US2063848A

US2063848A - Injection internal combustion engine

Info

Publication number: US2063848A
Application number: US756135A
Authority: US
Inventors: Meyer Alfred; Holzbaur Eugen
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch AG; Robert Bosch GmbH
Priority date: 1933-12-23
Filing date: 1934-12-05
Publication date: 1936-12-08
Anticipated expiration: 1953-12-08

Description

Dec. 8, 1936. A. MEYER ET AL INJECTION INTERNAL COMBUSTION ENGINE `Filed DeC. 5, 1954 Patented Dec. 8, 1936 UNITED STATES PATENT OFFICE INJECTION INTER-.NAL COMBUSTION ENGINE Application December 5, 1934, Serial No. 756,135

In Germany December 23, 1933 2 Claims.

The present invention relates to injection internalucombustion engines in whichthe beginning of the injectionis adjusted automatically in accordance with the speed of the engine independently ofthe quantity of fuel delivered.

It is known tol adjust the beginning of the injection in dependence on the speed of the engine by a centrifugal governor or by the liquid pressure produced by a pump but a simple centrifugal governor is not adapted for the great uctuations in speed which occur, for example, in motor vehicles whilst liquid governors have the drawback that they soon become inoperative on the slightest leakage.

According to the present invention the members for adjusting the beginning of -the injection are moved by a servo-motor connected to the air suction pipe of the engine, and thus pneumatically operated, this servo-motor being adapted to adjust the beginning of the injection in dependence upon the conditions of air flow and pressure which prevail in the airsuction pipe and vary in conformity with the speed. Such a servo-motor, controlled by the conditions of flow and pressure in the suction pipe, is, as regards packing, much less sensitive than a servo-motor which is controlled by a liquid pressure that fluctuates with the alterations in speed.

Furthermore, it is simpler and cheaper in construction than a centrifugalgovernor suitable for the purpose intended, and for which, -furthermore, a special drive must be provided.

One form of construction embodying this invention is illustrated in the accompanying drawing in which: Y e

Figure 1 shows an injection pump intended for al four-cylinder engine having an injection adjuster and delivery quantity controller built thereon, as well as the suction pipe of the engine and a servo-motor connected thereto for actu-` ating the adjuster. e

a is the casing of the injection pump, in which four separate pumps are arranged sideby side in a row, and the pistons b of which are driven by a cam-shaft c mounted in the casing. The fuel conveyed is delivered through the outlets d to theinjection nozzles (not shown) and into the engine cylinders, which are also not shown. The quantity delivered by the pumps can be varied in known manner by rotating the pistons b, which are provided with an inclined controlling edge. This rotation is effected by means of a controlling rod e common to all the separate pumps and slidably mounted in the pump casing.

The fuel is supplied to the suction chamber p common to all the separate pumps in the pump casing by a piperq.

The driving shaft c of the separate pumps has at its end which receives the drive screw-threadlike oblique grooves I Il, in which engages onehalf of a displaceable sleeve Il, The other half lof the sleeve engages in longitudinal grooves'.

I2 in .the end of a shaft I3, arranged co-axially with the pump-shaft c, and mounted in a. cover I4 secured on the pump casing and driven from the engine. The sleeve II rotates with the two shafts I3 and c. In a groovel in it between two iianges I5engage the forked ends of a lever I6, which is fastened on a shaft I1, mounted in the cover I4. An'adjusting lever I8 is secured to an end of the shaft that projects from the cover, and is connected by a rod I9, a lever and a rod 2| with. the piston 22 of a servo-motor. The piston 22 is arranged in a cylinder 23, in which is also located a spring 21 which has a tendency to push thepiston into its one end position in which the'sleeve II is in a position which gives thevlatest beginning of the injection. To' the bottom of the servo-motor cylinder y23 is connected one end of a pipe 24, the other obliquely cut-away end of which projects into the air suction pipe f of the four-cylinder engine in such a way that the air current moving along the suction pipe f produces a strong injectorlike suction action in the pipe 24 and thus also Iin the cylinder space 25 of the servo-motor. In the arrangement shown the end or mouth of the pipe 24 is directed away from the air inlet to the inlet pipe.

A throttle valve g is provided in the suction pipe behind the place, viewed in the direction of flow of the air, at which the pipe 24 projects into the suction pipe and this throttle valve can be adjusted at will by the driver by means-of a rod h. Behind the throttle valve, one end ofv a pipe j' is connected to the suction pipe `f of the engine, and the other end of the pipe opens into a cylinder chamber i in which is a piston k. A

`spring m arranged in the/chamber i has a tendency to push the piston coupled to the controlling rod e into a position in which the pump pistons b force the greatest delivery quantity into the pipes d. The cylinder n enclosing the piston is justs the beginning of the injection tothe speed assumes a position corresponding to the air current which prevails in the suction pipe f. When the engine is running' rapidly and thethrottle valve is open, theair current is at its strongest, so that the piston of the servo-motor is drawn farthest to the right and the earliest beginning of the injection is adjusted. In orderxwhen starting, and also when climbing hills, where the motor, notwithstanding the fully open throttle Valve, is only slowly rotating and the air current thus does not sumce to adjust for early beginning of injection, also to enable the beginning of theinjection to be advanced, a traction member such as a cord 26, operable at will by the driver, is provided on the lever 20.

We declare that what we claim is:

1. In an injection 'internal combustion engine having an air inlet duct, a throttle valve in said duct, a fuel pump, control means including a pneumatic servo-motor connected to the4 air inlet duct between the throttle valve and the engine for automatically adjusting the quantity of A fuel delivered by said pump in dependence upon the air current prevailing in the air suction pipe and varying in conformity with the engine speed, means, independent of said control means, for

ual meansfor adjusting said last-mentioned means.

2. In an injection internal vcombustion engine having an air inlet duct, a throttle valve in said duct and a fuel pump, a pneumatic servo-motor connected to the air inlet pipe between the throtr tle valve and the engine for governing the quantity of fuel delivered by said pump in dependence upon the air current prevailing in the air suction pipe and varying in conformity with engine speed, and a second pneumatic servo-motor connected to the air inlet pipe on that side of the valve remote from the engine for automatically adjusting the beginning of the injection delivered by said pump according to the air current prevailing in the air suction pipe and varying in conformity with the engine speed.

' ALFRED MEYER.

EUGEN HOLZBAUR.