US1922539A - Fuel supplying pump for internal combustion engines of the airless fuel injection type - Google Patents

Description

Aug. 15, 1933. J Q GRQFF 1,922,539

FUEL SUPPLYING PUMP FOR INTERNAL COMBUSTION ENGINES OF THE AIRLESS FUEL INJECTION TYPE Filed Dec. 14. 1929 H}: a 2h; 22

E l6 1 'W 5 l J L INVENTOR ATTORNEYS Patented Aug. 15, 1933 UNITED STATES PATENT OFFICE Joseph' C. Groff, Allentown, Pa.

Application December 14, 1929 Serial No. 414,016

14 Claims.

The present invention relates to pumps for supplying and injecting liquid fuel into the combustion spaces of internal combustion engines of the fuel injection type, though more particularly to pumps for effecting so called solid or airless-injection of the fuel.

In internal combustion engines of the fuel injection type it is necessary and desirable that certain individual combustion regulating factors, .which determine operation of the engine, be respectively subject to independent control and adjustment. First, provision should be made for varying the quantity of fuel supplied to the power cylinder per cycle in accordance with the load requirements. Second, provision should be made to change or adjust the timing of injection commencement in order to secure the most efficient operation at various engine speeds and when using different grades of fuel. Third, provision should be made to change the velocity of the fuel as supplied to the injection valve by the fuel pump in order to achieve the utmost efficiency of fuel injection and attendant combustion for all of the various conditions of engine operation including that of starting from the cold condition.

Heretofore constructions have been devised in which so-called by-pass valves have been used auxiliary to the pump itself for accomplishing certain of the above results. In some constructions variation in the quantity of fuel supplied per cycle has been effected without the use of a by-pass valve and this has been accomplished by varying the amplitude of stroke of the fuel pump plunger. However, the constructions employed heretofore brought about an objectionable change in the velocity with which the fuel was injected when the quantity of fuel supplied was so varied.

The present invention has for its objects the provision of a novel construction which will permit the three control adjustments above mentioned to be accomplished without employing a by-pass valve for any of the controls and particularly the first and to also provide a construction in which the relation and disposition of the parts is such that each control may be adjusted independently of and Without affecting adjustment of another control.

A further object of the present invention resides in the provision of a pump construction which will embody simplicity of mechanism and which will afford quietness and reliability in operation.

Other and more detailed objects and advantages of the present invention will be hereinafter pointed out in the accompanying specification and claims, and shown in the drawing which by way of illustration, show preferred embodiments of my invention.

In the drawing:

Figure 1 is a transverse sectional elevation which illustrates diagrammatically the principle and arrangement of the linkage and parts of a fuel injecting pump embodying my present invention, particularly for engines which need not be reversed and which develop relatively small horsepower per cylinder at rather high speed. It is taken substantially on line 1-1 in Fig. 2 facing in the direction of the arrows and shows the arrangement of the parts just prior to the instant of commencement of fuel injection.

Fig. 2 is a detailed sectional View taken substantially on line 2-2 in Fig. 1 facing in the direction of the arrows. For the sake of clearer illustration certain of the parts appearing in Fig. 1 have been omitted in Fig. 2.

25 is a fuel pumping plunger which is preferably of the differential type and adapted to reciprocate Within the differential cylinder member 40 with a close sliding fit and to effect a pressure tight joint therewith. Upon any downward movement of the plunger 25 the annular pumping chamber 39 is supplied and filled with liquid fuel via supply pipe 34, automatic inlet valve 35, and conduit 36. Preferably the fuel supplied via pipe 34 should exist therein under a relatively low but positive pressure in order to eliminate any tendency for the pump chamber 39 to become air-bound. This may be accomplished by any of various known means such as a supply pump of the constant pressure type or a gravity feed tank not shown in the drawing.

Upon completion of any downward movement of plunger 25, and after chamber 39 and conduit 36 have been completely filled with fuel, flow of fuel via inlet valve 35 ceases and said valve automatically closes.

Upon and by any subsequent upward movement of plunger 25, fuel is displaced thereby and forced out of the annular space 39 and is injected into the combustion space of the engine via conduit 36, automatic non-return discharge valve 37, discharge pipe 38 and any suitable known injecting valve of the airless automatic spring loaded type (not shown in the drawing).

Plunger 25 and its crosshead 27 are arranged to be given reciprocating movement by means of link 21 which is pivotally connected to said crosshead and plunger at one end by pin 24, and

which carries any suitable bearing member, h as roller 22, at its other end. Link 21 and its roller bearing 22 is adapted to be oscillated, about pin 24 as a pivot point, through any desired angle, as illustratively denoted by arc 28, which is always substantially constant in amplitude of swing.

Oscillation of link 21 and its roller bearing 22 may be effected in any suitable known manner such as by means of connecting rod 20 and cranklike operating member 19 which preferably rotates in the direction indicated by arrow 23. It should be understood that crank 19 is driven by the engine and would always be in fixed time relation thereto. In the case of a two-cycle engine, the fuel pump operating crank 19 would rotate at the same speed as the engine crankshaft. However, in the case of a four cycle engine crank 19 would be driven so as to rotate only half as fast as the engine crankshaft. This drive of 19 from the engine may be accomplished in any suitable known fashion such as by gearing or chain drive not shown in the drawing.

The roller bearing 22 at the lower end of link 21 is adapted to rollably contact with a guiding member 9 which presents a bearing surface having a concave curvature in the shape of an arc of a circle the radius of which is equal to the length of link 21 between center 24 and the contacting surface of roller 22, (i. e. equal to length of link 21 between its centers plus the radius of roller 22). Also, the center of curvature of guiding member 9 is located on the straight path traversed by pivot point 24 as plunger 25 is given reciprocating movement, and with the parts as shown in Fig. 1 the aforesaid center of curvature is located at point 24.

Plunger 25 and roller 22 always tend to return downwards and to exert a downward pressure upon the driving parts with which they contact by virtue of compression spring 41.

The quantity of fuel delivered and injected by the pump is dependent upon and determined by the amplitude of movement of plunger 25. According to the present invention this is accomplished by interposing an adjustable camlike member 14 which acts to guide roller 22 and 'to displace it upwards away from the aforementioned guiding member 9. The amplitude of such upward displacement of roller 22 may be adjusted as desired by altering the angular position of control lever 18 which acts through shaft 16 to depress or elevate the position of the eccentrically mounted supporting member '7 and of interposer member 14 as well, through any desired vertical range 17. Thus, the amplitude of upward pumping movement of roller 22 and of plunger 25 would be at a maximum, for maximum engine load, such as illustratively indicated by vertical range 26, fractionally less at reduced engine loads and nothing for the condition wherein the engine would be coasting to a standstill with its power cut off. With regard to this last named condition, it should be understood that interposer member 14-12 will have been sufficiently depressed below the bearing surface of guiding member 9 so as to permit roller 22 to traverse a circular path having its center always located and fixed at point 24 (for the operating condition just outlined) and to therefore impart no upward movement to plunger 25.

The timing of injection commencement for any given adjustment of quantity of fuel and of the velocity with which it is supplied and injected,

may have its adjustment changed by advancing or retarding the position of interposer 14-12 horizontally (in Fig. 1) with respect to the direction of oscillation of link 21 and its roller bearing 22. This may be done in any suitable manner such as by means of control lever 31 which acts through eccentric shaft 3 to move point 8 of supporting member 7 to the left or right through a substantially horizontal range as illustratively denoted by 32. In Fig. 1, movement of point 8, and of interposer 14, to the left would result in advanced timing while movement to the right of its indicated position would result in delayed timing of injection commencement.

With regard to the velocity or rate at which fuel is supplied by the pump to the injecting valve (not shown in drawing) it should be understood that such velocity is dependent upon and determined by the velocity of upward movement of plunger 25. Adjustable change of the velocity of upward pumping movement of plunger 25 is effected in the novel manner shown in Fig. 1 by changeably adjusting the degree of tilt or slope of the guiding and displacing surface 12 of interposer member 14 with respect to the horizontal and to the guiding member 9. That is to say, the velocity of upward pumping movement of roller 22 and of plunger 25 will increase as the angle of slope of 12 is increased with respect to the horizontal and vice versa. Referring to Fig. 1, adjustable variation of the degree of tilt of 12 is effected by angular movement of control lever 10 which acts to bodily displace the eccentrically mounted rod 15 through a range illustratively denoted by 13.

With the various parts occupying the positions shown in Fig. 1, roller 22 is in rolling contact with the curved guiding surface of member 9. and subsequent movement of roller 22 to the right will contact it with the straight sloping surface 12 of interposer member 14, and will cause it to be displaced upwardly away from said guiding member 9 until it reaches the top end portion of said sloping surface 12. Upon roller 22 swinging further to the right and upon its passing over the aforementioned top end portion of 12, said roller 22 will contact with a secondary guiding portion 5 of interposer 14. This secondary portion 5 affords a guiding surface for roller 22 to contact with, which has a concave curvature of the same length radius 30 as guiding member 9, and which always has its center of curvature located substantially on the straight path traversed by the reciprocating point of pivotal connection 24 between link 21 and plunger 25.

Any suitable known means, such as the compensating linkage completed by link 6, may be employed to automatically position the aforementioned secondary portion 5, about its point of pivotal mounting 4 on interposer 14, so that its instantaneous center of curvature always lies substantially on the aforementioned straight path traversed by 24, regardless of what control adjusting movements are given to said interposer 14.

I prefer to restrict contacting of roller 22 with the sloped displacing surface 12 of interposer 14 to within the central and substantially middle third portion 29 of the total angle 28 through which link 21 and its roller bearing 22 oscillate. In other words, I prefer to restrict fuel pumping action to substantially the central third zone of the range of oscillation, for in this zone there results the most uniform rate of swing of link 21 by crank 19 to thus secure desirable lessening of the fluctuations in rate of swing as associated with the harmic motion action of said crank.

Accordingly, with my novel construction each swing of oscillating link 21 and roller 22 from extreme left to extreme right, as determined by crank 19 and as indicated in Fig. 1 by the dotted lined portions of roller 22, is made up of three phases of movement of roller 22 and plunger 25. First, roller 22 rollably contacts with the curved guiding member 9 during which period (substantially one-third of total angle of swing of link 21) no upward pumping movement of plunger 25 takes place. Secondly, roller 22 subsequently contacts with the sloped displacing surface 12' of interposer 14 and during such contact (lasting over substantially the central or following one-third of the total angle of swing of link 21 depending upon the engine load) there results upward pumping movement of plunger 25. Third, and lastly, roller 22 overruns the sloped displacing surface 12 and rollably contacts with the adjacent and secondary curved guiding portion 5, at which instant upward movement of plunger 25 ceases to have thus completed a fuel pumping stroke. Upon the return swing of link 21 and roller 22, from right to left of Fig. 1, movement of plunger 25 is again experienced only so long as roller 22 contacts with sloped surface 12 to thus produce downward movement of plunger 25 during which fuel enters and fills the pumping chamber 39 via supply pipe 34 as previously described. This may be better understood by referring to the heavily dotted line 33 in Fig. 1 which indicates the path taken by roller 22 as its link 21 is swung back and forth by crank 19 with the various parts occupying the positions indicated.

I do not limit embodiment of my invention solely to the construction herein illustrated, as it will be apparent to one skilled in the art that analogous means, which, though not entirely desirable, may be employed to achieve the novel principles of operation involved in my fuel pump. For example, interposer member 14 might be devoid of depressive and elevating adjustment through the vertical range 17 and instead guiding member 9 could be adapted to effect such vertical adjusting movement with respect to 14, without departing from the broad scope of my invention.

What I claim is:

1. A fuel supplying and injection control system for an internal combustion engine of the fuel injection type having a power piston and including fuel pumping means having a pumping plunger, a quantity of fuel control for varying the quantity of fuel delivered per pumping cycle, a time of injection commencement control for varying the time of injection commencement with respect to the position of the power piston of the engine, a change of velocity control for changing the velocity at which fuel is delivered and injected by the pump, means related with each control to provide for the adjustment of each control without any substantial change in ,the desired adjustment of the other controls, the aforementioned quantity control means comprising means for changing the amplitude of stroke of the pumping plunger while maintaining substantially unchanged the time of injection commencement and/or the velocity of fuel injection by the plunger.

2. A fuel supplying and injection control system for internal combustion engines of the fuel injection type which employ a power piston and including in combination fuel pumping means which include a pumping plunger, means for varying the quantity of oil fuel supplied per pumping cycle of the plunger, said means comprising means for changing the amplitude of stroke of the pump plunger while maintaining substantially unchanged the velocity of fuel delivered by the pump and/or the time of injection commencement.

3. A fuel supplying and injection control system for internal combustion engines of the fuel injection type including .in combination with a fuel pumping plunger, of triple control means for changing the action of the pumping plunger itself, each control being operable independently of the other two controls. and being operable for adjustment while maintaining substantially unchanged the respective desired adjustments of the other controls.

4. The invention set forth in claim 3 in which one control includes means to effect a change in amplitude of stroke of the pumping plunger to change the quantity of fuel supplied per stroke while maintaining substantially unchanged the velocity at which fuel is delivered by the plunger when the quantity of fuel delivered by the plunger is varied by said means.

5. The invention set forth in claim 3 in which one control includes means to effect a change in amplitude of stroke of the pumping plunger to change the quantity of fuel delivered per stroke and in which another control includes means to change the velocity of movement of the pumping plunger and in which the other control includes means to effect a change in the time of initiation of movement of the plunger.

6. Afuel supplying and injection control system for internal combustion engines of the fuel injection type which have a pumping plunger for injecting the fuel and including devices for effecting control of quantity of fuel-supply, velocity of fuel supply and timing of injection commencement wholly by the action of the pumping plunger itself, said devices including means for effecting substantially independently any one of the aforesaid control adjustments of the action of the plunger while maintaining substantially unchanged the action of the plunger as regards the other. two adjustments.

7. A fuel supplying and injection control system for internal combustion engines of the fuel injection type which have a pumping plunger for injecting the fuel and including device for effecting control of quantity of fuel supply, velocity of fuel supply and timing of injection commencement wholly by the action of the pumping plunger itself, said devices including means for effecting substantially independently any two'of the aforesaid control adjustments of the action of the plunger while maintaining substantially unchanged the action of the plunger as regards the remaining adjustment.

8. A fuel injecting system including a pumping plunger, a link pivotally connected thereto, cranklike operating means for oscillating the link, and including in combination therewith a bearing member on the link and a guiding member adapted for cooperation therewith and having a radius of concave curvature corresponding to the length of the link from its point 4 of pivotal connection with the plunger to the contacting point between the bearing member on the link and the guiding member to provide for interruption of movement of the pumping plunger.

9. The invention set forth in claim 8 in which an adjustable link displacing interposer member is provided which cooperates with the bearing member upon the link to displace it away from the guiding member upon oscillation of the link.

10. The invention set forth in claim 8 in which an adjustable link displacing interposer member is provided which cooperates with the bearing member upon the link to displace it away from the guiding member upon oscillation of the link, and means cooperating with said interposer member for effecting a tilting displacement of the interposer member for the purpose described.

11. The invention set forth in claim 8 in which an adjustable link displacing interposer memher is provided which cooperates with the bearing member upon the link to displace it away from the guiding member upon oscillation of the link, and means for effecting a displacement of the interposer member back or forth with respect to and substantially in the plane of the direction of oscillation of the link.

12. The invention set forth in claim 8 in which an adjustable link displacing interposer member is provided which cooperates with the bearing member upon the link to displace it away from the guiding member upon oscillation of the link, and means for effecting a relative change of level adjustment of the interposer member with respect to the guiding member.

13. The invention set forth in claim 8 in which an adjustable link displacing interposer member is provided which cooperates with the bearing member upon the link to displace it away from the guiding member upon oscillation of the link, said interposer including a secondary guiding portion which has the same radius of concave curvature as that of the guiding member.

14. The invention set forth in claim 8 in which interposing means are provided comprising an adjustable link displacing interposer member is provided which cooperates with the bearing member upon the link to displace it away from the guiding member upon oscillation of the link, said interposer means including a supplemental guiding portion which is pivotally mounted upon the interposer member and variably adjusted with respect thereto by a compensating linkage so that the instantaneous center of curvature of the supplemental guiding portion is always located substantially on the path traversed by the reciprocating point of pivotal connection between the link and pump plunger.

JOSEPH C. GEOFF.

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