CN212079456U - Diesel engine combustion chamber - Google Patents
Diesel engine combustion chamber Download PDFInfo
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- CN212079456U CN212079456U CN202020786871.1U CN202020786871U CN212079456U CN 212079456 U CN212079456 U CN 212079456U CN 202020786871 U CN202020786871 U CN 202020786871U CN 212079456 U CN212079456 U CN 212079456U
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
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Abstract
The embodiment of the utility model discloses diesel engine combustion chamber, include: the piston comprises a central platform, a pit area, a lip, a step area and a piston top; one end of the boundary curve of the pit area is connected with a platform side bus extending from the side surface of the central platform to the bottom of the combustion chamber, and the other end of the boundary curve is connected with the lip through a flow guide line extending to the top of the combustion chamber; the lip is connected with the top surface of the piston through a step-shaped curved surface, and a step area is formed above the step-shaped curved surface; the included angle formed by the flow guide line and the radial outer side horizontal direction of the combustion chamber is an acute angle; when the piston is positioned at the top dead center, the ratio of the length of a connecting line from the contact point of the oil beam line and the diversion line to the starting point of the bottom end of the diversion line to the total length of the diversion line is in a preset proportion range. This technical scheme suppresses nitrogen oxide through the regional area of oxygen boosting that reduces to be surrounded by high temperature and produces, and the guide gas mixture accelerates soot later stage oxidation to cylinder center motion simultaneously, has realized not reducing when keeping diesel engine thermal efficiency, effectively reduces the effect that nitrogen oxide and soot discharged.
Description
Technical Field
The utility model relates to a diesel engine technical field, concretely relates to diesel engine combustion chamber.
Background
At present, the emission regulation of the most severe California heavy-duty diesel engine in the world requires that the emission of nitrogen oxides is reduced to one tenth of the emission regulation of the national VI on the premise that the emission of soot is equivalent to the emission regulation level of the national VI. And reducing nox emissions often requires a certain loss in thermal efficiency of the diesel engine. In addition, the generation of nitrogen oxides and soot is closely related to the in-cylinder oil-gas mixing process, the combustion process and the like, and is limited by the combustion characteristics of the diesel engine, and the difficulty of reducing the nitrogen oxides and the soot is high at the same time, so that the in-cylinder oil-gas mixing process and the combustion process need to be reasonably and accurately designed to be realized.
The existing combustion chamber design only considers the acceleration mixing rate and the increase of the air utilization rate. The carbon smoke in the cylinder is usually generated under the high-temperature oxygen-deficient environment, the nitrogen oxide is generated under the high-temperature oxygen-enriched state, the existing combustion chamber design can improve the local oxygen-deficient state, so that the generation of the carbon smoke is reduced, the acceleration of the mixing rate is also favorable for accelerating the combustion rate, and the higher thermal efficiency is obtained.
However, the rapid oil-gas mixing in the combustion chamber can cause a large amount of fuel steam to be combusted simultaneously, the temperature and the pressure in the cylinder are increased, the whole diesel engine adopts a lean combustion technology, the area of an oxygen-rich area is large, the combustion chamber accelerates the air flow movement in the cylinder, the interaction of a high-temperature area and the oxygen-rich area can be promoted, and the generation of nitrogen oxides is caused. The idea of reducing nitrogen oxides in the existing combustion chamber is focused on further accelerating the oil-gas mixing rate, and the highest combustion temperature is reduced by forming relatively homogeneous and dilute mixed gas, so that the generation of nitrogen oxides is controlled. However, it is difficult to achieve a satisfactory effect of controlling nitrogen oxides under conditions requiring a large amount of fuel injection, such as heavy duty diesel engines and heavy loads.
SUMMERY OF THE UTILITY MODEL
The embodiment of the utility model discloses diesel engine combustion chamber has realized when keeping the diesel engine thermal efficiency not to reduce, effectively reduces the effect that nitrogen oxide and soot discharged.
In a first aspect, the embodiment of the utility model discloses a diesel engine combustion chamber, which is a symmetrical structure with the central line as the symmetry axis, and comprises a central platform, a pit area, a lip, a step area and a piston top; wherein the content of the first and second substances,
the central platform is located in the center of the combustion chamber;
the pit area is concave, the boundary curve of the pit area is positioned at the bottom of the combustion chamber and is arc-shaped, one end of the pit area is connected with a platform side bus extending from the side surface of the central platform to the bottom of the combustion chamber, and the other end of the pit area is connected with the lip opening through a flow guide line extending to the top of the combustion chamber; the diversion line is a common tangent of a pit curvature circle and a lip curvature circle;
the lip is positioned below the piston top and is in an arc-shaped convex shape; the lip is connected with the top surface of the piston through a step-shaped curved surface, and a step area is formed above the step-shaped curved surface;
the inner side first included angle formed by the platform side surface generatrix and the radial outer side horizontal direction of the combustion chamber, the second included angle formed by the diversion line and the radial outer side horizontal direction of the combustion chamber, and the third included angle formed by the piston top and the tail end tangent of the step area bottom curve on the upper side of the piston top are acute angles;
the injection angle of the oil beam in the combustion chamber is an included angle between the oil beam injected from an oil injection hole of the combustion chamber and the vertical direction; when the piston is positioned at the top dead center, the ratio of the length of a connecting line from a contact point of an oil beam line ejected from an oil injection hole of the combustion chamber and the guide line to the starting point of the bottom end of the guide line to the total length of the guide line is within a preset proportion range.
Optionally, the first included angle ranges from 37 ° to 42 °.
Optionally, the second included angle is in a range of 73 ° to 80 °.
Optionally, the third included angle ranges from 73 ° to 85 °.
Optionally, the ratio range of the distance between two intersection points formed by a horizontal line passing through the center of the curvature circle of the lip and the left and right diversion lines and the distance between the two ends of the opening at the two sides of the combustion chamber is as follows: 0.74-0.78.
Optionally, a ratio of a vertical height from the piston to the center of the curvature circle of the lip to a vertical height from the piston to the bottom of the pit area ranges from: 0.43 to 0.47.
Optionally, the preset proportion range is as follows: greater than 0.51 and less than 0.88.
The embodiment of the utility model provides a technical scheme, the direction of the water conservancy diversion line of boundary curve through changing the connection pit district and lip, be the acute angle through the contained angle design that forms water conservancy diversion line and the radial outside horizontal direction of combustion chamber promptly, can realize the separation in high temperature region and oxygen-enriched district to a great extent, the higher burning initial stage of highest temperature in the jar promptly makes the high temperature district oxygen deficiency, oxygen-enriched district and high temperature contactless, through reducing the regional area of oxygen-enriched surrounded by high temperature, reduce the interact in high temperature and oxygen-enriched district, it generates to restrain nitrogen oxide. In addition, in order to avoid the high temperature district oxygen deficiency to make the problem that burning initial stage soot generated the increase, the utility model discloses again through the terminal slope of design step district curve, can make the gas mixture move to the cylinder center more for the oxidation of burning later stage soot to can reduce the heat dissipation loss, thereby compensate initial stage burning rate's reduction, guarantee the thermal efficiency loss not. Therefore, the embodiment of the utility model provides a technical scheme can reduce nitrogen oxide and soot emission simultaneously under the prerequisite of not losing the thermal efficiency, and still can guarantee to restrain the effect that harmful substance generated when great fuel injection quantity. Additionally, the embodiment of the utility model provides a technical scheme realizes above-mentioned technological effect through design combustion chamber profile and injection angle, and is less to having the engine design change, does not increase extra cost.
The utility model discloses an innovation point includes:
1. the contained angle design that the blast line and the radial outside horizontal direction of combustion chamber formed through the boundary curve that will connect the pit district and lip is the acute angle, can realize the separation in high-temperature region and oxygen-enriched district to a great extent, restraines nitrogen oxide and generates, has solved under the condition that the thermal efficiency is not lost, is difficult to reduce the problem that nitrogen oxide and soot generated the utility model discloses an one of the innovation point.
2. On prior art's basis, through the terminal tangent line with piston top and step district bottom curve at the contained angle increase that the piston top upside formed, can make the gas mixture move to the cylinder center more for the oxidation of burning later stage soot, and can reduce the heat dissipation loss, thereby compensate the reduction of initial stage rate of combustion, the problem of thermal efficiency loss has been solved, can be under the prerequisite of not losing the thermal efficiency, reduce nitrogen oxide and soot simultaneously and discharge, and still can guarantee the effect that restraines the harmful substance and generate when great fuel injection quantity, be the utility model discloses an one of the innovation point.
3. Through the distance between two nodical points that the water flat line in the centre of a circle of curvature circle and the left and right sides water conservancy diversion line that will cross the lip formed respectively, set up to 0.74 ~ 0.78 with the scope of the distance ratio between the combustion chamber both sides opening end, and with the piston top to the vertical height in the centre of a circle of curvature circle of lip, set up to 0.43 ~ 0.47 with the scope of the vertical height ratio of piston top to pit district bottom, can ensure reasonable pit district and step district volume ratio, realize the make full use of to the air in the combustion chamber, be one of the innovation point of the utility model.
4. The spray angle of the oil beam that the nozzle opening through setting up the combustion chamber erupted and vertical direction, when the piston was in the top dead center promptly, the contact point of oil beam line and water conservancy diversion line is greater than 0.51 to the line length of water conservancy diversion line bottom starting point and the ratio of water conservancy diversion line total length, and be less than 0.88 within range, can ensure the guide of fuel spraying through the water conservancy diversion line, can flow to pit district and step district respectively with reasonable proportion, make full use of the air in the combustion chamber, the guide effect of each profile of full play combustion chamber also, thereby reduce the soot and discharge, and reduce heat transfer loss, be one of the innovation points of the utility model.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without creative efforts.
Fig. 1 is a schematic structural diagram of a combustion chamber of a diesel engine according to an embodiment of the present invention;
FIG. 2a is a schematic representation of a prior art combustion chamber in-cylinder air-to-fuel equivalence ratio;
FIG. 2b is a schematic representation of in-cylinder temperature of a combustion chamber in the prior art;
FIG. 2c is a schematic diagram of the in-cylinder air-to-fuel equivalence ratio of the combustion chamber provided by the embodiment of the present invention;
FIG. 2d is a schematic view of in-cylinder temperature of a combustion chamber provided by an embodiment of the present invention;
FIG. 2e is an illustration of color bars for fuel to air equivalence ratio;
FIG. 2f is an illustration of color bands for temperature;
FIG. 3a is a schematic diagram of in-cylinder soot distribution at 28 ℃ A ATDC in a combustion chamber according to an embodiment of the present invention;
FIG. 3b is a schematic graph of in-cylinder soot distribution at 28 ℃ A ATDC for a prior art combustor;
FIG. 3c is a schematic diagram of the distribution of soot in the combustion chamber at 40 ℃ A ATDC according to an embodiment of the present invention;
FIG. 3d is a graph showing in-cylinder soot distribution at 40 ℃ A ATDC for a prior art combustor;
FIG. 3e is a schematic diagram of the distribution of soot in the combustion chamber at 70 ℃ A ATDC according to the embodiment of the present invention;
FIG. 3f is a graph showing in-cylinder soot distribution at 70 ℃ A ATDC for a prior art combustor;
FIG. 3g is a color bar legend for soot mass fraction;
fig. 4 is a schematic view of a combustion chamber injection angle according to an embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.
It should be noted that the terms "comprises" and "comprising" and any variations thereof in the embodiments and drawings of the present invention are intended to cover non-exclusive inclusions. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those steps or elements listed, but may alternatively include other steps or elements not listed, or inherent to such process, method, article, or apparatus.
Example one
Referring to fig. 1, fig. 1 is a schematic structural diagram of a combustion chamber of a diesel engine according to an embodiment of the present invention. The combustion chamber is a symmetrical structure with the center line as a symmetry axis and can rotate around the center line for a circle. The combustion chamber includes: the piston comprises a central platform 1, a pit area M, a lip 5, a step area N and a piston top 7; wherein the content of the first and second substances,
the central platform 1 is positioned at the central position of the combustion chamber; the pit area M is concave, the boundary curve 3 of the pit area is positioned at the bottom of the combustion chamber, is arc-shaped and is a curvature circle with a fixed radius R1, one end of the pit area is connected with a platform side bus 2 extending from the side surface of the central platform to the bottom of the combustion chamber, and the other end of the pit area is connected with a lip 5 through a flow guide line 4 extending to the top of the combustion chamber; the diversion line 4 is a common tangent line of the pit curvature circle and the lip curvature circle, and takes the point A as a starting point and the point B as an end point.
The lip 5 is positioned below the piston top 7, is in a circular arc convex shape and is a curvature circle with a fixed radius R2; the lip 5 is connected with the top surface of the piston through a step-shaped curved surface, and a step area N is formed above the step-shaped curved surface;
the first included angle theta 1 of the inner side formed by the platform side surface bus 1 and the radial outer side horizontal direction of the combustion chamber, the second included angle theta 2 formed by the diversion line 4 and the radial outer side horizontal direction of the combustion chamber and the third included angle theta 3 formed by the tail end tangent line of the piston top and the step area bottom curve on the upper side of the piston top are acute angles.
Illustratively, the first included angle ranges from 37 to 42, and the second included angle ranges from 73 to 80. The reason for this is as follows, please refer to fig. 2 a-2 f specifically:
FIG. 2a is a schematic representation of a prior art combustion chamber in-cylinder air-to-fuel equivalence ratio; FIG. 2b is a schematic representation of in-cylinder temperature of a combustion chamber in the prior art; FIG. 2c is a schematic diagram of the in-cylinder air-to-fuel equivalence ratio of the combustion chamber provided by the embodiment of the present invention; FIG. 2d is a schematic view of in-cylinder temperature of a combustion chamber provided by an embodiment of the present invention; FIG. 2e is an illustration of color bars for fuel to air equivalence ratio; FIG. 2f is an illustration of color bands for temperature. As shown in fig. 2a, 2b, 2e and 2f, the high temperature rich mixture in the combustion chamber of the prior art forms a stronger plume, and surrounds a larger area of the oxygen-rich region, such as the circled portion a in fig. 2a, which is influenced by the movement of the plume, and as the combustion process progresses, the oxygen-rich region surrounded by high temperature inevitably moves relative to the high temperature region, thereby promoting the generation of nitrogen oxides. In contrast, as shown in fig. 2c, 2d, 2e and 2f, the embodiment of the present invention provides a combustion chamber that is surrounded by the high-temperature rich mixed gas and has a small area in the oxygen-rich region, and to a great extent, the high-temperature region and the oxygen-rich region are separated, so that in the early stage of the combustion with high temperature in the cylinder, the high temperature is concentrated in the rich region, i.e. the oxygen-poor region, and less interacts with the oxygen-rich region, thereby suppressing the generation of nitrogen oxides. Therefore, it is necessary to suppress the high-temperature rich air from forming a high swirl along the wall surface of the pit. This is achieved by extending the flow leader 4 away from the central axis of the combustor, while suitably increasing the slope of the platform side generatrix 2. Considering the problem of thermal efficiency, the descending amplitude of the oil-gas mixing rate cannot be too large, so that the diversion line 4 cannot extend outwards too much, and the slope of the platform side bus 2 cannot be too large. Therefore, the utility model relates to a combustion chamber shape designs the contained angle theta 2 of water conservancy diversion line 4 and the radial outside horizontal direction of combustion chamber into: theta 2 is more than or equal to 73 degrees and less than or equal to 80 degrees, and the range of an inner acute angle theta 1 formed by the platform side bus 2 and the radial outer side horizontal direction of the combustion chamber is as follows: theta 1 is more than or equal to 37 degrees and less than or equal to 42 degrees.
Preferably, an inner first included angle theta 1 formed by the platform side generatrix 1 and the radial outer side horizontal direction of the combustion chamber is 39.2 degrees, and a second included angle theta 2 formed by the diversion line 4 and the radial outer side horizontal direction of the combustion chamber is 77.4 degrees, so that compared with the combustion chamber in the prior art, the high-temperature dense mixed gas is prevented from forming high plume along a boundary curve of a pit area, the area of an oxygen-enriched area surrounded by high temperature is reduced, and the generation of nitrogen oxides is prevented.
The utility model discloses diesel engine combustion chamber, for reducing the soot and discharging, and reduce heat transfer loss, ensure the effect that the thermal efficiency does not reduce, move to the cylinder center through the guide gas mixture, reduce near the burning and the soot generation of cylinder wall, promote the soot oxidation in burning later stage and realize. The specific description can be provided by 3 a-3 g, and fig. 3a is a schematic diagram of the distribution of soot in the cylinder of the combustion chamber provided by the embodiment of the present invention at 28 ℃ A ATDC; FIG. 3b is a schematic graph of in-cylinder soot distribution at 28 ℃ A ATDC for a prior art combustor; FIG. 3c is a schematic diagram of the distribution of soot in the combustion chamber at 40 ℃ A ATDC according to an embodiment of the present invention; FIG. 3d is a graph showing in-cylinder soot distribution at 40 ℃ A ATDC for a prior art combustor; FIG. 3e is a schematic diagram of the distribution of soot in the combustion chamber at 70 ℃ A ATDC according to the embodiment of the present invention; FIG. 3f is a graph showing in-cylinder soot distribution at 70 ℃ A ATDC for a prior art combustor; FIG. 3g is a graphical illustration of color bands for soot mass fraction. As shown in fig. 3a, 3b, 3c, 3d and 3g, because of the lack of oxygen in the high temperature region in the combustion early stage, although the soot generation in the combustion chamber provided by the embodiment of the present invention is higher than that in the combustion chamber of the prior art at the time of 28 ℃ a ATDC and the time of 40 ℃ a ATDC representing the middle process of combustion, the soot generated at this time does not enter the exhaust pipe yet, and cannot represent the soot finally discharged into the atmosphere. Simultaneously, because the embodiment of the utility model provides a combustion chamber guide gas mixture more moves to the cylinder center, and soot generation also concentrates on the cylinder center, consequently the later stage of burning can be more fully contacted with oxygen, and soot oxidation rate is higher, consequently at 70 ℃ A ATDC moment representing the atmospheric soot emission of actual entering, as shown in 3e, 3f and 3g, the utility model provides a soot quality of combustion chamber is less than the typical combustion chamber among the prior art, explains the utility model provides a combustion chamber finally gets into atmospheric soot quality through the blast pipe and is less than the typical combustion chamber among the prior art. Meanwhile, the combustion is concentrated in the center of the cylinder, so that the heat transfer loss is reduced, and the heat efficiency is improved.
Further, in order to guide the mixture to move towards the center of the cylinder and combust, the included angle theta 3 formed by the tangent line of the tail end of the curve at the bottom of the stepped area and the top of the piston needs to be properly increased. The utility model relates to a combustion chamber shape requires that the piston top does with the range of contained angle theta 3 of the terminal tangent line of step district bottom curve at the piston top upside formation: theta 3 is more than or equal to 73 degrees and less than or equal to 85 degrees.
Preferably, θ 3 is 76.9 °, which is advantageous in that the mixture can be further directed toward the center of the cylinder and burned to accelerate the late oxidation of soot, thereby reducing the amount of soot discharged.
Further, as shown in fig. 1, the embodiment of the utility model provides a combustion chamber, D1 are the distance D1 between two nodical points that the water flat line of the curvature circle centre of a circle of crossing the lip and left and right sides water conservancy diversion line formed respectively, and D2 is the distance between the combustion chamber both sides opening end, and the ratio scope of D1 and D2 ratio is:
in addition, as shown in fig. 1, H1 is the vertical height of the piston from the top to the center of the curvature circle of the lip, H2 is the vertical height of the piston from the top to the bottom of the pit area, and the ratio of H1 to H2 ranges from:
the design can ensure reasonable volume proportion of the pit area and the step area, and realize the full utilization of air in the combustion chamber.
Preferably, the ratio of D1 to D2 is 0.76; the ratio of H1 to H2 is 0.45, so that the ratio of the pit area to the step area can be optimized, air in the combustion chamber is fully utilized, and the reduction of the discharge amount of nitrogen oxides and soot is facilitated.
In addition, the embodiment of the present invention also provides a spray angle for the combustion chamber of the diesel engine, specifically refer to fig. 4, and fig. 4 is a schematic view of a spray angle of a combustion chamber provided by the embodiment of the present invention, and the design of the spray angle is suitable for all combustion chambers meeting the above design requirements. The design requires that the included angle between the oil jet ejected from the oil jet hole of the combustion chamber and the vertical direction is taken as the ejection angle theta 4. When the piston is positioned at the top dead center, the ratio of the length of a connecting line from a contact point O of an oil beam line sprayed from the oil spray hole and the guide line to a starting point A at the bottom end of the guide line according to the spraying angle to the total length of the guide line is within a preset proportion range.
For example, as shown in fig. 4, the ratio of the connection length | OA | from the contact point O of the oil line CO and the diversion line AB to the starting point a at the bottom end of the diversion line to the total length | AB | of the diversion line is greater than 0.51 and less than 0.88. Preferably, the injection angle θ 4 may be 73.4 °, and in this case, the ratio of | OA | to | AB | is 0.70, and this design can ensure that the fuel spray is guided by the guide line 4, and can flow to the pit area and the land area respectively in a reasonable ratio, thereby making full use of the air in the combustion chamber and also making full use of the guiding effect of the profile of each part of the combustion chamber.
Specifically, under the three operating conditions of a low rotating speed point, such as 1200r/min, 1840N · m, a maximum torque point, such as 1400r/min, 2070N · m, and a rated power point, such as 1800r/min, 1840N · m, compared with the combustion chamber of the prior art, by adopting the combustion chamber and the injection angle thereof provided by the embodiment of the present invention, the emission of nitrogen oxides can be respectively reduced by 20.3%, 16.2%, 13.3%, the emission of soot can be respectively reduced by 35.0%, 38.2%, 45.7%, and the indication indicator shows a little power under the same fuel injection quantity. Namely, the utility model discloses can be under the condition that the thermal efficiency is not lost, effectively reduce nitrogen oxide and soot simultaneously and discharge.
The embodiment of the utility model provides a technical scheme, the direction of the water conservancy diversion line of boundary curve through changing the connection pit district and lip, be the acute angle through the contained angle design that forms water conservancy diversion line and the radial outside horizontal direction of combustion chamber promptly, can realize the separation in high temperature region and oxygen-enriched district to a great extent, the higher burning initial stage of highest temperature in the jar promptly makes the high temperature district oxygen deficiency, oxygen-enriched district and high temperature contactless, through reducing the regional area of oxygen-enriched surrounded by high temperature, reduce the interact in high temperature and oxygen-enriched district, it generates to restrain nitrogen oxide. In addition, in order to avoid the high temperature district oxygen deficiency to make the problem that burning initial stage soot generated the increase, the utility model discloses again through the terminal slope of design step district curve, can make the gas mixture move to the cylinder center more for the oxidation of burning later stage soot to can reduce the heat dissipation loss, thereby compensate initial stage burning rate's reduction, guarantee the thermal efficiency loss not. Therefore, the embodiment of the utility model provides a technical scheme can reduce nitrogen oxide and soot emission simultaneously under the prerequisite of not losing the thermal efficiency, and still can guarantee to restrain the effect that harmful substance generated when great fuel injection quantity. Additionally, the embodiment of the utility model provides a technical scheme realizes above-mentioned technological effect through design combustion chamber profile and injection angle, and is less to having the engine design change, does not increase extra cost.
It should be noted that the foregoing is only a preferred embodiment of the present invention and the technical principles applied. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail with reference to the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the scope of the present invention.
Claims (7)
1. A combustion chamber for a diesel engine, characterized in that said combustion chamber is of a symmetrical construction with its centre line as axis of symmetry, said combustion chamber comprising: the piston comprises a central platform, a pit area, a lip, a step area and a piston top; wherein the content of the first and second substances,
the central platform is positioned at the central position of the combustion chamber;
the pit area is concave, the boundary curve of the pit area is positioned at the bottom of the combustion chamber and is arc-shaped, one end of the pit area is connected with a platform side bus extending from the side surface of the central platform to the bottom of the combustion chamber, and the other end of the pit area is connected with the lip opening through a flow guide line extending to the top of the combustion chamber; the diversion line is a common tangent of a pit curvature circle and a lip curvature circle;
the lip is positioned below the piston top and is in an arc-shaped convex shape; the lip is connected with the top surface of the piston through a step-shaped curved surface, and a step area is formed above the step-shaped curved surface;
the inner side first included angle formed by the platform side surface generatrix and the radial outer side horizontal direction of the combustion chamber, the second included angle formed by the diversion line and the radial outer side horizontal direction of the combustion chamber, and the third included angle formed by the piston top and the tail end tangent of the step area bottom curve on the upper side of the piston top are acute angles;
the injection angle of the oil beam in the combustion chamber is as follows: an included angle between an oil beam ejected from an oil injection hole of the combustion chamber and the vertical direction; when the piston is positioned at the top dead center, the ratio of the length of a connecting line from the contact point of an oil beam line ejected from the oil injection hole and the guide line to the starting point of the bottom end of the guide line to the total length of the guide line is within a preset proportion range.
2. The combustor of claim 1, wherein:
the range of the first included angle is 37-42 degrees.
3. The combustor of claim 1, wherein:
the range of the second included angle is 73-80 degrees.
4. The combustor of claim 1, wherein:
the range of the third included angle is 73-85 degrees.
5. The combustion chamber of claim 1,
the ratio range of the distance between two intersection points formed by a horizontal line passing through the circle center of the curvature circle of the lip and the diversion lines on the left side and the right side and the distance between the two ends of the openings on the two sides of the combustion chamber is as follows: 0.74-0.78.
6. The combustion chamber of claim 1,
the ratio range of the vertical height from the piston to the center of the curvature circle of the lip to the vertical height from the piston to the bottom of the pit area is as follows: 0.43 to 0.47.
7. The combustion chamber of claim 1,
the preset proportion range is as follows: greater than 0.51 and less than 0.88.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
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| CN202020786871.1U CN212079456U (en) | 2020-05-13 | 2020-05-13 | Diesel engine combustion chamber |
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| CN202020786871.1U CN212079456U (en) | 2020-05-13 | 2020-05-13 | Diesel engine combustion chamber |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114352431A (en) * | 2022-03-17 | 2022-04-15 | 潍柴动力股份有限公司 | Piston and engine |
| CN114526152A (en) * | 2022-04-22 | 2022-05-24 | 潍柴动力股份有限公司 | Combustion chamber and diesel engine |
-
2020
- 2020-05-13 CN CN202020786871.1U patent/CN212079456U/en active Active
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114352431A (en) * | 2022-03-17 | 2022-04-15 | 潍柴动力股份有限公司 | Piston and engine |
| CN114352431B (en) * | 2022-03-17 | 2022-06-07 | 潍柴动力股份有限公司 | Piston and engine |
| CN114526152A (en) * | 2022-04-22 | 2022-05-24 | 潍柴动力股份有限公司 | Combustion chamber and diesel engine |
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