JPS5968593A - Variable capacity type compressor - Google Patents

Abstract

PURPOSE:To make the titled compressor start operation smoothly preventing liquid compression from occuring by a method wherein, when the titled compressor is started, a spool in a control valve mechanism is provided so that it is energized in the direction to open a bypass hole. CONSTITUTION:When a compressor is stopped, a spool 19 in a control valve mechanism 12 is in a status wherein the spool 19 is energized in the direction to a high pressure chamber 20 through a spring 22 inserted in a low pressure chamber 21 i.e. a bypass hole 11 is opened. In such a status, a rotor 5 may be rotated by means of transmitting the driving force of an engine to a driving shaft 4. Then a part of refrigerant fed in the terminal direction along the rotary direction of the rotor 5 in a compression chamber 6 is flown into an inlet chamber 9 side through the bypass hole 11. Through these procedures, the compressor may start operation smoothly relieving the liquid compression in case the liquefied refrigerant gas remains in an inlet pipe.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a variable compression capacity compressor that can automatically control compression capacity in accordance with changes in indoor cooling load. More specifically, the control valve is automatically opened and closed by using the change in the differential pressure that occurs between the pressure in the suction stroke in the compression chamber (suction stroke pressure Prj) and the pressure in the compression stroke in the compression chamber (compression stroke pressure PH). By automatically opening and closing the control valve, the compression capacity in the compression chamber is automatically adjusted by releasing a portion of the refrigerant gas that is in the middle of compression in the compression chamber to the suction chamber during low cooling loads. The present invention relates to an improvement of the control valve mechanism of a variable capacity compressor that is installed to enable the control of the variable capacity compressor, and its purpose is to improve its control function.

Conventionally, variable capacity compressors that automatically control the compression capacity as the cooling load changes indoors have been developed using a method that utilizes the differential pressure that occurs between the pressure in the suction chamber and the pressure in the compression chamber. When comparing the differential pressure that occurs between the pressure in the suction chamber and the pressure in the compression chamber, the change in the differential pressure increases in proportion to the height of the pressure in the suction chamber. A method of adjusting the compression capacity by automatically opening and closing the compressor (Japanese Unexamined Patent Publication No. 122191/1982) has previously been proposed.

The proposal is to create a communication passage that connects the working space (compression chamber) formed in the area surrounded by the liner (cylinder block), front and rear side plates, and rotor, and the suction chamber. An on-off valve that controls the opening and closing of the communication passage is provided.The on-off valve consists of a valve body that blocks the port of the communication passage, a spring that biases the valve body in the opening direction, a support plate for the valve body, and a partition into an open side and a closed side. The valve element is normally biased in the direction of opening the port of the communication passage by the action of a spring, while the bellows frame exists between the valve body and the valve body to prevent the opening of the port. The pressure inside the suction chamber is applied to the side, and the pressure inside the working space (compression chamber) (approximately three times the pressure inside the suction chamber) is applied to the closed side. When the pressure difference between the pressure inside the working space (compression chamber) exceeds the set pressure of the spring, the valve body automatically closes the communication passage by moving the bellows flam in the closing direction. It is set up so that you can get it.

However, in the method described above in which the on-off valve is controlled by changes in the differential pressure that occurs between the pressure in the suction chamber and the pressure in the compression chamber, the pressure drop when entering the compression chamber from the suction chamber , the pressure inside the compression chamber relative to the suction pressure will be lower than the theoretical value. Therefore, the pressure in the direction opposite to the biasing force of the spring becomes small, and the differential pressure becomes small9. Even if the cooling load has not decreased to the set value, the communication passage opens. This is more likely to occur at high speed rotations, and when gear shifting or the like is performed while the vehicle is running, the capacity is frequently changed and the flow of refrigerant gas may become unstable.

The present invention is an attempt to improve the conventional situation as described above, and the pressure during the suction stroke in the compression chamber (
By controlling the on-off valve based on changes in the differential pressure that occurs between the suction stroke pressure (PL) and the pressure during the compression stroke (compression stroke pressure PH), the control function of the on-off valve is further improved. It is characterized by the fact that it is possible to do so. More specifically, refrigerant gas is sent into the suction chamber from the suction pipe and is sent into the compression chamber through the suction hole opened in the side grate. As shown in Figure 6, the pressure decreases slightly in the process of being sent to When comparing the differential pressure obtained between the pressure PH during the compression stroke and the pressure PL during the suction stroke in the compression chamber and the pressure PH during the compression stroke in the compression chamber, PHP3 < This is an attempt to improve the inequality PH-PL in view of the fact that it holds true, and its feature is that it is able to obtain more reliable control of the on-off valve compared to the conventional method described above. 0 The gist of the present invention is that a bypass hole is provided through a side plate interposed between a suction chamber and a compression chamber so as to communicate the suction chamber and compression chamber; The spool is provided so that it can be freely opened and closed in the direction perpendicular to the bypass hole. A high pressure chamber communicating with the compression stroke of the chamber and a low pressure chamber communicating with the suction stroke of the compression chamber are provided, and the spool is configured to move in the closing direction via the pressure difference generated between the high pressure chamber and the low pressure chamber. .

Specific embodiments of the present invention will be described below with reference to illustrative drawings.

In each of the drawings shown in FIGS. 1 to 5, (1) indicates a housing that constitutes the outer shell of the compressor. Same housing (1
) are front housing (IA) and rear housing
(IB) and the same front housing (I
In A), a cylinder block (2) is fitted, and front side plates (3A) and catcher side plates (3B) are fitted on both sides of the cylinder block (2) with the cylinder block (2) in between. The cylinder block (2) is formed into a hollow cylindrical shape with openings at both front and rear ends, and the inner wall surface of the hollow portion is formed into a cylindrical shape concentric with the outer peripheral surface of the cylinder block (2). Both the front and rear openings of the cylinder block (2) are connected to the above-mentioned side plates (3A) (3B).
is shielded by and both sides play) (3
A) (ab) A drive shaft (4) is installed horizontally between them.

The drive shaft (4) is provided with its center line offset relative to the cylinder block (2), and a rotor τ (5) is integrally fixed to the drive shaft (4). Four rotors (5)
is provided so that a part of its outer circumferential wall can slide against the inner wall surface of the cylinder block (2), and the rotor (5)
A compression chamber (6) is formed between the outer peripheral wall of the cylinder block (2) and the inner wall surface of the cylinder block (2). Further, vane grooves (7) are formed in the rotor (5), and vanes (8) are fitted into each vane groove (7) so as to be freely retractable into the compression chamber (6). It will be done.

A suction chamber (9) is provided between the front housing (IA) and the front side plate (3A).
9) has a suction pipe (
A suction port (9)' is provided which connects to the main body (not shown).

Also, the front side plate (3A) has a compression chamber (6).
A suction hole 00) is opened corresponding to one end of the rotor (5), that is, a starting end along the rotational direction of the rotor (5). Further, a bypass hole (formerly known as a bypass hole) is provided through the front side plate (3A), and is located approximately midway between the suction stroke and the compression stroke (early stage of the compression stroke) of the compression chamber (6). At this time, it is also possible to make a bypass hole in the cylinder peripheral surface and provide the spool in the cylinder block.

The bypass hole (11) is provided so as to communicate between the compression chamber (6) and the suction chamber (9).
(3A), a control valve mechanism (12) is provided in a direction perpendicular to the bypass hole (old). (Control valve mechanism 0
2) will be discussed later. ) On the other hand, at the other end of the compression chamber (6), that is, at a position corresponding to the terminal end along the rotational direction of the rotor (5), a part of the cylinder block (2) is cut out so as to be connected to the inner wall surface of the rear housing (IB). A discharge chamber (13) is formed between the discharge chambers (13) and 1.
3) and the terminal end of the compression chamber (6) are communicated through a discharge hole (I4). (15) is a discharge valve that covers the discharge hole (14), and (16) is a retainer that regulates the opening angle of the discharge valve. Lubricating oil separation chamber 07 between
) is formed.

The separation chamber Q71 is provided so as to communicate with the discharge chamber α via a through hole 08) opened in the side chamber (3B). The opening of the through hole 08) has a filter (
(not shown) is provided in the separation chamber 00, and a reservoir portion for lubricating oil to be separated by the filter is provided in the separation chamber 00. Also in the same separation chamber 00 is the rear housing (IB).
A discharge hole 06)' connected to a discharge pipe (not shown) is provided on the side.

In the control valve mechanism σ, a spool OQ for opening and closing the bypass hole (11) is provided in correspondence with the bypass hole (11) so as to be slidable in a direction orthogonal to the bypass hole (11). . Pressure chambers such as a high pressure chamber (a) and a low pressure chamber Q1) are provided at both ends of the same sugur O. A spring (A) is interposed in the low pressure chamber +21), and the spool (19) is normally biased toward the top of the high pressure chamber via the spring (A) to open the bypass hole 0). It is set up as shown in A first pressure guiding hole is extended from the high pressure chamber (4), and its tip faces the compression chamber (6) during the compression stroke, and its tip is located at the opening position of the bypass hole 01). The same bypass hole (l) is also connected to the discharge hole (+4).
)K are provided so as to open relatively close to each other. In addition, a second pressure introducing hole (good) is extended from the lower chamber (c), and its tip faces the compression chamber (6) during the suction stroke, and its tip is compared to the suction hole (10). It is provided so as to open at a position close to the target. The first pressure-conducting hole (a) and the second pressure-conducting hole (c) are formed to have a diameter as small as possible in order to provide a throttling effect.

Next, its effect will be explained.

When the compressor is stopped, each part inside the compressor, namely the suction chamber (9), the compression chamber (6), the discharge chamber θ■2 separation chamber 0
7) are in substantially the same pressure state. Further, in the control valve mechanism 02, the spool θ is biased toward the high pressure chamber (4) via the spring (A), that is, the bypass hole (II) is in an open state.

In the above state, by transmitting the driving force of the engine to the drive shaft (4) through the connection operation of the electromagnetic clutch (not shown), a state in which the rotor (5) rotates is obtained, and Each vane (8) is inserted into each vane groove (7) through the rotation of the rotor (5).
is extruded by the centrifugal action, and the curl action at the tip is exerted from the incomplete position, resulting in a rotating state. Through the rotation of each of the vanes (8), the refrigerant gas is sent from the evaporator (not shown) through the suction pipe line into the suction chamber (9) through the suction hole (10) and into the compression chamber (
6) It is sucked into the body. The refrigerant gas drawn into the compression chamber (6) is gradually compressed while being sent through the compression chamber (6) from its starting end toward its terminal end through the rotating action of the vane (8). The refrigerant gas sent inside the compression chamber (6) to its terminal position is discharged through the discharge hole 04) and the discharge chamber 0■7 through hole 0.
8) It is sent out through the discharge hole 07)' through the 5 separation chambers 7) in the discharge pipe toward the condenser (not shown).

On the other hand, as mentioned above, a part of the refrigerant gas sent in the compression chamber (6) toward the terminal end along the rotational direction of the rotor (5) is in the middle of compression, that is, in the suction hole (5) of the compression chamber (5). 10)
It flows out toward the suction chamber (9) through a bypass hole 0]) which opens at an arbitrary intermediate position.

In this way, part of the refrigerant gas is compressed into the suction chamber (9).
) side, it is possible to smoothly start up the compressor when starting, and reduce the starting torque. It is possible to alleviate the liquid compression effect when the refrigerant gas remains in a liquefied state.

By repeating the rotation of the rotor (5), the compression pressure in the compression chamber (6) is gradually increased, and part of the compressed gas increased in the compression chamber (6) in this way is The high pressure chamber (20) is fed into the high pressure chamber (20) through the first pressure guiding hole (20).
) will be increased.

For example, when the cooling load is large, such as at the start of operation, the pressure inside the suction chamber (9) is relatively high, and when the cooling load is reduced, the pressure inside the suction chamber (9) is relatively high. It gets lower. And suction stroke pressure PL and compression stroke pressure P
As shown in Figure 6, the differential pressure ΔP generated between When the indoor cooling load is large and therefore the pressure inside the suction chamber (9) is high, the differential pressure generated between the suction stroke pressure PL and the compression stroke pressure PH becomes large. And that differential pressure is the spring (
b) When the pressure exceeds the set pressure of spool 09
) is pressed in the direction of the low pressure chamber ■υ force against the biasing pressure of the spring (a), and the same spool θ [phase] is pushed, and the bypass hole O])
A state is obtained in which the As a result, part of the refrigerant gas in the compression chamber (6) is sent into the compression chamber (6) without flowing out to the suction chamber (9) through the bypass hole (11). All of them are compressed and the discharge hole 04)
, the discharge chamber 032 through hole 08)5, and the condenser is sent out in one direction through the discharge pipe line through the separation chamber 071. That is, 1
00chi operating state is obtained.

On the other hand, as the indoor cooling load decreases and the pressure in the suction chamber (9) decreases, the suction stroke pressure PL and the compression stroke pressure P
The differential pressure between H also becomes smaller. When the differential pressure is lower than the set pressure of the spring (A) in the control valve mechanism Q4, the spool (121), which had been pressed toward the low pressure chamber 121) by the differential pressure and blocked the bypass hole (1υ), is
In 19), a state is obtained in which the bypass hole 01) is biased toward the high-pressure chamber via the spring cover, that is, a state in which the bypass hole 01) is opened.

When the spool 09) opens the bypass hole (]υ, a part of the refrigerant gas that is being compressed in the compression chamber (6) flows out to the suction chamber (9) through the bypass hole (11).

In this way, a portion of the refrigerant gas in the compression chamber (6) flows out to the suction chamber (9) side, thereby reducing the compression pressure in the compression chamber (6). That is, an effect of reducing the compression capacity of refrigerant gas can be obtained as the cooling load in the room decreases.

By forming the first pressure impulse hole (A) with a diameter as small as possible and giving the first pressure impulse hole (C) a throttling effect, the inside of the compression chamber (6) is With respect to the pressure increase, the transmission of the same pressure increase to the high pressure chamber (E) can be delayed in time, and a sudden pressure increase in the high pressure chamber (E) can be prevented. In this way, by being able to prevent a sudden pressure rise in the high pressure chamber (A), the opening and closing of the spool 09), that is, the direction in which the bypass hole (1]) is closed rather than the state in which the bypass hole (1]) is opened, is prevented. can be moved slowly, and the transition to full operation at startup can be smoothly performed without applying shock to each part.

Also, during steady operation, it is possible to prevent the spool 0@ from moving too sensitively to pressure changes in the compression chamber (6).
The movement of the same spool can be stabilized. Also, the second pressure impulse hole (c) should be formed to have a diameter as small as possible in the same way as the above-mentioned pressure impulse hole (c), and the second pressure impulse hole (c) should have a constriction effect. If the spool 09) opens the bypass hole (1), then the bypass hole (11) will open.
) when moving in the closing direction])
The internal pressure can be reduced slowly, and together with the throttling effect of the first pressure guiding hole (a), the impact mitigation effect at the time of transition to full operation can be further enhanced.

Although not shown, a check valve is provided in the first pressure guiding hole (c) to reduce the pressure in the high pressure chamber (a) to the compression chamber (6).
) can be maintained at the same pressure as the peak pressure at the position facing the tip opening of the first pressure guiding hole (c).

By being able to maintain the pressure within the high pressure chamber (A) in a constant state in this way, pressure changes within the high pressure chamber (A) can be minimized and the movement of the spool (19) can be minimized. A further stabilizing effect can be obtained. On the other hand, since the spool (19) is slidably provided in the direction perpendicular to the bypass hole (11), the spool 09) is affected by the compression pressure in the compression chamber (6). The sliding movement can be performed only by the differential pressure generated between the compression stroke pressure PH and the suction stroke pressure PL without being affected. In this way, by allowing the spool 09) to slide without being affected by the compression pressure in the compression chamber (6), its accuracy can be improved, while the compression stroke pressure PH and suction stroke By allowing one of the spools to slide due to the slight pressure difference that occurs between the pressures PL and PL, it is possible to use a spring (A) with a weaker biasing force, making it easier to assemble the spool. At the same time, since the differential pressure between the compression stroke pressure PH and the suction stroke pressure PL is small, the leakage of pressure from the spool 09) part is naturally reduced, and as a result, the clearance of the insertion part of the spool 09) is reduced. It can be made large. By increasing the clearance in this manner, sliding resistance can be reduced.

The present invention is configured as described above, and with the above configuration, the compressor can be operated at full capacity when the indoor cooling load is large, and the indoor cooling load is reduced. In such cases, the compression capacity of the compressor can be automatically adjusted in response to the indoor cooling load so that the operating rate of the compressor can be lowered.In addition, in the present invention, the spool can be kept open at all times. is provided so that it is biased in the direction of opening the bypass hole, and a high pressure chamber and a low pressure chamber are provided on both sides of the spool with the same spool in between, and the high pressure chamber is compressed through the first pressure guiding hole. Indoor compression stroke (
The low pressure chamber is connected to the suction stroke (suction stroke pressure PL) of the compression chamber through the second pressure guiding hole, and the differential pressure obtained between these two strokes, that is, the compression stroke pressure By opening and closing the spool through changes in the differential pressure that occurs between PH and suction stroke pressure PL, it is possible to prevent malfunction of the spool due to the influence of pressure drop, and the spool can be opened and closed appropriately. I was able to get him to do it. In other words, it has become possible to obtain a highly reliable control valve mechanism.

Further, in the present invention, a spool is provided in a direction perpendicular to the bypass hole, and the spool is opened and closed through a change in the differential pressure generated between the compression stroke pressure PH and the suction stroke pressure PL. By doing so, the spool can be opened and closed without being affected by the compression pressure in the compression chamber, and its accuracy has been improved. By arranging the spool so that it is biased in the direction of opening the bypass hole, it is possible to smoothly start up the spool at the time of startup, and to prevent the occurrence of liquid compression. I was able to do it0

[Brief explanation of drawings]

FIG. 1 is a side sectional view (A-B-C line sectional view in FIG. 3) of a compressor according to the present invention, and FIG. 2 is a D--
3 is a sectional view taken along line D, FIG. 3 is a sectional view taken along line E-E, FIGS. 4 and 5 are sectional views showing the operating state of the control valve mechanism,
FIG. 6 is a graph showing changes in the differential pressure between the suction stroke pressure and the compression stroke pressure. (1) Housing, (IA) Front housing, (I
B) Rear housing, (3) cylinder block, (3)
A) Front side plate, (3B) Rear side plate, (4) Drive shaft, (5) Rotor, (6) Compression chamber,
(7) Vane groove, (8) Vane, (9) Suction chamber, (9)
'Suction port, (10) Suction hole, (11) Bypass hole, 02
! 1 control valve mechanism, 03 discharge chamber, 04) discharge hole, α equalizing discharge valve, 0 side retainer 1 (17) separation chamber, αη′ discharge port,
08) Through hole, OO spool, (a) high pressure chamber, (21) low pressure chamber, (a) spring, (a) first pressure hole, (c) second pressure hole. / Patent applicant Toyota Industries Corporation D Figure 2 8 1 11 δ Figure 4 9J5

Claims (2)

[Claims] (1) A bypass hole is provided through the side plate interposed between the suction chamber and the compression chamber to communicate the suction chamber and the compression chamber, and the spool is inserted into the bypass hole in a direction perpendicular to the bypass hole. The spool is provided so as to be openable and closable, and the spool is normally biased in the direction of opening the bypass hole, and among the pressure chambers formed at both ends of the spool, the one on the side opposite to the direction of the bias is % indicates that one is in communication with the compression chamber during the compression stroke, and the other is in communication with the compression chamber during the suction stroke.
A variable capacity compressor. (2) The bypass hole is provided so as to face a position approximately halfway between the suction stroke and the compression stroke in the compression chamber, and the second pressure guiding hole communicating with the low pressure chamber is provided so as to face a position close to the suction hole, and is connected to the high pressure chamber. The variable capacity type according to claim 1, wherein the communicating first pressure guiding hole is provided so as to face a position closer to the discharge hole than the opening position of the bypass hole and close to the bypass hole. compressor.