JPH09145172A - Thermocompression type refrigerating machine with built-in type variable capacity type compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an evaporator from being frozen even when a solenoid clutch is saved. SOLUTION: When an evaporator is not cooled, an opening and closing valve 72 is opened. The pressure of a high pressure chamber 12 is guided to a pressure chamber 70 and a flow rate regulating valve 61 is closed. At the same time, the pressure of the high pressure chamber 12 is guided to a crank chamber 44 so that the inclination of a swash plate is decreased. As a result, the capacity of a variable capacity type compressor 1 becomes minimum, and quantity of a refrigerant flowing through a refrigerating machine circuit is more decreased. Thus, the evaporator can be prevented from freezing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION A vapor compression refrigerator incorporating a variable displacement compressor according to the present invention is used in an air conditioner for a vehicle in order to cool and dehumidify the interior of a vehicle.

[0002]

2. Description of the Related Art A vapor compression refrigerator incorporated in an automobile air conditioner is constructed as shown in FIG. The compressor 1 compresses the refrigerant vapor sucked from the suction port and discharges it from the discharge port. The refrigerant discharged from the compressor 1 dissipates heat by exchanging heat with the air while passing through the condenser 2 to be condensed. The liquid refrigerant discharged from the condenser 2 passes through the liquid tank 3 and the expansion valve 4 and is then sent into the evaporator 5, where it is evaporated. Since the temperature of the evaporator 5 decreases due to the evaporation of the refrigerant inside the air, the air passing through the evaporator 5 can be cooled to cool or dehumidify the interior of the automobile.

The compressor 1 which constitutes such a vapor compression refrigerator of an automobile air conditioner is driven by a traveling engine of an automobile through a belt and a pulley. Therefore, when the automobile air conditioner is used, the power of the running engine is consumed to drive the compressor 1, and in some cases, the power performance may be insufficient or the power performance may become unstable. That is, when the electromagnetic clutch, which is attached to the pulley and is turned on and off according to the cooling load, is operated, the amount of the driving engine actually used for traveling greatly changes. It causes inconvenience. In order to eliminate or reduce such an inconvenience, it has become popular in recent years to use a so-called variable displacement type compressor that changes the discharge amount of the refrigerant as the compressor 1.

Variable capacity compressors have hitherto been disclosed in JP-A-59-46378, JP-B-2-61627, US Pat. No. 4,073,603 and 44,258.
It is well known as described in many publications such as the specification No. 37. 5 to 6 show an example of a variable displacement compressor which has been publicly implemented in Japan by the applicant company. In addition, FIG. 5 shows a state in which the capacity is maximized.
Shows the same minimum state. First, the known variable displacement compressor shown in FIGS. 5 and 6 will be described.

A casing 6 constituting the compressor 1.
Includes a central cylinder case 7 sandwiched between a head case 8 and a crank case 9 from both sides in the axial direction (the left-right direction in FIGS. 5 to 6), and further coupled by a plurality of coupling bolts 10. Inside the head case 8 is a low-pressure chamber 1
1, 11 and high pressure chambers 12, 12 are provided. FIG.
Low pressure chamber 1 shown as being divided into a plurality of
1 and 11 communicate with each other, and communicate with a single suction port 17 (see FIGS. 1 to 3 showing an embodiment of the present invention, omitted in FIGS. 5 to 6) provided on the outer surface of the head case 8. ing. Similarly, the high-pressure chambers 12 and 12 communicate with each other, and also communicate with a single discharge port (not shown) provided on the outer surface of the head case 8. The suction port 17 is connected to the outlet of the evaporator 5 (FIG. 4), and the discharge port is connected to the inlet of the condenser 2 (FIG. 4).

A drive shaft 13 is rotatably supported in the casing 6 in a state of being bridged between the cylinder case 7 and the crankcase 9. Also, inside the casing 6, a plurality (for example, 5 to 6 at equal intervals in the circumferential direction) is provided.
Cylinders 14 are formed individually (only one is shown in the drawing). In the case of a known compressor, the central axis of each cylinder 14 is formed parallel to the drive shaft 13, but it is not necessarily strictly parallel if it is substantially parallel.
In particular, depending on the connection structure of the swash plate 27 described later and the piston 16 described below, the central axis of each cylinder 14 approaches the drive shaft 13 in a direction in which the central axis of each cylinder 14 approaches the drive shaft 13 as the head case 8 approaches. Inclining about 3 degrees may prevent uneven wear of the inner peripheral surface of the cylinder 14 and the outer peripheral surface of the piston 16. However, regarding this point,
Since it is described in Japanese Patent Application No. 7-28321 and is not related to the gist of the present invention, detailed description thereof will be omitted. In any case, as long as the piston 16 can smoothly reciprocate in the cylinder 14 as the drive shaft 13 rotates, the center axis of each cylinder 14 may be slightly inclined with respect to the drive shaft 13. Absent. Pistons 16 are fitted inside the plurality of cylinders 14 formed in the cylinder case 7 in such a manner so as to be displaceable in the axial direction.

On the other hand, a first hub 20 is fixed to a portion of the intermediate portion of the drive shaft 13 facing the inner surface of the end wall 19 of the crankcase 9, and the first hub 20 is fixed to the drive shaft 13. I am trying to rotate with it. A thrust roller bearing 21 is provided between the first hub 20 and the end wall 19.
Is provided so that the thrust load applied from the piston 16 to the first hub 20 can be supported. In addition, a second hub 22 is provided in a portion of the drive shaft 13 which is closer to the cylinder case 7 than the first hub 20 in the middle portion of the drive shaft 13 in the axial direction of the drive shaft 13 (left and right in FIGS. Direction) is fitted so that it can be displaced freely. Then, one end face in the axial direction of the second hub 22 (the right end face in FIGS. 5 to 6) and the first hub 2 described above.
The first compression spring 23 is connected to the stop ring 25 fixed to the outer peripheral surface of the intermediate portion of the drive shaft 13 and the other end surface in the axial direction (left end surface of FIGS. 5 to 6). The respective compression springs 24 are provided. Therefore, the second hub 2
2 is the first and second compression springs 23, 24 when the force from the piston 16 is not applied (stop state).
It is held in a neutral position determined by the elasticity of.

On both sides of the second hub 22, the left and right sides (front and back of FIGS. 5 to 6) 1 with the drive shaft 13 sandwiched therebetween 1
A pair of pivots 26 are provided. These pair of pivots 26 are
Each is provided in a direction orthogonal to the drive shaft 13. Then, by the pair of pivots 26, the swash plate 27
Is pivotally supported. The swash plate 27 has an L-shaped cross section and is formed in an annular shape as a whole, and has a cylindrical portion 28 formed in the central portion.
Is pivotally supported on the pivot shaft 26 so as to be swingably supported around the second hub 22.

A drive arm 29 is provided on the outer peripheral surface of the first hub 20, and a bifurcated follower arm 30 is provided on the back surface (right side surface of FIGS. 5 and 6) of the swash plate 27. Arm 30
The distal end of the drive arm 29 is sandwiched between the distal ends of the. An arcuate elongated hole 31 is formed in the distal end of the drive arm 29 in the diameter direction of the drive shaft 13, and an engaging pin 32 fixed to the distal end of the driven arm 30 is inserted into the elongated hole 31. Let's play together. Therefore, the swash plate 27 changes the inclination angle with respect to the drive shaft 13 as the second hub 22 moves in the axial direction with respect to the drive shaft 13. It should be noted that the engagement pin 32 corresponds to a pivot shaft which is disposed at a position diametrically outward from the central axis of the drive shaft in a twisted positional relationship with the drive shaft and rotates together with the drive shaft. The swash plate 27
Is rotatably supported around the intermediate portion of the drive shaft 13 in a state of being pivotally supported by an engagement pin 32 corresponding to the pivot shaft, as well as adjusting the tilt angle and rotating with the drive shaft 13. However, by controlling the length of the long hole 31 or providing a stopper (not shown) between the swash plate 27 and the second hub 22, the swash plate 27 is moved relative to the drive shaft 13. I try not to be completely vertical. The reason will be described later.

An oscillating plate 33 is provided on one side surface (left side surface in FIGS. 5 and 6) of the swash plate 27, and is rotated with respect to the swash plate 27 via a deep groove type radial ball bearing 34 and a thrust roller bearing 35. Only freely supported. Further, by engaging a guide 36 provided on a part of the outer peripheral surface of the rocking plate 33 (lower end portion of FIGS. 5 to 6) and a guide rail 37 fixedly mounted in the casing 6, the rocking plate 33 It prevents the rotation of 33.
Therefore, the swing plate 33 is formed by the drive shaft 13 and the swash plate 27.
Only swing with the rotation of.

A plurality of circumferential positions of the rocking plate 33 and the pistons 16 are connected by connecting rods 38 which are transmission members. The connecting rods 38 are connected at their both ends to the swing plate 33 and the piston 16 so as to be swingable.
Pushes and pulls the pistons 16 in accordance with the swing displacement of the swing plate 33, and reciprocates the pistons 16 in the cylinder 14 in the axial direction.

On the other hand, in order to partition the low pressure chamber 11 and the high pressure chamber 12 from each of the cylinders 14, a partition plate 39 is provided at the abutting portion of the cylinder case 7 and the head case 8.
Is sandwiched. Then, the partition plate 39 is connected to the suction port 40 that connects the low pressure chamber 11 and the cylinder 14 to each other.
(See FIG. 1 showing an embodiment of the present invention) and the high pressure chamber 12
And a discharge port 41 that communicates with the cylinder 14. An intake valve 42 (see FIG. 1) that allows the refrigerant vapor to flow only from the low pressure chamber 11 to each of the cylinders 14 is provided at the intake port 40 portion of these. Further, at the discharge port 41 portion, a discharge valve 43 is provided to flow the refrigerant vapor only from the cylinders 14 toward the high pressure chamber 12. Reed valves are generally used as the intake valve 42 and the discharge valve 43.

Further, the high pressure chamber 12 and the casing 6
Between the crank chamber 9 and the crank chamber 44 in which the swash plate 27 exists, these chambers 12, 4
A pressure adjusting passage 45 for communicating the four members is provided. The pressure adjusting passage 45 includes a through hole 46, a valve accommodating space 47, a through hole 48 provided in the head case 8 and the partition plate 39.
And a passage 50 formed in the drive shaft 13. A pressure adjusting valve 51 is provided in the valve housing space 47 in series with the pressure adjusting passage 45. The pressure adjusting valve 51 opens and closes the pressure adjusting passage 45 in accordance with an electric signal that changes with a change in the cooling load or a refrigerant pressure in the low pressure chamber 11 that also changes with a change in the cooling load. Or adjust the opening.

Further, the crank chamber 44 and the low pressure chamber 1
First and second throttle channels 52 and 53 connecting the two chambers 11 and 44 are provided between the first and second chambers. The first throttle channel 52 is provided between a through hole (not shown) formed in the cylinder case 7 for inserting the coupling bolt 10 and the through hole and the low pressure chamber 11. And the restricted aperture 54. The first throttle channel 52 constantly connects the crank chamber 44 and the low pressure chamber 11 with each other. On the other hand, the second throttle channel 53 has a through hole 55 formed in the cylinder case 7, a through hole 56 formed in the partition plate 39, a through hole 57 formed in the head case 8, and a valve housing. The space 47 and the through hole 58 are provided. A diaphragm plug 59 is provided in the middle of the through hole 57.
In the valve housing space 47 existing between the through holes 57 and 58, a part of the pressure adjusting valve 51 is provided in series with the second throttle channel 53. Therefore, in the example shown in the figure, the pressure adjusting valve 51 controls not only the pressure adjusting passage 45 but also the opening and closing of the second throttle passage 53 or the adjustment of the opening degree in conjunction therewith.

The operation of the variable displacement compressor 1 constructed as described above is as follows. In order to cool or dehumidify the interior of the automobile, when operating the vapor compression refrigerator, a driven pulley (not shown) attached to the outer end of the drive shaft 13 (right end in FIGS. 5 to 6) is used. It is rotationally driven by a running engine of an automobile via a drive pulley and a belt (not shown). As a result, the swash plate 27 rotates,
The oscillating plate 33 oscillates without rotating to reciprocate the plurality of pistons 16 in the cylinder 14. With such a reciprocating movement of the piston 16, the refrigerant vapor in the low pressure chamber 11 communicating with the suction port 17 is sucked into the cylinder 14 through the suction port 40. The refrigerant vapor is then compressed in the cylinder 14 and then discharged through the discharge port 41 to the high pressure chamber 1.
Sent to 2.

When the cooling load is large and a large amount of refrigerant vapor needs to be compressed by the compressor 1, the pressure regulating valve 51 closes the pressure regulating passage 45 and opens the second throttle passage 53. . As a result, the crank chamber 44
The pressure in the high-pressure chamber 12 is not introduced into the crank chamber 44, and the pressure in the crank chamber 44 is not limited to that in the first throttle channel 52, but also the second throttle valve as shown by a thick arrow in FIG. Channel 5
It is discharged to the low pressure chamber 11 also through 3. As a result, the pressure in the crank chamber 44 decreases.

By the way, the pressure in the crank chamber 44 is
The plurality of pistons 16 are added to the rear rear surface (right surface in FIGS. 5 to 6). On the other hand, the pressure in the compression space of the cylinder 14 is applied to the front surface (the left surface in FIGS. 5 and 6) of each piston 16. Therefore, each of the pistons 16 tends to be pushed to the lower pressure side by a force corresponding to the difference between the pressure in the crank chamber 44 and the pressure in the compression space. Then, the total of the moments determined by the magnitude of these forces applied to each piston 16 and the position of the engagement pin 32 is applied in the direction in which the inclination angle of the swash plate 27 is changed. Of course, the pressure in the compression space changes depending on the stroke of the piston 16, but since the plurality of pistons 16 are arranged at equal intervals in the circumferential direction, the moment is generated by the bottom dead center that separates from the engagement pin 32. It becomes the largest for the piston 16 near the point. When the pressure in the crank chamber 44 is lowered as described above, the crank chamber 4
5 becomes sufficiently lower than the pressure in the compression space, and the pistons 16 are directed toward the swash plate 27.
At ~ 6, the pushing force to the right becomes stronger. Therefore, as shown in FIG. 5, the swash plate 27 is greatly inclined in the direction away from the cylinder 14 on the side far from the engagement pin 32. As a result, the stroke of each piston 16 accompanying the rotation of the swash plate 27 increases, and the capacity of the compressor 1 increases.

On the other hand, when the cooling load is small and the amount of refrigerant vapor discharged from the compressor 1 is small, the pressure adjusting valve 51 opens the pressure adjusting passage 45 and the second throttle passage. Close 53. As a result, FIG.
As indicated by a thick arrow, the pressure in the high pressure chamber 12 is introduced into the crank chamber 44, and the pressure in the crank chamber 44 enters the low pressure chamber 11 only through the first throttle channel 52. Is discharged. As a result, the crank chamber 44
The pressure inside becomes high.

When the pressure in the crank chamber 44 is increased as described above, the pressure in the crank chamber 44 becomes higher than the pressure in the compression space, and each piston 16
In order to move away from the swash plate 27, the force pushing leftward in FIGS. Therefore, the swash plate 27 becomes nearly vertical (stands up) with respect to the drive shaft 13, as shown in FIG.
As a result, the pistons 1 are rotated with the rotation of the swash plate 27.
The stroke of 6 is reduced, and the capacity of the compressor 1 is reduced. When the cooling load is in the middle, the pressure adjusting valve 51 adjusts the pressure in the crank chamber 44 to an intermediate level, and the tilt angle of the swash plate 27 is in the state shown in FIG. 5 and the state shown in FIG. It regulates in the middle.

As is clear from the above description, in the case of the variable displacement compressor in which the stroke of the piston 16 is adjusted by changing the inclination angle of the swash plate 27, even when the displacement (stroke of the piston 16) is minimized. The swash plate 27 is not perpendicular to the drive shaft 13.
The reason for this is that the discharge amount of the refrigerant cannot be reduced to zero due to the principle of such a variable displacement compressor. That is,
In such a variable displacement compressor, the difference between the pressure in the compression space and the pressure in the crank chamber 44 is used to change the inclination angle of the swash plate 27. Such a pressure difference occurs only when the piston 16 reciprocates in the cylinder 14. The swash plate 2
7 is perpendicular to the drive shaft 13, and each piston 16
If the stroke is set to zero, the pressure difference cannot be generated and the swash plate 27 cannot be held at the minimum capacity position. Therefore, in the case of the variable displacement compressor of the above type, even if the capacity is minimized, a certain amount of refrigerant vapor is sucked and further discharged. The ratio of the minimum capacity to the maximum capacity is determined by design and is not necessarily uniform, but generally the minimum capacity is 1/1 of the maximum capacity.
About 0 is secured.

In the case of a vapor compression refrigerating machine which constitutes a vehicle air conditioner by incorporating the variable displacement compressor configured and functioning as described above, this is because the capacity of the variable displacement compressor cannot be made zero. Therefore, the use of an electromagnetic clutch becomes essential. That is, the variable displacement compressor 1
Draws a refrigerant that cannot be ignored even when the capacity is minimized from the evaporator 5 and discharges it toward the condenser 2. Therefore, if the compressor 1 is continuously driven even when the ambient temperature is low such as in winter, the evaporator 5 freezes. In order to prevent this freezing, the compressor 1 must be stopped, and a mechanism therefor is required.

For this reason, conventionally, an electromagnetic clutch is provided between the driven pulley for driving the drive shaft 13 and the end of the drive shaft 13. When it is necessary to drive the compressor 1 for cooling, dehumidification, etc., the electromagnetic clutch is engaged, and when it is not necessary to drive the compressor 1 in winter, etc., the electromagnetic clutch is disconnected, and the driven pulley is driven. The drive shaft 13 is prevented from rotating regardless of the rotation.

[0023]

In the case of a vapor compression refrigerating machine incorporating a conventional variable displacement compressor, the structure is complicated and a high degree of durability is required. Therefore, it is expensive and heavy in weight. The use of an electromagnetic clutch is mandatory. Therefore, the production cost and weight of the entire vapor compression refrigerator are inevitable. In view of such circumstances, the present invention reduces the manufacturing cost of a vapor compression refrigerating machine incorporating a variable displacement compressor by making it possible to prevent the evaporator from freezing without using the electromagnetic clutch. It is intended to reduce the weight.

[0024]

A vapor compression refrigerating machine incorporating a variable capacity compressor according to the present invention, as in the vapor compression refrigerating machine incorporating a conventional variable capacity compressor described above, absorbs the sucked refrigerant. The compressor includes a compressor that discharges the compressed refrigerant, a condenser that radiates and condenses the refrigerant discharged from the compressor, and an evaporator that evaporates the refrigerant discharged from the condenser and returns the evaporated refrigerant to the compressor.

In the case of the invention described in claim 1, the compressor includes a casing, a low pressure chamber which is provided in the casing and communicates with an outlet of the evaporator through an intake port, and a discharge port which is provided in the casing. A high-pressure chamber leading to the inlet of the condenser,
A drive shaft rotatably supported in the casing, a plurality of cylinders formed inside the casing substantially parallel to the drive shaft, and fitted inside each of the cylinders so as to be displaceable in the axial direction. A piston, a pivot shaft disposed in a position diametrically outward from the central shaft of the drive shaft in a torsional positional relationship with the drive shaft and rotating with the drive shaft, and a state of being pivotally supported by the pivot shaft. And a swash plate that is rotatably supported around the intermediate portion of the drive shaft and is adjustable together with the drive shaft, and a transmission member that transmits the displacement of the swash plate due to the rotation of the drive shaft to the pistons. A suction valve for flowing the refrigerant vapor only from the low pressure chamber to the cylinders, a discharge valve for flowing the refrigerant vapor only from the cylinders to the high pressure chamber, and the inside of the high pressure chamber and the casing. Diagonal Is a variable capacity compressor having a pressure adjusting passage communicating with a crank chamber in which the pressure chamber exists, a pressure adjusting valve provided in the middle of the pressure adjusting passage, and a throttle passage connecting the crank chamber and the low pressure chamber. is there. Also, in this variable displacement compressor, the swash plate is not completely perpendicular to the drive shaft.

Particularly, in the vapor compression refrigerator incorporating the variable capacity compressor of the present invention, the evaporator is provided in the middle of the refrigerant passage existing between the outlet of the evaporator and the low pressure chamber. A flow control valve is provided to shut off the refrigerant or reduce its flow rate when it is not necessary to cool it.

In the case of the invention described in claim 2, the flow rate regulating valve includes a valve body displaceably provided in the valve space,
A spring for urging this valve body in a direction to open the refrigerant passage,
And a pressure chamber for displacing the valve body against the elastic force of the spring when the pressurized gas is introduced into the interior.
Further, a pressure introducing passage is provided between the pressure chamber and the high pressure chamber, and a control valve capable of controlling connection and disconnection between the pressure chamber and the high pressure chamber in the middle of the pressure introducing passage. Is provided.

Further, in the case of the vapor compression refrigerator incorporating the variable displacement compressor according to claim 3, the pressure adjusting passage between the high pressure chamber and the crank chamber is omitted, and instead the low pressure chamber and the crank are replaced. A pressure adjusting passage is provided between the chamber and the chamber, and a throttle channel connecting the crank chamber and the low pressure chamber is omitted.

[0029]

The vapor compression refrigerating machine incorporating the variable capacity compressor of the present invention having the above-mentioned structure is provided with a flow regulating valve when it is not necessary to cool the evaporator.
Cut off the refrigerant or reduce its flow rate. For this reason, in the case of the invention described in claim 2, the control valve provided in the middle of the pressure introducing passage is opened to introduce the pressure in the high pressure chamber into the pressure chamber of the flow regulating valve. As a result, the valve body constituting the flow rate control valve is displaced against the elastic force of the spring, and the refrigerant passage existing between the outlet of the evaporator and the low pressure chamber is closed. As a result, the amount of refrigerant sucked from the evaporator to the compressor becomes zero or very small. Therefore, the amount of the refrigerant circulating through the entire vapor compression refrigerator is zero or extremely small, and the temperature decrease of the evaporator is zero or small enough to be ignored. As a result, there is no risk of the evaporator freezing even if the operation of the variable displacement compressor is not stopped.

[0030]

1 to 3 show an embodiment of the present invention.
It should be noted that the feature of the present invention is that the evaporator 5 (FIG. 4) can be operated even when the variable capacity compressor 1 is continuously operated at a low temperature.
In order to prevent the freezing, the amount of the refrigerant vapor sucked from the evaporator 5 into the low pressure chamber 11 of the compressor 1 is reduced. As the basic structure of the variable displacement compressor 1, the conventional structure shown in FIGS. 5 to 6 or various structures described in the above-mentioned documents and known in the related art can be adopted. Therefore, the description of the same parts as the conventional one will be omitted or simplified, and the characteristic parts of the present invention will be mainly described below.

A valve holding hole 60 functioning as a refrigerant passage is formed between the suction port 17 communicating with the outlet of the evaporator 5 and the low pressure chamber 11 provided in the head case 8, and the valve holding hole 60 is provided in the valve holding hole 60. A flow control valve 61 is provided. The flow control valve 61 includes a valve casing 62, a valve body 63, and a compression spring 64.
Consisting of Of these, the valve housing 62 is formed in a cylindrical shape by injection molding a synthetic resin having oil resistance and refrigerant resistance, or by drawing a metal tube. An inlet hole 65 communicating with the suction port 17 and an outlet hole 6 communicating with the low pressure chamber 11 are provided on both side surfaces of an intermediate portion of the valve casing 62.
6 and 6 are provided. In addition, one end portion of the valve casing 62 (see FIGS.
The left end of 3) is bent inward in the diametrical direction to form a spring receiving portion 67 having a U-shaped cross section. The valve housing 62 may be omitted, and the inner surface shape of the valve holding hole 60 formed in the head case 8 may be a desired shape (such as the inner surface shape of the valve housing 62).

The inside of the valve casing 62, which is the valve space, is formed by injection molding a synthetic resin having oil resistance and refrigerant resistance, or by forging or die-casting a metal material. The valve body 63 is attached in the axial direction (see FIGS.
It is fitted so that it can be displaced. The valve body 63 has a bottomed cylindrical main portion 68 and a main portion 68 protruding from the central portion of the outer end surface (the left end surface in FIGS. 1 to 3) of the main portion 68.
The protrusion 69 having a smaller diameter than that of the spring casing 67 is fitted in the valve casing 62 in a state where the protrusion 69 and the spring receiving portion 67 face each other. The compression spring 64 is provided between the outer end surface of the valve body 63 and the spring receiving portion 67, and the inlet hole 65 is provided.
In order to make the valve hole 63 communicate with the outlet hole 66, the valve body 63 is provided with an elastic force in a direction to be retracted from between the holes 65 and 66. Further, the valve body 63 is provided in a part of the valve casing 62.
With respect to the above, the portion opposite to the compression spring 64 is a pressure chamber 70, and the pressure in the high pressure chamber 12 can be introduced into the pressure chamber 70.

To this end, the pressure chamber 70 and the high pressure chamber 1
A pressure introducing path 71 is provided between the head case 8 and
It is provided as a passage formed inside. The pressure chamber 70 and the high pressure chamber 12 are provided in the middle of the pressure introducing passage 71.
An electromagnetic on-off valve 72, which is a control valve that can freely control communication with and disconnection from, is provided. Further, in the case of the illustrated embodiment, one end of a branch passage 73 is connected to a portion between the on-off valve 72 and the pressure chamber 70 in the middle of the pressure introduction passage 71, and the other end of the branch passage 73 is connected. It is opened to the crank chamber 44.
Then, a check valve 74 is provided in the middle of the branch passage 73. The check valve 74 guides the refrigerant vapor (pressure) only from the pressure introducing passage 71 to the crank chamber 44.

These on-off valve 72, branch passage 73 and check valve 7
4 is combined so as to fulfill the following functions. When the on-off valve 72 is opened, the pressure in the high-pressure chamber 12 is introduced into the crank chamber 44 and the pressure chamber 70, and the inclination angle of the swash plate 27 (Figs. 5 to 6) of the compressor 1 is reduced as shown in Fig. 5. Then, the capacity of the compressor 1 is minimized and the flow rate control valve 61 is closed. When the on-off valve 72 is closed, the pressure in the high pressure chamber 12 is not introduced into the pressure chamber 70, but the pressure remaining in the pressure chamber 70 is released to the crank chamber 44. Even when the pressure in the crank chamber 44 rises due to the action of the pressure regulating valve 51 with the on-off valve 72 closed, the pressure in the pressure chamber 70 does not rise.

Therefore, the combination of the opening / closing valve 72, the branch passage 73 and the check valve 74 is not necessarily required as long as the functions (1) to (3) can be fulfilled. For example, an electromagnetic on-off valve may be provided instead of the check valve 74, or the pressure introduction passage 71 may be replaced with the on-off valve 72 and the check valve 74.
The purpose can also be achieved by providing a three-way valve at the branch portion between the branch path 73 and the branch path 73. However, in these cases, after the pressure in the pressure chamber 70 is reduced after the use of the compressor 1 is started, the valve is closed or switched in order to disconnect the communication between the pressure chamber 70 and the crank chamber 44. Do. or,
When using a three-way valve, this three-way valve is
It is necessary to have the function of (3). (1) A function of connecting all three ports so that the high pressure chamber 12 communicates with both the pressure chamber 70 and the crank chamber 44. (2) A function of connecting only the two ports so that the two chambers 70, 44 communicate with each other in order to release the pressure in the pressure chamber 70 into the crank chamber 44. (3) A function of shutting off all ports so that the lowered pressure in the pressure chamber 70 does not rise due to the pressure in the high pressure chamber 12 and the crank chamber 44. Further, the branch passage 73 and the check valve 74 may be omitted. On-off valve 7 even if omitted
When 2 is opened, the low pressure chamber 1 is
The pressure of No. 1 decreases, and the pressure adjusting valve 51 is opened. Then, the pressure in the high pressure chamber 12 is introduced into the crank chamber 44. Therefore, as compared with the case where the branch passage 73 and the check valve 74 are provided, the inclination angle of the swash plate 27 can be made small as described below with only a slight time delay.

The operation of the vapor compression refrigerator in which the variable capacity compressor of the present invention having the above-described structure is incorporated is as follows.
It is as follows. First, in order to cool or dehumidify the interior of the automobile, when it is necessary to cool the evaporator 5, the on-off valve 72 provided in the middle of the pressure introducing passage 71 is closed. In this state, the diaphragm 75 provided in the pressure regulating valve 51 is displaced according to the balance between the pressure of the low pressure chamber 11 and the elasticity of the compression spring 76, and the high pressure chamber 12 and the crank chamber 4
Restrict communication with 4. That is, when the cooling load is high and the pressure of the low-pressure chamber 11 is high, the crank chamber 4 tends to be disconnected from the high-pressure chamber 12 and the crank chamber 44.
Lower the pressure in 4. Then, as shown in FIG.
The inclination angle of 7 is increased to increase the capacity of the compressor 1. In contrast, the cooling load is low and the low pressure chamber 11
When the pressure is low, the high pressure chamber 12 and the crank chamber 4 are
4, the pressure in the crank chamber 44 is increased, the inclination angle of the swash plate 27 is decreased, and the capacity of the compressor 1 is decreased, as shown in FIG.

On the other hand, when it is not necessary to cool the evaporator 5 in the winter, etc., the on-off valve 72 provided in the middle of the pressure introducing passage 71 is opened to regulate the pressure in the high pressure chamber 12 to the flow control valve 61.
Is introduced into the pressure chamber 70. As a result, this flow control valve 6
The valve element 63 constituting No. 1 is displaced against the elastic force of the compression spring 64 and closes the valve holding hole 60 which is a refrigerant passage existing between the outlet of the evaporator 5 and the low pressure chamber 11. As a result, the amount of the refrigerant sucked from the evaporator 5 to the compressor 1 becomes extremely small. That is, the main portion 6 of the valve body 63 is provided between the inlet hole 65 and the outlet hole 66 formed in the valve casing 62.
Since 8 enters, the refrigerant flowing from the inlet hole 65 to the outlet hole 66 is blocked by the main portion 68, and the flow rate thereof is greatly reduced. Therefore, the amount of the refrigerant circulating through the entire vapor compression refrigerator is also extremely small, and the temperature decrease of the evaporator 5 is so small that it can be ignored. As a result, even if the operation of the variable displacement compressor 1 is not stopped, there is no fear that the evaporator 5 freezes. Incidentally, the valve casing 62
Since there is a slight gap between the inner peripheral surface of the compressor and the outer peripheral surface of the main portion 68, and a small amount of refrigerant vapor and lubricating oil flows through this gap, even when the compressor 1 continues to operate, The rotation support portion of No. 1 is not damaged by poor lubrication.

In the illustrated embodiment, in order to change the inclination angle of the swash plate 27, the pressure in the high pressure chamber 12 is introduced into the crank chamber 44, and the pressure in the crank chamber 44 is passed through the throttle passage. The case where the present invention is carried out with respect to a variable displacement compressor having a structure that allows it to escape into the low pressure chamber 11 has been described. However, the present invention is not limited to the variable displacement compressor having such a structure, but can be carried out with respect to the structure described in, for example, Japanese Patent Publication No. 2-61627.
However, in this case, the pressure adjusting passage is replaced between the high pressure chamber 12 and the crank chamber 44, and the low pressure chamber 11 and the crank chamber 4 are replaced.
4 and the throttle channel connecting the crank chamber 44 and the low pressure chamber 11 is omitted. When such a structure is adopted, the high-pressure refrigerant vapor for increasing the pressure in the crank chamber 44 is reduced to the inner peripheral surface of the cylinder 14 and the outer peripheral surface of the piston 16 (to reduce the discharge amount of the refrigerant). A so-called blow-by gas that passes through between the outer periphery of the mounted piston ring) is used. When reducing the pressure in the crank chamber 44 to increase the discharge capacity, the pressure adjusting valve in the middle of the pressure adjusting passage is opened to discharge the blow-by gas from the crank chamber 44 to the low pressure chamber 11. On the contrary, when the pressure in the crank chamber 44 is increased in order to reduce the discharge capacity, the pressure adjusting valve in the middle of the pressure adjusting passage is closed to allow the blow-by gas to flow into the crank chamber 4.
Collect in 4.

Even in the case of such a structure, the evaporator 5
Is provided between the pressure chamber 70 and the high-pressure chamber 12 of the flow-rate regulating valve 61 as shown in FIGS. By providing a control valve such as an on-off valve 72 in the middle of the pressure introducing passage 71 provided in the above, it is possible to obtain the same operational effect as the illustrated embodiment.

The flow regulating valve and the pressure introducing passage do not necessarily have to be built in the casing 6 of the compressor 1. For example, a flow control valve is provided in the middle of a pipe connecting the outlet of the evaporator 5 and the suction port 17 of the variable displacement compressor 1, and a pressure introducing passage (pipe) is connected to the pressure chamber of the flow control valve at one end. The other end can be connected in the middle of a pipe connecting the discharge port of the compressor 1 and the inlet of the condenser 4. In this case, it is necessary to provide a branch pipe leading to the crank chamber 44 in the middle of the pressure introducing passage. The point is that the conditions of the circuit diagram shown in FIG. 1 should be satisfied. In the case of such a configuration, it is necessary to circulate the pipes and to connect the pipes in an airtight manner, but there is an advantage that the compressor that has already been manufactured can be used only by making a small modification.

Further, the structure itself of the variable displacement compressor is not limited to the structure shown in FIGS. 5 to 6, but the structures described in the above publications and known in the related art can be adopted. For example, Japanese Patent Publication No. 2-61627 discloses a structure in which a rocking plate and a connecting rod are omitted, and a swash plate and an arm portion which is a transmission member integrally formed with a piston are connected via a spherical sliding shoe. A variable displacement compressor is described. The present invention can of course be implemented using a variable displacement compressor having such a structure. Furthermore, for example, JP-A-58-1
As described in Japanese Patent No. 62780, the present invention can be implemented by utilizing a so-called opposed piston type variable displacement compressor in which a cylinder and a piston are arranged on both sides of a swash plate. Of course, the structure of the suction valve 42 and the discharge valve 43 is not limited to the reed valve, and valves having various structures can be used.

Further, the flow rate regulating valve 61, which is the main point of the present invention,
However, it is not limited to the structure of the embodiment shown in FIGS. The point is that the valve body provided displaceably in the valve space in the middle of the refrigerant passage connecting the outlet of the evaporator 5 and the low pressure chamber 11, the spring for urging the valve body in the opening direction, and the internal pressure It is sufficient that it has a pressure chamber that displaces the valve body against the elastic force of the spring with the introduction of gas.
In particular, in the illustrated embodiment, the flow control valve 6 is used to reduce the flow rate.
In order to minimize the inclination angle of the swash plate 27 at the same time as closing 1, the flow rate regulating valve 61 is closed by the pressure in the high pressure chamber 12. According to such a structure, the capacity reduction of the compressor 1 and the flow rate regulation of the circulating refrigerant can be simultaneously and surely interlocked. However, if it is not necessary to interlock them, the structure of the flow rate regulating valve 61 may be simpler, and the driving for opening and closing can be performed electromagnetically instead of refrigerant pressure.

[0043]

The vapor compression refrigerator incorporating the variable capacity compressor of the present invention is constructed and operates as described above, and therefore has a complicated structure and requires a high degree of durability, and is therefore expensive. Moreover, it is possible to construct an automobile air conditioner by omitting the electromagnetic clutch, which is a heavy component. As a result, the cost and weight of the vehicle air conditioner can be significantly reduced.

[Brief description of the drawings]

FIG. 1 is a refrigerant circuit diagram of a compressor portion showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing an open state of a flow control valve.

FIG. 3 is a sectional view showing a closed state of the same.

FIG. 4 is a circuit diagram of a vapor compression refrigerator.

FIG. 5 is a sectional view showing a known variable displacement compressor in a state in which a discharge amount is maximized.

FIG. 6 is a sectional view similarly showing a state in which the discharge amount is minimized.

[Explanation of symbols]

 1 Compressor 2 Condenser 3 Liquid Tank 4 Expansion Valve 5 Evaporator 6 Casing 7 Cylinder Case 8 Headcase 9 Crankcase 10 Coupling Bolt 11 Low Pressure Chamber 12 High Pressure Chamber 13 Drive Shaft 14 Cylinder 16 Piston 17 Suction Port 19 End Wall 20 First Hub 21 Thrust Roller Bearing 22 Second Hub 23 First Compression Spring 24 Second Compression Spring 25 Stop Ring 26 Axis 27 Swash Plate 28 Cylindrical Part 29 Drive Arm 30 Driven Arm 31 Long Hole 32 Engagement Pin 33 Swing Plate 34 Radial ball bearings 35 Thrust roller bearings 36 Guides 37 Guide rails 38 Connecting rods 39 Partition plates 40 Suction ports 41 Discharge ports 42 Suction valves 43 Discharge valves 44 Crank chambers 45 Pressure adjustment passages 46 Through holes 47 Valve storage spaces 48, 49 Through holes 50 Passage 5 1 Pressure Control Valve 52 First Throttle Flow Path 53 Second Throttle Flow Path 54 Throttle Hole 55 Through Holes 56, 57, 58 Through Hole 59 Throttle Plug 60 Valve Holding Hole 61 Flow Control Valve 62 Valve Casing 63 Valve Body 64 Compression Spring 65 Inlet hole 66 Outlet hole 67 Spring receiving part 68 Main part 69 Projecting piece 70 Pressure chamber 71 Pressure introducing passage 72 Opening valve 73 Branch passage 74 Check valve 75 Diaphragm 76 Compression spring

Claims (3)

[Claims] Claim: What is claimed is: 1. A compressor that compresses a suctioned refrigerant and then discharges it, a condenser that radiates and condenses the refrigerant discharged from the compressor, and a refrigerant that is discharged from the condenser and then returns to the compressor. An evaporator, and as the compressor, a casing, a low pressure chamber that is provided in the casing and communicates with an outlet of the evaporator through an intake port, and a high pressure chamber that is provided in the casing and communicates with an inlet of the condenser through a discharge port, A drive shaft rotatably supported in the casing, a plurality of cylinders formed inside the casing substantially parallel to the drive shaft, and fitted inside each of the cylinders so as to be displaceable in the axial direction. The piston and the drive at a position diametrically outward from the center axis of the drive shaft. A pivot that is arranged in a twisted positional relationship with the drive shaft and rotates together with the drive shaft, and a tilt angle adjustment and rotation with the drive shaft around the intermediate portion of the drive shaft while being pivotally supported by the pivot shaft. A swash plate supported by, a transmission member that transmits the displacement of the swash plate due to the rotation of the drive shaft to the pistons, an intake valve that flows the refrigerant vapor only from the low pressure chamber to the cylinders, A discharge valve that allows the refrigerant vapor to flow from each of the cylinders only toward the high pressure chamber, a pressure adjustment passage that connects the high pressure chamber and the crank chamber where the swash plate exists inside the casing, and a pressure adjustment passage of the pressure adjustment passage. A steam incorporating a variable capacity compressor which is provided with a pressure regulating valve provided on the way and a throttle channel connecting the crank chamber and the low pressure chamber, and in which the swash plate is not completely perpendicular to the drive shaft. Compression In a freezer, a flow rate regulating valve that is provided in the middle of a refrigerant passage existing between the outlet of the evaporator and the low pressure chamber and shuts off the refrigerant or reduces its flow rate when it is not necessary to cool the evaporator. A vapor compression refrigerator that incorporates a variable displacement compressor, which is characterized in that 2. A flow rate regulating valve, wherein a valve body is provided displaceably in a valve space, a spring for urging the valve body in a direction to open the refrigerant passage, and a pressure gas introduced into the interior. And a pressure chamber for displacing the valve element against the elastic force of the spring, and a pressure introducing passage is provided between the pressure chamber and the high pressure chamber. The vapor compression refrigerating machine incorporating the variable capacity compressor according to claim 1, wherein a control valve capable of controlling connection and disconnection between the pressure chamber and the high pressure chamber is provided in the. 3. A pressure adjusting passage between the high pressure chamber and the crank chamber is omitted, and instead a pressure adjusting passage is provided between the low pressure chamber and the crank chamber, and a throttle flow connecting the crank chamber and the low pressure chamber. A vapor compression refrigerating machine in which the variable capacity compressor according to claim 1 or 2 in which a passage is omitted is incorporated.