JP2529908Y2 - Scroll compressor - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll compressor suitable for an air conditioner for a vehicle.

[0002]

2. Description of the Related Art One example of a conventional scroll compressor is shown in FIG.
Or shown in FIG. In FIG. 8, reference numeral 1 denotes a closed housing, which is fastened to the cup-shaped main body 2 and the bolts 3 thereto.
It comprises a cup-shaped main body 2, a front end plate 4 fastened thereto by bolts 3, and a cylindrical member 6 fastened to this by bolts 5. A main shaft 7 penetrating the cylindrical member 6 is rotatably supported by the housing 1 via bearings 8 and 9.

A fixed scroll 10 and an orbiting scroll 14 are disposed in the housing 1. The fixed scroll 10 has an end plate 11 and a spiral wrap 12 erected on the inner surface thereof. The fixed scroll 10 is fixed in the housing 1 by being fastened to the cup-shaped main body 2 by bolts 13. The housing 1 is partitioned by bringing the outer peripheral surface of the end plate 11 into close contact with the inner peripheral surface of the cup-shaped body 2, a discharge cavity 31 is formed outside the end plate 11, and a suction cavity is formed inside the end plate 11. Room 28 is limited. A discharge port 29 is formed in the center of the end plate 11, and the discharge port 29 is bolted to the outer surface of the end plate 11 together with a retainer 35.
It is opened and closed by a discharge valve 30 fastened by 36. The orbiting scroll 14 includes an end plate 15 and a spiral wrap 16 erected on its inner surface, and the spiral wrap 16 has substantially the same shape as the spiral wrap 12 of the fixed scroll 10. I have.

The orbiting scroll 14 and the fixed scroll 10 are mutually eccentric by an orbital radius of rotation, and are engaged with each other at an angle shifted by 180 °. Thus, the tip seal 17 buried at the distal end surface of the spiral wrap 12 is in close contact with the inner surface of the end plate 15, and the chip seal 18 buried at the distal end surface of the spiral wrap 16 is in close contact with the inner surface of the end plate 11. Then, the side surfaces of the spiral wraps 12 and 16 are, as shown in FIG.
A plurality of compression chambers 19a and 19b which are closely symmetric with respect to the center of the spiral are formed by b, c and d.

A drive bush 21 is rotatably fitted via a bearing 23 inside a cylindrical boss 20 protruding from the center of the outer surface of the end plate 15, and a hole 24 formed in the drive bush 21 is provided. An eccentric pin 25 projecting eccentrically from the inner end of the main shaft 7 is rotatably fitted therein. A balance weight 27 is attached to the drive bush 21. A rotation preventing mechanism which also serves as a thrust bearing is provided between the outer surface of the end plate 15 and the inner surface of the front end plate 4.
26 are located.

When the main shaft 7 is rotated, the orbiting scroll 14 is driven by a orbiting drive mechanism including the eccentric pin 25, the drive bush 21, the boss 20, and the like. , While revolving around a circular orbit whose radius is the revolution radius, that is, the amount of eccentricity between the main shaft 7 and the eccentric pin 25. Then
The line contact portions a to d of the spiral wraps 12 and 16 gradually move toward the center of the spiral, and as a result, the compression chambers 19a and 19b move toward the center of the spiral while reducing their volumes. Along with this, the gas flowing into the suction chamber 28 through the suction port (not shown) is taken into the compression chambers 19a and 19b from the outer terminal openings of the spiral wraps 12 and 16 and is compressed and moved to the center. From here, the liquid is discharged to the discharge cavity 31 by pushing and opening the discharge valve 30 through the discharge port 29, and flows out from there through a discharge port (not shown).

As shown in FIGS. 9 and 10, a pair of cylinders 32a and 32b having one end communicating with the suction chamber 28 are formed in the end plate 11 of the fixed scroll 10. 32b are located on both sides of the discharge port 29 and extend in parallel with each other. The end plate 11 has a pair of compression chambers 19.
Bypass ports 33a and 33b are provided to allow the gas in the middle of compression to bypass the cylinders 32a and 32b from inside the cylinders a and 19b. The pistons 34a, 34b for opening and closing the bypass ports 33a, 33b are provided in the cylinders 32a, 32b.
The pistons 34a, 34b are pushed slidably in a sealed manner, and the pistons 34a, 34b are pushed backward by the elastic force of the return springs 41a, 41b interposed in a compressed state between the pistons 34a, 34b. Is guessed. The bottom of the cup-shaped main body 2 is hermetically pierced, and one part of the control valve 38 protrudes outside.
The control valve 38 is installed
As shown in JP-A-344485 and Japanese Utility Model Laid-Open Publication No. 1-179186, a control pressure which can be expressed as a linear function of a low pressure and an intermediate pressure between these pressures by sensing a discharge pressure and a suction pressure is generated. .

During the full-load operation of the compressor, the high-pressure control gas generated by the control valve 38 is introduced into the cylinders 32a and 32b through the holes 39a and 39b, and is introduced into the inner end faces of the pistons 34a and 34b. And return it to the return spring 41
The bypass ports 33a and 33b are closed by advancing against the resilience of the a and 41b. On the other hand, during the unload operation of the compressor, the pressure of the control gas generated from the control valve 38 is reduced. Then, each piston 34a, 34b
Is retracted by the elastic force of the return springs 41a, 41b to occupy the position shown in the drawing, and the gas under compression from the pair of compression chambers 19a, 19b passes through the bypass ports 33a, 33b and is drilled in the pistons 34a, 34b. Communication holes 42a, 42b, blind holes 43a, 43b, cylinder 32
The liquid flows out into the suction chamber 28 via a and 32b.

[0009]

In the above-mentioned conventional compressor, the compression chambers 19a and 19b are point-symmetric with respect to the center of the spiral.
Are formed, a pair of bypass ports 33a, 33b and a pair of cylinders 32a, 32b are connected to the end plate 11 to bypass the gas being compressed from the compression chambers 19a, 19b, respectively.
And the pistons 34a, 34b, the return springs 41a, 41b, and the spring receivers are respectively provided in the pair of cylinders 32a, 32b.
Since it is necessary to provide two sets of 40a, 40b, etc., there is a problem that the structure becomes complicated, the number of parts, the number of assembling and processing steps increase, and the cost and weight increase. Also,
Since the control valve 38 is hermetically attached to the housing 1 with a part thereof protruding out of the housing 1, not only the external dimensions of the compressor are increased, but also the control valve 38 is obstructed when handling the compressor. There was a risk of being damaged upon hit. Further, the mounting structure and the sealing structure for mounting the control valve 38 become complicated, and not only the man-hour for mounting the control valve 38 is increased, but also the discharge pressure and the suction pressure are guided to the control valve 38, and the control generated by the control valve 38 is performed. Pressure to cylinder 32
There is a problem that it is very difficult to lead to a and 32b, and the man-hour is increased.

[0010]

SUMMARY OF THE INVENTION The present invention has been devised to solve the above-mentioned problems, and the gist of the invention is that the fixed scroll and the orbiting scroll incorporated in the housing are angled with respect to each other. A compression chamber is formed by shifting and meshing, and the orbiting scroll is revolved by a orbiting drive mechanism while preventing its rotation by a rotation preventing mechanism. In a scroll type compressor for compressing an inhaled gas and discharging the compressed gas into a discharge cavity formed in the housing, a bypass port communicating with the compression chamber is formed in an end plate of the fixed scroll, and the bypass port is formed. A capacity including a bypass passage that communicates with the suction chamber and a piston valve that opens and closes the bypass passage. The control block is fixedly installed outside the end plate of the fixed scroll, and a cavity whose one end opens to the suction chamber is formed in the displacement control block. The piston detects the discharge pressure and the suction pressure in the cavity. A scroll type housing a control valve for generating a control pressure for operating the valve, and an electromagnetic coil to which an electric signal for controlling the control valve is input is arranged in the suction gas atmosphere in the cavity. In the compressor.

[0010]

According to the present invention, the bypass port communicates with the bypass passage of the displacement control block by fixing the displacement control block outside the fixed scroll end plate. By inputting an electric signal to the electromagnetic coil, a control pressure generated by the control valve is applied to the piston valve, and the piston valve is operated to open and close the bypass passage.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention is shown in FIGS. Compression chambers 19a and 19b are provided on the end plate 11 of the fixed scroll 10.
Are provided with a pair of bypass ports 33a and 33b that communicate with the bypass port. The capacity control block 50 installed outside the end plate 11 of the fixed scroll 10 has a concave portion provided on the outer peripheral edge of its inner surface.
51 is fitted into the convex portion 10a provided on the outer peripheral edge of the outer surface of the end plate 11, and the bolt 13 is passed through the bolt hole 52 formed in the cup-shaped main body 2 and the capacity control block 50, and the tip is inserted. It is fixed to the housing 1 together with the fixed scroll 10 by being screwed into the end plate 11. Then, by bringing the rear outer peripheral surface of the capacity control block 50 into close contact with the inner peripheral surface of the cup-shaped main body 2, the inside of the housing 1 is moved into the suction chamber 28.
And a discharge cavity 31. A discharge hole 53 communicating with the discharge port 29 is formed in the center of the capacity control block 50, and the discharge hole 53 is formed by a discharge valve 30 fastened with a bolt 36 together with a retainer 35 on the outer surface of the capacity control block 50. It can be opened and closed. A blind hole-shaped cylinder 54 is drilled on one side of the discharge hole 53, and a blind hole-shaped cavity 55 is bored on the other side in parallel with the cylinder 54, and the open ends of the cylinder 54 and the cavity 55 are opened. Are in communication with the suction chamber 28, respectively. Then, the inner surface of the capacity control block 50 and the cylinder 54
Communicating holes 89a, 89b and 92 are formed.

A cup-shaped piston valve 56 is hermetically slidably housed in the cylinder 54.
The control pressure chamber 80 is limited to one side of the chamber and the chamber 81 is limited to the other side.
Communicates with the suction chamber 28. The piston valve 56 is pushed toward the inside of the cylinder 54 by a coil spring 83 interposed between the piston valve 56 and the spring receiver 82. An annular concave groove 93 formed in the outer peripheral surface of the piston valve 56 is always in communication with the chamber 81 through a plurality of holes 94.

On the other hand, a control valve 58 is provided in the cavity 55.
The gap between the cavity 55 and the control valve 58 is partitioned by O-rings 59, 60, 61, 62, thereby limiting the atmospheric pressure chamber 63, the low pressure chamber 64, the control pressure chamber 65, and the high pressure chamber 66. ing. The atmospheric pressure chamber 63 communicates with the atmosphere outside the housing 1 through a through hole 67 and a pressure guiding tube (not shown).
The low pressure chamber 64 communicates with the suction chamber 28 through the through hole 68, and the control pressure chamber 65 communicates with the control pressure chamber 80 through the through hole 69, the concave groove 70, and the through hole 71.
The high-pressure chamber 66 communicates with the discharge cavity 31 through a through-hole 72. The control valve 58 detects a high pressure HP in the discharge cavity 31 and a low pressure LP in the suction chamber 28, and generates a control pressure AP.
Can be appropriately changed by inputting an electric signal to the electromagnetic coil 58a. The electromagnetic coil 58a is arranged in the suction gas atmosphere in the cavity 55.

As shown in FIG. 7, the inner surface of the capacity control block 50 has grooves 70, 90, 91, a first recess 86, and a second recess.
87, a third recess 88 is drilled. The first, second, and third recesses 86, 87, and 88 are formed by bringing a sealing material 85 embedded in a land 84 surrounding the recesses into close contact with the outer surface of the end plate 11 of the fixed scroll 10, thereby controlling the capacity of the capacity control block. The seal material 85 is formed between the inner surface of the end plate 11 and the outer surface of the end plate 11.
Are separated from each other by First recess 86 is groove 7
0, communicates with the control pressure chambers 65 and 80 through the through holes 69 and 71, and the second recess 87 communicates with the compression chambers 19a and 19b during compression through a pair of bypass ports 33a and 33b. With the chamber 81 of the cylinder 54 through the communication holes 89a, 89b,
The third recess 88 communicates with the discharge hole 53 via the concave grooves 90 and 91, and communicates with the chamber 81 of the cylinder 54 via the communication hole 92. The bypass ports 33a and 33b are arranged at positions where they communicate with the compression chambers 19a and 19b until the compression chambers 19a and 19b finish the gas suction and enter the compression stroke and reduce the volume to 50%. ing. Other configurations are the same as those of the conventional one shown in FIGS. 8 to 10, and corresponding members are denoted by the same reference numerals.

However, during the unload operation of the compressor, the control pressure AP generated at the control valve 58 decreases. When the control pressure AP is introduced into the control pressure chamber 80 through the through hole 69, the concave groove 70, and the through hole 71, the piston valve 56 is pushed by the restoring force of the coil spring 83 and occupies the position shown in FIG. . Thus, since the communication holes 89a, 89b and the communication hole 92 are opened, the gas which is being compressed in the compression chambers 19a, 19b passes through the bypass ports 33a, 33b, the second recess 87, and the communication holes 89a, 89b. The gas entering the chamber 81, while coming to the center of the spiral, is discharged from the discharge port 29, the discharge hole 53, the third recess 88, the grooves 90, 91,
The gas enters the chamber 81 via the communication hole 92, merges in the chamber 81, and is discharged to the suction chamber 28. As a result, the capacity of the compressor becomes zero. During a full load operation of the compressor, the control valve 58 generates a high control pressure AP. Then, this high control pressure AP enters the control pressure chamber 80, and the piston valve
Press the 56 inner end face. Thus, the piston valve 56 advances against the elastic force of the coil spring 83, and occupies the position where its outer end is in contact with the spring receiver 82, that is, the position shown in FIG. In this state, since the communication holes 89a and 89b and the communication hole 92 are all closed by the piston valve 56, the compression chamber
The gas compressed at the center of the spiral wound in the 19a and 19b passes through the discharge port 29 and the discharge hole 53, pushes and opens the discharge valve 30 and is discharged into the discharge cavity 31, and then, through a discharge port (not shown). It is discharged outside. Compressor capacity from 0% to 100
When changing within the range of%, the control valve 58
The control pressure generated in is changed as appropriate. When the control pressure AP acts on the inner end face of the piston valve 56 via the control pressure chamber 80, the piston valve 56 stops at a position where the pressing force by the control pressure AP and the resilient force of the coil spring 83 are balanced.
Therefore, while the control pressure AP is high, only the communication holes 89a and 89b are opened, and the gas which is being compressed in the compression chambers 19a and 19b passes through the communication holes 89a and 89b.
The gas is discharged into the suction chamber 28 by an amount corresponding to the opening degrees of a and 89b.
When the control pressure gradually decreases and the communication holes 89a and 89b are fully opened, the capacity of the compressor is reduced to 50%. Further, when the control pressure AP decreases, the communication hole 92 opens, and when it is fully opened, the capacity of the compressor becomes zero. In this way, the capacity of the compressor can be varied from 0% to 100%. Then, by appropriately changing the electric signal input to the electromagnetic coil 58a of the control valve 58, the displacement control characteristic of the compressor can be arbitrarily changed. In the above embodiment, the cylinder 54
A bypass passage is formed by the chamber 81, the communication holes 89a, 89b, 92, etc., and the bypass passage is opened and closed by the piston valve 56. However, the bypass passage and the piston valve are not limited to those shown in the drawings, and various structures and shapes are provided. Of course, it is possible.

[0016]

In the present invention, since the capacity control block is fixedly installed outside the fixed scroll end plate, the processing of the fixed scroll and the capacity control block becomes easy, and the cost thereof can be greatly reduced. A bypass port communicating with the compression chamber is formed in the end plate of the fixed scroll, a bypass passage communicating the bypass passport with the suction chamber in the displacement control block, a piston valve opening and closing the bypass passage, a discharge pressure and suction pressure. Built-in control valve that detects pressure and generates control pressure to operate piston valve, so discharge pressure and suction pressure can be easily led to control valve and control pressure generated by control valve easily. Can lead to the piston valve, reduce the external dimensions of the compressor, prevent damage to the control valve due to collisions, simplify the control valve mounting structure and seal structure, and reduce the number of mounting steps. Can be reduced. Further, since the control valve is housed in a cavity which is formed in the capacity control block and one end of which is opened to the suction chamber, and the electromagnetic coil is arranged in the suction gas atmosphere in the cavity, an electric signal is input to the electromagnetic coil. Thus, even if the electromagnetic coil generates heat, it can be cooled by the low-temperature intake gas, so that the reliability of the control valve can be improved.

[0017]

[Brief description of the drawings]

FIG. 1 is a partial longitudinal sectional view showing one embodiment of the present invention.

FIG. 2 is a perspective view taken along the arrow II of FIG.

FIG. 3 is a sectional view taken along the line III-III in FIG. 6;

FIG. 4 is a view taken in the direction of arrows along the line IV-IV in FIG. 6;

FIG. 5 is a sectional view taken along line VV in FIG. 4;

6 is a sectional view taken along the line VI-VI of FIG.

7 is a view taken in the direction of arrows VII-VII in FIG. 5;

FIG. 8 is a longitudinal sectional view showing one example of a conventional scroll compressor.

FIG. 9 is a transverse sectional view taken along the line IX-IX of FIG. 8;

10 is a partial sectional view taken along line XX of FIG. 9;

[Explanation of symbols]

 Reference Signs List 1 housing 10 fixed scroll 14 orbiting scroll 19a, 19b compression chamber 28 suction chamber 31 discharge cavity 33a, 33b bypass port 50 capacity control block 54, 81, 89a, 89b, 92 bypass passage 56 piston valve 55 cavity 58 control valve 58a electromagnetic coil

Claims (1)

(57) [Scope of request for utility model registration] 1. A compression chamber is formed by engaging a fixed scroll and an orbiting scroll incorporated in a housing with their angles shifted from each other to form a compression chamber. A scroll compressor that compresses a gas drawn into the compression chamber from a suction chamber formed in the housing by revolving orbiting by the orbit and discharges the gas into a discharge cavity formed in the housing. The end plate has a bypass port communicating with the compression chamber, a bypass passage for passing the bypass port to the suction chamber, and a capacity control block containing a piston valve for opening and closing the bypass passage. It is fixed on the outside of the plate and one end is sucked into this capacity control block. A cavity that opens to the entrance is bored, and a control valve that senses discharge pressure and suction pressure and generates a control pressure for operating the piston valve is housed in the cavity, and an electric power supply for controlling the control valve is provided. A scroll-type compressor, wherein an electromagnetic coil to which a signal is input is arranged in the suction gas atmosphere in the cavity.