Untitled record

Dec. 7, 1937.

R- L’ORANGE

LIQUID FUEL INJECTION PUMP

Re. 20,573

Original Filed June 26, 1933

<img file="USRE20573E_D0001.tif" />

Reissued Dec. 7, 1937

Re. 20,573

UNITED STATES PATENT OFFICE

20,513

LIQUID FUEL INJECTION PUMP •!^4SS?Stt^,SS.·

Simms, London, England

Original No. 1,999,330, dated April 30,1935, Serial ° No. 677,724, June 26,1933. ^AM*^caH^on ’ issue April 2, 1937, Serial No. 134,691 (CL 103—41) tions for a pump in accordance with the invention, illustrating a modification of Figure * =

Figure 5 is a view similar to a portion of Figure 1 Seating a modified construction of pump in accordance with the invention.

Figures 1 to 3 illustrate the preferred embodiment of the pump in accordance with the invention In this construction the pump comprises an outer casing I in which a cylinder liner 2 is se cured against a shoulder 3 by means of a P^lu&amp; Sed into the casing and bearing upon the uoner end of the liner through the intermediary of a detachable cylinder head 5 and a P^ac_^f washer 6' a discharge valve 7 controlled by a spring 8 is seated on the cylinder ^he®^^dp°“· the discharge passage 9, the spring 8 re wtlng against a dlseharse pipe union ¹ · secured to “iSiiWSSSSdto be reciprocated to thJSeot the Ito® 2 and J.²⁰ lower extension 13 having a loot 1«, which la gripped between the bottom of a cylindrical slide and a washer 16, the latter being pressed against the bottom of the slide 15 by a spring IT which reacts against a washer 18 ^lo^^{d aBa}^ ²⁵a. shoulder 19 in the casing I; the slide 15 is ar ranged to reciprocate in a guide bore 20 formed in the^casing I and the spring IT serves as a return spring for the plunger 12 which is arranged to be moved in an upward direction by means of a 30 cam acting against the bottom of thes sUde 15 or against a roller secured thereto, the said cam being of known construction and which it is not necessarv to illustrate in the drawing.

Z extension 13 of the plunger is provided 35 with a pair of diametrically opposed lugs ²¹ which Stend into slots 22 formed in a sleeve 23 so as to be reciprocable in the said slots axially of the The sleeve 23 is pivotally mounted around 'the lower end of the liner :² and rotation 40 of the sleeve effects rotation of the Pinger ^relatively to the liner by means of the lugs 31. A split ring 24 is clamped to «le tipi^r ^e*^d °^f * sleeve 23 by a screw 25 and an armi 26 is pro vided upon the ring 24 and arranged to extend 45 to the exterior of the pump through an opening in the casing I. The control rod or the UKe for effecting rotation ofI the sleeve and_yPtanger is arranged to be secured to the arm 26 by means oi ^a The plunger 12 is provided with an . extending from the upper end of the Plumer about half the length thereof and lateral aper tures 30 are arranged to establish communlca ’ tion between the lower end of the said bore and 55

Claims.

This invention is for improvements in and relating to liquid fuel injection pumps M the reciprocating plunger type m winch the quantity of fuel delivered by the plunger is regulated by by5 passing a variable portion of the fuel (known as the “spill”) at each delivery stroke by means of a discharge port or passage co-operating witii a control edge inclined with respect to the long! tudinal axis of the plunger, the port or an end 10 of the passage and the control edge being disposed one on the plunger and the other on the cylinder . and the amount of “spill” being varied by rela- i tive rotation between the plunger and its cylinder so as to vary the moment at which the port crosses the control edge and thereby determine the amount of the spill and consequently the «mount, of fuel delivered from the pump for injection into an engine cylinder.

In pumps of the above type m which the suction 20 is controlled by means of a port or ports ^adaP^d to be covered and uncovered by the plunger acting as a slide valve, without the employment of a suction valve, it is usual for the suction passage opening into the cylinder space of the pump to be 25 utilized for the return flow of the spill, or for the passages for the suction and spill to be so arranged as to produce eddies in the liquid in the suction passage and interference between the two distinct actions referred to.

It is one of the objects of this invention to overcome the above defect and to provide ^a *** injection pump in which the flow of the liquid through the suction passages is effected at all times in the same direction in a similar manner ³⁵ to the flow of steam in a uniflow steam engine, and thus by the avoidance of reversals in the fluid stream and the elimination of a suction valve which tends by its opening and closing to cause oscillations in the fluid, the formation ⁴⁰ of eddies in and the production of gas bubbles from the liquid is avoided.

Other features of the invention are pointed out in the ensuing description and in the ap⁴⁵ ^In order that the invention may be fully understood, reference is directed to the accompanying drawing, in which

Figure 1 is a vertical section of the upper porrn tion of a liquid fuel injection pump constructed in accordance with the invention;

Figure 2 is a vertical section at right angles to ^Figure 3 is a section on the line 3—3 of Figure 1;

Figure 4 is a detail of inlet and outlet connec10 an annular recess 31 formed in the cylinder wall ^of„^theJj^{ner 2} around the plunger. Lateral passages 32 are formed in the liner and establish communication between the annular recess 31 and ^{passa8e 33} formed in the casing I around the liner 2. The annular passage 33 is ^m communication with an inlet pasM^f rh^{med m a P}-^{Pe Union 35 of a fuel} supply 70 |’ K^{he PiPe 111110,1 35 being secured} to the casing I by a union nut 37.

A helical recess 38 having closed upper and lower ends is formed in the exterior of the plung^{6 2 ail}rf?u maintained at all times in communication with a discharge space constituted by an ¹⁵ the ^^{ar reCe}i^So ^{39 formed} In the liner 2 around the plunger 12 and lateral passages 40, Figure 3 ^{ln the llner 2 t0} establish communi-’ cation between the annular recess 39 and an an20 HmT i^eC&lt;rL^{4 formed in} the casing I around the 20 liner 2. The annular recess 41 is arranged in communication with a spill outlet passage 42 termed in the pipe union 35 and communicating with the supply pipe 36. The upper end of the ₉- ^{81-0076 38 18} arranged to co-act with a ²³ ii?^C x^{et or recess 48} formed in the upper end of the bore of the liner 2 and which is provided with an Inclined control edge 44.

fn the operation of the pump liquid fuel is 30 sa^¹M^{<J irom}.^{the plpe 38} through the inlet pas° SSL*^{4, annular}. Passage 33, lateral passage 32 thThX «“i⁸⁵ A* ^{and lateral} apertures 30 to the XL” ^{the BXlal} P^{lunger and} thence to the compression space in the cylinder head 5 35 wKhⁿthe^Sa^{he J}?^{teral apertures 30 are} in register ³⁵ difltaJi ^a”^{nular rec}°ss 31 and the necessary ”ί}^{pressure ex}lsts between the space in eyUn^er head 6 and in the supply pipe 36 STS? ^{Upward strok}® ^of the plunger, as soon 40 SJ? lateral passages 30 have moved past the ^of th® ^annular recess 31, the liquid fuel in the cylinder is delivered under pressure ^{he valve} J ^and thence to tne fuel injection nozzle arranged to be supplied by the pump, until « X ««S Sf ?^e, '^r°™> —“ «» siirA in A^{th or recess 43} when the presXⁿJj^he. ^cyIlnder space instantly drops and ¹⁵ discharged during the remainder of the mpression stroke through the groove 38 into 50 sages’wX fh^CeSS ”ί ^^{1106 through} the pas50 sages 40 to the annular recess 41, spill outlet ?^{nd back Into the} suction pipe 36.

tion^thin V^{he plunger 18} shown in a posi*?> X^hlr^{h the groove 38} is arranged to by55 during the delivery stroke so that

A delivered past the valve 7. Upon rotation of the plunger however, in the direction of i- through the medium of the Ρ°^{Ιηί at} which the upper edge of the 60 ?^{8 P es the} control edge 44 may be ar^β° ^t0 °^CC}^lr_i^{at any point} within a predetermined range later in the compression stroke of ^{s pIupger}- ^so that the length of the plunger ^betJL^een th® moment when the lateral apertures 30 are closed by passing beyond the °° ™^PP7 ^e?^ge%^{the annular recess} »» and the mo! th! °^{f the gr00V}® ^{38 Pa}®SCS

Η n ^{1 e}^^{ge 44} determines the amount of the fuel delivered past the delivery valve 7 to the injection nozzle.

⁷⁰ fuel th” *?&lt;^{e observed} the flow of the fuel into the cylinder space or pump chamber of the nZ L™^ei!^{ted thr}°^{Ugh SUCtl0}° Passages in tile pump which are quite distinct from those - ^which effect the discharge of the spill ‘ 5 from the pump so that the flow of liquid through

20,573 ^{1 passages is} always in the same direction, whilst the pump is also free from the osci? lation of liquid which is caused by the provision of a suction valve. Eddies of the liquid in the suction passages are thus completely avoided as ^al?2^th® Production of gas bubbles from the liquid. ff®l^lcal arrangement of the groove 38 causes ^awl}^lrllng °f the spill in the annular recess 39 which,tends by centrifugal action to discharge the spill through the passages 40, thus facilitating the d^eharge °f the spill and producing a suction S^^CyllX ^space during such discharge whilst the tangential arrangement of the passages 40 with respect to the annular recess 41 iacilitates the discharge of the spill from the annular recess 39 to the annular recess 41 in which the fuel is again caused to whirl and so facilitate its discharge through the tangentially arranged spill outlet passage 42. Damping of the flow of the spill which is caused by sudden changes and reversals in the direction of flow and avoided °^{f adequate} discharge spaces, is thus

It will be observed that the location of the annular suction recess 31 at a more remote point ί from the cylinder head than the annular recess 39 for the spill and which is subjected to higher pressure than the annular suction recess 3 i serves to prevent leakage of liquid fuel past the plunger 12 in a downward direction, because any liquid leaking from the annular recess 39 downwardly is intercepted by the annulus 31.

• ™^tbe modification of the invention illustrated m Figure 4, the outlet for the spill from the pump s maintained separate from the fuel supply in- 35 let, the fuel supply pipe 36 being arranged to coni^he A^QUld !^{uel to the lnlet} Passage 34 lead^lng x ^^{be ou}^er annular suction passage 33 whilst a discharge pipe 45 is arranged in communicationwith the spill outlet passage 42 lead- 40 ing from the outer annular spill recess 41. in this modification it is possible to supply fuel to tne pipe 36 under pressure through a primary pum^p, whilst the pipe 45 may be arranged to discharge the spill directly back into the fuel tank. 45 Referring to the modified construction of pump ⁵’ ^{the various} Parts have been designated by the same reference numerals as in Figures 1 to 3, where possible, but with the addition of 100. In this construction, liquid fuel is 50 supplied through an inlet passage 134 to an annular suction passage 133 disposed around the Iw’dirorH¹¹** ^,?²«o,^{and thence} through passages 132 directly past the plunger 112 to the cylinder space or pump chamber, the suction ports formed by the passages 132 being uncovered by the plunger at the end of the suction stroke. The spill is discharged through an axial bore 129 in the plunger and thence through a port 150 formed U3 Xv ·“ X ^{pIanger int0 a} Pocket or recess 143 sunk in the cylinder wall and the upper portion of which may be in the form of v XX The spill leaves the pocket (43 through one or more passages 140 and passes into an annular 1 5^{rom wlllch u} is discharged through ?«n^P j^Ute passage 142. Preferably, the port ISO and passages 140 and 142 are tangentially arranged with respect to the pocket or recess ^{-41 for th}® same reason as that stated with reference to Figures 1 to 3

The pocket or recess (43 is provided with a ικηΤΧΧ ^{44 Whlch co}^oP^erates with the port ISO to determine the moment at which the spill commences in a similar manner to that of the end of the groove 38 with the control edge 44

7.0

20,078 above described, the plunger I II being «>tete1We by control means of the same character as that disclosed in Figures 1 and 2. T utors