JPH0152596B2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to a variable compression capacity compressor that can automatically control the compression capacity in accordance with changes in the cooling load in a vehicle interior, and more specifically to a variable compression capacity compressor that can be used in a suction compartment or a compression compartment. A control valve is provided so as to be able to automatically open and close by utilizing a change in the differential pressure that occurs between the pressure in the suction stroke (suction stroke pressure _PL ) and the pressure in the compression stroke in the compression chamber (compression stroke pressure _PH ), The compression capacity in the compression chamber can be automatically adjusted by automatically opening and closing the control valve to release 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. This invention relates to an improvement in the control valve mechanism of a variable capacity compressor that can be installed as much as possible.

Conventional technology Conventionally, a variable capacity compressor that automatically controls the compression capacity as the cooling load changes in the vehicle interior utilizes changes in the differential pressure that occurs between the pressure in the suction chamber and the pressure in the compression chamber. In consideration of the fact that when comparing the change in the differential pressure that occurs between the suction stroke pressure P _L and the compression stroke pressure P _H , the change in the differential pressure increases in proportion to the height of the pressure in the suction stroke. The applicant has previously proposed a method of adjusting the compression capacity by automatically opening and closing a control valve mechanism using changes in the differential pressure.

The above proposal means that, as shown in FIGS. 7 and 8, the suction chamber 9 is attached to the front side plate 3A interposed between the suction chamber 9 and the compression chamber 6 (see FIGS. 1 and 2).
A bypass passage 11 is provided so as to communicate with the compression chamber 6, and the bypass passage 11 is connected to the compression chamber 6.
A spool 19 is provided so as to be slidable in a direction perpendicular to the bypass passage 11 in order to control the opening and closing of the bypass passage 11.
A high pressure chamber 20 and a low pressure chamber 21 are provided facing each other on both sides of the spool 19, and the high pressure chamber 20 is connected through the first pressure guiding hole 24. provided so as to communicate with the compression stroke (compression stroke pressure P _H ) of the compression chamber 6,
Furthermore, the low pressure chamber 21 is connected to the suction chamber 9 through the second pressure guiding hole 23.
Or the suction stroke of the compression chamber 6 (suction stroke pressure P _L )
The bypass passage 11 is closed in a pressure state in which the differential pressure generated between the compression stroke pressure P _H and the suction stroke pressure P _L as the pressure rises in the suction stroke exceeds the set pressure of the spring 22. Compression stroke pressure P _H due to pressure drop in suction stroke
In a state where the differential pressure generated between P _L and the suction stroke pressure P
By opening the refrigerant gas so that a part of the refrigerant gas in the middle of compression escapes to the suction chamber 9 side, the compressor can be operated at full capacity when the cooling load in the vehicle interior is large. The compressor is provided so that its compression capacity can be automatically adjusted in response to changes in the cooling load in the vehicle interior so that the operating rate of the compressor can be lowered when the cooling load in the vehicle interior is reduced. In this proposal, when the electromagnetic clutch is connected at the time of startup, a large pressure difference is generated between the compression stroke pressure P _H and the suction stroke pressure P _L , and the bypass passage 11 in the open state is instantaneously As a result, the start-up shock at startup cannot be sufficiently relaxed.

When the engine is suddenly accelerated during operation, the differential pressure generated between the compression stroke pressure P _H and the suction stroke pressure P _L becomes even larger, and the spool 19 moves toward the low pressure chamber 21 side (in the direction of blocking the bypass path 11). This results in a state where the engine rotates at high speed with 100% cooling load applied, that is, a full load operation state, and the interior of the vehicle becomes supercooled.

This may cause problems such as:

Purpose of the Invention The present invention is an attempt to improve the conventional situation as described above, and the purpose of the present invention is to improve the operating characteristics of the control valve mechanism during startup and sudden acceleration. .

Structure of the Invention That is, the present invention is characterized by reducing the torque at startup to alleviate the start-up shock and preventing full load operation during sudden acceleration. A high-pressure chamber and a low-pressure chamber are provided facing each other at both ends of a spool that is movably provided in a side plate that separates the chamber and the suction chamber, and the low-pressure chamber is communicated with the suction stroke of the suction chamber or the compression chamber, and A spring is interposed in the low pressure chamber to urge the spool toward the high pressure chamber, while a bypass hole communicating with the high pressure chamber is provided on the compression chamber side in the side plate in correspondence with the compression stroke of the compression chamber. A plurality of bypass holes communicating with the suction chamber are provided on the suction chamber side, the opening positions of which are displaced relative to the bypass holes on the compression chamber side, and the spool is provided with a bypass communication hole. One end communicates with the high pressure chamber, and the other end can selectively communicate with the plurality of bypass holes through sliding of the spool, and can be closed by a wall portion formed between the bypass holes. The reason is that it is configured in such a way that it is set up.

Embodiments 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 6, reference numeral 1 indicates a housing constituting the outer shell of the compressor. The housing 1 is the front housing 1
A and a rear housing 1B, and the front housing 1A has a cylinder block 2.
However, a front side plate 3A and a rear side plate 3B are fitted on both sides of the cylinder block 2 with the same 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 part 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 shielded by the side plates 3A, 3B, and a drive shaft 4 is horizontally suspended between the side plates 3A, 3B. The drive shaft 4 is provided with its center line offset relative to the cylinder block 2, and a rotor 5 is integrally fixed to the drive shaft 4. The rotor 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 a compression chamber 6 is formed between the outer circumferential wall of the rotor 5 and the inner wall surface of the cylinder block 2. Ru. 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.

A suction chamber 9 is provided between the front housing 1A and the front side plate 3A.
A suction port 9' connected to a suction pipe (not shown) is provided on the front housing 1A side. Further, a suction hole 10 is opened in the front side plate 3A in correspondence with one end of the compression chamber 6, that is, a starting end along the rotational direction of the rotor 5.

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 to form a discharge chamber 13 between the cylinder block 2 and the inner wall surface of the front housing 1A. The discharge chamber 13 and the terminal end of the compression chamber 6 are provided so as to communicate with each other through a discharge hole 14. Reference numeral 15 indicates a discharge valve that covers the discharge hole 14, and reference numeral 16 indicates a retainer that regulates the opening angle of the discharge valve 15. Further, a lubricating oil separation chamber 17 is formed between the rear housing 1B and the rear side plate 3B. The separation chamber 17 is provided so as to communicate with the discharge chamber 13 through a through hole 18 opening in the rear side plate 3B. A filter (not shown) is provided at the opening of the through hole 18, and a lubricant reservoir is provided in the separation chamber 17 to be separated by the filter. Also, in the separation chamber 17 there is a rear housing 1.
Discharge port 1 connected to the discharge pipe line (not shown) on the B side
7' is provided.

A compression chamber 6 is provided in the front side plate 3A.
Approximately midway between the suction stroke and the compression stroke (early stage of the compression stroke)
A bypass passage 11 is located in and communicates between the compression chamber 6 and the suction chamber 9 (the bypass passage 11 is located in the bypass hole 11a, 11b, 11b' and the spool 19
It is formed by a bypass communication hole 11c bored in the. ) and a valve mechanism (hereinafter referred to as "control valve mechanism 12") that controls opening and closing of the bypass passage 11. A spool 19 is slidably provided in the control valve mechanism 12, and a pair of pressure chambers consisting of a high pressure chamber 20 and a low pressure chamber 21 are provided at both ends of the spool 19 facing each other. The low pressure chamber 21 is provided so as to communicate with the suction stroke of the compression chamber 6 via a pressure guide hole 23, and the tip of the pressure guide hole 23 is provided so as to open at a position relatively close to the suction hole 10. Further, a spring 22 is interposed in the low pressure chamber 21, and is provided so as to normally bias the spool 19 toward the high pressure chamber 20. In addition, at this time, the high pressure chamber 2
A locking piece 31 is provided on the inner end surface of the plug member 30 that seals the high pressure chamber 20, and more specifically, the locking piece 31 is provided with a locking piece 31 as shown in FIG. By protruding with a thickness smaller than the diameter of the bypass communication hole 11c, even when the end of the spool 19 is in contact with the locking piece 31, the bypass communication hole 11c and the high pressure chamber 20, and by extension, It is configured to ensure communication with the bypass hole 11a. However, if the locking piece 31 is
Instead of protruding from the plug member 30, a groove may be formed on the inner end surface of the plug member 30 so that the bypass communication hole 11c and the high pressure chamber 20 communicate with each other through the groove. The high pressure chamber 20 is the compression chamber 6 of the front side plate 3A.
It is provided so as to communicate with the compression chamber 6, more specifically, the early stage of the compression stroke of the compression chamber 6 (the middle part between the suction stroke and the compression stroke) through the bypass hole 11a that opens on the side, and is bored in the spool 19. The suction chamber is connected to the suction chamber through the bypass communication hole 11c and the bypass holes 11b and 11b' that open toward the suction chamber 9 side of the front side plate 3A in correspondence with the communication groove 11e on the circumferential surface of the spool 19 that is continuous with the bypass communication hole 11c. It is provided so as to communicate with 9. That is, there is a spool 19 on the suction chamber 9 side of the front side plate 3A.
multiple pieces (two pieces in this example) along the sliding direction of
The bypass holes 11b and 11b' are connected to the wall part 1 between them.
1d, and are arranged in parallel. The bypass communication hole 11c bored in the spool 19 is connected to both the bypass holes 11 through the sliding movement of the spool 19.
b, 11b' so as to be able to selectively communicate with them. More specifically, it communicates with the bypass hole 11b that opens toward the high pressure chamber 20 when stopped and started, and during operation, the bypass communication hole 11c is connected by the wall surface 11d formed between the bypass holes 11b and 11b'. It is provided so as to communicate with a bypass hole 11b' which is closed and opens closer to the low pressure chamber 21 during rapid acceleration.

Next, its effect will be explained.

When the compressor is stopped, each part within the compressor, that is, the suction chamber 9, the compression chamber 6, the discharge chamber 13, and the separation chamber 17, are at approximately the same pressure. In addition, in the control valve mechanism 12, the high pressure chamber 20 and the low pressure chamber 21 are in the same pressure state, so that the spool 19 is biased toward the high pressure chamber 20 via the spring 22, as shown in FIG. , the compression chamber 6 and the suction chamber 9 have a bypass hole 11a, a high pressure chamber 20, and a bypass communication hole 11.
c, in a state of communication via the bypass hole 11b.

With each part in the above state, the rotor 5 and each vane 8 can be rotated by transmitting the driving force of the engine to the drive shaft 4 through the connection operation of an electromagnetic clutch (not shown). It will be done.
Through the rotation of each vane 8, the refrigerant gas is sent from the evaporator (not shown) into the suction chamber 9 through the suction pipe through the suction hole 10 and into the compression chamber 6.
sucked inside. The refrigerant gas sucked 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 vanes 8 . And in this way, the compression chamber 6
The refrigerant gas sent inside to its terminal position is discharged through the discharge hole 1.
4. After passing through the discharge chamber 13, the through hole 18, and the separation chamber 17, the discharge pipe is sent out from the discharge port 17' toward the condenser (not shown), but the bypass passage 11 is opened as described above. In other words, the compression chamber 6 and the suction chamber 9 are connected to the bypass hole 11a, the high pressure chamber 20, the bypass communication hole 11c,
By being in communication via the bypass hole 11b, a part of the refrigerant gas sent in the compression chamber 6 toward the terminal end along the rotational direction of the rotor 5 as described above flows into the suction chamber during compression. It flows out to the 9th side.

In this way, a part of the refrigerant gas in the middle of compression flows out to the suction chamber 9 side through the bypass path 11, so that the start-up of the compressor can be performed smoothly and the starting torque can be reduced. A relieving effect can be obtained.

At this time, the pressures (P _H , P _L ) acting on the high pressure chamber 20 and the low pressure chamber 21 change as shown in FIG. 9, and the spool reaches an intermediate position, which will be described later, at the time indicated by the horizontal axis. (Conventionally, the spool is switched as early as the horizontal axis as shown in Fig. 10.) This is because the bypass gas pressure directly acts on the high pressure chamber 20, which increases the wave-like change in P _H , and because the bypass This is thought to be because it takes extra time to reach a certain value as the pressure tries to escape, but this greatly contributes to a better reduction in starting torque than in the past.

By repeating the rotation of the rotor 5 as described above, the compression pressure in the compression chamber 6 is gradually increased.
A part of the compressed gas increased in the high pressure chamber 2
0, the pressure in the high pressure chamber 20 ((compression stroke pressure P _H ) is gradually increased. In this way, the compression stroke pressure P _H is increased, and the same compression stroke pressure P _H In a state where the differential pressure generated between the suction stroke pressure P _L obtained in the low pressure chamber 21 exceeds the set pressure of the spring 22, the spool 19 overcomes the biasing pressure of the spring 22, and the low pressure chamber 2
Pressed in one direction. That is, high pressure chamber 20 and low pressure chamber 2
1 is a bypass communication hole 11 that is balanced in the state shown in FIG. 5 (intermediate position) and is bored in the spool 19.
The effect of closing the wall portion 11d by the wall portion 11d can be obtained. By blocking the bypass passage 11 in this way, a part of the refrigerant gas in the compression chamber 6 does not flow out to the suction chamber 9 side through the bypass passage 11, and all of it is compressed into the discharge hole 14. , the discharge chamber 13, the through hole 18, and the separation chamber 17, and are sent out through the discharge pipe toward the condenser. That is,
100% operational status is obtained.

Furthermore, as the cooling load in the vehicle compartment decreases and the pressure in the suction chamber 9 decreases, the differential pressure between the suction stroke pressure P _L and the compression stroke pressure P _H also decreases. When the pressure difference is lower than the set pressure of the spring 22 installed in the low pressure chamber 21, the pressure difference presses the bypass communication hole 11c toward the wall portion 11d. The spool 19, which has been in a closed state, slides toward the high pressure chamber 20 via the biasing pressure of the spring 22, and the bypass communication hole 11c is closed.
a state in which a part of the is in communication with the bypass hole 11b again,
That is, a part of the refrigerant gas that is being compressed in the compression chamber 6 is released to the suction chamber 9 side, and the compression capacity is reduced, that is, a so-called partial cooling load operating state is obtained. Then, the electromagnetic clutch is disengaged again, resulting in the state shown in FIG. 4, that is, the spool 19
is urged toward the high pressure chamber 20 by the spring 22, and returns to the state where the bypass communication hole 11c and the bypass hole 11b are aligned.

On the other hand, when the compressor is suddenly accelerated during operation, as the engine rotational speed increases, the compressor rotational speed also inevitably increases. As the rotational speed of the compressor increases, the differential pressure generated between the compression stroke pressure P _H in the high pressure chamber 20 and the suction stroke pressure P _L in the low pressure chamber 21 also increases further. As the differential pressure between the two chambers increases in this way, the spool 19 slides further toward the low pressure chamber 21 than in the state shown in FIG. 5, and as shown in FIG.
1c is in communication with the bypass hole 11b', and by establishing the communication state of the bypass path 11 in this way, a part of the refrigerant gas that is being compressed in the compression chamber 6 is transferred to the bypass hole 11a and the high pressure Chamber 20, bypass communication hole 11c, bypass hole 11
An effect of releasing air to the suction chamber 9 side through b' is obtained. In addition, due to the refrigerant gas in the compression chamber 6 being released to the suction chamber 9 side in this way, the compression stroke pressure P _H and the suction stroke pressure
The differential pressure that occurs between P _L will suddenly decrease, but due to this sudden decrease in the differential pressure that occurs between the compression stroke pressure P _H and the suction stroke pressure P _L , the spool 19 will spring. High pressure chamber 2 by 22
0 direction, the bypass communication hole 11c and the bypass hole 11b are brought into communication as shown in FIG. 4, and a part of the refrigerant gas that is being compressed in the compression chamber 6 is bypassed as in the case of startup. Hole 11a, high pressure chamber 20, bypass communication hole 11c, bypass hole 1
The effect of releasing air into the suction chamber 9 through 1b is obtained. While this relief effect is obtained, the high pressure chamber 2
0 will gradually increase, but the pressure difference generated between the compression stroke pressure P _H in the high pressure chamber 20 and the suction stroke pressure P _L in the low pressure chamber 21 exceeds the biasing pressure of the spring 22. In the state,
The spool 19 slides in the direction of the low pressure chamber 21, and as shown in FIG.
1d returns to the closed state, that is, the normal 100% operating state.

Effects of the Invention The present invention is constructed as described above, and includes:
By configuring as described above, it is possible to reduce the start-up torque at the time of start-up, and also to obtain a smooth start-up.

In addition, when the compressor is suddenly accelerated during operation, it is possible to alleviate the shock that occurs due to the sudden increase in the rotation speed of the compressor, and it is also possible to appropriately deal with supercooling. I was able to do it.

[Brief explanation of drawings]

FIG. 1 is a side sectional view (second view) of a compressor according to the present invention.
A-B-C line sectional view in the figure), Figure 2 is the 1st
3 is a sectional view taken along line EE in the figure, FIGS. 4 to 6 are enlarged views showing the operating state of the control valve mechanism, and FIG. 7 is a sectional view showing the conventional structure. Figure 8 is a sectional view of the control valve mechanism part,
9 and 10 are graphs showing the states of pressure changes in the high pressure chamber and the low pressure chamber, respectively. FIG. 9 is related to the present invention, and FIG. 10 is related to the prior art. 1...Housing, 1A...Front housing,
1B...Rear housing, 2...Cylinder block, 3A...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 path, 11a, 11b, 11b'...Bypass hole, 1
1c...Bypass communication hole, 11d...Wall surface portion, 12...
Control valve mechanism, 13...Discharge chamber, 14...Discharge hole, 15
...Discharge valve, 16...Retainer, 17...Separation chamber, 1
7'...Discharge port, 18...Through hole, 19...Spool, 2
0...High pressure chamber, 21...Low pressure chamber, 22...Spring, 23...
Pressure hole.

Claims (1)

[Claims] 1. A high-pressure chamber and a low-pressure chamber are provided facing each other at both ends of a spool that is movably provided in a side plate that separates a compression chamber and a suction chamber, and the low-pressure chamber is communicated with the suction chamber or the suction process of the compression chamber, and A spring is installed in the low-pressure chamber to bias the spool toward the high-pressure chamber, and a bypass hole communicating with the high-pressure chamber is provided in the side plate on the compression chamber side in correspondence with the compression process of the compression chamber. At the same time, a plurality of bypass holes communicating with the suction chamber are provided on the suction chamber side, the opening positions of which are displaced relative to the bypass holes on the compression chamber side, and a bypass communication hole is bored in the spool to communicate with the suction chamber. One end of the hole communicates with the high pressure chamber, and the other end can selectively communicate with the plurality of bypass holes through the sliding of the spool during partial capacity operation, and between the bypass holes during full capacity operation. A variable compression capacity compressor that can be closed by a wall portion formed therein.