JPH02238190A - Capacity changeable scroll type compressor - Google Patents

Abstract

PURPOSE:To make it possible to change the compression capacity in multi-stages by providing a fluid hole connecting a compression chamber with the low pressure side along the spiral of a fixed scroll at a position closer to the center part than a fluid entrance to the compression chamber and providing a compression delay valve mechanism and a suction throttle valve mechanism. CONSTITUTION:A suction throttle valve mechanism 8 provided in a suction passage 71 reaching a suction chamber 7 in a first housing 1 is composed of a spool 82 through a spring 83 in a column-like cylinder 81. The opening area of the suction passage 71 is changed corresponding to the pressure of a pressure control chamber 8a separated by bellows 85 connected with the spool 82. A fluid hole 91 is formed in the bottom plate of a fixed scroll 10 along the spiral of the fixed scroll 10 at a closer position to the center part than a fluid entrance 72 connected with a compression chamber 5 in the middle of compression from the suction chamber 7, so the compression chamber 5 is connected with the suction chamber 7. This fluid hole 91 is opened and closed by a compression delay valve mechanism 92 equipped with a valve 921 driven by an electromagnetic 920.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a variable displacement scroll compressor having a suction throttle valve mechanism suitable for use in vehicle air conditioning.

[Conventional technology] Conventionally, a variable displacement scroll compressor (hereinafter simply referred to as a compressor), which is driven by an engine via an electromagnetic clutch, has been known for compressing refrigerant gas used for vehicle air conditioning. (JP-A-571-48089, JP-A-60-101-295).

The compressor described in Japanese Patent Application Laid-open No. 57-148089 is equipped with a fluid hole that bypasses refrigerant gas during compression, and a compression delay valve mechanism that opens and closes this fluid hole.

In this compressor, the fluid passage is provided in a circumferential range closer to the center of the fixed scroll along the spiral direction than the fluid inlet to the compression chamber.

Further, the compressor described in Japanese Patent Application Laid-Open No. 60-101295 is equipped with a fluid hole and a compression delay valve mechanism, and also includes a suction throttle valve mechanism that operates in conjunction with the compression delay valve mechanism. This compressor is provided with a three-way valve that integrates a compression delay valve mechanism and a suction throttle valve mechanism.

[Problems to be Solved by the Invention] The compressor described in JP-A-57-1-48089 has a problem in that the variable range is insufficient. That is, in this type of compressor, even if the compression delay valve mechanism is opened to prevent overcooling, a compression chamber is not formed after the contact point between the movable scroll and the fixed scroll passes through the fluid passage hole. Although the volume of the compression chamber formed is reduced, the compression work is actually performed by the revolution of the movable scroll. For this reason, compression work is performed even in a supercooled state, and the supercooled state is greatly promoted. In other words, with only the compression delay valve mechanism, the capacity decreases only to a small extent, and the variable range is insufficient. Therefore, when the engine speed changes over a wide range, conventional compressors designed to provide sufficient capacity at low engine speeds have excessive cooling capacity at high engine speeds, resulting in excessive cooling. To avoid this, the electromagnetic clutch is frequently connected and disconnected. If the electromagnetic clutch is frequently connected and disconnected, the engine load will fluctuate significantly, and the acceleration performance and driving feeling of the vehicle will inevitably be adversely affected.

Furthermore, in the compressor described in JP-A-60-101-295, the suction throttle valve mechanism and the compression delay valve mechanism are interlocked with each other. When bypassed, the suction throttle valve mechanism simultaneously shifts to the closed state. Therefore, the flow of refrigerant gas sucked into the compressor is reduced from the initial stage of reducing the compression capacity. Since the refrigerant gas contains not only refrigerant but also lubricating oil, it is reduced from the initial stage of reducing compression capacity to the lubricating oil supplied to the inside of the compressor. Therefore, poor lubrication within the compressor tends to occur, which in turn adversely affects the durability of the compressor. Moreover, in this compressor, since the suction throttle valve mechanism and the compression delay valve mechanism operate simultaneously, there is also the problem that only one level of the low capacity range obtained by adjustment can be selected.

The present invention aims to solve the technical problem of varying the capacity of a compressor in multiple stages without reducing the lubrication function as much as possible.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides a compression chamber that is in the middle of compression and a low pressure at a position closer to the center of the fixed scroll along the spiral direction than the fluid inlet to the compression chamber. A compression delay valve mechanism that opens and closes the fluid passage, and a suction throttle valve mechanism that adjusts the opening area of the suction passage leading to the suction chamber are each independently provided. A new technical method is adopted.

[Function] In the variable scroll compressor of the present invention, when the valve of the compression delay valve mechanism is opened, the refrigerant gas in the middle of compression is bypassed to the suction chamber through the fluid hole. Therefore, the compression action is disabled until the contact point between the movable scroll and the fixed scroll passes through the fluid hole, and compression of the refrigerant gas starts after the contact point passes through the fluid hole. When the valve of the compression delay valve mechanism is closed, the refrigerant gas is completely compressed regardless of the position of the contact. In addition, by adjusting the opening area of the suction passage with the suction throttle valve mechanism, the amount of refrigerant gas sucked before suction can be adjusted, and the compression capacity can be changed as desired.

Furthermore, in the variable capacity scroll compressor of the present invention, since the compression delay valve mechanism and the suction throttle valve mechanism are provided independently, regardless of the initial stage of reducing the compression capacity, Also, in order to prevent the cooling capacity from becoming excessive, the capacity is reduced by one step of either the compression delay valve mechanism or the suction throttle valve mechanism, and then the capacity is further reduced by one step by the other of the suction throttle valve mechanism or the compression delay valve mechanism. be able to. Further, if desired, the compression delay valve mechanism and the suction throttle valve mechanism can be operated simultaneously. Therefore, the lubricating oil supplied to the inside of the compressor is not reduced in conjunction with the refrigerant gas bypass. In other words, by operating the compression delay valve mechanism at the initial stage of reducing the compression capacity, and operating the suction throttle valve mechanism at the stage when it is necessary to roughly reduce the compression capacity, the internal flow of the compressor at the initial stage is reduced. The supply of lubricating oil is not blocked.

Therefore, poor lubrication within the compressor is less likely to occur, and the durability of the compressor is improved. In addition, the reduction in capacity, which was slight with the compression delay valve mechanism alone, is further reduced to two stages by the suction throttle valve mechanism, and the variable range of refrigerant gas is further expanded.

[Example] Hereinafter, an example embodying the present invention will be described with reference to the drawings.

FIG. 1 shows a scroll compressor (hereinafter simply referred to as a compressor) which is an embodiment of the present invention. In this compressor, a fixed scroll 10 is supported in a first housing 1 that includes a suction chamber 7 therein, and a movable scroll 20 is supported in a second housing 2 that is connected to the first housing 1 by a fastening means. A shaft 4 is rotatably supported within a third housing 3 that is coupled to the second housing 2 by a fastening means. A drive pin 41 is installed eccentrically at the inner end of the large diameter portion 40 of the shaft 4, and a counterweight 42 and an eccentric pusher 43 are coupled to the drive pin 41. The eccentric pusher 43 supports the movable scroll 2o via a bearing 44. An anti-rotation mechanism 45 is disposed near the connection between the second and third housings 2 and 3, and this anti-rotation mechanism 45 allows the movable scroll 2 to
0 is capable of only revolving motion and is prevented from rotating, and meshes with the fixed scroll 10, and the spiral grooves of both scrolls 10 and 20 form a compression chamber 5 (5a to 5e) (see FIG. 2). Further, as shown in FIG. 1, a discharge port 61 that communicates with the compression chamber 5e at the end of compression is provided in the central portion of the fixed scroll 10, and a discharge port 6 that communicates with the discharge port 61 is connected to the first housing. It is formed inside 1.

The most characteristic configuration of this embodiment is that this compressor includes a suction throttle valve mechanism 8, a fluid passage hole 91, and a compression delay valve mechanism 92.
It is equipped with

That is, the suction throttle valve @8 includes a cylinder 81 that is attached to the suction passage 71 leading to the suction chamber 7 and has a cylindrical space extending in the axial direction, and a cylinder 81 that is slidably held in the cylindrical space of the cylinder 81. spool 82 and spool 82
is held via a spring 83 and the cylinder 8
A cover 8 having an inverted U-shaped cross section that covers the third housing 3 side of 1.
4. The cylinder 81 has a cylindrical space that communicates with the intake port 810 on the first housing 1 side, and communicates with the suction passage 71 approximately at the center. Spool 82
is a pressure hole 82 that communicates with the cylindrical space of the cylinder 81.
0, and is provided with a bellows 85 attached to the back surface of the cylinder 81 from a protrusion on the side surface. bellows 85
The inside of the cover 84 is divided into a space including the pressure hole 820 and a space not including the pressure hole 820. Further, the cover 84 is formed with an atmospheric pressure intake hole 841 that communicates with a space that does not include the pressure hole 820. In this way, the cylindrical space of the cylinder 81 is defined as a pressure control chamber 8a.

Further, a fluid passage hole 91 is formed in the bottom plate of the fixed scroll 10 at a position closer to the center along the spiral direction of the fixed scroll 10 than the fluid introduction port 72 that communicates from the suction chamber 7 to the compression chamber 5 in the middle of compression. It is set up. Through this fluid passage hole 91, the compression chambers 5a, 5b in the middle of compression communicate with the suction chamber 7 (see FIG. 2).

Further, the compression delay valve @92 includes a valve 921 that opens and closes the fluid passage hole 91 using an electromagnet 920. That is, a plate-shaped valve 921 made of a ferromagnetic material that closes the fluid passage 91 in the normal state is attached to the suction chamber 7 side of the fluid passage 91 with a screw 922. An electromagnet 920 is attached to the inner surface of the housing 1. The electromagnet 920 is fixed to a boss portion formed in the first housing 1 and connected to a battery via wiring (not shown).

In the compressor configured as described above, refrigerant gas is introduced from the intake port 810 via the suction throttle valve @8. At this time, the suction pressure is high and the pressure hole 820 is opened from the pressure control chamber 8a.
If the force that tries to expand the internal volume of the bellows 85 through the atmospheric pressure and the biasing force of the spring 83,
The spool 82 moves in a direction to widen the communication area between the suction passage 71 and the pressure control chamber 8a, and a large amount of refrigerant gas is supplied from the suction passage 71 to the suction chamber 7. Furthermore, if the suction pressure is low and the force that attempts to expand the internal volume of the bellows 85 from the pressure control chamber 8a through the pressure hole 820 is returned to atmospheric pressure and the biasing force of the spring 83, the spool 82 will move toward the suction passage 71. A small amount of refrigerant gas is supplied to the suction chamber 7 from the suction passage 71.

Further, in the compressor of this embodiment, the refrigerant gas taken into the suction chamber 7 is roughly manipulated by the operation of the compression delay valve mechanism 9. That is, when the electromagnet 920 is excited by a predetermined signal, the valve 921 is pulled toward the electromagnet 920 and the fluid passage hole 91 is opened. At this time, as shown in FIG. 2, the refrigerant gas present in the compression chambers 5a and 5b in the middle of compression is bypassed to the suction chamber 7 via the fluid passage hole 91.

Then, the compression work is not performed until the contact point between the movable scroll 20 and the fixed scroll 10 passes through the fluid passage hole 91. As a result, the timing to start compressing the refrigerant gas is delayed as desired. In addition, the electromagnet 92 is
0 is de-energized, the valve 921
Return to the side and close the fluid passage hole 91. At this time, the refrigerant gas existing in the compression chambers 5a and 5b in the middle of compression performs compression work as usual as the movable scroll 20 revolves.

Thereafter, the pressure of the refrigerant gas is sequentially increased by the volume change of the compression chamber 5 due to the orbital movement of the movable scroll 20 (5a to 5e in FIG. 2), and the refrigerant gas is discharged from the discharge port 61 in the center of both scrolls 10 and 20. The valve 62 is pushed open to lead out into the discharge chamber 6 formed in the first housing 1, and then to a refrigeration circuit (not shown).

In this way, in the compressor of this embodiment, the compression delay valve 8M49
2 and the suction throttle valve mechanism 8 are provided independently, so that the compression delay valve mechanism 9 prevents the cooling capacity from becoming excessive.
After the capacity is reduced by one step by either the suction throttle valve mechanism 2 or the suction throttle valve mechanism 8, the capacity can be further reduced by one step by the other one of the suction throttle valve mechanism 8 or the compression delay valve mechanism 4M92. Further, if desired, the compression delay valve mechanism 92 and the suction throttle valve a mechanism 8 can be operated simultaneously. For this reason,
At the initial stage of reducing the compression capacity, the compression delay valve mechanism 9
By activating the suction throttle valve mechanism 8 at a stage when it is necessary to roughly reduce the compression capacity by activating the compressor 2, the supply of lubricating oil to the inside of the compressor at the initial stage is not blocked. Therefore, poor lubrication within the compressor is less likely to occur, and the durability of the compressor is improved. In addition, the reduction in capacity, which was slight with the compression delay valve mechanism 92 alone, is roughly reduced to two stages by the suction throttle valve mechanism 8, and the variable range of refrigerant gas is further expanded.

[Effects of the Invention] As described in detail above, the present invention is equipped with a fluid passage, and also has a compression delay valve mechanism and a suction throttle valve mechanism independently. At this stage, the compression delay valve mechanism is operated, and at the stage when the compression capacity needs to be further reduced, the suction throttle valve mechanism is operated, thereby minimizing the deterioration of the lubrication function of the compressor.

Furthermore, in the present invention, the reduction in capacity, which would have been slight with the compression delay valve mechanism alone, can be roughly reduced in multiple stages using the suction throttle valve mechanism, so the variable range of refrigerant gas can be further expanded. .

[Brief explanation of drawings]

1 and 2 relate to a variable capacity scroll compressor according to an embodiment of the present invention, in which FIG. 1 is a sectional view in the axial direction, and FIG. 2 is a sectional view in the direction perpendicular to the axis of both scrolls. 1... First housing 10... Fixed scroll 2
...Second housing 20...Movable scroll 3.
...Third housing 5 (5a to 5e)...Compression chamber 7...: To suction 71...Suction passage 72...
・Inlet port 8...Suction throttle valve mechanism

Claims (1)

[Claims] (1) A fixed scroll, a movable scroll that meshes with the fixed scroll through revolution to form a compression chamber, and a movable scroll that supports the fixed scroll and the movable scroll and has a suction chamber inside. In a variable capacity scroll compressor including a housing, the compression chamber in the middle of compression communicates with the low pressure side at a position closer to the center along the spiral direction of the fixed scroll than the fluid inlet to the compression chamber. A compression delay valve mechanism that extends through a fluid passage and opens and closes the fluid passage, and a suction throttle valve mechanism that adjusts the opening area of the suction passage leading to the suction chamber are each independently provided. A variable capacity scroll compressor.