JPH0825381B2 - External controller for variable capacity compressor - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for externally controlling a variable capacity compressor called an internal capacity variable type in an air conditioner installed in a vehicle.

(Prior Art) Conventionally, as a vehicle air conditioner of this type, a compressor drivingly connected to an in-vehicle engine via an electromagnetic clutch mechanism and a gas refrigerant discharged from the compressor are cooled by heat exchange with air. It is equipped with a condenser (condenser) that condenses to a liquid state and an evaporator (evaporator) that evaporates the liquid refrigerant that passed through this condenser and cools the interior of the vehicle by the heat of vaporization. When the temperature drops below the specified temperature, this is detected by the frost switch and the OF
The one in which the drive of the compressor is stopped by the F operation is generally well known and is widely installed in actual vehicles.

That is, when the engine speed increases, the amount of refrigerant discharged from the compressor driven by the engine increases and a large amount of refrigerant circulates in the refrigerant circuit, so the capacity of the compressor increases, whereas Since the heat load is almost constant, the capacity becomes surplus, and the drive of the compressor is stopped in order to eliminate this surplus portion.

However, in that case, from the viewpoint of reducing the driving force for driving the compressor of the engine and improving EER (energy consumption efficiency), rather than temporarily stopping the operation of the compressor and then recondensing it, the compressor It is preferable to continue the operation by reducing the capacity from the steady state. For example, looking at the dependence of these devices on the coefficient of performance among compressors, condensers, and evaporators, the smaller the capacity of the compressor, the lower the work capacity of the compressor itself, but the contribution rate of the condenser and evaporator is relatively large. It becomes large and the overall coefficient of performance increases. In other words, while the work capacity of the compressor is decreasing, the overall enthalpy is the same, so the EER increases.

Therefore, as a compressor that meets such requirements,
Hitherto, as disclosed in Japanese Patent Application Laid-Open No. Sho 60-261721, a compressor with a variable internal capacity has been proposed. this is,
When the compressor capacity becomes excessive, a part of the refrigerant sucked into the compressor body is bypassed from the middle of the compression stroke and returned to the suction side, so that the capacity of the compressor can handle the heat load in the vehicle compartment Is controlled automatically.

(Problems to be solved by the invention) However, on the other hand, in the air conditioner equipped with the proposed variable internal capacity compressor, since the capacity of the compressor is automatically controlled to the capacity corresponding to the heat load in the vehicle interior,
The following problems occur.

For example, when knocking occurs in an engine mounted on a vehicle, it is necessary to reduce the driving load on the compressor of the engine to reduce the load on the engine output as much as possible and suppress knocking. However, when the above-mentioned compressor with a variable internal capacity is used, it has a function of adjusting the operating capacity only in accordance with the room temperature state, and the compressor load cannot be reduced due to the occurrence of engine knocking. Therefore, in the case of the above-mentioned conventional example, there is a drawback that vibration due to knocking cannot be reduced.

The present invention has been made in view of the above point, and an object of the present invention is to add to the original automatic internal capacity control in the internal capacity variable compressor as described above,
By appropriately controlling the capacity from the outside according to the occurrence of engine knocking, it is possible to reduce the vibration due to engine knocking while utilizing the function of the variable capacity compressor.

(Means for Solving the Problems) In order to achieve this object, the solving means of the present invention temporarily prohibits the internal capacity control of the compressor at the time of knocking of the engine, and holds the capacity at a minimum capacity. It is something that is done.

Specifically, the configuration of the present invention is as shown in FIG.
In the automotive air conditioner 1, a suction port 21 for sucking the refrigerant, a discharge port 22 for discharging the refrigerant that has been sucked from the suction port 21 and has undergone a compression stroke, and a refrigerant to the suction side during the compression stroke of the refrigerant. Bypass passage to bypass 39
And a variable capacity mechanism 50 for controlling opening and closing of the bypass passage 39 according to the suction pressure of the refrigerant, and externally controlling a variable capacity compressor for a vehicle air conditioner driven by the engine 12 mounted on the vehicle. The target is an external control device.

The bypass passage 39 is provided in the compressor.
A minimum capacity setting mechanism SV for driving the variable capacity mechanism 50 to set the refrigerant discharge capacity to a minimum is provided so as to fully open.

Further, the knocking detection means 111 for detecting knocking of the engine and the output of the knocking detection means 111 are received, and when the engine is knocked, the compressor 2
And a capacity control means 100 for driving the minimum capacity setting mechanism SV so that the minimum capacity is set to the minimum capacity.

(Operation) With the above configuration, in the present invention, the variable displacement mechanism 50 adjusts the bypass amount of the refrigerant to the suction side in the compression stroke of the compressor 2 of the air conditioner 1 of the vehicle, which is high during normal operation of the vehicle. Cooling operation is performed with efficiency.

Then, when the engine knocks while the vehicle is running, it is detected by the knocking detection means 111, by the capacity control means 100 receiving the output of this knocking detection means 111, the bypass passage 39 is forcibly opened fully,
That is, the minimum capacity setting mechanism SV is controlled so that the discharge capacity of the compressor 2 is set to the minimum.

Therefore, during normal traveling, while utilizing the automatic control of the internal capacity by the variable internal capacity compressor 2, the internal capacity control is forcibly prohibited from the outside of the compressor 2 when the engine is knocked, and the compressor 2 is minimized. Since it is fixed to the capacity state, the compressor load is reduced and the engine load is reduced.
Vibration due to engine knocking can be reduced.

(Example) Hereinafter, the Example of this invention is described based on drawing.

FIG. 2 shows the overall configuration of the embodiment of the present invention.
Is an air conditioner installed in an automobile, and the air conditioner 1
Is disposed at the front end of the engine room of the vehicle body and the compressor 2, which is drivingly connected to the vehicle-mounted engine 12 via the electromagnetic clutch mechanism 13 and the transmission belt 14, and cools the gas refrigerant by heat exchange with traveling wind to cool the liquid. A condenser 3 that condenses into a refrigerant, a receiver tank 4 that stores the liquid refrigerant, and an expansion valve that is a temperature-type automatic expansion valve that decompresses the liquid refrigerant to a pressure suitable for evaporation and expands it to control the heating degree of the refrigerant to a constant value. 5 and an evaporator 6 which is arranged in the vehicle interior and evaporates a liquid refrigerant to cool the air in the vehicle interior by the heat of vaporization thereof. By connecting these devices 2 to 6 by a refrigerant pipe 7, the refrigerant is provided. The circuit 8 is configured. Reference numeral 9 is a temperature-sensitive cylinder of the expansion valve 5 attached to the refrigerant pipe 7 that returns from the evaporator 6 to the compressor. Reference numeral 11 denotes a fan attached to the evaporator 6.

The compressor 2 is a vane type variable displacement compressor. The basic structure of the variable displacement compressor 2 is similar to that of a normal vane compressor. That is, the main body 20 of the compressor 2 is
As shown in enlarged detail in FIG. 3, a ring-shaped side housing 23 is joined to the front and rear surfaces of the side housing 23 in an airtight manner, and a cylindrical working chamber 24 is provided inside the side housing 23.
Front and rear housings 25 and 26 that form a rotor, a cylindrical rotor 27 that is rotatably fitted in the working chamber 24 of the side housing 23 with an offset with respect to the center of the working chamber 24, and the rotor 27. And a pair of through vanes 28, 28, which are supported so as to be retractable from the outer peripheral portion thereof and whose end portions are in sliding contact with the inner peripheral wall of the working chamber 24 to partition the working chamber 24. A suction port 21 for sucking the refrigerant into the chamber 24, and a suction chamber 29 communicating with the suction port 21.
And are formed. A discharge port 22 for discharging the refrigerant that has been sucked from the suction port 21 and has undergone a compression stroke is formed in the side housing 23, and a discharge chamber (not shown) communicating with the discharge port 22 is formed in the rear housing 26. Has been done. Further, the rotary shaft 31 of the rotor 27 is connected to the electromagnetic clutch mechanism 13, and when the electromagnetic clutch mechanism 13 is turned on, the rotor 27 is rotationally driven by the output of the engine 12, and with the rotation of the rotor 27, By gradually reducing the volume of the portion partitioned by the vanes 28, 28 in the working chamber 24 in the side housing 23, the gas refrigerant sucked from the suction port 21 of the side housing 23 is compressed and discharged from the discharge port 22. It is designed to let you.

In this basic configuration, a spool valve 32 is provided in the front housing 25 of the compressor body 20. A pressure regulator 40 composed of a needle valve is attached to a lower portion extending over both the side housing 23 and the rear housing 26.

As shown in FIG. 4, the spool valve 32 is a cylindrical valve housing 33, and is slidably fitted in the valve housing 33 so that the housing 33 has a spring chamber 35 and a pressurizing chamber 36. The pressure chamber 36 includes a partitioning cylindrical valve body 34, and the pressurizing chamber 36 includes a front housing 25 and a side housing in the compressor body 20 via a port 33a of the valve housing 33 and a communication passage 37 connected to the port 33a.
It is communicated with a predetermined gap portion between the refrigerant 23 and 23, and the pressure inside thereof is set to a pressure approximately midway between the suction pressure and the discharge pressure of the gas refrigerant. Further, a spring 38 for urging the valve element 34 toward the pressurizing chamber 36 side is contracted in the spring chamber 35, and the spring chamber 35 communicates with the suction chamber 29 in the front housing 25 through the port 33b. Has been done. Further, in the valve housing 33, four bypass holes 39a to 39b are provided in the middle of the sliding range of the valve body 34 inside, and the bypass holes 39a and 39b among them are opposed to each other in the center line direction of the housing 33 and bypassed. The holes 39a, 39a (39b, 39b) are arranged in series in the direction of the center line of the housing 33 and opened.
The bypass holes 39a, 39a located on one side (right side in FIG. 3) of the housing 33 are provided on the other side (same left side) of the bypass holes 39b, 39a on the part corresponding to the middle of the refrigerant compression stroke in the working chamber 24. 39b are respectively communicated with the suction chamber 29,
Bypass holes 39a facing the diametrical direction of the housing 33,
39b and a spring chamber located between the bypass holes 39a and 39b
By a part of 35, bypass passages 39, 39 for bypassing the refrigerant to the suction chamber 29 (suction side) are formed during the compression stroke of the refrigerant compressed in the working chamber 24. And
The urging force of the intermediate pressure in the pressurizing chamber 36 against the valve body 34 is applied to the refrigerant suction pressure in the spring chamber 35 by the spring inside the spring.
When it is larger than the biasing force obtained by adding the spring force of 38,
By moving 34 downward in FIG.
39a to 39b are closed to close the bypass passage 39, while when the valve is small, the valve body 34 is moved upward to open the bypass holes 39a to 39b to open the bypass passage 39.
It is designed to open.

On the other hand, the pressure regulator 40 includes a valve housing 44 in which first and second two pressure chambers 42, 43 communicating with each other via a valve opening 41 are formed, and the valve opening 41 in the valve housing 44. Valve body 45 that can be opened and closed
And is fitted into the second pressure chamber 43 of the valve housing 44,
A diaphragm 46 for partitioning the second pressure chamber 43 into a suction pressure chamber 43a and an atmospheric pressure chamber 43b. The diaphragm 46 is integrally connected to the valve body 45 via a rod 47. In the atmospheric pressure chamber 43b, the diaphragm 46 is connected to the valve opening direction of the valve body 45 (the valve body 45 is connected to both the first and second pressure chambers 4).
The spring 48 is biased in the direction of communicating the 2,43). The first pressure chamber 42 is connected to the communication passage 37.
(A predetermined gap between the front housing 25 and the side housing 23 in the compressor body 20)
And the suction pressure chamber 43a in the second pressure chamber 43 is communicated with the suction chamber 29, and the atmospheric pressure chamber 43b in the second pressure chamber 43 is open to the atmosphere, and the suction pressure chamber 43a for the diaphragm 46 is opened. When the urging force due to the refrigerant suction pressure therein is larger than the urging force of the atmospheric pressure in the atmospheric pressure chamber 43b plus the spring force of the spring 48 therein, the diaphragm 46 is moved downward in FIG. The valve body 41 integrated with the valve 46 closes the valve opening 41 to block the communication between the first pressure chamber 42 and the suction chamber 29, while on the contrary, when it is small, the diaphragm 46 is moved upward in the figure. The valve opening 41 is opened so that the first pressure chamber 42 and the suction chamber 29 communicate with each other. Therefore, the spool valve 32 and the pressure regulator 40 automatically control the refrigerant suction pressure of the compressor body 20 so as to keep the refrigerant suction pressure substantially constant, and when the rotation speed (engine speed) of the compressor 2 is low and its capacity is low. By closing the pressure regulator 40 and closing the bypass passage 39 by increasing the pressure in the pressurizing chamber 36 of the spool valve 32, the capacity of the compressor 2 is maintained at the maximum capacity while the rotational speed of the compressor 2 is increased. As a result, the pressure regulator 40 is opened due to the pressure drop in the suction chamber 29 that accompanies the valve opening, and the pressure in the pressurizing chamber 36 of the spool valve 32 is lowered in accordance with the valve opening operation. By moving 34 in the figure upwards and opening the bypass passage 39 to bypass the gas refrigerant inside, The variable capacity mechanism 50 is configured so that the capacity of the compressor 2 is reduced in accordance with the increase in the rotational speed thereof, that is, the surplus capacity is eliminated when the capacity of the compressor 2 exceeds the heat load in the vehicle compartment. Has been done.

Further, as a feature of the present invention, as shown in FIG. 4, the first pressure chamber 42 of the pressure regulator 40 is connected to the communication passage 37.
The communication passage 49 and the suction chamber 29, which communicate with each other, are further connected by a communication passage 51 so that the refrigerant can flow therethrough, and the communication passage 51 is provided with a normally closed solenoid valve SV for opening and closing the communication passage 51. , Solenoid valve SV
In the closed state, the variable displacement mechanism 50 is operated to bring the compressor 2 into the internal control state, while when the solenoid valve SV is opened, the pressure in the suction chamber 29 is made equal to the intermediate pressure and the spring 35 Spool valve 32 due to the urging force of
Position the valve body 34 of the
Is kept fully open and the refrigerant bypass amount is kept at the maximum, whereby the capacity of the compressor 2 is set to the minimum capacity. That is, the solenoid valve SV functions as a minimum capacity setting mechanism that drives the variable capacity mechanism 50 so that the bypass passage 39 is fully opened and sets the refrigerant discharge capacity to a minimum.

In FIG. 4, 52 is an orifice for alleviating a sudden flow of the refrigerant.

As shown in FIG. 2, a control unit 100 for controlling the air conditioner 1 from outside the compressor 2 is arranged outside the compressor 2, and the control unit 100 includes a knock sensor NS arranged in the engine 12. A knock control unit 101 that receives the knocking signal of 1) and processes the knocking signal is connected to be able to send and receive the signal. The knock control unit 101 is
As shown in FIG. 5, a filter that receives a knocking signal from the knock sensor NS and an ignition pulse signal from the ignition device 102, and selects and outputs only a portion involved in actual knocking from the former vibration waveform signal. The masking circuit 103 and the output of the filter masking circuit 103 are received, and only 1 is applied to a knocking signal having a constant amplitude.
And a waveform shaping circuit 104 that outputs two pulse signals. Knock sensor NS, filter masking circuit 10
The 3 and the waveform shaping circuit 104 constitute knocking detection means 111 that detects that knocking has occurred in the engine 12. The external control unit 100 of the air conditioner 1 receives the pulse signal of the waveform shaping circuit 104 and holds the pulse signal for a certain time, and a one-shot multi circuit 105 for amplifying the DC voltage. A comparator 106 is arranged. The output signal of the one-shot multi-circuit 105 is connected to the negative input terminal 106a of the comparator 106, while the positive input terminal 106b is connected to the positive DC power source and the ground side through resistors, respectively. . Further, the output terminal 106c of the comparator 106 is connected to the transistor 107 via a resistor.
Of the transistor 107, while the collector 107b of the transistor 107 is connected to the positive DC power source through the solenoid 108a of the electromagnetic relay 108 and the emitter 1 of the transistor 107.
07c is connected to the ground side. The relay switch 108b, which is normally off, of the electromagnetic relay 108 is grounded via the coil of the electromagnetic valve SV.

As described above, when knocking of the engine 12 occurs and a pulse signal is output from the knocking detection means 111, a pulse signal of a constant width is output from the one-shot multi-circuit 105, the comparator 106, the transistor 10
7. The electromagnetic relay 108 is sequentially operated, the electromagnetic valve SV is opened, the variable capacity mechanism 50 operates as described above, and the compressor 2 is forcibly set to the minimum capacity state. ing. Therefore, the control unit
The capacity control means 100 operates the minimum capacity setting mechanism SV so that the compressor 2 is set to the minimum capacity when the magnitude of the engine knock detected by the knock detection means 111 is a predetermined value or more. Is configured.

Reference numeral 109 is a main control device that is connected to the waveform shaping circuit 104 of the knock control unit 101 and that controls the ignition timing and the air-fuel ratio of the engine 12 according to the magnitude of knocking to suppress knocking. .

Next, the operation of this embodiment will be described. In the air conditioner 1, the gas refrigerant discharged from the condenser 2 is condensed into the liquid refrigerant by the condenser 3, and the liquid refrigerant is expanded by the expansion valve 5 and then expanded. The vehicle interior is cooled by the heat of vaporization of the refrigerant in the evaporator 6 after being evaporated in the evaporator 6 and then taken into the compressor 2.

While the air conditioner 1 is operating as described above, the knock control unit is operated during stable operation in which the knocking of the engine 12 mounted on the vehicle does not reach a predetermined value.
In 101, since the pulse signal is not output from the one-shot multi-circuit 105 and the electromagnetic relay 108 is not turned ON, the electromagnetic valve SV in the compressor 2 is kept closed, and the operation of the variable capacity mechanism 50 causes the compressor 2 to operate. Is operated under capacity control. That is, the compressor 2
When the rotation speed is low and its capacity is low, the pressure regulator 40 is closed and the pressurizing chamber of the spool valve 32 is closed.
The bypass passage 39 is closed due to the increase in the internal pressure of the compressor 36, so that the capacity of the compressor 2 is maintained at the maximum capacity, while the capacity of the compressor 2 is increased by the increase of the rotation speed of the compressor 2, and the inside of the suction chamber 29 is accordingly The pressure regulator 40 opens due to the pressure drop, and the pressurizing chamber 36 in the spool valve 32 is accompanied by the valve opening operation.
The internal pressure decreases, the valve body 34 moves so as to open the bypass passage 39, and the gas refrigerant is bypassed inside the compressor 2, so that the capacity of the compressor 2 decreases in accordance with the increase in the rotation speed. To be controlled.

On the other hand, when the magnitude of knocking of the engine 12 detected by the knock sensor NS becomes larger than a predetermined value during the operation of the engine 12, the knock control unit 10
A pulse signal is output from 1, and in the main control device 109 that receives the output signal from the knock control unit 101, the ignition timing of the engine 12 is retarded and the knocking is suppressed. At the same time, in the control unit 100, a pulse signal is output from the one-shot multi-circuit 105 and the comparator 106
And the transistor 107 is activated and the electromagnetic relay 1
08 operates and the solenoid valve SV is opened. By this opening operation of the solenoid valve SV, the suction chamber 29 is brought into an intermediate pressure state and the pressure inside the suction chamber 29 and the intermediate pressure are balanced, and as a result, the valve element 34 of the spool valve 32 is moved by the biasing force of the spring 38 It is positioned at the rising end position in FIG. 4, and the bypass amount of the refrigerant to the suction chamber 29 side is maximized by holding the bypass passage 39 in the fully open state, whereby the capacity of the compressor 2 is fixed to the minimum capacity.

Therefore, when the knocking of the engine 12 of the automobile becomes large in this way, the internal capacity control of the compressor 2 is forcibly prohibited from the outside, and the compressor 2
Is fixed to the minimum capacity state, the load for driving the compressor 2 of the engine 12 can be reduced, the engine load can be reduced accordingly, and vibration due to knocking of the engine 12 can be reduced.

In the above embodiment, the variable displacement compressor 2 is of the through vane type, but other types of variable displacement compressor such as a swash plate type may of course be used.

(Effects of the Invention) As described above, according to the present invention, in the vehicle air conditioner, the compressor driven by the vehicle-mounted engine can be selected between the variable capacity operating state and the minimum capacity operating state according to the suction pressure of the refrigerant. Variable capacity compressor,
When the engine knocks, the internal capacity control of the compressor is prohibited, and the capacity is fixed and maintained at the minimum capacity state, so that the automatic internal capacity control by the variable internal capacity compressor is utilized during normal engine operation. On the other hand, when the engine knocks, it is possible to reduce the drive load of the compressor of the air conditioner to reduce the engine load and reduce the vibration due to the engine knocking.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of the present invention. FIG. 2 and subsequent drawings show an embodiment of the present invention, FIG. 2 is an overall configuration diagram, FIG. 3 is a developed sectional view showing a variable displacement mechanism of a compressor, FIG. 4 is its schematic sectional view, and FIG. FIG. 3 is a schematic circuit configuration diagram of a knock control unit. 1 ... Air conditioner, 2 ... Compressor, 21 ... Suction port, 22 ... Discharge port, 39 ... Bypass passage, 50 ... Variable capacity mechanism, SV ... Solenoid valve (minimum capacity setting mechanism), 100
...... Control unit (capacity control means), 111 ……
Knocking detection means.

Claims (1)

[Claims] 1. A suction port for sucking the refrigerant, a discharge port for discharging the refrigerant sucked from the suction port and having passed through a compression stroke, and a bypass passage for bypassing the refrigerant to the suction side during the compression stroke of the refrigerant. An external control device that has a variable displacement mechanism that controls opening and closing of the bypass passage according to the suction pressure of the refrigerant, and that externally controls a variable displacement compressor for an air conditioner that is driven by an engine mounted on the vehicle. The compressor is provided with a minimum capacity setting mechanism that drives the variable capacity mechanism to set the refrigerant discharge capacity to a minimum so that the bypass passage is fully opened, and a knocking detection that detects knocking of the engine. Means and the output of the knocking detection means, and when the engine knocks, the compressor is set to the minimum capacity. Yo external control device for a variable displacement compressor characterized in that a capacity control means for operating the minimum capacity setting mechanism.