JPH01244916A - Air conditioning control device for automobile - Google Patents

Abstract

PURPOSE:To contrive the control of lubrication deterioration and power loss by calculating a workload being based on the speed of an engine for running and the information of capacity of a variable displacement compressor further stopping it when the workload is not more than a predetermined value. CONSTITUTION:An automobile air conditioner is provided with a variable displacement compressor 24 constituting a room cooling cycle with an evaporator 6. A turning effect is transmitted to the compressor 24 from an engine 25 for running through an electromagnetic clutch 26. Here the air conditioner respectively provides a means 81 detecting a speed of the running engine 25 and a means 80 detecting information of the compressor 24 for its volume or information giving an influence to the volume. Being based on the engine speed and the volume information respectively detected in each means 81, 80, a workload is calculated in a microcomputer 15. As the result, when the workload decreases to a predetermined value or less, an off-signal is output to the compressor 24 from the microcomputer 15.

Description

[Detailed description of the invention] (Industrial application field) The present invention is a control device for an automobile air conditioner.

More specifically, the present invention relates to a control device for a variable displacement compressor.

(Prior Art) In recent years, variable capacity compressors with variable discharge capacity have been developed in contrast to compressors with constant discharge capacity. As shown in, for example, Japanese Patent Laid-Open No. 162087/1987, a variable displacement compressor has a characteristic that its discharge capacity changes as compared to the pressure difference between the crank chamber and the suction chamber. In automobile air conditioners that use this variable capacity compressor, a comprehensive signal is calculated to obtain the required air discharge temperature from the set temperature, vehicle interior temperature, outside temperature, and amount of solar radiation, and based on this, a variable capacity type compressor is used. The capacity of the compressor and the opening of the air mix door are controlled to provide comfortable air conditioning inside the vehicle.

(Problem to be solved by the invention) When the temperature inside the vehicle gets close to the set temperature, the heat load decreases, so the air mix door is returned to its opening position, and the capacity of the variable displacement compressor decreases accordingly. As a result, the heat exchange capacity will decrease. In particular, variable capacity compressors use a control system that keeps them rotating throughout the air conditioning control, and when the heat load decreases, the capacity is controlled to be low.

Even during such low capacity control, the compressor also rotates at high speed when the vehicle is running at high speed.

If the rotating parts are not sufficiently lubricated, accidents such as seizure may occur. However, as the amount of refrigerant returned is decreasing, the lubricating oil contained in the refrigerant is also decreasing, causing the lubricating oil to run out. There were also problems caused by.

Furthermore, during idling, cooling capacity is hardly required, but a loss of driving force (energy) occurs due to one revolution. Even in this case, the amount of returned refrigerant decreased, causing problems due to lack of lubricating oil.

Therefore, in this invention, in view of the above-mentioned problems.

The purpose is to resolve problems by determining the rotation control of a variable capacity compressor, especially the stopping of rotation during low capacity control, in relation to the amount of work.

(Means for Solving the Problems) Means for solving the problems of this invention is a variable capacity engine that is rotated by transmitting rotational force in a traveling engine, and whose capacity is variably controlled depending on internal and external conditions. In an automobile air conditioning control device equipped with a type compressor, a rotation speed detector detects the rotation speed of the driving engine, a capacity detection means detects the capacity of the compressor or information affecting the capacity, and the The amount of work is calculated based on the rotation speed detected by the rotation speed detector and the capacity information detected by the capacity detection means, and when the amount of work is less than a predetermined amount, the variable displacement compressor The object of the present invention is to include a control means for outputting an off signal to the OFF signal.

(Function) Therefore, the amount of work is calculated based on the rotation speed of the driving engine and the capacity of the compressor, and if the amount of work is less than the predetermined amount, even if the variable displacement compressor is driven, it will not affect the air conditioning control. By determining that there is no lubricant and stopping the drive, it is possible to prevent problems caused by a lack of lubricant.

In other words, even if the capacity is low, there are many cases in which it is determined that there is work to be done during high-speed rotation, and the drive is continued.

On the other hand, when idling, it is judged that the amount of work is small,
In many cases, the drive is stopped.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, an outline of an automobile air conditioner is shown, which has an inside air inlet 2 and an outside air inlet 3 on the most upstream side of an air conditioning duct 1, and a part where the inside air inlet 2 and the outside air inlet 3 are divided into two parts. is provided with an intake door 4, which allows selection of air to be introduced into the air conditioning duct 1 and outside air.

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

An air mix door 8 is provided in front of the heater core 7, and by adjusting the opening degree of the air mix door 8, the amount of air passing through the heater core 7 and the amount of air bypassing the heater core 7 can be changed. As a result, the temperature of the blown air is controlled.

Furthermore, the downstream side of the air conditioning duct 1 is divided into a vent outlet 9, a lower outlet 10, and a defrost outlet 11, and a compartment 13 is divided into a vent outlet 9, a lower outlet 10, and a defrost outlet 11.
Mode doors 12a, 1 are opened inward, and mode doors 12a, 1 are provided in the separated parts.
2b and 12c are provided, and this mode door '12a
, 12b, and 12c, a desired blowing mode can be obtained.

The microcomputer 15 includes a central processing unit (not shown), a read-only memory RAM, and a human output board I1.
0, etc., which is itself well known. The microcomputer 15 receives the vehicle interior temperature from the inside air sensor 16, the outside air temperature from the outside air sensor 17, and the amount of solar radiation from the U radiation sensor 18, and further inputs the set temperature and blowout mode from the keyboard unit 19 (not shown). , the number of rotations of the blower, the switching signal of the intake door, the on/off status of the air conditioner switch, etc. are input.

This microcomputer 15 operates an intake actuator 20. which moves the intake door 4 according to a predetermined program based on the various input signals mentioned above. Control signals are output to the blower drive circuit 21 that controls the rotation speed of the blower 5, the mix door actuator 22 that moves the air mix door 8, and the mode actuator 23 that moves the mode doors 12a to 12c, respectively, to control the amount of introduced air. Selection, control of air volume, control of blowing air temperature, and control of blowing mode are performed.

In the above-mentioned automotive air conditioner, the variable capacity compressor 2 constitutes a cooling cycle with the evaporator 6.
4, rotational force is transmitted from the driving engine 25 via the electromagnetic clutch 26, sucks and compresses the refrigerant, flows to the evaporator 6 through the condenser 27, receiver tank 28, and expansion valve 29, and returns to the compressor 24. It makes up the cooling cycle that is returned to the air conditioner.

The variable capacity compressor 24 is of a wobble plate type as shown in FIG.
is fixed, and is surrounded by a housing 32 and a cylinder block 33 to form a crank chamber 34. Further, a cylinder head 35 is fixed to the other end of the cylinder block 33 with a valve plate 36 interposed therebetween.

The drive shaft 37 is rotatably supported by the housing 32 and the cylinder block 33, and a thrust flange 38 rotatably supported by the housing 32 is fixed to the drive shaft 37 within the crank chamber 34. has been done. Also,
This thrust flange 38 also has a crank chamber 34.
A drive hub 39 is swingably supported inside via a link 40. This drive hub 39 is a drive shaft 37
It is rotatably and swingably supported by a hinge ball 41 that is externally covered. This hinge ball 41 is pressed from both sides by elastic members 42 a and 42 b provided around the drive shaft 37 .

The wobble plate 43 is rotatably supported with respect to the drive hub 39 within the crank chamber 34, engages with the housing 32 via a slider 44, and engages with the hinge ball 4.
Only swinging around 1 as a fulcrum is allowed.

A plurality of pistons 45 are connected to this wobble plate 43 via piston rods 46. This piston 45.

It is slidably inserted into the cylinder bore 47 formed in the cylinder block 33 described above, and is surrounded by the valve plate 36, the piston 45, and the cylinder bore 47 to form a compression chamber. When the piston 45 is in the suction stroke, the suction valve 49 is opened and the valve plate 3 is opened.
cylinder head 35 through the suction hole 48 formed in 6.
When the piston 45 is in the discharge stroke, the discharge valve 51 is opened and the cylinder head 3 is communicated with the low pressure chamber 50 in the cylinder head 3 through the discharge hole 52 formed in the valve plate 36.
5 communicates with a high pressure chamber 53 defined from a low pressure chamber 50.

The low pressure chamber 50 and high pressure chamber 53 are the cylinder head 35
They are respectively connected to an inlet (not shown) and an outlet 54 formed in the inlet 54 .

The pressure control valve 60 is inserted and fixed into a control valve insertion hole 61 formed in the cylinder block 33, cylinder head 35, and valve plate 36, and a suction pressure chamber 62 communicating with the cylinder block 33 of the pressure control valve 60 is formed. ing.

The pressure control valve 60 has a case 63 and a valve seat body 64 fixed to one end of the case 63, and a solenoid 65 is provided inside the case 63.

This solenoid 65 is composed of an electromagnetic coil 66, an armature 67, and a stator 68.
is movable in the axial direction with respect to the case 63, the stator 68 is fixed to the case 63, and the armature 6
7 and the stator 68, whose end surfaces face each other, and a magnetic force is generated between them in response to energization of the electromagnetic coil 66, which causes the valve body 7 to be described later.
The force with which 1 is pressed is adjusted.

The valve seat body 64 is formed with a first communication hole 69 connected to the crank chamber 34 described above and a second communication hole 70 connected to the suction pressure chamber 62 described above.

A valve seat surface is formed around the other end of the first communication hole 69, and a poppet-shaped valve body 71 can be seated on this valve seat surface. This valve body 71 is connected to a pressure responsive member 72 made of, for example, a bellows, and this pressure responsive member 72 is
It is housed in a storage chamber 73 that communicates with the suction pressure chamber 62 through the second communication hole 70, and contracts as the suction pressure Ps increases, pulling the valve body 71 to the left in the figure. . Further, this valve body 71 is connected and fixed via a connecting rod 44 extending from the armature 67 to the center of the stator 68 and a connecting pin 45, and as the magnetic force of the solenoid 35 becomes stronger, it receives a pressing force in the right direction in the figure. It has become. Therefore, the valve body 41 is located at a point where the suction pressure Ps acting on the bellows 42, the magnetic force acting on the solenoid 35, and the spring force pressing the armature 67 are balanced, and due to their suspension, there is a gap between the valve body and the valve seat surface. By adjusting the degree of opening, that is, the degree of communication between the crank chamber 34 and the suction pressure chamber 62, the angle of the wobble plate 43 with respect to the drive shaft 37 can be changed depending on the pressure difference between the two chambers when the compressor is operating. The compression capacity is controlled by

80 is a pressure detector for suction pressure PS, which is located in the cylinder head 3.
5 and arranged in the suction pressure chamber 62. This detection signal is input to the microcomputer 15. Note that the suction pressure Ps and the compression capacity Q of the compressor are
The relationship is as shown in the figure.

Reference numeral 81 is a detector for detecting the rotational speed of the driving engine 25, and this detection signal is also input to the microcomputer 15.

The variable capacity compressor 24 configured as described above has a temperature Tr in the vehicle interior.
The compression capacity is controlled according to a predetermined pattern, which will not be described in detail, based on a comprehensive signal T calculated from the set temperature Td, the outside air temperature Ta, the amount of solar radiation Ts, etc. The calculation formula for the total signal T is: T = ATr + BTa + CTs - DTd + E (A, B, C
, D, and E are constants. ).

The variable displacement compressor 24 is controlled to be cycled according to a flowchart as shown in FIG.

An example of this cycling control is shown in FIG.

At start step 100, execution of the program is started, and at the first step 101, initial setting is performed to set the flag of the magnetic clutch to 0. When this is completed, at step 102, the interior temperature Tr of the vehicle is read from the inside air sensor 16. , in step 103, the engine rotation speed detector 8
Read the engine speed NE from Step 10.
4, the capacity of the variable displacement compressor 24, that is, the compression capacity Q is read.

Then, in step 105, the amount of work W of compression is calculated. That is.

It is calculated as workload W=NEXQ.

Note that when reading the compression volume fQ of the compressor from the suction pressure Ps, the calculation formula for the amount of work W is as follows in step 106.
It is determined whether the flag of the magnetic clutch is set or not, and if the flag is 0, the process proceeds to step 107, where the work iw is compared with a predetermined amount X, and it is determined whether it is higher or lower than that. . If the amount is larger than the predetermined amount X, it is determined that compression of the refrigerant is currently necessary, and the magnetic clutch 26 continues to be in the ON state.

If it is smaller than the predetermined value X, the process proceeds to step 108, where it is determined that compression of the refrigerant is currently unnecessary, and the magnetic clutch 26 is turned off. Then, in step 109, a flag indicating that the magnetic clutch is OFF is set, and in step 110, the vehicle interior temperature Tr when the magnetic clutch is OFF is stored.

If it is determined in step 106 that the magnetic clutch is already in the OFF state.

Proceeding to step 111, the vehicle interior temperature Tr is compared with the currently stored vehicle interior temperature 1'r' + χ' (for example, 2'), and if the vehicle interior temperature Tr is small, the clutch remains in the OFF state. , when the vehicle interior temperature Tr increases, the process proceeds to step 112 and the magnetic clutch 26 is turned off.
The flag of the magnetic clutch is changed to 0 in step 113. Cycling of variable displacement compressors is performed in this way, but since it is performed when the amount of work is extremely small,
Since rotation is stopped when the amount of lubrication is small compared to the amount of returned refrigerant, it is possible to suppress the occurrence of problems that occur when the amount of lubrication is insufficient.

In this embodiment, the work is calculated using the suction pressure PS of the variable displacement compressor as one factor in calculating the amount of work, but the outside air temperature Ta or the overall signal T, which affects the capacity of the compressor, is also used.
It is also possible to judge the amount of work by replacing it with .

(Effects of the Invention) As described above, according to the present invention, the amount of work of the traveling engine is calculated based on the rotation speed and the capacity of the compressor or information that affects the capacity, so that it is not necessary to actually drive the engine. It is determined whether or not there is.

For this reason, especially during low capacity control, when a small amount of lubricating oil is returned by stopping, problems with the rotating sliding surface can be suppressed.

Furthermore, power loss can be eliminated by introducing drive stop control.

[Brief explanation of the drawing]

The figures show an embodiment of the present invention, in which Figure 1 is a configuration diagram of an automobile air conditioner, Figure 2 is a sectional view of a variable displacement compressor, and Figure 3 is a sectional view of a variable displacement compressor.
The figure is a flowchart showing an example of cycling control of the variable displacement compressor of the present invention, and FIG. 4 is a characteristic diagram showing the relationship between suction pressure PS and compression capacity Q. 6... Evaporator, 15... Microcomputer as control means, 24... Variable displacement compressor, 25
... Traveling engine, 26... Magnetic clutch, 80... Suction force detector, 81... Engine rotation speed detector. Patent applicant: Diesel Equipment Co., Ltd. Figure 3 Figure 4 Noj＼ ↓ Both inhalers PS Hitoe

Claims (1)

[Scope of Claim] An automobile air conditioning control device comprising a variable displacement compressor that is rotated by transmission of torque from a traveling engine and whose capacity is variably controlled depending on internal and external conditions, comprising: a rotation speed detector for detecting the rotation speed of an engine for use in a vehicle; capacity detection means for detecting a capacity of a compressor or information affecting the capacity; and a rotation speed detected by the rotation speed detector and the capacity detection means. The compressor is characterized by comprising control means for calculating the amount of work based on the capacity information detected by the means, and outputting an off signal to the variable displacement compressor when the amount of work is less than a predetermined amount. Automotive air conditioning control device.