GB1579182A - Apparatus for controlling the flow combustible mixture to an internal combustion engine - Google Patents

Description

(54) APPARATUS FOR CONTROLLING THE FLOW OF COMBUSTIBLE MIXTURE TO AN INTERNAL COMBUSTION ENGINE (71) We, COLT INDUSTRIES OPER ATING CORPORATION, a corporation organized and existing under the laws of the State of Delaware, United States of America, and having a principal place of business at 430 Park Avenue, New York, New York, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is performed, to be particularly described in and by the following statement: This invention relates to apparatus for controlling the flow of combustible mixture to an internal combustion engine.

Heretofore, it has been accepted prior art practice to provide what was generally referred to as a fast idle cam which was positioned generally in accordance with the position of the choke valve of an associated carburetor. As is well known in the art, such choke valves were and are usually positioned to coact with a swingable abutment operatively connected to the engine throttle valve as to thereby be effective for holding the throttle valve open a greater degree during cold engine operation while permitting the throttle valve to close to an established idling or curb idle position, once the engine has attained some preselected operating temperature. as by permitting such swingable abutment to engage either a lowest step portion on the cam or engaging a positive non-movable abutment or stop portion formed as on the carburetor body structure.Such closing of the throttle to a curb idle position determined the absolute maximum closing of the throttle under all conditions of engine operation as well as during engine shut-down. Generallv. in the past, such prior art arrangements have been found to be adequatc. However, because of governmentally imposed standards relating to engine exhaust emissions. it has become necessary to provide different fuel metering characteristics to the fuel metering devices associated with such engines. This, in turn, has, among other things, caused the engine to have a tendency to continue to run even after the engine ignition is turned off; such often being referred to as engine "dieseling".It has been discovered that one way of being able to terminate or avoid such "dieseling" is to further close the throttle valve beyond its normal curb idle position.

However, as for reasons already discussed, such is not possible with the prior art arrangements.

Further, it is highly desirable to at times during periods of, for example. idle throttle position engine operation, to cause the throttle valve to if possible automatically open a slightly increased amount as to compensate for variations in loads, possibly suddenly, imposed upon the engine. The provision of such throttle position modulating means along with the requirement that the throttle valve be permitted to, at a selected time, move even further closed than the normal maximum closure of curbidle, has not been attainable with prior art structures.

Accordingly. the invention is primarily directed to the solution of the preceding as well as other related and attendant problems.

The invention consists in apparatus for controlling the flow of combustible mixture to an internal combustion engine, comprising: throttle valve means. spring means urging said throttle valve means towards the closed position: variablv positionable abutment means effective for operative engage mcnt with said throttle valve means when said throttle valve means is moved toward said closed position. first means for moving said abutment means to a first position whereat said throttle valve means when moved toward said closed position operatively engages said abutment means to thereby hold said throttle valve means opened a predetermined amount, said first means comprising solenoid means effective, when energised, to establish said first position to which said abutment means may be moved, said solcnoid means being effective upon deenergization thereof to permit said abutment means to move to a second position whereat said throttle valve means when operatively engaging said abutment means is open an amount less than the opening of said throttle valve means when said abut mcnt means was operatively engaged by said throttle valve means in said first position, and pressure responsive motor means adapted for connection to a source of vacuum developed by said engine, said motor means being effective to respond to the application of vacuum thereto to cause said abutment means to he moved to other positions in a direction towards the throttle valve means whereat said throttle valve means when operatively engaging said abutment means is held open an amount greater than the opening of said throttle valve means when said abutment means was operatively engaged by said throttle valve means in said first position.

One method of performing the invention will now he described with reference to the accompanying drawings.

In the drawings wherein. for purpose of clarity, certain details and/or elements may be eliminated from one or more views: Figure 1 illustrates apparatus. in fragment tary view. having throttle means the relatively closed positions of which are determincd hy variable position throttle stop and modulating apparatus employing teachings of the invention: and Figure 2 is an enlarged generally axially extending cross-sectional view of the throttle stop and modulating apparatus of Figure 1.

Referring now in greater detail to the drawings, Figure 1 illustrates an induction apparatus, such as, for example, a carburetor 10. carried on an intake manifold 12 of an associated engine 14. As generally indicated the inductive apparatus or carburetor 10 has induction passage means 16 formed therethrough with throttle valve means 18 situat@d therein and carried as by a pivotally rotatable throttle shaft 20. The throttle valve 18 is variably rotatably openable within induction passage 16 as to thereby accordingly control the flow of motive fluid through the induction passage 16 and into the intake passage 22. communicating therewith. of intake manifold 12.

A throttle lever 24, suitably sccured to throttle shaft 20 for rotation therewith, has a first arm portion 26 to which suitable throttle actuating linkage means 28 is operatively conn@cted and leading to, for example, the vehicle operator's throttle actuating foot pedal whereby movement of the linkage means 28 to the right causes clockwise opening movement of the throttle valve 18.

As is well known, suitable throttle return spring means 29 may be provided to continually yieldingly urge the throttle 18 in a closing direction. An other arm 30 of lever 24 is preferably provided with an integrally formed generally transversely extending flange-like portion 32 which threadably carries a screw member 34 which has its end 36 effective for abuttingly engaging a stop member 38 of the variable position throttle stop and modulating apparatus 40. A spring 42 may be carried generally about the shank of screw 34 and axially contained as between flange 32 and the head 44 of screw 34 as to thereby aid in frictionally retaining screw 34 in any threadably selected position relative to flange 32.

Referring to Figure 2, the apparatus 40 is illustrated as comprising a generally tubular outer body section or housing 46 which contains. in the lower portion thereof, a bobbin member 48. The bottom end of housing 46 may be secured as to a tubular or bushing-like member 5() which, as illustrated may have its outer portion 52 suitably received within and retained by related mounting bracket means 56.

An electrically energizable field winding or coil 58 is carried generally about the centrally disposed tubular portion 6() of bobbin 48 as to be situated generally between axially opposite radially extending annular flange portions 62 and 64. One electrical end 65 of coil 58 may be electrically connected to a terminal member 66, carried as by tubular portion 60, while the other electrical end. as is generally well known in the art. may be suitably grounded as through housing 46 to support bracket 56 as generally depicted. for example, at 68 of Figure I.

A passage 7() formed in tubular portion 60 slidibly receives therein an elongated tubular member 72 fixedly secured at its upper end 74 to the lower wall 78 of a housing section 76 of a modulating assembly 80. A second tubular member 82 has its upper end received by member 72 and fixedly secured thereto as being. for example. press-fitted therein to form a functionally unitarv structure with housing section 76 and tubular member 72. While upper tubular member 72 is slidably received within passage 70 of portion 60. lower tubular member 82 is slidable within a passage 84 of bushing member 50.

The modulator assembly 80 is illustrated as being comprised of lower housing section 76 and upper housing section X6 which cooperate to generally peripherally contain and retain a diaphragm member 88 to which the upper end 90 of a rod 92 is secured as by oppositely disposed diaphragm plates 94 and 96. Diaphragm 88 serves generally as a flexible common wall separating variable chambers 98 and 100. A spring 102 is situated generally within chamber 100 serves to continually resiliently urge di diaphragm 88 and rod 92 upwardly. As generally depicted at 104, suitable vent passage means are provided as in the wall of housing section 86 as to thereby place chamber 98 as at substantially atmospheric pressure.

Rod 92, slidably received within upper and lower tubular members 72 and 82, has its lower end 108 fixedly received within a tubular extension 110 of abutment member 38 having an outer end abutment surface 114 and an inner end abutment surface 116.

As illustrated, the inner abutment surface 116 is adapted to at times cooperatively abut against lower end abutment surface 118 of lower tubular member 82. Preferably, a flexible boot-like or bellows seal 120 is operatively secured at its opposite ends to bushing member 50 and abutment member 38. Somewhat similarly. a flexible bellowslike seal 122 is operatively secured at its opposite ends respectively to tubular housing section 46 and lower housing section 76 of dashpot assembly 8().

As generally depicted in Figure 1, a suitable source of electrical potential 124, electrically grounded as at 126, is electrically connected at its other terminal as to a vehicular key-operated ignition switch 128 which, when closed, completes an electrical circuit via conductor means 130 to the associated engine ignition system 132. As illustrated. terminal 66 is electrically connected, via conductor means 134, to conductor 132 as to thereby cause energization of solenoid coil means 58 upon closure of switch means 12X.

For purposes of illustration let it be assumed that the ignition switch 128 is closed thereby causing solenoid coil 58 to be energized resulting in tubular member 72.

acting as a solenoid armature. being moved downwardly until annular end surface 136 of member 72 abuts against opposed end surface 138 of hushing member 5() thereby assuming the position as shown in Figure 2.

Now if it is further assumed that throttle valve 18 is rotated some substantial distance in the opening direction. it can be scen that screw abutment 34 will generally move in a direction away from movable abutment means 38. Spring l()2. of course, movcs diaphragm 88. rod 92 and abutment means 38 generally upwardly (or inwardlv) until surface 116 abuts against surface 118. At this time movable abutment member 38 will have assumed a position whereat its abutment surface 114 will be at a relatively extended distance generally depicted by line 114a.If at this time throttle 18 is permitted to return toward its curb idle position, lever 24 (Figure 1) rotates counter-clockwise and in so doing end 36 of screw 34 contacts surface 114 (at position 114a) and at that time further closing movement of throttle valve 18 is prevented and a normal curb idle position of the throttle valve is determined.

As shown, a conduit portion 150 has one end in communication with chamber 100 and has its other end communicating as by conduit means 152 with a source of engine or manifold vacuum as within intake passage 22. As also generally indicated in Figure 1, passage means 152 may comprise suitable valving means generally depicted as at 154. Without, for now, describing the function of valving means 154, let it be assumed that a sufficient magnitude of manifold vacuum is communicated to chamber 100.As a consequence thereof, the force of spring 102 (and as will be evident the force of spring 29, too) is at least partly overcome by the force resulting from the pressure differential across diaphragm 88 resulting in rod 92 and abutment 38 being moved downwardly some distance as to, for example, where abutment surface 114 assumes a position as generally depicted by line 114b the force with which the abutment member 38 is modulated outwardly to its position 114b is sufficient to hold the throttle valve 18 in a corresponding position.

With respect to valve means 154. such may comprise. for example. either or both; (a) engine and/or vehicle speed responsive valve means 156 so as to thereby complete communication between chamber 100 and passage 22 whenever engine and/or vehicle speed is above a predetermined speed, thereby enabling the modulating structure to further open the throttle valve 18 during a selected range of speed experienced during engine and/or vehicle deceleration with such having the benefit of leaning the fuel-air mixture flowing to the engine, or (b) electrical switching means 158 effective to complete communication between chamber 100 and passage 22 whenever additional loads are placed on the engine as by for example, turning on the vehicular air conditioner system.Consequently. the throttle valve 18 is caused to be opened a slightly greater amount during curb idle operation. as compared to normal curb idle operation. and thereby accommodates the increased load placed on the engine. Many of such means 156 and 158 are well known in the art and the precise structure thereof forms no part of this invention.

Assuming now that abutment member 38 is in either of its positions 114a or 1 14b and throttle stop screw 34 is held thereagainst.

let it be further assumed that the ignition switch 12X is opened in order to shut-down the engine 14. When this happens solenoid coil 58 is dc-encrgized thereby releasing armature means 72 and permitting return spring means 29, because of its continuing biasing force, to move abutment member 38, tubular member 82 armature 72 and housing sections 76 and X6 generally upwardly. Such motion continues until the laterally extending portion of end surface 116 of abutment 38 engages the recessed surface 14() of end hushing member 50.At that time the end abutment surface 114 of abutment member 112 assumes a position generally depicted by line 114( while the modulator assembly X() and housing section 86 assume positions as generally depicted at 80c and 86c.Consequently, end 36 of screw means 34 has moved the distance generally represented between lincs 1141) and 1 14c and as a rcsult thereof throttle shaft 2() and throttle valve 18 have rotated in the counter-clockwise or throttle-closing-direction a related amount bcvontl that which was previously established is the normal curbidle throttle position. Accordingly. the per missiblc flow through induction passage means 1( p;ist throttle valve means 18 is even further restricted. if not totally prevented, thereby reducing. or climinating.

the further flow of motive fluid to the engine 14 and preventing the occurrence of engine "dieseling" after the ignition system is de-energized.

Although only a preferred embodiment of the invention his been disclosed ind de scribed . it is apparent that other embodi- mcnts ind modifications of the invention are possible within the scope of the appended claims.

WHAT WE CLAIM IS: 1. Apparatus for controlling the flow of combustible mixture to an internal combus- tion engine. comprising: throttle valve means, spring means urging said throttle valve means towards the closed position: vaiinbly positionable abutment means effective for operative engagement with said throttle valve means when said throttle means is moved toward s;iid closed position.

first means for moving said abutment means to a first position whereat said throttle valve means when moved toward said closed position operatively engages said abutment means to thereby hold said throttle valve means opened a predetermined amount.

said first means comprising solenoid means.

effective. when energised to establish said first position to which said abutment means may be moved. said solenoid means being effective upon de-energization thereof to permit said abutment means to move to a second position whereat s;i id t brot t lc valve means when operatively engaging siicl abut- ment means is open an amount less than the opening of said throttle valve means said abutment means was operatively engaged by said throttle valve means in said first position, and pressure responsive motor means adapted for connection to a source of vacuum developed said engine, said motor means being effective to respond to the application of vacuum thereto to cause said abutment means to be moved to other positions in a direction towards the throttle valve means whereat said throttle valve means when operatively engaging said abutment means is held open an amount greater than the opening of said throttle valve means when said abutment means was operatively engaged by said throttle valve means in said first position.

2. Apparatus according to Claim 1, wherein said first position corresponds to normal idling throttle position, and wherein said throttle valve means when in said second position is effective to at least greatly restrict any flow of combustible mixture past said throttle valve means and thereby at least minimize the possibility of said associated engine "dieseling" after the ignition system of said engine has been turned off.

3. Apparatus according to claim 1 wherein said second position is effectively equivalent to said throttle valve means being fully closed.

4. Apparatus according to any of the preceding claims wherein said pressure responsive motor means comprises chamber means. movable wall means at least partly defining said chamber means. motion transmitting means operatively interconnecting said abutment means and said wall means.

said chamber means being in communication with conduit means. and said conduit means being adapted for connection to said source of vacuum. and wherein said source of vacuum comprises engine intake man @fold vacuum of said engine.

5. Apparatus according to claim 4 wherein said solenoid means comprises armaturc means and coil means. wherein said armature means is operatively connected to said chamber means. and wherein said armature means said chamber means and said wall means are movable to and from operating positions corresponding to said first and second positions upon energization and de-energization of said coil means.

6. Apparatus according to claim 5 wherein said coil means is energized whenever the ignition system of said associ atcd engine is turned on. and wherein said coil means is de-energized whenever said ignition system is turned off.

7. Apparatus according to claim 6 wherein upon energization of said coil means said armature means chamber means and wall means are moved to one of said operating positions corresponding to said

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (12)

**WARNING** start of CLMS field may overlap end of DESC **. switch 12X is opened in order to shut-down the engine 14. When this happens solenoid coil 58 is dc-encrgized thereby releasing armature means 72 and permitting return spring means 29, because of its continuing biasing force, to move abutment member 38, tubular member 82 armature 72 and housing sections 76 and X6 generally upwardly. Such motion continues until the laterally extending portion of end surface 116 of abutment 38 engages the recessed surface 14() of end hushing member 50.At that time the end abutment surface 114 of abutment member 112 assumes a position generally depicted by line 114( while the modulator assembly X() and housing section 86 assume positions as generally depicted at 80c and 86c.Consequently, end 36 of screw means 34 has moved the distance generally represented between lincs 1141) and 1 14c and as a rcsult thereof throttle shaft 2() and throttle valve 18 have rotated in the counter-clockwise or throttle-closing-direction a related amount bcvontl that which was previously established is the normal curbidle throttle position. Accordingly. the per missiblc flow through induction passage means 1( p;ist throttle valve means 18 is even further restricted. if not totally prevented, thereby reducing. or climinating. the further flow of motive fluid to the engine 14 and preventing the occurrence of engine "dieseling" after the ignition system is de-energized. Although only a preferred embodiment of the invention his been disclosed ind de scribed . it is apparent that other embodi- mcnts ind modifications of the invention are possible within the scope of the appended claims. WHAT WE CLAIM IS:

1. Apparatus for controlling the flow of combustible mixture to an internal combus- tion engine. comprising: throttle valve means, spring means urging said throttle valve means towards the closed position: vaiinbly positionable abutment means effective for operative engagement with said throttle valve means when said throttle means is moved toward s;iid closed position.

first means for moving said abutment means to a first position whereat said throttle valve means when moved toward said closed position operatively engages said abutment means to thereby hold said throttle valve means opened a predetermined amount.

said first means comprising solenoid means.

effective. when energised to establish said first position to which said abutment means may be moved. said solenoid means being effective upon de-energization thereof to permit said abutment means to move to a second position whereat s;i id t brot t lc valve means when operatively engaging siicl abut- ment means is open an amount less than the opening of said throttle valve means said abutment means was operatively engaged by said throttle valve means in said first position, and pressure responsive motor means adapted for connection to a source of vacuum developed said engine, said motor means being effective to respond to the application of vacuum thereto to cause said abutment means to be moved to other positions in a direction towards the throttle valve means whereat said throttle valve means when operatively engaging said abutment means is held open an amount greater than the opening of said throttle valve means when said abutment means was operatively engaged by said throttle valve means in said first position.

2. Apparatus according to Claim 1, wherein said first position corresponds to normal idling throttle position, and wherein said throttle valve means when in said second position is effective to at least greatly restrict any flow of combustible mixture past said throttle valve means and thereby at least minimize the possibility of said associated engine "dieseling" after the ignition system of said engine has been turned off.

3. Apparatus according to claim 1 wherein said second position is effectively equivalent to said throttle valve means being fully closed.

4. Apparatus according to any of the preceding claims wherein said pressure responsive motor means comprises chamber means. movable wall means at least partly defining said chamber means. motion transmitting means operatively interconnecting said abutment means and said wall means.

said chamber means being in communication with conduit means. and said conduit means being adapted for connection to said source of vacuum. and wherein said source of vacuum comprises engine intake man @fold vacuum of said engine.

5. Apparatus according to claim 4 wherein said solenoid means comprises armaturc means and coil means. wherein said armature means is operatively connected to said chamber means. and wherein said armature means said chamber means and said wall means are movable to and from operating positions corresponding to said first and second positions upon energization and de-energization of said coil means.

6. Apparatus according to claim 5 wherein said coil means is energized whenever the ignition system of said associ atcd engine is turned on. and wherein said coil means is de-energized whenever said ignition system is turned off.

7. Apparatus according to claim 6 wherein upon energization of said coil means said armature means chamber means and wall means are moved to one of said operating positions corresponding to said

first position.

8. Apparatus according to claim 7 wherein said solenoid means further comprises a bobbin member carrying said coil means, wherein said armature means is axially centrally slidably received by said bobbin member, wherein said chamber means comprises housing means operatively fixedly secured to said armature means for movement therewith, wherein said motion transmitting nieans comprises a rod member axially slidably received through said armature means, wherein said abutment means comprises an abutment member, said abutment member being fixedly secured to and carried by one end of said rod member, wherein said wall means comprises a diaphragm member, and wherein an other end of said rod member opposite to said one end is secured to said diaphragm.

9. Apparatus according to claim 4 and further comprising valving means interposed between said chamber means and said source of vacuum, said valving means upon being opened being effective to admit said manifold vacuum to said chamber means as to thereby cause said abutment means to move to said other position.

10. Apparatus according to claim 9 wherein said valving means is responsive to engine speed as to thereby become opened during a predetermined range of engine speed greater than the normal idling engine speed.

11. Apparatus according to claim 9 wherein said valving means is responsive to indicia of adding engine load as to thereby become opened and cause said abutment means to move from said first position to one of said other positions and consequently provide for an opening of said throttle valve means during idling operation greater than the opening of said throttle valve means during normal idling operation.

12. Apparatus as hereinabove described with reference to and as illustrated in the accompanying drawings.