JP3590431B2 - Scroll compressor - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a scroll compressor used for air conditioning or pneumatic machines, and more particularly to a structure of an overcompression countermeasure mechanism.
[0002]
[Prior art]
7 to 9 are longitudinal sectional views showing a conventional scroll compressor disclosed in, for example, JP-A-61-116085. In the figure, a scroll compressor 2 is built in the upper part and a motor 3 as a driving source is built in a lower part in the closed containers 1a, 1b, 1c. The scroll compressor 2 includes a fixed scroll member 4 in which a spiral wrap 4b formed of an involute curve or a curve similar to the involute curve is formed upright on a disk 4a on a disk, and the fixed scroll member 4 is substantially formed. The orbiting scroll member 5 having the same shape of the end plate 5a and the wrap 5b is engaged with each other with the wraps 4b and 5b facing inward, and the Oldham ring 6 for preventing the orbiting scroll member 5 from apparently rotating is fixed to the fixed scroll member 4. It is provided between the frame 7 which is a stationary part fixed to the orbiting member and the orbiting scroll member 5. In the center of the end plate 4a of the fixed scroll 4, a discharge port 4c for guiding the compressed refrigerant gas to the high-pressure chamber 15 and a pair of bypass holes 4d communicating from the compression chamber 13 to the high-pressure chamber 15 during compression, and Above the bypass hole 4d, a valve seat 4e, a reed valve type bypass valve 9 and a stopper 10 are fixed to the back surface of the fixed scroll end plate 4a by bolts 14. Further, a boss 5c into which the crankshaft 8 is inserted is provided on the back surface of the orbiting scroll 5. The crankshaft 8 is supported by a bearing portion 7a of a frame 7. The rotor 3a of the motor 3 is attached to one end, and the boss 5c of the orbiting scroll 5 is inserted to the other end. Reference numeral 11 denotes a suction pipe for guiding the refrigerant gas into the compressor, and reference numeral 12 denotes a discharge pipe for discharging the high-pressure refrigerant gas in the high-pressure chamber 15 to the outside.
[0003]
Next, the operation will be described. When the crankshaft 8 is rotated by the rotation of the rotor 3a of the motor 3, the orbiting scroll 5 retains the attitude of the refrigerant gas taken into the compressor from the suction pipe 11 by the action of the Oldham ring 6 which is a rotation preventing mechanism. It orbits with respect to the fixed scroll 4 and is taken into a pair of compression chambers 13 formed by meshing of both scroll wraps 4b and 5b. Then, the compression chamber 13 is gradually moved from the outer peripheral portion of the scroll to the center portion by the orbital motion of the orbiting scroll 5, and its volume is reduced. As a result, the low-pressure refrigerant gas taken into the compression chamber 13 is compressed in the above-described process, and the pressure increases.
[0004]
Here, a pair of compression chambers 13 formed by the two scroll wraps 4b, 5b move toward the center after the inhalation is completed with the orbiting movement of the orbiting scroll 5, and are provided at the center of the fixed scroll member 4. While communicating with the discharge port 4c, the pressure in the pair of compression chambers 13 is constantly raised to a constant pressure by the suction pressure and the volume change of the compression chamber 13 regardless of the discharge pressure. That is, scroll compressors have a built-in compression ratio that is determined by the spiral geometry.
[0005]
Therefore, in the conventional scroll compressor, when the ratio between the condensing pressure (high pressure) and the evaporating pressure (low pressure) is smaller than the built-in compression ratio, the pressure in the pair of compression chambers 13 is increased before communicating with the discharge port 4c. Since the pressure reaches the condensing pressure (high pressure), the reed valve type bypass valve 9 is pushed up from the pair of bypass holes 4d to discharge the refrigerant gas in the middle of compression to the high pressure chamber 15, and the pressure in the compression chamber 13 is reduced to the condensing pressure (high pressure). ) To prevent overcompression loss. When the ratio between the condensing pressure (high pressure) and the evaporating pressure (low pressure) is larger than the volume ratio of the built-in scroll compressor, the pressure in the compression chamber 13 is kept constant even when the pressure reaches the position of the bypass hole 4d. ), The bypass valve 9 is not opened and the same compression stroke as the conventional one is continued. The high-pressure refrigerant gas discharged from the compression chamber 13 to the high-pressure chamber 15 in this way is sent out of the closed vessel 1 through the discharge pipe 12.
[0006]
[Problems to be solved by the invention]
Since the conventional scroll compressor is configured as described above, since the bypass valve 9 attached to the pair of bypass holes 4d constituting the over-compression loss countermeasure mechanism is a reed valve type, it includes the pair of bypass holes 4d. Even if the pressure in the compression chamber 13 during the compression reaches the condensing pressure (high pressure), the spring force of the reed valve type bypass valve 9 itself delays the opening of the bypass hole 4d and prevents the refrigerant gas from flowing out. The effect of countermeasures against overcompression loss was not obtained.
Also, when the opening timing of the pair of bypass holes 4d is shifted, the pressures in the pair of compression chambers 13 become unbalanced, causing extra torque fluctuation and vibration.
Furthermore, since the bypass valve 9, the stopper 10, and the valve seat 4e are independently provided above the pair of bypass holes 4d, the number of parts increases, the number of processing locations increases, and the number of assembly locations increases. Had become.
When the reed valve type bypass valve 9 is fixed with bolts 14 or rivets or the like, the fixed scroll head plate 4a is distorted, and a gap is formed between the fixed scroll head plate 4a and the orbiting scroll head plate 5a, thereby increasing leakage loss. Had been lowered.
[0007]
The present invention has been made in order to solve the above-mentioned problems, and there is no delay in opening a bypass valve that opens and closes a pair of bypass holes, a sufficient overcompression countermeasure effect is obtained, and machining and assembly are performed. An object of the present invention is to provide a scroll compressor which is easy to perform and does not warp a fixed scroll end plate during assembly.
[0008]
[Means for Solving the Problems]
The scroll compressor according to claim 1, wherein the scroll compressor has an over-compression prevention mechanism that allows refrigerant to escape from a compression chamber in the middle of compression to a high-pressure chamber via a bypass valve from a pair of bypass holes formed in the end plate of the fixed scroll. The bypass valve is a free valve shared by a pair of bypass holes having a hole through which discharge gas passes in the center, and is housed in a discharge chamber having a stopper of a bypass valve at an upper portion provided at the center of the rear surface of the end plate of the fixed scroll. is there.
[0009]
A scroll compressor according to a second aspect is characterized in that, in the first aspect, the valve seat of the bypass hole is formed in a ring shape.
[0010]
A scroll compressor according to a third aspect is the scroll compressor according to the second aspect, wherein the bypass valve is formed in a ring shape.
[0011]
A scroll compressor according to a fourth aspect of the present invention is the scroll compressor according to the first aspect, further comprising an axially compliant mechanism having a high / low pressure partition and a sealing component on a rear side of the end plate of the fixed scroll, and a lower surface of the high / low pressure partition being a bypass valve. It is characterized in that it is used as a stopper.
[0012]
According to a fifth aspect of the present invention, there is provided a scroll compressor according to the first aspect, further comprising an axially compliant mechanism having a high / low pressure partition plate, a vertically movable second seal component, and a seal component on the rear side of the end plate of the fixed scroll. The lower surface of the second seal component is used as a stopper for the bypass valve.
[0013]
[Action]
In the scroll compressor according to the first aspect, when the pressure in the pair of compression chambers during compression becomes slightly higher than the high pressure, the bypass valve, which is a free valve, opens quickly and simultaneously opens the pair of bypass valve holes. To prevent the pressure in the compression chamber from being unbalanced. Further, since the bypass valve is not fixed to the fixed scroll head, the fixed scroll head is not distorted.
[0014]
In the scroll compressor according to the second aspect, when the valve seat is formed on the back surface of the fixed scroll head plate, it can be easily formed on the same processing surface with the same processing tool.
[0015]
The scroll compressor according to claim 3 is easy to assemble by making the bypass valve ring-shaped.
[0016]
In the scroll compressor according to the fourth aspect, a high / low pressure partition plate, which is an existing component, can be used for the stopper.
[0017]
In the scroll compressor according to the fifth aspect, the second seal component, which is an existing component, can be used for the stopper.
[0018]
【Example】
Embodiment 1 FIG.
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a partial longitudinal sectional view of a scroll compressor according to Embodiment 1 of the present invention, and FIG. 2 is an exploded perspective view of the same. In the figures, the same or corresponding parts as those of the conventional scroll compressor shown in FIGS. 7 to 9 are denoted by the same reference numerals, and description thereof will be omitted.
In FIG. 1, a head plate 4 a of the fixed scroll 4 has a discharge port 4 c for guiding the refrigerant gas compressed at the center to the high-pressure chamber 15, and a pair of compression chambers 13 communicating with the high-pressure chamber 15 during compression. 4d is provided. The valve seat 4e provided above the bypass hole 4d has a ring shape that covers the pair of bypass holes 4d as shown in FIG. 2 when viewed from above. Above the valve seat 4e, a hole is formed in the center so as not to prevent the flow path of the high-pressure refrigerant gas discharged from the discharge port 4c, and has substantially the same shape as the valve seat 4e. A bypass valve 9 which is one free valve that is formed and is not connected anywhere is provided, and a stopper 10 that regulates a lift amount of the bypass valve 9 is fixed to the fixed scroll 4 above the bypass valve 9. The discharge chamber 20 is formed by the center of the rear surface of the end plate 4a and the stopper 10.
[0019]
Next, the operation will be described. In the compression operation of the scroll compressor, when the ratio between the condensing pressure (high pressure) and the evaporation pressure (low pressure) is smaller than the volume ratio of the scroll compressor, the pair of compression chambers 13 including the pair of bypass holes 4d is discharged. Before communicating with the port 4c, the pressure in the pair of compression chambers 13 reaches the condensing pressure (high pressure). When the compression stroke further proceeds and the pressure in the compression chamber 13 becomes slightly higher than the condensing pressure (high pressure), the bypass valve 9 is pushed up by the upper and lower differential pressures to open a pair of bypass holes 4 d and reach the stopper 10. To reach. At this time, since the bypass valve 9 is a free valve that is not directly connected to other parts and does not hinder its vertical movement, the pressure of the compression chamber 13 below the bypass valve 9 increases the upper condensing pressure ( When the pressure is slightly higher than (high pressure), the pair of bypass holes 4d can be opened with almost no delay in opening. That is, there is almost no over-compression loss.
[0020]
Further, as described above, the bypass valve 9 is movable inside the cylindrical wall provided on the back surface of the fixed scroll end plate 4a in the radial direction, and between the valve seat 4e and the stopper 10 in the vertical direction. Since the stopper 10 is fitted in a cylindrical wall portion provided on the back surface of the fixed scroll head plate 4a, a bolt or a rivet is tightened near the surface of the fixed scroll head plate 4a forming the compression chamber 13 so that the surface of the fixed scroll head plate 4a is fixed. Distortion does not reduce the performance of the compressor due to an increase in leakage loss due to the formation of a gap between the orbiting scroll head 4b. Moreover, since the valve seat 4e of the bypass valve 9 has a ring shape covering the pair of bypass holes 4d, when the valve seat 4e is formed on the back surface of the fixed scroll head plate 4a, for example, the same processing is performed. It is very easy to form the same processing surface with a tool, and only one bypass valve 9 and one stopper 10 are installed in the pair of bypass holes 4d, so that the number of parts can be reduced as compared with the conventional case.
[0021]
Embodiment 2. FIG.
In the first embodiment, the cylindrical stopper 10 is fixed so as to cover the cylindrical wall provided on the back surface of the fixed scroll head plate 4a. However, as shown in FIG. In this case, the same effect as in the first embodiment can be obtained.
[0022]
Embodiment 3 FIG.
As shown in FIG. 4, the movable range of the bypass valve 9 is between the valve seat 4e and the stopper 10 in the up-down direction, and the inner surface of the stopper 10 in the radial direction is a cylindrical stopper. The same effect as that of the first embodiment can be obtained even when 10 is installed on the back surface of the fixed scroll head plate 4a.
[0023]
Embodiment 4. FIG.
As shown in FIG. 5, a scroll compressor having an axial compliant mechanism, for example, a fixed scroll 4 is arranged so as to be movable only in the axial direction with respect to a frame 7, and the pressure in the sealed container 1 is high. Between the low-pressure partition plate 16 and the high / low-pressure partition plate 16 and the back surface of the fixed scroll head plate 4a, for example, a resin material or the like is formed, and either the inner diameter or the outer diameter side is tapered, and the difference between the upper and lower spaces Scroll compression in which the tapered portion is pressed in a wedge shape by pressure to improve the sealing property, and the high-pressure chamber 15 and the low-pressure space are separated by a sealing member 17 installed movably up and down due to sliding of the other cylindrical surface. In the machine, the function of the stopper 10 of the bypass valve 9 is provided on the lower surface of the high / low pressure partition plate 16 installed above the bypass valve 9. , The same effect as in Example 1 with the possible divert a stopper 10 on an existing conventional parts can be obtained.
[0024]
Embodiment 5 FIG.
In addition, a scroll compressor having an axially compliant mechanism is provided with, for example, a metal second seal part 18 which can be moved up and down between a high / low pressure partition plate 16 and the seal part 17 as shown in FIG. In the scroll compressor, the same effect as in the fourth embodiment can be obtained by providing the function of the stopper 10 of the bypass valve 9 on the lower surface of the second seal component 18 installed above the bypass valve 9.
[0025]
【The invention's effect】
The scroll compressor according to claim 1, wherein the scroll compressor has an over-compression prevention mechanism that allows refrigerant to escape from a compression chamber in the middle of compression to a high-pressure chamber via a bypass valve from a pair of bypass holes formed in the end plate of the fixed scroll. The bypass valve is a free valve shared with a pair of bypass holes having a hole through which discharge gas passes in the center, and is housed in a discharge chamber having a stopper for the bypass valve in the upper part provided in the center of the back surface of the end plate of the fixed scroll. As a result, the overcompression loss is small and the performance is improved, the torque fluctuation is reduced because the pair of bypass holes are opened at the same time, the vibration is reduced, and the bypass valve is not fixed to the fixed scroll with bolts or rivets. There is no distortion and the number of parts is reduced, so that the cost is reduced.
[0026]
In the scroll compressor according to the second aspect of the present invention, the valve seat of the bypass hole is formed in a ring shape in the case of the first aspect. It can be easily formed and the production cost can be reduced.
[0027]
According to a third aspect of the present invention, in the scroll compressor according to the second aspect, since the bypass valve is formed in a ring shape, assemblability is improved and manufacturing cost can be reduced.
[0028]
A scroll compressor according to a fourth aspect of the present invention is the scroll compressor according to the first aspect, further comprising an axially compliant mechanism having a high / low pressure partition and a seal component on the rear side of the end plate of the fixed scroll. Because the stopper is used as the stopper, existing parts can be used for the stopper, and an inexpensive scroll compressor with good assemblability without increasing the number of parts can be obtained.
[0029]
According to a fifth aspect of the present invention, there is provided a scroll compressor according to the first aspect, further comprising an axially compliant mechanism having a high / low pressure partition plate, a vertically movable second seal component, and a seal component on the rear side of the end plate of the fixed scroll. Since the lower surface of the second seal component is used as a stopper for the bypass valve, existing components can be used for the stopper, and the number of components does not increase, and an inexpensive scroll compressor with good assemblability can be obtained.
[Brief description of the drawings]
FIG. 1 is a partial vertical sectional view of a scroll compressor according to Embodiment 1 of the present invention.
FIG. 2 is an exploded perspective view of a main part of the scroll compressor according to Embodiment 1 of the present invention.
FIG. 3 is a partial vertical sectional view of a scroll compressor according to Embodiment 2 of the present invention.
FIG. 4 is a partial vertical sectional view of a scroll compressor according to Embodiment 3 of the present invention.
FIG. 5 is a partial vertical sectional view of a scroll compressor according to Embodiment 4 of the present invention.
FIG. 6 is a partial vertical sectional view of a scroll compressor according to Embodiment 5 of the present invention.
FIG. 7 is a longitudinal sectional view of a conventional scroll compressor.
FIG. 8 is a longitudinal sectional view of a main part of a conventional scroll compressor.
FIG. 9 is a cross-sectional view of a main part of a conventional scroll compressor.
[Explanation of symbols]
Reference Signs List 4 fixed scroll, 4a fixed scroll head plate, 4d bypass hole, 4e valve seat, 9 bypass valve, 10 stopper, 13 compression chamber, 15 high pressure chamber, 16 high and low pressure partition plate, 17 sealing parts, 18 second sealing parts.

Claims (5)

In a scroll compressor having an over-compression prevention mechanism that allows refrigerant to escape from a compression chamber in the middle of compression to a high-pressure chamber via a bypass valve from a pair of bypass holes formed in a head plate of a fixed scroll, the bypass valve has a discharge gas in the center. A scroll that is housed in a discharge chamber having a stopper for the bypass valve at an upper portion provided at the center of the rear surface of the end plate of the fixed scroll. Compressor. The scroll compressor according to claim 1, wherein the valve seat of the bypass hole has a ring shape. 3. The scroll compressor according to claim 2, wherein the bypass valve has a ring shape. The scroll compression according to claim 1, further comprising an axial compliant mechanism having a high / low pressure partition and a seal component on a rear side of the end plate of the fixed scroll, wherein a lower surface of the high / low pressure partition is used as a stopper of a bypass valve. Machine. It is provided with a high-low pressure partition plate on the rear side of the end plate of the fixed scroll, an axially compliant mechanism having a vertically movable second seal part and a seal part, and a lower surface of the second seal part as a stopper for a bypass valve. The scroll compressor according to claim 1, wherein:

Images