Engine piston, engine and vehicle

Abstract

The utility model provides an engine piston, an engine and a vehicle, and belongs to the technical field of vehicles. An intake valve avoiding part, an exhaust valve avoiding part and an inner concave part which are concave downwards are formed on the top surface of the piston body; the concave depth of the inner concave part is greater than the concave depth of the intake valve avoiding part and the concave depth of the exhaust valve avoiding part; the concave face of the inwards-concave part is an oval spherical face, and the short axis direction of the inwards-concave part is the interval direction of the intake valve avoiding part and the exhaust valve avoiding part. Due to the fact that the inwards-concave part which is concave downwards is arranged on the top face of the piston body, the space of a combustion chamber can be correspondingly enlarged, the air flow flowing space can be enlarged, tumble collapse can be delayed, the tumble strength can be improved, emission of an engine is reduced, and fuel economy is improved. In addition, the tumble intensity in the cylinder is improved by improving the top surface structure of the piston body, the air inlet performance is not affected, the piston body is easy to manufacture and form, and the improvement cost is low.

Description

Technical Field

[0001] The utility model belongs to the technical field of vehicles, and more specifically, relates to an engine piston, an engine and a vehicle. Background Art

[0002] Reducing engine emissions and improving fuel economy are the current development trends of gasoline engines, diesel engines, and hydrogen internal combustion engines. In the existing technology, most of the technical means are to use high compression ratio, high tumble airway, intake manifold flap, CVVL, etc. These technologies are to improve the state of the working medium in the engine cylinder to improve the combustion condition in the cylinder. Among them, the high tumble airway is to improve the tumble ratio in the cylinder by changing the airway structure; the intake manifold flap is to improve the state of the flow field in the cylinder by changing the angle of the flap, and to improve the tumble in the cylinder; CVVL is to improve the movement form of the airflow in the cylinder by changing the height difference between the opening of the two valves.

[0003] For high tumble air ducts, changing the structure of the air duct can improve the tumble in the cylinder, but it will also reduce the air duct flow coefficient, thereby affecting the engine's intake capacity and engine performance. This phenomenon has a greater impact on naturally aspirated engines and hydrogen internal combustion engines; for intake manifold flaps, this structure will increase the cost of the entire vehicle and reduce the reliability of the engine; for CVVL, since the compression ratio is too high and the charging efficiency cannot be too high, the overall power performance of the machine is poor, and it needs to be achieved with the help of a special crankshaft and connecting rod system, and the structure and manufacturing process are complicated. Utility Model Content

[0004] The utility model aims to provide an engine piston, an engine and a vehicle, aiming to solve the technical problems in the prior art of improving the combustion condition in the cylinder by improving the state of the working medium in the engine cylinder, but the improvement cost is high and the engine performance is affected.

[0005] To achieve the above-mentioned purpose, the technical solution adopted by the utility model is: to provide an engine piston, comprising: a piston body; a left portion of the top surface of the piston body is formed with a downwardly concave intake valve avoidance portion, and a right portion of the top surface is formed with a downwardly concave exhaust valve avoidance portion, and the top surface of the piston body is further provided with a downwardly concave inner concave portion between the intake valve avoidance portion and the exhaust valve avoidance portion; the concave depth of the inner concave portion is greater than the concave depth of the intake valve avoidance portion and the concave depth of the exhaust valve avoidance portion;

[0006] The concave surface of the inner concave portion is an ellipsoidal spherical surface, and the short axis direction of the inner concave portion is the spacing direction between the intake valve avoidance portion and the exhaust valve avoidance portion.

[0007] In a possible implementation, the ratio of the major axis diameter of the inner recess to the diameter of the piston body is 0.49-0.83; the ratio of the minor axis diameter of the inner recess to the diameter of the piston body is 0.405-0.607.

[0008] In some embodiments, the distance from the center point of the inner recess to the top surface of the piston body is 0.9-4 mm.

[0009] In a possible implementation, the short axis direction of the inner recess is defined as a first direction, and the long axis direction of the inner recess is defined as a second direction; the long axis of the inner recess deviates from the center line of the second direction of the piston body, and the long axis of the inner recess is close to the exhaust valve avoidance portion; the short axis of the inner recess coincides with the center line of the first direction of the piston body.

[0010] In some embodiments, the ratio of the distance from the long axis of the inner recess to the center line of the piston body in the second direction to the diameter of the short axis of the inner recess is 0.056-0.146.

[0011] In some embodiments, the intersection line of the outer edge of the inner recess and the inner edge of the intake valve avoidance portion is defined as the first intersection line, and the intersection line of the outer edge of the inner recess and the inner edge of the exhaust valve avoidance portion is defined as the second intersection line; in the second direction, the length of the first intersection line is less than the length of the second intersection line.

[0012] In some embodiments, in the second direction, the ratio of the length of the first intersection line to the major axis diameter of the inner recess is 0.083-0.166.

[0013] In a possible implementation, the top surface of the piston body also forms a first plane and a second plane; the first plane is located between the intake valve avoidance portion and the exhaust valve avoidance portion, and on one side of the long axis direction of the inner recess; the second plane is located between the intake valve avoidance portion and the exhaust valve avoidance portion, and on the other side of the long axis direction of the inner recess.

[0014] The engine piston provided by the utility model has the following beneficial effects: the engine piston of the utility model can increase the space of the combustion chamber accordingly, that is, increase the airflow space, and delay the collapse of the tumble flow, and the concave surface of the concave portion is an elliptical spherical surface, which can also increase the strength of the tumble flow, thereby reducing the emission of the engine and improving the fuel economy. Compared with the prior art, the utility model improves the tumble flow strength in the cylinder by improving the top surface structure of the piston body, which will not affect the intake performance, and the piston body is easy to manufacture and shape, and the improvement cost is low.

[0015] The utility model also provides an engine, comprising the above-mentioned engine piston.

[0016] The utility model also provides a vehicle, comprising the above engine.

[0017] The engine and vehicle provided by the utility model can improve the combustion condition in the cylinder, enhance the thermal efficiency of the engine, and reduce the original emission due to the adoption of the above-mentioned engine piston. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 A schematic diagram of the three-dimensional structure of an engine piston provided by an embodiment of the utility model;

[0020] Figure 2 A schematic diagram of the top view of the engine piston provided by an embodiment of the utility model;

[0021] Figure 3 for Figure 2 Schematic diagram of the cross-sectional structure along line AA.

[0022] In the figure: 1, piston body; 2, intake valve avoidance portion; 3, exhaust valve avoidance portion; 4, inner recessed portion; 5, first plane; 6, second plane; 7, first intersection line; 8, second intersection line; B1, major axis of the recessed portion; B2, center line of the second direction of the piston body; C, minor axis of the recessed portion. DETAILED DESCRIPTION

[0023] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0024] It should be noted that the directions or positional relationships indicated by "front", "rear", "inside", "outside", "up" and "down" in this embodiment are based on the direction of the vehicle itself, where the head of the vehicle represents "front", the rear of the vehicle represents "rear", the top of the vehicle represents "up", and the bottom of the vehicle represents "down", the "inside" side refers to the side facing inside the cab, and the "outside" side refers to the side facing outside the cab.

[0025] In addition, the front and rear direction of the vehicle body defined in the embodiments of the present invention refers to the front and rear direction of the forward direction of the vehicle during driving, the left and right direction of the vehicle body defined refers to the left and right direction of the forward direction of the vehicle during driving, and the up and down direction of the vehicle body defined refers to the up and down direction of the forward direction of the vehicle during driving.

[0026] Please also read Figures 1 to 3 The engine piston provided by the utility model is now described. The engine piston comprises a piston body 1; a downwardly concave intake valve avoidance portion 2 is formed on the left portion of the top surface of the piston body 1, and a downwardly concave exhaust valve avoidance portion 3 is formed on the right portion of the top surface; a downwardly concave inner concave portion 4 is further provided on the top surface of the piston body 1 between the intake valve avoidance portion 2 and the exhaust valve avoidance portion 3; the concave depth of the inner concave portion 4 is greater than the concave depth of the intake valve avoidance portion 2 and the concave depth of the exhaust valve avoidance portion 3; the concave surface of the inner concave portion 4 is an elliptical spherical surface, and the short axis direction of the inner concave portion 4 is the spacing direction of the intake valve avoidance portion 2 and the exhaust valve avoidance portion 3.

[0027] Specifically, the piston body 1 is arranged in the cylinder sleeve of the cylinder body, the top of the cylinder body is a cylinder head, and the cylinder head is provided with an intake passage and an exhaust passage, and the intake passage and the exhaust passage are respectively connected to the cylinder sleeve; the cylinder head also has an intake valve and an exhaust valve. The cylinder head and the cylinder body are both common structures in the prior art and will not be described in detail here.

[0028] If the direction of the axial center of the cylinder is the up-down direction, then the spacing direction of the intake valve and the exhaust valve is generally the left-right direction, and in conventional technology, the intake valve is located on the left and the exhaust valve is located on the right. It should be noted that the "left" and "right" of the top surface of the piston body 1 defined above are based on the positions of the intake valve and the exhaust valve. Therefore, the left part of the top surface of the piston body 1 is formed with a downwardly concave intake valve avoidance portion 2, and the right part of the top surface is formed with a downwardly concave exhaust valve avoidance portion 3.

[0029] The intake valve avoidance portion 2 is used to avoid the intake valve to avoid interference with the intake valve when the piston body 1 moves to the top dead center. The exhaust valve avoidance portion 3 is used to avoid the exhaust valve to avoid interference with the exhaust valve when the piston body 1 moves to the top dead center.

[0030] The top surface of the piston body 1 is also provided with a concave portion 4 which is concave downward, and the concave surface of the concave portion 4 is an elliptical spherical surface. When the airflow flows in the cylinder sleeve, it passes through the concave surface of the concave portion 4. Specifically, during the suction stroke, the piston body 1 moves from the top dead center to the bottom dead center, and fresh air flows into the cylinder body through the intake duct and the intake valve. As the piston body 1 moves downward, the vacuum degree in the cylinder increases. At the same time, as the lift of the intake duct increases, the flow cross-sectional area at the intake port increases, and the high-speed airflow flows into the cylinder sleeve, forming a tumble flow in the cylinder sleeve. The tumble flow passes through the inner wall of the cylinder sleeve and the concave surface of the concave portion 4; during the compression stroke, as the piston body 1 moves from the bottom dead center to the top dead center, the tumble flow in the cylinder sleeve is compressed. When approaching the top dead center, due to the spacing between the concave surface and the bottom surface of the cylinder head, the tumble flow is broken into smaller vortices and transmits its own energy to turbulence.

[0031] Compared with the prior art, the engine piston provided by the utility model can increase the space of the combustion chamber accordingly, that is, increase the airflow space, and delay the collapse of the tumble flow, and the concave surface of the concave portion 4 is an elliptical spherical surface, which can also increase the strength of the tumble flow, thereby reducing the emission of the engine and improving the fuel economy. Compared with the prior art, the utility model improves the tumble flow strength in the cylinder by improving the top surface structure of the piston body 1, which will not affect the intake performance, and the piston body 1 is easy to manufacture and shape, and the improvement cost is low.

[0032] In some embodiments, the ratio of the major axis diameter of the inner recess 4 to the diameter of the piston body 1 is 0.49-0.83; the ratio of the minor axis diameter of the inner recess 4 to the diameter of the piston body 1 is 0.405-0.607.

[0033] If the diameter of the major axis is too large, the strength of the piston body 1 will be reduced, and the center line of the tumble flow cannot be guaranteed to be a straight line. If the center line of the tumble flow is a curve, the effect of enhancing the tumble flow is limited. If the diameter of the major axis is too small, a large-scale tumble flow cannot be formed.

[0034] If the diameter of the minor axis is too small, the airflow will rise prematurely and collide with the airflow at the edge of the cylinder head, and a single large-scale clockwise flow field cannot be formed. As a result, two clockwise rotating flow fields will affect each other, causing the airflow to further attenuate and affecting the strength of the flow field in the cylinder. If the diameter of the minor axis is too large, the strength of the piston body 1 will be reduced, and an elliptical spherical structure cannot be formed.

[0035] In some embodiments, the distance from the center point of the inner concave portion 4 to the top surface of the piston body 1 is 0.9-4 mm. If the above depth exceeds 4 mm, it will affect the strength of the piston body 1 and the reliability of the piston body 1. If the above depth is less than 0.9 mm, the concave effect of the ellipsoidal surface is poor, and the airflow will directly hit the top surface of the piston body 1 and then rebound, forming multiple clockwise rotating vortices, resulting in flow field attenuation.

[0036] In some embodiments, the inner recess 4 may be formed as follows: Figure 2 The structure shown, see Figure 2 , define the short axis direction of the inner recess 4 as the first direction, and the long axis direction of the inner recess 4 as the second direction; the long axis of the inner recess 4 deviates from the center line B2 of the second direction of the piston body 1, and the long axis B1 of the inner recess 4 is close to the exhaust valve avoidance portion 3; the short axis C of the inner recess 4 coincides with the center line of the first direction of the piston body 1.

[0037] Preferably, the ratio of the distance from the major axis B1 of the inner recess 4 to the center line B2 of the piston body 1 in the second direction to the minor axis diameter of the inner recess 4 is 0.056-0.146.

[0038] The center point of the concave surface of the inner concave portion 4 directly affects the position of the vortex center of the airflow, thereby affecting the formation of the flow field. Since the concave surface of the inner concave portion 4 is an ellipsoidal spherical surface, the long axis of the inner concave portion 4 deviates from the center line B2 of the piston body 1, and the ratio of the eccentric distance to the short axis diameter of the inner concave portion 4 is in the range of 0.056-0.146, the center point of the concave surface of the inner concave portion 4 can be infinitely close to the central axis of the cylinder liner, that is, the position of the vortex center of the airflow is infinitely close to the central axis of the cylinder liner to improve the tumble flow intensity.

[0039] In some embodiments, the piston body 1 can also be used as follows Figure 1 and Figure 2 The structure shown, see Figure 1 and Figure 2 , define the intersection line of the outer edge of the inner recess 4 and the inner edge of the intake valve avoidance portion 2 as the first intersection line 7, and the intersection line of the outer edge of the inner recess 4 and the inner edge of the exhaust valve avoidance portion 3 as the second intersection line 8; in the second direction, the length of the first intersection line 7 is less than the length of the second intersection line 8, and the ratio of the length of the first intersection line 7 to the major axis diameter of the inner recess 4 is 0.083-0.166.

[0040] It should be noted that the intake valve avoidance portion 2, the recessed portion 4 and the exhaust valve avoidance portion 3 are connected in sequence without any other transition relationship. Since the intake valve is larger than the exhaust valve, the avoidance size of the intake valve avoidance portion 2 is larger than the avoidance size of the exhaust valve avoidance portion 3. The larger the avoidance size of the intake valve avoidance portion 2, the smaller the length of the first intersection line 7.

[0041] The ratio of the length of the first intersection line 7 to the major axis diameter of the inner recess 4 is 0.083-0.166. If the ratio exceeds the above range, the avoidance size of the intake valve avoidance portion 2 becomes smaller, which will interfere with the intake valve; if the ratio is smaller than the above range, the airflow will directly collide with the intake valve avoidance portion 2 and rise and rebound, causing the flow field to attenuate.

[0042] In some embodiments, the piston body 1 can also be used as follows Figure 1 and Figure 2 The structure shown, see Figure 1 and Figure 2 The top surface of the piston body 1 also forms a first plane 5 and a second plane 6; the first plane 5 is located between the intake valve avoidance portion 2 and the exhaust valve avoidance portion 3, and on one side of the long axis direction of the inner recess 4; the second plane 6 is located between the intake valve avoidance portion 2 and the exhaust valve avoidance portion 3, and on the other side of the long axis direction of the inner recess 4.

[0043] On the top surface of the piston body 1, except for the intake valve avoidance portion 2, the recessed portion 4 and the exhaust valve avoidance portion 3, there are only the first plane 5 and the second plane 6. Preferably, the first plane 5 and the second plane 6 are respectively perpendicular to the central axis of the piston body 1.

[0044] The first plane 5 and the second plane 6 are the highest parts of the piston body 1, that is, there are no other convex points on the top surface of the piston body 1. During the inhalation process, the piston body 1 moves from the top dead center to the bottom dead center, and the airflow rotates clockwise along the cylinder liner wall and the top surface of the piston body 1. If there is an obvious bulge on the top surface of the piston body 1, the airflow will directly hit the bulge, and part of the airflow will rebound, which will weaken the movement of the airflow and further affect the strength of the tumble flow in the cylinder.

[0045] Based on the same inventive concept, the utility model also provides an engine, including the above engine piston. Meanwhile, the utility model also provides a vehicle, including the above engine.

[0046] The engine and vehicle provided by the utility model can improve the combustion condition in the cylinder, enhance the thermal efficiency of the engine, and reduce the original emission due to the adoption of the above-mentioned engine piston.

[0047] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An engine piston, characterized in that: The piston body (1) comprises a piston body; a downwardly concave intake valve avoidance portion (2) is formed on the left portion of the top surface of the piston body (1); a downwardly concave exhaust valve avoidance portion (3) is formed on the right portion of the top surface; a downwardly concave inner concave portion (4) is further provided on the top surface of the piston body (1) between the intake valve avoidance portion (2) and the exhaust valve avoidance portion (3); the concave depth of the inner concave portion (4) is greater than the concave depth of the intake valve avoidance portion (2) and the concave depth of the exhaust valve avoidance portion (3); The concave surface of the inner concave portion (4) is an ellipsoidal spherical surface, and the short axis direction of the inner concave portion (4) is the spacing direction between the intake valve avoidance portion (2) and the exhaust valve avoidance portion (3).

2. The engine piston according to claim 1, characterized in that The ratio of the major axis diameter of the inner recess (4) to the diameter of the piston body (1) is 0.49-0.83; the ratio of the minor axis diameter of the inner recess (4) to the diameter of the piston body (1) is 0.405-0.

607.

3. The engine piston according to claim 2, characterized in that: The distance from the center point of the inner recess (4) to the top surface of the piston body (1) is 0.9-4 mm.

4. The engine piston according to claim 1, characterized in that The top surface of the piston body (1) is also formed with a first plane (5) and a second plane (6); the first plane (5) is located between the intake valve avoidance portion (2) and the exhaust valve avoidance portion (3), and on one side of the long axis direction of the inner recess (4); the second plane (6) is located between the intake valve avoidance portion (2) and the exhaust valve avoidance portion (3), and on the other side of the long axis direction of the inner recess (4).

5. The engine piston according to claim 1, characterized in that The short axis direction of the inner recess (4) is defined as the first direction, and the long axis direction of the inner recess (4) is defined as the second direction; the long axis of the inner recess (4) deviates from the center line of the second direction of the piston body (1), and the long axis of the inner recess (4) is close to the exhaust valve avoidance portion (3); the short axis of the inner recess (4) coincides with the center line of the first direction of the piston body (1).

6. The engine piston according to claim 5, characterized in that The ratio of the distance from the major axis of the inner recess (4) to the center line of the piston body (1) in the second direction to the minor axis diameter of the inner recess (4) is 0.056-0.

146.

7. The engine piston according to claim 5, characterized in that The intersection line of the outer edge of the inner recess (4) and the inner edge of the intake valve avoidance portion (2) is defined as a first intersection line (7), and the intersection line of the outer edge of the inner recess (4) and the inner edge of the exhaust valve avoidance portion (3) is defined as a second intersection line (8); in the second direction, the length of the first intersection line (7) is less than the length of the second intersection line (8).

8. The engine piston according to claim 7, characterized in that In the second direction, the ratio of the length of the first intersection line (7) to the major axis diameter of the inner recess (4) is 0.083-0.

166.

9. An engine, characterized in that: The invention comprises the engine piston as claimed in any one of claims 1 to 8.

10. A vehicle, characterized in that: Comprising the engine as claimed in claim 9.

Images