JP4338111B2 - Gas compressor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gas compressor mounted on a vehicle as a part of a car air conditioner system, and in particular, aims at simultaneously preventing vane chattering and reducing compressor power.
[0002]
[Prior art]
Conventionally, this type of gas compressor has, for example, a substantially elliptic cylinder 1 as shown in FIG. 4, and side blocks 2 and 3 are attached to both end faces of the cylinder 1. Further, a rotor 4 is installed horizontally inside the cylinder 1, and this rotor 4 is rotatably supported via a rotor shaft 5 at the center of the cylinder 1 and bearings 6 and 7 of the side blocks 2 and 3.
[0003]
As shown in FIG. 5, a plurality of slit-like vane grooves 8 are formed on the outer peripheral surface side of the rotor 4, and vanes 9 are attached to these vane grooves 8, respectively. It is provided so that it can protrude and retract toward the inner wall of the cylinder 1.
[0004]
The inside of the cylinder 1 is partitioned into a plurality of small chambers by the inner wall of the cylinder 1, the side blocks 2 and 3, the outer peripheral surface of the rotor 4, and both side surfaces on the tip end side of the vane 9, and the partitioned small chamber is referred to as a compression chamber 10. The compression chamber 10 repeats the change in volume as the rotor 4 rotates in the direction of arrow B in the figure.
[0005]
When the volume change of the compression chamber 10 occurs, the low-pressure refrigerant gas is sucked from the suction chamber 11 side to the compression chamber 10 side when the volume increases, and the refrigerant in the compression chamber 10 when the volume of the compression chamber 10 decreases. Gas compression and high-pressure refrigerant gas discharge from the compression chamber 10 to the discharge chamber 12 side are performed.
[0006]
That is, in the suction process until the volume of the compression chamber 10 reaches the maximum, the refrigerant gas in the suction chamber 11 is compressed through the suction passage 13 of the cylinder 1 and the like and the suction ports 14 of the side blocks 2 and 3. Inhaled into the chamber 10 side. When the volume of the compression chamber 10 becomes near the maximum, the compression chamber 10 is separated from the suction port 14 to become a sealed space, and the low-pressure refrigerant gas is confined in the sealed compression chamber 10. Thereafter, when the volume of the compression chamber 10 shifts from the maximum to the minimum, the low-pressure refrigerant gas in the compression chamber 10 is compressed according to the volume reduction amount. Further, when the volume of the compression chamber 10 becomes near the minimum, the pressure of the compressed high-pressure refrigerant gas opens the reed valve 16 attached to the discharge hole 15 of the cylinder 1 and the high-pressure refrigerant gas in the compression chamber 10 Flows out from the discharge hole 15 to the discharge chamber 17 on the outer peripheral surface side of the cylinder 1.
[0007]
The high-pressure refrigerant gas that has flowed into the discharge chamber 17 further passes through a discharge passage (not shown) of the rear side block 3 and then passes through an oil separator 18 attached to the side block 3. Discharge inside.
[0008]
An oil reservoir 20 is provided at the bottom of the discharge chamber 12, and the pressure Pd (hereinafter referred to as “discharge pressure”) of the high-pressure refrigerant gas discharged into the discharge chamber 12 acts on the oil in the oil reservoir 20. Yes. The oil in the oil reservoir 20 on which the discharge pressure Pd acts is formed on the side blocks 2 and 3, the oil holes 21 drilled in the cylinder 1, the bearings 6 and 7, and the side blocks 2 and 3 on the cylinder facing surface side. It passes through the Saray grooves 22 and 22 formed in that order and is supplied to the back pressure chamber 19 at the bottom of the vane 9.
[0009]
As described above, in the gas compressor shown in FIG. 4, the oil in the oil reservoir 20 on which the discharge pressure Pd acts is decompressed through the gaps of the bearings 6 and 7 and supplied to the back pressure chamber 19 side. Although a force to press 9 toward the inner wall of the cylinder 1, that is, a vane back pressure, is obtained, if this type of vane back pressure is too high, wear and compression of the tip of the vane 9 and the inner wall of the cylinder 1 with which the slidable contact occurs. In the gas compressor shown in the figure, although not shown in the figure, it is fixed to the oil hole inlet 20a of the rear side block 3 for the purpose of reducing the vane back pressure. It is conceivable to provide a diaphragm.
[0010]
However, if a fixed throttle as described above is provided, the compressor power can be reduced by lowering the vane back pressure, but at the same time, the chattering limit (hereinafter referred to as “chatter limit”) of the vane 9 deteriorates. There is a problem that chattering of the vane 9 is likely to occur compared to a case without a fixed aperture. This is because the vane back pressure is insufficient immediately before the volume of the compression chamber 10 becomes near the minimum and the refrigerant gas is discharged from the compression chamber 10. That is, when the stage immediately before the refrigerant gas discharge is reached, the pressure in the compression chamber 10 becomes maximum, and this large pressure is applied to the tips of the vanes 9 forming the front and rear walls 10a, 10b of the compression chamber 10, so that the vanes 9 The vane groove 8 tends to be pushed back to the bottom side with a large force. Since this causes chattering of the vane 9, a higher vane back pressure is required in the stage immediately before the refrigerant gas discharge than in the refrigerant gas suction process, the initial stage of compression, the middle stage, and the like. According to the machine, even when such a high vane back pressure is required, the vane back pressure is reduced by the fixed throttle, so that chattering due to insufficient vane back pressure, that is, the vane 9 is discharged from the cylinder 1. It is considered that the phenomenon of instantaneously sinking and jumping near the outlet 15 and colliding with the inner wall of the cylinder 1 is likely to occur.
[0011]
[Problems to be solved by the invention]
The present invention has been made to solve the above problems, and an object of the present invention is to provide a gas compressor suitable for simultaneously preventing vane chattering and reducing the power of the compressor. .
[0012]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the present invention comprises a cylinder having a substantially inner circumference, side blocks attached to both end faces of the cylinder, a rotor rotatably mounted inside the cylinder, A plurality of vanes provided so as to be able to project and retract from the outer peripheral surface of the rotor toward the inner wall of the cylinder, a back pressure chamber for applying a vane back pressure to the bottom of the vane, and the cylinder, the side block, the rotor, and the vanes. A compression chamber formed, and the volume of the compression chamber repeatedly changes in size by the rotation of the rotor, and the change in the volume of the compression chamber causes the suction of refrigerant gas from the suction chamber side to the compression chamber side. The refrigerant gas is compressed and the refrigerant gas is discharged from the compression chamber to the discharge chamber side, and the oil acting on the discharge pressure is supplied to the back pressure chamber side to reduce the vane back pressure. In the gas compressor of the structure that, in the oil supply passage to the back pressure chamber side, provided with a variable throttle means strength of the diaphragm based on the discharge pressure of the refrigerant gas changes, the variable throttle means, the refrigerant gas The bellows expands and contracts based on the discharge pressure of the bellows, and the spool valve is attached to the movable end of the bellows. it is characterized in that.
[0015]
In the present invention, when the discharge pressure is high, considering that vane chattering is unlikely to occur even when the vane back pressure is lowered, the supply oil to the back pressure chamber side is tightly squeezed to set the vane back pressure lower than before. In addition, when the discharge pressure is low, considering that vane chattering is more likely to occur if the vane back pressure is lowered, the supply oil pressure to the back pressure chamber side is loosened to reduce the vane back pressure. Can be set high.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a gas compressor according to the present invention will be described in detail with reference to FIGS. 1 and 2.
[0017]
In addition, if it demonstrates using the basic structure of the gas compressor of this embodiment, for example, FIG. 4 and FIG. 5 of a prior art example, the gas compressor has the cylinder 1 of inner periphery substantially elliptical shape, Side blocks 2 and 3 are attached to the surface, and the rotor 4 is rotatably mounted on the inner side of the cylinder 1. A plurality of vanes 9 are formed from the outer peripheral surface of the rotor 4 toward the inner wall of the cylinder 1. When the volume of the compression chamber 10 is changed by the rotation of the rotor 4, the low pressure from the suction chamber 11 side to the compression chamber 10 side through the intake passage 13 and the suction port 14 is changed. Since the suction of the refrigerant gas, the compression of the refrigerant gas in the compression chamber 10, the discharge of the refrigerant gas from the compression chamber 10 to the discharge chamber 12 through the discharge hole 15 and the like are the same as in the past, the same member is used. Are given the same symbols, Detailed description will be omitted.
[0018]
FIG. 1 shows an embodiment of a main part of a gas compressor according to the present invention. Even in the gas compressor of the present embodiment, the oil reservoir 20 is provided at the bottom of the discharge chamber 12, and the discharge pressure Pd of the high-pressure refrigerant gas acts on the oil in the oil reservoir 20. The oil in the oil reservoir 20 on which the discharge pressure Pd acts is finally supplied to the back pressure chamber 19 side at the bottom of the vane 9.
[0019]
The oil supply path 23 to the back pressure chamber 19 as described above is provided with the side blocks 2 and 3 and the oil holes 21 of the cylinder 1, the bearings 6 and 7, and the Sarai grooves 22 and 22 of the side blocks 2 and 3, as in the past. However, in the gas compressor of the present embodiment, the variable throttle means 40 is provided in the oil supply passage 23 to the back pressure chamber 19 side, specifically, in the oil hole inlet 21 a of the rear side block 3. Is provided.
[0020]
The variable throttle means 40 includes a spool valve 42 and a bellows 43 inside the valve housing 41, and the spool valve 42 intersects a flow path 44 (hereinafter referred to as “housing internal flow path”) inside the valve housing 41. It is installed to do.
[0021]
A constriction passage 42a is formed by partially cutting out the body abdomen of the spool valve 42, and the valve of the spool valve 42 is determined by the relative positional deviation between the constriction passage 42a and the housing internal flow path 44. The opening is determined.
[0022]
The bellows 43 is accommodated in a bellows storage chamber 45 provided in the middle of the housing internal flow path 44, and one end of the spool valve 42 is fixedly attached to a movable end 43a of the bellows 43.
[0023]
Note that the inlet side of the housing internal channel 44 opens into the oil reservoir 20, and the outlet side of the housing internal channel 44 is connected to the oil hole inlet 21 a of the rear side block 3.
[0024]
Accordingly, the oil in the oil reservoir 20 on which the discharge pressure Pd acts flows from the inlet of the housing internal flow path 44 into the housing internal flow path 44 and is also supplied to the bellows storage chamber 45 in the middle of the housing internal flow path 44. The expansion / contraction drive source of the bellows 43. That is, the bellows 43 is configured to be able to extend and contract based on the refrigerant gas discharge pressure Pd.
[0025]
The variable throttle means 40 configured as described above employs a structure in which the strength of the throttle changes based on fluctuations in the refrigerant gas discharge pressure Pd.
[0026]
That is, FIG. 2B shows the operation state of the variable throttle means 40 when the refrigerant gas discharge pressure Pd is relatively high. As shown in FIG. 2B, the discharge pressure Pd is When the pressure is high, the oil pressure in the oil reservoir 20 is also increased. The bellows 43 is contracted by the high-pressure (Pd _H ) oil and the spool valve 42 slides in the bellows contraction direction. It is set to be smaller. In this case, the constricted passage 42a of the spool valve 42 is completely separated from the housing internal flow path 44, the housing internal flow path 44 is closed by the tip of the spool valve 42, and the oil passes through the shaft clearance. Therefore, the amount of oil that passes through the housing internal flow path 44 and is pumped to the oil hole 21 side of the rear side block 3 is reduced. This means that a tight (strong) throttle is formed in the oil supply path 23 to the back pressure chamber 19 side when the refrigerant gas discharge pressure Pd becomes high.
[0027]
When the refrigerant gas discharge pressure Pd is reduced from the state shown in FIG. 2B, the oil pressure in the oil reservoir 20 is also reduced (Pd _H ). Therefore, as shown in FIG. The spool valve 42 is slid in the bellows extending direction and the valve opening degree of the spool valve 42 is set to increase as it extends. In this case, the constriction passage 42 a of the spool valve 42 and the housing internal flow path 44 communicate with each other, and the amount of oil that passes through the housing internal flow path 44 and is fed to the oil hole 21 side of the rear side block 3 increases. This means that a loose (weak) throttle is formed in the oil supply path 23 toward the back pressure chamber 19 when the discharge pressure Pd of the refrigerant gas becomes low.
[0028]
Next, the operation of the gas compressor configured as described above will be described with reference to FIGS.
[0029]
The gas compressor of this embodiment can be mounted on a vehicle as a part of a car air conditioner system. In such a usage mode, the operation of the gas compressor rotates the rotor 4 by using the engine of the vehicle as a power source. Therefore, during high-speed driving of the vehicle, the rotational speed of the rotor 4 in the gas compressor also increases, and accordingly, the discharge amount of the high-pressure refrigerant gas per unit time increases, and the discharge pressure of the refrigerant gas The increase in Pd is the same as in the prior art.
[0030]
FIG. 3 shows the relationship between the investigation of the actual vehicle pressure distribution and the chatter limit. In the figure, the regions A to G are actual vehicle pressure distributions. Of these, the region A has an outside air temperature of 40 ° C. When the outside temperature is 35 ° C. for the B region, when the outside temperature is 30 ° C., when the outside region is 25 ° C., when the outside region is 20 ° C., when the outside region is 20 ° C., when the outside region is 15 ° C. G area | region shows each actual vehicle pressure distribution in the case of 10 degreeC of external temperature. Also, the solid lines (1) to (4) in the figure are all chatter limit lines. Of these, the solid line (1) is when the aperture diameter is 2.6 mm (corresponding to the conventional product), and the solid line (2) is When the aperture diameter is 0.7 mm, the solid line (3) indicates the respective chatter limit lines when the aperture diameter is 0.5 mm, and the solid line (4) indicates the chatter limit line when the aperture diameter is 0.3 mm. The chatter limit line means that chattering is likely to occur in the right region, and chattering is unlikely to occur in the left region.
[0031]
As can be seen from FIG. 3, when the refrigerant gas discharge pressure Pd becomes high, there is a margin in the chatter limit, and even when the vane back pressure is set low, chattering of the vane 9 hardly occurs. Therefore, when the refrigerant gas discharge pressure Pd is high, it is not necessary to apply the vane back pressure equivalent to when the refrigerant gas discharge pressure Pd is low, but it is preferable to set the vane back pressure low to reduce the power of the compressor. In this regard, in the gas compressor of the present embodiment, the vane back pressure is automatically set low when the discharge pressure Pd increases.
[0032]
That is, in the gas compressor of the present embodiment, when the refrigerant gas discharge pressure Pd increases, the bellows 43 of the variable throttle means 40 automatically contracts based on the pressure fluctuation, and the valve opening of the spool valve 42 decreases. A tight throttle is formed in the oil supply passage 23 toward the back pressure chamber 19, specifically, at the oil hole inlet 21 a of the rear side block 3. Therefore, the oil in the oil reservoir 20 is tightly squeezed and depressurized in the vicinity of the oil hole inlet 21a, and then supplied to the back pressure chamber 19 side through the oil hole 21, the bearings 6 and 7, and the Sarai grooves 22 and 22. Therefore, a relatively low vane back pressure can be obtained. Therefore, when the discharge pressure Pd is high, a relatively high vane back pressure does not act on the vane 9 as in the conventional product, and the power of the compressor can be reduced compared to the conventional product. In this operation example, since the discharge pressure Pd is high, chattering of the vane 9 hardly occurs as described above even if the vane back pressure decreases, and chattering problems do not occur.
[0033]
Contrary to the above operation example, when the refrigerant gas discharge pressure Pd decreases, the bellows 43 of the variable throttle means 40 expands based on the pressure fluctuation, thereby increasing the valve opening degree of the spool valve 42 and loose throttle. It is formed at the oil hole inlet 21 a of the rear side block 3. For this reason, the oil in the oil reservoir 20 is supplied to the back pressure chamber 19 side through the oil hole 21, the bearings 6 and 7 and the Sarai grooves 22 and 22 without being squeezed much in the vicinity of the oil hole inlet 21a. A relatively high vane back pressure can be obtained. In this operation example, since the discharge pressure Pd is low, chattering of the vane 9 is likely to occur when the vane back pressure is low. Therefore, when the discharge pressure Pd is low, the vane back pressure is approximately the same as the conventional case. By increasing the pressure to the same level, chattering can be prevented from occurring.
[0034]
In the above embodiment, the variable throttle means 40 is provided at the oil hole inlet 21a. However, the variable throttle means 40 can be appropriately installed in the middle of the oil supply path 23 to the back pressure chamber side, It is not limited to the oil hole inlet 21a. Further, the diaphragm can be set not only to open and close, but also to change continuously.
[0035]
【The invention's effect】
In the present invention, as described above, the variable supply means is provided in the oil supply path to the back pressure chamber side so that the strength of the throttle changes based on the fluctuation of the discharge pressure of the refrigerant gas. For this reason, when the discharge pressure is high, considering that vane chattering is unlikely to occur even if the vane back pressure is low, the supply oil to the back pressure chamber side is tightly squeezed to set the vane back pressure low. It is possible to reduce the power of the compressor, and when the discharge pressure is low, considering that the vane chattering is relatively likely to occur if the vane back pressure is low, the supply oil to the back pressure chamber is throttled. Since the chattering can be effectively prevented by loosening the valve and setting the vane back pressure high, a gas compressor suitable for simultaneously reducing vane wear and compressor power and preventing vane chattering is provided. Can do.
[Brief description of the drawings]
FIG. 1 is an explanatory view of a main part of an embodiment of a gas compressor according to the present invention.
FIG. 2 is an operation explanatory diagram of a main part of the present invention shown in FIG.
FIG. 3 is an explanatory diagram of a relationship between a pressure distribution survey of an actual vehicle and a chatter limit.
FIG. 4 is a sectional view of a conventional gas compressor.
5 is a cross-sectional view taken along line CC in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Cylinder 2 Front side block 3 Rear side block 4 Rotor 5 Rotor shafts 6 and 7 Bearing 8 Vane groove 9 Vane 10 Compression chamber 11 Suction chamber 12 Discharge chamber 13 Suction passage 14 Suction port 15 Discharge hole 16 Reed valve 17 Discharge chamber 18 Oil separator 19 Back pressure chamber 20 Oil reservoir 21 Oil hole 21a Oil hole inlet 22 Salai groove 23 Oil supply path 40 Variable throttle means 41 Valve housing 42 Spool valve 42a Constriction passage 43 Bellows 43a Bellows 43a Bellows movable end 44 Inside housing Flow path 45 Bellows storage chamber Pd Discharge pressure

Claims (1)

An inner cylinder having a substantially elliptical shape, side blocks attached to both end faces of the cylinder, a rotor horizontally mounted on the inner side of the cylinder, and an outer peripheral surface of the rotor from the outer surface toward the inner wall of the cylinder A plurality of vanes provided so as to be able to appear and retract, a back pressure chamber that applies a vane back pressure to the bottom of the vane, and a compression chamber that is partitioned by the cylinder, the side block, the rotor, and the vane,
The volume of the compression chamber is repeatedly changed by the rotation of the rotor, and the change in the volume of the compression chamber causes suction of refrigerant gas from the intake chamber side to the compression chamber side, compression of the refrigerant gas in the compression chamber, and compression chamber In the gas compressor having a structure for obtaining the vane back pressure by discharging the refrigerant gas from the discharge chamber side to the discharge chamber side and supplying oil acting on the discharge pressure to the back pressure chamber side.
The oil supply path to the back pressure chamber side is provided with variable throttle means that changes the strength of the throttle based on the discharge pressure of the refrigerant gas ,
The variable throttle means includes a bellows that expands and contracts based on the refrigerant gas discharge pressure, and a spool valve that is attached to the movable end of the bellows. A gas compressor characterized by having a structure in which the opening degree changes .

Images