US2706975A - Engine speed governing device - Google Patents

Description

April 26, 1955 C..H. FRICK ETAL 5 ENGINE SPEED GOVERNING DEVICE Filed Oct. 15, 1952 2 Sheets-Sheet 1 Inventors By WW Attorneys April 26, 1955 c. H. FRICK ET AL 2,706,975 ENGINE SPEED GOVERNING DEVICE Filed Oct. 15, 1952 2 Sheets-Sheet 2 By v I United States Patent 2,706,975 ENGINE SPEED GOVERNING DEVICE Charles H. Frick, Pontiac, and Ralph J. Rays, Dearborn, Mich, assignors to General Motors Corporation, Detroit, Micli., a corporation of Delaware Application October 15, 1952, Serial No. 314,868 7 Claims. (Cl. 123-103) This invention relates to internal combustion engines and particularly speed governors therefor operatively controlling the fuel supply to the engine.

The present invention a view in plan of the elements shown in taken substantially on line accelerator pedal 4 through a linkage system 6, 7, 8 and 9. The duct 2 contains an auxiliary air intake passage 11 not controlled by the throttle valve 3, which is preferably of venturi shape whose throat 12 is tapped by a vacuum lin 13, 14 leading to one end of a cylinder 16 in which is mounted a piston member 17 shown in the form of a flexible diaphragm (Figure 2).

The fuel is supplied to the engine by one or more injector devices 18 whose delivery rate is controllable by a longitudinally reciprocable regulator member shown as a rod 21 which is suitably guided for movement on ing the fuel injectors 18.

Linkage means 26, 27 operatively associated with the ott le valve control linkage 7- -9 is also shown for an idler buffer spring 32 which operate to abut the arms 33 and 4 respectively of a fuel regulator control lever 36. The idler buffer spring 32 corresponds in function to the idler buffer spring 77 shown and described in the aforesaid Ervin application 2,706,975 Patented Apr. 26, 1955 tending to rotate the control lever 36 in a counterin clockwise direction about its pivotal axis defined by the at the upper and the buffer spring 32 effects a biasing action on the control lever arm 34 tending to rotate the control lever in the counterclockwise or fuel increasing direction. Also in this position of the on the arm 29 air flow through this venturi effects a the right hand side of the idler buifer spring 32.

For transmitting this diaphragm force to the control lever, a drum-like member ends are anchored for movement and the diaphragm 17 respectively. The connection of the band 47 to the drum member may be in the form of a simple stud or pin 48 projecting from the cylindrical surface 46 and extending through an opening provided therefor in the band member.

17 whereby the effective acted upon by the diaphragm increases at substantially a constant rate as the control lever is moved in a clockwise direction from its engine full fuel position to decrease the engine fuel supply in response to increasing engine speed. As a result, the movement of the control lever toward a decreased fuel setting (in response to increasing engine speed movement of the diaphragm) is seen in Figure 2, the eccentricity with respect to the moment arm of the control lever uniformly accelerated and the tendency of the governor to stabilize engine speed is enhanced.

Upon manually advancing the engine speed by depression of the accelerator pedal 4, the pin 41 on the link 26 rides up out of the notch 43 on the cam surface 42 and thence travels downwardly on this cam surface 42 to cause clockwise rotation of the arm 29, with the result that the control lever rotates counterclockwise about the axis of the shaft 37 under the biasing action of the torsion spring 38 and shifts the fuel regulator rod 21 to the right in the direction of increased fuel delivery. The movement of the fuel regulator rod in response to the pivoting movement of the control lever is effected by the cam action of the control lever slot 40 on pin 45 of the fuel regulator rod. A curvature, as shown, has been added to the lower end of the slot 40 in order that the linear velocity of movement of the fuel regulator rod relative to the angular velocity of the control lever movement will be decreased in the upper half of the governed load range. As a result, the aforesaid constant rate of change in moment arm length between the dia phragm and the control lever is rendered more effective in stabilizing the engine speed, particularly under conditions of part throttle operation.

While it is appreciated that various minor changes or alterations in the construction and relation of the parts will readily suggest themselves to persons skilled in the art, such changes shall not depart from the spirit and scope of the invention which is set forth in the following claims.

We claim:

1. In an engine speed governing device having a piston member responsive to engine intake vacuum and a reciprocably guided fuel regulating member controlled thereby, linkage means operatively connecting said members including a lever supported for pivotal movement about an axis, a drum member rigid with the lever and provided with a cylindrical surface having its axis eccentric to the pivotal axis of the lever, a flexible strap Wrapped about and anchored at one end to said cylindrical surface and anchored at its other end to the piston member, said lever having a slotted arm slidably embracing a pin on the fuel regulating member.

2. In an engine speed governing device having a first reciprocable member movable in one direction in response to increased engine intake vacuum and a second reciprocable member movable in said one direction to increase engine fuel supply and in the opposite direction to decrease said supply, linkage means for translating movement of said first member in sa1d one direction into movement of said second member in the said opposite direction including a lever having a fixed axis of pivotal movement, a cylindrical cam surface on the lever having its axis eccentric to said axis of pivotal movement, and a tension link having one end anchored to said cam surface and its other end anchored to reciprocate with said first member, said lever having a pin and slot driving connection with said second member.

3. In an engine speed governor, a piston member responsive to engine intake vacuum, a reciprocably guided fuel control rod carrying a transversely disposed driving pin, a lever mounted for pivotal movement about an axis parallel to and laterally spaced from said pin, said lever having an arcuate slot slidably embracing said pin and a cylindrical cam surface eccentric with said axis, and a flexible link interconnecting said lever and piston member and wrapped about at least a portion of said cam surface.

4. In an engine speed governor having a reciprocably guided fuel supply regulator movable in the direction to decrease the fuel supply by a piston member responsive to increasing engine speed, linkage means for translating increasing engine speed movements of the piston member into fuel decreasing movements of the regulator including a pin carried by and disposed transversely to the reciprocatory path of the regulator, a lever mounted for pivotal movement about an axis parallel to and spaced from said pin, said lever having a surface in slidable driving engagement with said pin and curved in the direction of decreasing fuel movement of the regulator, a cam surface on the lever having a curvature of varying radius from said pivotal axis, and a tension link having one end anchored to the piston member and its other end wrapped about said cam surface and anchored to the lever.

5. In an engine speed governing device having a piston member, actuating means effective at a predetermined engine speed for moving the piston member in one direction including means forming a restricted engine air inlet and a fiuid connection subjecting one side of the piston to the pressure within said inlet, a reciprocably guided engine fuel supply regulator, a pivoted lever for moving said regulator in the direction to decrease the fuel supply in response to movement of the piston member by said actuating means, and a resilient member for yieldably opposing said piston actuated movement of the regulator by the lever and for moving the regulator in the opposite direction when said actuating means is ineffective, the improvement consisting of a connection between the lever and piston member whose lineal distance from the lever fulcrum decreases at a substantially constant rate as the regulator is moved in the direction to decrease the fuel supply, and a connection between the lever and regulator in the form of a pin on the regulator and a curved camming surface therefor on the lever the radius of curvature of which surface decreases progressively to maintain a substantially linear relationship between piston movement and regulator movement.

6. In an engine speed governing device, the combina tion with a slidably reciprocal rod controlling the fuel supply to the engine, a pivoted lever having an arm slotted to slidably embrace a projection on said rod, a support providing a fixed axis for pivotal movement of the lever at a distance along said arm from the rod and a reciprocable member movable in one direction in response to increased engine speed for effecting pivotal movement of the lever in the direction to slidably drive said rod toward a decreased fuel supply position, of a connecting linkage between said members providing a moment arm for said reciprocal member relative to the pivotal axis of the lever which increases at constant rate during movement of the reciprocable member in said one direction, said connection including a flexible member and cylindrical cam, said cam being fixed to the lever and having its cylindrical axis eccentric with the lever pivotal axis, said flexible member being connected at one end to said reciprocable member and having its other end extending around said cam and movable With the lever about the lever axis.

7. In an engine speed governing device having a reciprocable rod controlling the engine fuel supply, a reeiprocable member for adjustably moving said rod toward a decreased fuel setting in response to increasing engine speed, and a pivoted lever for transmitting decreasing engine speed movements of said reciprocable member to said rod, said lever having a moving connection with said reciprocable member whose distance from the pivotal axis of the lever increases at a substantially constant rate during movement of the lever in the decreasing fuel direction and having a moving connection with said rod whose lineal velocities of movement about the pivotal axis of the lever and longitudinally of the rod are substantially constant throughout the operable range of pivotal movement of the lever.

References Cited in the file of this patent UNITED STATES PATENTS

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