JPH04321786A - Scroll compressor - Google Patents

Abstract

PURPOSE:To increase the increase rate of the compressor efficiency in a scroll compressor which is constituted so as to increase its refrigerating and heating capacity by means of gas injection. CONSTITUTION:The first compression chamber 5a, which is formed in the outermost peripheral section out of a plurality of the compression chambers 5 formed between fixed scroll 3 and a revolving scroll 4, when shifted in the center direction, is not communicated to the second compression chamber 5b, which is formed inside the first compression chamber 5a, and injection ports 21 and 22 are provided on a position separated from a wall face in the lap 3b of the fixed scroll 3 shifted toward the internal peripheral side at 360 deg. or more from the turn end section of the lap 3b of the fixed scroll 3 and on a position separated from a wall face outside the lap 3b of the fixed scroll 3 shifted toward the internal peripheral side at 180 deg. further than the former position respectively.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll compressor used in an air conditioner or the like and configured to increase heating and cooling capacity through gas injection.

0002

2. Description of the Related Art FIG. 6 is a cross-sectional view showing the structure of a conventional scroll compressor of this kind disclosed in, for example, Japanese Unexamined Patent Publication No. 60-29554, and FIG. 7 shows the main parts of the scroll compressor in FIG. FIG. 3 is a cross-sectional view showing the configuration. In the figure, 1 is an airtight container, 2 is a frame formed inside this airtight container 1, and 3 is a fixed structure consisting of an end plate 3a fixed on this frame 2 and a wrap 3b standing upright on this end plate 3a. The scroll 4 is composed of an end plate 4a and a wrap 4b standing upright on the end plate 4a, and the wrap 4b is attached to the fixed scroll 3.
This is a revolving scroll that is combined with the wrap 3b.

5 is each wrap 3a of both scrolls 3 and 4;
A plurality of compression chambers 6 formed between 4a are supported by the frame 2, and one end is a drive shaft connected to an electric motor 7 and the other end is connected to the revolving scroll 4, which is driven by the electric motor 7 and cooperates with the Oldham ring 8. The revolving scroll 4 is caused to revolve. 9 is a discharge pipe formed on the wall of the closed container 1; 10 is a suction pipe formed on the wall of the closed container 1 at a position facing the gas suction portion of the compression chamber 5; and 11 is formed on the end plate 3a of the fixed scroll 3. This is a discharge port for discharging compressed high-pressure gas from the innermost compression chamber 5 into the closed container 1.

Reference numerals 12 and 13 denote first and second injection ports, which are in contact with the wall surface of the wrap 3b of the fixed scroll 3, as shown in FIGS. The second injection port 13 is formed at a position inside the wrap 3b that has advanced 360 degrees inward from the position of the first injection port 12, and at a position outside the wrap 3b that has advanced 180 degrees inward from the position of the first injection port 12. has been done. 1
4 is the first and second injection port 12, 1
injection piping that communicates 3 with the outside of the closed container 1;
20 is a condenser 15, a primary expansion valve 16, a gas-liquid separator 17,
A refrigeration cycle in which a secondary expansion valve 18 and an evaporator 19 are connected in this order, the condenser 15 side is connected to the discharge pipe 9, the evaporator 19 side is connected to the suction pipe 10, and the gas-liquid separator 1
The gas phase section 7 is connected to the injection pipe 14 .

Next, the operation of the conventional scroll compressor configured as described above will be explained. The rotational force of the electric motor 7 is transmitted to the revolving scroll 4 via the drive shaft 6, and the revolving scroll 4 has an Oldham ring 8 which is a rotation prevention mechanism.
It performs an orbital motion that moves in a circular orbit. On the other hand, the refrigerant is drawn into the closed container 1 from the suction pipe 10 by this movement, and introduced into the compression chamber 5 formed by the fixed scroll 3 and the revolving scroll 4. The compression chamber 5 gradually moves toward the center and its volume decreases, and the refrigerant inside is compressed and once discharged from the discharge port 11 into the closed container 1, and then sent from the discharge pipe 9 to the refrigeration cycle 20. The air is then circulated through the condenser 15, the primary expansion valve 16, the gas-liquid separator 17, the secondary expansion valve 18, and the evaporator 19 in this order, and returns to the suction pipe 10 again.

On the other hand, in the injection operation, the refrigerant whose pressure has been reduced through the primary expansion valve 16 and has been partially vaporized is taken out from the gas phase section of the gas-liquid separator 17 and introduced into the closed container 1 through the injection pipe 14. The fuel is injected into the compression chamber 5 from the first and second injection ports 12 and 13. At this time, since the pressure inside the gas-liquid separator 17 is higher than the pressure on the suction side of the compression chamber 5, the gas refrigerant is injected immediately after the compression chamber 5 is sealed, increasing the heating and cooling capacity. Furthermore, it is already known that energy efficiency is improved because the rate of increase in input is smaller than the rate of increase in heating and cooling capacity.

[0007]

[Problems to be Solved by the Invention] The conventional scroll compressor is constructed as described above, and the first and second injection ports 12 and 13 are opened immediately after the compression chamber 5 is sealed by the fixed scroll 3 and the revolving scroll 4. Since the gas refrigerant is injected into the compression chamber 5, the increase in input for compressing the injected gas refrigerant at low pressure to high pressure again becomes relatively large, and the input for increasing the heating and cooling capacity increases. There was a problem in that the rate of increase in compressor efficiency, which is indicated by the rate of increase, was low.

[0008] This invention was made to solve the above-mentioned problems, and by injecting the air after the pressure in the compression chamber has increased to a certain extent, compression can be achieved while suppressing the ratio of increase in input to the increase in cooling and heating capacity. It is an object of the present invention to provide a scroll compressor with an excellent rate of increase in mechanical efficiency.

[0009]

[Means for Solving the Problems] A scroll compressor according to the present invention has a first compression chamber formed at the outermost periphery of a plurality of compression chambers formed between a fixed scroll and a revolving scroll. When moving toward the center, the fixed scroll does not communicate with the second compression chamber formed inside the first compression chamber, and one of the fixed scrolls extends more than 360 degrees inward from the end of the wrap of the fixed scroll. Equipped with two injection ports, one located inside the wrap of the scroll and away from the wall surface, and the other located further away from the wall surface outside the wrap of the fixed scroll, which is further 180 degrees inward than the other. It is something.

0010

[Operation] The injection port of the scroll compressor according to the present invention suppresses an increase in input for recompressing the injection gas refrigerant by injecting the refrigerant after the pressure within the compression chamber has increased to a certain extent.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing the configuration of a scroll compressor according to an embodiment of the present invention, FIG. 2 is a sectional view showing the relationship between the injection port and the wrap of the scroll compressor in FIG. 1, and FIG. 3 is a sectional view showing the positional relationship of the injection port. FIG. In the figure, the airtight container 1, frame 2, fixed scroll 3, end plate 3a, wrap 3b, revolving scroll 4, end plate 4a, wrap 4b, compression chamber 5, drive shaft 6, electric motor 7, Oldham ring 8, discharge pipe 9, suction The pipe 10, the discharge port 11 and the injection pipe 14 are the same as the conventional one shown in FIG. 21 and 22 are the first
As shown in FIGS. 2 and 3, the first injection port 21 is injected from the winding end of the wrap 3b of the fixed scroll 3 (360
+α)° At the inside position of the wrap 3b that has advanced to the inner circumference side,
The second injection port 22 is located at a position outside the wrap 3b that is further 180 degrees inward from the position of the first injection port 21, and has a dimension l within the range of the thickness t of the wrap 3b from the wall surface of the wrap 3b. They are formed with a certain distance between them.

Next, the operation of the scroll compressor in one embodiment of the present invention constructed as described above will be explained. First, as in the past, the rotational force of the electric motor 7 is applied to the drive shaft 6.
The refrigerant is transmitted to the revolving scroll 4 via the Oldham ring 8, and the revolving scroll 4 performs a revolving motion moving in a circular orbit by the Oldham ring 8. is inhaled. The two pairs of compression chambers 5 gradually move toward the center and their volumes decrease.
The internal refrigerant is compressed and once discharged into the closed container 1 through the discharge port 11.

Here, the compression chamber formed at the outermost periphery is referred to as a first compression chamber 5a, and the compression chamber formed next is referred to as a second compression chamber 5b. The refrigerant once discharged into the sealed container 1 is sent out from the discharge pipe 9 into a refrigeration cycle (not shown), and after circulating in the refrigeration cycle, it is returned to the suction pipe 10.
more inhaled. On the other hand, in the injection operation, the gas refrigerant separated into gas and liquid by the gas-liquid separator in the refrigeration cycle is introduced from the first and second injection ports 21 and 22 via the injection pipe 14. 21 and 22 are provided in the above positions, immediately after the first compression chamber 5a is formed, it is closed by the wrap 4b of the revolving scroll 4 and does not communicate with both first compression chambers 5a. Injection into the first compression chamber 5a is not performed. However, after the revolving scroll 4 further revolves from the time when both the first compression chambers 5a are formed and the pressure in both the first compression chambers 5a increases to a certain extent, both injection ports 21
, 22 open for the first time, and gas refrigerant is injected into both first compression chambers 5a while the revolving scroll 4 makes one revolution.

FIG. 4 is a characteristic diagram showing the pressure in the compression chamber 5 and the opening degree of the first and second injection ports 21 and 22 with respect to the revolution angle of the revolving scroll 4. In the figure, the curve shown by the solid line indicates the opening degree in one embodiment, and the broken line curve indicates the opening degree in the conventional one. As is clear from the figure, the positions of both injection ports 21 and 22 in the embodiment shown in FIG.
Both injection ports 12 and 1 in the conventional art shown in
Since it has moved toward the center by an angle α compared to position 3, the injection gas refrigerant is injected when the pressure in both first compression chambers 5a increases to a certain extent, and the injection gas refrigerant is used to increase the cooling and heating capacity. It can be seen that the increase in the input power required for recompression becomes smaller, and an increase in the rate of increase in compressor efficiency is achieved.

FIG. 5 is a characteristic diagram showing the rate of increase in compressor efficiency with respect to each operating frequency. In the figure, the curve shown by a solid line shows the rate of increase in one embodiment, and the curve shown by a broken line shows the rate of increase in the conventional one. are shown respectively. As is clear from the figure, the rate of increase is increasing in all regions including general commercial frequencies, except for the low frequency region. Furthermore, Figure 3
and the dimensions l and angle α shown in FIG.
It is determined by the dimension of b, and the thickness of wraps 3b and 4b is t
, the distance between the wraps 3b and 4b is L, and the hole diameter of both injection ports 21 and 22 is d, then 0<l<t-d [mm] 0<α<180/π cos-1(L+2d-3t/ L
−t) [°].

[0016]

As described above, according to the present invention, among the plurality of compression chambers formed between the fixed scroll and the revolving scroll, the first compression chamber formed at the outermost periphery is oriented toward the center. When moved, a second compression chamber is formed inside the first compression chamber.
One is located at a position away from the wall surface inside the fixed scroll wrap that is not in communication with the compression chamber of the fixed scroll, and one is located further inward from the winding end of the fixed scroll by 360° or more, and the other is located further away from the wall surface by 180° than the other. Equipped with two injection ports located away from the wall surface on the outside of the fixed scroll wrap that advances toward the inner periphery, increasing the efficiency of the compression chamber by suppressing the ratio of increase in input to the increase in heating and cooling capacity. This makes it possible to provide a scroll compressor with excellent efficiency.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the configuration of a scroll compressor in an embodiment of the present invention.

FIG. 2 is a sectional view showing the relationship between an injection port and a wrap of the scroll compressor in FIG. 1;

3 is a schematic diagram showing the positional relationship of injection ports of the scroll compressor in FIG. 1. FIG.

FIG. 4 shows the pressure inside the compression chamber with respect to the revolution angle of the orbiting scroll of the scroll compressor in FIG.
FIG. 3 is a characteristic diagram showing the opening degree of the injection port of FIG.

FIG. 5 is a characteristic diagram showing the rate of increase in compressor efficiency for each operating frequency of the scroll compressor in the figure.

FIG. 6 is a sectional view showing the configuration of a conventional scroll compressor.

7 is a cross-sectional view showing the configuration of main parts of the conventional scroll compressor in FIG. 6. FIG.

8 is a sectional view showing the relationship between the injection port and the wrap of the conventional scroll compressor in FIG. 6. FIG.

9 is a schematic diagram showing the positional relationship of injection ports of the conventional scroll compressor in FIG. 6. FIG.

[Explanation of symbols]

3 Fixed scroll 3a　End plate 3b Wrap 4 Revolution scroll 4a　End plate 4b Wrap 5 Compression chamber 5a First compression chamber 5b Second compression chamber

Claims (1)

[Claims] 1. A revolving scroll and a fixed scroll each having a spiral wrap upright on an end plate are combined with each other with both the wraps facing inward to form a plurality of compression chambers between each of the end plates and the wraps, In the scroll compressor, the refrigerant is guided to two injection ports provided at positions communicating with a first compression chamber formed at the innermost outer peripheral portion of the compression chamber of the end plate of the fixed scroll. When the first compression chamber moves toward the center, it does not communicate with the second compression chamber formed inside the first compression chamber, and one injection port is located 360 degrees from the end of the wrap of the fixed scroll. The other injection port is located at a position away from the wall surface inside the wrap of the fixed scroll that has advanced further inward by more than 180 degrees, and the other injection port is located outside the wrap of the fixed scroll that has advanced further inward by 180 degrees than the one injection port. A scroll compressor characterized by being installed at a position away from the wall surface.