JPS62237085A - Cam plate type compressor - Google Patents

Abstract

PURPOSE:To enable elimination of the need to mount a suction valve, by a method wherein a suction passage, intercommunicating the interior of a cylinder part and a cam plate chamber when a piston is situated at position near a bottom dead point, is formed in a housing, and only a delivery chamber is formed outside the housing. CONSTITUTION:A suction passage 411 is formed in a position in the vicinity of the bottom dead point of a piston 124 in a compression chamber 213, and the suction passage 411 is formed with plural suction passage holes 414 and a suction groove 413. The plural suction passage holes 414 are formed around a cylinder 123 within a housing 114, the one end thereof is open to a cam shaft chamber 225, and the other end is communicated with the suction groove 413. Thus, the cam plate chamber 225 is communicated with the compression chamber 213 through the suction passage hole 414 and the suction groove 413. As noted above, since the cam shaft chamber 225 and a cylinder 123 are communicated to a compression chamber 213 only through the suction passage 411 formed in the housing 114, a suction valve can be eliminated. Further, only a delivery chamber 214 may be formed outside the housing 114, and thus, a seal between the suction chamber and the delivery chamber can be sharply facilitated.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a swash plate compressor, which is effective for compressing refrigerant in, for example, an air conditioner for an automobile. [Prior Art] Conventional air conditioner for an automobile A swash plate compressor was used as the refrigerant compressor of the device. The swash plate compressor also had a technology in which the housing was provided with a communication passage that communicated the inside of the cylinder and the swash plate chamber (Japanese Patent Laid-Open No. 60-484
Publication No. 63).

The compressor having the communication passage uses the suction passage provided in the housing when adding additional fluid to the refrigerant sucked through the suction hole.

In other words, when the pressure of the refrigerant sucked through the suction hole is completely low, refrigerant having a higher pressure (intermediate pressure) than that pressure flows into the cylinder portion as an additional refrigerant with a pressure difference. However, in this conventional swash plate compressor, the refrigerant is normally sucked into the cylinder portion through a suction hole provided in the end plate. That is, the suction hole provided in the end plate is opened and closed by the suction valve, and only when the piston is in the suction stroke, the suction valve opens the suction hole and fluid flows into the cylinder portion.

Therefore, all conventional compressors have suction holes formed in the end plates. Therefore, each intake hole had its own intake valve.

However, forming the suction holes in the end plate in this manner not only complicates the formation process, but also causes problems such as damage to the suction valve and inhibition of improvement in suction efficiency.

[Problem that the invention seeks to solve]

The present invention was devised in view of the above points, and an object of the present invention is to eliminate the suction valve from a swash plate compressor.

[Configuration and operation]

That is, the compressor of the present invention adopts a configuration in which only the discharge holes are formed in the end plate. The suction hole is therefore
It is not formed on the end plate.

Fluid is supplied into the cylinder portion only from the suction passage formed in the housing. This suction passage communicates between the cylinder portion within the housing and the swash plate chamber.

The opening position of the cylinder portion of the suction passage is near the bottom dead center of the piston.

Therefore, in the compressor of the present invention, fluid is not sucked into the cylinder portion until the piston approaches the bottom dead center. Therefore, when the piston is near the bottom dead center, a large negative pressure is created within the cylinder section. Therefore, when the suction passage opens into the cylinder, a large pressure difference occurs between the pressure inside the swash plate and the pressure inside the cylinder. This differential pressure forces the fluid into the cylinder section. When the piston then enters the compression stroke, it immediately closes the suction passage. Therefore, during the suction stroke, the fluid is well compressed, and when the pressure exceeds a predetermined pressure, the discharge valve is opened and the fluid is discharged from the discharge port into the discharge chamber.

〔Example〕

An embodiment of the present invention will be described below based on the drawings.

Housing 113. The housing 114 allows the swash plate chamber 22
5 is formed. The front housing 12 is connected to the front open end of the housing 113 via an end plate 134.
1 is arranged. Further, an end plate 135 is similarly arranged at the rear open end of the housing 114, and the rear housing 115 is arranged via this end plate 135.

And the above-mentioned front housing 121. End plate 134. Housing 113. Housing 14. End plate 135 and rear housing 115 are integrally connected by through bolts 154. Also, between the housing 113 and the housing 114 is an O-ring 155.
The seal is held by the

The shaft 111 is an end play)134. Housing 1
Bearing 151 in 14. It is rotatably supported by a bearing 153. The tip of the shaft 111 extends outward from the front housing 121 and is connected to the electromagnetic clutch 313.
It receives the driving force of an automobile engine (not shown) through the motor.

Five compression chambers 213 are formed in each of the housing 113 and the housing 114. Each compression chamber 2
A piston 124 is slidably disposed on 13.

A swash plate 125 is connected to the shaft 111. Therefore, the swash plate 125 rotates together with the shaft 111. The rotation of this swash plate 125 is supported by a thrust bearing 211. The swash plate 125 is arranged obliquely with respect to the shaft 111, so that the swash plate 125 performs a rocking motion when rotating.

The rocking motion of the swash plate 125 is transmitted to the piston 124 via the shoe 131 and the ball 133. Therefore, the piston 12
4 reciprocates within the cylinder 123 in response to the movement of the swash plate 125.

Front housing 121 and rear housing 115
A discharge chamber 144 is formed inside each of them. This discharge chamber 144 is connected to the ball 133 and the end plate 13.
It communicates with the compression chamber 213 via a discharge port 214 formed in the compression chamber 213 . Further, a discharge valve plate 141 and a discharge valve plate 143 are disposed so that the discharge port 214 can be opened and closed. A suction passage 411 is formed in the compression chamber 213 near the bottom dead center of the piston 124 . As shown in FIG. 2, the suction passage 411 includes a plurality of suction passage holes 414 and an annular suction groove 413. The suction passage hole 414 is located in the housing 1
13, a plurality of them are formed around the cylinder 123, one end of which opens into the swash plate chamber 225, and the other end of which opens into the suction groove 4.
It communicates with 13.

Therefore, the swash plate chamber 225 includes the suction passage hole 414 and the suction groove 4.
13 to the compression chamber 213.

The assembly of the compressor having the above configuration will be explained below.

As shown in FIG. 3, an end plate 135 is disposed at the end of the cylinder 123, and the discharge valve plate 14 covers the discharge port 214 formed in the end plate 135.
1 is arranged. Further outward is Gaskent 223.
will be placed. This gasket 223 is made of a metal plate with an elastic body made of rubber attached to the outer surface. Further, an O-ring 231 is disposed on the outside thereof, and in this state, the rear housing 115 is finally disposed. As mentioned above, the cylinder 123 and the rear housing 115 are connected by the through bolt 1.
54.

FIG. 4 shows the cross-sectional shape of the housing 113.

As shown in the figure, five cylinders 123 are formed in the housing 113. Eight suction passage holes 414 are formed around each cylinder 123. The discharge passage 224 in FIG. 4 guides the refrigerant discharged into the discharge chamber 144 in the rear housing 115 to the discharge communication passage. Also, the through bolt 154 is the through hole 2 in Fig. 4.
It penetrates inside 33. FIG. 5 shows the shape of the end plate 135. This end plate 135 is formed with a discharge through hole 234 that faces the above-described discharge passage 224 . Furthermore, as is clear from Fig. 5, the discharge port 2
14 is open at a position communicating with the cylinder 123.

Further, the through bolt 154 opens a through hole 235 in the end plate 135.

FIG. 6 shows the shape of the discharge valve plate 141, and as shown in the figure, the discharge valve plate 141 is disposed at a position facing each discharge port 214.

FIG. 7 shows the shape of the gasket 223. This gasket 223 is placed in contact with one surface of the end plate 135. In particular, this gasket 223
4 and the shaft 111 part and the discharge chamber 1
44 and the outside.

FIG. 8 shows the rear housing 115. As is clear from FIG. 8, this rear housing 115 is formed with a flat portion having the same shape as the gasket 223, so that the rear housing 115 is effectively sealed. Note that the rear housing 115. Gasket 223. The end plates 135 each have through holes for the positioning bins 221 opened at the same position. Therefore, in the assembled state, a constant position is always maintained.

Next, the operation of the compressor having the above structure will be explained.

When the rotational driving force of the automobile engine rotates to the shaft 111 via the electromagnetic clutch 313, the shirt l-11
1 and the swash plate 125 rotate together. This swash plate 125
The piston 124 receives this rotation through the shoe 131 and the ball 133.

Therefore, as the shaft 111 rotates, the piston.

124 reciprocates within the cylinder 123. As shown in FIG. 12, the piston 124 reduces the volume of the compression chamber 213 on one side and reduces the volume of the compression chamber 213 on the opposite side.
Increase the volume of 13. Compression chamber 21 on the left side of Fig. 12
3, it is in the suction stroke state, but the snap ring 2
13 does not communicate with the outside. Therefore, the pressure inside the compression chamber 213 on the left side of FIG. 12 is negative pressure. In this state, the compression chamber 213 communicates with the suction passage 411 as shown in FIG. In the state of communication with this communication 411, a large pressure difference occurs between the internal pressure of the compression chamber 213 and the internal pressure of the swash plate chamber 225, and based on this pressure difference, the refrigerant in the swash plate chamber 225 flows into the compression chamber 213. pushed into.

When the suction passage 411 is open, the piston 124
In this state, the piston 124 is at the bottom dead center position.
The movement speed of is small. Therefore, the suction passage 411 is open to the compression chamber 213 for a relatively sufficient period of time. After that, when the piston 124 moves to the compression stroke, the volume of the compression chamber 213 decreases to become like the compression chamber 213 on the right side of FIG. 12.

When the volume of the compression chamber 213 is reduced to a predetermined value or more and the internal pressure is increased to a predetermined value or more, the compression chamber 213
The refrigerant inside opens the discharge valve plate 141 and discharges into the discharge chamber 144.
is discharged.

The refrigerant discharged into the discharge chamber 144 then flows into the discharge passage 224 of the housing 113 through the discharge through hole 234 of the end plate 135, and is then discharged from the discharge passage housing.

FIG. 9 shows a refrigeration cycle in which the compressor of this example is used. The refrigerant compressed within the compression chamber 213 then flows to the condenser 314, where it is liquefied at high pressure.

The condenser fan 315 promotes this liquefaction. The refrigerant liquefied in the condenser 314 is then stored in the accumulator 321, and only the liquid refrigerant passes through the expansion valve 3.
23 side. The expansion valve 323 reduces the pressure of the liquid refrigerant into a low-temperature, low-pressure mist. The depressurized refrigerant is led out to the evaporator 324, where it exchanges heat with the air inside the vehicle interior.

Air inside the vehicle cabin is introduced into the evaporator 324 by a fan 325. Therefore, the evaporator 324 absorbs heat of vaporization from the air inside the vehicle cabin, and uses the heat of vaporization to vaporize the low-pressure refrigerant inside the evaporator 324. The low-pressure refrigerant thus vaporized is again supplied to the suction passage housing 215 of the compressor. The refrigerant supplied to the suction passage housing 215 then flows into the swash plate chamber 225 as it is.

FIG. 10 shows this state. That is, P3
to P4 indicate the compression state in the compressor. P4-P1
The condensation state in the condenser 314 is shown up to . The condenser 314 liquefies the refrigerant while maintaining high pressure.

P1 and P2 indicate the reduced pressure state at the expansion valve 323.

The refrigerant whose pressure has been reduced by the expansion valve 323 is in a low-pressure atomized state as in the state of P2. P2 and P3 indicate the evaporation state in the evaporator 324.

As shown in P3, after passing through the evaporator 324, it is heated to a predetermined amount.

FIG. 11 shows the results of the study by the present inventors.

FIG. 11 shows a desirable opening position of the suction groove 413. As shown in this figure, the suction groove 413 is preferably located at a position of about 1 to 3% of the entire stroke of the piston. Particularly preferably, the position is 1.6 to 2.4% of the entire piston stroke.

If the opening position of the suction groove 413 is at the bottom dead center position of the piston, the time during which the suction groove 413 is open to the compression chamber 213 becomes too short. Therefore, sufficient refrigerant is not supplied to the compression chamber 213, and the volumetric efficiency of the compressor deteriorates.

On the contrary, the suction groove 413 may have opened too far from the bottom dead center position of the piston 124.
The refrigerant that has flowed into the pressure compartment 213 at one end escapes, which is undesirable. That is, the refrigerant introduced into the compression chamber 213 from the suction groove 413 may flow out from the compression chamber 213 to the suction groove 413 side again when the piston 124 enters the compression stroke.

In the compression shown in FIG. 1, the suction groove 413 is connected to the cylinder 123.
This test was conducted with the tube open all the way around it.

Therefore, it goes without saying that the study shown in FIG. 11 varies depending on the change in the opening area of the suction groove 413. FIG. 14 shows another embodiment of the present invention. In the example shown in FIG. 14, a suction groove 241 is formed within the housing 113. This suction groove 241 communicates between adjacent cylinders 123. Therefore,
In the embodiment shown in FIG. 4, the swash plate chamber 225 and the cylinder 123 communicate with each other via the suction groove 241.

In other words, in the example illustrated in FIG. 14, the swash plate chamber 225 and the cylinder 123 communicate only through the suction groove 241. That is, the refrigerant is sucked only from the portion of the cylinder 123 that faces the suction groove 241 .

Therefore, the opening area of the cylinder 123 and the suction groove 241 is smaller than the opening area of the suction groove 413 and the compression chamber 213 in the example shown in FIG. 1 described above. Therefore, there is a possibility that the suction refrigerant will be somewhat restricted in this suction groove 241 portion.

Therefore, in such embodiments, inhalation a
It is necessary to change the opening position of 241 to be a little closer to the top dead center than in the example shown in FIG. 11 described above.

〔Effect of the invention〕

As explained above, in the compressor of the present invention, the swash plate chamber and the cylinder communicate only through the suction passage formed in the housing, so the suction valve can be eliminated.

Furthermore, in the compressor of the present invention, there is no need to form a suction chamber outside the housing. In the compressor of the present invention, only the discharge chamber needs to be formed outside the housing, and therefore sealing between the suction chamber and the discharge chamber is greatly facilitated.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing one embodiment of the compressor of the present invention, FIG. 2 is a sectional view showing main parts of the compressor shown in FIG.
FIG. 4 is a perspective view showing the assembled state of the compressor shown in the figure, and FIG. 4 is a sectional view showing the housing shown in FIG. 1. Figure 5 is a front view showing the end plate shown in Figure 1, Figure 6 is a front view showing the discharge valve plate shown in Figure 1, Figure 7 is a front view showing the gas get shown in Figure 1, and Figure 8 is a front view showing the gas get shown in Figure 1. Fig. 1 is a front view showing the rear housing shown in Fig. 1, Fig. 9 is a circuit diagram showing a refrigeration cycle in which the compressor shown in Fig. 1 is used, Fig. 10 is an Ickle Mollier diagram shown in Fig. 9, and Fig. 11 is is an explanatory diagram showing the relationship between the opening position of the suction passage and the volumetric efficiency, FIGS. 12 and 13 are explanatory diagrams for explaining the operation of the compressor, and FIG. 14 is a housing of another embodiment of the compressor of the present invention. FIG. 115...Rear housing, 121...Front housing, 123...Cylinder, 124...Piston. 125...Swash plate, 411...Suction passage, 214...
-Discharge hole, 225...swash plate chamber.

Claims (1)

[Scope of Claims] A housing forming a plurality of cylinder parts and a swash plate chamber therein; a shaft rotatably disposed within the housing; a swash plate that rotates integrally with the shaft; a piston that is slidably disposed on the swash plate and reciprocates within the cylinder section in response to the reciprocating motion of the swash plate; an end plate that covers the open end of the cylinder section of the housing; and a piston formed on the end plate. a discharge port disposed on the opposite side of the cylinder portion via the end plate; a suction pressure passage that leads suction pressure to the swash plate chamber; and a discharge passage that discharges compressed fluid from the discharge chamber. A swash plate compressor, characterized in that the housing is formed with a suction passage that communicates between the inside of the cylinder portion and the swash plate chamber when the piston is located near bottom dead center.