JPH05296146A - Inlet control mechanism for swash plate type compressor - Google Patents

Abstract

PURPOSE:To attain epoch-making inlet control by omitting an inlet valve body, and utilizing the own movement of a piston for the opening/closing of a port. CONSTITUTION:A cylinder block 1 is formed being provided with a swash plate combined inlet chamber 8 enclosing swash plates moving jointly with a driving shaft, and plural bores 11 disposed at equal spaces surrounding the driving shaft; and pistons 12 moored to the swash plates are direct-acting in the respective bores 11. An inlet port 30 is formed between the respective bores 11 so as to be opened/closed by the sliding interface of the piston 12 and communicate the inlet chamber conductive parts of the adjacent bores 11, placed in the relation of following a compression chamber during the effective admission stroke, with the compression chamber, at time intervals. Inlet control of higher reliability can be thereby performed in addition to omitting an inlet reed valve.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a swash plate compressor mainly used for air conditioning of a vehicle, and more particularly to improvement of a suction control mechanism in a swash plate compressor equipped with a single-headed or double-headed piston. ..

[0002]

2. Description of the Related Art Generally, in the above swash plate type compressor, the outer end of a cylinder block having a plurality of bores is closed by a housing (cylinder head) via a suction lead valve and a valve plate and is internally provided in the housing. The suction lead valve opens and closes the discharge port on the valve plate by the pressure difference between the suction chamber pressure and the bore (compression chamber) pressure.

That is, FIG. 2 illustrates a general-purpose double-headed swash plate type compressor, in which both ends of cylinder blocks 1 and 2 arranged in front and back are provided with front and rear valve plates 3 and 4, respectively. Are closed by front and rear housings 5 and 6, and these are joined by a plurality of bolts 7 inserted into the bolt insertion holes 1a and 2a. A swash plate chamber 8 is formed in the connecting portion of the cylinder blocks 1 and 2, and a rotary swash plate 10 fixed to a drive shaft 9 penetrating the central shaft holes 1b and 2b of the cylinder blocks 1 and 2 is housed therein. ing. The cylinder blocks 1 and 2 have a plurality of pairs of bores 1.
1 surrounds the drive shaft 9 and is equally divided. A double-headed piston 12 is fitted into each bore 11, and each piston 12 is anchored to the rotary swash plate 10 via a hemispherical shoe 13. ing.

The front and rear housings 5 and 6
The suction chambers 14 and 15 are formed on the center side of each of them, and the discharge chambers 16 and 17 are formed on the outer peripheral side thereof. In addition, the front and rear valve plates 3 and 4 have suction holes 18 for sucking low-pressure refrigerant gas into the respective bores 11 from the suction chambers 14 and 15, respectively.
19 and discharge holes 20 and 21 for discharging the compressed high-pressure refrigerant gas into the discharge chambers 16 and 17 from each bore 11. Further, suction lead valves 22 and 23 are provided on the cylinder blocks 1 and 2 of the valve plates 3 and 4,
The discharge lead valve 2 is provided on the housing 5, 6 side of the valve plates 3, 4.
4 and 25 are interposed.

The flange attached to the rear cylinder block 2 is provided with a suction port (not shown) that opens into the swash plate chamber 8. The swash plate chamber 8 is located between the bores 11 of both cylinder blocks 1 and 2. And a plurality of suction passages 28 and 29 that communicate with the discharge chambers 14 and 15 are formed. The refrigerant gas sucked into the swash plate chamber 8 from the suction port passes through the suction passages 28 and 29, It is configured to be installed in 15.

[0006]

As described above, the conventional swash plate type compressor utilizes the bending of the suction lead valve interposed between the cylinder block and the valve plate to utilize the refrigerant gas in the bore. However, such a suction lead valve is liable to cause fatigue deterioration due to severe cyclic deformation. Such a problem is being sought for some time. Also, too much emphasis is placed on the rigidity of the valve body,
If this is attempted to be solved by increasing the thickness, on the contrary, there is a problem that the suction delay becomes large and the power loss is further promoted.

An object of the present invention is to provide a revolutionary suction control mechanism in which the suction valve body is completely omitted and the movement of the piston itself is used for opening and closing the port.

[0008]

In order to solve the above problems, the present invention provides a swash plate chamber / suction chamber that houses a rotary swash plate that cooperates with a drive shaft, and a plurality of equally spaced swash plate chambers surrounding the drive shaft. And a piston that is moored to the rotating swash plate and moves linearly in each bore.The space between the bores is opened / closed by the sliding interface of the piston, and is in the effective suction stroke. A novel technical means is adopted in which a suction port is formed to temporally communicate the compression chamber and the suction chamber conducting portion of the adjacent bore in a tracking relationship.

[0009]

In the swash plate type compressor according to the present invention, the top of the compression chamber where the suction is substantially started and the suction chamber connecting portion of the adjacent bore which is in a relationship of being tracked based on the rotation of the rotary swash plate are provided. It is connected by the suction port formed between the bores,
In particular, the opening position on the suction chamber conducting portion side is set beforehand so as to match the stroke trajectory of the piston sliding interface. Therefore, each compression chamber is communicated with the suction chamber (swash plate chamber) through the suction port only during the effective suction stroke, and is sucked by at least one piston sliding interface involved in the suction port during the other operation strokes. Communication with the room is cut off. That is, since the suction port formed between the bores is opened and closed accurately based on the periodic movement of the piston sliding interface, in addition to the omission of the suction lead valve, which has been regarded as a problem, it is more reliable. High inhalation control can be steadily performed.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional explanatory view in which a four-cylinder compressor is developed around a bore, and a relative operation relationship between a specific bore in the center and both bores adjacent to the bore is depicted. The compressor of the present invention also has a function as a suction chamber in which the swash plate chamber is directly connected to the suction port. In addition to the suction valve mechanism, the suction chamber and the swash plate chamber provided in the housing communicate with each other. Although the structure of the suction system is slightly different, such as the removal of the suction passage, the basic elements of the swash plate compressor are not different from the conventional one, so the same symbols are attached to the equivalent elements. Therefore, detailed illustration and description of the configuration not directly related to the present invention will be omitted.

In the figure, 1 is a cylinder block, 3 is a valve plate having a discharge hole 20, 8 is a suction chamber which also serves as a swash plate chamber, 11a is a specific bore which serves as a reference for explanation, 11
b and 11c indicate bores adjacent to them, and 12a and 12c
Similarly, b and 12c indicate pistons that directly move in the bores 11a, 11b and 11c. A suction port 30 that opens and closes between the bores of the cylinder block 1 by a sliding interface of the piston and that communicates with a compression chamber in an effective suction stroke and a suction chamber conducting portion of an adjacent bore in a tracking relationship with each other in a timely manner. Are formed.

Now, FIGS. 1A to 1D show the specific bore 1.
1A is a step-by-step transition of the operation stroke. In (A), the piston 12a in the specific bore 11a occupies the top dead center position, and based on the rotation direction of the rotating swash plate indicated by the arrow S, FIG. , A suction stroke in which the piston 12b is moving downward in the preceding adjacent bore 11b on the right side of the drawing, and a compression in which the piston 12c is moving upward in the adjacent bore 11c on the left side in the drawing which is also tracking,
It means that it is in the discharge process. That is, at this point, both openings 30a and 30b of the suction port 30 formed between the bores 11a and 11c are closed by the sliding interfaces of the pistons 12c and 12a, and the suction port 30 is in a non-communication state. It has been.

From this state, when the piston 12a starts moving downward and the refrigerant gas remaining in the top clearance is re-expanded (B), the opening 30a located at the suction conduction portion of the bore 11c is further moved to the piston 12c. Although it is opened by the upward movement, the opening 30b located in the compression chamber of the bore 11a is still closed in a form that matches the top end of the piston 12a.

During this effective suction stroke, in which the piston 12a continues further downward movement from this state to the bottom dead center position (C),
By opening both openings 30a and 30b, the suction port 30 is completely opened, and the low-pressure refrigerant gas in the suction chamber 8 is discharged into the bore 11
It is sucked into the compression chamber of the bore 11a from the suction chamber conducting portion of c via the suction port 30. It should be noted that the opening 30a located at the suction chamber conducting portion of the bore 11c is closed by the sliding interface of the piston 12c that is moved downward in a time period when the piston 12a reaches the bottom dead center position.

Therefore, during the compression and discharge strokes in which the piston 12a which has turned upward from this state reaches the top dead center, the sliding interface of the piston 12c closes the opening 30a, that is, the suction chamber 8 and the suction port 30 are shut off. The state is firmly maintained, and the upward movement of the sliding interface of the piston 12a closes the opening 30b (D). The compression chamber after the time point (D) is further blocked from communicating with the suction port 30 itself, and the discharge is completed again (A). Return to the state of. The compressed high-pressure refrigerant gas is discharged from the discharge hole 20 via the discharge valve mechanism, and is discharged to the known refrigeration circuit via the discharge chamber and the discharge flange as in the conventional case.

As described above, in the suction control mechanism of the compressor of the present invention, the suction port that connects the compression chamber of each bore and the suction chamber conducting portion of the adjacent bore that is in a tracking relationship accurately opens and closes through the periodic movement of the piston. Since each compression chamber is allowed to communicate with the suction chamber only during the effective suction stroke, extremely high precision suction control can be performed. In the above-mentioned embodiment, the opening position of the suction port in the compression chamber is provided in consideration of the re-expansion of the residual refrigerant gas. However, the design is such that the opening directly communicates with the top clearance. However, this does not hinder the practice of the present invention.

[0017]

As described above in detail, according to the present invention, the suction chamber connecting portions of the adjacent bores which are opened and closed by the sliding interface of the piston between the bores and have the tracking relationship with the compression chamber during the effective suction stroke are provided. Since the suction port that communicates with each other in a timed manner is formed, the following excellent effects are exhibited. (1) Since there is no fear of fatigue deterioration as seen in the suction reed valve, the durability and reliability of the compressor are improved. (2) Since the suction start timing is mechanically set based on the operating position of the piston, the problem of power loss due to suction delay can be solved. (3) In addition to the omission of an independent suction valve body, the suction chamber provided inside the housing and the suction passage connecting the suction chamber and the swash plate chamber are all unnecessary, which simplifies the machine body and reduces manufacturing costs. Can be significantly reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional explanatory view in which a compressor according to an embodiment of the present invention is developed around a bore, and FIGS. 1A to 1D show a suction control state during one cycle stepwise.

FIG. 2 is a sectional view showing a conventional swash plate compressor.

[Explanation of symbols]

1 is a cylinder block, 3 is a valve plate, 8 is a suction chamber (swash plate chamber), 11a, 11b and 11c are bores, 12a and 12
b and 12c are pistons, 30 is an intake port, 30a, 3
0b is an opening

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshiyuki Nakajima 2-chome, Toyota-cho, Kariya city, Aichi Stock company Toyota Industries Corp.

Claims (1)

[Claims] 1. A cylinder block having a swash plate chamber and a suction chamber for accommodating a rotary swash plate cooperating with a drive shaft, and a plurality of equally spaced bores surrounding the drive shaft, and the rotary swash plate. A piston which is moored to each of the bores and moves linearly in each of the bores, and between the bores is opened and closed by a sliding interface of the pistons, and the suction chambers of adjacent bores are in a tracking relationship with the compression chamber during the effective suction stroke. And a suction control mechanism for a swash plate compressor in which a suction port that communicates with the section in a timely manner is formed.