JPS59102615A - Method of controlling car air-conditioning system - Google Patents

Abstract

PURPOSE:To reduce fuel consumption and minimize compressor power in a car cooler and also to enhance car traveling characteristics by calculating the fuel consumption, determining the minimum value of variable thermostat judging level that is obtained by inversely varying the level against variation in the fuel consumption and by controlling a compressor at the level above said minimum value. CONSTITUTION:Data on water temperature 32, throttle valve opening 33, intake- air temperature 34, intake air quantity 35, engine r.p.m. 36, and car speed 37 are input to an electronics controlled fuel injection equipment 30 in order to determine the fuel injection quantity and to control fuel injection valves 40 to 43. And signals on the fuel injection quantity, engine r.p.m. and car speed are output to an air-conditioning control part 50. The air-conditioning control part 50 calculates a variable thermostat judging level set value for temperature control, using these values in addition to the room temperature 51, outside air temperature 52, sun heat 53, set temperature 54, and evaporator temperature 55. It also calculates the minimum judging value from the fuel consumption and controls the compressor 56 within the rang in which the set value is equal to or above the minimum value.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for controlling a cooling system such as a car air conditioner or a car cooler installed in a vehicle.

The compressor of a cooling system such as a car air conditioner or car cooler installed in a vehicle is driven by the output of the engine, so when the cooling system is used, the running output of the engine decreases by the amount of driving the compressor. Output may be insufficient during acceleration or under high load. Therefore, during acceleration or high load, the compressor of the cooling system is stopped, or in the case of a variable capacity compressor, its output capacity is controlled to the minimum in order to reduce the load on the engine as much as possible. Furthermore, some cooling systems perform the above-mentioned control when the heat load, such as room temperature, falls below a certain value.

However, since the conventional cooling system control described above is performed regardless of the fuel efficiency (km/ff) of the engine, even if the fuel efficiency deteriorates due to deterioration of the engine or vehicle, it is not possible to perform cooling control that is commensurate with the fuel efficiency. This is a factor that causes a decline in driving performance.

The present invention has been made in view of the above points, and aims to improve fuel efficiency, power saving, driving performance, etc. by sequentially calculating the fuel efficiency of the engine and performing cooling control commensurate with the calculated fuel efficiency. In order to achieve this object, the present invention provides an electronically controlled fuel injection device that determines the fuel injection amount according to the operating state of the engine and performs fuel control, and an electronically controlled fuel injection device that is driven by the engine. In a method for controlling a cooling system for a vehicle, the cooling system is equipped with a cooling system in which the compressor is controlled to be activated or stopped by a variable thermostat that operates according to the temperature of the evaporator. and determining the minimum value of the determination level of the variable thermostat by changing it in the opposite direction to the change in fuel efficiency, and determining the minimum value of the determination level of the variable thermostat for temperature control calculated by the temperature parameter. The present invention provides a method for controlling a vehicle cooling system, which sets the determination level to a minimum value or higher, and performs cooling control commensurate with fuel efficiency.

An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows a flowchart of a method for controlling a vehicle cooling system according to the present invention. When the cooling system, for example, an air conditioner, is powered on, it is initialized (step 1), and a room temperature sensor, an outside temperature sensor, a solar radiation sensor, etc. Detection signals from each sensor are input to the control unit of the cooling system (step 2).

Each of these input signals is replaced with a comprehensive signal necessary for temperature control of the computer (step 3).

Next, step 4) to detect the set temperature of the room temperature, calculate the difference between the set temperature signal and the above-mentioned overall signal, that is, the difference (thermal load) 8T between the set temperature and the room temperature (step 5), and calculate this temperature difference ΔT. Control the mix door and compressor of the air conditioner based on the corresponding signals (Step 6.7)
.

In step 7, the compressor is controlled in a way that is appropriate for fuel efficiency. The compressor control command is sent to the compressor control subroutine (step 8), which calculates the operating (on) mode of the compressor based on the temperature difference ΔT (step 9), and determines whether the compressor is in the operating mode, that is, the cooling mode. If the answer is negative (No), proceed to step 21 and turn off the compressor.
If the answer is yes, that is, if cooling is required, a set value TT of the temperature determination level of the variable thermostat necessary for temperature control is calculated based on the temperature difference T (step 11). Next, the fuel injection amount calculated by the electronically controlled fuel injection device according to the operating state of the engine and engine parameters such as engine speed, etc.
Steps 12 and 13.1 Enter data representing vehicle speed.
4), Sequentially calculate the fuel consumption Δ at that moment (step 15
).

This fuel consumption A (km/β) is calculated as follows.

The injection amount per engine cylinder and injection is Q((1),
The number of cylinders is K, and the engine speed is N (rpm).

If the vehicle speed is V (km/h), then 1 per minute
The fuel consumption per cylinder is Q-N/2 (Q/m1n) (1
) (However, it is assumed that the engine is a 4-cycle engine), and when converted to fuel consumption per hour, it is 30Q.
-N (ρ/h)・・・・・・・・・・・・・・・(2
). Therefore, the fuel consumption of the entire engine is calculated by multiplying equation (2) by the number of cylinders.

-Q-N (Q/h)・・・・・・・・・・・・(
3). When the vehicle speed V (km/h) is divided by this equation (3) and converted into fuel efficiency, the fuel efficiency A is expressed by the following equation.

A=V/30 -Q-N (km/<1)...
(4) Here, since 30 is a constant, C=1/30
Then, the above equation (4) is expressed as the following equation.

A = C-V/Q-N (km/ 11) =・=”
(5) In this way, the fuel consumption Δ of the engine is calculated one after another.

Based on this calculated fuel consumption A, the minimum value Trn i r) of the temperature judgment level of the variable thermostat is calculated (
Step 16). This fuel efficiency A and the minimum value Tm of the judgment level
The relationship with in is expressed, for example, in a graph as shown in FIG. 2, and the minimum value Twin of the determination level changes in the opposite direction to the increase or decrease in fuel consumption. That is, the minimum value Tm1n of the temperature determination level is, for example, 20 when the fuel efficiency A is high (good).
(km/Q) or more, the level goes to LOW, which lowers the minimum cooling temperature, and when fuel efficiency A is low (bad), for example, 5 (kn+/Ω) or less, it goes to HIGH.
) level, raising the minimum cooling temperature, and fuel efficiency A is 5~5.
It decreases linearly between 20 (km/Q).

Next, the set value TT of the temperature determination level calculated in step 11 and the minimum value T m i calculated in step 16
Step 17), the answer is affirmative (Yes).
), that is, when the set value TT is in the area (1) outside the straight line of the graph in FIG. 2, the judgment level of the variable thermostat is set to the set value TT (step I8).
, in the case of negative (No), that is, when the set value TT is in the area (I[) inside the straight line of the grab in FIG. 2, the determination level is set to the minimum value T m in step 22
), the set value T↑ is always set to a value greater than or equal to the minimum value Tmin.

Next, step 19.23 detects the temperature TE of, for example, the cooling fins of the evaporator of the cooling system.
), compare the set value TT and the fin temperature TE and calculate T E
> Tr (step 20), and if the answer is negative (No), that is, if the fin temperature TE is lower than the set value Tt (for example, 0°C), the compressor is no longer operated. If the evaporator is allowed to cool down, the fin surface of the evaporator will freeze and the cooling capacity will decrease, so the compressor must be stopped (turned off).
(Step 21), and if it is affirmative (Yes), that is, if the fin temperature is higher than the set value TT (1-0°C), there is still cooling capacity of the evaporator and the compressor is activated (on).
(Step 25).

Furthermore, if the process proceeds to step 22, the minimum value T min
and the fin temperature TE, T E :> T mi
step 24), and if the answer is negative (No), the compressor is stopped in the same way as described above;
In the case of affirmation (Yes), the compressor is operated.

Thus, when fuel efficiency is high, the temperature determination level of the thermostat is lowered to increase the cooling capacity, and when fuel efficiency is low, the temperature determination level is increased to lower the cooling capacity, thereby controlling the compressor in a manner commensurate with the fuel efficiency.

Next, mode control (step 26), blower control (step 27), and inside/outside air door control (step 28) are performed in the same manner as the control of a normal air conditioning system, and the calculated fuel efficiency A, etc. is displayed (step 29). . Note that it is not always necessary to display fuel consumption.

As described above, the air conditioner is controlled by controlling the drive of the compressor in accordance with the fuel efficiency.

FIG. 3 shows a block diagram of a cooling system to which the control method of the present invention is applied. Water temperature sensor 32. Throttle valve opening sensor 33. Intake air temperature sensor 34. Intake air amount sensor 35. Engine parameters output from each sensor such as the engine rotation sensor 3.6 and vehicle speed sensor 37 are input, the fuel injection amount is sequentially calculated based on these parameters, and a corresponding fuel injection amount signal is output. , high-pressure fuel is supplied and injected to each of the fuel injection valves 40 to 43 in a predetermined order at a predetermined timing synchronized with engine rotation. Such fuel control is well known.

On the other hand, the control unit 50 of the cooling system includes a room temperature sensor 51, an outside temperature sensor 522, a solar radiation sensor 53, and so on. Room temperature setting device 54. Each temperature parameter output from the evaporator temperature sensor 55, the fuel injection amount signal, engine rotation speed signal, vehicle speed signal, etc. from the control unit 30 of the fuel injection device are input, and the room temperature is determined.

Calculate the difference ΔT between the set temperature and the room temperature based on each signal of outside temperature, solar radiation, set room temperature, etc. Step 5 in Figure 1), and use this temperature difference ΔT to determine the temperature of a variable thermostat (not shown) for temperature control. First, calculate the level setting value TT.
In step 11) of the figure, the fuel consumption A of both equations (5) is calculated based on the fuel injection amount signal, engine speed signal, vehicle speed signal, etc., and the minimum value T m of the temperature judgment level of the thermostat is calculated.
Calculate i n (step 15.16 in Figure 1). Then, the compression fi 56 is driven and stopped (ON, OFF) controlled within a range where the set value TT does not exceed the minimum value Tm1n, and a control signal corresponding to the temperature difference T is outputted to the mix door 57. Mode door 58. Blower 59, internal/external air door 60
Steps 6.26, 27, 28 in Figure 1)
Furthermore, the calculated fuel consumption and the like are displayed on the display unit 61.

In this embodiment, a case has been described in which the fuel consumption is calculated sequentially and the compressor capacity is determined based on the calculated fuel consumption, but the present invention is not limited to this. It is also possible to calculate where the current fuel consumption is located on the equal fuel consumption curve, and control the temperature determination level of the variable thermostat to a value commensurate with that. 4. As explained above, according to the present invention, the electronically controlled fuel injection device that determines the fuel injection amount according to the operating state of the engine and performs fuel control, and the compressor driven by the engine are connected to each other according to the temperature of the evaporator. A method for controlling a cooling system for a vehicle, which is equipped with a cooling system that is activated or stopped by a variable thermostat 1 that operates according to The minimum value of the determination level of the variable thermostat is determined by changing it in the opposite direction to the change in fuel consumption, and the minimum value of the determination level of the variable thermostat for temperature control calculated based on the temperature parameter is set as the minimum value of the determination level of the variable thermostat calculated by the temperature parameter. Since the air conditioner is set to a value higher than the value and air conditioning control is performed in accordance with the fuel efficiency, fuel efficiency and power saving are achieved, and driving performance is improved. Furthermore, since the necessary data can be obtained from the electronically controlled fuel injection device, no special detection device is required, and the cost is low.

It is also possible to display the calculated fuel consumption.

[Brief explanation of the drawing]

FIG. 1 is a flowchart showing an embodiment of the method for controlling a vehicle cooling system according to the present invention, FIG. 2 is a graph showing the relationship between fuel efficiency and maximum compressor capacity in the method of the present invention, and FIG. 1 is a block diagram showing an embodiment of a cooling system to which the method of the present invention is applied. 30...Fuel injection system W control section, 31-37...Sensor. 40-43...Fuel injection valve, 50...Cooling system control unit, 51-55...Sensor, 56...Compressor,
57-60... Cooling control object, 61... Display unit. Applicant: Diesel Kiki Co., Ltd. Agent Patent Attorney Toshihiko Watanabe I Figure 2 (Fuel Efficiency) Procedural Amendment. (2) Relationship with Patent Application No. 211663 of 1982 and the title of invention case Patent applicant address 3-6-7 Shibuya, Shibuya-ku, Tokyo (5)
Name (333) Representative of Diesel Kiki Co., Ltd.
Sei Mochizuki (6) Sunshine Koken Plaza No. 301 170 Telephone: 03 (983) 0926 Column for detailed explanation and column for brief explanation of drawings /'^1 Contents of amendment The scope of the claims of the present application is attached Correct as shown. In the specification of the present application, page 4, line 17, "Step 4" is corrected to "Step 4." In lines 18 to 19 of the same page, the words "difference between set temperature and room temperature (thermal load)" are corrected to "or heat load." Delete "(20℃)" on page 8, line 17. On page 10, line 18 of the same page, the text "room temperature" is corrected to "general signal." In the 6th line of the same page, "Do not exceed J" is corrected to "Do not exceed". Page 13, line 2, ``The maximum value J of the compressor capacity''
"Minimum value of temperature determination level of variable thermostat" 6 Claims [1. A method for controlling a cooling system for a vehicle, which is equipped with a cooling system in which a driven compressor is activated or stopped by a variable thermostat that operates according to the temperature of an evaporator. The fuel consumption is calculated based on the determined fuel injection amount and predetermined engine parameters, and the minimum value of the judgment level of the variable thermostat is determined by changing the fuel consumption in the opposite direction to -ζ, and the temperature is determined by 1γ based on the temperature parameter. A cooling system for a vehicle, characterized in that the minimum value of the judgment value of the variable thermostat for control is set to be greater than the minimum value of the determined judgment level, and cooling control commensurate with fuel efficiency is performed. Control method. 2. The method for controlling a vehicle cooling system according to claim 1, wherein the predetermined engine parameters are a vehicle speed signal and an engine rotation speed signal. 3. The method of controlling a vehicle cooling system according to claim 1, wherein the compressor is an on/off control type compressor. ”

Claims (1)

[Scope of Claims] 1. An electronically controlled fuel injection device that performs fuel control by determining the amount of fuel to be injected according to the operating state of the engine, and 3. A method for controlling a cooling system for a vehicle equipped with a cooling system whose operation or stop is controlled by a variable thermostat that operates includes calculating fuel consumption based on the determined fuel injection amount and predetermined engine parameters, and comparing changes in the fuel consumption with the fuel consumption. Deciding the minimum value of the determination level of the variable thermostat by changing it in the opposite direction, and setting the minimum value of the determination level of the variable thermostat for temperature control calculated by the temperature parameter to be equal to or higher than the determined minimum value of the determination level. A method for controlling a vehicle cooling system, characterized in that the cooling control is performed in a manner commensurate with fuel consumption. 2. The method for controlling a vehicle cooling system according to claim 1, wherein the predetermined engine parameters are a vehicle speed signal and an engine rotation speed signal. 3. The method of controlling a vehicle cooling system according to claim 1, wherein the compressor is an on/off control type compressor.