CA1212591A - Engine governor with reference for throttle limiter - Google Patents
Engine governor with reference for throttle limiterInfo
- Publication number
- CA1212591A CA1212591A CA000432299A CA432299A CA1212591A CA 1212591 A CA1212591 A CA 1212591A CA 000432299 A CA000432299 A CA 000432299A CA 432299 A CA432299 A CA 432299A CA 1212591 A CA1212591 A CA 1212591A
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- Canada
- Prior art keywords
- throttle
- speed
- engine
- motor
- contact
- Prior art date
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Abstract
ABSTRACT
An engine speed governor is provided for exercising overriding control on a throttle regulating the flow of fuel to the engine. A reversible motor is coupled to the over-riding throttle control means to drive it in a closed throttle direction or an open throttle direction. An electronic circuit is provided controlling the motor for operation at respective high or low speeds according to the speed of the motor and the position of the throttle relative to a reference position. The motor operates at its higher speed until the reference position is reached and thereafter at a lower speed, the lower speed being such that it is slower than the response capability of the engine to a change in throttle position, thus minimizing engine speed oscillation.
An engine speed governor is provided for exercising overriding control on a throttle regulating the flow of fuel to the engine. A reversible motor is coupled to the over-riding throttle control means to drive it in a closed throttle direction or an open throttle direction. An electronic circuit is provided controlling the motor for operation at respective high or low speeds according to the speed of the motor and the position of the throttle relative to a reference position. The motor operates at its higher speed until the reference position is reached and thereafter at a lower speed, the lower speed being such that it is slower than the response capability of the engine to a change in throttle position, thus minimizing engine speed oscillation.
Description
Back~round of the Invention The background of engine governors in general, and a full disclosure of my previous invention in combined engine and load speed governors, is contained in my u.S. ~atent ~o. 4,1~1,103 iss~led on January 1, 1930. My aforesaid engine governor was of a dyna-mically-surging type which allowed engine speed to oscillate rather rapidly (and forcefully for a vehicle in a lower gear ratio) about its predetermined limit.
While such oscillations are not damaging to the engine and may be helpful in encouraging a truck driver to "get out" of a lower ~ear ratio and into a higher ratio where the engine will be operating more efficiently, it is also advantageous to have an engine governor which allows the engine to be accelerated to its predetermined speed limit with less overshoot beyond that limit than provided by my previous ~ynamically-surging governor, and which will thereafter bring the engine quickly to run in close approximation to the predetermined speed limit, wandering from it only perhaps 1% when in a very low gear and less in higher gears, and that probably not on any cyclical basis. Such action is obtained basically by positioning the engine throttle to a pre-determined reference position upon acceleration of the engine to a predetermined speed and actuation of the engine governor there-by, rather than by driving the throttle toward a full-closed position as in my previous patent application aforesaid.
Such a smooth and gentle control is advantageous for full economy, and for driver and/or passenger comfort, especially for an application such as a school ~us engine, and is typical of my present invention which provides such an engine speed governor and also com~ines it with a load speed governor essen-tially likc that oi my aforesaid patent. The 12~5~
present combination functions to safely control engine and load speeds generally like the combination of my aforesaid patent, except smoothly, without the previously~experienced dynamic-surging in engine speed control mode.
Like my previous invention, the apparatus of the present invention is a standard unit which may be connected to the standard carburetor, i~nition system, and speedometer cable of any engine and vehicle, so that it may be applied at the fac-tory or in the field without inconvenience, and spare parts for this apparatus will be the same for any engine-vehicle combina-tion. However, my present invention also contemplates the use of a lost-motion type overriding carburetor linkage (in place of the equally usable linkage-lengthening capsule disclosed in my aforesaid patent~ which gives a more conventional feel to the accelerator pedal, but with a more complicated parts situation, since each different engine-carburetor combination may require different linkage parts and adaptations. Also, use of a conventional pulse generator connected to the tachometer drive of a Diesel engine is contemplated for application of the apparatus of the present invention thereto.
_mmary of the Invention In an engine speed governor for an engine having a throttle movable between an open throttle position and a closed throttle position for regulating the flow of fuel to the engine, said governor being of the type comprising an overriding throttle closing~means, engine speed sensing means for produc-ing a speed signal, and control means for moving the throttle ~z~
closing means to a position for limiting the engine speed to a predetermined governed value, the improvement wherein said con-trol means includes actuating means including a reversible motor coupled with the overriding throttle closing means for driving it in the close throttle direction or the open thrott~
direction, electronic circuit means coupled with said speed sensing means and with said motor for energizing the motor, said circuit including means responsive to a predetermined speed signal for energizing the motor for relatively high speed operation in the close throttle direction until the overriding throttle closing means reaches a reference position, said circuit means including means for energizing the motor for relatively low speed operation in either the close throttle or open throttle direction after the overriding throttle closing means reaches said referance position, said low speed operation of the motor being slow~rthan the response capability of the engine to a change in flow of fuel to the engine whereby engine speed oscillations are minimized.
Preferably, the actuating means includes first and second stationary electrical contacts and a movable electric contact which is movable concurrently with said overriding throttle closing means, said movable contact being sequential-ly engaged with said first contact, neither of said contacts and then with said second contact when the overriding throttle limiting means moves from wide open throttle position to close throttle position, said first contact being connected with said circuit means for causing it to energize the motor for high speed operation when said first contact is engaged by said ,,/,~.'.~., ~
movable contact and for causing it to energize the motor for low speed operation when said first contact is disengaged by said movable contact, said second contact being connected with said circuit means for causing it to stop the motor when said second contact is engaged by said movable contacts, said cir-cui*means being operative to reversibly energize said motor at said slow speed in accordance with changes in said speed sig-nal.
Further features of the invention will become appar-ent from the following description with xeference to theaccompanying drawings.
Figure 1 is a diagrammatic view showing the engine and load speed governor of the present invention connected to a transmission, carburetor linkage, and accelerator pedal of an engine connected to vehicle wheeIs by the transmission;
Figure 2 is a diagrammatic view showing mechanical details of the governor proper;
Figure 3 shows the throttle linkage of Figure ~ in a different configuration;
Figure 4 found on.the same sheet as Figure 7, shows the switch plate o the present governor as connected to the electronic control portion thereof; :
Figure 5 shows a schematic circuit diagram of an electronic control providing for positioning the throttle-limiting at a reference position;
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Figure 6 shows a schematic circuit diagram of the portion o~ an alternate electronic circuit providing slow motion of the throttle-limitiny means in one direction; and .. ... _ .. . .
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Fig. 7 shows a schematic diagram of a portion of an electronic circuit providing slow motion of the throttle-limiting means as desirea.
Description of the Preferred Embodiment In the illustrated preferred embodiment, as shown schematically in Fig. 1, an internal combulstion engine 20 has connected thereto a transmission 22 or driving a load 24 such as the drive wheels of a truck. The transm.ission 22 is of the usual con~truction which allows automatic or ma~lual shifting of the gears therein t~ provide various ratios of speeds ~etween the engine 20 and the load 24. Typically, in a truck, the ~ransmission 22 is sh.ifted into "low gear" to start the load 24 moving at very low speeds, as from a standing start, so that the engine 20 can operate at a rotational speed of thousands of revolutions per minute, where it operates most efficiently, while the load 24 is eased into motion by a friction clutch or hydraulic connection (not shown) included in the transmission 22, and a very large torque is applied through the gearing of the transmission 22 to the axle 26 of the drive wheels 28 of the load 24, it ~eing understood that the engine 20 and the transmission 22 are attached to and part of the load 24. As the drive wheels 28 pick up speed, and before the engine 20 reaches some safe limit to its.short term rotational speed, such as 4,400 rpm for example, it is desirable to shift the transmission 22 into a "higher gear" ratio where the wheels 28 will turn at a higher rpm relative to the engine 20, and the power of the engine 20 will be applied through the transmission 22 to the wheels 28 to farther accelerate their speed until the engine 20 again approaches its safe rotational speed. This process of accelerating the engine 20 toward its maximum speed and shifting into a "higher gear" continues until the wheels 28 are d~iving the
While such oscillations are not damaging to the engine and may be helpful in encouraging a truck driver to "get out" of a lower ~ear ratio and into a higher ratio where the engine will be operating more efficiently, it is also advantageous to have an engine governor which allows the engine to be accelerated to its predetermined speed limit with less overshoot beyond that limit than provided by my previous ~ynamically-surging governor, and which will thereafter bring the engine quickly to run in close approximation to the predetermined speed limit, wandering from it only perhaps 1% when in a very low gear and less in higher gears, and that probably not on any cyclical basis. Such action is obtained basically by positioning the engine throttle to a pre-determined reference position upon acceleration of the engine to a predetermined speed and actuation of the engine governor there-by, rather than by driving the throttle toward a full-closed position as in my previous patent application aforesaid.
Such a smooth and gentle control is advantageous for full economy, and for driver and/or passenger comfort, especially for an application such as a school ~us engine, and is typical of my present invention which provides such an engine speed governor and also com~ines it with a load speed governor essen-tially likc that oi my aforesaid patent. The 12~5~
present combination functions to safely control engine and load speeds generally like the combination of my aforesaid patent, except smoothly, without the previously~experienced dynamic-surging in engine speed control mode.
Like my previous invention, the apparatus of the present invention is a standard unit which may be connected to the standard carburetor, i~nition system, and speedometer cable of any engine and vehicle, so that it may be applied at the fac-tory or in the field without inconvenience, and spare parts for this apparatus will be the same for any engine-vehicle combina-tion. However, my present invention also contemplates the use of a lost-motion type overriding carburetor linkage (in place of the equally usable linkage-lengthening capsule disclosed in my aforesaid patent~ which gives a more conventional feel to the accelerator pedal, but with a more complicated parts situation, since each different engine-carburetor combination may require different linkage parts and adaptations. Also, use of a conventional pulse generator connected to the tachometer drive of a Diesel engine is contemplated for application of the apparatus of the present invention thereto.
_mmary of the Invention In an engine speed governor for an engine having a throttle movable between an open throttle position and a closed throttle position for regulating the flow of fuel to the engine, said governor being of the type comprising an overriding throttle closing~means, engine speed sensing means for produc-ing a speed signal, and control means for moving the throttle ~z~
closing means to a position for limiting the engine speed to a predetermined governed value, the improvement wherein said con-trol means includes actuating means including a reversible motor coupled with the overriding throttle closing means for driving it in the close throttle direction or the open thrott~
direction, electronic circuit means coupled with said speed sensing means and with said motor for energizing the motor, said circuit including means responsive to a predetermined speed signal for energizing the motor for relatively high speed operation in the close throttle direction until the overriding throttle closing means reaches a reference position, said circuit means including means for energizing the motor for relatively low speed operation in either the close throttle or open throttle direction after the overriding throttle closing means reaches said referance position, said low speed operation of the motor being slow~rthan the response capability of the engine to a change in flow of fuel to the engine whereby engine speed oscillations are minimized.
Preferably, the actuating means includes first and second stationary electrical contacts and a movable electric contact which is movable concurrently with said overriding throttle closing means, said movable contact being sequential-ly engaged with said first contact, neither of said contacts and then with said second contact when the overriding throttle limiting means moves from wide open throttle position to close throttle position, said first contact being connected with said circuit means for causing it to energize the motor for high speed operation when said first contact is engaged by said ,,/,~.'.~., ~
movable contact and for causing it to energize the motor for low speed operation when said first contact is disengaged by said movable contact, said second contact being connected with said circuit means for causing it to stop the motor when said second contact is engaged by said movable contacts, said cir-cui*means being operative to reversibly energize said motor at said slow speed in accordance with changes in said speed sig-nal.
Further features of the invention will become appar-ent from the following description with xeference to theaccompanying drawings.
Figure 1 is a diagrammatic view showing the engine and load speed governor of the present invention connected to a transmission, carburetor linkage, and accelerator pedal of an engine connected to vehicle wheeIs by the transmission;
Figure 2 is a diagrammatic view showing mechanical details of the governor proper;
Figure 3 shows the throttle linkage of Figure ~ in a different configuration;
Figure 4 found on.the same sheet as Figure 7, shows the switch plate o the present governor as connected to the electronic control portion thereof; :
Figure 5 shows a schematic circuit diagram of an electronic control providing for positioning the throttle-limiting at a reference position;
5;9:~L
Figure 6 shows a schematic circuit diagram of the portion o~ an alternate electronic circuit providing slow motion of the throttle-limitiny means in one direction; and .. ... _ .. . .
'' ~'i':' ~25~
Fig. 7 shows a schematic diagram of a portion of an electronic circuit providing slow motion of the throttle-limiting means as desirea.
Description of the Preferred Embodiment In the illustrated preferred embodiment, as shown schematically in Fig. 1, an internal combulstion engine 20 has connected thereto a transmission 22 or driving a load 24 such as the drive wheels of a truck. The transm.ission 22 is of the usual con~truction which allows automatic or ma~lual shifting of the gears therein t~ provide various ratios of speeds ~etween the engine 20 and the load 24. Typically, in a truck, the ~ransmission 22 is sh.ifted into "low gear" to start the load 24 moving at very low speeds, as from a standing start, so that the engine 20 can operate at a rotational speed of thousands of revolutions per minute, where it operates most efficiently, while the load 24 is eased into motion by a friction clutch or hydraulic connection (not shown) included in the transmission 22, and a very large torque is applied through the gearing of the transmission 22 to the axle 26 of the drive wheels 28 of the load 24, it ~eing understood that the engine 20 and the transmission 22 are attached to and part of the load 24. As the drive wheels 28 pick up speed, and before the engine 20 reaches some safe limit to its.short term rotational speed, such as 4,400 rpm for example, it is desirable to shift the transmission 22 into a "higher gear" ratio where the wheels 28 will turn at a higher rpm relative to the engine 20, and the power of the engine 20 will be applied through the transmission 22 to the wheels 28 to farther accelerate their speed until the engine 20 again approaches its safe rotational speed. This process of accelerating the engine 20 toward its maximum speed and shifting into a "higher gear" continues until the wheels 28 are d~iving the
2 ~
oad or truck 24 along at a safe and suitable road speed, at which time the transmission will be in its nominal "high gear", the load or truck 24 may be running along at 50 mi:Les per hour, and the engine 20 may be revolving at 3,000 rpm.
It is aesirable that the road speed of the load 24 should be controlled or governed to some safe speed such as 55 miles per hour and it is also desirable that the speed of ~he engine 20 be ~overned or controlled to .its maximum safe speed ~r long term operatlon, such as a speed o,f 4000 rpm, and the engine and load speed governor 30 of the illustrated embodiment of this invention has overriding means for limiting the flow of the,energy-supplying means or fuel to the engine to automatically and selectively con-trol both speeds with peculiar advantages to each.
The governor 30 is shown schematically in F",ig. 1 connec-ted to the load side of the transmission 22 by the flexible rotary cable 31, which may be the typical "speedometer cable", and which transmits rotary motion at a speed proportional to ~he speed of the - wheels 28. A gear 32 connected to the cable 31 inside the housing 33 drives an output gear 34 which is connected to a speedometer cable C for driving a s~eedometer S which may be locate~ on the dashboard of the truck cab. Governor 30 is connected to the carburetor throttle plate 35 of the carburetor 36 of the engine 20 by a flexible pull cable 38 enclosed within a flexible sheath 40 of fixed length attached to and extended from the governor 30, as shown in Figs. 1 and 2. The connection between throttle plate 35 and cable 38 is by means of the throttle arm 42 mounted on throttle shaft 44 to which the throttle plate 35 is affixed, and a stud 46 fixed in the free end 48 of the throttle arm 42 intermediately thereof forms a mounting point for a pivotable eye fitting 50 which is per~anently attached to the free end of the cab3e 38.
oad or truck 24 along at a safe and suitable road speed, at which time the transmission will be in its nominal "high gear", the load or truck 24 may be running along at 50 mi:Les per hour, and the engine 20 may be revolving at 3,000 rpm.
It is aesirable that the road speed of the load 24 should be controlled or governed to some safe speed such as 55 miles per hour and it is also desirable that the speed of ~he engine 20 be ~overned or controlled to .its maximum safe speed ~r long term operatlon, such as a speed o,f 4000 rpm, and the engine and load speed governor 30 of the illustrated embodiment of this invention has overriding means for limiting the flow of the,energy-supplying means or fuel to the engine to automatically and selectively con-trol both speeds with peculiar advantages to each.
The governor 30 is shown schematically in F",ig. 1 connec-ted to the load side of the transmission 22 by the flexible rotary cable 31, which may be the typical "speedometer cable", and which transmits rotary motion at a speed proportional to ~he speed of the - wheels 28. A gear 32 connected to the cable 31 inside the housing 33 drives an output gear 34 which is connected to a speedometer cable C for driving a s~eedometer S which may be locate~ on the dashboard of the truck cab. Governor 30 is connected to the carburetor throttle plate 35 of the carburetor 36 of the engine 20 by a flexible pull cable 38 enclosed within a flexible sheath 40 of fixed length attached to and extended from the governor 30, as shown in Figs. 1 and 2. The connection between throttle plate 35 and cable 38 is by means of the throttle arm 42 mounted on throttle shaft 44 to which the throttle plate 35 is affixed, and a stud 46 fixed in the free end 48 of the throttle arm 42 intermediately thereof forms a mounting point for a pivotable eye fitting 50 which is per~anently attached to the free end of the cab3e 38.
3~2~
The extended end of the flexible sheath 40 is attached to a bracket 52 mounted to the carburetor 36 for holding the end of the sheath 40 in general alignmen~ with the stud 46 and the eye fitting 50 on the extending end of the cable 38. A first tension spring 54 is stretched between a first pin 56 installed near the extremity of the free end 48 of the throttle arm 42 and a second pin 58 is fixed in relation to the carburetor 36 for hold-ing the throttle plate 35 in its normally nominally closed or idle position as shown in Fig. 1 in solid lines. An accelerator arm 60 is mounted for free ro~ation on the throttle shaft 44 and is connected to the throttle arm 42 by a second extension spring 62 stretched between a third pin 64 and a fourth pin 66, the pins being respectively fixed in the free ends of the arms 42 and 60.
The spring 62 is substantially stronger than the spring 54. A
stop 68 on an extending portion 70 of the accelerator arm 6~ is biased against the throttle arm 42 by the spring 62 under normal idling conditions for the engine 20.
An accelerator pedal 72 is normally biased to an idle position against a pedal stop 74 by a third extension spring 76 of suitable strength and is suitably freely pivoted on a pedal shaft 78 for pedal actuation to a full or wide open throttle position (indicated by the numeral 72') against a floorboard stop 80. The lower end of the pedal 72 is connected to a fifth pin 82 mounted on the free end of the accelerator arm 60 by a link 84 pivotable at the pedal 72 and the pin 82. The link 84 is of suit- -ably adjusted length to place the pedal 72, the accelerator arm 60, and the throttle arm 42 simultaneously in their respective normal or idle positions as shown in solid lines in Fig. 1.
When the governor 30 is in its normal or unactuated condition, the cable 38 may be freely pulled out from its sheath 0 by pivoting the throttle arm 42 counter-clockwise against the bias of the spring 54. By depressing the pedal 72 against stop 80 to its wide open position, the accelerator arm 60 will be rotated counterclockwise to its wide open throttle position as shown in broken lines and indicated by the numeral 60' in Fig. l;
and the spring 62 will pull the throttle arm 42 to its wide open throttle position as shown in broken lines and indicated by the numeral 42'.
When the governor 30 has been actuated as described hereinafter, ~nd the eye fitting S~ at the extending end of the cable 38 has been pulled back toward its normal or idle position as shown in solid lines, the counter-clockwise movement of the throttle arm 42 will be limited accordingly, and the spring 62 will be stretched as necessary to accommodate any mismatch between the position of the pedal 72 and the position of the throttle arm 42. The extreme mismatch, as shown in Fig. 3,,occurs when the pedal 72 is at the wide open throttle position and the throttle arm 42 has been limited to its idle positi~n by withdrawal move-ment of the cable 38, the spring 62 is at its maximum stretched condition, and the cable 38 extending from the governor 30 is thereby fully overriding the call from the accelerator pedal 72 for full throttle. Intermediate positions of the pedal 72 and the arm 60 are available at the will of the operator, as are intermediate positions of the throttle arm 42 as permitted by the limiting action of the cable 38.
The pedal 72 is thereby free to be positioned wherever the operator desires, and so long as the governor cable 38 is in its fully extended, normal, non-limiting position, the accelerator arm 60 and the throttle arm 42 will be biased together by the . spring 62 to move as one, and the throttle plate~* will~open _g_ ~nd close accordin~ to the positi~n of the pedal 72, If the.cable is retracted to limit the thxottle openin~, the spring 62 will stretch as necessary upon depression o~ the pedal 72 so tha~ the accelerator pedal will have a generally normal feel just a~ a conventional accelerator pedal and thrott'Le linkage, The accelera-tor pedal and throttle and carburetor linkage disclosed i6 schematic and representative of infinite rnechanically equivalent variations to suit particular engine-carburetor-vehicle combina-tions. Particularly, torsion springs may be substituted for the tension springs disclosed, for space and configuration consiaera-tions~ and a similar apparatus coùld be adapted for use with the control lever of a Diesel or gasoline fuel injection system, or other means of limiting the ~low of energy-supplying means to a motor or engine, even an electric one.
The construction and operation of the load speed gover-nor portion 86 of the present invention as shown in Fig. 2 is generally the same as that disclosed in my aforesaid patent~
e~ ~, and no further disclosure is neede~ herein except to point out the additional elements incorporated therewith as shown in Figs. 2 and 4 to provide means for movin~ the Farrier 88 to a pre-determined reference position upon actuation of the engine speed governor portion 90 of the engine and load speed governor 30:
An arcuate switch plate 92 is mounted to pivot for adjust-ment about the carrier sha~t 94 which is affixed to the housing 33 by means of a bracket 96 attached inside the housing. The plate 92 is formed of insulating material and is mounted on a metal hub 98 which is mounted for pivoting on the shaft 94. The hub 98 has an attachment flange 100 to which the plate 92 is fastened by rivets 102. The plate 92 is located directly behind the~carrier ~10--2~
,8 within the housing 33, and th~ bracket 96 sup~arts the shaft 94 between the carrier 88 and the hub 98. The shaft 94 and hub 98 mounted thereon extend rearwardly through an opening in the housing 33. Outside the hou~ing 33 a crank arm 104 is attached to the hub 98 and has an extending end in which is mounted a pivotable stud 106 having a threaded cross hole into which is threaded an adjustment screw 108. The shank o~ the screw 108 at the head end thereof passes through a clearance hole in a stud 110 fastened to the outside of the housing 33, and a compression spring 112 mounted on the screw 108 between the s~uds 106 and 110 holds the two studs 106 and 110 biased firmly apart to a distance limited by the head 114 of the screw 108.
Thus, rotary adjustment of the screw 108 acts to change the distance between the studs 106 and 110, thereby pivoting the switch plate 92 about the shaft 94 to set the plate 92 at any desired position within a suitable range of ad~ustment. Such positioning is desirable in order to angularly place a reference . position ccntact 116 as desired in relation to the carrier 88~
The contact 116 is mounted on the switch plate 92 in arcuate rela-tion to the hub 98, and is connected to an electrical lead 118.
for connection to the electronic control portion 119 of the governor 30 as explained hereinafter. The contact 116 extends clockwise from a generally central portion of the arcuate shape of the plate 92, and a somewhat similar limiting contact 120 is mounted on the plate 92 spaced a small gap 122 counter-clockwise from the contact 116 and extending along the same arc as contact 116 in a counter-clockwise direction generally to the left side of the plate 92. The contact 120 is connected to an electrical lead 124 for connection to the electronic cont~ol portion 119.
An electrically conductive spring leaf 126 ha~ing a ~2~
arrier electrical contact 128 at one end thereof is fastened at the other end to the rear side of the carrier 88 by rivets 130 and i~ sprung away from the carrier 88 fox spring-biased contact wi~h the switch plate 92 and the contacts 116 and 120 along the arcs thereof whereve~ the carrier 88 may be positioned as explained .~; ,i.n my aforementioned patent a~ sYr~Ds or to be explained herein-after. By its connection to the carrier 88, the contact 128 is a grounding contact so far as the electronic control portion of the governor is concerned. In Fig. 4 the carrier'~8 has ~een broken away, and the spring leaf 126 and the contac~ 128 are shown in more detail in relation to the switch plate 92. ~he lef~, or counter-clockwi6e end of the reference position contact 116 forms the actual reference point or position to which the carrier contact 128 is moved and homed for establishing a reference position for , the carrier 88 and thereby the overriding means for limiting the flow of energy-supplying means which is an obje~t of the present invention.
A reversible electric motor 132 is included in the electronic control 119, as are the accelerate or open throttlP
contact 134, the decelerate or close throttle ~Gnta~t 136, and the grounding contacts 138 which control the motor 132 at the command of the load speed governor 86 to turn the lead screw 140 which in turn causes the carrier 88 to move in rotation on the shaft 94.
In simplest terms, the governor 30 of the present inven-tion functions as follows: In the absence of a signal to the contrary, either from the load speed governor 86 or the enyine speed governor 90, the load speed governor 86 acts to move the carrier 88 to its extreme counter-~lockwise, rest, o:r wide-open-throttle position as shown in Fig. 2, where the flow of fuel or 5~:~
.~ergy-supplying means to the en~ine 20 is not li~ited at all by the governor 30, bu~ is dependent upon the operator-positioned accelerator and throttle linkages as described hereinbefore and ~;,in my a~orementioned prior patent ~ ea~on. Thenr tn the absence of a load speed su~icient to actuate the load speed gover-. nor B6 as described in my aforesaid patent (e.g. whenthe transmission 22 i~ in neutral, or in a lower gear ratio where the engine must reach a speed far a~ove the governed speed in order to actuate the load speed governor ~t the electronic con-trol 119 may assume control of the ~overn~r 30 as explained here-after.
The electxonic control 119 monitors the speed of the engine 20 for detection of operation of the engine ~t a pxe-determined governed or set speed such as 4000 xpm, and at at leas~
three other speeds having predetermined relations to the set speed: A precall speed which may be 600 rpm b~low the set speed, a close throttle speed which may be ~D rpm below the set speed, and an overspeed speed which may ~e 300 rpm above the set speea.
Upon acceleration of the engine and detection of the precall speed, 3400 rpm in this example, the control 119 initiates a timing circuit, ~nd, if within a predetermined time period such a~ .2 seconds, the close throttle speed of 3600 rpm is ~etec~ed, then the control 119 will connect electrical power (from the ~ngine electrical system) to the motor 132 to cause it to rotate in close throttle ~irection, thereby turning the lead screw liO
appropriately to cause the carrier 88 to move in clockwise or close throttle direction away from its rest position. Once initiated, thi~ close throttle movement of the carrier 88 will continue until the carrier contact 128 touches the reference position con-tact 116, thereby automatically moving the carrier 88 to~a reference ~3 s~ -~ sition which has been preset to allow an unloaded engine speed just slightly above the set speed (4000 rpm in this example) of the electronic control ll~. If acceleration o~ the speed of th~
engine 20 from 3400 rpm *o 3600 rpm takes longer than .2 seconds, the control 119 takes no urther action, and the engine speed governor 90 remains unactuated until the enyine speed reaches the 4000 rpm set speed, at which time the control 119 energizes the motor 132 in the close throttle direction to move the carrier 88 to its reference position.
If upon arrival of the carrier 88 at its reference position, the engine speed is detected by the electronic control 119 to be at 4Q00 rpm ox within a ranye thereabove extending to 4300 rpm ~the overspeed speed in this example), then the electronic control 119 will react to the carrier contact 128 touching (there-by making electrical contaat with) the reference position contact 116 by reversing the energization of the motor~l32 to the open throttle mode, whereupon the carrier 88 is moved counter-clockwise until the carrier contact 128 breaks contact with the reference position contact 116. Once the electrical circuit between con-tacts 128 and 116 is broken, a continuing detecti~n of an engine speed within the aforesaid range of 4000~4300 rpm causes the con-trol 119 to again energize the motor 132 in the closed throttle direction to drive the carrier contact 1~8 back to the reference position contact 116 for ~ontinuing repetition of the open throttle-close throttle driving.cycle in a so-called "alternating circuit" mode of operation so long as the engine speed remains in the 4000-4300 rpm range. In the preferred embodiment of the present in~ention, the movement of the carrier contact during the repetitive cycle may be only .005-.010 inch, so that the cable 38 may move little or none, what with normal clearances and backlash n the apparatus. The throttle plate 35 is thus lLmited to being opened to a corresponding reference position, even though the accelerator pedal may be ~ully depressed, and will initially be closed to the reference position by the overriding action of the carrier 38. If upon arrival of the carrier contact 128 at the reference contact 116, the engine speea i5 below 4000 rpm, the control 119 will reverse the motor 132 to the open throttle direction and release control c~ the motor 132 to the load speed governor contacts 134 and 138 fox return of the carrier 88 to its wide-open-throttle or rest position.
If upon arrival of the carrier contact 128-at the reference contact 116 the engine speed has reachea the overspeed speed of 4300 rpm, then the control 119 will cause the electrical contact between contacts 128 and 116 to be ignorled, and the carrier 88 will continue to be driven in close throttle dire~tion past the reference contact 116 until the control 119 detéct6 engine speed within the 4000-4300 rpm r~nge or the carrier reach~ its maximum close throttle, idle, or overspeed position. This condition normally will occur only when an overrunning load ha~ been applied to the governed engine, such as running the associated vehicle down a steep hill, or when the switch plate 92 has been miss-set. Upon deceleration of the engine speed to within the 4000-4300 rpm range, the control 119 will energize the motor 132 in the open throttle direction until the carrier contact 128 loses contact with the reference position contact 116 and the governor 90 will revert to the alternating circuit mode of operation.
In normal operation, three operating conditions should be considered, the first being that where the engine cannot main-tain ~he governed or set speed with the throttle plat~e 35 at its reference position because of a heavy load such as an uphill grade, ~2~5~
SQ that engine speed ~lls below .the ~xempl~r~ 4000 rpm set speed a~ter having attatned it u~der ~ull throttle and actuated the carrier 88 toward its re~erence position to limit the throttle plate 35 to some lesser opening, As soon as the engine reacts to moving the throttle plate toward its refer~ence position by dPcele-rating below 4000 rpm, the governor 90 will be deactuated by the contxol 119, and the carrier 88 will-be moved toward open throttle until the engine again accelerates to the set speed of 4000 rpm, which will reverse the carrier into movement towa~d closed throttle once again--thus the throttle plate 35 will oscilla~e throug~ a limited range of positions as necessary to hold ~he .engine speed .very near the set speed, the frequency and magnitude of the oscillations of the throttle plate 35 and the engine speed being determined by the interrelationships of engine ~ower, load applied, and gear ratio being used in the transmission 22, or accelerational decelerational capacity of the engine, togethe~ with the response speed of the motor 132 and its screw 140 driving the carrier 88.
The second operating condition is that where the reference position of the throttle plate 35 is just sufficient to maintain the engine speed in the 4000-4300 rpm range--in this case, the con-trol ll9 will keep the governor 90 in its alternating circuit mode of operation, and the engine speed may wander within the 4000-4300 rpm range while the throttle plate 35 is held at its reference posi-tion (assuming that the accelerator pedal 72.is held depressed at least sufficiently to open the throttle plate 3S that far). If the engine speed goes outside the 4000 4300.rpm range, the governor 30 will be de-actuated below 4000 rpm or ~o into the overspeed mode of close throttle arive as explained hereinbefore above 4300 rpm.
The third operating condition is that where an over-running load such as a moderate downhill grade is imposed on the ngine 20 ~uch that when the ~oyernor 30 has acted to close the throttle pl~te 35 to its idle or overspeecl position, as previously explained, ~hen ~he engine speed drops below 4300 rpm, thereby causing the carrier 88 to m~ve back towarcl its re~erence position.
Assum.ing the accelerator pedal 72 being sufficiently depxessed, the throttle plate 35 will open until the engine speed again goes above 4300 rpm and the control 119 causes the carrier to move in close throt~le direction again, and the cycle will repeat, allowiny small oscillations of the throttle plate 35 about an average position permitting an engine speed of about 4300 rpm and small oscillations of the engine speed about 4300 rpm. Here again, the parameters of engine accelerational/decelerational ability~ gear ratio, and carriex 88 response time determining the period and magnitude of the oscillations.
Operation of the engine 20 at speeds below the set speeds is perfectly free of any control by the ~ngine speed governor 90 except in the aforementioned case of rapid acceleration between precall and close throttle speeds of 3400 and 3600 rpm respec-tively.
An electronic logi~ module 144 (not shown in Figs. 1 and 2) for the electronic control portion 119 of the governor 90 is mounted within the housing 33 of the governor 30. As shown schematically in Fig. 5, the module 144 includes conventional integrated circuits and electronic components which opexate as described below to receive negative pulse signals from an internal combustion engine ignition coil (or alternatively from a pulse generator connected to a Diesel engine or other prime mover), and signals from the switch plate contac~ 116 and the open and close throttle contact5 134 and 136 respectively, in order to control the reversible electric motor 132 as described hereinb~fore.
25~:~
To control engine speed a method is first needed to -detect the engine speed. This is accomplished by a frequency to voltage converter. The engine speed is proportional -to the number of ignition pulses per minute as monitored at the negative terminal of the ignition coil of the engine 20. These pulses are fed into terminal A. Voltage divider resistors Rl and R2 are selected so that the transistor Ql (normally off) will turn on once for each ignition pulse. A resistor R3, a variable potent-iometer Pl and a capacitor Cl form a resistor-capacitor timing network. For each ignition pulse, the transistor Ql will turn on, and in turn fully discharge the capacitor Cl. As the engine speed increases, the transistor Ql will -turn on more frequently.
With the transistor Ql off, the capacitor Cl starts to charge.
As the voltage rises on the capacitor Cl to approximately 1/2 of the ten volt supply voltage, the logic norgate ICl-l of the quad norgate ICl will have its output (pin 3) change state from high to low. When the output is high, the capacitor C2 is being charged through the resistor R4. A change in output from high to low will cause the capacitor C2 to be discharged. sy properly selecting the values of R3, Pl, Cl, R4 and C2, an average voltage will appear on the capacitor C2 which is proportional to engine speed. The faster the engine speed (ignition pulses) the higher the voltage, the slower the engine speed the lower the average voltage.
A voltage comparator circuit is used to determine when various predetermined engine speeds occur. The speeds are:
precall, close throttle, governed, and overspeed. The circuit consists of four voltage comparators IC2-l, IC2-2, IC2-3 and IC2-4 and five resis-tors Rl9, R5, R9, R10, and Rll which set the individual voltages at which each comparator functions.
The precall and close throttle comparators operate S~ 3 cooperativel~ in sequence. Their pur~ose is to determine whether the engine is accelerating ~n speed so ~ast that the engine speed governor should be actuated ~e~ore the set speed is reached. If this condition occurs, the precall and close throttle com~arators IC2-1 and IC2-2 act toge~er to start the go~ernor operating even ~efore the predetermined governed speed is reached. A typical example would have the precall speed set at 3400 RPM, the close throttle speed at 3600 RPM, the governed speed at 4000 RPM and the overspeed at 4300 ~PM. }~ the engine should accelerate between 3400 and 3600 RPM within 200 milisec, this rate ~f acceleration would cause the close throttle norgate ICl-2 to ~unction to operate and activate the governor. When the engine speed increases at a - slower rate the precall close throttle circuitry is inoperative and plays no part in the operation.
Upon reaching 4000 RPM, the governor or set speed compaxator IC2-3 begins its normal governing. 'At 4300 RPM the overspeed comparator IC2-4 turns on, causing the governor 90 to go toward completely closing the throttle plate 35.
When the engine acceleration exceeds the normal governor reaction capability, the close throttle comparator IC2-2 causes the control 119 to start the governing process prior to 4000 RPM
being reached. In the event of such a condition, the precall and close throttle comparators IC2~1 and IC2-2 provide signals to the close throttle norgate IC1-2 which in turn provides a signal to a flip-flop circuit composed of the two norgates ICl-3 and ICl-4. With the proper signal the flip-flop circuit is set so that the output of pin 4 o~ ICl-4 goes high and acts through the norgates IC3-1 and IC3-2 of the quad norgate IC3 to cause the transistor Q2 to drive the motor 132 and the associated carrier contact 128 in the close throttle direction. Upon the c~arrier . ~ --19 -, j,:
.
~ontact 128 reachin~ the normally open re~erence position contac~
116 of the s~itch pl~te 92 the ~lip flop circuit receives a reset signal ~om the norgate IC3-3 at pi,n 5 of the norgate ICl-4 and pin 4 thereof goes low. The precall close throttle function cannot reoccur unless the engine speed drops below the 3400 RP~
precall level, and only then could the process be repeated, The quad norgate IC3 comprises the logic circuitry which allows the electronic logic module 114 to control the governor 90 in proper sequence. Pin 6 of norgate IC3-1 is normally low. With a high signal at pin 6, the output pin 4 o~ norgate IC3-1 goes low and causes the output pin 10 o~ norgate IC3-Z to go high. This will turn on the transistor Q2 and d~ive the motor 132 in the close throttle direction. The motor continues driving the carrier 88 in the close throttle direction until its contact 128 reaches the reference position contact 116. Grounding the reference con-tact 116 causes pin 2 of the norgate to go low;and pin 3 thereof to go high. Pin 3 going high will cause pin 10 of the norgate IC3-2 to now go low. When pin 10 goes low, it causes pin 11 of the norgate IC3-4 to go high which turns on the transistor Q3, driving the motor 132 in the open throttle ~irection. The carrier 88 going in the open throttle direction will remove the carrier contact 128 from the reference contact 116 and change pin 2 of the norgate IC3-3 from low back to high and the process will keep repeating~ This operation is known as the alternating circuit feature since the motor 132 will alternately drive the carrier co~tact 128 on and off the reference contact 116. The amount of movement is very small and effectivel~ keeps the carrier 88 at its reference position at the threshold of the reference position - contact 116.
Should the engine speed keep increasing to 4300 RPM as ~ ;
does happen in some isolated in~tances, it is necessary that the alternating circuit mode be overridden so that the motor will ,,-,, drive the carrier contact 128 past the threshold of the reference contact 116 ully in the close throttle dire~tion. When such an instance is detected by the overspeed comparator IC2-~, pin 14 thereof goes high and continually holds pln 3 of the norgate IC3-3 low~ This overcomes the effect of the reference contact-116 being grounded at pin 2 o~ the norgate IC3-3 and allows pin 10 of the norgate IC3~2 to remain high as long as the overspeed condition exists. Dropping below the overspeed value of 4300 RPM allows the governor comparator IC2-3 cixcuitry to govern as normal.
The Zener diode ~1 in series with the resistor R 18 across the 12 volt battery supply voltage, as shown in Fig. 5, pro~ides,a stabilized 10 vo~t supply for the logic module 144 as indicated at various points therein.
An alternative second embodiment of the engine speed governor 90 provides for operation of the motor 13~ t,and thereby the carrier B8) at a substantially slower speed in open throttle direction than in close throttle direction--approximately 15-18 seconds to rotate the carrier 88 from idle position to wide-open-throttle position as compared to about 3 seconds to rotate it from wide-open-throttle to idle position. The slower speed is accomplished by the circuitry of Fig. 6, which shows in schematic detail the changes and additions to the circuitry of Fig. 5--the portions of Fig. 5 which are not repeated in Fig. 6 are identical in both circuits. The additional resistor ~20 in the connection between the transistor ~3 and the motor 132 serves to reduce the voltage supplied to the motor, and with the resultant reduced speed, it is desirable that, upon arrival of the carrier contact 30 128 at the reference contact 116 subse~uent to actuation of the governor 90, that the contact 128 should remain at the reference ~2~S~
~ntact so long as the engine speed remains in the 4000-4300 RPM
range~ There~ore, the pin 13 of th.e norgate IC3-4 is now connec.ted to limiting ctrcultry comprising the transistors Q4, QS, and Q6 and their'associated added componentsO ~ow, when the contact 128 touches the contac~ 116, the motox 132 is turned of, and so long as the engine speed remains in the 400~-~'lO0 RPM xange, it remains off. If the engine speed drops below ~000 RPM, the governor com-.
parator IC2-3 will cause the motor 132 to run in open throttle direction ~a~ the slow speed) until the engine again rises to 4000 rpm, or until the carrier B8 moves i~ Qpen throttle direc-tion sufficiently for the carrier contact 128 to cross the narrow gap 122 and touch the limiting contact 120 on the switch plate 92--in either case, the open throttle drive ceases; and in the first case the yovernor comparator IC2-3 causes the motor 132 to drive in the close throt'tle direction, while in the secona case the carrier contact 128 remains at the limiting contact until the engine either rises to 4000 RPM and the governor comparator IC2-3 causes close throttle drive, or the engine drops below the precall speed of 3400 RPM and the precall comparator IC2-1 causes open throttle drive, carrying the carrier contac*'l28 past its initial contact with the limiting contact 120 toward the wide-open-throttle position of the carrier 88.
This second,'slow speed, embodiment is advantageous for lessening engine speed oscillations, but is disadvantageous in that the slow travel of the carrier 88 toward open throttle may sometimes handicap the operator who is trying to get a rapid acceleration of the engine for shifting gears.
Yet a third embodiment of my engine speed goVernor inven-tion provides for normally fast travel of the carrier 88 toward its reference position upon actuation o~ the engine speed governor 9~
O until the ca~rier contact 128 moves of~ the limiting contact 120, at which ~he motor 132 drops to a very slow speed resulting 1n clockwise mo~ement of the caxrier 88 about lts shaft 94 at the rate o~ about one-third RP~, whlch would ~e roughly e~uivalent to full travel ~rom wide-open-throttle position ~o idle throttle positlon in about thirty seconds~ ~n objective of this slow speed is to move the carrier 88 in limiting control of ~he throttle plate 35 at a slower rate than the response capability of the engine 20, thereby minimizing engine speed oscillations r Since the response capability of the engine will vary considerahly according to loads and gear ratios, recovery time ~from the loss of engine speed due to sudden application of a heavy ~oad while running at the governed speed under light load) could be somewhat slow--however, this is not the usual condition and is overweighed by the stability of thP system for normal operation.
The relation of engine response capa~1lity rate ana throttle limiting means movement rate is a complex one, but cons.ider that any engine running at idle speed and having full throttle suddenly applied will take a second or two to reach a speed of say 40G0 RPM, and if a governor acts to close the throttle quickly to closed or idle throttle position upon attainment of the 4000 RPM speed, the engine speed will overshoot or overrun the 4000 RPM speed and then decelerate below the 4000 RPM speed and undershoot or underrun it, even though the governor acts to open to full throttle again immediately upon the speed dropping ~elow 4000 RPM. This may cause oscillations of engine speed o~
1000 RPM or more in an unloaded engine, rapidly enough to be disturbing to its operator, and resulting in a governor with very poor regulation. This is an example of a throttle limiting means moving at a very ~uch ~aster rate than the engine response capa-bility rate, and results in out-of-phase operation o~ engine and ~ 25~
throttle as explained in m~ aforesaid patent.
On the other hand~ ~t has been found that where thethrottle can only be moved between idle and full positions over a perio~ o~ about twent~ sec~nds or more, then in phase operation o~ engine and throttle occurs~ as in the present invPntion, and very good governor regulation can be obtained~ The engine has the capability of increasing its speed w:ith very little lag behind the throttle position~ even under heavy or ~ull load, meaning that if the throttle is opened half-way at this slow rate or 19 slower~ that the engine will have come up in speed slowly with the slow opening and will have achieved its m~imum sustained speed for ~his throttle opening and particular load momentarily after the throttle movement stops, ana will overrun the afoxesaid maximum ~ustained insignificantly, thereby staying essentially in phase with the throttle, even under no load conditions. In the commercial engine application ran~e conslaered so far, an approximately twenty to twenty-five second throttle movement period seems about the optimum for sati6~ac~ory governor regula~
tion for a smoothly operating governor and a period as short as seven or eight seconds causes objectiona~l~ os~illations. Of course, to obtain satisfactory restraint ~nder no load engine r~n-up conditions and satisfactory recovery from sudden load applications, it is desirable to have fast throttle closing upon sudde~ acceleration o~ the engine, and fast throttle opening upon sudden deceleration. The apparatus of the present invention provides such cap~bility for both fast and slow throttle movement through the use of a reference position for the throttle limiting means, such that throttle movement will be slow under normal conditions, but may be swift when needed for recov~ry of control of a rapidly fluctuating engine speed caused by so~e factor external to the governor. To date, the apparatus of the present invention is the onl~ known solution to this problem for every-day commercial use~ e.g., ~s ~or truck and bus engines. Upon arrival at its re~erence posltion, assum.ing that the engine speed still lies in the 4000-4300 RPM range, the carrier stops and remain~ in place, moving there~om only upon detection of engine speed outside the 4000-4300 RPM range, and only at the above-mentioned slow speed, whether in open throttle or close throttle direction.
When the engine speed drops below 4000 RPM, the motor 132 is energized at the slow speed in open throttle direction and continues in that direction until the carrier contact 128 hits the limiting contact 120 and halts there, unless in the meantime the engine speed has risen again to 4000 RPM to cause the motor 132 to be reversed to close throttle direction, or has dropped below the 3400 RPM precall speed which will cause t~e carrier 88 to contlnue to open throttle direction, but at high speed after touching the contact 120. I~ the carxier contact 128 is halted upon touching the limiting contact 120, it remains there pending detection of engine speed rising to 4000 RPM to cause close throttle drive at the slow speed, or engine speed falling below the 3400 RPM precall speed to cause open throttle drive just as in the second embodiment; however, the motor 132 will return to its normal fast speed because the carrier contact 12B is contact-ing the limiting contact 120.
As a practical matter, on a long steep grade in a truck engine application, where a considerably open throttle position is xequired to maintain the engine at the 4000 RPM
governed speed, a~ter the throttle limiting means has been moved to the reference position, then the governor will allow the ~2~S9~
throttle to slowly open farthex to a point where its average position furnishes just the ~uel needed to maintain 4000 RPM with only minor oscillatlons therea~out as the throttle is opened and cl~sed slightly b~ governor detection o engine speed falling below 4000 RPM and then rising back to that speed.
The circuitry for ~btaining the slow-motor speed in both directions, and only when the carrier contact 128 is out of contact with the limiting contact 120~ comprises essentially a suitable resistor R31 placed in the 12 volt common supply connec-tion to the motor 132 as shown in Pig. 7 in partial schematicdetail. The resistor R31 reduces the voltage across the motor 132 sufficiently to cause it to run at the desirable low speea in close throttle direction where the force o~ the load speed governor spring 142 and throttle apparatus springs must be overcome, and a second resistor R30 in the open throttle connec-tion between the transistor Q3 and the motor 132 reduces the voltage across the motor even farther to compensate ~or the over-running force applied by the governor spring 142 and throttle apparatus springs when the motor runs in throttle openiny direc-tion. A PNP transistor ~7 is connected in parallel with theresistor R31 and is controlled indirectly through additional circuitry (not shown) associated with the limiting contact 120 by the condition thereof. When contact 120 is grounded by contact with the carrier contact 128, the transistor Q7 is caused to be conductive, the resistor R31 is shunted out o~ the circuit and is of no effect, and the motor 132 runs at normal fast speed.
When the carrier contact 128 leaves the limiting contact 120, leaving it ungrounded, then the transistor Q7 goes non-conducting and all current to the motor 132 must pass through the resistor 31, so that the motor runs at the desirable slow speed~
~3L2~
This third, slow speed, embodiment lessens the oscilla-tiQnS of en~ine speed, Rnd would be preferable to the first, alternatin~ circuit, embodiment except that the low motor voltages rPquired to obtain a suit~bl~ slow operation o~ the motor 132 may not provlde su~icient startin~ torque ~or reliable motor operation under extreme cold weather conditions~ However, gover-nors 30 according to this third embodiment have worked satis-factorily in moderate tempexature conditions and commercially demonstrate the advantages of slow speed operation of the motor 1~ 132.
Control o~ the motor 132 by the load speed governor 86 ~through movement of the carrier 88 and its open throttle and close throttle contacts 134 and 136 respectively, by action of the flyball mechanism 146 to move the grounding contacts 138~ is ~the same as that disclosed in my aforementioned prior patent ~ re~bil~ whereby the load speed governor can overridingly run the motor 132 in close throttle direction in resp~nse to suit-ably high load speed at any time, and the engine speed governor 90 can aO likewise at any time in response to a suitably high engine speed, ~t the load speed governor can only run the motor 132 in open throttle direction in response to a suitably low load speed when the engine speed governor 90 is als~ calling concurrently for the motor to operate in that direction in response to a suitabl~ low engine speed by making the transistor Q3 cbnductive, and vice-versa.
The present invention has been described in detail above for purposes o~ illustration only and is not intended to be limited b~ this description or otherwise to excluae any variation or equivalent arrangement that would be apparent from, or reasonably su~gested by, the foregoing disclosure to the skill of the a~t, Buch as the substitution of vacuum or mechanical 259~ -~r other actuators~ for the electrically driven lead screw dis-closed herein, the substitu~ion o~ centrifugal or magnetic or other engine speed responsi~e means ~or the electronic module disclosed herein, or the substit~tion of magnetic or electronic or other load speed respons~ve:means ~or the fly ball mechanism disclosed herein. I.e., the scope of the present in~ention is to be determined by the scope of the appended claims.
~2~-
The extended end of the flexible sheath 40 is attached to a bracket 52 mounted to the carburetor 36 for holding the end of the sheath 40 in general alignmen~ with the stud 46 and the eye fitting 50 on the extending end of the cable 38. A first tension spring 54 is stretched between a first pin 56 installed near the extremity of the free end 48 of the throttle arm 42 and a second pin 58 is fixed in relation to the carburetor 36 for hold-ing the throttle plate 35 in its normally nominally closed or idle position as shown in Fig. 1 in solid lines. An accelerator arm 60 is mounted for free ro~ation on the throttle shaft 44 and is connected to the throttle arm 42 by a second extension spring 62 stretched between a third pin 64 and a fourth pin 66, the pins being respectively fixed in the free ends of the arms 42 and 60.
The spring 62 is substantially stronger than the spring 54. A
stop 68 on an extending portion 70 of the accelerator arm 6~ is biased against the throttle arm 42 by the spring 62 under normal idling conditions for the engine 20.
An accelerator pedal 72 is normally biased to an idle position against a pedal stop 74 by a third extension spring 76 of suitable strength and is suitably freely pivoted on a pedal shaft 78 for pedal actuation to a full or wide open throttle position (indicated by the numeral 72') against a floorboard stop 80. The lower end of the pedal 72 is connected to a fifth pin 82 mounted on the free end of the accelerator arm 60 by a link 84 pivotable at the pedal 72 and the pin 82. The link 84 is of suit- -ably adjusted length to place the pedal 72, the accelerator arm 60, and the throttle arm 42 simultaneously in their respective normal or idle positions as shown in solid lines in Fig. 1.
When the governor 30 is in its normal or unactuated condition, the cable 38 may be freely pulled out from its sheath 0 by pivoting the throttle arm 42 counter-clockwise against the bias of the spring 54. By depressing the pedal 72 against stop 80 to its wide open position, the accelerator arm 60 will be rotated counterclockwise to its wide open throttle position as shown in broken lines and indicated by the numeral 60' in Fig. l;
and the spring 62 will pull the throttle arm 42 to its wide open throttle position as shown in broken lines and indicated by the numeral 42'.
When the governor 30 has been actuated as described hereinafter, ~nd the eye fitting S~ at the extending end of the cable 38 has been pulled back toward its normal or idle position as shown in solid lines, the counter-clockwise movement of the throttle arm 42 will be limited accordingly, and the spring 62 will be stretched as necessary to accommodate any mismatch between the position of the pedal 72 and the position of the throttle arm 42. The extreme mismatch, as shown in Fig. 3,,occurs when the pedal 72 is at the wide open throttle position and the throttle arm 42 has been limited to its idle positi~n by withdrawal move-ment of the cable 38, the spring 62 is at its maximum stretched condition, and the cable 38 extending from the governor 30 is thereby fully overriding the call from the accelerator pedal 72 for full throttle. Intermediate positions of the pedal 72 and the arm 60 are available at the will of the operator, as are intermediate positions of the throttle arm 42 as permitted by the limiting action of the cable 38.
The pedal 72 is thereby free to be positioned wherever the operator desires, and so long as the governor cable 38 is in its fully extended, normal, non-limiting position, the accelerator arm 60 and the throttle arm 42 will be biased together by the . spring 62 to move as one, and the throttle plate~* will~open _g_ ~nd close accordin~ to the positi~n of the pedal 72, If the.cable is retracted to limit the thxottle openin~, the spring 62 will stretch as necessary upon depression o~ the pedal 72 so tha~ the accelerator pedal will have a generally normal feel just a~ a conventional accelerator pedal and thrott'Le linkage, The accelera-tor pedal and throttle and carburetor linkage disclosed i6 schematic and representative of infinite rnechanically equivalent variations to suit particular engine-carburetor-vehicle combina-tions. Particularly, torsion springs may be substituted for the tension springs disclosed, for space and configuration consiaera-tions~ and a similar apparatus coùld be adapted for use with the control lever of a Diesel or gasoline fuel injection system, or other means of limiting the ~low of energy-supplying means to a motor or engine, even an electric one.
The construction and operation of the load speed gover-nor portion 86 of the present invention as shown in Fig. 2 is generally the same as that disclosed in my aforesaid patent~
e~ ~, and no further disclosure is neede~ herein except to point out the additional elements incorporated therewith as shown in Figs. 2 and 4 to provide means for movin~ the Farrier 88 to a pre-determined reference position upon actuation of the engine speed governor portion 90 of the engine and load speed governor 30:
An arcuate switch plate 92 is mounted to pivot for adjust-ment about the carrier sha~t 94 which is affixed to the housing 33 by means of a bracket 96 attached inside the housing. The plate 92 is formed of insulating material and is mounted on a metal hub 98 which is mounted for pivoting on the shaft 94. The hub 98 has an attachment flange 100 to which the plate 92 is fastened by rivets 102. The plate 92 is located directly behind the~carrier ~10--2~
,8 within the housing 33, and th~ bracket 96 sup~arts the shaft 94 between the carrier 88 and the hub 98. The shaft 94 and hub 98 mounted thereon extend rearwardly through an opening in the housing 33. Outside the hou~ing 33 a crank arm 104 is attached to the hub 98 and has an extending end in which is mounted a pivotable stud 106 having a threaded cross hole into which is threaded an adjustment screw 108. The shank o~ the screw 108 at the head end thereof passes through a clearance hole in a stud 110 fastened to the outside of the housing 33, and a compression spring 112 mounted on the screw 108 between the s~uds 106 and 110 holds the two studs 106 and 110 biased firmly apart to a distance limited by the head 114 of the screw 108.
Thus, rotary adjustment of the screw 108 acts to change the distance between the studs 106 and 110, thereby pivoting the switch plate 92 about the shaft 94 to set the plate 92 at any desired position within a suitable range of ad~ustment. Such positioning is desirable in order to angularly place a reference . position ccntact 116 as desired in relation to the carrier 88~
The contact 116 is mounted on the switch plate 92 in arcuate rela-tion to the hub 98, and is connected to an electrical lead 118.
for connection to the electronic control portion 119 of the governor 30 as explained hereinafter. The contact 116 extends clockwise from a generally central portion of the arcuate shape of the plate 92, and a somewhat similar limiting contact 120 is mounted on the plate 92 spaced a small gap 122 counter-clockwise from the contact 116 and extending along the same arc as contact 116 in a counter-clockwise direction generally to the left side of the plate 92. The contact 120 is connected to an electrical lead 124 for connection to the electronic cont~ol portion 119.
An electrically conductive spring leaf 126 ha~ing a ~2~
arrier electrical contact 128 at one end thereof is fastened at the other end to the rear side of the carrier 88 by rivets 130 and i~ sprung away from the carrier 88 fox spring-biased contact wi~h the switch plate 92 and the contacts 116 and 120 along the arcs thereof whereve~ the carrier 88 may be positioned as explained .~; ,i.n my aforementioned patent a~ sYr~Ds or to be explained herein-after. By its connection to the carrier 88, the contact 128 is a grounding contact so far as the electronic control portion of the governor is concerned. In Fig. 4 the carrier'~8 has ~een broken away, and the spring leaf 126 and the contac~ 128 are shown in more detail in relation to the switch plate 92. ~he lef~, or counter-clockwi6e end of the reference position contact 116 forms the actual reference point or position to which the carrier contact 128 is moved and homed for establishing a reference position for , the carrier 88 and thereby the overriding means for limiting the flow of energy-supplying means which is an obje~t of the present invention.
A reversible electric motor 132 is included in the electronic control 119, as are the accelerate or open throttlP
contact 134, the decelerate or close throttle ~Gnta~t 136, and the grounding contacts 138 which control the motor 132 at the command of the load speed governor 86 to turn the lead screw 140 which in turn causes the carrier 88 to move in rotation on the shaft 94.
In simplest terms, the governor 30 of the present inven-tion functions as follows: In the absence of a signal to the contrary, either from the load speed governor 86 or the enyine speed governor 90, the load speed governor 86 acts to move the carrier 88 to its extreme counter-~lockwise, rest, o:r wide-open-throttle position as shown in Fig. 2, where the flow of fuel or 5~:~
.~ergy-supplying means to the en~ine 20 is not li~ited at all by the governor 30, bu~ is dependent upon the operator-positioned accelerator and throttle linkages as described hereinbefore and ~;,in my a~orementioned prior patent ~ ea~on. Thenr tn the absence of a load speed su~icient to actuate the load speed gover-. nor B6 as described in my aforesaid patent (e.g. whenthe transmission 22 i~ in neutral, or in a lower gear ratio where the engine must reach a speed far a~ove the governed speed in order to actuate the load speed governor ~t the electronic con-trol 119 may assume control of the ~overn~r 30 as explained here-after.
The electxonic control 119 monitors the speed of the engine 20 for detection of operation of the engine ~t a pxe-determined governed or set speed such as 4000 xpm, and at at leas~
three other speeds having predetermined relations to the set speed: A precall speed which may be 600 rpm b~low the set speed, a close throttle speed which may be ~D rpm below the set speed, and an overspeed speed which may ~e 300 rpm above the set speea.
Upon acceleration of the engine and detection of the precall speed, 3400 rpm in this example, the control 119 initiates a timing circuit, ~nd, if within a predetermined time period such a~ .2 seconds, the close throttle speed of 3600 rpm is ~etec~ed, then the control 119 will connect electrical power (from the ~ngine electrical system) to the motor 132 to cause it to rotate in close throttle ~irection, thereby turning the lead screw liO
appropriately to cause the carrier 88 to move in clockwise or close throttle direction away from its rest position. Once initiated, thi~ close throttle movement of the carrier 88 will continue until the carrier contact 128 touches the reference position con-tact 116, thereby automatically moving the carrier 88 to~a reference ~3 s~ -~ sition which has been preset to allow an unloaded engine speed just slightly above the set speed (4000 rpm in this example) of the electronic control ll~. If acceleration o~ the speed of th~
engine 20 from 3400 rpm *o 3600 rpm takes longer than .2 seconds, the control 119 takes no urther action, and the engine speed governor 90 remains unactuated until the enyine speed reaches the 4000 rpm set speed, at which time the control 119 energizes the motor 132 in the close throttle direction to move the carrier 88 to its reference position.
If upon arrival of the carrier 88 at its reference position, the engine speed is detected by the electronic control 119 to be at 4Q00 rpm ox within a ranye thereabove extending to 4300 rpm ~the overspeed speed in this example), then the electronic control 119 will react to the carrier contact 128 touching (there-by making electrical contaat with) the reference position contact 116 by reversing the energization of the motor~l32 to the open throttle mode, whereupon the carrier 88 is moved counter-clockwise until the carrier contact 128 breaks contact with the reference position contact 116. Once the electrical circuit between con-tacts 128 and 116 is broken, a continuing detecti~n of an engine speed within the aforesaid range of 4000~4300 rpm causes the con-trol 119 to again energize the motor 132 in the closed throttle direction to drive the carrier contact 1~8 back to the reference position contact 116 for ~ontinuing repetition of the open throttle-close throttle driving.cycle in a so-called "alternating circuit" mode of operation so long as the engine speed remains in the 4000-4300 rpm range. In the preferred embodiment of the present in~ention, the movement of the carrier contact during the repetitive cycle may be only .005-.010 inch, so that the cable 38 may move little or none, what with normal clearances and backlash n the apparatus. The throttle plate 35 is thus lLmited to being opened to a corresponding reference position, even though the accelerator pedal may be ~ully depressed, and will initially be closed to the reference position by the overriding action of the carrier 38. If upon arrival of the carrier contact 128 at the reference contact 116, the engine speea i5 below 4000 rpm, the control 119 will reverse the motor 132 to the open throttle direction and release control c~ the motor 132 to the load speed governor contacts 134 and 138 fox return of the carrier 88 to its wide-open-throttle or rest position.
If upon arrival of the carrier contact 128-at the reference contact 116 the engine speed has reachea the overspeed speed of 4300 rpm, then the control 119 will cause the electrical contact between contacts 128 and 116 to be ignorled, and the carrier 88 will continue to be driven in close throttle dire~tion past the reference contact 116 until the control 119 detéct6 engine speed within the 4000-4300 rpm r~nge or the carrier reach~ its maximum close throttle, idle, or overspeed position. This condition normally will occur only when an overrunning load ha~ been applied to the governed engine, such as running the associated vehicle down a steep hill, or when the switch plate 92 has been miss-set. Upon deceleration of the engine speed to within the 4000-4300 rpm range, the control 119 will energize the motor 132 in the open throttle direction until the carrier contact 128 loses contact with the reference position contact 116 and the governor 90 will revert to the alternating circuit mode of operation.
In normal operation, three operating conditions should be considered, the first being that where the engine cannot main-tain ~he governed or set speed with the throttle plat~e 35 at its reference position because of a heavy load such as an uphill grade, ~2~5~
SQ that engine speed ~lls below .the ~xempl~r~ 4000 rpm set speed a~ter having attatned it u~der ~ull throttle and actuated the carrier 88 toward its re~erence position to limit the throttle plate 35 to some lesser opening, As soon as the engine reacts to moving the throttle plate toward its refer~ence position by dPcele-rating below 4000 rpm, the governor 90 will be deactuated by the contxol 119, and the carrier 88 will-be moved toward open throttle until the engine again accelerates to the set speed of 4000 rpm, which will reverse the carrier into movement towa~d closed throttle once again--thus the throttle plate 35 will oscilla~e throug~ a limited range of positions as necessary to hold ~he .engine speed .very near the set speed, the frequency and magnitude of the oscillations of the throttle plate 35 and the engine speed being determined by the interrelationships of engine ~ower, load applied, and gear ratio being used in the transmission 22, or accelerational decelerational capacity of the engine, togethe~ with the response speed of the motor 132 and its screw 140 driving the carrier 88.
The second operating condition is that where the reference position of the throttle plate 35 is just sufficient to maintain the engine speed in the 4000-4300 rpm range--in this case, the con-trol ll9 will keep the governor 90 in its alternating circuit mode of operation, and the engine speed may wander within the 4000-4300 rpm range while the throttle plate 35 is held at its reference posi-tion (assuming that the accelerator pedal 72.is held depressed at least sufficiently to open the throttle plate 3S that far). If the engine speed goes outside the 4000 4300.rpm range, the governor 30 will be de-actuated below 4000 rpm or ~o into the overspeed mode of close throttle arive as explained hereinbefore above 4300 rpm.
The third operating condition is that where an over-running load such as a moderate downhill grade is imposed on the ngine 20 ~uch that when the ~oyernor 30 has acted to close the throttle pl~te 35 to its idle or overspeecl position, as previously explained, ~hen ~he engine speed drops below 4300 rpm, thereby causing the carrier 88 to m~ve back towarcl its re~erence position.
Assum.ing the accelerator pedal 72 being sufficiently depxessed, the throttle plate 35 will open until the engine speed again goes above 4300 rpm and the control 119 causes the carrier to move in close throt~le direction again, and the cycle will repeat, allowiny small oscillations of the throttle plate 35 about an average position permitting an engine speed of about 4300 rpm and small oscillations of the engine speed about 4300 rpm. Here again, the parameters of engine accelerational/decelerational ability~ gear ratio, and carriex 88 response time determining the period and magnitude of the oscillations.
Operation of the engine 20 at speeds below the set speeds is perfectly free of any control by the ~ngine speed governor 90 except in the aforementioned case of rapid acceleration between precall and close throttle speeds of 3400 and 3600 rpm respec-tively.
An electronic logi~ module 144 (not shown in Figs. 1 and 2) for the electronic control portion 119 of the governor 90 is mounted within the housing 33 of the governor 30. As shown schematically in Fig. 5, the module 144 includes conventional integrated circuits and electronic components which opexate as described below to receive negative pulse signals from an internal combustion engine ignition coil (or alternatively from a pulse generator connected to a Diesel engine or other prime mover), and signals from the switch plate contac~ 116 and the open and close throttle contact5 134 and 136 respectively, in order to control the reversible electric motor 132 as described hereinb~fore.
25~:~
To control engine speed a method is first needed to -detect the engine speed. This is accomplished by a frequency to voltage converter. The engine speed is proportional -to the number of ignition pulses per minute as monitored at the negative terminal of the ignition coil of the engine 20. These pulses are fed into terminal A. Voltage divider resistors Rl and R2 are selected so that the transistor Ql (normally off) will turn on once for each ignition pulse. A resistor R3, a variable potent-iometer Pl and a capacitor Cl form a resistor-capacitor timing network. For each ignition pulse, the transistor Ql will turn on, and in turn fully discharge the capacitor Cl. As the engine speed increases, the transistor Ql will -turn on more frequently.
With the transistor Ql off, the capacitor Cl starts to charge.
As the voltage rises on the capacitor Cl to approximately 1/2 of the ten volt supply voltage, the logic norgate ICl-l of the quad norgate ICl will have its output (pin 3) change state from high to low. When the output is high, the capacitor C2 is being charged through the resistor R4. A change in output from high to low will cause the capacitor C2 to be discharged. sy properly selecting the values of R3, Pl, Cl, R4 and C2, an average voltage will appear on the capacitor C2 which is proportional to engine speed. The faster the engine speed (ignition pulses) the higher the voltage, the slower the engine speed the lower the average voltage.
A voltage comparator circuit is used to determine when various predetermined engine speeds occur. The speeds are:
precall, close throttle, governed, and overspeed. The circuit consists of four voltage comparators IC2-l, IC2-2, IC2-3 and IC2-4 and five resis-tors Rl9, R5, R9, R10, and Rll which set the individual voltages at which each comparator functions.
The precall and close throttle comparators operate S~ 3 cooperativel~ in sequence. Their pur~ose is to determine whether the engine is accelerating ~n speed so ~ast that the engine speed governor should be actuated ~e~ore the set speed is reached. If this condition occurs, the precall and close throttle com~arators IC2-1 and IC2-2 act toge~er to start the go~ernor operating even ~efore the predetermined governed speed is reached. A typical example would have the precall speed set at 3400 RPM, the close throttle speed at 3600 RPM, the governed speed at 4000 RPM and the overspeed at 4300 ~PM. }~ the engine should accelerate between 3400 and 3600 RPM within 200 milisec, this rate ~f acceleration would cause the close throttle norgate ICl-2 to ~unction to operate and activate the governor. When the engine speed increases at a - slower rate the precall close throttle circuitry is inoperative and plays no part in the operation.
Upon reaching 4000 RPM, the governor or set speed compaxator IC2-3 begins its normal governing. 'At 4300 RPM the overspeed comparator IC2-4 turns on, causing the governor 90 to go toward completely closing the throttle plate 35.
When the engine acceleration exceeds the normal governor reaction capability, the close throttle comparator IC2-2 causes the control 119 to start the governing process prior to 4000 RPM
being reached. In the event of such a condition, the precall and close throttle comparators IC2~1 and IC2-2 provide signals to the close throttle norgate IC1-2 which in turn provides a signal to a flip-flop circuit composed of the two norgates ICl-3 and ICl-4. With the proper signal the flip-flop circuit is set so that the output of pin 4 o~ ICl-4 goes high and acts through the norgates IC3-1 and IC3-2 of the quad norgate IC3 to cause the transistor Q2 to drive the motor 132 and the associated carrier contact 128 in the close throttle direction. Upon the c~arrier . ~ --19 -, j,:
.
~ontact 128 reachin~ the normally open re~erence position contac~
116 of the s~itch pl~te 92 the ~lip flop circuit receives a reset signal ~om the norgate IC3-3 at pi,n 5 of the norgate ICl-4 and pin 4 thereof goes low. The precall close throttle function cannot reoccur unless the engine speed drops below the 3400 RP~
precall level, and only then could the process be repeated, The quad norgate IC3 comprises the logic circuitry which allows the electronic logic module 114 to control the governor 90 in proper sequence. Pin 6 of norgate IC3-1 is normally low. With a high signal at pin 6, the output pin 4 o~ norgate IC3-1 goes low and causes the output pin 10 o~ norgate IC3-Z to go high. This will turn on the transistor Q2 and d~ive the motor 132 in the close throttle direction. The motor continues driving the carrier 88 in the close throttle direction until its contact 128 reaches the reference position contact 116. Grounding the reference con-tact 116 causes pin 2 of the norgate to go low;and pin 3 thereof to go high. Pin 3 going high will cause pin 10 of the norgate IC3-2 to now go low. When pin 10 goes low, it causes pin 11 of the norgate IC3-4 to go high which turns on the transistor Q3, driving the motor 132 in the open throttle ~irection. The carrier 88 going in the open throttle direction will remove the carrier contact 128 from the reference contact 116 and change pin 2 of the norgate IC3-3 from low back to high and the process will keep repeating~ This operation is known as the alternating circuit feature since the motor 132 will alternately drive the carrier co~tact 128 on and off the reference contact 116. The amount of movement is very small and effectivel~ keeps the carrier 88 at its reference position at the threshold of the reference position - contact 116.
Should the engine speed keep increasing to 4300 RPM as ~ ;
does happen in some isolated in~tances, it is necessary that the alternating circuit mode be overridden so that the motor will ,,-,, drive the carrier contact 128 past the threshold of the reference contact 116 ully in the close throttle dire~tion. When such an instance is detected by the overspeed comparator IC2-~, pin 14 thereof goes high and continually holds pln 3 of the norgate IC3-3 low~ This overcomes the effect of the reference contact-116 being grounded at pin 2 o~ the norgate IC3-3 and allows pin 10 of the norgate IC3~2 to remain high as long as the overspeed condition exists. Dropping below the overspeed value of 4300 RPM allows the governor comparator IC2-3 cixcuitry to govern as normal.
The Zener diode ~1 in series with the resistor R 18 across the 12 volt battery supply voltage, as shown in Fig. 5, pro~ides,a stabilized 10 vo~t supply for the logic module 144 as indicated at various points therein.
An alternative second embodiment of the engine speed governor 90 provides for operation of the motor 13~ t,and thereby the carrier B8) at a substantially slower speed in open throttle direction than in close throttle direction--approximately 15-18 seconds to rotate the carrier 88 from idle position to wide-open-throttle position as compared to about 3 seconds to rotate it from wide-open-throttle to idle position. The slower speed is accomplished by the circuitry of Fig. 6, which shows in schematic detail the changes and additions to the circuitry of Fig. 5--the portions of Fig. 5 which are not repeated in Fig. 6 are identical in both circuits. The additional resistor ~20 in the connection between the transistor ~3 and the motor 132 serves to reduce the voltage supplied to the motor, and with the resultant reduced speed, it is desirable that, upon arrival of the carrier contact 30 128 at the reference contact 116 subse~uent to actuation of the governor 90, that the contact 128 should remain at the reference ~2~S~
~ntact so long as the engine speed remains in the 4000-4300 RPM
range~ There~ore, the pin 13 of th.e norgate IC3-4 is now connec.ted to limiting ctrcultry comprising the transistors Q4, QS, and Q6 and their'associated added componentsO ~ow, when the contact 128 touches the contac~ 116, the motox 132 is turned of, and so long as the engine speed remains in the 400~-~'lO0 RPM xange, it remains off. If the engine speed drops below ~000 RPM, the governor com-.
parator IC2-3 will cause the motor 132 to run in open throttle direction ~a~ the slow speed) until the engine again rises to 4000 rpm, or until the carrier B8 moves i~ Qpen throttle direc-tion sufficiently for the carrier contact 128 to cross the narrow gap 122 and touch the limiting contact 120 on the switch plate 92--in either case, the open throttle drive ceases; and in the first case the yovernor comparator IC2-3 causes the motor 132 to drive in the close throt'tle direction, while in the secona case the carrier contact 128 remains at the limiting contact until the engine either rises to 4000 RPM and the governor comparator IC2-3 causes close throttle drive, or the engine drops below the precall speed of 3400 RPM and the precall comparator IC2-1 causes open throttle drive, carrying the carrier contac*'l28 past its initial contact with the limiting contact 120 toward the wide-open-throttle position of the carrier 88.
This second,'slow speed, embodiment is advantageous for lessening engine speed oscillations, but is disadvantageous in that the slow travel of the carrier 88 toward open throttle may sometimes handicap the operator who is trying to get a rapid acceleration of the engine for shifting gears.
Yet a third embodiment of my engine speed goVernor inven-tion provides for normally fast travel of the carrier 88 toward its reference position upon actuation o~ the engine speed governor 9~
O until the ca~rier contact 128 moves of~ the limiting contact 120, at which ~he motor 132 drops to a very slow speed resulting 1n clockwise mo~ement of the caxrier 88 about lts shaft 94 at the rate o~ about one-third RP~, whlch would ~e roughly e~uivalent to full travel ~rom wide-open-throttle position ~o idle throttle positlon in about thirty seconds~ ~n objective of this slow speed is to move the carrier 88 in limiting control of ~he throttle plate 35 at a slower rate than the response capability of the engine 20, thereby minimizing engine speed oscillations r Since the response capability of the engine will vary considerahly according to loads and gear ratios, recovery time ~from the loss of engine speed due to sudden application of a heavy ~oad while running at the governed speed under light load) could be somewhat slow--however, this is not the usual condition and is overweighed by the stability of thP system for normal operation.
The relation of engine response capa~1lity rate ana throttle limiting means movement rate is a complex one, but cons.ider that any engine running at idle speed and having full throttle suddenly applied will take a second or two to reach a speed of say 40G0 RPM, and if a governor acts to close the throttle quickly to closed or idle throttle position upon attainment of the 4000 RPM speed, the engine speed will overshoot or overrun the 4000 RPM speed and then decelerate below the 4000 RPM speed and undershoot or underrun it, even though the governor acts to open to full throttle again immediately upon the speed dropping ~elow 4000 RPM. This may cause oscillations of engine speed o~
1000 RPM or more in an unloaded engine, rapidly enough to be disturbing to its operator, and resulting in a governor with very poor regulation. This is an example of a throttle limiting means moving at a very ~uch ~aster rate than the engine response capa-bility rate, and results in out-of-phase operation o~ engine and ~ 25~
throttle as explained in m~ aforesaid patent.
On the other hand~ ~t has been found that where thethrottle can only be moved between idle and full positions over a perio~ o~ about twent~ sec~nds or more, then in phase operation o~ engine and throttle occurs~ as in the present invPntion, and very good governor regulation can be obtained~ The engine has the capability of increasing its speed w:ith very little lag behind the throttle position~ even under heavy or ~ull load, meaning that if the throttle is opened half-way at this slow rate or 19 slower~ that the engine will have come up in speed slowly with the slow opening and will have achieved its m~imum sustained speed for ~his throttle opening and particular load momentarily after the throttle movement stops, ana will overrun the afoxesaid maximum ~ustained insignificantly, thereby staying essentially in phase with the throttle, even under no load conditions. In the commercial engine application ran~e conslaered so far, an approximately twenty to twenty-five second throttle movement period seems about the optimum for sati6~ac~ory governor regula~
tion for a smoothly operating governor and a period as short as seven or eight seconds causes objectiona~l~ os~illations. Of course, to obtain satisfactory restraint ~nder no load engine r~n-up conditions and satisfactory recovery from sudden load applications, it is desirable to have fast throttle closing upon sudde~ acceleration o~ the engine, and fast throttle opening upon sudden deceleration. The apparatus of the present invention provides such cap~bility for both fast and slow throttle movement through the use of a reference position for the throttle limiting means, such that throttle movement will be slow under normal conditions, but may be swift when needed for recov~ry of control of a rapidly fluctuating engine speed caused by so~e factor external to the governor. To date, the apparatus of the present invention is the onl~ known solution to this problem for every-day commercial use~ e.g., ~s ~or truck and bus engines. Upon arrival at its re~erence posltion, assum.ing that the engine speed still lies in the 4000-4300 RPM range, the carrier stops and remain~ in place, moving there~om only upon detection of engine speed outside the 4000-4300 RPM range, and only at the above-mentioned slow speed, whether in open throttle or close throttle direction.
When the engine speed drops below 4000 RPM, the motor 132 is energized at the slow speed in open throttle direction and continues in that direction until the carrier contact 128 hits the limiting contact 120 and halts there, unless in the meantime the engine speed has risen again to 4000 RPM to cause the motor 132 to be reversed to close throttle direction, or has dropped below the 3400 RPM precall speed which will cause t~e carrier 88 to contlnue to open throttle direction, but at high speed after touching the contact 120. I~ the carxier contact 128 is halted upon touching the limiting contact 120, it remains there pending detection of engine speed rising to 4000 RPM to cause close throttle drive at the slow speed, or engine speed falling below the 3400 RPM precall speed to cause open throttle drive just as in the second embodiment; however, the motor 132 will return to its normal fast speed because the carrier contact 12B is contact-ing the limiting contact 120.
As a practical matter, on a long steep grade in a truck engine application, where a considerably open throttle position is xequired to maintain the engine at the 4000 RPM
governed speed, a~ter the throttle limiting means has been moved to the reference position, then the governor will allow the ~2~S9~
throttle to slowly open farthex to a point where its average position furnishes just the ~uel needed to maintain 4000 RPM with only minor oscillatlons therea~out as the throttle is opened and cl~sed slightly b~ governor detection o engine speed falling below 4000 RPM and then rising back to that speed.
The circuitry for ~btaining the slow-motor speed in both directions, and only when the carrier contact 128 is out of contact with the limiting contact 120~ comprises essentially a suitable resistor R31 placed in the 12 volt common supply connec-tion to the motor 132 as shown in Pig. 7 in partial schematicdetail. The resistor R31 reduces the voltage across the motor 132 sufficiently to cause it to run at the desirable low speea in close throttle direction where the force o~ the load speed governor spring 142 and throttle apparatus springs must be overcome, and a second resistor R30 in the open throttle connec-tion between the transistor Q3 and the motor 132 reduces the voltage across the motor even farther to compensate ~or the over-running force applied by the governor spring 142 and throttle apparatus springs when the motor runs in throttle openiny direc-tion. A PNP transistor ~7 is connected in parallel with theresistor R31 and is controlled indirectly through additional circuitry (not shown) associated with the limiting contact 120 by the condition thereof. When contact 120 is grounded by contact with the carrier contact 128, the transistor Q7 is caused to be conductive, the resistor R31 is shunted out o~ the circuit and is of no effect, and the motor 132 runs at normal fast speed.
When the carrier contact 128 leaves the limiting contact 120, leaving it ungrounded, then the transistor Q7 goes non-conducting and all current to the motor 132 must pass through the resistor 31, so that the motor runs at the desirable slow speed~
~3L2~
This third, slow speed, embodiment lessens the oscilla-tiQnS of en~ine speed, Rnd would be preferable to the first, alternatin~ circuit, embodiment except that the low motor voltages rPquired to obtain a suit~bl~ slow operation o~ the motor 132 may not provlde su~icient startin~ torque ~or reliable motor operation under extreme cold weather conditions~ However, gover-nors 30 according to this third embodiment have worked satis-factorily in moderate tempexature conditions and commercially demonstrate the advantages of slow speed operation of the motor 1~ 132.
Control o~ the motor 132 by the load speed governor 86 ~through movement of the carrier 88 and its open throttle and close throttle contacts 134 and 136 respectively, by action of the flyball mechanism 146 to move the grounding contacts 138~ is ~the same as that disclosed in my aforementioned prior patent ~ re~bil~ whereby the load speed governor can overridingly run the motor 132 in close throttle direction in resp~nse to suit-ably high load speed at any time, and the engine speed governor 90 can aO likewise at any time in response to a suitably high engine speed, ~t the load speed governor can only run the motor 132 in open throttle direction in response to a suitably low load speed when the engine speed governor 90 is als~ calling concurrently for the motor to operate in that direction in response to a suitabl~ low engine speed by making the transistor Q3 cbnductive, and vice-versa.
The present invention has been described in detail above for purposes o~ illustration only and is not intended to be limited b~ this description or otherwise to excluae any variation or equivalent arrangement that would be apparent from, or reasonably su~gested by, the foregoing disclosure to the skill of the a~t, Buch as the substitution of vacuum or mechanical 259~ -~r other actuators~ for the electrically driven lead screw dis-closed herein, the substitu~ion o~ centrifugal or magnetic or other engine speed responsi~e means ~or the electronic module disclosed herein, or the substit~tion of magnetic or electronic or other load speed respons~ve:means ~or the fly ball mechanism disclosed herein. I.e., the scope of the present in~ention is to be determined by the scope of the appended claims.
~2~-
Claims (6)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. In an engine speed governor for an engine having a throttle movable between an open throttle position and a close throttle position for regulating the flow of fuel to the engine, said governor being of the type comprising an overriding throttle closing means, engine speed sensing means for producing a speed signal, and control means for moving the throttle closing means to a position for limiting the engine speed to a predetermined governed value, the improvement wherein said control means includes:
actuating means including a reversible motor coupled with the overriding throttle closing means for driving it in the close throttle direction or the open throttle direction, electronic circuit means coupled with said speed sensing means and with said motor for energizing the motor, said circuit including means responsive to a predetermined speed signal for energizing the motor for relatively high speed operation in the close throttle direction until the overriding throttle closing means reaches a reference position, said circuit means including means for energizing the motor for relatively low speed operation in either the close throttle or open throttle direction after the overriding throttle closing means reaches said reference position, said low speed operation of the motor being slower than the response capability of the engine to a change in flow of fuel to the engine whereby engine speed oscillations are minimized.
actuating means including a reversible motor coupled with the overriding throttle closing means for driving it in the close throttle direction or the open throttle direction, electronic circuit means coupled with said speed sensing means and with said motor for energizing the motor, said circuit including means responsive to a predetermined speed signal for energizing the motor for relatively high speed operation in the close throttle direction until the overriding throttle closing means reaches a reference position, said circuit means including means for energizing the motor for relatively low speed operation in either the close throttle or open throttle direction after the overriding throttle closing means reaches said reference position, said low speed operation of the motor being slower than the response capability of the engine to a change in flow of fuel to the engine whereby engine speed oscillations are minimized.
2. The invention as defined in Claim wherein, said actuating means includes first and second stationary electrical contacts and a movable electrical contact which is movable concurrently with said overriding throttle closing means, said movable contact being sequentially engaged with said first contact, neither of said contacts and then with said second contact when the overriding throttle limiting means moves from wide open throttle position to close throttle position, said first contact being connected with said circuit means for causing it to energize the motor for high speed operation when said first contact is engaged by said movable contact and for causing it to energize the motor for low speed operation when said first contact is disengaged by said movable contact, said second contact being connected with said circuit means for causing it to stop the motor when said second contact is engaged by said movable contacts, said circuit means being operative to reversibly energize said motor at said slow speed in accordance with changes in said speed signal.
3. The invention as defined in Claim 2 wherein, said circuit means includes means for deenergizing the motor when the movable contact moves from said second contact to said first contact when the engine speed is less than a predetermined governed value, said circuit means being operative to energize the motor in the close throttle direction at said slow speed when the engine speed exceeds the governed value.
4. The invention as defined in Claim 2 wherein, said circuit means includes means for energizing the motor at said high speed in the open throttle direction when the engine speed is less than a predetermined precall value.
5. The invention as defined in Claim 1 wherein movement of said overriding throttle closing means from wide open throttle to close throttle would require approximately three seconds at said high speed and would require at least eight seconds at said low speed.
6. The invention as defined in Claim 1 wherein movement of said overriding throttle closing means from wide open throttle to close throttle would require approximately 20 to approximately 25 seconds at said low speed.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000432299A CA1212591A (en) | 1983-07-12 | 1983-07-12 | Engine governor with reference for throttle limiter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000432299A CA1212591A (en) | 1983-07-12 | 1983-07-12 | Engine governor with reference for throttle limiter |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1212591A true CA1212591A (en) | 1986-10-14 |
Family
ID=4125658
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000432299A Expired CA1212591A (en) | 1983-07-12 | 1983-07-12 | Engine governor with reference for throttle limiter |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1212591A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106121832A (en) * | 2016-08-12 | 2016-11-16 | 江门市英合创展电子有限公司 | A kind of inlet manifold path control of gear train transmission |
-
1983
- 1983-07-12 CA CA000432299A patent/CA1212591A/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106121832A (en) * | 2016-08-12 | 2016-11-16 | 江门市英合创展电子有限公司 | A kind of inlet manifold path control of gear train transmission |
| CN106121832B (en) * | 2016-08-12 | 2022-10-11 | 江门市英合创展电子有限公司 | Gear set transmission intake manifold access controller |
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