JPH0549504B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a fog removal device for a vehicle that prevents fog from forming on the inner surface of a glass.

(Prior Art) A defogging device for a vehicle that operates a compressor of an air conditioner and a defogging means when a signal from a dew condensation sensor becomes larger than a predetermined value is known from Japanese Patent Laid-Open Publication No. 56-90717, etc. It is.

(Problem to be solved by the invention) However, because atmospheric sensors such as dew condensation sensors have poor responsiveness, they are unable to keep up with sudden changes in humidity, such as when many people board the vehicle at once in the winter, resulting in delays in defogging operations. . Therefore, the fogging determination level is generally set low, but on the other hand, when the humidity changes slowly, the fogging operation is performed even when there is no fogging, which is a problem in terms of energy saving and comfort.

Therefore, in order to solve the above problems, the present invention reliably detects when the humidity in the vehicle interior changes rapidly and defogs the window glass, and also allows the humidity in the vehicle interior to change gradually. Even in the case of
It is an object of the present invention to provide a defogging device for a vehicle that can suppress energy loss in a defogging means as much as possible.

(Means for Solving the Problems) Therefore, the present invention provides: a degree of fogging detection means for detecting the degree of fogging of the window glass of a vehicle; a fogging removal means for removing the fogging of the window glass of the vehicle; and the degree of fogging. a cloudy degree determining means for determining whether the degree of cloudiness detected by the detecting means is greater than or equal to a predetermined value; and a rate of change determining means for determining whether the rate of change in the degree of cloudiness is greater than or equal to a predetermined value; , whether the degree of cloudiness is determined to be equal to or higher than a predetermined value by the degree of cloudiness determining means;
Alternatively, the gist thereof is a defogging device for a vehicle, comprising an actuating means for activating the defogging means when the rate of change in the degree of fogging is determined by the rate of change determining means to be equal to or higher than a predetermined value. .

(Function) According to the present invention, at least the cloudiness degree is determined to be equal to or greater than a predetermined value by the cloudiness degree determination means, or the change rate of the cloudiness degree is determined to be equal to or greater than a predetermined value by the change rate determination means. When it is determined that this is the case, the operating means operates the defogging means to defog the vehicle window glass.

In other words, when the rate of change in the degree of cloudiness is greater than a predetermined value, that is, if the rate of change in the degree of cloudiness is rapid, the degree of cloudiness detection means cannot follow the rapid change in the degree of cloudiness, and the rate of change in the degree of cloudiness is higher than the actual degree of cloudiness. Even if a low value is detected, the fogging on the window glass is reliably removed.

Further, when the rate of change in the degree of cloudiness is smaller than a predetermined value, that is, the rate of change in the degree of cloudiness is gradual, when the degree of cloudiness is determined by the cloudiness degree determination means to be equal to or higher than the predetermined value, that is, if the rate of change in the degree of cloudiness is Since the defogging means is activated only when the
Window glass can be defogged while minimizing energy loss in the defogging means.

(Effects of the Invention) As described above, the present invention is capable of defogging window glass while minimizing energy loss in the defogging means, regardless of whether the rate of change in the degree of fogging is rapid or gradual. Because it is possible to
This is extremely effective in terms of both energy saving and safety.

(Embodiment) FIG. 1 shows a car air conditioner control device combined with a defogging device. In the figure, 1
is a ventilation duct, 1a is an outside air passage, 1b is an inside air passage, 2 is an inside/outside air switching damper, 3 is a blower motor,
4 is an evaporator of the refrigeration cycle CC driven by the engine EG, 5 is a heater core, 6 is a bypass passage, 7 is an air mix damper, 8 is an outlet switching damper, 1c is an upper blowing passage, and 1d is a lower blowing passage. . 10 is a control unit, 11 is a switch panel, 12 is a display panel, 13 is a main switch, 1
4 is a battery, 21 is an inside temperature sensor, 22 is an outside temperature sensor, 23 is a room temperature setting device, 24 is an air mix damper opening sensor, 25 is a dew condensation sensor that detects the windshield surface humidity, 31 is for compressor connection An electromagnetic clutch, 32 is an electromagnetic valve for opening and closing a hot water valve, and 33, 34, and 35 are actuators for driving a damper. 9 is a defogger that raises the temperature of the rear glass to remove fog. In this embodiment, the evaporator 4 constitutes a fog removing means, and the dew condensation sensor 25 constitutes a fog degree detecting means.

Next, in the above configuration, the control unit includes a digital computer, and the overall operation of the apparatus will be explained with reference to the operation flowchart of FIG. 2 showing the operation thereof. In this embodiment, a cloudy degree determining means is configured in step 801, which will be described later.
Step 802 constitutes a change rate determining means, and step 810 constitutes an actuation means.

The arithmetic processing of the air conditioning control program is started from a start step 101, and the process proceeds to a signal input routine 102. In this signal input routine, the analog detection signals of the inside temperature sensor 21, outside temperature sensor 22, room temperature setting device 23, opening sensor 24, and dew condensation sensor 25 are sequentially converted into digital signals by the built-in A/D converter. stored in RAM.

Steps 103 to 107 are the same as normal air conditioning control.

In the anti-fog control routine 108, based on the detection signal of the dew condensation sensor 25, anti-fog control is performed when conditions are such that fogging occurs.

The details of the anti-fog control routine are shown in FIG.

In step 801, it is determined whether the dew condensation sensor detection value Hs ₁ is larger than a predetermined value A, and if the determination is
If the determination is YES, proceed to step 807; if the determination is NO, proceed to step 802. In step 802, it is determined whether the rate of change in the detected value is greater than a predetermined value B. Here, Hso is a detected value T seconds ago. If the determination in step 802 is YES, the process proceeds to step 807, and if the determination is NO, the process proceeds to step 803.

Step 803 to Step 806 is Step 807
This is to restore the contents (data) changed from the normal air conditioning control state in the anti-fog control from step 813 to step 813.

In step 803, it is determined whether flag H=0.
Flag H is used to determine whether compressor operation is commanded in normal air conditioning control. H≠
If it is 0, proceed to step 804, cut off the compressor from the engine, and proceed to step 805. H=0
If so, skip step 804 and proceed to step 805. In step 805, the defogger 9 is stopped, and in step 806, the flag F is set to 0, and the defogging control routine is exited.

On the other hand, in the anti-fog control, in step 807 it is determined whether the flag F=1. If flag F=1, the defogging control routine is exited as is.

If F≠1, the process advances to step 808, where it is determined whether the compressor is connected. step
If the judgment in 808 is NO, proceed to step 809 and H=1
Then, in step 810, the compressor is connected,
Proceed to step 812. Judgment in step 808 is YES
If so, proceed to step 811, set H=0, and proceed to step 811.
Proceed to 812. In step 812, the defogger 9 is operated, and in step 813, the flag F is set to 1 and the defogging control routine is exited.

In this way, the anti-fog control is based on the sensor detection value Hs ₁
This is carried out when the predetermined value A is exceeded, or when the temporal change rate (Hs ₁ −Hso)/T exceeds the predetermined value B.

As shown in FIG. 4, as an anti-fog control routine (step 108 in FIG. 2), fogging can be determined by comparing the result of a composite calculation of the sensor level and the slope of its change with a predetermined value C. You can do it like this. Here, in step 901, Hs ₁ is the recent dew condensation sensor level, Hso is _the dew condensation sensor level T seconds ago, K is a time constant, and C is a constant.

Incidentally, the determination reference values A and B in FIG. 3 and C in FIG. 4 may be provided with hysteresis as shown in FIG. 5 to prevent chattering.

In the example shown in FIG. 4, when hysteresis is provided for the value of C, the control error is small and it is particularly effective. The reason for this will be explained with reference to FIG.

Under normal control, the glass surface humidity increases linearly, and when anti-fog control is performed, it decreases linearly.
In such a case, the change in the sensor detection value takes the form of a parallel shift of the change in the glass surface humidity by a time constant K. Therefore, the glass surface humidity is _C2
The sensor detection value is still C ₂ −K
(dHs ₁ /dt). dHs ₁ /dt≒(Hs ₁ −
Hso)/T, so Hs ₁ = C ₂ −K(dHs ₁ /dt)
Anti-fogging control may be performed at the time of ≒C ₂ −K(Hs ₁ −Hso)/T. In other words, Hs ₁ +K(Hs ₁ −
Hso)/T≈C ₂ , and the control shown in FIG. 4 completely compensates for the delay in response under the above assumption, and also reduces the control error during actual control.

The embodiment explained above is based on digital calculation, but the compressor ON and def/o
Control such as ON may also be performed.

Also, as a means of removing fog from window glass,
In addition to compressor coupling and defogger operation,
You can increase the capacity of the compressor, switch the air conditioning outlet to a defroster, increase the air volume,
Measures such as increasing the amount of outside air introduced may also be used.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of the embodiment, FIG. 2 is a flowchart showing an overview of the control program of the control unit in FIG. 1, and FIG. 3 is a flowchart showing details of the anti-fog control routine 108 in FIG. Chaat, 4th
FIG. 5 is a flowchart showing a modification of the anti-fog control routine, FIG. 5 is an explanatory diagram showing the application of hysteresis to the determination value, and FIG. 6 is an explanatory diagram of the effect of hysteresis. 4... an evaporator serving as a cloud removal means, 10
. . . a control unit, and 25 .

Claims (1)

[Scope of Claims] 1. A fogging degree detecting means for detecting the fogging degree of a window glass of a vehicle; a fogging removing means for removing the fogging from the window glass of the vehicle; and a fogging degree detecting means detecting the fogging degree detected by the fogging degree detecting means. a cloudy degree determining means for determining whether the rate of change in the degree of cloudiness is greater than or equal to a predetermined value; and it is determined that the degree of cloudiness is equal to or higher than a predetermined value,
Alternatively, the fog removing device for a vehicle may include an actuating means for activating the fog removing means when the change rate determining means determines that the change rate of the fogging degree is equal to or higher than a predetermined value.