The present invention relates to spark-ignited internal combustion engines.
In internal combustion engines, it is conventional to initiate combustion with the use of spark plugs. In conventional spark plugs, a body which defines a longitudinal axis is provided. The body has, adjacent one end thereof, a metal ring which is orientated coaxially with the longitudinal axis. The body further includes a metal tube which: is orientated coaxially with the longitudinal axis; extends from the ring towards the other end of the body; and is externally-threaded for engagement in a corresponding threaded bore in an engine block in use. A porcelain insulator also forms part of the body. The insulator has a portion disposed inside the tube. This portion extends axially, from inside the tube, beyond the ring, and has an elongate void extending axially therethrough. An elongate positive electrode occupies the void and extends axially beyond the insulator to a terminus which defines the one end of the body. Conventional spark plugs also include an electrode leg. The electrode leg has two arms transversely connected to one another, with one arm extending axially from the ring and beyond the electrode and the other arm extending radially inwardly from the one arm so as to terminate in an end portion that is axially-spaced from the terminus. The spark gap in this conventional plug is the space defined between the positive electrode and the electrode leg, this gap being substantially entirely obstructed in the axial direction by the electrode leg.
An adapter for use with a spark plug body and an engine block forms one aspect of the invention. The plug body defines a longitudinal axis and has: adjacent one end, a metal ring which is orientated coaxially with the longitudinal axis; a metal tube which is orientated coaxially with the longitudinal axis, extends from the ring towards the other end of said body and is externally-threaded for engagement in a corresponding threaded bore in said engine block in use; an insulator having a portion disposed inside the tube, which portion extends axially, from inside the tube, beyond the ring, and has an elongate void extending axially therethrough; and an elongate positive electrode which occupies the void and extends axially beyond the insulator to a terminus which defines the one end of said body. The adapter:
According to another aspect of the invention, in the adapter for use with a spark plug body and an engine block, the ground electrode extender can comprise a fixed portion that is welded to the ring, thereby to secure the adapter to said body and hold the positive electrode extender in said electrically-conducting contacting relation to the positive electrode.
According to another aspect of the invention, in the adapter for use with a spark plug body and an engine block, the ground electrode extender can: further comprise a remote portion that is spaced apart from the fixed portion and from the ring; and be configured such that a spark gap defined between the positive electrode extender and the ground electrode extender comprises an elongate channel defined between the positive electrode extender and the remote portion of the ground electrode extender, which elongate channel opens axially and away from the body and is substantially unobstructed in the axial direction.
According to another aspect of the invention, in the adapter for use with a spark plug body and an engine block, the positive electrode extender can comprise a radially extending bar and the ground electrode extender can comprise four elongate electrode portions, each orientated parallel to the positive electrode extender, with two of the elongate portions disposed on each radial side of the bar and spaced with respect to the bar and one another such that the spark gap comprises four parallel channels, the innermost pair of flanking electrode portions defining the remote portion of the ground electrode extender and the outermost pair of flanking electrode portions forming part of the fixed portion.
According to another aspect of the invention, in the adapter for use with a spark plug body and an engine block, the adapter can further comprise an insulator disposed between and secured to each of: the fixed portion of the ground electrode extender; and the radially extending bar and the remote portion of the ground electrode extender.
According to another aspect of the invention, in the adapter for use with a spark plug body and an engine block, the radially extending bar can project axially beyond the remote portion of the ground electrode extender.
According to another aspect of the invention, in the adapter for use with a spark plug body and an engine block, in the ground electrode extender, the remote portion can project axially beyond the fixed portion.
According to another aspect of the invention, in the adapter for use with a spark plug body and an engine block:
According to another aspect of the invention, in the adapter for use with a spark plug body and an engine block, the spark plug body can further comprise an annular insulator disposed between and secured to each of (i) the fixed portion; and (ii) the inner and outer rings, the outer diameter of the insulator being smaller than the outer diameter of the outer ring, to provide said annular channel between the outer ring and the fixed portion.
According to another aspect of the invention, in the adapter for use with a spark plug body and an engine block, the positive electrode extender can project axially beyond the inner ring.
According to another aspect of the invention, in the adapter for use with a spark plug body and an engine block, the inner ring can project axially beyond the outer ring.
An adapter for use with a spark plug and an engine block forms another aspect of the invention. The spark plug is of the type having a spark plug body and an electrode leg. The spark plug body defines a longitudinal axis and has: adjacent one end, a metal ring which is orientated coaxially with the longitudinal axis; a metal tube which is orientated coaxially with the longitudinal axis, extends from the ring towards the other end of the body and is externally-threaded for engagement in a corresponding threaded bore in said engine block in use; an insulator having a portion disposed inside the tube which portion extends axially, from inside the tube, beyond the ring, and has an elongate void extending axially therethrough; and an elongate positive electrode which occupies the void and extends axially beyond the insulator to a terminus which defines the one end of the body. The electrode leg has two arms transversely connected to one another, with one arm extending axially from the ring and beyond the electrode and the other arm extending radially inwardly from the one arm so as to terminate in an end portion that is axially-spaced from the terminus. The adapter is secured, in use, to said body and comprises: a positive electrode extender which, in use, is in electrically-conducting contacting relation to the positive electrode; and a ground electrode extender which, in use, is in electrically-conducting contacting relation to the electrode leg. The adapter is configured such that a spark gap defined between the positive and ground electrode extenders comprises an elongate channel which opens axially away from the body and is substantially unobstructed in the axial direction.
According to another aspect of the invention, the adapter for use with a spark plug and an engine block can be adapted for snap-fit engagement with said spark plug for use.
According to another aspect of the invention, in the adapter for use with a spark plug and an engine block, the positive electrode extender can comprise a resilient clip portion, said clip portion being defined by an open loop which has an opening smaller than the diameter of the positive electrode, which loop, for use, is orientated such that its opening presents towards the positive electrode and urged radially between the electrode leg and the positive electrode, to allow the positive electrode to enter the loop and provide for said snap-fit engagement.
According to another aspect of the invention, in the adapter for use with a spark plug and an engine block, for use, the loop can be urged towards the one arm of the electrode leg.
According to another aspect of the invention, the adapter for use with a spark plug and an engine block can further comprise a socket portion of the positive electrode extender, said socket portion being defined by a closed loop adapted to receive in tight-fitting electrically-conducting contacting relation, the positive electrode, which loop, for use, is orientated such that its opening presents towards the positive electrode, and urged between the electrode leg and the positive electrode, to widen the space between the positive electrode and the electrode leg and allow the positive electrode to enter the loop, whereupon the electrode leg springs back to provide for said snap-fit engagement.
According to another aspect of the invention, in the adapter for use with a spark plug and an engine block, for use, the loop can be urged towards the one arm of the electrode leg.
According to another aspect of the invention, the adapter for use with a spark plug and an engine block can further comprise an insulator disposed between and secured to each of the positive and ground electrode extenders.
According to another aspect of the invention, in the adapter for use with a spark plug and an engine block, the ground electrode extender can project axially beyond the positive electrode extender.
According to another aspect of the invention, the insulator can be porcelain.
A spark plug for use with an engine block forms another aspect of the invention. This spark plug comprises: a metal tube which is orientated coaxially about and defines a longitudinal axis and is externally-threaded for engagement in a corresponding threaded bore in said engine block in use; an insulator having a portion disposed inside the tube, which portion extends axially beyond the tube; a positive electrode extending through the insulator and projecting beyond the portion of the insulator that extends beyond the tube; and a ground electrode coupled to the metal tube. In this spark plug, the positive and ground electrodes are configured such that a spark gap defined between the positive and ground electrodes comprises an elongate channel which opens axially and away from said insulator and is substantially unobstructed in the axial direction.
According to other aspects of the invention, the ground electrode can be annular and can define a void having: a central portion which is occupied by the positive electrode in use; an annular channel surrounding the central portion; and a plurality of lobes, each being positioned with respect to the central portion in a manner analogous to the placement of the planet gears with respect to the sun gear in a planetary gear.
According to another aspect of the invention, the plurality of lobes can consist of seven lobes.
According to other aspects of the invention, if
R1 is the radius of each planet gear
R2 is the distance from the axis of each planet gear to the axis of the sun gear
R3 is the outer radius of the ground electrode
R4 is the outer radius of the annular channel
R1:R2:R3:R4:R5 can be about 0.12:0.305:0.475:0.25
The invention relates to the production of spark plugs having spark gap geometries characterized by the presence of at least one elongate channel which opens axially and away from the spark plug body and is substantially unobstructed in the axial direction. Other advantages, features and characteristics of the present invention, as well as methods of operation and functions of the related elements of the structure, and the combination of parts and economies of manufacture, will become more apparent upon consideration of the following detailed description and the appended claims with reference to the accompanying drawings, the latter being briefly described hereinafter.
By way of background, a spark plug 100 according to the prior art is illustrated in side elevation in
The plug body 102 defines a longitudinal axis X-X and has a metal ring 104, a metal tube 106, an insulator 108 and an elongate positive electrode 110. Metal ring 104 is adjacent one end 114 of the plug body 102 and is orientated coaxially with the longitudinal axis X-X. The metal tube 106 is orientated coaxially with the longitudinal axis X-X, extends from the ring 104 towards the other end 112 of said body 102 and is externally-threaded for engagement in a corresponding threaded bore in said engine block in use (not shown). The insulator 108 has a portion 116 disposed inside the tube 106, which portion 116 extends axially, from inside the tube 106, beyond the ring 104, and has an elongate void 118 extending axially therethrough. The positive electrode 110 occupies the void and extends, from a terminal 120 at the other end 112 of the body 102, axially beyond the insulator 108 to a terminus 122 which defines the one end 114 of said body 102.
The electrode leg 124 has two arms 126,128 transversely connected to one another, with one arm 126 extending axially from the ring 104 and beyond the electrode 110 and the other arm 128 extending radially inwardly from the one arm 126 so as to terminate in an end portion 130 that is axially-spaced from the terminus 122.
Against this backdrop, a method of producing a spark plug according to an exemplary embodiment of the present invention is hereinafter described.
In the method, a conventional spark plug body is utilized, as will be evident upon comparison of
The spark plug body 102 utilized in this exemplary embodiment may be obtained by removing the electrode leg from a conventional spark plug, procured, for example, through automotive supply retailers. Alternatively, the spark plug body 102 may, for example, be obtained via a custom order from a spark plug manufacturer.
In addition to the spark plug body, the method involves the use of an adapter 20, such as that shown in
Once a suitable spark plug body and an adapter have been obtained, the exemplary method comprises the step of securing the adapter 20 to the spark plug body 102. In the adapter 20 shown in
Once secured, positive electrode extender 22 is in electrically-conducting contacting relation to positive electrode 110 and ground electrode extender 36 is in electrically-conducting contacting relation to the metal ring 104.
In the adapter illustrated in
As shown in
The insulator 40 comprises an annular disc portion 34, through which the positive electrode extender 22 passes and which is disposed between: the fixed portion 30; and the inner 24 and outer 26 rings. The outer diameter of annular disc portion 34 is smaller than the outer diameter of the outer ring 26, to define an annular channel 32 between the outer ring 26 and the fixed portion 30. As best seen in
In this arrangement, a spark gap 50 defined between the positive 22 and ground 36 electrode extenders comprises:
Another adapter is shown in
Seven further embodiments of this adapter are shown in
In another exemplary embodiment, the invention can be carried out with a conventional spark plug, i.e. which includes the electrode leg. An example of an adapter 206 used in this embodiment is illustrated in snap-fit engagement with a conventional spark plug 212 in
Seven further embodiments of this adapter are shown in
As another alternative utilizing conventional spark plugs, ring-lock type adapters, as hereinafter described, can be provided. In this alternative, the adapter can further comprise a socket portion of the positive electrode extender, said socket portion being defined by a closed loop adapted to receive in tight-fitting electrically-conducting contacting relation, the positive electrode. As shown by the sequence of
Each of the illustrated positive 302 and ground 304 electrode extenders has portions on both sides of the substrate 310, connected via plated through-holes 350 as previously mentioned, which portions are configured that a spark gap 500 defined between the positive 302 and ground 304 electrode extenders comprises an elongate channel which opens axially away from the body and is substantially unobstructed in the axial direction.
In each of the embodiments illustrated herein, the insulator, i.e. 40/202/310 may comprise porcelain, or other suitable materials, and the positive 22/200/302 and ground 36/204/304 electrode extenders may comprise copper, or other conductive materials.
Testing has been carried out of spark plugs according to the invention. The testing involved the use of a pair of 2007 Chevrolet Silverado Extended Cabs with 4800 Vortec® Engines. Modifications were made to the vehicle fuel tanks, to permit to permit the tanks to be easily drained; otherwise, the vehicles were utilized in “stock” condition (but for the spark plugs of the present invention, as indicated in the table.) In each test, the vehicles were filled with fuel and driven along a controlled access highway along a common route, with cruise-control locked at 100 km/hr. At the completion of the run, the tanks were refilled; the amount of fuel that was required to be added to refill the tank equates to the amount of fuel consumed during the test.
The test results are reproduced below in Table 1:
As evident from the test results, spark plugs according to the invention can have advantageous impacts on fuel mileage. Without intending to be bound by theory, it is believed that this advantage may flow from the presence of spark gap geometries characterized by the presence of at least one elongate channel which opens axially and away from the spark plug body and is substantially unobstructed in the axial direction, in contradistinction, for example, to conventional spark plugs as illustrated in
Whereas twenty-one exemplary embodiments of the invention are herein illustrated and described, of three general types, it will be evident that further modifications can be made, both in terms of shape/geometry, size and manner of connection.
A yet further variation is shown in
However, this structure differs in the elongated channel is defined by a void having: a central portion 606 which is occupied by the positive electrode in use; an annular channel 604 surrounding the central portion; and a plurality, namely, seven lobes 602, each being positioned with respect to the central portion in a manner analogous to the placement of the planet gears with respect to the sun gear in a planetary gear. In terms of the specific geometry of the illustrated structure, and with reference in part to the notional planetary gear, if:
R1 is the radius of each planet gear
R2 is the distance from the axis of each planet gear to the axis of the sun gear
R3 is the outer radius of the ground electrode
R4 is the outer radius of the annular channel
then R1:R2:R3:R4:R5 is about 0.12:0.305:0.475:0.25
To so use structure 600, it is welded to the ring 104 in a manner such that the structure surrounds the positive electrode terminus 122 in spaced relation. A structure of this type, constructed from 12 GA CRS, and sized to provide a 0.40 mm spark gap, has been extensively tested with a 2011 GMC Siena 4×4 Crew Cab, with a 4.8 L engine.
The test results are tabulated below in Table 2 and show two types of tests: ROAD type and DYNO type.
In the ROAD type tests, the test vehicle was driven, under similar driving conditions, twice along a common route [a small variation in distance travelled in one of the tests was associated with local road conditions] and measurements of fuel consumption and distance travelled were made.
In the DYNO type test, the vehicle was loaded on a dynamometer and driven from rest at 100 km/hr until the engine reached a predetermined threshold temperature, and measurements of distance travelled and fuel consumed were made.
In Table 2, the terms indicated below having the meanings attributed thereto:
In view of the above, it will be evident that the structure of
Yet further variations are possible. Accordingly, it should be understood that the invention is to be limited only by the accompanying claims, purposively construed.
This application is a Continuation of application Ser. No. 14/233,522 filed on Apr. 28, 2014, which is a National Phase of Application PCT/CA2011/001184 claims the benefit of U.S. Provisional Application 61/509,270 filed on Jul. 19, 2011.
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Number | Date | Country | |
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20150194791 A1 | Jul 2015 | US |
Number | Date | Country | |
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61509270 | Jul 2011 | US |
Number | Date | Country | |
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Parent | 14233522 | US | |
Child | 14662371 | US |