Cylinder head of a liquid-cooled internal combustion engine

Abstract

This utility model pertains to engine engineering, specifically to the design of internal combustion engine (ICE) cylinder heads. The technical result achieved by the proposed utility model consists of improving mixture formation, flame front propagation, and complete fuel combustion in the ICE cylinder head, as well as purging and cleaning the area around the spark plug. This results in reduced exhaust gas toxicity and fuel consumption, as well as an increased service life for the ICE. This result is achieved by the ICE cylinder head containing intake and exhaust ports with valves on one side of the cylinder head, a combustion chamber containing a protrusion for accommodating the spark plug, located on the cylinder axis, and displacer surfaces.A new feature of the utility model is that the apex of the angle formed by the plane of the spark plug protrusion with the plane of the head mating to the cylinder block is rounded, with the boundaries of the rounding being two lines, one on the plane to the block, removed from the valve axis, and the other line in a perpendicular plane extending at a distance from the plane of mating to the cylinder block towards the opening for installing the spark plug. 5 fig.

Description

[0001] The utility model relates to the field of engine engineering, namely to the design of the cylinder head of an internal combustion engine (ICE).

[0002] A known design of an internal combustion engine cylinder head, according to Russian Federation Patent No. 2117801, IPC F02F 1 / 24, published August 20, 1998, comprises a combustion chamber, as well as intake and exhaust ports with valves opening on one side. The cylinder head's combustion chamber has displacement surfaces on both the port side and the spark plug side.

[0003] A disadvantage of this design is the reduced mixture flow velocity due to the impact of the incoming fuel mixture jets on the combustion chamber walls due to imperfect shape. Due to the large difference in distances from the mixture's ignition point to points on the opposite wall of the chamber, combustion is impaired and detonation characteristics are reduced. These shortcomings lead to reduced filling at maximum loads, reduced maximum power, increased exhaust toxicity, and increased engine wear. This cylinder head does not provide optimal displacer areas, leading to increased minimum engine speeds, resulting in increased fuel consumption and wear on moving engine parts.

[0004] The closest design for the same purpose with similar essential features is the cylinder head of an internal combustion engine (Patent for invention of the Russian Federation 2565647C1 IPC F02F 1 / 24, F02B 23 / 08, published on 20.10.2015), containing intake and exhaust channels with valves extending to one side of the cylinder head and a combustion chamber with displacer surfaces located in it, wherein the combustion chamber on the plane of contact of the cylinder head with the block has a shape formed by an arc with a radius equal to 0.63-0.65 of the cylinder diameter, with a center spaced from the center of the cylinder at a distance of 0.28-0.30 of the cylinder diameter towards the spark plug, the arc is conjugated by radii equal to 0.30-0.32 of the cylinder diameter, with a diameter drawn from the center of the cylinder and equal to the diameter cylinder, and on the opposite side the shape of the chamber is formed by a diameter equal to the diameter of the cylinder, conjugated with radii equal to 0.30-0.32 of the cylinder diameter, with centers lying on the axis of the valves,spaced from the cylinder axis at a distance of 0.06-0.08 of the cylinder diameter, the mating radii are limited by a line spaced from the cylinder axis at a distance of 0.35-0.37 of the cylinder diameter, the combustion chamber walls are inclined towards the bottom of the chamber and have a transition radius in the plane of the transverse axis of the cylinder of 14°…16° and a radius of 12-14 mm, respectively, and in the plane along the axis of the valves 4°…6° and a radius of 5-7 mm.,

[0005] The disadvantage of this cylinder head design is that the poorly organized flow of the air-fuel mixture within the combustion chamber results in unstable combustion, which is a major factor limiting fuel efficiency and increasing exhaust emissions. In this design, the combustion chamber has a protrusion for the spark plug, and the surface of this protrusion under the spark plug forms a sharp-edged angle with the block's mating surface. This design feature prevents the uniform movement of the air-fuel mixture along the so-called "axial vortex," especially when the piston is at top dead center (TDC) on the compression stroke. The sharp edge also helps reduce flame front propagation from the spark plug toward the displacers' outermost portions.

[0006] The sharp edge and protruding part of the spark plug create a zone of carbon and soot accumulation. Contamination of the spark plug electrodes causes misfires, which is the main cause of detonation and uneven engine operation. All this leads to reduced combustion uniformity, reduced environmental and energy performance, and reduced service life of the internal combustion engine's cylinder head.

[0007] The objective of the utility model is to eliminate the above-mentioned design deficiencies.

[0008] The technical result achieved by the proposed utility model consists in improving the processes of mixture formation, flame front propagation and complete combustion of fuel in the cylinder head of an internal combustion engine, as well as purging and cleaning the area around the spark plug, resulting in a decrease in the toxicity of exhaust gases and fuel consumption, as well as an increase in the service life of the internal combustion engine.

[0009] The specified result is achieved due to the fact that the cylinder head of an internal combustion engine, containing intake and exhaust channels with valves extending to one side of the cylinder head, a combustion chamber located therein, having a protrusion for accommodating a spark plug, located on the axis of the cylinder, and the surfaces of the displacers, according to the utility model, the apex of the angle formed by the plane of the protrusion of the spark plug with the plane of contact of the head with the cylinder block is made with a rounding, wherein the boundaries of the rounding are two lines, one on the plane to the block is removed from the axis of the valves, and the other line in a perpendicular plane passes at a distance from the plane of contact with the cylinder block towards the hole for installing the spark plug.

[0010] The combustion chamber design, with a protrusion on the cylinder axis, allows the spark plug to be positioned closer to the center of the combustion chamber, which promotes uniform flame front propagation during combustion of the fuel-air mixture, even to the most distant wall areas, where afterburning can be prolonged and incomplete. The proposed protrusion is essential for the combustion chamber, as it solves this problem. The rounded corner of the protrusion ensures minimal resistance to mixture flow, intensifies the vortex motion of the charge, and cleans the spark plug. Equidistant distances from the ignition point to the outer walls of the chamber, additional turbulence of the mixture, and its movement into the ignition zone contribute to improved combustion and increased resistance to engine detonation.The combustion chamber dimensions and shape ensure optimal displacer areas, no more than 30% of the total cylinder area, as recommended by the open source textbook "Internal Combustion Engines. Theory of Operating Processes," edited by V.N. Lukanin and M.G. Shatrov, 2005, Moscow, "Higher School," p. 129. Rounding the apex angle facilitates unimpeded supply of the working mixture to the spark plug area, reliable ignition of the mixture, rapid combustion, and cleanliness of the spark plug. The essence of the utility model is illustrated by drawings.

[0011] Fig. 1 - general view of the cylinder head;

[0012] Fig. 2 - bottom view of the cylinder head;

[0013] Fig. 3-view B of Fig. 2;

[0014] Fig. 4 - section A-A of Fig. 2;

[0015] Fig. 5 - view E of Fig. 4.

[0016] Cylinder head 1 for an internal combustion engine comprises intake ports 2 and exhaust ports 3, each with intake valves 4 and exhaust valves 5 installed on one side. Cylinder head 1 houses combustion chamber 6. The chamber is formed by inclined walls 8 and 10, which are connected by side walls 7 and 9, which smoothly mate with each other. Displacer zones 11 and 12, respectively, are adjacent to inclined walls 8 and 10. A spark plug protrusion 16 with an opening 21 is located on the cylinder axis 13. Its plane 20 forms an angle F with the plane of the block 19. This angle F has a rounded apex 14.

[0017] The cylinder head operates as follows. During the intake stroke, the working mixture enters the combustion chamber 6 through the intake port 2 and intake valve 4, flowing along the inclined wall 8 of the combustion chamber, as well as along the side wall 9 along the surface of the inclined wall 10, and moves to the protrusion of the spark plug 16 with a smooth transition to the bottom of the chamber. The intake port 2, the axis of which is offset in plan relative to the axis of the intake valve 4, imparts a swirl to the fuel mixture flow around the valve axis. Due to this, at the outlet of the mixture flow from the valve gap into the combustion chamber 6 and further into the cylinder, a directed mixture flow is created along the side wall 9 towards the protrusion of the hole for installing the spark plug. The smooth mating of the intake port wall with the wall of the combustion chamber and the cylinder wall transforms the movement of the mixture from rotation around the valve axis to rotation around the vertical axis of the cylinder (axial vortex).

[0018] As a result, by the middle of the intake stroke, a stable axial rotation of the charge around the vertical axis of the cylinder is formed in the combustion chamber and cylinder of the internal combustion engine. The fuel-air flow is sensitive to the profile of the combustion chamber. However, protrusion 16 in the flow path does not act as an obstacle, thanks to the rounding of the apex of angle F. Protrusion 16 is necessary for this combustion chamber design, as it allows the spark plug to be positioned closer to the center of the chamber for uniform combustion of the mixture and to avoid detonation. At the same time, to ensure good scavenging of exhaust gases, carbon deposits, and soot, it is necessary to smooth the apex of angle F of the protrusion, formed by the intersection of the plane of protrusion 20 with the plane of the head-to-block mating 19. This prevents energy loss from the axial rotation of the charge and preserves it until the mixture is ignited by the spark plug.

[0019] Towards the end of the compression stroke, the charge's energy is enhanced by the displacement of a portion of the charge from the gap between the flat surfaces of the cylinder head and the piston crown (displacer surfaces 11, 12), including under the spark plug. Additionally, vortex flows (a radial vortex) are created in the central part of the chamber; the mixture is intensively mixed and tends to move in a directed direction toward the spark plug. The axial vortex mixes with the radial vortex, which promotes enhanced turbulence and uniform ignition of the mixture. The absence of a sharp edge at the apex of the angle between the plane of the camshaft and the plane facing the block facilitates flow movement from the displacement zone to the center of the chamber and directly to the spark plug.Thus, by the end of the compression stroke, the initial ignition source is intensively developing in the combustion chamber cavity and an intensive internal vortex movement of the working mixture is prepared for its rapid and high-quality combustion throughout the entire volume, without unburned remote areas that are sources of pre-ignition and detonation.

[0020] The presence of displacers and a rounded protrusion not only creates additional charge turbulence in the main chamber by pushing the mixture out of the relatively rapidly decreasing gaps at the end of the compression stroke, but also accelerates combustion during the combustion stage by drawing the burning mixture into these same gaps during the piston's downward stroke. The turbulent flame front from the initial combustion center, which forms near the spark plug electrode, spreads evenly in all directions throughout the combustion chamber, combusting the fuel mixture even in the outer layers adjacent to the walls.

[0021] At the next stage, the exhaust valves 5 open and the exhaust gases are released through the exhaust channels 3, which is accompanied by complete purging and cleaning of the spark plug area due to the rounding of the top corner of the protrusion.

[0022] The rounding can be achieved by machining (on a milling or grinding machine), but it is preferable to perform the rounding during the casting of the cylinder head housing, thereby avoiding additional machining. Casting also ensures a rounded spark plug protrusion angle, which results in smooth combustion chamber walls with smooth transitions and no sharp edges. When rounding, the spark plug and plug hole diameters must be taken into account, as these engine designs may use cylinder heads with different spark plug diameters.

[0023] The effectiveness of the claimed technical solution was confirmed experimentally. For this purpose, a cylinder head with a rounded spark plug lobe angle was installed on a production vehicle. This improvement was achieved mechanically, using a milling machine.

[0024] The special case of rounding the top of the candlestick protrusion angle has the following actual indicators:

[0025] - distance M from the center of the valves to the rounding line 17 - 32.8 mm;

[0026] - distance G from plane 19 adjacent to the block to line 18 of rounding 1.9 mm.

[0027] The cylinder head installed in the vehicle is successfully operated, proving the technical result.

[0028] The advantage of the proposed design is that, compared to existing internal combustion engine cylinder head designs, this utility model ensures rapid filling of the cylinders with the working mixture, improving mixture formation and combustion due to the optimal combustion chamber configuration, the relative positioning of the spark plugs and valves, and the vortex nature of the working charge. This increases flame propagation speed and makes it possible to clean the spark plug to prevent detonation. This results in reduced fuel consumption and reduced exhaust toxicity, as well as increased component lifespan and the service life of the cylinder head.

Claims

A cylinder head of an internal combustion engine comprising inlet and outlet channels with valves extending to one side of the cylinder head, a combustion chamber located therein, having a protrusion for accommodating a spark plug, located on the axis of the cylinder, and displacer surfaces, characterized in that the apex of the angle formed by the plane of the protrusion of the spark plug with the plane of contact of the head with the cylinder block is made with a rounding, wherein the boundaries of the rounding are two lines, one on the plane to the block is removed from the axis of the valves, and the other line in a perpendicular plane passes at a distance from the plane of contact with the cylinder block towards the opening for installing the spark plug.

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