SU1726818A1 - Internal combustion engine liner-cylinder cooling jacket - Google Patents

Abstract

The invention relates to mechanical engineering. The shirt consists of a body into which the thin-walled protective is pressed. Avtulka. In the middle part of the housing and the protective sleeve there are coaxially arranged openings for adapters 3 and 4, and the diameters of the openings 3 of the housing are larger than the diameters of the openings 4. Surfaces E, B, C, D, D near the openings for adapters are reinforced and coated with an anticorrosive composition . The protective sleeve protects the anticorrosive coating of the housing over the surface E from contact with cooling water, and over the surface B from its main flow. The design allows restoring the anticorrosive coating over the surfaces of housing B and C with the necessary periodicity under operating conditions without dismantling the working cylinder, for which only adapters are removed. 2 Il. BUT

Description

FIG. 2

FIELD OF THE INVENTION The invention relates to mechanical engineering, namely engine building.

The known design of the jacket of the working cylinder, intended to form a cavity for the circulation of cooling water, is at the same time a shroud of the sleeve to provide it with the necessary strength, having holes for adapters into which the nozzles are inserted, and a indicator tap. To increase the fatigue strength of the jacket, the places with the highest concentration of stresses (surfaces near the holes for adapters) are strengthened and then applied to them with an anticorrosive coating.

The disadvantage of such shirts is that during engine operation, the flow of cooling water, washing areas with anti-corrosion coating, gradually, over time, destroys them, subsequently causing intense corrosion of exposed areas, which leads to a sharp decrease (not less than 2%). 3 times) the limit of their fatigue strength.

The experience of operating these shirts installed on the 10D100 diesel generator showed their lack of reliability associated with failure due to the appearance of cracks in the holes for the adapters, the thickness in most cases developing from the inner surface of the jacket and is there after the destruction of the anti-corrosion coating.

The restoration of the anticorrosion coating on the inner surface of the jacket with the necessary periodicity under operating conditions presents certain difficulties, because it is connected with the excavation of the working cylinder and pressing out of the jacket from it.

The aim of the invention is to increase the life of the jacket by increasing the safety of the necessary part of its anti-corrosion coating during operation.

The goal is achieved by the fact that the cooling jacket of the cylinder liner of the internal combustion engine, comprising a housing with adapter holes, the surfaces in the zone of which are reinforced and protected with an anti-corrosion coating, the jacket is provided with a protective sleeve with holes for adapters rigidly connected to the housing, each hole in the sleeve made with a diameter smaller than the diameter of the corresponding coaxial holes in the housing.

FIG. 1 shows the proposed shirt design; FIG. 2 is a section A-A in FIG. one.

The shirt consists of a body 1, into which a thin-walled protective sleeve 2 is pressed. In the middle part of the body and the protective sleeve there are coaxially arranged holes for adapters 3 and 4, and the diameters of the holes of the body 3 are slightly larger than the diameters of the holes 4 in the sleeve. For the entrance of cooling water, holes 5 are made, and for the exit - holes 6. Surfaces E, B, C, D, D near the holes for adapters are reinforced and coated with an anti-corrosion compound. The reliability of the anticorrosive coating of surface E is ensured by the absence of its contact with cooling water. The anticorrosive coating of surface B is separated from the intense main flow of cooling water (cooling cavity of the liner) by a protective sleeve and limits the part of the main flow expanded after spraying it to the adapter to cool it. This makes it possible to provide lower than the prototype speeds of water over the surface of the anticorrosive coating in this place, and therefore, greater than that of it, the durability of the coating in operation. In addition, the anticorrosion coating of the surface B can be restored to the required conditions at regular intervals, without dismantling the working cylinder, for this it is only necessary to remove the adapter from the cylinder. At certain sizes of the adapter, the optimum value of the water velocity over the surface B can be obtained by varying the diameters of the holes for the adapters of the protective sleeve and the housing while observing this condition: the diameters of the holes of the protective sleeve should be less than the coaxial holes of the housing. This is necessary not only to protect the anticorrosive coating of the case, but also to restore it to the operating conditions and especially when filling it at the interface with the protective sleeve. The anticorrosive coating of surface B (enclosures) is in favorable conditions, protected by a rubber gasket on the adapter's seal, and, if necessary, can also be restored under service conditions. The places with the highest concentration of stresses of the protective sleeve are in the same conditions as the similar parts. prototype, and therefore, to approximate its service life to the service life of the body, the corresponding compressive stresses are created in it during installation. In addition, even the occurrence of cracks in the protective sleeve is not an obstacle to further relatively long-term operation of the working cylinder, since the carrying capacity of the jacket, like the sleeve banding, in this case is not reduced as much (due to the thickness of the protective thickness that is small compared to the shell). bushings), as is the case with the prototype in the destruction of its anti-corrosion coating.

The level of tangential stresses on the inner surface of the prototype jacket when loaded with internal pressure P is

Gtp p

F2 - “

where gv is the radius of the inner surface of the shirt;

n is the radius of the outer surface of the shirt.

The tangential stresses on the inner surface of the case in the event of a cracked protective sleeve at the same internal pressure are

1+ (lL ± I) 2

4 g

-ЈL ± lf

4 g

where t is the wall thickness of the protective sleeve.

With real shirt sizes, the change in the level of maximum tangential stresses in this case is almost linearly dependent on the wall thickness of the jacket (body). For example, the prototype jacket of the working cylinder of a 10D 100 engine has dimensions: Guts 12.15 cm, Di 13.8 cm. In the proposed jacket for this engine, its body may have dimensions: Guts + t (12.15 + 0.4) cm, h 13.8 cm

The tangential stresses along the inner surface under loading with the same inner pressure P are 7.9 P for the Otp prototype jacket, and 10.5P for the proposed shirt body, i.e., only 1.33 times more; while

The fatigue strength of the prototype jacket in the event of the destruction of the anticorrosion coating can be reduced by no less than 2-3 times. In this case, an additional factor should be taken into account, which influences the decrease in the fatigue strength limit of the jacket, which is associated with the destruction of areas with stress concentration as a result of corrosion of the surface hardened layer, i.e.

the elimination of the effect of the use of hardening shirts.

Claims (1)

Claims The cooling jacket sleeve of a cylinder of an internal combustion engine, comprising a housing with adapter openings, the surfaces in the zone of which are strengthened and protected with an anti-corrosion coating, which in order to increase the service life by reliability of the anticorrosion coating; the jacket is provided with a protective sleeve with holes for adapters rigidly connected to the body, each hole in the sleeve being made with a diameter smaller diameter corresponding coaxial hole in the housing. Fy