JPS6214405B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION In vehicle air conditioning control, the present invention selectively connects a cooling mechanism to an on-vehicle power source to adjust cooling capacity.
This aims to realize power-saving air conditioning control by reducing the operating rate of the cooling mechanism.

Conventionally, in vehicle air conditioning control systems that include a refrigerant compressor driven by an on-board engine, there has been a demand to reduce the engine load as much as possible by automatically controlling activation and shutdown according to the cooling capacity requirements of air conditioning control. There is.

Various proposals have been made to meet this requirement, but all of them operate and stop the cooling mechanism based on a single control parameter, which is sufficient to further reduce the operating rate of the cooling mechanism. No solution has been proposed.

The purpose of the present invention is to carefully select and condition two control parameters to strictly determine the need for cooling capacity, control the operation and stop of the cooling mechanism, and further reduce the operating rate of the cooling mechanism. It is something to do.

The present invention determines the stop condition of the cooling mechanism based on the outside temperature of the vehicle, which ultimately affects the final control output of the temperature control system, and determines the final control output of the control system determined based on various control parameters. By determining the operating condition of the cooling mechanism based on the indicated signal, and adopting the operating condition when both conditions occur simultaneously,
It is characterized by stricter judgment of cooling capacity to prevent the operating rate of the cooling mechanism from increasing due to erroneous judgment of conditions.

The present invention will be described below with reference to illustrated embodiments. The overall configuration is shown in FIG. 1, and the air conditioning unit 2 that regulates the air supplied to the vehicle interior 1 consists of an electric blower 3 that takes in air from outside the vehicle interior, and a refrigeration cycle 5 that includes a refrigerant evaporator (evaporator) 4. Cooling section and hot water heater (heater core 3) 6
and a heating section including an air mixture ratio adjusting damper (A/M damper) 7.

The electric control device 8 includes an inside temperature sensor 9 on the input side,
The outside temperature sensor 10, the opening sensor 11 of the A/M damper 7, the temperature setting device 12, and the limit switch 15 that opens when the opening of the A/M damper 7 is in a certain area near the maximum cooling position are connected, and the output side An electromagnetic clutch 13 for switching between operation and stop of the refrigeration cycle 5, an actuator 14 for controlling the opening degree of the A/M damper 7, and an electric blower 3 are connected to the refrigeration cycle 5.
The opening degree of the A/M damper 7 is controlled via the actuator 14 according to the vehicle interior temperature, vehicle exterior temperature, and set temperature, and the blowing capacity of the electric blower 3 is controlled to adjust the amount of heat of the air supplied to the vehicle interior. Adjust. In addition, a first condition determined from the outside temperature of the vehicle and the set temperature;
The second condition determined by the opening degree of the A/M damper 7, that is, the heating capacity required of the heating section, is comprehensively determined, and the electromagnetic clutch 13 is switched between energization and deenergization to operate and stop the cooling section. control.

The air conditioning unit 2 is of a known configuration having a so-called air mix system, and a known configuration for controlling the opening degree of the A/M damper 7 and the rotational speed of the electric blower 3 by electric control means is also adopted. can do. FIG. 2 shows the configuration of an electrical system consisting of an electrical control device and other electrical components. The inside air temperature sensor 9, the outside air temperature sensor 10, which is made up of a heat-sensitive resistor, the opening sensor 11, which is made up of a variable resistor, and the temperature setter 12 are connected to the input stage of the differential amplifier circuit 16 as shown in the figure. The output signal is amplified by a power amplifier 17 and drives an actuator 14 consisting of an electro-pneumatic converter to control the opening degree of the A/M damper 7. The mechanical displacement produced by the actuator 14 is linked to a change in the resistance value of the current limiting variable resistor 19 of the electric blower 3, and adjusts the amount of air blown out from the air conditioning unit 2.

Referring to FIG. 2, a control circuit for the electromagnetic clutch 13 for controlling the operation and stop of the refrigeration cycle 5 will be explained. A variable resistor 12A whose resistance value changes in conjunction with the temperature setter 12 is connected to the resistor 20, and a voltage generated at the connection point corresponding to the set temperature is input to one input terminal of the voltage comparison circuit 21. A signal voltage determined by the resistance value of the outside temperature sensor 10 is input to the other input terminal of the voltage comparison circuit 21 via the input resistor 22.
No. 1 generates an output signal that becomes high level at its output point A when the outside temperature of the vehicle is several degrees Celsius lower than the set temperature.

The limit switch 15 is connected in series with a resistor 22 between the power supplies, and the voltage at the connection point B is at a high level when the A/M damper 7 is near the maximum cooling position.
At other times, the level is low.

The output signals at points A and B are input to the R-S flip-flop 25 via the inverter 23 and the AND gate 24, and when the point B is low level and the point A is high level, the flip-flop 25 is reset and output. Terminal Q is at a low level (earth voltage), and when point B is at a high level, the flip-flop 25 is set regardless of the level at point A, and the output terminal Q is at a high level. The level signal produced at the output terminal of flip-flop 25 then energizes or de-energizes power amplifier 26 and electromagnetic clutch 13.

The voltage divided by the resistors 27 and 28 is applied via the resistor 29 to the input stage of the differential amplifier circuit 16 for additive amplification.

In the above configuration, when the ignition switch 30 is closed and the air conditioning switch 31 is closed, the opening degree of the A/M damper 7 is first controlled by the operation of the temperature control circuit centered on the differential amplifier circuit 16. The temperature inside the vehicle can be brought close to the set temperature. Further, the rotational speed of the electric blower 3 is adjusted according to the opening degree of the A/M damper 7.

When a large cooling capacity is required, such as when the vehicle interior temperature is much higher than the set temperature, the temperature control circuit moves the A/M damper 7 to the maximum cooling side, so the limit switch 15 opens and the flip-flop The flop flop 25 is set and the electromagnetic clutch 13 is energized to operate the refrigeration cycle.
As a result, the air conditioning unit 2 adjusts the temperature of the air cooled by the evaporator 4 while partially heating it with the heater core 6.

If the temperature outside the vehicle is relatively low, as the temperature inside the vehicle approaches the set temperature, the A/
The M damper 7 gradually moves from the maximum cooling position to the heating position. Then, at a certain point, the limit switch 15 closes, but the refrigeration cycle 5 remains in operation due to the self-holding action of the flip-flop 25.

However, under conditions where the outside temperature of the vehicle is considerably lower than the set temperature, the cooling capacity becomes unnecessary when the temperature inside the vehicle approaches the set temperature. When the A/M damper 7 is away from the maximum cooling position, when the output signal of the voltage comparison circuit 21 becomes high level, the flip-flop 25 is reset via the AND gate 24, and the electromagnetic clutch 13 is deenergized. The refrigeration cycle is stopped. Thereby, the air conditioning unit 2 partially heats the air outside the vehicle interior with the heater core 6 and adjusts the temperature thereof. The same applies when the temperature inside the vehicle is already close to the set temperature when the air conditioning switch 31 is turned on, and the flip-flop 2
5 is placed in a reset state without being set, and the refrigeration cycle 5 is stopped from the beginning.

Once the refrigeration cycle 5 is stopped, it is not reactivated until the limit switch 15 is opened, that is, until the A/M damper 7 is moved near the maximum cooling position according to the required heating capacity. Therefore, even if the outside temperature rises temporarily, the refrigeration cycle 5 does not start operating immediately.

In addition, when the refrigeration cycle 5 is operated, the resistors 27, 2
The divided voltage generated at the connection point 8 is the refrigeration cycle 5
During operation, the voltage is applied to the differential amplifier circuit 16 to slightly correct the opening degree of the A/M damper 7 toward the heating side, thereby preventing stepwise changes in the temperature of the blown air due to activation and stoppage of the refrigeration cycle 5.

In the embodiment described above, instead of using the limit switch 15, the resistance value of the opening sensor 11 may be determined by a voltage comparison circuit in order to determine the heating capacity required of the heating section. Alternatively, the magnitude of the output signal of the differential amplifier circuit 16 may be determined. Therefore, the present invention can also be applied to an air conditioning unit that does not use the A/M damper 7, such as a type that adjusts the temperature or flow rate of hot water passing through the heater core 6.

Furthermore, in implementing the present invention, a digital computer may be used that processes all functions of the control circuit according to a predetermined software control program.

As described above, in the present invention, when the outside temperature of the vehicle is lower than the set temperature by a predetermined value or more and the heating capacity required of the heating part is greater than the predetermined value, the operation of the cooling part is stopped, and the operation of the cooling part is temporarily stopped. When the cooling unit is stopped, the cooling unit is activated when the heating capacity required of the heating unit reaches a predetermined value indicating the vicinity of maximum cooling, so the decision to activate or stop is made based on two parameters: the outside temperature of the vehicle and the heating capacity. It is possible to prevent malfunction of the cooling unit by making a strict judgment based on the above, and has an excellent effect on reducing the operating rate of the cooling unit.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram showing an example of an air conditioning control device for an automobile that implements the method of the present invention, and FIG. 2 is an electrical wiring diagram showing an electrical control system of the device shown in FIG. 4... Refrigerant evaporator (evaporator) that forms the main part of the cooling section, 6, 7... Hot water heater (heater core) and adjustment damper that forms the main part of the heating section, 8... Electric control device, 9... Car an inside temperature sensor that detects the indoor temperature; 10... an outside temperature sensor that detects the outside temperature of the vehicle; 12... a temperature setting device that operates the set temperature;
13... Electromagnetic clutch that drives the cooling section, 15...
... Limit switch, 21 ... Voltage comparison circuit, 2
5...R-S flip-flop.

Claims (1)

[Claims] 1. Operation of the cooling section located upstream of the heating section,
In an automotive air conditioning control method that includes stop control and automatically adjusts the amount of heat of air supplied to the vehicle interior by controlling the heating capacity of the heating section in relation to the vehicle interior temperature, vehicle exterior temperature, and set temperature, the vehicle exterior temperature is lower than the set temperature by a predetermined value, and a second condition in which the heating capacity required of the heating section is smaller than the predetermined value is detected, and when only the first condition occurs, the cooling When the second condition occurs, the cooling unit is brought into a stopped state, and when both conditions disappear, the cooling part is maintained in an operating state or a stopped state according to the condition before the disappearance. Automotive air conditioning control method.