JPH0255636B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention involves interlocking a pair of spiral bodies at different angles, giving a relative circular orbital motion to one of the spiral bodies; The present invention relates to a scroll compressor in which compressed gas is discharged from the center by moving a closed space formed between the spaces toward the center while decreasing the volume, and particularly relates to a scroll compressor capable of changing the capacity. .

(Prior Art) A compressor used in a cooling device or the like only needs to have a small capacity once the temperature reaches a set temperature. That is, the compression ratio of the compressor does not need to be so large. Various scroll type compressors that can change the compression ratio have been known for a long time, and one example is disclosed in Japanese Patent Application No. 132487/1987 (Japanese Patent Application Laid-open No.
This is a compressor described in Japanese Patent No. 291792).

In the above compressor, when changing the compression ratio,
As shown in FIG. 7, by driving the solenoid valve 45,
High pressure gas from a discharge chamber (not shown) is introduced into the cylinder 49 through a high pressure gas introduction pipe (not shown), and the elastic force of the spring 43 and the intermediate pressure chamber 26
Push down the piston 44 against the pressure of step 2,
Closing the opening 50 increases the compression ratio, while
When the solenoid valve 45 is closed, the piston 44 is pressed upward by the elastic force of the spring 43, and as a result, the intermediate pressure chamber 262 is communicated with the suction communication chamber 263 via the cylinder 49. Ru. Therefore, the gas bypassed to the intermediate pressure chamber 262 flows to the suction communication chamber 263 via the cylinder 49. As a result, the amount of compressed gas discharged from the sealed space into the discharge chamber (not shown) decreases. That is,
This will substantially reduce the capacity of the enclosed space.

(Problem to be Solved by the Invention) In the case of the above-mentioned compressor, when the solenoid valve is closed to reduce the compression ratio from the maximum compression ratio (i.e., the state in which the solenoid valve is open), the inside of the cylinder is The high-pressure gas leaks little by little from the so-called fitting gaps in the piston rings, and the pressure inside the cylinder gradually decreases. Then, when the force pushing down the piston due to the internal pressure of the cylinder becomes smaller than the force pushing up the piston due to the pressure in the intermediate pressure chamber and the spring, the piston starts moving upward. However, when the piston moves upward, the internal volume of the cylinder above the piston decreases, so the pressure inside the cylinder increases, and the piston is pushed down slightly again. That is, the piston is gradually pushed upward while vibrating, and this vibration continues until the pressure inside the cylinder above the piston drops significantly.

As described above, in the case of the conventional variable capacity scroll compressor, the piston vibrates during the process of varying the capacity, which causes problems in the durability of the piston and also generates noise. Another problem is that stable variable capacity cannot be achieved due to the vibration of the piston.

(Means for Solving the Problems) According to the present invention, the compressor housing includes a fluid inlet and a fluid outlet, and a first spiral body, which is fixedly disposed within the compressor housing. a fixed scroll member; a second spiral body;
a fixed scroll member and a movable scroll member overlapped with each other such that the spiral body meshes with the first spiral body at an angle shifted from the first spiral body to form a closed fluid pocket between the spiral bodies; By making it move in a circular orbit while preventing its rotation, the suction gas is taken into the fluid pocket from the suction chamber communicating with the fluid suction port, and the suction gas is transferred from the discharge port provided in the center of the fixed scroll member to the discharge chamber. In a scroll compressor configured to discharge high-pressure gas to a fluid outlet through a fluid outlet, the fixed scroll member is provided with a fluid bypass hole at a position extending inward from an outermost end of the first spiral body. an intermediate pressure chamber that communicates the fluid bypass hole and the suction chamber via a check valve, a first opening that communicates with the intermediate pressure chamber, and a second opening that communicates with the suction chamber. a cylinder into which discharge gas is introduced; a piston slidably disposed within the cylinder; and a control valve mechanism that controls introduction of the discharge gas into the cylinder; The piston slides due to the pressure difference between the discharge gas pressure introduced into the intermediate pressure chamber and the pressure in the intermediate pressure chamber.
The compression capacity is maximized when the opening of The variable capacity scroll is further provided with a gas venting means for releasing the discharged gas introduced into the cylinder into the suction chamber through the second opening when the scroll moves to the second position. A mold compressor is obtained.

(Examples) Hereinafter, the present invention will be described in detail with reference to examples shown in the drawings.

Referring to FIG. 1, the illustrated cord compression machine 1 has a compressor housing 10 consisting of a front end plate 11 and a cup-shaped portion 12 installed therein.

The front end plate 11 has a through hole 111 formed at its center through which the main shaft 14 is inserted, and an annular protrusion 112 concentric with the through hole 111 formed on the back surface. The cup-shaped portion 12 is
The opening is fitted onto the annular projection 112 of the front end plate 11 and fixed. Note that an O-ring 18 is clamped at the joint to provide sealing.

A disk rotor 141 is fixed to the inner end of the main shaft 14, and this disk rotor 141 is rotatably supported within the through hole 111 by a ball bearing 13.

The front end plate 11 also has a main shaft 14
It has a sleeve 15 extending forward so as to surround it. Sleeve 15 is attached to the front surface of front end plate 11 by screws (not shown). A ball bearing 19 is installed at the front end inside the sleeve 15, and the ball bearing 19 is attached to the main shaft 14.
is rotatably supported. A shaft seal assembly 16 is assembled on the main shaft 14 within the sleeve 15.

On the outer surface of the sleeve 15, a pulley 171 is rotatably supported by a bearing 31, and an electromagnet 172 is fixed. On the other hand, an armature plate 30 is elastically supported on the end of the main shaft 14 that protrudes from the sleeve 15. That is, the pulley 171, electromagnet 172 and armature plate 30 cause the electromagnetic clutch 1 to
7, which transmits the rotation of an external drive source (for example, an automobile engine) to the pulley 171 via the belt, and by energizing the electromagnet 172, the armature plate 30 is moved to the pulley 1.
By adsorbing it to 71, rotational force is transmitted to the main shaft 14.

A fixed scroll member 20, a movable scroll member 21, a movable scroll drive mechanism, and a movable scroll rotation prevention mechanism 22 are provided in the cup-shaped portion 12 whose opening is closed by the front end plate 11.

The fixed scroll member 20 generally has a side plate 201
and a spiral body 202 fixed to one side thereof, and the side plate 201 is fixed to the cup-shaped portion 12 at several places with bolts 23. Further, a partition wall 121 is formed inside the cup-shaped portion 12 so as to protrude in the axial direction, and a gasket 32 is arranged between the back surface of the side plate 201 and the front end surface of the partition wall 121 that contacts the back surface. It is sealed. Therefore, the inside of the cup-shaped portion 12 is separated by the side plate 201 of the fixed scroll member into a front chamber 25 in which the spiral body 202 is arranged and a rear chamber 26. Furthermore, the rear chamber 26 has a partition wall 12
1, a discharge chamber 261 and an intermediate pressure chamber 262
and a suction communication chamber 263 communicating with the suction chamber 251 of the front chamber 25. Note that sealing between the front end surface of the partition wall 121 and the back surface of the side plate 201 may be performed by providing a groove in the front end surface of the partition wall 121 and using a seal ring.

A movable scroll member 21 is arranged within the chamber 25 . The movable scroll member 21 has a side plate 21
1 and a spiral body 212 fixed to one side thereof, the spiral body 212 is engaged with the spiral body 202 with an angular deviation of 180°, and a sealed space is formed between both spiral bodies. ing. The movable scroll member 21 is rotatably installed on a drive wheel 27 eccentrically connected to the inner end surface of the disk rotor 141 via a radial bearing 28 . On the other hand, a fixed ring 222 fixedly connected to the front end plate 11, a movable ring 215 fixed to the side plate 211 of the movable scroll member 21 so as to face this, and ball receiving holes 241, 242 formed in both rings. The rotation prevention mechanism 22 is constituted by the arranged balls 224.

The compressor housing 10 has a fluid inlet 35 and a fluid outlet 36 for connection to an external fluid circuit.
and is provided. Refrigerant gas is supplied through the fluid suction port 35
Suction chamber 2 formed on the outside of both scroll bodies from
51 and taken into the closed space between both scroll members 20 and 21, and the movable scroll member 2
The fluid moves to the center while being compressed by the circular orbital motion of the fixed scroll member 20, and is blown out from the discharge port 204 provided at the center of the side plate 201 of the fixed scroll member 20 via the discharge valve 37 to the discharge chamber 261, from which the fluid discharge port 3
6 into the fluid circuit.

By the way, the intake of fluid into the closed space between both scroll members 20 and 21 is normally carried out through a total of two channels formed between the outer end of one spiral body 202 or 212 and the outer surface of the other spiral body. This is done through the fluid intake. That is, the fluid intake port is opened and closed according to the circular orbit movement of the movable scroll member 21, and at that time both scroll members 20,
The fluid is taken into the sealed space between 21. Here, since the positions of the outer ends of the spiral bodies 202 and 212 are expressed by the so-called final expansion/opening angle φend, the position of the fluid intake port is also substantially determined by the final expansion/opening angle φend.

Further, referring to FIG. 2a, the fixed scroll member 20 has a final expansion and opening angle φend
exceeds 4π, and intermediate pressure chamber 2
It has two fluid bypass holes 205 and 206 communicating with 62. One fluid bypass hole 20
6 corresponds to the position of a certain extension angle φ ₁ of the spiral body 202 and is provided so as to open inside the spiral body 202 . The other fluid bypass hole 20
5 is a certain expansion and opening angle (φ ₁ −π) of the spiral body 202
It corresponds to the position of , and is provided so as to open to the outside of the spiral body 202 . Therefore, the fluid bypass holes 205 and 206 both correspond to positions closer to the center along the spiral direction than the fluid intake ports (two locations). Here, the angular positions at which the fluid bypass holes 205 and 206 are provided are selected within the range defined by φend>φ ₁ >φend−2π (1).

Now, the formation of the fluid bypass holes 205 and 206 is as follows.
This is done by applying a drill to the side plate 201 of the fixed scroll member 20 from the side opposite to the spiral body 202. At this time, one fluid bypass hole 206 is formed at a position slightly cut into the inner surface of the spiral body 202, and the other fluid bypass hole 205 is formed at a position slightly cut into the outer surface of the spiral body 202. do. Both of these fluid bypass holes 205 and 206 are also arranged so that when the end of the spiral body 212 of the movable scroll member 21 comes into contact with the portion of the side plate 201 of the fixed scroll member 20 where the fluid bypass hole 205 (or 206) is provided, Also, the spiral body 21
A sealing member 213 fitted into the groove at the end of 2
The compressed fluid is designed to prevent the compressed fluid from communicating beyond the part of the spiral body 212 to the space on the opposite side separated by the spiral body 212. fluid bypass hole 205,
Since 206 is formed by biting into the spiral body 202, it is possible to have a sufficiently large cross-sectional area while satisfying such design conditions. Note that a plurality of fluid bypass holes 205 and 206 may be formed adjacent to each other along the spiral direction, or the plurality of holes may be integrated to form a long hole, thereby increasing the cross-sectional area. .

Further, on the side plate 201 of the fixed scroll member 20 opposite to the spiral body 202, plate-shaped valves 41 are fixed with screws 42 or the like at positions corresponding one-to-one to the fluid bypass holes 205 and 206, respectively. It is used as a check valve. Note that the valve 41 has a fluid bypass hole 2.
It is better to provide a portion that fits into the fluid bypass holes 205 and 206 when the holes 05 and 206 are closed.

Furthermore, referring also to FIG. 2b, the side plate 201 of the fixed scroll member 20 has spiral bodies 202,
A communication hole 4 that communicates the suction chamber 251 and the suction communication chamber 263 is located at a position on the outside of the spiral from the position of the fluid intake port that is substantially determined by the final expansion/opening angle φend of 2.
0 is set.

A cylinder 49 is installed in the intermediate pressure chamber 262, and the inner wall surface of the cylinder 49 is provided with a tapered step as shown in the figure, and this step allows the cylinder 49 to be connected to the first cylinder portion, 1st
It is divided into a second cylinder part located below the cylinder part and having a smaller diameter than the first cylinder part. Openings 39 and 50 are formed in the side and bottom parts of the second cylinder part, respectively. The side opening 39 is connected to the suction communication chamber 26.
3, and the bottom opening 50 is connected to the intermediate pressure chamber 26.
It is connected to 2. Further, at the upper end of the cylinder 49, a plate 52 with a connecting hole 51 formed in the center is disposed via an O-ring 521. A solenoid valve 45 is attached. A high-pressure gas introduction pipe 46 from the discharge chamber 261 is connected to this electromagnetic valve 45. A piston 44 having a substantially I-shaped cross section is disposed within the cylinder 49, and a piston ring 47 is attached to the piston 44 to prevent leakage of high pressure gas.

This piston ring 47 has a so-called gap 471 formed therein, as shown in FIG. In the first cylinder portion of the piston 44, as shown in FIG. 1, a piston ring 47 is in contact with the inner wall surface of the cylinder, and a gap 471 of the piston ring 47 is in a wide open state. On the other hand, in the second cylinder portion, the piston ring 47 is pressed in the radial direction, and the gap 471 is slightly opened.

Next, the operation of this compressor will be explained.

With reference to FIG. 1, by rotation of the main shaft 14,
When the movable scroll member 21 performs a revolution, the refrigerant gas that has entered the suction chamber 251 from the fluid suction port 35 is taken into the fluid pocket formed between both the spiral bodies 202 and 212, and is compressed until it reaches the center. and is discharged from the discharge port 204 into the discharge chamber 261.

When the electromagnetic valve 45 is open, high pressure gas is introduced into the cylinder chamber 49 through the high pressure gas introduction capillary 46 . Due to this high-pressure gas force, that is, the pressure inside the cylinder 49 becomes higher than the pressure in the intermediate pressure chamber 262, the piston 44 is pressed downward, and the opening 50 at the bottom of the cylinder 49 is blocked by the piston 44. be done. When the opening 50 is blocked, the gas pressure in the intermediate pressure chamber 262 increases due to the gas bypassed from the fluid bypass holes 205 and 206, and the valve 41 is closed. Note that in this case, the pressure inside the cylinder 49 is higher than the pressure in the intermediate pressure chamber 262. Therefore, the fluid bypass hole 205,
The bypass gas cannot be returned to the suction chamber 251 through 206, resulting in a high compression ratio. When the piston 44 is blocking the opening 50, the upper end of the piston 44 is slightly below the boundary between the first cylinder part and the second cylinder part, that is, the step part (therefore, the piston 44 is slightly below the step part). 2
The piston 44 and cylinder 49 are designed to be located in the cylinder portion of the cylinder.

When the solenoid valve 45 is closed to reduce the compression ratio from the maximum compressor state, the introduction of high pressure gas from the discharge chamber 261 to the cylinder 49 is cut off. The upper end of the piston 44 exists in the second cylinder part, and as mentioned above, the gap between the piston rings 47 and the gap is slightly opened, so high pressure gas leaks little by little from this gap, causing the cylinder to leak. 49 internal pressure gradually decreases. When the pressure inside the cylinder 49 becomes lower than the pressure in the intermediate pressure chamber 262, the piston 44 moves slightly upward. At this time, the upper end of the piston 44 passes over the tapered stepped portion and enters the first cylinder portion. As a result, as described above, the force pressing the piston ring 47 in the radial direction is removed, and the gap between the piston rings 47 is widened. Therefore, high-pressure gas flows out from this gap at once, and the pressure inside the cylinder 49 drops significantly. As a result, the piston 44 is pushed upward at once, and the intermediate pressure chamber 262 and the suction communication chamber 2
63, and the pressure in the intermediate pressure chamber 262 is reduced. When the pressure in the intermediate pressure chamber 262 decreases,
Valve 41 is opened and fluid bypass holes 205, 20
The gas bypassed from 6 to the intermediate pressure chamber 262 enters the suction communication chamber 263 through the cylinder 49.
Therefore, the amount of compressed gas discharged into the discharge chamber 261 from the closed space formed between both scroll members decreases, and the compression ratio decreases.

In this way, when reducing the capacity of the compressor,
When the piston 44 moves slightly upward and reaches a predetermined position, the high-pressure gas in the cylinder flows out from the gap between the piston rings 47, causing the piston 44 to move upward all at once, causing vibration in the piston. Never.

Furthermore, in the above embodiment, unlike the conventional example shown in FIG. 7, the spring 43 that biases the piston up and down is not used.
Therefore, the opening 50 connecting the intermediate pressure chamber 262 and the cylinder 49 can be made larger. As a result, the pressure loss between the intermediate pressure chamber 262 and the suction communication chamber 263 is reduced, and responsiveness is particularly improved when changing the compression ratio from a decrease to a maximum compression ratio.

Next, a second embodiment of the present invention will be described with reference to FIG.

In this embodiment, the inner wall of the cylinder 49 is provided with a groove 491 extending in the vertical direction. This groove 49
1 extends downward from the upper end of the cylinder 49 to a predetermined position. Intermediate pressure chamber 262 and cylinder 4
9 is closed by the piston 44, the upper end of the piston 44 is located slightly below the lower end of the groove 491. When the solenoid valve 45 is changed from the open state to the closed state, high pressure gas gradually leaks from the slightly opened gap in the piston ring 47.
When the pressure inside the cylinder 49 becomes lower than the pressure in the intermediate pressure chamber 262, the piston 44 moves slightly upward. When the piston 44 moves upward slightly, a gap is formed between the piston 44 and the groove 491, and high-pressure gas flows all at once into the suction communication chamber 263 through this gap, causing the pressure in the cylinder 49 to drop significantly. As a result, the piston 44 moves upward at once and does not vibrate.

Further, in the third embodiment shown in FIG. 5, the inner wall surface of the cylinder 49 has a first cylinder portion formed in a tapered shape so that the diameter increases upward, and a first cylinder portion having a constant diameter. It is divided into a second cylinder part which is continuous to the lower side of the cylinder part. An opening 39 and an opening 5 are formed on the side and bottom surfaces of the second cylinder part, respectively.
0 is set. When the opening 50 is closed by the piston 44 (the electromagnetic valve 45 is open), the piston 44 is firmly in contact with the inner wall surface of the cylinder 49 (the inner wall surface of the second cylinder portion). . Next, when the solenoid valve 45 is closed, the piston 44 moves slightly upward, and the piston 44 moves upward.
When the upper end of the piston 44 reaches the first cylinder portion, a gap is formed between the piston 44 and the inner wall surface of the cylinder 49, allowing the high pressure gas to escape all at once.

Furthermore, in the embodiment shown in FIG. 6, a pore (bypass passage) 492 is provided that communicates the upper part of the cylinder 49 with a predetermined position (substantially in the center) of the cylinder. When the piston 44 is blocking the opening 50 (the electromagnetic valve 45 is open), one end of the pore 492 is blocked by the upper part of the piston 44.
Next, when the solenoid valve 45 is closed, high pressure gas leaks from the slightly opened gap in the piston ring 47, and when the piston 44 moves slightly upward, one end of the pore 492 is opened. , the high-pressure gas in the cylinder 49 flows into the suction communication chamber all at once, and the piston 44 moves upward at once.

(Effects of the Invention) As explained above, according to the scroll compressor of the present invention, the piston does not vibrate during the capacity variation process, so the durability of the piston is improved, and moreover, noise is generated. There will be nothing to do. Furthermore, there is an advantage that the responsiveness of capacitance variation is improved and the capacitance can be stably varied.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a first embodiment of a scroll compressor according to the present invention, and FIG.
-A' line sectional view, Figure 2b is a BB' line sectional view of Figure 1, Figure 3 is a perspective view of the piston ring, and Figure 4 is a second embodiment of the scroll compressor according to the present invention. Cross-sectional view showing the variable capacity mechanism used in the example, No. 5
The figure is a sectional view showing a variable capacity mechanism used in a third embodiment of a scroll compressor according to the present invention, and FIG. 6 is a sectional view showing a variable capacity mechanism used in a fourth embodiment of a scroll compressor according to the present invention. A cross-sectional view showing,
FIG. 7 is a diagram showing a variable capacity mechanism used in a conventional scroll compressor. 1... Compressor, 10... Compressor housing, 1
DESCRIPTION OF SYMBOLS 1... Front end plate, 12... Cup-shaped part, 13... Ball bearing, 14... Main shaft, 15... Sleeve, 16... Shaft seal assembly, 20... Fixed scroll member, 21...
Movable scroll member, 22...Rotation prevention mechanism, 2
51...Suction chamber, 27...Drive wheel, 36...Fluid outlet, 35...Fluid inlet, 39...Side opening, 41...Check valve, 43...Spring, 44
... Piston valve, 45 ... Solenoid valve, 46 ... High pressure gas introduction pipe, 50 ... Bottom opening.

Claims (1)

[Claims] 1. A compressor housing including a fluid inlet and a fluid outlet, a first spiral body, a fixed scroll member fixedly disposed within the compressor housing, and a second spiral body, a movable scroll member superimposed on the fixed scroll member such that the second spiral body meshes with the first spiral body at an angle shifted from each other to form a closed fluid pocket between both spiral bodies; By causing the movable scroll member to perform circular orbital motion while preventing its rotation, suction gas is drawn into the fluid pocket from the suction chamber communicating with the fluid suction port, and the center of the fixed scroll member is In the scroll type compressor, the high-pressure gas is discharged from a discharge port provided in a section to the fluid discharge port via a discharge chamber, and the fixed scroll member includes an outermost end of the first spiral body. a fluid bypass hole is provided at a position extending from the inside; an intermediate pressure chamber that communicates the fluid bypass hole and the suction chamber via a check valve; a first opening that communicates with the intermediate pressure chamber; A cylinder including a second opening communicating with a suction chamber and into which discharge gas is introduced, a piston slidably disposed within the cylinder, and a control valve mechanism that controls introduction of the discharge gas into the cylinder. and the piston slides due to a pressure difference between the discharge gas pressure introduced into the cylinder and the pressure in the intermediate pressure chamber, and the first opening is closed by the piston. When the compression capacity is maximized and the first opening is closed, the piston is slid in the direction of opening the first opening, and when the piston moves to a predetermined position, A variable capacity scroll type compressor, characterized in that it is provided with a gas venting means for releasing the discharge gas introduced into the cylinder into the suction chamber through the second opening.