GB2192227A

GB2192227A - Variable ratio throttle valve operating mechanism

Info

Publication number: GB2192227A
Application number: GB08714758A
Authority: GB
Inventors: Raymond Stocker
Original assignee: Ford Motor Co
Current assignee: Ford Motor Co
Priority date: 1986-07-02
Filing date: 1987-06-24
Publication date: 1988-01-06
Also published as: DE3721801A1; GB8714758D0; DE3721801C2; JPS6323058A; GB2192227B

Description

GB2192227A 1 SPECIFICATION of opening movement of the throttle valve as

the accelerator pedal is depressed through its Multi ratio accelerator cable mechanism final opening angle with a lesser linear travel of the cable mechanism, this being accom This invention relates in general to a cable 70 plished by an automatic switching from a lever mechanism for connecting a vehicle accelera- arm of one length to another of a shorter tor pedal to an engine throttle body throttle length as the fulcrums change, and in a valve linkage. More particularly, it relates to smooth efficient manner upon continued de one that provides for a slow initial rate of pression of the vehicle accelerator pedal mov movement of the throttle valve in response to 75 ing the throttle lever and throttle valve from a depressing the accelerator pedal through a closed to a wide open throttle position.

large angle followed by a faster rate of move- According to the present invention there is ment of the throttle valve in response to con- provided a variable rate movement mechanism tinued depression of the accelerator pedal for use with the accelerator cable mechanism through its final movment. This reduces coast- 80 connected to a motor vehicle type throttle to-drive driveline backlash, pedal tip-in noise body having an air/airfuel induction passage or feel, while at the same time providing a (12) controlled by a throttle valve (14) rotata more precise low speed pedal control. The bly mounted therein for a pivotal movement multi-rate control of the invention also pro- between positions (17,18) variably opening vides a better feel and control by the operator 85 and closing the induction passage, the throttle with respect to the opening of the carburetor body having a throttle lever (20) secured for throttle valve, and one without the so-called rotation with the throttle valve (14) for rotat driveline clunk that can result from changes in ing the same and a cable mechanism (52) op direction of application of torque when the drieratively connecting the vehicle accelerator vetrain shifts from a coast to a drive condi- 90 pedal (19) to the throttle lever, the improve tion. ment comprising, cam and cam follower con The use of multi-rate movement control trol means (43, 44, 46) connecting the end of mechanisms in general to provide different the cable mechanism (52) to the throttle lever rates of movement of a particular member is (20) and including a cam (43) secured at one known. For example, my patent, U.S. 95 end to the cable mechanism one end, the cam 3,446,091, shows and describes a cam and having a cam surface (48) thereon, and cam cam follower mechanism that provides differ- follower means (34, 36) pivotally secured to ent rates of movement of the -accelerator and projecting from the throttle lever (20) and pedal to maintain comfortable and positive op- having a plurality of parts (34, 36) engagable eration. My patent, U.S. 4,429,589, further 100 with the cam surface (48), the plurality of shows a dual ratio accelerator-arm assembly parts being radially spaced from one another providing dual fulcrums for various rate move- and from the throttle lever pivot (16) whereby ments of the arm to control the opening continued linear movement of the cable movement of the carburetor throttle valve. mechanism (53) by rotation of the vehicle ac Other patents of interest illustrating other 105 celerator pedal (19) from an initial. at-rest en dual movement mechanisms are those to Gri- gine idle speed position initially effects an ar ffin et a[, U.S. 4,476,068; lacoponi, U.S. cuate pivotal opening movement of the throt 4,352,483; and Tanahashi et al, U.S. tle lever (20) at a first rate of movement by 4,411,845; all of which indicate cam and cam the forced arcuate pivotal movement of a first follower means for providing different rate 110 part (36) of the cam follower means parts by movements of elements associated with a car- the cam surface (48) about another part (34) buretor throttle valve. of the cam follower means parts as a fulcrum Still further prior art of interest are the followed by an arcuate pivotal movement of mechanism shown and described by Mitrovich, the throttle lever at a second different rate of U.S. 2,814,957; See et al, 1,926,634; Voser, 115 movement by the forced arcuate pivotal move U.S. 3,086,406; Ludwig, U.-S. 1,916,323; and ment of a second part (34) of the cam fol Warren, U.S. 1,928,083. lower means parts by the cam surface (48) While the above references show-in general about another part (36) of the cam follower devices providing dual rate movements, none means parts as a fulcrum.

show a simple and cost efficient multi-fulcrum 120 The multi-rate movement accelerator cable cable control mechanism such as will be de- mechanism embodying the invention consists scribed. More particularly, the mechanism con- of essentially few parts, is easy to assemble sists of a simple cam and camfollower device and disassemble, and yet provides a slow, having a number of pivot points that alternate initial rate of movement of the throttle valve in as fulcrums depending upon the position of 125 response to depression of the vehicle acceler the accelerator pedal to cause a slow initial ator pedal through a large angle comparable to opening movement of the throttle body throt- approximately seventy percent of its total tra tle valve as the accelerator pedal is depressed vel, followed by a faster rate of the remaining through a large angle effecting a large linear opening movement of the throttle valve in re travel of the cable, followed by a faster rate 130 sponse -to the remaining thirty percent of an- 2 -. GB 2 192 227A 2 gular movement of the accelerator pedal to ing cable linkage provides a finer tuning of the the throttle valve wide open position, the two movement of the throttle valve compared to movements together being accomplished that of the prior art.

smoothly and efficiently without an appreciable Returning now to Fig. 1, fixedly attached to indication to the vehicle operator of a change 70 throttle valve shaft 16 is a bellcrank type lever in the rate of movement. 20. The upper arm or end 22 of the lever is The invention will now be described further bent and provided with a right angled flange by way of example with reference to the ac- 24 for engagement with the end of a known company drawings in which: type of dash pot mechanism 26. The details Figure I illustrates schematically a side ele- 75 of construction and operation of the latter are vational view, with parts broken away and in known and therefore not given since they are section, of a cable mechanism embodying the believed to be unnecessary for an understand invention; ing of the invention. Suffice it to say that, in Figure 2 is a top view of a detail of Fig. 1; general, the dash pot slows closing of the Figure 3 is an enlarged view of a detail of 80 throttle valve lever 20 to the engine idle Fig. 1, with parts broken away and in section; speed position when the accelerator pedal is Figure 4 is a cross-sectional view taken on released to prevent stalling of the vehicle by a plane indicated by and viewed in the direc- too rapid a cut-off of supply of air to the tion of the arrows IV-IV of Fig. 3; vehicle.

Figures 5'and 6 are side elevational views, 85 The upper arm 22 of throttle lever 20 in with parts removed for clarity, of modifica- this case has a pair of holes or apertures 30, tions; and 32 (also see Fig. 3) at varying or different Figure 7 is an end elevational view of the radial distances from the pivot shaft 16. Each - embodiment shown in Fig. 5. of the holes is adapted to receive pivotally Fig. 1 shows an assembly that connects the 90therein a shaft 34, 36, the shafts having apconventional vehicle accelerator pedal to a propriate cotter pin type holes 38, 40 at their throttle body throttle valve in a manner to be ends (Fig. 4) into which is inserted a keeper described to provide the dual rate movement 42.

desired. More particularly, the assembly in- Both pins 34 and 36 are adapted to be cludes a portion 10 of a conventional throttle 95 inserted and project into the hollow interior of body having the usual air/air-fuel induction the oval shaped cam portion 43 of a cam, passage 12. Flow is controlled by a plate type cam follower type lever 44 formed at its other throttle valve 14 that is fixedly- mounted on a end with a rod like actuating end 46. A pair shaft 16 that is rotatably mounted in the sideof retaining plates 50, 52 fixedly secured on walls of the carburetor. The valve 14 rotates 100 pins 34, 36 enclose the open sides of the from the,an'engine idle speed closed throttle cam. The cam lever assembly thus consists of position -17 to a wide open- throttle position a rod 46 having a washer like end 43 having 18. In conventional constructions, initial dein this case an essentially heart-shaped interior pression of the vehicle accelerator pedal 19 cam surface 48 with which a pair of pins 34, provides -a fast corresponding movement of 105 36 engage, and the sides of which are en throttle valve 14 through a large opening closed by a pair of plates 50, 52 affixed to angle, thus providing a relatively fast forward the pins that are pivotally mounted to throttle vehicle acceleration. This also may result in lever 20. As will be described more clearly - driveline "clunk" due to a reverse application later, this construction permits an operation of torque being applied as the drivetrain 110 that includes an initial linear movement of rod changes from a coast-down overrunning con46 a large distance with a slow pivotal move dition to -a drive condition. - ment of the throttle lever 20 in response One of the main purposes of the invention thereto, and a subsequent smaller linear travel is to eliminate the unsmooth accelerations and of rod 46 providing a faster angular move- "clunk"/noise conditions by delaying or slow- 115 ment - of the throttle lever 20.

ing down the response of the'throttle valve to The rod end 46 of cam lever 44 is secured the large'-initial angular depression of the to one end of a Bowden wire type calbe 52, vehicle accelerator pedal until -the throttle valve the latter projecting ftough a fitting 54 and reaches a predetermined olieningi at which - the vehicle firewall 56 for attachment to the point the. rate of movement of the throttle 120 upper end 58 of the vehicle accelerator pedal valve is increased essentially without an inbellcrank lever 60, as shown. The fitting 54 in crease h the rate of movement of the vehicle this case is screwed to a engine bracket 62 accelerator pedal so that the transition from to which is attached one end of a throttle closed to: wide open throttle positions is con- - valve return spring 64. The opposite end of stant and uniform. This also " permits a more 125 the spring is secured to the lower crank arm accurate -control of Jhe opening movement of portion 66 of throttle lever 20.

the throttle valve compared-to prior construc- Before proceeding to the operation, it tions since the initial slow ate of movement should be clear from the above that the dis of the. throttle valve in response to a large tancd from the throttle lever pivot 16 to pin travel of the-accelerator pedal and correspond-130 34 will establish one lever arm of a certain 3 GB2192227A 3 length; while the distance from pivot 16 to and lever 20 to the initial position 72 as the the pin 36 will establish a shorter lever arm, fulcrum changes from pin 36 to pin 34, shift thereby providing different rates of movement ing the pivoting from the shorter to the longer of throttle lever 20 depending upon which pin lever arm.

is acting as a fulcrum about Which the other 70 Figs. 5-7 show modified versions of the pin pivots. cam lever assembly shown and described in In operation, therefore, depression of accel- Figs. 1-4. More particularly, Fig. 5 shows the erator pedal 19 will draw cable 52 leftwardly, use of a one piece tang 78 instead of two as seen in Fig. 1, to move rod 46 and cam pins engaging cam surface 48'. In this in- 43 in the same direction. The geometry, i.e., 75 stance, the continuous surface of the tang the contour of cam surface 48, is such that provides an infinite number of fulcrums or pi with outer pin 34 attached to throttle lever 20 vot points cooperating with the cam surface at the greater radial distance from pivot shaft 48'. Cam surface 48' would be contoured so 16, leftward movement of the whole assembly as to progressively vary the rate of movement will swing pin 34 on an arc as shown about 80 of the throttle lever 20 upon depression of pivot 16, by movement of the cam follower the vehicle accelerator pedal, surface 48 against pin 34. This will establish Fig. 6 is a showing similar to Fig. 5; how pin 34 as a fulcrum about which pin 36 will ever, in this case, instead of a one piece tang move in a counterclockwise direction because 78, an additional pin 80 pivotally secured to of its attachment to lever 20 until pin 36 85 throttle lever 20 is placed radially between the reaches the end point 70 of the essentially two pins 34', 36'. Again, the pin 80 provides heart-shaped cam surface ' The reaction then an additional fulcrum when it engages the cam will shift the fulcrum from outer pin 3.4 to the surface 48" and about which the other pins radially inner pin 36 as evidenced in Fig. 3 by can pivot to provide a different rate of move the movement of pin 34. It will be noted that 90 ment of throttle lever 20 than those estab rod 46 will have travelled loftwardly a rela- lished by engagement of pins 34 and 36 with tively large distance as compared to the rela- the cam surface. The cam surface 48" again, tively small angular movement of pin 36 be- would be contoured to provide the desired fore pin 36 is stopped at the point 70. This cooperation with the number of pins provided.

small slow movement of pin 36, however, will 95 It will also be clear that embodiments other provide an opening movement of the throttle than those of Figs. 5 and 6 could be provided valve of approximately fifty percent of its total showing more pins than that of Fig. 6, for opening. example, accompanied by an appropriate con The throttle lever now will pivot about the touring of the cam surface with which each point 16 using the shorter lever arm from the 100 cooperates.

pivot to the pin 36 as the control. Pin 36 From the foregoing, therefore, it will be now is established as the fulcrum about which seen that the invention provided an accelerator the pin 34 will pivot. Continued leftward cable mechanism establishing variable rates of movement of cam lever 46, therefore, now movement of the throttle lever in response to continues the counterclockwise pivotal move- 105 depression of the vehicle accelerator pedal, ment of throttle lever 20 about its pivot using and a mechanism that is simple in construc the shorter arm to determine the travel. The tion and consists of few parts that are easy pin 34 now rotates counterclockwise at a to assemble and disassemble and is efficient faster rate in proportion to the rate of pivotal in operation.

movement of lever 20. Thus, -the throttle 110

Claims

valve opens at a faster rate than initially. CLAIMS

However, insofar as the vehicle operator is 1. A variable rate movement mechanism concerned, depression of the vehicle accelera- for use with the accelerator cable mechanism tor pedal has been made essentially in a conconnected to a motor vehicle type throttle stant, smooth manner from initial opening to 115 body having an air/air- fuel induction passage its wide open throttle position, since the (12) controlled by a throttle valve (14) rotata change in rate of movement of the throttle bly mounted therein for a pivotal movement valve is essentially imperceptible. The three between positions (1,7,18) variably opening throttle lever positions, i.e., initial 72, change- and closing the induction passage, the throttle over 74, and wide open throttle 76, are indi- 120 body having a throttle lever (20) secured for cated'in Fig. 3 in dotted lines ' ' The differences rotation with the throttle valve (14) for rotat in linear travel of the rod 46 also will be clear. ing the same and a cable mechanism (52) op Of course, release of the velii-cle accelerator eratively connecting the vehicle accelerator pedal 19 towards the closed throttle valve po- - pedal (19) to the throttle lever, the improve sition will cause a movement of the parts and 125 ment comprising, cam and cam follower con operation, in reverse; i.e., throttle valve 14 trol means (43, 44, 46) connecting the end of first will move clockwise at a fast rate as pin the cable mechanism (52) to the throttle lever 34 is forced rightwardly or clockwise-to the (20) and including a cam (43) secured at one changeover position 74 shown, followed by El end to the cable mechanism one end, the cam slower pivotal movement of the throttle valve 130having a cam surface (48) thereon, and cam 4 GB2192227A 4 follower means (34, 36) pivotally secured to and projecting from the throttle lever (20) and having a plurality of parts (34, 36) engagable with the cam surface (48), the plurality of parts being radially spaced from one another and from the throttle lever pivot (16) whereby continued linear movement of the cable mechanism (53) by rotation of the vehicle accelerator pedal (19) from an initial at-rest en- gine idle speed position initially effects an arcuate pivotal opening movement of the throttle lever (20) at a first rate of movement by the forced arcuate pivotal movement of a first 1 part (36) of the cam follower means parts by the cam surface (48) about another part (34) of the cam follower means parts as a fulcrum followed by an arcuate pivotal movement of the throttle lever at a second different rate of movement by the forced arcuate pivotal move- ment of 6 second part (34) of the cam follower means parts by the Cam- Surface (48) about another part (36) of the cam follower means parts as a fulcrum. -
2. A mechanism as claimed in Claim 1, wherein the cam has a hollow interior with the internal wall defining the cam surface and the cam follower parts project outwardly from the throttle lever into the hollow interior for engagement with the cam surface.
3. A mechanism as claimed in Claim 1, wherein the cam comprises a ringlike element having an inner cam contoured -surface, the cam follower parts projecting outwardly from the throttle lever into the proximity of the cam surface for engagement therewith.
4. A mechanism as claimed in Claim 3, wherein the cam follower parts comprise a plurality of pins pivotally secured to the throttle lever at different radial extents from, the lever pivot.
5. A mechanism as claimed in Clairn 3, wherein the cam follower comprises a onepiece tang and the cam surface is contoured for cooperation with the tang surface to pro- vide an infinite number of fulcrum points.
6. A mechanism as claimeTin Claim 3, wherein the - cam follower parts comprise at least three radially spaced pins extending at right angles: from the throttle lever into the hollow interior of the cam for engagement with the cam surface therein.
7. A varibble rate movement mechanism for use with the accelerator cable mechanism connected to a motor vehicle type throttle body substantially as hereinbefbre described with reference to, and a illustrated in, the accompanyihg drawings.- Printed for Her, Majesty's Stationery Office by Burgess & Son (Abingdon) Ltd, Dd 89916C5, 1988. Published at The Patent Office, 25 Southampton Buildings, London, WC2A 'I AY, from which copies may.be obtained.