A compressed air cooling pipe for two-stage air compressor

Abstract

The application discloses a compressed air cooling pipe for a two-stage air compressor, which comprises a cooling pipe assembly, the cooling pipe assembly comprises a cooling pipe, a locking piece and a sealing piece, the cooling pipe comprises a first connecting pipe and a second connecting pipe, the first connecting pipe and the second connecting pipe are sealingly connected through the sealing piece, the first connecting pipe and the second connecting pipe are movably connected through the locking piece, and the first connecting pipe and the second connecting pipe can move relatively to shorten or lengthen the distance between the two ends of the cooling pipe. The first connecting pipe and the second connecting pipe are used for achieving the segmented flexible connection of the cooling pipe, so that the quality problem of the integral rigid cooling pipe caused by machining errors can be solved completely, and the machining, manufacturing and installation of the cooling pipe are facilitated.

Description

Technical Field

[0001] This invention relates to air compressors, and more specifically, to a compressed air cooling pipe for a two-stage air compressor. Background Technology

[0002] Driven by the rapid development of new energy vehicles, the vehicle air compressor industry has made significant progress. As the name suggests, a two-stage air compressor can compress air in two stages. Since a lot of heat is generated during the air compression process, the high-temperature gas after the first stage compression must be cooled before entering the second stage compression to improve volumetric efficiency and overall machine stability. Currently, the industry generally uses an external integrated bent copper tube as the cooling pipe from the first stage air outlet to the second stage air inlet.

[0003] However, this cooling pipe structure has shortcomings: to improve the heat dissipation efficiency of the cooling pipe, it is bent multiple times. After multiple bends, the center distance deviation between the two ends of the joint can reach 2-4mm. If the distance between the two ends of the cooling pipe is greater than the distance between the two air compressor chamber connection ends, the connection ends will tend to expand outward after the cooling pipe is installed, affecting its sealing effect and resulting in a high defect rate. If the distance between the two ends of the cooling pipe is less than the distance between the two air compressor chamber connection ends, the cooling pipe needs to be manually expanded outward during installation. This method can cause deformation and damage to the cooling pipe body and also affect the quality of the cooling pipe. Therefore, it is urgent to improve this. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a compressed air cooling pipe for a two-stage air compressor. Through the first connecting pipe and the second connecting pipe, the segmented flexible connection of the cooling pipe is realized. This not only completely solves the quality problems caused by the processing error of the integral rigid cooling pipe, but also facilitates the processing, manufacturing and installation of the cooling pipe.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a compressed air cooling pipe for a two-stage air compressor, comprising a cooling pipe assembly, the cooling pipe assembly comprising a cooling pipe, a locking element and a sealing element, the cooling pipe comprising a first connecting pipe and a second connecting pipe, the first connecting pipe and the second connecting pipe being sealed together by the sealing element, the first connecting pipe and the second connecting pipe being movably connected by the locking element, the first connecting pipe and the second connecting pipe being able to move relative to each other, so that the distance between the two ends of the cooling pipe is shortened or lengthened.

[0006] Furthermore, the first connecting tube includes a flared portion, the second connecting tube includes an outwardly turned portion, one end of the second connecting tube located in the outwardly turned portion is inserted into the flared portion, the locking member includes a threaded sleeve and a through hole, the threaded sleeve is sleeved on the outer wall of the flared portion and threadedly connected to the outer wall of the flared portion, the second connecting tube passes through the through hole, and the cross-sectional dimension of the outwardly turned portion is larger than the cross-sectional dimension of the through hole.

[0007] Furthermore, the sealing element is sleeved on the outer wall of the second connecting pipe, and the outer wall of the sealing element is sealed to the inner wall of the flared part. One end of the sealing element abuts against the threaded sleeve located on one side of the through hole.

[0008] Furthermore, the cooling pipe assembly also includes an elastic element, one end of which abuts against the outwardly flared portion and the other end of which abuts against the bottom of the flared portion;

[0009] The second connecting pipe compresses the elastic element to shorten the distance between the two ends of the cooling pipe;

[0010] The second connecting pipe squeezes the seal to increase the distance between the two ends of the cooling pipe.

[0011] Furthermore, a baffle is fixed to the end of the outward-turned portion, and the end of the elastic member abuts against the side of the baffle away from the outward-turned portion. The baffle includes a flared opening, and the size of the flared opening facing the first connecting pipe is smaller than the size facing the second connecting pipe. The first connecting pipe and the second connecting pipe are connected through the flared opening.

[0012] Furthermore, the cooling pipe assembly also includes an elastic fin ring and a first threaded sleeve. The elastic fin ring and the first threaded sleeve are both sleeved on the outside of the cooling pipe. There are two first threaded sleeves, which abut against both ends of the elastic fin ring respectively. The two first threaded sleeves are located on the outside of the first connecting pipe and the second connecting pipe respectively. The two first threaded sleeves can approach each other to compress the elastic fin ring.

[0013] Furthermore, the outer walls of both the first connecting pipe and the second connecting pipe are fixed with second threaded sleeves, and the first threaded sleeve and the second threaded sleeve are threadedly connected.

[0014] Furthermore, it also includes a first pressure sensor and a second pressure sensor, which are located at opposite ends of the cooling pipe.

[0015] Furthermore, it also includes an air compressor body, which includes a primary air outlet and a secondary air inlet arranged opposite to each other. The cooling pipe assembly also includes connectors fixed to both ends of the cooling pipe, and the two connectors are respectively connected to the primary air outlet and the secondary air inlet.

[0016] Furthermore, the two connectors are respectively fixed to the ends of the first connecting pipe and the second connecting pipe. The connector at the end of the first connecting pipe is connected to the primary air outlet through a pin sleeve, and the connector at the end of the second connecting pipe is connected to the secondary air inlet through another pin sleeve.

[0017] The pin sleeve includes a connecting ring, a boss, and an air passage hole. The connector includes a ball sleeve. The boss passes through the ball sleeve and is threadedly connected to the air compressor body. The air passage hole is located on the periphery of the boss and inside the ball sleeve. A first sealing ring and a second sealing ring are sleeved on the outside of the boss. One end of the first sealing ring abuts against the outside of the air compressor body and the other end abuts against the inside of the connector. One end of the second sealing ring abuts against the outside of the connector and the other end abuts against the inside of the boss.

[0018] The primary air outlet, the first connecting pipe, the second connecting pipe, and the secondary air inlet form a two-stage air supply path.

[0019] In summary, the present invention has the following beneficial effects:

[0020] The cooling pipe is divided into a two-section structure of a first connecting pipe and a second connecting pipe, and the two rigid pipes are flexibly connected by elastic elements and sealing elements. This not only provides a reliable sealing effect between the first and second connecting pipes, but also allows for fine adjustment of the distance. When the second connecting pipe squeezes the elastic element, the distance between the two ends of the cooling pipe is shortened; when the second connecting pipe squeezes the sealing element, the distance between the two ends of the cooling pipe is lengthened. This not only effectively solves the quality problems caused by processing errors in integral rigid cooling pipes, but also facilitates the processing, manufacturing, and installation of cooling pipes. Attached Figure Description

[0021] Figure 1 This is a structural schematic diagram of an air compressor from a first-view perspective.

[0022] Figure 2 This is a structural schematic diagram of an air compressor from a second-view perspective.

[0023] Figure 3 This is a sectional view of an air compressor;

[0024] Figure 4 for Figure 3 Enlarged view at point A;

[0025] Figure 5 This is a schematic diagram of the cooling pipe assembly.

[0026] Figure 6 This is an exploded view of the cooling pipe assembly;

[0027] Figure 7 This is a cross-sectional view of the cooling pipe assembly;

[0028] Figure 8 for Figure 7 Enlarged view at point B;

[0029] Figure 9 for Figure 7 Enlarged view at point C.

[0030] Reference numerals: 1. Air compressor body; 11. Primary air outlet; 12. Secondary air inlet; 2. Cooling pipe assembly; 21. Cooling pipe; 211. First connecting pipe; 2111. Flared end; 212. Second connecting pipe; 2121. Outwardly turned end; 22. Elastic wing ring; 23. Connector; 231. Ball sleeve; 24. Locking element; 241. Threaded sleeve; 242. Through hole; 25. Elastic element; 26. Sealing element; 27. Baffle; 271. Trumpet mouth; 28. First threaded sleeve; 29. ​​Second threaded sleeve; 3. Pin sleeve; 31. Connecting ring; 32. Boss; 33. Air passage hole; 4. First sealing ring; 5. Second sealing ring; 6. First pressure sensor; 7. Second pressure sensor. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] like Figures 1 to 9 As shown, this embodiment discloses a compressed air cooling pipe for a two-stage air compressor, used for cooling and conveying compressed air from the two-stage air compressor. Specifically, the two-stage air compressor includes an air compressor body 1, which includes a primary air outlet 11 and a secondary air inlet 12 arranged opposite to each other. The primary air outlet 11 is connected to the primary compression chamber, and the secondary air inlet 12 is connected to the secondary compression chamber. The primary air outlet 11 and the secondary air inlet 12 are connected by a cooling pipe assembly 2 placed outside the air compressor body 1. The primary air outlet 11, the cooling pipe assembly 2, and the secondary air inlet 12 form a two-stage air supply path. The air compressed in the primary compression chamber is cooled in the cooling pipe assembly 2 and then enters the secondary compression chamber from the secondary air inlet 12 for compression.

[0033] like Figure 3 and Figure 4As shown, the cooling pipe assembly 2 includes a cooling pipe 21 and a connector 23. The connector 23 is welded and fixed to both ends of the cooling pipe 21. Both the cooling pipe 21 and the connector 23 are made of copper. Copper has good thermal conductivity, which is beneficial for the heat dissipation of the primary compressed air. The two connectors 23 are respectively sealed to the primary air outlet 11 and the secondary air inlet 12 through pin sleeves 3. Specifically, the pin sleeve 3 includes a connecting ring 31, a boss 32, and an air passage hole 33. The connector 23 includes a ball sleeve 231, which communicates with the interior of the cooling pipe 21. The boss 32 passes through the ball sleeve 231 and is threadedly connected to the air compressor body 1. The boss 32 of the pin sleeve 3 located at the first-stage air outlet 11 is inserted into the first-stage air outlet 11 and is threadedly connected to the first-stage air outlet 11. The boss 32 of the pin sleeve 3 located at the second-stage air inlet 12 is inserted into the second-stage air inlet 12 and is threadedly connected to the second-stage air inlet 12. There are three air passage holes 33. The air passage holes 33 are located around the boss 32 and inside the ball sleeve 231. The interior of the cooling pipe 21 is connected to the interior of the air compressor body 1 through the air passage holes 33.

[0034] like Figure 1 As shown, when installing the cooling pipe assembly 2, the cooling pipe assembly 2 is directly sleeved on the outside of the air compressor body 1, with one connector 23 facing the first-stage air outlet 11 and the other connector 23 facing the second-stage air inlet 12, and then locked and fixed by the pin sleeve 3.

[0035] The outer side of the boss 32 is fitted with a first sealing ring 4 and a second sealing ring 5. Both the first sealing ring 4 and the second sealing ring 5 are made of rubber. One end of the first sealing ring 4 abuts against the outer side of the air compressor body 1 and the other end abuts against the inner side of the connector 23. One end of the second sealing ring 5 abuts against the outer side of the connector 23 and the other end abuts against the inner side of the boss 32. By setting the first sealing ring 4 and the second sealing ring 5, the connection between the connector 23 and the air compressor body 1 (the first-stage air outlet 11 and the second-stage air inlet 12) can be sealed to prevent gas leakage at the connection.

[0036] like Figure 5 As shown, the cooling pipe 21 includes a first connecting pipe 211 and a second connecting pipe 212. Two connectors 23 are respectively fixed to the ends of the first connecting pipe 211 and the second connecting pipe 212. The connector 23 located at the end of the first connecting pipe 211 is connected to the primary air outlet 11 through a pin sleeve 3, and the connector 23 located at the end of the second connecting pipe 212 is connected to the secondary air inlet 12 through another pin sleeve 3. The primary air outlet 11, the first connecting pipe 211, the second connecting pipe 212 and the secondary air inlet 12 form a secondary air supply path.

[0037] like Figure 6 , Figure 7 and Figure 9As shown, the cooling pipe assembly 2 also includes a locking member 24, an elastic member 25, and a sealing member 26. The first connecting pipe 211 and the second connecting pipe 212 are movably connected by the locking member 24. Specifically, the first connecting pipe 211 includes a flared portion 2111, and the second connecting pipe 212 includes an outwardly turned portion 2121. One end of the second connecting pipe 212 located in the outwardly turned portion 2121 is inserted into the flared portion 2111. The locking member 24 includes a threaded sleeve 241 and a through hole 242. The threaded sleeve 241 is sleeved on the outer wall of the flared portion 2111 and is connected to the flared portion 2111. 1. The outer wall is threaded, and the second connecting tube 212 passes through the through hole 242. The cross-sectional dimension of the outwardly turned part 2121 is larger than the cross-sectional dimension of the through hole 242. There is a gap of 1mm-1.5mm between the outer wall of the second connecting tube 212 and the through hole 242. By setting the gap, the second connecting tube 212 and the second connecting tube 212 can move relative to each other. When the threaded sleeve 241 is threadedly connected to the flared part 2111, the first connecting tube 211 and the second connecting tube 212 will not separate because the size of the outwardly turned part 2121 is larger than the size of the through hole 242.

[0038] Both the elastic element 25 and the sealing element 26 are rubber components. The first connecting pipe 211 and the second connecting pipe 212 are sealed together by the sealing element 26. Specifically, one end of the elastic element 25 abuts against the outwardly turned portion 2121 and the other end abuts against the bottom of the flared portion 2111. The sealing element 26 is sleeved on the outer wall of the second connecting pipe 212, and the inner wall of the sealing element 26 seals against the outer wall of the second connecting pipe 212. The outer wall of the sealing element 26 seals against the inner wall of the flared portion 2111. One end of the sealing element 26 abuts against the threaded sleeve 241 on one side of the through hole 242, and the other end abuts against the outwardly turned portion 2121 on the side away from the first connecting pipe 211. The elastic element 25 is a rubber ring, and the sealing element 26 is separated by the outwardly turned portion 2121. After the cooling pipe assembly 2 is assembled, both the elastic element 25 and the sealing element 26 have basic pressure. The compression means that the bottom of the outward-flared part 2121 and the flared part 2111 has a pre-compression amount on the elastic element 25, and the bottom of the outward-flared part 2121 and the threaded sleeve 241 has a pre-compression amount on the sealing element 26. Through this setting, the basic seal of the first connecting pipe 211 and the second connecting pipe 212 can be achieved, avoiding leakage when the initial compressed air enters the cooling pipe 21. Since both the elastic element 25 and the sealing element 26 are flexible elements, the distance between the two ends of the cooling pipe 21 can be increased by continuing to compress the sealing element 26, and the distance between the two ends of the cooling pipe 21 can be shortened by continuing to compress the elastic element 25. The compensation stroke range is ±2mm, which completely covers the processing and installation errors. Furthermore, both the elastic element 25 and the sealing element 26 have a compression amount during the relative movement of the second connecting pipe 212.

[0039] During the processing of the cooling pipe assembly 2, it is inevitable that the distance between the two joints 23 will be greater or less than the distance between the primary air outlet 11 and the secondary air inlet 12. If the cooling pipe 21 is an integral structure, it will always be under stress after installation. This will not only affect the sealing effect at the joints 23, but also cause stress concentration at the weld between the joints 23 and the cooling pipe 21, leading to fatigue cracking during actual use and affecting the quality of the air compressor. In this embodiment, the cooling pipe 21 is divided into a two-section structure of a first connecting pipe 211 and a second connecting pipe 212. The two rigid pipes are flexibly connected by an elastic element 25 and a sealing element 26. This not only provides a reliable sealing effect between the first connecting pipe 211 and the second connecting pipe 212, but also allows for fine adjustment of the distance. When the second connecting pipe 212 squeezes the elastic element 25, the distance between the two ends of the cooling pipe 21 is shortened. When the second connecting pipe 212 squeezes the sealing element 26, the distance between the two ends of the cooling pipe 21 is lengthened. This not only effectively solves the quality problems caused by processing errors in the integral rigid cooling pipe 21, but also facilitates the processing, manufacturing, and installation of the cooling pipe 21.

[0040] like Figure 9 As shown, a metal annular baffle 27 is welded and fixed to the end of the outward-turned portion 2121. The end of the elastic member 25 abuts against the side of the baffle 27 away from the outward-turned portion 2121. The baffle 27 includes a flared opening 271. The size of the flared opening 271 facing the first connecting pipe 211 is smaller than the size facing the second connecting pipe 212. The first connecting pipe 211 and the second connecting pipe 212 are connected through the flared opening 271. When compressed air passes through the flared opening 271, since the opening of the flared opening 271 is smaller than the inner diameter of the elastic member 25, it will block part of the compressed air. The blocked compressed air will generate a thrust on the baffle 27, causing the second connecting pipe 212 to move to the right and compress the sealing member 26. This can effectively improve the sealing effect of the first connecting pipe 211 and the second connecting pipe 212 at the connection and reduce the risk of gas leakage.

[0041] like Figure 7 and Figure 8As shown, the cooling pipe assembly 2 also includes an elastic fin ring 22, a first threaded sleeve 28, and a second threaded sleeve 29. The elastic fin ring 22, the first threaded sleeve 28, and the second threaded sleeve 29 are all sleeved on the outside of the cooling pipe 21. The elastic fin ring 22 is made of elastic steel and has elasticity; it is slidably connected to the cooling pipe 21. By setting the elastic fin ring 22, heat conduction can be achieved in the cooling pipe 21, improving the cooling efficiency of the compressed air. There are two second threaded sleeves 29, which are respectively fixed to the outside of the first connecting pipe 211 and the second connecting pipe 212. The outer wall of the second threaded sleeve 29 has external threads. There are two first threaded sleeves 28, corresponding one-to-one with the second threaded sleeves 29. The inner wall of the first threaded sleeve 28 has internal threads and is threadedly connected to the second threaded sleeve 29. The two first threaded sleeves 28 respectively abut against both ends of the elastic fin ring 22. Rotating the two first threaded sleeves 28 allows them to move closer together, compressing the elastic fin ring 22. Specifically:

[0042] In this embodiment, both the elastic element 25 and the sealing element 26 are vulnerable parts. In particular, the sealing element 26 will experience a decrease in static sealing performance under long-term pressure. That is, leakage will occur at the connection between the first connecting pipe 211 and the second connecting pipe 212 when the air compressor is first started. When leakage occurs, the elastic ring 22 can be compressed by shortening the distance between the two first threaded sleeves 28. When the compression of the elastic ring 22 increases, the outward stretching force of the first connecting pipe 211 and the second connecting pipe 212 will also increase, thereby increasing the initial compression of the sealing element 26 by the second connecting pipe 212 and improving the static sealing performance of the sealing element 26. Furthermore, since the first connecting pipe 211 and the second connecting pipe 212 are connected by a detachable locking element 24, the replacement of the elastic element 25 and the sealing element 26 is very convenient.

[0043] like Figure 1 and Figure 2 As shown, in this embodiment, a first pressure sensor 6 and a second pressure sensor 7 are fixedly installed at both ends of the cooling pipe 21, respectively. The first pressure sensor 6 is used to collect the pressure of the gas flowing out of the first-stage outlet 11. The second pressure sensor 7 is used to collect the gas pressure flowing into the secondary air inlet 12. The system detects whether a leak has occurred at the connection between the first connecting pipe 211 and the second connecting pipe 212 by judging the pressure difference between the first pressure sensor 6 and the second pressure sensor 7. Specifically:

[0044] S1. Determine the reference pressure difference. :

[0045]

[0046] Reference pressure difference : Calibrate the standard pressure difference under the same speed and pressure when the new machine is assembled and sealed in good condition;

[0047] S2. Set the allowable leakage threshold. :

[0048]

[0049] K is the safety margin factor, which is generally taken as 0.02MPa~0.05MPa (calibrated according to the air compressor operating conditions).

[0050] S3, Computer calculates real-time differential pressure. :

[0051] ;

[0052] S4. Leakage Assessment:

[0053] The seal is normal; A leak occurred inside cooling pipe 21, and the system issued an alarm.

[0054] By collecting the inlet and outlet pressures of the cooling pipe 21 through the first pressure sensor 6 and the second pressure sensor 7, and using the leakage judgment formula to calculate the differential pressure threshold, internal leakage can be monitored in real time without stopping or disassembling the machine, and early warning of faults can be given.

[0055] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A compressed air cooling pipe for a two-stage air compressor, characterized in that, The cooling pipe assembly (2) includes a cooling pipe (21), a locking element (24), an elastic element (25), and a sealing element (26). The cooling pipe (21) includes a first connecting pipe (211) and a second connecting pipe (212). The first connecting pipe (211) and the second connecting pipe (212) are sealed together by the sealing element (26). The first connecting pipe (211) and the second connecting pipe (212) are movably connected by the locking element (24). The first connecting pipe (211) and the second connecting pipe (212) can move relative to each other to shorten or lengthen the distance between the two ends of the cooling pipe (21). The first connecting tube (211) includes a flared portion (2111), and the second connecting tube (212) includes an outwardly turned portion (2121). One end of the second connecting tube (212) located in the outwardly turned portion (2121) is inserted into the flared portion (2111). One end of the elastic member (25) abuts against the outwardly turned portion (2121) and the other end abuts against the bottom of the flared portion (2111). The second connecting pipe (212) compresses the elastic element (25) to shorten the distance between the two ends of the cooling pipe (21); The second connecting pipe (212) presses against the seal (26) to increase the distance between the two ends of the cooling pipe (21); The locking member (24) includes a threaded sleeve (241) and a through hole (242). The threaded sleeve (241) is fitted on the outer wall of the flared portion (2111) and threadedly connected to the outer wall of the flared portion (2111). The second connecting tube (212) passes through the through hole (242). The cross-sectional dimension of the outwardly turned portion (2121) is larger than the cross-sectional dimension of the through hole (242). The sealing member (26) is fitted on the outer wall of the second connecting tube (212). The outer wall of the sealing member (26) is sealed and fitted with the inner wall of the flared portion (2111). One end of the sealing member (26) abuts against the threaded sleeve (241) located on one side of the through hole (242).

2. The compressed air cooling pipe for a two-stage air compressor according to claim 1, characterized in that, A baffle (27) is fixed to the end of the outward-turned part (2121). The end of the elastic member (25) abuts against the side of the baffle (27) away from the outward-turned part (2121). The baffle (27) includes a flared mouth (271). The size of the flared mouth (271) facing the first connecting pipe (211) is smaller than the size facing the second connecting pipe (212). The first connecting pipe (211) and the second connecting pipe (212) are connected through the flared mouth (271).

3. A compressed air cooling pipe for a two-stage air compressor according to claim 1, characterized in that, The cooling pipe assembly (2) further includes an elastic fin ring (22) and a first threaded sleeve (28). The elastic fin ring (22) and the first threaded sleeve (28) are both sleeved on the outside of the cooling pipe (21). There are two first threaded sleeves (28) and they respectively abut against the two ends of the elastic fin ring (22). The two first threaded sleeves (28) are located on the outside of the first connecting pipe (211) and the second connecting pipe (212) respectively. The two first threaded sleeves (28) can approach each other so that the elastic fin ring (22) is compressed.

4. A compressed air cooling pipe for a two-stage air compressor according to claim 3, characterized in that, The outer walls of the first connecting pipe (211) and the second connecting pipe (212) are both fixed with second threaded sleeves (29), and the first threaded sleeve (28) and the second threaded sleeve (29) are threadedly connected.

5. A compressed air cooling pipe for a two-stage air compressor according to claim 1, characterized in that, It also includes a first pressure sensor (6) and a second pressure sensor (7), which are located at both ends of the cooling pipe (21).

6. A compressed air cooling pipe for a two-stage air compressor according to claim 1, characterized in that, It also includes an air compressor body (1), which includes a primary air outlet (11) and a secondary air inlet (12) arranged opposite to each other. The cooling pipe assembly (2) also includes connectors (23) fixed to both ends of the cooling pipe (21). The two connectors (23) are respectively connected to the primary air outlet (11) and the secondary air inlet (12).

7. A compressed air cooling pipe for a two-stage air compressor according to claim 6, characterized in that, The two connectors (23) are respectively fixed to the ends of the first connecting pipe (211) and the second connecting pipe (212). The connector (23) at the end of the first connecting pipe (211) is connected to the first-stage air outlet (11) through a pin sleeve (3), and the connector (23) at the end of the second connecting pipe (212) is connected to the second-stage air inlet (12) through another pin sleeve (3). The pin sleeve (3) includes a connecting ring (31), a boss (32) and an air passage hole (33). The connector (23) includes a ball sleeve (231). The boss (32) passes through the ball sleeve (231) and is threadedly connected to the air compressor body (1). The air passage hole (33) is located on the periphery of the boss (32) and inside the ball sleeve (231). A first sealing ring (4) and a second sealing ring (5) are sleeved on the outside of the boss (32). One end of the first sealing ring (4) abuts against the outside of the air compressor body (1) and the other end abuts against the inside of the connector (23). One end of the second sealing ring (5) abuts against the outside of the connector (23) and the other end abuts against the inside of the boss (32). The primary air outlet (11), the first connecting pipe (211), the second connecting pipe (212) and the secondary air inlet (12) form a secondary air supply path.

Images