JP3111668B2 - Refrigerant gas suction structure in piston type compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerant gas in a piston type compressor in which a piston is accommodated in a plurality of cylinder bores arranged around a rotary shaft and the piston reciprocates in conjunction with the rotation of the rotary shaft. It relates to a suction structure.

[0002]

2. Description of the Related Art In a conventional piston compressor (for example, see Japanese Patent Application Laid-Open No. 3-92587), a suction port between a compression chamber and a suction chamber defined in a cylinder bore by a piston is provided by a flapper valve in the compression chamber. It can be opened and closed. The refrigerant gas in the suction chamber pushes the flapper valve open by the suction operation of the piston moving from the top dead center side to the bottom dead center side, and flows into the compression chamber. In the discharge stroke in which the piston moves from the bottom dead center side to the top dead center side, the flapper valve closes the suction port, and the refrigerant gas in the compression chamber is discharged from the discharge port to the discharge chamber.

The opening / closing operation of the flapper valve is based on the pressure difference between the compression chamber and the suction chamber. If the pressure in the suction chamber is higher than the pressure in the compression chamber, the flapper valve bends and opens the suction port. . The pressure in the suction chamber becomes higher than the pressure in the compression chamber during the suction operation of the piston moving from the top dead center to the bottom dead center.

[0004]

The flapper valve, which is an elastic deformation, acts as an elastic resistance, and the flapper valve does not open unless the pressure in the suction chamber exceeds the pressure in the pressure chamber to some extent. That is, the opening of the flapper valve is delayed. Lubricating oil is mixed in the refrigerant gas for lubricating the inside of the compressor, and this lubricating oil is sent together with the refrigerant gas to a required lubricating portion in the compressor. This lubricating oil can enter anywhere in the refrigerant gas flow area, and the lubricating oil also adheres between the flapper valve closing the suction port and its close contact surface. This attached lubricating oil increases the close contact force between the close contact surface and the flapper valve, further delaying the start of the flapper valve's bending deformation. Such a delay in the start of bending deformation causes a decrease in the amount of refrigerant gas flowing into the compression chamber, that is, a decrease in volumetric efficiency. Also, when the flapper valve is open, the elastic resistance of the flapper valve acts as a suction resistance, and the refrigerant gas inflow decreases.

[0005] In a swash plate type compressor which is a kind of piston type compressor, refrigerant gas in a compression chamber is discharged to a discharge chamber by forward movement of a double-headed piston, and refrigerant gas in a suction chamber is moved back by a double-headed piston. Inhaled to. A plurality of double-headed pistons are used and housed in cylinder bores arranged at equal angular intervals around the rotation axis. The compression chamber is connected to the discharge chamber via the discharge port, and is connected to the suction chamber via the suction port via the suction port.
The discharge port is opened and closed by a discharge valve, and the refrigerant gas in the compression chamber is discharged to the discharge chamber while pushing the discharge valve. The suction port is opened and closed by a suction valve, and refrigerant gas in the suction chamber is sucked into the compression chamber while pushing down the suction valve.

[0006] There are one suction chamber before and after the cylinder,
It communicates with the swash plate chamber via a suction passage in the cylinder block. The external suction refrigerant gas pipe communicates with the swash plate chamber through the inlet, and the refrigerant gas is first introduced into the swash plate chamber by a suction action accompanying the reciprocating operation of the double-headed piston, and the suction passage and suction in the cylinder block. It is introduced into the compression chamber through the chamber.

[0007] The arrangement interval of the cylinder bores is increased to such an extent that the required strength of the cylinder block can be secured. The size of the arrangement interval is proportional to the size of the arrangement radius of the cylinder bores. The arrangement radius increases as the arrangement interval increases, and the arrangement radius decreases as the arrangement interval decreases. However, usually, the suction passages are provided one by one between a plurality of cylinder bores arranged at equal angular positions around the rotation shaft, and the existence of such passages causes a decrease in the strength of the cylinder block. Therefore, it is difficult to reduce the arrangement radius of the cylinder bores as long as the configuration in which the suction passage extends through the cylinder block is adopted, and it is difficult to make the compressor compact.

Further, the presence of the suction passage in the cylinder block causes a pressure loss, and the compression efficiency is reduced. The present invention provides a piston-type compressor that improves volumetric efficiency,
It is another object of the present invention to provide a swash plate type compressor capable of making the entire compressor compact.

[0009]

According to a first aspect of the present invention, a piston is accommodated in a plurality of cylinder bores arranged around a rotary shaft, and the piston reciprocates in conjunction with the rotation of the rotary shaft. In the type compressor, a suction passage for introducing refrigerant gas into a compression chamber defined by a piston in a cylinder bore is formed in a rotary valve, and a sliding contact peripheral surface of the rotary valve has a tapered shape. An inner peripheral surface of a receiving hole for receiving the rotary valve is tapered, so that the compression chamber and the suction passage are sequentially communicated with each other in synchronization with reciprocation of a piston, and slidably in an axial direction of the rotary valve. Is accommodated in the accommodation hole, and a sealing force for urging the rotary valve from the large-diameter end to the small-diameter end is applied to the rotary valve.

According to a second aspect of the present invention, the double-headed piston is housed in a plurality of pairs of cylinder bores which are arranged around the rotary shaft and are paired before and after, and the rotational movement of the swash plate supported by the rotary shaft is controlled by the double-headed piston. In a piston type compressor for converting the reciprocating motion of a rotary valve, a suction passage for introducing refrigerant gas into a compression chamber defined by a double-headed piston in a cylinder bore is formed in a rotary valve, and a sliding contact peripheral surface of the rotary valve is formed. Is formed in a tapered shape so as to sequentially communicate with the compression chamber and the suction passage in synchronization with the reciprocating motion of the double-headed piston, and slidably support the rotary valve on a rotating shaft, and a large-diameter end of the rotary valve. The portion side was exposed to the discharge pressure region, and the small-diameter end portion of the rotary valve was exposed to the swash plate chamber in the suction pressure region.

[0011]

The suction passage in the rotary valve sequentially communicates with a plurality of compression chambers as the rotary valve rotates. This communication is performed in synchronization with the operation of sucking the piston into one of the front and rear compression chambers. When the suction passage and the compression chamber communicate with each other, the piston moves toward the bottom dead center, and the pressure in the compression chamber is reduced to a pressure equal to or lower than the suction passage pressure (suction pressure). This pressure drop causes the refrigerant gas in the suction passage to flow into the compression chamber.

The rotary valve is urged from the large-diameter end to the small-diameter end by applying a higher refrigerant gas pressure to the large-diameter end than to the small-diameter end. By this bias, the tapered peripheral surface of the rotary valve is pressed against the tapered inner peripheral surface of the housing hole, and the seal on the tapered peripheral surface of the rotary valve is secured.

When the refrigerant gas pressure is applied to the large-diameter end of the rotary valve at a lower pressure than that of the small-diameter end, a spring force is applied to the large-diameter end to make the rotary valve have a large-diameter end. Part is urged toward the small diameter end. By this bias, the tapered peripheral surface of the rotary valve is pressed against the tapered inner peripheral surface of the housing hole.

The configuration in which the refrigerant gas in the swash plate chamber is introduced into the compression chamber via a rotary valve eliminates the need for a conventional suction passage in a cylinder block. By omitting the suction passage in the cylinder block, the arrangement radius of the cylinder bores can be reduced, and the entire compressor can be made compact.

[0015]

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

As shown in FIG. 1, receiving holes 1a and 2a are formed at the center of a pair of front and rear cylinder blocks 1 and 2 which are joined. Valve plates 3 and 4 are joined to the end faces of the cylinder blocks 1 and 2, and support holes 3 a and 4 a are provided through the valve plates 3 and 4. Annular positioning projections 3b, 4b are projected from the peripheral edges of the support holes 3a, 4a.
a, 2a. Pins 5 and 6 are inserted through the valve plates 3 and 4 and the cylinder blocks 1 and 2, and the rotation of the valve plates 3 and 4 with respect to the cylinder blocks 1 and 2 is prevented by the pins 5 and 6.

Support holes 3a, 4a of valve plates 3, 4
A rotatable shaft 7 is rotatably supported via conical roller bearings 8 and 9, and a swash plate 10 is fixedly supported on the rotatable shaft 7. Cylinder block 1 forming swash plate chamber 11
2, an inlet 12 is formed, and the inlet 12 is connected to an external suction refrigerant gas pipe (not shown).

As shown in FIGS. 3 and 4, a plurality of cylinder bores 13, 1
3A, 14 and 14A are formed. As shown in FIG. 1, a pair of cylinder bores 13, 14, 13A, 1
4A (five pairs in this embodiment) has double-headed pistons 15, 1
5A is reciprocally accommodated. Double-headed piston 1
Hemispherical shoes 16, 17 are interposed between 5, 5A and the front and rear surfaces of the swash plate 10. Accordingly, the rotation of the swash plate 10 causes the double-headed pistons 15, 15A to move back and forth in the cylinder bores 13, 14, 13A, 14A.

A front housing 18 is joined to the end face of the cylinder block 1, and a rear housing 19 is also joined to the end face of the cylinder block 2. As shown in FIGS. 5 and 6, a plurality of pressing projections 18a, 19a are provided on the inner wall surfaces of the housings 18, 19, respectively.
An annular plate-shaped preload applying spring 20 is interposed between the holding projection 18a and the outer ring 8a of the conical roller bearing 8. The holding projection 19 a is in contact with the outer ring 9 a of the conical roller bearing 9. The inner races 8b, 9b sandwiching the rollers 8c, 9c together with the outer races 8a, 9a are in contact with the steps 7a, 7b of the rotary shaft 7. The cylinder block 1, the valve plate 3, and the front housing 18 are fastened and fixed by bolts 21. The cylinder block 1, the cylinder block 2, the valve plate 4, and the rear housing 19 are fixed by bolts 22. The conical roller bearings 8 and 9 receive both the radial load and the thrust load on the rotating shaft 7. The tightening of the bolt 21 causes the preload applying spring 20 to bend and deform, and this bending deformation applies a preload in the thrust direction to the rotary shaft 7 via the conical roller bearing 8.

A discharge chamber 2 is provided in both housings 18 and 19.
3, 24 are formed. Double-headed piston 15, 15A
The compression chambers Pa and Pb defined in the cylinder bores 13, 14, 13A, and 14A are connected to the discharge chambers 23 and 24 via the discharge ports 3c and 4c on the valve plates 3 and 4, respectively. The discharge ports 3c and 4c are opened and closed by flapper valve type discharge valves 31 and 32, respectively. The opening of the discharge valves 31 and 32 is regulated by retainers 33 and 34. Discharge valve 3
The retainers 1 and 32 and the retainers 33 and 34 are fixed on the valve plates 3 and 4 by bolts 35 and 36. The discharge chamber 23 communicates with a not-shown external discharge refrigerant gas pipe via a discharge passage 25.

Reference numeral 26 denotes a discharge chamber 23 along the peripheral surface of the rotating shaft 7.
This is a lip seal that prevents refrigerant gas from leaking from the compressor to the outside. Rotary valves 27 and 28 are slidably supported by the steps 7 a and 7 b on the rotating shaft 7. Seal rings 39 and 40 are interposed between the rotary valves 27 and 28 and the rotating shaft 7. Rotary valve 2
The reference numerals 7 and 28 are accommodated in the accommodation holes 1a and 2a so as to be rotatable in the direction of arrow Q in FIG.

As shown in FIG. 2, the receiving holes 1a and 2a have a tapered shape, and the diameter of the receiving holes 1a and 2a decreases from the end faces of the cylinder blocks 1 and 2 toward the inside. Rotary valve 2
The peripheral surfaces 27c, 28c of 7, 7 are tapered in the same shape as the receiving holes 1a, 2a. The peripheral surfaces 27c, 28c of the rotary valves 27, 28 can be fitted exactly to the inner peripheral surfaces of the housing holes 1a, 2a. That is, the large-diameter end 27a side of the rotary valve 27 faces the discharge chamber 23 side, and the rotary valve 2
The small-diameter end 27b side of 7 faces the swash plate chamber 11 side.
The large-diameter end 28a side of the rotary valve 28 is
4 side, and the small-diameter end 28b side of the rotary valve 28 faces the swash plate chamber 11 side.

In the rotary valves 27 and 28, suction passages 29 and 30 are formed. The inlets 29a, 30a of the suction passages 29, 30 open on the small-diameter ends 27b, 28b, and the outlets 29b, 30b of the suction passages 29, 30 open on the tapered peripheral surfaces 27c, 28c.

As shown in FIG. 3, cylinder bores 13, 13 are provided on the inner peripheral surface of the accommodation hole 1a for accommodating the rotary valve 27.
The same number of suction ports 1b as A are arranged at equal angular positions. Suction port 1b and cylinder bores 13, 13
A is always in one-to-one communication with A, and each suction port 1b is connected to a circulating region of the outlet 29b of the suction passage 29.

Similarly, as shown in FIG. 4, the cylinder bore 1 is formed on the inner peripheral surface of the accommodation hole 2a for accommodating the rotary valve 28.
The same number of suction ports 2b as 4, 14A are arranged at equal angular intervals. Suction port 2b and cylinder bore 1
The suction ports 2b are always in communication with the suction ports 4 and 14A in a one-to-one correspondence, and each suction port 2b is connected to a circulation area of the outlet 30b of the suction passage 30.

In the state shown in FIGS. 1, 3 and 4, the double-headed piston 15A is at the top dead center position with respect to one cylinder bore 13A and at the bottom dead center position with respect to the other cylinder bore 14A. Double-headed piston 15A has cylinder bore 13
When the suction stroke from the top dead center to the bottom dead center starts, the suction passage 29 communicates with the compression chamber Pa of the cylinder bore 13A. By this communication, the refrigerant gas in the swash plate chamber 11 is sucked into the compression chamber Pa of the cylinder bore 13A via the suction passage 29. On the other hand, when the double-headed piston 15A enters the discharge stroke from the bottom dead center position to the top dead center position with respect to the cylinder bore 14A, the communication of the suction passage 30 with the compression chamber Pb of the cylinder bore 14A is cut off. Due to this communication interruption, the refrigerant gas in the compression chamber Pb of the cylinder bore 14A is discharged from the discharge port 4c to the discharge chamber 24 while pushing down the discharge valve 3.

The suction and discharge of the refrigerant gas are performed in the compression chambers P of the other cylinder bores 13 and 14 in the same manner. One end of the rotating shaft 7 projects outside from the front housing 18, and the other end projects into the discharge chamber 24 on the rear housing 19 side. A discharge passage 37 is formed in the axis of the rotating shaft 7. The discharge passage 37 is connected to the discharge chamber 24.
It is open to. Discharge chamber 2 on front housing 18 side
3 is provided at a peripheral portion of the rotating shaft 7 surrounded by
8 is formed, and the discharge chamber 23 and the discharge passage 37 are communicated with each other by the outlet 38. Therefore, the front and rear discharge chambers 23 and 24 communicate with each other through the discharge passage 37, and the refrigerant gas in the discharge chamber 24 joins the discharge chamber 23 from the discharge passage 37.

In the case of the flapper valve type suction valve, the lubricating oil increases the suction force between the suction valve and its close contact surface, and the opening start timing of the suction valve is delayed by the suction force. This delay causes the suction resistance due to the elastic resistance of the suction valve to reduce the volumetric efficiency. However, when the rotary valves 27 and 28 that are forcibly rotated are used, there is no problem of the suction force due to the lubricating oil and the suction resistance due to the elastic resistance of the suction valve, and the pressure in the compression chambers Pa and Pb increases the suction in the swash plate chamber 11. If the pressure is slightly lower, the refrigerant gas is immediately released into the compression chambers Pa and Pb.
Flows into. Therefore, when the rotary valves 27 and 28 are used, the volume efficiency is greatly improved as compared with the case where the flapper valve type suction valve is used.

The structure in which the refrigerant gas sucked from the swash plate chamber 11 is sucked into the compression chambers Pa and Pb through the suction passages 29 and 30 in the rotary valves 27 and 28 is constituted by a plurality of cylinders in a conventional swash plate compressor. Eliminates the need for a suction passage. Further, the configuration in which the discharge refrigerant gas discharged into the discharge chamber 24 is guided to the discharge passage 25 via the discharge passage 37 in the rotating shaft 7 eliminates the need for the discharge passage in the cylinder block in the conventional swash plate type compressor. By eliminating the suction passage and the discharge passage from the cylinder blocks 1 and 2, the arrangement intervals of the cylinder bores 13, 13A, 14, and 14A can be reduced. The decrease in the arrangement interval of the cylinder bores 13, 13A, 14, 14A is caused by the cylinder bores 13, 13A, 14, 14A.
This leads to a reduction in the arrangement radius of the cylinder block A,
2 is achieved. Therefore, diameter reduction and weight reduction of the entire compressor are achieved.

The refrigerant gas in the swash plate chamber 11 is supplied to the compression chambers Pa, P
b, the pressure in the compression chamber P becomes lower than the pressure in the swash plate chamber 11.
a, Pb. From the swash plate chamber 11 to the compression chambers Pa and P
If the flow path resistance in the refrigerant gas flow path up to b, that is, the suction resistance is high, the pressure loss increases, and the compression efficiency decreases. By employing the rotary valves 27 and 28, the length of the refrigerant gas flow path from the swash plate chamber 11 to the compression chambers Pa and Pb is shortened, and the suction resistance is reduced as compared with the conventional case. Therefore, loss is reduced and compression efficiency is improved.

The swash plate chamber 11 is a suction pressure region, and the discharge chamber 2
Reference numerals 3 and 24 are discharge pressure regions. Therefore, the discharge chamber 23,
There is a possibility that the discharged refrigerant gas of 24 leaks along the peripheral surfaces 27c and 28c of the rotary valves 27 and 28. The peripheral surfaces 27c, 28c of the rotary valves 27, 28 are tapered, and the inner peripheral surfaces of the receiving holes 1a, 2a for receiving the rotary valves 27, 28 are also tapered. or,
The large-diameter ends 27a and 28a of the rotary valves 27 and 28 are exposed to the discharge pressure area, and the small-diameter ends 27b and 28b are exposed to the suction pressure area. That is, the rotary valve 2
7, 28 are small-diameter end portions 27a from the large-diameter end portions 27a, 28a side.
b, 28b. By this bias, the tapered peripheral surfaces 27c, 28c of the rotary valves 27, 28 are pressed against the inner peripheral surfaces of the housing holes 1a, 2a, and the rotary valve 2
7 and 28 rotate while slidingly contacting the inner peripheral surfaces of the receiving holes 1a and 2a. Therefore, the refrigerant gas discharged from the discharge chambers 23, 24 does not leak to the swash plate chamber 11 from between the peripheral surfaces 27c, 28c of the rotary valves 27, 28 and the inner peripheral surfaces of the housing holes 1a, 2a.

The seals at the tapered peripheral surfaces 27c and 28c are obtained by the difference between the high and low pressures of the refrigerant gas, and the seal between the rotary valves 27 and 28 and the rotating shaft 7 is ensured by the seal rings 39 and 40.

Sliding contact surface 27 of rotary valves 27 and 28
The configuration in which c and 28c are tapered prevents leakage of the discharged refrigerant gas, and improves the volumetric efficiency. Moreover, the accommodation hole 1
The work of fitting the rotary valves 27 and 28 into the holes a and 2a is also facilitated.

If the sliding peripheral surface of the rotary valve has a straight shape, the inner peripheral surface of the housing hole also needs to be straight. In the case of such a straight shape, it is necessary to provide a clearance between the peripheral surface of the rotary valve and the inner peripheral surface of the accommodation hole in order to smoothly rotate the rotary valve in the accommodation hole. The presence of this clearance causes leakage of the discharged refrigerant gas. It is also conceivable to interpose a seal ring between the rotary valve and the accommodation hole.
However, the seal ring comes into sliding contact with the inner peripheral surface of the housing hole, and wear and deterioration occur in a short time. In addition, the work of inserting the rotary valve into the accommodation hole becomes troublesome.

Sliding contact surface 27 of rotary valves 27 and 28
The configuration in which c and 28c are tapered has the following advantages. Sliding contact between the tapered inner peripheral surfaces of the accommodation holes 1a, 2a and the tapered peripheral surfaces 27c, 28c of the rotary valves 27, 28 causes wear on the sliding contact peripheral surfaces, but the rotary valves 27, 28 are attached to the accommodation holes 1a, 2a. Always make good sliding contact. That is, the rotary valves 27 and 28 and the accommodation hole 1
The seal between a and 2a has a self-replenishing function, and the sealability does not decrease. Even if the linear expansion coefficients of the rotary valves 27 and 28 are different from the linear expansion coefficients of the cylinder blocks 1 and 2, the self-replenishing function of the seal is always ensured. Therefore, the sealing performance does not change even when the temperature inside the compressor changes. In addition, the rotary valves 27 and 28 can be made of synthetic resin.
The tapered configuration of the sliding contact peripheral surfaces 27c and 28c contributes to the weight reduction of the compressor.

The present invention is, of course, not limited to the above embodiment. For example, as shown in FIGS. 7 and 8, an embodiment in which the present invention is embodied in a variable displacement type swash plate type compressor is also possible. It is.

As shown in FIG. 7, a rotary shaft 44 is rotatably supported by the cylinder block 41 and the front housing 42 via conical roller bearings 56A and 56B. A rotation driving body 46 is connected to and supported by a rotation support 45 fixed to the rotation shaft 44 so as to be capable of changing the inclination angle by engaging a pin 47 with an elongated hole 45b on an arm 45a. The rotary driving body 46 is swingably supported by shaft pins 48a protruding from left and right sides of a guide sleeve 48 on the rotary shaft 44, and a swing swash plate 49 is relatively rotatable on the rotary driving body 46. It is supported by.

Each of the pistons 50, 50A, 50B in the plurality of cylinder bores 41a (six in this embodiment) is connected to the swash plate 49 via the piston rod 50a.
The rotational motion of the rotating shaft 44 is converted into a reciprocating swing of the swinging swash plate 49 via the rotating support 45 and the rotating driver 46,
The pistons 50, 50A, 50B move back and forth in the cylinder bore 41a.

Cylinder block 41 and rear housing 4
3, a valve plate 51, a valve forming plate 52
And the retainer forming plate 53 is sandwiched. Discharge chamber 43a and the compression chamber P of the rear housing 43, P _1, P ₂
Are connected via a discharge port 51a on the valve plate 51. The discharge valve 52a on the valve forming plate 52 opens and closes the discharge port 51a on the discharge chamber 43a side, and the retainer 53a on the retainer forming plate 53 regulates the amount of bending deformation of the discharge valve 52a.

Housing recesses 41b, 43b are formed in the center of the opposed end surfaces of the cylinder block 41 and the rear housing 43, and the end of the rotating shaft 44 projects into the housing recess 41b. The two receiving recesses 41b and 43b are
A conical storage chamber having an axial center in the axial direction is formed, and a rotary valve 54 is rotatably stored in the storage chambers 41b and 43b. The peripheral surface 54c of the rotary valve 54 is tapered, and the accommodation chambers 41b and 43b are also tapered.

The end face of the accommodation recess 43b and the rotary valve 5
4, a gap is provided between the small-diameter end portion 54a and the small-diameter end portion 54a.
A coupling 55 is fitted and fixed to the large-diameter end 54 b of the rotary valve 54. The protruding end 44a of the rotating shaft 44 protruding into the housing recess 41b and the coupling 55 are fitted so as to be relatively non-rotatable and slidable. The rotary valve 54 is integrated with the rotation shaft 44 and
In 3b, it rotates in the direction of arrow R in FIG.

A suction passage 57 is formed in the rotary valve 54. Housing recess 43b of rotary valve 54
An inlet 57a of the suction passage 57 is formed on the side end surface, and an outlet 57b of the suction passage 57 is formed on the peripheral surface of the rotary valve 54. An inlet 43c is formed at the center of the rear housing 43 so as to be connected to the housing recess 43b.
It communicates with c.

The compression chambers P,
The same number of suction ports 41c as P ₁ and P ₂ are arranged at equal angular intervals. Each suction port 41c is connected to a circulation area of the outlet 57b of the suction passage 57. In the state shown in FIGS. 7 and 8, the piston 50A is at the top dead center position, and the piston 50B at the 180 ° rotationally symmetric position is at the bottom dead center position.

The refrigerant gas sucked into the compression chambers P, P ₁ , and P ₂ is discharged by the discharge chamber 43 a while being compressed by the discharge operation of the piston from the bottom dead center position to the top dead center position. The stroke of the piston changes in accordance with the pressure difference between the internal pressure and the suction pressure in the compression chamber through the piston, and the tilt angle of the swash plate 49 that affects the compression capacity changes. The pressure in the crank chamber 42a is controlled by supplying the refrigerant gas in the discharge pressure area to the crank chamber 42a and controlling the discharge of the refrigerant gas in the crank chamber 42a to the suction pressure area by a control valve mechanism (not shown). That is, the pressure in the crank chamber 42a is higher than the suction pressure.

The pressure in the crank chamber 42a acts on the large-diameter end 54b of the rotary valve 54,
The pressure inside acts on the small diameter end 54 a of the rotary valve 54. By this pressure action, the rotary valve 54 is urged from the large-diameter end 54b side to the small-diameter end 54a side, and the tapered peripheral surface 54c of the rotary valve 54 is accommodated in the storage chambers 41b and 43.
b. Therefore, the high-pressure refrigerant gas in the compression chamber does not leak from the sliding contact peripheral surface 54c of the rotary valve 54 to the inlet 43c or the crank chamber 42a side.

The present invention is further applicable to an embodiment as shown in FIG. In this embodiment, the pressure in the swash plate chamber 11 acts on the large-diameter ends 58a, 59a of the rotary valves 58, 59, and the pressure in the discharge chambers 23, 24 reduces the small-diameter ends 58b, 59b.
Is acting on. Seal springs 60, 61 are interposed between the large diameter ends 58a, 59a and the swash plate 10. The tapered peripheral surfaces 58c, 59c of the rotary valves 58, 59 are pressed against the tapered inner peripheral surfaces of the housing holes 1a, 2a by the spring force of the seal springs 60, 61.

The large-diameter ends 58a, 59a and the small-diameter ends 58
If the spring force of the seal springs 60, 61 is set so as to exceed the pressure difference acting on the taper peripheral surface 59,
The sealing properties at c and 60c are properly secured. If this set spring force is made as small as possible, the tapered peripheral surface 58
Excessive pressure contact between c, 59c and accommodation holes 1a, 2a is avoided. That is, by applying the minimum spring force necessary for the seal to the rotary valves 58 and 59, excessive pressure contact can be avoided, and power loss due to sliding contact can be minimized.

FIGS. 7 and 8 show a configuration employing a seal spring.
The present invention can also be applied to the swinging swash plate type compressor.

[0049]

As described above in detail, according to the present invention, the refrigerant gas is introduced into the compression chamber through the suction passage in the rotary valve, and the sliding surface of the rotary valve is tapered.
Since a sealing force that urges the rotary valve from the large-diameter end to the small-diameter end is applied to the rotary valve, leakage of refrigerant gas between the discharge pressure area and the suction pressure area partitioned by the rotary valve is prevented. This has an excellent effect that the volume efficiency can be improved.

Further, the swash plate compressor has an excellent effect that the whole compressor can be made compact.

[Brief description of the drawings]

FIG. 1 is a side sectional view of an entire compressor showing an embodiment embodying the present invention.

FIG. 2 is an enlarged side sectional view of a main part.

FIG. 3 is a sectional view taken along line AA of FIG. 1;

FIG. 4 is a sectional view taken along line BB of FIG. 1;

FIG. 5 is a sectional view taken along line CC of FIG. 1;

FIG. 6 is a sectional view taken along line DD of FIG. 1;

FIG. 7 is a side sectional view of the entire compressor showing another example.

FIG. 8 is a sectional view taken along line EE of FIG. 7;

FIG. 9 is a side sectional view of the entire compressor showing another example.

[Explanation of symbols]

1a, 2a: accommodation hole, 7: rotating shaft, 11: swash plate chamber serving as suction pressure area, 23, 24 ... discharge chamber serving as discharge pressure area, 2
7, 28: rotary valve, 27a, 28a: large-diameter end, 27b, 28b: small-diameter end, 27c, 28c: tapered peripheral surface, 29, 30: suction passage, 41b, 43b: accommodation recess.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazuya Kimura 2-1-1, Toyotamachi, Kariya, Aichi Prefecture Inside Toyota Industries Corporation (58) Field surveyed (Int. Cl. ⁷ , DB name) F04B 27 / 08

Claims (2)

(57) [Claims] 1. A piston type compressor in which a piston is accommodated in a plurality of cylinder bores arranged around a rotation shaft and the piston reciprocates in conjunction with rotation of the rotation shaft, the piston is partitioned into the cylinder bore by the piston. A suction passage for introducing the refrigerant gas into the compression chamber is formed in the rotary valve, and the sliding contact peripheral surface of the rotary valve is tapered, and the inner peripheral surface of the accommodation hole for accommodating the rotary valve is tapered. The rotary valve is housed in the housing hole so as to sequentially communicate the compression chamber and the suction passage in synchronization with the reciprocating motion of the piston, and is slidable in the axial direction of the rotary valve. A refrigerant gas suction structure in a piston type compressor in which a sealing force urging from a radial end to a small diameter end is applied to a rotary valve. 2. A double-headed piston is accommodated in a plurality of pairs of cylinder bores arranged before and after arranged around the rotation shaft, and the rotation of the swash plate supported by the rotation shaft is converted to the reciprocation of the double-headed piston. In converting piston type compressor,
A suction passage for introducing refrigerant gas into a compression chamber defined by a double-headed piston in a cylinder bore is formed in the rotary valve, and the sliding surface of the rotary valve has a tapered shape and a housing for housing the rotary valve. The inner peripheral surface of the hole is tapered so that the compression chamber and the suction passage are sequentially communicated with each other in synchronization with the reciprocating motion of the double-headed piston, and the rotary valve is slidably supported on the rotary shaft. A refrigerant gas suction structure in a piston type compressor in which a large diameter end of a valve is exposed to a discharge pressure region and a small diameter end of a rotary valve is exposed to a swash plate chamber in a suction pressure region.