JP3381310B2 - Suction plate compressor intake mechanism - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable or fixed capacity swash plate type compressor used for air conditioning of vehicles, and more particularly to a suction mechanism for refrigerant gas. [0002] Conventional swash plate compressors of this type include:
For example, a configuration as shown in JP-A-56-162281 is known. [0003] In this conventional configuration, an intake passage communicating the crank chamber and the compression chamber of the cylinder bore is formed, and the crank chamber and the compression chamber of the cylinder bore communicate with each other when the piston comes near the bottom dead center. It has become.
During the suction stroke of the piston, the refrigerant gas in the suction chamber is guided to the compression chamber via the suction valve in accordance with the suction operation of the piston. Through the compression chamber. [0004] In such a swash plate compressor, the refrigerant gas sucked from the suction chamber receives throttling resistance when passing through the suction valve. Since the lubricating oil in the gas may be difficult to open due to the adhesive force, the suction from the suction chamber is not sufficiently performed. In addition, refrigerant gas leaks during a compression stroke from a minute gap between the piston and the cylinder bore. In order to solve the problem of the decrease in efficiency of the compressor, the intake from the crank chamber to the compression chamber is also performed through the intake passage when the piston passes near the bottom dead center of the piston. However, when the rotation speed of the compressor is high and the refrigerant gas leakage to the crank chamber is small,
Suction from the crank chamber cannot be performed sufficiently, and the temperature inside the crank chamber becomes high due to sliding heat. When the pressure in the crank chamber is not sufficient, the intake is not sufficiently performed. The present invention has been made in view of the problems existing in the prior art described above, and has as its object to provide a communication passage between a crank chamber and a suction chamber so that a piston can move near a bottom dead center. It is an object of the present invention to provide an efficient swash plate compressor in which air is sufficiently sucked from a crank chamber into a compression chamber when the compressor passes. [0006] In order to achieve the above object, the present invention is configured as follows. That is, a plurality of cylinder bores positioned between the crank chamber and the suction chamber and the discharge chamber are arranged around the rotation axis, the pistons are accommodated in the cylinder bores, and are supported on the rotation shaft in the crank chamber. In a swash plate type compressor provided with an intake passage for engaging a piston with a swash plate and communicating the crank chamber with a compression chamber of a cylinder bore when the piston is located near the bottom dead center, between the crank chamber and the suction chamber The communication passage is provided in the. Further, in the present invention, it is effective to provide a check valve in the communication passage that allows only the movement of the refrigerant gas from the suction chamber to the crank chamber. In the swash plate type compressor of the present invention constructed as described above, the refrigerant gas is sucked directly from the suction chamber into the compression chamber of the cylinder bore during the suction stroke of the piston, and the piston is moved near the bottom dead center. When the refrigerant gas is located in the compression chamber, the refrigerant gas is sucked into the compression chamber via the communication passage, the crank chamber, and the intake passage. The refrigerant gas flowing into the cylinder bore via the crank chamber cools the crank chamber and supplies lubricating oil contained in the gas to the sliding contact portion. Further, when the leakage coolant gas from the cylinder bore during the compression stroke is large, the check valve with the boost in the crank chamber closes the communication passage to prevent the backflow of refrigerant gas into the suction chamber. The refrigerant gas leaked into the crank chamber is introduced from the intake passage into the cylinder bore. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment in which the present invention is embodied in a swash plate type variable displacement compressor having a single piston will be described below with reference to FIGS. As shown in FIG. 1, a front housing 2 is joined to a front end of a cylinder block 1 which is a part of a housing of the entire compressor. A rear housing 3 is joined and fixed to the rear end of the cylinder block 1 via a valve plate 4. A bearing 7 is provided in the front housing 2.
A disk-shaped rotary support 8 is supported via the rotary support 8, and a rotary shaft 9 is fixed to the rotary support 8. Rotating shaft 9
Is supported by the cylinder block 1 via a bearing 10. A swash plate support 11 having a spherical shape is slidably supported on the rotating shaft 9, and a swash plate 12 is slidably supported on the swash plate support 11. A connecting piece 13 is fixed to the swash plate 12, and a guide pin 14 is attached to the connecting piece 13.
Is fixed. A support arm 8a protrudes from the rotary support 8, and a support pin 15 is supported by the support arm 8a. The guide pin 14 is slidably fitted into an end of the support pin 15. The swash plate 12 can rotate integrally with the rotating shaft 9 by the cooperation of the support pin 15 and the guide pin 14. A plurality of cylinder bores 1a are provided in the cylinder block 1 so as to be located between the crank chamber 2a and a suction chamber 3a and a discharge chamber 3b which will be described later, and these are arranged around a rotation shaft 9. . A single-headed piston 16 is housed in the cylinder bore 1a. A pair of shoes 17 is fitted into the neck 16a of the single-headed piston 16. The periphery of the swash plate 12 is sandwiched between both shoes 17,
Of the swash plate 12 in the tilted state,
Is converted into a back and forth reciprocating swing of the single-headed piston 16 via
The single-headed piston 16 moves back and forth in the cylinder bore 1a. In the rear housing 3, a suction chamber 3a and a discharge chamber 3b are defined. On the valve plate 4, a suction port 4a having a suction valve 5a and a discharge port 4b having a discharge valve 5b are formed. The refrigerant gas in the suction chamber 3a pushes the suction valve 5a out of the suction port 4a by the operation of the single-headed piston 16 and flows into the cylinder bore 1a. The refrigerant gas flowing into the cylinder bore 1a is discharged from the discharge port 4b to the discharge chamber 3b by pushing the discharge valve 5b away from the discharge port 4b by the reverse operation of the single-headed piston 16. The stroke of the single-headed piston 16 changes according to the pressure in the crank chamber 2a and the suction pressure in the cylinder bore 1a. That is, the inclination angle of the swash plate 12 that affects the compression capacity changes. The pressure in the crank chamber 2a is applied to the rear housing 3
Is controlled by a capacity control valve (not shown) attached to the controller. The crank chamber 2a and the suction chamber 3a are connected by a throttle passage 1b. The displacement control valve has a passage communicating with the discharge chamber 3b, the suction chamber 3a, and the crank chamber 2a. The compressor detects the refrigerant gas pressure (suction pressure) introduced from the suction chamber 3a and guides the required amount of the high-pressure discharge refrigerant gas introduced from the discharge chamber 3b to the crank chamber 2a. The swash plate 12 is installed at an appropriate inclination so that the swash plate 12 is operated. In this manner, the inclination angle of the swash plate 12 is determined by the maximum inclination position at which the swash plate 12 contacts the inclination restriction protrusion 8b and the minimum inclination restriction ring 18 on which the swash plate support 11 is fixed on the rotating shaft 9. It is restricted between the contact position and the minimum inclination position. That is, the discharge capacity is controlled within this inclination range of the swash plate 12. The intake passage 19 provided in the cylinder block 1 has one end opening to the crank chamber 2a and the other end opening to the side wall of the cylinder bore 1a. When the single-headed piston 16 approaches the bottom dead center when the swash plate 12 is at the maximum inclination angle (see FIG. 1), the intake passage 19
And the compression chamber 20 of the cylinder bore 1a. The communication passage 21 formed continuously in the side walls of the front housing 2 and the cylinder block 1 and in the valve plate 4 has one end opened to the crank chamber 2a and the other end opened to the suction chamber 3a. I have. A cylindrical body 22 is inserted near the opening end of the communication passage 21 on the suction chamber side as shown in FIG.
As shown in FIG. 3, the cross section is formed in such a shape that a semicircle is joined to the upper side of a perfect circle into which the cylindrical body 22 just fits. The communication passage 21 has a reduced diameter on the side communicating with the crank chamber in the cylinder block 1, and a spring 24 is interposed between the suction chamber side end surface of the small diameter passage and the inner bottom of the cylindrical body 22. ing. The spring 24 has a natural length and is set such that the bottom of the cylindrical body 22 opens the opening 23 of the valve plate 4. The cylinder 22 and the spring 24 constitute a check valve 25. That is, when the pressure in the suction chamber 3a is higher than the pressure in the crank chamber 2a, the refrigerant gas in the suction chamber 3a moves the cylinder 22 toward the crank chamber 2a against the urging force of the spring 24. The refrigerant gas is supplied to the suction chamber 3a.
From the communication passage 21 through the opening 23 through the cylindrical body 22
After passing through the upper semicircular passage and the small-diameter passage, it flows into the crank chamber 2a. Further, if the pressure in the crank chamber 2a is higher than the pressure in the suction chamber 3a,
Since the refrigerant gas in the cylinder chamber 22a presses the cylindrical body 22 against the spring 24 against the suction chamber opening 23, the refrigerant gas is supplied to the crank chamber 2a.
Cannot flow out to the suction chamber 3a through the communication path 21. In other words, the check valve 25 allows only one-way passage of the refrigerant gas from the suction chamber 3a to the crank chamber 2a in the communication passage 21. Next, the operation of the swash plate type variable displacement compressor configured as described above will be described. When the cooling load is large, the suction pressure increases, and the supply of the discharged refrigerant gas to the crank chamber 2a is cut off by the capacity control valve.
The pressure in a decreases, and the inclination angle of the swash plate 12 increases. Accordingly, the stroke of the single-headed piston 16 is increased, and a large-capacity operation is performed. At this time, with the reciprocating operation of the single-headed piston 16, the refrigerant gas in the suction chamber 3a pushes the suction valve 5a from the suction port 4a and flows into the compression chamber 20.
At the same time, when the single-headed piston 16 reaches the vicinity of the bottom dead center, the intake passage 19 communicates the crank chamber 2a with the compression chamber 20, so that the refrigerant gas in the crank chamber 2a also passes through the intake passage 19 through the compression chamber 20a. Is flowed into. When the single-headed piston 16 moves forward, the compressed refrigerant gas pushes the discharge valve 5 b out of the discharge port 4 b to discharge the discharge chamber 3.
b. When the amount of refrigerant gas leaking from the cylinder 1a during the compression passage is small, the compression chamber 20
The refrigerant gas pressure in the crank chamber 2a is
The refrigerant gas pressure becomes lower than the refrigerant gas pressure in the suction chamber 3a, and the refrigerant gas in the suction chamber 3a moves toward the crank chamber 2a through the communication passage 21. And, the refrigerant gas in the suction chamber 3a is
, The air is supplied to the compression chamber 20 from the crank chamber 2a. FIGS. 4 and 5 are graphs showing a comparison between the swash plate type compressor of this embodiment and a conventional swash plate type compressor. FIG. 4 shows a time change of the refrigerant gas pressure in the compression chamber 20, and FIG. 5 shows a PV diagram in the compression chamber 20. In both graphs, the broken line is that of the conventional swash plate type compressor, and the solid line is This is for the swash plate type compressor of this embodiment. Also, P
s represents the suction pressure, and Pd represents the discharge pressure. In section t in FIG. 4, the single-headed piston 16 passes near the bottom dead center and the intake passage 19 is opened, so that the pressure in the compression chamber 20 of the compressor in this embodiment is equal to the pressure in the conventional compression chamber. Than rises. For this reason, in FIG. 5, the pressure in the compression chamber 20 at the bottom dead center of the piston 16 is higher than that of the conventional compressor by ΔPs, and the compressor is more than the conventional compressor by an area indicated by hatching in the drawing. You're doing extra work. That is, the efficiency of the compressor is increasing. In this embodiment, since the refrigerant gas having a pressure higher than the suction pressure is not guided to the crank chamber 2a through the communication path 21, the crank chamber 2
There is no concern that the intake air to a influences the inclination of the swash plate 12. Further, when the compressor gas is largely leaked from the compression chamber 20 such as when the compressor is operated at a low speed, the cylinder 22 closes the opening 23 of the valve plate 4 as the pressure in the crank chamber 2a increases. This prevents refrigerant gas from flowing out of the crank chamber 2a to the suction chamber 3a. Therefore, the refrigerant gas leaked from the compression chamber 20 to the crank chamber 2 a is again introduced into the compression chamber 20 via the intake passage 19. On the other hand, when the cooling load is small, the suction pressure decreases, and the discharged refrigerant gas is supplied to the crank chamber 2a by the displacement control valve. Therefore, the pressure in the crank chamber 2a increases, and the inclination angle of the swash plate 12 is reduced. Decrease. Therefore, the stroke of the single-headed piston 16 is reduced, and the small-capacity operation is performed.
At this time, even when the piston 16 is near the bottom dead center, the intake passage 19 is not opened, so that intake from the crank chamber 2a to the compression chamber 20 is not performed. At this time, the refrigerant gas pressure in the crank chamber 2a is always higher than the suction pressure.
Since the refrigerant gas in the inside has a function of pressing the cylinder 22 toward the suction chamber in the communication passage 21, there is no fear that the refrigerant gas in the crank chamber 2a flows out to the suction chamber 3a through the communication passage 21. For this reason, small capacity operation of the compressor is performed as usual. In this embodiment, when the compressor operates at a large capacity, the refrigerant gas is supplied from the suction chamber 3a through the communication passage 21 when the refrigerant gas pressure in the crank chamber 2a becomes lower than the suction pressure. The pressure in the chamber 2a is always kept substantially equal to or higher than the suction pressure. Therefore, when the single-headed piston 16 passes near the bottom dead center, the intake from the crank chamber 2a to the compression chamber 20 through the intake passage 19 is sufficiently performed, and the efficiency of the compressor is increased. Further, the suction gas introduced into the crank chamber 2a contributes to cooling and lubrication of sliding portions such as the shoes 17, the swash plate 12, and the like. Further, during the small capacity operation of the compressor, the intake passage 19 is not opened, and the intake from the crank chamber 2a to the compression chamber 20 is not performed. At this time, due to the check valve structure in the communication passage 21, there is no fear that the refrigerant gas in the crank chamber 2a leaks to the suction chamber side through the communication passage 21. In this embodiment, since the efficiency of the compressor is increased as described above, it is not necessary to increase the processing accuracy of the single-headed piston 16 and the cylinder bore 1a in order to increase the efficiency. In this embodiment, the cylinder 22 and the pressing spring 24
Although the check valve 25 of the communication passage 21 is configured by the above, the check valve used in this embodiment is not limited to this configuration. For example, a check valve 26 having a configuration as shown in FIG. 6 may be used. This allows only the movement of the refrigerant gas from the suction chamber 3a to the crank chamber 2a by forming a check valve 26 having the same configuration as the suction valve 5a on the valve plate 4. When the check valve 26 is used, the cross-sectional shape of the communication passage 21 is not limited to the above-described shape, and may be a simple circle. In this embodiment, the compressor may be changed to a single-head piston swash plate fixed displacement compressor. In addition, the throttle passage 1b is provided with a small gap between the single-headed piston 16 and the cylinder bore 1a during the compression stroke, so that the crank chamber 2
In order to prevent the pressure in the crank chamber 2a from excessively increasing due to the refrigerant gas leaking into the crank chamber 2a, it may be provided between the crank chamber 2a and the suction chamber 3a. However, when the check valve is not provided in the communication passage 21 in the fixed displacement compressor, the refrigerant gas escapes from the communication passage 21 to the suction chamber 3a, so that it is not necessary to provide the throttle passage 1b. When the swash plate-type fixed displacement compressor having this configuration is operated, the intake air from the crank chamber 2a to the compression chamber 20 via the intake passage 19 is taken whenever the single-head piston 16 passes near the bottom dead center, and the efficiency of the compressor is reduced. Rises. Also at this time, the refrigerant gas is replenished from the suction chamber 3a to the crank chamber 2a as the pressure in the crank chamber 2a decreases, so that sufficient intake air is always drawn from the crank chamber 2a to the compression chamber 20. The present invention is not limited to the configuration of the above-described embodiment, but may be embodied by arbitrarily changing the configuration of each unit without departing from the spirit of the present invention. For example, the present invention can be used for a variable displacement type and fixed displacement type swash plate type compressor with a double-headed piston, or a wobble type compressor in which a swash plate and a single-headed piston are connected by a rocking plate and a rod. As described in detail above, according to the present invention,
Since the refrigerant gas is sufficiently sucked into the compression chamber, the efficiency is improved, and the performance of the compressor is improved, and the cooling and lubricating ability in the crank chamber is improved, and the reliability of the compressor is also improved. It has excellent effects. Further, by providing a check valve in the intake passage, it is possible to avoid a decrease in efficiency due to the backflow of the refrigerant gas from the crank chamber to the suction chamber, and to improve the efficiency by applying to a variable displacement type. It is possible.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of an entire compressor according to one embodiment of the present invention. FIG. 2 is an enlarged partial cross-sectional view showing a configuration near a suction chamber side opening of a communication passage in the compressor of FIG. FIG. 3 is a partial sectional view taken along line AA of FIG. 2; FIG. 4 is a graph of pressure time response illustrating features of the compressor of the present invention. FIG. 5 is a PV diagram showing characteristics of the compressor of the present invention. FIG. 6 is a partial sectional view showing another example of the check valve used in one embodiment. [Description of References] 2a: crank chamber, 3a: suction chamber, 16: piston, 1
9: intake passage, 20: compression chamber, 21: communication passage, 25, 2
6. Check valve

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hisakazu Kobayashi 2-1-1 Toyota-cho, Kariya-shi, Aichi Pref. Inside the Toyota Industries Corporation (72) Inventor Soyoshi Hibino 2-1-1, Toyota-cho, Kariya-shi, Aichi pref. Toyota Industries Corporation (72) Inventor Akihiro Amano 2-1-1 Toyota-cho, Kariya-shi, Aichi Prefecture Co., Ltd.Tokyo Automatic Loom Works (72) Inventor Takahiro Hamaoka 2-1-1 Toyota-cho, Kariya-shi, Aichi Prefecture Toyota Corporation (56) References JP-A-5-106554 (JP, A) JP-A-56-162281 (JP, A) JP-A-62-674 (JP, A) JP-A-5-296146 (JP) , a) JitsuHiraku Akira 62-148787 (JP, U) JitsuHiraku Akira 53-136605 (JP, U) real public flat 5-40303 (JP, Y2) (58 ) investigated the field (Int.Cl. ^7, DB ) F04B 27/08

Claims (1)

(57) [Claim 1] A plurality of cylinder bores located between a crank chamber, a suction chamber, and a discharge chamber are arranged around a rotation axis, and a piston is housed in the cylinder bore. A swash plate type compression system in which a piston is linked to a swash plate supported on a rotating shaft in a crank chamber, and an intake passage is provided for communicating the crank chamber and a compression chamber of a cylinder bore when the piston is located near bottom dead center. in machine, the communicating passage is provided between the suction chamber and the crank chamber, the communicating
Only transfer of refrigerant gas from suction chamber to crank chamber in passage
A swash plate type compressor provided with a check valve that allows pressure .