Ventilation structure of a crankcase

Abstract

The application provides a ventilation structure of a crankcase and belongs to the technical field of engines. The technical problem that the oil containing impurities driven by airflow flows back to the oil pan through the one-way valve and affects the quality of circulating oil when the ventilation structure of the existing crankcase works normally is solved. In the ventilation structure of the crankcase, the crankcase comprises a crank chamber and a ventilation chamber, the ventilation structure comprises a one-way valve plate which can only make the air in the crank chamber flow into the ventilation chamber, the inner side wall of the ventilation chamber is provided with a backflow groove, the inner cavity of the backflow groove is communicated with the crank chamber, the one-way valve plate is arranged in the up-down direction and can close the opening of the backflow groove, the upper end of the one-way valve plate is a free end, and the lower end of the one-way valve plate is fixedly connected to the opening end surface of the backflow groove. The ventilation structure of the crankcase ensures the quality of oil circulation under the condition of realizing the pressure stability of the crank chamber.

Description

Technical Field

[0001] This invention belongs to the field of engine technology and relates to a crankcase ventilation structure. Background Technology

[0002] When the engine is running, the high-pressure combustible mixture and burned gases in the combustion chamber will leak into the crankcase to some extent through the gap between the piston assembly and the cylinder, causing blow-by. Blow-by consists of unburned fuel vapor, water vapor, and exhaust gases, which dilute the engine oil, reduce its performance, and accelerate its oxidation and deterioration. Water vapor condenses in the engine oil, forming sludge and clogging the oil passages; acidic gases in the exhaust mix with the lubrication system, leading to corrosion and accelerated wear of engine parts; blow-by can also cause excessive pressure in the crankcase, damaging the crankcase seal and causing oil leakage. To prevent excessive crankcase pressure, extend the service life of the engine oil, reduce wear and corrosion of parts, and prevent engine oil leaks, crankcase ventilation is essential.

[0003] Patent application CN102042055A discloses an engine equipped with a ventilation mechanism. The ventilation mechanism includes: a ventilation passage leading to a crankcase; a ventilation chamber communicating with the crankcase via the ventilation passage; and a ventilation valve disposed within the ventilation chamber, which opens when the internal pressure of the crankcase exceeds a predetermined value, allowing blow-by gas to flow from the crankcase into the ventilation chamber.

[0004] The above structure can achieve the ventilation effect of crankcase, but when the engine is working normally, the oil containing impurities carried by the airflow will flow back to the oil pan through the one-way valve, affecting the quality of the circulating oil. Summary of the Invention

[0005] In view of the above-mentioned problems existing in the prior art, the present invention provides a crankcase ventilation structure. The technical problem to be solved by the present invention is to achieve stable air pressure while ensuring the quality of engine oil.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] A ventilation structure for a crankcase, the crankcase including a crankcase chamber and a ventilation chamber, the ventilation structure including a one-way valve that allows only air from the crankcase chamber to flow into the ventilation chamber, characterized in that the inner wall of the ventilation chamber has a return groove, the inner cavity of the return groove is connected to the crankcase chamber, the one-way valve is arranged vertically to close the opening of the return groove, the upper end of the one-way valve is a free end, and the lower end of the one-way valve is fixedly connected to the open end face of the return groove.

[0008] The crankshaft chamber houses the crankshaft body and connecting rod components. The vent chamber is adjacent to the crankshaft chamber and is used to guide and utilize the gas discharged due to increased pressure within the crankshaft chamber. The crankshaft chamber and vent chamber are connected to ensure smooth gas flow after pressure relief. A one-way valve ensures the airtightness of the internal environment of the crankshaft chamber. A return groove is provided on the inner wall of the vent chamber, and the one-way valve, positioned vertically, closes the opening of the return groove. The free end of the one-way valve is located at the upper end, and the lower end of the one-way valve is fixed to the open end face of the return groove. This allows the pressurized air in the crankcase to close the upper end of the one-way valve. The oil mist condensed on the one-way valve plate from bottom to top will slide down to the lower end of the return groove. It will be constrained by the one-way valve plate and slowly flow back. The one-way valve plate can be a metal spring plate or a rubber valve plate, etc. At the same time, metal shavings and other impurities generated during engine break-in will also adhere to and collect at the one-way valve plate when the pressurized gas is discharged, and then deposited with the oil at the lower end of the return groove, preventing it from flowing into the lubrication oil circuit and causing mechanical damage. At the same time, the one-way valve plate can be removed during maintenance to easily clean the return groove, ensuring the quality of oil circulation under the condition of stable crankshaft chamber pressure.

[0009] In the aforementioned crankcase ventilation structure, a deposition groove extending to the one-way valve plate is formed on the bottom surface of the inner cavity of the return groove. This increases the depth of scale buildup, further ensuring that metal shavings and other impurities can be deposited in the deposition groove, making the scale concentrated and preventing random oil backflow, thus ensuring convenient maintenance and oil circulation quality.

[0010] In the aforementioned crankcase ventilation structure, the inner wall of the reflux groove has an opening that communicates with the crankshaft chamber from bottom to top, and the opening is arranged opposite to the deposition tank below. In this way, the oil mist gas flowing from the crankshaft chamber into the reflux groove first flows downwards and contacts the cooled engine oil in the deposition tank, pre-cooling it, before entering the reflux groove and flowing upwards, making long-stroke contact with the one-way valve plate and the inner wall of the reflux groove, further condensing and refluxing, thus improving the reflux and deposition effect.

[0011] In the aforementioned crankcase ventilation structure, a pressure baffle is connected to the opening of the return groove. The one-way valve is clamped between the pressure baffle and the open end face of the return groove. The pressure baffle is strip-shaped, and its upper end is bent away from the one-way valve. This pressure baffle effectively constrains the deformation range of the one-way valve, preventing warping deformation at other locations on the valve and ensuring stable pressure relief and stable impurity deposition.

[0012] In the aforementioned crankcase ventilation structure, the bottom surface of the deposition tank is inclined towards the side where the one-way valve is located. This causes impurities deposited in the deposition tank to accumulate near the one-way valve, preventing them from flowing out of the groove along with the oil when it overflows, thus ensuring effective deposition.

[0013] In the aforementioned crankcase ventilation structure, the pressure baffle is fixed to the open end face of the return groove by bolts arranged circumferentially around the pressure baffle. This arrangement of the one-way valve plate's fixing points around the circumference improves the sealing effect of the one-way valve plate.

[0014] In the aforementioned crankcase ventilation structure, the pressure baffle has several clearance holes. This helps reduce the probability of leakage from the one-way valve plate due to insufficient flatness of the pressure baffle, thus ensuring the sealing effect of the one-way valve plate.

[0015] In the aforementioned crankcase ventilation structure, the inner wall of the ventilation chamber has a protruding ring, and the inner cavity of the protruding ring forms the reflux groove. The one-way valve plate is fixed on the protruding ring. This improves the heat exchange efficiency between the oil mist in the reflux groove and the cooler air in the ventilation chamber, thereby promoting the condensation rate.

[0016] In the aforementioned crankcase ventilation structure, the crankcase is equipped with a combustion chamber and a balance chamber, with the return groove located below the balance chamber. This arrangement of the return groove below the balance chamber, which does not participate in combustion heating, helps to lower the ambient temperature within the passage and improves condensation efficiency.

[0017] Compared with the prior art, the advantages of the present invention are as follows:

[0018] In the ventilation structure of this crankcase, the pressurized air inside the crankcase pushes up the upper end of the one-way valve plate, and the oil mist condensed on the one-way valve plate slides down to the lower end of the return groove and slowly flows back as the liquid level rises. At the same time, metal shavings and other impurities generated during engine break-in will also adhere to and collect at the one-way valve plate when the pressurized air is discharged, and then deposit with the oil at the lower end of the return groove, preventing it from flowing into the lubrication oil passage and causing mechanical damage. In addition, the one-way valve plate can be removed during maintenance to easily clean the groove, ensuring the quality of oil circulation under stable crankcase pressure. Attached Figure Description

[0019] Figure 1 This is a three-dimensional structural diagram of the engine in this embodiment.

[0020] Figure 2 This is a cross-sectional structural diagram of this embodiment.

[0021] Figure 3 yes Figure 2 Enlarged view of part A in the image.

[0022] Figure 4 This is a three-dimensional exploded structural diagram of the hidden portion of the structure in this embodiment.

[0023] Figure 5 yes Figure 4 Enlarged view of part B in the image.

[0024] In the diagram, 1 is the crankshaft chamber; 2 is the ventilation chamber.

[0025] 3. Reflux groove; 31. Sedimentation tank; 32. Through port;

[0026] 4. One-way valve plate;

[0027] 5. Pressure baffle; 51. Through hole;

[0028] 6. Bolts; 7. Raised rings; 8. Combustion cylinder block; 9. Balance cylinder block. Detailed Implementation

[0029] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0030] like Figure 1-5As shown, in the ventilation structure of this crankcase, the crankcase includes a crankcase 1 and a ventilation chamber 2, which are connected. The ventilation structure includes a one-way valve 4 that allows air from the crankcase 1 to flow into the ventilation chamber 2. The inner wall of the ventilation chamber 2 has a return groove 3, and the inner cavity of the return groove 3 is connected to the crankcase 1. The one-way valve 4 is arranged vertically to close the opening of the return groove 3. The upper end of the one-way valve 4 is a free end, and the lower end of the one-way valve 4 is fixed to the open end face of the return groove 3. Crankcase 1 is a chamber that houses the crankshaft body and connecting rod components. Vent chamber 2 is arranged adjacent to crankcase 1 and is used to guide the gas discharged due to increased pressure in crankcase 1. It connects crankcase 1 and vent chamber 2 to achieve smooth gas flow after pressure relief. One-way valve 4 ensures the sealing of the internal environment of crankcase 1. By setting the upper end of one-way valve 4 as a free end and opening a sedimentation groove 31 at the lower end of the return groove 3, the pressurized air in the crankcase will push up the upper end of one-way valve 4. The one-way valve plate 4 is a strip-shaped metal spring. Oil mist condensed on the one-way valve plate 4 slides into the deposit 31. Simultaneously, metal shavings and other impurities generated during engine break-in also adhere to and collect on the one-way valve plate 4 when pressurized air is discharged, thus depositing along with the oil into the deposit trough 31. This prevents the oil from flowing into the lubrication circuit and causing mechanical damage. Furthermore, during maintenance, the one-way valve plate 4 can be disassembled for easy cleaning of the deposit trough 31, ensuring oil circulation quality under stable crankshaft chamber 1 pressure. Further, a pressure baffle 5 is connected to the open end face of the return groove 3. The one-way valve plate 4 is clamped between the pressure baffle 5 and the open end face of the return groove 3. The pressure baffle 5 is strip-shaped, with its upper end bent away from the one-way valve plate 4. This pressure baffle 5 effectively constrains the deformation range of the one-way valve plate 4, preventing warping deformation at other locations and ensuring stable pressure relief and stable impurity deposition. The pressure baffle 5 is fixed to the crankcase by three bolts 6 arranged circumferentially along the pressure baffle 5. This arrangement of the fixing points of the one-way valve plate 4 around the circumference improves the sealing effect of the one-way valve plate 4. The pressure baffle 5 has three clearance holes 51. This reduces the probability of leakage of the one-way valve plate 4 due to insufficient flatness of the pressure baffle 5, ensuring the sealing effect of the one-way valve plate 4. Preferably, the bottom surface of the sedimentation tank 31 is inclined from top to bottom towards the side where the one-way valve plate 4 is located. This causes impurities deposited in the sedimentation tank 31 to accumulate on the side close to the one-way valve plate 4, preventing impurities from flowing out of the sedimentation tank 31 along with the oil when the oil overflows, thus ensuring the sedimentation effect. The inner wall of the return groove 3 has an opening 32 that communicates with the crankcase 1 from bottom to top, and the opening 32 is arranged opposite to the sedimentation tank 31 below. The crankcase is equipped with a combustion block 8 and a balance block 9, which can be existing assemblies. The reflux groove 3 is located below the balance block 9. In this way, the reflux groove 3 is arranged below the balance block 9, which does not participate in the combustion heating, which helps to reduce the ambient temperature within the reflux groove 3 and improve the condensation effect.

[0031] like Figure 4 , Figure 5 As shown, the inner wall of the ventilation chamber 2 has a protruding ring 7, and the inner cavity of the ring 7 forms a reflux groove 3. This improves the heat exchange efficiency between the oil mist in the reflux groove 3 and the cooler air in the ventilation chamber 2, thereby promoting the condensation rate.

[0032] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

Claims

1. A ventilation structure of a crankcase comprising a crank chamber (1) and a scavenge chamber (2), the ventilation structure comprising a one-way valve flap (4) which allows gas flow from the crank chamber (1) only into the scavenge chamber (2), characterized in that, The inner wall of the ventilation chamber (2) has a reflux groove (3), the inner cavity of the reflux groove (3) is connected to the crankshaft chamber (1), the one-way valve plate (4) is arranged in the vertical direction to close the opening of the reflux groove (3), the upper end of the one-way valve plate (4) is a free end, and the lower end of the one-way valve plate (4) is fixed to the open end face of the reflux groove (3); the bottom surface of the inner cavity of the reflux groove (3) is provided with a sedimentation groove (31) extending to the one-way valve plate (4), the bottom surface of the sedimentation groove (31) is inclined downward toward the side where the one-way valve plate (4) is located, the inner wall of the reflux groove (3) has an opening (32) that communicates with the crankshaft chamber (1) from bottom to top, and the opening (32) is arranged opposite to the sedimentation groove (31) below.

2. The ventilation arrangement of the crankcase according to claim 1, characterized in that A pressure baffle (5) is connected to the opening of the reflux groove (3). The one-way valve plate (4) is sandwiched between the pressure baffle (5) and the opening end face of the reflux groove (3). The pressure baffle (5) is strip-shaped and the upper end of the pressure baffle (5) is bent away from the one-way valve plate (4).

3. Crankcase ventilation arrangement according to claim 2, characterized in that The pressure baffle (5) is fixedly connected to the open end face of the return groove (3) by bolts (6) arranged around the pressure baffle (5).

4. The crankcase ventilation structure according to claim 2, characterized by The pressure baffle (5) has several clearance holes (51).

5. The crankcase ventilation structure according to claim 1 or 2, characterized in that, The inner wall of the ventilation chamber (2) has a protruding ring (7), the inner cavity of the protruding ring (7) forms the return groove (3), and the one-way valve plate (4) is fixed on the protruding ring (7).

6. The crankcase ventilation structure according to claim 1, characterized by The crankcase is provided with a combustion cylinder block (8) and a balance cylinder block (9), and the return groove (3) is located below the balance cylinder block (9).

Images