JPH03258974A - Swash plate type compressor - Google Patents

Abstract

PURPOSE:To make it difficult for a space part to have the influence of the pressure pulsation in an inlet chamber caused by the successive inflow of a coolant gas into a cylinder through an inlet hole by providing a throttle part in which the passage sectional area from the space part provided in the inlet part of the inlet chamber to the inlet chamber having the inlet hole is 60-80% of the sectional area of an inlet passage. CONSTITUTION:A space part 38 is provided in the inlet part of an inlet chamber 34 communicated to an inlet passage 37. A throttle part part 39 in which the passage sectional area from the space part 38 to the inlet chamber 34 having an inlet hole 29 is 60-80% of the sectional area of the inlet passage. The space part 38 is difficult to have the influence of the pressure pulsation in the inlet chamber 34 caused by the successive inflow of a coolant gas in the intake chamber 34 from the inlet hole 29 into a cylinder 9 through an inlet valve 39, and the inlet pressure pulsation of the coolant gas entered from an inlet port 36 is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a swash plate compressor for car air conditioners used for air conditioning of automobiles.

A conventional swash plate compressor compresses refrigerant gas by reciprocating a piston in conjunction with a swash plate that rotates or oscillates within a plurality of axially aligned cylinders. At this time, the plurality of pistons sequentially perform suction and suction with a predetermined phase difference.
Since compression and discharge are repeated, pulsations occur in the suction pressure and discharge pressure, causing vibration and noise.

Conventional techniques for reducing the above-mentioned pressure pulsations include a structure in which the internal volume of the suction chamber and the discharge chamber themselves are increased, and a suction passage communicating with the suction chamber or the discharge chamber, as described in Japanese Patent Application Laid-Open No. 1-138381. Alternatively, a fat expansion space is provided in the discharge passage. Further, as described in Japanese Patent Application Laid-Open No. 1-138380, a partition wall is provided between each discharge hole opening into the discharge chamber to prevent direct mutual interference of the discharged fluid.

Problems to be Solved by the Invention In the above-mentioned swash plate compressor, it is impossible to increase the internal volume of the suction chamber and discharge chamber, especially when used in a car air conditioner, due to constraints on the external shape and dimensions of the compressor. .

Further, in a structure in which a fat swelling space is provided in a suction passage or a discharge passage communicating with a suction chamber or a discharge chamber, the following problems arise. First, on the suction side, suction refrigerant gas flows into the cylinder from a suction hole communicating with the suction chamber via a suction valve in response to the reciprocating motion of multiple pistons, so the refrigerant gas in the suction chamber The flow rate and direction changes, increasing pressure pulsations. At this time, if the cross-sectional area of the passage communicating from the fat expansion space to the suction chamber is equal to or larger than the passage cross-sectional area communicating from the suction port to the fat expansion space, the pressure in the fat expansion space will be affected by pressure pulsations in the suction chamber. Pulsation also increases, and the effect of reducing suction pressure pulsation cannot be obtained. In addition, when a member having a constricted portion is inserted into the suction passage to form a fat expansion space, the volume of the fat expansion space itself cannot be increased, suction pressure pulsation cannot be reduced, and the passage cross-sectional area of the constriction portion cannot be increased. becomes smaller, and compressor efficiency decreases due to pressure loss. On the other hand, on the discharge side, the refrigerant gas compressed within the cylinder is sequentially discharged from the discharge hole to the discharge chamber via the discharge valve, so that pressure pulsations occur within the discharge chamber. At this time, the resonant frequency of the sealed discharge chamber exists around IKHz, and due to this frequency mode, a high frequency component is added to the pressure pulsation wave at the outer periphery of the discharge chamber, which corresponds to the antinode, increasing the pressure pulsation. Therefore, if the discharge passage is communicated at a position close to the outer periphery of the discharge chamber, pressure pulsations with many high frequency components will occur in the refrigerant gas flowing out, and the effect of reducing discharge pressure pulsations due to the fat expansion space will not be obtained.

Furthermore, even in a structure in which a partition wall is provided between each discharge hole opening into the discharge chamber to prevent direct mutual interference of the discharge fluid, the resonance frequency of the discharge chamber is shifted due to the above-mentioned reason, but the discharge passage is Since the pressure pulsation wave is connected to a position close to the part, the pressure pulsation wave has many high frequency components, and the discharge pressure pulsation increases.

In view of the above problems, the present invention provides a highly efficient swash plate compressor with less pulsation and noise by reducing suction and discharge output pulsations with a simple structure.

Means for Solving the Problems In order to solve the above-mentioned problems, a first invention of the present invention includes a cylinder block in which a plurality of cylinders are formed, and a cylinder block that is fitted into the cylinders and moves reciprocatingly in conjunction with a swash plate. a plurality of pistons, a valve plate in which a plurality of suction holes and discharge holes are formed corresponding to the cylinders, a suction valve and a discharge valve that open and close the suction holes and the discharge holes, and an opening end of the cylinder that is connected to the valve plate; A rear cover closed through a plate, a suction chamber communicating with the suction hole and a discharge chamber communicating with the discharge hole formed in the rear cover in a sealed manner, and a suction port provided in the rear cover and the suction chamber. In a swash plate compressor having a communicating suction passage and a discharge passage communicating between a discharge port and the discharge chamber, a space is provided at an entrance portion of the suction chamber that communicates with the suction passage, and a space is provided from the space to the suction hole. A constricted portion is formed in which the cross-sectional area of the passage to the suction chamber in which the suction passage is disposed is 60 to 80% of the cross-sectional area of the suction passage.

In a second aspect of the invention, a discharge passage formed in the rear cover is opened at the center of the discharge chamber, and the discharge chamber and the discharge passage are interlocked.

Effect The effect of the first aspect of the present invention with the above configuration is that the cross-sectional area of the passage from the space provided at the inlet portion of the suction chamber to the suction chamber in which the suction hole is arranged is 60 to 80 times the cross-sectional area of the suction passage. By forming the constricted part, the space part is able to absorb the influence of pressure pulsations in the suction chamber caused by the refrigerant gas in the suction chamber sequentially flowing into the cylinder from the suction hole through the suction valve.
Suction pressure pulsations of refrigerant gas flowing from the suction port are reduced.

Further, the second aspect of the present invention works because the discharge passage is opened in the center of the discharge chamber, and the discharged refrigerant gas is caused to flow out through the discharge passage from the center, which corresponds to the node of the frequency mode of the resonance frequency of the discharge chamber. Since no high frequency component is added to the pressure pulsation waves of the refrigerant gas flowing out from the discharge hole to the discharge chamber via the discharge valve, it is possible to reduce the discharge pressure pulsations.

Therefore, since pressure pulsations during suction and discharge can be reduced, vibrations and noise can be prevented from occurring, pressure loss is small, and efficiency is high.

Example Regarding the swash plate compressor in the first example of the present invention,
This will be explained with reference to FIGS. 1 to 3.

FIG. 1 shows the overall structure of a variable capacity rocking swash plate compressor. Reference numeral 1 denotes a cylinder block, both ends of which are sealed with a crankcase 2 and a rear cover 3. 4 is a shaft supported by a radial bearing 56 and further held in the axial direction by a thrust bearing 7.8. The cylinder flock 1 has a plurality of cylindrical cylinders 9 penetrating in the axial direction.
A piston 10 is fitted into each cylinder 9 so as to be able to reciprocate, and is directionally connected to a non-rotating rocking plate 12 by a rod 11 having ball joints at both ends. The swing plate 12 is attached to the rotating swash plate 13 via a thrust bearing 14 and a radial bearing 15, and is held in the axial direction by a thrust washer 16 and a retaining ring 17.

As shown in FIG. 2, the rotating swash plate 13 has a sleeve 18 slidably mounted on the shaft 4 and a pair of pivot pins 19.
The common axis of the pivot pin 19 intersects the axis of the shaft 4 at right angles to allow the tilting of the rotating swash plate 13 and the swing plate 12. A drive lug 20 is fastened to the shaft 4, and has a protrusion 22 with a guide slot 21 for guiding the inclination of the rotating swash plate 3, and the protrusion 22 is formed on the rotating swash plate 13. It is held against the ear 23 by a transverse pin 24 that engages with the ear 23 and is guided by sliding in the guide slot 21, and rotates the rotating swash plate 13 as the shaft 4 rotates. A guide portion 25 is formed on the outer periphery of the swing plate 12, and a slider 26 having a spherical bearing portion is fitted so as to be slidable toward the center of the swing plate 12. 1 and is slidably engaged with a guide rod 27 disposed in the axial direction of the shaft 4, the rocking plate 12 can tilt together with the rotating swash plate 13; This prevents them from rotating together.

In FIG. 1, 28 is a valve plate in which a plurality of suction holes 29 and discharge holes 30 are formed, and a suction valve 31, a discharge valve 32, and a discharge valve holding plate 33 are arranged facing each other at both ends of the cylinder block. 1 and the rear cover 3.

As shown in FIG. 3, a suction chamber 34 communicating with the plurality of suction holes 29 and a discharge chamber 35 communicating with the plurality of discharge holes 30 are formed in the rear cover 3 in a sealed manner. 36 is a suction port, and 37 is a suction passage which communicates with a space 38 provided at the entrance of the suction chamber 34.

Reference numeral 39 denotes constricted portions that have a cross-sectional area from the space 38 to the suction chamber 34 that is 60 to 80% of the cross-sectional area of the suction passage 37, and are provided at two locations. 40 is a discharge port, and 41 is a discharge passage, which communicates with the discharge chamber 35.

In FIG. 1, 42 is a crank chamber, 43 is a control spring mounted on the shaft 4, and 44 is a control valve disposed in the rear cover 3 for controlling the internal pressure of the crank chamber 42.

The operation of the swash plate compressor configured as above will be explained. When the shaft 4 is driven from the outside, the rotary swash plate 13 engages with the protrusion 22 of the drive lug 20 through the ears 23.
rotates at an angle of inclination. The rocking plate 12 is the rotating swash plate 1
3, a slider 2 which is slidably arranged via a thrust bearing 14 and a radial bearing 15, and has a spherical bearing fitted into a guide portion 25 located on the outer periphery of the swing plate 12.
6 is slidably engaged with the guide rod 27, the swing plate 12 is prevented from rotating and swings according to the inclined surface of the rotary swash plate 13. Therefore, the piston 10, which is directionally connected to the rocking plate 12 via the rod 11 having ball joints at both ends, reciprocates in the axial direction within the cylinder 9. Thereby, the refrigerant gas in the suction chamber 34 is transferred from the suction hole 29 to the cylinder 9 via the suction valve 31 during the suction stroke in which the piston 10 moves from the top dead center to the bottom dead center.
and flows out from the discharge hole 30 to the discharge chamber 35 via the discharge valve 32 during the compression and discharge strokes in which the fluid flows from the bottom dead center to the top dead center.

The cooling capacity is controlled by changing the inclination angle of the rocking plate 12 and varying the stroke of the piston 10, thereby continuously changing the volume of the cylinder 9, that is, the displacement amount. The inclination angle of the rocking plate 12 is determined by the pressure control by the control valve 44 that controls the internal pressure of the crank chamber 42 behind the piston 10 relative to the suction pressure, the force acting on the front and back of the piston 10, and the axis acting on the rotating swash plate 13. It is determined by the balance of moments around the bottle 19. therefore,
When the heat load is high, the inclination angle of the rocking plate 12 is maximized so that there is no pressure difference between the suction pressure and the internal pressure of the crank chamber 42, and the displacement is maximized. On the other hand, when the heat load is low and the suction pressure becomes lower than the suction pressure control point set in the control valve 44, the control valve 44 operates to increase the internal pressure of the crank chamber 44 and reduce the inclination angle of the rocking plate 12. As a result, the stroke of the piston 10 is reduced, and the displacement is reduced.

The positioning of the pivot pin 12 and the rotating swash plate 13 is determined by a pair of pivot pins 19 connected to the sleeve 18 and a horizontal pin 24 that slides into a guide slot 21 formed in the drive lug 20. 10 is given a constant top dead center position.

Here, the suction refrigerant gas returned from the refrigeration cycle flows from the suction port 36 through the suction passage 37 into the space 38 provided at the entrance of the suction chamber 34 . The space 38 has a considerably larger volume than the suction passage 37, and
The refrigerant gas expands and flows into the suction chamber 34 in which a plurality of suction holes 29 are provided through the throttle portions 39 provided at two locations. The refrigerant gas in the suction chamber 34 sequentially flows into the cylinder 9 from the suction hole 29 via the suction valve 31 in accordance with the reciprocating motion of the piston 10, so that the refrigerant gas in the suction chamber 34 changes in flow velocity and direction. This causes pressure pulsations, which also affects the inside of the space 38, and is particularly large when the flow is into the cylinder 9 from the suction hole 29 near the space 38. The two constricted portions 39, which are set at ~80%, reduce the degree of influence of pressure pulsations within the space 38, and as a result, suction pressure pulsations are reduced.

Here, if the passage cross-sectional area of the constriction part 39 is larger than 80% of the cross-sectional area of the suction passage 37, the constriction part 39 has almost no effect and the suction pressure pulsation is not reduced. On the other hand, when the cross-sectional area of the passage is less than 60%, pressure loss occurs, resulting in a decrease in efficiency. Therefore, the passage cross-sectional area of the throttle portion 39 is 60 to 80% of the cross-sectional area of the suction passage 37, which is effective in reducing suction pressure pulsations. .

Next, a second embodiment of the present invention will be described. In this embodiment, in the first embodiment (see FIGS. 1 and 3),
A discharge passage 41 formed in the rear cover 3 is opened at the center of a sealed discharge chamber 35, and the discharge chamber 34 and the discharge passage 41 are communicated with each other. Thereby, in order to cause the refrigerant gas in the discharge chamber 35 to flow from the central part of the discharge chamber 34 corresponding to the node of the resonance frequency mode through the discharge passage 41 to the discharge port 40, it flows from the discharge hole 30 to the discharge chamber 35 via the discharge valve 32. No high-frequency component is added to the pressure pulsation waves of the refrigerant gas that sequentially flowed out, and the discharge pressure pulsation can be reduced. Figure 4 (a), fb) shows the waveform of discharge pressure pulsation, and Figure 4 (b+) is a comparative example in which the discharge passage 41 opens at the outer periphery of the discharge chamber 35. However, in this embodiment in which the discharge passage 41 is opened at the center of the discharge chamber 35, as shown in FIG.

FIG. 5 shows a third embodiment of the invention. A discharge port 40 is formed at the rear end of the rear cover 3, and a discharge passage 41 opens at the center of the discharge chamber 35, and has the same effect as the above embodiment.

Effects of the Invention As described above, in the present invention, the cross-sectional area of the passage from the space provided at the inlet of the suction chamber to the suction chamber in which the suction hole is arranged is 60 to 80% of the cross-sectional area of the suction passage. By forming the throttle part, the space part is less susceptible to pressure pulsations in the suction chamber that occur when refrigerant gas sequentially flows into the cylinder from the suction hole, and suction pressure pulsations can be reduced.

In addition, by opening the discharge passage in the center of the discharge chamber and letting the discharged refrigerant gas flow out through the discharge passage from the center, which corresponds to the node of the resonance frequency mode of the discharge chamber, high frequency components are prevented from entering the pressure pulsation waves of the refrigerant gas. First, the discharge pressure pulsation can be reduced to a low range.

Therefore, suction and discharge pressure pulsations can be reduced with a simple configuration without adding any parts, and vibrations due to pressure pulsations can be reduced.
Not only can noise generation be prevented, but pressure loss is also small.
This can prevent a decrease in efficiency.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view of a swash plate compressor according to a first embodiment of the present invention, FIG. 2 is a partial cross-sectional view of the same, and FIG. It is a longitudinal cross-sectional view of the rear cover of the swash plate compressor in the 3rd Example. 1...Cylinder block, 3...Rear cup-9...Cylinder, 10...Piston, 13...Swash plate, 28... ... Valve plate, 29 ... Suction hole, 30 ... Discharge hole,
31...Suction valve, 32...Discharge valve, 3
4...Suction chamber, 35...Discharge chamber, 36
...Suction port, 37...Suction passage,
38...Space part, 39...Aperture part, 4
0...Discharge port, 41...Discharge passage.

Claims (2)

[Claims] (1) A cylinder block in which a plurality of cylinders are formed, a plurality of pistons that are fitted into the cylinders and reciprocate in conjunction with a swash plate, and a plurality of suction holes and discharge holes are formed corresponding to the cylinders. a valve plate, a suction valve and a discharge valve that open and close the suction hole and the discharge hole, a rear cover that closes the open end of the cylinder via the valve plate, and the suction hole that is formed in a sealed manner in the rear cover. A swash plate type comprising a suction chamber communicating with the discharge hole, a discharge chamber communicating with the discharge hole, a suction passage communicating the suction port provided in the rear cover with the suction chamber, and a discharge passage communicating the discharge port with the discharge chamber. In the compressor, a space is provided at the entrance of the suction chamber that communicates with the suction passage, and the cross-sectional area of the passage from the space to the suction chamber in which the suction hole is arranged is 60% of the cross-sectional area of the suction passage. A swash plate compressor characterized by forming a constricted portion with a narrowing area of 80%. (2) The swash plate compressor according to claim 1, wherein a discharge passage formed in the rear cover is opened at a central portion of the discharge chamber, and the discharge chamber and the discharge passage are communicated with each other.