US2929332A - Pump - Google Patents

Description

E. R. PIERCE March 22, 1960 PUMP Filed Deb. so, 1954 2 Sheets-Sheet 1 ATTORNEY March 22, 1960 E. R. PIERCE 2,929,332

- PUMP Filed Dec. 30. 1954 2 Sheets-Sheet 2 INVENTOR ATTORNEY United States Patent "cc Motors Corporation, Detroit, Mich., a corporation of Delaware Application December 30, 1954, Serial No. 478,765

13 Claims. (Cl. 103-148) The present invention relates to pumps and more particularly to pumps especially adapted for supplying fuel to internal combustion engines.

In the operation of internal combustion engines of the spark ignited type, the fuel is atomized and mixed with air to form a combustible charge. Usually the atomization and mixing occur in a carburetor and the charge is carried to the combustion chamber by an intake manifold. Under such circumstances, the fuel par ticles frequently precipitate out of the charge. As a result the fuel economy and the performance of the engine may be improved by injecting the fuel into the air as close to the combustion chamber as possible. This may be accomplished by employing a plurality of fuel nozzles each of which is disposed adjacent an intake valve and is supplied by a fuel pump. In engines of the size normally employed in automotive vehicles, the quantity of fuel injected during each cycle is very small especially when the engine is operating at or near idle conditions. Thus the pump employed must have a very small capacity. As a consequence the various parts of the pump require such a large amount of precision machining that the cost has discouraged the use of such systems on mass produced automobiles.

It is now proposed to provide a pump which is particularly adapted for use on an internal combustion engine while at the same time it will be economical to manufacture and reliable in operation. The pump may include a cylinder and a piston reciprocably disposed therein. One end of the cylinder may be open so that the piston may be reciprocably driven therethrough. The opposite end of the cylinder may be closed and have a resilient plug disposed therein. This plug may be compressed in its position so that it will positively engage the end of the piston, the side walls of the cylinder, and the end wall of the cylinder. A pumping chamber may be formed in the end of the cylinder by a recess in the end of the plug and/or the cylinder end wall. One or more passages may be provided which will communicate with this chamber to form the inlet and outlet of the pump. The inward movement of the piston will compress the plug and cause the volume of the pumping chamber to decrease and force the liquid therefrom. When the piston moves outwardly the plug will expand and draw a fresh supply of fluid into this chamber.

By placing the pumping chamber in the end of the cylinder, any fiuid escaping between the working parts of the pump must pass between the plug and the cylinder walls. Since the plug is resiliently deformable it will tightly engage all portions of the cylinder wall and prevent the escape of any fluids. In addition, when the liquid is under the most pressure, the plug will be compressed and thus be forced against the cylinder walls more tightly. This will in turn improve the sealing action and prevent the liquid escaping. As a result the clearance space between the piston and cylinder will not form a part of the seal and thus reduce the tolerances required in producing the parts.

The capacity of the pump will be determined by the capacity of the pumping chamber, and the capacity of this chamber may be controlled by the size of the recess in the plug and/or the end wall of the cylinder. Thus the pump capacity may be altered without changing the bore or stroke. It is therefore apparent that a small capacity pump may be made without necessitating the use of extremely small precision parts.

In the two sheets of drawings:

Figure l is a view of a pump structure employing the present invention, portions of the pump being broken away.

Figure 2 is a fragmentary view of a pump similar to that in Figure 1 but employing a modified form of the present invention.

Figure 3 is a fragmentary view of a pump similar to that in Figure 1 but employing a modified form of the present invention.

Figure 4 is a fragmentary view of a pump similar to that in Figure 1 but employing a modified form of the present invention.

Figure 5 is a fragmentary view of a pump similar to that in Figure 1 but employing a modified form of the present invention.

Figure 6 is a fragmentary view of a pump similar to i that in Figure 1 but employing a modified form of the present invention.

Figure 7 is a fragmentary view of a pump similar to that in Figure 1 but employing a modified form of the present invention.

Figure 8 is a fragmentary view of a pump similar to that in Figure 1 but employing a modified form of the present invention.

Referring to the drawings in more detail the present invention may be embodied in any suitable pump 10. In the present instance the pump 10 may be disposed in a casing 12 having other similar pumps mounted therein, each of which is adapted to pump fuel to one or more cylinders of an internal combustion engine as shown. in copending applications Serial No. 511,954 on Fuel Injection System by John Dolza, now Patent No. 2,890,- 690 and Serial No. 512,448 on Fuel Injection Pump by John Dolza, now abandoned.

The casing 12 may have a plurality of walls 14 that are secured together to form a compartment 16 that encloses a rotating cam 18 driven by the engine and having an eccentric periphery 20.

The pump 10 comprises a housing 22 having a barrel portion 24 and an enlarged end portion 26. The end portion 26 may form a flange 28 that engages one wall 14 of the casing 12 while the barrel portion 24 pro- 'jects through an opening 30 in the Wall 14 into the compartment 16 inside the casing 12. The pump 10 may be secured in this position by any suitable means such as bolts. The barrel portion 24 which projects into the compartment 16 has the inner end thereof adjacent the cam 18.

A passage 32 may extend into the barrel portion 24 with one end thereof forming an opening 33 in the inner end of the barrel portion 24. This passage 32 may have a generally cylindrical side Wall 34 and an end wall 36 that is disposed normal to the axis of the passage 32. A plunger or piston 38 may be disposed in the cylindrical passage 32 with the outer end project-- the barrel portion to form inlet and outlet openings 42 and 44, respectively, in the opposite sides of the barrel portion 24. This passage 40 may be interconnected with the cylindrical passage 32 by a small pas- Patented Mar. 22, teen sage 46 that intersects the center of the supply passage 40 and also forms an opening 48 in the center of the end wall 36. Inlet and outlet passages 50 and 52 may be formed in the casing 12.so as to communicate wtih the inlet and outlet openings 42 and 44 in the opposite sides of the barrel portion 24. The inlet passage 50 may be connected to a source of liquid such as a fuel tank, while the outlet passage 52 may be adapted to discharge the liquid into any suitable device suchas a nozzle.

Inlet and outlet valves 54 and 56, respectively, may be provided to control the flow of liquids into and out of the pump 10. The present inlet valve 54 is disposed in the supply passage and it includes a plate biased to seat on a valve insert by a spring. The outlet valve 56 is disposed in the outlet passage 52 and is similar to the inlet valve and includes a plate biased. to seat on a valve insert by a spring.

A plug 58 of resilient material may be provided in the closed end of the cylindrical passage 32 so as to engage the plunger 38 and the end wall 36 of the cylindrical passage 32. This plug 58 is preferably] of a resilient material which is easily compressible but which is elastic enough to immediately return to its original shape when released. The diameter of the plug 58 is preferably equal to or slightly larger than the diameter of the cylindrical passage 32 so that the plug 58 will firmly engage the side walls 34' of the passage 32.

creases, the plunger 38 will move inwardly and further compress'the plug 58. As this rotation continues and the cam lift decreases, the plug 58 will expand and move the plunger 38 outwardly thereby retaining the plunger 38 against the cam periphery 20 at all times.

The end of the plug 58 may have a recess 60 provided in the end which engages the end wall 36. This recess 60 may cooperate with the end wall 36 to form a pumping chamber. This chamber may be of any desired shape but in the present embodiment, it is a semi-spherical shape and is preferably positioned to register with the opening 48 formed by the passage 46. The recess is substantially the same diameter as the passage 46. When the cam 18 is rotating so that the lift is increasing, the plunger 38 will be forced into the cylinder 32. This will'tend to compress the plug 58 andcause the plug material to flow into the pumping chamber and decrease the volume thereof. Thus if there is any fluid in the chamber, it will be forced to flow from the chamber into the supply passage 40 and out through the outlet valve 56. As the cam 18 continues to rotate and the lift decreases the resilient action of the plug 58 will cause the plug 58 to expand and retain the plunger 38 against the cam 18. At the same time the expansion of the plug 58 will allow the plug 58 to return to its original shape; thus the pumping chamber will regain its original capacity. Consequently, the fluid will be drawn through the inlet valve 54 into the pumping chamber so the cycle can be repeated.

Before any fuel can escape from the pumping chamher, it must leak through the space between the cylindrical side walls 34 of the passage 32 and the exterior of the plug 58. However, since the plug 58 is resilient it will tightly engage the side walls 34 even if there are some irregularities therein. Thus an effective seal will be provided. It should be noted that when the pressure in the fluid is high, the plug 58 will also be highly compressed thereby increasing the sealing action at this time. By providing a small amount of taper 59 in the side walls 34 of the cylinder 32 adjacent its inner end, the lateral pressure between the plug 58 and cylinder Thus the plug 58 will' 4' 32 may be even further increased, especially if the plug 58 has a cylindrical exterior.

It will thus be seen that an etfective seal will be pro vided between the plug 58 and the cylinder wall 34. Therefore the space between the plunger 38 and the side wall 34 will not have to form a seal. As a consequence tolerances employed in'machining these parts may be greatly relaxed.

In the embodiment shown in Figure 2, the pump 10 includes a housing 22 similar to that in the preferred embodiment;'- This housing 22 may include an enlarged end portion 26 that has a flange 28 to abut against a wall 14 of the casing 12 and a barrel portion 24 that projects through an opening 30 in the wall 14 so the the inner end terminates adjacent a. cam 18 inside of the casing 12;

The barrel portion 24 may include a passage 32 that extends axially inwardly from the inner end thereof to forman opening in the inner end of the barrel portion.

24. The passage'32 may have a cylindrical side wall 34 and an end wall 36 disposed normal to the axis thereof. A supply passage 40 may extend transversely through the barrel portion 24 to form inlet and outlet openings 42and 44, respectively, onpthe opposite sides of the'barrel. portion 24. A smallpassage 46' may extend axially of the housing 22 so that one end will intersect the middle of thesu'pply passage 40 and the other end will form an opening 48 in the end wall 36.

A cylindrical plunger 38 may be disposed in the. passage 3250 as to projectthrough the opening and. en-- gage the periphery 20 of a cam 18- or other. suitable driving means.

The cylindrical passage 32 may have a resilient plug.

58 disposed in the inner end thereof which is of materialsimilar to that in the. first embodiment. The sides of this plug 61 may be substantially cylindrical. and of a large enough diameter to fit snugly against the cylindrical side wall 34 of the passage 32. One end 62 of the plug 61 may abut the inner end of the plunger 38 while the of the plug 61 will fiowinto the recess 66. Any liquid v in the pumping chamber will be. forced to flow into the small passage '46 and out of the outlet opening. When the. plunger 38 is free to move out of the passage 32,

the plug 61 will expand and return to its free state. The end 64 of the plug 58 will return to a plane and withdraw from the pumping chamber. The liquid will then flow through the inlet opening, the small passage 46 and into thepumping chamber.

The embodiment shown in Figure 3 is similar to the v previous embodiments. It includes a housing 22 having 'anenlarged end portion 26 that forms a flange 28 to abut against a wall of the casing and a barrel portion 24 that projects through an opening in the wall so the inner substantially cylindrical side walls 34 and a plane end A fluid wall 36 disposed normal to the axis thereof. supply passage 40may extend transversely through the barrel portion'to form inlet and outlet openings on the opposite sides of the barrel portion 24. A small passage 46 may extend axially so that one end communicates with the center of the transverse passage 40 while the other end forms an opening 48 in the end wall 36.

A substantially cylindrical plunger 38 may be disposed. in the cylindrical passage 32 so asto projectthroughthe opening and engage the periphery of a cam 18 or other suitable driving means.

A resilient plug 68 may be disposed in the cylindrical passage 32 between the plunger 38 and the end wall 36. The exterior of the plug 68 may be cylindrical so as to engage the cylindrical wall 34 of the passage 32. One end 70 of the plug 68 may abut the inner end of the plunger 33 while the other end engages the end wall 36 of the passage 32. This end 78 of the plug 68 may have a recess 72 with a cylindrical side wall 74 and a plane end wall 76 that extends inwardly so as to cooperate with the end wall 36 to form a pumping chamber that communicates with the opening 48 formed by the axial passage 46. When the cam rotates to force the plunger 38 into the passage 32, the plug 68 will be compressed. This in turn will cause the volume of the pumping chamber to be materially reduced. Consequently, any fluid in the chamber will be forced to fiow through the axial passage 46 and pass through the outlet opening. When the cam will permit the plunger 38 to move out of the passage 32, the resilient action of the plug 68 will bias the plunger 38 against the periphery of the cam. At this time the pumping chamber will assume its original shape and its volume. Thus the fluid may be drawn from the inlet into the pumping chamber. In order to increase the biasing action of the plug 68 and reinforce the side walls 74 thereof, a spring 78 may be provided. In the present instance the spring 78 forms a helix that is embedded in the walls 74 of the plug 68.

In the embodiment shown in Figure 4, the pump includes a housing 22 having an enlarged end portion 26 that forms a flange 28 to abut against a wall of the casing and a barrel portion 24 that projects through an opening in the wall so the inner end terminates adjacent a cam inside of the casing. A passage 32 may extend inwardly from one end of the barrel portion 24 so as to form an opening in the end thereof. This passage 32 may have a cylindrical side wall 34 and an end wall 36 that is disposed normal to the axis of the passage 32. A supply passage 40 may extend transversely of the barrel portion with the opposite ends thereof forming inlet and outlet openings on the sides of the barrel portion 24.

A passage 46 of reduced diameter may extend axially of the barrel portion 24 so as to form an opening 48 in the end wall 36 and to intersect the center of the supply passage 40. A plunger 38 may be reciprocably disposed in the passage 32 to project through the opening and engage a suitable driving means such as a cam.

A resilient plug 80 may be disposed in the end of the cylindrical passage 32 with the exterior thereof snugly engaging the side walls 34. This plug 80 may be in the form of a hollow sleeve 81 that has one end 82 thereof engaging the plunger 38 and the other end 84 engaging a seat 86 formed by a rigid washer-shaped member that engages the end wall. The passage 88 in the sleeve may form a pumping chamber that communicates with the.

opening 48 formed by the small passage 46. Thus as the cam moves the plunger 38 in and out, the sleeve 81 will be compressed and alternately increase and decrease the volume of the pumping chamber.

The embodiments shown in Figures 5 and 6 are substantially identical. They may include a housing 22 having a barrel portion 24, a mounting flange 28 and a plunger 38 reciprocably disposed in the passage 32. A resilient plug 90 may be disposed in the inner end of the passage 32 to seat on a washer member 86 and engage the side walls and the plunger 38. These plugs 90 may have recesses 92 and 94 therein that form pumping chambers that communicate with the supply passage 40 by means of a small passage 46 and the opening in the washer member 86.

In the embodiment of Figure 5, the recess 92 in the plug 98 comprises a cylindrical passage 96: extending inwardly from the end thereof. The bottom 98 of this passage 96 may comprise a plane surface that is disposed normal to the axis of the passage 96.

In the embodiment shown in Figure 6, the recess 96 in the plug is semi-spherical and extends part way into the plug 90 to form a pumping chamber. This chamber communicates with the supply passage. Thus when the plunger 38 reciprocates, the fluid will flow from the intake to the pumping chamber and out the outlet.

In theembodiment shown in Figure 7, the pump 10 includes a housing 22 having an enlarged end portion that forms a flange to abut against a wall of the casing and a barrel portion 24 that projects through an opening in the wall so that the inner end terminates adjacent a cam inside of the casing. A passage 102 may extend axially inwardly from the inner end of the barrel portion 24 so as to form an opening in the end adjacent the cam. This passage 182 may include a threaded cylindrical side wall 104 and an end wall 186 disposed normal to the axis thereof. A supply passage 40 may extend substantially transversely through the barrel portion 24 and form inlet and outlet openings on the opposite sides thereof. A small axial passage 46 with one end thereof intersecting the center of the supply passage 48 may be provided so that the other end thereof forms an opening 48 in the end wall 36 of the passage 32.

A member 105 with a threaded exterior may be threaded into the passage 102 so as to project through the opening and terminate adjacent the cam. The mem-- ber 105 may have a passage 188 that extends axially therethrough. This passage 108 may include a cylinof the plug 114 may be a plane disposed normal to the axis of the cone so as to abut the end of the plunger 38. The larger end of the cone may have a conical passage extending inwardly therefrom to form a pumping chamber which registers with the opening formed by the small passage 46. V

In the embodiment shown in Figure 8, the pump 10 includes a housing 22 having an enlarged end portion that forms a flange to abut against a wall of the casing and a barrel portion 24 that projects through an opening in the wall so that the inner end projects toward a cam disposed inside of the casing. A cylindrical passage 118 may extend inwardly from the end of the barrel portion 24 adjacent the cam. A supply passage 40 may extend transversely to form inlet and outlet openings on the opposite sides thereof. A small passage 46 may interconnect the end of the cylindrical passage 118 with the center of the supply passage 40. A substantially cylindrical resilient sleeve 128 may be disposed in the cylindrical passage 118 so that the exterior thereof will form a snug fit against the side walls of the cylindrical passage 118. A passage may extend through the resilient member 128 with the outer end portion 122 thereof being larger in diameter than the smaller end portion 124. A plunger 38 may be reciprocably disposed in the larger portion 122 so that it will project therefrom to engage a cam. A resilient plug 126 may be disposed in the enlarged portion 122 so as to abut the plunger 38 and seat on the shoulder 128 formed by the reduced portion. A recess 138 may be formed in the end of the plug 126 so as to form a pumping chamber that registers with the reduced end portion 124. Thus when the plunger 38 is driven axially into the passage 122, the capacity of the pumping chamber will decrease and force the fluid out of the chamber. It should be noted that the use of the resilient sleeve 128 will insure a good sealing action around the walls of the plunger 38 and the cylindrical passage 122 thereby greatly relaxing the tolerances required in the production of these parts.

Various changes and modifications of the embodiments of'the-invention described herein may be made bythose skilled in the art without departing from the spirit and principles of the invention.

What is claimed is:

1. A pump comprising a housing having a passage extending inwardly from one end thereof to form side and endwalls, a plunger reciprocably disposed in said passage and slidably engaging said side wall, a resilient plug being wholly' disposed in said passage and abuttingly engaging said end wall and said plunger, said plug being peripherally supported by said passage walls, a pumping chamber formed between said end wall and said plug, and inlet and outlet means communicating with said pumping chamber.

2. A pump comprising a housing having a passage extending inwardly from one end thereofto form a side surface and an end wall, a plunger reciprocably disposed in; said passage, a resilient plug disposed in said passage to abut the end surface of said plunger, said plug having an end wall engaging said first mentioned'end wall, at least one of said walls having a recess therein to form a pumping chamber, said plugiand said chamber b'eiiigpositioned so thatthe pressure insaid chamber will force the exterior of said plug against said walls and surfaces, and inlet and outlet means communicating with said chamber.

3. A pump comprising'a housing having a passage extending inwardly from one end thereof to form side andend walls, said side walls including a substantially cylindrical portion and a tapered portion disposed be tween said cylindrical portion and said end wall, a substantially cylindrical plunger reciprocably disposed in said cylindrical portion, a resilient plug disposed in said tapered portion to engage said end wall and said plunger, apumping chamber formed between said end wall and said plug and inlet and outlet means communicating with said pumping chamber.

4. A pump comprising a housing having a passage extending inwardly from one end thereof to form side and end walls, a plunger reciprocably disposed in said passage, a resilient plug disposed in said passage to abut said plunger and having an end thereof engaging said end Wall, inlet and outlet means communicating with said passage to form an opening in said end wall, said end of saidplug having a recess with a diameter substantially identical to said opening.

5. A pump comprising a housing having a passage extending inwardly from one end thereof to form side and end walls, a plunger reciprocably disposed in said passage, an inlet and outlet passage communicating with said passage to form an opening in said end wall, a resilient plug disposed in said passage between said end wall and said plunger, said plug having a recess extending inwardly to form side walls engaging said first side wall and form a pumping chamber positioned to register withithe opening formed by said inlet and outlet passage.

6'. A pump comprising a housing having a passage extending inwardly from one end thereof to form side and end walls, a plunger reciprocably disposed in said passage, an inlet and outlet passage communicating with said passage to form an opening in said end wall, a resilient plug disposed in said passage between said end wall'and'said plunger, said plug having a recess extending inwardly to form side walls engaging said first side wall and form a pumping chamber positioned to register with the opening formed by said inlet and outlet passage, and spring means disposed in said side walls.

7. A pump comprising a housing having a passage extending inwardly from one end thereof to form a side wall having a substantially cylindrical portion and an end wall disposed normal to the axis thereof, a plunger reciprocably disposed in said cylindrical portion and having an inner end parallel to said end wall, a resilient plug disposed in said passage, said plug having a plane end engaging-'saidend of said plunger and a substantially cylindrical side wallwhic'h forms a pumping chamber opening toward said end wall, and inlet and outlet means communicating with said pumping chamber.

8. A pump comprising a housing having a passage extending inwardly from one end thereof to form side and end walls, a plunger reciprocably disposed in said passage, a resilient plug disposed in said passage between said end wall and said plunger, one end of said plug having a substantially semispherical recess positioned to cooperate with said end wall to form a pumping chamber, and inlet and outlet means communicating with said pumping chamber.

9. A pump comprising a housing having a passage extending inwardly from one end thereof and forming an end wall, inlet and outlet means communicating with said passage and forming an opening in said end wall, a member disposed within said first passage and having a second passage extending therethrough, said second passage including a'substantially cylindrical outer portion and a tapering inner portion, a plunger reciprocably disposed in said cylindrical portion, a truncated conical plug of resilient material'disposed in said tapered portion and having the smaller end thereof engage said plunger and the larger end thereof engage said end wall, a pumping chamber formed between said end wall and said plug, said inlet and outlet means communicating with said pumping chamber.

10. A pump comprising a housing having a passage extending inwardly from one end thereof to form an end wall, a member disposed within said passage and having a passage extending'therethrough, said passage including a substantially cylindrical outer portion and a divergently tapered inner portion, a truncated conical plug of resilient material disposed in said tapered portion, the small end of said plug engaging the end of said plunger and the larger end of said plug engaging said end wall, a recess extending inwardly into said plug from said large end to form a pumping chamber, inlet and outlet means communicating with said outlet chamber.

11. A pump comprising a housing having a passage having. an enlarged portion and a reduced portion with an annular shoulder formed therebetween, a plunger reciprocably disposed in said enlarged portion, a resilient plug disposed in said enlarged portion between said plunger and engaging said shoulder, a recess formed in said plug to form a pumping chamber communicating with said reduced portion, and inlet and outlet means communicating with said reduced portion.

12. A pump comprising a housing having a passage extending inwardly from one side thereof, said passage having a side wall and an end wall, a plunger reciprocably disposed within said passage and having at least a portion ofthe exterior thereof slidably engaging said side walls, a resilient plug of a compressible elastic material disposed wholly withinand peripherally supported by said passage side wall, the opposite ends of said plug freely engaging the end of said plunger and said end wall, said resilient plug. forming at least one side of a pumping chamber.

13. A pump'comprising a housing having a passage extending inwardly from one side thereof, said passage including a side wall with a substantially cylindrical surface thereofand an end wall having at least a portion thereof normal to the axis of said cylinder, 21 plunger reciprocably disposed within said passage and having at least a portion ofthe exterior thereof slidably engaging said cylindrical surface, a resilient plug of a compressible elastic material disposed wholly within said passage and supported by said side wall, said plug including end wall portions continuously engaging said plunger and said end wall, said'plug and said end wall forming a pumping chamber, said plug being compressible as a result of reciprocating movement of said plunger to cause a variation in the capacity of said chamber.

(References on following page) 9 10 References Cited in the file of this patent FOREIGN PATENTS UNITED STATES PATENTS 438,353 Italy Aug. 6, 1948 3,315,331; 115101111 July 1(2), 952 508,784 Belgium Feb. 15, 1952 3 I'OWHE 2 195 5 09 54 F A 19 1925 2,791,969 Berliner May 14, 1957

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