JPH0116700B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a demist control device for preventing fogging from forming on the inner surface of an automobile glass.

(Prior art) Demist control involves the driver manually turning on the compressor, adjusting the blower setting lever to adjust the amount of outside air introduced, and adjusting the mode setting lever to set the defrost mode. However, if the driver were to perform such an operation, it would be a major hindrance to driving and could be dangerous. For this purpose, the applicant proposed Japanese Patent Application Laid-Open No. 57-70721.

(Problems to be Solved by the Invention) In this conventional example, operations to operate the compressor and increase the amount of introduced air were performed based on the outside air temperature by simply operating the wiper. In other words, since humidity conditions are not taken into consideration, if the operating outside air temperature of the compressor is set high, when the outside temperature is low and it rains, outside air will be introduced, and high humidity outside air will be introduced, resulting in a low demisting effect. Setting the temperature low improves the dehumidifying effect, but even when a sufficient demisting effect can be obtained even by introducing relatively low-humidity outside air other than when it rains, the compressor is operated, resulting in large power consumption.

Therefore, an object of the present invention is to save power and improve demisting by changing the operating outside air temperature of a compressor for dehumidification by adding the humidity condition of outside air.

(Means for Solving the Problems) The gist of the present invention is to provide a demist switch or a dew condensation sensor that detects the occurrence of fogging, an outside air sensor that detects outside air temperature, a wiper operating switch that detects the wiper operating state, and a demist control switch. The control means is configured to set the compressor to a demist state when the signal is output, and to change the operating outside air temperature of the compressor depending on whether the wiper is in operation or not.

(Function) Therefore, the humidity condition of the outside air is determined by the wiper operation, and when the wiper is operating in high humidity, the operating outside air temperature of the compressor is set lower to improve the demisting effect, and when the wiper is not operating, the humidity condition of the outside air is determined. In order to obtain a demisting effect by utilizing the outside air temperature with low humidity, the operating outside air temperature of the compressor can be set to be high, thereby saving power and solving the above-mentioned problem.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

In FIG. 1, an embodiment of the automotive air conditioner and its control circuit of the present invention is shown. As a result, outside air or inside air is selectively introduced from the outside air port 3 or the inside air port 4 depending on the position of the inside/outside air switching door 5, and is force-fed to the evaporator 6 of the air conditioning case 1, which will be described below.

The position of the inside/outside air switching door 5 is determined by the actuator 7.
Opening/closing is controlled by the output from the control circuit 8 via.

The evaporator 6 cools the introduced air.
The evaporator 6, compressor 9, condenser 10, and liquid tank 11 constitute a cooling cycle, which is driven by turning on and off the electromagnetic clutch 12 of the compressor 9. The drive is controlled by the control circuit 8. This is done using the output of

The heater core 13 is located downstream of the evaporator 6 and has the function of warming the introduced air.
The water heater 14 is opened and closed by an actuator 15 for air mix door control to control the heating temperature, and the air volume supplied by the air mix door 16 provided upstream of the heater core 13 is controlled.

Although not shown, the opening degree of the air mix door 16 is controlled by the output of the control circuit 8 via the actuator 15 in accordance with the set value of a temperature control lever, so that the cold air that has passed through the evaporator 6 is supplied to the heater core 13. The temperature of the blown air is controlled by changing the mixing ratio with the air (cold air) that bypasses the heater core 13.

The most downstream part of this device is branched into an upper air outlet 17, a lower air outlet 18, and a defrost air outlet 19, mode switching doors 20, 21 are arranged at the branching points, and each door 20, 21 is connected to each actuator 22,
Switching is controlled by the output from the control circuit 8 via 23.

The control circuit 8 executes software arithmetic processing according to an air conditioner control program, and the outside air sensor 24 detects the outside air temperature, the inside air sensor 25 detects the interior temperature of the vehicle, and the demist switch or dew condensation sensor 26
The demist signal is set in the mode setter 27, each mode signal is set in the temperature control setting 28, and the set temperature is set in the temperature control setting 28.
Wiper operation signals are input to the wiper switch 29, and are internally processed according to a predetermined program.

In the above-mentioned configuration, the vehicle is running with the desired air conditioning condition set by the passenger's mode selection and temperature setting, but when fogging occurs, the demist signal is automatically or manually controlled by the dew condensation sensor or the demist switch 26. It is input to circuit 8. The control circuit 8 starts a demisting operation in response to a demisting signal. The demisting operation is performed according to the flow shown in FIG.

That is, when the engine of the vehicle starts operating, the control circuit 8 starts arithmetic processing at a start step 100, and in step 101 it is determined whether or not the power switch for starting the air conditioner is on. In step 102, the air conditioning is controlled, and in step 102 it is determined whether the output from the demist switch or the condensation sensor is ON.
Proceeding to step 103, a display indicating that demisting control is in progress is displayed, and demisting operation begins. Then, the process proceeds to step 104, where it is determined whether or not the wiper switch is in operation. If the wiper switch is on during rain, the process proceeds to step 105, where the outside air temperature is set to a predetermined temperature, which in this embodiment is 6 degrees or less. If so, proceed to step 108, the compressor 9 is turned off,
If the temperature is 10 degrees or more, the process proceeds to step 107, where the compressor 9 is turned on and the operating outside air temperature of the compressor 9 is determined.

If the wiper switch is off (when it is not raining and the humidity is relatively low), the process proceeds to step 106, and if the outside air temperature is below a predetermined temperature, in this example 10 degrees Celsius or less, the process proceeds to step 108, where the compressor is turned off. is turned off, and if the temperature is 14 degrees or higher, the process proceeds to step 107, where the compressor is turned on, the operating outside air temperature of the compressor is determined, and the wiper switch is set higher than when the wiper switch is turned on. There is.

Proceeding to step 107, if the compressor is turned on, the maximum demist (MAXIMUM-DEMIST) control step 110 is performed via timer set step 109.
In step 110, at least the rotation of the blower is at high speed and the mode is a differential mode;
Internal air circulation with some outside air introduced is optimal. This maximum demisting is performed in step 112 of gentle demisting (COMFORT DEMIST) after a certain period of time has passed through timer judgment step 111.
will be moved to In the case of a comfort demist, at least the blower rotation speed is low and the mode is vent or bi-level.

Proceeding to step 108, if the compressor is to be turned off, step 11 of setting the timer is executed.
Maximum Demist (MAXIMUM) via 4
DEMIST) control proceeds to step 115.

That is, in the maximum demist, at least the blower rotates at high speed, the mode is the differential mode, and outside air is introduced. After a certain period of time has elapsed via timer determination step 116, the maximum demist proceeds to step 117 and determines whether the outside temperature is considerably low. That is, it is determined whether the temperature is -9 degrees or less or -5 degrees or more. If the temperature is -9 degrees or less, the process proceeds to step 118 and is controlled to maximum demist, the blower is set at high speed and the mode is set to face mode. Default mode, introducing outside air. If the temperature is -5 degrees or more, the process proceeds to step 119, where the mode is transferred to the comfort demist mode, where the blower is set to low speed, the mode is face mode or differential mode, and outside air is introduced.

(Effects of the Invention) As described above, according to the present invention, in controlling the demist, the operating outside air temperature of the compressor is changed depending on the humidity state of the outside air, and specifically, the humidity state is changed by the wiper operation. When the wiper is on, detected by the on/off switch, the humidity of the outside air is high, so the demisting effect of introducing outside air is low. Since the humidity of the outside air is low when the compressor is off, a sufficient demisting effect can be obtained by introducing outside air, so that the compressor can operate at a higher outside air temperature, resulting in power savings.

In addition, the above-mentioned conventional example (Japanese Unexamined Patent Publication No. 57-70721)
In the , the wiper switch and demist switch are used in combination, so even when the wipers are turned on to remove dust from the windshield, for example, the system switches to demist control even when it is not raining. However, in the present invention, the demist switch and the wiper switch are provided separately, so malfunctions as in the prior art do not occur.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention;
FIG. 2 is a flowchart of the present invention. 2...Blower, 8...Control circuit, 9...Compressor, 24...Outside air sensor, 29...Wiper switch.

Claims (1)

[Claims] 1: a demist switch or a dew condensation sensor that detects the occurrence of fog; an outside air sensor that detects the outside temperature; a wiper operating switch that detects the wiper operating state; and a demist state when a demist control signal is output. 1. A demist control device for an air conditioner for an automobile, comprising a control means for setting the outside air temperature at which a compressor is operated depending on whether a wiper is in operation or not.