the outside air temperature sensor 36. In other words, if a temperature detecting sensor 23 detects that a panel 21 is being heated before the time set by the timer 32, electrifying the electric heating element 22 is cut off at once.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a snowmelt heating device for a vehicle panel that melts ice and snow adhering to a windshield or the like, and more particularly to a technique for efficiently performing on / off control of energization.

[0002]

2. Description of the Related Art In order to drive a vehicle safely in winter,
Various techniques have been proposed in which an electric heating element is arranged on a front window panel, a tail lamp cover, a headlight, a door mirror or the like to melt ice and snow adhering thereto. For example, regarding snow melting of windshields
8, actual development 61-204863, actual development 63-4382
3 and so on. Regarding the lamp cover
54450, Actual Kai 01-21904, Actual Kai 04-3
1034 and the like.

A general feature of these techniques is that an electric heating element is arranged on a vehicle panel such as a window panel or a lamp cover panel to remove ice and snow and dew adhered from the vehicle by heating, and a winter road (snow road).
The point is to secure driving safety.

However, when the panel is heated by the electric heating element, there is a risk of ignition if the panel temperature rises excessively. Therefore, the applicant has arranged a thermostat for detecting the panel temperature, and applies the thermostat to the electric heating element at an appropriate heating temperature. We proposed the technology to cut off the power supply of the
Issue).

FIG. 6 shows this overheat prevention means.
An electric heating element 3 is arranged on a cover 2 which covers the tail lamp 1, and a thermostat 4 is provided at an appropriate position on the cover 2 so that the electric power to the electric heating element 3 is cut off when the surface temperature of the cover exceeds a predetermined temperature (for example, 40 ° C.). It is configured to do. In addition, 5 is a tank truck vehicle body, 6 is snow that is rolled up during winter road running, and 7 is a cover frame that holds down the cover.

[0006] Since then, several techniques for disposing a thermostat for preventing overheating have been proposed. FIG. 7 shows an example thereof, in which a thermostat 11 is arranged on the inner side surface of the translucent panel 10, and a partition wall cover 12 for protecting the thermostat 11 is arranged. 13 is a lead wire, 1
Reference numeral 4 is a partition cover mounting member (actually open flat 4-38).
No. 534).

[0007]

By the way, these techniques for controlling the ON / OFF of the electric heating element by using a thermostat are not suitable for the timing of starting overheating and the timing of stopping overheating.
It deviates from the original purpose of ensuring safety by snow melting and is merely monitoring the temperature change of the panel, and there are many cases where meaningless power supply is maintained.

For example, even when the OFF timing by the thermostat is set to 40 ° C. and the ON timing is set to 30 ° C., the detected temperature is, so to speak, irrelevant to the adhesion of ice and snow and dew condensation, and snow is attached to the tail lamp and the front window. Even if you don't do it, you'll continue heating without meaning.

Further, as shown in FIG. 7, when the thermostat is surrounded by the partition wall cover 12, the detected temperature is always higher than the panel surface temperature due to the trapped heat of the lamp inside the cover, and for the original purpose. It also fails to detect the surface temperature of a certain panel. This is because the error becomes too large.

Unlike the power consumption of a blower fan or a stereo device, energization of an electrothermal element that requires a large amount of power puts pressure on the power of the entire vehicle. For example, the engine power is lowered by the excessive movement of the alternator, which hinders the acceleration for avoiding the danger or causes the engine to stall at the start of the vehicle.

Therefore, an object of the present invention is to more efficiently perform snow melting heating in a vehicle panel such as a front window, a rear window, a headlight, a tail lamp, etc. on which ice and snow adheres to prevent safe driving.

[0012]

In order to achieve the above object and achieve the object, a snow melting heating apparatus for a vehicle panel according to the present invention has an electrothermal element disposed on a light transmitting panel for a vehicle, On the technical premise of a snow melting heating device for controlling on / off of energization to the electric heating element by a temperature detecting means arranged at an appropriate position, an energization starting means for supplying power to the electric heating element by turning on a heating switch is provided while the switch is provided. O
A power cutoff means is provided for canceling energization to the electric heating element when a predetermined time has passed from N.

[0013]

According to the present invention, the heating switch for starting the energization of the heating element is constituted by an ignition key or a dedicated switch, and the switch is turned on to supply power to the heating element. In addition, since a power cutoff means is provided for releasing the power supply to the electric heating element after a lapse of a predetermined time from turning on the heating switch, the snow melting heating of the panel is performed after melting the ice and snow at a necessary portion at the time of vehicle start or snowfall. Stopped,
Reduce unnecessary power consumption.

[0014]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows an example of a snow melting heating device for a vehicle according to the present invention. First, the overall configuration will be described. Reference numeral 21 is a vehicle translucent panel such as a front window panel or tail lamp cover, 22 is an electric heating element disposed on the translucent panel 21, 23 is a temperature detecting sensor such as a thermostat disposed at an appropriate position on the translucent panel 21, 24 Reference numeral 31 is an energization control circuit for controlling on / off of energization to the electric heating element 22 by the temperature sensor 23, and 31 is a heating switch for starting energization to the electric heating element 22, specifically, an ignition switch or a dedicated electric heating It is a switch.
32 is a timer circuit that measures the time from when the heating switch 31 is turned on, and 33 is the heating switch 31.
An energization start circuit that supplies power to the electric heating element 22 by turning on the switch 31 is a power cutoff circuit that releases energization to the electric heating element 22 when a predetermined time has elapsed since the switch 31 was turned on.

The transparent panel 21 may be made of glass or resin. Further, the electric heating element 2 arranged on the translucent panel 21.
2 is a heating wire that generates heat when the power is turned on, a heating film,
For example, a light absorption film. The heating wire or the heating film may be arranged inside or outside the translucent panel 21, or may be sandwiched between the panels.

The type and position of the temperature detection sensor 23 are not limited. Speaking of type, thermostat using metal,
For example, a thermistor including a heat sensitive element as a terminal. The material of the metal element or the composite element of the temperature detecting portion is arbitrary. The detection sensitivity may be blunt, for example, causing an error of about 2 to 3 ° C. As described above, the temperature detection of the translucent panel 21 is to prevent overheating in case of emergency, and the detection temperature of the temperature sensor 23 is set to a band of about 30 to 40 ° C.
This is because even if an error of about 0 ° C occurs, an accident due to sensor accuracy cannot be considered.

The temperature detecting sensor 23 may be arranged on the inner or outer surface of the translucent panel 21. However, since it is easily affected by low temperature outside air when it is arranged on the outer side surface, it is desirable to provide a protective cover having a box shape or the like so that the temperature of the translucent panel 21 can be accurately detected. On the contrary, in the case of arranging it on the inner side surface of the translucent panel 21, the temperature detecting portion is exposed without providing a protective cover that easily traps heat. This is because if the protective cover is provided, the error between the detected temperature and the panel 21 temperature becomes too large.

The heating switch 31 may be of any type.
That is, the switch is not limited to the ignition switch or the dedicated switch arranged on the instrument panel, but a switch including an outside air temperature sensor or the temperature sensor 23 may be applied. This is because it is sufficient to detect the adhesion of snow or frost or the possibility thereof and to heat the translucent panel 21 to recover the translucency.

In the timer circuit 32, the heating switch 31 is turned off.
Measure the time from when N operations were performed. The installation location does not matter. When the electric heating element 22 is arranged only on the tail lamp, it may be arranged at an appropriate position on the rear end portion of the vehicle, and when it is operated together with the snow melting of the front window panel, the timer count is shared with the engine control IC and other electronic parts. It doesn't matter. The energization start circuit 33 turns on the heating switch 31.
It is a relay switch or the like that operates by operation.

The power cutoff circuit 34 turns on the switch 31.
When a predetermined time, for example, 10 minutes (600 seconds) has passed from the operation, the power supply to the electric heating element 22 is cut off. This power-off time depends on the material of the panel on which the electric heating element 22 is arranged, the thickness, the resistance value of the electric heating material 22, the overheating efficiency, the supply current voltage,
It can be set arbitrarily according to the outside temperature. For example, as shown in FIG. 2 and FIG. 3, the operating time of the timer 32 is changed based on the signal from the outside air temperature sensor 36 that detects the outside air temperature, and when the corresponding time is reached, the electric power is supplied to the electric heating element 22. Cut off.

According to this structure, the power supply can be cut off after a lapse of a predetermined time after the energization of the electric heating element 22 is started, so that the temperature of the translucent panel 21 does not reach the set superheat temperature. However, excessive snow melting heating can be stopped, and a decrease in engine power can be prevented. Of course, when the temperature detection sensor 23 detects the heating state of the panel 21 before the time set by the timer, the energization control circuit 24 shuts off the energization to the electric heating element 22, thus preventing an accident due to heating of the panel as in the conventional device. You can do it.

FIG. 4 shows another embodiment of the present invention.
In addition to the configuration of the above-described embodiment, humidity sensors 41 and 42 are arranged on the outer surface and the inner surface of the translucent panel 21, respectively, and the cloudy state of the translucent panel 21 is detected to control the energization of the electrothermal element 22.

The humidity sensors 41 and 42 are, for example, a thin conductive film printed on the panel surface, and a zinc phosphate film whose resistance changes with humidity is covered on the thin conductive film.
When it exceeds 5%, electricity is applied to the heating element. For such a cloud sensor, various currently known means can be applied. The locations of the sensors 41, 42 do not matter.

According to this structure, as shown in FIG.
After the heating switch 31 is turned on, the temperature detection sensor 23
Thus, it is determined whether the panel surface temperature is the cutoff temperature X or higher (S-1). When the temperature is equal to or lower than the temperature X, it is determined whether or not the time from turning on the heating switch 31 has passed the cutoff time T (S-2). When the time T has not been reached, it is determined whether or not the humidity M detected by the humidity sensors 41 and 42 is equal to or higher than a predetermined value. When the panel humidity is equal to or higher than a predetermined value required to heat and evaporate, the electric heating element 22 is energized. Perform (S-3). Further, even if the heating switch 31 such as an ignition switch is turned on and other energization conditions are met,
When the panel surface temperature X is equal to or higher than the cutoff temperature, or when the cutoff time T has elapsed, the humidity M detected by the humidity sensors 41 and 42 is detected.
When is less than or equal to a predetermined value, the power supply to the electrothermal element 22 is stopped (S-1) to (S-3).

As a result, for example, the electric heating element 2 can be operated from when the engine is started by turning the ignition key.
Even if it is set to start energizing 2, the heating element 22 is not energized when the outside temperature is high (summer, etc.) or the panel is not clouded, and the on / off control is performed under the most rational conditions. Can be done. Therefore, it is possible to prevent the engine power from being lowered or stalled due to unnecessary power supply, and it is possible to ensure the safety of vehicle traveling.

In the snow melting heating apparatus according to the present invention, it is possible to control the conditions for starting energization of the electric heating element by the outside air temperature sensor. In this case, it is desirable that the outside air temperature sensor be installed, for example, at the rear end of the vehicle (near the tail lamp, etc.) to minimize the detection error due to the wind flow. For example, when the energization start temperature is set to 0 ° C. outside temperature,
If the energization is started by the outside air temperature sensor, it is possible to prohibit energization from the beginning during the period from early spring to summer and December when snow accumulates. Of course, also in this case, it is possible to shut off the power supply by the timer or prohibit the unnecessary snow melting heating by the humidity sensor.

[0027]

As described above, the snow melting heating apparatus for a vehicle according to the present invention is a power source for releasing the power supply to the electric heating element when a predetermined time has elapsed after the heating switch for starting the power supply to the electric heating element is turned on. When the vehicle is started or snowfall, the panel heating stops after melting the ice and snow at the necessary places, and unnecessary power consumption can be suppressed because the blocking means is provided, so if ice and snow adheres to the road, safe driving is hindered. In, it is possible to perform the heating snow melting of the panel more efficiently.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of a snow melting heating device according to the present invention.

FIG. 2 is a block diagram showing another embodiment of the snow melting heating apparatus according to the present invention.

FIG. 3 is a graph showing a relationship between an outside air temperature and a power interruption time.

FIG. 4 is a block diagram showing another embodiment of the snow melting heating apparatus according to the present invention.

FIG. 5 is a flowchart showing an example of control of the snow melting heating device shown in FIG.

FIG. 6 is a diagram showing an example of a conventional snow melting heating device.

FIG. 7 is a diagram showing another example of a conventional snow melting heating device.

[Explanation of symbols]

 21 Light-shielding panel 22 Electrothermal element 23 Temperature detection sensor 24 Energization control circuit 31 Heating switch 32 Timer circuit 33 Energization start circuit 34 Power cutoff circuit 36 Outside air temperature sensor 41, 42 Temperature sensor

Claims (1)

[Claims] 1. A snow melting heating apparatus for a vehicle panel, wherein an electrothermal element is disposed on a translucent panel for a vehicle, and temperature detection means disposed at an appropriate position on the translucent panel controls on / off of energization to the electrothermal element. The snow melting of the vehicle panel is provided with an energization starting means for supplying power to the electric heating element by turning on the heating switch, and a power interruption means for releasing the energization for the electric heating element after a lapse of a predetermined time from turning on the switch. Heating device.