JPH0429102Y2 - - Google Patents

Description

[Detailed description of the invention] [Purpose of the invention] (Field of industrial application) The invention is used for automotive cooling cycles,
The present invention relates to a variable capacity swash plate type compressor that can change the internal volume of the compression chamber.

(Prior Art) Fig. 4 is a diagram showing a cooling cycle 1 used in a general automobile air conditioner, in which a compressor 3 is driven by an engine (not shown) via a belt, a pulley 2, and a magnetic clutch 2a. Then, the gaseous refrigerant, which has been adiabatically compressed by the compressor 3 and has become high temperature and high pressure, is supplied to the condenser 4. In this condenser 4, the refrigerant is cooled by exchanging heat with external air, and becomes a high-pressure liquid refrigerant.
The refrigerant that has passed through the liquid tank 5, which temporarily stores this liquid refrigerant and removes moisture and dust from the refrigerant,
The refrigerant is throttled and expanded in the expansion valve 6 and flows into the evaporator 7 as a low-pressure mist of refrigerant. As a result, the air flowing into the vehicle interior is cooled by the evaporator 7 and becomes cold air, thereby cooling the vehicle interior.

When the cooling cycle 1 is activated, it has the effect of dehumidifying the air flowing into the vehicle interior, so the cooling cycle 1 can be used not only in the summer but also in the spring.
It is designed to operate even in autumn and winter. In the normal compressor 3, compressor 3
The amount of refrigerant discharged per rotation of the rotor portion is always constant, and the amount of refrigerant flowing into the evaporator 7 is controlled by the expansion valve 6 according to the heat load. In order to prevent the condensed water adhering to the outer surface of the evaporator 7 from freezing, if the outer surface of the evaporator 7 falls below a predetermined temperature, the compressor 3 is stopped by a thermoswitch (not shown). Therefore, when the outside air temperature is low and the heat load on the evaporator 7 is small, such as in the winter, the compressor 3 engages the clutch 2a more frequently than when the heat load is large, such as in the summer. It will turn on and off repeatedly. Furthermore, as mentioned above, in a normal compressor 3 in which the amount of refrigerant discharged per revolution is constant, even when the heat load is small, the power required to drive the compressor is different from when the heat load is large. do not have.

Therefore, recently, as the compressor 3 used in such a cooling cycle 1, the
A swash plate type compressor having a structure shown in Publication No. 158382 has been proposed. In this swash plate type compressor, the stroke of the piston within the cylinder is changed in accordance with the suction pressure of the compressor, thereby changing the discharge amount of the compressor. Therefore,
A desired amount of refrigerant is circulated according to the heat load of the evaporator 7 while keeping the suction pressure of the compressor constant.

According to such a variable capacity compressor, although the outside air temperature is low and the heat load is small, when the cooling cycle 1 is operated to perform dehumidification in the evaporator 7, the amount of refrigerant flowing through the entire cooling cycle 1 is reduced. Since the amount of refrigerant is small, the evaporation pressure of the refrigerant in the evaporator 7 is prevented from becoming too low due to excessive throttling in the expansion valve 6. Therefore, due to this, the evaporator 7
Since it is possible to avoid the so-called freezing phenomenon of the evaporator 7 at low load, which causes the condensed water to freeze, there is no need for a thermoswitch or the like to prevent this.

In addition, in order to heat the interior of the vehicle, as shown in Fig. 5, the engine coolant for cooling the engine E is utilized and transferred to the heater core, which is a heat exchanger.
The hot water flows into the HC via a hot water pipe 8. As a result, the air flowing into the passenger compartment is directed to this heater core.
The air is heated by the HC and cooled by the evaporator 7 to a desired temperature, and the air is then introduced into the vehicle interior. The temperature of the hot water flowing into the heater core HC is normally maintained at about 80° C. by the action of the radiator.

(Problems to be solved by the invention) In such a conventional variable capacity swash plate type compressor, since the stroke of the piston is changed based on the suction pressure of the compressor 3, for example, 2.1 kg/kg of refrigerant is used. When using Freon 12, which becomes saturated steam at 0°C at a pressure of cm ² ,
In order to prevent the condensed water in the evaporator 7 from freezing, the pressure of the refrigerant in the evaporator 7, that is, the suction pressure Ps of the compressor 3, is set to 2.1 Kg/ ^cm2 .
By changing the stroke of the piston,
The flow rate of refrigerant within the cooling cycle 1 is controlled.

However, if the engine coolant does not rise to the desired temperature as when the engine E is initially started, the air passing through the evaporator 7 is sufficiently cooled by the operation of the cooling cycle 1, so the heater core Since the temperature of the HC does not rise quickly, a sufficient temperature control effect within the vehicle interior cannot be obtained. In such cases, such as in spring or autumn, air heated by the heater core HC may be introduced into the vehicle interior while the cooling cycle 1 is operating.

Therefore, in view of the above-mentioned problems of the conventional technology, the present invention uses a variable capacity compressor to control its discharge capacity. The purpose is also to improve the temperature control effect in the vehicle interior.

[Structure of the invention] (Means for solving the problem) The present invention for achieving the above object integrates a plurality of pistons installed in the cylinder block so as to be able to reciprocate in the axial direction, and integrates them with the drive shaft. The piston is rotated and reciprocated by a driving swash plate attached so that its inclination angle can be changed, and the pressure in the compression chamber formed in front of the piston and the pressure in the crank chamber formed in the rear of the piston are changed. In a variable capacity swash plate type compressor that changes the stroke of the piston by changing the inclination angle of the drive swash plate in response to a change in differential pressure, a suction side communication passage that communicates between a suction port and the crank chamber is opened and closed. A second solenoid valve that opens and closes a discharge side communication passage that communicates a first solenoid valve and a discharge port with the crank chamber.
a pressure control valve having a solenoid valve, an actuating means for operating the pressure control valve, a water temperature sensor for detecting the temperature of hot water flowing into the heater core, and a signal from the water temperature sensor to determine whether the water temperature is below a predetermined value. a comparison means for comparing and calculating whether or not the water temperature is lower than or equal to a predetermined value; and setting the pressure of the refrigerant flowing into the suction port to a high pressure when the water temperature is below a predetermined value, and the refrigerant flowing into the suction port when the water temperature is above a predetermined value. A variable capacity swash plate type compressor is characterized in that it has a control means for setting the pressure at a reference pressure.

(Function) When the engine starts, the temperature of the engine coolant has not risen to the specified temperature, and if the cooling cycle is operating, the temperature of the air supplied to the passenger compartment by the evaporator will drop. From doing that,
The interior of the vehicle cannot be sufficiently heated using the engine coolant as a heat source. When this condition is detected, the variable capacity swash plate compressor is controlled to reduce the capacity of the refrigerant supplied to the evaporator, thereby reducing the pressure of the refrigerant in the evaporator.
In other words, the evaporation pressure is controlled to be higher than the standard pressure state. Since this evaporation pressure and the temperature of the evaporator have a certain relationship, the temperature of the evaporator at the time of starting the engine becomes high, making it possible to improve the heating effect in the vehicle interior.

(Example) An embodiment of the present invention will be described below.

1A to 1C are schematic sectional views showing a variable capacity swash plate type compressor according to an embodiment of the present invention, and FIG. 2A is a block diagram showing an example of a control device for a variable capacity swash plate type compressor according to the same embodiment. be.

The variable capacity swash plate type compressor 3 of the present invention has a cylinder block 24 as shown in FIGS. 1A to 1C.
And crankcase 1 attached to the rear end of this
7 and a head 30 attached to the tip of the cylinder block 24. For example, five pistons 23 are mounted within a cylinder 25 formed in the cylinder block 24 so as to be able to reciprocate in the axial direction. A crank chamber 12 is formed in the crankcase 17, and a cylinder block 24 and the crankcase 1 are connected to each other.
A drive rod 11a is fixed to the drive shaft 11 rotatably supported by the drive shaft 11, and a pin 1 is attached to the drive rod 11a.
A drive swash plate 13 is mounted within the crankcase 12 so as to be rotatable about the drive swash plate 1b. Therefore, the drive swash plate 13 rotates together with the drive shaft 11, and its inclination angle with respect to the drive shaft 11 is variable.

A non-rotating wobble plate 16 is in contact with the drive swash plate 13 through a thrust bearing 14 at its radial end surface and a radial bearing 15 at its inner peripheral surface. The angle changes as the inclination angle changes. The movement of the non-rotating wobble plate 16 in the thrust direction is regulated by a thrust washer 20 and a snap spring 21. The non-rotating wall plate 16 is connected to a shoe 19 slidably connected to a guide pin 18 fixed to a casing 17.
Rotation is prevented and movement in the direction of the drive shaft 11 is guided.

The piston 23 and the non-rotating wobble plate 16 are connected by a rod 22, and as the inclination angle of the drive swash plate 13 changes, the reciprocating stroke of each piston 23 is changed via the non-rotating wobble plate 16. Things are starting to change.

A valve plate 27 is attached between the cylinder block 24 and the head 30.
A compression chamber 26 is formed on the front surface of the piston 23, and a crank chamber 1 is formed on the rear surface of the piston 23.
It communicates with 2. As shown in the figure, this valve plate 27 has a suction port 28a that communicates with a suction port 29 formed in the head 30, and a discharge port 28a that communicates with a discharge port 33 formed in the head 30.
b is formed. Furthermore, this valve plate 27 has an inlet 2 at the time of the suction stroke when the piston 23 moves backward.
A suction valve 34a that opens 8a and closes the suction port 28a during the reverse stroke is attached, and a discharge valve 34 that opens the discharge port 28b during the discharge stroke and closes the discharge port 28b during the reverse stroke when the piston 23 moves forward during the discharge stroke.
b is installed.

The inclination angle of the drive swash plate 13 is changed by changing the pressure within the crank chamber 12. In order to control this pressure, a pressure control valve 51 is attached to the head 30.
The valve body 52 embedded in the suction port 29
A suction side pressure chamber 32 is formed which is communicated with the intake chamber through a communication passage 31. This valve body 52 is formed with a suction side communication passage 54 that communicates a supply passage 53 formed in the cylinder block 24 and the head 30 with the suction port 29 via the suction pressure chamber 32 and the communication passage 31. Further, a discharge side communication passage 55 is formed in the valve body 52, which communicates the discharge port 33 with the supply passage 53 via a discharge side pressure chamber 35 formed in the head 30.

A first electromagnetic valve 57 for opening and closing the suction side communication passage 54 is provided in the cylinder body 56 provided in the valve body 52.
Further, a second electromagnetic valve 58 for opening and closing the discharge side communication passage 55 is provided. These electromagnetic valves 57 and 58 are provided with a resilient force by a coil spring 59 in the direction of closing the communication passages 54 and 55, respectively. In order to control the opening and closing of the first solenoid valve 57, the valve body 52 is provided with a solenoid coil 60, as shown in FIG.
An electromagnetic coil 61 is provided in the valve body 52 to control the opening and closing of the valve body 52 .

An example of a control device for controlling the operation of the variable capacity swash plate compressor 3 described above is shown in FIG. 2A.
It is as follows. In order to detect the temperature of the engine coolant, a water temperature sensor 65 is provided, and this water temperature sensor 65 is attached to the engine E, the hot water pipe 8, or the heater core HC, as shown in FIG.

This water temperature sensor 63 is connected to a comparison means 70 as shown in FIG. 2A, and this comparison means 70
A comparison calculation is made to determine whether the temperature of the hot water is higher or lower than a predetermined temperature, for example about 60°C. This comparison means 7
0 is connected via control means 71 to actuation means 72 . The actuation means 72 supplies current to the electromagnetic coil 60 for opening and closing the suction side communication passage 54 of the pressure control valve 51, and also supplies current to the electromagnetic coil 60 for opening and closing the suction side communication passage 54 of the pressure control valve 51.
This is also for supplying current to the electromagnetic coil 61 for opening and closing. By operating the pressure control valve 51 in this way, the amount of refrigerant discharged from the compressor 3 is controlled. As a result, the pressure of the refrigerant at the suction port 29 of the compressor 3, that is, the pressure of the refrigerant inside the evaporator 7, is increased. It will be set to a predetermined pressure.

The control means 71 controls the pressure of the refrigerant in the suction port 29, that is, the pressure of the refrigerant in the evaporator 7, to be lower than a reference pressure of 2.1 Kg/cm ² when the water temperature is below a predetermined value Ta in response to a signal from the comparison means 70. In addition to setting a high pressure, for example around 3.3Kg/ ^cm2 ,
If the water temperature is higher than a predetermined value Ta, for example 60° C., a signal is sent to the actuating means 72 to set the pressure of the refrigerant flowing into the suction port 29 to the reference pressure of 2.1 kg/cm ² . .

Next, using the control device according to the embodiment of the present invention shown in FIG. 2A, the operating state of the variable capacity swash plate compressor 3 of the present invention shown in FIGS.
This will be explained with reference to Figure A.

When the signal from the water temperature sensor 65 is read (step), the engine coolant temperature T becomes the set temperature.
A comparison is made to see if it is lower than Ta (for example, about 60°C) (step). If the detected hot water temperature T is lower than the set temperature Ta, the control means 71
The actuating means 72 actuates the pressure control valve 51 in response to a signal from the evaporator 7, so that the pressure of the refrigerant in the suction port 29, that is, the pressure of the refrigerant in the evaporator 7, increases, for example.
High pressure control is achieved at ^around 3.3Kg/cm2 (step).
On the other hand, if the detected temperature T of the hot water is higher than the set temperature Ta, the pressure inside the evaporator 7 is controlled to the standard pressure state (step).

Such high pressure control or reference pressure control is set by controlling the amount of refrigerant discharged from the discharge port 33 of the compressor 3.

That is, in order to discharge a large amount of refrigerant from the discharge port 33, as shown in FIG. 1A, the first solenoid valve 57 of the pressure control valve 51 is controlled to open and the second solenoid valve 58 is closed. . By opening the first electromagnetic valve 57 in this way, the suction pressure Ps, which is lower than the discharge pressure Pd, is guided into the crank chamber 12 via the suction side communication passage 54 and the supply passage 53. , the pressure acting on the rear surface (inside the crank chamber 12) of the piston during the suction stroke (not shown) becomes smaller than the pressure acting on the front surface (compression chamber 26), and as shown in FIGS. 1A and B, the drive swash plate 13,
In other words, the angle of inclination of the non-rotating wobble plate 16 with respect to the drive shaft 11 increases. As a result, the pressure inside the evaporator 7 is set to the standard pressure (for example, 2.1 Kg/cm ² ). In FIG. 1, A shows a state in which the illustrated piston 23 has advanced to the top dead center, and FIG. 1 B shows a state in which the illustrated piston 23 has retreated to the bottom dead center.

To reduce the amount of refrigerant from the discharge port 33, as shown in FIG. 1C, open the second solenoid valve 58 of the pressure control valve 51 to reduce the relatively high pressure Pd from the discharge port 33. It is supplied into the crank chamber 12 via the supply path 53. As a result, the inclination angle of the non-rotating wobble plate 16 becomes nearly perpendicular to the drive shaft 11, and the amount of refrigerant discharged from the compressor 3 decreases. As a result, the pressure of the refrigerant in the evaporator 7 becomes a relatively high pressure, for example, about 3.3 kg/cm ² .

Next, it is a diagram showing a control device for the variable capacity swash plate type compressor 3 according to the second embodiment of the present invention shown in FIG. Comparing means 7
I am trying to send it to 0.

In this case, as shown in FIG. 3B, the outside air temperature M is detected (step), and it is determined whether or not this outside air temperature is below a predetermined temperature Ma of, for example, about 20° C. (step). If the outside air temperature M
is below this predetermined temperature Ma, the pressure control valve 51 is controlled to adjust the capacity of the compressor 3,
The pressure inside the evaporator 7 is controlled at high pressure (step), and under other conditions, the pressure is controlled at the reference pressure (step).

FIG. 2C is a diagram showing a third embodiment of the present invention, in which a humidity sensor 67 for detecting the humidity in the vehicle interior is connected to a comparing means 70, and as shown in FIG. 3C, The engine coolant temperature is at the specified value.
Ta or less, and the humidity H in the vehicle interior is less than the specified humidity Ha ₁ , and the humidity is lower than this.
When Ha ₂ or higher, that is, when the amount to be dehumidified is small relative to the appropriate humidity, the discharge amount from the compressor 3 is controlled so that the pressure of the refrigerant in the evaporator 7 becomes high. I have to. Further, if the humidity becomes Ha ₂ or less, the compressor is turned off, and if the humidity becomes Ha ₁ or more, reference pressure control is performed.

Therefore, in the step shown in FIG. 3C, if it is determined that the humidity in the vehicle interior is equal to _or higher than the predetermined humidity Ha1, the reference pressure control is performed. If the humidity is determined to be lower than Ha ₁ and further lower than Ha ₂ in step, the compressor is turned off (step), and if the humidity is higher than Ha ₂ , high pressure control is activated (step). . As a result, when the engine coolant has not risen to a predetermined temperature and the humidity is low, the pressure of the refrigerant in the evaporator 7 becomes high.

[Effects of the invention] As explained above, according to the invention, when the temperature of the engine coolant used as a heat source for heating the vehicle interior is below a predetermined temperature, that is, when the engine is started, In the initial case, the cooling effect of the evaporator is greater than the heating effect of the heater core through which the engine coolant circulates, so when this condition is detected, the refrigerant discharge capacity from the compressor is reduced. Since the pressure of the refrigerant in the evaporator, that is, the evaporation pressure, is set higher than the reference value, it is possible to improve the temperature control effect when the engine is started.

[Brief explanation of drawings]

1A to 1C are schematic sectional views showing a variable capacity swash plate type compressor according to an embodiment of the present invention, and Fig. 2A is a block diagram showing a control device for a variable capacity swash plate type compressor according to an embodiment of the present invention. Figure, Figure 2B
is a block diagram showing a control device according to another embodiment of the present invention, FIG. 2C is a block diagram showing a control device according to still another embodiment, and FIG. FIG. 3B is a flowchart showing the operating state of the control device shown in FIG. 2B; FIG. 3C is a flowchart showing the operating state of the control device shown in FIG. 2C; The figure is a schematic diagram showing a cooling cycle, and FIG. 5 is a schematic diagram showing a heating device that communicates engine coolant with a heater core. 11... Drive shaft, 12... Crank chamber, 13...
... Drive swash plate, 16 ... Wobble plate, 23 ... Piston, 26 ... Compression chamber, 28a ... Suction port,
28b...Discharge port, 54...Suction side communication path,
55...Discharge side communication path, 57...First solenoid valve, 5
8...Second solenoid valve, 65...Water temperature sensor, 66...
... outside air sensor, 67 ... humidity sensor, 70 ... comparison means, 71 ... control means, 72 ... actuation means,
HC...Heater core.

Claims (1)

[Scope of utility model registration request] A plurality of pistons 23 mounted in the cylinder block 24 so as to be able to reciprocate in the axial direction are connected to the drive shaft 11.
The pressure in the compression chamber 26 formed in front of the piston 23 and the pressure in the compression chamber 26 formed in the rear of the piston 23 are controlled so that the pressure in the compression chamber 26 formed in the front of the piston 23 and the pressure in the compression chamber 26 formed in the rear of the piston 23 are In the variable capacity swash plate type compressor, the stroke of the piston is changed by changing the inclination angle of the driving swash plate 13 due to a change in the pressure difference between the intake port 29 and the pressure inside the crank chamber 12. a pressure control valve 51 having a first electromagnetic valve 57 that opens and closes a suction side communication passage 54 that communicates with the crank chamber 12; and a second electromagnetic valve 58 that opens and closes a discharge side communication passage 55 that communicates the discharge port 33 with the crank chamber 12; , an operating means 72 that operates the pressure control valve 51, a water temperature sensor 65 that detects the temperature of the hot water flowing into the heater core HC, and a signal from the water temperature sensor 65 to determine whether the water temperature is below a predetermined value. Comparison means 70 for comparing and calculating
When the water temperature is below a predetermined value, the pressure of the refrigerant flowing into the suction port 29 is set to a high pressure, and when the water temperature is above a predetermined value, the pressure of the refrigerant flowing into the suction port 29 is set to a reference pressure. A variable capacity swash plate type compressor, characterized in that it has a control means 71 for setting.