JPH05164044A - Refrigerant gas suction guide structure in piston type compressor - Google Patents

Abstract

PURPOSE:To reduce loss of motive power by way of restraining abnormal pressure failure in a cylinder bore as well as restraining suction pulsation of refrigerant gas to an actuation chamber in the cylinder bore from a suction chamber at the time of rotation of a rotary valve. CONSTITUTION:A valve storage chamber 25 is formed in a central hole 1b of a cylinder block 1, and a rotary valve 26 to be rotated by a rotational axis is provided in this valve storage chamber 25. Additionally, in this rotary valve 26, a suction passage 28 capable of communicating a suction chamber and a suction communication passage 1c provided on the cylinder block 1 through to each other and a suction guide groove 29 are formed. Furthermore, at a suction process early stage, advancing edge surface 31 positioned on the advancing side of the suction guide groove 29 in the valve rotational direction is adjusted in timing so as to correspond with the suction communication passage 1c later than the point of time when compression residual gas in an actuation chamber 30 finishes re-expansion. Additionally, a cutoff passage 33 to allow inflow and outflow of a small amount of gas by approaching the advancing side surface 31 against the outer peripheral surface of the rotary valve 26 is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerant gas guide mechanism in a piston type compressor.

[0002]

2. Description of the Related Art Generally, a swing type swash plate type piston compressor forms a crank chamber by joining a cylinder block having a plurality of cylinder bores for accommodating pistons in parallel with each other and a front end surface of the cylinder block. A front housing and a rear housing that is joined to the rear end surface of the cylinder block to define an intake chamber and a discharge chamber are provided, and the crankshaft is provided in the crank chamber by rotation of a rotation shaft supported by the center hole of the cylinder block and the front housing. By reciprocating the piston in the cylinder bore through a drive mechanism having a swing swash plate, the refrigerant gas sucked from the suction chamber is compressed and discharged to the discharge chamber. More specifically, between the cylinder block and the rear housing, a valve plate penetrating the suction hole and the discharge hole, a suction plate having a suction valve for opening and closing the suction hole, and opening and closing the discharge hole are provided. A discharge plate having a discharge valve that operates is interposed. And
When the piston is in the suction stroke, the suction valve of the suction plate is opened, and the refrigerant gas in the suction chamber is sucked from the suction hole of the valve plate into the working chamber for suction and compression in the cylinder bore, and when the piston enters the compression stroke, When the suction valve closes the suction hole and the pressure in the working chamber becomes equal to or higher than a predetermined pressure, the discharge valve of the discharge plate opens and the compressed refrigerant gas in the working chamber is discharged to the discharge chamber from the discharge hole of the valve plate.

[0003]

In the above piston type compressor, the lubricating oil is mixed in the refrigerant gas, and this oil adheres to the clearance between the flat plate-shaped intake valve and the valve plate. When the suction valve elastically deforms against its own elasticity to open the suction hole at the beginning of the suction stroke, the suction force of the oil makes it difficult for the suction valve to separate from the contact surface of the valve plate, and the suction operation is performed. And the suction pressure of the working chamber in the cylinder bore decreases more than necessary, resulting in power loss of the compressor.

In order to solve the above problems, the applicant of the present application has proposed a novel compressor refrigerant gas suction mechanism different from the prior art. In this suction mechanism, a valve accommodating chamber communicating with the suction chamber is provided in the center of the cylinder block and the rear housing, and the valve accommodating chamber and the working chamber in each of the cylinder bores are formed in the cylinder block. A rotary valve that communicates with each other through a communication passage and that is rotated in synchronization with the reciprocating motion of the piston is stored in the valve storage chamber, and a suction passage that is in constant communication with the suction chamber is formed in the center of the rotary valve. At the same time, an outer peripheral surface of the rotary valve is provided with a suction guide groove in the circumferential direction that communicates with the suction communication passage only during the suction stroke and that communicates with the suction passage.

Therefore, when the piston is in the suction stroke due to the rotation of the rotary shaft, the refrigerant gas is sucked into the working chamber from the suction chamber through the gas suction passage of the rotary valve, the suction guide groove and the suction communication passage formed in the cylinder block. Because
The suction operation of the refrigerant gas is smoothly performed, and it is possible to eliminate the decrease in the responsiveness of the operation of the flat plate-shaped suction valve and the power loss described above.

The rotary valve type suction guide mechanism has a top clearance in the working chamber in the cylinder bore when the piston is at the top dead center in the cylinder bore.
At the initial stage of the piston starting the suction stroke from the top dead center, the compressed gas remaining in the working chamber re-expands and flows back to the suction guide groove side of the rotary valve, causing a power loss. In order to prevent this, at the beginning of the suction operation in which the piston retracts from the top dead center, as shown by the chain double-dashed line in FIG. 4, so that the suction communication passage does not communicate with the suction guide groove of the rotary valve, When the re-expansion of the residual gas in the working chamber is completed P, the valve opening timing is delayed by a predetermined angle α so that the suction guide groove communicates with the suction communication passage to start the suction operation.

However, in the suction guide mechanism having such a structure, the re-expansion end time point P of the residual gas varies depending on the operating condition of the compressor, so that the re-expansion end time point lags behind the valve opening time point. , The reverse flow of gas from the working chamber to the suction communication passage causes power loss, and conversely,
When the end of re-expansion comes earlier than the valve opening time, the guide groove of the rotary valve and the suction communication passage are rapidly communicated with each other in a state where the working chamber has a negative pressure. The new inflow created a new problem of large inhalation pulsation.

An object of the present invention is to provide a refrigerant gas suction guide mechanism in a piston type compressor which can suppress suction pulsation by a rotary valve in a suction stroke and reduce power loss.

[0009]

In order to achieve the above object, the present invention provides a piston type compressor in which a housing and / or a cylinder block forming a suction chamber is provided with a valve accommodating chamber communicating with the suction chamber. , The valve accommodating chamber and the cylinder bores accommodating the piston are respectively communicated by a suction communication passage, and the valve accommodating chamber accommodates a rotary valve that is rotated in synchronization with the reciprocating motion of the piston. A suction guide groove is formed in the circumferential direction, which can communicate with a suction communication passage that communicates with the working chamber in the cylinder bore during the suction stroke, and the suction passage that constantly communicates the suction chamber and the suction guide groove inside the rotary valve. And the compressed gas remaining in the top clearance in the cylinder bore is delayed from the time when the re-expansion is completed, Timing adjustment is performed so that the leading end surface of the inlet guide groove, which is located on the leading side in the rotary valve rotation direction, corresponds to the gas suction communication passage, and the rotary valve outer peripheral surface near the leading end surface of the gas suction guide groove or the suction communication passage On the outer peripheral surface of the valve accommodating chamber, a cutout passage for allowing a small amount of gas inflow and outflow is provided from the end of re-expansion of the residual compressed gas until the preceding end face corresponds to the suction communication passage. ..

[0010]

According to the present invention, in the intake stroke of the compressor, when the re-expansion end timing of the residual gas in the working chamber in the cylinder bore is later than the intake start timing of the rotary valve by the notch passage, the residual gas is sucked by the notch passage. Although it flows back from the communication passage to the suction guide groove side of the rotary valve, the amount of this gas is small, so no power loss occurs.

Further, when the actual re-expansion timing of the residual gas is earlier than the suction start timing of the rotary valve, that is, the timing when the suction guide groove and the suction communication passage start communicating with each other via the notch passage. , While the working chamber in the cylinder bore is not in communication with the suction guide groove, the working chamber has a slight negative pressure, but immediately after that, the working chamber and the suction guide groove communicate with each other by the notch passage, so the pressure in the working chamber becomes excessive. When the leading end surface of the suction guide groove of the rotary valve passes through the suction communication passage and the suction guide groove and the suction communication passage are communicated with each other, the gas from the rotary valve suddenly decreases. Inhalation is not performed to a different working chamber, and thus the suction pulsation is suppressed.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is embodied in a swing swash plate type variable displacement compressor will be described below with reference to FIGS.

A front housing 2 is joined and fixed to the front end surface of the cylinder block 1, and a crank chamber 3 as a drive chamber is formed inside the front housing 2. A rear housing 4 is provided on the rear end surface of the cylinder block 1.
Are joined and fixed via a valve plate 5, a discharge plate 6 and a retainer plate 7. A partition wall 4a formed inside the rear housing 4 defines a suction chamber 8 at the center and a discharge chamber 9 at the outer peripheral side. Further, a discharge hole 5a is formed in the valve plate 5, a discharge valve 6a is formed in the discharge plate 6 so as to correspond to the discharge hole 5a, and an open position of the discharge valve 6a is regulated in the retainer plate 7. A retainer 7a is formed.

On the cylinder block 1 and the front housing 2, a rotary shaft 10 has radial bearings 11, 1.
It is rotatably supported by an external power source via 2.
A rotary support 13 is fitted and fixed on the rotary shaft 10 so as to be located in the crank chamber 3. A thrust bearing 14 is interposed between the rotary support 13 and the front housing 2. Further, the rotary support 1
A long hole 13b is formed in the arm portion 13a protruding from the outer periphery of the rotary shaft 3, and a rotary swash plate 16 is connected to the long hole 13b via a connecting pin 15 so as to be tiltable in the front-rear direction. A swing swash plate 17 is rotatably supported by a boss portion 16a of the rotary swash plate 16, and a pin 19 is attached to a sleeve 18 reciprocally fitted on the rotary shaft 10 by a pin 19.
The boss portion 16a is rotatably connected. Further, the swing swash plate 17 is prevented from rotating by a guide rod 20 penetratingly fixed to the cylinder block 1 and the front housing 2, and is allowed to tilt in the front-rear direction.
In this embodiment, the drive mechanism K is constituted by the rotary support 13, the rotary swash plate 16, the swing swash plate 17, the piston rod 22, and the like.
Are configured.

Pistons 21 are housed in cylinder bores 1a formed at a plurality of positions (five in this embodiment) in parallel with the rotary shaft 10 with respect to the cylinder block 1, and each piston 21 has a piston rod 22 interposed therebetween. Are connected to the swing swash plate 17, respectively. A spring bearing 23 is mounted on the rotary shaft 10, and a coiled spring 24 is interposed between the spring bearing 23 and the sleeve 18, and the tilt angle of the swing swash plate 17 is constantly increased. It is urged to increase the compression capacity.

By the central hole 1b of the cylinder block 1, the central hole 5b of the valve plate 5, the central hole 6b of the discharge plate 6, the central hole 7b of the retainer plate 7, and the inner peripheral surface 4b of the partition wall 4a of the rear housing 4, A cylindrical valve accommodating chamber 25 that communicates with the suction chamber 8 is formed. The valve accommodating chamber 25 and each of the cylinder bores 1a are communicated with each other through a plurality of suction communication passages 1c formed in the cylinder block 1. A cylindrical rotary valve 26 for sucking a refrigerant gas is rotatably housed in the valve housing chamber 25. Then, the engaging convex portion 10a formed on the rear end surface of the rotary shaft 10 is fitted into the engaging hole 26a formed on the front end surface of the rotary valve 26, and is connected to the rotary shaft 10 by the key 27 so as to be synchronously rotatable. There is. Further, the rear end surface of the rotary valve 26 is regulated by the step portion 4c formed on the inner peripheral surface of the partition wall 4a so as not to move rearward.

A suction passage 28 communicating with the suction chamber 8 is formed at the center of the rotary valve 26, and an outer end surface of the rotary valve 26 is constantly communicated with an inner end portion of the suction passage 28.
A suction guide groove 29 is formed which can communicate with the suction communication passage 1c only during the suction stroke.

Then, the rotary shaft 10 is rotated, the swing swash plate 17 is swung back and forth through the rotary support 13, the connecting pin 15, and the rotary swash plate 16, and a plurality of piston rods 22 are used. When the piston 21 is sequentially reciprocated at different timings, the rotary valve 26 is rotated by the rotary shaft 10, and when the piston 21 shifts to the intake stroke, the leading side in the valve rotation direction (see arrow) in FIG. The leading end surface 31 of the intake guide groove 29 located at the position passes through in the direction of opening the intake communication passage 1c provided in the cylinder block 1, and as a result, the intake valve 8 is removed from the rotary valve 2
6, the suction passage 28, the suction guide groove 29, and the suction communication passage 1c
Through this, the refrigerant gas is drawn into the working chamber 30 in the cylinder bore 1a. Further, at the end of the suction stroke, the trailing end surface 32 of the suction guide groove 29 located on the trailing side with respect to the valve rotation direction passes in the direction of closing the suction communication passage 1c and the refrigerant into the working chamber 30 in the cylinder bore. Inhalation of gas is stopped. Further, when the rotary shaft 10 and the rotary valve 26 are rotated and the piston 21 is moved to the discharge stroke, the outer peripheral surface of the rotary valve 26 causes the suction communication passage 1c.
The refrigerant gas compressed in the working chamber 30 is discharged to the discharge chamber 9 from the discharge hole 5a formed in the valve plate 5 by opening the discharge valve 6a.

Although not shown, the rear housing 4 is provided with an opening / closing control valve for opening / closing a communication passage connecting the discharge chamber 9 and the crank chamber 3, and an opening / closing control valve for opening / closing a communication passage connecting the crank chamber 3 and the suction chamber 8. A moment in the front-rear direction acting on the swing swash plate 17 via the piston rod 22 is provided by adjusting the pressure difference between the pressure in the crank chamber 3 and the pressure in the suction chamber 8 acting on both front and rear surfaces of the piston 21. Is adjusted to change the inclination angle of the swing swash plate 17 about the connecting pin 15 to change the pinton stroke and control the compression capacity.

Next, the essential part of the present invention will be described.
As shown in FIGS. 3 and 4, in the suction stroke of the compressor, the piston 21 descends from the top dead center and the compressed gas remaining in the top clearance of the working chamber 30 in the cylinder bore 1a is more predetermined than the reexpansion end point P. Delayed by angle θ,
The leading end surface 31 of the gas suction guide groove 29 corresponds to the gas suction communication passage 1c and the suction guide groove 29 and the suction communication passage 1 respectively.
The timing is adjusted so that it can communicate with c.

Further, the leading end face 3 of the gas suction guide groove 29.
A cutout passage 33 that allows only a small amount of gas to flow in and out is provided within the range of the angle θ with respect to the outer peripheral surface of the rotary valve 26 near 1. The notch passage 33 is designed so that the passage area decreases from the leading end surface 31 toward the tip.

Therefore, in the intake stroke of the compressor, when the re-expansion end point P of the residual gas in the cylinder bore working chamber 30 is later than the intake start timing by the cutout passage 33 of the rotary valve 26, the cutout passage 33 causes The residual gas flows backward from the suction communication passage 1c to the suction guide groove 29 side of the rotary valve 26, but since the amount of this gas is small,
Power loss is slight and not a problem.

Further, the actual end point P of re-expansion of the residual gas is earlier than the start point of intake of the rotary valve 26, that is, the start point of communication between the intake guide groove 29 and the intake communication passage 1c via the cutout passage 33. In that case, the working pressure in the working chamber 30 becomes a little negative in a short time when the working chamber 30 in the cylinder bore is not communicated with the suction guiding groove 29, but immediately after that, the working chamber 30 and the suction guiding groove 29 are separated by the notch passage 33. Are prevented from being communicated with each other and the pressure in the working chamber 30 is suppressed from decreasing. Therefore, the leading end face 3 of the suction guide groove 29 of the rotary valve 26 is suppressed.
When the main suction operation is started in correspondence with the suction communication passage 1c, the rapid suction of gas from the suction guide groove 29 into the working chamber 30 is not performed, and thus the suction pulsation is suppressed. ..

FIG. 5 shows a cycle diagram during the suction / compression operation in which the horizontal axis represents the volume of the cylinder bore working chamber 30 and the vertical axis represents the pressure of the working chamber 30. As is clear from this figure, in the conventional example indicated by the chain double-dashed line, when the actual residual gas expansion end point P is early and the rotary valve 26 is opened much later than that, the total area in the cycle is It is clear that the power loss is increased. On the other hand, in this embodiment, as shown by the solid line in FIG. 5, a large pressure drop does not occur in the early stage of the intake stroke, so that the total area in the cycle is reduced and the power loss is suppressed.

The present invention is not limited to the above-mentioned embodiment, but can be embodied as follows. (1) As shown in FIG. 6, a cutout passage 33 having the same width is formed from the tip to the outer peripheral surface of the rotary valve 26 from the leading end of the intake gas guide groove
Form so that it becomes deeper as you go to 8.

(2) As shown in FIG. 7, a cutout passage 34 is provided on the cylinder block side. (3) The valve housing chamber 25 is formed only on the cylinder block 1 side or the rear housing 4 side.

(4) In addition to the swing swash plate type variable displacement compressor,
For example, embodying a capacity-invariant swash plate type piston compressor.

[0028]

As described above in detail, the present invention can suppress the suction pulsation of the refrigerant gas from the suction chamber to the working chamber in the cylinder bore during the rotation of the rotary valve, and at the same time, reduce the abnormal pressure in the cylinder bore. There is an effect that power loss can be suppressed by suppressing the above.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment in which the present invention is embodied in a swing swash plate type variable displacement compressor.

FIG. 2 is a perspective view of a rotary valve.

FIG. 3 is a cross-sectional view showing a housed state of a rotary valve.

FIG. 4 is a graph showing the relationship between the rotation angle of the rotary valve, the pressure in the working chamber, and the valve opening.

FIG. 5 is a cycle diagram showing the relationship between the volume inside the working chamber and the pressure inside the working chamber.

FIG. 6 is a perspective view of a rotary valve showing another embodiment of the present invention.

FIG. 7 is a cross-sectional view showing a rotary valve assembling structure showing another embodiment of the present invention.

[Explanation of symbols]

1 cylinder block, 1a cylinder bore, 1c intake communication passage, 2 front housing, 3 crank chamber,
4 rear housing, 4a partition wall, 5 valve plate, 8 suction chamber, 9 discharge chamber, 10 rotary shaft, 13 rotary support, 16 rotary swash plate, 17 swing swash plate, 21 piston, 25 valve accommodating chamber, 26 rotary valve Two
8 suction passage, 29 suction guide groove, 30 working chamber, 3
1, 32 The leading end face and the trailing end face of the suction guide groove 29 located on the leading side and the trailing side in the rotation direction of the rotary valve, 3
3,34 Notch passage, K drive mechanism.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Chuichi Kawamura 2-1-1 Toyota-cho, Kariya City, Aichi Stock Company Toyota Industries Corp.

Claims (1)

[Claims] 1. A cylinder block having a plurality of cylinder bores for accommodating pistons formed in parallel with each other, a plurality of housings joined to the cylinder block to form a suction chamber, a discharge chamber and a drive chamber, and the cylinder block and the drive. A piston configured to reciprocate the piston in a cylinder bore through a drive mechanism by the rotation of a rotary shaft supported by a housing on the chamber side to compress the gas sucked from the suction chamber and discharge the gas to the discharge chamber. In the type compressor, a valve accommodating chamber that communicates with the suction chamber is provided for the housing and / or the cylinder block that forms the suction chamber, and the valve accommodating chamber and the cylinder bores are communicated with each other through a suction communication passage, The valve accommodating chamber houses a rotary valve that is rotated in synchronization with the reciprocating motion of the piston. A suction guide groove is formed on the outer periphery of the rotary valve in the circumferential direction so as to be able to communicate with a suction communication passage that communicates with the working chamber in the cylinder bore during the suction stroke, and the suction chamber and the suction guide groove are formed inside the rotary valve. The suction passage that always communicates is formed, and the compressed gas remaining in the top clearance in the cylinder bore is positioned ahead of the gas suction guide groove in the rotary valve rotation direction by a predetermined angle after the end of re-expansion. Timing adjustment is performed so that the end surface corresponds to the gas intake communication passage, and the residual compressed gas is re-compressed to the outer peripheral surface of the rotary valve near the leading end surface of the gas intake guide groove or the peripheral surface of the valve accommodating chamber near the intake communication passage. A piston type compressor provided with a cutout passage that allows a small amount of gas to flow in and out from the end of expansion until the preceding end face corresponds to the suction communication passage. Refrigerant gas suction guide mechanism in.