US3001757A - Magnetic fuel injection nozzle - Google Patents

Description

Sept. 26, 1961 T. M. BALL MAGNETIC FUEL INJECTION NOZZLE Filed April 9, 1958 INVENTOR. 720/774 54 ZZ,

BY H vwuuq'hlm Unitcd States Patent 3,001,757 MAGNETIC FUEL INJECTION NOZZLE Thomas M. Ball, Bloomfield Hills, Mich., assignor to Chrysler Corporation, Highland Park, Mich, a corporation of Delaware Filed Apr. 9, 1958, Ser. No. 727,484 3 Claims. (Cl. 251-140) This invention relates to improvements in fuel injection nozzles of the type employed on internal combustion engines.

Fuel injection nozzles of the aforesaid type are conventionally installed on the intake manifold of internal combustion engines. In such installations the nozzle is usually located in close proximity to the intake valve and is intended to deliver pulsations of fuel to the intake manifold adjacent to the intake valve in response to electrical pulses transmitted to the nozzle by a sensory system. The amount of fuel delivered to the manifold by each fuel pulsation is controlled by the nozzle which is in turn controlled by the engine operating conditions as interpreted by said sensory system.

Fuel injection nozzles installed as aforesaid have, prior to my invention, an inherent and most objectionable action in that they do not respond instantaneously to electrical impulses sent by the sensory system and consequently do not deliver the exact amount of fuel required by the engine at any particular time. This gives rise to poor engine performance through the improper fuel-air mixture delivered to the engine, and results inloss of power and fuel economy.

It is an object of my invention to provide an improved fuel injection nozzle adapted for installation as aforesaid but which will overcome the above objections.

Another object is to provide a fuel injection nozzle of simple construction in relation to other nozzles 'known heretofore which, when installed on an engine intake manifold, will operate efficiently in providing the proper amount of fuel to the manifold as required by the engine at each instant of operation of said engine.

Another object is to provide a fuel injection nozzle with a valve capable of opening and closing many times per second in response to magnetic fields of very short duration created by an electrical coil and a sensory system, which sensory system supplies current impulses to said coil in response to engine fuel requirements.

Another object is to provide a fuel injection nozzle having a solenoid operated valve wherein the valve closing means is a thin disc and has a relatively large surface area disposed in the flux path of said solenoid, so that the disc will be susceptible to the magnetic fields produced by the solenoid coil and will respond practically instantaneously to the magnetic fields to open said valve.

Another object is to provide a fuel injection nozzle having a solenoid operated valve wherein the valve closing means is readily responsive to magnetic fields produced by said solenoid and wherein the responsive nature of said valve closing means to magnetic fields permits the use of relatively weak magnetic fields in opening said valve.

In carrying out my invention I use a magnetically operated valve located within the injection nozzle. This valve comprises a port which is closed and opened by a thin, lightweight disc which responds very rapidly to a a magnetic field. The unique shape of this disc allows a relatively small electrical coil producing a low magnitude magnetic field to be employed in moving said disc to an open position with respect to said port. The use of this small coil avoids the excessive retention of magnetism by the coil and provides a sharply defined magnetic flux cycle. This relatively low magnitude magnetic field also avoids the building up of magnetism in the disc to a point which would retard the return of the disc to the port closing position at the termination of the energization of the coil. Asa result of this sharply defined, low magnitude flux cycle the disc is able to respond practically instantaneously to the electrical pulse transmitted to the electrical coil by the sensory system.

Further objects and advantages of my invention will be apparent from the following detailed illustration thereof, reference being had to the accompanying drawings, in which:

FIGURE 1 schematically shows an injection nozzle mounted on an automotive engine and attached to various electrical components of the sensory system;

FIGURE 2 is a cross-sectional detail of the injector of FIGURE 1;

FIGURE 3 is a full section through 33 of FIG- URE 2;

FIGURE 4 is a cross-sectional detail of a variation of the injector of FIGURE 1; and

FIGURE 5 is a full section through'55 of FIGURE 4.

In FIGURE 1 is shown a portion of an automotive cylinder block 6 having reciprocably mounted therein a piston 8. A cylinder head 10 is mounted on said block and sealed thereto by gasket 12 and bolts (not shown). Mounted in head 10 is a spark plug 14, an intake valve 16, and a fuel injection nozzle 18 having a fuel inlet line 9 extending thereto. Valve 16 is reciprocable in bushing 20. An exhaust valve (not shown) is also reciprocably mounted in head 10. Fuel injection nozzle 18 is electrically connected to triggering selector 22 by electrical conduit 24.

Located on the triggering selector 22 are injector lead terminals 26, 28, 30, 32, 34, 36, and 38, and two output terminals 40 and 42. The lead terminals are selectively energized within the triggering selector by means of a distributor rotor which selectively distributes the current to brushes within the trigger selector housing which carry the current to the lead terminals. Conduit 24 canies the triggering selector output pulse current to the solenoid of the injection nozzle 18.

A modulator 44 receives energizing current from the triggering selector 22 through conduit 46. A rotating lobe cam and two sets of breaker contacts within the triggering selector housing distribute energizing current to the conduit 46. The modulator 44 carries its own distributing system and distributes energizing current to a resistance box through conduit 48. This resistance box contains various resistances, the Voltages across which are affected by atmospheric and engine conditions. The changes in the voltages across these resistances are carlied to the modulator 44 through conduit 50 and are recorded in said modulator. The modulator interprets these voltage changes and evaluates them in terms of the fuel requirements of the engine at the particular instant that the voltage variations are received in the modulator.

The evaluated fuel requirements are then converted in the modulator to current pulsations of a length proportional to the engine fuel requirements at that parto a lower housing portion 62. portion 62 are received in cooperating threads in engine head as shown in FIGURE 1. Secured to housing ticular instant. These pulsations are transmitted to the triggering selector 22 by conduit 54. Suitable means within the triggering selector, which may be a conventional rotor, picks up these pulsations from the modulator and selectively distributes them to the individual injector nozzle solenoids which are energized for a length of time substantially equal to the length of the current pulsation received by the triggering selector from the modulator. Solenoid lead 56 is connected at an appropriate place to the input side of the triggering selector circuit.

In FIGURE 2 is shown a liquid fuel injection nozzle 58 having an upper housing portion 60 threadedly secured Threads 64 on said portion 62 by threads 66 is a valve body designated generally as 68. Recess 70 in housing portion 62 slidably receives the enlarged head 72 of valve body 68. A slot 74 is located in the reduced threaded end of valve body 68 to receive a screw driver bit for adjustment of valve body 68 longitudinally of housing portion 62. A seal ring 76 of suitable fuel corrosion resistant material located in groove 78 of valve body 68 creates a fluid tight seal between said body and housing portion 62.

An aperature or port 81 centrally located in body 68 provides a fluid passage completely through said body and opens at the top end thereof into a fuel receiving well 80 located in head 72 of said valve body. An accurately machined seat 82 is located on top of head 72 and encircles well 80. An annular valve disc or wafer 84 of magnetizable material having a face 86 accurately machined to coincide with the machined seat 82 of body 68 is positioned on top of said seat and resiliently retained thereon by spring 88. This disc may be of Permalloy or hypernik metal both of which metals have high magnetic permeability and low residual magnetism. A recess 85 in the top of disc 84 receives an end of spring 88 and provides a means for limiting the lateral movement of disc 84 and insures the complete coverage of seat 82 by disc face 86 at all times that said disc face is in contact with said seat. Since the maximum distance of travel of the disc away from the seat 82 is approximately five thousandths of an inch, the tendency of the disc to move laterally is not great. As an additional precaution against too great alateral movement of the disc, annular shoulder 83 partially defining recess 90 in lower housing portion 62 is provided to abut the outer edge of disc 84 should such lateral movement occur. It is anticipated that as an alternative to the use of spring 88 and recess 85 as a means to prevent the lateral displacement of the disc, the annular shoulder 83 may be used exclusively.

,This free passage of fuel completely around the disc prevents the formation of a pressure difierential on the opposite surfaces of the disc which would affect its controlled movement. A plastic ring 89 secured to armature 96 provides a fluid tight, non-magnetic seal between retaining plate 108 and armature 96.

A solenoid 92 comprising a casing generally designated as "94 and armature 96 is positioned within upper housing portion 60 and rests on shoulder 98 of lower housing portion 62. The solenoid casing 94 comprises a cylindrical side portion 100, an integral top end portion .102 fitted into groove 104 of armature 96, a bottom flange 4 106, and a bottom retaining plate 108 slidably fitted over the lower end of armature 96. Upper housing portion 60 is threadedly received in lower housing portion 62 by threads 110 and bears against flange 106 of the solenoid housing 74 to thereby lock the solenoid assembly in position within nozzle 58. Leads 112 and 114 of solenoid 92 extend through apertures 116 and 118 respectively in casing 94 and are electrically insulated therefrom by bushings 120 and 122 respectively. Armature 96 has a longitudinal spring receiving recess 124 located therein. Fluid inlet aperture 126 is located in the top of upper housing portion 60 and leads into chamber 128 which opens into chamber 130 through several openings located in flange 106 and retaining plate 108. The electrical current 'used to actuate the fuel injection system is supplied by the automotive battery or generator.

The solenoid housing portions 94, 96, 98, and 106 are of magnetizable material adapted to carry the magnetic field induced when solenoid 92 is energized. The annular insulator 89 effects a gap in the magnetic circuit, which is bridged by the underlying wafer or valve disc 84. In this regard, the under surfaces of the members 89 and 108 are flush and parallel to the upper surface of the valve disc 84. Thus the disc 84 by virtue of its broad area is eifective to carry an optimum proportion of the magnetic field and is substantially immediately responsive thereto in controlling fuel flow, as described below.

In FIGURE 4 is shown a variation in the structure of an injectionnozzle which is essentially comparable to that of FIGURE 1. This variation 198 comprises a lower housing portion 200 having seated therein a port retaining plate 202 having spaced apertures 204 therethrough as shown in FIGURE 5 which is a sectional view along 5-5 of FIGURE 4. Mounted in apertures 204 are valve bodies 206 having flanges 208 thereon which abut retaining plate 202 and limit the extent of insertion of said valve bodies 206 therein. The fuel intake necks 210 of the bodies 206 are machined across the top to place the tops of all the bodies 206 in substantially a common plane. Restricted apertures 212 extend into enlarged aperture 213 in each valve body- Mounted adjacent the periphery of retaining plate 202 is a spring retaining ring 214 which interlocks with the valve disc return spring 216 by means of shoulders 218 and 220 located1on the spring 216 and retaining ring 214 respectively. Valve disc 222 having'a plane face 224 is normally urged into engagement with the tops of bodies 206 to close the latter. Shoulders 226 and 228 on disc 222 abut spring 216 on the bottom and inner edge thereof and prevent said disc from moving substantially in any direction except longitudinally with respect to the injector nozzle 198.

An upper nozzle housing portion 230 is secured to portion 200 by cooperating groove 232 and indent 234 in the upper housing portion and lower housing portion respectively and by shoulder 238 and flange 236. A ring 240 positioned in said groove 232 insures a fluid tight seal between housing portions 200 and 230.

Integral with housing portion 230 is an armature 242 having a threaded fuel inlet connection 244 on one end thereof, a fuel outlet 246 at the other end thereof and a connecting fuel passage 248 therein. Mounted around said armature is a solenoid coil 250 having leads 252 and 254 extending through metal grommets 256 and 258 respectively located in apertures 260 and 262 in the upper nozzle housing 230. Suitable terminal tabs 264 and 266 are secured to the top of housing portion 240 by said grommets 256 and 258 respectively and are insulated from housing portion 230 by insulation members 268 and 270 respectively. Grommets 258 and 256 are hollow metal rivets which are spaced from the walls of apertures 260 and 262 in housing portion 230. Insulating washers 274 and 272 insulate the lower portions of grommets 256 and 258 respectively from housing portion 230. Leads 252 and 254 are soldered to their respective grommets. Insulative spool 276 carries the coil 250. A coil retainer plate 27 8 frictionally fitted into upper housing portion 230 holds coil 250 in position within the nozzle housing. Spaced segments 280 of plate 278 and rim 282 of armature 242 abut rims 288 and 284 respectively of disc 222 when the disc is magnetically pulled upwards from ports 206.

The operation of the nozzle of FIGURES l, 2, and 3 is as follows. A supply of liquid fuel under substantially constant pressure is forced into the nozzle inlet 126 through fuel feed line 9. The fuel under pressure fills interstices 128, 132, 87, 30, 124, and 130. Seat 86 of valve disc 84 covers the fuel receiving well 80 in valve head 72 by laying flat against the port seat 82. Spring 88 resiliently urges said disc against seat 82. When an electrical pulse is received by the nozzle solenoid 92 from the triggering selector 22 the magnetic field produced by the solenoid pulls the disc 84 away from seat 82 against the weaker pressure of spring 88 and toward the end of the armature 96. The fuel under pressure consequently flows into well 80 in valve head 72, out through the aperture 81 of the valve body 68 and into the vicinity of the engine intake valve port. When the electrical pulse as determined by the modulator 44 ends, the solenoid 92 is deenergized and the spring 88 forces the disc 84 back against valve seat 82 and stops further flow of the fuel into the port well 80.

The operation of the nozzle of FIGURE 4 is essentially the same. The variation in fuel flow is readily apparout, the flow being through passage 248, underneath disc 222, into the ports 206 and through apertures 212 and 213 to the engine fuel intake system. It is noted that a free passage of fuel under pressure to both sides of the disc 222 is provided in essentially the same manner as in the structure of the nozzle of FIGURE 2.

In both structures the actual distance that the disc 84 or 222 must travel away from the ports in order to open the same and allow the necessary fuel therethrough is very small and is measured in thousandths of an inch. The length of time that the disc remains away from the ports is measured in milliseconds and is determined by the modulator current pulse transmitted to the in jector solenoid by the triggering selector. Since the injector solenoid must become energized many times a second when the engine is running at high speeds, the disc which the solenoid must pull away from the valve ports must be of such a weight and shape as to take best advantage of the short duration of the magnetic field produced by the solenoid. The disc must respond instantaneously to the field produced by the solenoid and must thereafter respond instantaneously to the tension of the return spring 88 or 216 with a minimum susceptibility to residual magnetic forces when the solenoid is deenergized.

I have determined that the best shape of the disc is substantially flat, one-half to three-quarters of an inch in diameter, and thirty to forty thousandths of an inch in thickness. When so shaped the disc is very light and is immediately susceptible to the magnetic field of the solenoid particularly since the relatively large surface area of the disc is transverse to the plane of the greatest field force produced by the solenoid. It is noted that any time lag in the response of the disc to the induced field of the coil is detrimental to the timing of the fuel injection system and the resulting performance of the engine. This time lag is an important error factor since the total time that the disc is normally in its port opening position during one flux cycle is in the vicinity of 0.5 millisecond.

While the preferred embodiments of the invention has been described and shown, it is understood that alterations and modifications may be made thereto, provided the said alterations and modifications fall within the scope of the appended claims.

What I claim is:

1. A post acting low inertia solenoid valve for controlling the flow of fluids in relatively small quantities comprising a housing, a flow control port therein, a freely shiftable valve disc having one side engageable with said port to close the same, the edges of said disc being spaced from said housing to enable limited and comparatively frictionless movement of said disc toward and away from said port, the other side of said disc being substantially flat and continuous, the space between said disc and housing comprising conduit means for passage of fuel therethrough upon movement of sa d disc from said port, means yieldingly urging said disc toward said valve port, said disc being of a magnetic material susceptible of being shifted from said port by a magnetic field, a plate of magnetic material having its peripheral portion secured to the inside of said housing and spaced from said disc, apertures in said plate forming part of said conduit means, and an electrical coil in said housing having an armature extending through said plate and spaced from said disc, said coil being spaced from the inside of said housing to form part of said conduit means.

2. In a liquid fuel control system for an internal combustion engine, fluid conduit means adapted for connecting an engine with a source of liquid fuel, a hollow valve housing comprising a part of said conduit means and having a valve port, a freely shiftable valve disc having one side engageable with said port to close the same, the edges of said disc being spaced from said housing to enable limited and comparatively frictionless movement of said disc toward and away from said port, the other side of said disc being substantially fiat and continuous, the space between said disc edges and housing comprising part of said conduit means for passage of fuel therethrough upon movement of said disc from said port, means yieldingly urging said disc toward said valve port, said disc being of a magnetic material susceptible of being shifted from said port by a magnetic field, a plate of mag netic material having its peripheral portion secured to the inside of said housing and spaced from said disc, apertures in said plate forming part of said conduit means, and an electrical coil in said housing having an armature extending through said plate and spaced from said disc, said coil being spaced from the inside of said housing to form part of said conduit means.

3. In a liquid fuel control system for an internal combustion engine, fluid conduit means adapted for connecting an engine with a source of liquid fuel, a hollow valve housing comprising a part of said conduit means and having a valve port, a freely shiftable valve disc having one side engageable with said port to close the same upon movement of said disc, the edges of said disc being spaced from said housing to enable limited and comparatively frictionless movement of said disc toward and away from said port, the other side of said disc being substantially fiat and continuous, the space between said disc edges and housing comprising part of said conduit means for passage of fuel therethrough upon movement of said disc from said port, means yieldingly urging said disc toward said valve port, said disc being of a magnetic material susceptible of being shifted from said port by a magnetic field, a plate of magnetic material having its peripheral portion secured to the inside of said housing and spaced from said disc, apertures in said plate forming part of said conduit means, an electrical coil in said housing having an armature extending through said plate and spaced from said disc, said coil being spaced from the inside of said housing to form part of said conduit means, and electrical insulating means interposed between said metal plate and said armature for preventing shunting of magnetic flux away from said disc.

(References on following page) References Cited in the file of this patent UNITED STATES PATENTS Bickley Feb. 26, 1957 10 8 Hales Apr. 1,1958 Ray June 10, 1958 Rhodes Nov. 18, 1958 Beck Apr. 4, 1959 Gunkel Oct. 27, 1959 Nickells Ian. 26, 1960 OTHER REFERENCES SAE Journal, April 1957, pp. 26-29 (123439.17).

UNITED STATES PATENT OFFICE CERTIFICATE OF CQRRECTION Patent No 3,001,757 I I September 26, 1961 Thomas M. Ball It is hereby certified that error appears in {the above numbered patentrequiring correction and that the said Letters Patent should read as "corrected below.

Column 2, line 541: before "through" insert 52 column 3, line 56 for "formed" read forced column 4, line 68, for "240" read 230 column 5 line 15, for "lpying" read lying column 6, line 13, before "and" insert edges Signed and sealed this 6th day of March 1962.

(SEAL) Attest:

ERNEST w. SWIDER' DAVID L. LADD Attesting Officer Commissioner of Patents

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