Engine piston structure for reducing fuel consumption

Abstract

The present invention discloses an engine piston structure for reducing fuel consumption, comprising a piston, wherein the top surface of the piston is recessed along the axial direction of the piston to form a combustion chamber, the axial cross section of the cavity of the combustion chamber is an ω-shaped body of revolution, and the axis of revolution of the body of revolution coincides with the center line of the corresponding cylinder liner; a first gap is provided between the top surface of the piston and the engine cylinder head, and the first gap is between 0.7% and 0.85% of the piston stroke; a second gap is provided between the firepower shore of the piston and the engine cylinder liner, and the second gap is between 0.7% and 0.8% of the cylinder diameter of the cylinder liner; a shrinking structure with an annular arc-shaped protrusion is provided in the middle of the combustion chamber, and the diameter ratio of the shrinking to the inner diameter of the cylinder liner is between 0.55 and 0.57; the shrinking ratio of the combustion chamber is maintained between 0.95 and 0.98. The present invention can improve the combustion condition, make the combustion more complete, and reduce the fuel consumption of the whole machine.

Description

Technical Field

[0001] The invention relates to the technical field of engines, in particular to an engine piston structure capable of reducing fuel consumption. Background Art

[0002] The principle of combustion in a car's internal combustion engine is that gasoline and air are mixed and burned to generate power. The amount of power generated by combustion depends on the ratio of the two, which is theoretically 14.7:1. In this way, the gasoline burns most fully in the engine to generate the greatest power. No matter which one is more or less, it will affect the power output of the engine. Not only will the car be powerless, but it will also consume a lot of fuel, damage the engine, and accelerate wear. The shape of the combustion chamber is one of the keys to the engine's combustion system. It must be reasonably designed according to the characteristics of the engine's operating conditions, so that the airflow and gasoline are fully mixed to achieve the best ratio, thereby achieving full combustion.

[0003] The piston assembly includes the piston, piston ring, piston pin and cylinder liner, and is one of the core moving parts of the internal combustion engine to control the combustion volume. When the piston is at the top dead center, the volume formed by the top of the piston and the bottom of the cylinder head is called the combustion volume, which is further divided into the effective combustion volume and the dead volume. The effective combustion volume is the effective combustion volume, and the dead volume is the volume that the engine cannot effectively burn. The smaller the dead volume, the higher the combustion efficiency.

[0004] For example, the matching clearance of the existing S04 National VI model piston assembly is as follows: crankshaft crank radius 60mm, connecting rod length 192mm, piston compression height 71.3mm, body height 323mm, calculated piston protrusion height 0.3mm, compression clearance 1mm; this gap will cause oxygen-deficient combustion and form a combustion dead zone; piston head fire land diameter: 103.165±0.025mm, cylinder bore inner diameter: 105(0,+0.022)mm, calculated clearance: 1.81~1.882mm, the reserved larger gap causes a combustion dead zone, affects combustion efficiency, and causes increased oil consumption.

[0005] Therefore, the clearance between the above-mentioned traditional piston solution and the valve and cylinder head is too large; at the same time, the clearance between the piston and the cylinder hole is too large; the dead zone volume control is not ideal, and the combustion efficiency does not meet the requirements. Summary of the invention

[0006] In view of the above-mentioned existing defects, the purpose of the present invention is to provide an engine piston structure with reduced fuel consumption, improve the combustion conditions, make the combustion more complete, and reduce the fuel consumption of the whole machine.

[0007] The technical solution of the present invention is as follows:

[0008] An engine piston structure for reducing fuel consumption comprises a piston, wherein the top surface of the piston is recessed along the axial direction of the piston to form a combustion chamber, the axial cross section of the cavity of the combustion chamber is an ω-shaped body of revolution, and the axis of revolution of the body of revolution coincides with the center line of the corresponding cylinder liner;

[0009] A first gap is provided between the piston top surface and the engine cylinder cover, wherein the first gap is between 0.7% and 0.85% of the piston stroke;

[0010] A second gap is provided between the fire land of the piston and the cylinder liner of the engine, and the second gap is between 0.7% and 0.8% of the cylinder diameter of the cylinder liner;

[0011] A constriction structure with an annular arc-shaped protrusion is arranged in the middle of the combustion chamber, and the diameter ratio of the constriction to the inner diameter of the cylinder sleeve is between 0.55 and 0.57; the constriction ratio of the combustion chamber is maintained between 0.95 and 0.98.

[0012] Specifically, the height of the necking from the top surface of the combustion chamber is 6.8 mm.

[0013] Specifically, the bottom of the combustion chamber is configured to be a concave ring, and the radius of the concave ring is 5.8 mm.

[0014] Specifically, the distance from the lowest point of the bottom of the combustion chamber to the top surface of the combustion chamber is 17 mm.

[0015] Specifically, a truncated cone is arranged at the center of the combustion chamber, the bottom of the truncated cone is inclined to the bottom of the combustion chamber, the diameter of the top surface of the truncated cone is 7 mm, and the distance from the top surface to the top surface of the combustion chamber is 4.5 mm.

[0016] Specifically, the combustion chamber top surface and the combustion chamber neck are connected by an arc transition with a radius of 2 mm.

[0017] Specifically, the combustion chamber constriction is connected to the combustion chamber bottom through an arc transition with a radius of 2.5 mm.

[0018] Specifically, the table top is connected to the bottom of the combustion chamber via an arc transition with a radius of 0.5 mm.

[0019] The beneficial effects of the present invention are:

[0020] After adopting the above structure, by improving the design of the original piston structure and combustion chamber, the compression clearance of the whole machine is controlled to 0.7% to 0.85% of the piston stroke, the piston fire land clearance is controlled to 0.7% to 0.8% of the cylinder liner diameter, and the piston shrinkage ratio is controlled to between 0.95 and 0.98. It has been proven that it can make the combustion more complete and reduce the fuel consumption of the whole machine. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The figure is a schematic diagram of an engine piston structure for reducing fuel consumption according to the present invention.

[0022] Figure 2 The present invention is a cross-sectional view of a piston combustion chamber of an engine piston structure for reducing fuel consumption.

[0023] Figure 3 This is a comparison chart of specific fuel consumption versus speed before and after optimization in an embodiment of the present invention.

[0024] In the figure, 1-cylinder head, 2-valve, 3-cylinder gasket, 4-cylinder liner, 5-piston, 6-first gap, 7-second gap, 8-combustion chamber, 9-narrowing, 10-cone, 11-concave ring, D-narrowing ratio. DETAILED DESCRIPTION

[0025] In order to explain the technical content, purpose and effect of the present invention in detail, the following is an explanation in combination with embodiments and accompanying drawings. In the description of the embodiments, it should be understood that the terms indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, which are only for the convenience of describing the present embodiment and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention.

[0026] Example 1

[0027] like Figure 1-2 As shown, according to a specific implementation of the present scheme, a fuel-saving engine piston structure comprises a piston 5, wherein the top surface of the piston 5 is recessed along the axial direction of the piston 5 to form a combustion chamber 8, wherein the axial cross-section of the cavity of the combustion chamber 8 is an ω-shaped body of revolution, wherein the axis of revolution of the body of revolution coincides with the center line of the corresponding cylinder liner 4; a first gap 6 is provided between the top surface of the piston 5 and the engine cylinder head 1, a second gap 7 is provided between the fire land of the piston 5 and the engine cylinder liner 4, and a ring-shaped arc-shaped convex constriction 9 structure is provided in the middle of the combustion chamber 8;

[0028] Combination Figure 1 , 2 As shown, the diameter ratio of the piston 5 refers to the ratio of the diameter of the narrowest part of the necking 9 structure to the inner diameter of the cylinder liner 4, as shown in FIG. Figure 2 As shown, the necking ratio D of the piston 5 refers to the ratio of the diameter of the narrowest part of the necking 9 structure to the widest part of the lower part of the necking 9 structure;

[0029] The first gap 6 is between 0.7% and 0.85% of the stroke of the piston 5; the second gap 7 is between 0.7% and 0.8% of the cylinder diameter of the cylinder liner 4; the diameter ratio of the necking 9 to the inner diameter of the cylinder liner 4 is between 0.55 and 0.57; the necking ratio D of the combustion chamber 8 is maintained between 0.95 and 0.98.

[0030] This embodiment controls the whole machine compression clearance, piston land clearance, and piston shrinkage ratio D. For the upper part of the combustion chamber 8, the compression height is redesigned. The compression clearance is the height from the top surface of the piston 5 to the bottom surface of the cylinder head 1, corresponding to Figure 1 The dead zone volume of the first gap 6 is reduced; the ratio of fuel oil and steam injected into the upper part of the combustion chamber 8 is reasonable; after the fuel oil and steam enter the middle part of the ω-shaped combustion chamber 8, they are guided by the inclined surface to the concave ring 11 at the bottom of the combustion chamber 8, and the steam has sufficient movement space to ensure that the steam will not be retained in the upper part of the combustion chamber 8; and then guided by the bottom concave ring 11 to the constriction 9; by optimizing the diameter ratio and constriction ratio D structure of the combustion chamber 8, most of the steam rushes to the bottom surface of the cylinder head 1 through the constriction 9 structure and returns to the center of the combustion chamber 8, which has a good guiding effect on the steam and strengthens the full mixing of the fuel and air; the remaining part of the steam climbs up the top surface of the piston 5 along the constriction 9 and moves in the direction of the cylinder liner 4; because the valve 22 is set close to the second gap 7, the diameter of the firepower shore is redesigned, that is, it is reduced Figure 1 The dead volume of the second gap 7 in the middle promotes a reasonable small part of steam to enter the second gap 7 for full mixing, which helps to improve the combustion efficiency and reduce the pressure at the cylinder gasket 3. Therefore, by adjusting the gap, the combustion chamber 8 is redesigned to improve the combustion condition, make the combustion more complete, and reduce the fuel consumption of the whole machine; thereby reducing the heat transfer loss of the combustion chamber 8 during the combustion process, making the fuel burn more completely, thereby improving the thermal efficiency of the engine and reducing the fuel consumption of the whole machine, and in summary, the purpose of the present invention is achieved.

[0031] Example 2

[0032] This embodiment further optimizes the structure and size of the combustion chamber 8 on the basis of the embodiment 1. In this embodiment, the first gap 6 is 0.89 mm; the crankshaft crank radius is 60 mm, and the piston 5 stroke is 2×60=120 mm, that is, the first gap 6 is 0.74% of the piston 5 stroke. The diameter of the fire land is 104.165±0.025 mm, the inner diameter of the cylinder liner 4 is 105(0,+0.022) mm, the second gap 7 is 0.7375-0.7735 mm, that is, the gap value of the second gap 7 is 0.7% of the cylinder diameter of the cylinder liner 4, the shrinkage ratio D is 59 / 60.8=0.97, and the diameter ratio is 59 / 105=0.56.

[0033] As the preferred technical solution of this embodiment, the height of the necking 9 from the top surface of the combustion chamber 8 is 6.8 mm, and the bottom of the combustion chamber 8 is arranged in the shape of a concave ring 11, and the radius of the concave ring 11 is 5.8 mm; the distance from the lowest point of the bottom of the combustion chamber 8 to the top surface of the combustion chamber 8 is 17 mm; a frustum 10 is arranged in the center of the combustion chamber 8, and the bottom of the frustum 10 is inclined to transition to the bottom of the combustion chamber 8, the diameter of the top surface of the frustum 10 is 7 mm, and the distance from the surface to the top surface of the combustion chamber 8 is 4.5 mm; the top surface of the combustion chamber 8 and the necking 9 of the combustion chamber 8 are connected by a circular arc transition with a radius of 2 mm; the necking 9 of the combustion chamber 8 and the bottom of the combustion chamber 8 are connected by a circular arc transition with a radius of 2.5 mm; the table top and the bottom of the combustion chamber 8 are connected by a circular arc transition with a radius of 0.5 mm.

[0034] Figure 3 A fuel consumption versus speed comparison diagram is provided for comparing a fuel consumption reduction engine piston 5 structure using the above-mentioned embodiment 2 with that before optimization. It can be seen from the diagram that, at low speeds, fuel consumption is significantly reduced, with a maximum reduction of 3.2%.

[0035] Although the present invention has been described in detail above with specific embodiments, it is obvious to those skilled in the art that some modifications or improvements can be made to the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all belong to the scope of protection claimed by the present invention.

Claims

1. An engine piston structure for reducing fuel consumption, comprising a piston, wherein the top surface of the piston is recessed along the axial direction of the piston to form a combustion chamber, the axial cross section of the cavity of the combustion chamber is an ω-shaped body of revolution, the axis of revolution of the body of revolution coincides with the center line of the corresponding cylinder liner, and is characterized in that: A first gap is provided between the piston top surface and the engine cylinder cover, wherein the first gap is between 0.7% and 0.85% of the piston stroke; A second gap is provided between the fire land of the piston and the cylinder liner of the engine, and the second gap is between 0.7% and 0.8% of the cylinder diameter of the cylinder liner; A ring-shaped arc-shaped protruding necking structure is provided in the middle of the combustion chamber, and the diameter ratio between the narrowest part of the necking structure and the inner diameter of the cylinder liner is between 0.55 and 0.57; the necking ratio of the combustion chamber is maintained between 0.95 and 0.

98.

2. The engine piston structure for reducing fuel consumption according to claim 1, characterized in that: The height of the necking structure from the top surface of the combustion chamber is 6.8 mm.

3. The engine piston structure for reducing fuel consumption according to claim 1, characterized in that: The bottom of the combustion chamber is arranged in a concave ring shape, and the radius of the concave ring is 5.8 mm.

4. The engine piston structure for reducing fuel consumption according to claim 1, characterized in that: The distance from the lowest point of the bottom of the combustion chamber to the top surface of the combustion chamber is 17 mm.

5. The engine piston structure for reducing fuel consumption according to claim 1, characterized in that: A truncated cone is arranged at the center of the combustion chamber, the bottom of the truncated cone is inclined to the bottom of the combustion chamber, the diameter of the top surface of the truncated cone is 7 mm, and the distance from the truncated cone surface to the top surface of the combustion chamber is 4.5 mm.

6. The engine piston structure for reducing fuel consumption according to claim 1, characterized in that: The combustion chamber top surface and the combustion chamber necking structure are connected via an arc transition with a radius of 2 mm.

7. The engine piston structure for reducing fuel consumption according to claim 1, characterized in that: The combustion chamber necking structure is connected to the bottom of the combustion chamber through an arc transition with a radius of 2.5 mm.

8. The engine piston structure for reducing fuel consumption according to claim 5, characterized in that: The table top of the truncated cone is connected to the bottom of the combustion chamber through an arc transition with a radius of 0.5 mm.

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