JP2002005064A - Scroll compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such a problem that compression efficiency of scroll compressors remarkably drop in a state of a small flow rate because leakage of scroll compressors is almost equal regardless of a large flow rate and a small flow rate. SOLUTION: A scroll compressor has two compression chambers, a first scroll part 1 forming one compression chamber and a second scroll part 2 forming another compression chamber. The air compressed in the second scroll part 2 is supplied to a first compression space 13 via a communicating port 19 which is provided with an opening and closing valve 21. In a state of a large flow rate, the opening and closing valve 21 is opened so that the air compressed in both of the first and second scroll parts 1, 2 is supplied downstream. In a state of a small flow rate, the volume of leakage is small because the air is compressed only in the first scroll part 1. In addition, because the volume of leakage in the second scroll part 2 does not affect the flow rate, the rate of the leakage loss is reduced, and the compression efficiency is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll compressor, and is a technique suitable for use in a technique for supplying supercharging air or the like to a vehicle engine or the like.

[0002]

2. Description of the Related Art In a scroll compressor, a pair of scrolls are relatively revolved in a circular motion, and a plurality of working chambers formed by meshing of teeth are moved toward the center to reduce the volume of the working chamber. And compress the fluid introduced into the working chamber. In order to ensure the tightness of the working chamber, a tip seal that seals a gap with the opposed bottom plate is disposed at the tip of both teeth.

[0003]

As a conventional technique for ensuring the airtightness of the working chamber, a technique disclosed in Japanese Patent Application Laid-Open No. 9-195958 is known. This technique improves the shape and the like of the tip seal, strongly presses the tip seal against the bottom plate, and improves the sealing performance of the tip seal. However, since most of the leakage occurring in the scroll compressor is leakage from a lateral gap formed between the movable tooth portion and the fixed tooth portion, it is difficult to achieve a complete seal only with the tip seal. . Further, even in the case of a seal using a tip seal, the tip of the tooth portion has a spiral shape and the leakage length is long. For this reason, it is difficult to completely seal the tip seal.

[0004] Here, if the leakage length is the same, the amount of leakage of the scroll type compressor is either when the movable scroll is driven at a high speed at a high flow rate or when the movable scroll is driven at a low flow rate at a low flow rate. , Not much. For this reason, when the flow rate is low, the ratio of the leakage amount becomes large, and a disadvantage that the compression efficiency is greatly reduced occurs. An object of the present invention is to provide a scroll compressor in which the rate of leakage at a low flow rate is reduced to improve the compression efficiency at a low flow rate.

[0005]

According to the first aspect of the present invention, the scroll compressor is divided into a first scroll section and a second scroll section, and compression is performed by the first scroll section. By providing an opening / closing valve at a communication port for guiding the fluid compressed by the second scroll portion to the discharge pressure space into which the compressed fluid is guided, the compression of the fluid by only the first scroll portion and the first and second scroll portions can be prevented. Fluid compression by both can be switched by opening and closing the on-off valve.

Therefore, at the time of low flow rate driven at low rotation,
By compressing the fluid only with the first scroll part,
The size reduction allows the amount of leakage in the first scroll portion to be reduced, and the amount of leakage in the second scroll portion becomes irrelevant. Thereby, in the low flow rate region, the ratio of the leakage loss can be reduced, and the compression efficiency at the time of low flow rate can be improved.

[Means of Claim 2] By adopting the means of Claim 2 and using an on-off valve as a mechanical on-off valve, control means for opening and closing the on-off valve becomes unnecessary, and the cost is reduced. be able to.

According to the third aspect of the present invention, the first movable scroll and the second movable scroll are integrated to reduce the size of the scroll compressor having two scroll portions. it can.

[0010] According to the fourth aspect of the present invention, the second scroll portion operates to compress the fluid by opening the open hole provided in the fixed bottom plate of the second fixed scroll by the control valve. No longer do. Therefore, the on-off valve is closed and the first
By opening the opening hole at a low flow rate in which the fluid compressed only by the scroll portion is supplied downstream, the second scroll portion idles, so that the load on the scroll compressor can be reduced.

[Means of Claim 5] By adopting the means of claim 5 and using a mechanical opening / closing valve for the control valve, there is no need for a control means for opening and closing the control valve, and the cost is reduced. be able to.

According to a sixth aspect of the present invention, the first scroll portion and the second scroll portion are arranged on both sides of the electric motor for driving the compressor by adopting the means of the sixth aspect.
The heat dissipation of the compressed fluid is improved.

According to a seventh aspect of the present invention, a clutch is disposed between the electric motor and the second movable scroll, and the operation of the second scroll portion is controlled by the clutch. With this arrangement, the operation of the second scroll unit can be accurately controlled according to the rotation speed of the electric motor.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described based on two examples. [First Embodiment] FIG. 1 shows a first embodiment and is a sectional view of a scroll compressor. The scroll compressor is
For example, the first scroll section 1 forms two compression chambers for compressing air, and forms one compression chamber.
And a second scroll portion 2 forming the other compression chamber. A first movable scroll of the first scroll section 1;
The second movable scroll of the scroll portion 2 is an integral one in which a first movable tooth portion 4 and a second movable tooth portion 5 are formed on both surfaces of a common movable bottom plate 3. This is referred to as a movable scroll 6. This common movable scroll 6
A first fixed scroll 7 and a second fixed scroll 8 are arranged on both sides of the first fixed scroll 7.

The first scroll portion 1 meshes with a spiral first movable tooth portion 4 formed on a common movable scroll 6 and a spiral first fixed tooth portion 11 formed on a first fixed scroll 7. The combined structure is adopted. Air is introduced into the first scroll portion 1 from the first suction port 12 formed on the side surface of the first fixed scroll 7 by causing the common movable scroll 6 to make a revolving circular motion relatively to the first fixed scroll 7. In addition, by moving the working chamber formed by the engagement of the first fixed teeth 11 and the first movable teeth 4 toward the center, the volume of the working chamber is reduced to compress the air. Then, the inner peripheral first compression space 13
Air (corresponding to a discharge pressure space in the first embodiment) is supplied downstream from a discharge port 14 formed in the center of the first fixed scroll 7 through a discharge port 15.

The second scroll portion 2 meshes with the spiral second movable tooth portion 5 formed on the common movable scroll 6 and the spiral second fixed tooth portion 16 formed on the second fixed scroll 8. The combined structure is adopted. By causing the common movable scroll 6 to make a revolving circular motion relative to the second fixed scroll 8, air is introduced into the second scroll portion 2 from the second suction port 17 formed on the side surface of the second fixed scroll 8. In addition, by moving the working chamber formed by the engagement of the second fixed teeth 16 and the second movable teeth 5 toward the center, the volume of the working chamber is reduced to compress the air. Then, the inner peripheral second compression space 18
Is supplied to the first compression space 13 through a communication port 19 formed in the inner periphery of the movable bottom plate 3, and then supplied downstream from the discharge port 14 through the discharge port 15. In addition, a suction port 20 for supplying air to the first suction port 12 and the second suction port 17 is connected to the upper side in the drawing of the first and second fixed scrolls 7 and 8.

Here, the communication port 19 shown above is provided with an opening / closing valve 21 for opening and closing the communication port 19.
By closing the communication port 19, the air compressed by the second scroll part 2 cannot be supplied to the first compression space 13, and only the air compressed by the first scroll part 1 is discharged from the discharge port 14. The on-off valve 21 is a mechanical on-off valve that closes the communication port 19 when the internal pressure of the first compression space 13 (discharge pressure space) is low, and opens the communication port 19 when the internal pressure of the first compression space 13 is high. As a specific example, the on-off valve 21 includes a reed valve 22 made of a spring plate and a pin 23 for fixing one end of the reed valve 22 to the movable bottom plate 3 on the second compression space 18 side. When the internal pressure of the first compression space 13 is low, the reed valve 22 closes the communication port 19, and when the internal pressure of the first compression space 13 is high, the reed valve 22 opens the communication port 19.

Further, the second fixed bottom plate 24 of the second fixed scroll 8 is provided with a plurality of open holes 25 for communicating the inside and the outside of the second fixed scroll 8. Each opening 25 has a control valve 26 for opening and closing the opening 25.
By opening each open hole 25, the compression of air in the second scroll portion 2 becomes invalid, and the load on the second scroll portion 2 can be reduced.

The control valve 26 opens the opening 25 when the internal pressure of the second scroll portion 2 is low,
Is a mechanical opening / closing valve that closes the opening hole 25 when the internal pressure is high. As a specific example, each control valve 26 is attached to a plate 27 fixed to the outer surface of the second fixed bottom plate 24. This plate 27 is provided with each open hole 2
The control valve 26 is provided so as to open and close the open hole 25 by opening and closing the through hole 28 formed in the plate 27.

Each of the control valves 26 is disposed in a recess formed on the outer surface of the second fixed bottom plate 24. Like the above-described on-off valve 21, a reed valve 29 made of a spring plate is used.
And a pin 30 for fixing one end of the reed valve 29 from the inside of the plate 27. Each of the control valves 26 is such that the reed valve 29 opens the open hole 25 when the internal pressure of the second scroll portion 2 is low, and the reed valve 29 closes the open hole 25 when the internal pressure of the second scroll portion 2 is high. It is.

A cover 31 is hermetically mounted on the outer surface of the plate 27 so as to cover each through hole 28 with a gap therebetween, and the inside of the cover 31 communicates with the inside of the suction port 20 described above. It is provided as follows.

On the other hand, a rotary shaft 32 for revolving the common movable scroll 6 is made of a metal material such as iron, and is rotatably driven by an electric motor (not shown in the first embodiment). This rotating shaft 32 is
It is rotatably supported via first and second bearings 33 and 34 arranged at the centers of the fixed scroll 7 and the second fixed scroll 8. At an intermediate position of the rotating shaft 32,
An eccentric shaft 35 that rotates eccentrically with respect to the rotation center of the rotating shaft 32 is provided, and the common movable scroll 6 is driven by the eccentric shaft 35.

The common movable scroll 6 performs a revolving circular motion with respect to the first and second fixed scrolls 7 and 8, and is formed of a metal material such as an aluminum alloy or iron. 3, first and second movable tooth portions 4,
5 and a central boss 36, which are provided integrally. The central boss 36 is a tubular bulge projecting from the movable bottom plate 3 in the left-right direction in the figure, and is provided to receive the eccentric rotation of the eccentric shaft 35 via a bearing 37 mounted inside. First and second movable tooth portions 4, 5
Is a spiral body that stands upright from the movable bottom plate 3 and has a tip seal 38 mounted at the tip to prevent leakage from the sliding contact surface.

The first fixed scroll 7 is also made of a metal material such as an aluminum alloy or iron. In addition to the first fixed teeth 11, the first fixed bottom plate 40 and the first outer cylindrical portion 41 are also provided. And these are provided integrally. The first outer cylindrical portion 41 is a cylindrical shape that accommodates the first fixed tooth portion 11 and the first movable tooth portion 4 disposed therein, and the above-described first air inlet 12 is provided on a side surface. Have been. The first fixed tooth portion 11 is a spiral body that stands upright from the first fixed bottom plate 40 integrally, and is approximately 18
It is engaged with the first movable tooth portion 4 in a state shifted by 0 °.
Further, a tip seal 38 for preventing leakage from the sliding contact surface is also attached to the tip of the first fixed tooth portion 11.

Similarly to the first fixed scroll 7, the second fixed scroll 8 is also formed of a metal material such as an aluminum alloy or iron.
4. In addition to the second fixed tooth portion 16, a second outer cylinder portion 42 is provided,
These are provided integrally. Second outer cylinder 42
Is a cylindrical member that is joined to the end surface of the first outer cylinder portion 41 described above. The second suction port 17 for air described above is provided on the side surface, and the second fixed tooth portion 16 and the second Two movable tooth portions 5 are accommodated. The second fixed tooth portion 16 is a spiral body integrally upright from the second fixed bottom plate 24, and is meshed with the second movable tooth portion 5 while being shifted from the second movable tooth portion 5 by approximately 180 °. Further, a tip seal 38 for preventing leakage from the sliding contact surface is also attached to the tip of the second fixed tooth portion 16.

The operation of the scroll compressor employing the above configuration will be described separately for a low flow rate and a high flow rate. (At low flow rate) When the scroll compressor is required to compress low flow rate air, the rotation speed of the electric motor is set low by the control means (not shown in the first embodiment), and the common movable scroll 6 Revolves at low rotation speed. In this state, since the internal pressure of the second scroll portion 2 is low, each control valve 26 opens the opening 25. Then, the compression of the air in the second scroll unit 2 becomes invalid, and the second scroll unit 2 idles. On the other hand, at the time of the low rotation, the first scroll portion 1 performs low-speed air compression. In this state, since the internal pressure of the first compression space 13 (discharge pressure space) on the inner circumference is low, the on-off valve 21 closes the communication port 19. As a result,
Only the air compressed by the first scroll part 1 alone is supplied downstream from the outlet 14.

When the scroll compressor is required to compress a high flow rate of air, the control means sets the number of revolutions of the electric motor to a high value.
Performs orbital circular motion at a high rotation speed. Then, the internal pressure of the second scroll portion 2 increases, and each control valve 26 closes the opening 25. For this reason, air is compressed also in the second scroll section 2. On the other hand, at the time of this high rotation, the first scroll portion 1 also performs high-speed compression of air, so
The internal pressure of the compression space 13 increases, and the on-off valve 21 is connected to the communication port 19.
open. As a result, the air compressed by the first scroll portion 1 and the air compressed by the second scroll portion 2 merge and are supplied downstream from the discharge port 14.

The features of the scroll compressor according to the first embodiment will be described. As described above, when the flow rate is high, the on-off valve 21 is opened, and the air compressed by both the first and second scroll portions 1 and 2 is supplied downstream from the discharge port 14. The valve 21 is closed and the first scroll part 1 is closed.
Only the compressed air is supplied downstream from the discharge port 14. Thus, when the flow rate is low, the first scroll unit 1
Because of the compression of air only by
The amount of leakage in the scroll part 1 decreases, and the amount of leakage in the second scroll part 2 becomes irrelevant. Therefore, in the low flow rate region, the ratio of the leakage loss can be reduced, and the compression efficiency at the time of low flow rate can be improved.

Since the first movable scroll and the second movable scroll are integrated as a common movable scroll 6, the size of the scroll compressor can be reduced, and the mountability on a vehicle or the like is improved. Since the on-off valve 21 is a mechanical on-off valve using the reed valve 22, a control unit for opening and closing the on-off valve 21 becomes unnecessary, and the cost can be reduced.

The second fixed bottom plate 24 of the second fixed scroll 8
And a control valve 26 for opening and closing is provided in the open hole 25 to open the open hole 25 when the flow rate is low, so that the second scroll portion 2 can be opened when the flow rate is low.
, And the driving load of the scroll compressor at a low flow rate can be reduced. In addition, the control valve 26 is a mechanical open / close valve using the reed valve 29,
Control means for opening and closing the control valve 26 becomes unnecessary,
Costs can be reduced.

[Second Embodiment] FIG. 2 shows a second embodiment and is a sectional view of a scroll compressor. In the second embodiment, the main differences from the first embodiment will be described. In the second embodiment, the same reference numerals as those in the first embodiment denote the same functions. In this scroll compressor, a first scroll unit 1 is arranged on one side of an electric motor 50 and a second scroll unit 2 is arranged on the other side of the electric motor 50. The movable scroll 52 is provided independently.

As described above, since the first movable scroll 51 and the second movable scroll 52 are independently provided, the first fixed scroll 7 is fastened to the first housing 53 and the second scroll portion 2 The second fixed scroll 8 is fastened to the second housing 54 and provided so as to maintain the hermeticity inside the second scroll portion 2.

A first rotating shaft 55 for rotating the first movable scroll 51 is provided in common with an output shaft of the electric motor 50, and the first movable scroll 51 revolves according to the number of rotations of the electric motor 50. Rotate. On the other hand, a second rotating shaft 56 that rotationally drives the second movable scroll 52 is connected to an output shaft of the electric motor 50 by an electromagnetic clutch 57.
The rotation torque of the electric motor 50 is transmitted to the second rotating shaft 56 by the connection of the electromagnetic clutch 57, and the transmission of the rotation torque is interrupted by the disconnection of the electromagnetic clutch 57, and the second rotation The shaft 56 is provided so as not to be driven.

The electromagnetic clutch 57 is connected to the electric motor 50
The intermittent is controlled by the control means 60 for controlling the rotation speed of the electric motor 50. When the rotation speed of the electric motor 50 is higher than the predetermined rotation speed, the electromagnetic clutch 57 is connected, and the rotation speed is lower than the predetermined rotation speed. At times, the electromagnetic clutch 57 is disconnected. In addition, between the first rotating shaft 55 and the first housing 53 and between the second rotating shaft 56 and the second housing 5.
4, first and second bearings 33 and 34 are arranged, and the first rotating shaft 55 and the second rotating shaft 56 are rotatably supported by the first housing 53 and the second housing 54. Have been.

A first rotating shaft 55 is provided with a first
A first eccentric shaft 61 that rotates eccentrically with respect to the rotation center of the rotating shaft 55 is provided, and the first movable scroll 51 is driven by the first eccentric shaft 61.
The first movable scroll 51 includes a first projecting boss 62 projecting from the first movable bottom plate 58 toward the electric motor 50. The first protruding boss 62 is a cylindrical bulge, and is provided to receive the eccentric rotation of the first eccentric shaft 61 via the first bearing 63 mounted inside.

The second rotating shaft 56 has a second
A second eccentric shaft 64 that rotates eccentrically with respect to the rotation center of the rotating shaft 56 is provided, and the second movable scroll 52 is driven by the second eccentric shaft 64.
The second movable scroll 52 includes a second projecting boss 65 that projects from the second movable bottom plate 59 toward the electric motor 50. The second protruding boss 65 is also a cylindrical bulge, and is provided to receive the eccentric rotation of the second eccentric shaft 64 via the second bearing 66 mounted inside.

At the center of the first fixed bottom plate 40, a first discharge port 71 for discharging the air compressed by the first scroll portion 1 to the outside is formed, and the first discharge port 71 is compressed by the first scroll portion 1. The discharged air is supplied downstream from the discharge port 15 through the first discharge port 71. A second discharge port 72 for discharging the air compressed by the second scroll portion 2 to the outside is also formed at the center of the second fixed bottom plate 24. The second discharge port 72 is connected to the discharge port 1 through a communication pipe 73.
The air compressed by the second scroll portion 2 passes through the second discharge port 72 and the communication pipe 73 and is supplied downstream from the discharge port 15.

Here, the second discharge port 72 and the communication pipe 7
Numeral 3 corresponds to a communication port for guiding the air compressed by the second scroll section 2 to the discharge pressure space of the first scroll section 1. The second discharge port 72 is provided with the second discharge port 72. An on-off valve 21 for opening and closing is provided. When the internal pressure of the discharge port 15 (the discharge pressure space into which the air compressed by the first scroll portion 1 is guided) is low, the on-off valve 21
This is a mechanical opening / closing valve that closes the discharge port 72 and opens the second discharge port 72 when the internal pressure of the discharge port 15 is high. As in the first embodiment, a reed valve 22 made of a spring plate material, Is fixed to the inner surface of the second fixed bottom plate 24.

The operation of the scroll compressor employing the above configuration will be described separately for a low flow rate and a high flow rate. (At low flow rate) When the scroll type compressor is required to compress low flow rate air, the control means 60 controls the electric motor 5
0 is set low and the electromagnetic clutch 5
7 is cut. Then, since the rotation torque is not transmitted to the second movable scroll 52, the first movable scroll 5
Only 1 performs a revolving circular motion at a low rotation speed, and performs low-speed air compression in the first scroll unit 1. At this time, since the internal pressure in the discharge port 15 is in a low state, the on-off valve 21 closes the second discharge port 72, and only the air compressed by the first scroll unit 1 flows downstream from the discharge port 15. Supplied.

(High flow rate) When the scroll compressor is required to compress a high flow rate of air, the control means 60 sets the rotation speed of the electric motor 50 high and connects the electromagnetic clutch 57. . Then, the second rotating shaft 56
Is also driven, so that the second scroll portion 2 also compresses air. At this time, since the first scroll portion 1 also compresses air at high speed, the internal pressure in the discharge port 15 increases, and the on-off valve 21 opens the second discharge port 72. As a result, the air compressed by the first scroll unit 1 and the air compressed by the second scroll unit 2 merge at the discharge port 15 and are supplied downstream.

The features of the scroll compressor according to the second embodiment will be described. As described above, when the flow rate is high, the on-off valve 21 is opened to supply the air compressed by both the first and second scroll portions 1 and 2 to the downstream, and when the flow rate is low, the on-off valve 21 is opened. Is closed, and only the air compressed by the first scroll section 1 alone is supplied downstream. As described above, when the flow rate is low, the air is compressed only by the first scroll portion 1. Therefore, as in the first embodiment, the amount of leakage of the first scroll portion 1 is reduced by miniaturization, and
The amount of leakage in the scroll section 2 is not relevant. For this reason,
In the low flow rate region, the ratio of leakage loss can be reduced, and the compression efficiency at low flow rates can be improved.

Since the first scroll part 1 and the second scroll part 2 are separately arranged on both sides of the electric motor 50, the heat radiation area of the compressed air is increased as compared with the first embodiment, and the heat radiation of the compressed air is improved. I do. Since the operation of the second scroll unit 2 is controlled by the electromagnetic clutch 57, the air compression operation by the second scroll unit 2 can be accurately controlled according to the rotation speed of the electric motor 50, and high reliability is achieved. Obtainable.

In the above two embodiments, an example has been shown in which air is compressed by a scroll type compressor. However, the present invention may be applied to a gas refrigerant of a refrigeration cycle or a device which compresses other fluids such as hydrogen. .

[Brief description of the drawings]

FIG. 1 is a sectional view of an integrated scroll compressor (first embodiment).

FIG. 2 is a sectional view of a split type scroll compressor (second embodiment).

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 1st scroll part 2 2nd scroll part 3 movable bottom plate 4 1st movable tooth part 5 2nd movable tooth part 6 Common movable scroll (1st, 2nd movable scroll in 1st Example) 7 1st fixed scroll 8th 2 fixed scroll 13 first compression space (discharge pressure space in the first embodiment) 19 communication port 21 on-off valve 24 second fixed bottom plate 25 open hole 26 control valve 50 electric motor 51 first movable scroll 52 second movable scroll 57 electromagnetic Clutch 60 Control means 72 Second discharge port (communication port in the second embodiment)

Claims (7)

[Claims] 1. A scroll compressor in which a first scroll portion is formed by a first movable scroll and a first fixed scroll, and a second scroll portion is formed by a second movable scroll and a second fixed scroll. A scroll type wherein an opening / closing valve for opening and closing the communication port is provided at a communication port for guiding the fluid compressed by the second scroll section to a discharge pressure space into which the fluid compressed by the first scroll section is guided. Compressor. 2. The scroll-type compressor according to claim 1, wherein the on-off valve is a mechanical on-off valve that closes the communication port when the internal pressure of the discharge pressure space is low and opens the communication port when the internal pressure is high. A scroll compressor characterized by the following. 3. The scroll compressor according to claim 1, wherein the first movable scroll and the second movable scroll are:
A scroll type compressor, wherein the movable bottom plate is provided with movable teeth on both sides thereof, and the communication port is provided on an inner periphery of the movable bottom plate. 4. The scroll-type compressor according to claim 1, wherein the second fixed bottom plate of the second fixed scroll has the second fixed bottom plate.
A scroll compressor, comprising: an open hole communicating between the inside of the fixed scroll and the outside; and a control valve for opening and closing the open hole. 5. The scroll compressor according to claim 4, wherein the control valve closes the opening when the internal pressure of the second fixed scroll is high, and opens the opening when the internal pressure is low. A scroll compressor characterized by being a valve. 6. The scroll type compressor according to claim 1, wherein said first scroll section and said second scroll section are:
A scroll compressor, which is arranged on both sides of an electric motor for driving a compressor. 7. The scroll-type compressor according to claim 6, further comprising: a clutch capable of intermittently transmitting rotational torque in a rotational torque transmission path between the electric motor and the second movable scroll. A scroll compressor comprising: control means for disengaging the clutch when the rotation speed of the electric motor is lower than a predetermined rotation speed, and connecting the clutch when the rotation speed is higher than the predetermined rotation speed.