US3532082A

US3532082A - Minimum-maximum governor with midrange regulation

Info

Publication number: US3532082A
Application number: US736306A
Authority: US
Inventors: Jerry A Clouse; Marvin A Gates; John H Parks
Original assignee: Caterpillar Tractor Co
Current assignee: Caterpillar Inc
Priority date: 1968-06-12
Filing date: 1968-06-12
Publication date: 1970-10-06
Anticipated expiration: 1987-10-06
Also published as: GB1264036A; DE1929483A1; BE733111A; FR2010724A1; DE1929483C3; JPS4844714B1; DE1929483B2

Description

United States Patent inventors Jerry A. Clouse Washington; Marvin A. Gates, Chillicothe; John H. Parks, Peoria, lllinois App]. No. 736,306

Filed June 12, 1968 Patented Oct. 6, 1970 Assignee Caterpillar Tractor Co.

Peoria, Illinois a corporation of California MINIMUM-MAXIMUM GOVERNOR WITH MIDRANGE REGULATION 4 Claims, 2 Drawing Figs.

U.S.Cl 123/140, 123/98, 73/537 int. Cl F02d 1/04 Field 01 Search .1 73/537; 123/98, 140

[56] References Cited I UNITED STATES PATENTS 2,139,194 12/1938 Lichtenstein 123/140 2,159,863 5/1939 Schilling 73/537 2,669,983 2/1954 Reddy et al.. 123/140 2,631,025 3/1953 Bone 73/537 2,957,351 10/1960 Heinzman 73/537 2,960,327 11/1960 Gaubatz .1 73/537 FOREIGN PATENTS 384,976 1/1933 Great Britain 1. 73/517 Primary Examiner-James J. Gill Assistant Examiner-Herbert Goldstein Almrney- Fryerffjensvold, Feix, Phillips and Lempio ABSTRACT: A governor which has separate springs for high speed and low speed regulation and has a third spring effective at midrange engine speeds to prevent sudden acceleration of the engine, which is undesirable and may occur, for exampl when the engine is operated under light load.

mvfifi l giimlllmm 11111111111111 5 iililllillhlll Patented Oct. 6, 1970 ll 2 2 2 a mm wm nH l ud T l h m lm u T. k\\ mm wm e %m rom Q Q 7 Q S mvz amons JERRY A; CL

JOHN H.- PARKS ag i r -w TTORNEYS I NARVIN'RGR MlNlMUM-MAXTMUM GOVERNOR WITH MIDRANGE REGULATION The present invention was designed for use on compression ignition engines used in trucks where a foot accelerator pedal is generally employed for adjusting the engine governor, but it is also applicable to engines in other types of service. Considering the truck application, for example, there are occasions when increased engine speed demanded is opposed by a heavy load and acceleration is gradual. In the absence ofload or where the load is very light, acceleration may take place so suddenly as temporarily to interfere with the operator's control and create an awkward and sometimes dangerous situation.

The present invention provides means in the form of a third governor spring which is effective after the minimum range spring controlling low speeds has obtained full compression. It is at this time that unduly rapid acceleration often occurs. The third spring of the present invention then becomes operative, providing high regulation governing, to prevent such acceleration.

The invention is described in detail in the following description by reference to the accompanying drawing and objects and advantages of the invention will become apparent as the description proceeds.

In the drawing:

FIG. 1 is a central vertical section through a governor embodying the present invention; and

FIG. 2 is a perspective view which shows a spring which is employed for midrange regulation.

The governor shown is contained in the housing secured to one end of a fuel pump housing, a portion of which is shown at 12. Conventional flyweights 14 are pivoted, as at 15, to a rotatable carrier 16. Gear teeth 17 are formed on one of the carriers and mesh with the gear 18 which is engine driven in this case by a camshaft, a portion of which is shown at 19 in the pump housing. Outward movement of the flyweights caused by engine speed and inward movement which results from varying the force of the governor springs, results in adjustment of a fuel feed rack in the pump housing shown at 20 and this rack imparts angular adjustment through a gear 21 to a plunger 22 of one of the several engine fuel pumps, all in a conventional manner. The transmission of motion from the flyweights to the fuel rack 20 is accomplished by a double acting hydraulic servomechanism generally indicated at 24 and explained in detail in Parks & Wellwood Pat. No. 3,145,624. It will suffice for an understanding of the present invention to know that the governor flyweights move and are adjusted by a reaction member 26 on a valve spool 27 which controls flow of fluid under pressure through a passage 28 to and from a chamber 29 which is effective through a piston 30 to adjust the fuel rack. In the present governor a control lever 32 actuated through suitable linkage from an accelerator pedal (not shown) may be moved in a counterclockwise direction and has a bifurcated end bearing against the end of a collar 34 to move it toward the right, as viewed in the drawing, for com pressing the springs of the governor spring assembly. It is slidable on a bearing 36 which is pressed into a suitable bore in the end of the housing 10. The spring assembly is shown as in shutdown condition and upon starting of the engine at low idle or slightly greater speed setting, the flyweights will swing outwardly and urge the reaction member 26 against a seat 38 of a low speed spring 40 seating at its opposite end against the seat 42 of the heavier high speed range spring 44. This spring has a seat 46 at its opposite end slidable on a sleeve 48'and has an assembled preload. The sleeve 46 also acts as a seat for a midrange governor spring 50 which has an opposite seat formed on the collar 34. One form which the midrange spring 50 may assume is that ofa finger spring such as that illustrated in H6. 2, though other springs having a. comparable rate and 5 force may of course be used. As the engine is started, the low speed range spring 40 will be slightly compressed so that the engine will start at or above a low idle position. To increase the speed toward the top of the minimum governed range, the

accelerator is actuated to swing lever 32 counterclockwise with no deflection of the high speed spring due to its preload and only slight deflection of the stiff midrange spring so that motion will be transmitted through collar 34, spring seat 46 and sleeve 48 to compress spring 40. As the maximum speed under the low speed range spring is approached, the end of the sleeve abuts spring seat 38 so that the spring is no longer functioning. If at this point further counterclockwise motion is imparted to lever 32 it would normally move the rack directly and result in rapid acceleration until the: engine speed reached a point where the tlyweight force equalled the high speed preload force at which time normal governing would occur. The midrange spring 50 prevents this acceleration. lt is not preloaded and will be compressed, acting through preloaded spring 44 and now ineffective spring assembly 40 and will be effective with the flyweights 14 to govern engine speed in the midrange. Further movement of lever 32 demanding greater engine speed will compress spring 50 to the point where its stiffness equals that of the preloaded high speed range spring 44 and the two will act together in opposition of outward movement of the flyweights in the conventional manner.

We claim:

1. In a fuel feed rack actuator for a compression ignition engine, a governor comprising separate spring means for regulating the speed of the engine at low, intermediate and high speeds, respectively, first, second and third serially arranged spring means, said spring means adapted to be operatively connected to a fuel feed rack to regulate movement of said fuel feed rack and adapted to urge said fuel feed rack in a first direction, speed responsive means connected to said serially arranged springs to urge them in a second direction in opposition to movement in said first direction, said first spring means having a predetermined low spring rate to regulate movement of said fuel feed rack at predetermined low speeds to prevent excessive acceleration of said engine at said low speeds, said third spring means having a predetermined intermediate spring rate to regulate movement of said fuel feed rack at said predetermined low speeds and at predetermined intermediate speeds to prevent excessive acceleration of said engine at said low speeds and said intermediate speeds, said first spring means ineffective to regulate movement of said fuel feed rack at speeds above said predetermined low speeds, and said second spring means having a predetermined high spring rate to regulate movement of said fuel feed rack at predetermined high speeds to prevent excessive acceleration of said engine at said high speeds, said third spring means effective with said second spring means to regulate movement of said fuel feed rack at said predetermined high speeds.

2. A governor as in claim 1 wherein said third spring comprises a finger spring having variable rate.

3. A governor as in claim 2 wherein said third spring cooperates with said first spring to cause a smooth transition from the low speed to the intermediate speed.

4. A governor as in claim 1 wherein said first and second spring means comprise coil springs and said third spring means comprises a finger spring and said second spring is assembled in the governor under a predetermined preload.