MX2008009428A - Ultrasonic fuel injector - Google Patents

Abstract

A fuel injector for delivering fuel to an engine in which a housing of the injector has an internal fuel chamber and at least one exhaust port in fluid communication with the fuel chamber. A valve member is moveable relative to the housing between a closed position in which fuel within the fuel chamber is inhibited against exhaustion from the housing, and an open position in which fuel is exhaustable from the housing. An ultrasonic waveguide separate from the housing and valve member is disposed at least in part within the fuel chamber to ultrasonically excite fuel within the fuel chamber prior to the fuel exiting through the at least one exhaust port in the open position of the valve member. An excitation device is operable in the open position of the valve member to ultrasonically excite the ultrasonic waveguide.

Description

ULTRASONIC FUEL INJECTOR FIELD OF THE INVENTION This invention relates generally to fuel injectors for delivering fuel to an engine, and more particularly to an ultrasonic fuel injector in which the ultrasonic energy is applied to the fuel by the injector before delivery to the engine.

BACKGROUND Fuel injectors are commonly used to deliver fuel to the combustion chambers of the engine cylinders. Typical fuel injectors comprise a box including a nozzle having one or more ejection ports through which fuel is ejected from the injector for delivery into the combustion chamber. A valve member, such as what is commonly referred to as a bolt or needle, is movably located in the fuel injector housing. In its closed position the valve member seals against the nozzle to prevent fuel injection and in the open position the fuel is injected from the nozzle through the ejection ports. In operation, the high pressure fuel is maintained within the injector box with the valve member in its closed position. The valve member is intermittently opened to inject the high pressure fuel through the port or the nozzle ejection ports for delivery to the combustion chamber of the engine.

The fuel efficiency of the internal combustion engine incorporating such an injector is based in part on the size of the drop of fuel injected into the combustion chamber. That is, the smaller drop sizes tend to provide a more efficient fuel burn in the combustion process. Attempts to improve fuel efficiency have included tightening the nozzle ejector port (s), and / or substantially increasing the high fuel pressure at which the injector operates, to promote more atomized fuel spraying from the injector. the injector. For example, it is common for such fuel injectors to operate at fuel pressures greater than 8,000 pounds per square inch (550 bar), and still as high as 30,000 pounds per square inch (2070 bar). These fuel injectors are also exposed to elevated operating temperatures, such as around 85 ° C (185 ° F) or more.

In attempts to further increase fuel efficiency, it is known to subject the ejected fuel from the nozzle through the ejection port to ultrasonic energy to facilitate the improved atomization of the fuel delivered to the combustion chamber. For example, U.S. Patent No. 6,543,700 (to Jameson et al.), The entire disclosure of which is incorporated herein by reference, discloses a fuel injector in which the valve needle is formed at least in part from a magnetorestrictive material that responds to magnetic fields that change at ultrasonic frequencies. When the valve needle is positioned to allow fuel to be expelled from the valve body (for example the nozzle), a magnetic field that changes at ultrasonic frequencies is applied to the magnetorestrictive part of the valve needle. Therefore, the valve needle is ultrasonically driven to impart ultrasonic energy to the fuel as it exits the injector through the outlet orifices.

In the ultrasonic fuel injector described in U.S. Patent No. 5,330,100 (Malinowski), the fuel injector nozzle is itself constructed to ultrasonically vibrate so that the ultrasonic energy is imparted to the fuel as the fuel flows. fuel out to through the injector outlet hole. In such a configuration, there is a risk that by vibrating the nozzle itself results in a cavitation erosion (for example due to cavitation of the fuel within the exit orifice) of the nozzle at the exit orifice.

The United States of America related patents numbers 5,803,106 (de Cohen et al.); 5,868,153 (de Cohen and others); 6,053,424 (from Gipson et al.) And 6,380,264 (from Jameson et al.) Generally describe an apparatus for increasing the flow rate of pressurized liquid through an orifice by applying the energy ultrasonically to the pressurized liquid. In particular, the pressurized liquid is delivered into the chamber of a box having a die tip that includes an outlet orifice (or exit orifices) through which the pressurized liquid exits the chamber. An ultrasonic horn extends longitudinally partly within the chamber and partly outwardly from the chamber and has a diameter that decreases toward a tip positioned on one side of the outlet orifice to amplify the ultrasonic vibration of the horn at its tip. A transducer is attached to the outer end of the horn to vibrate the horn ultrasonically. An application for which the apparatus is described as being useful is with a fuel injector for an internal combustion engine.

A disadvantage of such an arrangement is that exposure of the various components to the high pressure at which a fuel injector operates imparts substantial stress on the components. In particular, because part of the ultrasonic horn is submerged in the chamber and another part is not, there is a substantial pressure differential imparted to the different segments of the horn, resulting in additional stress on the horn. In addition, such an apparatus can not easily accommodate an operating valve member which is common in some ultrasonic liquid delivery devices to control delivery of liquid from the device.

SYNTHESIS In one embodiment, a fuel injector for delivering fuel to an engine generally comprises a box having an internal fuel chamber and at least one ejection port in fluid communication with the fuel chamber so that the fuel leaves the injector of fuel in the at least one ejector port for delivery to the engine. A valve member is moved relative to the box between a closed position in which fuel within the fuel chamber is inhibited against ejection from the box through at least one ejector port, and a position open in which the fuel is expelled from the box through at least one ejection port. An ultrasonic waveguide separated from the box and the valve member is located at least partially inside the fuel chamber to ultrasonically excite the fuel within the fuel chamber before the fuel exits through at least an ejection port in the open position of the valve member. An exciting device is operable in the open position of the valve member to ultrasonically excite the ultrasonic waveguide.

In another embodiment, a fuel injector for delivering fuel to an engine generally comprises a box having an internal fuel chamber and at least one ejection port in fluid communication with the fuel chamber so that the fuel leaves the fuel injector in at least one exhaust port for delivery to the engine. A valve member is moved relative to the box between a closed position in which fuel within the fuel chamber is inhibited against ejection from the box through at least one ejector port, and a position open in which the fuel is expelled from the box through at least one ejection port. An ultrasonic waveguide is separated from the box and the valve member and is elongated and has a terminal end placed inside the internal fuel chamber of the box. The waveguide has a circumference, with the circumference increasing as the waveguide extends lengthwise of the waveguide towards its terminal end. An exciting device is operated in the open position of the valve member to ultrasonically excite the waveguide.

In yet another embodiment, a fuel injector for the delivery of fuel to an engine generally comprises a box having an internal fuel chamber and at least one ejection port in fluid communication with the fuel chamber so that the fuel exits of the fuel injector in at least one ejection port for delivery to the engine. A valve member is moved relative to the box between a closed position in which fuel within the fuel chamber is inhibited against ejection from the box through at least one ejection port, and a position open in which the fuel is expelled from the box through at least one ejection port. An ultrasonic waveguide assembly comprises an ultrasonic waveguide separated from the housing and the valve member and positioned at least in part within the fuel chamber, and an exciting device operated in the open position of the valve member to ultrasonically excite the ultrasonic waveguide inside the fuel chamber. The waveguide assembly is elongated and has a total length of about one half wavelength.

According to yet another embodiment, a fuel injector for delivering fuel to a motor finally comprises a box having an internal fuel chamber and at least one ejection port in fluid communication with the fuel chamber so that the fuel exits of the fuel injector in at least one ejection port for delivery to the engine. A control system operates the fuel injector to direct the fuel within the fuel member to the box to be expelled from the box through at least one ejection port. An elongated ultrasonic waveguide is separated from the case and at least a portion of the waveguide extends longitudinally within the fuel chamber of the case and has a terminal end proximate to at least one ejection port. The part of the waveguide is tubular and defines an inner conduit of the portion, wherein the tubular portion of the waveguide is open at its terminal end to allow fuel in the fuel chamber to flow into said inner conduit of the tubular part of the waveguide. An excitation device is operated to ultrasonically excite the ultrasonic waveguide.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a longitudinal cross section of an embodiment of an ultrasonic liquid delivery device of the present invention illustrated in the form of a fuel injector for integrating the fuel to an internal combustion engine; Figure 2 is a longitudinal cross section of the fuel injector of Figure 1 taken at an angular position different from that in which the cross section of Figure 1 is taken; Figure 3 is an expanded view of a first part of the cross section of Figure 1; Figure 4 is an expanded view of a second part of the cross section of Figure 1; Figure 5 is an expanded view of a third part of the cross section of Figure 2; Figure 6 is an expanded view of a fourth part of the cross section of Figure 1; Figure 6a is an expanded view of a central part of the cross section of Figure 1; Figure 7 is an expanded view of a fifth part of the cross section of Figure 1; Figure 8 is a fragmented and amplified view of the cross section of Figure 1; Figure 9 is a perspective view of a waveguide assembly and other internal components of the fuel injector of Figure 1; Y Fig. 10 is a fragmentary cross-section of a part of a fuel injector box of the fuel injector of Fig. 1, with the internal components of the fuel injector omitted to reveal the construction of the box.

Corresponding reference characters indicate corresponding parts through the drawings.

DETAILED DESCRIPTION With reference now to the drawings and in particular to FIG. 1, an embodiment of an injector of Ultrasonic fuel to deliver fuel to an engine (not shown) is generally designated as No. 21. The fuel injector can be used with land, air and marine vehicles, electric power generators and other devices that employ a motor. In particular, the fuel injector is suitable for use with engines that use diesel fuel. However, it is understood that the term "fuel" as used herein is intended to mean any fuel used in the operation of an engine and is not limited to diesel fuel.

The fuel injector 21 comprises a box, indicated generally with the numeral 23, to receive the pressurized fuel from a source (not shown) of fuel and deliver an atomized spray of fuel droplets to the engine, such as to a combustion chamber of the engine. motor. In the illustrated embodiment, the box 23 comprises an elongated main body 25, a nozzle 27 (sometimes referred to as a valve body (and a retaining member 29 (eg, a nut) that retains the main body, the nozzle, and the nut in conjunction with each other In particular, a lower end 31 of the main body 25 sits against an upper end 33 of the nozzle 27. The retaining member 29 suitably clamped (eg, threadedly fastened) to the outer surface of the body to push the matching ends 31 and 33 of the main body and the nozzle 27 together.

The terms "upper" and "lower" are used here in accordance with the vertical orientation of the fuel injector 21 illustrated in the various drawings and are not intended to describe a necessary orientation of the fuel injector in use. That is, it is understood that the fuel injector 21 can be oriented in a manner other than the vertical orientation illustrated in the drawings and remain within the scope of this invention. The terms "axial" and "longitudinal" are here referred to directionally in the longitudinal direction of the fuel injector (e.g. the vertical direction in the illustrated embodiments). The terms "transverse", "lateral" and "radial" refer here to a direction normal to the axial direction (for example longitudinal). The terms "interior" and "exterior" are also used with reference to a direction transverse to the axial direction of the fuel injector, with the term "interior" referring to an inward direction of the fuel injector and the term "exterior" referring to a direction towards the outside of the injector.

The main body 25 has an axial hole 35 extending longitudinally along its extension.

The cross-sectional dimension of the hole 35 (for example, the diameter of the circular hole illustrated in Figure 1) varies along the discrete longitudinal segments of the hole for purposes that will be apparent. In particular, with reference to Figure 3, at the upper end 37 of the main body 25 the cross-sectional dimension of the hole 35 is stepped to form a seat 39 for seating a conventional solenoid valve (not shown) on the main body with a part of the solenoid valve extending down into the central hole of the main body. The fuel injector 21 and the solenoid valve are held together by a suitable connector (not shown). The construction and operation of suitable solenoid valves are known to those skilled in the art and are therefore not described herein except to the extent necessary. Examples of suitable solenoid valves are described in U.S. Patent No. 6,688,579 entitled "Solenoid Valve for Controlling a Fuel Injector of an Internal Combustion Engine"; 6,827,332 entitled "Solenoid Valve" and 6,874,706 entitled "Solenoid Valve comprising a Rotating / Plug-in Connection". Other suitable solenoid valves may also be used.

The cross-sectional dimension of the central hole 35 is also stepped inward as it extends down the solenoid valve seat to define a shoulder 45 which seats a bolt support 47 extending longitudinally (and coaxially in the illustrated embodiment) into the center hole. As illustrated in Figure 4, the orifice 35 of the main body 25 is further narrowed in cross section by extending longitudinally down the segment of the hole in which the pin holder 47 extends, and at least in part defines a camera low pressure 49 of the injector 21.

Longitudinally below the low pressure chamber 49, the central hole 35 of the main body 25 is further narrowed to define a segment of guide channel 51 (and a high pressure ceiling) (figures 4 and 5) of the hole for less in part locate suitably a valve needle 53 (largely a valve member) of the injector 21 within the hole as described hereinafter. With reference to Figure 8, the cross-sectional dimension of the orifice 35 then increases as the hole extends longitudinally down the guide channel segment 51 to the open lower end 31 of the main body 25 to partly (for example together with the nozzle 27). as will be described) defining a high pressure chamber 55 (widely an internal fuel chamber and even more widely an internal liquid chamber) of the injector box 23.

A fuel inlet 58 (Figures 1 and 4) is formed on the side of the main body 25 in the middle of the upper and lower ends 37 and 31 thereof and communicates with the upper and lower diverging channels 59 and 61 which are extends inside the main body. In particular, the upper distribution channel 59 extends from the fuel inlet 57 upwardly into the main body 25 and opens into the hole 35 generally adjacent the pin holder 47 secured within the hole, and more particularly just below the shoulder 45 on which the bolt support is seated. The lower distribution channel 61 extends from the fuel inlet 57 downwardly into the main body 25 and opens into the central orifice 35 generally in the high pressure chamber 55. A delivery tube 63 extends inwardly through the main body 25 in the fuel inlet 57 and maintained in conjunction with the main body by a suitable sleeve 65 and the threaded fitting 67. It is understood that the fuel inlet 57 may be located elsewhere than as illustrated in the figures 1 and 4 without departing from the scope of the invention. It is also understood that the fuel can be delivered only to the high pressure chamber 55 of the box 23 and remain within the scope of this invention.

The main body 25 also has an outlet 69 (figures 1 and 4) formed on its side through which the low pressure fuel is ejected from the injector 21 for delivery to a suitable fuel return system (not shown) . A first return channel 71 is formed in the main body 25 and provides a fluid communication between the outlet 69 and the low pressure chamber 49 of the central hole 35 of the main body. A second return channel 73 is formed in the main body 25 to provide a fluid communication between the outlet 69 and the open upper end 37 of the main body. It is understood, however, that one or both of the return channels 71 and 73 can be omitted from the fuel injector 21 without departing from the scope of this invention.

With a particular reference now Figures 6-8, the illustrated nozzle 27 is generally elongated and is coaxially aligned with the main body 25 of the fuel injector box 23. In particular, the nozzle 27 has an axial hole 75 aligned coaxially with the axial hole 35 of the main body 25, particularly at the lower end 31 of the main body, so that the main body and the nozzle together define the high-pressure chamber 55 of the fuel injector box 23. The cross-sectional dimension of the nozzle orifice 75 is stepped outwardly at the upper end 33 of the nozzle 27 for defining a shoulder 77 for seating a mounting member 79 in the fuel injection box 23. The lower end (also referred to as a tip 81) of the nozzle 27 is generally conical.

In the middle of the tip 81 and the upper end 33 the cross-sectional dimension (eg the diameter in the illustrated embodiment) of the nozzle orifice 75 is generally uniform along the length of the nozzle as illustrated in Figure 8. One or more ejection ports 83 (two are visible in the cross section of FIG. 7 while the additional ports are visible in the cross section of FIG. 10) are formed in the nozzle 27, such as at the tip 81 of FIG. the nozzle in the illustrated embodiment, through which the high pressure fuel is ejected from the box 23 for delivery to the engine. As an example, in a suitable embodiment, the nozzle 27 can have eight ejection ports 83, with each ejection port having a diameter of about 0.15 millimeters. However, it is understood that the number of ejection ports and the diameter thereof may vary without departing from the scope of this invention. The lower distribution channel 61 and the high pressure chamber 55 together widely define here a flow path within the box 23 along which the high fuel flows. pressure from the fuel inlet 57 to the discharge ports 83 from the nozzle 27.

Referring now to FIGS. 1 and 3, the bolt support 47 comprises an elongate tubular body 85 and a head 87 integrally formed with the upper end of the tubular body and sized in a cross-section larger than the tubular body for locating the support bolt on the shoulder 45 of the main body 25 within the central hole thereof. In the illustrated embodiment the pin bracket 47 is aligned coaxially with the axial hole 35 of the main body 25, with the tubular body 85 of the pin bracket being dimensioned for a sealing engagement generally with the main body within the axial bore of the main body . The tubular body 85 of the bolt support 47 defines an internal longitudinally extending channel 91 of the bolt support for slidably receiving an elongate bolt 93 inside the bolt support.

The head 87 of the bolt support 47 has a generally concave or plate-shaped recess 95 formed centrally on its upper surface, and a hole 97 extending longitudinally from the center of this recess to the inner channel 91 of the bolt support. As illustrated in Figure 3, an annular gap 99 is formed between the wall lateral of the bolt support 47 and the inner surface of the main body 25 in the upper part of the hole 35 of the main body. A feed channel 101 extends transversely through the side wall of the tubular body 85 of the pin support 47 to the inner channel 91 generally at the upper end of the channel, with the feed channel 101 being open at its outer end transverse to the annular gap 99. The feed channel 101 is in fluid communication with the upper distribution channel 59 in the main body 25 through an annular gap 99 for receiving the high pressure fuel inside the feed channel, the inner channel of the tubular body 85 above the bolt 93 and the hole 97 extend longitudinally inside the head 87 of the bolt support 47.

The pin 93 is elongated and suitably extends coaxially within the bolt support channel 91 and the axial hole 35 of the main body 25. An upper segment of the bolt 93 is slidably received within the internal channel of the bolt support 47 in a closely spaced relation thereto while the rest of the bolt extends longitudinally outwardly from the bolt support downward to the low pressure chamber 49 of the orifice 35 of the main body 25. As illustrated in Figure 3, an upper end 103 of pin 93 (for example in the upper part of the inner channel 101 of the pin bracket 47) is tapered to allow the high pressure fuel to be received within the internal channel of the pin bracket above the upper end of the pin.

Also positioned within the low pressure chamber 49 of the main body orifice 35 is a tubular sleeve 107 (FIG. 4) which surrounds the bolt 93 just below the bolt support 47 (for example butted against the bottom of the bolt support. ) and defining a spring seat, a hammer 109, butted against the lower end of the bolt in coaxial relationship with the bolt and having an upper end defining an opposed spring seat, and a spiral spring 111 retained within the hammer and spring sleeve with the bolt passing longitudinally through the spring.

The valve needle 53 (widely the valve member) is elongated and extends coaxially within the hole 35 of the main body 25 from an upper end 113 (FIG. 2) of the valve needle abutting the bottom of the hammer 109, toward down through the guide channel segment 51 (FIG. 8) of the main body orifice, and further down through the high pressure chamber 55 to a terminal end 115 of the valve needle positioned in close proximity to the tip 81 of the nozzle 27 within the high pressure chamber. As best illustrated in Figures 4 and 8, the valve needle 53 is dimensioned in cross section for a closely spaced relationship with the main body 25 in the guide channel segment 51 of the axial hole 35 to maintain proper alignment of the Valve needle in relation to nozzle 27.

Referring particularly to Figure 7, the terminal end 115 of the illustrated valve needle 53 is generally conical in accordance with the conical shape of the tip 81 of the nozzle 27 and defines a closure surface 117 adapted to seal generally against the inner surface of the nozzle tip in a closed position (not shown) of the valve needle. In particular, in the closed position of the valve needle 53, the closing surface 117 of the valve needle seals against the inner surface of the nozzle tip 81 on the discharge ports 83 to seal the nozzle (and more broadly the fuel injector box 23) against the fuel being expelled from the nozzle through the discharge ports. In an open position of the valve needle (illustrated in Figure 7), the sealing surface 117 of the needle valve 53 is spaced from the interior surface of the nozzle tip 81 to allow fuel in the high pressure chamber. 55 the flow between valve needle 53 and nozzle tip 81 to ejection ports 83 for discharge from the fuel injector 21.

In general, the spacing between the closure surface 117 of the valve end end of the valve needle 115 and the opposite surface of the nozzle tip 81 in the open position of the valve needle is suitably in the range of about 0.051 millimeters to about of 0.64 millimeters. However, it is understood that the spacing may be greater or less than the range specified above without departing from the scope of this invention.

It is contemplated that the nozzle 27, and more particularly the tip 81, may alternatively be configured so that the discharge ports 83 are positioned elsewhere than on the interior nozzle surface that seats the closing surface 117 of the valve needle. 53 in the closed position of the valve needle. For example, the ejection ports 83 may be positioned downward (in the direction in which fuel flows to the discharge ports) of the nozzle surface that seats the closing surface 117 of the valve needle. 53 and remains within the scope of this invention. A suitable example of such a valve needle, nozzle tip and expulsion port arrangement is described in U.S. Patent No. 6,543,700, the disclosure of which is incorporated herein by reference to the extent that it is consistent with this.

It will be understood that the pin 93, the hammer 109 and 1 valve needle 53 are therefore jointly moved longitudinally on a common axis within the fuel injector box 23 between the closed position and the open position of the valve needle. The spring 111 positioned between the sleeve 107 and the hammer 109 suitably presses the hammer, and therefore the valve needle 53, towards the closed position of the valve needle. It is understood that other valve configurations suitable for controlling the flow of fuel from the injector for delivery to the engine are possible without departing from the scope of this invention. For example, the nozzle 27 (largely the box 23) may have an opening through which the valve needle 53 extends outwardly from the nozzle through which the fuel exits the nozzle for delivery to the engine. In such an embodiment the terminal end 115 of the valve needle 53 will seal against the outer nozzle 27 thereof in the closed position of the valve needle. It is also understood that the operation of the valve needle 53 can be controlled differently than by a solenoid valve 41 and remain within the scope of this invention. It is further understood that the valve needle 53 or other arrangement of Valves can be omitted altogether from the fuel injector 21 without departing from the scope of this invention.

With particular reference now to FIGS. 8 and 9, an ultrasonic waveguide 121 is formed separate from the valve needle 53 and the fuel injector housing 23 and extends longitudinally within the high pressure chamber 55 of the housing. to a terminal end 123 of the waveguide positioned just above the tip 81 of the nozzle 27 to ultrasonically energize the fuel in the fuel chamber just before the fuel leaves the injector 21 through the discharge ports 83 formed in the mouthpiece. The illustrated waveguide 121 is suitably elongated and tubular, having a side wall 125 defining an internal passage 127 extending along its length between the longitudinally opposite upper and lower ends (the upper end being indicated at point 129). The lower end of the waveguide 121 defines the terminal end 123 of the waveguide.The illustrated waveguide 121 has a generally annular cross section (eg circular) .However, it is understood that the waveguide 121 can be shaped in cross section in another shape than the annular one without departing from the scope of this invention It is also contemplated that the waveguide 121 can be tubular along less than its full length, and that can be generally solid along its length. In other embodiments, it is contemplated that the valve needle may be generally tubular and the waveguide placed at least partly within the interior of the valve needle.

In general, the waveguide can be constructed of a metal that has adequate acoustic and mechanical properties. Examples of suitable metals for the construction of the waveguide include, without limitation, aluminum, monel, titanium, and some alloys of steels. It is also contemplated that all or part of the waveguide may be coated with another metal. The ultrasonic waveguide 121 is secured within the fuel injector housing 23, and more suitably in the high pressure chamber 55 as in the embodiment illustrated, by the mounting member 79. The mounting member 79, located longitudinally between the ends 123 and 129 of the waveguide 121, generally defines an upper segment 131 of the waveguide extending longitudinally up (in the illustrated embodiment) from the mounting member 79 to the upper end 129 of the waveguide and a lower segment 133 extending longitudinally downwardly from the mounting member to the terminal end 123 of the waveguide.

Even when the illustrated embodiment the waveguide 121 (for example both upper and lower segments of the same) is placed completely inside the high pressure chamber 55 of the box, it is contemplated that only a part of the waveguide can be placed inside the high pressure chamber without departing from the scope of this invention. For example, only the lower segment 133 of the waveguide 121, including the terminal end 123 thereof, may be placed within the high pressure chamber 55 while the upper segment 131 of the waveguide is placed outside of the the high pressure chamber, and may or may not be subjected to a high pressure fuel inside the injector box 23.

The internal cross-sectional dimension (for example the inside diameter in the illustrated embodiment) of the waveguide 121 (for example the cross-sectional dimension of the inner passage 127 thereof) is generally uniform along the length of the waveguide and is suitably sized to accommodate the valve needle 53, which extends coaxially within the inner conduit of the waveguide along the entire length of the waveguide (above the waveguide to stop with the hammer 109 in the illustrated embodiment). It is understood, however, that the valve needle 53 may be extended only along a portion of the inner conduit 127 of the waveguide 121 without departing from the scope of this invention. It is also understood that the interior cross-sectional dimension of the waveguide 121 may be other than the uniform along the length of the waveguide. In the illustrated embodiment, the terminal end 115 of the valve needle 53, and more suitably the closing surface 117 of the valve needle, is positioned longitudinally outwardly of the terminal end 123 of the waveguide 121 in both open and closed positions. closed of the valve needle. It is understood, however, that the closing surface 117 of the terminal end 115 of the valve needle 53 requires only to extend outwardly from the terminal end 123 of the waveguide 121 in the closed position of the valve needle and can be placed completely or partially within the inner conduit 127 of the waveguide in the open position of the valve needle. as best illustrated in FIG. 7, the cross-sectional dimension (eg the diameter in the illustrated embodiment) of the portion of the valve needle 53 extending inside the inner conduit 127 of the waveguide 121 is sized slightly smaller that the cross-sectional dimension of the inner conduit of the waveguide to define in part the flow path for the high-pressure fuel within the box, and more adequately defines a part of the flow path extending between the wall lateral waveguide 125 and the valve needle along the length of the valve needle. For example, in one embodiment the valve needle 53 is transversely spaced (eg spaced radially in the illustrated embodiment) from the side wall of the waveguide 125 within the interior conduit 127 of the waveguide in the range of about 0.013 millimeters to about 0.064 millimeters.

Along a pair of longitudinally spaced segments (e.g. a segment 137 (Figure 7) being adjacent to the terminal end 123 of the waveguide 121 and the other segments 139 (Figure 6a) being adjacent and just above the mounting member 79) of the valve needle 53 within the duct 127, the cross-sectional dimension of the valve needle 53 is increased so that the valve needle is in a sliding contact relationship that is even or more closely spaced with the waveguide Within the conduit to facilitate proper alignment there and to inhibit transverse movement of the valve needle within the conduit. The outer surface of the valve needle 53 in these segments has one or more floors (not shown) formed therein to in part define the portion of the flow path that extends within the inner passage 127 of the waveguide 121. Alternatively, the outer surface of the valve needle 53 may be longitudinally grooved in these segments to allow fuel to flow into the inner conduit 127 of the waveguide 121 beyond such segments.

With particular reference to Figure 7, the outer surface of the wave guide side wall 125 is transversely spaced from the main body 25 and the nozzle 27 to further define the flow path along which the fuel flows. high pressure from the fuel inlet 57 to the discharge or ejection ports 83, and more suitably forms a part of the outward flow path, or outwardly of the waveguide 121. In general, the outer cross-sectional dimension (for example the outer diameter in the illustrated embodiment) of the side wall of the waveguide 125 is uniform along a length thereof in the middle of an enlarged portion 195 of the waveguide longitudinally positioned in and / or adjacent to the terminal end 123 of the waveguide 121, and another enlarged portion 153 positioned longitudinally to one side of the upper end 129 of the waveguide. As an example, the transverse spacing (eg radial in the illustrated embodiment) between the waveguide side wall 125 and the nozzle 27 upwardly (for example in relation to the direction in which the fuel flows from the upper end 33). from the nozzle to the discharge or discharge ports 83) of the terminal end 123 of the waveguide which is suitably in the range of about 0.025 millimeters to about 0.533 millimeters.

However, the spacing may be smaller or greater than that without departing from the scope of this invention.

The outer cross-sectional dimension of the portion 195 of the lower segment 133 of the waveguide 121 suitably increases, and more adequately is flared or tapered transversely outwardly to one side of or more suitably at the terminal end 123 of the guidewire. wave. For example, the cross-sectional dimension of this enlarged portion 195 of the lower segment 133 of the waveguide 121 is dimensioned for a sliding contact relationship even or closely spaced with the nozzle 27 within the center hole 75 thereof to maintain a suitable axial alignment of the waveguide (and therefore of the valve needle 53) within the high pressure chamber 55.

As a result, the part of the flow path between the waveguide 121 and the nozzle 27 is generally narrower on one side of or at the terminal end 123 of the waveguide relative to the flow path immediately upstream of the end waveguide terminal to generally restrict fuel flow past the terminal end of the waveguide to generally restrict fuel flow beyond the terminal end of the waveguide to the ejection ports 83. The enlarged part 195 of the lower segment 133 of the Waveguide 121 also provides an ultrasonically increased excited surface area to which fuel flowing beyond terminal end 123 of the waveguide is exposed. One or more floors 197 (FIG. 9) are formed on the outer surface of the enlarged portion 195 of the lower segment 133 to facilitate the flow of fuel along the path beyond the terminal end 123 of the waveguide 121 for the flow of the ejection ports 83 of the nozzle 27. It is understood that the amplified portion 195 of the waveguide side wall 115 may be staggered outwardly instead of tapered or flared. It is also contemplated that the upper and lower surfaces of the enlarged portion 195 may be contoured instead of straight and remain within the scope of this invention.

In one example, the enlarged portion 195 of the lower waveguide segment 133, for example, on and / or to one side of the terminal end 123 of the waveguide, has a maximum external cross-sectional dimension (e.g., outside diameter). in the illustrated embodiment) of about 5.35 millimeters, while the maximum outer cross sectional dimension of the waveguide immediately upward of this enlarged portion may be in the range of about 4.06 millimeters to slightly less than about 5.35 millimeters .D.

The transverse spacing between the terminal end 123 of the waveguide 121 and the nozzle 27 defines an open area through which the fuel flows along the flow path beyond the terminal end of the waveguide. The one or more ejection ports 83 define an open area through which the fuel leaves the box 23. For example, where an ejection port is provided the open area through which the fuel leaves the box 23 is defined as the cross-sectional area of the ejection port (e.g. where the fuel enters the ejection port) and where the multiple ejection ports 83 are present in the open area through which the ejection port extends. Box fuel is defined as the sum of the cross-sectional area of each ejection port. In one embodiment, a proportion of the open area at the terminal end 123 of the waveguide 121 and the nozzle 27 for the open area through which the fuel exits the box 23 (for example the discharge or ejection ports). ) is suitably in the range of about 4: 1 to about 20: 1.

It is understood that in other suitable embodiments the lower segment 133 of the waveguide 121 can have a generally uniform outer cross sectional dimension along its entire length (eg so that no enlarged part 195 is formed), or it may decrease in the outer cross-sectional dimension (eg, essentially narrow towards its terminal end 123) without departing from the scope of the invention.

Referring again to Figures 8 and 9, an exciting device adapted to energize the waveguide 121 to mechanically vibrate ultrasonically is suitably positioned entirely within the high pressure chamber 55 along with the waveguide and is generally indicated with the number 145. In one embodiment, the excitation device 145 suitably responds to the high frequency electric current (e.g., ultrasonic frequency) to vibrate the waveguide ultrasonically. As an example, the excitation device 145 may suitably receive the high frequency electric current from a suitable generating system (not shown) that is operated to deliver the high frequency alternating current to the excitation device. The term "ultrasonic" as used herein is taken to mean having a frequency in the range of about 15 Kilohertz to about 100 Kilohertz. As an example, in one embodiment the generating system can suitably deliver the alternating current to the excitation device at an ultrasonic frequency in the range of about 15 kilohertz to about 100 kilohertz, more suitably in the range of about 15 kilohertz to around 60 kilohertz, and more adequately still in the range of around 20 kilohertz to around 40 kilohertz. Such generation systems are well known to those skilled in the art and do not need to be described further here.

In the illustrated embodiment, the exciting device 145 comprises a piezoelectric device, and more suitably a plurality of stacked piezoelectric rings 147 (for example at least and in the illustrated embodiment four) surrounding the upper segment 131 of waveguide 121 and seated on a shoulder 149 formed by the mounting member 79. An annular ring 151 surrounds the upper segment 131 of the waveguide 121 above the piezoelectric rings 147 and lies against the uppermost ring. Suitably, the ring 151 is constructed of a high density material. For example, a suitable material from which the ring 151 can be constructed is tungsten. It is understood, however, that the ring 151 can be constructed of other suitable materials and remain within the scope of this invention. The enlarged portion 153 to one side of the upper end 129 of the waveguide 121 has an increased outer cross-sectional dimension (eg, an enlarged outer diameter in the illustrated embodiment) and is threaded along this segment. The ring 151 is internally threaded to screw the ring on the waveguide 121. The ring 151 is suitably tightened downwardly against the piezoelectric ring stack 147 to compress the rings between the collar and the shoulder 129 of the mounting member 79.

The waveguide 121 and the excitation device 145 of the embodiment illustrated together broadly define a waveguide assembly, generally indicated at 150, to ultrasonically energize the fuel in the high pressure chamber 55. Thus, the assembly of Full waveguide 150 is placed completely inside the high-pressure fuel chamber 55 of the fuel injector 21 and is therefore generally exposed uniformly to the high-pressure environment within the fuel injector. As an example, the illustrated waveguide assembly is particularly constructed to act as both an ultrasonic horn and a transducer to ultrasonically vibrate the ultrasonic horn. In particular, the lower segment 133 of the waveguide 121 as illustrated in FIG. 8 generally acts in the manner of an ultrasonic horn while the upper segment 131 of the waveguide, and more suitably the portion of the upper segment that it extends generally from the mounting member 79 to the location in which the ring 151 holds the upper segment of the waveguide together with the exciting device ( example the piezoelectric rings) acts in the manner of a transducer.

With the delivery of the electric current (for example the alternating current delivered at an ultrasonic frequency) to the piezoelectric rings 147 of the illustrated embodiment said piezoelectric rings expand and contract (particularly in the longitudinal direction of the fuel injector 21) at the frequency ultrasonic to which the current is delivered to the rings. Because the rings 147 are compressed between the collar 151 (which is attached to the upper segment 131 of the waveguide 21) and the mounting member 79, the expansion and contraction of the rings cause the upper segment of the The waveguide elongates and contracts ultrasonically (for example, generally at the frequency at which the piezoelectric rings expand and contract) as in the manner of a transducer. The elongation and contraction of the upper segment 131 of the waveguide 121 in this manner excites the resonant frequency of the waveguide, and in particular along the lower segment 133 of the waveguide, resulting in an ultrasonic vibration of the waveguide. the waveguide along the lower segment, for example in the manner of an ultrasonic horn.

As an example, in one embodiment the displacement of the lower segment 133 of the waveguide 121 resulting from the ultrasonic excitation thereof can be up to about six times the displacement of the piezoelectric rings and the upper segment of the waveguide . It is understood, however, that the displacement of the lower segment 133 can be amplified more than six times, or that this may not be amplified at all, and remain within the scope of this invention.

It was contemplated that a part of the waveguide 121 (for example a part of the upper segment 131 of the waveguide) can alternatively be constructed from a magnetorestrictive material that responds to magnetic fields that change at ultrasonic frequencies. In such embodiment (not shown) the excitation device may comprise a magnetic field generator placed in whole or in part within the box 23 and operable in response to receiving electric current to apply a magnetic field to the magnetorestrictive material wherein the magnetic field changes to ultrasonic frequencies (eg on-off to off, from one magnitude to another, and / or a change in direction).

For example, a suitable generator may comprise an electric coil connected to the generation system which delivers current to the bovine at frequencies ultrasonic The magnetorestrictive part of the waveguide and the magnetic field generator of such incorporation therefore act together as a transducer while the lower segment 133 of the waveguide 121 again acts as an ultrasonic horn. An example of a suitable magnetorestrictive material and a magnetic field generator is described in U.S. Patent No. 6, 543,700, the disclosure of which is incorporated herein by reference to the extent that it is consistent therewith.

Although the complete waveguide assembly 150 is illustrated as being positioned within the high pressure chamber 55 of the fuel injector housing 23, it is understood that one or more components of the waveguide assembly may be completely positioned or partially outside the high pressure chamber, and can still be placed outside the box, without departing from the scope of this invention. For example, where the magnetorestrictive material is used, the magnetic field generator (widely the excitation device) may be located in the main body 25 or in another component of the fuel injector box 23 and be only partially exposed to or completely sealed from the high pressure chamber 55. In another embodiment, the upper segment 131 of the waveguide 121 and the piezoelectric rings 147 (and the ring 151) can be located together outside the high pressure chamber 55 without departing from the scope of this invention as long as the terminal end 123 of the waveguide is positioned within the high pressure chamber.

By placing the piezoelectric 147 and the collar 151 around the upper segment 131 of the waveguide 121, the complete waveguide assembly 150 does not need to be longer than the waveguide itself (for example as opposed to the length of the waveguide). a set in which a transducer and an ultrasonic horn are arranged in a conventional end-to-end or "stacked" arrangement). As an example, the general waveguide assembly 150 may suitably have a length equal to about one half of the resonant wavelength (otherwise commonly referred to as a one-half wavelength) of the waveguide. In particular, the wave guide assembly 150 is suitably configured to resonate at an ultrasonic frequency in the range of about 15 kilohertz to about 100 kilohertz, more suitably in the range of about 15 kilohertz to about 60 kilohertz, and even more adequately in the range of around 20 kilohertz to around 40 kilohertz. The wavelength waveguide assembly of a half 150 operating at such frequencies has a respective overall length (corresponding to one half wavelength) in the range of about 133. millimeters to about 20 millimeters, more adequately in the range of about 133 millimeters to about 37.5 millimeters and even more adequately in the range of about 100 millimeters to about 50 millimeters. As a more particular example, the waveguide assembly 150 illustrated in FIGS. 8 and 9 is configured to operate at a frequency of about 40 kilohertz and has an overall length of about 50 millimeters. It is understood, however, that the box 23 can be dimensioned sufficiently to allow a waveguide assembly having a full wavelength to be installed there. It is also understood that in such an arrangement the waveguide assembly may comprise an ultrasonic horn and a transducer in a stacked configuration.

An electrically non-conductive sleeve 155 (which is cylindrical in the illustrated embodiment but can be shaped otherwise) is seated on the upper end of the collar 151 and extends upwardly from the collar to the upper end of the high pressure chamber 55. The sleeve 155 is suitably constructed of a generally flexible material. As an example, a suitable material from which the sleeve 155 can be constructed is an amorphous thermoplastic polyetherimide material available from General Electric Company, United States of America, under the trademark ULTEM. However, other materials are not electrically Suitable conductors, such as ceramic materials, may be used to construct the sleeve 155 and remain within the scope of this invention. The upper end of the sleeve 155 has an integrally formed annular flange 157 extending radially outwardly therefrom, and a set of four longitudinally extending slots 159 defining four flexible appendages generally 161 at the upper end of the sleeve. A second annular flange 163 is formed integrally with the sleeve 155 and extends radially outwardly from the sleeve just below the longitudinally extending slots 159, for example in the longitudinally spaced relationship with the annular flange 157 positioned at the upper end of the sleeve. sleeve.

A contact ring 165 constructed of an electrically conductive material circumscribes the sleeve 155 in the middle of the longitudinally spaced annular flanges 157 and 163 of the sleeve. In one embodiment, the contact ring 165 is suitably constructed of brass. It is understood, however, that the contact ring 165 may be constructed of other suitable electrically conductive materials without departing from the scope of this invention. It is also understood that a contact device other than a ring, such as a single-point contact device, a flexible and / or spring loaded appendage or other suitable electrically conductive device, can be used without sharing of the scope of the invention. In the illustrated embodiment, the interior cross-sectional dimension (eg diameter) of the contact ring 165 is sized slightly smaller than the outer cross-sectional dimension of the longitudinal segment of the sleeve 155 that extends between the annular flanges 157 and 163.

The contact ring 165 is inserted into the sleeve 155 by pushing the contact ring telescopically down on the upper end of the sleeve. The force of the ring 165 against the annular flange 157 at the upper end of the sleeve 155 pushes the appendices 161 to flex (eg bend) radially inward to allow the ring to slide down past the annular flange formed in the upper end of the sleeve and for seating the ring on the second annular flange 163. The appendices 161 resiliently move back towards their initial position, providing frictional contact between the contact ring 165 and the sleeve 155 and retaining the contact ring between annular flanges 157 and 163 of the sleeve.

A guide ring 167 constructed of an electrically non-conductive material circumscribes and electrically insulates the contact ring 165. As an example, the guide ring 167 can (but does not necessarily require) be constructed from Same material as the sleeve 163. In one embodiment, the guide ring 167 is properly retained on the sleeve, and more suitably on the contact ring 165 for a clamp, or a frictional adjustment of the guide ring on the contact ring. For example, the guide ring 167 may be a discontinuous broken ring along a slot as illustrated in FIG. 9. The guide ring 167 is therefore circumferentially expanded in a slot for adjusting the guide ring on the ring of contact 165 and with the subsequent release is elastically and securely closed around the contact ring.

In a particularly suitable embodiment, an annular location protrusion 169 extends radially inwardly from the guide ring 167 and is received in the annular groove 171 formed in the contact ring 165 to properly locate the guide ring on the contact ring . It is understood, however, that the contact ring 165 and the guide ring 167 can be mounted on the sleeve 155 in another manner than that illustrated in FIGS. 8 and 9 without departing from the scope of this invention. At least one and more suitably a plurality of frustoconically or tapered shaped openings 173 are formed radially through the guide ring 167 to allow access to the contact ring 165 to deliver the electric current to the contact ring.

As best seen in Figure 5, an insulating sleeve 175 constructed of a suitable electrically non-conductive material extends through an opening in the side of the main body 25 and has a generally conically shaped terminal end 177 configured to seat within a of the openings 173 of the guide ring 167. The insulating sleeve 175 is held in place by a suitable fitting 179 which threadably holds the main body 25 within the opening 173 and has a central opening through which the sleeve extends. insulating. The suitable electrical wiring 181 extends through the insulating sleeve 175 into the electrical contact with the contact ring 165 at one end of the wire and is in electrical communication at its opposite end (not shown) with a source (not shown) of current electric The additional electrical wiring 183 extends from the contact ring 165 downwards along the outside of the sleeve 155 within the high pressure chamber 55 and in electrical communication with an electrode (not shown) positioned between the uppermost piezoelectric ring 147 and the next lower piezoelectric ring. A separate wire 184 electrically connects the electrode to another electrode (not shown) positioned between the lowermost piezoelectric ring 147 and the ring just above it. The mounting member 79 and / or the waveguide 121 provide the ground for the current delivered to the piezoelectric rings 147. In particular, a ground wire 185 is connected to the mounting member 79 and extends up between the two piezoelectric rings 147 in contact with an electrode (not shown) placed between them. Optionally, a second ground wire (not shown) can extend from between the two middle piezoelectric rings 147 in contact with another electrode (not shown) between the uppermost piezoelectric ring and the collar 151.

With particular reference now to Figures 6, 6a, 8 and 9, the mounting member 79 is suitably connected to the waveguide 121 in the middle of the ends 123 and 129 of the waveguide. More suitably, the mounting member 79 is connected to the waveguide 121 in a nodal region of the waveguide. As used herein, the "nodal region" of the waveguide 121 refers to a longitudinal region or segment of the waveguide along which very little or no longitudinal displacement occurs during the ultrasonic vibration of the waveguide. wave and transverse displacement (for example radial in the illustrated embodiment) is generally maximized. The transverse displacement of the waveguide 121 suitably comprises the transverse expansion of the waveguide but may also include the transverse movement (for example bending) of the waveguide.

In the illustrated embodiment, the configuration of the waveguide 121 is such that a nodal plane (e.g., a plane transverse to the waveguide in which longitudinal displacement does not occur while transverse displacement is generally maximized) is not present . Rather, the nodal region of the illustrated waveguide 121 is generally dome-shaped so that at any given longitudinal location within the nodal region some longitudinal displacement may still be present while the primary displacement of the waveguide is the transverse displacement.

It is understood, however, that waveguide 121 may be suitably configured to have a nodal plane (or nodal point as mentioned sometimes) and that the nodal plane of such a waveguide is considered to be within the meaning of nodal region as defined herein. It is also contemplated that the mounting member 79 may be positioned longitudinally up or down the nodal region of the waveguide 121 without departing from the scope of the invention.

The mounting member 79 is suitably configured and arranged in the fuel injector 21 for Vibrationally isolating the waveguide 121 from the fuel injector housing 23. That is, the mounting member 25 inhibits transference of the transverse (eg radial) and longitudinal mechanical vibration of the waveguide 121 to the injector housing. of fuel 23 while maintaining the desired transverse position of the waveguide within the high pressure chamber 55 and allowing the longitudinal displacement of the waveguide within the fuel injector box. As an example, the mounting member 79 of the illustrated embodiment generally comprises an annular inner segment 187 extending transversely (eg radially in the illustrated embodiment) outwardly of the waveguide 121, an annular outer segment 189 extending transverse to the waveguide in a spaced relation transversely to the inner segment, and an annular interconnection fabric 191 transversely extends between and interconnects the inner and outer segments. Although the inner and outer segments 187 and 189 and the interconnecting fabric 191 extend continuously around the circumference of the waveguide 121, it is understood that one or more of these elements may be discontinuous about the waveguide such as in the manner of the spokes of a wheel without departing from the scope of this invention.

In the embodiment illustrated in Figure 6a, the inner segment 187 of the mounting member 79 has a a generally flat upper surface defining the shoulder 149 on which the exciting device 145, for example the piezoelectric rings 147, are seated. A lower surface 193 of the inner segment 187 is suitably contoured as it extends from the adjacent waveguide 121 to its connection with the interconnecting fabric 191, and more suitably has a contour of mixed radius. In particular, the contour of the lower surface 193 in the tissue seal 191 and the inner segment 187 of the mounting member 79 is suitably a smaller radius contour. (for example a sharper, less tapered or more corner type) to facilitate tissue distortion during vibration of the waveguide 121. Contour of the lower surface 193 in the joint of the inner segment 187 of the mounting member 79 and the waveguide 121 is suitably a contour of relatively larger radius (e.g. more tapering or smoother) to reduce the tension in the inner segment of the mounting member with the distortion of the interconnecting fabric 191 during the vibration of the waveguide.

The outer segment 189 of the mounting member 79 is configured to seat down against a shoulder formed by the nozzle 27 generally adjacent the upper end 33 of the nozzle. As can be seen in Figure 6, the internal cross-sectional dimension (eg internal diameter) of the nozzle 27 is stepped inwardly to one side of the upper end 33 of the nozzle, for example longitudinally below the mounting member 79, so that the nozzle is longitudinally spaced from the contoured lower surface 193 of the inner segment 187 and the interconnecting fabric 191 of the peripheral member. assembly to allow displacement of the mounting member during ultrasonic vibration of the waveguide 121. The mounting member 79 is suitably sized in cross section so that at least one outer edge margin of the outer segment 189 is positioned longitudinally between the shoulder of the nozzle 27 and the lower end 31 of the main body 25 of the fuel injector box 23 (for example the surface of the main body that sits against the upper end 33 of the nozzle). The retaining member 29 of the fuel injector 21 pushes the nozzle 27 and the main body 25 together to secure the edge margin of the outer segment of the mounting member 189 therebetween.

The interconnecting fabric 191 is constructed to be relatively thinner than the inner and outer segments 187 and 189 of the mounting member 79 to facilitate flexing and / or bending of the tissue in response to ultrasonic vibration of the waveguide 121. As an example, in an embodiment the thickness of the interconnecting fabric 191 of the mounting member 79 may be in the range of about 0. 2 millimeters to around 1 millimeter, and more adequately of about 0.4 millimeters. The interconnecting fabric 191 and the mounting member 79 suitably comprise at least one axial component 192 and at least one transverse component (eg radial in the illustrated embodiment) 194. In the illustrated embodiment, the interconnecting fabric 191 has a a pair of transversely spaced axial components 192 connected by the transverse component 194 so that the fabric is generally U-shaped in cross section.

It is understood, however, that other configurations having at least one axial component 192 and at least one transverse component 194 are suitable, such as L-shaped, H-shaped, I-shaped, U-shaped. inverted, the inverted L shape, and the like, without departing from the scope of this invention. Additional examples of suitable interconnecting fabric configurations 191 are illustrated and described in U.S. Patent No. 6,676,003, the disclosure of which is incorporated herein by reference to the extent that it is consistent therewith.

The axial components 192 of the fabric 191 depend on the respective inner and outer segments 187 and 189 of the mounting member and are generally cantilevered with respect to the transverse component 194. Thus, the axial component 192 is capable of dynamically bending and / or bending relative to the outer segment 189 of the mounting member in response to the transverse vibrational displacement of the inner segment 187 of the mounting member to insulate by both the box 23 of the transverse displacement of the waveguide. The transverse component 194 of the fabric 191 is cantilevered to the axial components 192 so that the transverse component is capable of bending and flexing dynamically in relation to the axial components (and therefore in relation to the outer segment 189 of the mounting member) in response to the axial vibratory displacement of the inner segment 187 so as to isolate the case 23 from the axial displacement of the waveguide.

In the illustrated embodiment, the waveguide 121 expands radially as well as moves slightly axially in the nodal region (eg where the mounting member 79 is connected to the waveguide) with the ultrasonic excitation of the guide cool. In response to the U-shaped interconnect member 191 (for example the axial and transverse components 192, 194 thereof) are generally bent and flexed, and more particularly roll relative to the fixed outer segment 189 of the mounting member 79, for example similar to the way in which a toilet plunger head rolls with axial displacement of the plunger handle. Thus, the interconnecting fabric 79 isolates the fuel injector box 23 from the ultrasonic vibration of the waveguide 21, and in the illustrated embodiment this more particularly insulates the outer segment 189 of the mounting member from the vibratory displacement of the inner segment 187 of it. Such configuration of the mounting member 79 also provides sufficient bandwidth to compensate for nodal region changes that may occur during ordinary operation. In particular, the mounting member 79 can compensate for changes in the real-time location of the nodal region that arise during the current transfer of the ultrasonic energy through the waveguide 121. Such changes or movements can occur, example, due to changes in temperature and / or other environmental conditions within the high-pressure chamber 55.

Although in the illustrated embodiment the inner and outer segments 187 and 189 of the mounting member 79 are generally positioned in the same longitudinal location in relation to the waveguide, it is understood that the inner and outer segments may be longitudinally offset from one another without departing from the scope of this invention. It was also contemplated that the interconnecting fabric 191 may comprise only one or more axial components 192 (for example the transverse component 194 may be omitted) and remain within the scope of this invention. For example, where the waveguide 121 has a nodal plane and the mounting member 79 is located on the nodal plane, the mounting member needs only be configured to isolate the transverse displacement of the waveguide. In an alternate embodiment (not shown) it is contemplated that the mounting member may be placed on or to one side of the anti-nodal region of the waveguide, such as one of the opposite ends 123 and 129 of the waveguide . In such an embodiment, the interconnecting fabric 191 may comprise only one or more transverse components 194 for isolating the axial displacement of the waveguide (for example, very little or no transverse displacement occurs in the anti-nodal region).

In a particularly suitable embodiment, the mounting member 79 is of a single piece construction. Even more suitably the mounting member 79 can be formed integrally with the waveguide 121 as illustrated in Figure 6. However, it is understood that the mounting member 79 can be constructed separate from the waveguide 121 and remain within of the scope of this invention. It is also understood that one or more components of the mounting member 79 can be constructed separately and can be properly connected otherwise assembled together.

In a suitable embodiment the mounting member 79 is further constructed to be generally rigid (for example resistant to static displacement under load) such as to retain the waveguide 121 (and therefore the valve needle 53) in a proper alignment within the high pressure chamber 55. For example, the rigid mounting member in an embodiment may be constructed of a non-elastomeric material, more suitably of metal, still more suitably the same metal of which the waveguide is constructed. The term rigid is not, however, intended to mean that the mounting member is incapable of dynamic bending and / or bending in response to the ultrasonic vibration of the waveguide. In other embodiments, the rigid mounting member may be constructed of an elastomeric material that is sufficiently resistant to static displacement under load but that is otherwise capable of flexing and / or bending dynamically in response to ultrasonic vibration of the waveguide. Although the mounting member 79 illustrated in FIG. 6 is constructed of a metal, and more suitably constructed of the same material as the waveguide 121, it is contemplated that the mounting member may be constructed of other generally rigid and suitable materials without depart from the scope of this invention.

Referring again to Figures 6 and 8, the flow path along which the fuel flows inside the high-pressure chamber 55 of the fuel injector box 23 is defined in part by the transverse spacing between the inner surface of the nozzle 27 and the outer surface of the lower segment 133 of the waveguide 121 (e.g. of the mounting member 79) and between the inner surface of the main body 25 and the outer surfaces of the exciting device 145, the ring 151 and the handle 155 (for example above the mounting member). The fuel flow path is in fluid communication with the fuel inlet 57 of the main body 25 of the injection box 23 generally in the sleeve 155 so that the high pressure fuel entering the flow path from the inlet fuel flows down (in the illustrated embodiment) along the flow path to the nozzle tip 81 for discharge from the nozzle 27 through the discharge ports 83. As previously described, the additional high-pressure fuel flows into the inner conduit 127 of the waveguide 121 between the waveguide and the valve needle 53.

Because the mounting member 79 extends transverse to the waveguide 121 within the high pressure chamber 55, the lower end 31 of the main body 25 and the upper end 33 of the nozzle 27 are suitably configured to allow the flow path of Fuel generally deviates around the mounting member as fuel flows into the high pressure chamber. For example, as best illustrated in Figure 10, suitable channels 199 are formed in the lower end 31 of the main body 25 in fluid communication with the upstream flow path of the mounting member 79 and are aligned with the respective channels 201 formed at the upper end 33 of the nozzle 27 in fluid communication with the downstream flow path of the mounting member. Thus, the high pressure fuel flowing from the fuel inlet 57 downwards along the upward flow path of the mounting member 79 (e.g. between the main body 25 and the sleeve 155 / collar 151 / rings piezoelectric 147) is directed through the channels 199 in the main body around the mounting member and through the channels 201 in the nozzle 27 to the downward flow path of the mounting member (eg between the nozzle and the guide of wave 121).

In one embodiment, the fuel injector is operated by a suitable control system (not shown) to control the operation of the solenoid valve in the operation of the exciting device 145. Such control systems are known to those skilled in the art. and they do not need to be further described here except to the extent necessary. Unless this is happening an operation of Injection, the valve needle 53 is pressed by the spring 111 into the hole 35 of the main body 25 to its closed position with the terminal end 115 of the valve needle in sealing contact with the nozzle tip 81 to close the ports of the valve. discharge or discharge 83. The solenoid valve provides a seal in the recess 95 formed in the head 87 of the bolt support 47 to close the orifice 97 extending longitudinally through the bolt support. No current is provided by the control system to the waveguide assembly in the closed position of the valve needle 53.

The high pressure fuel flows from a fuel source (not shown) into the fuel injector 21 into the fuel inlet 57 of the box 23. The proper fuel delivery systems to deliver pressurized fuel from the fuel source to the injector of fuel 21 are known in the art and do not need to be described further here. In one embodiment, the high pressure fuel can be delivered to the fuel injector 21 at a pressure in the range of 8,000 pounds per square inch (550 bar) to about 30,000 pounds per square inch (2070 bar). The high pressure fuel flows through the supra-distribution channel 59 of the main body 25 to the annular gap 99 between the main body and the support bolt 47, and through the feed channel 101 of the bolt support inside the internal channel 91 of the bolt support above the bolt 93 and up through the hole 97 in the bolt support. The high pressure fuel also flows through the high pressure flow path, for example, through the lower distribution channel 61 of the main body 25 to the high pressure chamber 55 to fill the high pressure chamber, both towards outside the waveguide 121 and into the inner conduit 127 of the waveguide. In this condition the high pressure fuel above the bolt 93, together with the pressure of the spring 111, inhibits the high pressure fuel in the high pressure chamber 55 from pushing the valve needle 53 into its open position.

When the injector control system determines that a fuel injection to the combustion engine is required, the solenoid valve is energized by the control system to open the bolt support hole 97 so that the high pressure fuel flows out from the bolt support to the fuel return channel 71 at the upper end 37 of the main body 25 as the lower pressure fuel, thereby lowering the fuel pressure behind (for example above) the bolt 93 within the bolt support. Therefore, the high pressure fuel in the high pressure chamber 55 is not capable of pushing the valve needle 53 against the pressure of the spring 111 to the open position of the valve needle. In the open position of the valve needle 53, the terminal end 115 of the valve needle is sufficiently spaced from the nozzle tip 81 in the discharge ports 83 to allow the fuel in the high pressure chamber 55 to be discharged to the through the discharge ports.

With energization of the solenoid valve to allow the valve needle 53 to move to its open position, such as approximately concurrently thereof, the control system also directs the high frequency electric current generator to deliver the current to the excitation device 145, for example, the piezoelectric rings 147 in the embodiment illustrated, through the contact ring 165 and the suitable wiring 183 that electrically connects the contact ring to the piezoelectric rings. As previously described, the piezoelectric rings 147 are caused to expand and contract (particularly in the longitudinal direction of the fuel injector 21) generally to the ultrasonic frequency at which the current is delivered to the drive device 145.

The expansion and contraction of the rings 147 cause the upper segment 131 of the waveguide 121 to lengthen and contract ultrasonically (for example, generally at the same frequency that the piezoelectric rings expand and contract). The elongation and contraction of the upper segment 131 of the waveguide 121 in this manner excites the waveguide (for example suitably at the resonant frequency of the waveguide), and in particular along the lower segment 133 of the waveguide. waveguide, resulting in ultrasonic vibration of the waveguide along the lower segment and in particular to the expanded portion 195 of the lower segment at the terminal end 123 thereof.

With the valve needle 53 in its open position, the high pressure fuel in the high pressure chamber 55 flows along the flow path, and in particular beyond the ultrasonically vibrating terminal end 123 of the waveguide. 121, to the discharge ports 83 of the nozzle tip 81. The ultrasonic energy is applied by the terminal end 123 of the waveguide 121 to the high pressure fuel upwards (along the flow path) of the discharge ports 83 for generally atomizing the fuel (for example to decrease the drop size and narrow the drop size distribution of the fuel leaving the injector 21). The ultrasonic energization of the fuel before leaving the discharge ports 83 produces a pulsation, generally a cone-shaped spray of the atomized liquid fuel delivered into the combustion chamber served by the fuel injector 21.

In the illustrated embodiment of Figures 1-10 and as previously described herein, the operation of the pin 93, and hence the valve needle 53 is controlled by the solenoid valve (not shown). It is understood, however, that other devices, such as without limitation, cam operated devices, piezoelectric or magnetorestrictive operated devices, hydraulically operated devices or other suitable mechanical devices, with or without fluid amplification valves, can be used for controlling the operation of the valve needle without departing from the scope of this invention.

When introducing the elements of the present invention on the preferred embodiments thereof, the articles, "a", "an", "the" and "said" are intended to mean that there are one or more elements. The terms "comprising", "including" and "having" are intended to be inclusive and mean that there may be more additional elements than the elements listed.

As various changes can be made to the above constructions and methods without departing from the scope of the invention, it is intended that all of the material contained in the above description and shown in the accompanying drawings should be interpreted as illustrative and not in a limiting sense.

Claims (22)

jan. R E I V I N D I C A C I O N S

1. A fuel injector to deliver fuel to an engine, the fuel injector comprises: a box having an internal fuel chamber and at least one discharge port in fluid communication with the fuel chamber whereby the fuel leaves the fuel injector in at least one discharge port for delivery to the engine; a valve member that can be moved relative to the box between a closed position in which fuel within the fuel chamber is inhibited against discharge from the box through at least one discharge port, and a open position in which fuel is discharged from the box through at least one discharge port; Y an ultrasonic waveguide separated from the box and the valve member, the waveguide being positioned at least partly within the fuel chamber to ultrasonically excite the fuel within the fuel chamber before said fuel leaves the fuel chamber. through at least one discharge port in the open position of the valve member; Y an excitation device operated in the open position of the valve member to ultrasonically excite said ultrasonic waveguide.

2. The fuel injector as claimed in clause 1, characterized in that the waveguide is elongated and is gally tubular along at least a part thereof, said tubular part having a terminal end placed inside the fuel chamber.

3. The fuel injector as claimed in clause 2, characterized in that the tubular part of the waveguide defines an inner conduit within the waveguide, said valve member being at least partially elongated by gally extending in shape coaxial within the inner conduit of the tubular part of the waveguide.

4. The fuel injector as claimed in clause 1, characterized in that the waveguide and the excitation device together define an ultrasonic waveguide assembly, said ultrasonic waveguide assembly having a length of about one half of wavelength.

5. The fuel injector as claimed in clause 1, characterized in that the tubular part of the waveguide has a longitudinally extending side wall, said side wall being flared gally transverse to the outside gally at the terminal end of said tubular part.

6. The fuel injector as claimed in clause 1, characterized in that the waveguide is elongated and comprises a transducer segment responsive to the excitation device for ultrasonically vibrating, and an ultrasonic horn segment, said transducer segment and said segment of ultrasonic horn being integrally formed in an end-to-end relationship longitudinally.

7. The fuel injector as claimed in clause 1, characterized in that the box is essentially insulated against the transfer of ultrasonic gy from the waveguide to the box.

8. The fuel injector as claimed in clause 1, characterized in that the fuel injector has a first flow path through which the pressurized fuel is received by the fuel injector and is directed to flow through the fuel injector. same up to at least one discharge port for ejection from the fuel injector, said first flow path being defined at least in part by the fuel chamber of the box, and a second flow path through which the fuel flows at a lower pressure than a pressure of the pressurized fuel flowing through the first flow path, the fuel injector having an outlet in fluid communication with the second flow path for the discharge of the fuel from the second flow path.

9. The fuel injector as claimed in clause 1, characterized in that the waveguide has a total length of about one half wavelength.

10. A fuel injector to deliver fuel to an engine, the fuel injector comprises: a box having an internal fuel chamber and at least one discharge port in fluid communication with the fuel chamber whereby the fuel leaves the fuel injector in at least one discharge port for delivery to the engine; a valve member that can be moved relative to the box between a closed position in which fuel within the fuel chamber is inhibited against discharge from the box through at least one discharge port, and a open position in which fuel is discharged from the box through at least one discharge port; an ultrasonic waveguide separated from the box and the valve member, said waveguide being elongated and having a terminal end placed inside the internal fuel chamber of the box, said waveguide having a circumference, said circumference increasing to extending the waveguide longitudinally from the waveguide to the terminal end; Y an excitation device operating in the open position of the valve member to ultrasonically excite said waveguide.

11. The fuel injector as claimed in clause 10, characterized in that the waveguide extends generally longitudinally within the fuel chamber of the box, the waveguide is transversely spaced from the box within the chamber of fuel to define a flow path between the guide wave and the box along which the fuel flows into the fuel chamber of the box to at least one discharge port in the open position of the valve member, said narrow flow path as the path of the valve extends. flow to the terminal end of the waveguide.

12. The fuel injector as claimed in clause 10, characterized in that the waveguide extends generally longitudinally within the fuel chamber of the box, the waveguide is spaced transversely from the box within the chamber of fuel, said transverse spacing tapers towards said terminal end of the waveguide.

13. The fuel injector as claimed in clause 10, characterized in that the waveguide is generally cylindrical and extends longitudinally inside the fuel chamber of the box, the terminal end of the waveguide having a first outer diameter , a segment of said waveguide adjacent said terminal end of the waveguide having a second outer diameter substantially smaller than said first outer diameter of the terminal end of the waveguide.

14. The fuel injector as claimed in clause 10, characterized in that the waveguide has a length and is positioned within the fuel chamber along essentially the entire length of said waveguide.

15. The fuel injector as claimed in clause 10, characterized in that the waveguide comprises a transducer segment responsive to the excitation device for ultrasonically vibrating and an ultrasonic horn segment, said transducer segment and said segment of ultrasonic horn being integrally formed in an end-to-end relationship longitudinally.

16. A fuel injector to deliver fuel to an engine, the fuel injector comprises: a box having an internal fuel chamber and at least one discharge port in fluid communication with the fuel chamber whereby the fuel leaves the fuel injector in at least one discharge port for delivery to the engine; a valve member that can move relative to the box between a closed position in which the fuel inside the fuel chamber is inhibited against discharge from the box through at least one discharge port, and an open position in which fuel is discharged from the box through at least one port download Y an ultrasonic waveguide assembly comprising an ultrasonic waveguide spaced from the housing and a valve member and positioned at least in part within said fuel chamber, and an exciting device operating in the open position of the member of valve for ultrasonically exciting said ultrasonic waveguide within said fuel chamber, said waveguide assembly being elongated and having a total length of about one half wavelength.

17. The fuel injector as claimed in clause 16, characterized in that the waveguide extends longitudinally in its entirety within the fuel chamber of the box, said fuel injector further comprising a mounting member for mounting the guide of wave inside said box, said mounting member being in contact with the waveguide and secured to the box at a location spaced transversely from said waveguide.

18. The fuel injector as claimed in clause 16, characterized in that the mounting member is configured to essentially vibrationally insulate the waveguide box.

19. A fuel injector to deliver fuel to an engine, the fuel injector comprises: a box having an internal fuel chamber and at least one discharge port in fluid communication with the fuel chamber whereby the fuel leaves the fuel injector in at least one discharge port for delivery to the engine.; a control system for operating the fuel injector to direct the fuel into the fuel chamber of the box to be expelled from the box through at least one discharge port; Y an elongated ultrasonic waveguide separated from the case, at least a portion of the waveguide extends longitudinally within the fuel chamber of the case and having a terminal end proximate to at least one discharge port, said part of the waveguide being tubular and defining an inner conduit of said part, said tubular part of the waveguide being open at its end terminal for allowing the fuel in the fuel chamber to flow within the inner conduit of said tubular part of the waveguide; Y an excitation device that operates to ultrasonically excite said ultrasonic waveguide.

20. The fuel injector as claimed in clause 19, characterized in that the waveguide is elongated and has a length, said waveguide being tubular along its entire length so that the inner conduit of the guidewire wave extends along the full length of the waveguide.

21. The fuel injector as claimed in clause 20, characterized in that the waveguide is completely positioned within the fuel chamber of the box and has an opposite end of the terminal end, said opposite end being open to allow the fuel in the fuel chamber flow within the inner conduit of the waveguide along essentially the entire length of the waveguide.

22. The fuel injector as claimed in clause 19, characterized in that the box is isolated in essentially vibratory form from the waveguide. SUMMARY A fuel injector for delivering fuel to an engine in which an injector box has an internal fuel chamber and at least one discharge port in fluid communication with the fuel chamber. A valve member is moved relative to the box between a closed position in which the fuel within the fuel chamber is inhibited against discharge from the box, and an open position in which the fuel is discharged from the box. An ultrasonic waveguide separated from the case and a valve member is located at least partially inside the fuel chamber to ultrasonically excite the fuel within the fuel chamber before the fuel exits through at least a discharge port in the open position of the valve member. An exciting device is operated in the open position of the valve member to ultrasonically excite the ultrasonic waveguide.