US2337731A

US2337731A - Injection nozzle

Info

Publication number: US2337731A
Application number: US390227A
Authority: US
Inventors: Buck Foster
Original assignee: International Harverster Corp
Current assignee: Navistar Inc
Priority date: 1941-04-25
Filing date: 1941-04-25
Publication date: 1943-12-28
Anticipated expiration: 1960-12-28

Description

F. BUCK INJECTION NOZZLE Dec. 28, 1943.

'Filed April 25. 1941 operation of solid fuel injection combustion chamber of the engine Patented Dec. 28, 1943 INJECTION NOZZLE Foster Buck, Lisle, Ill., assignor to International Harvester Company, a corporation of New Jersey Application April 25, 1941, Serial No. 390,227

Claims.

This invention relates to an injection nozzle particularly adapted for solid fuel injection engines. More specifically, the invention relates to a pressure operated injection nozzle; In the. engines, a fuel pump is usually utilized for delivering metered charges of fuel to an injection nozzle. The present invention is adaptable to that type of injection system in which the metered charge is delivered at a pressure suflicient for injection. In

this type, a self-opening valve is utilized which opens when the desired injection pressure is attained and closes when the injection is completed and when the pressure drops below the proper injection pressure.

The principal object of the invention is to provide a simplified and improved pressure operated injection nozzle.

A more specific object is to provide a nozzle unit including an injection valve the opening of which is regulated by the lateral expansion, or flow, of an elastic material.

Other more specific objects will be apparent from the detailed description to follow.

In the drawing:

Figure 1 is a cross section of a portion of a Diesel engine cylinder head showing a portion of thepiston and the cylinder block with the pre-cup and the injection unit shown in elevation;

Figure 2 is a section through the center of the injection unit and the pre-cup showing also the supply line to the injection unit;

Figure 3 is an enlarged sectional view showing the seal for the injection unit assembly and the resilient material which regulates the opening and closing of the injection valve.

In the portion of the engine disclosed, a cylindr: head His shown mounted on a block ll having a removable cylinder sleeve l2 in which a piston i3 is mounted for reciprocation. A sleeve-like bore I4 extending at an angle through the cylinder head is provided with a discharge passage l5 communicating with the formed above the piston I3. A cylindrical pre-cup member l6 fitted into the bore I4 is provided with a discharge passage l'l communicating with the discharge passage in the cylinder 'head. This pre-cup construction is conventional and is shown only as illustrating a particular engine in which a nozzle incorporating the invention may be satisfactorily utilized. The injection unit includes a casing in the form of a cylindrical member l8 fitted into the bore l4 abutting the upper end of the pre-cup member IS. The member l8 may be held in position by any suitable means such as laterally extending lugs 19, one of which is shown in Figure 1. A nut 20 is also shown threaded on a stud for securing said member in position. A longitudinal bore 2| extends centrally through the casing I8; Said bore is constricted at its lower end to form a discharge passage 22 of smaller diameter. The two bores are connected by a beveled seat 23. An orifice member 24 provided with a beveled seat 25 is loosely fitted in the combustion chamber end of the bore 2l, being seated on the beveled seat 23. In assembly, said member is dropped into position due to its loose fit in the bore 2 I. A seal is maintained by the two beveled seating surfaces. A valve member 26 has a stem portion slidably extending through the bore 2|, and a head portion 21 located ina chamber 28 formed by an enlargement of the bore 2|. A threaded plug 29 is screwed into the enlarged bore in the casing member l8 and at its lower end abuts an annular sealing member 30 fitted around the outer wall of the chamber 28.

As best shown in Figure 3, the head portion 21 of the valve member is provided with an annular bulged, or raised, portion 3! which is spaced from an oppositely bulged, or raised, portion 32 on the inner face of the plug 29. An annular resilient member 33, formed preferably of neoprene or some similar oil resistant, resilient material, is fitted between the top surface of the head portion 21 of the valve and the bottom surface, or face, of the threaded plug 29.

The member 83,-as will be noted by inspection of Figure 3, is appreciably thinner at its midsection than at the periphery and at the center around theopening which is formed therein. The functioning of this particular construction will be pointed out in connection with the description of the operation of the invention.

A bleed opening 34 communicates with the I center opening in the member 33 and the atmosphere through the plug 29.

A fuel supply-line 35 is connected by a fitting 36 with a, threaded bore 31 formed in the member l8. Said bore communicates with a conduit or passageway38 formed in the member l8 leading to the bore 2| adjacent the top of the orifice member 24. v

The stem of the valve member 26 is provided with a ground flat face 39 which fits on a ground flat top on the orifice member 24. Said orifice member is provided with an internal bore 40 which communicates with a restricted discharge orifice 4| communicating with the discharge passage 22. Due to the loose fit of the orifice member 24, as previously described, it may rock slightly upon its seat in the bore 2| to enable a sealing fit to be maintained by the flattened end of the valve member and the upper surface of is adjusted, the valve' member 26 lifts-oil the seat formed on the orifice member 24 to inject the metered amount of fuel, ceasing when the pressuredrops in the supply line. It is very desirable that the valve should close in such a manner as to prevent dribbling of fuel with consequent poor combustion. In the construction of this invention, the valve opening is controlled by endwise flow of resilient material in a relatively thin section. The thinner cross section of the member 33 is the controlling factor in determining the pressure necessary to open the valve, and also is the controlling factor in determining the amount of opening. It will be readily understood that by making the member 33 much thicker in cross section, a lower pressure will be operable to open the valve an amount sufficient for delivery of fuel. on the other hand, it will be obvious that by making the section very thin a condition could be reached in which the member would amount to a thin gasket which would prevent opening of the nozzle except at extremely high pressures. Applicant has, therefore, provided a construction in which control of the opening pressure of a valve may be regulated by the thickness of a resilient material and the lateral expansion required to provide axial movement of a valve member. It will be noted in Figure 3 that the periphery of the member 33 and the inner portion around the central opening is shown slightly curved as if the material had bulged outwardly and inwardly at these locations. This showing has been exaggerated in Figure 3 to illustrate what happens when compression of the member takes place. By increasing the thickness of the resilient material at points where the flowing material must be extruded, it has been found possible to maintain a bond between a material such as neoprene and the surfaces of the adjacent metal elements. This construction, as well as the control of the valve opening by the thickness of the material, is an important feature of applicants invention.

It will be understood that applicant has shown and described only a preferred embodiment of his improved injection nozzle unit, and that he claims as his invention all forms and modifications of a resilient valve control element covered by the appended claims.

What is claimed is:

1. An injection nozzle unit comprising a casing, said casing being formed with a bore adapted to communicate with a combustion chamber, a valve member mounted insaid bore, a discharge valve formed by said valve member at the discharge end of said bore, means for supplying fuel under injection pressure to said bore adjacent the valve,

said valve member being formed with a head.

portion member, an abutment member provided as a part of the casing adjacent to and overlying said head member, the adjacent surfaces of said head and abutment members being in closely spaced relation, and a member of resilient distortable material mounted between said surfaces,

said resilient member being under compression to urge the valve into closed position and being axially thinner in certain sections than in others, and the contacting surfaces of the head, abutment, and resilient members being constructed and arranged to provide for opening pressure control of the valve at said thinner sections.

2. An injection nozzle unit comprising a casing formed with a bore, a valve member mounted in said bore, a discharge valve formed by said'valve member at the discharge end of said bore, means for supplying fuel under injection pressure to said bore adjacent the valve member, said valve member being formed with a head portion, an abutment member being provided as a part of the casing adjacent said head portion of the valve member, the adjacent surfaces of said head portion and abutment members being in closely spaced relation, and a relatively thin member of resilient material mounted between said surfaces and bonded thereto, said resilient member being axially thinner in certain sections than in others, the bonded surfaces of said head portion, abutment member, and resilient member being constructed and arranged to provide for opening pressure control of the valve at said thinner portions and to provide for the flow of extruded material from th thinner sections to the thicker sections without excessive movement along the bonded edges thereof.

3. An injection nozzle unit comprising a casing, a bore formed in said casing, a valve member mounted in said bore, a discharge valve formed by said valve member at the discharge end of said bore, means for supplying fuel under injection pressure to said bore adjacent the valve, said valve member being formed with a head portion member, an abutment member provided as a part of the casing adjacent said head member, the adjacent surfaces of said head portion and abutment members being in closely spaced relation and being provided with mating annular raised portions, and a relatively thin member of resilient material mounted under compression between said surfaces and bonded thereto, said resilient member due to said raised portions being thinner in certain sections than in others to provide" for opening pressure control of the valve at said thinner portions and to provide for the flow of extruded material from the thinner sections to the thickersections without excessive movement along the bonded edges thereof.

4. An injection nozzle unit comprising a casing, said casing being formed with a .bore for communicating with the combustion chamber at one end and an enlarged bore at-the other end, a valve member mounted in said bore, a discharge valve formed by said valve member at the discharge end of said bore, means for supplying fuel under injection pressure to said bore adjacent the valve, said valve member being formed with an enlarged circular head portion member in said enlarged bore, an abutment member fitted in said enlarged bore, the. adjacent surfaces of said head portion and abutment members being in closely spaced relation and each being provided with an outwardly projecting annular rib portion, said rib portions lying opposite and closely adjacent one another, and an annular member of resilient material mounted between said surfaces and bonded thereto, said resilient member due' to said rib portions being thinner in its intermediate section than at each side thereof for opening pressure control of the valve at the thinner section and to provide for the flow of extruded material during compression from the thinner section in both radial directions to the thicker sections without excessive movement and strain along the bonded surfaces thereof.

5. An injection valve unit comprising valve means adjustable to control injection by said unit, a valve-adjusting member having a portion advanceable concomitantly to an adjustment of said valve means, a reaction member having a portion in opposed relation to said advanceable portion and approachable by said advanceable having a portion in opposed relation to said advanceable portion and approachable by said advanceable portion during the advance thereof, a resilient flowable body disposed between said ortions for distortion thereby pursuant to said approach to yieldingly resist adjustment of the valve, and body deflecting means comprising a generally annular surface formation upon one of said portions in generally coaxial relation with the axially advanceable portion and of less extent' radially of said members than said body to engage the same and to control the flow pattern thereof during its distortion.

7. An injection valve unit comprising valve means adjustable to control injection by said' unit, a valve adjusting member having a portion axially advanceable concomitantly to an adjustment of said valve means, a reaction member having a portion in opposed relation to said advanceable portion and approachable by said ad-, vanceable portion during the. advance thereof. e

a resilient flowable body disposed between said portions for distortion thereby pursuant to said approach to yieldingly resist adjustment or the valve, and body-deflecting means comprising opposed generally annular embossments respectively upon said portions in generally coaxial relation v with the axially advanceable portion to control the flow pattern or said body during its distortion.

8. An injection valve unit comprising a casing having a valve stem bore receivable of injection fluid under pressure, valve means at an end of said bore, abutment means having a portion at the opposite end of said bore in axial registry therewith, a valve stem movable axially within said bore for controlling said valve means and presenting an end portion in opposed relation with said abutment means portion, an annular elastic wafer disposed compressedly between said opposed portions to urge the valve stem in the direction of said valve means but being further compressible by and to oppose movement of the valve stem in the opposite direction, and means upon at least one of said opposed portions for resisting inward radial displacement of the radially outward part of the wafer under the pressure exerted thereon by said fluid.

9. An injection valve unit comprising a casing having a valve stem bore receivable of injection fluid under pressure, valve means at an end of saidbore, abutment means having a portion at the opposite end of said bore in axial registry therewith and having a breather opening, a valve 'stem movable axially withinsaid bore for controlling said valve means and presenting an end portion in opposed relation with said abutment means portion and breather opening, an annular elastic wafer disposed compressedly between said opposed portions to urge the valve stem in the direction of said valve means, said wafer being thus cooperable with said. opposed portions in bounding a space communicative with said breather opening and being further compressible by and to oppose movement of the valve stem in the opposite direction incident to crowding an inner radial part of said water into said space, and means upon at least one of said opposed portions for resisting inward radial displacement of the radially outward part of the wafer under the pressure exerted thereon by said fluid.

10. An injection valve unit comprising a casing having a valve stem bore receivable of injection fluid under pressure, valve means at an end of said bore, abutment means having a portion at the opposite end of said bore in axial registry therewith, a valve stem movable axially within said bore for controlling said valve means and presenting an end portion in opposed relation with said abutment means portion, an elastic water disposed compressedly between said opposed portions to urge the valve stem in the direction of said valve means but being further compressible by and to oppose movement of the valve stem in the opposite direction, and embossment means upon at least one of said opposed portions to concentrate at such embossment means the compressive force on the wafer to obtain unit pressure thereon sufllciently exceeding unit pressure of the fluid on the wafer that distortional flow o! thewafer will occur despite resistance thereto by the fluid pressure upon the exposed surface of the wafer.

, FOSTER BUCK.