US2132446A - Speed governing apparatus for injection internal combustion engines - Google Patents

Description

Oct. 11, .1938.

A. SCHWEIZER 2,132,446 SPEED GOVERNING APPARATUS FOR INJECTION INTERNAL COMBUSTION ENGINES Filed Nov. 21, 1954 4 Sheets-Sheet 1 Oct. 11, 1938. A. SCHWEIZER SPEED GOVERNING APPARATUSEOR INJECTION INTERNAL COMBUSTION ENGINES Filed Nov. 21, 1954 4 Sheets-Sheet 2 Oct. 11, 1938. A. SCHWEIZER SPEED GOVERNING APPARATUS FOR INJECTION INTERNAL COMBUSTIONENGINES 4 Sheets-Sheet 3 Filed Nov. 21, 1934 25 25 1 Oct. 11, 1938. r I A. SCHWEIZER 6 SPEED GOVERNING APPARATUS FOR INJECTION INTERNAL COMBUSTION ENGINES Filed Nov. 21, 1934 4 Sheets-Sheet 4 Patented Get. 11, 1938 UNITED STATES PATENT OFFICE 2,132,446 SPEED GOVERNING APPARATUS FOR IN- JECTION GINES INTERNAL COMBUSTION EN- Application November 21, 1934, Serial No. 754,160 In Germany December 1, 1933 9 Claims.

The present invention relates to speed governing apparatus for injection internal combustion engines.

In injection internal combustion engines havingv a speed-governing apparatus which responds to a difierence, varying with the speed of the engine, between two pneumatic pressures, the pressure influenced by the speed may be regarded as a mean value from the pressure strokes produced by the separate piston strokes. When the engine is running slowly, the drawback becomes evident in such governors that this pressure and the effective fall in pressure fluctuates to such an extent about the mean value that the'governing member influenced by the latter follows these separate fluctuations and makes governing strokes that are undesirably large.

According to the invention, these undesirably large governing strokes which occur at low engine speeds are damped. This can be attained by means which permit, at least in the region of the idle running position of the governing member, an influencing of the pressure conditions, by way of a damping of the governing movement which overcomes the dependence of the pneumatic fall in pressure on the engine speed.

One possible method of influencing the pressure conditions in the manner previously described consists in a throttling-preferably automaticat the desired moment of the free passage in at least one of the pipes carrying the pneumatic governing medium. Such throttle valves cause the fluctuations in the magnitude of the pneumatic pressures arising from the separate piston strokes to be communicated so slowly to the governing member, that before the fluctuation in one direction is fully completed, a reversal of the direction of fluctuation has begun. In this way the governing member makes substantially smaller strokes than when the passage through the pipes is unhindered. Its movements are thus greatly damped.

Another mode of damping the governing movement by influencing the pressure conditions according to the invention may also be attained by the opening-preferably efiected automaticallyat the desired moment of a narrow connecting pipe between the different pressures acting on the two sides of the governing member. In this case, the stronger of the two pressures isweakened, and the weaker one strengthened. So long as the said pipe is open the displacing force acting on the governing member is reduced, so that the governingstrok-es of this member become considerably smaller than when the pipe is closed.

Several examples of construction of the invention are shown diagrammatically in the accompanying drawings in which:-

Figure 1 is an elevation of an injection internal combustion engine having an injection pump and vacuum governor.

Figure 2 is a partial section, on an enlarged scale, through the injection pump, the governor, of one of the examples of theinvention, and the suction pipe of the engine. Figures 3-13 show various further examples of construction on the scale of Figure 2.

The lower part I of the engine carries four cylinders 2 and an injection pump 3, which is driven fromthe engine shaft 4 by gearing 5. The fuel is-supplied to the injection pump, in the direction of the arrow, by a pipe 6, from a container (not shown). From the injection pump four pressure pipes 1 lead to the nozzles in the cylinders 2. The charge of air is drawn in through the common suction pipe 8. In the suction pipe a throttle-valve 9 is provided, which is operated from a pedal 91) through a lever 9a connected to it. From the suction pipe 8 a vacuum pipe l5 leads to the governor 3a of the pump 3.

The governor 3a (see Figures 2, 3 and 6) contains a chamber in which a piston 24 is longitudinally movable. In the case of Figure 2, the vacuum is supplied to the part of the chamber situated to the left of the piston 24, and, as it increases, moves the piston 24 to the left against the action of a return spring 21, said spring comprising means for applying a relatively constant pressure on one side of said control member or piston 24. The piston 24 is fastened by a nut 28 to the end of a toothed rackbar 23, which projects from the pump into the governing chamber.

The governing of the amount of fuel delivered for spraying is effected by the movement of the rackbar 23. In Figure 2 the conditions are selected as follows:--If the rackbar is moved to the left, the eifective quantity delivered is reduced to all the pumps. uniformly. On the movement of the rackbar to the right the amount delivered for spraying to all the pumps is increased. The rackbar 23 meshes with a pinion 22. the pump pistons l6, driven by a cam shaft i8 coupled to the engine, is connected in such a way with such a pinion that it must follow the rotary movements of the pinion without this latter having to participate in thestrokes of the piston. By a simultaneous and similar angular movement of the pistons the position of the oblique controlling edge 2| provided on each of them is so adjusted relative to the suction and return Each of flow passage 20, that the effective stroke of the pump pistons ceases earlier or later according to the adjusted position of the oblique controlling edges, and the fuel forced by the piston in the remaining part of each pressure stroke of the pump, flows back through the passage 20 into the suction chamber l9 in the pump casing 3 connected with the fuel supply pipe 6.

This governing apparatus works asfollowsz- A vacuum obtaining in the suction pipe during the running of the engine extends through the pipe I 5 to the governing chamber 3a. If now, for example, owing to the engine being relieved of load, its speed increases whilst the adjustment of the throttle-valve remains the same, the vacuum in the suction pipe 8 exceeds the vacuum previously existing.

The increased vacuum then draws the piston, together with the governing rod 23 to the left, whereby the amount of fuel injected at each piston stroke is reduced. The speed and thus also the vacuum in the suction pipe will thereupon drop. The piston 24 has a tendency to set itself in the position corresponding to this vacuum. A definite mean speed corresponds in this caseassuming the position of the throttle-valve remains the sameto a definite position of the piston 24. The voluntary alteration of the speed is effected by adjustment of throttle-valve 9.

In the example according to Figure 2, the governing movement of the piston 24 is clamped by the unthrottled connection between one part of the chamber and the atmosphere being throttled at low speeds by contractions in the cross section which are automatically produced. When the engine is running under load the said chamber part is connected by two openings with the outer air, namely, on the one hand by the narrow opening 25 in the bottom of the chamber, and also by the substantially larger opening 29. The latter is capable of being closed by a valve 28, which has a pin (28a and 281) respectively) on both sides. Of these pins, the former is guided in a ring 290. which is held by two ribs at the centre of the opening 29, and the other in a yoke 30 provided on the casing 3a.

A spring 3| tends to close the valve on its seat. So long, however, as the piston 24 is in the right hand half of the chamber, and thus touches the pin 28a, the valve is raised from its seat. Only when the engine is under a lower load (for example,running idle when standing) does the piston 24 move so far to the left that it passes out of contact with the pin 28a. The valve 28 thereupon closes and the cross section of the connection of the casing 30. to atmosphere consisting hitherto of the sum of the cross sections of the two openings 25 and 29, is reduced to that of the narrow opening 25. This contraction of the cross section of the pipe prevents the air which is present in the right hand half of the chamber from escaping quickly enough during the strong movements of the governing member produced by the suction strokes of the separate engine pistons occurring when the engine is running idle, and also subsequently it cannot flow in again quickly enough, so that the governing movement is strongly damped.

In the examples according to Figs. 13-13, the vacuum in the suction pipe is supplied to the right-hand part of the chamber, in contrast to the construction shown in Fig. 2, whilst the lefthand chamber is connected with the atmosphere. The injection pump in this case is, of course, so constructed and arranged (the rackbar 23 envalve is closed.

throttle-valve 9, which serves for adjusting the 10 speed. The available cross-section for the connection of the left-hand part of the chamber with the atmosphere is composed of the narrow opening 25 and the larger opening 32 provided in the chamber 33. The chamber 33 is connected 15 in its turn to the pipe 34, which comes from the left-hand governing chamber. The opening 32 is closed by a valve 35 by means of a spring 36. An extension rod provided on the foot lever rod is moved to the left on the opening of the throttle-valve, and thereby presses against the valve plunger 31, and so opens the valve against the force of its closing spring 36. On the closing of the throttle 9, the parts 90 and 31 come out of contact, whereby the valve 35 closes and the cross-section for connecting the governor chamber with the atmosphere is reduced to the crosssection of the small opening 25. By this means the desired damping of the governor movement is efiected.

The example according to Figs. 4 and 5 also shows the possibility of damping the governor movement by contraction of the cross-sections in the pipe leading from the governing chamber to the atmosphere in dependence on the position of the throttle-valve. In this case, however, variation in the damping efi'ect is gradual, in contrast to the already described constructions. This is attained by a disc 40, revolubly arranged on the casing 30. in front of the opening 25, which in this case is a large one. This disc has a slot ll concentric with the pivotal axis and the width of which measured in a radial direction constantly increases over its length. The disc is coupled to the foot-pedal 9b, and thus also to the throttlevalve 9, by an arm 40a and the rod 90. When of the slot 4| lies before the opening 25. As the opening of the throttle-valve 9 increases, an increasingly wider part of the slot 4| comes before the opening 25. The damping of the governing movements is thus greatest when the throttle- Figs. 6 and 7 show another form of construction of the invention, in which the damping of the governing movement is brought about by the pipe l5 leading from the suction pipe to the governor being connected with the atmosphere, on a correspondingposition of the throttle, by a small opening 38a, and-thereby the changing vacuum producing the great fluctuations in governing is weakened by introducing extra air. For this purpose, a chamber 38, having a small opening 33a is intercalated in the pipe I5. In front of this opening a slide 39 is movable to and fro in a slot 38b. This slide is so connected by a rod 90 with the throttle-valve movement, that when the throttle-valve 9 is opened, the slide 39 closes the opening 38, and when the valve 9 is closed, opens it by an opening 39a provided in it.

In the examples hitherto described, the damping of the governing movement has been effected in dependence on the position of mechanical controlling members. In the following examples of construction such additional controlling members the throttle-valve is closed, the narrowest part are avoided. The damping of the governing movement is obtained in these cases by the branching of the pipe l between the suction pipe 8 and the governor 3a, the branching being so selected that this pipe is connected, when the throttle-valve is closed, by its one branch to the vacuum and by its other branch to the open air. The particular pressure conditions in the vicinity of the throttle-valve are thereby utilized. When the throttle-valve is open, the same vacuum obtains all about the valve. The branch pipes thus convey the same pressure. It is only as closure of the valve proceeds that a difference in the pressures before and behind the valve is produced, namely, when the valve is closed a vacuum prevails behind it-in the direction of the suction current and in front of it a pressure corresponding approximately to the atmospheric pressure. The pipe I 5 is therefore so branched or enlarged in, all the examples shown in Figs.

, 8-13, that it is in communication with the space in front of the throttle-valve even when the throttle-valve is closed. In this way, as in the example according to Figs. 57, the action of the vacuum causing the strong governing movements is weakened when the throttle-valve is closed, by introducing extra air and thus a damping of the governing movement is obtained.

In Fig. 8, the pipe l5 is branched into two branches l5a and I5!) and introduced into the suction pipe 8 directly before and behind the closed throttle-valve 9 on the same side of the suction pipe. In Fig. 9, the branches l5a and l5b also open directly before and behind the closed throttle-valve into the suction pipe, but at two diametrically opposite points on the same. In

Fig'. 10, the pipe I 5 has an enlargement I50, which is so introduced into the suction pipe 8 that it more Venturi tubes lllbeing built into the suction pipe 8 so as to reinforce the vacuum at great I current speeds. The branches I 5a and I 5b open,

in this case, similarly as in Figs. 8-10, into the suction pipe 8 at the narrowest point in the Venturi tube or tubes II). In this case, the throttlevalve 9 can be situated either, as in Fig. 11, at the narrowest point of the Venturi tube l0, and the branches I51: and I5!) open directly before and behind it (Fig. 11), or the throttle may also be arranged between two Venturi tubes Ill (Fig. 12) the branches l5a and I5!) then each opening into one of these Venturi tubes. The introduction of these branches at two diametrically opposite points into a Venturi tube, corresponding to the construction in Fig. 9, is simplified where a Venturi tube is employed. In order to avoid separate pipe connections to the opposite points of entrance, according to Fig. 13, the Venturi tube I0 is provided with an external annular groove Ina, which at two diametrically opposite positions has connecting pipes lllb leading to the interior of the Venturi tube and into which gine, means housing said control member and.

defining with the two sides thereof two chambers,

one on each side of said control, member, means for applying a relatively constant pressure on one side of said control member, means connecting one of said chambers to the atmosphere, means connecting the other of said chambers to the intake manifold on the engine side of the throttle valve, whereby the pressure variations in the intake manifold will function to displace said control member by differential pressure acting thereon and to adjust the fuel injection means, and means responsive to the position of the throttle valve in the'intake manifold corresponding to the idling speed of the engine to vary the instantaneous value of the differential pressure and functioning to reduce the value of said difdefining with the two sides thereof two chambers,

one on each side of said control member, means for applying a relatively constant force to one side of said control member, means connecting one of said chambers to the atmosphere, means "connecting the other of said chambers to the intake manifold on the engine side of the throttle valve whereby the pressure variations in the intake manifold will function to displace said control member by differential force acting thereon to adjust the fuel injection means, and means responsive to the position of the throttle valve in the intake manifold corresponding to the idling speed of the engine and operable only at engine idling speed to vary the instantaneous value of the differential force and functioning to reduce the value of said differential force and dampen its action in displacing said control member in a direction reducing the fuel supply to idling quantitles.

3. The combination with an intern'alcombustion engine of the injection type having an air intake manifold and a throttle valve therein, of adjustable fuel injection means, a displaceable control member connected to said fuel injection means for controlling the fuel supply to said engine, means housing said control member and defining with the two sides thereof two chambers, one on each side of said control member, means for applying a relatively constant pressure on one side of, said control member, means connecting one of said chambers to the atmosphere, means connecting the other of said chambers to the intake manifold on the engine side of the throttle valve, whereby the pressure variations in themtakemanifold will function to displace said control member by differential pressure acting thereon and to adjust the fuel injection means, and additional means directly connected to and operable by said throttle valve for connecting one of said chambers to the atmosphere, said additional means operable, when said throttle valve is in the position for idling speed of the engine, to vary the instantaneous value of the differential pressure and functioning to reduce the value of said differential pressure and dampen its action in displacing said control member in a direction reducing the fuel supply to idling quantities.

4. The combination with an internal combustion engine of the injection'type having an air intake manifold and a throttle valve therein, of adjustable fuel injection means, a displaceable control member connected to said fuel injection means for controlling the fuel supply to said engine, means housing said control member and defining with the two sides thereof two chambers, one on each side of said control member, means for applying a relatively constant pressure on one side of said control member, means connecting one of said chambers to the atmosphere, means connecting the other of said chambers to the intake manifold on the engine side of the throttle valve, whereby the pressure variations in the intake manifold will function to displace said control member by differential pressure acting thereon and to adjust the fuel injection means, and additional means, controlled by and dependent upon the position of said throttle valve, for connecting said atmospheric pressure chamber to the atmosphere, said additional means operable, when said throttle valve is in the position for idling speed of the engine, to vary the instantaneous value of the differential pressure and functioning to reduce the value of said differential pressure and dampen its action in displacing said control member in a direction reducing the fuel supply to idling quantities.

5. The combination with an internal combus tion engine of the injection type having an air intake manifold and a throttle valve therein, of adjustable fuel injection means, a displaceable control member connected to said fuel injection means for controlling the fuel supply to said engine, means housing said control member and defining with the two sides thereof two chambers,

one on each side of said control member, means for applying a relatively constant pressure on one side of said control member, means connecting one of said chambers to the atmosphere, means connecting the other of said chambers to the intake manifold on the engine side of the throttle valve to create a reduced pressure therein, whereby the pressure variations in the intake manifold will function to displace said control member by differential pressure acting thereon and to adjust the fuel injection means, and additional means directly connected to and operable by said throttle valve for connecting said reduced-pressure chamber to the atmosphere, said additional means operable, when said throttle valve is in the position for idling speed of the engine, to vary the instantaneous value of the differential pressure and functioning to reduce the value of said differential pressure and dampen its action in displacing said control member in a direction reducing the fuel supply to idling quantities.

6. The combination with an internal combustion engine of the injection type having an air intake manifold and a throttle valve therein, of adjustable fuel injection means, a displaceable control member connected to said fuel injection means for controlling the fuel supply to said en-= gine, means housing said control member and defining with the two sides thereof two chambers, one on each side of said control member, means for applying a relatively constant pressure on one side of said control member, means connecting one of said chambers to the atmosphere, means connecting the other of said chambers to the intake manifold on the engine side of the throttle valve, whereby the pressure variations in the intake manifold will function to displace said control member by differential pressure acting thereon and to adjust the fuel injection means, and means responsive to the position of the throttle valve in the intake manifold corresponding to the idling speed of the engine to vary the degree of communication of at least one of the connections to the housing for said control member to vary the instantaneous value of the differential pressure and functioning to reduce the value of said differential pressure and dampen its action in displacing said control member in a direction reducing the fuel supply to idling quantities.

7. The combination with an internal combustion engine of the injection type having an air intake manifold and a throttle valve therein, of adjustable fuel injection means, a displaceable control member connected to said fuel injection means for controlling the fuel supply to said engine, means housing said control member and defining with the two sides thereof two chambers, one on each side of said control member, means for applying a relatively constant pressure on one side of said control member, means connect ing one of said chambers to the atmosphere, means connecting the other of said chambers to the intake manifold at points located on the engine side and the opposite side of the throttle valve when in its closed position whereby the pressure variations in the intake manifold will function to displace said control member by differential pressure acting thereon to adjust the fuel injection means, said last-mentioned connecting means being controlled by said throttle valve to vary the instantaneous value of the differential pressure and functioning when the throttle valve is in the position for idling speed of the engine to reduce the value of said differential pressure and dampen its action in displacing said control member in a direction re ducing the fuel supply to idling quantities.

8. The combination with an internal combustion engine of the injection type having an air intake manifold and a throttle valve therein, of choke tube means in said intake manifold and surrounding said throttle valve, said choke tube means being provided with lateral openings communicating respectively with the engine side and the opposite side of the throttle valve when in its closed position, adjustable fuel injection means, a displaceable control member connected to said fuel injection means for controlling the fuel supply to said engine, means housing said control member and defining with the two sides thereof two chambers, one on each side of said control member, means for applying a relatively constant pressureon one side of said control member, means connecting one of said chambers to the atmosphere, and a branched duct connecting the other of said chambers to the openings in said choke tube means in said intake manifold, whereby the pressure variations in the intake manifold will function to displace said control member by differential pressure acting thereon to adjust the fuel injection means, said openings being controlled by said throttle valve to varythe instantaneous value of the differential pressure and functioning when the throttle valve is in the position for idling speed of the engine to reduce the value of said differential pressure and dampen its action in displacing said control member in a direction reducing the fuel supply to idling quantities. l

9. Speed governing apparatus for internal combustion engines having a fuel injection pump and an air-suction intake pipe and a throttle valve therein, comprising a displaceable control memher, a housing enclosing said control member, means eifecting movement of said control memher in one direction by differential fluid pressure, said means comprising a permanently open connection from said housing to atmosphere on one side of said control member and a like connection from said housing on the opposite side of said control member to said air intake pipe at a point therein on the engine side of said throttle valve, means connecting said control member to said pump and operative to reduce the rate of delivery of said pump in accordance with the displacement of said control member in said one direction, means applying a resisting force to said control member in opposition to the effect of said differential fluid pressure, and a valve connected to said housing on said opposite 'side of said control member adapted to be controlled by said throttle valve as it moves into its position corresponding to idle running of the engine, in order to connect said housing on said opposite side of said control member with atmosphere and thus to check further'movernent of said control member toward a position of reduced fuel supply which would result in stalling of the engine.

ALFRED SCHWEIZER.

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