JP2013124648A - Compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress flowing out of lubricating oil in the interior of a compressor to the outside of the compressor caused by movement of a refrigerant within a refrigeration cycle due to temperature changes when the compressor operation stops.SOLUTION: A compressor includes a housing, a suction region (passage 31 for suction) and a discharge region (passage 33 for discharge) defined and formed in a housing, a shaft journaled in the housing, and a compression mechanism which, on the basis of rotational motion of the shaft, sucks refrigerant from the suction region and discharges the refrigerant to the discharge region. The compressor further includes a bypass passage 40 for making the suction region communicate with the discharge region, a valve element 41 capable of closing the bypass passage 40 from the discharge-region side, and a spring 42 for biasing the valve element 41 toward the discharge-region side (toward the direction in which the valve is open).

Description

  The present invention relates to a compressor for a refrigeration cycle used in a vehicle air conditioner and the like, and in particular, the lubricating oil inside the compressor flows out of the compressor due to the movement of refrigerant in the refrigeration cycle due to temperature change when the compressor is stopped. The present invention relates to a compressor having a function of suppressing the above.

  The refrigeration cycle used in air conditioners for automobiles has an evaporator on the passenger compartment side with a partition wall (fire fall) separating the engine compartment side and the passenger compartment side, and a condenser, compressor, etc. on the engine compartment side Is arranged. In such a refrigeration cycle, when the vehicle is warmed by solar radiation in the daytime when the compressor is not in operation, as shown in FIG. While the temperature of the evaporator A rises, the temperature of the condenser B and the compressor C arranged in the engine room does not rise as much as the evaporator A. In addition, since the compressor C having a large heat capacity is difficult to be heated, the refrigerant becomes condensed in the compressor because the temperature is the lowest in the refrigeration cycle. For this reason, the liquid exceeding the oil storage capacity is retained in the compressor by the oil (lubricating oil) and the liquefied refrigerant.

In contrast, when the vehicle is no longer heated by solar radiation in the evening, the temperature of the condenser having a small heat capacity gradually decreases, and the temperatures of the evaporator, the compressor, and the condenser are as follows.
Evaporator temperature> Compressor temperature> Condenser temperature For this reason, this temperature difference causes the condenser pressure to become the lowest in the refrigeration cycle, and the refrigerant staying in the compressor in which the oil is melted by the pressure from the evaporator is the condenser. The phenomenon of being pushed out to the side occurs.

  When such a phenomenon due to temperature change is repeated, the oil retained in the compressor is gradually carried out of the compressor, and the oil remaining in the compressor is depleted. For this reason, if the air conditioner is operated after a state where the air conditioner is not used for a long time, the compressor may be seized due to poor lubrication.

  In order to eliminate such inconvenience, conventionally, as shown in Patent Document 1 below, a low-pressure pipe connected to a suction port of a compressor and a high-pressure pipe connected to a discharge port in a refrigeration cycle are conventionally used. A check valve that allows refrigerant flow when the refrigerant pressure on the low-pressure piping side (evaporator side) is higher than the refrigerant pressure on the high-pressure piping side (condenser side). If the refrigerant pressure on the low-pressure piping side becomes higher than the refrigerant pressure on the high-pressure piping side when the compressor is stopped, the check valve is opened due to this pressure difference, and the refrigerant on the low-pressure piping side is bypassed. A configuration has been proposed in which the oil flows from the compressor to the high-pressure pipe side so that the refrigerant hardly flows into the compressor.

Japanese Patent Laid-Open No. 7-218007

  However, in the check valve disclosed in the above-described patent document, a compression coil spring is disposed on the high-pressure piping side of the valve body constituting the check valve, and the valve body is biased in the closing direction by the biasing force of the compression coil spring. As long as the refrigerant pressure on the low-pressure pipe side (evaporator side) does not increase by the amount corresponding to the spring force of the compression coil spring with respect to the refrigerant pressure on the high-pressure pipe side (capacitor side), the bypass passage is It will not be opened. For this reason, even though the refrigerant pressure on the low pressure pipe side (evaporator side) is higher than the refrigerant pressure on the high pressure pipe side (condenser side), the pressure reaches the pressure that pushes the valve body against the spring force of the compression coil spring. If not, the pressure difference causes the liquid refrigerant in the compressor to be pushed out together with the oil to the high-pressure pipe side (condenser side), and the oil in the compressor may still be exhausted.

  The present invention has been made in view of such circumstances, and when the operation of the compressor is stopped, the lubricating oil inside the compressor flows out of the compressor due to the movement of the refrigerant in the refrigeration cycle due to temperature change. It is a main subject to provide a compressor that can effectively suppress this.

  In order to achieve the above object, a compressor according to the present invention includes a housing, a suction region and a discharge region defined in the housing, a shaft pivotally supported in the housing, and rotational movement of the shaft. And a compression mechanism that sucks the refrigerant from the suction region and discharges the refrigerant to the discharge region, the bypass passage communicating the suction region and the discharge region, and the bypass passage can be closed from the discharge region side. And a spring that urges the valve body toward the discharge region (toward the valve opening direction).

  Therefore, according to the above-described configuration, when the compressor is stopped, the refrigerant pressure in the discharge region (high-pressure piping side) partitioned in the housing and the refrigerant pressure in the suction region (low-pressure piping side) are balanced. Since the bypass passage is always open, even if the refrigerant pressure on the suction region side (low pressure piping side) slightly increases than the refrigerant pressure on the discharge region side (high pressure piping side) due to temperature change, the suction region side (low pressure) The refrigerant pressure on the piping side) can be quickly released to the discharge region side (high pressure piping side) through the bypass passage, and the remaining oil in the compressor can be taken out together with the liquid refrigerant to the high pressure piping side. Disappear.

  Here, in the bypass passage, a valve opening formed to have a diameter smaller than the outer diameter of the valve body, and a diameter larger than the outer diameter of the valve body provided on the discharge region side than the valve opening. Preferably, the valve housing hole is formed directly or via a holder, and the valve body is housed in the valve housing hole so as to be movable along the axial direction thereof.

  According to such a configuration, when the compressor starts operation, the valve element accommodated in the valve accommodating hole quickly moves through the valve accommodating hole, and the bypass passage is closed by the valve element. In this state, the compressor is stopped again until the pressure difference between the discharge region and the suction region becomes small enough that the spring can be moved toward the discharge region (toward the valve opening direction) by the spring force of the spring. Will be maintained.

When the compressor starts operation, as shown in FIG. 7, if the valve body A is located in a space where the discharge region is opened, the discharge region passes through the bypass passage B to the suction region. The refrigerant gas to be introduced does not pass through the side of the valve element A, passes between the valve element A and the periphery of the opening end of the bypass passage B, and flows into the suction region as it is. The inconvenience that the body A does not close the bypass passage B and the refrigerant gas blows out from the discharge region to the suction region.
However, if the above-described configuration is adopted, the refrigerant that is going to flow from the discharge region side to the suction region side passes through the side surface of the valve body held in the valve housing hole, and then passes through the valve port to the suction region. Since the refrigerant flows out, the flow of the refrigerant works against the spring force so as to push the valve body toward the valve port side, and the valve body quickly closes the valve port by this force. Once the valve body closes the valve opening, the discharge pressure and the suction pressure act on the front and back of the valve body, and this pressure difference maintains the closed state against the spring force of the spring.

  In order to obtain such an action more effectively, the area of the passage between the outer peripheral surface of the valve body and the inner peripheral surface of the valve housing hole may be made smaller than the area of the valve port. preferable. As a result, the pressure drop from the discharge region to the suction region in the bypass passage is preferentially given before and after passage of the valve body, not before and after passage of the valve body, and the pressure is reliably ensured upstream and downstream of the valve body. The valve element can be moved quickly by generating a difference.

  The housing is constituted by a shell member that is divided into two in the axial direction of the shaft, and the discharge region and the suction region are defined by the respective shell members, and the discharge port that communicates with the discharge region and the suction region In the compressor in which the suction port that communicates is formed in one shell member, the refrigerant that moves due to the temperature change described above flows to the high-pressure piping side without passing through the compressor as much as possible, and the oil inside the compressor flows out. In order to eliminate as much as possible, the bypass passage is preferably provided in the one shell member provided with the discharge port and the suction port.

  In the configuration described above, the valve body is made of a steel ball, the spring housed in the valve mouth is made of a compression coil spring, and the valve body is located at a portion that transitions from the valve mouth to the valve housing hole. It is good to implement | achieve by the structure provided with the valve-seat surface to seat.

  As described above, according to the present invention, the suction region and the discharge region defined in the housing of the compressor are connected by providing the bypass passage, and the valve body can be closed from the discharge region side to the bypass passage. And a spring for urging the valve body toward the discharge region (toward the valve opening direction), the refrigerant pressure in the suction region, that is, the low-pressure pipe side (evaporator side) Even when the refrigerant pressure on the condenser side is only slightly higher, the refrigerant pressure on the suction area side (low pressure pipe side) is quickly released to the discharge area side (high pressure pipe side) via the bypass passage. Therefore, there is no possibility that the oil that has stopped in the compressor is taken out of the compressor together with the liquid refrigerant.

  Further, the bypass passage has a valve port formed with a diameter smaller than the outer diameter of the valve body, and a valve housing hole formed with a diameter larger than the outer diameter of the valve body on the discharge region side than the valve port. The compressor started operation by forming it directly or through a holder, holding the spring at the valve opening, and accommodating the valve element in the valve accommodating hole so as to be movable along its axial direction. Immediately after the valve body is moved against the spring force of the spring by the refrigerant that flows through the side of the valve body through the side of the valve body, the valve opening can be quickly closed and the state can be maintained stably. It becomes possible.

  At this time, the passage area between the outer peripheral surface of the valve body and the inner peripheral surface of the valve housing hole is made smaller than the area of the valve port, so that the compressor flows through the bypass passage immediately after the start of operation. It is possible to cause the valve body to react more sensitively with the refrigerant to be used, and it is possible to close the valve opening quickly and reliably.

  Further, the housing is constituted by a shell member divided into two in the axial direction of the shaft, and a discharge region and a suction region are defined in each shell member, and a discharge port communicating with the discharge region and a suction port communicating with the suction region However, in the compressor formed in one shell member, the bypass passage is provided in the one shell member provided with the discharge port and the suction port, so that the refrigerant is contained in the compressor even when the bypass passage is provided in the compressor. As a result, only the vicinity of the port is passed without passing through as much as possible, and oil can be reliably prevented from being taken out.

Fig.1 (a) is sectional drawing which shows the example of the compressor provided with the bypass channel which concerns on this invention, FIG.1 (b) is the figure which looked at the rear shell member from the axial direction inner side. FIG. 2 is a conceptual diagram for explaining the flow of refrigerant in the compressor according to the present invention, wherein (a) is a side sectional view thereof, and (b) is a sectional view taken along line BB in (a). It is. FIG. 3 is a cross-sectional view of the rear shell member, which is a view cut along line AA in FIG. 1B (a view cut so that a bypass passage can be seen). FIG. 4 is an enlarged cross-sectional view showing a portion where a valve body and a spring are provided in the bypass passage, (a) is a view showing a state where the valve body is separated from the valve seat surface, and (b) These are figures which show the state in which the valve body is seated on the valve seat surface. FIG. 5 is an enlarged cross-sectional view showing a portion where the valve body and the spring are provided in the bypass passage, and is a diagram for explaining the flow of the refrigerant flowing through the bypass passage and the behavior of the valve body. FIG. 6 is a graph showing temperature changes of the evaporator, condenser, and compressor of the refrigeration cycle mounted on the vehicle, and a schematic diagram illustrating the flow of refrigerant and oil when the compressor is stopped. . FIG. 7 is a diagram for explaining the flow of the refrigerant and the behavior of the valve body when the valve body is located in the space where the discharge region is opened.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  1 and 2, a compressor 1 is a reciprocating type used in a refrigeration cycle using a refrigerant as a working fluid. The compressor 1 includes a front side cylinder block 2 and a front side cylinder block 2. The rear cylinder block 4 to be assembled, the front side shell member 6 assembled to the front side (left side in the figure) of the front side cylinder block 2 via the valve plate 5, and the rear side (in the figure) , Right side) and a rear side shell member 8 assembled through a valve plate 7. The front side shell member 6 and the rear side shell member 8 are respectively connected to adjacent cylinder blocks 2, 4. The opening end side is extended so as to cover and are fitted to each other in the axial direction. The front shell member 6, the valve plate 5, the front cylinder block 2, the rear cylinder block 4, the valve plate 7, and the rear shell member 8 are fastened in the axial direction by fastening bolts 9. The side shell member 6 and the rear side shell member 8 constitute a housing of the compressor that is divided into two in the axial direction.

  Inside the front cylinder block 2 and the rear cylinder block 4, there is formed a swash plate storage chamber 10 which is provided by assembling the respective cylinder blocks 2 and 4, and the swash plate storage chamber 10 has a front A shaft 12 is rotatably supported via a radial bearing 19 in shaft support holes 11 formed in the side cylinder block 2 and the rear side cylinder block 4. One end of the shaft 12 protrudes from the front-side shell member 6, and a relay member 14 attached in the axial direction by a bolt 13 is fixed to a portion protruding from the front-side shell member 6. The front shell member 6 is integrally formed with a boss portion 6a extending to the front side so as to cover the shaft. The boss portion 6a is connected to a drive source (not shown) via a belt. A pulley 16 is rotatably fitted via a bearing 15. The pulley 16 transmits rotational power to the shaft 12 via the relay member 14.

  In each cylinder block 2, 4, a plurality of cylinder bores 17 are formed in parallel to the shaft support hole 11 and at equal intervals on the circumference centered on the shaft 12. A double-ended piston 18 having heads at both ends is inserted into each cylinder bore 17 so as to be reciprocally slidable. A compression chamber 25 is defined between the double-ended piston 18 and the valve plates 5 and 7. Yes.

  A swash plate 20 that is housed in the swash plate housing chamber 10 and rotates together with the shaft 12 is fixed to the shaft 12. The swash plate 20 is rotatably supported with respect to the front cylinder block 2 and the rear cylinder block 4 via a thrust bearing 21, and a mooring concave portion whose peripheral portion is formed at the center of the double-headed piston 18. A pair of hemispherical shoes 22 moored at 23 is sandwiched between the front and rear. Therefore, when the shaft 12 rotates and the swash plate 20 swings and rotates, the swinging and rotating motion is converted into the reciprocating motion of the double-headed piston 18 via the shoe 22, and the volume of the compression chamber 25 changes. Yes.

  Each of the valve plates 5 and 7 has a suction hole 26 that is opened and closed by a suction valve (not shown) provided on the cylinder block side end face, and a discharge hole 27 that is opened and closed by a discharge valve (not shown) provided on the shell member side end face. Are formed corresponding to each cylinder bore 17. The front-side shell member 6 and the rear-side shell member 8 include a suction chamber 28 for storing the refrigerant supplied to the compression chamber 25, and a discharge chamber 29 for storing the refrigerant discharged from the compression chamber 25. Are set up separately.

  The suction chamber 28 formed in each shell member 6, 8 is connected to the swash plate storage chamber 10 via a low pressure passage 30, and the swash plate storage chamber 10 is connected to the suction passage 31. And communicates with a suction port 32 connected to an external cycle formed in the rear shell member 8.

  Further, the discharge chamber 29 formed in each shell member 6, 8 communicates with a discharge port 34 provided in the rear side shell member 8 through a discharge passage 33, and through this discharge port 34 the outside Connected with cycle.

  Therefore, during the suction stroke in which the volume of the compression chamber 25 increases as the double-headed piston 18 reciprocates, the suction port 32 leads to the suction chamber 28 via the suction passage 31, the swash plate storage chamber 10, and the low pressure passage 30. When the compressed refrigerant is sucked into the compression chamber 25 through the suction hole 26 and the volume of the compression chamber 25 is reduced, the refrigerant compressed in the compression chamber 25 is discharged through the discharge hole 27 into the discharge chamber. The gas is discharged from the discharge chamber 29 through the discharge passage 33 to the discharge port 34 provided in the rear shell member 8, and is pumped from the discharge port 34 to the external cycle.

  By the way, as shown in FIG. 3, the rear shell member 8 has a vicinity of the suction port 32 of the suction passage 31 serving as a suction region and a vicinity of the discharge port 34 of the discharge passage 33 serving as a discharge region. A bypass passage 40 that communicates is formed. The bypass passage 40 is configured by connecting passage-forming holes 40a and 40b that are formed in the inner surface of the discharge passage 33 of the rear shell member 8 and the inner surface of the suction passage 31 to each other. Thus, a valve body 41 and a spring 42 are accommodated in a passage forming hole 40 a formed from the discharge passage 33.

  Specifically, as shown in FIG. 4, a valve opening 43 formed in a passage forming hole 40 a drilled from the discharge passage 33 of the bypass passage 40 with a diameter smaller than the outer diameter of the valve body 41. And a valve housing hole 44 formed with a diameter larger than the outer diameter of the valve body 41 on the discharge region side (discharge passage 33 side) with respect to the valve port 43 in the passage forming hole 40a of the bypass passage 40. A valve seat surface 45 on which the valve element 41 is seated is formed in a tapered shape at a portion formed directly along the axial direction and transitioning from the valve accommodating hole 44 to the valve port 43 with a gradually decreasing diameter.

  In this example, the valve body 41 is constituted by a steel ball, and the spring 42 is constituted by a compression coil spring. The spring 42 is accommodated and held in the valve port 43. It is accommodated and held in the accommodation hole 44 and is constantly urged by the spring 42 toward the ejection region side (the ejection passage 33 side). In addition, a stopper member is installed in the vicinity of the opening end of the valve housing hole 44 that opens to the discharge passage 33 and opens in the inner peripheral surface of the valve housing hole 44 and extends in a direction different from the axial direction of the valve housing hole 44. A hole 46 is formed, and a stopper member 47 press-fitted into the stopper member mounting hole 46 is protruded and fixed so as to pass through the valve accommodation hole 44. Accordingly, the valve body 41 is held in the valve housing hole 44 in a state where the valve body 41 can move along the axial direction and the movement range is regulated by the stopper member 47.

  Further, the passage area between the outer peripheral surface of the valve body 41 and the inner peripheral surface of the valve housing hole 44 (the surface perpendicular to the axis of the valve housing hole 44 and the cross-sectional area of the valve housing hole 44 The value obtained by subtracting the cross-sectional area is set smaller than the cross-sectional area of the valve port 43.

  In the above configuration, in a state where the compressor 1 is not in operation, in the state where the refrigerant pressure on the high-pressure piping side and the refrigerant pressure on the low-pressure piping side of the compressor are balanced so as to be substantially equal, There is almost no pressure difference before and after the valve body 41 of the bypass passage 40 formed between the region and the suction region, and the valve body 41 is pushed away from the valve seat surface 45 by being pushed toward the discharge region by the spring force of the spring 42. (The state of FIG. 4A).

  In this state, the temperature of the refrigeration cycle equipment increases due to the influence of solar radiation, and then the vehicle is not heated by solar radiation, and the temperatures of the evaporator, the compressor, and the condenser are: evaporator temperature> compressor temperature> condenser temperature In this relationship, the refrigerant tends to flow from the low pressure pipe side to the high pressure pipe side through the compressor 1 by the pressure from the evaporator, but the valve body 41 of the bypass passage 40 is separated from the valve seat surface 45. Therefore, the vicinity of the suction port 32 in the suction region and the vicinity of the discharge port 34 in the discharge region are in communication with each other by the bypass passage 40, and the refrigerant on the low-pressure piping side passes through the bypass passage 40 to the inside of the compressor. It will flow quickly to the high-pressure piping side without passing through. For this reason, the refrigerant flowing from the low-pressure pipe side does not take out the oil inside the compressor, and it becomes possible to prevent the oil inside the compressor from being depleted.

  On the other hand, immediately after the compressor starts operation, the refrigerant compressed by the piston and discharged to the discharge region is discharged outside the compressor and partly passes through the bypass passage to the suction region. Try to flow. At this time, as shown in FIG. 5, the refrigerant that flows from the discharge region side to the suction region side passes through the side surface of the valve body 41 accommodated in the valve accommodating hole 44, and then passes through the valve port 43. However, since the passage area between the valve element 41 and the valve accommodating hole 44 is set smaller than the cross-sectional area of the valve port 43, the pressure drops greatly here. A pressure difference is surely generated between the upstream and downstream of the valve body 41. For this reason, the refrigerant presses the valve element 41 toward the valve opening 43 against the spring force of the spring 42, and the valve element 41 quickly seats on the valve seat surface 45 by this force and closes the valve opening 43. Will be. Once the valve body 41 closes the valve opening 43, the discharge pressure and the suction pressure act before and after the valve body 41, and the closed state is stably maintained against the spring force of the spring 42 by this pressure difference. The

In this state, the compressor 1 is stopped again, the pressure difference between the discharge region side and the suction region side becomes sufficiently small, and the valve element 41 moves toward the discharge region side by the spring force of the spring 42 (in the valve opening direction). It will be maintained until it moves.
In particular, in the above-described configuration, the area of the passage between the outer peripheral surface of the valve body 41 and the inner peripheral surface of the valve housing hole 44 is set to be smaller than the area of the valve port 43, so that the compressor 1 operates. Immediately after starting the operation, the refrigerant that flows through the bypass passage 40 through the side of the valve body 41 surely generates a pressure difference between the front and rear of the valve body 41, thereby moving the valve body more quickly and reliably Can be closed.

In the above-described configuration, an example in which the valve port 43, the valve accommodating hole 44, and the valve seat surface 45 are integrally formed by processing the inner wall of the passage in the middle of the bypass passage 40 is shown. The spring 42 and the valve element 41 may be accommodated in a holder in which the valve accommodating hole 44 and the valve seat surface 45 are formed to be formed in a cartridge shape, and this may be installed in the middle of the bypass passage 40.
In the above example, an example of a reciprocating compressor using a double-headed piston has been shown as a compressor. However, the compressor is not limited to this, and other piston compressors may be of other types. A similar configuration can be adopted in the compressor.

DESCRIPTION OF SYMBOLS 1 Compressor 6 Front side shell member 8 Rear side shell member 12 Shaft 31 Suction passage 32 Suction port 33 Discharge passage 34 Discharge port 40 Bypass passage 41 Valve body 42 Spring 43 Valve port 44 Valve accommodation hole 45 Valve seat surface

Claims (5)

Based on a housing, a suction region and a discharge region defined in the housing, a shaft pivotally supported in the housing, and a rotational movement of the shaft, refrigerant is sucked from the suction region and discharged to the discharge region. A compressor equipped with a compression mechanism,
A bypass passage communicating the suction region and the discharge region;
A valve body capable of closing the bypass passage from the discharge region side;
A spring for urging the valve body toward the discharge region;
The compressor characterized by having. In the bypass passage,
A valve port formed with a diameter smaller than the outer diameter of the valve body, and a valve accommodation hole formed on the discharge region side with respect to the valve port and formed with a diameter larger than the outer diameter of the valve body are formed. Has been
The compressor according to claim 1, wherein the valve body is accommodated in the valve accommodation hole so as to be movable along an axial direction thereof.   The compressor according to claim 2, wherein a passage area between an outer peripheral surface of the valve body and an inner peripheral surface of the valve housing hole is smaller than an area of the valve port.   The housing is configured by a shell member that is divided into two in the axial direction of the shaft, and the discharge region and the suction region are defined by the respective shell members, and a discharge port that communicates with the discharge region and the suction region. The suction port that communicates is formed in one shell member, and the bypass passage is provided in the one shell member provided with the discharge port and the suction port. The compressor in any one.   5. The valve seat according to claim 1, wherein the valve body is a steel ball, and a valve seat surface on which the valve body is seated is formed at a portion that transitions from the valve port to the valve housing hole. The compressor in any one.

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