KR101336557B1 - Variable displacement swash plate type compressor - Google Patents

Abstract

The present invention relates to a variable displacement swash plate type compressor, and includes a second valve (50) for selectively opening and closing a second communication path (14) connecting the crank chamber (10) and the suction chamber (30). When the cooling load is small and the first communication path 12 is opened, the second valve 50 blocks the second communication path 14 to reduce the pressure loss of the crank chamber 10 through the second communication path 14. Prevent. When the first communication path 12 is closed because the cooling load increases, the second valve 50 opens the second communication path 14 through the pressure transfer hole 57 to increase the pressure of the crank chamber 10. By transferring to the suction chamber 30, the inclination angle of the swash plate can be increased quickly. In addition, the second valve 50 opens the second communication path 14 through the liquid refrigerant discharge hole 55 at the initial operation of the compressor to quickly discharge the liquid refrigerant accumulated in the crank chamber to the suction chamber. According to the variable displacement swash plate compressor having such a configuration, the swash plate inclination angle is controlled quickly and the power consumption of the compressor is reduced.

Description

Variable displacement swash plate type compressor

The present invention relates to a variable displacement swash plate compressor, and more particularly, to a variable displacement swash plate compressor configured to minimize power consumption for controlling the inclination angle of the swash plate.

As a compressor used in a vehicle air conditioner or the like, there is a variable displacement swash plate type compressor (hereinafter referred to as a compressor) capable of variably controlling the discharge capacity.

The compressor includes a cylinder block in which a plurality of cylinder bores are formed radially, a front housing coupled to a front end of the cylinder block to form a crank chamber, and a rear housing coupled to a rear end of the cylinder block to form a suction chamber and a discharge chamber. Include. And a plurality of bolts are fastened through the front housing, the cylinder block, the rear housing to complete the overall appearance of the compressor.

The drive shaft is installed to penetrate the front housing and the cylinder block to receive a driving force from the engine and to rotate. And the drive shaft is provided with a swash plate for reciprocating the piston in the cylinder bore, the swash plate is configured to change in a state perpendicular to the drive shaft or inclined at a predetermined angle.

The working fluid of the suction chamber is compressed according to the linear reciprocating movement of the piston connected to the swash plate in a state flowing into the cylinder bore through the drive shaft and the compressed working fluid is discharged through the discharge chamber.

At this time, if the inclination angle of the swash plate is large, the stroke of the piston is large, and the discharge amount of the working fluid is large. If the inclination angle of the swash plate is small, the stroke of the piston is small, and the discharge amount of the working fluid is small.

The inclination angle of the swash plate is determined by the difference between the crankcase pressure and the suction chamber pressure. Usually, when the pressure of the crankcase increases, the inclination angle of the swash plate decreases (that is, the swash plate moves in a direction perpendicular to the driving shaft). When the pressure of the crank chamber is lowered, the inclination angle of the swash plate is increased (that is, the swash plate is inclined with respect to the drive shaft). In fact, the inclination angle of the swash plate can be adjusted by changing the pressure of the crank chamber.

This pressure change of the crankcase is controlled by a control valve. That is, the control valve changes the pressure of the crank chamber by selectively communicating the crank chamber and the discharge chamber. For example, the control valve includes a valve for selectively shielding a valve hole communicating the crank chamber and the discharge chamber, so that the valve hole is opened when the cooling load is low. At this time, a part of the high-pressure working fluid discharged to the discharge chamber is introduced into the crank chamber, and the pressure of the crank chamber is increased.

In the conventional compressor, an orifice hole for always communicating the crank chamber and the suction chamber is formed. When the cooling load becomes high, the control valve closes the valve hole so that the crank chamber and the discharge chamber are blocked. By lowering the pressure of the thread, the inclination angle of the swash plate is increased.

On the contrary, when the cooling load is lowered, the control valve opens the valve hole to communicate the crank chamber and the discharge chamber. At this time, the pressure of the discharge chamber is transferred to the crank chamber, so that the inclination angle of the swash plate is increased. It becomes smaller.

According to the conventional compressor having such a configuration, when the stop time of the compressor is long, the compressor temperature is lowered, and the refrigerant in the liquid state (hereinafter referred to as 'liquid refrigerant') is accumulated in the crank chamber. Thus, when the compressor is operated in the state where the liquid refrigerant is full, the pressure drop of the crankcase is not made quickly, and there is a problem that it takes a long time until the initial startup of the compressor.

Further, according to the conventional compressor, since the orifice hole always communicates with the crank chamber and the suction chamber, even when the control valve opens the valve hole in order to reduce the inclination angle of the swash plate, the pressure of the crank chamber is increased through the orifice hole. Exit to the suction chamber. This causes a problem that more power is consumed to increase the pressure of the crankcase.

It is an object of the present invention to provide a variable displacement swash plate compressor configured to selectively open a communication path connecting a crank chamber and a suction chamber.

According to a feature of the invention, the present invention comprises a housing for forming a crank chamber, a discharge chamber, a suction chamber; A drive shaft installed through the housing and rotating by a driving force of the engine; A swash plate installed inside the crank chamber and having a variable inclination with respect to the drive shaft; A first valve for selectively opening and closing a first communication path connecting the crank chamber and the discharge chamber and adjusting the angle of the swash plate; And a second valve for selectively opening and closing a second communication path connecting the crank chamber and the suction chamber.

Wherein the second valve is configured to block the second communication path when the first valve opens the first communication path, and the second communication path when the first valve closes the first communication path. It is configured to open.

The second valve is provided with a valve housing forming a valve chamber therein, and is installed to be movable up and down inside the valve chamber, and opens the second communication path to transfer pressure of the crank chamber to the suction chamber. And a third passage connecting the upper portion of the valve chamber and the first communication passage, and a fourth passage connecting the lower portion of the valve chamber and the crank chamber.

The valve body further includes a liquid refrigerant discharge hole for discharging the liquid refrigerant by opening the second communication path, wherein the liquid refrigerant discharge hole has a pressure of the third passage and the fourth passage at the time of initial operation of the compressor. When the same, the second communication path is opened to discharge the liquid refrigerant of the crank chamber to the suction chamber.

The second communication path is blocked as the valve body moves downward when the first valve opens the first communication path, and the valve body moves upward when the first valve closes the first communication path. As such, the pressure transfer hole opens the second communication path.

The lower cross-sectional area of the valve body is characterized in that it is formed larger than the upper cross-sectional area.

According to the present invention, the second valve is configured to selectively open and close the second communication path for communicating the crank chamber and the suction chamber, and the liquid refrigerant accumulated in the crank chamber is opened by opening the second communication path during the initial operation of the compressor. Quickly discharge to the suction chamber. Accordingly, the pressure of the crankcase is rapidly lowered at the time of initial driving of the compressor, thereby facilitating control of the inclination angle of the swash plate.

In addition, according to the present invention, when the cooling load decreases, the second valve blocks the second communication path to minimize the pressure loss of the crankcase through the second communication path. When the cooling load increases, the second valve opens the second communication path so that the inclination angle of the swash plate can be increased quickly. Therefore, the power consumption of the compressor is reduced.

1 is a block diagram showing a state when the compressor according to the invention the initial drive.
Figure 2 is a block diagram showing a state when the first valve is opened in the compressor according to the present invention.
3 is a configuration diagram showing a state when the first valve is closed in the compressor according to the present invention.

1 to 3 schematically show only the characteristic components of the present invention, and the general components of the remaining variable displacement swash plate compressor are omitted. General configurations of the variable displacement swash plate compressor except for the characteristic configuration of the present invention will be described with reference to the contents described in the related art.

The crank chamber 10, the discharge chamber 20, and the suction chamber 30 are respectively formed in the housing of the compressor. The crank chamber 10 is provided with a drive shaft that rotates to receive the driving force of the engine, the swash plate is installed on the drive shaft for reciprocating the piston installed in the housing. The swash plate is configured to change in a state perpendicular to the drive shaft or inclined at a predetermined angle.

The inclination angle of the swash plate is determined by the difference between the crank chamber pressure Pc and the suction chamber pressure Ps. Usually, when the pressure Pc of the crank chamber is increased, the inclination angle of the swash plate is decreased (that is, the swash plate is Moving in a direction orthogonal to the drive shaft), and when the pressure Pc of the crank chamber is lowered, the inclination angle of the swash plate is increased (that is, the swash plate is inclined with respect to the drive shaft). In fact, the inclination angle of the swash plate can be adjusted by changing the pressure Pc of the crank chamber.

The pressure change of the crank chamber 10 is controlled by the first valve 40. The first valve 40 is installed in the first communication path 12 connecting the crank chamber 10 and the discharge chamber 20, and selectively opens the first communication path 12. For example, when the cooling load is lowered, the first valve 40 opens the first communication path 12 to increase the pressure Pc of the crank chamber. On the contrary, when the cooling load increases, the first valve 40 blocks the first communication path 12 to lower the pressure Pc of the crank chamber.

On the other hand, the crank chamber 10 and the suction chamber 30 are connected to each other by a second communication path (14). The second communication path 14 is provided with a second valve 50 for selectively opening and closing the second communication path 14. The second valve 50 opens and closes the second communication path 14 by a relationship between the pressure Pd of the discharge chamber and the pressure Pc of the crank chamber according to the operation of the first valve 40. do.

Hereinafter, the configuration of the second valve 50 will be described in more detail.

The second valve 50 is provided with a valve housing 51 that forms a valve chamber 52 therein, and is installed to be movable up and down in the valve chamber 52 and the second communication path 14. And a valve body 53 formed with a pressure transfer hole 57 which opens to transfer the pressure of the crank chamber 10 to the suction chamber 30. In addition, the upper portion of the valve chamber 52 and the first communication passage 12 are connected by a third passage 16, and the lower portion of the valve chamber 52 and the crank chamber 10 have a fourth passage ( 18).

The valve body 53 is further provided with a liquid refrigerant discharge hole 55 for opening the second communication path 14. In this embodiment, the liquid refrigerant discharge hole 55 and the pressure transfer hole 57 are formed in parallel with each other, and the liquid refrigerant discharge hole 55 is formed above the pressure transfer hole 57.

The liquid refrigerant discharge hole 55 may open the second communication path 14 at the initial operation of the compressor to exit the liquid refrigerant accumulated in the crank chamber 10 into the suction chamber 30. Make sure Since the liquid refrigerant discharge hole 55 is for allowing the liquid refrigerant to escape, the hole size of the liquid refrigerant discharge hole 55 is larger than that of the pressure transfer hole 57.

The pressure transfer hole 57 opens the second communication path 14 when the first valve 40 is closed to block the first communication path 12, and the crank chamber pressure Pc is sucked in. It is to be delivered to the chamber 30 serves to lower the pressure of the crank chamber 10.

On the other hand, the upper end and the lower end of the valve body 53 are supported by the elastic body 54 in the valve chamber 52. The elastic body 54 is such that the liquid refrigerant discharge hole 55 is in a position to open the second communication path 14 when the pressure acting on the upper and lower portions of the valve body 53 is the same. It serves to support the valve body 53.

The valve body 53 moves up and down in the valve chamber 52 by a pressure difference acting on the third passage 16 and the fourth passage 18. At this time, the pressure of the third passage 16 and the fourth passage 18 depends on the pressure change of the crank chamber 10 according to the operation of the first valve 40. Accordingly, the valve body 53 opens and closes the second communication path 14 by a relationship between the pressure Pd of the discharge chamber and the pressure Pc of the crank chamber according to the operation of the first valve 40. It can be said that.

For example, as shown in FIG. 2, when the first valve 40 is opened to open the first communication path 12, a relatively high discharge chamber pressure Pd is transmitted through the first communication path 12. 10) It is delivered to the inside, at which time some pressure (P1) is to push the upper portion of the valve body 53 through the third passage (16). As a result, the valve body 53 moves downward to block the second communication path 14. Here, the relationship between the pressure P1 acting on the third passage 16, the pressure P2 acting on the fourth passage 18, and the crankcase pressure Pc is equal to P1> Pc> P2.

On the contrary, as shown in FIG. 3, when the first valve 40 is closed, the first communication passage 12 is closed. At this time, the pressure of the crank chamber 10 is the third passage 16 and the fourth passage 18. The same acts on the upper and lower portions of the valve body 53 through). That is, the crankcase pressure Pc of the shielded state is transmitted to the third passage 16 and the fourth passage 18 evenly, so that the pressure P3 and the fourth passage 18 acting on the third passage 16. The pressure (P4) acting on) becomes equal.

However, in the present embodiment, since the lower cross-sectional area of the valve body 53 is larger than the upper cross-sectional area, if the pressure applied to the upper and lower portions of the valve body 53 is the same, the force acting on the lower portion of the valve body 53 is reduced. Since the valve body 53 is larger than the force acting on the upper portion, the valve body 53 moves upward as shown in FIG. 3. Accordingly, the pressure transfer hole 57 opens the second communication path 14.

Thus, in order to move the valve body 53 upward, the pressure drop generated in the upper and lower portions of the valve body 53 may be configured to be different. That is, the pressure drop in the upper portion of the valve body 53 may be larger than the pressure drop in the lower portion. To this end, in the present embodiment, the lower cross-sectional area is larger than the upper cross-sectional area of the valve body 53. Alternatively, the fourth passage 18 is shorter than the third passage 16 so that the fourth cross-section is shorter than the fourth cross-section. The pressure on the passage 18 may be greater than the pressure on the third passage 16.

Hereinafter, the operation of the variable displacement swash plate compressor according to the present invention will be described.

1 shows the initial operating state of the compressor. When the operation of the compressor is started, the first valve 40 opens the first communication path 12, whereby the crank chamber 10 and the discharge chamber 20 communicate with each other. Immediately before the first valve 40 is opened, the valve body 53 of the second valve 50 is supported by the elastic body 54. At this time, a second communication path is provided by the liquid refrigerant discharge hole 55. 14 is opened.

As such, when the second communication path 14 is opened, the liquid refrigerant accumulated in the crank chamber 10 is transferred to the suction chamber 30 through the second communication path 14 and the liquid refrigerant discharge hole 55. Discharged. Accordingly, the pressure of the crankcase is rapidly lowered at the time of initial driving of the compressor and the time taken to operate the maximum capacity of the compressor is reduced.

Next, FIG. 2 shows an operation state of the compressor when the cooling load is small. When the cooling load is small, the compressor should be driven in a direction in which the inclination angle of the swash plate becomes small (so that the swash plate stands up with respect to the drive shaft).

To this end, first, the first valve 40 is opened to open the first communication path 12. Then, the crank chamber 10 and the discharge chamber 20 communicate with each other so that a high pressure of the discharge chamber 20 is transferred into the crank chamber 10. At this time, a portion P1 of the pressure flowing into the crank chamber 10 through the first communication passage 12 is instantaneously introduced into the upper portion of the valve chamber 52 through the third passage 16. The valve body 53 moves downward by the pressure flowing into the valve chamber 52 and the second communication path 14 is closed.

As such, since the valve body 53 blocks the second communication path 14, there is no pressure loss inside the crank chamber 10 through the second communication path 14. Therefore, the power consumption for increasing the pressure of the crank chamber 10 is reduced, it is possible to increase the crank chamber pressure more quickly, it is possible to quickly control the swash plate angle.

Finally, Figure 3 shows the operating state of the compressor when the cooling load is large. When the cooling load is large, the compressor should be driven in the direction in which the inclination angle of the swash plate increases (so that the swash plate is inclined with respect to the drive shaft).

To this end, first, the first valve 40 closes the first communication path 12 to block communication between the crank chamber 10 and the discharge chamber 20. At this time, the pressure of the crank chamber 10 acts the same size on the upper and lower portions of the valve chamber 52 through the third passage 16 and the fourth passage (18). However, since the lower cross-sectional area of the valve body 53 is larger than the upper cross-sectional area, a relatively large force is applied to the lower portion of the valve body 53 to push up the valve body 53 upward.

Then, this time, the pressure transfer hole 57 of the valve body 53 opens the second communication path 14. As such, when the second communication path 14 is opened through the pressure transfer hole 57, the pressure of the crank chamber 10 is released to the suction chamber 30. Accordingly, the pressure of the crank chamber 10 is quickly lowered and the time for maximizing the inclination angle of the swash plate is reduced, thereby improving the performance of the compressor.

The scope of the present invention is not limited to the embodiments described above, but may be defined by the scope of the claims, and those skilled in the art may make various modifications and alterations within the scope of the claims It is self-evident.

Description of the Related Art [0002]
10: crank chamber 12: first communication path
14: second passage 16: third passage
18: fourth passage 20: discharge chamber
30: suction chamber 40: first valve
50: second valve 51: valve housing
53: valve body 54: elastic body
55: liquid refrigerant discharge hole 57: pressure transfer hole

Claims (6)

A housing forming the crank chamber 10, the discharge chamber 20, and the suction chamber 30;
A drive shaft installed through the housing and rotating by a driving force of the engine;
A swash plate installed inside the crank chamber 10 and having a variable inclination with respect to the drive shaft;
A first valve 40 for selectively opening and closing the first communication path 12 connecting the crank chamber 10 and the discharge chamber 20 and adjusting the angle of the swash plate;
It includes a second valve 50 for selectively opening and closing the second communication path 14 connecting the crank chamber 10 and the suction chamber 30 ,
The second valve 50 is configured to block the second communication path 14 when the first valve 40 opens the first communication path 12, and the first valve 40 is A variable displacement swash plate compressor, characterized in that configured to open the second communication path (14) when the first communication path (12) is closed. delete The method of claim 1, wherein the second valve 50
A valve housing 51 which forms a valve chamber 52 therein;
A pressure transfer hole 57 is installed to be movable up and down inside the valve chamber 52 and opens the second communication path 14 to transfer the pressure of the crank chamber 10 to the suction chamber 30. The valve body 53 is formed,
A third passage 16 connecting the upper portion of the valve chamber 52 and the first communication passage 12, and
And a fourth passage (18) connecting the lower portion of the valve chamber (52) and the crank chamber (10). The liquid refrigerant discharge hole (55) of claim 3, wherein the valve body (53) further includes a liquid refrigerant discharge hole (55) for discharging the liquid refrigerant by opening the second communication path (14). When the pressure of the third passage 16 and the fourth passage 18 are the same at the time of initial operation of the compressor, the second communication passage 14 is opened to suck the liquid refrigerant of the crank chamber 10 into the suction chamber. Variable displacement swash plate compressor characterized in that the discharge to 30. The method of claim 3, wherein the second communication path 14 is blocked as the valve body 53 moves downward when the first valve 40 opens the first communication path 12,
When the first valve 40 closes the first communication path 12, the pressure transfer hole 57 opens the second communication path 14 as the valve body 53 moves upward. Variable displacement swash plate compressor characterized in that. 6. A variable displacement swash plate compressor according to claim 5, wherein a lower cross-sectional area of the valve body (53) is formed larger than an upper cross-sectional area.

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