Second-stage air cylinder suction hole structure of two-stage compressor, compressor pump body and compressor

Abstract

The invention relates to the technical field of compressors, in particular to a second-stage air cylinder suction hole structure of a two-stage compressor, a compressor pump body comprising the second-stage air cylinder suction hole structure of the two-stage compressor and the compressor comprising the compressor pump body. The second-stage air cylinder air suction hole structure of the two-stage compressor is used for communicating an airflow through hole in an intermediate plate with an inner cavity of a second-stage air cylinder, the airflow through hole is a kidney-shaped hole, and the second-stage air cylinder air suction hole structure of the two-stage compressor comprises an air suction hole formed in the second-stage air cylinder. The air suction hole is a notch formed by beveling from the first end face, close to the middle plate, of the second-stage air cylinder to the inner diameter wall face of the second-stage air cylinder, and the projection of the air suction hole on the plane perpendicular to the axis of the second-stage air cylinder is quadrilateral and covers the airflow through hole. The through-flow area of the second-stage air suction channel on the middle plate and the second-stage air cylinder is not limited, materials can be reduced by forming the air suction holes through beveling, and the strength of a blade groove and the inner diameter of the second-stage air cylinder is definitely improved.

Description

Technical Field

[0001] The present invention relates to the technical field of compressors, and in particular to a suction hole structure of the second-stage cylinder of a two-stage compressor, a compressor pump body including the suction hole structure of the second-stage cylinder of the two-stage compressor, and a compressor including the compressor pump body. Background Art

[0002] Generally, for the gas inhaled by a compressor, after being compressed in the cylinder, due to the increase in density, the airflow channels inside the pump body are relatively abundant. Although smaller than the flow area of the suction hole, they are generally not much smaller. For example, for a 21cc displacement cylinder, the diameter of the suction hole is 15mm, and the flow area is about 180mm 2 , and the flow area of the pump body is about 160mm 2 .

[0003] The characteristic of a two-stage compressor is that the suction of the second stage is determined by the exhaust and injection volume of the first stage. In addition to the exhaust volume of the first stage, the injection volume is also increased. Moreover, the ambient temperature of compressors applied in the existing market is getting lower and lower, and the required injection volume may account for 40%-60% of the compressor. Then, the suction volume of the second-stage cylinder is 1.4-1.6 times that of the first-stage cylinder. Taking the working condition of an ambient temperature of -2°C as an example, the suction properties of the first stage are: suction temperature 8°C, suction pressure 0.762MPa, and suction density 27.411kg / m 3 ; the suction properties of the second stage are: suction temperature 15.25°C, suction pressure 1.29MPa, and suction density 42.86kg / m 3 . Conducting theoretical calculations based on this example, the flow area of the second-stage suction needs to be 0.895-1.023 times that of the first-stage suction flow area, that is, the flow area of the second-stage suction is close to the first-stage suction flow area.

[0004] In a two-stage compressor, an intermediate plate is provided between the first-stage cylinder and the second-stage cylinder to separate the two-stage cylinders. The intermediate plate is provided with air flow holes to facilitate the exhaust of the first-stage cylinder to flow through the air flow holes on the intermediate plate into the second-stage cylinder, thereby compressing the gas in the compressor multiple times. The air flow holes on the intermediate plate usually adopt a single-hole design, that is, there is one air flow hole on the intermediate plate, and a single-hole suction hole is correspondingly provided at a position on the inner diameter wall surface of the second-stage cylinder corresponding to the air flow hole on the intermediate plate for connecting the air flow hole on the intermediate plate with the inner cavity of the second-stage cylinder. The exhaust of the first-stage cylinder passes through the air flow hole on the intermediate plate and enters the second-stage cylinder through the suction hole of the second-stage cylinder.

[0005] If the air flow holes on the intermediate plate are designed outside the piston movement range, that is, outside the inner diameter of the cylinder, then the air flow holes are restricted by the inner diameter of the cylinder and the outer diameter of the intermediate plate, and the air intake holes of the cylinder need to be machined against the inner diameter of the cylinder, and a certain sealing distance also needs to be ensured, resulting in a large limitation on the diameter of the air flow holes on the intermediate plate, and it can only be designed to 60%-70% of the flow area of the first-stage air intake holes.

[0006] If the flow areas are the same, that is, the diameter of the air flow holes on the intermediate plate is to be made the same as the diameter of the first-stage air intake holes, then within the radial range where the air intake holes can be opened, that is, within the range from the inner diameter of the piston to the outer diameter of the cylinder, there are the following disadvantages: 1) The holes are equivalent to being larger than the existing relative piston movement angle, that is, the time for air intake to close is delayed, the air intake backflow increases, and the air intake efficiency decreases; 2) The air intake channel is closer to the blade groove, and the blade groove is more likely to deform during machining and under the force during the operation of the compressor; 3) The holes need to cover a larger part within the piston movement range. When the piston rotates to this angle, this area of the intermediate plate is hollow, and the piston support surface becomes smaller, which may cause the piston to tilt. Piston tilt is more likely to cause wear and seizure of the compressor. That is, the limitations of the air intake holes of the cylinder are very large, and the diameter cannot be made large.

[0007] In the prior art, the air flow holes on the intermediate plate are designed as kidney-shaped holes to ensure the flow area, but for the second-stage cylinder air intake holes to ensure that the air intake start and end angles are within the optimal range, a large amount of redundancy will occur (as shown by the shaded part in Figure 1 ). Summary of the Invention

[0008] In view of the above defects of the prior art, the technical problem to be solved by the present invention is to provide a second-stage cylinder air intake hole structure for a two-stage compressor, which can effectively reduce the limitation of the flow area of the second-stage air intake channel on the intermediate plate and the second-stage cylinder.

[0009] To solve the above technical problems, the present invention adopts the following technical solutions:

[0010] The present invention provides a second-stage cylinder air intake hole structure for a two-stage compressor, which is used to connect the air flow holes on the intermediate plate with the inner cavity of the second-stage cylinder. The air flow holes are kidney-shaped holes. The second-stage cylinder air intake hole structure for a two-stage compressor includes air intake holes provided on the second-stage cylinder. The air intake holes are notches formed by obliquely cutting from the first end face of the second-stage cylinder close to the intermediate plate to the inner diameter wall surface of the second-stage cylinder. The projection of the air intake holes on a plane perpendicular to the axis of the second-stage cylinder is a quadrilateral and covers the air flow holes.

[0011] Preferably, the air inlet hole has an air inlet formed on the first end face of the second-stage cylinder. The air inlet has an outer edge close to the outer diameter wall surface of the second-stage cylinder. The air flow through hole has an outer portion close to the outer peripheral side surface of the intermediate plate and an inner portion close to the inner peripheral side surface of the intermediate plate divided by the center line of the kidney-shaped hole. The projection contour line of the outer edge of the air inlet and the outer portion of the air flow through hole on a plane perpendicular to the axis of the second-stage cylinder overlaps.

[0012] Preferably, the air inlet further has two side edges respectively extending from both ends of the outer edge to the inner diameter wall surface of the second-stage cylinder, and the two side edges are respectively tangent to both ends of the outer edge.

[0013] Preferably, the projection of the inner diameter wall surface of the second-stage cylinder between the intersection points of the two side edges and the inner diameter wall surface of the second-stage cylinder on a plane perpendicular to the axis of the second-stage cylinder and the projection of the air inlet on a plane perpendicular to the axis of the second-stage cylinder together form a quadrilateral.

[0014] Preferably, the air inlet hole has an air outlet formed on the inner diameter wall surface of the second-stage cylinder. The air outlet has an upper edge far from the first end face of the second-stage cylinder, and the axial distance between the upper edge and the second end face of the second-stage cylinder far from the intermediate plate is not less than 2 mm.

[0015] Preferably, the air inlet hole has an air inlet formed on the first end face of the second-stage cylinder and an air outlet formed on the inner diameter wall surface of the second-stage cylinder. The air inlet and the air outlet are smoothly connected by an inclined cut surface formed between the first end face of the second-stage cylinder and the inner diameter wall surface of the second-stage cylinder.

[0016] The present invention also provides a compressor pump body, including the air inlet hole structure of the second-stage cylinder of the two-stage compressor as described above.

[0017] The present invention also provides a compressor, including the compressor pump body as described above.

[0018] Compared with the prior art, the present invention has significant progress:

[0019] In the present invention, the projection of the air intake hole on the second-stage cylinder along the axial direction is designed as a quadrilateral and covers the air flow through-hole on the intermediate plate. For the air flow through-hole on the intermediate plate in the shape of a kidney-shaped hole, the air intake port of the air intake hole located on the first end face of the second-stage cylinder can fit the envelope surface of the kidney-shaped air flow through-hole on the intermediate plate to the greatest extent, so that the kidney-shaped air flow through-hole on the intermediate plate is less restricted, and the kidney-shaped air flow through-hole on the intermediate plate can be designed according to the required flow area, realizing that the flow areas of the second-stage intake passage of the two-stage compressor on the intermediate plate and the second-stage cylinder are not restricted, and can be designed according to the actual design requirements. The second-stage intake passage can follow the change of the envelope line of the kidney-shaped air flow through-hole on the intermediate plate and fit it. Since there is no restriction on the inner diameter and radial breadth of the second-stage cylinder, the kidney-shaped air flow through-hole on the intermediate plate can be made narrow, so that under the condition of unchanged flow area, the forward movement of the intake end angle can be realized, reducing the intake loss. The air intake hole is formed on the second-stage cylinder by means of bevel cutting. For the same flow area, the bevel cutting method can reduce the material and make it smaller, and significantly improve the strength of the blade groove and inner diameter of the second-stage cylinder. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 In FIGS. 1a and 1b, there are two examples of redundancy between the air flow through-hole on the intermediate plate and the air intake hole of the second-stage cylinder in the prior art.

[0021] Figure 2 FIG. is a schematic diagram of the cooperation between the air intake hole structure of the second-stage cylinder of the two-stage compressor according to an embodiment of the present invention and the intermediate plate.

[0022] Figure 3 FIG. is a cross-sectional schematic diagram of the cooperation between the air intake hole structure of the second-stage cylinder of the two-stage compressor according to an embodiment of the present invention and the intermediate plate.

[0023] Figure 4 FIG. is a schematic diagram of the projection of the air intake hole structure of the second-stage cylinder of the two-stage compressor according to an embodiment of the present invention and the air flow through-hole on the intermediate plate in a plane perpendicular to the axis of the second-stage cylinder.

[0024] Figure 5 FIG. is a schematic diagram of the structure of one end view of the air intake hole structure of the second-stage cylinder of the two-stage compressor according to an embodiment of the present invention.

[0025] Figure 6 FIG. is a schematic diagram of the structure of the other end view of the air intake hole structure of the second-stage cylinder of the two-stage compressor according to an embodiment of the present invention.

[0026] Figure 7 FIG. is a schematic diagram of the structure of the intermediate plate in an embodiment of the present invention.

[0027] Among them, the reference numerals are explained as follows:

[0028] 1 Intermediate plate

[0029] 11 Inner peripheral side

[0030] 12 Outer peripheral side

[0031] 10 Air flow through hole

[0032] 101 Outer part

[0033] 102 Inner part

[0034] 2 Second-stage cylinder

[0035] 21 First end face

[0036] 22 Second end face

[0037] 23 Inner diameter wall surface

[0038] 24 Outer diameter wall surface

[0039] 20 Suction hole

[0040] 201 Suction port

[0041] 201a Outer edge

[0042] 201b Side edge

[0043] 202 Exhaust port

[0044] 202a Upper edge

[0045] 203 Inclined cutting surface Specific embodiments

[0046] The following further details the specific embodiments of the present invention in conjunction with the accompanying drawings. These embodiments are only for illustrating the present invention and are not intended to limit the present invention.

[0047] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0048] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "installed", "connected", and "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0049] In addition, in the description of the present invention, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0050] As Figures 2 to 7 shown, it is an embodiment of the suction hole structure of the second-stage cylinder of the two-stage compressor provided by the present invention.

[0051] Refer to Figure 2 , the suction hole structure of the second-stage cylinder of the two-stage compressor in this embodiment is used to connect the air flow hole 10 on the intermediate plate 1 with the inner cavity of the second-stage cylinder 2. The intermediate plate 1 is arranged between the first-stage cylinder and the second-stage cylinder 2 of the two-stage compressor and separates the first-stage cylinder from the second-stage cylinder 2. The exhaust gas of the first-stage cylinder flows through the air flow hole 10 on the intermediate plate 1 into the inner cavity of the second-stage cylinder 2, so as to compress the gas in the compressor multiple times. Combining Figure 7 , the air flow hole 10 on the intermediate plate 1 adopts a single-hole design, and moreover, the air flow hole 10 on the intermediate plate 1 is an oval hole to ensure the flow area. The intermediate plate 1 is an annular plate axially penetrated in the middle, having an inner peripheral side surface 11 and an outer peripheral side surface 12.

[0052] Combining Figures 3 to 6 , both ends of the second-stage cylinder 2 along the axis respectively have a first end surface 21 and a second end surface 22. The first end surface 21 is close to the intermediate plate 1, and the second end surface 22 is far from the intermediate plate 1. Both the first end surface 21 and the second end surface 22 are annular surfaces axially penetrated in the middle. The second-stage cylinder 2 also has an inner diameter wall surface 23 and an outer diameter wall surface 24. The inner diameter wall surface 23 connects the inner ring edges of the first end surface 21 and the second end surface 22 to form the inner cavity of the second-stage cylinder 2, and the outer diameter wall surface 24 connects the outer ring edges of the first end surface 21 and the second end surface 22.

[0053] The suction hole structure of the second-stage cylinder of the two-stage compressor in this embodiment includes a suction hole 20 provided on the second-stage cylinder 2. The suction hole 20 is a notch formed by obliquely cutting from the first end face 21 of the second-stage cylinder 2 close to the intermediate plate 1 to the inner diameter wall surface 23 of the second-stage cylinder 2. Thus, the suction hole 20 has a suction port 201 formed on the first end face 21 of the second-stage cylinder 2 and an air outlet 202 formed on the inner diameter wall surface 23 of the second-stage cylinder 2. The suction port 201 is in cooperation and communication with the air flow through-hole 10 on the intermediate plate 1, and the air outlet 202 leads to the inner cavity of the second-stage cylinder 2. The suction port 201 and the air outlet 202 are connected by an inclined plane 203 formed between the first end face 21 of the second-stage cylinder 2 and the inner diameter wall surface 23 of the second-stage cylinder 2 to form the suction hole 20. The suction hole 20 connects the air flow through-hole 10 on the intermediate plate 1 with the inner cavity of the second-stage cylinder 2. The air flow through-hole 10 on the intermediate plate 1 and the suction hole 20 on the second-stage cylinder 2 constitute the second-stage suction channel of the two-stage compressor. The exhaust gas of the first-stage cylinder flows into the inner cavity of the second-stage cylinder 2 through the air flow through-hole 10 on the intermediate plate 1 and the suction hole 20 on the second-stage cylinder 2. In this embodiment, the projection of the suction hole 20 on the plane perpendicular to the axis of the second-stage cylinder 2 is quadrilateral and covers the air flow through-hole 10 on the intermediate plate 1.

[0054] In this embodiment, the axial projection of the suction hole 20 on the second-stage cylinder 2 of the two-stage compressor second-stage cylinder suction hole structure is designed as a quadrilateral and covers the air flow through-hole 10 on the intermediate plate 1. For the waist-shaped air flow through-hole 10 on the intermediate plate 1, the suction port 201 of the suction hole 20 located on the first end face 21 of the second-stage cylinder 2 can fit the envelope surface of the waist-shaped air flow through-hole 10 on the intermediate plate 1 to the greatest extent, so that the waist-shaped air flow through-hole 10 on the intermediate plate 1 is less restricted. The waist-shaped air flow through-hole 10 on the intermediate plate 1 can be designed according to the required flow area, realizing that the flow areas of the second-stage suction channel of the two-stage compressor on the intermediate plate 1 and the second-stage cylinder 2 are not restricted, and can be designed according to the actual design requirements. The second-stage suction channel can follow the envelope line of the waist-shaped air flow through-hole 10 on the intermediate plate 1 and fit. Since there is no restriction on the inner diameter and radial breadth of the second-stage cylinder 2, the waist-shaped air flow through-hole 10 on the intermediate plate 1 can be made narrow. Thus, on the premise of the same flow area, the forward movement of the suction end angle can be realized, reducing the suction loss. The suction hole 20 is formed on the second-stage cylinder 2 by an oblique cutting method. For the same flow area, the oblique cutting method can reduce the material and make it smaller, and significantly improve the strength of the blade groove and inner diameter of the second-stage cylinder 2.

[0055] See Figure 4 and Figure 6, the suction port 201 of the suction hole 20 located on the first end face 21 of the second-stage cylinder 2 has an outer edge 201a close to the outer diameter wall surface 24 of the second-stage cylinder 2. The air flow through-hole 10 on the intermediate plate 1 has an outer portion 101 and an inner portion 102 divided by the center line of the kidney-shaped hole. The outer portion 101 is close to the outer peripheral side surface 12 of the intermediate plate 1, and the inner portion 102 is close to the inner peripheral side surface 11 of the intermediate plate 1. Preferably, in this embodiment, the projection contour line of the outer edge 201a of the suction port 201 on a plane perpendicular to the axis of the second-stage cylinder 2 overlaps with the projection contour line of the outer portion 101 of the air flow through-hole 10 on a plane perpendicular to the axis of the second-stage cylinder 2. Thus, the suction port 201 of the suction hole 20 completely fits the envelope surface of the kidney-shaped air flow through-hole 10 on the intermediate plate 1 to the greatest extent.

[0056] Furthermore, the suction port 201 of the suction hole 20 located on the first end face 21 of the second-stage cylinder 2 also has two side edges 201b. The two side edges 201b respectively extend from both ends of the outer edge 201a to the inner diameter wall surface 23 of the second-stage cylinder 2, and the two side edges 201b are respectively tangent to both ends of the outer edge 201a. That is, the tangents at both ends of the outer edge 201a of the suction port 201 intersect with the inner diameter wall surface 23 of the second-stage cylinder 2, and the connecting lines from the two intersection points to the corresponding ends of the outer edge 201a form the two side edges 201b of the suction port 201. The two side edges 201b and the outer edge 201a together constitute the suction port 201 of the suction hole 20.

[0057] In this embodiment, the projection of the inner diameter wall surface 23 of the second-stage cylinder 2 between the intersection points of the two side edges 201b of the suction port 201 of the suction hole 20 and the inner diameter wall surface 23 on a plane perpendicular to the axis of the second-stage cylinder 2 and the projection of the suction port 201 on a plane perpendicular to the axis of the second-stage cylinder 2 together constitute a quadrilateral, that is, the axial projection of the suction hole 20. The projection of the suction port 201 on a plane perpendicular to the axis of the second-stage cylinder 2 is also the combination of the projections of the two side edges 201b of the suction port 201 on a plane perpendicular to the axis of the second-stage cylinder 2 and the projection of the outer portion 101 of the air flow through-hole 10 on a plane perpendicular to the axis of the second-stage cylinder 2.

[0058] See Figure 3 , Figure 5 and Figure 6 , the air outlet 202 of the suction hole 20 located on the inner diameter wall surface 23 of the second-stage cylinder 2 has an upper edge 202a far from the first end face 21 of the second-stage cylinder 2. Preferably, in this embodiment, the axial distance between the upper edge 202a of the air outlet 202 and the second end face 22 of the second-stage cylinder 2 far from the intermediate plate 1 is T, and T is not less than 2 mm, thereby defining the bevel angle of the suction hole 20.

[0059] In this embodiment, the two ends of the upper edge 202a of the air outlet 202 of the air suction hole 20 extend approximately along the axial direction of the second-stage cylinder 2 towards the first end face 21 of the second-stage cylinder 2 until they intersect with the first end face 21 and intersect with the two side edges 201b of the air suction port 201 respectively.

[0060] See Figure 5 and Figure 6 , in this embodiment, preferably, the air suction port 201 and the air outlet 202 of the air suction hole 20 are smoothly connected through an inclined section 203. That is, the inclined section 203 formed by the inclined cutting between the first end face 21 of the second-stage cylinder 2 and the inner diameter wall surface 23 is a smooth section, which is more conducive to the flow of fluid.

[0061] Based on the structure of the air suction hole of the second-stage cylinder of the two-stage compressor of the present invention, the embodiment of the present invention further provides a compressor pump body. The compressor pump body of this embodiment includes the structure of the air suction hole of the second-stage cylinder of the two-stage compressor described above. The compressor pump body of this embodiment further includes an intermediate plate 1. The intermediate plate 1 is arranged between the first-stage cylinder and the second-stage cylinder 2 of the two-stage compressor and separates the first-stage cylinder and the second-stage cylinder 2. The intermediate plate 1 is provided with an air flow through hole 10. The air flow through hole 10 on the intermediate plate 1 adopts a single-hole design, and moreover, the air flow through hole 10 on the intermediate plate 1 is a kidney-shaped hole to ensure the flow area. The air suction hole 20 arranged on the second-stage cylinder 2 in the structure of the air suction hole of the second-stage cylinder of the two-stage compressor described above communicates the air flow through hole 10 on the intermediate plate 1 with the inner cavity of the second-stage cylinder 2. The exhaust gas of the first-stage cylinder flows into the inner cavity of the second-stage cylinder 2 through the air flow through hole 10 on the intermediate plate 1 and the air suction hole 20 on the second-stage cylinder 2, so as to compress the gas in the compressor multiple times.

[0062] Based on the compressor pump body of the present invention, the embodiment of the present invention further provides a compressor. The compressor of this embodiment includes the compressor pump body described above.

[0063] The above description is only a preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and substitutions can be made, and these improvements and substitutions should also be regarded as the protection scope of the present invention.

Claims

1. A suction hole structure of the second-stage cylinder of a two-stage compressor, which is used to connect the air flow through hole (10) on the intermediate plate (1) with the inner cavity of the second-stage cylinder (2). The air flow through hole (10) is an oval hole, and it is characterized in that, The suction hole structure of the second-stage cylinder of the two-stage compressor includes a suction hole (20) provided on the second-stage cylinder (2). The suction hole (20) is a notch formed by obliquely cutting from the first end face (21) of the second-stage cylinder (2) close to the intermediate plate (1) to the inner diameter wall surface (23) of the second-stage cylinder (2). The projection of the suction hole (20) on a plane perpendicular to the axis of the second-stage cylinder (2) is a quadrilateral and covers the air flow hole (10).

2. The suction hole structure of the second-stage cylinder of the two-stage compressor according to claim 1, wherein, The suction hole (20) has a suction port (201) formed on the first end face (21) of the second-stage cylinder (2). The suction port (201) has an outer edge (201a) close to the outer diameter wall surface (24) of the second-stage cylinder (2). The air flow hole (10) has an outer part (101) close to the outer peripheral side surface (12) of the intermediate plate (1) and an inner part (102) close to the inner peripheral side surface (11) of the intermediate plate (1) divided by the center line of the kidney-shaped hole. The projection contour line of the outer edge (201a) of the suction port (201) overlaps with the outer part (101) of the air flow hole (10) on a plane perpendicular to the axis of the second-stage cylinder (2).

3. The suction hole structure of the second-stage cylinder of the two-stage compressor according to claim 2, characterized in that, The suction port (201) also has two side edges (201b) respectively extending from both ends of the outer edge (201a) to the inner diameter wall surface (23) of the second-stage cylinder (2). The two side edges (201b) are respectively tangent to both ends of the outer edge (201a).

4. The suction hole structure of the second-stage cylinder of the two-stage compressor according to claim 3, characterized in that, The projection of the inner diameter wall surface (23) of the second-stage cylinder (2) between the intersection points of the two side edges (201b) and the inner diameter wall surface (23) of the second-stage cylinder (2) on a plane perpendicular to the axis of the second-stage cylinder (2) and the projection of the suction port (201) on a plane perpendicular to the axis of the second-stage cylinder (2) together form the quadrilateral.

5. The suction hole structure of the second-stage cylinder of the two-stage compressor according to claim 1, characterized in that, The suction hole (20) has an air outlet (202) formed on the inner diameter wall surface (23) of the second-stage cylinder (2). The air outlet (202) has an upper edge (202a) far from the first end face (21) of the second-stage cylinder (2). The axial distance between the upper edge (202a) and the second end face (22) of the second-stage cylinder (2) far from the intermediate plate (1) is not less than 2 mm.

6. The suction hole structure of the second-stage cylinder of the two-stage compressor according to claim 1, characterized in that, The suction hole (20) has a suction port (201) formed on the first end face (21) of the second-stage cylinder (2) and an air outlet (202) formed on the inner diameter wall surface (23) of the second-stage cylinder (2). The suction port (201) and the air outlet (202) are smoothly connected by an inclined plane (203) formed between the first end face (21) of the second-stage cylinder (2) and the inner diameter wall surface (23) of the second-stage cylinder (2).

7. A compressor pump body, characterized in that, It includes the suction hole structure of the second-stage cylinder of the two-stage compressor according to any one of claims 1 to 6.

8. A compressor, characterized in that, It includes the compressor pump body according to claim 7.

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