US3327695A - Throttle positioner with dashpot - Google Patents

Description

June 27, 1967 K. H. RHODES 3,327,695

THROTTLE POSITIONER WITH DASHPOT Filed Jan. 28, 1965 22 /2 -/50 /a @f/ifi? BY rg0 M4-M. vbzck.

United States Patent 3,327,695 THROTTLE PUSITIQNER WITH DASHIT Keith H. Rhodes, Racine, Wis., assigner to Walker Mannfacturing Company, a corporation of Delaware Filed Ian. 28, 1965, Ser. No. 428,648 6 Claims. (Cl. 12S-163) This invention relates to a positioning device for the Vthrottle valve of an internal combustion engine, and more particularly to a positioning device that reduces induction system vacuum upon deceleration and retards the rate of closing the throttle valve to prevent stalling.

In general, it is an object of the present invention to provide a throttle positioning device that is responsive to the induction system vacuum to effect opening or cracking of the engine throttle valve during decelerating so that an unduly rich mixture will not be drawn into the engine cylinders and discharged into the atmosphere from `the exhaust system.

It is another object of the present invention to provide a throttle positioning device of the above character that embodies an integral dashpot for retarding the rate of closing of the throttle valve to prevent engine stalling.

It is another object of the present invention to provide a throttle positioning device of the aforementioned type that is entirely automatic in operation.

It is yet another object of the present invention to `provide a throttle positioning device -that has a negligible effect on the fuel economy of the associated internal combustion engine.

It is a further object of this invention to provide a throttle positioning device that may be used on a wide variety of engines.

It is yet another object of this invention to provide a throttle positioning device that has an extremely simple construction and may be conveniently installed on an internal combustion engine.

A throttle positioning device for the throttle valve of an internal combustion engine embodying this invention includes means responsive to the pressure in the induction system posterior to the throttle valve for moving the throttle valve from a normal idle position to a partially open position when the vacuum in the induction system is greater than the normal idle vacuum. Means are additionally provided for retarding the rate of movement of the throttie valve from the partially open position to the normal idle position when the induction system vacuum returns to normal idle vacuum.

Other objects and advantages of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying dra ing, wherein:

FIGURE 1 is a partial side elevational view of an internal combustion engine incorporating a preferred embodiment of this invention and,

FIGURE 2 is an enlarged cross sectional View of the throttle positioning device shown in FIGURE 1.

Referring now in detail to FIGURE 1 of the drawing, a throttle positioning device, indicated generally by the reference numeral 10, is shown in operative association with an internal combustion engine 11. The internal combustion engine 11 has an induction system comprising an intake manifold 12 and a charge forming device in the form of a carburetor, shown partially at 14. The outlet of the carburetor 14 registers with an upwardly extending inlet section 16 of the intake manifold 12. A throttle plate 18 is pivotally supported within an induction passage ice 19 of the charge forming device 14 by a throttle valve shaft 20. A throttle control lever 21 is aixed to one end of the shaft 20. The depending end of the throttle control lever 21 is pivotally connected to a throttle control rod 22 that is actuated by an accelerator pedal (not shown) by means of any suitable accelerator linkage. A throttle return spring 24 is connected vthrough a fitting or coupling 26 to the throttle control rod 22 to urge the throttle linkage and throttle valve 18 ltoward the normal idle position, as illustrated in FIGURE 1.

The throttle positioning device 10 is rigidly attached to the engine 11 through an appropriately shaped mounting bracket 28. The mounting bracket 28 is welded to another bracket 30 which is aixed to the engine 11, as by bolts 32 and 34.

Referring now to FIGURE 2, it will be seen that the throttle positioning device 10 includes a valve housing, generally designated 36, that is preferably fabricated of a die casting of a strong, light weight material such as aluminum or the like. The housing 36 is generally circular in cross section and is mounted on the side of an upwardly extending section 38 of the mounting bracket 23 and is rigidly secured thereto by a plurality of circumferentially spaced screws 40 (only one of which is illustrated) that extend through suitable apertures in the bracket section 38, the housing 36, and through an annular cup-shaped shell 42 that is attached to the bracket section 33 on the side opposite to the housing 36. Suitable gaskets 43 are secured to the opposite sides of the bracket section 38 to provide an air-tight seal between the housing 36, the shell 42, and the bracket section 38.

An annular flange section 44 is formed around the periphery of the shell 42 and is secured by a rolled seam or joint 46 to an annular flange section 50 of a second cup-shaped shell 52. The space dened by the shells 42 and 52 forms a diaphragm chamber 54. An annular diaphragm 56, that is preferably constructed of a flexible and deformable material such as synthetic rubber or the like, is secured within the chamber S4 by compressing its outer periphery between the ange sections 44 and 50 of the shells 42 and 52. It may be noted that the outer periphery of the diaphragm 56 acts as a gasket to provide an airtight seal between the flange sections 44 and 50 of the yshells 42 and 52.

The shell 52 is provided with a central opening defined by an annular outwardly extending ange section 58. Press fitted within the flange section 58 is a circular pull rod sleeve 0r guide 60 that is formed with a central bore 62. As illustrated in FIGURE 2, an elongated cylindrical pull rod 64, that extends through the bore 62, has a threaded inner end section 65 extending into the diaphragm chamber 54. The pull rod end section 65 extends through a central aperture 66 in the diaphragm 56, and the diaphragm 56 is secured to the end section 65 interjacent a diaphragm retainer ring 68 and an annular diaphragm retainer plate 70 by a nut '72 that is threaded on the end section 65.

The retainer ring 68 is formed with an annular concentric shoulder section 74 within which is seated one end of a helical spring 76. The opposite end of the spring 76 bears against the guide 60 and is coaxially disposed around the pull rod 64. It will be seen that the loading of the spring 76 between the retainer plate 70 and the guide 60 yieldably maintains the diaphragm 56 and the pull rod 64 in their respective positions illustrated in the solid line view of FIGURE 2.

A plurlity of atmospheric vent holes 79 are formed in the shell 52 so that the outer (right) side of the diaphragm 56 will be exposed to atmospheric pressure. It also will be seen that the diameter of the bore 62 in the guide 60 is slightly larger than that adjacent portion of the pull rod 64 so that atmospheric air may freely flow around the rod 64 and pass into the diaphragm chamber 54 between the shell 52 and the diaphragm 56.

The outer (right) end of the pull rod 64 is formed with a sleeve section 80 within which one end of a pull cable 82 is rigidly fastened by `a set screw 84. The opposite end of the cable 82 extends through and is freely slidable within an opening in the coupling 26 (FIGURE 1). A throttle stop 83 is adjustably secured `on the outer end of the pull cable 82 such that during engine decelerating conditions (when the accelerator pedal is not depressed), longitudinal movement of the cable 32 towards the device will effect movement of both the throttle control lever 21 and the throttle plate 18. During normal throttle operaton of the engine, the coupling 26 will overridethe cable 82 and throttle control will be maintained solely through longitudinal movement of the rod 22 in response to manual operation of the accelerator pedal. It will be apparent, of course, that a number of alternate forms of overriding type throttle-control device linkages may be satisfactorily used and that the structure herein described is merely exemplary insofar as such linkage constructions are concerned.

Referring again to FIGURE 2, centrally formed in the valve housing 36 is an annular valve bore S6, one (right) end of which is formed with a conically shaped valve seat 88. Extending coaxially of the bore S6 and being reciprocable therewithin, is a valve member 90 that is formed with a frusto-conical end section 92 that is adapted to engage the valve seat 88, thereby providing an air-tight seal between the diaphragm chamber 54 and the interior of the valve housing 36. The valve member 90 is also formed with a medial section 94 onto which is threaded an annular spring retainer cup 96. A valve spring 98, that is disposed around the valve member l*medial section 94, extends between an annular recess 100 formed in the spring retainer cup 96 and an inwardly extending cylindrical section 101 of the valve housing 36. It will be seen that the spring 98 resiliently forces the retainer cup 96 away from the valve housing section 78, thus yieldably maintaining the valve member end section 92 engaged with the valve seat 88.

A flexible disk-shaped diaphragm 102, that is preferably fabricated from the same material as the diaphragm 56, is mounted on the side of the valve housing 36 opposite the shells 42 and 52 by an annular cup-shaped cover plate 104 and a plurality lof circumferentially spaced screws 106 that extend through the outer peripheral sections of the diaphragm 102 and plate 104 and are screwed into the side of the valve housing 36. The diaphragm 100 is formed with a central sleeve section 108 that defines a central aperture 110 through which extends a cylindrical outer end section 112 of the valve member 90. It may be noted that the diameter of the aperture 110 is slightly smaller than the valve section 112 so that when it is inserted through the aperture 110, an air-tight seal is provided between the diaphragm 102 and the valve member 90. The cover plate 104 also is formed with a central opening 114 and a plurality of air bleed holes 11S, the latter of which communicate atmospheric air to an annular chamber 116 defined by the cover plate 104 and the diaphragm 102. The outer end of the valve section 112 protrudes through the central opening 114 and it will be seen that the opening `114 is sufficiently large to permit air to ow to and from the chamber 116 around the valve section 112.

A diametrically extending slot 118 is formed in the outer end of the valve section 112 and a suitable tool such as a screwdriver or the -like may be inserted therein to rotate the valve 90 and thereby adjust the relative axial position of the spring retaining cup 96 along the threaded valve medial section 94. Also provided on the outer end of the valve section 112 is a retaining ring 120 that is preferably of the snap-on type and is adapted to limit the axial inward movement of the valve member 90.

An atmospheric vent passage 122 extends radially through the valve body 36 so that atmospheric air may enter the diaphragm chamber S4 on the left hand side of the diaphragm 56. The vent passage 122 has a restricted orifice 124 between its ends, however, -to restrict the air tiow to and from the diaphragm chamber 54.

Mounted on the side of the intake manifold 12 is a fitting 128 (FIGURE l) that communicates the interior of the manifold 12 posterior to the throttle valve 18 with one end of a flexible vacuum line 130. The opposite end of the vacuum line 130 is stretched around the outer end of la hollow tube 132 that is press fitted within a suitable bore 134 formed in the top of the valve housing 36. It will thus be seen that the manifold vacuum existing within the intake manifold 12 will be transmitted through the vacuum line 130 and the tube 132 to the interior of the valve housing 36.

Operation The throttle positioning device 10 is secured lby brackets 28 and 38 to the automotive engine in a location that will allow the pull cable 82 a straight pull on the fitting 26, and the position of the stop 83y is adjusted such that the cable 82 is taut `when the engine throttle plate 18 is in its closed or hot idling position and the diaphragm is in its extreme right hand position as shown in the dotted line view of FIGURE 2. When the engine is idling, the position of the retainer cup 96 is adjusted Vby rotating the valve 90 such that the tension of the spring 98 is just sufficient tov maintain the valve section 92 engaged with the valve seat 88.

When the manifold Vacuum increases within the manifold 12, 'as occurs upon deceleration of the engine, the internal pressure within the valve housing 36 will decrease, whereby the atmospheric pressure present within the chamber 116 will exceed the pressure within the valve housing 36 and the diaphragm 102 will be forced in- Wardly, thereby biasing the cup 96 inwardly and unseating the valve member 90.

As the valve becomes unseated, the air within the diaphragm chamber 54 is transferred through the valve bore 86, the interior of the valve housing 36 and out through the tube 132 and vacuum line 130, thereby effecting a partial vacuum within the chamber 54. The atmospheric vent passage 122 will limit the actual vacuum that is produced within the diaphragm chamber, of course. Atmospheric pressure, which is communicated to the outer (right) side of the diaphragm 56 through the bore 62 and the bleed holes 79, and the action o-f the spring 76, then bias the diaphragm 56 and the retainer plate 70 inwardly to draw the pull rod 64 inwardly through the guide 60. This effects a corresponding inward movement of the pull cable 82. As the cable 82 moves, the lower end of the throttle control lever 21 is rotated clockwise with the throttle shaft 20 thereby partially opening or cracking the throttle plate 18. The opening of the throttle plate 18 limits the manifold vacuum within the manif-old 12 and, accordingly, reduces the vacuum upon the idle discharge circuit of the carburetor 14. This reduces the emission of unburned hydrocarbons from the engine exhaust upon deceleration.

When the automotive engine reaches an idling condition or begins to accelerate, the vacu-um within the manifold 12 and the interior of the valve housing 36 is relieved, whereby the spring 98 biases the cup 96 to the left and reseats the valve 90. As the valve 90 becomes seated, the vacuum within the chamber 54 is relieved by virtue of atmospheric air passing into the chamber 54 through the air vent passage 122 and the throttle return spring 24 acting through the cables S2 returns the diaphragm S6 to the dotted line position illustrated in FIGURE 2.

The throttle positioning device also may function as an antistall dashpot in the following manner. When the throttle-valve 18 is open through the throttle actuating linkage including the throttle actuating rod 22, the tension upon the cable 82 is released. The throttle return spring 24, therefore, will no longer act upon the diaphragm 56 through the pull rod 64. The coil spring 76 then urges the diaphragm 56 to the solid line position shown in FIGURE 2. When this occurs, air is driven from the diaphragm chamber 54 through the atmospheric vent passage 122. If the throttle valve 18 is rapidly closed by relieving pressure upon the accelerator pedal, tension is again exerted -upon the cable 82. The spring 24 then tends to compress the spring 76, which is weaker or has a lower rate. The diaphragm 56 is then drawn toward the dotted line position. 'Ihe rate of movement of the diaphragm 56 and the pull rod 64- is reduced, however, because its rapid movement tends to create a partial vacuum within the diaphragm chamber 54 because of the restricted orifice 124 in the atmospheric vent passage 122. The size of the orifice 124 will determine the rate at which the diaphragm S6 may return to the dotted line position. It should be readily apparent that this action delays the rate of closing of the throttle valve 18 so that stalling of the engine may be precluded.

While it will be apparent that the preferred embodiment herein illustrated is well calculated to fulfill the objects stated, it will be appreciated that the present invention is susceptible to modification, variation and change without departing from the proper scope and fair meaning of the subjoined claims.

What is claimed is:

1. A combined fluid motor and dashpot for controlling a throttle valve of an internal combustion engine induction system comprising an expansible fluid chamber defined in part by a movable Wall, said wall being adapted to be operatively connected to the throttle valve for movement to a iirst position when the throttle valve is in a normal idle position and a normal pressure exists in said fluid chamber, biasing means for exerting a force upon said wall tending to move said wall from said first position to a second position, said biasing means being incapable of moving said wall from its rst position to its second position when the throttle -valve is in the normal idle position and the normal pressure exists in said ii-uid chamber and capable of moving said wall from its rst position t-o its second position when the throttle valve is opened beyond a predetermined partially opened position, fluid pressure responsive means responsive to the vacuum in the nduction system posterior to the throttle valve for altering the pressure within said fluid chamber from said normal pressure for 4movement of said wall from said iirst position to a second position wherein the throttle valve is moved to the predetermined partially opened position when the vacuum exceeds normal idle vacuum, and means for returning the pressure within said chamber to said normal pressure at a restricted rate when the induction system vacuum is at least equal to normal idle vacuum for retarding the movement of said wall from said second position to said first position to retard the closing of the throttle valve.

2. A combined iiuid motor and dashpot for controlling a throttle valve of an internal combustion engine induction system comprising an expansible iiuid chamber defined in part by a movable wall, first biasing means for urging said wall to a first position, second biasing means for biasing said Wall to a second position, said first biasing means being stronger than said second biasing means whereby said wall is normally biased to said first position, said wall being adapted to be operatively connected to the throttle valve and being in said rst position when the throttle valve is in a normal idle position, and uid pressure responsive means responsive to induction system vacuum for altering the pressure within said chamber for moving said wall from said first position to a second position wherein the throttle Valve is partially open when the induction system vacuum exceeds normal idle vacuum, said second biasing means being effective to move said wall from said first position to said second position when the throttle valve is open a greater extent that the partially open position, and means for returning the pressure within said chamber to a normal pressure at a restricted rate when the induction system pressure is at least equal to normal idle vacuum and the throttle valve is moved to the normal idle position for `retarding the movement of the throttle valve from the partially open position to the idle position.

3. A combined tiuid motor and -dashpot for controlling a throttle valve of an internal combustion engine induction system comprising an expansible fluid chamber deiined in part by a diaphragm, said diaphragm being adapted to to be operatively connected to the throttle valve, first biasing means for urging said diaphragm to a first position wherein the throttle valve is in a normal idle position, second biasing means for biasing said diaphragm to a second position wherein the throttle valve is in a partially opened position, said first biasing means being stronger than said second biasing means whereby said diaphragm is normally biased to said first position, means including a pressure responsive valve for exposing said fiuid chamber to induction system Vacuum when the induction system vacuum is greater than normal idle vacuum for moving said diaphragm from said first position to said second position to partially open the throttle valve to reduce the vacuum in the induction system, said second biasing means being eiiective to move said ydiaphragm from said lirst position to said second position when the throttle valve is open a greater extent than the partially opened position, and venting means for normally venting said uid chamber to atmospheric pressure, said venting means offering a substantially greater resistance to iiow than said first named means for restricting rate of movement of said `diaphragm from said second position to said first position to retard the movement of the throttle valve from the partially opened position to the normal idle position.

4. An internal combustion engine comprising an induction system, a throttle valve for controlling the fiow through said induction system, a combined iiuid motor and dashpot for controlling said throttle valve comprising an expansible fluid chamber, defined in part by a diaphragm, linkage means operatively connecting said diaphragm to said throttle valve, first biasing means for urging said throttle valve to a normal idle position and said ydiaphragm to a first position, second biasing means for biasing said Idiaphragm to a second position, and said throttle valve to a partally opened position, said first biasing means being stronger than said second biasing means whereby said diaphragm is normally biased to said first position, means including a pressure responsive valve for exposing said iiuid chamber to induction system vacuum when the induction system vacuum is greater than normal idle vacuum for moving said diaphragm from said first position to said second position to partially open said throttle valve to reduce the vacuum in the induction system, said linkage means including a lost motion device for relieving said diaphragm from the action of said first biasing means when said throttle valve is opened past said partially opened position, said second biasing means being effective to move said diaphragm from said first position to said second position when said throttle valve is open a greater extent than said partially opened position, and venting means for normally venting said fluid chamber to atmospheric pressure, said venting means offering a substantially greater resistance toV fiow than said first named means for restricting rate of movement of said diaphragm from said second position to said yfirst position to retard the movement of said throttle valve from the 7 partially opened position to the normal idle position under References Cited the `acti-ori of said first biasing means. UNITED STA E PATE TS 5. A combined fluid motor and dashpot as set forth in T s N claim 1 wherein the uid pressure responsive means com- 2,005,262 5/1935` Liverance L 123 103- prises a pressure responsive valve. 5 3,027,884 4/1962 Baie 123-97 6. A combined fluid motor and ydashpot as set forth in t A claim 1 wherein the means for returning thel pressure MARK NEWMAN Primm?) Examm'er' Within the chamber to the normal pressure at a restricted .RALPH D, BLAKESLEE, Examiner.

rate comprises a normally opened atmospheric vent.

Claims (1)

1. A COMBINED FLUID MOTOR AND DASHPOT FOR CONTROLLING A THROTTLE VALVE OF AN INTERNAL COMBUSTION ENGINE INDUCTION SYSTEM COMPRISING AN EXPANSIBLE FLUID CHAMBER DEFINED IN PART BY A MOVABLE WALL, SAID WALL BEING ADAPTED TO BE OPERATIVELY CONNECTED TO THE THROTTLE VALVE FOR MOVEMENT TO A FIRST POSITION WHEN THE THROTTLE VALVE IS IN A NORMAL IDLE POSITION AND A NORMAL PRESSURE EXISTS IN SAID FLUID CHAMBER, BIASING MEANS FOR EXERTING A FORCE UPON SAID WALL TENDING TO MOVE SAID WALL FROM SAID FIRST POSITION TO A SECOND POSITION, SAID BIASING MEANS BEING INCAPABLE OF MOVING SAID WALL FROM ITS FIRST POSITION TO ITS SECOND POSITION WHEN THE THROTTLE VALVE IS IN THE NORMAL IDLE POSITION AND THE NORMAL PRESSURE EXISTS IN SAID FLUID CHAMBER AND CAPABLE OF MOVING SAID WALL FROM ITS FIRST POSITION TO ITS SECOND POSITION WHEN THE THROTTLE VALVE IS OPENED BEYOND A PREDETERMINED PARTIALLY OPENED POSITION, FLUID PRESSURE RESPONSIVE MEANS RESPONSIVE TO THE VACUUM IN THE INDUCTION SYSTEM POSTERIOR TO THE THROTTLE VALVE FOR ALTERING THE PRESSURE WITHIN SAID FLUID CHAMBER FROM SAID NORMAL PRESSURE FOR MOVEMENT OF SAID WALL FROM SAID FIRST POSITION TO A SECOND POSITION WHEREIN THE THROTTLE VALVE IS MOVED TO THE PREDETERMINED PARTIALLY OPENED POSITION WHEN THE VACCUM EXCEEDS NORMAL IDLE VACUUM, AND MEANS FOR RETURNING THE PRESSURE WITHIN SAID CHAMBER TO SAID NORMAL PRESSURE AT A RESTRICTED RATE WHEN THE INDUCTION SYSTEM VACUUM IS AT LEAST EQUAL TO NORMAL IDLE VACUUM FOR RETARDING THE MOVEMENT OF SAID WALL FROM SAID SECOND POSITION TO SAID FIRST POSITION TO RETARD THE CLOSING OF THE THROTTLE VALVE.

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