JPH0213208Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a demist control device for a vehicle air conditioner.

(Prior art) Demist control for vehicle air conditioners includes a humidity sensor that detects the humidity on the inner surface of the car window, and when the humidity detected by the humidity sensor exceeds a predetermined value, it is determined that there is condensation. As disclosed in the publication, this was accomplished by opening the demist outlet, driving the cooler or introducing outside air, and operating the demist means to increase the amount of air blown. Furthermore, this demisting operation has been performed only by the output of the humidity sensor, regardless of the operating state of the vehicle-driving internal combustion engine (hereinafter also referred to as on-vehicle internal combustion engine).

(The problem that the invention attempts to solve) However, when you get into a stopped vehicle and start it,
In other words, the temperature inside the vehicle is not controlled when the internal combustion engine starts, and when the outside air temperature is low, the temperature inside the vehicle is also low, and the relative humidity inside the vehicle is high. When determining dew condensation based on the output, there is a problem in that the dew condensation state is determined even though it is not, and the demisting means is activated, causing the demisting state to continue.

However, if the number of passengers is small, for example, one person, once the demist control is performed, the windows will often not fog up. In such a case, in order to maintain the vehicle interior temperature at a comfortable temperature, it is desirable not to perform demist control more than necessary.

The present invention has been made in view of the above, and an object of the present invention is to provide a demist control device for a vehicle air conditioner that can minimize demist control, save power, and maintain a comfortable vehicle interior temperature. With the goal.

(Means for achieving the object) In order to resolve the above-mentioned problems, the present invention was constructed as shown in FIG.

This air conditioner for a vehicle includes a humidity sensor 1 that detects the humidity on the inner surface of a car window, and operates a demisting means 3 when a first discrimination means 2, which discriminates that there is condensation based on the output of the humidity sensor 1, determines that there is condensation. In the demist control device of the device, a second determining means 4 determines that the demist control is being performed for the first time after starting the vehicle drive internal combustion engine, and the second determining means 4 determines that the demist control is being performed for the first time. and a control means 5 for operating the demisting means for a predetermined period from when the demisting means is activated.

(Function) When the first determining means 2 determines that there is dew condensation based on the output of the humidity sensor 1, the demisting means 3 is activated to perform demisting control. That is, the demist outlet is opened, the cooler is driven, and the amount of air blown is increased to perform demisting.

When the second determining means 4 determines that the demisting control is being performed for the first time after the vehicle drive internal combustion engine is started, the demisting means 3 is operated for a predetermined period of time from the generation of the determined output of the second determining means 4. It is operated by the control means 5. As a result, in many cases, such as when there are few occupants, once the demist control is performed, the car window glass will not fog up, and the demist control will not be performed more than necessary, such as immediately after starting the internal combustion engine for driving the vehicle.

(Example of idea) The present invention will be explained below with reference to examples.

FIG. 2 is a block diagram showing the configuration of an embodiment of the present invention.

21 is an air conditioner main body, and 22 is a control device that controls the air conditioner main body.

The air conditioner main body 21 has an intake damper 24 that controls whether the intake air is to be circulated as internal air, partially introduced into the outside air, or completely introduced into the outside air, from the upstream side to the downstream side of the duct 23.
A blower 25 that blows the air sucked in through the vehicle compartment 30, an evaporator 26 that exchanges heat with the blown air while a cooler 36 (described later) is in operation, and an evaporator 2
6, a mix damper 27 that controls the amount of air diverted to a heater 28 (to be described later), a heater core 28 that acts as a heater by circulating the cooling water of the in-vehicle internal combustion engine 29, and heats the passing air, and a vehicle interior 30.
mode switching damper 31 that selects the air outlet for
_{1,312 .}

The compressor 32, condenser 33, receiver tank 34, and expansion valve 35 together with the evaporator 26 constitute a cooler 36. Furthermore, the rotation of the output shaft of the on-vehicle internal combustion engine 29 is transmitted to a pulley 37. The rotation of pulley 37 is transmitted to compressor 32 via magnetic clutch 38, and compressor 32 is driven by this transmission.

Air outlets to the vehicle interior 30 include a vent outlet 39 that blows air toward the occupant's face, a heat outlet 40 that blows air from the occupant's feet, and a defrost outlet 41 that blows air along the inner surface of the windshield. mode switching damper 31 ₁ ,
31 ₂ selectively opens one or two of the air outlets.

The intake damper 24 is driven by a motor actuator 45, the mix damper 27 is driven by a motor actuator 46, and the mode switching dampers 31 ₁ and 31 ₂ are driven by a motor actuator 47. In addition, in Fig. 2, 48~
Reference numeral 52 represents a drive circuit for driving the motor actuator 45, the blower 25, the magnetic clutch 38, and the motor actuators 46 and 47, respectively.

On the other hand, an inside air temperature sensor 53 that detects the air temperature inside the vehicle, a solar radiation amount detection sensor 54 that detects the amount of solar radiation,
an evaporator outlet air temperature sensor 55 that detects the evaporator outlet air temperature, that is, the temperature at point A;
An outside air temperature sensor 56 for detecting the outside air temperature, a setting device 57 for setting the vehicle interior temperature, and a potentiometer 58 for detecting the opening degree of the mix damper are provided.
Furthermore, a humidity sensor 61 is provided near the car window to detect the humidity on the inner surface of the car window. The output of each temperature sensor, the output of the setting device 57, the output of the potentiometer 58, and the output of the humidity sensor 61 are supplied to an A/D converter (hereinafter referred to as ADC) 59 via a multiplexer (not shown) and converted into digital data. The digital data converted by the ADC 59 is supplied to the microcomputer 60.

The microcomputer 60 is basically a CPU,
It has a ROM that stores programs, a RAM that stores data, an input port, an output port, and a timer. Digital data output from the ADC 59 according to the program written in the ROM is read through the input port,
The data processed and calculated by the CPU is output to the drive circuits 48 to 52 via output ports, and is controlled via the opening of the intake damper 24, the drive, stop, and air flow rate of the blower 25, and the magnetic clutch 38. The operation of the compressor 32 and the opening degree of the mix damper are controlled to bring the vehicle interior temperature to the set temperature. In addition, blowout mode control is performed to select and open the blowout outlet corresponding to the blowout air temperature.

The operation of the present invention will be explained in accordance with the program stored in the ROM of the microcomputer 60 with reference to the flowcharts of FIGS. 3 and 5.

When the program starts running when the power is turned on, initial settings such as clearing the RAM and setting flag F are performed (step a), and the output digital data from the ADC 59 is read through the input port and stored in the specified RAM. It is temporarily stored in the area (step b). Vehicle interior temperature control signal (hereinafter referred to as
(denoted as total data) T=T _R +K ₁ T _E +K ₂ T _A +
K ₃ T _S −K ₄ T _D +K ₅ is calculated and stored (step c). Here, _TR represents the vehicle interior air temperature, T _E represents the evaporator outlet air temperature, T _A represents the outside air temperature, and T _S represents the amount of solar radiation, which are detected by the sensors 53 to 56. T _D is the set temperature set by the setting device 57, and K ₁ to K ₅ are constants. Therefore, the integrated data T is related to the deviation between the set cabin temperature and the detected cabin air temperature, and also corresponds to a value corrected by the evaporator outlet air temperature T _E , the amount of solar radiation T _S , and the outside air temperature T _A. , it can also be said to be a value related to the heat load for controlling the vehicle interior air temperature to the set vehicle interior temperature.

Following step c, the outlet temperature data T _F = T _E +
K ₆ θ+β is calculated and stored (step d).
Here, θ indicates the opening degree of the mix damper 27, and the opening degree when all the air that has passed through the evaporator 26 passes through the heater core 28 is θ=
It is set to 100% (full heat). Furthermore, K ₆ and β are constants. Therefore, the blowout temperature data
T _F corresponds to the temperature of the air blown into the vehicle compartment 30.

Following step d, the air flow rate is controlled (step e). The air blowing amount is controlled by applying a voltage to the drive motor of the blower 25 in accordance with the pattern shown in FIG. 4a in accordance with the total data T. Following step e, the mix damper opening degree is calculated according to the pattern shown in FIG. The compressor driving temperature is calculated according to the pattern shown in FIG. 4c in accordance with the combined data T, and the driving of the compressor 32 is controlled depending on whether or not the evaporator outlet air temperature T _E exceeds the calculated compressor driving temperature. The compressor drive control is performed (step g). Next, intake damper opening degree control is performed to control the opening degree of the intake damper 24 in relation to the amount of air blown and the drive mode of the compressor 32 (step h). Further, mode control is performed to open the heat outlet 40, the vent outlet 39, or the heat outlet 40 and the vent outlet 39 according to the data T _F (step i), and then demist control is performed (step j). , step b is executed again.

When entering the demist control in step j, it is checked from the output of the humidity sensor 61 whether or not there is dew condensation on the inner surface of the car window glass (step _j1 ), and if it is determined that there is no condensation, the demist control is stopped. (Step j ₇ ). In step _j1 , when the humidity detected by the humidity sensor 61 is equal to or higher than a predetermined value, it is determined that there is a condensation state. If it is determined in step j ₁ that there is dew condensation, it is checked whether a flag F indicating that demist control is being performed for the first time after the on-vehicle internal combustion engine is started is set (step j ₂ ). When flag F is set, that is, when it is determined that demist control is being performed for the first time after the on-vehicle internal combustion engine is started, the timer starts counting (step j ₃ ), and demist control starts (step j _{4 )} . ). The demist outlet 41 is opened,
Demist control is performed by driving the cooler 36 or bringing in outside air, and increasing the amount of air blown as shown by the broken line in FIG. 4a. Following the demist control in step _j4 , it is checked whether the timer set time has elapsed (step _j5 ), demist control is performed until the timer set time has elapsed, and when the timer set time has elapsed, flag F is set.
is reset (step _j6 ). Following step _j6 , the demisting control is stopped (step _j7 ), and step b is executed. In step j ₂ , when flag F is reset, that is, when demist control is not performed for the first time after the in-vehicle internal combustion engine is started, demist control is started following step j ₂ (step j ₈ ), and then step b is started. executed.

Therefore, when the humidity detected by the humidity sensor 61 exceeds a predetermined value, it is determined that there is condensation, and demist control is performed. If demist control is performed for the first time after starting the on-board internal combustion engine, it is performed for a certain period of time. become.

Further, instead of steps _j3 to _J5 , when it is determined that demist control is performed for the first time as shown in _FIG . It is checked whether R is greater than or equal to a predetermined value K (step j ₁₀ ), and step j ₆ is executed. In this case, once
When demist control is performed, the humidity decreases and the resistance value exhibited by the humidity sensor 61 increases. Demist control is performed until this resistance value reaches a predetermined value K. Therefore, in this case, the timer can be omitted.

(Effects of the invention) As explained above, according to the invention, after the in-vehicle internal combustion engine is started, it is determined whether the demist control is being performed for the first time, and if the demist control is being performed for the first time, the demist control is continued for a predetermined period of time. Because I did it like this,
Even in a case where the relative humidity is high because the temperature inside the vehicle is low immediately after the vehicle internal combustion engine is started, the demist control is not performed unnecessarily. Therefore, the comfort of the vehicle interior temperature is not compromised, and it also contributes to power savings.

[Brief explanation of the drawing]

Figure 1 is a functional block diagram of the present invention. FIG. 2 is a block diagram showing the configuration of an embodiment of the present invention. 3 and 5 are flowcharts for explaining the operation of one embodiment of the present invention. FIG. 4 is a diagram for explaining the operation of one embodiment of the present invention. FIG. 6 is a flowchart showing a modification of one embodiment of the present invention. 1...Humidity sensor, 2...First discrimination means, 3...
... Demist means, 4 ... Second discrimination means, 5 ... Control means.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A humidity sensor is provided to detect the humidity on the inner surface of the car window, and when the first discrimination means determines that there is condensation based on the output of the humidity sensor, the demisting means is provided. In a demist control device for a vehicle air conditioner that operates, a second determining means determines that the demist control is being performed for the first time after starting the vehicle drive internal combustion engine; 1. A demist control device for a vehicle air conditioner, comprising: a control means for operating a demist means for a predetermined period of time. (2) The demisting device for a vehicle air conditioner according to claim 1, wherein the predetermined period is a period set by a timer. (3) The demist control device for a vehicle air conditioner according to claim 1, wherein the predetermined period is a period until the humidity detected by the humidity sensor reaches a preset humidity.