SU1004664A1 - Fuel pump for i.c. engine - Google Patents

Description

(54) FUEL PUMP FOR INTERNAL ENGINES

one

This invention relates to mechanical engineering, in particular to fuel pumps for internal combustion engines.

Fuel pumps for internal combustion engines are known, comprising a pump casing and at least one 5 pump piston located in a pump cylinder, having at least one flow hole lying in the plane of the camshaft, controlled by the edge of the bottom of the pump shaft, to supply a portion fuel pressure back into the fuel line of the pump housing, and reinforcement, used to absorb the shock of the reverse flow of fuel, located opposite the flow through hole of the pump.ts cylinder

The fuel ducts in the pump housings are manufactured exclusively by machining and are closed out with plugs or threaded plugs in the pump housing. Regarding the 20 cavitation protection against fuel coming out of the high-pressure pump cylinder bore, there are two main directions of execution.

Combustion

However, the direction of execution is used as baffle elements to close the fuel bore channel threaded plugs and screw plugs or baffle bolts and cylindrical wrap screws inserted into the pump casing.

Also known are fender plugs inserted into the heating ducts of the pump housing and reinforced with threaded plugs of the fuel duct. These designs are relatively expensive and require precise and not always simple sealing and do not provide tightness until the end of their service life.

In the other direction of execution, cavitation protection is achieved by means of fenders, which are used in various forms. They are placed in the fuel conduit for reinforcing the wall or arranged annularly or semi-annularly around the cylinder or on the pump cylinder in the region of the flow orifice.

Claims (7)

The purpose of the invention is to measure the prior art with respect to the fuel piping channels of fuel pumps and their protection against cavitation so that, while constantly functioning in the manufacturing process, to obtain improved performance properties as well as economic advantages. The invention is based on the task of creating a fuel pump, in which, to prevent leaks, threaded plugs or plugs for closing the fuel line on the pump housing, which also serve as cavitation protection from the high-pressure jet of the pump jet, are no longer available. Here it is necessary to preserve the protection against cavitation in the fuel line. This goal is achieved by the fact that the fuel line channel is gagged on the end surfaces of the pump casing and is unworked, and at the end end, where the opening for the pump cylinder reverse flow faces the restriction of the fuel line channel, reinforcement is located as a baffle element. Further features of the invention consist in various structural forms of reinforcement and its reinforcement. One structural form of reinforcement consists of a base, on the outer edge of which there are grips for reinforcement. Another structural form consists of a base with a pipe, on the shell of which there are holes. Strengthening of reinforcement is also possible through gluing technology. A further feature of the invention is that reinforcement is poured together to prevent cavitation when casting the pump casing. In this case, the reinforcement can be formed as a base with a gorge-like edge protrusion. Another form of reinforcement consists of a base with a head located in the middle. FIG. 1 shows a fuel pump, with a partial cut; in fig. 2 is a reinforcement means for protection from cavitation, made in the form of a gorge-like marginal protrusion; in fig. 3 - the same, in the form of a base with a pin; in fig. 4 - the same, in the form of a base with grippers; in fig. 5 is the same, in the form of a base with a nozzle. In the housing 1 of the fuel pump of FIG. 1, in which the flow orifices 5 and 6 of the individual cylinders 7 of the coco are in the same plane as the cam shaft 10, there is a fuel line 2 and. 3, which intersects the flow ports 5 and 6 of the pump cylinder 7 and does not extend onto the end surfaces 4 of the pump casing 1. This fuel conduit 2 and 3 is untreated and is cast when the casing 1 is cast with it. The end end 8 of the fuel line 2, which is loaded with a jet of fuel flowing out of the flow hole 6 of the cylinder 7 of the pump under high pressure, is protected by an inserted reinforcement 9 to prevent cavitation. Presented in FIG. 2 and 3 types of reinforcement are provided for casting. Accordingly, FIG. 2, on the base 11, there is a hill-shaped marginal protrusion 12, which serves to reinforce and fix the position on the core, which simulates the contour of the fuel supply channel 2 and 3 during the casting process. In the embodiment shown in FIG. 3, the reinforcement consists of a base 13 with a pin 14 located in the middle, which in the casting process will be folded to fix its position on the casting rod for the fuel conduit 3. The reinforcement 9 is constructed as shown in FIG. 4 from the base 15, on the outer edge of which the bent grippers 16 are located. This base 15 is pressed into the end end 8 of the fuel duct 2, and the grippers 16 provide a fixed fit in the fuel duct 2. Another form of reinforcement according to FIG. 5 consists of a base 17 with a nozzle 18 on the shell of which openings 19 are located. This base 17 with a nozzle 18 is inserted into the end end of the fuel duct 2, and the nozzle 18 provides for fixing the position in the fuel duct 2. The holes 12 located in the shell of the nozzle 18 are provided for removing fuel that accumulates between the outer surface of the nozzle and the wall of the fuel duct 2. Strengthening the reinforcement 9 is also possible by gluing technology. In another form, the reinforcement 9 is molded when the pump casing is cast with it. Claim 1. Fuel pump for internal combustion engines, comprising a housing and at least one pump piston housed in a pump cylinder having at least one flow hole lying in the plane of the camshaft and controlled by the edge of the piston head pump, for feeding a portion of high-pressure fuel back into the fuel line of the pump casing, to the reinforcement, which serves to absorb the shock of the reverse flow of fuel, opposite the flow orifice of the pump; characterized by the fact that the fuel line channel is filled with end surfaces 4 of the pump housing 1 and is not worked out, reinforcement is placed at the front end of the fuel pipe channel 2, the flow hole 6 of the cylinder of pump 1 is opposite the fuel pipe channel to prevent cavitation. 2. Pump according to Claim 1, characterized in that the reinforcement consists of a base 15 with grippers 16 located on its outer edge. 3. Pump according to Claim 1, characterized in that the reinforcement consists of a base 17 with a pipe 18, on the shell of which holes 19 are located. 4. Pump according to claim 1, characterized in that the reinforcement 9 is glued 5. A pump according to claim 1, characterized in that the reinforcement 9 is cast at the frontal end of the fuel line 2 in the pump casing 1. 6. A pump according to claim 1 and 5, characterized in that the reinforcement consists of a base 11 with a pot-shaped edge protrusion 12. 7. Pump on PP. 1 and 5, characterized in that the reinforcement consists of a base 13, in the middle of which a pin 14 is located. It is recognized as an invention according to the results of the examination carried out by the Office for the Invention of the German Democratic Republic. ten PPE .2