JP3019538B2 - Vane type compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vane type compressor which is effective as a refrigerant compressor used in, for example, an air conditioner of an automobile.

[0002]

2. Description of the Related Art As a refrigerant compressor for an air conditioner of an automobile, a vane compressor having a vane slidably mounted in a vane groove formed in an eccentric rotor has been conventionally used. This kind of vane type compressor includes a main housing, front and rear side plates covering both ends of the main housing, the eccentric rotor accommodated in the main housing, and rotated by a shaft, and the eccentric rotor. A compression chamber is formed by a space surrounded by the vane attached to the rotor, and the volume of the compression chamber changes, thereby sucking, compressing, and discharging the refrigerant.

In such a compressor, when the compressor is stopped for a long period of time, the refrigerant in the compressor is liquefied, and when the compressor is restarted, liquid compression occurs and there is a concern that vanes and the like may be damaged.

That is, when the compressor is stopped for a long period of time, the refrigerant in the compressor liquefies due to a difference in ambient temperature between the evaporator and the compressor, and the refrigerant in the front housing communicates with the compression chamber via the compression chamber and the suction hole. The refrigerant becomes full.

When a large amount of liquid refrigerant accumulates in the compression chamber, when the compressor is started, the liquid refrigerant is incompressible and cannot be compressed in the compression chamber, so that the pressure in the compression chamber becomes abnormally high. turn into. For this reason, excessive pressure is applied to the vane, and the vane is damaged.

[0006]

Conventionally, a relief valve for a liquid refrigerant is provided between the compression chamber and the oil separation chamber, and when the pressure in the compression chamber rises abnormally, the liquid in the compression chamber is released through the relief valve. A structure is employed in which the refrigerant escapes to the oil separation chamber.

However, when liquid refrigerant is accumulated only in the compression chamber, it is not possible to prevent the rise of abnormal pressure to a certain extent by discharging the liquid refrigerant through the relief valve. When the liquid refrigerant is accumulated in both chambers, since the amount of stored liquid refrigerant is large, there is a disadvantage that the opening area of the relief valve alone is insufficient to eliminate the liquid refrigerant and a pressure rise cannot be avoided. .

The present invention has been made in view of such circumstances, and an object of the present invention is to prevent liquid refrigerant accumulated in a front housing from flowing into a compression chamber,
An object of the present invention is to provide a vane-type compressor capable of preventing the occurrence of liquid compression and preventing damage to the vane.

[0009]

In order to achieve the above object, the present invention provides a main housing, an eccentric rotor rotated in the main housing, a vane installed in the eccentric rotor, and a main housing and an eccentric. A compression chamber that is surrounded by a rotor and a vane and changes in volume by rotation of the eccentric rotor, a suction chamber formed in a front housing connected to the main housing, and a front plate that partitions the main housing and the front housing. A suction hole formed to guide the refrigerant in the suction chamber to the compression chamber; a discharge hole for sending the refrigerant pressurized in the compression chamber;
The liquid refrigerant in the compression chamber escapes when
A relief valve having a release valve, wherein a partition wall is formed in front of the suction hole located in the suction chamber, and a substantial opening of the suction hole is formed at an upper end of the partition wall. The opening is provided at an upper position of the suction chamber.

[0010]

According to the present invention, the substantial opening of the suction hole of the compression chamber is opened at the upper part of the suction chamber formed in the front housing, so that the liquid refrigerant accumulated in the suction chamber is compressed. When the compressor is started, only the liquid refrigerant in the compression chamber is pressurized, so that the pressure rise is suppressed and the pressure is quickly released, so that the abnormal pressure rise can be avoided. it can.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to an embodiment shown in the drawings.

1 to 6 show the entire structure of a through-vane type compressor, and 1 is a main housing. The main housing 1 is made of, for example, cast iron (FC), and has a slightly distorted cylindrical inner surface 2 as shown in FIG.

The front end of the main housing 1 is closed by a front plate 3, and a front housing 4 is connected to the front plate 3. A suction chamber 5 is formed between the front plate 3 and the front housing 4. The rear end of the main housing 1 is closed by a rear plate 6, and a rear housing 7 is connected to the rear plate 6. An oil separation chamber 8 is provided between the rear plate 6 and the rear housing 7.
Are formed.

The front housing 4, the front plate 3, the main housing 1, the rear plate 7, and the rear housing 7 are integrally connected by through bolts 9.

Reference numeral 10 denotes a rotor, which integrally has a drive shaft 11 at one end and a support shaft 12 at the other end.

The rotor 10 is disposed eccentrically in the main housing 1, and the drive shaft 11 and the support shaft 12 at both ends are rotatable by bearings 13 and 14 attached to the front plate 3 and the rear plate 6. It is supported by. The drive shaft 11 penetrates through the front housing 5 and is led out to the outside. The outer end of the drive shaft 11 is driven to rotate by the engine of the automobile. The drive shaft 11 and the front housing 5 are kept liquid-tight by a shaft seal 15.

As shown in FIG. 2, the rotor 10 has a cross-shaped vane groove 16 formed therein. Each of the vane grooves 16 extending in the radial direction accommodates a vane 17. These vanes 17 are made of a high silicon aluminum alloy or the like and are accommodated in the vane grooves 16 so as to be slidable in the radial direction.

The inner surface 2 of the main housing 1, the front plate 3, the rear plate 7, the rotor 10, and each vane 1
7 form compression chambers 18. The volumes of these compression chambers 18 change with the rotation of the rotor 10. The region where the volume of the compression chambers 18 increases is a suction stroke, and the region where the volume of the compression chambers 18 decreases is a compression stroke and a discharge stroke following the compression stroke.

On the side wall of the main housing 1, the compression chamber 1
The discharge chamber housing 2 faces the position where the discharge stroke 8 is located.
0 is attached. The discharge chamber housing 20 has a discharge chamber 21 formed therein. And the main housing 1
The compression chamber 18 located in the discharge stroke and the discharge chamber 2
1 is opened, and the discharge hole 22 is opened and closed by a discharge valve 23 having a check valve structure.

The discharge chamber housing 20 communicates with an oil separation chamber 8 formed in the rear housing 7 through a discharge passage 24 formed in the rear plate 6.

A discharge pipe 25 for sending out the refrigerant in the oil separation chamber 8 is connected to the rear housing 7.

The rear plate 6 includes a compression chamber 1.
A relief valve (sludge valve) 2 for releasing the pressure of the compression chamber 18 to the oil separation chamber 8 when the pressure 8 is in the compression stroke.
6 are formed. The structure of the relief valve 26 is shown in FIG.
Is opened and closed by a ball valve 28, which is pressed by a spring 29. Therefore,
When the pressure in the compression chamber 18 becomes an abnormal pressure equal to or higher than a predetermined value, the ball valve 28 opens the relief port 27 and the compression chamber 18
This has the function of escaping the refrigerant in the oil separation chamber 8 directly. 29a is an adjusting bolt for adjusting the pressing force of the spring 29.

The front plate 3 is formed with a suction hole 30 which faces when the compression chamber 18 is in the suction stroke, and this suction hole 30 communicates with the suction chamber 5 formed in the front housing 4. This suction chamber 5 has a suction pipe 31
Through an evaporator (not shown).

The front plate 3 has a suction hole 30.
A partition wall 32 is formed facing the opening facing the suction chamber 5. The partition wall 32 is shown in detail in FIGS. 4 and 5. The partition wall 32 partitions the inlet of the suction hole 30 and the suction chamber 5. Is formed, and the opening 33 substantially serves as an inlet of the suction hole 30. The opening 33 is opened at a relatively high position in the suction chamber 5 as shown in FIGS. The opening area of the opening 33 is equal to or larger than the opening area of the suction hole 30 so that the partition wall 32 does not narrow the opening area of the suction hole 30.

In FIG. 1, the position of the opening 33 is shown at a position lower than the actual position.

A guide wall 35 projects from the inner surface of the front housing 4 so as to face the partition wall 32.
The partition wall 32 and the guide wall 35 constitute a gas-liquid separation wall in the suction chamber 5. That is, when the refrigerant is introduced into the suction chamber 5 through the suction pipe 31, the refrigerant
And collides with the guide wall 35 to remove the liquid component of the refrigerant into the suction chamber 5.
And has a function of separating gas components into an upper position of the suction chamber 5.

The position of the suction hole 30 in the front plate 3 is located on the right side of the center as shown in FIG. 4, while the suction pipe 31 is located on the left side in FIG. The refrigerant introduced from the pipe 31 does not flow directly into the opening 33 serving as the inlet of the suction hole 30.

An oil return hole 3 communicating the compression chamber 18 with the lower part of the suction chamber 5 is formed in the lower part of the partition wall 32.
6 are formed. This oil return hole 36 has a diameter of 2 mm
The oil return hole 36 supplies the oil accumulated at the bottom in the suction chamber 5 to the compression chamber 18 and mixes the oil component with the vaporized refrigerant.

The operation of the vane-type compressor according to the embodiment having such a configuration will be described.

When the rotational force of the vehicle driving engine is transmitted to the drive shaft 11 via an electromagnetic clutch (not shown), the rotor 10 rotates in the main housing 1. With this rotation, in a region where the volume of the compression chamber 18 expands, the refrigerant introduced into the suction chamber 5 from the evaporator of the refrigeration cycle is sucked into the compression chamber 18 through the suction hole 30.

The sucked refrigerant is compressed as the volume of the compression chamber 18 decreases, and is discharged into the discharge chamber 21 by pushing and opening the discharge valve 23 through the discharge hole 22.

This refrigerant is sent from the refrigerant passage 24 to the oil separation chamber 8, and after separating the lubricating oil in the oil separation chamber 8, is discharged from the discharge pipe 25 to the condenser side of the refrigeration cycle.

When the compressor is stopped, the refrigerant in the suction chamber 5 and the compression chamber 18 is liquefied because the ambient temperatures of the evaporator and the compressor are different.

When the stoppage period of the compressor is short, the amount of refrigerant to be liquefied is small.
The liquefied refrigerant in the discharge chamber 8 is compressed together with the compressed gas refrigerant.
It is discharged to 1. Alternatively, when the liquefied refrigerant in the compression chamber 18 is compressed and this pressure reaches or exceeds the operating pressure of the relief valve 26,
Since the ball valve 28 of the relief valve 26 opens the relief port 27, and thus the refrigerant in the compression chamber 18 is directly released to the oil separation chamber 8, abnormal pressure rise in the compression chamber 18, that is, liquid compression can be prevented. .

However, when the stop period of the compressor is long, the amount of the liquefied refrigerant increases, and the compression chamber 18 in the main housing 1 and the suction chamber 5 in the front housing 4 reach a full state. When the compressor is restarted in this state, the liquefied refrigerant in the compression chamber 18 is compressed, causing liquid compression and damaging the vane.

That is, in the conventional case, as shown schematically in FIG. 6, when the liquid refrigerant is full over the compression chamber 18 and the suction chamber 5, all of the liquid refrigerant in both the chambers 18 and 5 is removed. However, the passage area of the relief port 27 of the relief valve 26 is too small, and the opening of the relief port 27 is delayed, so that it takes a long time for removal, and during this time, an abnormal pressure rise sometimes occurs.

This state will be described with reference to the characteristics shown in FIG.
Assuming that the clutch that connects the engine and the compressor is connected at the point a, the pressure rise of the liquid compression is relatively low because the clutch is not completely connected and has a resistance greater than the transmission torque of the clutch for one or two rotations after startup. , As shown by point b,
When the rotation reaches about 5 rotations, the clutch is completely engaged, and the transmission torque of the clutch is completely transmitted to the rotor 10, and the peak value P of the abnormal pressure is generated. That is, in the conventional case, the peak value P of the abnormal pressure is 100 to 150 ms from the start.
Over time, the pressure can reach 350-400 kg / cm ^2, which can cause damage to the vanes 16.

On the other hand, in the case of the present invention, even if the liquefied refrigerant reaches the full state in the compression chamber 18 and the suction chamber 5 of the front housing 4 by stopping the compressor for a long period of time, FIG. As schematically shown in FIG. 2, since the substantial opening 33 of the suction hole 30 is opened at the upper position in the suction chamber 5, the liquefied refrigerant at a position lower than the opening 33 is compressed by the partition wall 33. Flow into chamber 18 is prevented.

Therefore, the compression chamber 18 does not need to liquid-compress all the liquefied refrigerant, and only the liquefied refrigerant in the compression chamber 18 needs to be excluded. If the liquefied refrigerant only in the compression chamber 18 is excluded, the liquefied refrigerant can be excluded from the discharge hole 22 and discharged through the relief valve 26, so that an abnormal increase in pressure is prevented.

This state will be described with reference to the characteristics shown in FIG.
Assuming that the clutch connecting the engine and the compressor is connected at point a, the pressure rise of the liquid compression is relatively low since the clutch is not completely connected and has a resistance greater than the transmission torque of the clutch for one or two revolutions after startup. However, in the case of this embodiment, since the amount of the liquefied refrigerant to be removed is small, the liquefied refrigerant can be pumped by one or two rotations after the start. Therefore, b
Even if the transmission torque of the clutch is completely applied to the rotor 10 due to the complete connection of the clutch at this point, no abnormal pressure rise occurs because no liquefied refrigerant remains at this point.

The peak value P of the pressure generated during this period is represented by b
Before reaching the point, that is, in the case of the present embodiment, the peak value P of the pressure falls within 15 to 30 ms after the start-up.
The level is limited to a level of 0 to 200 kg / cm ² , so that damage to the vane 16 can be prevented.

The liquefied refrigerant remaining in the suction chamber 5 at a position lower than the opening 33 of the suction hole 30 is
The oil is gradually supplied from the suction chamber 5 to the compression chamber 18 through an oil return hole 36 formed in the lower part of the cylinder and is discharged to the discharge side together with the vaporized refrigerant.

In a normal operation state, when refrigerant is introduced into the suction chamber 5 through the suction pipe 31, the refrigerant is
And collides with the partition wall 32 and the guide wall 35, and the collision promotes gas-liquid separation. That is,
When the refrigerant collides with the partition wall 32 and the guide wall 35, the liquid component accumulates in the lower part of the suction chamber 5, and the gas component reaches the upper position of the suction chamber 5.

However, the liquefied refrigerant,
In particular, when lubricating oil mixed with the refrigerant gas and supplied for lubricating and sealing each moving part accumulates in the suction chamber 5, lubrication of each moving part becomes impossible, and the sealing performance of each part deteriorates. There is a concern that the discharge temperature of the refrigerant will increase.

In particular, in an operation state such as a low speed and a high load, the lubricating oil tends to accumulate in the suction chamber 5 due to the gas-liquid separation action of the partition wall 32 and the guide wall 35.

However, in this embodiment, the partition wall 32
The oil collected in the suction chamber 5 is supplied to the compression chamber 18 through the oil return hole 36, mixed with the refrigerant gas, and supplied to each moving part. Therefore, lubrication is smoothly performed, the sealing performance of each part is improved, and an increase in the discharge temperature of the refrigerant can be prevented.

FIG. 9 shows the result of measuring the relationship between the discharge pressure Pd and the discharge temperature Td for each structure.

In the case A of the related art, since there is no partition wall 32, no oil stays in the suction chamber 5, and the rise of the discharge temperature is small.

On the other hand, in the case B where the partition wall 32 is provided and the oil return hole 36 is not formed, since the oil accumulates in the suction chamber 5, the discharge temperature rises remarkably.

However, in the case of the present embodiment C in which the oil return hole 36 is formed in the partition wall 32, the oil in the suction chamber 5 is supplied to the compression chamber 18 through the oil return hole 36, so that the discharge temperature is prevented from rising. can do.

The present invention is not limited to the above embodiment.

For example, the guide wall 35 is not always necessary, and may be omitted.

The partition wall 32 is not limited to being formed integrally with the front plate 3, but may be formed as a separate structure or the front housing 4.

[0054]

As described above, according to the present invention, since the substantial opening of the suction hole of the compression chamber is opened at the upper part of the suction chamber, the liquid refrigerant accumulated in the suction chamber is discharged. When the compressor is started, only the liquid refrigerant in the compression chamber needs to be removed, so that the pressure rise in the compression chamber is suppressed. Therefore, liquid compression, that is, abnormal pressure rise, is prevented, and vane damage and the like can be prevented.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a through-vane type compressor showing an embodiment of the present invention.

FIG. 2 is a side sectional view of the embodiment.

FIG. 3 is a sectional view taken along line III-III in FIG. 1;

FIG. 4 is a side view of a front plate.

FIG. 5 is a sectional view of a front plate.

FIG. 6 is a diagram schematically showing a conventional structure.

FIG. 7 is a diagram schematically illustrating the structure of the present embodiment.

FIG. 8 is a characteristic diagram showing a relationship between time and generated pressure in a conventional case.

FIG. 9 is a characteristic diagram showing a relationship between time and generated pressure in the case of the present embodiment.

FIG. 10 is a characteristic diagram showing a relationship between a discharge pressure and a discharge temperature.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Main housing, 3 ... Front plate, 4 ... Front housing, 5 ... Suction chamber, 6 ... Rear plate, 7 ... Rear housing, 8 ... Oil separation chamber, 10 ... Rotor, 11
... Drive shaft, 16 ... Vane groove, 17 ... Vane, 18
... compression chamber, 20 ... discharge chamber, 22 ... discharge hole, 23 ... discharge valve, 26 ... relief valve, 30 ... suction hole, 31 ... suction pipe,
32: partition wall, 33: opening, 35: guide wall, 36: oil return hole.

Claims (2)

(57) [Claims] An eccentric rotor rotated in the main housing, a vane installed in the eccentric rotor, a volume enclosed by the main housing, the eccentric rotor and the vane, and rotated by the eccentric rotor. A variable compression chamber, a suction chamber formed in a front housing connected to the main housing, and a suction hole formed in a front plate defining the main housing and the front housing and guiding refrigerant in the suction chamber to the compression chamber. When a discharge hole for feeding a pressurized refrigerant by the compression chamber, the compression
The liquid refrigerant in the compression chamber is
A relief valve, comprising: a relief valve; The vane compressor is characterized in that the opening is open at an upper position of the suction chamber. 2. The vane type compressor according to claim 1, wherein an oil return hole communicating between the compression chamber and a lower part of the suction chamber is formed in a lower part of the partition wall.