JPH08247053A - Scroll compressor - Google Patents

Abstract

PURPOSE: To resolve the opening delay of a by-pass valve by making the by-pass valve a free valve, and storing it in a discharge chamber provided on the back face of a fixed scroll in a scroll compressor releasing a refrigerant from a pair of by-pass holes provided on the end plate of the fixed scroll to a high- pressure chamber through the by-pass valve. CONSTITUTION: A discharge port 4c for guiding the compressed refrigerant gas to a high-pressure chamber 15 is provided at the center section of the end plate 4a of a fixed scroll 4, and a pair of by-pass holes 4d discharging the refrigerant gas under compression to a high-pressure chamber 15 are provided at other positions. A valve seat 4e provided above the by-pass holes 4d is formed into a ring shape concurrently covering a pair of by-pass holes 4d, and a ring- shaped by-pass valve 9 which is a free valve is arranged above the valve seat 4e. The lift quantity of the bypass valve 9 is regulated by a stopper 10 fixed to the fixed scroll 4, and a discharge chamber 20 is formed with the stopper 10 and the back face center section of the end plate 4a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll compressor used for an air conditioner or an air machine, and more particularly to a structure of a mechanism against excessive compression.

[0002]

2. Description of the Related Art FIGS.
It is a longitudinal cross-sectional view which shows the conventional scroll compressor shown by 085 gazette. In the figure, closed containers 1a, 1b, 1
In c, a scroll compression unit 2 is built in the upper part and a motor 3 as a drive source is built in the lower part. In the scroll compression unit 2, a fixed scroll member 4 is formed by erecting downward a spiral wrap 4b consisting of an involute curve or a curve similar to this on an end plate 4a on a disk, and the fixed scroll member 4 is substantially The orbiting scroll member 5 including the end plate 5a and the wrap 5b having the same shape is wrapped with the wraps 4b, 5
An Oldham ring 6 for interlocking b toward the inside and for preventing apparent rotation of the orbiting scroll member 5 is provided between the orbiting scroll member 5 and a frame 7 which is a stationary portion fixed to the fixed scroll member 4. It is a thing.
A discharge port 4c for guiding the compressed refrigerant gas to the high pressure chamber 15 is provided at the center of the end plate 4a of the fixed scroll 4.
And a pair of bypass holes 4d communicating from the compression chamber 13 in the middle of compression to the high pressure chamber 15, and a valve seat 4e, a reed valve type bypass valve 9 and a stopper 10 above the bypass hole 4d by a bolt 14 for a fixed scroll end plate 4a. It is fixed on the back. Further, a boss portion 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 the bearing portion 7a of the frame 7, and the rotor 3a of the motor 3 is attached to one end of the crankshaft 8.
The boss portion 5c of the orbiting scroll 5 is inserted into the other end. Reference numeral 11 is a suction pipe for guiding the refrigerant gas into the compressor, and 12 is a discharge pipe for discharging the high pressure refrigerant gas in the high pressure chamber 15 to the outside.

Next, the operation will be described. Refrigerant gas taken into the compressor from the suction pipe 11 is rotated by the rotation of the rotor 3a of the motor 3 to rotate the crankshaft 8, and the orbiting scroll 5 is maintained in its posture by the action of the Oldham ring 6 which is a rotation preventing mechanism. It makes an orbiting motion with respect to the fixed scroll 4 and is taken into a pair of compression chambers 13 formed by the meshing of both scroll wraps 4b and 5b.
Then, the compression chamber 13 gradually moves from the outer peripheral portion of the scroll to the central portion by the orbiting motion of the orbiting scroll 5, and the volume thereof decreases. As a result, the low-pressure refrigerant gas taken into the compression chamber 13 is compressed in the above process and its pressure rises.

Here, the pair of compression chambers 13 formed by the scroll wraps 4b and 5b move toward the center after the suction is completed with the orbiting motion of the orbiting scroll 5, and move toward the center of the fixed scroll member 4. The pressure of the pair of compression chambers 13 is constantly raised to a constant pressure by the suction pressure and the volume change of the compression chambers 13 regardless of the discharge pressure while communicating with the discharge port 4c provided at. In other words, scroll compressors have a built-in compression ratio that is determined by the geometry of the spiral.

Therefore, in the conventional scroll compressor, when the ratio of the condensation pressure (high pressure) to the evaporation pressure (low pressure) is smaller than the built-in compression ratio, the pressure of the pair of compression chambers 13 communicates with the discharge port 4c. Since the condensation pressure (high pressure) is reached before the operation, the reed valve type bypass valve 9 is pushed up through the pair of bypass holes 4d to discharge the refrigerant gas in the middle of compression to the high pressure chamber 15, so that the pressure in the compression chamber 13 is condensed. It prevents the pressure from rising higher than the pressure (high pressure) and reduces the over-compression loss. Further, when the ratio of the condensing pressure (high pressure) to the evaporating pressure (low pressure) is larger than the built-in volume ratio of the scroll compressor, the pressure in the compression chamber 13 reaches the condensing pressure (high pressure) even when it reaches the position of the bypass hole 4d. 2), the bypass valve 9 is not opened and the compression stroke similar to the conventional one is continued.
The high-pressure refrigerant gas thus discharged from the compression chamber 13 to the high-pressure chamber 15 is sent out of the closed container 1 through the discharge pipe 12.

[0006]

Since the conventional scroll compressor is constructed as described above, the bypass valve 9 attached to the pair of bypass holes 4d constituting the mechanism against excessive compression loss is a reed valve type. Even when the pressure of the compression chamber 13 including the pair of bypass holes 4d in the middle of compression reaches the condensing pressure (high pressure), the opening delay of the bypass holes 4d occurs due to the spring force of the reed valve type bypass valve 9 itself. Refrigerant gas outflow was hindered, and sufficient measures against excessive compression loss were not obtained. Further, when the opening timings of the pair of bypass holes 4d are deviated, the pressures of the pair of compression chambers 13 become unbalanced, resulting in excessive torque fluctuation and vibration. Furthermore, above the pair of bypass holes 4d,
Since the bypass valve 9, the stopper 10, and the valve seat 4e are provided independently of each other, the number of parts, the number of processing points, and the number of assembly points increase, leading to an increase in cost. In addition, the reed valve type bypass valve 9 is attached to the bolt 1
4 or when fixing with a rivet or the like, the fixed scroll end plate 4a is distorted and a gap is formed between the fixed scroll end plate 4a and the orbiting scroll end plate 5a, so that the leakage loss increases and the performance deteriorates.

The present invention has been made in order to solve the above-mentioned problems, and there is no delay in opening a bypass valve for opening and closing a pair of bypass holes, a sufficient effect of overcompression is obtained, and machining is possible. An object of the present invention is to provide a scroll compressor that is easy to assemble and does not distort the fixed scroll end plate during assembly.

[0008]

According to a first aspect of the present invention, there is provided a scroll compressor, wherein a refrigerant is allowed to escape from a pair of bypass holes formed in an end plate of a fixed scroll to a high pressure chamber through a bypass valve. In a scroll compressor that has a prevention mechanism, the bypass valve is a free valve that is shared by a pair of bypass holes that have a hole through which the discharge gas passes, and a stopper for the bypass valve is installed at the upper part of the center of the fixed scroll end plate. It is housed in the discharge chamber that it has.

A scroll compressor according to a second aspect is the scroll compressor according to the first aspect.
In the described one, the valve seat of the bypass hole has a ring shape.

The scroll compressor of claim 3 is the same as that of claim 2.
The described one is characterized in that the bypass valve has a ring shape.

A scroll compressor according to a fourth aspect is the first aspect.
In the described one, the fixed scroll is provided with an axially compliant mechanism having a high / low pressure partition plate and a seal component on the rear side of the end plate, and the lower surface of the high / low pressure partition plate is used as a stopper of the bypass valve.

The scroll compressor of claim 5 is the same as that of claim 1.
The fixed scroll is provided with an axially compliant mechanism having a high / low pressure partition plate, a vertically movable second seal part and a seal part on the rear side of the end plate of the fixed scroll, and the lower surface of the second seal part is a stopper of the bypass valve. It is characterized by

[0013]

In the scroll compressor of claim 1, 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 promptly and the pair of bypass valve holes are simultaneously opened. Prevents over-compression and prevents the pressure in the compression chamber from becoming unbalanced. Moreover, since the bypass valve is not fixed to the fixed scroll end plate, the fixed scroll end plate is not distorted.

In the scroll compressor according to the second aspect, when the valve seat is formed on the back surface of the fixed scroll end plate, it can be easily formed on the same processed surface by the same processing tool.

The scroll compressor of claim 3 can be easily assembled by forming the bypass valve in a ring shape.

In the scroll compressor according to the fourth aspect, the existing high and low pressure partition plate can be used as the stopper.

In the scroll compressor of the fifth aspect, the existing second seal component can be used as the stopper.

[0018]

【Example】

Example 1. Embodiment 1 of the present invention will be described below with reference to the drawings. 1 is a partial vertical cross-sectional view of a scroll compressor according to Embodiment 1 of the present invention, and FIG. 2 is an exploded perspective view of the relevant part. In the figure, the same or corresponding parts as those of the conventional scroll compressor shown in FIGS. 7 to 9 are designated by the same reference numerals, and the description thereof will be omitted. In FIG. 1, the end plate 4a of the fixed scroll 4 has a discharge port 4c for guiding the refrigerant gas compressed in the central portion to the high pressure chamber 15, and a pair of communication ports from the compression chamber 13 in the middle of compression to the high pressure chamber 15. The bypass hole 4d is provided. Further, the valve seat 4e provided on the upper part of the bypass hole 4d has a ring shape which covers the pair of bypass holes 4d when viewed from above, as shown in FIG. Above the valve seat 4e, a hole having a substantially same shape as that of the valve seat 4e is formed in the center so as not to prevent the passage of the high pressure refrigerant gas discharged from the discharge port 4c. A bypass valve 9, which is a molded free valve that is not connected to anywhere, is installed, and a stopper 10 that restricts the lift amount of the bypass valve 9 is fixed to the fixed scroll 4 above the bypass valve 9. A discharge chamber 20 is formed by the central portion of the rear surface of the end plate 4a and the stopper 10.

Next, the operation will be described. In the compression operation of the scroll compressor, when the ratio of the condensation pressure (high pressure) to the evaporation pressure (low pressure) is smaller than the built-in volume ratio of the scroll compressor, the pair of compression chambers 13 including the pair of bypass holes 4d discharge. Before communicating with the port 4c, the pressure in the pair of compression chambers 13 reaches the condensation pressure (high pressure). When the compression stroke further progresses and the pressure in the compression chamber 13 becomes slightly higher than the condensation pressure (high pressure), the bypass valve 9
Is pushed up by the differential pressure between the upper and lower sides, and the pair of bypass holes 4
Open d and reach the stopper 10. At this time, since the bypass valve 9 is a free valve that is not directly connected to other parts and has no obstruction for vertical movement, the pressure of the compression chamber 13 below the bypass valve 9 is equal to the upper condensing pressure ( When the pressure becomes slightly higher than (high pressure), the pair of bypass holes 4d can be opened with almost no opening delay. That is, almost no overcompression loss occurs.

Further, as described above, the bypass valve 9 is movable in the radial direction inside the cylindrical wall provided on the rear surface of the fixed scroll end plate 4a, and in the vertical direction between the valve seat 4e and the stopper 10. However, since the stopper 10 is fitted in the cylindrical wall portion provided on the rear surface of the fixed scroll end plate 4a, the fixed scroll end plate is fixed by tightening bolts or rivets near the surface of the fixed scroll end plate 4a forming the compression chamber 13. The surface 4a is distorted and a gap is created between the surface 4a and the orbiting scroll end plate 4b, so that the leakage loss increases and the performance of the compressor is not deteriorated. Moreover, since the valve seat 4e of the bypass valve 9 has a ring shape that covers the pair of bypass holes 4d, when the valve seat 4e is formed on the rear surface of the fixed scroll end plate 4a, for example, the same processing is performed. It becomes extremely easy to mold on the same machining surface with a tool,
Since only one bypass valve 9 and one stopper 10 are installed in the pair of bypass holes 4d, the number of parts can be reduced as compared with the conventional case.

Example 2. In the first embodiment, the cylindrical wall provided on the back surface of the fixed scroll end plate 4a is fixed so as to cover the cylindrical stopper 10. However, as shown in FIG.
By installing a ring or the like as the stopper 10 on the back surface of the fixed scroll end plate 4a, the same effect as that of the first embodiment can be obtained.

Example 3. 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 in the radial direction is the inner surface of the cylindrical stopper 10. Example 1 even when 10 is installed on the back surface of the fixed scroll end plate 4a
The same effect can be obtained.

Embodiment 4 FIG. As shown in FIG. 5, a scroll compressor having an axially compliant mechanism, for example, the fixed scroll 4 is arranged so as to be movable only in the axial direction with respect to the frame 7, and the pressure in the closed 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 end 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 is large. A scroll compression in which the high pressure chamber 15 and the low pressure space are partitioned by a seal component 17 which is installed by a pressure so that the tapered portion is pressed in a wedge shape to improve the sealing property, and the sliding of the other cylindrical surface allows the vertical movement. In the machine, the stopper 1 of the bypass valve 9
By giving the function of 0 to the lower surface of the high / low pressure partition plate 16 installed above the bypass valve 9, the stopper 10 can be used as an existing conventional component and the same effect as that of the first embodiment can be obtained. .

Example 5. Further, in a scroll compressor having an axially compliant mechanism, a vertically movable second seal component 18, for example, metallic, is provided between the high and low pressure partition plate 16 and the seal component 17, as shown in FIG. In the scroll compressor, the same effect as that of the fourth embodiment can be obtained by providing the lower surface of the second seal component 18 installed above the bypass valve 9 with the function of the stopper 10 of the bypass valve 9.

[0025]

According to the scroll compressor of the first aspect of the present invention, there is provided an over-compression preventing mechanism for allowing the refrigerant to escape from the compression chamber in the middle of compression to the high-pressure chamber through the bypass valve through the pair of bypass holes formed in the end plate of the fixed scroll. In a scroll compressor, the bypass valve is a free valve that is shared by a pair of bypass holes that have a hole through which the discharge gas passes, and is a discharge chamber that has a stopper for the bypass valve in the upper part provided at the center of the back face of the fixed scroll end plate. Since it is configured to be housed, overcompression loss is small and performance is improved, torque fluctuation is reduced because a pair of bypass holes are opened at the same time and vibration is reduced, and the bypass valve is not fixed to the fixed scroll with bolts or rivets. Therefore, there is no distortion of the fixed scroll end plate and the number of parts is small, so that the cost is low.

The scroll compressor of claim 2 is the same as that of claim 1.
In the one described, since the valve seat of the bypass hole is ring-shaped, when the valve seat is formed on the back surface of the fixed scroll end plate, for example, it can be easily formed on the same processed surface by the same processing tool, and the manufacturing cost can be reduced.

The scroll compressor of claim 3 is the same as that of claim 2.
In the described one, since the bypass valve has a ring shape, the assembling property is improved and the manufacturing cost can be reduced.

A scroll compressor according to claim 4 is the scroll compressor according to claim 1.
In the described one, an axial compliant mechanism having a high-low pressure partition plate and a seal component is provided on the rear side of the fixed scroll end plate, and the lower surface of the high-low pressure partition plate is configured as a bypass valve stopper. The parts can be used, and the number of parts does not increase, and an inexpensive scroll compressor with good assembling can be obtained.

A scroll compressor according to claim 5 is the scroll compressor according to claim 1.
The fixed scroll is provided with an axially compliant mechanism having a high / low pressure partition plate, a vertically movable second seal part and a seal part on the rear side of the end plate of the fixed scroll, and the lower surface of the second seal part is a stopper of the bypass valve. With this configuration, existing parts can be used for the stopper, and an inexpensive scroll compressor with good assembling can be obtained without increasing the number of parts.

[Brief description of drawings]

FIG. 1 is a partial vertical cross-sectional view of a scroll compressor according to a first embodiment of the present invention.

FIG. 2 is an exploded perspective view of essential parts of the scroll compressor according to the first embodiment of the present invention.

FIG. 3 is a partial vertical sectional view of a scroll compressor according to a second embodiment of the present invention.

FIG. 4 is a partial vertical sectional view of a scroll compressor according to a third embodiment of the present invention.

FIG. 5 is a partial vertical sectional view of a scroll compressor according to a fourth embodiment of the present invention.

FIG. 6 is a partial vertical sectional view of a scroll compressor according to a fifth embodiment of the present invention.

FIG. 7 is a vertical cross-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]

4 fixed scroll, 4a fixed scroll end plate, 4d
Bypass hole, 4e valve seat, 9 bypass valve, 10
Stoppers, 13 compression chambers, 15 high pressure chambers, 16 high and low pressure partition plates, 17 seal parts, 18 second seal parts.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tatsuya Sugita 3-18-1, Oga, Shizuoka-shi Shizuoka Mfg. Co., Ltd. (72) Inventor Kenji Suzuki 3--18-1, Oka, Shizuoka Shizuoka Factory (72) Inventor Takeshi Fushiki 3-18-1 Oga, Shizuoka City Mitsubishi Electric Corporation Shizuoka Factory

Claims (5)

[Claims] 1. A scroll compressor having an overcompression preventing mechanism for allowing refrigerant to escape from a compression chamber in the middle of compression to a high pressure chamber through a pair of bypass holes formed in an end plate of a fixed scroll through the bypass valve, wherein the bypass valve is , A free valve shared by the pair of bypass holes having a hole through which the discharge gas passes, and housed in a discharge chamber having a stopper for the bypass valve in the upper part provided at the center of the back surface of the end plate of the fixed scroll. Scroll compressor characterized by. 2. 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. 4. The fixed scroll is provided with an axially compliant mechanism having a high pressure plate and a low pressure partition plate on the rear surface side of the fixed scroll, and the lower surface of the high pressure plate is used as a stopper of the bypass valve. 1. The scroll compressor according to 1. 5. An axially compliant mechanism having a high / low pressure partition plate, a vertically movable second seal part, and a seal part is provided on the rear side of the end plate of the fixed scroll, and the second part is provided.
The scroll compressor according to claim 1, wherein the bottom surface of the seal component is a stopper of the bypass valve.