JPS6218086Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a control device for an automobile air conditioner, and is particularly intended to save energy by controlling the capacity of a compressor.

The compressor for compressing refrigerant in a car air conditioner is driven by the car's engine, so leaving the compressor running all the time increases the load on the engine and wastes energy. Become. Therefore, conventionally, as shown in Japanese Patent Laid-Open No. 57-70724, when the difference between the cabin temperature and the set temperature reaches a predetermined value, the electromagnetic clutch of the compressor is disengaged to stop the compressor. In addition, in order to prevent a sudden change in the temperature of the blown air, a device is known in which the air mix door is moved to the maximum cooling position.

However, in the past, the compressor was controlled simply based on the difference between the cabin temperature and the set temperature, and no consideration was given to mode switching, so there was a drawback that effective energy saving could not be achieved.

Therefore, this idea was created by focusing on the fact that the required cooling capacity is almost determined depending on the mode selection, and the goal was to further save energy, and the configuration to achieve this goal is shown in Figure 1. has been done. That is, in FIG. 1, a calculation means 54 for calculating a basic control value according to the outputs of at least the temperature setting device 30 and the vehicle interior temperature detector 31 is provided, and the basic control value by this calculation means 54 is used during cooling operation. Correction is made by the correction means 55 in accordance with the operation of the mode switch 28 which can switch between a plurality of modes. Based on the control value corrected by the correction means 55, the control means 56 controls the adjustment amount of the capacity variable means 17 which changes the capacity of the compressor 8. Therefore, the capacity of the compressor 8 is controlled by determining the control value not only according to the outputs of the temperature setting device 30 and the vehicle interior temperature detector 31 but also according to the operation of the mode switch 28, so that the above-mentioned problem is achieved. It is something that can be done.

Examples of this invention will be described below with reference to the drawings.

In Fig. 2, to first explain the outline of an automotive air conditioner, an inside air inlet 2 and an outside air inlet 3 are formed in the form of two branches on the most upstream side of an air conditioning case 1. A switching door 4 is provided, and the air to be introduced into the air conditioning case 1 is selected between inside air and outside air by the inside/outside air switching door 4.

The blower 5 is for sucking air into the air conditioning case 1 and blowing it to the downstream side, and an evaporator 6 and a heater core 7 are provided on the downstream side of the blower 5.

The evaporator 6 constitutes a cooling cycle together with a compressor 8, a condenser 9, a liquid tank 10, and an expansion valve 11.
The heater core 7 is inserted into a hot water cycle in which engine cooling water circulates. The compressor 8
is connected to an engine for driving an automobile via an electromagnetic clutch 12 and a belt transmission device including a pulley 13, and is configured to stop driving by connecting and connecting the electromagnetic clutch 12. Further, the discharge passage 14 and suction passage 15 of the compressor 8 are short-circuited across a solenoid valve 16, and the amount of discharged refrigerant returned to the suction side is determined according to the degree of opening of this solenoid valve 16. The capacity of the compressor 8 is adjusted in multiple stages or continuously so that as the opening degree of the clutch 16 increases, the capacity of the compressor 8 becomes smaller, and together with the electromagnetic clutch 12, the capacity of the compressor 8 is changed, including stopping its drive. It constitutes the capacity variable means 17 shown. In addition, as the capacity variable means 17,
In addition to this embodiment, the number of cylinders of the compressor 1 may be changed, or the pulley ratio of the belt transmission device may be changed.

An air mix door 18 is provided in front of the heater core 7, and the ratio of air passing through the heater core 7 to air not passing through the heater core 7 is adjusted depending on the opening degree of the air mix door 18. This air mix door 18 is connected to a temperature setting lever 21 of an operation panel 20 via a link mechanism 19, so that it can be manually operated.

The downstream side of the air conditioning case 1 includes an upper outlet 22,
It is divided into a lower air outlet 23 and a defrost air outlet 24 that open into the vehicle interior, and mode doors 25 and 26 are provided in the separated parts.
6 is operated by an actuator 27. This actuator 27 has a built-in drive circuit, and is driven in response to each push button switch of the mode switch 28 on the operation panel 20.
As shown in the diagram, the mode can be changed by moving the button to the vent, bilevel, heat, and defrost positions.

The microcomputer 29 is a central processing unit.
It is equipped with a CPU, a memory ROM for storing program means and fixed data, a memory RAM for temporarily storing data, and an input/output device I/O. The microcomputer 29 includes a temperature setting device 30 consisting of a variable resistor that works in conjunction with the temperature setting lever 21, and a vehicle interior temperature detector 31 consisting of a heat sensitive element such as a thermistor for detecting the vehicle interior temperature.
The analog signal output from
It is converted into a digital signal and input via the .
The microcomputer 29 also includes the mode switch 28 and an operation panel 20.
Signals from the air conditioner switch 34 and blower switch 35 provided in the microcomputer 29 are inputted, and the microcomputer 29 performs appropriate arithmetic processing to send drive signals to the electromagnetic clutch drive circuit 36 and the electromagnetic valve drive circuit 37. It also sends a drive signal to the blower drive circuit 38 to control the rotational speed of the blower 5.

In this embodiment, the analog signals input to the microcomputer 29 are limited to the outputs of the temperature setting device 30 and the vehicle interior temperature detector 31, but other embodiments may be used as well. Of course, it is possible to add outside air sensors, solar radiation sensors, evaporator sensors, etc.
Moreover, the air mix door 18 can also be operated by an actuator.

Next, an example of the control operation in the microcomputer 29 will be explained based on the flowchart shown in FIG. , signals from the temperature setting device 30 and the vehicle interior temperature setting device 31, which are analog data, are input. Then, in step 42, the capacity X of the compressor 8 is calculated as a value proportional to the difference between the vehicle interior temperature and the set temperature, and this capacity X is used as the basic control value, so that the calculation means 54 shown in FIG. is configured.
Next, the process proceeds to step 43, where the rotational speed N, which is the basic control value for the blower 5, is similarly calculated.

In the next step 44, the signal selected by the mode switch 28 is input, and the process proceeds to step 45, where it is determined whether the current mode is the vent mode, and if the mode is the vent mode, the maximum cooling capacity is required. Therefore, the capacity
6 and output to the electromagnetic clutch drive circuit 36, electromagnetic valve drive circuit 37 and blower drive circuit 38,
Normal control with no limit to the maximum value is performed with the correction amount set to 0.

On the other hand, if it is determined in step 45 that the mode is not the vent mode, the process proceeds to step 47 and it is determined whether or not the mode is the bi-level mode. As a result, in bilevel mode, the cooling capacity is not required as much as in vent mode, so step 4
8 and 49, the maximum value of the capacity X is regulated to, for example, 1/2 of the maximum capacity, and steps 50 to 52
As a result, the rotational speed N of the blower is regulated to an intermediate rotational speed, and the process proceeds to step 46. On the other hand, step 4
If it is determined in step 7 that the mode is not bilevel mode, there is no longer a need for cooling, so in step 53 the capacity X is set to 0, that is, the compressor 8
The correction is made so as to stop the driving of the
6, a stop signal is sent to the electromagnetic clutch drive circuit 36 to stop driving the compressor 8. That is, steps 48, 49, and 53 constitute the correction means 55 shown in FIG. is made up of.

Incidentally, in this embodiment, the correction means 55
Although the maximum value of the basic control value of the calculating means 54 is regulated, other embodiments may include dividing the basic control value or subtracting a predetermined value from the basic control value within a range where the answer is not less than 0. , or fixing it to a predetermined value, various calculation methods can be adopted.

As mentioned above, according to this invention, the capacity of the compressor can also be changed in response to the operation of the mode switch, which can switch between multiple modes during cooling operation, so energy savings can be achieved without the occupants being particularly conscious of it. can be further advanced. In addition, the compressor is controlled by variable capacity rather than on/off, which reduces the number of on/off shocks and prevents sudden changes in the temperature of the blown air. There is no need to take measures to prevent sudden changes in temperature, so it can be used as a simple control device that allows manual operation of the air mix door.
This has the advantage of being able to lower costs due to the reduction in the number of parts and the simplicity of control.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a control device for an automotive air conditioner according to this invention, Fig. 2 is a block diagram of the embodiment of the same, and Fig. 3 is a flowchart showing an example of control operation in the microcomputer used in the above. It is. 8... Compressor, 17... Capacity variable means,
28...Mode switch, 30...Temperature setting device,
31... In-vehicle temperature detector, 54... Calculating means,
55... Correction means, 56... Control means.

Claims (1)

[Scope of utility model registration request] Calculating means for calculating a basic control value according to the outputs of at least the temperature setting device and the vehicle interior temperature detector;
A correction means for correcting the basic control value of the calculation means in accordance with the operation of a mode switch capable of switching between a plurality of modes during cooling operation, and a capacity of the compressor is adjusted based on the control value corrected by the correction means. a control device for controlling an adjustment amount of a capacity variable device, wherein the correction device regulates a basic control value of the calculation device in a mode other than a vent mode.