CN217401024U - Engine piston and engine - Google Patents

Abstract

The utility model provides an engine piston and engine. The engine piston comprises a top, a conical boss-shaped protruding structure is arranged on the top, and an inner concave portion is arranged on the upper end face of the protruding structure. The top of the piston is provided with the convex structure in the shape of a conical table, and the upper end face of the convex structure is provided with the concave part which is concave inwards, so that the compression ratio of the engine is increased, the tumble ratio and the turbulence intensity of fluid in the cylinder are improved, the combustion pressure of mixed gas is effectively improved, the thermal efficiency of the engine is increased, and the oil consumption is reduced.

Description

Engine piston and engine

Technical Field

The utility model relates to a but not limited to engine technical field especially relates to an engine piston and engine.

Background

At present, because the existing direct injection engine in a cylinder has higher fuel injection pressure, most pistons are of flat-top structures. The compression ratio of the engine can only be 10-13, and the piston with a flat top structure also influences the tumble ratio and turbulence intensity of fluid in the cylinder, so that the combustion heat efficiency of the engine is not improved, and the oil consumption of the engine is not reduced.

In addition, the piston is used as a key part for reciprocating motion in an engine cylinder, the top of the piston and a cylinder cover of the engine are combined to form a combustion chamber, and whether the structural design of the top of the piston is reasonable or not can directly influence the flow of gas in the cylinder, so that the atomization of fuel oil and the generation of mixed gas are influenced, and the combustion performance of the engine is influenced.

The above description is included in the technical recognition scope of the inventors, and does not necessarily constitute the prior art.

SUMMERY OF THE UTILITY MODEL

An embodiment of the utility model provides a novel engine piston, this piston structure include the top, the top is equipped with the protruding structure of toper platform form, the up end of protruding structure is equipped with interior concave part.

After the technical scheme is adopted, the embodiment of the utility model provides a following beneficial effect has:

the top of the piston is provided with the convex structure in the shape of a conical table, and the upper end face of the convex structure is provided with the concave part which is concave inwards, so that the compression ratio of the engine is increased, the tumble ratio and the turbulence intensity in the cylinder are improved, the combustion pressure of mixed gas is improved, the heat efficiency of the engine is increased, and the oil consumption is reduced.

Other aspects will be apparent upon reading and understanding the attached drawings and detailed description.

Drawings

The accompanying drawings are included to provide a further understanding of the technical solutions of the present invention, and are incorporated in and constitute a part of this specification, together with the embodiments of the present invention for explaining the technical solutions of the present invention, and do not constitute a limitation on the technical solutions of the present invention.

FIG. 1 is a schematic front view of a prior art engine flat-top piston configuration;

fig. 2 is a schematic front view of a piston structure according to an embodiment of the present invention;

fig. 3 is a schematic front view of a piston structure according to an exemplary embodiment of the present invention;

fig. 4 is a schematic top view of a piston structure according to an exemplary embodiment of the present invention;

fig. 5 is a schematic sectional front view of a piston structure according to an exemplary embodiment of the present invention;

fig. 6 is a schematic sectional front view of a piston structure according to an exemplary embodiment of the present invention;

fig. 7 is a schematic diagram of a partial top view of a piston structure according to an exemplary embodiment of the present invention;

fig. 8 is a schematic diagram of a partial top view of a piston structure according to an exemplary embodiment of the present invention;

fig. 9 is a tumble ratio comparison diagram of fluid in an engine cylinder according to another embodiment of the present invention;

fig. 10 is a graph comparing the turbulent kinetic energy of fluid in an engine cylinder according to another embodiment of the present invention.

Reference numerals:

100, -a piston;

100-a piston;

1-top;

11-convex structure, 12-concave part, 13-first transition surface, 14-second transition surface, 15-third transition surface, 16-upper end surface, 17-first concave pit, and 18-second concave pit.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments with reference to the accompanying drawings. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention.

As shown in fig. 1, most of the conventional engine pistons 100 are flat-top structures, and the compression ratio of the engine can only be set to 10-13, so that the tumble ratio and turbulence intensity of fluid in an engine cylinder are affected, the combustion thermal efficiency of the engine is not improved, and the oil consumption of the engine is not reduced.

The compression ratio of the engine is a degree of compression of the air-fuel mixture in the engine, and is a ratio of a total volume of a cylinder before compression to a volume of the cylinder after compression (i.e., a volume of a combustion chamber). Typically, the compression ratio of the engine is not variable because the combustion chamber volume and the displacement volume are fixed parameters and are fixed in the design. When the stroke of the piston reaches the lowest point in a certain cylinder of the engine, the point is called a bottom dead center, and the volume formed by the whole cylinder including the combustion chamber is the maximum stroke volume. When the piston moves reversely and reaches the highest point, the point is called the top dead center, the formed volume is the condition that the volume of the whole piston moving stroke is minimum, and the compression ratio to be calculated is the ratio of the maximum stroke volume to the minimum volume.

The tumble ratio is a ratio between the rotation speed of the air-fuel mixture rolling in the combustion chamber and the rotation speed of the engine, and a larger value indicates a better combustion effect and a stronger engine power.

The piston is a relatively mature part of the engine and is generally composed of four parts, namely a top part, a head part, a skirt part and a piston pin boss.

The utility model discloses a main improvement point embodies at the top of engine piston, will be right below the utility model relates to a technical scheme makes detailed introduction.

In one embodiment of the present invention, as shown in fig. 2-8, a novel engine piston 100 is provided. The piston 100 comprises a top part 1, a conical boss-shaped protruding structure 11 is further arranged on the top part 1, the taper of the conical boss can be set to be any value (for example, 160 degrees) between 155 and 165 degrees, an inward concave part 12 is further arranged on the upper end face of the protruding structure 11, namely the small-diameter end face of the conical boss, and the maximum depth of the inward concave part 12 can be set to be any value (for example, 2.6mm) between 2.0 and 3.0 mm. The concave portion 12 may be configured as a concave surface as shown in the figure, and the specific profile of the concave surface may be self-adjusting. Wherein the top part 1 can be provided as a dish as shown in fig. 2, and a raised structure 11 is provided on the upper end surface of the dish top part.

The top 1 of the piston 100, the cylinder cover and the cylinder wall form a novel combustion chamber, so that the flowing performance of fluid in the combustion chamber is improved, the compression ratio of an engine cylinder is also improved, the combustion pressure of mixed gas is also improved, the thermal efficiency of the engine is increased, and the oil consumption of the engine is also reduced.

In some exemplary embodiments, as shown in fig. 4 to 8, the concave portion 12 is disposed at the middle of the upper end surface of the convex structure 11, i.e., at the end point of the outer circumference of the non-upper end surface, so as to increase the contact area with the fluid when the piston 100 does work, and improve the smoothness of the reciprocating motion of the piston 100.

In some exemplary embodiments, as shown in fig. 4-8, the outer surface of the concave portion 12 is partially spherical, and the radius of the spherical surface can be set to any value between 55.0mm and 65.0mm (for example, SR60mm), that is, when the concave portion 12 is matched with the cylinder head of a cylinder, a spherical combustion chamber can be formed, and in addition, the squish design that the outer conical surface of the convex structure 11 forms a slope with the cylinder wall of the cylinder improves the tumble ratio and turbulence intensity of fluid in the cylinder so as to improve the combustion performance of the engine.

In some exemplary embodiments, as shown in fig. 6, the spherical center of the partial spherical surface of the concave portion 12 is located on the axis of the engine piston 100, i.e. the axis after forming the spherical combustion chamber is substantially the same as the axis of the piston 100, and a deviation within an angle of 3 ° is allowed, when the piston 100 reciprocates, the convex structure 11 on the top portion 1 of the piston 100 also reciprocates to form the spherical combustion chamber, and the mixed gas in the compression cylinder performs work.

In some exemplary embodiments, as shown in fig. 7, in order to avoid the sharp edge formed at the junction area of the two structural features from affecting the flow performance of the fluid and to make the flow of the fluid smoother, a first transition surface 13 with smooth transition is provided between the outer conical surface of the protruding structure 11 and the surface of the inner concave portion 12. The first transition surface 13 can be a circular arc surface, and the radius of the fillet is set to any value between 2.0mm and 5.0 mm.

In some exemplary embodiments, as shown in fig. 8, the upper end surface of the protruding structure 11 of the tip portion 1 is arranged around the inner recess 12, i.e. the inner recess 12 does not occupy the entire upper end surface of the protruding structure 11, such that the upper end surface is arranged annularly around the inner recess 12, i.e. the annularly shaped upper end surface 16 shown in fig. 8.

In other exemplary embodiments, as shown in fig. 8, since the raised structure 11 is provided with the annular upper end surface 16, in order to improve the smoothness of the fluid in the cylinder, the raised structure 11 is further provided to include a second transition surface 14 which is provided between the inner concave portion 12 and the region of the annular upper end surface 16 and is smoothly transited, and a third transition surface 15 which is provided between the annular upper end surface 16 and the outer conical surface of the raised structure 12 and is smoothly transited, that is, a smooth transition treatment is performed at the intersection of two structural features to improve the flow performance of the fluid.

Additionally, in some exemplary embodiments, as shown in FIG. 4, to avoid exhaust valves (not shown) and intake valves (not shown) in an engine, an avoidance feature is provided on the crown 1 of the piston 100. For example, a first recess 17 is provided on the raised structure 11 to avoid the exhaust valve, wherein the first recess 17 is adapted to the structural shape of the exhaust valve. And a second pit 18 is arranged on the convex structure 11 to avoid an air inlet valve, and the shape of the second pit 18 is matched with the structural shape of the air inlet valve to avoid the convex structure 11 from influencing the normal air inlet and exhaust of the engine.

In some exemplary embodiments, in order to avoid the damage to the shape of the combustion chamber and thus the adverse effect on the combustion performance caused by the formation of the above-mentioned relief pits, the first pits 17 and the second pits 18 may be disposed on the outer periphery of the inner concave portion 12, i.e., the arrangement of the pits does not damage the spherical combustion chamber formed by the inner concave portion 12 and the cylinder head.

In another embodiment of the present invention, a novel engine (not shown in the figure) is also provided. The engine includes an engine piston 100 as described in any of the embodiments above. Of course, the engine is provided with other conventional components of the existing engine, such as an oil injector, an intake passage, an intake valve, a spark plug, an exhaust valve, an exhaust passage and the like, besides the piston 100, and the conventional components are generally installed at corresponding positions on a cylinder head, so as to form a cylinder head assembly of the engine.

As shown in fig. 9 and 10, it can be seen that, in the engine using the piston 100, the tumble ratio and the turbulent kinetic energy of the fluid in the cylinder are improved significantly by comparing the performance of the fluid in the cylinder of the engine mounted with the conventional flat-top piston and the engine mounted with the piston 100 according to any of the embodiments of the present invention.

In fig. 9 and 10, reference A, B, C shows a conventional direct injection flat top piston 100 assembled in an engine, and reference D shows a piston 100 provided in the present invention as described above and assembled in an engine.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like, indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be construed as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or to implicitly indicate the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise explicitly specified or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly, e.g., as being fixedly connected, detachably connected, or integrated; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

In the present application, unless expressly stated or limited otherwise, the first feature may be directly on or directly under the second feature or indirectly via intermediate members. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature "under," "beneath," and "under" a second feature may be directly under or obliquely under the second feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

While embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations of the above embodiments may be made by those of ordinary skill in the art without departing from the scope of the present invention.

Claims (10)

1. The engine piston comprises a top and is characterized in that the top is provided with a conical boss-shaped protruding structure, and an inner concave part is arranged on the upper end face of the protruding structure.

2. The engine piston of claim 1 wherein said recess is disposed in the middle of the upper end surface of said boss structure.

3. The engine piston of claim 2 wherein said surface of said fillet is provided as a partial spherical surface.

4. The engine piston of claim 3 wherein said partial spherical surface has a center of sphere lying on an axis of said engine piston.

5. An engine piston according to any of claims 1 to 4, wherein a smooth first transition surface is provided between the outer conical surface of the raised formation and the surface of the recess.

6. An engine piston according to any of claims 1 to 4, wherein the upper end surface of the raised formation is disposed around the recess and is annular.

7. The engine piston of claim 6, wherein said lobe formation further includes a smooth second transition surface between said concave recess and said annular upper end surface, and a smooth third transition surface between said annular upper end surface and said outer conical surface of said lobe formation.

8. An engine piston as claimed in any one of claims 1 to 4, wherein said raised formation is provided with a first recess for avoiding the exhaust valve; and a second pit is arranged on the protruding structure and used for avoiding the air inlet valve.

9. The engine piston of claim 8, wherein said first dimples and said second dimples are each disposed about an outer periphery of said inner recess.

10. An engine comprising an engine piston as claimed in any one of claims 1 to 9.

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