WO2015097844A1

WO2015097844A1 - Scroll compressor

Info

Publication number: WO2015097844A1
Application number: PCT/JP2013/085038
Authority: WO
Inventors: 啓武田; 彰士松村; 太田原　優; 佑介上橋; 和夫櫻井; 三宅　成志
Original assignee: 日立アプライアンス株式会社
Priority date: 2013-12-27
Filing date: 2013-12-27
Publication date: 2015-07-02

Abstract

The objective of the present invention is to provide a scroll compressor such that deformation of a holding part or a release valve retainer when a release valve retainer is provided is suppressed, thereby improving reliability. The scroll compressor is provided with a fixed scroll and turning scroll, each comprising a spiral wrap provided on a base plate, a compression chamber formed by the wraps being engaged with each other, and a discharge space whereto a working fluid that has been compressed in the compression chamber is discharged, said scroll compressor being characterized in that: the scroll compressor is provided with a release flow path which is provided on the base plate of the fixed scroll and allows the discharge space and the compression chamber to communicate with each other, and a release valve device which is disposed in the release flow path and opens the release flow path when the pressure in the compression chamber is higher than that in the discharge space by a predetermined value or greater; the release valve device comprises a release valve, which is a valve body for closing the release flow path, an elastic body for biasing the release valve with a pressing force for closing the release flow path, and an elastic body holding member for holding the elastic body; and the elastic body holding member has a fixed part fixed onto the fixed scroll.

Description

Scroll compressor

The present invention relates to a scroll compressor.

As background art in this technical field, there is JP 2013-19322 (Patent Document 1). According to this publication, “a fixed scroll has a release valve device that opens a circuit so that the compression chamber communicates with the discharge pressure chamber when the pressure in the compression chamber rises above a set pressure. A release passage that communicates with the discharge pressure chamber, a release valve that opens and closes the release passage, a valve pressing body that applies an elastic pressing force to the release valve disposed between the release valve and the retainer, and a valve pressing body A retainer that limits the movement range of the release valve, and the release pressure of the release valve is pressed against the retainer by the elastic pressing force in any state of closing the release flow path and opening the release flow path. As a result, “the deformation of the retainer and the valve pressing body due to the collision and the collision noise are suppressed while the deformation to the fixed scroll due to the press-fitting of the valve pressing body when the release valve device is arranged is suppressed. To suppress, it is described that can "to enhance the performance and reliability of the scroll compressor.

JP 2013-19322 A

With the structure of the release valve device disclosed in Patent Document 1, the valve pressing body holding member is pressed against the retainer by the elastic pressing force regardless of whether the release valve closes the release flow path or opens the release flow path. It is turned on. Accordingly, it is described that, in addition to the generation of a collision sound between the retainer and the valve pressing body holding member, deformation of the retainer or the valve pressing body holding member due to the collision can be suppressed, and reliability can be improved. In this way, by adopting a structure in which the valve pressing body holding member is always held from above by the retainer, the movement of the valve pressing body holding member in the vertical direction is suppressed, and sound and deformation due to a collision are reduced.

However, although the sound and deformation due to the collision were reduced, it could not be eliminated, and the sound and deformation due to the collision occurred when the release flow rate was high.

Therefore, an object of the present invention is to provide a scroll compressor that improves the reliability by suppressing the deformation of the presser part and the release valve receptacle when a release valve device is provided.

In order to solve the above problems, for example, the configuration described in the claims is adopted. The present application includes a plurality of means for solving the above-described problems. To give an example, “the fixed scroll and the orbiting scroll in which the spiral wrap is provided on the base plate and the fixed scroll and the orbiting scroll are mutually connected. In a scroll compressor comprising a compression chamber formed by meshing and a discharge space in which a working fluid compressed in the compression chamber is discharged, the discharge space provided in the base plate of the fixed scroll and the compression A release flow path communicating with the chamber, and a release valve device that is disposed in the release flow path and opens the release flow path when the pressure in the compression chamber is higher than the discharge space by a predetermined value or more. The apparatus includes a release valve that serves as a valve body that closes the release flow path, and an elastic body that urges the release valve to apply a pressing force that closes the release flow path. Comprising an elastic body holding member that holds the elastic member, wherein the elastic body holding member is characterized by "having a fixed portion fixed to the stationary scroll.

According to the present invention, the collision between the valve pressing body holding member and the retainer can be eliminated, and the reliability of the scroll compressor can be improved. Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

It is a figure explaining the structure of the scroll compressor of Example 1. FIG. It is a figure explaining the structure of the conventional release valve apparatus. It is the figure which showed the valve opening state of the conventional release valve apparatus, and the flow of the working fluid. It is a figure explaining the structure of the release valve apparatus of Example 1. FIG. It is a figure explaining the structure of the release valve apparatus of Example 1 which used the fixing method of the elastic body holding member as one bolt. It is a figure explaining the structure of the release valve apparatus of Example 2. FIG. It is the figure which showed the valve opening state of the release valve apparatus of Example 2, and the flow of the working fluid. It is a figure explaining the structure of the release valve apparatus of Example 3. FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Example 1 will be described with reference to FIGS. First, the overall structure of the scroll compressor will be described with reference to FIG. The scroll compressor 1 is configured by storing a compression chamber 2 and a drive unit 3 in a sealed container 4.

In the compression chamber 2, the compression operation is performed by reducing the volume of the compression chamber 2 that is mechanically configured by meshing the fixed scroll 18 and the orbiting scroll 19 by the rotating action of the drive unit 3. Along with this compression operation, the working fluid is sucked into the compression chamber via the suction port 5 and the suction space, and the sucked working fluid is discharged to the discharge space 20 in the sealed container 4 through the compression stroke, and further discharged. It is discharged from the sealed container 4 via the port 6.

The drive unit 3 includes an electric motor 9 including a stator 7 and a rotor 8, a crankshaft 10, a frame 11, a sub frame 12, and a sub bearing housing 15 as basic elements. Here, the electric motor 9 is driven by an electric input from an inverter (not shown) via the electric terminal 16 and imparts a rotating action to the crankshaft 10. The crankshaft 10 includes a main shaft portion 10a, a sub shaft portion 10b, and an eccentric pin portion 10c. The shaft support portion 13 disposed on the frame 11 and the shaft support portion 14 disposed on the auxiliary bearing housing 15 constitute a shaft support portion that rotatably engages the main shaft portion 10a and the sub shaft portion 10b of the crankshaft 10. .

In addition, lubrication to the shaft support

portions

13 and 14 and the sliding portions of the orbiting scroll 19 and the fixed scroll 18 or the flow into the compression chamber causes the working fluid in each compression chamber to leak into the compression chamber on the low-pressure side, and for heating and re-operation. Oil 17 for preventing thermal fluid loss by compression is stored in the sealed container 4, and the subframe 12 engaged with the frame 11 and the subbearing housing 15 is fixed to the sealed container 4.

Next, the configuration of the release valve device will be described. The release valve device 21 is a device for allowing working fluid to escape from the compression chamber 2 to the discharge pressure space 20 during overcompression when the pressure in the compression chamber 2 of FIG. It is possible to reduce power consumption and bearing load by preventing over-compression by letting the working fluid escape.

The release valve device 21 is disposed at a plurality of locations of the fixed scroll 18 corresponding to the plurality of compression chambers 2 formed by the fixed scroll 18 and the orbiting scroll 19.

Gas refrigerant or liquid refrigerant, mist-like lubricating oil or the like is drawn into the compression chamber 2 as a working fluid from the suction port 5 of the fixed scroll 18 depending on the operating conditions. In the process in which the working fluid is compressed by the orbiting movement of the orbiting scroll 19, the pressure in the compression chamber 2 may be overcompressed so as to be equal to or higher than the discharge pressure. The release valve device 21 is closed during an operation state in which overcompression does not occur. However, during such overcompression, the release valve device 21 is opened. Thus, the working fluid can be released from the compression chamber 2 to the discharge pressure space 20 by the communication between the compression chamber 2 and the discharge pressure space 20.

FIG. 2A shows a cross-sectional view of an example of a conventional release valve device 21 as viewed from the lateral direction. The release valve device 21 includes a release valve 23 that opens and closes a release hole 22 communicating with the compression chamber 2, an elastic body 24 that presses the release valve 23 in a direction to close the flow path of the release hole 22 when the valve is closed, and an elastic body 24. An elastic body holding member 25 for holding and receiving the release valve 23 when the valve is opened, and a presser plate 26 for holding the elastic body holding member 25 and the release valve 23 so as not to move to the discharge pressure space 20 are provided.
Further, a space for connecting the compression chamber 2 formed in the fixed scroll 18 and the discharge pressure space 20 and arranging the release valve device 21 will be referred to as a release valve chamber 27.

FIG. 2B is a view of the release valve device 21 as viewed from above, and FIG. 2C is a view of the elastic body holding member 25 as viewed from below. The elastic body holding member 25 is formed of a sintered metal or a carbon steel material, and a central escape passage 25a and a peripheral escape passage 25b are formed.

Further, the elastic body holding member 25 is formed in a cylindrical shape, and is provided with a convex portion that protrudes toward the compression chamber 2 at the lower portion, and one end of the elastic member 24 is integrally combined with this convex portion by press fitting or the like. . This convex part is comprised so that a diameter may become small as it goes to the compressor side. A disc-shaped or different-diameter circular release valve 23 is attached to the elastic member 24, and the release valve 23 acts to close the release hole 22 when the valve is closed by the biasing force of the elastic member 24 toward the compression chamber 2 side. . Further, the release valve 23 contacts the annular valve seat portion of the fixed scroll 18 when the valve is closed.

The release hole 22 is formed so as to have a smaller diameter than the wrap thickness of the orbiting scroll 19, and the release valve chamber 27 is formed as a hole having a large diameter with respect to the release hole 22. Since the volume of the release hole 22 becomes a part of the volume of the compression chamber 2 and becomes a dead volume accompanied by re-expansion loss of the gas remaining in the compression stroke, the volume of the release hole 22 is preferably suppressed as much as possible. Further, the diameter of the hole forming the release valve chamber 27 is larger than that of the release hole 22 in order to ensure a sufficient release flow path so as not to impair the function of escaping the working fluid.

FIG. 3 shows a state in which the release member 23 is opened by the action of the elastic member 24 in the conventional release valve device 21 so that the working fluid flows from the compression chamber 2 to the discharge pressure space 20 to release the pressure. At this time, the working fluid in the compression chamber 2 flows from the release hole 23 to the release valve chamber 27, and further flows to the central relief passage 26 a and the surrounding relief passage 26 b formed in the elastic body holding member 25, and to the discharge pressure space 20. Flowing into. Thus, the release flow path of the working fluid by the release valve device 21 is formed from the release hole 22 to the release valve chamber 27, the central relief flow path 25a, and the internal relief flow path 25b.

At this time, the release valve 23 moves away from the valve seat portion so as to come into contact with the release valve receiving portion 25c formed on the convex portion of the elastic body holding member 25. Further, as shown in FIG. 3, the release valve device space 21 has a large-diameter lower release valve chamber 27a and a small-diameter in the fixed scroll 18 in order to restrict the elastic body holding member 25 from approaching the release hole 22 side more than necessary. The upper release valve chamber 27b is formed in a two-stage shape. The elastic body holding member 25 is formed of a cylindrical body, has an outer diameter slightly smaller than the inner diameter of the release valve chamber 27, and has a gap that can move vertically in the upper release valve chamber 27b.

In the structure shown in FIGS. 2 to 3, when the compression chamber 2 is overcompressed and the working fluid pushes up the release valve 24, the release valve 23 and the release valve receiving portion 25c of the elastic body holding member 25 collide with each other. Further, when the release valve 23 and the elastic body holding member 25 collide, the elastic body holding member 25 is pushed up, and the elastic body holding member 25 and the presser plate 26 collide.
Then, wear occurs at the contact surfaces of the release valve 23, the release valve receiving portion 25c, the elastic body holding member 25, and the presser plate 26, and the reliability such as cracking of the release valve 23 and penetration of the elastic body holding member 25 through the presser plate 26 is achieved. There is a risk of lowering.

Particularly, the collision between the elastic body holding member 25 and the presser plate 26 is elastic from the viewpoint of securing the flow area of the working fluid in addition to the large collision force because the elastic body holding member 25 is heavier than the release valve 23. Since it is difficult to secure a contact area between the body holding member 25 and the presser plate 26, the structure is likely to cause wear.

Conventionally, the elastic body holding member collision force to the presser plate 26 has been suppressed by suppressing the movable range of the elastic body holding member 25. However, in order to suppress the movable range of the elastic body holding member 25, high processing accuracy is required for the depths of the elastic body holding member 25 and the upper release valve chamber 27b.

Further, a method of eliminating the need for the presser plate 26 by constricting the elastic body holding member 25 to the upper release valve chamber 27b is conceivable. However, the fixed scroll 18 is deformed by the interference fit, and the inside of the compression chamber 2 or the fixed state is fixed. There is a possibility that leakage of the working fluid occurs at the flange portion of the scroll 18 and the thermal fluid loss increases.

Furthermore, when a refrigerant containing 70% by weight or more of R32 is used as the working fluid, the heat insulation coefficient is higher than when a refrigerant having R32 of less than 70% by weight is used, and the pressure in the compression chamber is likely to rise. There is a possibility that reliability cannot be ensured by the above-described countermeasures. Therefore, in this embodiment, the structure shown in FIG. 4 is adopted.

FIG. 4 is a view for explaining the release valve device 21 of this embodiment. FIG. 4A shows a cross-sectional view of the release valve device 21. 4B is a view of the release valve device 21 viewed from the discharge pressure space 20 side (upper side), and FIG. 4C is a view of the elastic body holding member 25 viewed from the lower side. 4, the flow of the working fluid and the opening / closing structure of the release valve 23 are basically the same as those in FIG. 2 and will not be described. However, the shape of the elastic body holding member 25 and the release valve chamber 27 are different from those in FIG. The diameter is mainly different.

As shown in FIG. 4 (a), the elastic body holding member 25 of this embodiment has a shape in which the elastic body holding member 25 and the presser plate 26 of the release valve device 21 having the conventional structure shown in FIG. The member 25 is structured to be directly fixed to the base plate 18a on the side opposite to the wrap of the fixed scroll 18 with a bolt or the like.

As for the fixing location of the elastic body holding member 25, in addition to the structure of two or more locations as shown in FIG. 4, it may be fixed at one location as shown in FIG. As shown in FIG. 2, in the case of the conventional structure in which the elastic body holding member 25 is pressed from above by the holding plate 26, since the elastic body holding member 25 itself is not directly fixed to the fixed scroll 18, the holding plate 26 is fixed at one place. When fixed, the release valve is activated and the opposite side of the fixed portion becomes unstable with respect to the force by which the elastic body holding member 25 is pushed up. In this embodiment, since the elastic body holding member 25 itself is fixed to the fixed scroll 18, the elastic body holding member 25 does not become unstable with respect to the pushing force of the elastic body holding member 25 even on the opposite side of the fixed portion, and is fixed at one place. It can be. Thereby, cost and work man-hours can be reduced by reducing the number of parts of the fixing member.

According to this embodiment, the elastic body holding member 25 and the presser plate 26 do not collide and there is no risk of wear. In addition to the conventional working fluid, a refrigerant containing 70% by weight or more of R32 is used as the working fluid. Even in the case, high reliability can be obtained. Further, the inner periphery of the release valve chamber 27 can be made larger than the outer periphery of the insertion portion inserted into the release valve chamber 27 of the elastic body holding member 25 to make a clearance fit, and heat fluid loss due to deformation of the fixed scroll 18 can be achieved. Since the influence of this is as small as the conventional structure, there is no risk of an increase in power consumption.

Conventionally, the arrangement has been adjusted by supporting the elastic body holding member 25 at the step portion with the inner surface of the release valve chamber 27 being two steps, but the elastic body holding member 25 is arranged on the side opposite to the wrapping side of the fixed scroll 18. By fixing to the base plate 18a, the inner surface of the release valve chamber 27 can be made into one step with a constant hole diameter (cross-sectional area), and the workability is also improved.

Next, a second embodiment of the scroll compressor of the present invention will be described. This embodiment is the same as the first embodiment except for the point relating to the release flow path of the elastic body holding member, and the description of the portions having the same functions is omitted in FIG. Indicates. 6A is a longitudinal sectional view of the release valve device 21, FIG. 6B is a view of the release valve device 21 viewed from the discharge pressure space 20 side (upper side), and FIG. The figure which looked at the body holding member 25 from the pressure chamber 2 side (lower side) is shown. In the first embodiment, as shown in FIG. 4, the working fluid escape passage is provided in the central escape passage 25a and the internal escape passage 25b of the elastic body holding member 25, but the structure of the second embodiment is shown in FIG. Thus, the escape passage of the elastic body holding member 25 is only the central escape passage 25a, and an outer peripheral release passage 27c is provided as shown in FIGS. 6 and 7 to secure the passage area.

The outer peripheral release channel 25 c is formed by the side surface of the insertion portion of the elastic body holding member 25 inserted into the release valve chamber 27 and the inner surface of the release valve chamber 27. Therefore, according to the present embodiment, the release flow path can be secured without complicated processing inside the elastic body holding member 25. Further, since it is possible to reduce the outer diameter and the width of the portion inserted into the release valve chamber 27 of the elastic body holding member 25 with respect to the structure of the first embodiment, the material cost can be suppressed. The holding member 25 can be manufactured at a low cost.

Next, a third embodiment of the scroll compressor according to the present invention will be described. This embodiment is the same as the first embodiment and the second embodiment except for the shape of the elastic body holding member 25 and the fixing method to the fixed scroll 18, and the description of the portions having the same functions is omitted.

FIG. 8 shows the structure of the release valve device 21 of the third embodiment. 8A is a longitudinal sectional view of the release valve device 21, and FIGS. 8B and 8C are views of the release valve device 21 viewed from the discharge pressure space 20 side (upper side). d) shows a view of the elastic body holding member 25 as seen from the compression chamber 2 side (lower side). In the first and second embodiments, the method of fixing the elastic body holding member 25 to the fixed scroll 18 is fixed to the surface of the base plate 18a on the opposite side of the fixed scroll 18 with the fixing bolt 28. In the example, screw portions 25d are provided on the outer periphery of the elastic body holding member 25 and the inner periphery of the release valve chamber 27 of the fixed scroll, and the elastic body holding member 25 is screwed into the fixed scroll 18 so that the elastic body holding member 25 is fixed to the fixed scroll 18. Secure to. That is, a male screw portion is formed on the side surface of the insertion portion of the elastic body holding member 25 inserted into the release valve chamber 27, and a female screw portion corresponding to the male screw portion is formed on the inner surface of the release valve chamber 27 to be elastic. The body holding member 25 is screwed to the fixed scroll 18.

Further, in order to assemble the elastic body holding member 25 with respect to the surface of the base plate 18 a on the side opposite to the wrap of the fixed scroll 18, the protruding portion of the elastic body holding member 25 from the fixed scroll 18 has a larger diameter than the release valve chamber 27. .

The protruding portion of the elastic body holding member 25 from the fixed scroll 18 has a hexagonal shape as shown in FIG. 8 (a) or as shown in FIG. 8 (b) so that the operation of screwing the elastic body holding member 25 into the fixed scroll 18 is facilitated. It is preferable to use a hexagonal hole shape.

DESCRIPTION OF SYMBOLS 1 ... Scroll compressor 2 ... Compression chamber 3 ... Drive part 4 ... Sealed container 5 ... Suction port 6 ... Discharge port 7 ... Stator 8 ... Rotor 9 ... Electric motor 10 ... Crankshaft 10a ... Crankshaft main bearing part 10b ... Crank Shaft sub-bearing portion 10c Crankshaft eccentric pin portion 11 Frame 12 Sub-frame 13 Shaft support portion 14 Shaft support portion 15 Sub-bearing housing 16 Electric terminal 17 Oil 18 Fixed scroll 18a Base plate 19 Orbiting scroll 21 · Release valve device 22 · Release hole 23 · Release valve 24 · Elastic body 25 · Elastic body holding member 25a · Elastic body holding member central relief passage 25b · Elastic body holding member internal escape passage 25c · Release valve receptacle Portion 25d · elastic body holding member fixing screw portion 26 · holding plate 27 · release valve chamber 27a · lower release valve chamber 27b · upper release valve chamber 27c · elastic body holding Zaigaishu release passage 28 ‥ elastic holding member fixing bolts

Claims

A fixed scroll and orbiting scroll provided with a spiral wrap on the base plate, a compression chamber formed by meshing the fixed scroll and the orbiting scroll wrap, and a working fluid compressed in the compression chamber are discharged. A scroll compressor having a discharge space,
A release passage provided on the base plate of the fixed scroll and communicating the discharge space and the compression chamber, and the release when the pressure in the compression chamber is higher than the discharge space by being disposed in the release passage is higher than a predetermined value. A release valve device that opens the flow path,
The release valve device includes a release valve that is a valve body that closes the release flow path, an elastic body that urges the release valve to close the release flow path, and an elastic body holding member that holds the elastic body. And comprising
The scroll compressor according to claim 1, wherein the elastic body holding member has a fixed portion fixed to the fixed scroll.
The scroll compressor according to claim 1, wherein
The release channel communicates with the discharge space, a release valve chamber into which the release valve device is inserted, a release hole that communicates with the release valve chamber and the compression chamber and is closed by the release valve from the release valve chamber side. And having
The elastic body holding member has an insertion portion to be inserted into the release valve chamber,
A scroll compressor, wherein the inner periphery of the release valve chamber is formed to be larger than the outer periphery of the insertion portion, whereby the elastic body holding member is fixed with a clearance fit.
The scroll compressor according to claim 2,
A scroll compressor characterized in that the release valve chamber is provided with a constant hole diameter.
The scroll compressor according to claim 2,
The fixed portion is formed facing the base plate surface on the side opposite to the wrap of the fixed scroll,
The scroll compressor, wherein the base plate surface and the fixing portion are fixed by bolts.
The scroll compressor according to claim 4, wherein
The scroll compressor according to claim 1, wherein the fixing portion is formed integrally with the insertion portion, and is fixed to the base plate surface on the side opposite to the wrap of the fixed scroll by a bolt at one place.
The scroll compressor according to claim 2,
The scroll compressor characterized in that the release flow path in the release valve chamber is constituted by a side surface of the insertion portion and the release valve chamber inner surface.
The scroll compressor according to claim 2,
The fixing portion is constituted by a male screw portion formed in the insertion portion,
A scroll compressor characterized in that the elastic body holding member is fixed to the fixed scroll by screwing the male screw part into a female screw part formed on the inner surface of the release valve chamber.
The scroll compressor according to any one of claims 1 to 7,
The scroll fluid characterized in that the working fluid contains R32 in an amount of 70% by weight or more.