US 3311100 A
Description (OCR text may contain errors)
R. ,J. MADDALOZZO I 3,311,100
TEMPERATURE COMPENSATED FUEL INJECTION PUMP March 28, 1967 2 Sheets-Sheet l Filed NOV. 18, 1964 INVENTOR. RAYMOND JMADDALOZZO NW k March 28, 1967 R. J. MADDALOZZO 3,311,100
TEMPERATURE COMPENSATED FUEL INJECTION PUMP 2 Sheets-Sheet 2 Filed Nov. 18. 1964 Qm N AR Wm wl MW Rs INVENTOR. R AYMOND J. MADDALOZZO United States Patent g" oration of Delaware P Filed Nov. 18, 1964, Ser. No. 411,899
7 Claims. (Cl. 123-140) The present application relates to temperature compensated fuel injection, and particularly to a fuel m ect on pump having means for increasing the fuel delivery setting of the pump as fuel temperature increases.
Speed sensitive, fuel supplying apparatus for a d1esel engine as herein contemplated has means which, in the usual manner, is operatively connected to the eng ne crankshaft and operatively connected to a fuel injection pump for controlling the quantity of fuel pumped to the engine cylinders; the means referred to lncludes a movable member, usually a governor arm, and a stop mechanism to limit travel of the governor arm in the rated load position.
One disadvantage of such apparatus is that m1nor drop off of pump pressure or a minor reduction in fuel rate, or both, cause the power output of the engine to decrease at certain times, when governor arm movement has ceased in the fuel increasing direction because of the limitation imposed by the stop mechanism.
It has been found that under a rising temperature condition, fuel density decreases and it is desirable that the fuel weight per pumping stroke be restored back to a rated reference value. Also, the fuel viscosity decreases and it is equally desirable that the fuel pressure be restored back to a rated reference value. My invention directly senses the temperature of fuel being discharged on the pumping stroke and continuously controls ad ustment of the stop mechanism as a function of that temperature, so as to keep the engine power output matched to the load as now will be explained.
Various features, objects, and advantages will either be specifically pointed out or become apparent when, for a better understanding of my invention, reference is made to the following description taken in conjunction with the accompanying drawings which show a preferred embodiment thereof, and in which:
FIGURE 1 is a longitudinal sectional view of a rotary distributor, fuel injection pump embodying the present 1nvention;
FIGURE 2 is a front face, elevational view of the pump governor arm, taken along the transverse section lines II-II of FIGURE 1; and
FIGURE 3 shows the governor arm in side elevational view corresponding to FIGURE 1, and is taken along the section lines IIIIII of FIGURE 2.
More particularly in the drawings, the housing or casing for the injection pump device shown has three bolted together sections consisting of a pump housing 12 at one end, a primary pump housing 16 at the opposite end, and a so-called distributor head housing 14 assembled between the end sections or housings. An engine connected pump shaft 18 extends longitudinally through the device and is journalled for rotation in spaced apart roller and sleeve bearings 20 and 22, respectively, fixed in the main housing 12 and in the distributor head housing 14. The particular fuel injection device illustrated is intended for a six cylinder, four stroke cycle, solid injection diesel engine, in which case the pump shaft 18 is driven in time to the engine and at a proportionate speed to crankshaft speed, specifically, at one-half crankshaft speed.
A control lever assembly shaft 24 is supported in trans- 3 ,31 1,100 Patented Mar. 28, 1967 "ice verse disposition in the upper portion of the pump housing 12. The shaft 24 carries an operators control lever 26 (FIGURE 2) and rotates in bearings in the housing in response to movement of the control lever. A governor arm 28 has a bored, tubular mid-portion which r-otatably receives the shaft 24 and which functions as a bearing enabling the arm 28 and the supporting shaft 24 to relatively rotate with a rocking motion independently of one another.
The governor arm 28 includes first and second upstanding arm portions 30 and 32 and 21 depending arm portion 34. The governor arm 28 carries a roller 36 on the depending arm portion 34 for engaging and setting the position of a governor sleeve 38 which establishes the fuel rate. The governor arm 28 is controlled by a compression spring 40 which engages the second upstanding arm portion 32, and by an assembly of governor weights 42 which transmit force thereto through a governor sleeve cup 43, the governor sleeve 38, the roller 36, and into the depending governor arm portion 34.
Stop mechanism, generally indicated at 44, is carried in part by the first upstanding governor arm portion 30, and in part by a mounting pad 46 inside the pump houslng 12 so as to be in the path of and to limit rocking movement of the governor arm 28 in the fuel increasing direction. The predetermined maximum fuel movement is confined to the range of a gap G between the rear face of the first upstanding arm portion 30 and the adjacent front face of a torque range upper limit torque screw or stop screw 48. The stop screw 48 is the fixed part of the mechanism against which a spring pressed plunger 50 bottoms when the governor arm moves in a fuel increasing direction between the rated load and overload positions. The first upstanding arm portion 30 is the moving part of the stop mechanism, threadably receiving therein a right hand bolt member 52 which has limited movement in its threads when rotated. The bolt member can be readily reversed in its location so that, without change or impairment of its function, the bolt member can be carried by the fixed part 48 and operatively engage the moving part or portion 30. In any. case, the member 52 is automatically adjusted as will now be explained.
The bolt member 52 has a head at the rear end and, when the upstanding first arm portion moves from the engine idle position indicated by the broken lines 30d into the solid line position shown in FIGURE 3, the head engages the plunger 50. The forward end of the member 52 is fiat at the side, and has secured thereto by means of a headed fastener 54 the inner end of a bimetal spiral fiat spring 56. The spiral spring 56 is a right hand coil as viewed in- FIGURE 2 and the outer end is secured by a headed fastener 58 to the base of the first upstanding governor arm portion 30.
The pump housing 12 stays full of fuel, the body of such fuel 60 being continually replenished with a circulating stream of fuel freshly discharged on the pumping stroke of the device. The bimetal element or spring 56 is therefore constantly submerged in and forced to remain precisely at the temperature of fuel discharged on the pumping stroke. -The density decreases when the fuel is heated, and the delivered fuel weight per effective pumping stroke becomes proportionally less with the resulting increases of fuel volume per unit of fuel weight. The internal leakage also increases when the fuel is heated, because fuel viscosity reduces and more fuel leaks past the pump plungers on a pumping stroke. Hence, the pumping becomes less effective for two reasons, and the shrinkage of fuel weight per stroke must be compensated for by lengthening the effective stroke between the timing port point-of-cutoff and the metering port point-of-spill.
When there is a rise in the fuel temperature, heating and coiling the bimetal spring 56 by a like amount, the spring 3 element reduces in its outside diameter to take the position shown by the broken lines 56b in FIGURE 2, thus relatively rotating the bolt member 52 in the arm portion 30 so that the arm portion moves out of the plane of the paper. towards the viewer. In other words, the
arm portion 30 takes the rearward position indicated by and the fuel governor sleeve 38 takes a reduced fuel 7 setting toward the rear.
There are several driven components within the housing 10 of the present fuel injector device, the power input being the torque applied to a gear 62 on the shaft 18, the gear being operated by the engine at a proportionate speed already indicated, e..g., one-half of the crankshaft speed. i
A governor component comprises the 'flyweights 42, the governor sleeve cup 4-3 engaged by the flyweights, and a transversely disposed shaft 64 carried by the pump shaft 18 and rotatably supporting the flyweights 42 so that they freely revolve about the shaft 18 and freely rotate about the shaft 64.
The control component includes the control lever assembly shaft 24,.a cam, not shown, connected between the shaft 24 and a pivotal control arm 66, and a tensioned yoke connection (not shown) between the upper end of the arm 66 and a spring seat 68 for adjusting the compression in the compression spring 40. Operation of the control lever (appearing at 26, FIGURE 2) so as to move the spring seat 68 to the right as viewed in FIGURE 1, applies more spring pressure to the governor arm 28 causing it to advance the fuel setting; movement of the spring seat 68 in a direction leftwardly as viewed in FIGURE 1 allows the spring 40 to move in that direction and reduces the pumped quantity of fuel by reducing the fuels setting.
A maximum torque control component includes the stop mechanism 44. By application of a tool to the right hand end' of the stop screw 48 as viewed in FIGURE 1, the screw can be axially adjusted in its threads to increase or decrease the available gap G. The spring biased plunger- 50 is shown in the rated loaded position in FIGURE 3, whereas it appears in the overload position bottomed against the stop screw 48 in FIGURE 1. In orderto have any effect, the overload on the engine must give rise 1 to sufficient pressure on the governor arm 28 to overcome theforce of the helical coil, biasing spring illustrated within the plunger 50, and the amount by which the overload condition can be ultimately extended is limited by the position of the stop screw 48.
Atiming plate assembly component 70 is carried in part on the inside of the pump housing 12 and carried in part on the governor sleeve 38 to which a cam stud 72 'is mounted. An automatic device '74 can be provided which is connected into the timing plate assembly for automatically advancing the timing under certain conditions of engine operation.
A dual sleeve component includes a timing sleeve '76 which rotatably receives the pump shaft 18, also the governor sleeve 38 which is between the governor component and the timing sleeve 76, and an alignment pin -7 8 connected between the sleeves 38 and '76 holding them so as to be nonrotatable but relatively axially movable to one another. The timing sleeve 76 has a connection, not shown, to the pivoted control arm 66, also known as a spring 1 arm 66. v
which is intersected at one end by first transverse passages terminating in metering ports 82 and by second transverse passages terminating in timing ports 84 (FIG- URE 3). The angular position into which the timing sleeve '76 is relatively rotated establishes the point at g which the timing ports 84 rotate past a longitudinally extending spill groove 86 in the sleeve, thus interrupting the spillageof pumped fuel from the passage 80 and initiating fuel injection to the cylinders according to their sequence in the firing order. The angular and axial position into which the governor sleeve 38 is set by the timing component and by the governor component, respectively, establishes the point at which the metering ports 82 rotate into registry with a helical spill groove 88 in the sleeve to spill the pumped fuel from the passage 80', thus terminating fuelflow each time after a predetermined metered quantity of fuel has been delivered to the nozzles at the cylinders.
A pumping component which is located in the so-called distributor head housing 14 comprises a transversely disposed, generally cylindrically shaped pump chamber 90 formed in the shaft 18 and communicating with the passage 80, a pair of rotary and reciprocating plungers '92 slidably received in the opposite outer ends of the chamber 90, a cam ring 94 fixed in the housing 14 in the plane of the plungers 92, a pair of rotary and reciprocating cam followers or rollers 96 which ride along a set of six inwardly protruding cams on the ring 94, and an interposed tappet 98 connecting each roller to a different one of the plungers 92 so that the plungers will periodically compress and then release an interposed spring 100 on respective pumping and suction strokes.
A distributor component comprises a retraction valve 102 connected in the longitudinal passage 80 so as to unseat or open in a direction away from the pump component, a set of suction ports 104 which intersect the passage 80 on the pump side of the valve 102 and which periodically communicate with an annular chamber 106 which holds the so-called transfer fuel in the housing 14, a distributor port 108 which intersects the passage 80' on the opposite side of the valve 102 and which, during two revolutions of the engine crankshaft, communicates at uniformly spaced apart intervals with each of six housing passages 109, and a set of fuel lines 112 leading from the six housing passages to the respective nozzles in the cylinders of the engine, not shown.
A primary pump component within the housing 16 includes a spur gear transfer pump mechanism 110 journalled in the housing 16, and a longitudinally disposed pump shaft 112 having a square or hexagonal head 114 at one end coupled in a socket in the shaft 80, and having a fork-shaped opposite end 116 coupled to the mechanism 110 for operating the primary or transfer pump.
The structure, operating principles, ports interrelationship, and overall theory regarding the several components of the pump device are detailed in Shallenberg US. Patent No. 2,947,299. Those details of the components and other common subject matter as disclosed in the patent are incorporated herein by reference.
Briefly, diesel fuel from a tank 118, which fuel is ultimately drawn into the pump chamber 90, flows in a path including a fuel tank outlet conduit 120, a transfer intake port 122 which is in the housing 16 and which communicates with the suction side of the spur gear transfer pump mechanism 110, a transfer outlet port 124 which communicates with the pressure side of the mechanism 110, a transfer conduit 126 leading from the outlet port 124 and including therein a final filter 128, the annular chamber '106, a communicating passage 130 in the housing 14 which is connected during shaft rotation to the suction ports 104 in periodically timed relation, a set of diagonal intake passages 132 formed in the shaft 18, and thence into the pump chamber 90.
On the discharge stroke of the pump plungers, the fuel follows a sequence of separate flow in a three-way split path. During predetermined initial collapsing movement of the plungers 92 toward one another, fuel escapes into the pump housing 12 through the spill slot 86 until the spill is cut off by the sleeve 76 covering the timing port 84. During further collapsing movement of the plungers 92, fuel pressure increases so as to open the retraction valve 102 and thereby allows fuel to be forced through the registering one of the nozzle lines 112. During final, radi-ally inward collapsing movement of the plungers 92, the spill slot 88 registers with a metering port 82 so as to spill the balance of the pumped fluid into the pump housing 12.
Excess fuel from the constantly replenished body of fuel 60 in the housing 12 passes in the main in a path through a threaded outlet 134 in the top of the housing, through an orifice (not shown) restricting a return conduit 136, and through the return conduit 136 so as to be returned to the fuel tank 118. The balance of excess fuel causes a positive internal pressure in the range of 6-15 p.s.i. in the pump housing 12 and thereafter escapes through a spring loaded recirculation valve (not shown) connected between the housing 12 and the suction side of the spur gear transfer pump mechanism 110; thus such balance of the excess fuel is directly recirculated by the transfer mechanism 110.
The coiled strip bimetal element carried by the governor arm hereof, and particularly the mounting structure for that element, are believed novel. The coil construction affords multiplied length whereby the element at the inner end produces large movement with small temperature changes at the higher temperatures. The offset between the fastener 58 at the outside ofthe bimetal element, and the fastener 54 in the center of the element at the flat side of the bolt member 52 affords high torque leverage for the element both in turning the member 52 and in resisting reaction or reverse movement of the memher 5 2. Finally, the threads connecting the member 62 and the first arm portion 30 of the governor arm introduce a high mechanical advantage enabling the bimetal element to drive in the direction of the bolt as output member, but affording an irreversible drive connection whereby axial th-r -usts introduced into the bolt are ineffective to turn the bolt from the position set by the bimetal element. In a word, the bimetal element hereof is not in the direct force transmitting path of the stop mechanism, and hence is not a working or physically stressed member at the joint.
In one physically constructed embodiment of the invention, the bimetal element had an imperceptible effect on the engine below 80 F. At or above 80 F., the bimetal element markedly contracted in diameter with temperature increases up to the maximum Working temperature encountered in the fuel. The total angular travel of the element at its inner end was 216 and, due to the mechanical advantage, the total bolt member travel was 0.019" in the axial direction as a result of the 216 rotation. There were eight coil turns in the spiral. Irrespective of the fuel temperatures in excess of 80 F.,the rated load power output of the engine was maintained and, under overloading, the overload power output was maintained. No loss of calibration or requirement for recalibration was needed, because of the excellent repeatability of operation due to having the element in the present structurally unstressed mounting.
What is claimed is:
'1. Fuel control mechanism for providing different fuel settings for an engine, said mechanism comprising:
first and second cooperating parts between which an operative gap is maintaind for adjustment purposes and which control the fuel setting in accordance with the amount of gap maintained;
one of said parts carrying an associated bolt member capable of limited threaded adjustment with respect thereto and engageable with the means on the other part to control the amount of gap; and
a spiral, bimetal spring strip to adjust the amount of gap and having a fixed outer end anchored to said one part and having a free inner end drivingly connected to the associated bolt member to rotate the bolt member and change the gap;
said spring strip having at least approximately four coil turns, and winding and unwinding as the fuel temperature changes, in a manner to adjust the axial position of the bolt member for changing the gap to permit movement in a fuel increasing direction when the fuel temperature increases, and vice versa.
2. Fuel control for providing different fuel settings for an engine, said fuel control comprising:
a. chamber for holding fuel;
mechanism disposed in said chamber at a level at least below the normal fuel level and comprising first and second cooperating parts between which an operative gap is maintained for adjustment purposes and which control the fuel setting in accordance with the amount of gap maintained;
one of said parts carrying an associated screw member capable of limited threaded adjustment with respect thereto and engageable with contact means on the other part to control the amount of gap; and
a spiral, bimetal flat spring immersed in the fuel having a fixed end anchored to said one part and having a free end connected to the associated screw member to rotate the screw member and change the gap, said spring winding and unwinding to change the gap as the fuel temperature changes, in a manner to adjust the position of the screw member in a fuel increasing direction when the fuel temperature increases and in a fuel decreasing direction when the fuel temperature decreases.
3. In the fuel system of a diesel engine:
means operatively connected to the engine crankshaft and operatively connected to a fuel injection pump for controlling the quantity of fuel which the pump delivers to the engine cylinders, said means comprising governor and governor sleeve and governor arm mechanisms;
means comprising stop mechanism to limit the quantity of fuel and establishing with the first named means an operative gap, the two-named means having thereon respective first and second cooperating parts between which the operative gap is maintained for adjustment purposes and which control the fuel setting in accordance with the gap maintained;
the second part being on the stop mechanism and comprising a support;
the first part comprising an arm portion on the governor arm mechanism and movable therewith, said first part carrying an associated screw member capable of limited threaded adjustment with respect thereto and engageable with contact means on the other part to control the gap length;
means comprising a screw rotating, temperature responsive element connected between said first .part and its associated screw member to adjust the position of the screw member in a fuel increasing direction when the fuel temperature increases and in a fuel decreasing direction when the fuel temperature decreases; and, in combination with all of the foregoing a chamber common thereto and adapted to befilled with fuel so that all structures within the chamber are submerged in fuel.
4. The invention of claim 3,
said governor sleeve mechanism comprising a rotating pump shaft having spill port means for discharging at least a portion of fuel pumped on each stroke of the fuel injection pump; and
at least one sleeve encircling the shaft having relatively fixed spill slot means which, during each pumping stroke, register at one or more times with the spill Z port means and direct the discharged fuel so as to keep said chamber filled in a manner constantly displacing the existing fuel therein with freshly pumped fuel. I 5. Fuel pump control mechanism providing different fluid output settings, said mechanism comprising:
first and second cooperating parts between which an operative gap is maintained for adjustment purposes and which control the pump setting in the high power range in accordance with the gap maintained;
each of saidparts carrying an associated member capable of limited movement with respect thereto and engageable with the member on the other part to control the length of gap; and
two springs each connected between a different one of said parts and its associated member so as to provide a bias for moving the members;
the spring on the first part comprising a spiral coil,
fiat, bimetal spring, and the associated member comprising abolt member which is rotated by the bimetal spring to change the gap length;
said first part carrying the bolt member threaded thereto so as to relatively axially move in its threads in response to rotation, and having the spring fixed at one end of the spiral to the first part and connected at the free end to the bolt member for screwing the bolt member so as to change the gap length in response to temperature changes;
the-associated member on the second part comprising a plunger, and the spring comprising a helical coil, return spring biasing the plunger in a gap-opening direction relative to the second part.
6. In a fuel pump control providing different fluid output settings and including a governor arm part, mechanism therein which comprises:
first and second cooperating parts between which an operative gap is maintained for adjustment purposes and which control the pump setting in the high power range'in accordance with the gap length maintained, one of the parts comprising a governor arm part;
each of said parts carrying an associated member capable of limited movement with respect thereto and engageable with the member on the other part to control the length of gap; and
a spring on the governor arm part comprising a spiral coil, flat, bimetal spring, the associated member on the governor arm part being connected to the bimetal spring and comprising a bolt member Which is rotated by the bimetal spring to change the gap length;
the governor arm part carrying the bolt member threaded thereto so as to relatively axially move in its threads in response to rotation, and having the spring fixed at one end of the spiral to the governor arm part and connected at the free end to bolt member for screwing the bolt member so as to change the gap length in response to temperature changes.
7. In a fuel pump control providing different fluid output settings and including a governor arm part, mechanism therein which comprises:
first and second cooperating parts between which an operative gap is maintained for adjustment purposes and which control the pump setting in the high power range in accordance with the gap length maintained, one of the first and second parts comprising a governor arm part;
each of said parts carrying an associated member capa- Me of limited movement with respect thereto and engageable with the member on the other part to control the length of gap; and
two springs each connected between a different one of said parts and its associated member so as to provide a bias for moving the members;
the spring on the governor arm part comprising a spiral coil, fiat, bimetal spring, and the associated member on the governor arm part comprising a bolt member which is rotated by the bimetal spring to change the gap length;
the governor arm part carrying the bolt member threaded thereto so as to relatively axially move in its threads in response to rotation, and having the spring fixed at one end of the spiral to the first part and connected at the free end to the bolt member for screwing the bolt member so as to change the gap length in response to temperature changes.
References Cited by the Examiner UNITED STATES PATENTS 2,790,432 4/1957 Shallenberg et al. 123-139 2,836,162 5/1958 Dressler 123-140 2,895,465 7/ 1959 Humber et al. 123-140 2,965,087 12/1960 Bischofr et al. 123l40 3,096,716 7/1963 Chmura 123-1403 X MARK NEWMAN, Primary I Examiner. LAURENCE'M. GOODRIDGE, Examiner.