JP3083002B2 - Reciprocating compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a reciprocating compressor suitable for use in vehicle air conditioning.

[0002]

2. Description of the Related Art Conventionally, each piston reciprocates in a plurality of bores formed in a cylinder block in parallel with a drive shaft, as in a swash plate compressor described in Japanese Patent Application Laid-Open No. Sho 59-145378, for example. Compressors that compress refrigerant gas are known. In this type of compressor, a drive shaft is fitted and supported in a central shaft hole of a cylinder block, and each piston is linked to a swash plate in a crank chamber that cooperates with the drive shaft to move directly in each bore. A housing is joined to the end surface of the cylinder block via a valve plate, and a suction chamber for supplying refrigerant gas into the bore and a discharge chamber for discharging refrigerant gas compressed by a piston in the bore are formed in the housing. Is formed. The suction of the refrigerant gas from the suction chamber into the bore is performed by moving the piston to the bottom dead center position, and by setting the suction port formed in the valve plate and the pressure in the bore provided on the bore side of the suction port. And a suction valve that opens a suction port in response to the pressure. Further, the discharge of the refrigerant gas from the bore to the discharge chamber is performed by moving the piston to the top dead center position, the discharge port formed in the valve plate, and the discharge port provided on the discharge chamber side of the discharge port inside the bore. This is performed via a discharge valve that opens a discharge port according to pressure.

[0003]

However, in the conventional compressor, the suction valve is configured to overcome its own elastic force acting in the direction of maintaining the valve closed state and to open the valve. Is big. This pressure loss leads to a decrease in volumetric efficiency. Therefore, the present applicant has filed Japanese Patent Application No.
No. 229166 proposes a reciprocating compressor having excellent volumetric efficiency. In this compressor, a conduction path that radially communicates each bore with the central shaft hole is formed, and a rotary valve is coupled to the drive shaft so as to be synchronously rotatable. The rotary valve is formed with a suction passage that sequentially connects the passage of each bore in the suction stroke and the suction chamber.

In the proposed compressor, the rotation valve rotates in synchronization with the drive shaft, so that the refrigerant gas in the suction chamber is sequentially sucked into each bore, and the suction operation of the refrigerant gas in each bore is smooth and stable. The pressure loss is extremely reduced. Thus, this compressor can maintain sufficient volumetric efficiency. However, in this compressor, as shown in FIG. 6, for example, the gas under compression or the residual gas in the piston head causes high pressure in the seal portion facing the passages 2F, 2B, 2A of the respective bores in the compression / discharge process. P is acting. For this reason, the rotary valve 91 slidably rotatable in the central shaft hole 90a includes the bore passages 2F and 2A in the compression stroke and the bore passage 2F in the discharge stroke.
Displaced from the B side to the conduction paths 2C to 2E of the bore in the suction stroke, the gap C for sliding concentrates on the conduction paths 2F, 2B, 2A of the bore in the compression / discharge stroke. Therefore, the gas under compression or the residual gas moves through the gap C into the passages 2C to 2E of the bore in the suction stroke, and from the both end surfaces of the rotary valve 91, the crank chamber or the central shaft hole 90a.
Also moves to the suction chamber communicating with the. Incidentally, reference numeral 91a is a suction passage. For this reason, the power efficiency is reduced, and the already high-temperature gas is recompressed to further increase the temperature, so that the discharge temperature is increased and the performance of the air conditioner is reduced.

An object of the present invention is to maintain sufficient volumetric efficiency, ensure sufficient power efficiency, and suppress an increase in discharge temperature.

[0006]

In order to solve the above-mentioned problems, a reciprocating compressor according to the present invention has a cylinder block having a plurality of bores around an axis, and is inserted into a center shaft hole of the cylinder block. In a reciprocating compressor including a supported drive shaft and a piston linked to a swash plate in a crank chamber cooperating with the drive shaft and moving directly in the bore, each of the bores and the central shaft hole is provided. A radial conduction path is formed between the two, and a rotary valve having a suction path that sequentially connects the conduction path of each bore in the suction stroke and the suction chamber is connected to the drive shaft so as to be synchronously rotatable. In addition, a novel configuration is adopted in which an urging means is interposed between the drive shaft and the rotary valve to urge the rotary valve toward the passage of the bore during the compression / discharge process.

[0007]

In the reciprocating compressor of the present invention, the rotation valve rotates in synchronization with the drive shaft, so that the refrigerant gas in the suction chamber flows through the suction passage of the rotation valve and the passages of the respective bores in the suction stroke. Thus, the suction operation of the refrigerant gas is smoothly and stably continued in each bore, so that the pressure loss is extremely reduced.

At this time, even if a high pressure acts on the seal portion facing the passage of each bore in the compression / discharge process due to the gas being compressed or the residual gas, the rotary valve is interposed between the rotary shaft and the drive shaft. Since the urging means is urged toward the conduction path side of the bore during the compression / discharge stroke, the gap for sliding does not concentrate on the conduction path side of the bore in the compression / discharge stroke. For this reason, the gas under compression or the residual gas moves through the gap into the conduction path of the bore in the suction stroke, or moves from both end faces of the rotary valve to the crank chamber or the suction chamber communicating with the center shaft hole. Is prevented.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments 1 and 2 embodying the present invention will be described below with reference to the drawings. (Embodiment 1) In FIGS. 1 and 2, reference numeral 1 denotes a cylinder block having a central shaft hole 1a penetrating in the axial direction and six bores 1A to 1F. 2 and a rear housing 4 is joined to the other end surface via a ring-shaped valve plate 3. In the crankcase 5 in the front housing 2,
The drive shaft 6 is inserted into the front housing 2 and the center shaft hole 1a of the cylinder block 1 and rotatably supported. A rotor 7 is fixed on the drive shaft 6, and a long hole 8 a penetrates a distal end of a support arm 8 extending to the rear side of the rotor 7. A pin 8b is slidably fitted into the elongated hole 8a, and a swash plate 9 is slidably connected to the pin 8b.

A sleeve 10 is loosely fitted on the drive shaft 6 adjacent to the rear end of the rotor 7 and is always urged toward the rotor 7 by a coil spring 11 and protrudes from the left and right sides of the sleeve 10. A pivot 10a (only one is shown) is fitted into an engagement hole (not shown) of the swash plate 9, and the swash plate 9 is supported so as to be able to swing around the pivot 10a. A rocking plate 12 is supported on the rear side of the swash plate 9 via a thrust bearing or the like.
The rotation of the rocking plate 12 is restricted by a notch (not shown). In addition, six connecting rods 14 are moored at equal intervals on the outer edge of the swing plate 12, and each connecting rod 14 has a bore 1A to 1A.
It is moored with the piston 15 in 1F. Therefore,
The rotational movement of the drive shaft 4 is converted into forward and backward swing of the swing plate 12 by the intervention of the rotor 7 and the swash plate 9, and each piston 15 reciprocates in the bores 1 </ b> A to 1 </ b> F. The stroke of the piston 15 and the tilt angle of the rocking plate 12 are changed in accordance with the pressure difference from the suction pressure. The pressure in the crank chamber 5 is controlled by a control valve (not shown) provided in the rear housing 4 based on the cooling load.

The rear housing 4 is provided with a suction chamber 17 which is opened at the rear end face at the center and communicates with the central shaft hole 1a of the cylinder block 1. A discharge chamber 18 is provided outside the suction chamber 17. Are formed. Valve plate 3
Has a discharge port 3 communicating with the head of each of the bores 1A to 1F.
a, and a retainer 21 is interposed between the discharge port 3a and the discharge chamber 18 via a discharge valve 20.

As shown in FIG. 2, the cylinder block 1 has radially extending conductive paths 2A to 2F between the bores 1A to 1F and the central shaft hole 1a. At the end of the drive shaft 6 extending into the central shaft hole 1a, a columnar rotary valve 22 that slides with the central shaft hole 1a is mounted. The rear side of the rotary valve 22 is provided with a thrust bearing and a disc spring. It is supported on the inner wall of the suction chamber 17 through the inner wall.

As shown in FIG. 3, the rotary valve 22 extends in the axial direction from the center of the axis on the suction chamber 17 side, and has a suction passage 25 formed at an outer peripheral surface thereof and opening at a predetermined angle.
Valve body 23 made of stainless steel and crank chamber 5 of rotary valve body 23
And a connecting member 24 which is press-fitted on the side and fixed by a seat nut on the bottom surface of the suction passage 25. A rectangular parallelepiped coupling concave portion 24a is formed in the coupling member 24, and a rectangular parallelepiped coupling convex portion 6a protruding from the tip of the drive shaft 6 is non-rotatably engaged with the coupling concave portion 24a. . The connecting concave portion 24a and the connecting convex portion 6a are formed with opposing seat surfaces, and a coil spring 26 as an urging member is interposed on these seat surfaces. As shown in FIG. 4, the biasing force F of the coil spring 26 is set at the center of the opening angle of the suction passage 25 in the symmetric direction, and the high pressure acting on the rotary valve 22 due to the gas under compression or the residual gas of the piston head. It is set larger than P.

The compressor configured as described above is disposed in a circuit as a refrigeration system for vehicle air conditioning and is used. When the compressor is operated and the drive shaft 6 shown in FIG. 1 rotates, the swash plate 9 swings while rotating together with the drive shaft 6, and the swing plate 12 is restricted from rotating with respect to the swash plate 9. Performs only a swinging motion, whereby the piston 15 reciprocates in the bores 1A to 1F. When the piston 15 starts moving from the top dead center toward the bottom dead center in the bores 1A to 1F, the bores 1A to 1F enter a suction stroke. When the piston 15 starts moving from the bottom dead center toward the top dead center in the bores 1A to 1F, the bores 1A to 1F enter a compression / discharge stroke.

As shown in FIG. 2, when the rotary valve 22 rotates in the direction of the arrow in synchronization with the drive shaft 6, for example, at the stage shown in FIG. 1E, the conduction paths 2C to 2E communicate with the suction passage 25, and the refrigerant gas in the suction chamber 17 passes through the suction passage 25,
It is sequentially sucked into each of the bores 1C to 1E via the conduction paths 2C to 2E. On the other hand, the bores 1F and 1A in the compression stroke do not communicate with the suction passages 25 in their conduction paths 2F and 2A.
The rotary valve 22 is closed by a sealing portion. At this time, the pressure in the bores 1F and 1A is still lower than the pressure in the discharge chamber 18, and the discharge valve 20 is closed. Also, the bore 1 </ b> B in the discharge stroke has its conduction path 2 </ b> B not communicating with the suction path 25, and is closed by the seal portion of the rotary valve 22. However, at this time, the pressure in the bore 1B becomes higher than the pressure in the discharge chamber 18, and the discharge valve 20 is opened.

Thereafter, when the rotary valve 2 rotates, the bore 1B
Ends the discharge stroke and shifts to the suction stroke, and the bore 1E ends the suction stroke and starts the compression stroke. Thus, each of the bores 1A to 1F sequentially repeats the suction, compression, and discharge strokes via the rotary valve 22 that rotates in synchronization with the reciprocation of the piston 15. At this time, the bores 1A to 1F in the suction stroke are communicated with the suction chamber 17 through the conduction paths 2A to 2F and the suction passage 25, and the suction operation of the refrigerant gas is continued smoothly and stably. Is made very small.

At this time, for example, as shown in FIG. 4, the gas under compression or the residual gas is placed in the seal portion facing the passages 2F, 2A, 2B of the bores 1F, 1A, 1B in the compression / discharge process. Causes a high pressure P to act. However,
The rotary valve 22 is urged by the urging force F of the coil spring 26 toward the center of the opening angle of the suction passage 25 in a symmetrical direction, and since this urging force F is larger than the high pressure P, FP
= F 'is displaced toward the conduction path 2A side of the bore 1A at the end of compression. For this reason, the gap C for the sliding of the rotary valve 22 is equal to the conduction path 2C of each of the bores 1C to 1E in the suction stroke.
~ 2E, each bore 1 in the compression / discharge process
F, 1A, and 1B are provided with rotary valves 2F, 2A, and 2B.
It is suitably sealed by two sealing parts. For this reason, the gas under compression or the residual gas is supplied to the bore 1 in the suction stroke.
It is prevented from moving into the conduction paths 2C to 2E of C to 1E and from moving to the crank chamber 5 or the suction chamber 17 from both end faces of the rotary valve 22.

Therefore, in this compressor, it is possible to prevent a decrease in power efficiency while maintaining sufficient volumetric efficiency, and it is not necessary to recompress already high-temperature gas to further increase the temperature. It is possible to suppress the rise in temperature and maintain the performance of the air conditioner. (Embodiment 2) In this compressor, as shown in FIG. 5, the difference F 'between the urging force F of the coil spring 26 and the high pressure P due to the gas under compression or the residual gas is changed by the rotation of the opening angle of the suction passage 25. It is set slightly ahead of the direction start point. Other configurations are the same as those of the compressor of the first embodiment, and a detailed description thereof will be omitted.

In this compressor, strictly speaking, for example, the conduction path 2B of the bore 1B in the discharge stroke presses the rotary valve 22 with the discharge pressure, and the conduction paths 2F, 2A of the bores 1F and 1A in the compression stroke compress. Since the rotary valve 22 is pressed by the pressure and the discharge pressure is higher than the compression pressure, the high pressure P is directed to the conduction path 2B. Even in such a case, in this compressor, since the rotary valve 22 is displaced to the conduction path 2B side of the bore 1B during the discharge stroke by the force F ', the bore in which the leakage is most required to be prevented by the discharge stroke is required. The conduction path 2B of 1B is suitably sealed. For this reason, with this compressor, it is possible to further prevent a decrease in power efficiency as compared with the compressor of Embodiment 1, and to suppress an increase in discharge temperature.

[0020]

As described in detail above, the reciprocating compressor of the present invention employs the configuration described in the claims, so that the power efficiency can be reduced while maintaining sufficient volumetric efficiency. Since it is possible to prevent the temperature of the air-conditioning system from being increased by preventing the already high-temperature gas from being recompressed, it is possible to suppress the rise in the discharge temperature and maintain the performance of the air conditioner.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a compressor according to a first embodiment.

FIG. 2 is a cross-sectional view of the compressor according to the first embodiment.

FIG. 3 is a cross-sectional view of a rotary valve according to the compressor of the first embodiment.

FIG. 4 is a schematic diagram showing a relationship between a rotary valve and a conduction path in the compressor according to the first embodiment.

FIG. 5 is a schematic diagram showing a relationship between a rotary valve and a conduction path in the compressor according to the second embodiment.

FIG. 6 is a schematic diagram showing a relationship between a rotary valve and a conduction path in the compressor of the previous proposal.

[Explanation of symbols]

1: Cylinder block 1a: Central shaft hole 1A
~ 1F ... Bore 3 ... Valve plate 4 ... Rear housing 6 ...
Drive shaft 5 ... Crank chamber 9 ... Swash plate 15
... Piston 17 ... Suction chamber 18 ... Discharge chamber 2A
２2F: conduction path 22: rotary valve 25: suction path 26
... Coil spring

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F04B 27/08

Claims (1)

(57) [Claims] 1. A cylinder block having a plurality of bores around an axis, a drive shaft fitted and supported in a central shaft hole of the cylinder block, and a swash plate in a crank chamber cooperating with the drive shaft. A reciprocating compressor having a piston that moves linearly in the bore, wherein a radial conduction path connecting the bore and the central shaft hole is formed between the bore and the central shaft hole. A rotary valve having a suction passage for sequentially connecting a passage of each bore and a suction chamber in a suction stroke is coupled to be rotatable synchronously, and the rotary valve is compressed and discharged between the drive shaft and the rotary valve. A reciprocating compressor comprising an urging means for urging the bore during the stroke toward the side of the conduction path.