SU1320478A1 - Cylinder head for air-cooled internal combustion engine - Google Patents

Abstract

The invention relates to the field of mechanical engineering, in particular to diesel engines with aluminum alloy heads. The purpose of the invention is to increase the reliability and durability of the engine, primarily the valves and the nozzle, by leveling the temperature of the cylinder head. The walls of the exhaust channel (VC) are made in one piece with the base of the molded thermoisolation, with its insert (TV). The base thickness of the VC is variable and has a maximum value at a point remote from the center of the head towards the VC of 0.2-0.4 of the cylinder radius and located on the line, the angle between the lines of the axes of the channels is 40-70 °. The variable thermal resistance of the base of the TV, proportional to its local crowd, contributes to the equalization of the temperature field in the two-valve heads. By this, the heat flux through the heat-insulating walls of the VC is reduced, and the deformation and warping of the TB are eliminated. 4 il. i cl with about 4 oo

Description

The invention relates to air-cooled internal combustion engines, in particular to diesel engines with aluminum alloy heads.

The purpose of the invention is to increase the reliability and durability of an engine, primarily valves and a nozzle spray, by leveling the temperature of the cylinder head floor.

FIG. 1 shows a cylinder head for an internal combustion engine; in fig. 2 shows a section through the center of the head and the point of maximum thickness of the heat insulating insert; in fig. Figure 3 shows a characteristic plot of temperatures along the contour of the firing head of a two-valve air-cooled engine cylinder head; in fig. 4 is a plot of the temperature of the head in cross section corresponding to line 11 in FIG. 3

Wu Gdol

-I,

ten

where b is the current thickness of the insert base;

T and Q - local temperature and heat flux through the firing head of the head; HDD - working temperature allowed

the main material of the head; And, is the thermal conductivity coefficient of the insert material.

The variable thermal resistance of the base of the insert, proportional to its local thickness, in the proposed design turns out to be better adapted to the existing heat fluxes in the two to five valve heads for air cooling and helps to level their temperature field. Simultaneous reduction of the heat flux through the heat-insulating walls of the exhaust channel further enhances - positive effect of templite alignment, the heat-insulating insert from the material floor of the head, a more uniform rial with a lower coefficient of heat and temperature field of the head

water content, such as heat-resistant cast iron or steel. The insert consists of a base 2 of variable thickness and an inner wall 3 of the outlet channel. At the base of the insert there are holes for pressing in the sockets 4 of the outlet 5 and the inlet 6 channels, a hole for installing the nozzle, and in the wall

In the housing 1 of aluminum alloy, the outlet channel has a hole for pressing in the sleeve 7 of the exhaust valve. The flat surface 8 of the base of the insert forms the firing head of the head. The thickness of the base of the insert 2, decreasing towards the periphery, has a maximum value at point 9, which is removed from the center 10 of the head towards the outlet channel on

thermal insulation insert eliminates its deformation and warping, contributing to improving the reliability and durability of the engine, especially the injector valves. Constructive execution of the base of the insert in one piece with the walls of the outlet channel also contributes to increasing the rigidity of the insert and the cylinder head as a whole.

thirty

Claims (1)

Invention Formula A cylinder head for an air cooled, internal combustion engine comprising intake and exhaust ports. stand / equal to 0.2-0.3 in opposite directions, and ra, and lies on line 11, constituting an angle a with the line of the 12 axes of the channels, equal to 40-70 °. The insert is cast as a single unit in a separate form, then, after machining, it is placed in a chill mold together with rods for the head housing, and the metal of the housing is poured there (as a rule, aluminum-aluminum alloy). The thickness of the base of the thermally insulating insert at any point of the bottom of the fire can be determined using the well-known heat conduction equation using the formula 40 45 a molded heat insulating insert, in the base of which there are holes for valves and nozzles, characterized in that, in order to increase the reliability and durability of the engine by leveling the temperature field of the head, the walls of the exhaust channel are made in one piece with the insert base, the latter being of variable thickness The maximum of which is offset from the center of the head towards the outlet channel by 0.2-0.4 of the cylinder radius and located on the line constituting 40-70 ° with the line of the axes of the channels. Wu Gdol -I, ten  five field floor of the head, more uniform temperature field of the head with the proposed thermal insulation insert eliminates its deformation and warping, contributing to improving the reliability and durability of the engine, especially the injector valves. Constructive execution of the base of the insert in one piece with the walls of the outlet channel also contributes to increasing the rigidity of the insert and the cylinder head as a whole. Invention Formula A cylinder head for an air cooled, internal combustion engine comprising intake and exhaust ports. directed in opposite directions and a molded heat insulating insert, in the base of which there are holes for valves and nozzles, characterized in that, in order to increase the reliability and durability of the engine by leveling the temperature field of the head, the walls of the exhaust channel are made in one piece with the insert base, the latter being of variable thickness The maximum of which is offset from the center of the head towards the outlet channel by 0.2-0.4 of the cylinder radius and located on the line constituting 40-70 ° with the line of the axes of the channels. FIG. / 7 FIG. 2 (Riga.Z FIG.