WO2018198862A1

WO2018198862A1 - Scroll compressor, and air conditioner

Info

Publication number: WO2018198862A1
Application number: PCT/JP2018/015740
Authority: WO
Inventors: 啓武田; 太田原　優; 彰士松村; 隆雅足立; 洋平山本
Original assignee: 日立ジョンソンコントロールズ空調株式会社
Priority date: 2017-04-25
Filing date: 2018-04-16
Publication date: 2018-11-01
Also published as: JP2018184872A

Abstract

A scroll compressor (S) comprises: a fixed scroll (10) having a spiral-shaped wrap (12) which is disposed upright on a base plate (11); an orbiting scroll (20) having a spiral-shaped wrap (22) which is disposed upright on a base plate (21); and an electric motor (2) that causes the orbiting scroll to orbit. The fixed scroll (10) and the orbiting scroll (20) are disposed such that the wraps (12, 22) thereof engage with each other. The orbiting scroll (20) is a CV graphite cast iron product. The fixed scroll (10) is a gray cast iron product or a CV graphite cast iron product.

Description

Scroll compressor and air conditioner

The present invention relates to a scroll compressor and an air conditioner including the same.

In air conditioners, scroll compressors are used as devices for compressing gaseous refrigerant (working fluid). A scroll compressor is a device that compresses refrigerant by using a fixedly installed scroll member (hereinafter referred to as “fixed scroll”) and a scroll member that performs a revolving motion (hereinafter referred to as “revolving scroll”). The scroll compressor forms a compression chamber between the fixed scroll and the orbiting scroll by rotating the orbiting scroll, and compresses the refrigerant in the compression chamber.

In recent years, the scroll compressor has been downsized in order to reduce the environmental load by reducing the amount of material used. However, when the size of the orbiting scroll is reduced without changing the rotation speed (orbiting speed), the refrigerant circulation rate (kg / s) per unit time is reduced, so that the compression efficiency of the scroll compressor is lowered. Thereby, the cooling capacity of the air conditioner using the scroll compressor is lowered. Therefore, downsizing of the scroll compressor that does not change the rotation speed (orbiting speed) of the orbiting scroll is not preferable. Therefore, when the scroll compressor is downsized, it is necessary to ensure the same refrigerant circulation amount per unit time as before the downsizing in order to ensure the same compression efficiency as before the downsizing. And in order to satisfy | fill such a request, it is preferable that a scroll compressor rotates a turning scroll at high speed (high-speed turning).

Therefore, for example, in Patent Document 1, in order to realize high-speed rotation (high-speed rotation) of the orbiting scroll while realizing downsizing of the scroll compressor, a fixed scroll such as FC250 (Japanese Industrial Standard (JIS)) or the like is used. It has been proposed that the orbiting scroll be formed of spheroidal graphite cast iron such as FCD600 (Japanese Industrial Standard (JIS)), for example, while being formed of gray cast iron. Spheroidal graphite cast iron has a relatively large tensile strength (eg, a greater tensile strength than gray cast iron of the same weight). Therefore, the orbiting scroll made of spheroidal graphite cast iron can ensure sufficient strength even if the wall thickness is reduced. By reducing the wall thickness of such a spheroidal graphite cast iron orbiting scroll, it is possible to reduce the weight while ensuring sufficient strength. Moreover, the orbiting scroll made of spheroidal graphite cast iron can reduce the centrifugal force applied to itself during rotation (turning). Therefore, the conventional scroll compressor described in Patent Document 1 can achieve high-speed rotation (high-speed rotation) of the orbiting scroll by using the orbiting scroll made of spheroidal graphite cast iron. The conventional scroll compressor described in Patent Document 1 can improve the refrigerant circulation amount per unit time by rotating the orbiting scroll at a high speed (high speed orbiting). Yes.

JP 2016-3645 A

However, as described below, the conventional scroll compressor described in Patent Document 1 has a problem that the processing tool is easily worn when the orbiting scroll is manufactured.

The conventional scroll compressor described in Patent Document 1 uses a orbiting scroll made of spheroidal graphite cast iron in order to realize high-speed rotation (high-speed rotation) of the orbiting scroll. However, since spheroidal graphite cast iron is a material having a relatively high tensile strength, it is difficult to process. Therefore, in the conventional scroll compressor described in Patent Document 1, when the orbiting scroll is manufactured by cutting the spheroidal graphite cast iron, the processing tool is easily worn.

The present invention has been made to solve the above-described problem, and achieves high-speed rotation (high-speed rotation) of the orbiting scroll while reducing the amount of wear of the processing tool, and air including the same. The main purpose is to provide a harmony machine.

In order to achieve the above object, the present invention has a fixed scroll having a spiral wrap erected on a base plate and a spiral wrap erected on the base plate, and between the fixed scroll and the fixed scroll. An orbiting scroll forming a compression chamber for compressing the working fluid; and an electric motor for orbiting the orbiting scroll, wherein the orbiting scroll is a CV graphite cast iron product, and the fixed scroll is a gray cast iron product or a CV graphite cast iron. A scroll compressor characterized by being a product, and an air conditioner including the scroll compressor.
Other means will be described later.

According to the present invention, the wear amount of the machining tool can be reduced while realizing high-speed rotation (high-speed rotation) of the orbiting scroll.

It is composition explanatory drawing of the air conditioner which concerns on embodiment. It is a longitudinal cross-sectional view of the scroll compressor which concerns on embodiment. It is a cross-sectional view of the fixed scroll and the turning scroll of the scroll compressor which concerns on embodiment seen from the lower side. It is explanatory drawing of the amount of wear of a processing tool.

Hereinafter, an embodiment of the present invention (hereinafter referred to as “the present embodiment”) will be described in detail with reference to the drawings. Each figure is only schematically shown so that the present invention can be fully understood. Therefore, the present invention is not limited to the illustrated example. Moreover, in each figure, the same code | symbol is attached | subjected about the common component and the same component, and those overlapping description is abbreviate | omitted.

[Embodiment]
The present embodiment provides a scroll compressor S that reduces the amount of wear of a processing tool while realizing high-speed rotation (high-speed rotation) of the orbiting scroll. In particular, the present embodiment provides a scroll compressor S that can use, as a working fluid, a gas containing 70 wt% or more of an R32 refrigerant by rotating the orbiting scroll at a high speed (high-speed orbiting). Intended. Hereinafter, the configuration of the air conditioner 101 using the scroll compressor S will be described first, and then the configuration of the scroll compressor S will be described.

<Configuration of air conditioner>
Hereinafter, with reference to FIG. 1, it demonstrates per structure of the air conditioner 101 which concerns on this embodiment. FIG. 1 is a configuration explanatory diagram of the air conditioner 101.

As shown in FIG. 1, the air conditioner 101 includes a scroll compressor S, a four-way valve 102, a cooling / heating throttle device 103 such as an expander, an indoor heat exchanger 104, and an outdoor heat exchanger 105. These are configured to be annularly connected by a predetermined pipe 106.

The air conditioner 101 can perform a cooling operation and a heating operation by switching the four-way valve 102. The air conditioner 101 uses the indoor heat exchanger 104 as an evaporator and the outdoor heat exchanger 105 as a condenser during cooling operation. On the other hand, the air conditioner 101 uses the indoor heat exchanger 104 as a condenser and the outdoor heat exchanger 105 as an evaporator during heating operation.

1, a solid line arrow X indicates the circulation direction of the gaseous refrigerant (working fluid) during the cooling operation, and a broken line arrow Y indicates the circulation direction of the refrigerant during the heating operation. The air conditioner 101 operates as follows, for example, during cooling operation.

During the cooling operation, the air conditioner 101 first compresses the refrigerant with the scroll compressor S. At this time, the refrigerant is compressed to be in a high temperature and high pressure state. The air conditioner 101 sends the refrigerant in that state to the outdoor heat exchanger 105 via the four-way valve 102.

In the outdoor heat exchanger 105, the refrigerant exchanges heat with the air, dissipates heat by the heat exchange, and condenses. The air conditioner 101 sends the condensed refrigerant into the cooling / heating throttle device 103.

In the cooling / heating throttle device 103, the refrigerant expands in an equal enthalpy state, and enters a gas-liquid two-phase flow state in which a low-temperature and low-pressure gas refrigerant and a liquid refrigerant are mixed. The air conditioner 101 sends the refrigerant in that state to the indoor heat exchanger 104.

In the indoor heat exchanger 104, the liquid refrigerant exchanges heat with air, absorbs heat and vaporizes by the heat exchange, and becomes a gas refrigerant. At this time, the indoor heat exchanger 104 cools the surrounding air by vaporizing the liquid refrigerant. As a result, the air conditioner 101 exhibits a cooling function.

Thereafter, the air conditioner 101 returns the refrigerant from the indoor heat exchanger 104 to the scroll compressor S. The air conditioner 101 again compresses the refrigerant with the scroll compressor S, and then sequentially sends the refrigerant to the four-way valve 102, the outdoor heat exchanger 105, the cooling / heating throttle device 103, and the indoor heat exchanger 104.

Thus, in the air conditioner 101, the scroll compressor S, the four-way valve 102, the outdoor heat exchanger 105, the cooling / heating throttle device 103, and the indoor heat exchanger 104 constitute a refrigerant circulation system, and the refrigerant is between them. The refrigeration cycle is formed by repeating the circulation.

<Configuration of scroll compressor>
Hereinafter, the configuration of the scroll compressor S will be described with reference to FIGS. 2 and 3. FIG. 2 is a longitudinal sectional view of the scroll compressor S. FIG. 3 is a cross-sectional view of the fixed scroll and the orbiting scroll of the scroll compressor according to the embodiment as viewed from below.

The scroll compressor according to the present invention includes both an open scroll compressor and a hermetic scroll compressor. Here, description will be made assuming that the scroll compressor S is a hermetic scroll compressor. The description will be made assuming that the scroll compressor S is a vertical device. The scroll compressor S will be described on the assumption that a gas containing 70 wt% or more of R32 refrigerant is used as a working fluid.

As shown in FIG. 2, the scroll compressor S includes a compression mechanism unit 1, an electric motor 2 that drives the compression mechanism unit 1, and a hermetic container 70 that houses them. In the illustrated example, the compression mechanism unit 1 is disposed above the inside of the sealed container 70, and the electric motor 2 is disposed near the center inside the sealed container 70.

The compression mechanism unit 1 includes a fixed scroll 10 and a turning scroll 20. The fixed scroll 10 is a scroll member fixedly installed. The orbiting scroll 20 is a scroll member that performs an orbiting motion.

A suction port 13 is provided on the outer peripheral side of the fixed scroll 10. A compression chamber 4 is provided inside the fixed scroll 10. The refrigerant is fed into the compression chamber 4 from the suction port 13 and is compressed in the compression chamber 4. Thereby, a refrigerant | coolant will be in a high voltage | pressure state. Thereafter, the refrigerant is discharged from the compression chamber 4 to the discharge chamber 5 provided inside the sealed container 70.

As shown in FIG. 3, the fixed scroll 10 includes a base plate 11 (see FIG. 2) and a spiral wrap 12 erected on the base plate 11. Similarly, the orbiting scroll 20 also has a base plate 21 (see FIG. 2) and a spiral wrap 22 erected on the base plate 21.

The orbiting scroll 20 is disposed to be opposed to the fixed scroll 10 so as to be orbitable. That is, the orbiting scroll 20 is arranged so that the base plate 21 faces the base plate 11 and the wrap 22 meshes with the wrap 11 with respect to the fixed scroll 10.

Near the outer periphery of the fixed scroll 10, a suction chamber 14 communicating with the suction port 13 (see FIG. 2) is provided. In addition, a discharge port 15 communicating with the discharge chamber 5 (see FIG. 2) is provided at the center of the fixed scroll 10. The suction chamber 14 is a space before the compression chamber 4 is formed, and is divided into a space on the compression chamber 4 side and a space on the suction chamber 14 side when the compression chamber 4 is formed.

The scroll compressor S forms the compression chamber 4 for compressing the refrigerant between the wrap 12 of the fixed scroll 10 and the wrap 22 of the orbiting scroll 20 by turning the orbiting scroll 20.

Two compression chambers 4 are formed on the outer line side and the inner line side of the wrap 22 of the orbiting scroll 20. Hereinafter, the compression chamber 4a formed on the outer line side of the wrap 22 of the orbiting scroll 20 is referred to as “outer line side compression chamber 4a”, and the compression chamber 4b formed on the inner line side of the wrap 22 of the orbiting scroll 20 is referred to as “inner side compression”. Room 4b ".

Returning to FIG. 2, the compression mechanism unit 1 and the electric motor 2 are connected via a rotating shaft 30. The electric motor 2 compresses the refrigerant by driving the orbiting scroll 20 of the compression mechanism unit 1 through the rotating shaft 30.

The rotary shaft 30 is supported by a main bearing 46 provided above the electric motor 2 and a sub-bearing 56 provided below the electric motor 2. The main bearing 46 is fixed to the frame 40. The frame 40 is a member fixed to the inner wall surface of the sealed container 70. The auxiliary bearing 56 is fixed inside the sealed container 70.

A crank pin 31 is provided at the tip (upper end) of the rotating shaft 30. The crankpin 31 is inserted into the orbiting bearing 26 of the shaft support portion 23 that protrudes from the back surface (on the side opposite to the lap) of the base plate 21 of the orbiting scroll 20. The slewing bearing 26 is a bearing formed inside the shaft support portion 23.

The shaft support 23 and the slewing bearing 26 are provided at a position deviated from the center of the base plate 21. The crank pin 31 has a shape that swells in one direction so as to be fitted to the swivel bearing 26.

A rotation prevention joint 51 is provided on the back surface of the base plate 21 of the orbiting scroll 20. The rotation prevention joint 51 is a joint that restricts the rotation of the orbiting scroll 20 with respect to the fixed scroll 10. The anti-rotation joint 51 is disposed between the orbiting scroll 20 and the frame 40.

In the scroll compressor S, when the electric motor 2 rotates the rotary shaft 30, the crankpin 31 rotates eccentrically. In accordance with this, the orbiting bearing 26 orbits and the orbiting scroll 20 orbits at the same time. At this time, the rotation prevention joint 51 restricts the rotation of the orbiting scroll 20 with respect to the fixed scroll 10. Therefore, the turning scroll 20 turns without rotating with respect to the fixed scroll 10.

At this time, the refrigerant is introduced into the suction chamber 14 from the suction port 13. In the suction chamber 14, the compression chamber 4 is formed by the wrap 12 of the fixed scroll 10 and the wrap 22 of the orbiting scroll 20 in accordance with the orbiting motion of the orbiting scroll 20.

The compression chamber 4 moves to the center side with the orbiting motion of the orbiting scroll 20. At that time, the volume of the compression chamber 4 decreases. Thereby, the scroll compressor S compresses the refrigerant sucked into the compression chamber 4. The compressed refrigerant is discharged from the discharge port 15 to the discharge chamber 5.

<Material of scroll member>
In the present embodiment, the fixed scroll 10 is made of gray iron castings, and the orbiting scroll 20 is made of CV graphite cast irons. Therefore, the fixed scroll 10 is a gray cast iron product, and the orbiting scroll 20 is a CV graphite cast iron product.

Gray cast iron is cast iron having massive graphite in the structure of the material. On the other hand, CV graphite cast iron is cast iron having worm-like graphite in the material structure. Below, the kind of each cast iron, tensile strength, and Brinell hardness (HB) are demonstrated. In addition, here, the spheroidal graphite cast iron (Spheroidal graphite iron スクロール castings) used for the material of the orbiting scroll described in Patent Document 1 (Japanese Patent Laid-Open No. 2016-3645) described above will also be described. Spheroidal graphite cast iron has spherical graphite in the structure of the material.

(1) Examples of gray iron castings include FC100, FC150, FC200, FC250, FC300, and FC350 defined in JIS G5501-1995. However, the present invention is not limited to only these examples.
Table 1 shows the type, tensile strength, and Brinell hardness (HB) of gray cast iron. The unit of tensile strength is “N / mm ² ”. Brinell hardness (HB) is unitless.

(2) Spheroidal graphite iron castings include, for example, FCD350-22, FCD350-22L, FCD400-18, FCD400-18L, FCD400-15, FCD450-10, FCD500 defined in JIS G5502-2001. -7, FCD600-3, FCD700-2, FCD800-2 and the like.
Table 2 shows the types of spheroidal graphite cast iron, tensile strength, and Brinell hardness (HB).

(3) Examples of CV graphite cast irons include FCV300, FCV350, FCV400, FCV450, FCV500 and the like defined in JIS G5505-2013. However, the present invention is not limited to only these examples.
Table 3 shows the type, tensile strength, and Brinell hardness (HB) of CV graphite cast iron.

As described above, in this embodiment, the fixed scroll 10 is formed of gray cast iron, and the orbiting scroll 20 is formed of CV graphite cast iron. The reason will be described below. Here, an example (see Table 4 and Table 5) is illustrated as an example of the scroll compressor S according to the present embodiment, and Comparative Examples 1 and 2 (see Table 4 and Table 5) are compared with the Example. Explain why.

Comparative Example 1 corresponds to a configuration example of a scroll compressor according to a technique prior to the conventional scroll compressor described in Patent Document 1 (Japanese Patent Laid-Open No. 2016-3645). On the other hand, Comparative Example 2 corresponds to a configuration example of a conventional scroll compressor described in Patent Document 1 described above.

Here, the scroll compressor S1 (not shown) of the comparative example 1, the scroll compressor S2 (not shown) of the comparative example 2, and the scroll compressor S of the example have the same configuration, the same shape, and the same size. It is assumed that only the material forming the orbiting scroll 20 is different.

As shown in Table 4, in Comparative Example 1, Comparative Example 2, and Example, the material of the fixed scroll 10 is FC250 made of gray cast iron. On the other hand, as shown in Table 5, the material of the orbiting scroll 20 of Comparative Example 1 is gray cast iron FC250. The material of the orbiting scroll 20 of Comparative Example 2 is spheroidal graphite cast iron FCD600. The material of the orbiting scroll 20 of the embodiment is FCV450 of CV graphite cast iron.

(Comparative Example 1)
Here, for the scroll compressor S1 (not shown) of Comparative Example 1, the rotational speed (orbiting speed) of the orbiting scroll 20 is changed in order to reduce the amount of material used and reduce the environmental load. It is assumed that the miniaturization has been achieved. Then, as the scroll compressor S1 (not shown) is downsized, the refrigerant circulation rate (kg / s) per unit time decreases, so the compression efficiency of the scroll compressor S1 (not shown) decreases. Thereby, the cooling capacity of the air conditioner 101 using the scroll compressor S1 (not shown) is lowered. Therefore, downsizing of the scroll compressor S1 (not shown) that does not change the rotation speed (turning speed) of the orbiting scroll 20 is not preferable. Therefore, when the scroll compressor S1 (not shown) is downsized, it is necessary to secure a refrigerant circulation amount per unit time equivalent to that before downsizing in order to ensure the same compression efficiency as before downsizing. There is. In order to satisfy such a demand, the scroll compressor S1 (not shown) preferably rotates the orbiting scroll 20 at a high speed (high speed orbit).

However, when the orbiting scroll 20 is rotated at high speed (high-speed orbiting), the centrifugal force of the orbiting scroll 20 increases. As a result, the load applied to peripheral components of the orbiting scroll 20 (for example, bearings such as the orbiting bearing 26, the main bearing 46, and the auxiliary bearing 56, and the members such as the rotating shaft 30 and the frame 40 that supports the rotating shaft 30) increases. . As a result, the reliability of the peripheral parts of the orbiting scroll 20 is reduced, vibration and noise are increased, and the compression efficiency is reduced. In order to ensure the reliability of the peripheral parts of the orbiting scroll 20, it is desired to increase the size of the peripheral parts of the orbiting scroll 20 and the area of a portion to which a high load is applied. However, increasing the size of the peripheral parts of the orbiting scroll 20 and the area of a portion to which a high load is applied hinders the downsizing of the scroll compressor S1 (not shown). Therefore, in the scroll compressor S1 (not shown), the centrifugal force of the orbiting scroll 20 is reduced in order to ensure the refrigerant circulation amount per unit time equivalent to that before the downsizing without inhibiting the downsizing. It is desirable.

In order to reduce the centrifugal force of the orbiting scroll 20, it is necessary to reduce the weight of the orbiting scroll 20. In order to reduce the weight of the orbiting scroll 20, downsizing of the orbiting scroll 20 is effective. However, when the orbiting scroll 20 is downsized, the thickness of the orbiting scroll 20 (for example, the thickness of the base plate 21, the thickness of the wrap 22, the thickness of the shaft support portion 23, etc.) is reduced. The strength of the will decrease. Therefore, in this case, it is desirable to form the orbiting scroll 20 with a special material having a high tensile strength (for example, high-strength gray cast iron). However, such materials are difficult to obtain due to low flowability. Also, such materials are difficult to process due to their high tensile strength. And when such a material cuts and manufactures the turning scroll 20, it is easy to wear a processing tool. For this reason, when the orbiting scroll 20 is formed of such a material, the service tool life is shortened, so that the frequency of replacement of the work tool increases, and as a result, the work replacement time of the work tool increases. Therefore, it is not preferable to form the orbiting scroll 20 with such a material because the productivity of the orbiting scroll 20 is lowered and the manufacturing cost is increased. For the reasons described above, it is difficult to achieve downsizing of the scroll compressor S1 (not shown) of Comparative Example 1 while realizing the high-speed rotation (high-speed rotation) of the orbiting scroll 20.

(Comparative Example 2)
The scroll compressor S2 (not shown) of the comparative example 2 is different from the scroll compressor S1 (not shown) of the comparative example 1 described above in that the orbiting scroll 20 is formed of spheroidal graphite cast iron (FCD600). It is different. Spheroidal graphite cast iron (FCD600) has a greater tensile strength than gray cast iron (FC250) used in Comparative Example 1. Here, description will be made assuming that the tensile strength of spheroidal graphite cast iron (FCD600) is 600 N / mm ² or more and less than 700 N / mm ² .

Scroll compressor S2 of Comparative Example 2 (not shown), as the material of the orbiting scroll 20, for example, tensile strength was the "700 N / mm ^2" very close 699N / mm ² of CV graphite cast iron to the upper limit value of the , The tensile strength of the material can be “2.8” times the lower limit (250 N / mm ² ) of gray cast iron (FC250) used in Comparative Example 1. Therefore, in this case, when the scroll compressor S2 (not shown) of the comparative example 2 is compared with the scroll compressor S1 (not shown) of the comparative example 1 described above, the thickness (for example, Even if the thickness of the base plate 21, the thickness of the wrap 22, the thickness of the shaft support portion 23, etc. is reduced by a factor of “0.36”, sufficient strength can be secured. Note that the value of “2.8” times as described above is calculated by “699/250”. Further, the above-mentioned value of “0.36” is calculated by “1 / 2.2.8”.

Such a scroll compressor S2 (not shown) of Comparative Example 2 can be reduced in weight while ensuring sufficient strength by reducing the thickness of the orbiting scroll 20. Moreover, the scroll compressor S2 (not shown) of Comparative Example 2 can reduce the centrifugal force applied to the orbiting scroll 20 when the orbiting scroll 20 rotates (turns). Therefore, the scroll compressor S2 (not shown) of Comparative Example 2 can realize the high-speed rotation (high-speed rotation) of the orbiting scroll 20. The scroll compressor S2 (not shown) of Comparative Example 2 can improve the refrigerant circulation rate per unit time by rotating the orbiting scroll 20 at a high speed (high speed orbit), and thus can be reduced in size. I have to.

However, the spheroidal graphite cast iron (FCD600) used in Comparative Example 2 has a higher tensile strength than the gray cast iron (FC250) used in Comparative Example 1, and is difficult to process. And spheroidal graphite cast iron tends to wear a processing tool, when manufacturing the turning scroll 20 by cutting. For this reason, when the orbiting scroll 20 is formed of spheroidal graphite cast iron, the useful life of the processing tool is shortened, so that the frequency of replacement of the processing tool increases, and as a result, the time for exchanging the processing tool increases. Therefore, it is not preferable to form the orbiting scroll 20 with spheroidal graphite cast iron because the productivity of the orbiting scroll 20 is lowered and the manufacturing cost is increased. For the above reason, the scroll compressor S2 (not shown) of Comparative Example 2 is desired to reduce the wear amount of the processing tool.

(Example)
In contrast to the scroll compressor S1 (not shown) of the comparative example 1 and the scroll compressor S2 (not shown) of the comparative example 2, the scroll compressor S of the embodiment is a scroll scroll made of CV graphite cast iron (FCV450). 20 is different.

Similar to the spheroidal graphite cast iron (FCD600) used in Comparative Example 2, the CV graphite cast iron (FCV450) has a larger tensile strength than the gray cast iron (FC250) used in Comparative Example 1. . In consideration of the strength and weight of the orbiting scroll 20 to be manufactured and the ease of processing the material, the tensile strength of the CV graphite cast iron used in the examples is preferably 450 N / mm ² or more. Further, the tensile strength of the CV graphite cast iron used in the examples is sufficiently smaller than the upper limit of the tensile strength of the spheroidal graphite cast iron (FCD600) used in Comparative Example 2 (for example, less than 550 N / mm ^2). ) Is preferable.

Scroll compressor S of such an embodiment, the material of the orbiting scroll 20, for example, a very close 549N / mm ² of CV graphite cast iron to the upper limit of the tensile strength was the "less than 550 N / mm ^2" In this case, the tensile strength of the material can be set to “2.2” times the lower limit (250 N / mm ² ) of gray cast iron (FC250) used in Comparative Example 1. Therefore, in this case, when the scroll compressor S of the embodiment is compared with the scroll compressor S1 (not shown) of the comparative example 1 described above, the thickness of the orbiting scroll 20 (for example, the thickness of the base plate 21). Even if the thickness of the sheath 22 (the thickness of the wrap 22 and the thickness of the shaft support portion 23) is reduced by "0.46" times, sufficient strength can be ensured. Note that the value of “2.2” times as described above is calculated by “549/250”. Further, the above-mentioned value of “0.46” is calculated by “1 / 2.2”.

Moreover, when the scroll compressor S of an Example uses the CV graphite cast iron of 450 N / mm < ² > whose tensile strength is a lower limit as a material of the turning scroll 20, for example, the tensile strength of the material is compared with Comparative Example 1. Can be set to “1.8” times the lower limit (250 N / mm ² ) of gray cast iron (FC250) used in the above. In other words, the scroll compressor S of the embodiment has a strength that is at least “1.8” times that of the orbiting scroll 20 when compared with the scroll compressor S1 (not shown) of the first comparative example. can do. In other words, when compared with the scroll compressor S1 (not shown) of Comparative Example 1 described above, the scroll compressor S of the embodiment has a minimum allowable tensile strength against a load applied to the orbiting scroll 20 of “1. 8 ”times. Therefore, in this case, when the scroll compressor S of the embodiment is compared with the scroll compressor S1 (not shown) of the comparative example 1 described above, the thickness of the orbiting scroll 20 (for example, the thickness of the base plate 21). Even if the thickness of the sheath 22 (the thickness of the wrap 22 and the thickness of the shaft support portion 23, etc.) is reduced by a factor of “0.56”, sufficient strength without damage can be ensured. Note that the value of “1.8” times described above is calculated by “450/250”. Further, the above-mentioned value of “0.56” is calculated by “1 / 1.8”.

As with the scroll compressor S2 (not shown) of the comparative example 2, the scroll compressor S of such an embodiment is turned by reducing the thickness of the orbiting scroll 20 and reducing the thickness. It is possible to reduce the weight of the orbiting scroll 20 by reducing the thickness of the orbiting scroll 20 while ensuring sufficient strength of the scroll 20. And the scroll compressor S of an Example can reduce the centrifugal force added to the turning scroll 20 at the time of rotation (turning) of the turning scroll 20 by reducing the weight of the turning scroll 20. Therefore, the scroll compressor S of the embodiment can realize high-speed rotation (high-speed rotation) of the orbiting scroll 20. And the scroll compressor S of an Example can improve the refrigerant | coolant circulation amount (kg / s) per unit time by rotating the turning scroll 20 at high speed (high-speed turning). Therefore, the scroll compressor S of the embodiment can be downsized while ensuring the same compression efficiency as the scroll compressor S1 (not shown) of the comparative example 1 described above. In addition, the refrigerant | coolant circulation amount per unit time means the refrigerant | coolant circulation amount in the compression process of 1 rotation of the turning scroll 20, for example.

Moreover, the scroll compressor S of an Example has the tensile strength of a value sufficiently smaller than the upper limit of the tensile strength of the spheroidal graphite cast iron (FCD600) used in Comparative Example 2 as the material of the orbiting scroll 20. CV graphite cast iron (FCV450) is used. As a result, the scroll compressor S of the embodiment can improve the workability of the material as compared with the scroll compressor S2 (not shown) of the comparative example 2 when the orbiting scroll 20 is manufactured, and wear of the processing tool. The amount can be reduced. Since the scroll compressor S of such an example can prolong the useful life of the processing tool as compared with the scroll compressor S2 (not shown) of the comparative example 2, it reduces the replacement frequency of the processing tool, As a result, the working time for exchanging the processing tool can be reduced.

FIG. 4 shows the amount of wear of the processing tool when the orbiting scroll 20 is manufactured in the comparative example 1, the comparative example 2, and the example. FIG. 4 is an explanatory diagram of the wear amount of the processing tool. In FIG. 4, the horizontal axis indicates the number of orbiting scrolls processed, and the vertical axis indicates the wear amount of the processing tool. Further, the symbol “Th” indicates a replacement reference value of the machining tool. The line graph shown in FIG. 4 shows the number of processed orbiting scrolls 20 calculated from the result of processing a part of the orbiting scroll 20.

As shown in FIG. 4, in Comparative Example 1, even when 100 or more orbiting scrolls 20 were machined, the amount of wear of the machining tool did not reach the machining tool replacement reference value Th at all. Therefore, the comparative example 1 can be used over a relatively long period of time without exchanging the processing tool. This is because gray cast iron (FC250) used in Comparative Example 1 is a material with relatively high workability.

On the other hand, there is a great difference in workability between the spheroidal graphite cast iron (FCD600) used in Comparative Example 2 and the gray cast iron (FC250) used in Comparative Example 1. Therefore, in Comparative Example 2, the amount of wear of the machining tool reaches the machining tool replacement reference value Th simply by machining the number of orbiting scrolls 20 that do not reach 50 units. Therefore, the comparative example 2 can use a processing tool only for a comparatively short period. In such a comparative example 2, since the replacement frequency of the machining tool is increased as compared with the comparative example 1, the time for exchanging the machining tool is increased. As a result, the comparative example 2 decreases the productivity of the orbiting scroll 20 and increases the manufacturing cost.

On the other hand, there is no significant difference in workability between CV graphite cast iron (FCV450) used in Examples and gray cast iron (FC250) used in Comparative Example 1. For this reason, in the embodiment, as in Comparative Example 1, even when 100 or more orbiting scrolls 20 are machined, the wear amount of the machining tool does not reach the machining tool replacement reference value Th at all. For this reason, the embodiment can be used for a relatively long period of time without exchanging the processing tool. Compared with Comparative Example 2, such an example can reduce the replacement frequency of the processing tool to the same level as that of Comparative Example 1, and therefore can reduce the replacement work time of the processing tool. As a result, the embodiment can improve the productivity of the orbiting scroll 20 and reduce the manufacturing cost as compared with the comparative example 2.

In the scroll compressor S of the embodiment, the tensile strength of the CV graphite cast iron forming the orbiting scroll 20 is preferably 450 N / mm ² or more. Moreover, it is preferable that the tensile strength of the CV graphite cast iron which forms the turning scroll 20 is less than 550 N / mm < ² >.

Further, in the scroll compressor S of the example, the Brinell hardness of the CV graphite cast iron forming the orbiting scroll 20 is 170 or more and less than 250, and the tensile strength of the gray cast iron forming the fixed scroll 10 is 250 N / mm ^2. It is preferably less than 300 N / mm ² and the Brinell hardness of the gray cast iron is 241 or less. In the scroll compressor S, the Brinell hardness of CV graphite cast iron and the tensile strength and Brinell hardness of gray cast iron are within such ranges, so that the wear resistance accompanying the contact between the orbiting scroll 20 and the fixed scroll 10 is reduced. Can be improved. As a result, the scroll compressor S can suppress a decrease in compression performance due to wear. This is because the Brinell hardness of the CV graphite cast iron which is the material of the orbiting scroll 20 and the Brinell hardness of the gray cast iron which is the material of the fixed scroll 10 are set to the same value, so that the orbiting scroll 20 and the fixed scroll 10 are in contact with each other. This is because it becomes difficult to wear out.

In the embodiment, the tensile strength of CV graphite cast iron has become less than 450 N / mm ² or more 550 N / mm ^2, and illustrates FCV450 One example of such a CV graphite cast iron. However, the present invention is not limited only to this illustration.

<Main features of the scroll compressor according to the embodiment>
(1) Since the scroll compressor S according to the present embodiment uses CV graphite cast iron (for example, FCV450) that is easier to process than the spheroidal graphite cast iron (for example, FCD600) as the material of the orbiting scroll 20, wear of the processing tool The amount can be reduced. Therefore, the scroll compressor S can be used over a relatively long period of time without exchanging the processing tool. Since such a scroll compressor S can reduce the replacement frequency of a processing tool, it can reduce the replacement work time of a processing tool. As a result, the productivity of the orbiting scroll 20 can be improved and the manufacturing cost can be reduced.

(2) Since the scroll compressor S according to the present embodiment uses CV graphite cast iron (for example, FCV450) that is easy to obtain as a material of the orbiting scroll 20, the productivity of the orbiting scroll 20 is also increased. And the manufacturing cost can be reduced.

(3) As described above, in the present embodiment, the scroll compressor S that can use, as the working fluid, the gas containing 70 wt% or more of the R32 refrigerant by rotating the orbiting scroll at a high speed (high speed revolution). Is intended to provide. This is due to the following reason.

The R32 refrigerant is a working fluid having a lower density than the conventionally used R410A refrigerant. Such R32 refrigerant leaks between the outer side compression chamber 4a (see FIG. 3) and the inner side compression chamber 4b (see FIG. 3) through the tip of the wrap 22 of the orbiting scroll 20 during the operation of the scroll compressor. It tends to be easy. In particular, at the time of low speed operation of the scroll compressor, since the time from the start of compression to the completion of compression is longer than at the time of high speed operation, the leakage amount of R32 refrigerant increases.

Further, when the thickness of the wrap 22 of the orbiting scroll 20 is reduced in order to reduce the weight of the orbiting scroll 20, the area of the tip of the wrap 22 is reduced. As a result, during the operation of the scroll compressor, the time required for communication between the outer line side compression chamber 4a (see FIG. 3) and the inner line side compression chamber 4b (see FIG. 3) is prolonged. The amount increases.

In order to reduce the leakage amount of the R32 refrigerant, it is effective to rotate the orbiting scroll 20 at a high speed (high speed rotation). However, when the orbiting scroll 20 is rotated at a high speed (high-speed orbiting), the centrifugal force of the orbiting scroll 20 increases. Therefore, if the scroll compressor does not reduce the weight of the orbiting scroll 20, peripheral components of the orbiting scroll 20 (for example, bearings such as the orbiting bearing 26, the main bearing 46, and the auxiliary bearing 56, the rotating shaft 30, and the rotating shaft 30). The load applied to the member (such as the frame 40 supporting the frame) increases. As a result, the reliability of the peripheral parts of the orbiting scroll 20 is reduced, vibration and noise are increased, and the compression efficiency is reduced.

However, the scroll compressor S according to the present embodiment can reduce the weight of the orbiting scroll 20 while ensuring the strength of the orbiting scroll 20. Therefore, the scroll compressor S according to the present embodiment can rotate the orbiting scroll 20 at a high speed (high speed revolution), and can efficiently reduce the leakage amount of the R32 refrigerant. Such a scroll compressor S according to the present embodiment can use, for example, a gas containing 70 wt% or more of R32 refrigerant as the working fluid. Further, the scroll compressor S according to the present embodiment can improve the reliability of peripheral components of the orbiting scroll 20, reduce vibration and noise, and improve the compression efficiency. Further, the scroll compressor S according to this embodiment can reduce the environmental load because the global warming potential of the R32 refrigerant is lower than the global warming potential of the R410A refrigerant that has been conventionally used.

As described above, according to the scroll compressor S according to the present embodiment, it is possible to reduce the amount of wear of the processing tool while realizing high-speed rotation (high-speed rotation) of the orbiting scroll 20.

The present invention is not limited to the above-described embodiment, and includes various modifications. For example, the above-described embodiment has been described in detail for easy understanding of the present invention, and is not necessarily limited to one having all the configurations described. In addition, a part of the configuration of the embodiment can be replaced with another configuration, and another configuration can be added to the configuration of the embodiment. Moreover, it is possible to add / delete / replace other configurations for a part of each configuration.

For example, in the above-described embodiment, the material of the fixed scroll 10 has been described as being gray cast iron (FC250). However, the material of the fixed scroll 10 can also be CV graphite cast iron. For example, the material of the fixed scroll 10 can be the same FCV 450 as the orbiting scroll 20. In addition, when the fixed scroll 10 is formed with FCV450, the tensile strength of the fixed scroll 10 is 450 N / mm ² or more, and the Brinell hardness of the fixed scroll 10 is 170 or more and less than 250.

DESCRIPTION OF SYMBOLS 1 Compression mechanism part 2 Electric motor 4 Compression chamber 4a Outer line side compression chamber 4b Inner line side compression chamber 5 Discharge chamber 10 Fixed scroll 11,21

Base plate

12,22 Lap 13 Suction port 14 Suction port 15 Discharge port 20 Orbiting scroll 23 Shaft support part 26 Rotating bearing 30 Rotating shaft 31 Crank pin 40 Frame 46 Main bearing 51 Anti-rotation joint 56 Sub bearing 70 Sealed container 101 Air conditioner 102 Four-way valve 103 Air conditioning / heating throttle device 104 Indoor heat exchanger 105 Outdoor heat exchanger 106 Piping S Scroll compression Machine

Claims

A fixed scroll having a spiral wrap erected on the base plate;
A orbiting scroll having a spiral wrap standing on a base plate and forming a compression chamber for compressing a working fluid with the fixed scroll;
An electric motor for turning the orbiting scroll,
The orbiting scroll is a CV graphite cast iron product,
The scroll compressor, wherein the fixed scroll is a gray cast iron product or a CV graphite cast iron product.
The scroll compressor according to claim 1, wherein
A scroll compressor characterized in that the tensile strength of the CV graphite cast iron product is 450 N / mm 2 or more.
The scroll compressor according to claim 1, wherein
A scroll compressor, wherein the CV graphite cast iron product has a Brinell hardness of 170 or more and less than 250.
The scroll compressor according to claim 1, wherein
The scroll compressor characterized in that the tensile strength of the gray cast iron product is 250 N / mm 2 or more and less than 300 N / mm 2 , and the Brinell hardness is 241 or less.
The scroll compressor according to claim 1, wherein
A scroll compressor using a gas containing 70% by weight or more of R32 refrigerant as the working fluid.
A scroll compressor;
A heat exchanger,
The scroll compressor is
A fixed scroll having a spiral wrap erected on the base plate;
A orbiting scroll having a spiral wrap standing on a base plate and forming a compression chamber for compressing a working fluid with the fixed scroll;
An electric motor for turning the orbiting scroll,
The orbiting scroll is a CV graphite cast iron product,
The air conditioner characterized in that the fixed scroll is a gray cast iron product or a CV graphite cast iron product.