JPH11117881A - Vane compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To relieve a shock upon starting without increasing the cost. SOLUTION: In a vane compressor, a movable valve 20 for regulating the intake flow rate is slidably located in an intake passage 11, and the movable valve 30 is subjected to an urging force of a compression spring 31 and a pressure in an intake port 6a in such a direction that the passage area decreases, and is also subjected to a pressure in a discharge chamber 10 through a pressure introduction passage 1b in such a direction that the passage area increases. Thus, the movable valve 30 slides in accordance with a difference between a force caused by the pressure of the discharge chamber 10 exerted to the movable valve 30 through the pressure introduction passage 1b, and a resultant of the urging force of the compression chamber 31 and the pressure in the inlet port 6a, which is exerted to the movable valve 30 in a direction in which the passage area decreases. Accordingly, the passage area of the intake passage 11 varies in accordance with a position of the movable valve 30.

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, and more particularly, to a fixed displacement type vane type compressor.

[0002]

2. Description of the Related Art In a swash type compressor or a wobble type compressor, refrigerant gas is drawn into a suction chamber from a suction port of a compressor housing through a suction port and then into a compression chamber through a suction port. Since the suction valve is mounted on the port, the suction chamber and the compression chamber communicate with each other via the suction port only when the suction valve is opened, and the refrigerant gas in the suction chamber is sucked into the compression chamber.

On the other hand, in the vane type compressor, the compression chamber and the suction chamber communicate with each other via the suction port only from the start to the end of the suction stroke. Does not require a suction valve.

[0004]

However, as described above, the vane type compressor does not require a suction valve, so that when the compressor is started, a large amount of refrigerant gas or liquid rapidly flows into the compression chamber through the suction port. As a result, the startup shock (shock generated when a large amount of refrigerant gas or the like suddenly flows into the compression chamber) was large.

On the other hand, a variable displacement vane compressor is started with a minimum displacement, so that the starting shock is not large.

However, the variable displacement vane compressor has a problem that a complicated variable displacement mechanism is required and the cost is high.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a vane-type compressor that can mitigate a starting shock without increasing costs.

[0008]

According to a first aspect of the present invention, there is provided a vane-type compressor comprising: a low-pressure passage for communicating a suction port of a compressor housing with a compression chamber; A movable valve that is slidably housed in the middle and changes a passage area of the low-pressure passage, an urging member that urges the movable valve in a passage area decreasing direction, and a refrigerant that guides a refrigerant from a high-pressure chamber to the movable valve. A pressure introduction path for applying a pressure in the direction of increasing the passage area to the pressure, the pressure of the high-pressure chamber acting on the movable valve through the pressure introduction path, the urging force of the urging member, and the passage area decreasing to the movable valve. The movable valve slides according to a difference from a resultant force of the pressure of the suction port acting in a direction, and a passage area of the low-pressure passage changes according to a position thereof.

When the compressor is started, the difference between the pressure in the high-pressure chamber and the pressure in the low-pressure passage is substantially zero, and the movable valve is urged in the direction of decreasing the passage area by the urging force of the urging member. Is the smallest, and the amount of the refrigerant gas sucked into the compression chamber from the low-pressure passage is the smallest, so that the starting shock is reduced. Further, when the compressor is started in a state where the liquid refrigerant is present in the refrigeration cycle, the low-pressure passage is restricted by the movable valve, so that the liquid refrigerant flowing from the suction port is gasified before reaching the compression chamber, So-called liquid compression is less likely to occur.

The vane type compressor according to the second aspect of the present invention,
2. The vane compressor according to claim 1, wherein the urging member is a compression spring, and the compression spring does not compress until a difference between the pressure in the high-pressure chamber and the pressure in the suction port reaches a predetermined value. It is characterized by having an initial set load.

Even if the compressor is stopped and restarted, the difference between the pressure in the high-pressure chamber and the pressure in the suction port does not reach a predetermined value, so that the passage area of the low-pressure passage is kept small during restart. In addition, the amount of the refrigerant gas sucked into the compression chamber is small, and almost no starting shock occurs.

[0012]

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

FIG. 1 is a longitudinal sectional view of a vane compressor according to an embodiment of the present invention, FIG. 2 is a view taken along the line II-II of FIG. 1, and FIG. 3 is a line III-III of FIG. FIG. 4 is a perspective view of the movable valve, and FIG. 5 is a curve diagram showing the relationship between the passage area and the difference between the discharge pressure and the suction pressure (differential pressure).

This vane type compressor has a cam ring 1,
A rotor 2 rotatably housed in the cam ring 1, a drive shaft 7 of the rotor 2, a front head 5 fixed to a front end face of the cam ring 1, and an O-ring 22 on a rear end face of the cam ring 1. Rear head 6 to be fixed
And a front side block 3 housed in the front head 5. The cam ring 1, the front head 5, and the rear head 6 are axially coupled by bolts 50. The front end of the drive shaft 7 is rotatably supported by the front side block 3 via a bearing 8, and the rear end of the drive shaft 7 is supported by the rear head 6 via a bearing 9.

The rear end face of the front side block 3 is fixed to the front end face of the cam ring 1.
The rear end face of the front side block 3 is a cam ring 1
Is closed, and the front end surface of the rotor 2 can contact the rear end surface of the front side block 3. Front end 3a of front side block 3
Is fitted to the boss 5b of the front head 5 via an O-ring 51. In the front head 5, a discharge chamber (high-pressure chamber) 10 into which a high-pressure refrigerant gas discharged from a compression chamber 15 described later flows is formed.

The front end face of the rear head 6 closes the rear opening of the cam ring 1, and the rear end face of the rotor 2 can contact the front end face of the rear head 6. The rear head 6 has a refrigerant gas inlet 6a. As shown in FIG. 2, an annular suction passage 11 is formed on the front end surface of the rear head 6.
A suction port 32 for sending the refrigerant gas from the suction passage 11 to the compression chamber 15 is provided. The suction passage 11 has a suction port 6a.
Is in communication with In this embodiment, the suction passage 11 and the suction port 32 constitute a low-pressure passage.

As shown in FIG. 3, between the inner peripheral surface of the cam ring 1 and the outer peripheral surface of the rotor 2, two upper and lower compression spaces 1 are provided.
2 are formed. The rotor 2 has a plurality of vane grooves 13.
Are provided, and a vane 14 is slidably inserted into these vane grooves 13. The compression space 12 is a vane 14
To form a plurality of compression chambers 15, and the volume of each compression chamber 15 changes with the rotation of the rotor 2.

A movable valve accommodating chamber 1a is formed in the cam ring 1 so as to oppose a part of the suction passage 11 in the axial direction, and a high-pressure introduction guides the refrigerant gas in the discharge chamber 10 to the movable valve accommodating chamber 1a. A passage 1b is formed (only one movable valve accommodating chamber 1a and the high-pressure introduction passage 1b are visible in FIG. 1).

As shown in FIG. 1, a movable valve 30 is slidably accommodated in a space defined by a movable valve accommodating chamber 1a and a part of the suction passage 11 which are axially opposed to each other. A compression spring (biasing member) 31 for pressing the bottom surface 30b of the movable valve 30 against the abutting surface 1d is housed. The movable valve 30 is a bottomed cylinder, and the cylinder is provided with holes 30a at regular intervals in the circumferential direction (see FIG. 4).

Further, the cam ring 1 is formed with a discharge valve accommodating chamber 1c as shown in FIG. The discharge valve housing chamber 1c houses the discharge valve 19 and a stopper 40 for suppressing the opening amount of the discharge valve 19. The front side of the discharge valve housing chamber 1c is open to the discharge chamber 10. The discharge valve housing chamber 1c and the compression chamber 15 communicate with each other via the discharge port 16 when the discharge valve 19 is opened. The high-pressure refrigerant gas in the compression chamber 15 is discharged through the discharge port 16 and the discharge space 1c.
Flows into zero.

Next, the operation of the vane compressor will be described.

The rotational power of the engine (not shown) is
, The rotor 2 rotates. The refrigerant gas flowing out of the outlet of the evaporator (not shown) enters the suction port 6a, and is sucked from the suction port 6a into the compression chamber 15 through the hole 30a of the movable valve 30, the suction passage 11, and the suction port 32.

Since the volume of the compression chamber 15 changes with the rotation of the rotor 2, the refrigerant gas confined in the compression chamber 15 is compressed, and the compressed refrigerant gas is discharged to the discharge port 16.
Flows through the discharge valve 19 to the discharge valve storage chamber 1c.

The high-pressure refrigerant gas flowing into the discharge valve chamber 1c from the discharge port 16 flows into the discharge chamber 10 and is discharged from a discharge port (not shown).

If the operation of the compressor is stopped for a long time, the difference between the pressure in the discharge chamber 10 and the pressure in the suction port 6a becomes almost zero. (The passage area decreasing direction), and the bottom surface 30b of the movable valve 30 is pressed against the abutting surface 1d (the state shown in FIG. 1). At this time, the passage area of the suction passage 11 narrowed by the movable valve 30 is the smallest. Therefore, when the compressor is started, the amount of the refrigerant gas sucked into the compression chamber 15 from the suction port 32 is minimized, and the start shock is reduced.

When the compressor is started, the liquid refrigerant flowing from the suction port 6a rapidly expands and gasifies when flowing out of the hole 30a of the movable valve 30 into the suction passage 11, so that the so-called liquid compression (compressor start-up) is performed. (A phenomenon in which the liquid refrigerant flowing into the compression chamber is sometimes compressed) is less likely to occur.

After the compressor is started, when the pressure in the discharge chamber 10 rises and the pressure in the discharge chamber 10 exceeds the combined force of the urging force of the compression spring 31 and the pressure of the suction port 6a, the movable valve 30 is moved to the rear side (passage area). Move in the increasing direction). As a result, the passage area of the suction passage 11 gradually increases, and the amount of the refrigerant gas drawn into the compression chamber 15 from the suction port 32 gradually increases (see FIG. 5).

When the difference between the pressure in the discharge chamber 10 and the pressure in the suction port 6a exceeds a predetermined value, the passage area of the suction passage 11 becomes maximum. At this time, the amount of the refrigerant gas sucked into the compression chamber 15 from the suction port 32 is maximized.

After the compressor has been operated for a while (after sufficient cooling), once the operation is stopped, the pressure in the discharge chamber 10 gradually decreases, and the pressure in the discharge chamber 10 and the pressure in the suction port 6a are reduced. Since the difference is reduced, the passage area of the suction passage 11 is gradually reduced. Therefore, even if the compressor is started again, since the refrigerant gas is sucked in a state where the passage area of the suction passage 11 is small, the starting shock hardly occurs.

According to this embodiment, when the compressor is started, the movable valve 30 is urged to the front side by the urging force of the compression spring 31, and the passage area of the suction passage 11 is the smallest. The amount of the refrigerant gas sucked into 15 is the smallest, and the starting shock is reduced. In addition, since the startup shock can be reduced with a simple configuration without using the variable displacement mechanism of the conventional variable displacement vane compressor, the cost can be reduced.

Further, when the compressor is started, the amount of the liquid refrigerant flowing from the suction port 32 is reduced, and the hole 30 of the movable valve 30 is opened.
Since gasification occurs when passing through a, liquid compression hardly occurs.

Further, as described above, the passage area of the suction passage 11 changes according to the difference between the pressure of the discharge chamber 10 and the pressure of the suction port 6a. Since the compression spring 31 compresses by a corresponding amount, the cooling capacity is limited at a low load, and the power loss is reduced.

As a modification of the above-described embodiment, by selecting a compression spring 31 having a specific spring constant, the difference between the pressure in the discharge chamber 10 and the pressure in the suction port 6a reaches a predetermined value. The compression spring 31 may not be compressed, and the compression spring 31 may be compressed only when the differential pressure reaches a predetermined value.

According to this modification, even if the compressor is once stopped and restarted, the pressure in the discharge chamber 10 and the suction port 6
Since the difference from the pressure a does not reach the predetermined value, the passage area of the suction passage 11 at the time of restart is kept small, the amount of the refrigerant gas sucked into the compression chamber 15 is small, and the starting shock hardly occurs. .

[0035]

As described above, according to the vane type compressor of the first aspect of the present invention, the shock at the time of starting the compressor can be reduced with a simple structure without increasing the cost.

When the compressor is started in a state where liquid refrigerant is present in the refrigeration cycle, the low-pressure passage is restricted by the movable valve. Gasification, so-called liquid compression hardly occurs.

According to the vane type compressor of the second aspect of the present invention, even if the compressor is once stopped and restarted, the passage area of the low-pressure passage is kept small at the time of restarting. The amount of refrigerant gas sucked into the room is small, and almost no starting shock occurs. That is, even when the time from the stop of the compressor operation to the start of the compressor is short, the start shock can be reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a vane type compressor according to one embodiment of the present invention.

FIG. 2 is an arrow view along the line II-II in FIG.

FIG. 3 is an arrow view along a line III-III in FIG. 1;

FIG. 4 is a perspective view of a movable valve.

FIG. 5 is a curve diagram showing a relationship between a passage area and a difference between a discharge pressure and a suction pressure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cam ring 1b Pressure introduction path 6 Rear head 6a Suction port 10 Discharge chamber 11 Suction path 15 Compression chamber 30 Movable valve 30a Hole 30b Bottom part 31 Compression spring 32 Suction port

Claims (2)

[Claims] A low-pressure passage that communicates a suction port of a compressor housing with a compression chamber; a movable valve that is slidably housed in the middle of the low-pressure passage to change a passage area of the low-pressure passage; An urging member that urges the valve in the direction of decreasing the passage area; and a pressure introduction path that guides the refrigerant from the high-pressure chamber to apply pressure to the movable valve in the direction of increasing the passage area. The movable valve slides according to the difference between the pressure of the high-pressure chamber acting on the valve, the urging force of the urging member, and the resultant force of the pressure of the suction port acting on the movable valve in the direction of decreasing the passage area. A vane-type compressor in which the passage area of the low-pressure passage changes according to the position thereof. 2. The method according to claim 1, wherein the biasing member is a compression spring, and the compression spring has an initial set load that does not compress until the difference between the pressure in the high-pressure chamber and the pressure in the suction port reaches a predetermined value. The vane type compressor according to claim 1, wherein