JPS6135756Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) This invention relates to a variable displacement compressor used in an air conditioner, specifically a compressor that controls the amount of refrigerant discharged according to load fluctuations of the air conditioner. .

(Prior Art) In general, in a so-called multi-type air conditioner in which one outdoor unit is intended to operate multiple indoor units, there are cases in which all indoor units are operated and cases in which one indoor unit is operated. The required air conditioning load differs greatly, and in the case of a multi-type air conditioner using one compressor, there is a risk of wasteful consumption of compressor power and a rise in the temperature of the refrigerant sucked into the compressor motor coil. In order to prevent burnout accidents, it is necessary to adjust the amount of refrigerant discharged from the compressor according to the fluctuations in the load.

Conventionally, however, when operating all indoor units, the compressor is operated at high capacity, and when operating one indoor unit, the amount of refrigerant discharged is reduced to operate at low capacity. ing.

Furthermore, even in the case of a separate type air conditioner with one outdoor unit and one indoor unit, load fluctuations may occur due to load fluctuations during cooling operation and heating operation, or load fluctuations due to differences in indoor temperature during each operation. Even so, it is desirable to adjust the amount of refrigerant discharged from the compressor.

Therefore, as shown in FIG. 4, the compressor used in the air conditioner as described above is equipped with an intermediate discharge valve e between the suction port c and the discharge port d of the cylinder chamber b formed in the housing a. A discharge hole f is provided,
By opening or closing this intermediate discharge valve e, the intermediate discharge hole f is communicated with or disconnected from the suction port c side, and during operation under a high load state, the intermediate discharge hole f is closed by the discharge valve e. When operating at a high capacity or under a low load state, by closing the discharge valve e and opening the intermediate discharge hole f, a part of the refrigerant in the middle of the compression stroke in the cylinder chamber b is directed to the suction port c side. The system is being bypassed for low-capacity operation.

Conventionally, in order to open and close the intermediate discharge valve e, a discharge pipe g connected to the discharge port d of the cylinder chamber b and a back chamber of the intermediate discharge valve e are connected outside the housing a. A first on-off valve i is interposed in the middle of the passage h, and a first on-off valve i in the passage h
and the back chamber are communicated with the inlet c to the cylinder chamber b via a passage j, and this passage j
A second on-off valve k is interposed in the middle.

However, during high load operation, the second on-off valve k
is closed, and by opening the first on-off valve i, a passage h is opened, and a part of the high-pressure refrigerant passing through the discharge pipe g is guided to the back chamber of the intermediate discharge valve e, and this high-pressure refrigerant causes the discharge valve e to be opened. By pushing it, the intermediate discharge hole f is closed, and the entire amount of refrigerant sucked through the suction port c is compressed and discharged to perform high capacity operation.

Also, during low load operation, the first on-off valve i is closed and the second on-off valve k is opened to open the passage j.
Then, the back chamber of the intermediate discharge valve e is communicated with the low-pressure suction port c, and accordingly, the intermediate discharge valve e is pushed by the high-pressure refrigerant in the cylinder chamber b, and the intermediate discharge hole f is opened. The cylinder chamber b is opened and a portion of the refrigerant in the middle of the compression stroke in the cylinder chamber b is bypassed to the suction port c to perform low capacity operation.

(Problem to be solved by the invention) However, when using the opening operation means for the intermediate discharge valve e as described above, the passages h, j and the on-off valves i,
Since the refrigerant k is provided outside the compressor housing a, the control high-pressure refrigerant in the passage h is cooled by the outside air and liquefied during high-capacity operation, and therefore, when switching to low-capacity operation In other words, when the first on-off valve i is closed and the second on-off valve k is opened, the liquefied refrigerant in the passage between the back chambers of these on-off valves i, k and the intermediate discharge valve e flows into the second on-off valve.
Simultaneously with the opening of the on-off valve k, liquid flows into the cylinder chamber b through the suction port c, causing rapid compression within the cylinder chamber b, which may cause the compressor to lock (stop). It can happen.

Furthermore, since each of the passages h and j is located outside the housing a, the flow resistance of the control refrigerant in each of the passages h and j is large, causing a power loss of the compressor. , j exchanges heat with the outside air, which has the drawback of increasing heat loss in the compressor.

The present invention was devised to solve the above-mentioned defects.The purpose of this invention is to eliminate the adverse effects of outside air by incorporating the opening/closing operation means of the intermediate discharge valve into a sealed housing, and to provide control during high-capacity operation. When the refrigerant is liquefied by outside air, it is possible to prevent the liquefied refrigerant from flowing into the suction side when switching to low-capacity operation, and it is also possible to eliminate heat loss in the compressor. In order to minimize the power loss of the compressor by reducing the flow resistance of the compressor, the switching operation between high capacity operation and low capacity operation by the opening/closing operation means can be performed by placing the opening/closing operation means in the sealed housing. To provide a variable capacity compressor which can operate accurately without malfunction by eliminating the adverse effects caused by changes in oil temperature, for example, which occur when the compressor is installed internally.

(Means for Solving the Problems) A variable displacement compressor according to the present invention has an upper head 11 and a lower head 1 inside a closed housing 1.
2 and a cylinder 14, the compression element B is provided with an intermediate discharge hole 12d that opens to the cylinder chamber 14a, and an intermediate discharge valve 16 that opens and closes the intermediate discharge hole 12d,
The intermediate discharge hole 12d by the intermediate discharge valve 16
It is a variable displacement compressor in which the compression capacity in the cylinder chamber 14a can be changed by opening and closing the rear chamber 18 of the intermediate discharge valve 16, and the compression element B inside the closed housing 1.
A switching control valve 21 is formed to switch between the suction side and the discharge side, and this switching control valve 21 is installed inside the sealed housing 1, and the switching control valve 21 and the back chamber 18 are connected to each other. Back chamber 18
a communication passage 3 that communicates with the suction side or the discharge side of the compression element B inside the sealed housing 1;
2b is provided inside the hermetically sealed housing 1, while two identically shaped first and second bimetals 28a and 28b are connected at a predetermined interval in the operating direction of the switching control valve 21, and the first bimetal 2
8a is operatively connected to the switching control valve 21, and the second bimetal 28b is connected to a stationary member that supports the switching control valve 21, and one of the first and second bimetals 28a and 28b is connected to the switching control valve 21. An electric heater 31 is attached to each bimetal 28.
a, 28b are built into the hermetically sealed housing 1.

(Function) Intermediate discharge hole 12d opens into cylinder chamber 14a
The rear chamber 18 of the intermediate discharge valve 16 that opens and closes is provided inside the sealed housing 1 with a switching control valve 21,
By switching the inside of the sealed housing 1 between the suction side and the discharge side, the passage for the control refrigerant leading to the back chamber of the intermediate discharge valve, which was conventionally provided outside the housing, can be eliminated, and the control refrigerant can be transferred to the outside air. This makes it possible to eliminate the adverse effects of refrigerant and to reduce the flow resistance of the refrigerant compared to the conventional method.

Also, a first switch that switches the switching control valve 21
And the second bimetals 28a and 28b deform the switching control valve 21 at the same time and in the same direction when the bimetals are affected by a temperature change inside the closed housing 1.
The switching control valve 21 can be operated accurately by deforming only the bimetal on one side to which the heater 31 is attached only when the heater 31 is energized.

(Example) Hereinafter, a variable displacement compressor according to the present invention will be described based on an example shown in the drawings.

The one shown in Figures 1 and 2 is a sealed high-pressure dome type rotary compressor that employs a bypass system, and has a cylindrical sealed housing 1 with a bottom plate 2 at the bottom and a cover plate 3 at the top. Motor element A above inside
and the compression element B is press-fitted and supported by one member constituting each of these elements A and B, specifically, the stator 8 of the motor element A and the upper head 11 of the compressor element B, A suction pipe 4 is attached to the side wall of the housing 1, and a discharge pipe 6 and an electric wire fitting 7 to the stator 8 are attached to the cover plate 3, respectively.

Further, the motor element A consists of the stator 8 and a motor shaft 10 fixed to the motor rotor 9, and the compression element B is sandwiched between the upper head 11 and the lower head 12 and both heads 11, 12. The cylinder 14 has a rotor 13 attached thereto. The upper head 11 has a suction passage 11a that communicates with the suction pipe 4, a suction port 11b that opens into the cylinder chamber 14a of the cylinder 14 and is equipped with a suction valve 11d, and a discharge passage that opens into the housing 1. 11c, and the cylinder 14 has a suction port 14b communicating with the suction port 11b, and a cylinder chamber 14.
a discharge valve 14e that communicates with a via a communication passage 14d.
A discharge port 14c and the discharge passage 11 with
The communication passage 14f leading to the cylinder chamber 14
They are provided on the suction side and the discharge side of a.

Also, the rotor 1 installed inside the cylinder chamber 14a
3 slidably supports two vanes (not shown), and the motor shaft 10 is opened in the center and fixed to the motor shaft 10. When driven, it rotates together with the motor shaft 10, compresses the refrigerant sucked in from the suction port 11b, and discharges it to the discharge port 14c.

The rotor 13 may be of the sliding vane type as described above or may be of the rolling piston type.

Further, the lower head 12 has a communication groove 1 that communicates the lower suction port 14b and the cylinder chamber 14a.
2a, and the discharge port 14c is connected to the communication path 14.
In addition to providing a communication groove 12c communicating with f, an intermediate discharge hole 12d, a valve hole 12e, and a bypass passage 12f are formed, and an intermediate discharge valve 16 is attached to the valve hole 12e.

The intermediate discharge hole 12d is connected to the cylinder chamber 14.
The valve hole 12e has a larger diameter than the inner diameter of the discharge hole 12d, and the valve hole 12e has a larger diameter than the inner diameter of the discharge hole 12d. Hole 12
The valve hole 12 is formed in the same direction as d.
A tapered sealing surface that slopes outward toward the rear is formed at the front end of e, that is, the connection to the discharge hole 12d.

Further, the valve hole 12e is passed through to the lower end of the lower head 12, and a guide rod is attached to the tip of the lower end.
It is closed by fitting the stopper 20 having 9.
This guide rod 19 allows an intermediate discharge valve 16, which will be described next, to be guided without misalignment.

Further, the intermediate discharge valve 16 attached to the valve hole 12e formed as described above is mainly constructed using a synthetic resin such as Polyflon, and has a head that protrudes into the discharge hole 12d and closes the discharge hole 12d. 16a, and a seal portion 1 connected to the seal surface.
6b, a cylindrical main body 16c having a smaller diameter than the inner diameter of the valve hole 12e, and an annular protrusion 16 that contacts the inner peripheral surface of the valve hole 12e at the rear end of the main body 16c.
d, and a spring 17 is interposed between the protruding portion 16d and a step provided in the middle of the valve hole 12e, and the discharge valve 16 is always biased so that the intermediate discharge hole 12d is opened. are doing.

In the middle of the valve hole 12e, a bypass passage 12f is opened which communicates with the communication hole 12a and communicates the intermediate discharge hole 12d with the suction side of the cylinder chamber 14a and the suction port 14b. As will be described later, the back chamber 18 of the discharge valve 16 at 12e is connected to the suction port 14b, which is the suction side of the compression element B inside the hermetic housing 1, and the airtight housing 1.
It is connected to a switching control valve 21 that selectively switches the internal space of the sealed housing 1, which is the discharge side of the compression element B inside the housing. and,
By operating this switching control valve 21, the back chamber 18
When high-pressure refrigerant and oil are introduced into the internal space of the sealed housing 1, the discharge valve 16 is moved against the spring 17 to close the intermediate discharge hole 12d.

At this time, the head 16a of the discharge valve 16 enters into the intermediate discharge hole 12d, closes the discharge hole 12d, and presses against the seal surface of the valve hole 12e of the seal portion 16b, thereby connecting the cylinder chamber 14a and the valve. Hole 12
e, and furthermore, the protrusion 16
d contacts the inner circumferential surface of the valve hole 12e, and the valve hole 1
2e and the bypass passage 12f, and the back chamber 18 are sealed.

The switching control valve 21 for switching and controlling the intermediate discharge valve 16 is provided in the lower head 12 and built into the housing 1.

This switching control valve 21 is installed in the middle of the bypass passage 12f in the lower head 12, specifically, on the opening side to the communication groove 12a.
The suction port 14 has one end on the suction side of the compression element B inside the sealed housing 1.
open to the bypass passage 12f communicating with b;
The other end has a valve hole 22a that opens into the internal space of the housing 1, which is the discharge side of the compression element B inside the sealed housing 1, and the valve hole 2
The valve housing 22 includes a valve housing 22 having a valve seat 22b at the upper end of the valve housing 2a, a spool 23 which is movably installed in the valve hole 22a of the valve housing 22, and an actuating body 25 having a through hole 25a in the center.

The spool 23 has lands 2 on both its upper and lower ends.
3a and 23b, and is always urged downward by a spring 24. Further, the operating body 2
5 is located below the spool 23, and has a valve seat at the upper end of the through hole 25a on which the lower land 23b is seated, and is always urged downward by a spring 26.

Thus, the intermediate portion of the valve hole 22a is connected to a communication passage 33 and an annular chamber 32 that is always in communication with the communication passage 33.
It communicates with a communication passage 32b, which is in constant communication with the back chamber 18 of the intermediate discharge valve 16, via a.

The spool 23 is operatively connected to a bimetal 28, which will be described later, via the operating body 25. Due to this connection, the spool 23 is lifted up via the operating body 25, and the upper land 23a is normally is away from the valve seat 22b,
An intermediate portion of the valve hole 22a is connected to the bypass passage 1.
It is open to 2F. The through hole 25a of the actuating body 25 is closed with the lower land 23b seated on its valve seat, which prevents the high pressure gas refrigerant in the housing 1 from flowing into the valve hole 22a. .

The bimetal 28 controls the operation of the spool 23 and the actuating body 25, and connects the middle part of the valve hole 22a, in other words, the back chamber 18 communicating with the middle part to either the bypass passage 12f or the inside of the housing 1. This is for selectively switching to one side, and the one shown in the drawing uses two first and second bimetals 28a, 28b of the same shape, and a connecting rod 29, 29, the first bimetal 28a is connected to the lower part of the operating body 25, and the second bimetal 28b is supported via a support 30 to the oil sump 27 fixed to the valve housing 22. The electric heater 3 is connected to this second bimetal 28b.
1 attached in a coil shape.

The bimetals 28a, 28b have an inverted V-shape with both ends inclined upward and the middle part located at the lower side, with the second bimetal 28b at the lower side, and both ends of each bimetal 28a, 28b are connected to the connecting rod 29. , 29, and the central portion is attached to the operating body 25 and the support body 30, respectively.

However, if the electric heater 31 is energized,
Since the second bimetal 28b is heated, the second bimetal 28b is deformed into a horizontal position due to this heating, and the actuating body 25 and the spool 23 are moved downward via the first bimetal 28a.

When the electric heater 31 is energized, the first bimetal 28a is not heated, so the first bimetal 28a is not deformed, and the deformation of the second bimetal 28b is caused by the deformation of the connecting rods 29, 29.
and the actuating body 2 via the first bimetal 28a.
5, which causes the actuating body 25 and the spool 23 to move downward.

The spool 23 is moved downward by the action of the spring 24 due to the downward movement of the operating body 25.
After the upper land 23a is seated on the valve seat 22b, it stops, and from then on, only the actuating body 25 moves downward, and the through hole 25a opens by the downward movement of the spool 23 after the downward movement is stopped. Back chamber 18
is switched into the inside of the housing 1 through the through hole 25a.

Further, the oil reservoir 27 has a box shape as a whole,
Openings 27a, 27a are provided at a predetermined height above the bottom of the opposing side walls, and an oil reservoir chamber 27b is formed below the openings 27a, 27a. 27b, the second bimetal 28b is disposed at the bottom of the housing 1, so that even if the lubricating oil stored at the bottom of the housing 1 decreases, the oil storage chamber 2
A constant amount of oil is maintained in the heater 7b, and this oil compensates for overheating of the heater 31.

As described above, the two first and second bimetals 28a and 28b, which have the same shape as the bimetal 28,
By configuring these bimetal 2
Even if the bimetals 28a, 28b are deformed due to a change in the temperature inside the housing 1 where the bimetals 8a, 28b are disposed, that is, the temperature of the discharged gas, these two bimetals 28a, 28b
They deform at the same time and in the same direction, and therefore, the actuating body 25 is no longer actuated by these deformations, and is actuated only by energizing the heater 31. In other words, malfunctions due to temperature changes can be prevented.

Incidentally, since the bimetals 28a and 28b are connected at a predetermined interval, reliable operation of the actuating body 25 can be expected without the temperature influence of the heater 31 being exerted on the first bimetal 28a in the upper part. be.

Furthermore, the heater 31 is of low voltage (12V) in order to prevent overcurrent during shooting.

The present invention is constructed as described above, and the intermediate discharge valve 16 is opened and closed by the operation of the switching control valve 21 to perform high capacity operation and low capacity operation.

When performing high capacity operation, the heater 31
By energizing the heater 31, the bimetal 28 is operated to move the lower actuating body 25 and the spool 23 downward, so that the middle part of the valve hole 22a, in other words, the middle part of the valve hole 22a. The back chamber 18 of the discharge valve 16 is opened into the inside of the housing 1.

Due to this opening, the high-pressure discharged gas refrigerant discharged into the housing 1 and the high-pressure oil stored in the inner bottom of the housing 1 are transferred from the through hole 25a of the actuating body 25 to the communication passage 33 provided in the valve housing 22. , the back chamber 1 via the annular chamber 32a and the communication passage 32b.
The intermediate discharge valve 16 is moved upward against the spring 17 by the high-pressure discharged gas refrigerant and oil, and the intermediate discharge valve 16 is closed to close the bypass passage 12f, thereby achieving high capacity operation. I will do it. In addition, when performing low capacity operation, this is done by turning off the power to the heater 31, and when the heater 31 is not energized, the actuating body 25 and the spool 23 move upward, causing the actuating body 25 to move upward. The through hole 25a is closed by the lower land 23b of the spool 23 to block the inflow of the high-pressure discharged gas refrigerant, and the space between the upper land 23a of the spool 23 and the valve seat 22b is opened to connect the back chamber 18 to a communication path. 32b, the annular chamber 32a and the communication passage 33 communicate with the bypass passage 12f, that is, the low-pressure suction side of the cylinder chamber 14a, and thereby the intermediate discharge valve 16 is moved downward by the spring 17 to open the bypass passage 12f. It is opened and operated at low capacity.

The heater 31 is linked to the cooling/heating switch of the air conditioner to energize the heater 31 during heating to operate the compressor at high capacity, and to operate the compressor at high capacity without energizing the heater 31 during cooling. It may be configured to perform low capacity operation, but it may also be linked to an indoor or outdoor thermostat to perform high capacity or low capacity operation depending on the indoor or outdoor temperature. Furthermore, in the case of a multi-type air conditioner, the heater 31 may be linked to the changeover switch of the indoor unit.In other words, when the air conditioning load is high, the heater 31 is energized to increase the capacity. This is done in order to perform low capacity operation without energizing the heater 31 when the load is low.

In the drawing, reference numeral 34 denotes an oil pump provided below the lower head 12 in conjunction with the motor shaft 10, which supplies lubricating oil stored in the lower part of the housing 1 to each part of the compression element B.

In the embodiment described above, by providing the bypass passage 12f in the lower head 12 and opening the intermediate discharge valve 16, the refrigerant in the middle of the compression stroke is bypassed from the bypass passage 12f to the suction port side.
This is a so-called bypass system in which the intermediate discharge valve 16 is closed to switch from high capacity operation to low capacity operation, but without providing the bypass passage 12f,
The intermediate discharge valve 16 is opened, and midway through the refrigeration cycle, a reduced intermediate pressure refrigerant is introduced between the discharge pressure and the suction pressure, and the discharge amount is increased.
It is also possible to apply a so-called introduction method in which the low-capacity operation is switched to the high-capacity operation with the cap 6 closed.

In this system, as shown in FIG. 3, a four-way switching valve 100 is connected to the suction pipe 4 and the discharge pipe 6, and an indoor heat exchanger 1 is connected to the four-way switching valve 100.
A gas-liquid separator 105 is interposed between 01 and the outdoor heat exchanger 102 via pressure reduction mechanisms 103 and 104, forming a refrigeration cycle as shown by the solid line arrow during cooling and as shown by the dotted line arrow during heating. From the gas region of the gas-liquid separator 105, the pressure reducing mechanism 10
A gas pipe 106 that guides a gas refrigerant reduced to an intermediate pressure is extended from one of the gas pipes 1 and 104.
06 is a valve hole 12 in which the intermediate discharge valve 16 is installed.
e, which is connected midway through the intermediate discharge valve 16.
When opened by the function of the switching control valve 21, the gas pipe 106 is communicated with the intermediate discharge hole 12d,
The intermediate pressure gas refrigerant separated by the gas-liquid separator 105 is delivered to the cylinder chamber 1 from the intermediate discharge hole 12d.
4a, thereby enabling high capacity operation to increase the discharge amount. Note that when the intermediate discharge valve 16 is closed, the discharge amount decreases, resulting in low capacity operation.

Further, in the case of the above structure, the rotor 13 is of a rolling piston type that does not use vanes. This rolling piston type rotates the rotor 13 eccentrically, and even when the intermediate discharge hole 12d is opened to introduce gas refrigerant at an intermediate pressure, the intermediate discharge hole 12d is closed by the eccentric rotation of the rotor 13. Discharge hole 12
d does not communicate with the suction port b.

(Effects of the invention) As described above, the present invention enables high-capacity operation and low-capacity operation by opening and closing the intermediate discharge hole using the intermediate discharge valve, and thus enables operation at an appropriate capacity depending on the load. The operation rate can be improved, and since the switching control valve that switches and controls the intermediate discharge valve is built into the housing, the control refrigerant is liquefied by outside air during high-capacity operation, unlike conventional compressors. This prevents liquefied refrigerant from flowing into the suction side when switching to capacity operation, which prevents the compressor from locking up, and eliminates heat exchange between the control refrigerant and the outside air, which reduces the compressor's performance. Not only can heat loss be prevented, but the flow resistance of the control refrigerant can be reduced, and the power loss of the compressor can be minimized.

In addition, bimetals that operate the switching control valve are placed in pairs facing each other at a predetermined distance from above and below,
By attaching a heater to one of the bimetals and switching the control valve by switching on and off the current to the heater, the control valve can be prevented from malfunctioning even if the ambient temperature during the bimetal cycle changes to any temperature. The control valve can be reliably operated only by energizing the heater, and by providing a predetermined distance between the upper and lower bimetals, the heater does not affect the temperature of the upper bimetal. This allows the control valve to be operated accurately.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of the compressor according to the present invention, showing a low capacity operating state, FIG. 2 showing the same high capacity operating state, and FIG. 3 showing another embodiment of the compressor. FIG. 4 is a vertical sectional view of the main part showing the embodiment, and is a diagram showing a conventional example. B... Compression element, 1... Housing, 11...
Upper head, 12... Lower head, 12d... Intermediate discharge hole, 14... Cylinder, 14a... Cylinder chamber, 16... Intermediate discharge valve, 18... Back chamber, 2
1...Switching control valve, 28a...First bimetal,
28b...Second bimetal, 31...Electric heater, 32b...Communication path.

Claims (1)

[Scope of utility model registration request] Inside the closed housing 1, an upper head 11,
A compression element B consisting of a lower head 12 and a cylinder 14 is installed inside, and a cylinder chamber 1 is installed in this compression element B.
4a, and an intermediate discharge valve 1 that opens and closes the intermediate discharge hole 12d.
6 is provided, and the cylinder chamber 14 is opened and closed by the intermediate discharge valve 16 to open and close the intermediate discharge hole 12d.
A variable displacement compressor is capable of changing the compression capacity in a, and the rear chamber 18 of the intermediate discharge valve 16 is switched between the suction side and the discharge side of the compression element B inside the sealed housing 1. A switching control valve 21 is formed and the switching control valve 21 is installed inside the sealed housing 1, and the switching control valve 21 and the back chamber 18 are connected to each other so that the back chamber 18 is connected to the back chamber 18 of the sealed housing 1. A communication passage 32b communicating with the suction side or the discharge side of the compression element B inside is provided inside the sealed housing 1, while two first and second passages having the same shape are provided.
bimetals 28a and 28b are connected at a predetermined interval in the operating direction of the switching control valve 21, and
A bimetal 28a is operatively connected to the switching control valve 21, and a second bimetal 28b is connected to a stationary member that supports the switching control valve 21,
An electric heater 31 is attached to either one of the first and second bimetals 28a, 28b, and each bimetal 28a, 28b is connected to the sealed housing 1.
A variable displacement compressor characterized by having a built-in.