Injection pump

#This invention relates to a fuel injection pump for an internal combustion engine and more particularly to a multiple plunger injection pump. The plungers are arranged in alignment in one line, and have a common housing with a governor therein. All chambers are filled with fuel, which lubricate and with fuel, which lubricates and cool the moving parts.

#A multiple plunger injection pumps with the pressure units arranged in alignment in one line, having well known advantages and being widely used for some time, have also some basic shortcomings in connection with new engines, particularly small and high-speed ones. They are too large and too heavy and are relatively expensive. Basic designs of these pumps have not been changed for dozens of years, and the main direction of their development tends to diminish the distance between pressure sections and the length of pressure unit (on which the pump height depends) with simultaneous attempts for maximal simplification of various secondary construction details, and lowering of production costs.

#Considerable simplification of construction, reduction of dimensions and weight, as well as of cost of production of multisection series pumps was reached in pumps with flange or flange-yoke fitting of barrels of pressure units mounted directly or with flange sleeve in the pump housing holes as for example, the pump according to Polish patent application No. P.139465. In these solutions, the sleeve flange or barrel flange is to connect the pressure unit with the pump housing, to set the so-called initial stroke (beginning of compression) and to regulate equal metering of each pressure unit of the pump. Regulation of initial stroke is carried out with spacer washers placed between the flange and pump housing; metering is regulated by turning the barrel flange in relation to the plunger. Thus, fitting and regulation are much easier, and there is no need for a side access to the internal part of the pump, serving previously for fitting and regulation of the pump, and particularly for setting the initial stroke with regulation screw in tappet. Removal of the regulation screw in the tappet diminished the pump height too.

#The present invention is shown as an example in the drawings, where:

#FIG. 1 shows the pump in axial cross-section with section I-I shown in FIG. 2;

#FIG. 2 is an axial longitudinal section with partial side view; and

#The pump has a housing 1 with the rotation speed regulator (governor) and mechanisms located in the chamber 2 which is closed with a cover 3. The main pump elements are clearly shown in the cross-section (FIG. 1). The pressure units consisting of barrel 4 and plunger 5 are mounted in the holes 6 of the housing by using the flange mounting sleeves 7 screwed on the housing with screws 8.

#Above the barrel 4 in the sleeve, the valve 9 is situated. The latter cuts off the connection between the working chamber 10 of the pressure unit and, (not shown) injection pipe screwed to the stub pipe 11 screwed which is into the sleeve 7. The stub pipe pushes the housing 12 of the cut-off valve to the front surface of the barrel 4 and thereby the flange 13 of the barrel 4 to the flange 14 in the lower part of the mounting sleeve. On the lower part of the barrel 4, projecting from the mounting sleeve 7, the sleeve 15 with toothed ring 16 is rotationally mounted. It is meshed with control rod 17. The sleeve 15, slidably coupled with the plunger 5, abuts with the flange against the upper disc 18 of the spring 19 the disc is fastened in the hole 6 of the housing with expansion ring 20. The bottom disc 21 of the spring, mounted in the roll tappet 22, is separably coupled with the foot 5a of the plunger 5. The spring 19 pushes the tappet 22 to the cam 23 of the transmission shaft 24 having bearings in the bottom part of the pump housing 1. At the end of the transmission shaft 24 projecting to the chamber 2 of the rotation regulator mechanism, the inertial rotation meter 25 is situated; it is coupled by the system of levers with the rod 17 regulating the pump metering.

#The inlets of housing holes 6, where the pressure units are mounted, are tightly closed with mounting sleeves equipped with ring gasket 26. In the pump housing beneath the bottom edge of the mounting sleeve, two longitudinal holes 27 and 28 are located; traverse holes 6 are provided for pressure units. In one of them, the control rod 17 is slidably mounted with bearing; the next one 28 provides the channel delivering the fuel to the space 29 of pressure unit supply. The space of the supply is separated from the rest of the pump interior by top discs 18 of the springs. The barrel 4 of the pressure unit has two side holes 30 and 31, supply and overflow ones, which connect the work chamber with the supplying space.