JPH02108872A - Variable capacity compression device - Google Patents

Abstract

PURPOSE:To enable to perform the control in an air-conditioning system and the like stably as well as positively by constructing the title device such as to judge the compression capacity on the basis of the pressure detecting signals form a pressure detecting means. CONSTITUTION:The discharge capacity of cooling medium of a compressor 10 varies according to the change of the inclination of a cam plate 23 against a driving shaft 15. The inclination of the cam plate 23 is determined by the cooling medium pressure in a cylinder 16 and a pressure chamber 17; that is, if the pressure in the pressure chamber 17 rises to be high, the pressure acting on the rear face of a piston 27 also becomes high, and the piston 27 does not thereby recede largely from the top dead center. Consequently, the position of the bottom dead center of the piston 27 changes corresponding to the pressure in the pressure chamber 17, and the inclination of the cam plate 23 coupled with the piston 27 against the right-angled face of the driving shaft becomes smaller as the pressure in the pressure chamber 17 rises, as well as the reciprocating strokes become small.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a variable capacity compression device that is applied to, for example, an auto air conditioner for automobiles and used to compress refrigerant.

(Prior Art) Refrigerant compression devices used in automobile air conditioners are directly driven by the automobile engine, and for this reason, the capacity has been increased in order to save power and improve drivability. Increasingly, changes are being made.

Since such a refrigerant compressor is connected to an automobile engine as a load, it is necessary to appropriately control the idle speed of the engine, especially in response to the operating conditions of the compressor. There is. When controlling the idle speed of the engine, the idle speed is always increased by a certain amount while the compressor is connected. Specifically, the idle control valve is opened by a certain amount when the compressor is connected. A possible control method is to do so. However, when such idle control is performed, when the compressor capacity is changed, the rotational speed of the engine becomes greatly different when the compressor capacity is large and small, and the engine rotation speed becomes large. Problems arise in which fuel consumption is wasted and comfort is impaired.

In order to solve this problem, a signal corresponding to the compressor capacity is output to the computer that performs engine idle control, and the engine speed is controlled in response to this compressor capacity signal. The idea is to make it possible to do so. However, it has been difficult to easily detect the capacity of the compressor itself.

[Problems to be Solved by the Invention] This invention was made in view of the above points. For example, when used in an automobile air conditioner and driven by an automobile engine, the compressor capacity is It is an object of the present invention to provide a variable capacity compression device in which the compressor capacity can be easily detected so that engine rotational speed control and the like can be effectively executed accordingly.

[Means for Solving the Problems] In the variable displacement compression device according to the present invention, a swash plate that is rotated by the drive shaft is attached to the drive shaft that is rotationally driven by the engine, for example. . A piston is connected to this swash plate, and as the drive shaft rotates, the piston reciprocates within the cylinder to perform a compression operation. A cylinder pressure intake port is formed that is selectively opened and closed, and the pressure inside the cylinder is detected by the pressure intake port.

[Function] The variable capacity compression device configured as described above is configured in a so-called swash plate type, and the bottom dead center position of the piston in the cylinder is set to change in accordance with the compressor capacity. Therefore, the cylinder pressure intake port is selectively opened and closed depending on the compressor capacity. Therefore, by determining whether or not the pressure inside the cylinder is detected at this pressure intake port, the bottom dead center position of the piston in the cylinder can be determined, and the compression is performed based on this determined bottom dead center position. Machine capacity can be determined.

[Embodiments of the invention] Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows the cross-sectional configuration of the compressor IO, which includes a first housing 11 and a second housing 12 each made of an aluminum alloy. are integrally coupled to form one housing body. Bearings 13 and 14 are formed in the first and second housings 11 and 12, respectively, and a drive shaft 15 is provided rotatably supported by the bearings 13 and 14.

Inside the first housing 11, the drive shaft 15 is provided.
A plurality of cylinders 16 are formed to surround the drive shaft 15 and have axes parallel to the drive shaft 15, and a pressure chamber 17 is provided inside the second housing 12 in communication with the cylinder 16. is formed.

A shaft seal mechanism 18 is formed between the second housing 12 that forms the pressure chamber 17 and the drive shaft 15, and the shaft seal mechanism 18 allows the refrigerant and lubricating oil in the pressure chamber 17 to be driven. This prevents leakage to the outside along the outer periphery of the shaft 15.

The drive shaft 15 has a guide pin 19 protrudingly formed within the pressure chamber 17.
9 is rotated integrally with the drive shaft 15. A locking pin 20 is connected to the guide pin 19, and the wobble 21 is rotated together with the driving shaft 15 by the locking pin 20. This wobble 21 is configured in a disc shape so that the drive shaft 15 passes through the center thereof, and the axis of the drive shaft 15 and the axis of the wobble 21 are set to be inclined at an arbitrary angle with respect to each other. I have to. Then, while the drive shaft 15 is being rotated, the wobble 21 is rotated with its surface swinging while the inclination angle specified by the drive shaft 5 remains set.

A bearing mechanism 22 is formed on the surface of this wobble 21, and a swash plate 23 is attached so as to be held via this bearing mechanism 22. That is, the swash plate 23 has the same slope as the wobble 21, and is rotatably connected to the wobble 21, so that the rotational force from the wobble 21 is not transmitted. . Therefore, the swash plate 23 is inside the pressure chamber 17.
It is not rotated together with the drive shaft 15, but is swung together with the wobble 21 when the drive shaft 15 rotates.

In this case, the first housing 11 and the second housing 1
2, and a connecting member 25 rotatably engaged with the swash plate 23 is slidably fitted onto the support rod 24. Therefore, rotation of the swash plate 23 is prevented by the support rod 24, and by moving the connecting member 25 along the support rod 24, the swash plate 23 is allowed to swing.

The swash plate 23 is connected via a connecting rod 26 to a piston 27 movably set within the cylinder 16. Specifically, balls are formed at both ends of the connecting rod 26, and the balls are fitted into recesses formed on the back surface of the piston 27 and the surface of the swash plate 23, respectively, and are held by appropriate holding members. The connecting rod 26 and the piston 27, and the swash plate 23 and the connecting rod 26 are each rotatably connected.

Here, as described above, the wobble 21 is connected to the guide pin 19 protruding from the drive shaft 15 by the locking pin 20, and the wobble 21 can be tilted with respect to the drive shaft 15. Further, the inclination angle of the swash plate 23 is changed as the inclination angle of the wobble 21 changes.

The wobble 21 is rotated as the drive shaft 15 rotates,
When that surface begins to swing, the swash plate 23 also swings, causing the piston 27 to reciprocate inside the cylinder 16 via the connecting rod 26. The inclination angle of the swash plate 23 determines the stroke of the reciprocating motion of the piston 27, and the variation in the inclination angle of the swash plate 23 becomes the variation in the reciprocating stroke of the piston 27.

A side plate 28 is provided on the side surface of the first housing 11.
is provided on the surface of this side plate 28,
A side housing 29 is provided.

Inside this side housing 29, a suction chamber 30 is formed to surround the drive shaft 15, corresponding to the position of the cylinder 1G, and furthermore, this suction chamber 30 is formed so as to surround the drive shaft 15.
A discharge chamber 31 is formed so as to be surrounded by. The suction chamber 30 and the discharge chamber 31 are formed by a suction hole 32 and a discharge hole 33 formed in the side plate 28, respectively.
It is communicated with the cylinder 16 via.

The suction hole 32 and the discharge hole 33 have a suction valve 34 that allows the refrigerant to flow from the suction chamber 30 toward the cylinder 16, and a discharge valve 35 that allows the refrigerant to flow from the cylinder 16 to the discharge chamber 31, respectively. It is formed.

The side housing 29 further includes a low pressure atmosphere chamber 3.
6 is formed. This low-pressure atmosphere chamber 36 is not shown in this figure, but is set to a common pressure state with the suction chamber 30. When this compressor 10 is used in an air conditioner, the suction chamber 30 is connected to the output side of the refrigerant expansion valve.

Further, this low-pressure atmosphere chamber 36 is communicated with the pressure chamber 17 through an extremely small passage 37, and the pressure in the low-pressure atmosphere chamber 36 is released to stabilize the pressure in this pressure chamber 17. A bellofram 38 constituting a pressure regulator is set within the low-pressure atmosphere chamber 36.

The bellofram 38 is equipped with a spring, and the inside of the bellofram 38 is set to, for example, atmospheric pressure, and the bellofram 38 is moved in response to the difference between this internal pressure and the pressure in the suction chamber 30.
is expanded and contracted.

An intermediate pressure chamber 39 is further formed between the low pressure atmosphere chamber 36 and the discharge chamber 31, and an operating rod 40 connected to the bellofram 38 passes through the intermediate pressure chamber 39 and reaches the discharge chamber 31. It is set as follows. In this case, the above operating rod 4
0 is introduced into the discharge chamber 31 through a passage 41 formed between the discharge chamber 31 and the intermediate pressure chamber 39, and a ball valve 42 is provided at the tip of the actuation rod 40.

When the bellofram 38 is extended, the ball valve 42 opens the passage 41 as shown in the figure, and when the bellofram 38 is contracted, the ball valve 42 closes the passage 41. As the bellofram 38 expands and contracts, The opening area of the passage 41 is now variably controlled.

The intermediate pressure chamber 39 is communicated with the pressure chamber 17 via communication passages 43 and 44 and an opening 45.

The side wall portion of the cylinder 16 is provided with the cylinder 1
First and second cylinder pressure intakes 46 and 47 are formed that open into the interior of B. This first and second
The cylinder pressure intakes 4B and 47 are formed at different positions in the direction of the axis of the cylinder 16, and although not shown in detail here, are guided to a pressure detection mechanism, and the pressure intakes are The pressure within the cylinder 16 at each portion 46 and 47 is detected. The cylinder pressure intakes 46 and 47 are
It is selectively closed by the piston 27, and the pressure inside the cylinder 1G cannot be detected in the closed state.

The variable capacity compressor 10 configured as shown in -F is used, for example, as a refrigerant compressor for an automobile air conditioner, and the drive shaft 15 is coupled to an electromagnetic clutch mechanism 48.
This clutch mechanism 48 is connected to an automobile engine (not shown) via a belt or the like. When the electromagnetic clutch mechanism 48 is connected, the engine drives the drive shaft 1
5 is now driven to rotate.

When the drive shaft 15 is rotationally driven, the wobble 21 is rotated while being attached to the drive shaft 15 at an angle through the guide pin 19, and the swash plate 23 performs a rocking motion in response to the rotation of the wobble 21. Do this. This rocking motion of the swash plate 23 is transmitted to the piston 27 via the connecting rod 2B, and the piston 27 reciprocates inside the cylinder 16 along its axis.

Corresponding to such reciprocating motion of the piston 27, during the suction stroke of the piston 27 (moves to the right in the figure), the refrigerant in the suction chamber 30 pushes open the suction valve 34 and fills the suction hole 3.
2 into the cylinder 16. Also piston 27
In the compression stroke (moving to the left in the diagram), cylinder 16
When the refrigerant therein is compressed and its pressure exceeds a predetermined value, the discharge valve 35 is pushed open and the compressed refrigerant is sent into the discharge chamber 31 through the discharge hole 33. The refrigerant discharged into the discharge chamber 31 is led to a condenser that constitutes a refrigerant circuit of the automobile air conditioner, although it is not shown in this figure.

The refrigerant discharge capacity of the compressor 10 is varied in accordance with changes in the inclination angle of the swash plate 23 with respect to the drive shaft 15. Further, the angle of inclination of the swash plate 23 is determined by the refrigerant pressure within the cylinder 16 and the pressure chamber 17.

That is, when the pressure inside the pressure chamber 17 increases and becomes high,
The pressure acting on the back side of the piston 27 is also increased, so that this piston 27 is not retracted far beyond top dead center. Therefore, the position of the bottom dead center of the piston 27 changes in response to the pressure in the pressure chamber 17, and the angle of inclination of the swash plate 23 connected to the piston 27 with respect to the plane perpendicular to the drive shaft 15 changes due to the pressure inside the pressure chamber 17. As the pressure in the chamber 17 increases, it decreases and the reciprocating stroke of the piston 27 decreases.

FIG. 2 shows the capacity of the compressor 10 and the inclination angle of the swash plate 23. First, in the large capacity state shown in (A), the piston 27 is set at the end of the cylinder 1B in the compression direction. Since the pressure inside the pressure chamber 17 is relatively low compared to the top dead center position (the state shown by the broken line in the figure), the bottom dead center is the position where the reciprocating stroke of the piston 27 is set to be sufficiently large. It is said that

In this case, the angle of inclination of the swash plate 23 with respect to the plane perpendicular to the drive shaft 15 is set to be large.

Furthermore, as shown in FIG. 2(B), in the medium capacity state, the pressure in the pressure chamber 17 is made slightly higher than in the case of the large capacity, so the bottom dead center position of the piston 27 moves. The reciprocating stroke of the piston 27 is made slightly smaller, and in the case of an even smaller capacity, the bottom dead center position of the piston 27 moves further as shown in FIG. 2 (C), and the reciprocating stroke of the piston 27 becomes even smaller. Ru. and,
The size of such a reciprocating stroke of the piston 27 is
It is set corresponding to the inclined state of the swash plate 23.

The pressure inside the pressure chamber 17 that changes the reciprocating stroke of the piston 27 in this way is controlled by the bellofram 38.
This is done with a pressure regulator configured using. That is, the pressure inside the bellofram 38 is set to, for example, atmospheric pressure, and the low pressure atmosphere chamber 36 is set to a common pressure state with the suction chamber 30 as described above. Therefore, when the refrigerant pressure in the suction chamber 30 becomes low, the bellow ram 38 begins to extend, and the ball valve 42 moves upward in the figure via the actuating rod 40, opening the passage 41. As a result, the discharge chamber 3
1 is an intermediate pressure chamber 39, a communication passage 43, 44, and an opening 45.
The pressure chamber 17 is connected to the pressure chamber 17 through the
By increasing the amount of communication, the pressure within the pressure chamber 17 is increased.

Then, the capacity of this compressor 10 is reduced.

Conversely, when the pressure inside the suction chamber 30 increases, the bellofram 38
begins to retract, causing the ball valve 42 to move downward, i.e., into the passage 4.
1, the degree of communication between the discharge chamber 31 and the pressure chamber 17 is lowered, the pressure within this pressure chamber 17 is lowered, and the capacity of this compressor IO is increased.

FIG. 3 shows the relationship between the internal pressure of the cylinder 16 and the stroke of the piston 27 at large, medium, and small capacities of the compressor 10. In this figure, the piston stroke is defined as the piston 27 at maximum capacity. It shows the distance from the bottom dead center of . That is, as the capacity of the compressor IO becomes smaller, the point at which the pressure within the cylinder 16 rises moves to the right in this figure, that is, in the direction where the piston stroke becomes larger.

Pressure intake ports 46 and 47 in the cylinder 1G are formed in accordance with the characteristics of the compressor IO at maximum capacity, medium capacity, and minimum capacity, respectively.
The intake ports 46 and 47 are set at positions a and b of the piston stroke, respectively.

Since the pressure inside the cylinder 16 fluctuates depending on the suction and discharge operation processes of the compressor 10, the pressure detection mechanisms set corresponding to the pressure intakes 46 and 47 should have a low response frequency. It is necessary to use

Alternatively, as shown in FIG. 2, the cylinder pressure intake ports 46 and 47 are configured to communicate with pressure buffer chambers 51 and 52, respectively, and a throttle mechanism is appropriately set in the communication path, 51 and 5
2, pressure switches 53 and 54 are installed to detect the behavior of the pressure in the chambers 51 and 52, respectively. With this configuration, the capacity state of the compressor 10 can be determined based on the operating states of the pressure detection switches 53 and 54.

That is, in a large capacity state, both the first and second cylinder pressure intakes 46 and 47 are opened into the interior of the cylinder 16, as shown in FIG. Basically, the inside of 52 is set to a high pressure state, and the high pressure state is detected by detection switches 53 and 54, respectively. Therefore, when both switches 53 and 54 detect high pressure, it is determined that the capacity of the compressor 10 is large.

Further, in the medium capacity state, as shown in FIG. 2(B), the bottom dead center of the piston 27 is moved in the direction of shortening the piston stroke, and the second pressure intake port 47 is
It is closed and does not open to the cylinder chamber. Therefore, in this state, only the pressure detection switch 46 detects the high pressure state, and it can therefore be determined that the capacity of the compressor 10 is medium capacity. Furthermore, (C
), when the position of the bottom dead center of the piston 27 has been moved significantly, the cylinder pressure intake ports 4B and 4
Both of the detection switches 53 and 54 are not opened in the cylinder chamber, so that neither of the detection switches 53 and 54 can detect high pressure. The minimum capacity state of the compressor 10 is determined based on the operating states of the pressure detection switches 53 and 54.

Here, the pressure detection switches 53 and 54 may be configured to use a switch mechanism that is turned on when a high pressure of, for example, 4 Kg f /cm2G or more is detected.

FIG. 4 schematically shows an automobile air conditioner system using the compressor 10 as described above, and shows the air conditioner switch 6.
0, the computer 61 starts operating, an operating current is supplied to the electromagnetic clutch 48, power from an engine (not shown) is coupled to the compressor 0, the compressor 10 is started, and the air conditioner system operates. is started.

The control computer 61 detects signals from the pressure detection switches 53 and 54 set in relation to the compressor 10, determines the capacity state of the compressor IO, Based on detection signals from a vehicle speed detector and an engine rotation speed detector (both not shown), an idle adjustment valve 62 set in the intake circuit of the engine is adjusted. 63 is a throttle valve driven by an accelerator pedal (not shown).

The structure of the compressor 10 in the second embodiment may be any structure as long as it uses a swash plate; for example, it may have a structure in which compression chambers are formed on both sides of the front and rear sides. good. Further, the mechanism for controlling the compressor capacity is not limited to one using a pressure regulator as in the above embodiment, but may also be a solenoid valve mechanism for controlling the capacity based on an external signal.

FIG. 5 shows another example of a compressor using a swash plate, in which a ball-shaped support member 71 having a spherical outer circumferential surface is set on the outer circumference of the drive shaft 15. This support member 71 supports the drive shaft 1
It has a cylindrical main body part that is fitted and set on the outer periphery of 5,
It is set to be movable in the direction of the axis on the outer periphery of the drive shaft 15,
Its axial position is determined by a plunger mechanism 72. Here, a control pressure is applied to the back side of the plunge mechanism 72 from a switching valve mechanism 73, and this control pressure moves the plunger mechanism 72 to the left in the figure and supports it. The member 71 is also moved leftward together with the plunger mechanism 72.

A disk-shaped swash plate 23 is fitted into the outer peripheral portion of the support member 71 having the spherical surface. That is, the swash plate 23 is rotatably and tiltably mounted and supported on the outer peripheral surface of the support member 71, and a connecting plate 74 is integrally attached to the swash plate 23. A pin 75 is rotatably provided integrally with 74.

On the other hand, a connecting member 76 is provided on the drive shaft 15 so as to be rotated integrally with the drive shaft 15.
An engagement groove 77 that is inclined to the axis of the drive shaft 15 is formed in the connecting member 76 . When the pin 75 is engaged with this engagement groove 77 and the connecting member 76 is rotated integrally with the drive shaft 15, the rotational force is transmitted to the pin 75 through the engagement groove 77, and the swash plate 23 is also rotated integrally with the drive shaft 15 at the outer periphery of the support member 71.

In this case, the support member 7I that supports the swash plate 23 is such that the axial position of the drive shaft 15 is changed by the plunger mechanism 72. The engagement position at 77 changes. For example, when the support member 71 is moved leftward from the state shown in the figure, the engagement position of the pin 75 also moves leftward within the engagement groove 77, and the inclination angle of the swash plate 23 with respect to the axis of the drive shaft 15 increases. begins to change.

The outer periphery of the swash plate 23 is fitted into a locking groove 79 formed in a coupling member 78 that is integrally set on the pistons 271 and 272 set in the cylinders 161 and 162, and When the swash plate 23 rotates, the pistons 271 and 272 reciprocate within the cylinders 161 and 162 as the outer peripheral portion of the swash plate 23 swings. For example, the compressing and discharging operation of the refrigerant is executed, and for example, the cylinder pressure intake port 46 shown in FIG.
and 47 are formed with openings.

In this compressor 10, the position of the plunger mechanism 72 is controlled and set by an external command, and the inclination angle of the swash plate 23 with respect to the drive shaft 15 is set corresponding to the position. Then, the reciprocating stroke of the pistons 271 and 272 is determined in accordance with the inclination angle of the swash plate 23, and the capacity of the compressor 10 is set. Cylinder pressure intake 46
The determination is made by detecting the intake pressure state of 47 parts.

In order to determine the capacity of the compressor 10, in the embodiment, two cylinder pressure intake ports 46, the first and second
．． 47, each of which has a pressure detection switch 53.
and 54 were installed. However, if at least one pressure intake port is formed, it is possible to determine whether the compressor capacity is in a large capacity state or a small capacity state. Furthermore, by forming a large number of cylinder pressure intakes (three or more) and setting a pressure detection mechanism for each, it is possible to determine the compressor capacity in even more detail. Control during idling can be executed with high precision.

[Effects of the Invention] As described above, according to the variable capacity compression device according to the present invention, the capacity can be easily determined using a simple pressure detection switch, and can be used, for example, in an air conditioner system installed in a car. The compression capacity of a refrigerant compressor that is used and is driven by being directly connected to an automobile engine can be easily and reliably determined. Therefore, the engine driving the compressor, especially the idle control, can be accurately executed, and the control in this type of air conditioner system etc. can be executed stably and reliably.

FIG. 5 is a diagram illustrating the configuration of a compressor according to another embodiment of the present invention.

10...Compressor, 1■, 12...Housing, 13
．． 14...Bearing, 15...Drive shaft, 16.161.
1B2...Cylinder, 17...Pressure chamber, 19...
Guide pin, 20... Locking pin, 23... Swash plate, 2
7.271.272... Piston, 30... Suction chamber, 31... Discharge chamber, 38... Verofram, 42...
・Ball valve, 46.47...Cylinder pressure intake,
51.52...Chamber, 53.54...Pressure detection switch, 71...Support member.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional configuration diagram illustrating a refrigerant compressor according to an embodiment of the present invention, FIG. 2 is a diagram illustrating the relationship between the piston stroke and capacity in the compressor, and FIG. 3 is a diagram illustrating the relationship between cylinder pressure and Figure 4 shows the relationship between the piston stroke and the compressor capacity. Figure 4 shows the applicant's representative and patent attorney Takehiko Suzue (A) who applied the above compressor to an air conditioner system. Figure 1 Figure 2 Figure 0-7 Figure 3 Figure 4

Claims (4)

[Claims] (1) A drive shaft to which rotational driving force is transmitted; a swash plate connected to the drive shaft so as to rotate integrally therewith and whose angle relative to the drive shaft is variable; and parallel to the drive shaft. A cylinder is formed in a state in which the cylinder is configured to selectively communicate with the suction chamber and the discharge chamber; A piston that reciprocates; a cylinder pressure intake port formed in the cylinder and opened corresponding to the bottom dead center position of the piston; and a detection means for detecting intake pressure from the cylinder pressure intake port. A variable capacity compression device comprising: a compression capacity determined based on a pressure detection signal from the pressure detection means. (2) The cylinder pressure intake port corresponds to at least two locations that can be selectively closed by the piston, corresponding to a plurality of bottom dead center positions set corresponding to the reciprocating stroke of the piston. A variable capacity compression device according to claim 1, wherein the variable capacity compression device is formed as follows. (3) The pressure detection means includes a chamber that is communicated with the cylinder pressure intake port and whose interior is set to a pressure state corresponding to the intake pressure, and a pressure switch that detects changes in the internal pressure of the chamber. A variable capacity compression device according to claim 1, wherein the variable capacity compression device comprises: (4) The pressure intake port is constituted by at least two openings set at different positions along the axis of the cylinder, and the at least two openings are connected to each other so as to communicate with each of the at least two openings. 2. The variable displacement compression device according to claim 1, wherein the pressure detection means is configured to independently detect the intake pressure of each opening.