JPS62975Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vehicle air conditioner, particularly to capacity control of a compressor.

Conventionally, the compressor that cools the evaporator is of a variable capacity type, and the capacity of this compressor is calculated based on the difference between the set temperature TD of a temperature setting device installed in the control panel and the cabin temperature TR detected by an inside air sensor, that is, the heat A system that controls according to the size of the load is known (British Patent No. 1158711), and a system that detects the engine load and performs control based on the engine load is also known (Japanese Patent Application Laid-Open No. 1983-1999). No. 195884). According to such a vehicle air conditioner, since the capacity of the compressor is controlled according to the heat load or the engine load, the compressor can be operated efficiently and power can be saved.

However, when controlling the compressor capacity based on the heat load, the heat load changes slowly, so controlling the compressor capacity relatively slowly does not pose a problem in terms of filling. If the capacity of the compressor were to be slowly switched to a smaller capacity when the engine speed suddenly increased, the engine load would not decrease almost simultaneously with acceleration, which would make acceleration difficult. Furthermore, if the capacity of the compressor is slowly switched to a large capacity during deceleration, there is a drawback that deceleration energy cannot be quickly absorbed and power saving cannot be efficiently achieved.

An object of the present invention is to eliminate the above drawbacks by changing the switching speed of the compressor capacity when changing the compressor capacity based on the engine load, and will be described in detail below using examples.

FIG. 1 is a block diagram showing an embodiment of a vehicle air conditioner according to the present invention.
is a control device that constitutes a vehicle air conditioner, and this control device 1 has a set temperature of a temperature setting device 2.
TD, vehicle interior temperature detected by interior air sensor 3
tr, outside air temperature ta detected by outside air sensor 4,
A signal corresponding to the solar radiation temperature ts detected by the solar radiation sensor 5 is input, and the control device 1 controls the temperature
For example, add tr, ta, and rs to obtain a total signal T, determine the difference F between this total signal T and the set temperature TD, and adjust the actuator 7 that drives the air mix door 6 according to the magnitude of this calculated value F. It also controls a rotation speed setting device 9 that sets the rotation speed of the blower 8, and a drive circuit 12 that drives an actuator 11 that adjusts the capacity of the compressor 10. In other words, when the calculated value F is large, the heat load is large, so the opening degree θ of the air mix door 6 is controlled to increase the mixing ratio of cold air, the rotation speed of the blower 8 is increased, and the capacity of the compressor 10 is increased. The calculated value F is controlled to approach almost zero.

The compressor 10, as shown in FIG.
A cooling cycle 19 includes a condenser 15, a liquid receiver 16, an expansion valve 17, and an evaporator 18 connected between the refrigerant discharge side pipe 13 and the refrigerant suction side pipe 14.
It comprises a pulley 20 for transmitting the rotational force of the engine to the compressor 10. A communication pipe 21 is connected between the pipes 13 and 14, and a cylindrical valve 22 is housed in the communication pipe 21. A hole 23 is provided along the central axis of the valve 22. The pipe 14 side is open and the opposite side is closed, and the side wall of the valve 22 has a plurality of ports 24, 2 extending perpendicularly and communicating with the hole 23.
4 are arranged along the extending direction of the valve 22.
A link 25 is connected to the valve 22 and moves reciprocally along the length of the actuator 11 in conjunction with the actuator 11, and the link 25 is guided to the outside through a sealing portion 26 provided in the pipe 13. For example, if the actuator 11 is rotated forward and the link 25 is moved in the direction of arrow A, and the valve 22 is moved in the direction of the pipe 14 to achieve the state shown in the figure, all of the refrigerant discharged from the compressor 10 will be sent out in the direction of the condenser 15. The capacity of the compressor increases. On the other hand, the actuator 11 is reversed, and the valve 22 is connected to the pipe 13.
When the refrigerant is moved in the direction, the refrigerant discharged from the compressor 10 passes through the port 24 and hole 23 to the pipe 1
4, so the capacity can be reduced. In this case, by increasing the amount of movement of the valve 22 in the direction of the pipe 13, the port 2 facing the space side of the pipe 13 is
4 increases, the amount of refrigerant directly guided to the pipe 14 side can be increased, and its capacity can be reduced. That is, by adjusting the amount of movement of the valve 22, the capacity of the compressor 10 can be changed almost continuously. Actuator 1 above
1 is a pulsed normal rotation voltage Ea from the drive circuit 12
When the forward rotation voltage Ea is input, the actuator 11 is rotated in the forward direction, so the capacity of the compressor 10 increases, and when the reverse rotation voltage Eb is input, the capacity of the compressor increases. becomes smaller. The drive circuit 12 is the control device 1
When the forward rotation signal S1 is supplied from
When the reversal signal S2 is supplied, the reversal voltage Eb is output, and when these signals S1 and S2 become zero, the output is turned off. The control device 1 determines a target value for the capacity of the compressor based on the magnitude of the calculated value F, and sets the capacity of the compressor to this target value. For example, when the current capacity of the compressor is smaller than the target value, a forward rotation signal S1 is output to increase the capacity, and when it is larger than the target value, a reverse rotation signal S2 is output to decrease the capacity, so that the capacity reaches the target value. When this point is reached, the signals S1 and S2 are set to zero and the operation of the drive circuit 12 is stopped. Note that the current capacity of the compressor is input to the control device 1 from a detector 28 that detects the capacity of the compressor.
The detector 28 is configured by a detector that detects the movement stroke of the link 25, for example.

The control device 1 is supplied with a signal M from an engine load detector 29 consisting of, for example, a detector for detecting negative pressure in the intake pipe of the engine.
The control device 1 has a driving state determining means 30 that determines whether the engine is accelerating, climbing a slope, decelerating, or running normally based on the signal M.
When the determination means 30 determines acceleration or hill climbing, it gives priority to the capacity control based on the calculated value F and sets the target value of the compressor capacity to zero or a small capacity. As a result, a reversal signal S2 is output, a reversal voltage Eb is output from the drive circuit 12, and the actuator 11 is reversed, so that the capacity of the compressor 10 is set to zero or a small capacity. On the other hand, when the determining means 30 determines deceleration, the control device 1 sets the target value of the capacity of the compressor 10 to the maximum or large capacity. As a result, the normal rotation signal S1 is output, and the actuator 11 is rotated in the normal direction, so that the capacity of the compressor becomes the maximum capacity or large capacity.

A speed controller 31 controls the operating speed of the actuator 11, and is driven by a control signal S3 outputted from the determining means 30 when the determining means 30 determines acceleration, hill climbing, or deceleration. , controls the drive circuit 12. As a result, the duty ratio (t/T) of the pulse voltages Ea and Eb as shown in FIG. 3 outputted from the drive circuit 12 is increased, and the rotational speed of the actuator 11 is increased. On the other hand, when the control signal S3 is not input, the speed controller 30 sets the duty ratio to a predetermined value.

Reference numeral 32 denotes a timer that is set by the control device when the judgment means 30 judges acceleration or hill climbing, and outputs a time-up signal S4 after a set time has elapsed. Set the value to, for example, 1/2 of the maximum capacity. Note that the timer 32 is reset when acceleration and hill climbing are completed.

The operation of the vehicle air conditioner having the above configuration will be explained below using the flowchart shown in FIG. 4 and the characteristic diagram shown in FIG. 5. First, the control device 1 sets a target value for the compressor capacity based on the calculated value F when the vehicle is running normally such as at a constant speed, and compares this target value with the current capacity detected by the detector 28. Judgment and forward rotation signal S1 or reverse rotation signal S
2 to set the capacity of the compressor 10 to a target value, and control the capacity of the compressor 10 to a size commensurate with the heat load.

Next, when acceleration or hill climbing is performed and the determining means 30 detects this, a control signal S is sent to the speed controller 31.
3 is sent, the speed controller 31 is connected to the drive circuit 12.
Set a large duty ratio for the pulse voltages Ea and Eb output from the At this time, the target value of the compressor capacity is set to zero or a small capacity. Therefore, the actuator 11 is reversed and the capacity of the compressor 10 is set to a small value, but at this time, since the duty ratio of the reverse voltage Eb is large, the operating speed of the actuator is fast, and the capacity of the compressor 10 is quickly switched to zero. . At this time, the timer 32 is set to start clock operation, and if the vehicle is still accelerating or climbing a hill even after the set time has elapsed, a time-up signal S4 is output from the timer 32. For example, set the target value to 1/2 of the maximum capacity. For this reason, the normal rotation signal S1 is output and the capacity of the compressor 10 is reduced to 1/1 of the maximum capacity.
Set to 2. In this way, by setting the compressor capacity to zero capacity and then setting the capacity to, for example, 1/2 of the maximum capacity after a set time has elapsed, the compressor can remain at zero capacity for long periods of time even if acceleration or hill climbing is performed for a long time. Since the air conditioner is not operated for a certain period of time, it is possible to solve the problem that the cooling performance is impaired.

Further, according to the present invention, when deceleration is performed, the target value of the capacity of the compressor is set to the maximum, so the compressor is set to the maximum capacity, and at this time, the speed controller 31 operates to increase the capacity of the compressor at high speed. Can be switched to maximum capacity. Therefore, it is possible to solve the problem that it takes time for the compressor to switch to the maximum capacity after deceleration, and that deceleration energy cannot be sufficiently absorbed. Therefore, power saving can be achieved. Note that if the acceleration or hill climbing ends before the set time elapses after the timer 32 is set, the timer 32 will be reset, so the control device 1 will control the capacity of the compressor 10 with normal control based on the calculated value F. .

As explained above, according to the vehicle air conditioner according to the present invention, control is performed to switch the capacity of the compressor by controlling the adjusting means for adjusting the capacity of the compressor when the engine load increases due to acceleration or climbing a hill, or when decelerating. The vehicle air conditioner has a speed control means for controlling the operating speed of the capacity adjusting means, and the speed controlling means controls the operating speed of the capacity adjusting means to normal when the engine load increases or when the engine decelerates. Since the compressor capacity can be switched to a small capacity or a large capacity at high speed, the load on the engine can be quickly reduced when accelerating and climbing hills, and acceleration and climbing hills can be performed smoothly. Furthermore, deceleration energy can be quickly absorbed during deceleration, resulting in power savings.

In this embodiment, the engine load detector 29 has been described as being composed of a detector that detects the negative pressure in the intake pipe of the engine, but it is also possible to detect a change in the engine rotation speed or the accelerator depression speed. It may also consist of things such as:

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the vehicle air conditioner according to the present invention, FIG. 2 is a simplified configuration diagram for explaining the main parts of the vehicle air conditioner according to the present invention, and FIG. FIGS. 4 and 5 are waveform diagrams for explaining the operation of the drive circuit constituting the invention, and FIGS. 4 and 5 are a flowchart and characteristic diagram for explaining the operation of the vehicle air conditioner according to the invention. DESCRIPTION OF SYMBOLS 1...Control device, 10...Compressor, 11...Actuator, 12...Drive circuit, 29...Engine load detector, 31...Speed controller, 32...Timer.

Claims (1)

[Scope of utility model registration request] In a vehicle air conditioner comprising a control device that controls a compressor capacity adjustment means based on a signal from a detection means that detects at least acceleration, hill climbing, or deceleration, speed control that controls the operating speed of the compressor capacity adjustment means. means is provided, and the speed control means is operated when acceleration, hill climbing, or deceleration is detected, and the operating speed of the capacity adjusting means is set to be faster than at a normal level other than acceleration, hill climbing, or deceleration. Characteristic vehicle air conditioner.