JPH04262074A - Variable-capacity swash plate compressor - Google Patents

Abstract

PURPOSE:To provide a variable-capacity swash plate compressor with a wide intake pressure control range without impairing the function to quickly change the discharge capacity. CONSTITUTION:In a variable-capacity swash plate compressor having the first communicating hole communicating a crank chamber 5 and an intake chamber 31, the first switch valve 54 opening/closing the first communicating hole, the second communicating hole communicating the crank chamber 5 and a discharge chamber 32, the second switch valve 47 opening/closing the second communicating hole, and operation point control means 40, 51, 56, 64 applying loads to the first switch valve 54 to displace the opening/closing operation point of the first switch valve 54, the operation point control means 40, 51, 56, 64 have forced full-open systems 46, 49 fully closing the second switch valve 47 when the first switch valve 54 is normally opened or closed and fully opening the second switch valve 47 forcefully.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a variable capacity swash plate type compressor, and more particularly to a variable capacity type compressor in which the crank chamber pressure is adjusted to change the inclination angle of the swash plate, thereby changing the discharge capacity. Regarding swash plate compressors.

0002

2. Description of the Related Art A conventional variable capacity swash plate compressor of this type includes a casing forming a crank chamber, a cylinder head in which a discharge chamber and a suction chamber are formed, and which closes one open end of the casing; A main shaft rotatably supported by a casing, a swash plate arranged in the crank chamber and rotated by rotation of the main shaft, and a swash plate arranged on an inclined surface of the swash plate and oscillated according to the rotation of the swash plate. a hinge mechanism that transmits the rotation of the main shaft to the swash plate and supports the swash plate at a variable inclination angle with respect to the main shaft; a plurality of cylinders, a piston that is reciprocatably arranged in the cylinder and connected to the rocking plate, a first communication passage that communicates between the crank chamber and the suction chamber, and the crank chamber and the suction chamber. and a control device for controlling communication between the suction chamber and the first communication path, and the control device senses the pressure in the suction chamber or the pressure in the crank chamber, and detects the pressure in the suction chamber or the crank chamber. a first on-off valve that opens and closes the communication passage; an operating point control means that applies a load to the first on-off valve to displace the opening/closing point of the first on-off valve; and the crank chamber and the discharge chamber. It has a second communication path that communicates with the second communication path, and an on-off valve that opens and closes the second communication path.

[0003] Then, depending on the rotational speed of the compressor or the load fluctuation on the evaporator side, the first on-off valve is opened and closed to adjust the pressure in the crank chamber and change the inclination angle of the swash plate, thereby increasing the discharge capacity. I'm making adjustments. In adjusting the inclination angle of the swash plate at this time, the first on-off valve is opened and closed in accordance with the input signal to the operating point control means to obtain a desired suction pressure. Further, the second on-off valve moves in conjunction with the first on-off valve, so that when the first on-off valve moves in the closing direction, the second on-off valve moves in the opening direction. When the suction pressure control point is changed from a low pressure to a high pressure by the operating point control means, that is, when the discharge capacity is to be decreased, the first on-off valve is closed and the second on-off valve is opened, and the above-mentioned discharge The chamber and the crank chamber are communicated with each other. Thereby, when the internal pressure of the crank chamber is quickly increased, the internal pressure of the crank chamber is quickly increased, and the inclination angle of the swash plate is changed, thereby reducing the discharge capacity.

In the case of a conventional variable capacity swash plate compressor, the second on-off valve moves in direct conjunction with the first on-off valve, so unless the first on-off valve is fully open, the second on-off valve moves The on-off valve does not close. The first opening/closing valve operates by detecting the suction chamber pressure and the crankcase chamber pressure, and the operating point control means changes the suction pressure control point from a low pressure to a high pressure, and the first opening/closing valve The valve closes and the second on-off valve opens, the internal pressure of the crank chamber increases and the discharge capacity decreases. In such cases, even if the discharge capacity decreases,
Because the pressure response, especially the suction pressure response, is slow, the state in which the first on-off valve is closed and the second on-off valve is open continues longer than necessary, causing the internal pressure in the crank chamber to rise excessively. The pressure difference between the suction pressure and the internal pressure of the crank chamber may become excessive. In this case, some of the internal parts of the compressor
An unreasonable force that would not be applied during normal operation is applied, which significantly reduces durability and may even lead to damage.

In order to avoid this problem, the conventional example takes the following measures. - Limit the opening degree of the second on-off valve to prevent the internal pressure of the crank chamber from rising suddenly. ■To prevent the internal pressure of the crank chamber from rising excessively, either provide a bypass passage that connects the crank chamber and the suction chamber separately from the first on-off valve, or restrict the valve from closing completely. do. (2) Limiting the suction pressure operating point control by the operating point control means to prevent sudden operating point change control. (2) The control range of the suction pressure control operation point by the operation point control means is made narrow so that the pressure difference between the suction pressure and the flank chamber does not increase more than necessary.

[0006]

[Problem to be solved by the invention] However, the above ■
and (2) had the disadvantage that the ability to quickly change the discharge volume was impaired. In addition, in ■ and ■ above,
This has the disadvantage that the control range of suction pressure is narrowed. Therefore, the technical problem of the present invention is to have a wide suction pressure control range safely and without damaging the compressor.
Another object of the present invention is to provide a variable capacity swash plate compressor with quick response to changes in discharge capacity.

[0007]

[Means for Solving the Problems] According to the present invention, a casing forming a crank chamber, a cylinder head forming a discharge chamber and a suction chamber and closing one open end of the casing, and a cylinder head rotatable in the casing a main shaft supported by the crankshaft, a swash plate disposed in the crank chamber and rotated by rotation of the main shaft, and a rocking plate disposed on an inclined surface of the swash plate and swinging in response to rotation of the swash plate. a hinge mechanism that transmits rotation of the main shaft to the swash plate and supports the swash plate at a variable angle of inclination with respect to the main shaft; and a plurality of cylinders formed in the casing radially outside of the main shaft. and,
A piston that is reciprocatably arranged in the cylinder and connected to the rocking plate, a first communication path that communicates between the crank chamber and the suction chamber, and a pressure in the suction chamber or the crank chamber. a first on-off valve that opens and closes the first communication passage by sensing the pressure of the first on-off valve, and an operating point control means that applies a load to the first on-off valve to displace the opening/closing point of the first on-off valve. and a variable capacity swash plate compressor having a second communication passage that communicates the crank chamber and the discharge chamber, and a second on-off valve that opens and closes the second communication passage; The means includes a forced opening/closing mechanism that fully closes the second opening/closing valve when the first opening/closing valve operates normally and opens/closes the second opening/closing valve. A variable capacity swash plate compressor with characteristics can be obtained.

[0008]

[Operation] In the variable capacity swash plate compressor of the present invention, in normal control that does not require rapid changes in discharge capacity,
By controlling the opening degree of the first on-off valve while keeping the second on-off valve fully closed by the operating point control means, the pressure in the crank chamber is controlled, and the angle of the swash plate is changed to increase the discharge capacity. Control. In particular, when it is desired to reduce the discharge volume or when a rapid change in discharge volume is required, the forced full opening means is operated by a control signal to the operating point control means to forcibly open the second on-off valve; The discharge gas is introduced into the crank chamber, causing a change in the swash plate angle, which reduces the discharge volume with a fast response time. At this time, the internal pressure in the crank chamber rises, but before it rises too much, the control signal to the operating point control means is switched from forced control to normal control, and the second on-off valve is closed. There is no possibility that the internal pressure in the crank chamber will increase any further. Therefore, the pressure difference between the crank chamber and the suction chamber will not become excessive.
Internal parts will not be damaged by applying excessive force that would not normally occur.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a sectional view of a variable capacity swash plate compressor according to an embodiment of the present invention. Referring to FIG. 1, a casing 1 has a substantially cylindrical shape, and a cylinder block 2 is integrally provided at one end thereof. A plurality of cylinders 3 are formed in the cylinder block 2 at regular intervals in the radial direction. The other end of the casing 1 is closed by a front end plate 4. This allows the cylinder block 2 and front end plate 4 inside the casing 1 to
A crank chamber 5 is configured in the area between.

The main shaft 10 passes through the front housing 4 and into the casing 1, and has one end connected to a needle bearing 1 provided in the center of the cylinder block 2.
A needle bearing 12 is rotatably supported by the needle bearing 1 and has the other end attached to the center of the front housing 4.
is rotatably supported by.

A rotor 13 is arranged within the crank chamber 5 and attached to the main shaft 10. A swash plate 15 is attached to the rotor 13 via a hinge mechanism 14. This allows the swash plate 15 to change its angle with respect to the main shaft 10. A part of the inner wall surface of the swash plate 15 is in contact with the main shaft 10 and is inclined along the axial direction of the main shaft 10.

A swing plate 21 is attached to the swash plate 15 via a bearing 20. A plurality of piston rods 22 are connected to the swing plate 21 by ball joints. The piston rod 22 is spherically connected to a piston 23 located within the cylinder 3.

In the crank chamber 5, a guide rod 24 is fixed to the casing 1 in parallel with the main shaft 10, and this guide rod 24 is held by one end of the swing plate 21. One end portion can swing relative to the guide rod 24 in the direction of the main axis.

A cylinder head 30 is mounted on the right end surface of the casing 1 with a valve plate 25 interposed therebetween.

The cylinder head 30 has a suction chamber 31 and a discharge chamber 32 formed therein. The suction chamber 31 is connected to a suction port 33. The discharge chamber 32 is connected to a discharge port 34. A suction hole 25a and a discharge hole 25b are formed in the valve plate 25, and the suction chamber 31 and the discharge chamber 32 communicate with the cylinder 3 via the suction hole 25a and the discharge hole 25b, respectively.

A control valve 40 is attached to the cylinder head 30 as operating point control means. This control valve 40 has a hole 41, a hole 42, a hole 4
3 and a hole 44 are provided. The hole 41 communicates with the discharge chamber 32 through a cavity 36 and a communication hole 33 formed in the cylinder head 30 . The hole 42 is the cylinder head 3
0 and communicates with the crank chamber 5 through a communication hole 34 formed in the cylinder block 2. The hole 43 is a communication hole 35 formed in the cylinder head 30 and cylinder block 2.
It communicates with the crank chamber 5 via. The hole 44 is connected to the suction chamber 31 through a communication hole 36 formed in the cylinder head 30.
communicate with.

The control valve 40 is the main body of the valve, and includes a main body suction element 51 that serves as both a forced opening/closing mechanism and an operating point control mechanism, and a forced opening/closing mechanism and an operating point control mechanism arranged inside the main body suction element 51. A cylindrical solenoid 56 that also serves as
, is inserted into the upper cavity 61 of the main suction element 51 and the cavity 6
2, a valve body (second opening/closing valve) 47 disposed inside the cavity 62, and a spring 46 as a forced opening/closing mechanism disposed to press and bias the valve body 47. , a spring 49 as a forced opening/closing mechanism disposed in the space 61, a presser member 48 disposed to press the spring 49 against the lower surface of the insertion member 63, and a forced opening/closing mechanism disposed inside the solenoid 56. A movable core 64 that also serves as a point control mechanism, a rod 50 that penetrates the main body attractor 51 and serves as a forced opening/closing mechanism that connects the holding member 48 and the movable core 64, are inserted adjacent to the lower side of the movable core 64. The insertion member 53, the movable core 64 and the insertion member 5
a spring 52 as a forced opening/closing mechanism arranged to be sandwiched between the valve body 52 and a valve body (first opening/closing valve) 54 arranged in an internal space 65 of the main body suction element 51 and connected to the insertion member 53;
, a member 57 attached to close the internal cavity 65 of the main body suction element 51, which is arranged to be sandwiched between the main body suction element 51 and the member 57, divides the cavities 65a and 65b, and is attached to the valve body 54. an adjacent diaphragm 55; an adjacent member 5 disposed within the cavity 65b and adjacent to the diaphragm 55;
8. The adjustment screw 59 is screwed into the adjacent member 58, and the spring 60 is disposed to sandwich the adjustment screw 59 and the adjacent member 58 so as to bias them. The operating point control means here refers to the valve body (
It applies a load to the first on-off valve) 54 to change the opening/closing point of the valve body (first on-off valve) 54, that is, the suction pressure control point, and the solenoid 56, main body suction element 51, and movable core It has 64. Referring also to FIGS. 2(a) and 2(b), the operating point control means controls the opening/closing operating point of the valve body (first on-off valve) 54 according to the value of the input current signal leading to the solenoid 56. There is.

When current is passed through the solenoid 56, the movable iron core 64 is attracted to the main body attractor 51, and applies an upward force to the valve body 54. However, this is only when the normal control current is applied, and the valve body 54 can move from fully open to fully closed. Furthermore, since the movable core 64 and the insertion member 53 are adjacent to each other and the forces of the springs 49 and 60 are applied from both ends, the presser member 48, the rod 51, and the movable core 64 are
4. The insertion member 53, the valve body 54, the diaphragm 55, and the adjacent member 58 move together in the axial direction of the control valve 40.

At this time, the air space 65a in the upper space of the diaphragm 55 is equal to the pressure in the suction chamber, and the air space 65b in the lower space is equal to the atmospheric pressure, so the diaphragm 55 moves in response to the suction chamber pressure. In other words, the opening degree of the valve body 54 changes and the flow rate of refrigerant gas from the crank chamber 5 to the suction chamber 31 is adjusted, so that the suction pressure is controlled according to the amount of current flowing through the solenoid 56. The opening degree of the valve body 54 is adjusted.

On the other hand, in the case of forcible control, that is, in the case of using a larger amount of current to energize the solenoid than in normal control, the operating point control means is given a forced signal from the outside, and as shown in FIG.
), the movable core 64 is strongly pulled by the body attractor 51 which is biased by the springs 46 and 49, which is a forced full opening mechanism, pushing up the valve body 47 and opening the spaces 62 and 61. communicate. This creates a gap between the movable core 64 and the insertion member 53.

[0021] Therefore, the discharge chamber 32 and the crank chamber 5 communicate with each other, and high discharge pressure flows into the crank chamber 5, so that the pressure inside the crank chamber 5 instantly increases, resulting in a rapid decrease in the discharge volume. becomes possible.

[0022]

According to the variable capacity swash plate type compression according to the present invention, the second on-off valve provided in the middle of the communication path leading from the discharge chamber to the crank chamber is forcibly controlled by the operating point control means. Since it is configured to fully open, it is possible to reduce the discharge volume with quick response. Moreover, by switching from forced control to normal control before the internal pressure of the crank chamber increases excessively, the second on-off valve is closed, so the internal pressure of the crank chamber does not increase more than necessary. , it is safe and will not damage the compressor. Furthermore, since the pressure in the crank chamber does not rise excessively, there is no need to provide a bypass passage communicating between the crank chamber and the suction chamber, and therefore a wide suction pressure control range can be achieved. Furthermore, in the present invention, even if the diameter of the second on-off valve that communicates the discharge chamber and the crank chamber is made larger than that of the conventional one, the pressure in the crank chamber will not increase excessively. By increasing , the responsiveness of the discharge volume reduction can be made even faster.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a variable capacity swash plate compressor according to an embodiment of the present invention.

[Fig. 2] (a) shows a solenoid 5 which is an operating point control means.
Valve body (first on-off valve) for the value of the input current signal to 6
54 is a diagram showing the opening degree of 54. (b) is a diagram showing the opening/closing operating point of the valve body (first opening/closing valve) 54, that is, the suction pressure control point with respect to the value of the input current signal.

[Explanation of symbols]

1 Casing 2 Cylinder block 3 Cylinder 4 Front end plate 5 Crank chamber 10 Main shafts 11, 12 Needle bearings 13 Rotor 14 Hinge mechanism 15 Swash plate 20 Bearing 21 Swing plate 22 Piston rod 23 Piston 24 Guide rod 25 Valve plate 30 Cylinder head 31 Suction chamber 32 Discharge chamber 33 Communication passage 34 Communication passage 35 Communication passage 36 Communication passage 40 Control valve 41 Communication hole 42 Communication hole 43 Communication hole 44 Communication hole 45 Adjustment screw 46 Spring 47 Valve body (second on-off valve) 48 Holding member 49 Spring 50 Rod 51 Main body suction element 52 Spring 53 Insertion member 54 Valve body (first on-off valve) 55 Bellows 56 Solenoid 57 Member 58 Adjacent member 59 Adjustment screw 60 Spring 61 Hole 62 Hole 63 Insertion member 64 Movable core 65a Blank space 65b Blank space 65c Blank space

Claims (4)

[Claims] Claim 1: A casing forming a crank chamber;
a cylinder head formed with a discharge chamber and a suction chamber and closing one open end of the casing; a main shaft rotatably supported by the casing; and a swash plate arranged in the crank chamber and rotated by rotation of the main shaft. a rocking plate disposed on the inclined surface of the swash plate and swinging in accordance with the rotation of the swash plate; a hinge mechanism that supports a variable inclination angle; a plurality of cylinders formed in the casing on the radially outer side of the main shaft; and a piston that is reciprocatably arranged within the cylinders and connected to the rocking plate. a first communication passage that communicates the crank chamber and the suction chamber; and a first on-off valve that opens and closes the first communication passage by sensing the pressure in the suction chamber or the pressure in the crank chamber. , an operating point control means for displacing the opening/closing point of the first on-off valve by applying a load to the first on-off valve; a second communication passage communicating between the crank chamber and the discharge chamber; In a variable capacity swash plate compressor having a second on-off valve that opens and closes a second communication passage, the operating point control means controls the operating point control means to control the operating point when the first on-off valve normally operates to open and close. A variable capacity swash plate compressor characterized by having a forced opening/closing mechanism that fully closes a second opening/closing valve and forcibly opens/closes the second opening/closing valve. 2. The variable capacity swash plate compressor according to claim 1, wherein the first on-off valve has a diaphragm or a bellows that senses the pressure in the suction chamber or the pressure in the crank chamber. A variable capacity swash plate compressor characterized in that its opening degree is adjusted according to the pressure in a chamber or the pressure in the crank chamber. 3. The variable capacity swash plate compressor according to claim 1, wherein the operating point control means includes a solenoid means excited by the flow of current, and an electromagnetic force generated in accordance with the amount of current supplied to the solenoid means. At the same time, the electromagnetic force has a movable iron core that operates in conjunction with the first on-off valve only when the solenoid means is energized with the normal amount of electricity that normally opens and closes the first on-off valve. A variable capacity swash plate compressor characterized in that a load is applied to a first on-off valve. 4. The variable capacity swash plate compressor according to claim 3, wherein the forced opening/closing mechanism operates when a forced full open signal for forcibly opening the second opening/closing valve is given to the solenoid means. , the movable iron core operates independently without interlocking with the first on-off valve, and applies displacement to the second on-off valve or a member that opens and closes the second on-off valve, and causes the second on-off valve to open and close. A variable capacity compressor that features an opening valve.