JPH08312528A - Swash plate type variable capacity compressor - Google Patents

Abstract

PURPOSE: To reduce cost by eliminating parts requiring difficult machining and improve durability and reduce uncomfortable feeling by eliminating parts causing remarkable abrasion and abnormal noise. CONSTITUTION: A sleeve 47 is fitted on a drive shaft 13 displaceably in the axial direction. A support cylinder 49 is slidably supported around this sleeve 47 by a pair of pins 53. A swash plate 27A is fixed to this support cylinder 49. A ring arm 56 is arranged between a drive arm 29 fixed to the drive shaft 13 and a driven arm 54 fixed to the swash plate 27A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The swash plate type variable displacement compressor according to the present invention is incorporated in an automobile air conditioner for cooling and dehumidifying the interior of an automobile, compresses the refrigerant sucked from the evaporator, and then converts it into a condenser. Discharge toward.

[0002]

2. Description of the Related Art A vapor compression refrigerator incorporated in an air conditioner for a vehicle 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 refrigerant evaporated in the evaporator 5 is sucked into the compressor 1 through the suction port.

The compressor 1 which constitutes a vapor compression refrigerator incorporated in such an air conditioner for an automobile is driven by a traveling engine of the 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 heretofore been disclosed in JP-A-59-46378, JP-B-64-1668, JP-B-2-61627, and US Pat. No. 4073.
It is described in many publications such as the specification No. 603 and the specification No. 4425837. 6 to 7 show an example of a swash plate type variable displacement compressor disclosed in Japanese Patent Publication No. 64-1668. Incidentally, FIG. 6 shows a state in which the capacity is maximized, and FIG. 7 shows a state in which the capacity is also minimized. First, the conventional variable displacement compressor shown in FIGS. 6 to 7 will be described.

A casing 6 constituting the compressor 1.
Attaches the central casing body 7 to the head case 8 and the end plate 9
And are sandwiched from both sides in the axial direction (left and right direction in FIGS. 6 to 7), and further coupled by a plurality of coupling bolts (not shown). Inside the head case 8 of these, the low pressure chamber 1
0 and 10 and a high pressure chamber 11 are provided. The high pressure chamber 11
The pressure in the low pressure chamber 10 is, of course, positive pressure. Further, a flat partition wall plate 15 is sandwiched between the casing body 7 and the head case 8. The low pressure chambers 10 and 10, which are shown as being divided into a plurality of parts in FIGS. 6 to 7, communicate with each other and to a single suction port 12a provided on the outer surface of the head case 8. . The high pressure chamber 11 also communicates with the discharge port 12b provided in the head case 8. Then, the suction port 12
a is connected to the outlet of the evaporator 5 (FIG. 5), and the discharge port 12b is connected to the inlet of the condenser 2 (FIG. 5).

A drive shaft 13 is rotatably supported in the casing 6 in a state of being bridged between the casing body 7 and the end plate 9. That is, both ends of the drive shaft 13 are supported by the casing body 7 and the end plate 9 by a pair of radial needle bearings 22a, 22b, and the drive shaft 13 is supported by a pair of thrust roller bearings 23a, 23b. The thrust load applied to is freely supported. Of the pair of thrust roller bearings 23a and 23b, one (right side of FIGS. 6 to 7) thrust roller bearing 23a.
Is an adjusting nut 24 and one end of the drive shaft 13 (see FIGS.
It is provided between the step portion 25 formed at the right end portion 7).
The adjusting nut 24 is screwed into a female screw portion formed in the center hole 26 of the casing body 7 so that the axial position can be adjusted. The other thrust roller bearing 23b (left side in FIGS. 6 to 7) is provided between the support bracket 20 and the end plate 9 described later. Inside the casing 6, a plurality of cylinders 14 (for example, 5 to 6 at a regular interval in the circumferential direction, only one is shown in the drawing) are formed around the drive shaft 13. In this way, pistons 16 are fitted inside the plurality of cylinders 14 formed in the casing body 7 so as to be displaceable in the axial direction.

Further, inside a part of the main body of the casing 7,
A crank chamber 18 is provided between a portion where the plurality of cylinders 14 are formed and the end plate 9. A sleeve 19 and a support bracket 20 are provided in this order in the intermediate portion of the drive shaft 13 located in the crank chamber 18 from the side where the cylinder 14 is provided. The outer diameter surface 19a (outer peripheral surface) of the sleeve 19 is a spherical convex surface, and the inner diameter surface (inner peripheral surface) is a cylindrical surface. And
The inner diameter surface of these is slidable with respect to the drive shaft 13. The support bracket 20 is externally fitted and fixed to the drive shaft 13 so as to rotate together with the drive shaft 13. Incidentally, one end surface of the sleeve 19 (see FIG.
7 to the left end surface of the support bracket 20 and one side surface of the base end portion (lower end portion of FIGS. 6 to 7) of the support bracket 20 (right side surface of FIGS. 6 to 7), a compression spring 21 is provided. The elastic force is applied to the cylinder 14 in a direction approaching the cylinder 14. Therefore, unless a force acts on the swash plate 27 described below, the sleeve 19 is displaced toward the cylinder 14 side until it abuts against the stop ring 28 as shown in FIG. (The inclination angle with respect to the drive shaft 13 increases. In other words, the inclination angle θ of the swash plate 27 with respect to the orthogonal plane of the drive shaft 13 decreases.).

An inner diameter portion of a swash plate 27 is fitted on the sleeve 19 so as to be swingable. That is, the inner diameter surface 27 a (inner peripheral surface) of the swash plate 27 is the outer diameter surface 1 of the sleeve 19.
9a is a spherical concave surface having substantially the same curvature. Then, the inner diameter surface 27a is slidably fitted onto the outer diameter surface 19a, so that the swash plate 27 is supported around the drive shaft 13 so as to be adjustable in displacement and inclination angle in the axial direction. are doing.

A drive arm 29 is provided on the outer peripheral edge (upper edge of FIGS. 6 to 7) of the support bracket 20 so as to project outward in the diametrical direction. An inclined elongated hole 30 is provided at the tip of the drive arm 29. On the other hand, a driven arm 31 is fixedly provided on a portion of the swash plate 27 that faces one side of the swash plate 27 (the left side of FIGS. 6 to 7). This driven arm 3
A guide pin 32 is formed at the tip of the drive shaft 1 in a twisted direction with respect to the drive shaft 13. This guide pin 32 is
The swash plate 27 is pivotally supported by adjusting the tilt angle by loosely engaging with the tilted elongated hole 30. That is, the swash plate 27
Moves with the guide pin 32 as the sleeve 19 slides on the drive shaft 13.

For example, the sleeve 19 is a compression spring 21.
In the state of approaching the support bracket 20 against the elasticity of the guide pin 32, the guide pin 32 is positioned at the outer end portion (in the diametrical direction about the drive shaft 13) of the inclined elongated hole 30, as shown in FIG. Moving. Then, in this state, the inclination angle θ of the swash plate 27 with respect to the orthogonal surface of the drive shaft 13 becomes large, the stroke of each piston 16 accompanying the rotation of the drive shaft 13 becomes long, and the capacity of the compressor 1 increases. .
On the other hand, when the sleeve 19 moves away from the support bracket 20 due to the elasticity of the compression spring 21, the guide pin 32 moves to the inner end of the inclined elongated hole 30 as shown in FIG. To do. Then, in this state, the inclination angle θ becomes small, the stroke of each piston 16 accompanying the rotation of the drive shaft 13 becomes short, and the capacity of the compressor 1 decreases.

As described above, a plurality of swash plates 27 supported around the drive shaft 13 in the circumferential direction and the pistons 16 are provided.
Is a pair of sliding shoes 17,
It is connected by 17. The inner side surfaces (surfaces facing each other) of each of the sliding shoes 17, 17 are flat surfaces, and are slidably contacted with the outer side portions of both side surfaces of the swash plate 27. The outer side surface of each of these sliding shoes 17, 17 (side surface opposite to the mating sliding shoe 17) is a spherical convex surface. And, the inner surface is the swash plate 2
The outer surfaces of both sliding shoes 17, 17 are positioned on a single spherical surface in a state of being in contact with both side surfaces of 7. On the other hand, at the rear end portion of each piston 16 (the end portion on the side far from the partition plate 15 and the left end portion in FIGS. 6 to 7), a connecting arm portion 34 that constitutes a transmission member together with the sliding shoes 17 is provided. Is formed integrally with each piston 16, and a holding portion 33 for holding the pair of sliding shoes 17, 17 is formed on each connecting arm portion 34. The holding portion 33 has spherical concave surfaces 35, 3 which are in close contact with the outer surfaces of the sliding shoes 17, 17 in close contact with each other.
5 are formed to face each other.

Further, a part of the inner peripheral surface of the casing body 7 that is aligned with the outer end of each of the connecting arm portions 34 is
One pair of guide surfaces 36 for each piston 16
Are formed so as to be separated in the circumferential direction. The circumferential edge of the outer end of each coupling arm 34 is guided by this guide surface 36, and can be displaced only in the axial direction of the piston 16 (left-right direction in FIGS. 6 to 7). Therefore, the piston 16 is also fitted in the cylinder 14 so as to be freely displaceable in the axial direction (non-rotatable). As a result, the connecting arm portions 34 push and pull the pistons 16 with the swing displacement of the swash plate 27, and the pistons 1
6 is moved back and forth in the cylinder 14 in the axial direction.

On the other hand, in order to partition the low pressure chamber 10 and the high pressure chamber 11 from the respective cylinders 14, the partition plate 15 sandwiched at the abutting portion of the casing body 7 and the head case 8 has the low pressure chamber 10 described above. And a suction port 37 for communicating the cylinder 14 with each other, and a discharge port 38 for communicating the high pressure chamber 11 with the cylinder 14. Then, a suction valve 39 is provided at the suction port 37 portion of these to flow the refrigerant vapor only from the low pressure chamber 10 toward the cylinders 14. A discharge valve 40 is provided at the discharge port 38 to flow the refrigerant vapor only from the cylinders 14 toward the high pressure chamber 11. As the suction valve 39 and the discharge valve 40, generally, reed valves as shown in the figure are used.

The low pressure chamber 10 and the crank chamber 18 are also provided.
A pressure adjusting passage 41 for communicating the two chambers 10 and 18 with each other is provided between and. A pressure adjusting valve 45 is provided in the pressure adjusting passage 41. The pressure adjusting valve 45 includes a bellows 42 that expands and contracts in the axial direction according to the ambient pressure, and a needle 44 that opens and closes the flow hole 43 as the bellows 42 expands and contracts. Then, the low-pressure chamber 1 that changes with the variation of the cooling load
The pressure adjusting passage 41 is opened / closed or its opening is adjusted in accordance with the refrigerant pressure in the zero portion. The above bellows 42
Is hermetically sealed with a gas of a predetermined pressure sealed inside.

The operation of the conventional variable displacement compressor 1 configured as described above is as follows. In order to cool or dehumidify the interior of the automobile, the drive shaft 13 is driven to rotate when operating the vapor compression refrigerator. As a result,
The swash plate 27 rotates to reciprocate the plurality of pistons 16 in the cylinder 14, respectively. With such reciprocating movement of the piston 16, the refrigerant vapor in the low pressure chamber 10 communicating with the suction port 12 a is sucked into the cylinder 14 through the suction port 37. The refrigerant vapor is then compressed in the cylinder 14 and then
It is sent out to the high pressure chamber 11 through the discharge port 38.

When the cooling load is large and a large amount of refrigerant vapor needs to be compressed by the compressor 1, the pressure of the refrigerant vapor sent from the evaporator 5 (FIG. 5) to the low pressure chamber 10 becomes high. The pressure in the pressure adjusting passage 41 communicating with the low pressure chamber 10 also increases. In this state,
The bellows 42 forming the pressure adjusting valve 45 contracts, and the needle 44 retracts from the flow hole 43. As a result, the crank chamber 18 has the flow passage 43 and the pressure adjusting passage 41.
Through the low pressure chamber 10 and the pressure in the crank chamber 18 becomes low.

By the way, the pressure in the crank chamber 18 is
The pistons 16 are added to the rear surface (left surface in FIGS. 6 to 7) of the pistons 16. On the other hand, the pressure in the compression space of the cylinder 14 (the space between the front surface of the piston 16 and the partition plate 15) is applied to the front surface (the right surface in FIGS. 6 to 7) of each piston 16. Therefore, each of the pistons 16 tends to be pushed to the lower pressure side by the force corresponding to the difference between the pressure in the crank chamber 18 and the pressure in the compression space. Then, the total of these forces applied to each piston 16 is applied in the direction in which the inclination angle of the swash plate 27 is changed. Of course,
Although the pressure in the compression space changes depending on the stroke of the piston 16, since the piston 16 reciprocates at high speed,
The pressure in the compression space can be considered as an average value of all strokes. Therefore, in the state where the pressure in the crank chamber 18 is lowered as described above, the pressure in the crank chamber 18 becomes sufficiently lower than the pressure in the compression space, and the pistons 16 and the swash plate 27 are moved. 6 to 7, the force of pushing leftward becomes stronger. On the other hand, as described above, the guide pin 32, which is a pivot for pivotally supporting the swash plate 27, is provided at a position diametrically outward from the center of the drive shaft 13. Therefore, the moment that each piston 16 presses the swash plate 27 is different for each piston 16, and is small for the piston 16 close to the guide pin 32 and large for the piston 16 far from the guide pin 32. Therefore, when the pressure in the crank chamber 18 is low, the side of the swash plate 27 farther from the guide pin 32 is the cylinder 1 as shown in FIG.
It is greatly inclined in the direction away from 4 (the angle θ is increased). 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 refrigerant vapor discharged from the compressor 1 is small, the evaporator 5 (FIG. 5) to the low pressure chamber 10 can be used.
The pressure of the refrigerant vapor fed to the low pressure chamber becomes low, and the pressure in the pressure adjusting passage 41 communicating with the low pressure chamber 10 also becomes low. In this state, the bellows 4 forming the pressure regulating valve 45 is
2 extends, and the tip of the needle 44 enters the flow hole 43. As a result, the communication between the crank chamber 18 and the low pressure chamber 10 is cut off. High-pressure refrigerant vapor (blow-by gas) leaking from the gap between the outer peripheral surface of the piston 16 and the inner peripheral surface of the cylinder 14 gradually enters the crank chamber 18, and thus the crank chamber 18 When the communication between the low pressure chamber 18 and the low pressure chamber 10 is cut off, the crank chamber 1
The pressure in 8 rises.

In this manner, when the pressure in the crank chamber 18 is high, the pressure in the crank chamber 18 is higher than the pressure in the compression space, and the pistons 1
In order to move 6 away from the swash plate 27, the force pressing rightward in FIGS. Therefore, as shown in FIG. 7, the swash plate 27 becomes nearly vertical to the drive shaft 13 (the angle θ becomes smaller). As a result, the stroke of each piston 16 accompanying the rotation of the swash plate 27 is reduced, and the capacity of the compressor 1 is reduced. When the cooling load is in the middle, the pressure adjusting valve 45 adjusts the pressure in the crank chamber 18 to an intermediate level, and the tilt angle of the swash plate 27 is as shown in FIGS. 6 and 7. It regulates in the middle.

[0020]

In the case of the conventional swash plate type variable displacement compressor, the swash plate 2 is provided around the drive shaft 13.
There are the following points to be solved due to the structure supporting 7.

The processing of the sleeve 19 and the swash plate 27 is troublesome, and the manufacturing cost of both these members 19 and 27 and the manufacturing cost of the swash plate type variable displacement compressor 1 incorporating these both members 19 and 27 are high. That is, in the case of the conventional structure shown in FIGS. 6 to 7, the spherical convex surface forming the outer diameter surface 19a of the sleeve 19 and the spherical concave surface forming the inner diameter surface 27a of the swash plate 27 are slidably engaged. Therefore, the inclination angle of the swash plate 27 with respect to the drive shaft 13 can be freely adjusted. Therefore,
In order to smoothly adjust the tilt angle of the swash plate 27 without rattling, it is necessary to finish the shapes and dimensions of the spherical convex surface and the spherical concave surface as specified. Such work is troublesome, and causes an increase in manufacturing costs of the sleeve 19 and the swash plate 27.

The engaging portion between the inclined elongated hole 30 and the guide pin 32 is easily worn, and abnormal noise due to collision of metals is easily generated at the engaging portion. That is, a large thrust load is applied from the plurality of pistons 16 to the contact portion between the inner edge of the inclined elongated hole 30 and the outer peripheral surface of the guide pin 32, while the contact portion makes a line contact. Therefore, a large surface pressure acts on this contact portion, and the engaging portion between the inclined elongated hole 30 and the guide pin 32 is easily worn. Further, since it is necessary to smoothly displace the guide pin 32 inside the inclined elongated hole 30, there is a gap between the inner edge of the inclined elongated hole 30 and the outer peripheral surface of the guide pin 32. There is a need. Therefore, during operation, the inner edge and the outer peripheral surface collide with each other, and the abnormal noise is likely to occur.

In view of such circumstances, the present invention has been invented to reduce the manufacturing cost and to provide a swash plate type variable displacement compressor which does not cause significant wear or unpleasant noise. is there.

[0024]

The swash plate type variable displacement compressor of the present invention is provided with a casing having an intake port and a discharge port, and is provided in this casing, like the conventional swash plate type variable displacement compressor described above. A low pressure chamber communicating with the suction port, a high pressure chamber communicating with the discharge port provided in the casing, a drive shaft rotatably supported in the casing, and a periphery of the drive shaft inside the casing. A plurality of cylinders, each of which is formed substantially parallel to the drive shaft, a piston that is displaceably fitted in the inside of each of the cylinders in the axial direction, and an inclination around the middle portion of the drive shaft. The swash plate rotatably supported together with the adjustment of the angle and the drive shaft, and the displacement of the swash plate in the axial direction of the drive shaft due to the rotation of the drive shaft, the displacement of each of the pins. A transmission member for transmitting the refrigerant vapor to the ton, a suction valve that causes the refrigerant vapor to flow only from the low pressure chamber to the cylinders, a discharge valve that causes the refrigerant vapor to flow only from the cylinders to the high pressure chamber, and the inside of the casing. And a pressure adjusting means for adjusting the pressure in the crank chamber in which the swash plate is present.

In particular, in the swash plate type variable displacement compressor of the present invention, a sleeve is supported around the intermediate portion of the drive shaft so as to be displaceable at least in the axial direction, and at a position diametrically opposite to the sleeve. A first pivot shaft provided to pivotally support an inner diameter portion of the swash plate; a support bracket fixed to a portion of the drive shaft farther from the cylinders than the sleeve and rotated with the drive shaft; A drive arm fixed to the support bracket, and a driven arm fixed to a portion of the swash plate facing the drive arm on one surface of the swash plate,
A link arm arranged between the tip of the driven arm and the drive arm, and a second axis parallel to the first axis that pivotally supports one end of the link arm on the tip of the drive arm. And a third pivot shaft that pivotally supports the other end of the link arm to the tip end portion of the driven arm and that is parallel to the first and second pivot shafts.

[0026]

With the swash plate type variable displacement compressor of the present invention configured as described above, the refrigerant sucked from the suction port is compressed and further discharged from the discharge port, and the suction port is rotated every time the drive shaft makes one rotation. The action of adjusting the amount of refrigerant sent from the discharge port to the discharge port is the same as that of the conventional swash plate type variable displacement compressor described above.

Particularly, in the case of the swash plate type variable displacement compressor of the present invention, a structure for supporting the swash plate with respect to the drive shaft in a freely tiltable angle is provided between the inner diameter portion of the swash plate and the sleeve. Since it is performed by the first pivot, it is not necessary to machine the outer diameter surface of this sleeve and the inner diameter surface of the swash plate into spherical surfaces. Therefore, processing of these sleeves and swash plates is easy,
It is possible to reduce the manufacturing cost of the swash plate type variable displacement compressor incorporating the sleeve and the swash plate.

Further, since the driving arm and the driven arm are connected by the second pivot shaft and the third pivot shaft and the link arm, significant wear does not occur at the portion for transmitting the rotation of the drive shaft to the swash plate.
Further, it is not necessary to provide a play in a portion for transmitting the rotation of the drive shaft to the swash plate, and a play due to wear hardly occurs. Therefore, even if the direction of the force applied to the swash plate changes with the rotation of the swash plate, no abnormal noise is generated in the transmitting portion.

[0029]

1 to 4 show an embodiment of the present invention.
The same parts as those of the conventional swash plate type variable displacement compressor described above are designated by the same reference numerals to omit or simplify the overlapping description, and hereinafter, differences from the conventional structure will be mainly described. In addition, between the end plates 9 and the partition plate 15 and both end surfaces of the casing body 7 constituting the casing 6 in the axial direction (the left-right direction in FIG. 1), and between the partition plate 15 and the head case 8.
Gaskets for maintaining airtightness are respectively sandwiched between and, but they are omitted for simplification.

A sleeve 47 and a support bracket 20a are sequentially provided in a portion of the drive shaft 13 located in the crank chamber 18 from the side where the cylinder 14 is provided. Of these, the sleeve 47 is formed in a cylindrical shape as a whole so as to be slidable with respect to the drive shaft 13. Further, inclined portions 48, 48 are formed at diametrically opposite positions and axially opposite positions of the sleeve 47, respectively. The inclined portions 48, 48 are formed so as to prevent interference with the support cylinder 49 described below. Further, a pair of circular holes 50, 50 are formed concentrically with each other in the middle portion of the sleeve 47. The formation positions of the circular holes 50, 50 in the circumferential direction are diametrically opposite to each other, and the inclined portions 4 are formed.
The position where 8 and 48 are formed (center of each inclined portion 48 and 48) is circumferentially offset by 90 degrees. The support bracket 20a is externally fitted and fixed to the drive shaft 13 so as to rotate together with the drive shaft 13.

The sleeve 47 having the above-mentioned shape is
Except for the above-mentioned inclined portions 48, 48, since it is composed of a simple cylindrical surface, even if the dimensions are accurately finished,
It can be easily formed. Further, the inclined portions 48, 48 are provided merely to prevent interference with the support cylinder 49, and neither dimensional accuracy nor shape accuracy is required (may be rough). Therefore, the manufacturing cost of the sleeve 47 is much lower than that of the sleeve 19 (FIGS. 6 to 7) incorporated in the conventional structure.

A support cylinder 49 fitted and fixed to the inner diameter portion of the swash plate 27A is swingably and pivotally supported on the sleeve 47. This support cylinder 49 is the same metal material as the swash plate 27A,
Alternatively, it is formed into a cylindrical shape by another metal material having a similar expansion coefficient, and is fitted and fixed to the inner diameter surface of the swash plate 27A by shrinkage fitting or cold fitting. or,
An outward flange-shaped flange portion 51 is formed at one end portion (the left end portion in FIGS. 1 and 2) of the support cylinder 49, and one surface (the right side surface in FIG. 1) of the flange portion 51 is located inside the swash plate 27A. The peripheral portion is in contact with the surface facing the support bracket 20a.
Therefore, the thrust load applied from the piston 16 to the swash plate 27A is supported by the support cylinder 49 via the flange portion 51.

In the case of the swash plate type variable displacement compressor of the present invention, the inner diameter surface of the swash plate 27A, the inner diameter surface and the outer diameter surface of the support cylinder 49 are simply cylindrical surfaces.
Therefore, the manufacturing cost of the swash plate 27A and the support cylinder 49 is low, and the manufacturing cost of the sleeve 47 is low, which contributes to the cost reduction of the swash plate type variable displacement compressor. It should be noted that no particularly large rotational force is applied between the inner diameter surface of the swash plate 27A and the outer diameter surface of the support cylinder 49. Therefore, only by fitting and fixing these two sides,
Sufficient practical strength can be secured, but if necessary, these two surfaces may be spline-engaged with each other. In this case, the cost is somewhat higher, but it is much cheaper than the conventional structure.

A pair of circular holes 52, 52 are formed concentrically with each other at the diametrically opposite positions in the middle portion of the support cylinder 49. Pins 53, 53, which are the first pivots, are bridged between the circular holes 52, 52 and the circular holes 50, 50 formed in the sleeve 47. As described above, the swash plate 27A is pivotally supported on the sleeve 47 by the pins 53, 53, so that the swash plate 27A is supported around the drive shaft 13 so as to be adjustable in displacement and inclination angle in the axial direction. are doing.

A drive arm 29 is provided on the outer peripheral edge (upper edge in FIG. 1) of the support bracket 20a so as to project outward in the diametrical direction. On the other hand, a driven arm 54 is fixed to a portion of the swash plate 27A that faces the driving arm 29 on one surface (the left surface in FIG. 1). In the case of the illustrated embodiment,
A mounting flange 55 formed at the base end portion (right end portion in FIGS. 1 and 2) of the driven arm 54 is screwed or welded to the swash plate 27A. However, the driven shaft 54 is replaced by the swash plate 2
It may be formed integrally with 7A. And this driven arm 5
4, a pair of link arms 56, 56 is provided between the tip of the drive arm 29 (the left end in FIG. 1) and the tip of the drive arm 29 (the upper end in FIG. 1).
Is provided. That is, one end (the left end in FIG. 1) of each of the link arms 56, 56 is attached to the tip end portion of the drive arm 29 and is parallel to the pin 53 which is the first pivot, and the pin 5 which is the second pivot.
It is pivoted by 7. In addition, the link arms 56, 56
The other end (right end in FIG. 1) of the driven arm 54 is pivotally supported by a pin 58 which is a third pivot parallel to the pins 53 and 57 which are the first and second pivots. There is. Such link arms 56, 56 are connected to the driving arm 29 and the driven arm 54.
The swash plate 27A is provided between the driving arm 2 and
9, the tilt angle is adjustable and pivotally supported. That is, the swash plate 27A is provided on the sleeve 4 with respect to the drive shaft 13.
With the sliding of 7, the pin 53 swings around the pin 53.

For example, the sleeve 47 is the compression spring 21.
In the state of approaching the support bracket 20a against the elasticity of the link arms 56, 56, the link arms 56, 56 serve as the second pivot.
It swings counterclockwise in FIG. Then, in this state, the inclination angle θ of the swash plate 27A with respect to the orthogonal plane of the drive shaft 13 becomes large, the stroke of each piston 16 accompanying the rotation of the drive shaft 13 becomes long, and the capacity of the compressor increases. On the other hand, the sleeve 47
Is based on the elasticity of the compression spring 21.
In a state away from the link arm 56, the link arms 56 swing about the pin 57 in the clockwise direction from the state shown in FIG. Then, in this state, the inclination angle θ becomes small, and the pistons 1 are rotated as the drive shaft 13 rotates.
The stroke of 6 is shortened and the capacity of the compressor is reduced. Even when the sleeve 47 moves most to the right in FIG. 1 (over the entire stroke range of the sleeve 47), the pin 58 is located outside the pin 57 in the diametrical direction of the drive shaft 13. Therefore, the swash plate 27A reliably swings as the sleeve 47 slides on the drive shaft 13.

The pins 57 and 58 which are the second and third pivots.
The outer peripheral surface of the sliding member slides on the mating surface as the link arms 56, 56 swing, but since the sliding portion makes surface contact with the cylindrical surfaces, the surface pressure of the sliding portion is small. Therefore, wear caused by sliding can be reduced. Further, the swing of the link arms 56, 56 can be made smooth without increasing the clearance between the pins 57, 58 and the mating surface. Therefore, no abnormal noise is generated due to collision of metals when the compressor is operating.

Further, in the case of the illustrated embodiment, the pressure in the crank chamber 18 is adjusted in order to change the capacity of the compressor in accordance with the cooling load, so that the communication state between the crank chamber 18 and the high pressure chamber 11 is set. I try to control it. Therefore, in the head case 8, there is provided a pressure adjusting valve 59 which is a pressure adjusting means for controlling the communication state between the crank chamber 18 and the high pressure chamber 11 according to the pressure in the low pressure chamber 10. An unillustrated throttle channel is provided between the crank chamber 18 and the low pressure chamber 10 so that the pressure in the crank chamber 18 is gradually released to the low pressure chamber 10. However, when the pressure regulating valve 59 is opened, the amount of refrigerant vapor sent from the high-pressure chamber 11 into the crank chamber 18 exceeds the amount of refrigerant vapor discharged through the throttle passage, and the crank chamber 18 The pressure inside is increasing.

As shown in detail in FIG. 4, the pressure adjusting valve 59 includes a diaphragm type actuator 60 and an opening / closing valve 61 which is opened and closed by the actuator 60. The inside of the case 62 that constitutes the actuator 60 is divided by a diaphragm 63 into an atmospheric pressure chamber 64 and a pressure introduction chamber 65. And this pressure introducing chamber 65
And the part 10a of the low pressure chamber 10 are communicated with each other, and the pressure in the pressure introducing chamber 65 is made equal to the pressure in the low pressure chamber 10. A push plate 66 is provided at the center of the diaphragm 63, and the push plate 66 is provided by a compression spring 67 provided in the atmospheric pressure chamber 64.
Are elastically pressed toward the pressure introducing chamber 65.
Therefore, when the pressure in the low pressure chamber 10 is high, the push plate 66 is displaced toward the atmospheric pressure chamber 64 side against the elasticity of the compression spring 67, and conversely, the low pressure chamber 10 is displaced.
When the internal pressure is low, it is displaced toward the pressure introducing chamber 65 side based on the elasticity of the compression spring 67.

On the other hand, the on-off valve 61 includes a valve seat 68, a ball 69 facing the valve seat 68, and a compression spring 70 that elastically presses the ball 69 toward the valve seat 68. The elasticity of the compression spring 70 is much weaker than that of the compression spring 67. And this on-off valve 61 is
When the ball 69 is separated from the valve seat 68, the high pressure chamber 11 communicates with the pressure introduction hole 71 communicating with the crank chamber 18, and when the ball 69 is in contact with the valve seat 68, the high pressure The communication between the chamber 11 and the pressure introduction hole 71 is cut off.

In order to open and close the opening / closing valve 61 as described above by the actuator 60 as described above, the base end portion (lower end portion in FIGS. 1 and 4) of the push rod 72 is connected to the central portion of the push plate 66. It is fixed. The tip end surface of the push rod 72 (the upper end surface in FIGS. 1 and 4) is opposed to the ball 69. This push rod 7
No. 2 does not push the ball 69 when the pressure in the pressure introducing chamber 65 is high and the push plate 66 is fully displaced to the atmospheric pressure chamber 64 side.
Due to the elasticity of the compression spring 70, the compression spring 70 comes into contact with the valve seat 68. On the other hand, when the pressure in the low pressure chamber 10 is low, the push rod 72 causes the compression spring 67 to move.
The ball 69 is pushed by the displacement of the push plate 66 based on the elasticity of the ball 69 to separate the ball 69 from the valve seat 68.

When the cooling load is large and a large amount of refrigerant vapor needs to be compressed by the compressor, the low pressure chamber 1
Since the pressure of the refrigerant sent to 0 becomes high, the pressure in the pressure introducing chamber 65 communicating with the low pressure chamber 10 also becomes high. In this state, the push rod 72 does not push the ball 69. As a result, the refrigerant vapor in the high pressure chamber 11 is not sent to the crank chamber 18, and the crank chamber 18
The pressure inside becomes low. In this state, for the same reason as in the case of the conventional structure described above, the inclination angle θ of the swash plate 27A with respect to the orthogonal plane of the drive shaft 13 becomes large, and the piston 16
The longer stroke increases the capacity of the compressor.

On the contrary, when the cooling load is small and it is not necessary to compress a large amount of refrigerant vapor in the compressor 1, the pressure of the refrigerant sent to the low pressure chamber 10 becomes low, so that the low pressure chamber 10 communicates with the low pressure chamber 10. The pressure in the pressure introducing chamber 65 also decreases. In this state, the push rod 72 pushes the ball 69. As a result, the refrigerant vapor in the high pressure chamber 11 is sent to the crank chamber 18, and the pressure in the crank chamber 18 increases. Then, the inclination angle θ of the swash plate 27A becomes smaller, the stroke of the piston 16 becomes shorter, and the capacity of the compressor decreases.

In the case of the illustrated embodiment, the pressure in the high pressure chamber 11 is introduced into the crank chamber 18 in order to change the capacity of the compressor. Therefore, compared with the case of the above-mentioned conventional structure,
The capacity can be changed quickly and reliably. That is, in the case of the above-described conventional structure, since the pressure in the crank chamber 18 is increased by the blow-by gas whose flow rate is not stable, the time required to increase the pressure in the crank chamber 18 to reduce the capacity of the compressor is required. It becomes long and unstable. On the other hand, the pressure in the high pressure chamber 11 is set to the crank chamber 1
In the case of the embodiment shown in FIG.
The time required to increase the pressure in 8 is short and stable. Therefore, as described below, the responsiveness when the capacity is suddenly reduced at the time of sudden acceleration is improved.

Although not shown, an electric auxiliary actuator such as a solenoid may be provided in series with the actuator 60 to displace the pusher plate 66 regardless of the pressure in the pressure introducing chamber 65. it can. For example, in some cases, the capacity of the compressor is reduced to reduce the load on the engine that drives the compressor regardless of the cooling load, such as during sudden acceleration or when climbing uphill. In such a case, for example, when the accelerator opening is large, the pusher plate 66 is pushed toward the pressure introducing chamber 65 by the auxiliary actuator.

Further, in the illustrated embodiment, the central axis of each cylinder 14 is formed parallel to the drive shaft 13, but it need not be strictly parallel if it is substantially parallel. In particular, as in the illustrated embodiment, the sliding shoe 1 in which the connecting portion between the swash plate 27A and the piston 16 is a pair.
In the case of the structure composed of 7 and 17, the central axis of each cylinder 14 approaches the drive shaft 13 as it approaches the head case 8, and the center axis of the cylinder 14 with respect to the drive shaft 13 has a predetermined angle (for example, 2 to 4). Cylinder 14 by tilting
In some cases, it is possible to prevent uneven wear of the inner peripheral surface of the piston 16 and the outer peripheral surface of the piston 16. However, this point is described in Japanese Patent Application No. 7-28321 and does not relate to the gist of the present invention, so a 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.

Further, the pair of sliding shoes 1 described above.
It is not always necessary to use the same size for 7 and 17. For example, the sliding shoe 17 closer to the compression space (to the right in FIG. 1) needs to support a thrust load applied to the piston 16 based on the pressure in the compression space, and therefore needs to have a certain size. is there. On the other hand, the load applied to the sliding shoe 17 near the end plate 9 (to the left in FIG. 1) is small. That is, the sliding shoe 17 near the end plate 9 has a piston 16
1 is displaced to the left in FIG. 1, and when the refrigerant vapor is sucked from the low pressure chamber 10 into the compression space, the thrust load accompanying the transmission of the force from the swash plate 27A to the connecting arm portion 34 is applied. is there. This thrust load is much smaller than the thrust load applied to the sliding shoe 17 near the compression space based on the above pressure. Therefore, from the viewpoint of load resistance, the sliding shoe 17 closer to the end plate 9 is provided.
Can be made smaller than the sliding shoe 17 closer to the compression space.

Therefore, if the shape of at least one of the holding portion 33 and the swash plate 27A formed on the connecting arm portion 34 is devised and the interference between the holding portion 33 and the swash plate 27A is prevented, the above-mentioned end is formed. The sliding shoe 17 near the plate 9 can be made smaller than the sliding shoe 17 near the compression space. Therefore, for example, of the pair of holding arms 46a and 46b forming the holding portion 33, the holding arm 46b closer to the end plate 9 is made smaller. If necessary, the portion closer to the tip (closer to the lower end in FIG. 1) than the chain line α in FIG. 1 may be omitted. Further, by forming a concave portion on one side surface (the left side surface in FIG. 1) of the swash plate 27A that may interfere with the tip end portion of the holding arm 46b, the holding portion 33 and the swash plate 2 are formed.
It is also possible to prevent interference with 7A. Of course, these may be combined to prevent interference.

Thus, by making the sliding shoe 17 near the end plate 9 smaller than the sliding shoe 17 near the compression space, the swash plate type variable displacement compressor can be made smaller and lighter. That is, the axial dimension of the holding portion 33 including the holding arms 46b can be reduced by the size of the sliding shoe 17 closer to the end plate 9. If the axial dimension of the holding portion 33 is reduced, the portion that reciprocates together with the piston 16 can be reduced in size and weight accordingly. It is very important to reduce the size and weight of the piston 16 that reciprocates at high speed during operation. If the piston 16 becomes lighter, the high speed operation of the compressor becomes possible. Can be realized.
Further, the reduction in the axial dimension leads to a reduction in the axial dimension of the crank chamber 18, and hence the axial dimension of the entire casing 6, and the swash plate type variable displacement compressor can be made smaller and lighter.

[0050]

Since the swash plate type variable displacement compressor of the present invention is constructed and operates as described above, the following effects can be obtained. The sleeve and the swash plate can be easily processed, and the production cost of the sleeve and the swash plate and the production cost of the swash plate type variable displacement compressor incorporating the sleeve and the swash plate can be reduced. Since there is no engaging portion that easily wears and produces abnormal noise, sufficient durability can be obtained, and an occupant or the like does not feel uncomfortable during driving.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of the present invention with a maximum discharge amount.

FIG. 2 is an exploded perspective view of a portion that pivotally supports an inner diameter portion of a swash plate.

FIG. 3 is an exploded perspective view of a portion that transmits the rotation of the drive shaft to a swash plate.

FIG. 4 is an enlarged view of part A of FIG.

FIG. 5 is a circuit diagram of a vapor compression refrigerator that constitutes an automobile air conditioner.

FIG. 6 is a cross-sectional view showing a conventional variable displacement compressor with a maximum discharge amount.

FIG. 7 is a sectional view showing a state in which the discharge amount is also minimized.

[Explanation of symbols]

 1 Compressor 2 Condenser 3 Liquid Tank 4 Expansion Valve 5 Evaporator 6 Casing 7 Casing Main Body 8 Head Case 9 End Plate 10 Low Pressure Chamber 10a Part 11 High Pressure Chamber 12a Suction Port 12b Discharge Port 13 Drive Shaft 14 Cylinder 15 Partition Plate 16 Piston 17 Sliding Shoe 18 Crank chamber 19 Sleeve 19a Outer surface 20, 20a Support bracket 21 Compression spring 22a, 22b Radial needle bearing 23a, 23b Thrust roller bearing 24 Adjustment nut 25 Step portion 26 Center hole 27, 27A Swash plate 27a Inner surface 28 Stop ring 29 Drive Arm 30 Inclined Long Hole 31 Driven Arm 32 Guide Pin 33 Holding Part 34 Connecting Arm Part 35 Spherical Concave Surface 36 Guide Surface 37 Suction Port 38 Discharge Port 39 Suction Valve 40 Discharge Valve 41 Pressure Adjustment Road 42 Bellows 43 Circulation hole 44 Needle 45 Pressure adjusting valve 46a, 46b Holding arm 47 Sleeve 48 Slope 49 Support tube 50 Circular hole 51 Collar 52 Circular hole 53 Pin 54 Driven arm 55 Mounting flange 56 Link arm 57, 58 Pin 59 Pressure regulating valve 60 Actuator 61 Open / close valve 62 Case 63 Diaphragm 64 Atmospheric pressure chamber 65 Pressure introducing chamber 66 Push plate 67 Compression spring 68 Valve seat 69 Ball 70 Compression spring 71 Pressure introducing hole 72 Push rod

Claims (1)

[Claims] 1. A casing having a suction port and a discharge port, a low pressure chamber provided in the casing and communicating with the suction port, a high pressure chamber provided in the casing and communicating with the discharge port, and in the casing. A rotatably supported drive shaft, a plurality of cylinders formed inside the casing, around the drive shaft, and substantially parallel to the drive shaft, and axially inside each of the cylinders. With a piston that is fitted so as to be freely displaceable,
The tilt angle is adjusted around the middle portion of the drive shaft and the swash plate rotatably supported together with the drive shaft, and the displacement of the swash plate in the axial direction of the drive shaft due to the rotation of the drive shaft are described above. A transmission member that transmits to each piston, an intake valve that allows the refrigerant vapor to flow only from the low pressure chamber to the cylinders, a discharge valve that causes the refrigerant vapor to flow from the cylinders only to the high pressure chamber, and In a swash plate type variable displacement compressor equipped with a pressure adjusting means for adjusting the pressure in a crank chamber in which the swash plate exists, a swash plate type variable displacement compressor is supported around an intermediate portion of the drive shaft so as to be displaceable at least in the axial direction A sleeve, a first pivot shaft provided at a diametrically opposite position of the sleeve to pivotally support an inner diameter portion of the swash plate, and an intermediate portion of the drive shaft that is farther from the cylinders than the sleeves. A support bracket fixed to the same and rotating together with the drive shaft, a drive arm fixed to the support bracket, and a driven arm fixed to a part of the swash plate facing the drive arm. A link arm arranged between the tip of the driven arm and the drive arm, and a second axis parallel to the first axis that pivotally supports one end of the link arm on the tip of the drive arm. A swash plate type variable displacement compressor, comprising: a third pivot that is parallel to the first and second pivots and that pivotally supports the other end of the link arm to the tip of the driven arm.