JP4568422B2 - Compressor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a compressor, and more particularly, to a compressor provided with a relief valve for allowing compressed gas to escape from a discharge chamber at an excessively high pressure.
[0002]
[Prior art]
Modern automobiles are equipped with an air conditioner in almost all vehicle types. Typically, the air conditioner includes a compressor driven by an engine. As the compressor, a scroll type compressor, a swash plate type compressor, and various other types of compressors can be used.
[0003]
The compressor of an air conditioner provided in a small car is designed to have a small body diameter and a small overall length because of the engine room. For safety, a relief valve is attached so that the air conditioning system does not exceed a predetermined pressure (see, for example, Japanese Patent Application Laid-Open Nos. 7-4356 and 9-203388). The relief valve is mounted in a place where there is no interference with the vehicle side.
[0004]
[Problems to be solved by the invention]
However, the relief valve increases the size of the compressor. For example, when a relief valve is attached to the back side of the compressor, the relief valve protrudes rearward and increases the size of the compressor. If the relief valve is attached to the lower side of the compressor, the refrigerating machine oil is also ejected together with the refrigerant when the relief valve is operated, ie, when the valve is opened. In the latter case, if the refrigerating machine oil touches a high-temperature part such as an engine, it may cause smoke or fire, which is dangerous.
[0005]
In order to avoid this danger, a part that defines the blowing direction is attached to the tip of the relief valve, but there are problems such as an increase in cost due to an increase in the number of parts and an increase in the overall length of the compressor.
[0006]
Therefore, an object of the present invention is to provide a small and inexpensive compressor provided with a relief valve that performs a predetermined function with less refrigeration of refrigeration oil.
[0007]
Another object of the present invention is to provide a compressor having a high degree of freedom in the relief valve mounting layout.
[0008]
[Means for Solving the Problems]
According to the present invention, a casing having a tubular portion, a compression mechanism disposed inside the tubular portion, a discharge chamber serving as a passage for compressed gas generated by the compression mechanism, and the discharge chamber In the compressor having a relief valve for allowing compressed gas to escape at an excessively high pressure, the compression mechanism includes a fixed scroll fixed to the casing, and a movable scroll that generates compressed gas in cooperation with the fixed scroll. wherein, the fixed scroll has a skirt fitted with a gap to the cylindrical portion, the Nobita gas passage in the circumferential direction between said skirt portion and said cylindrical portion is formed by the gap, the gas A compressor is obtained in which the opening of the passage is positioned above the discharge chamber and the relief valve is connected to the gas passage.
[0009]
The said opening part may be provided in the position higher than the oil level of the refrigerating machine oil collected in the lower part of the said discharge chamber.
[0010]
The casing may have a cup shape having a bottom portion in which one end of the cylindrical portion is closed, and the fixed scroll may face the bottom portion and form the discharge chamber therebetween.
[0011]
The skirt portion may be in contact with the bottom portion.
[0012]
You may provide the O-ring which prescribes | regulates the edge part of the said clearance gap between the said skirt part and the said cylindrical part.
[0013]
A hole communicating with the gas passage may be provided in the casing, and the relief valve may be assembled in the hole.
[0014]
A portion of the gas passage facing the relief valve may be enlarged.
[0015]
The gas passage may be formed to extend between the fixed scroll and the bottom so as to face the relief valve.
[0016]
The discharge chamber may have a discharge port for discharging compressed gas at an upper portion, and the opening may be located in the vicinity of the discharge port.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIG.1 and FIG.2, the compressor which concerns on the 1st Embodiment of this invention is demonstrated.
[0018]
The compressor shown in FIGS. 1 and 2 is a scroll type compressor used in an automotive air conditioner, and includes a cup-shaped casing 10 having a cylindrical portion 11 and a bottom portion 12 with one end thereof closed. A compression mechanism 13 is disposed inside the cylindrical portion 11.
The compression mechanism 13 includes a fixed scroll 14 fixed to the casing 10 and a movable scroll 15 in cooperation with the fixed scroll 14.
[0019]
The fixed scroll 14 has a spiral wall 14a and a plate body 14b integrated with one axial end of the spiral wall 14a. A discharge chamber 16 is formed between the plate 14 b of the fixed scroll 14 and the bottom 12 of the casing 10. A discharge port 14c is formed in the plate body 14b.
[0020]
The movable scroll 15 has a spiral wall 15a and a plate body 15b integrated with one axial end of the spiral wall 15a. The spiral wound walls 14a and 15a mesh with each other and form a compression chamber 17 between them.
[0021]
A cylindrical protrusion 15 c is formed on the plate body 15 b of the movable scroll 15. An eccentric bush 19 is rotatably inserted into the cylindrical convex portion 15c. An eccentric pin 22 of the main shaft 21 is engaged with the eccentric bush 19. The main shaft 21 is rotatably supported by a front housing 23 fixed to the other end of the cylindrical portion 11 of the casing 10. A rotor 24 is rotatably provided on the outer periphery of the front housing 23. The rotation of the rotor 24 is applied to and removed from the main shaft 21 by the electromagnetic clutch 25.
[0022]
A rotation preventing mechanism 26 is interposed between the movable scroll 15 and the front housing 23. The rotation prevention mechanism 26 allows the movable scroll 15 to revolve on a circular orbit but prevents rotation.
[0023]
Now, when the main shaft 21 is rotationally driven, the force is transmitted to the movable scroll 15 via the eccentric pin 22 and the eccentric bush 19. As a result, the movable scroll 15 revolves on a circular path without rotating, and in cooperation with the fixed scroll 14, the refrigerant gas is taken into the compression chamber 17 from the suction chamber 27 to generate the compressed gas. The compressed gas enters the discharge chamber 16 from the discharge port 14c, and is discharged from a discharge port 28 positioned further upward to a refrigeration circuit (not shown).
[0024]
The refrigerant gas is taken into the suction chamber 27 from the refrigeration circuit through a suction port (not shown). Along with the refrigerant gas, the refrigeration oil also circulates in the refrigeration circuit, and a part of it accumulates inside the compressor. The oil level of the refrigerating machine oil accumulated in the discharge chamber 16 is indicated by reference numeral 29.
[0025]
Further, the fixed scroll 14 has a skirt portion 31 that fits into the cylindrical portion 11 of the casing 10 with a gap and is in contact with the bottom portion 12. The gap between the cylindrical portion 11 and the skirt portion 31 is completely closed at one end in the axial direction by an O-ring 32 interposed therebetween, and the other end in the axial direction by the scroll abutting surface 33 of the bottom portion 12. Most of it is blocked. Thus, this gap forms a gas passage 34 that extends in the circumferential direction and communicates with the discharge chamber 16 at least at one location as indicated by a thick black line. In the illustrated example, the gas passage 34 has an opening 35 only in the vicinity of the discharge port 28 located at the upper portion, and communicates with the discharge chamber 16 through the opening 35.
[0026]
Further, a hole 36 communicating with the gas passage 34 is provided in the lower portion of the bottom portion 11 of the casing 10, and a relief valve 37 is assembled to the hole 36 and connected to the gas passage 34. As is well known, the relief valve 37 is for discharging compressed gas from the discharge chamber 16 to the outside when the discharge chamber 16 becomes excessively high in pressure. In addition, the inner surface of the casing 10 is subjected to processing for enlarging a portion of the gas passage 34 facing the relief valve 37.
[0027]
When the discharge chamber 16 becomes excessively high in pressure, a part of the compressed gas is discharged from the opening 35 through the gas passage 34 to the outside by the relief valve 37. Since the opening 35 is located at the upper part, there is little possibility that the refrigeration oil flows into the gas passage 34. Therefore, when the relief valve 37 is operated, that is, when the relief valve 37 is opened, the refrigerating machine oil is prevented from being ejected to the outside together with the refrigerant gas. That is, the relief valve 37 fulfills a predetermined function with less refrigeration oil jetting.
[0028]
Even if the position of the relief valve 37 is changed, as long as the opening 35 is positioned at the upper part, the ejection of refrigerating machine oil during the operation of the relief valve 37 is limited to a small extent. Therefore, various design changes can be made to the mounting layout of the relief valve 37 as long as they do not interfere with the fixing bolt 38, and the degree of freedom is high. In addition, there are no problems such as an increase in cost due to an increase in the number of parts and an increase in the overall length of the compressor.
[0029]
With reference to FIG.3 and FIG.4, the compressor which concerns on the 2nd Embodiment of this invention is demonstrated. The same parts as those in FIG.
[0030]
The compressors shown in FIGS. 3 and 4 are also scroll-type compressors used in automobile air conditioners. In this compressor, a gas passage 34 is formed to extend between the plate portion 14 b of the fixed scroll 14 and the bottom portion 12 of the casing 10 and is opposed to the relief valve 37. This also has the same effect as the compressor of FIG.
[0031]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a compact and inexpensive compressor having a relief valve mounting layout with a high degree of freedom in the mounting layout of the relief valve, which includes a relief valve that performs a predetermined function with less jetting of refrigeration oil.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a scroll compressor as a compressor according to a first embodiment of the present invention.
2 is a cross-sectional view taken along line II-II of the scroll compressor of FIG.
FIG. 3 is a cross-sectional view showing a scroll compressor as a compressor according to a second embodiment of the present invention.
4 is a cross-sectional view of the scroll compressor of FIG. 3 taken along line IV-IV.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Casing 11 Cylindrical part 12 Bottom part 13 Compression mechanism 14 Fixed scroll 14a Spiral wall 14b Plate 15 Movable scroll 15a Spiral wall 15b Plate 15c Cylindrical convex part 16 Discharge chamber 17 Compression chamber 19 Eccentric bush 21 Main shaft 22 Eccentric pin 23 Front housing 24 Rotor 25 Electromagnetic clutch 26 Rotation prevention mechanism 27 Suction chamber 28 Discharge port 29 Oil surface of refrigeration oil 31 Skirt portion 32 O-ring 33 Scroll abutting surface 34 Gas passage 35 Opening portion 36 Hole 37 Relief valve 38 Fixing bolt

Claims (9)

A casing having a cylindrical portion, a compression mechanism disposed inside the cylindrical portion, a discharge chamber serving as a passage for compressed gas generated by the compression mechanism, and compressed gas from the discharge chamber at an excessively high pressure In the compressor having a relief valve for releasing, the compression mechanism includes a fixed scroll fixed to the casing, and a movable scroll that generates compressed gas in cooperation with the fixed scroll. A skirt portion fitted with a gap in the cylindrical portion, and a gas passage extending in a circumferential direction is formed between the cylindrical portion and the skirt portion by the gap, and the opening of the gas passage is A compressor, which is located in an upper part of a discharge chamber and has the relief valve connected to the gas passage. The compressor according to claim 1, wherein the opening is provided at a position higher than an oil level of the refrigeration oil that accumulates in a lower portion of the discharge chamber . Said casing is of a cup shape having a bottom portion which closes one end of the tubular portion, said fixed scroll opposite to the bottom, according to claim 1 or 2 to form the discharge chamber therebetween Compressor. The compressor according to claim 3, wherein the skirt portion is in contact with the bottom portion . The compressor according to any one of claims 1 to 4 , further comprising an O-ring that defines an end portion of the gap between the skirt portion and the tubular portion. The compressor according to any one of claims 1 to 5, wherein a hole communicating with the gas passage is provided in the casing, and the relief valve is assembled in the hole.   The compressor according to claim 6, wherein a portion of the gas passage facing the relief valve is enlarged.   The compressor according to claim 6, wherein the gas passage is formed to extend between the fixed scroll and the bottom so as to face the relief valve. The compressor according to claim 1, wherein the discharge chamber has a discharge port for discharging compressed gas at an upper portion, and the opening is located in the vicinity of the discharge port.

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