A two-stage on-board air compressor and a control method thereof

Abstract

The application discloses a two-stage vehicle-mounted air compressor and a control method thereof, which comprises a crankcase, a cylinder case and an oil pump assembly. A crankshaft is rotatably arranged in the crankcase, and an oil guide channel is arranged in the crankshaft. The crankshaft is provided with a plurality of shaft portions, and an oil guide opening of the oil guide channel is arranged on the outer side of each shaft portion. The oil pump assembly comprises a shaft pump base, a pump core and a pump shaft. The shaft pump base is arranged in the crankcase, the shaft portion of the first end of the crankshaft is rotatably connected in the shaft hole of the shaft pump base, an oil guide ring groove is arranged on the inner wall of the shaft hole of the shaft pump base, and the oil guide ring groove is communicated with the oil guide opening of the shaft portion of the first end of the crankshaft. An oil inlet hole and an oil outlet hole are arranged in the shaft pump base, the pump core can drive the lubricating oil to be pumped from the oil inlet hole to the oil outlet hole, the oil inlet hole is provided with an oil inlet opening, and the oil outlet hole is communicated with the oil guide ring groove. The application can effectively lubricate the crankshaft, and ensures that the whole equipment can continuously and stably operate.

Description

Technical Field

[0001] This invention relates to a piston-type variable displacement pump, and more specifically, to a two-stage vehicle-mounted air compressor, and also to a control method for the two-stage vehicle-mounted air compressor. Background Technology

[0002] In a reciprocating compressor, an electric motor typically drives a crankshaft, which in turn drives a piston. The piston periodically compresses the air within the cylinder, producing pressurized air. To increase compression capacity and pressure, some reciprocating compressors employ two or more stages. This involves extending the crankshaft and incorporating multiple piston-connecting rod mounting sections, allowing for simultaneous piston operation and multi-stage compression to achieve a higher compression ratio.

[0003] For the crankshaft of a multi-stage compressor, part of the crankshaft is eccentrically set, and it will inevitably be affected by the eccentricity during operation. Therefore, the lubrication requirements of the crankshaft shaft are relatively high.

[0004] Currently, there are generally two forms of crankshaft lubrication for vehicle air compressors. The first is to increase the amount of lubricating oil in the crankcase and use the vibration and bumps of the vehicle during driving to allow the lubricating oil to splash onto the shaft parts that need lubrication. However, this type of lubrication is unstable, and the lubricating oil usually cannot enter the rotating connection parts of the shaft.

[0005] The second method involves installing a shaft pump at the end of the crankshaft and creating an oil inlet channel within the crankshaft. The shaft pump rotates with the crankshaft, drawing lubricating oil and channeling it into the oil inlet channel, allowing it to flow to all parts of the crankshaft for lubrication. However, in this lubrication method, due to the crankshaft's curvature, the internal oil channels also need to be curved. Furthermore, the lubricating oil has a certain viscosity, making smooth flow difficult. Especially after a period of operation, sludge and impurities accumulate in the lubricating oil, reducing its flow within the channels and hindering effective lubrication, particularly in areas far from the oil pump assembly, thus affecting the crankshaft's lubrication performance.

[0006] Therefore, a new technical solution is needed to address the above problems. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of the prior art and provide a two-stage vehicle air compressor and its control method.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: a two-stage vehicle air compressor, comprising a crankcase, a cylinder box, and an oil pump assembly. A crankshaft is rotatably mounted inside the crankcase, and an oil guide channel is provided inside the crankshaft. The crankshaft is provided with several shaft portions, and an oil guide port communicating with the oil guide channel is opened on the outer side of each shaft portion. The oil pump assembly includes a pump housing, a pump core, and a pump shaft. The pump housing is mounted on the crankcase, and the shaft portion at the first end of the crankshaft is rotatably connected to the shaft hole of the pump housing. An oil guide ring groove is opened on the inner circumference of the shaft hole of the pump housing, and the oil guide ring groove communicates with the oil guide port of the shaft portion at the first end of the crankshaft.

[0009] The shaft pump seat is provided with an oil inlet channel and an oil outlet channel, and the pump core can drive the lubricating oil to be pumped from the oil inlet channel to the oil outlet channel.

[0010] The oil inlet channel has an oil inlet, the oil outlet channel is connected to the oil guide ring groove, and a pressure boosting port is provided on the side of the oil outlet channel facing away from the pump core.

[0011] It also includes a pressure relief pipe and a pressure relief valve. The pressure relief valve is installed at the pressure relief port of the cylinder box, and one end of the pressure relief pipe is connected to the pressure relief side of the pressure relief valve, while the other end is used to guide air to the boost port.

[0012] The present invention is further configured such that one end of the oil inlet channel is connected to the input side of the pump core, the oil inlet is located at the other end of the oil inlet channel, the oil inlet is connected to an oil inlet pipe, and the end of the oil inlet pipe is immersed in the lubricating oil at the bottom of the crankcase.

[0013] The present invention is further configured such that a pressure relief connection is provided on the outside of the crankcase, the pressure relief pipe is connected to the pressure relief connection, and the pressure relief connection is connected to the pressure boosting port through a pressure boosting pipe.

[0014] The present invention is further configured such that a check valve is installed inside the pressurizing pipe fitting, and the check valve is capable of unidirectional flow from the pressurizing pipe fitting to the pressurizing port.

[0015] The invention is further configured such that a second check valve is installed in the oil outlet channel, and the second check valve is capable of unidirectional flow from the pump core to the oil guide ring groove; the oil guide ring groove and the booster port are both located on the side of the second check valve facing away from the pump core; and an exhaust pipe is connected to the upper side of the crankcase.

[0016] The present invention is further configured such that the pump core and pump shaft are rotatably mounted in the shaft pump seat, and the pump core is coaxially connected to the crankshaft and can maintain synchronous rotation.

[0017] The invention is further configured such that the cylinder box has a primary exhaust chamber and a secondary exhaust chamber, the secondary exhaust chamber has a pressure relief port, the primary exhaust chamber and the secondary exhaust chamber are connected by an air guide pipe, the air guide pipe is located outside the cylinder box; it also includes a cooling fan, the cooling fan is used to dissipate heat from the air guide pipe and the cylinder box.

[0018] The invention is further configured such that the cylinder box is provided with a primary intake chamber and a secondary intake chamber; the cylinder box is also provided with a primary cylinder block and a secondary cylinder block, the primary intake chamber and the primary exhaust chamber are unidirectionally connected to the primary cylinder block, the secondary intake chamber and the secondary exhaust chamber are unidirectionally connected to the secondary cylinder block, and air flows unidirectionally along the primary intake chamber, the primary cylinder block, the primary exhaust chamber, the secondary intake chamber, the secondary cylinder block, and the secondary exhaust chamber; the primary intake chamber has an intake port, and the secondary exhaust chamber has an exhaust port.

[0019] The present invention is further configured such that a first-stage piston and a second-stage piston are respectively provided in the first-stage cylinder block and the second-stage cylinder block, the first-stage piston is linked to the crankshaft through a first-stage connecting rod, and the second-stage piston is linked to the crankshaft through a second-stage connecting rod;

[0020] The crankshaft has four shaft sections, namely two central shaft sections and two eccentric shaft sections. The crankshaft is rotatably supported by the two central shaft sections, and a first-stage connecting rod and a second-stage connecting rod are rotatably mounted on the outer periphery of the two eccentric shaft sections, respectively.

[0021] This invention also provides a control method for a two-stage vehicle air compressor. The two-stage vehicle air compressor is used as described above. During operation, the compressed pressure value is controlled by controlling the heat dissipation of the cylinder box. When the temperature of the compressed air in the cylinder box is higher than a preset value, and the air pressure after secondary compression is higher than the pressure relief value, the pressure relief air can be introduced into the booster port of the shaft pump seat through the pressure relief pipe, pushing the lubricating oil in the oil guide channel.

[0022] In summary, the present invention has the following beneficial effects:

[0023] The oil pump assembly rotates with the pump shaft, drawing lubricating oil from the bottom of the crankcase and driving it to pump from the inlet to the outlet, thus continuously supplying lubricating oil into the crankshaft's oil guide channels. The lubricating oil in these channels flows along the channels to each shaft section, overflowing from the oil guide ports on each section, ensuring lubrication of all crankshaft components.

[0024] By opening a pressure boosting port outside the shaft pump base and connecting it with a pressure boosting pipe, pressurized gas can be introduced into the oil outlet channel through the pressure boosting pipe. The gas then flows through the oil outlet channel and the oil guide ring groove into the oil guide channel, which can push the lubricating oil in the oil guide channel to reach the shaft position furthest away from the oil pump assembly. Furthermore, the pressurized gas introduced into the pressure boosting port can come from the compressor itself. When the pressure in the secondary air outlet chamber of the cylinder box is too high, the pressure relief valve can be opened under pressure, allowing some air to be discharged from the pressure relief pipe and enter the pressure boosting port, thereby pushing the lubricating oil in the oil guide channel. The high-pressure gas can also clear the blockage in the oil guide channel, thus allowing the subsequent oil to flow smoothly. Attached Figure Description

[0025] Figure 1 This is a perspective view of a two-stage vehicle-mounted air compressor in this embodiment;

[0026] Figure 2 This is a cross-sectional view of a two-stage vehicle-mounted air compressor in this embodiment;

[0027] Figure 3 for Figure 2 A magnified view of a portion of the image;

[0028] Figure 4 This is a partial perspective sectional view of this embodiment;

[0029] Figure 5 This is a partial first transverse sectional view of this embodiment;

[0030] Figure 6 This is a partial second transverse sectional view of this embodiment;

[0031] Figure 7 This is a cross-sectional view of the crankshaft in this embodiment;

[0032] Figure 8 for Figure 7 A magnified view of a portion of the image;

[0033] Figure 9 This is a schematic diagram of the first connection structure between the booster pipe and the oil pump assembly in this embodiment;

[0034] Figure 10 This is a perspective view of another two-stage vehicle-mounted air compressor in this embodiment;

[0035] Figure 11 This is a schematic diagram of the second connection structure between the booster pipe and the oil pump assembly in this embodiment;

[0036] Figure 12 This is a schematic diagram of the pressure relief pipe and the two branch pipes in this embodiment.

[0037] Reference numerals: Crankcase 1; Pressure relief connection 101; Motor 2; Cylinder housing 3; First-stage cylinder block 31; First-stage piston 311; First-stage connecting rod 312; Second-stage cylinder block 32; Second-stage piston 321; Second-stage connecting rod 322; Partition 33; Through hole 1 331; Through hole 2 332; Through hole 333; Through hole 4 334; Connecting hole 1 335; Connecting hole 2 336; One-way valve structure 35; Cylinder head 34; First-stage intake chamber 341; First-stage exhaust chamber 342; Second-stage intake chamber 343; Second-stage exhaust chamber 344; Inlet 345; Outlet 346; Pressure relief port 347; Cooling fan 4; 5. Oil pump assembly; 500. Shaft hole; 501. Pump seat; 502. Pump core; 503. Pump shaft; 504. Oil inlet channel; 505. Oil inlet port; 506. Oil outlet channel; 507. Oil guide ring groove; 508. Pressure boosting port; 509. Pressure boosting fitting; 5010. Check valve 1; 5012. Check valve 2; 6. Pressure relief pipe; 61. Pressure relief valve; 62. First branch pipe; 621. Control valve 1; 63. Second branch pipe; 631. Control valve 2; 7. Exhaust pipe; 8. Crankshaft; 801. Oil guide channel; 802. Shaft part; 8021. Central shaft part; 8022. Eccentric shaft part; 803. Oil guide port; 9. Air guide connecting pipe. Detailed Implementation

[0038] 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.

[0039] This embodiment discloses a two-stage vehicle-mounted air compressor, referring to... Figures 1-11 The components are described in detail, including crankcase 1, motor 2, cylinder box 3, cooling fan 4, and oil pump assembly 5. Crankcase 1, motor 2, and cylinder box 3 are fixedly connected to each other, and cooling fan 4 can dissipate heat from cylinder box 3.

[0040] Reference Figure 2 , Figure 7 As shown, a crankshaft 8 is rotatably mounted inside the crankcase 1 and driven to rotate by a motor 2. The crankshaft 8 is provided with several shaft portions 802, which can form axial rotational motion and can serve to support the rotation of the crankshaft 8 or connect the piston connecting rod.

[0041] In this embodiment, the crankshaft 8 has four shaft portions 802, namely two central shaft portions 8021 and two eccentric shaft portions 8022. The two central shaft portions 8021 are located at both ends of the crankshaft 8 and can serve as rotational supports. The two eccentric shaft portions 8022 are located at a relatively central position on the crankshaft 8. The two eccentric shaft portions 8022 are eccentrically distributed at 180 degrees to each other. A first-stage connecting rod 312 and a second-stage connecting rod 322 are rotatably mounted on the outer periphery of the two eccentric shaft portions 8022, respectively.

[0042] A primary cylinder block 31 and a secondary cylinder block 32 are machined into the cylinder housing 3. A suitable primary piston 311 and a secondary piston 321 are respectively installed in the primary cylinder block 31 and the secondary cylinder block 32. The primary piston 311 is linked to the crankshaft 8 through the primary connecting rod 312, and the secondary piston 321 is linked to the crankshaft 8 through the secondary connecting rod 322.

[0043] During operation, the motor 2 drives the crankshaft 8 to rotate, and the crankshaft 8 drives the first-stage piston 311 and the second-stage piston 321 through the first-stage connecting rod 312 and the second-stage connecting rod 322 respectively, compressing the air twice.

[0044] Reference Figures 2-6 As shown, a partition plate 33 and a cylinder head 34 are stacked on top of the cylinder box 3. The partition plate 33 and the cylinder head 34 are fixedly connected to the main body of the cylinder box 3 and the connection is sealed, thereby ensuring that the internal chamber of the cylinder box 3 is in a sealed state. Specifically, the cylinder box 3 is provided with a primary exhaust chamber 342, a secondary exhaust chamber 344, a primary intake chamber 341, and a secondary intake chamber 343. The primary intake chamber 341 and the primary exhaust chamber 342 are unidirectionally connected to the primary cylinder block 31, and the secondary intake chamber 343 and the secondary exhaust chamber 344 are unidirectionally connected to the secondary cylinder block 32. Air flows unidirectionally along the primary intake chamber 341, the primary cylinder block 31, the primary exhaust chamber 342, the secondary intake chamber 343, the secondary cylinder block 32, and the secondary exhaust chamber 344.

[0045] Specifically, the primary exhaust chamber 342, secondary exhaust chamber 344, primary intake chamber 341, and secondary intake chamber 343 are all located on the upper side of the partition 33, while the primary cylinder block 31 and secondary cylinder block 32 are located on the lower side of the partition 33. Several through holes are formed in the partition 33 to connect the corresponding chambers to the cylinder blocks. The primary intake chamber 341 is connected to the primary cylinder block 31 via through hole one 331; the primary exhaust chamber 342 is connected to the primary cylinder block 31 via through hole two 332; the secondary intake chamber 343 is connected to the secondary cylinder block 32 via through hole three 333; and the secondary exhaust chamber 344 is connected to the secondary cylinder block 32 via through hole four 334. Furthermore, a one-way valve structure 35 is installed at each of the four through holes; specifically, a one-way valve plate can be used to achieve one-way flow.

[0046] Reference Figure 5 , Figure 6 As shown, the primary exhaust chamber 342 is provided with a connecting hole 335, and the secondary intake chamber 343 is provided with a connecting hole 336. The connecting holes 335 and 336 are connected by an air guide pipe 9, thereby connecting the primary exhaust chamber 342 and the secondary exhaust chamber 344. Air flows unidirectionally through the primary intake chamber 341, the primary cylinder block 31, the primary exhaust chamber 342, the secondary intake chamber 343, the secondary cylinder block 32, and the secondary exhaust chamber 344. The primary intake chamber 341 has an intake port 345, and the secondary exhaust chamber 344 has an exhaust port 346.

[0047] During compressor operation, crankshaft 8 rotates, driving first-stage piston 311 and second-stage piston 321 to achieve piston movement. Outside air enters the first-stage intake chamber 341 through intake port 345. First-stage piston 311 moves downward, drawing air from the first-stage intake chamber 341 into the first-stage cylinder 31. First-stage piston 311 moves upward, compressing the air. The compressed air enters the first-stage outlet chamber 342. The air in the first-stage outlet chamber 342 is input into the second-stage intake chamber 343 through air guide pipe 9. Second-stage piston 321 moves downward, drawing air into the second-stage cylinder 32. Second-stage piston 321 moves upward, compressing the air. The air then enters the second-stage outlet chamber 344, achieving two-stage compression. Finally, the compressed air is discharged from the outlet 346 of the second-stage outlet chamber 344.

[0048] During operation, the crankshaft 8 needs to rotate at each shaft part 802, and the shaft parts 802 need to be lubricated.

[0049] Reference Figure 7 , Figure 8 As shown, an oil guide channel 801 is provided inside the crankshaft 8. The oil guide channel 801 is located inside the crankshaft 8 and is provided along the bending direction of the crankshaft 8. An oil guide port 803 is provided on the outer side of each shaft part 802 to connect with the oil guide channel 801, so that the lubricating oil in the oil guide channel 801 can flow along the oil guide channel 801 to the oil guide port 803 of the shaft part 802, thereby lubricating the outer peripheral rotating connection of the shaft part 802.

[0050] This embodiment also includes an oil pump assembly 5, which is mounted on the crankcase 1 and is located approximately at one end of the crankshaft 8. Typically, the oil pump assembly 5 and the motor 2 are located at opposite ends of the crankshaft 8. The oil pump assembly 5 includes a pump housing 501, a pump core 502, and a pump shaft 503. The pump housing 501 has an end cap structure and is fixedly mounted on the side of the crankcase 1. The pump core 502 and pump shaft 503 are rotatably mounted within the inner cavity of the pump housing 501, with the pump shaft 503 as the center of rotation. The pump core 502 is fixedly mounted outside the pump shaft 503. The pump core 502 is coaxially connected to the crankshaft 8 and can maintain synchronous rotation. A shaft hole 500 is provided on the side of the shaft pump seat 501 facing the crankshaft 8. The shaft portion 802 of the first end of the crankshaft 8 is rotatably connected to the shaft hole 500 of the shaft pump seat 501. The end of the crankshaft 8 and the pump shaft 503 can be inserted into each other to form a rotational linkage. During the rotation of the crankshaft 8, the pump shaft 503 will be driven to run, and the oil pump assembly 5 can realize suction and pumping.

[0051] The pump housing 501 has an oil inlet channel 504 and an oil outlet channel 507. One end of the oil inlet channel 504 is connected to the input side of the pump core 502, and the other end of the oil inlet channel 504 has an oil inlet port 505. An oil inlet pipe 506 is connected to the oil inlet port 505, and the end of the oil inlet pipe 506 is immersed in the lubricating oil at the bottom of the crankcase 1.

[0052] Reference Figure 8 As shown, an oil guide ring groove 508 is provided on the inner circumference of the shaft hole 500 of the shaft pump seat 501. The oil guide ring groove 508 is connected to the oil guide port 803 of the shaft portion 802 at the first end of the crankshaft 8. One end of the oil outlet channel 507 is connected to the output side of the pump core 502, and the other end is connected to the oil guide ring groove 508.

[0053] As the pump core 502 rotates with the pump shaft 503, it can draw lubricating oil from the lubricating oil at the bottom of the crankcase 1, drive the lubricating oil from the oil inlet channel 504 to the oil outlet channel 507, and then enter the oil guide ring groove 508 along the oil outlet channel 507. From the oil guide ring groove 508, it enters the oil guide port 803 at the end of the crankshaft 8 and enters the oil guide channel 801. The lubricating oil will flow sequentially along the oil guide channel 801 to each shaft part 802 of the crankshaft 8, and overflow from the oil guide port 803 of each shaft part 802, thereby lubricating each shaft part 802 of the crankshaft 8.

[0054] Originally, under the suction action of the oil pump assembly 5, the lubricating oil could flow from one end to the other along the oil guide channel 801, lubricating all the shaft parts 802 of the crankshaft 8. After the equipment has been running for a certain period of time, some frictional iron filings and other impurities may be generated in the lubricating oil, which reduces the smoothness of the flow of the lubricating oil in the oil guide channel 801. Moreover, since the crankshaft 8 has a curved structure, its internal oil guide channel 801 also has a curved structure. The lubricating oil also has a certain viscosity. After running for a period of time, the lubricating oil cannot flow smoothly in the oil guide channel 801, resulting in some shaft parts 802 of the crankshaft 8 not being effectively lubricated, especially those parts far from the oil pump assembly 5.

[0055] Reference Figure 8 As shown, in this embodiment, the oil outlet channel 507 is also provided with a connected pressure boosting port 509, which is specifically located on the side opposite to the pump core 502. The pressure boosting port 509 is connected to a pressure boosting pipe 5010, through which pressurized gas can be introduced into the oil outlet channel 507, flowing through the oil outlet channel 507 and the oil guide ring groove 508 into the oil guide channel 801. This can promote the flow of lubricating oil in the oil guide channel 801, allowing the lubricating oil in the oil guide channel 801 to reach the shaft portion 802 furthest away from the oil pump assembly 5. At the same time, the oil pump assembly 5 can continuously draw lubricating oil into the oil guide channel 801, continuously replenishing the lubricating oil in the oil guide channel 801.

[0056] In addition, in this embodiment, the pressurized gas introduced into the booster port 509 can come from the compressor itself. This embodiment also includes a pressure relief pipe 6 and a pressure relief valve 61. A pressure relief port 347 is provided in the secondary outlet chamber 344 of the cylinder box 3. The pressure relief valve 61 is installed in the pressure relief port 347 of the cylinder box 3. One end of the pressure relief pipe 6 is connected to the pressure relief side of the pressure relief valve 61, and the other end is used to guide gas to the booster port 509. When the pressure in the secondary outlet chamber 344 of the cylinder box 3 is too high, the pressure relief valve 61 can be opened under pressure, allowing some air to be discharged from the pressure relief pipe 6 and enter the booster port 509, thereby pushing the lubricating oil in the oil guide channel 801. The high-pressure gas can also clear the oil guide channel 801, thus allowing the subsequent oil to flow smoothly.

[0057] Reference Figure 1 , Figure 8 , Figure 9 As shown, a pressure relief connection 101 is provided on the outside of the crankcase 1, and the end of the pressure relief pipe 6 is connected to the pressure relief connection 101. The pressure relief connection 101 and the pressure boosting port 509 are connected by a pressure boosting fitting 5010. Specifically, the pressure boosting fitting 5010 can be a fitting with a corresponding bending shape for connection. Alternatively, refer to... Figure 11As shown, the pressure relief connection 101 on the outside of the crankcase 1 is located directly above the pressure boosting port 509. A pressure boosting pipe 5010 is inserted directly downwards into the pressure relief connection 101, and the pressure boosting pipe 5010 can be sealed into the pressure boosting port 509 to achieve a sealed connection. The pressure boosting pipe 5010 can be shaped according to the position of the pressure relief connection 101 to facilitate communication between the pressure relief pipe 6 and the pressure boosting port 509.

[0058] In order to maintain the pressure balance inside the crankcase 1, an exhaust pipe 7 can be connected to the upper side of the crankcase 1 to discharge the gas introduced into the crankcase 1 in a timely manner, so as to maintain the operational stability of the crankcase 1.

[0059] In addition, to prevent pressurized gas introduced through the booster port 509 from entering the pump core 502 and thus avoiding pressure loss, a second check valve 5012 can be installed in the oil outlet channel 507. Both the guide ring groove 508 and the booster port 509 are located on the side of the second check valve 5012 facing away from the pump core 502. The second check valve 5012 can unidirectionally guide from the pump core 502 towards the guide ring groove 508, while simultaneously blocking flow from the booster port 509 towards the pump core 502, thereby ensuring smooth flow and guaranteeing that the introduced pressurized gas can effectively enter the oil outlet channel 507 to drive the oil.

[0060] Furthermore, a check valve 5011 is installed inside the pressure boosting fitting 5010 (or at the pressure boosting port 509). The check valve 5011 can conduct unidirectionally from the pressure boosting fitting 5010 to the pressure boosting port 509, while simultaneously cutting off flow from the pressure boosting port 509 to the pressure boosting fitting 5010. This prevents lubricating oil from overflowing towards the pressure boosting port 509 and the pressure boosting fitting 5010, and prevents oil from flowing back into the pressure relief pipe 6.

[0061] In this embodiment, by controlling the heat dissipation of the cylinder box 3, the temperature after two compressions in the cylinder box 3 is controlled, thereby controlling the pressure of the gas in the secondary exhaust chamber 344, thus achieving partial gas depressurization and exhaust. The depressurized and exhausted air then promotes the smooth flow of lubricating oil within the crankshaft 8. In different temperature environments, the appropriate depressurization pressure can be adjusted by regulating the pressure relief valve 61.

[0062] Reference Figure 1 , Figure 2 , Figure 5 As shown, the air guide pipe 9 is located outside the cylinder housing 3. Additionally, the two-stage vehicle air compressor in this embodiment also includes a cooling fan 4, which can dissipate heat from the air guide pipe 9 and the cylinder housing 3. In the two-stage vehicle air compressor, the air guide pipe 9 is located between the cooling fan 4 and the cylinder housing 3, and the air blown out by the cooling fan 4 can provide air cooling for both the air guide pipe 9 and the cylinder housing 3.

[0063] Alternatively, water cooling can be used in this embodiment. Specifically, a corresponding water flow path can be opened in the cylinder box 3 to effectively achieve temperature control and heat dissipation.

[0064] This embodiment also discloses a control method for a two-stage vehicle air compressor, which controls the two-stage vehicle air compressor as described in the above embodiment. During the operation of the two-stage vehicle air compressor, the pressure value after compression is controlled by controlling the heat dissipation of the cylinder box 3.

[0065] Specifically, the cooling fan 4 dissipates heat from the air guide pipe 9 and the cylinder box 3. During operation, the pressure in the secondary exhaust chamber 344 of the cylinder box 3 remains within the pressure limit range, and the air does not need to be depressurized. The heat dissipation of the cooling fan 4 can be reduced periodically, specifically by reducing the fan speed. At this time, the heat dissipation of the cylinder box 3 decreases, and the temperature will rise.

[0066] After the temperature of cylinder box 3 rises, the pressure of the same amount of air introduced will increase. When the temperature of the compressed air in cylinder box 3 is higher than the preset value, the pressure of the air after secondary compression is higher than the pressure relief value. The depressurized air can enter the pressure boosting port 509 of shaft pump seat 501 through pressure relief pipe 6, pushing the lubricating oil in oil guide channel 801. Then, the cooling fan 4 can be restarted to lower the temperature back to the corresponding level, and cylinder box 3 will stop depressurizing. This intermittent pressurization and unblocking of the lubricating oil in oil guide channel 801 can ensure that subsequent lubrication can always flow stably and smoothly.

[0067] Additionally, refer to Figure 12 As shown, the pressure relief pipe 6 can be configured to form two branch structures, namely a first branch pipe 62 and a second branch pipe 63. The first branch pipe 62 is connected to the pressure boosting port 509 to boost the oil guide passage 801. The second branch pipe 63 is directly connected to the external environment, which can directly relieve pressure and exhaust gas to the external environment. Control valve 621 and control valve 631 are installed on the first branch pipe 62 and the second branch pipe 63 respectively, so that the first branch pipe 62 and the second branch pipe 63 can be controlled separately to achieve different handling actions under pressure relief conditions.

[0068] 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 two-stage vehicle-mounted air compressor, characterized in that, The system includes a crankcase (1), a cylinder box (3), and an oil pump assembly (5). A crankshaft (8) is rotatably mounted inside the crankcase (1). The crankshaft (8) has an oil guide channel (801) inside and several shaft portions (802) are provided. Each shaft portion (802) has an oil guide port (803) on its outer side that connects to the oil guide channel (801). The oil pump assembly (5) includes a pump housing (501) and a pump core (502). 502) and pump shaft (503), the shaft pump seat (501) is installed in the crankcase (1), the shaft part (802) at the first end of the crankshaft (8) is rotatably connected in the shaft hole (500) of the shaft pump seat (501), and an oil guide ring groove (508) is provided in the inner circumference of the shaft hole (500) of the shaft pump seat (501), and the oil guide ring groove (508) is connected to the oil guide port (803) of the shaft part (802) at the first end of the crankshaft (8); The shaft pump base (501) is provided with an oil inlet channel (504) and an oil outlet channel (507). The pump core (502) can drive lubricating oil to be pumped from the oil inlet channel (504) to the oil outlet channel (507). The oil inlet channel (504) is provided with an oil inlet (505), the oil outlet channel (507) is connected to the oil guide ring groove (508), and a booster port (509) is provided on the side of the oil outlet channel (507) facing away from the pump core (502). It also includes a pressure relief pipe (6) and a pressure relief valve (61). The pressure relief valve (61) is installed at the pressure relief port (347) of the cylinder box (3). One end of the pressure relief pipe (6) is connected to the pressure relief side of the pressure relief valve (61), and the other end is used to guide air to the boost port (509). The cylinder box (3) is provided with a primary exhaust chamber (342) and a secondary exhaust chamber (344), and the secondary exhaust chamber (344) is provided with the pressure relief port (347).

2. A two-stage vehicle-mounted air compressor according to claim 1, characterized in that, One end of the oil inlet channel (504) is connected to the input side of the pump core (502), and the oil inlet (505) is located at the other end of the oil inlet channel (504). The oil inlet (505) is connected to the oil inlet pipe (506), and the end of the oil inlet pipe (506) is immersed in the lubricating oil at the bottom of the crankcase (1).

3. A two-stage vehicle-mounted air compressor according to claim 1, characterized in that, The crankcase (1) is provided with a pressure relief connection (101) on the outside. The pressure relief pipe (6) is connected to the pressure relief connection (101). The pressure relief connection (101) and the pressure boosting port (509) are connected through a pressure boosting fitting (5010).

4. A two-stage vehicle-mounted air compressor according to claim 3, characterized in that, The pressure boosting fitting (5010) is equipped with a check valve (5011), which is capable of unidirectional flow from the pressure boosting fitting (5010) to the pressure boosting port (509).

5. A two-stage vehicle-mounted air compressor according to claim 1, characterized in that, A check valve 2 (5012) is installed in the oil outlet channel (507). The check valve 2 (5012) can unidirectionally guide the oil flow from the pump core (502) to the oil guide ring groove (508). The oil guide ring groove (508) and the booster port (509) are both located on the side of the check valve 2 (5012) facing away from the pump core (502). An exhaust pipe (7) is connected to the upper side of the crankcase (1).

6. A two-stage vehicle-mounted air compressor according to claim 1, characterized in that, The pump core (502) and pump shaft (503) are rotatably mounted in the shaft pump seat (501). The pump core (502) is coaxially connected to the crankshaft (8) and can maintain synchronous rotation.

7. A two-stage vehicle-mounted air compressor according to claim 1, characterized in that, The primary exhaust chamber (342) and the secondary exhaust chamber (344) are connected by an air guide pipe (9), which is located outside the cylinder box (3); a cooling fan (4) is also included, which is used to dissipate heat from the air guide pipe (9) and the cylinder box (3).

8. A two-stage vehicle-mounted air compressor according to claim 7, characterized in that, The cylinder box (3) is also provided with a primary intake chamber (341) and a secondary intake chamber (343); the cylinder box (3) is also provided with a primary cylinder block (31) and a secondary cylinder block (32). The primary intake chamber (341) and the primary exhaust chamber (342) are unidirectionally connected to the primary cylinder block (31), and the secondary intake chamber (343) and the secondary exhaust chamber (344) are unidirectionally connected to the secondary cylinder block (32). Air flows unidirectionally along the primary intake chamber (341), the primary cylinder block (31), the primary exhaust chamber (342), the secondary intake chamber (343), the secondary cylinder block (32), and the secondary exhaust chamber (344); the primary intake chamber (341) is provided with an intake port (345), and the secondary exhaust chamber (344) is provided with an exhaust port (346).

9. A two-stage vehicle-mounted air compressor according to claim 8, characterized in that, The first-stage cylinder (31) and the second-stage cylinder (32) are respectively provided with a first-stage piston (311) and a second-stage piston (321). The first-stage piston (311) is linked to the crankshaft (8) through a first-stage connecting rod (312), and the second-stage piston (321) is linked to the crankshaft (8) through a second-stage connecting rod (322). The crankshaft (8) is provided with four shaft parts (802), namely two central shaft parts (8021) and two eccentric shaft parts (8022). The crankshaft (8) is rotatably supported by the two central shaft parts (8021), and a first-stage connecting rod (312) and a second-stage connecting rod (322) are rotatably mounted on the outer periphery of the two eccentric shaft parts (8022).

10. A control method for a two-stage vehicle air compressor, using a two-stage vehicle air compressor as described in any one of claims 1-9, wherein during the operation of the two-stage vehicle air compressor, the pressure value after compression is controlled by controlling the heat dissipation of the cylinder box (3); when the air temperature after compression in the cylinder box (3) is higher than a preset value, and the air pressure after secondary compression is higher than the pressure relief value, the pressure relief air can be introduced from the pressure relief pipe (6) into the booster port (509) of the shaft pump seat (501) to push the lubricating oil in the oil guide channel (801).

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