Ventilation Structure for a Crankcase

Abstract

The present disclosure provides a ventilation structure for a crankcase, and belongs to the technical field of engines. In the ventilation structure for a crankcase, the crankcase includes a crankshaft chamber and a ventilation chamber, the ventilation structure includes a one-way valve plate enabling only gas in the crankshaft chamber to flow into the ventilation chamber, an inner side wall of the ventilation chamber is provided with a backflow groove, an inner cavity of the backflow groove communicates with the crankshaft chamber, the one-way valve plate is disposed in an up-down direction and can close an opening of the backflow groove, an upper end of the one-way valve plate is a free end, and a lower end of the one-way valve plate is fixedly connected to an open end face of the backflow groove.

Description

TECHNICAL FIELD

[0001] The present disclosure belongs to the technical field of engines, and relates to a ventilation structure for a crankcase.BACKGROUND

[0002] During operation of an engine, a high-pressure combustible mixed gas and a combusted gas in a combustion chamber leak more or less through a gap between a piston group and a cylinder into a crankcase, resulting in gas blowby. Components of the blow-by gas include unburned fuel gas, water vapor, exhaust gas, and the like, which will dilute engine oil, reduce the performance of the engine oil, and accelerate the oxidation and deterioration of the engine oil. Water vapor condenses in the engine oil, which will form oil sludge, blocking an oil path; acid gases in the exhaust gas are mixed into a lubrication system, causing corrosion and accelerated wear of engine parts; and the blow-by gas can also cause the pressure of the crankcase to be too high, damaging sealing of the crankcase and causing leakage and loss of the engine oil. To prevent excessive pressure of the crankcase, prolong the service life of the engine oil, reduce wear and corrosion of parts, and prevent oil leakage from the engine, crankcase ventilation must be implemented.

[0003] A patent application document with Publication No.: CN102042055A discloses an engine equipped with a breather mechanism. The breather mechanism includes: a breather channel leading to a crankcase; a breather chamber communicating with the crankcase via the breather channel; and a vent valve disposed within the breather chamber, the vent valve being openable to enable blow-by gas to flow into the breather chamber from the crankcase once an internal pressure of the crankcase exceeds a predetermined value.

[0004] The above breather mechanism can achieve the ventilation effect of the crankcase, but during normal operation of the engine, engine oil containing impurities driven by an airflow will flow back to an oil pan of the crankcase through a one-way valve, affecting the quality of circulating engine oil.SUMMARY

[0005] For the above problems in the prior art, the present disclosure provides a ventilation structure for a crankcase. The technical problem to be solved by the present disclosure is to achieve stable air pressure while ensuring the quality of engine oil.

[0006] An object of the present disclosure can be achieved by the following technical solution:

[0007] Provided is a ventilation structure for a crankcase, the crankcase including a crankshaft chamber and a ventilation chamber, the ventilation structure including a one-way valve plate enabling only gas in the crankshaft chamber to flow into the ventilation chamber, wherein an inner side wall of the ventilation chamber is provided with a backflow groove, an inner cavity of the backflow groove communicates with the crankshaft chamber, the one-way valve plate is disposed in an up-down direction and is capable of closing an opening of the backflow groove, an upper end of the one-way valve plate is a free end, and a lower end of the one-way valve plate is fixedly connected to an open end face of the backflow groove.

[0008] The crankshaft chamber is a chamber accommodating a crankshaft body and connecting rod components, the ventilation chamber is arranged adjacent to the crankshaft chamber, and is configured to guide and utilize gas discharged by increasing an air pressure inside the crankshaft chamber, the crankshaft chamber communicates with the ventilation chamber to achieve smooth flow of gas pressure relief, and the one-way valve plate ensures the sealing of the environment inside the crankshaft chamber; and the one-way valve plate may be a metal spring plate or a rubber valve plate or the like. The backflow groove is formed in the inner side wall of the ventilation chamber, the one-way valve plate disposed in the up-down direction closes the opening of the backflow groove, the free end of the one-way valve plate is located at the upper end, and the lower end of the one-way valve plate is fixedly connected to the open end face of the backflow groove, so that pressurized gas within the crankcase will push the upper end of the one-way valve plate open, and oil mist condensed on the one-way valve plate from the bottom up will slide down to the lower end of the backflow groove, and is restricted by the one-way valve plate, and then the oil mist will be collected and slowly flows back, and at the same time, metal chips and other impurities generated during engine running-in will also be adhered and collected at the one-way valve plate as the pressurized gas is discharged, and are then deposited at the lower end of the backflow groove with the engine oil, so as to avoid mechanical damage caused by flowing into a lubricating oil path, and the quality of circulating engine oil is ensured under the condition that the pressure of the crankshaft chamber is stabilized.

[0009] In the ventilation structure for a crankcase described above, a bottom surface of the inner cavity of the backflow groove is provided with a deposition groove extending to the one-way valve plate. A bottom of the inner cavity of the backflow groove is the lower end of the backflow groove. In this way, setting the deposition groove can increase the deposition depth, further ensure that metal chips and other impurities can be deposited in the deposition groove, concentrate depositions without flowing back with the engine oil, and ensure convenience of maintenance and the quality of circulating engine oil.

[0010] In the ventilation structure for a crankcase described above, an inner wall of the backflow groove is provided with a through port communicating with the crankshaft chamber from bottom to top, and the through port is arranged opposite to the deposition groove located below the through port. In this way, oil mist flowing into the backflow groove from the crankshaft chamber will first flow downward to be in contact with engine oil cooled at the deposition groove, so as to be cooled in advance, then enter the backflow groove and flow upward and be in contact with the one-way valve plate and the inner wall of the backflow groove for a long stroke, and further condense and flow back, improving the backflow and deposition effects.

[0011] In the ventilation structure for a crankcase described above, a pressure baffle is connected at the opening of the backflow groove, the one-way valve plate is clamped between the pressure baffle and the open end face of the backflow groove, the pressure baffle has a strip shape, and an upper end of the pressure baffle is bent toward a side away from the one-way valve plate. In this way, the pressure baffle can effectively restrict the deformation range of the one-way valve plate, avoiding warping deformation at other positions of the one-way valve plate, and ensuring stable pressure relief and stable deposition effects of impurities.

[0012] In the ventilation structure for a crankcase described above, a bottom surface of the deposition groove is inclined toward a side where the one-way valve plate is located. In this way, the impurities deposited in the deposition groove will gather on a side close to the one-way valve plate, which can prevent the impurities from flowing out of the backflow groove with the engine oil when the engine oil overflows the backflow groove, ensuring the deposition effect.

[0013] In the ventilation structure for a crankcase described above, the pressure baffle is fixedly connected to the open end face of the backflow groove by bolts arranged circumferentially around the pressure baffle. In this way, fixed points of the one-way valve plate are arranged in a circumferential direction, which is beneficial to improving the sealing effect of the one-way valve plate. Moreover, the backflow groove can be conveniently cleaned after the one-way valve plate is disassembled during maintenance.

[0014] In the ventilation structure for a crankcase described above, the pressure baffle is provided with a plurality of avoidance through holes. In this way, reducing the probability of leakage of the one-way valve plate due to insufficient flatness of the pressure baffle is facilitated, ensuring the sealing effect of the one-way valve plate.

[0015] In the ventilation structure for a crankcase described above, the inner side wall of the ventilation chamber is provided with a protruding convex ring, an inner cavity of the convex ring forms the backflow groove, and the one-way valve plate is fixedly disposed on the convex ring. In this way, the heat exchange efficiency between the oil mist in the backflow groove and a cooler gas in the ventilation chamber is improved, thereby promoting the condensation rate.

[0016] In the ventilation structure for a crankcase described above, the crankcase is provided with a combustion cylinder and a balance cylinder, and the backflow groove is located under the balance cylinder. In this way, the backflow groove is arranged under the balance cylinder, which does not participate in the temperature rise of the combustion, advantageously reducing the ambient temperature in the channel and increasing the condensation effect.

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

[0018] In the ventilation structure for a crankcase, pressurized gas within the crankcase will push the upper end of the one-way valve plate open for ventilation, oil mist condensed on the one-way valve plate will slide down to the lower end of the backflow groove and slowly flows back as a liquid level rises, at the same time, metal chips and other impurities generated during engine running-in will also be adhered and collected at the one-way valve plate as the pressurized gas is discharged, and are then deposited at the lower end of the backflow groove with the engine oil, so as to avoid mechanical damage caused by flowing into a lubricating oil path, and at the same time, the groove can be conveniently cleaned after the one-way valve plate is disassembled during maintenance, thereby ensuring the quality of circulating engine oil under the condition that the pressure of the crankshaft chamber is stabilized.BRIEF DESCRIPTION OF THE DRAWINGS

[0019] FIG. 1 is a schematic perspective structural view of an engine in one embodiment.

[0020] FIG. 2 is a schematic cross-sectional structural diagram taken along a direction P-P of FIG. 1.

[0021] FIG. 3 is an enlarged view of a part A of FIG. 2.

[0022] FIG. 4 is a schematic perspective exploded structural view of a hidden part structure in this embodiment.

[0023] FIG. 5 is an enlarged view of a part B of FIG. 4.

[0024] In the drawings, 1, crankshaft chamber; 2, ventilation chamber;

[0025] 3, backflow groove; 31, deposition groove; 32, through port; 33, opening; 34, open end face;

[0026] 4, one-way valve plate; 41, free end;

[0027] 5, pressure baffle; 51, avoidance through hole;

[0028] 6, bolt; 7, convex ring; 8, combustion cylinder; 9, balance cylinder; and 10, crankcase.DETAILED DESCRIPTION

[0029] The following are specific embodiments of the present disclosure and the technical solutions of the present disclosure are further described with reference to the accompanying drawings, but the present disclosure is not limited to these embodiments.

[0030] As shown in FIGS. 1 and 2, in a ventilation structure for a crankcase, a crankcase 10 includes a crankshaft chamber 1 and a ventilation chamber 2, and the crankshaft chamber 1 communicates with the ventilation chamber 2. The crankshaft chamber 1 is a chamber accommodating a crankshaft body and connecting rod components, and the ventilation chamber 2 is disposed adjacent to the crankshaft chamber 1, and is configured to guide and utilize gas discharged by increasing an air pressure inside the crankshaft chamber 1, and the crankshaft chamber 1 communicates with the ventilation chamber 2 to achieve smooth flow of gas pressure relief.

[0031] As shown in FIGS. 2 and 3, the ventilation structure includes a one-way valve plate 4 enabling only gas in the crankshaft chamber 1 to flow into the ventilation chamber 2. The one-way valve plate 4 is a strip-shaped metal spring plate or a rubber valve plate. An inner side wall of the ventilation chamber 2 is provided with a backflow groove 3, the backflow groove 3 is provided with an opening 33, the inner side wall of the ventilation chamber 2 is provided with an open end face 34 at the opening 33, and an inner cavity of the backflow groove 3 communicates with the crankshaft chamber 1. The one-way valve plate 4 is disposed in an up-down direction and can close the opening 33 of the backflow groove 3. An upper end of the one-way valve plate 4 is a free end 41, and a lower end of the one-way valve plate 4 is fixedly connected to the open end face 34 of the backflow groove 3. A bottom surface of the inner cavity of the backflow groove 3 is provided with a deposition groove 31 extending to the one-way valve plate 4. The one-way valve plate 4 is detachably fixedly connected to the open end face 34 of the backflow groove 3. The one-way valve plate 4 ensures the sealing of the environment inside the crankshaft chamber 1; the upper end of the one-way valve plate 4 is the free end 41, and the deposition groove 31 is formed at a lower end of the backflow groove 3, so that pressurized gas in the crankcase 10 enters the backflow groove 3 from the crankshaft chamber 1, and is in contact with and acts on the one-way valve plate 4, on one hand, the pressurized gas will push the upper end of the one-way valve plate 4 open and is discharged to realize ventilation, on the other hand, engine oil in the form of an oil mist that comes with the pressurized gas will condense when being in contact with the one-way valve plate 4, and the oil mist condensed on the one-way valve plate 4 will slide down into the deposition groove 31 under the action of its own gravity. At the same time, metal chips and other impurities generated during engine running-in will also be adhered to and collected at the one-way valve plate 4 as the pressurized gas is discharged, and are then deposited into the deposition groove 31 will the engine oil to prevent mechanical damage caused by flowing into a lubricating oil path, and at the same time, the deposition groove 31 can be conveniently cleaned after the one-way valve plate 4 is disassembled during maintenance, and the quality of circulating engine oil can be ensured under the condition that the pressure of the crankshaft chamber 1 is stabilized.

[0032] Further, as shown in FIGS. 2 to 5, a pressure baffle 5 is connected to the open end face 34 of the backflow groove 3, the one-way valve plate 4 is clamped between the pressure baffle 5 and the open end face 34 of the backflow groove 3, the pressure baffle 5 has a strip shape, and an upper end of the pressure baffle 5 is bent toward a side away from the one-way valve plate 4. When the pressurized gas acts on the upper end of the one-way valve plate 4, the upper end of the one-way valve plate 4 deforms toward the upper end of the pressure baffle 5 to open an upper side of the opening 33 for pressure relief. In this way, the pressure baffle 5 can effectively restrict the deformation range of the one-way valve plate 4, avoiding warping deformation at other positions of the one-way valve plate 4, and ensuring stable pressure relief and stable deposition effects of impurities. The pressure baffle 5 is fixedly connected to the crankcase 10 by three bolts 6 arranged circumferentially around the pressure baffle 5. In this way, fixed points of the one-way valve plate 4 are arranged in a circumferential direction, which is beneficial to improving the sealing effect of the one-way valve plate 4. The pressure baffle 5 is provided with three avoidance through holes 51. In this way, reducing the probability of leakage of the one-way valve plate 4 due to insufficient flatness of the pressure baffle 5 is facilitated, ensuring the sealing effect of the one-way valve plate 4. Preferably, a bottom surface of the deposition groove 31 is inclined from top to bottom toward a side where the one-way valve plate 4 is located. In this way, the impurities deposited in the deposition groove 31 will gather on a side close to the one-way valve plate 4, which can prevent the impurities from flowing out of the deposition groove 31 with the engine oil when the engine oil overflows the deposition groove 31, ensuring the deposition effect. An inner wall of the backflow groove 3 is provided with a through port 32 communicating with the crankshaft chamber 1 from bottom to top, the inner cavity of the backflow groove 3 communicates with the crankshaft chamber 1 through the through port 32, and the through port 32 is arranged opposite to the deposition groove 31 located below the through port 32. The crankcase 10 is provided with a combustion cylinder 8 and a balance cylinder 9, the combustion cylinder 8 and the balance cylinder 9 may be the existing assembly, and the backflow groove 3 is located under the balance cylinder 9. In this way, the backflow groove 3 is arranged under the balance cylinder 9, which does not participate in the temperature rise of the combustion, advantageously reducing the ambient temperature in the backflow groove 3 and increasing the condensation effect.

[0033] As shown in FIGS. 4 and 5, the inner side wall of the ventilation chamber 2 is provided with a protruding convex ring 7, an inner cavity of the convex ring 7 forms the backflow groove 3, one end, facing away from the crankshaft chamber 1, of the convex ring 7 is provided with the opening 33, and an end face, provided with the opening 33, of the convex ring 7 is the open end face 34. In this way, the heat exchange efficiency between the oil mist in the backflow groove 3 and relatively cold air in the ventilation chamber 2 is improved, thereby promoting the condensation rate.

[0034] The specific embodiments described herein are merely illustrative of the spirit of the present disclosure. Those skilled in the art to which the present disclosure belongs may make various modifications or supplements or similar substitutions to the specific embodiments described without departing from the spirit of the present disclosure or being beyond the scope defined by the appended claims.

Examples

Embodiment Construction

[0029]The following are specific embodiments of the present disclosure and the technical solutions of the present disclosure are further described with reference to the accompanying drawings, but the present disclosure is not limited to these embodiments.

[0030]As shown in FIGS. 1 and 2, in a ventilation structure for a crankcase, a crankcase 10 includes a crankshaft chamber 1 and a ventilation chamber 2, and the crankshaft chamber 1 communicates with the ventilation chamber 2. The crankshaft chamber 1 is a chamber accommodating a crankshaft body and connecting rod components, and the ventilation chamber 2 is disposed adjacent to the crankshaft chamber 1, and is configured to guide and utilize gas discharged by increasing an air pressure inside the crankshaft chamber 1, and the crankshaft chamber 1 communicates with the ventilation chamber 2 to achieve smooth flow of gas pressure relief.

[0031]As shown in FIGS. 2 and 3, the ventilation structure includes a one-way valve plate 4 enabli...

TECHNICAL FIELD

[0001] The present disclosure belongs to the technical field of engines, and relates to a ventilation structure for a crankcase.BACKGROUND

[0002] During operation of an engine, a high-pressure combustible mixed gas and a combusted gas in a combustion chamber leak more or less through a gap between a piston group and a cylinder into a crankcase, resulting in gas blowby. Components of the blow-by gas include unburned fuel gas, water vapor, exhaust gas, and the like, which will dilute engine oil, reduce the performance of the engine oil, and accelerate the oxidation and deterioration of the engine oil. Water vapor condenses in the engine oil, which will form oil sludge, blocking an oil path; acid gases in the exhaust gas are mixed into a lubrication system, causing corrosion and accelerated wear of engine parts; and the blow-by gas can also cause the pressure of the crankcase to be too high, damaging sealing of the crankcase and causing leakage and loss of the engine oil. To prevent excessive pressure of the crankcase, prolong the service life of the engine oil, reduce wear and corrosion of parts, and prevent oil leakage from the engine, crankcase ventilation must be implemented.

[0003] A patent application document with Publication No.: CN102042055A discloses an engine equipped with a breather mechanism. The breather mechanism includes: a breather channel leading to a crankcase; a breather chamber communicating with the crankcase via the breather channel; and a vent valve disposed within the breather chamber, the vent valve being openable to enable blow-by gas to flow into the breather chamber from the crankcase once an internal pressure of the crankcase exceeds a predetermined value.

[0004] The above breather mechanism can achieve the ventilation effect of the crankcase, but during normal operation of the engine, engine oil containing impurities driven by an airflow will flow back to an oil pan of the crankcase through a one-way valve, affecting the quality of circulating engine oil.SUMMARY

[0005] For the above problems in the prior art, the present disclosure provides a ventilation structure for a crankcase. The technical problem to be solved by the present disclosure is to achieve stable air pressure while ensuring the quality of engine oil.

[0006] An object of the present disclosure can be achieved by the following technical solution:

[0007] Provided is a ventilation structure for a crankcase, the crankcase including a crankshaft chamber and a ventilation chamber, the ventilation structure including a one-way valve plate enabling only gas in the crankshaft chamber to flow into the ventilation chamber, wherein an inner side wall of the ventilation chamber is provided with a backflow groove, an inner cavity of the backflow groove communicates with the crankshaft chamber, the one-way valve plate is disposed in an up-down direction and is capable of closing an opening of the backflow groove, an upper end of the one-way valve plate is a free end, and a lower end of the one-way valve plate is fixedly connected to an open end face of the backflow groove.

[0008] The crankshaft chamber is a chamber accommodating a crankshaft body and connecting rod components, the ventilation chamber is arranged adjacent to the crankshaft chamber, and is configured to guide and utilize gas discharged by increasing an air pressure inside the crankshaft chamber, the crankshaft chamber communicates with the ventilation chamber to achieve smooth flow of gas pressure relief, and the one-way valve plate ensures the sealing of the environment inside the crankshaft chamber; and the one-way valve plate may be a metal spring plate or a rubber valve plate or the like. The backflow groove is formed in the inner side wall of the ventilation chamber, the one-way valve plate disposed in the up-down direction closes the opening of the backflow groove, the free end of the one-way valve plate is located at the upper end, and the lower end of the one-way valve plate is fixedly connected to the open end face of the backflow groove, so that pressurized gas within the crankcase will push the upper end of the one-way valve plate open, and oil mist condensed on the one-way valve plate from the bottom up will slide down to the lower end of the backflow groove, and is restricted by the one-way valve plate, and then the oil mist will be collected and slowly flows back, and at the same time, metal chips and other impurities generated during engine running-in will also be adhered and collected at the one-way valve plate as the pressurized gas is discharged, and are then deposited at the lower end of the backflow groove with the engine oil, so as to avoid mechanical damage caused by flowing into a lubricating oil path, and the quality of circulating engine oil is ensured under the condition that the pressure of the crankshaft chamber is stabilized.

[0009] In the ventilation structure for a crankcase described above, a bottom surface of the inner cavity of the backflow groove is provided with a deposition groove extending to the one-way valve plate. A bottom of the inner cavity of the backflow groove is the lower end of the backflow groove. In this way, setting the deposition groove can increase the deposition depth, further ensure that metal chips and other impurities can be deposited in the deposition groove, concentrate depositions without flowing back with the engine oil, and ensure convenience of maintenance and the quality of circulating engine oil.

[0010] In the ventilation structure for a crankcase described above, an inner wall of the backflow groove is provided with a through port communicating with the crankshaft chamber from bottom to top, and the through port is arranged opposite to the deposition groove located below the through port. In this way, oil mist flowing into the backflow groove from the crankshaft chamber will first flow downward to be in contact with engine oil cooled at the deposition groove, so as to be cooled in advance, then enter the backflow groove and flow upward and be in contact with the one-way valve plate and the inner wall of the backflow groove for a long stroke, and further condense and flow back, improving the backflow and deposition effects.

[0011] In the ventilation structure for a crankcase described above, a pressure baffle is connected at the opening of the backflow groove, the one-way valve plate is clamped between the pressure baffle and the open end face of the backflow groove, the pressure baffle has a strip shape, and an upper end of the pressure baffle is bent toward a side away from the one-way valve plate. In this way, the pressure baffle can effectively restrict the deformation range of the one-way valve plate, avoiding warping deformation at other positions of the one-way valve plate, and ensuring stable pressure relief and stable deposition effects of impurities.

[0012] In the ventilation structure for a crankcase described above, a bottom surface of the deposition groove is inclined toward a side where the one-way valve plate is located. In this way, the impurities deposited in the deposition groove will gather on a side close to the one-way valve plate, which can prevent the impurities from flowing out of the backflow groove with the engine oil when the engine oil overflows the backflow groove, ensuring the deposition effect.

[0013] In the ventilation structure for a crankcase described above, the pressure baffle is fixedly connected to the open end face of the backflow groove by bolts arranged circumferentially around the pressure baffle. In this way, fixed points of the one-way valve plate are arranged in a circumferential direction, which is beneficial to improving the sealing effect of the one-way valve plate. Moreover, the backflow groove can be conveniently cleaned after the one-way valve plate is disassembled during maintenance.

[0014] In the ventilation structure for a crankcase described above, the pressure baffle is provided with a plurality of avoidance through holes. In this way, reducing the probability of leakage of the one-way valve plate due to insufficient flatness of the pressure baffle is facilitated, ensuring the sealing effect of the one-way valve plate.

[0015] In the ventilation structure for a crankcase described above, the inner side wall of the ventilation chamber is provided with a protruding convex ring, an inner cavity of the convex ring forms the backflow groove, and the one-way valve plate is fixedly disposed on the convex ring. In this way, the heat exchange efficiency between the oil mist in the backflow groove and a cooler gas in the ventilation chamber is improved, thereby promoting the condensation rate.

[0016] In the ventilation structure for a crankcase described above, the crankcase is provided with a combustion cylinder and a balance cylinder, and the backflow groove is located under the balance cylinder. In this way, the backflow groove is arranged under the balance cylinder, which does not participate in the temperature rise of the combustion, advantageously reducing the ambient temperature in the channel and increasing the condensation effect.

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

[0018] In the ventilation structure for a crankcase, pressurized gas within the crankcase will push the upper end of the one-way valve plate open for ventilation, oil mist condensed on the one-way valve plate will slide down to the lower end of the backflow groove and slowly flows back as a liquid level rises, at the same time, metal chips and other impurities generated during engine running-in will also be adhered and collected at the one-way valve plate as the pressurized gas is discharged, and are then deposited at the lower end of the backflow groove with the engine oil, so as to avoid mechanical damage caused by flowing into a lubricating oil path, and at the same time, the groove can be conveniently cleaned after the one-way valve plate is disassembled during maintenance, thereby ensuring the quality of circulating engine oil under the condition that the pressure of the crankshaft chamber is stabilized.BRIEF DESCRIPTION OF THE DRAWINGS

[0019] FIG. 1 is a schematic perspective structural view of an engine in one embodiment.

[0020] FIG. 2 is a schematic cross-sectional structural diagram taken along a direction P-P of FIG. 1.

[0021] FIG. 3 is an enlarged view of a part A of FIG. 2.

[0022] FIG. 4 is a schematic perspective exploded structural view of a hidden part structure in this embodiment.

[0023] FIG. 5 is an enlarged view of a part B of FIG. 4.

[0024] In the drawings, 1, crankshaft chamber; 2, ventilation chamber;

[0025] 3, backflow groove; 31, deposition groove; 32, through port; 33, opening; 34, open end face;

[0026] 4, one-way valve plate; 41, free end;

[0027] 5, pressure baffle; 51, avoidance through hole;

[0028] 6, bolt; 7, convex ring; 8, combustion cylinder; 9, balance cylinder; and 10, crankcase.DETAILED DESCRIPTION

[0029] The following are specific embodiments of the present disclosure and the technical solutions of the present disclosure are further described with reference to the accompanying drawings, but the present disclosure is not limited to these embodiments.

[0030] As shown in FIGS. 1 and 2, in a ventilation structure for a crankcase, a crankcase 10 includes a crankshaft chamber 1 and a ventilation chamber 2, and the crankshaft chamber 1 communicates with the ventilation chamber 2. The crankshaft chamber 1 is a chamber accommodating a crankshaft body and connecting rod components, and the ventilation chamber 2 is disposed adjacent to the crankshaft chamber 1, and is configured to guide and utilize gas discharged by increasing an air pressure inside the crankshaft chamber 1, and the crankshaft chamber 1 communicates with the ventilation chamber 2 to achieve smooth flow of gas pressure relief.

[0031] As shown in FIGS. 2 and 3, the ventilation structure includes a one-way valve plate 4 enabling only gas in the crankshaft chamber 1 to flow into the ventilation chamber 2. The one-way valve plate 4 is a strip-shaped metal spring plate or a rubber valve plate. An inner side wall of the ventilation chamber 2 is provided with a backflow groove 3, the backflow groove 3 is provided with an opening 33, the inner side wall of the ventilation chamber 2 is provided with an open end face 34 at the opening 33, and an inner cavity of the backflow groove 3 communicates with the crankshaft chamber 1. The one-way valve plate 4 is disposed in an up-down direction and can close the opening 33 of the backflow groove 3. An upper end of the one-way valve plate 4 is a free end 41, and a lower end of the one-way valve plate 4 is fixedly connected to the open end face 34 of the backflow groove 3. A bottom surface of the inner cavity of the backflow groove 3 is provided with a deposition groove 31 extending to the one-way valve plate 4. The one-way valve plate 4 is detachably fixedly connected to the open end face 34 of the backflow groove 3. The one-way valve plate 4 ensures the sealing of the environment inside the crankshaft chamber 1; the upper end of the one-way valve plate 4 is the free end 41, and the deposition groove 31 is formed at a lower end of the backflow groove 3, so that pressurized gas in the crankcase 10 enters the backflow groove 3 from the crankshaft chamber 1, and is in contact with and acts on the one-way valve plate 4, on one hand, the pressurized gas will push the upper end of the one-way valve plate 4 open and is discharged to realize ventilation, on the other hand, engine oil in the form of an oil mist that comes with the pressurized gas will condense when being in contact with the one-way valve plate 4, and the oil mist condensed on the one-way valve plate 4 will slide down into the deposition groove 31 under the action of its own gravity. At the same time, metal chips and other impurities generated during engine running-in will also be adhered to and collected at the one-way valve plate 4 as the pressurized gas is discharged, and are then deposited into the deposition groove 31 will the engine oil to prevent mechanical damage caused by flowing into a lubricating oil path, and at the same time, the deposition groove 31 can be conveniently cleaned after the one-way valve plate 4 is disassembled during maintenance, and the quality of circulating engine oil can be ensured under the condition that the pressure of the crankshaft chamber 1 is stabilized.

[0032] Further, as shown in FIGS. 2 to 5, a pressure baffle 5 is connected to the open end face 34 of the backflow groove 3, the one-way valve plate 4 is clamped between the pressure baffle 5 and the open end face 34 of the backflow groove 3, the pressure baffle 5 has a strip shape, and an upper end of the pressure baffle 5 is bent toward a side away from the one-way valve plate 4. When the pressurized gas acts on the upper end of the one-way valve plate 4, the upper end of the one-way valve plate 4 deforms toward the upper end of the pressure baffle 5 to open an upper side of the opening 33 for pressure relief. In this way, the pressure baffle 5 can effectively restrict the deformation range of the one-way valve plate 4, avoiding warping deformation at other positions of the one-way valve plate 4, and ensuring stable pressure relief and stable deposition effects of impurities. The pressure baffle 5 is fixedly connected to the crankcase 10 by three bolts 6 arranged circumferentially around the pressure baffle 5. In this way, fixed points of the one-way valve plate 4 are arranged in a circumferential direction, which is beneficial to improving the sealing effect of the one-way valve plate 4. The pressure baffle 5 is provided with three avoidance through holes 51. In this way, reducing the probability of leakage of the one-way valve plate 4 due to insufficient flatness of the pressure baffle 5 is facilitated, ensuring the sealing effect of the one-way valve plate 4. Preferably, a bottom surface of the deposition groove 31 is inclined from top to bottom toward a side where the one-way valve plate 4 is located. In this way, the impurities deposited in the deposition groove 31 will gather on a side close to the one-way valve plate 4, which can prevent the impurities from flowing out of the deposition groove 31 with the engine oil when the engine oil overflows the deposition groove 31, ensuring the deposition effect. An inner wall of the backflow groove 3 is provided with a through port 32 communicating with the crankshaft chamber 1 from bottom to top, the inner cavity of the backflow groove 3 communicates with the crankshaft chamber 1 through the through port 32, and the through port 32 is arranged opposite to the deposition groove 31 located below the through port 32. The crankcase 10 is provided with a combustion cylinder 8 and a balance cylinder 9, the combustion cylinder 8 and the balance cylinder 9 may be the existing assembly, and the backflow groove 3 is located under the balance cylinder 9. In this way, the backflow groove 3 is arranged under the balance cylinder 9, which does not participate in the temperature rise of the combustion, advantageously reducing the ambient temperature in the backflow groove 3 and increasing the condensation effect.

[0033] As shown in FIGS. 4 and 5, the inner side wall of the ventilation chamber 2 is provided with a protruding convex ring 7, an inner cavity of the convex ring 7 forms the backflow groove 3, one end, facing away from the crankshaft chamber 1, of the convex ring 7 is provided with the opening 33, and an end face, provided with the opening 33, of the convex ring 7 is the open end face 34. In this way, the heat exchange efficiency between the oil mist in the backflow groove 3 and relatively cold air in the ventilation chamber 2 is improved, thereby promoting the condensation rate.

[0034] The specific embodiments described herein are merely illustrative of the spirit of the present disclosure. Those skilled in the art to which the present disclosure belongs may make various modifications or supplements or similar substitutions to the specific embodiments described without departing from the spirit of the present disclosure or being beyond the scope defined by the appended claims.

Examples

Embodiment Construction

[0029]The following are specific embodiments of the present disclosure and the technical solutions of the present disclosure are further described with reference to the accompanying drawings, but the present disclosure is not limited to these embodiments.

[0030]As shown in FIGS. 1 and 2, in a ventilation structure for a crankcase, a crankcase 10 includes a crankshaft chamber 1 and a ventilation chamber 2, and the crankshaft chamber 1 communicates with the ventilation chamber 2. The crankshaft chamber 1 is a chamber accommodating a crankshaft body and connecting rod components, and the ventilation chamber 2 is disposed adjacent to the crankshaft chamber 1, and is configured to guide and utilize gas discharged by increasing an air pressure inside the crankshaft chamber 1, and the crankshaft chamber 1 communicates with the ventilation chamber 2 to achieve smooth flow of gas pressure relief.

[0031]As shown in FIGS. 2 and 3, the ventilation structure includes a one-way valve plate 4 enabli...

Claims

1. A ventilation structure for a crankcase, a crankcase comprising a crankshaft chamber and a ventilation chamber, the ventilation structure comprising a one-way valve plate enabling only gas in the crankshaft chamber to flow into the ventilation chamber, wherein an inner side wall of the ventilation chamber is provided with a backflow groove, an inner cavity of the backflow groove communicates with the crankshaft chamber, the one-way valve plate is arranged in an up-down direction and is capable of closing an opening of the backflow groove, an upper end of the one-way valve plate is a free end, and a lower end of the one-way valve plate is fixedly connected to an open end face of the backflow groove.

2. The ventilation structure for a crankcase as claimed in claim 1, wherein a bottom surface of the inner cavity of the backflow groove is provided with a deposition groove extending to the one-way valve plate.

3. The ventilation structure for a crankcase as claimed in claim 2, wherein a bottom surface of the deposition groove is inclined toward a side where the one-way valve plate located.

4. The ventilation structure for a crankcase as claimed in claim 2, wherein an inner wall of the backflow groove is provided with a through port communicating with the crankshaft chamber from bottom to top, and the through port is arranged opposite to the deposition groove located below the through port.

5. The ventilation structure for a crankcase as claimed in claim 1, wherein a pressure baffle is connected at the opening of the backflow groove, the one-way valve plate is clamped between the pressure baffle and the open end face of the backflow groove, the pressure baffle has a strip shape, and an upper end of the pressure baffle is bent toward a side away from the one-way valve plate.

6. The ventilation structure for a crankcase as claimed in claim 5, wherein the pressure baffle is fixedly connected to the open end face of the backflow groove by bolts arranged circumferentially around the pressure baffle.

7. The ventilation structure for a crankcase as claimed in claim 5, wherein the pressure baffle is provided with a plurality of avoidance through holes.

8. The ventilation structure for a crankcase as claimed in claim 1, wherein the inner side wall of the ventilation chamber is provided with a protruding convex ring, an inner cavity of the convex ring forms the backflow groove and the one-way valve plate is fixedly disposed on the convex ring.

9. The ventilation structure for a crankcase as claimed in claim 1, wherein the crankcase is provided with a combustion cylinder and a balance cylinder, and the backflow groove is located under the balance cylinder.

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