Piston combustion chamber, engine and vehicle

Abstract

The application provides a piston combustion chamber, an engine and a vehicle, wherein the piston combustion chamber comprises: a piston body comprising a first platform; a pit portion comprising two ridge shoulders protruding from the first platform and a pit between the two ridge shoulders; an air intake valve pit and an exhaust valve pit respectively located on both sides of the pit portion and recessed relative to the first platform, the air intake valve pit comprising an air intake transition portion connected with the pit portion, the exhaust valve pit comprising an exhaust transition portion connected with the pit portion, an intersection line between the air intake transition portion and the pit being an air intake ridge line, and an intersection line between the exhaust transition portion and the pit being an exhaust ridge line; and in the height direction of the piston body, the exhaust ridge line is lower than the air intake ridge line. The piston combustion chamber provided by the application improves the turbulent kinetic energy of airflow in the combustion chamber, and in turn improves the combustion efficiency and power output characteristics of the engine.

Description

Technical Field

[0001] This application relates to the field of vehicle engine technology, and in particular to a piston combustion chamber, engine, and vehicle. Background Technology

[0002] As engine thermal efficiency continues to break through previous levels, increasingly higher compression ratios have become a trend. However, higher compression ratios lead to an increased tendency for knocking, while the in-cylinder flow field intensity decreases due to the reduced combustion chamber volume caused by the increased compression ratio. This, coupled with the deep Miller cycle, further deteriorates the in-cylinder flow field intensity. In-cylinder flow field intensity has a positive effect on the uniformity of the in-cylinder mixture and the flame propagation speed. Therefore, improving the in-cylinder flow field intensity under high compression ratio and deep Miller cycle conditions is urgently needed. Summary of the Invention

[0003] In view of this, the purpose of this application is to provide a piston combustion chamber, engine and vehicle to improve the in-cylinder flow field intensity of the engine.

[0004] To achieve the above objectives, this application provides a piston combustion chamber, comprising:

[0005] Piston body, including the first platform;

[0006] The recessed portion includes two ridges protruding from the first platform and a recess located between the two ridges;

[0007] The intake valve avoidance pit and the exhaust valve avoidance pit are located on both sides of the recessed portion and are recessed relative to the first platform. The intake valve avoidance pit includes an intake transition portion connected to the recessed portion, and the exhaust valve avoidance pit includes an exhaust transition portion connected to the recessed portion. The intersection line between the intake transition portion and the recessed portion is the intake ridge line, and the intersection line between the exhaust transition portion and the recessed portion is the exhaust ridge line.

[0008] In the height direction of the piston body, the exhaust ridge is lower than the intake ridge.

[0009] Based on the same inventive concept, this disclosure also provides an engine, comprising:

[0010] Cylinder block, including the housing cavity;

[0011] The piston combustion chamber is located within the accommodating cavity and can move vertically relative to the accommodating cavity;

[0012] The cylinder head combustion chamber is located at the top of the cylinder block and is disposed opposite to the piston combustion chamber.

[0013] Both the intake and exhaust lines are located on the cylinder head combustion chamber. When the piston combustion chamber moves to top dead center within the accommodating cavity, the end of the intake line is located in the intake escape valve pit, and the end of the exhaust line is located in the exhaust escape valve pit.

[0014] Based on the same inventive concept, this disclosure also provides a vehicle including the aforementioned engine.

[0015] As can be seen from the above, the piston combustion chamber, engine, and vehicle provided in this application, wherein the piston combustion chamber, in the height direction of the piston body, sets the exhaust ridge line lower than the intake ridge line, so that the recess between the two ridge shoulders is no longer symmetrical with respect to the center of the recess, that is, the recess becomes an eccentric recess, and the intake side of the recess is higher than the exhaust side, thereby making it easier for the airflow to break through the restriction of the recess, and thus making the airflow direction in the combustion chamber take the shape of a clam, getting rid of the regular elliptical arc airflow direction formed by symmetrical recesses in related technologies, expanding the effective flow space of the airflow, and the expanded flow space makes it easier to maintain the positive tumble flow of the airflow in the combustion chamber, thereby improving the turbulent kinetic energy of the airflow in the combustion chamber, and thus improving the combustion efficiency and power output characteristics of the engine. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in this application or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the engine structure according to an embodiment of this application;

[0018] Figure 2 This is a schematic cross-sectional view of a piston combustion chamber in related technologies.

[0019] Figure 3 This is a schematic diagram of the airflow direction between the piston combustion chamber and the cylinder head combustion chamber in related technologies;

[0020] Figure 4 This is a cross-sectional structural diagram of the piston combustion chamber in an embodiment of this application;

[0021] Figure 5 This is a schematic diagram of the airflow direction between the piston combustion chamber and the cylinder head combustion chamber in an embodiment of this application;

[0022] Figure 6 This is a schematic diagram of the planar structure of the piston combustion chamber according to an embodiment of this application. Figure 1 ;

[0023] Figure 7 This is a three-dimensional structural diagram of the piston combustion chamber according to an embodiment of this application. Figure 1 ;

[0024] Figure 8 This is a schematic diagram of the planar structure of the piston combustion chamber according to an embodiment of this application. Figure 2 ;

[0025] Figure 9 This is a three-dimensional structural diagram of the piston combustion chamber according to an embodiment of this application. Figure 2 ;

[0026] Figure 10 This is a schematic diagram of the trajectory of the guide channel according to an embodiment of this application, wherein the dashed arc is the trajectory line;

[0027] Figure 11 This is a schematic diagram showing the radius of the guide channel in an embodiment of this application;

[0028] Figure 12 This is a schematic diagram showing the angle between the bottom of the recess and the first platform in an embodiment of this application;

[0029] Figure 13a This is a schematic diagram of the first distance h1 and the second distance h2 of the piston combustion chamber in the related technology; Figure 13b This is a schematic diagram of the first distance h1 and the second distance h2 of the piston combustion chamber according to an embodiment of this application;

[0030] Figure 14 This is a schematic diagram showing the height relationship between the exhaust ridge line in this application embodiment and the exhaust ridge line in related technologies;

[0031] Figure 15 This is a schematic diagram of the turbulent kinetic energy curves of Embodiment 1, Embodiment 2 and Comparative Example 1 of this application.

[0032] In the diagram: 001, Cylinder block; 002, Piston combustion chamber; 003, Cylinder head combustion chamber; 004, Intake line; 005, Exhaust line; 100, Piston body; 101, First platform; 200, Recess; 201, Spine; 202, Second platform; 203, Recess; 300, Intake valve relief recess; 301, Intake transition section; 302, Intake ridge; 400, Exhaust valve relief recess; 401, Exhaust transition section; 402, Exhaust ridge; 403, Exhaust opening; 500, Guide groove; 501, First arc segment; 502, Second arc segment; 6, Machining tool. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0034] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar terms used in the embodiments of this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0035] For ease of description later, this application defines the center plane of the piston body 100, which passes through the intake ridge 302 and the exhaust ridge 402, as the piston center plane, as detailed in the following document. Figure 10 L1 in the diagram. The center plane of the recess 200 passing through the center plane of the two ridges 201 is defined as the center plane of the recess, see details in [link to diagram]. Figure 10 In L2, the center surface of the recess is perpendicular to the center surface of the piston, that is, surface L1 is perpendicular to surface L2.

[0036] As described in the background section, with the continuous improvement of engine thermal efficiency, higher compression ratios have become a trend. However, increased compression ratios lead to a greater tendency for knocking, while the combustion chamber volume decreases due to the increased compression ratio. Combined with the deep Miller cycle, this further deteriorates the in-cylinder flow field intensity. In-cylinder flow field intensity has a positive effect on the uniformity of the in-cylinder mixture and the flame propagation speed. Therefore, improving the in-cylinder flow field intensity under high compression ratio and deep Miller cycle conditions is urgently needed.

[0037] It should be noted that, as Figure 1 As shown, the engine includes a piston combustion chamber 002 and a cylinder head combustion chamber 003. The piston combustion chamber 002 refers to the combustion chamber portion formed at the top of the piston, while the cylinder head combustion chamber 003 refers to the combustion chamber portion formed below the bottom surface of the cylinder head. Typically, the piston combustion chamber 002, cylinder head combustion chamber 003, and cylinder walls together constitute the combustion chamber. The design of the combustion chamber has a significant impact on engine performance. Changes in the structure of either the piston combustion chamber 002 or the cylinder head combustion chamber 003 will alter the shape of the combustion chamber. These changes significantly affect the airflow direction and turbulent kinetic energy within the cylinder, thereby influencing the engine's combustion efficiency and power output characteristics.

[0038] This application improves the structure of the piston combustion chamber 002 to enhance the turbulent kinetic energy of the airflow within the combustion chamber. In related technologies, such as... Figure 2 As shown, the piston combustion chamber 002 includes: a recessed portion 200 and an intake valve avoidance recess 300 and an exhaust valve avoidance recess 400 located on both sides of the recessed portion 200; the recessed portion 200 includes two ridge shoulders 201 protruding from the first platform 101, and a recess 203 located between the two ridge shoulders 201; the intake valve avoidance recess 300 includes an intake transition portion 301 connected to the recessed portion 200, and the exhaust valve avoidance recess 400 includes an exhaust transition portion 401 connected to the recessed portion 200; the intersection line between the intake transition portion 301 and the recess 203 is the intake ridge line 302, and the intersection line between the exhaust transition portion 401 and the recess 203 is the exhaust ridge line 402; the intake ridge line 302 and the exhaust ridge line 402 are at approximately the same height and are substantially symmetrical with respect to the center plane L2 of the recess, and this substantially symmetrical relationship is reflected in... Figure 2 In the middle, the intersection point K of the intake ridge 302 and the piston center plane L1, and the intersection point J of the exhaust ridge 402 and the piston center plane L1, are basically symmetrical with respect to the center plane L2 of the recess, and point J is slightly higher than point K. This symmetrical arrangement of the intake ridge 302 and exhaust ridge 402 confines the positive tumble airflow within the recess 203. The limited space within the recess 203 is not conducive to maintaining positive tumble, and the airflow direction in the combustion chamber cross-section presents a relatively regular elliptical arc. (See [reference]). Figure 3 The more regular elliptical arc will affect the turbulent kinetic energy of the airflow in the combustion chamber.

[0039] The applicant discovered that to overcome the airflow restriction imposed by the recess 203, i.e., to disrupt the airflow direction of the elliptical arc, it is necessary to change the height of the intake ridge 302 or the exhaust ridge 402. Since the intake ridge 302 is adjacent to the intake valve, the turbulent kinetic energy of the airflow at the intake ridge 302 is inherently higher, thereby allowing the height of the exhaust ridge 402 to be reduced. Figure 4 As shown, this causes the exhaust ridge 402 and the intake ridge 302 to become asymmetrical, and causes the airflow direction in the combustion chamber cross-section to appear as an eccentric ellipse, as shown. Figure 5 The "clam shape" shown can solve the above problems.

[0040] The following is in conjunction with the appendix Figures 1-15 An embodiment of the piston combustion chamber 002 of this application will be described.

[0041] In some embodiments, such as Figure 4 , Figure 6 , Figure 7As shown, a piston combustion chamber 002 includes: a piston body 100, including a first platform 101; a recess 200, including two ridges 201 protruding from the first platform 101, and a recess 203 located between the two ridges 201; an intake valve avoidance recess 300 and an exhaust valve avoidance recess 400, respectively located on both sides of the recess 200 and recessed relative to the first platform 101. The intake valve avoidance recess 300 includes an intake transition portion 301 connected to the recess 200, and the exhaust valve avoidance recess 400 includes an exhaust transition portion 401 connected to the recess 200. The intersection line between the intake transition portion 301 and the recess 203 is an intake ridge line 302, and the intersection line between the exhaust transition portion 401 and the recess 203 is an exhaust ridge line 402. In the height direction of the piston body 100, the exhaust ridge line 402 is lower than the intake ridge line 302.

[0042] The first platform 101 is the main plane of the piston body 100, and the recess 200, intake valve pit 300 and exhaust valve pit 400 are all provided on this main plane.

[0043] In this embodiment, the exhaust ridge 402 is lower than the intake ridge 302. Figure 4 This is manifested in the fact that the intersection point J of the exhaust ridge 402 and the piston center surface L1 is lower than the intersection point K of the intake ridge 302 and the piston center surface L1. For the exhaust ridge 402 in this embodiment compared to... Figure 2 The exhaust ridge 402 in the relevant technology, such as Figure 14 As shown, at least the exhaust ridge 402 in this embodiment (corresponding to) Figure 14 The middle part of S2) is more than the exhaust ridge 402 in the related technology (corresponding to Figure 14 The middle part of S1) is lower. In subsequent embodiments, it will be mentioned that the ridge shoulder 201 in this application is higher than the ridge shoulder 201 in the related art. Therefore, in this embodiment, the exhaust ridge line 402 in the area other than the middle part is higher than the exhaust ridge line 402 in the related art.

[0044] It should be noted that the intake transition section 301 is the area where the bottom of the intake valve avoidance pit 300 connects to the recessed portion 200, and this area is a slope; the exhaust transition section 401 is the area where the bottom of the exhaust valve avoidance pit 400 connects to the recessed portion 200, and this area is a sloped plane; because the middle of the exhaust ridge 402 in this embodiment is lower than the middle of the exhaust ridge 402 in the related art, the middle of the side of the recess 203 near the exhaust valve avoidance pit 400 needs to be lowered so that the exhaust transition section 401 intersects with the middle of the recess 203 earlier and forms the exhaust ridge 402. That is, the exhaust ridge 402 in this embodiment will extend towards the side near the exhaust valve avoidance pit 400 compared to the exhaust ridge 402 in the related art, so that the recess 203 is no longer basically symmetrical with respect to the center plane of the recess, that is, the recess 203 becomes an eccentric recess 203, and the intake side of the recess 203 is higher and the exhaust side is lower, which is reflected in Figure 4 In the middle section, the intersection point K of the intake ridge 302 and the piston center surface L1 is higher than the intersection point J of the exhaust ridge 402 and the piston center surface L1. This allows the airflow to easily overcome the restriction of the recess 203, resulting in the airflow direction in the combustion chamber taking on a "clam-shaped" form. Figure 5 As shown.

[0045] In this embodiment, the piston combustion chamber 002 has the exhaust ridge 402 set lower than the intake ridge 302 in the height direction of the piston body 100. This makes the recess 203 between the two shoulders 201 no longer symmetrical with respect to the recess center plane L2, thus making the recess 203 an eccentric recess 203. The intake side of the recess 203 is higher than the exhaust side, which makes it easier for the airflow to break through the restriction of the recess 203. Consequently, the airflow direction in the combustion chamber takes the shape of a clam, which is different from the regular elliptical arc airflow direction formed by the symmetrical recess 203 in related technologies. This expands the effective flow space of the airflow. The expanded flow space makes it easier to maintain the positive tumble flow of the airflow in the combustion chamber, thereby improving the turbulent kinetic energy of the airflow in the combustion chamber and thus improving the combustion efficiency and power output characteristics of the engine.

[0046] In some embodiments, the recess 203 protrudes from the first platform 101 on the side near the intake valve recess 300, and is recessed relative to the first platform 101 on the side near the exhaust valve recess 400, so that the intersection point K of the intake ridge 302 and the piston center surface L1 is higher than the first platform 101, and the intersection point J of the exhaust ridge 402 and the piston center surface L1 is lower than the first platform 101.

[0047] like Figure 2As shown, the points K and J where the intake ridge 302 and exhaust ridge 402 intersect with the piston center plane L1 in the related technology are both located above the first platform 101. That is, the recess 203 is located on both sides of the exhaust valve recess 400 and the intake valve recess 300, protruding from the first platform 101. The recess 203 is also basically symmetrically distributed. The airflow entering the combustion chamber from the intake valve will form a regular elliptical arc between the symmetrical intake ridge 302 and exhaust ridge 402. As described in the foregoing embodiments, the exhaust ridge 402 of this application is lower than the intake ridge 302 to break the elliptical arc direction of the rule. In this embodiment, the intersection point K of the intake ridge 302 and the piston center plane L1 is set higher than the first platform 101, and the intersection point J of the exhaust ridge 402 and the piston center plane L1 is set lower than the first platform 101. It is further explained that the middle part of the exhaust ridge 402 (including the lowest point of the exhaust ridge 402) is lower than the first platform 101. That is, the length of the exhaust transition part 401 on the piston center plane L1 will be further shortened, which will increase the height difference between the intake side and the exhaust side of the recess 203, thereby further increasing the possibility of the airflow breaking through the elliptical arc direction and increasing the possibility of large-scale positive tumble in the combustion chamber, so as to improve the turbulent kinetic energy of the airflow in the combustion chamber.

[0048] In some embodiments, the intersection of the recess 203 and the piston center surface L1 is a downward-sloping arc; in other words, this arc forms an angle with the first platform 101. Figure 12 As shown, the arc is the arc between point J and point K.

[0049] For example, the angle α between the arc and the first platform 101 is 0.5-5°, specifically 0.5°, 1°, 2°, 3°, 4°, or 5°, without any specific limitation. This angle is primarily used to balance the structural integrity of the exhaust valve avoidance recess 400 with the degree of openness of the recess 203 on the exhaust side. If the angle α is too high, although the degree of openness of the recess 203 on the exhaust side increases, it will affect the structure of the exhaust valve avoidance recess 400. For example, it may be necessary to widen the exhaust valve avoidance recess 400 so that the exhaust transition portion 401 of the exhaust valve avoidance recess 400 can intersect with the recess 203 earlier. However, widening the exhaust valve avoidance recess 400 will affect the use of the exhaust valve. If the angle α is too small, it will reduce the degree of openness of the recess 203 on the exhaust side and reduce the height difference between the recess 203 on the intake and exhaust sides, which is not conducive to the formation of turbulent airflow.

[0050] refer to Figure 2 As shown, in the related art, the lowest point of the recess 203 is located in the middle of the recess 203, while in this embodiment, the intersection of the recess 203 and the piston center surface is a downward-sloping arc, that is, in this embodiment, the lowest point of the recess 203 is located on the exhaust ridge 402 (see...). Figure 4Specifically, point J on the exhaust ridge 402 means that the recess 203 is fully open on the exhaust side. The airflow entering the recess 203 will directly enter the exhaust valve pit 400 along the downward-sloping arc surface of the recess 203, further increasing the possibility of airflow flowing out of the recess 203 and increasing the possibility of large-scale positive tumble in the combustion chamber, thereby increasing the turbulent kinetic energy of the airflow in the combustion chamber.

[0051] In the foregoing embodiments, it is mainly shown that the exhaust side of the recess 203 of this application is lower than the intake side. Since the effective space for airflow is larger, the compression ratio of the airflow entering the combustion chamber will be reduced. In order to compensate for this loss of compression ratio, the structure of the piston combustion chamber needs to be further improved.

[0052] To address the above issues, in some embodiments, the ridge shoulder 201 includes a second platform 202 disposed away from the first platform 101. The intersection of the intake ridge line 302 and the piston center plane L1 is higher than the first platform 101 by a first distance h1, and the second platform 202 is higher than the first platform 101 by a second distance h2. The length of the second platform 202 in the direction from the intake ridge line 302 to the exhaust ridge line 402 is greater than the first distance h1 and less than the second distance h2.

[0053] like Figure 2 , Figure 4 As shown, in this embodiment, the width of the second platform 202 is narrower than that of the second platform 202 with the ridge shoulder 201 in related technologies. This is mainly to compensate for the compression ratio loss caused by the lower exhaust side of the recess 203 compared to the intake side. In this embodiment, the ridge shoulder 201 is raised, and to adapt to the roof-like structure of the cylinder head combustion chamber 003, the width of the second platform 202 is shortened. In this embodiment, the ridge shoulder 201 is raised, and the raised second platform 202 is higher than the first platform 101 by a second distance h2. For example, as shown... Figure 13b As shown, in this embodiment, the second distance h2 is 3.5-5 times the first distance h1 between the intersection of the intake ridge line 302 and the piston center plane L1 and the first platform 101. For example, if the first distance h1 is 2mm, then the second distance h2 is 8mm; Figure 13a As shown, in the related technology, the second distance h2 is 2-3.5 times the first distance h1. For example, if the first distance h1 is 2mm, then the second distance h2 is 5mm.

[0054] like Figure 1 , Figure 2As shown, in the related technology, the length of the second platform 202 in the direction from the intake ridge 302 to the exhaust ridge 402 is greater than the second distance h2. In this embodiment, the length of the second platform 202 in the direction from the intake ridge 302 to the exhaust ridge 402 is greater than the first distance h1 and less than the second distance h2. This indicates that the ridge shoulder 201 in this application has a larger increase in height compared to the ridge shoulder 201 in the related technology, and this increase can be changed by adjusting the second distance h2. This increase is mainly related to the degree of openness of the recess 203 on the exhaust side. When the degree of openness of the recess 203 on the exhaust side is high, the increase in height of the ridge shoulder 201 is greater; when the degree of openness of the recess 203 on the exhaust side is small, the increase in height of the ridge shoulder 201 is lower. The increase in height can offset the influence of the degree of openness of the recess 203 on the exhaust side on the intake compression ratio. That is, this embodiment effectively compensates for the compression ratio loss caused by the lower exhaust side of the recess 203 compared to the intake side by increasing the height of the ridge shoulder 201.

[0055] In some embodiments, such as Figure 8 , Figure 9 As shown, the piston combustion chamber 002 also includes a guide groove 500, which is disposed through the exhaust ridge 402. The guide groove 500 is a concave arc surface along the extension direction of the exhaust ridge 402, and the guide groove 500 is a downward arc surface in the direction from the pit 203 to the exhaust transition part 401.

[0056] In this embodiment, a guide groove 500 is provided at the exhaust ridge 402. That is, based on the pit 203 in the previous embodiment, which is fully opened on the exhaust side, a guide structure is added to further enhance the flow field intensity inside the cylinder. Figure 2 , Figure 3 As shown, because the exhaust ridge 402 is close to the bottom of the exhaust valve pit 400, and the guide groove 500 is a concave arc surface along the extension direction of the exhaust ridge 402, it will have a gathering effect on the flowing air. In addition, the guide groove 500 is a downward arc surface in the direction from the pit 203 to the exhaust transition part 401, that is, the airflow gathered by the guide groove 500 will more easily enter the bottom area of ​​the exhaust valve pit 400, increasing the possibility of large-scale positive tumble in the combustion chamber, thereby improving the turbulent kinetic energy of the airflow in the combustion chamber.

[0057] In some embodiments, such as Figure 8As shown, the opening of the guide channel 500 on one side of the recess 203 is smaller than the opening on the side of the exhaust transition portion 401. Specifically, the projection on the first platform 101 includes a first arc segment 501 located in the recess 203 and a second arc segment 502 located in the exhaust transition portion 401. The opening of the guide channel 500 on one side of the recess 203 corresponds to the first arc segment 501, and the opening of the guide channel 500 on one side of the exhaust transition portion 401 corresponds to the second arc segment 502. The area formed by the first arc segment 501 is narrower than the area formed by the second arc segment 502. That is, the opening of the guide channel 500 on one side of the recess 203 is smaller than the opening on one side of the exhaust transition portion 401. In other words, the area formed by the first arc segment 501 can form a gathering effect on the airflow, and the flow velocity will increase. The airflow with increased velocity pours out through the second arc segment 502 and enters the bottom area of ​​the exhaust valve pit 400. That is, the fan-shaped guide channel 500 can further improve the turbulent kinetic energy of the flowing air.

[0058] In some embodiments, two guide channels 500 are provided, and the two guide channels 500 are symmetrically arranged with respect to the piston center surface L1. The openings of the two guide channels 500 on one side of the exhaust transition portion 401 are respectively arranged opposite to the two exhaust openings 403 of the exhaust valve pit 400 on the edge of the piston body 100.

[0059] like Figure 8 , Figure 9 As shown, there are two guide channels 500, which are symmetrically arranged with respect to the piston center plane L1. The openings of the two guide channels 500 on the side of the exhaust transition section 401 are directly opposite to the two exhaust openings 403 of the exhaust valve avoidance pit 400 on the edge of the piston body 100. This allows the airflow gathered by the guide channels 500 to directly collide with the cylinder wall through the two exhaust openings 403 after entering the bottom area of ​​the exhaust valve avoidance pit 400, increasing the possibility of large-scale forward tumble in the combustion chamber and further improving its turbulent kinetic energy.

[0060] In some embodiments, such as Figure 10 As shown, the distance between the two intersection points of the guide groove 500 and the exhaust ridge 402 is 10%-25% of the diameter of the piston body 100; the distance between the intersection point closer to the piston center surface L1 and the piston center surface L1 is 10%-25% of the diameter of the piston body 100.

[0061] Extensive experiments have shown that the distance between the two intersection points M and N of the guide groove 500 and the exhaust ridge 402 is 10%-25% of the diameter of the piston body 100 (or the inner diameter of the cylinder body 001). For example, it can be 10%, 12%, 14%, 16%, 18%, 20%, 22%, 24%, or 25%, without specific limitations. Additionally, point M is the intersection point closest to the piston center plane L1, and its distance from the piston center plane L1 is also 10%-25% of the diameter of the piston body 100. For example, it can be 10%, 12%, 14%, 16%, 18%, 20%, 22%, 24%, or 25%, without specific limitations.

[0062] In this embodiment, the position of the guide groove 500 on the exhaust ridge 402 is further defined. It cannot be too close to the piston center surface L1. If both guide grooves 500 are close to the piston center surface L1, the flow fields within the two guide grooves 500 will affect each other, which is not conducive to airflow guidance. If both guide grooves 500 are far from the piston center surface L1, the airflow guided by the two guide grooves 500 will not easily gather to form a backflow, which will also affect the maintenance of positive tumble flow in the combustion chamber and consequently affect the flow field intensity. In addition, the width of the guide groove 500 cannot be too large, because it is located in the exhaust transition part 401 of the exhaust valve pit 400. The exhaust transition part 401 itself is relatively low. Therefore, the depth of the guide groove 500 will not be very deep. If the width is too large or too small, it will not be conducive to airflow gathering. Experiments show that when the distance between points M and N, and the distance between point M and the piston center plane L1 are both set to 10%-25% of the piston body diameter 100, the flow field intensity is better.

[0063] In some embodiments, such as Figure 10 As shown, the intersection of the trajectory line of the guide groove 500 and the piston center surface L1 is advanced 1-10mm towards the intake ridge line 302 compared to the center surface L2 of the recess; the distance between the tangent plane of the trajectory line and the piston center surface L1 is 15%-35% of the diameter of the piston body 100; the distance between the center of the trajectory line and the piston center surface L1 is 7%-15% of the diameter of the piston body 100; the radius of the concave arc surface is 10%-30% of the diameter of the piston body 100; and the lowest point of the concave arc surface is located above the first platform 101, with a distance of 0.1-2mm between it and the first platform 101.

[0064] It should be noted that the guide groove 500 in this embodiment is machined. During the machining process, the cutting head rotates and moves along a set trajectory line. After moving along the trajectory line, the guide groove 500 is formed on the piston combustion chamber 002. Therefore, the setting of this trajectory line is particularly important for machining. In addition, this trajectory line also directly affects the position, depth, and length of the guide groove 500. These dimensional data of the guide groove 500 are directly related to the guiding performance of the guide groove 500 and the turbulence effect of the airflow. Therefore, the setting of this trajectory line is also crucial to the guiding performance of the guide groove 500 and the turbulence effect of the airflow.

[0065] For example, since the trajectory line is three-dimensional, it needs to be determined by at least three points (starting point, center, and a process point), such as... Figure 10 As shown, the starting point is point Q, which intersects the piston's center surface; the intermediate point is point P, which intersects the tangent plane; the center of the circle is point O; the piston's center surface is L1; the recess's center surface is L2; ​​and the tangent plane of the trajectory line (the dotted arc in the figure represents this trajectory line) is L3. That is, the distance from point Q to surface L2 is c, where c is 1-10 mm. For example, c can be 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, or 10 mm. The body is not limited; the distance between surface L3 and surface L1 is d, where d is 15%-35% of the diameter of piston body 100. For example, d is 15%, 20%, 25%, 30%, or 35% of the diameter of piston body 100, and the specific value is not limited; the distance between point O and surface L1 is e, where e is 7%-15% of the diameter of piston body 100. For example, e is 7%, 9%, 11%, 13%, or 15% of the diameter of piston body 100, and the specific value is not limited.

[0066] In addition to the trajectory line, the radius of the machining tool 6 directly affects the width of the guide channel 500. For example, the radius R of the concave arc surface of the guide channel 500 is the radius of the machining tool 6. Figure 11 As shown, after numerous experiments, the radius R of the concave arc surface is 10% to 30% of the diameter of the piston body 100, with examples of 10%, 15%, 20%, 25%, and 30%, and no specific limitation is made.

[0067] The distance between the lowest point of the concave arc surface of the guide groove 500 processed by the above-mentioned trajectory line and the tool and the first platform 101 is 0.1-2mm, for example 0.1mm, 0.5mm, 1.0mm, 1.5mm, 2mm. For example, the lowest point is point J, which is located below the first platform 101.

[0068] The following is a comparative experiment between the technical solution in this case and related technical solutions:

[0069] In Example 1, the exhaust ridge 402 is lower than the intake ridge 302, and two guide grooves 500 are provided on the exhaust ridge 402.

[0070] Examples of relevant dimensions in this embodiment are as follows: the piston body 100 has a diameter of 60mm, c is 5mm, d is 25mm, e is 6mm, R is 25mm, the intersection point K of the intake ridge 302 and the piston center surface L1 is above the first platform 101 and the distance from the first platform 101 is 2mm, the intersection point J of the exhaust ridge 402 and the piston center surface L1 is below the first platform 101 and the distance from the first platform 101 is 1mm, the second distance h2 of the second platform 202 of the two shoulders 201 from the first platform 101 is 8mm, and the angle α between the intersection line of the recess 203 and the piston center surface and the first platform 101 is 2°.

[0071] Example 2: The exhaust ridge 402 is lower than the intake ridge 302.

[0072] Examples of relevant dimensions in this embodiment are as follows: the intersection point K of the intake ridge 302 and the piston center surface L1 is above the first platform 101 and the distance from the first platform 101 is 2mm; the intersection point J of the exhaust ridge 402 and the piston center surface L1 is below the first platform 101 and the distance from the first platform 101 is 1mm; the second platform 202 of the two ridge shoulders 201 is 8mm away from the first platform 101 at a second distance h2; the angle α between the intersection line of the recess 203 and the piston center surface and the first platform 101 is 2°.

[0073] Piston Combustion Chamber 002 in Comparative Example 1

[0074] Examples of relevant dimensions in this embodiment are as follows: the distance between point K, the intersection of the intake ridge 302 and the piston center surface L1, and the first platform 101 is 2mm; the distance between point J, the intersection of the exhaust ridge 402 and the piston center surface L1, and the first platform 101 is 2.1mm; and the second distance h2 between the second platform 202 of the two ridge shoulders 201 and the first platform 101 is 5mm.

[0075] Simulation experiments were conducted to simulate the average turbulent kinetic energy and compression ratio in the cylinder at ignition time for each embodiment and comparative example. The experiments showed that the compression ratio of Example 1 was two units higher than that of Comparative Example 1, and the compression ratio of Example 2 was three units higher than that of Comparative Example 1. The results of the average turbulent kinetic energy are as follows: Figure 15As shown, the turbulent kinetic energy of Example 1 is increased by 10% compared to that of Comparative Example 1, and the turbulent kinetic energy of Example 2 is 8% higher than that of Comparative Example 1. This demonstrates that the design of the exhaust ridge 402 being lower than the intake ridge 302, and the design of setting two guide grooves 500 on the exhaust ridge 402, combined with the increase in the ridge shoulder 201, can further improve the compression ratio, and further improve the airflow turbulent kinetic energy on the basis of improving the compression ratio. Therefore, the structural improvement of this application achieves the goal of improving the in-cylinder flow field intensity of the engine under high compression ratio and deep Miller cycle conditions.

[0076] Based on the same inventive concept, this application also provides an engine, comprising: a cylinder block 001, including a receiving cavity; a piston combustion chamber 002 as described in any of the above embodiments, located within the receiving cavity and movable vertically relative to the receiving cavity; a cylinder head combustion chamber 003, located at the top of the cylinder block 001, the cylinder head combustion chamber 003 being disposed opposite to the piston combustion chamber 002; an intake pipe 004 and an exhaust pipe 005, both located on the cylinder head combustion chamber 003, wherein when the piston combustion chamber 002 moves to top dead center within the receiving cavity, the end of the intake pipe 004 is located within the intake valve relief pit 300, and the end of the exhaust pipe 005 is located within the exhaust valve relief pit 400. The end of the intake pipe 004 is the intake valve, and the end of the exhaust pipe 005 is the exhaust valve.

[0077] Based on the same inventive concept, this application also provides a vehicle including the engine described in the above embodiments.

[0078] For example, when the engine has the piston combustion chamber 002 described in the above embodiments, it can have all the advantages and beneficial effects of the piston combustion chamber 002 described in the above embodiments, which will not be repeated here.

[0079] For example, when the vehicle is equipped with the engine described in the above embodiments, it can have all the advantages and beneficial effects of the engine described in the above embodiments, which will not be repeated here.

[0080] It should be noted that the above description describes some embodiments of this application. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in a different order than that shown in the above embodiments and still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0081] The various embodiments in this application are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0082] The description in this application is given for illustrative purposes and is not intended to be exhaustive or to limit the application to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described to better illustrate the principles and practical application of this application and to enable those skilled in the art to understand this application and design various embodiments with various modifications suitable for a particular purpose.

[0083] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of this application (including the claims) is limited to these examples; within the framework of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the embodiments of this application as described above, which are not provided in the details for the sake of brevity.

[0084] Although this application has been described in conjunction with specific embodiments thereof, many substitutions, modifications and variations of these embodiments will be apparent to those skilled in the art from the foregoing description.

[0085] The embodiments of this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the embodiments of this application should be included within the protection scope of this application.

Claims

1. A piston combustion chamber, characterized in that, include: The piston body includes the first platform; The recessed portion includes two ridges protruding from the first platform and a recess located between the two ridges; The intake valve avoidance pit and the exhaust valve avoidance pit are located on both sides of the recessed portion and are recessed relative to the first platform. The intake valve avoidance pit includes an intake transition portion connected to the recessed portion, and the exhaust valve avoidance pit includes an exhaust transition portion connected to the recessed portion. The intersection line between the intake transition portion and the recessed portion is the intake ridge line, and the intersection line between the exhaust transition portion and the recessed portion is the exhaust ridge line. In the height direction of the piston body, the exhaust ridge is lower than the intake ridge.

2. The piston combustion chamber according to claim 1, characterized in that, The recess protrudes from the first platform on the side near the intake valve pit, and is recessed relative to the first platform on the middle of the side near the exhaust valve pit, so that the intersection of the intake ridge line and the piston center surface is higher than the first platform, and the intersection of the exhaust ridge line and the piston center surface is lower than the first platform. The piston center surface is the center surface of the piston body that passes through the intake ridge and the exhaust ridge.

3. The piston combustion chamber according to claim 2, characterized in that, The intersection of the recess and the piston's center surface forms a downward-sloping arc.

4. The piston combustion chamber according to claim 2, characterized in that, The ridge includes a second platform located away from the first platform. The intersection of the intake ridge line and the piston center plane is higher than the first platform by a first distance. The second platform is higher than the first platform by a second distance. The length of the second platform in the direction from the intake ridge line to the exhaust ridge line is greater than the first distance and less than the second distance.

5. The piston combustion chamber according to claim 1, characterized in that, It also includes a guide channel, which is disposed through the exhaust ridge line. The guide channel is a concave arc surface along the extension direction of the exhaust ridge line, and the guide channel is a downwardly sloping arc surface in the direction from the concave pit to the exhaust transition part.

6. The piston combustion chamber according to claim 5, characterized in that, The opening of the guide groove on one side of the recess is smaller than the opening on the side of the exhaust transition section.

7. The piston combustion chamber according to claim 5, characterized in that, The guide channel is provided in two parts, which are symmetrically arranged with respect to the center plane of the piston. The openings of the two guide channels on one side of the exhaust transition section are respectively arranged opposite to the two exhaust openings of the exhaust valve pit on the edge of the piston body.

8. The piston combustion chamber according to claim 7, characterized in that, The distance between the two intersections of the guide groove and the exhaust ridge is 10%-25% of the piston body diameter; the distance between the intersection closer to the piston center surface and the piston center surface is 10%-25% of the piston body diameter.

9. The piston combustion chamber according to claim 7, characterized in that, The intersection of the guide groove's trajectory line and the piston's center surface is 1-10 mm further forward than the concave center surface towards the intake ridge; the distance between the tangent plane of the trajectory line and the piston's center surface is 15%-35% of the piston body diameter; the distance between the center of the trajectory line and the piston's center surface is 7%-15% of the piston body diameter; the radius of the concave arc surface is 10%-30% of the piston body diameter; and the distance between the lowest point of the concave arc surface and the first platform is 0.1-2 mm. The central surface of the pit is the central surface of the pit portion passing through the two ridge shoulders.

10. An engine, characterized in that, include: Cylinder block, including the housing cavity; The piston combustion chamber according to any one of claims 1 to 9 is located within the receiving cavity and is movable vertically relative to the receiving cavity; The cylinder head combustion chamber is located at the top of the cylinder block and is disposed opposite to the piston combustion chamber. Both the intake and exhaust lines are located on the cylinder head combustion chamber. When the piston combustion chamber moves to top dead center within the accommodating cavity, the end of the intake line is located in the intake escape valve pit, and the end of the exhaust line is located in the exhaust escape valve pit.

11. A vehicle, characterized in that, Includes the engine as described in claim 10.

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