US3645097A

US3645097A - Hydraulic governor

Info

Publication number: US3645097A
Application number: US865698A
Authority: US
Inventors: Noritoshi Tanaka
Original assignee: Diesel Kiki Co Ltd
Current assignee: Bosch Corp
Priority date: 1968-10-18
Filing date: 1969-10-13
Publication date: 1972-02-29
Anticipated expiration: 1989-02-28

Abstract

A hydraulic governor wherein a power piston is actuated only by oil pressure a gear pump in a fuel increasing direction and by a power spring in a fuel decreasing direction. A speed regulating lever is operatively connected to a speeder lever which is engaged with a floating lever which includes a mediate fulcrum and variable lever ratio. The speeder lever is interlocked to a link connected to the power piston. A load-limiting piston is adapted to open and close a path passing through the pressure side of the power piston and gear pump.

Description

United States Patent Tanaka [4 1 Feb. 29, 1972 [54] HYDRAULIC GOVERNOR Inventor: Noritoshi Tanaka, Higashi-Matsuyama-shi,

Japan Assignee: Diesel Kiki Kabushiki Kaisha, Tokyo,

Japan Filed: Oct. 13, 1969 Appl. No.: 865,698

Foreign Application Priority Data Oct. 18, 1968 Japan ..43/75572 US. Cl. ..60/52 SR, 91/366 Int. Cl ..Fl5b 15/18 Field of Search ..60/52 SR, 10.5; 91/366, 458

References Cited UNITED STATES PATENTS Parker ..9l/366 X 2,715,892 8/1955 Rodeck et a1. ..60/52 SR 3,148,501 9/1964 Oldenburger... ....91/366 3,412,648 11/1968 Newburgh ..91/366 Primary ExaminerEdgar W. Geoghegan Attorney-Larson, Taylor and Hinds ABSTRACT A hydraulic governor wherein a power piston is actuated only by oil pressure a gear pump in a fuel increasing direction and by a power spring in a fuel decreasing direction. A speed regulating lever is operatively connected to a speeder lever which is engaged with a floating lever which includes a mediate fulcrum and variable lever ratio. The speeder lever is interlocked to a link connected to the power piston. A load-limiting piston is adapted to open and close a path passing through the pressure side of the power piston and gear pump.

7 Claims, 1 Drawing Figure Patented M5. 29, 1972 now m nm m HYDRAULIC GOVERNOR This invention relates to and has for its object to provide a hydraulic governor having a load controller for effecting control of smoke limit, engine cutoff or fuel supply simultaneously and having sensitive controlling characteristics for adjusting instantaneous speed fluctuations and set speed fluctuations to a minimum.

ln order that this invention may be more readily understood, reference will now be made, by way of example, to

the accompanying drawing, which shows an operation of the hydraulic governor according to this invention.

The invention will be described on an embodiment with reference to the drawings. I

A drive shaft 1 which rotates in association with the speed of rotation of the engine, drives a gear pump 2 comprising gears 2a and 2b and serving as a working oil pressure source of the governor. A pilot valve bushing 3 is driven through the gear 2a attached to the drive shaft 1. The pilot valve bushing 3 has gear 2b at one end, flyweights 4 at the other end for detecting speed of rotation of the governor, and

ports

3a, 3b, and 3c on its cylindrical portion. The gear pump 2 has a suction valve and a discharge valve respectively on its inlet and outlet sides and is adapted for engines of any direction of rotation. In the pilot valve bushing 3, there is provided a pilot valve 5 axially movable by the centrifugal force of the flyweights 4, which'pilot valve controls the oil pressure exerted on a power piston 6 and a fuel-controlling rod 7 connected to the power piston. The flyweight 4 engage with the pilot valve 5 through the thrust bearing 5a and are balanced with the centrifugal force at its rotation speed by a speeder spring 8. When the rotation speed of the engine is balanced, the valve portion 5b of the pilot valve 5 closes the port 3b of the pilot valve bushing 3 and, then, forces of the flyweights 4 and the speeder spring 8 balance one another. But when the load on the engine is increased and the rotation speed thereof is lowered, the centrifugal force is reduced so that the pilot valve 5 is pressed downwardly from the position shown in the drawing bythe speeder spring'8 to communicate the port 3a with the port 3b. The oil pressure from the gear pump 2 thus acts within a chamber 6a on the power piston 6 to move the fuel-controlling rod 7 through a guide lever 9 in the direction of fuel increase. Reversely when the load on the engine is lessened the speed of rotation is accelerated and the centrifugal force of the flyweights 4 is increased, in consequence the pilot valve 5 moves upwardly against the force of the speederspring 8 to communicate the port 36 with the port SC to thus discharge the oil pressure in the chamber 6a of the power piston 6 into an oil reservoir 10 under the urgence of spring 11 acting on power piston 6 to move the fuel-controlling rod 7 in the direction of fuel decrease. Thus, the power piston 6 is operated in the direction of fuel increase only by means of oil pressure and in the direction of fuel decrease only by a spring force. In a passageway communicating the gear pump 2 with the pilot valve 5 there is provided an accumulator 12 comprising a piston 12a, a spring 12b and an exhaust port 120 for regulating the maximum accumulater pressure. In order to feed back the movement of the power piston 6 to the speeder spring 8, a guide lever 9 connected to the power piston 6 is provided with a pin 13, to which is engaged a long groove 16a at one end of a floating lever 16. Lever 16 is also provided with a long groove 16b at its other end. The floating lever 16 is supported to swing about a pin 15b provided at one end of a speed change lever 15 rotatable on a fulcrum 15a by the variation of a cam 14 engaging with an intermediate portion of the lever 15. To the long groove 16b at the other end of the floating lever 16 is engaged a pin 18a provided at an end of a speeder lever 18. The other end of the speeder'lever 18 is connected by a pin 18c to a rack 17 which rack is in engagement with a pinion 19a of a speed-regulating lever 19. The middle portion of said speeder lever 8 is connected by a pin 18b to a spring receiver 8a of the speeder spring 8 which spring receiver is movable in parallel with the rack 17.

The operation of the device is now described. The speed regulation of the governor is set by shifting the rack 17 by the speed-regulating lever 19 to set the loading of the speeder spring 8 whereby the engine speed can be set at a desirable value. If the load on the engine varies when the speed-regulating lever 19 is fixed, the power piston 6 shifts the fuel-controlling rod 7 to control the speed as mentioned above. Assuming that the power piston 6 moves in the direction of fuel decrease (the direction of the arrow in the figure) by increase of rotation due to decrease of load, then the floating lever 16 rotates counterclockwise on the fulcrum of the pin 15b of the speed change lever 15. At the same time, speeder lever 18 with the pin 18a engaged with the long groove 16b is rotated clockwise on the fulcrum of the pin 18c, so that the speeder spring 8 is deformed and sets up a new load. The pilot valve 5 is thus moved to a position for closing the port 3b of the pilot valve bushing 3 which was previously in communication with the port-3c and balanced by the centrifugal force of the flyweights 4. With an increase of load on the engine the shifting in the direction of fuel increase (the direction of the arrow in the figure) of the power piston 6 extends the speeder spring 8 in the opposite direction so that the rotation.

speed is settled slightly higher than the initial balanced condition. If the rotation speed in the balanced condition is N, and the settled rotation speed after fluctuation is N the fluctuation rate of the settled speed e will be represented by the formula:

which is determined according to the lever ratio of the described lever mechanism. If the displacement of the power piston 6 is x; the deformation of the speeder spring 8; and the distance between lever fulcrums or the pin 13 and the pin 15b, the pin 15b and the pin 18a, the pin 18a and the pin 18c and the pin 18c and the pin 18b are respectively 1,, l l and 1 there will be obtained the following formula:

From the above formula, it will be seen that as y is large so also 6 is large. That is, by large displacement of y the valve portion 5b of the pilot valve 5 tends to close the port 3b earlier so that the balanced condition of the load and the engine output is obtained at N, which is a much larger or lower value. Herein, as 1 and l, are constant y is determined by the ratio of l l and l (1, and i are constants). This is varied by displacement of the movable fulcrum 15b by rotation of the lever 15 by the speed change cam 14. Where l =0 the effect of the power piston 6 on the speeder spring 8 is lost so that the pilot valve 5 will completely follow the variation of the speed of rotation and can change settled speed 6 to zero.

The chamber 6b serves as a compensation mechanism on the side of the power spring 11 of the power piston 6 and communicates with the governor oil reservoir 10 through a needle valve 21 and also communicates through the passage 6c with the surface 50 on the end of the pilot valve 5 opposite speeder spring 8. In passage 60 is a passage for a piston 20 to moderate the variation of oil pressure exerted on the end surface 5c of the pilot valve 5, both end surfaces of which piston 20 communicate with the oil reservoir 10 and the passage 60 and which are pressed from the both sides by springs 20oand 20b. When the rotation speed of the engine rises, the power piston 6 shifts in the direction of fuel decrease by being pressed by power spring 11 so that the pressure in the chamber 6b of the power piston 6 decreases. Therefore, the oil flows fromthe governor oil reservoir 10 through the needle valve 21. When the flowing oil is throttled by the needle valve 21, the chamber 6!: has a negative pressure which urges pilot valve 5 against the centrifugal force of the flyweights 4. Thereby the movement or the response of the power piston 6 can be temporarily delayed relative to the variation of input. When the rotational speed of the engine decreases, the pilot valve 5 is pressed by the positive pressure in chamber 66 against the centrifugal force of the flyweights 4, whereby the response is similarly delayed. This operation will reduce the instantaneous fluctuation so as to prevent rapid variation in the rotation speed of the engine and also hunting due to a sudden variation of load, thereby serving to obtain a stable engine performance. The pressure chamber 6a of the power piston 6 communicates with a load-limiting mechanism 22 which comprises a piston 22a to open and close a side passage 6d communicating the pressure side chamber 60 of the power piston 6 and the oil reservoir 10. Piston 22a is engaged to pin 22:: in the middle of lever 22d, one end of which is rotatably engaged by a pin 22b to an end of the power piston 6 and the other end by a pin 22c intermediate the ends of the lever 22d followed by the cam 220. The piston 22a is pressed by a spring 22f to always contact the lever 22d with the cam 220.

The above-described mechanism limits the maximum amount of fuel to be supplied to the engine. When a power piston 6 moves sufficiently in the direction of fuel increase, the load-limiting piston 22a in association therewith moves against the spring 22f and the passage 6d is opened to the oil reservoir 10, whereby the oil in the chamber 6a pushing the power piston 6 against the power spring 11 is discharged into the oil reservoir so that the shifting of the power piston 6 is stopped at a certain position and the supply amount of fuel is limited to the value corresponding to said position. Accordingly, by adjusting the rotational angle of the cam 22c the opening and closing times of the passage 6d by the load-limiting piston 22a can be varied so that the limit position in the direction of fuel increase of the fuel-controlling rod 7 by the power piston 6 can be desirably adjusted. Thus it will be possible to control the smoke limit of the engine by the position of rotation of the cam 22c, to vary desirably the rated output corresponding to the use of the engine, and to stop the engine rapidly and securely without regard to the set speed at that time.

As hereinbefore described the governor of the present invention comprises two feedback systems of a mechanism for determining the fluctuation rate of a set speed and a compensation mechanism for deciding the instantaneous speed fluctuation and load limiting mechanism and these effects are broadly adjustable from the outside of the governor by means of the cam 14, needle valve 21 and load limiting cam 22c. As the governor of the invention has a small centrifugal force of the flyweight 44, the speeder spring 8 may be weak. Accordingly, the reactionary force of the speed-adjusting lever 19 is small and the device may well be operated by a smallsized motor and the speed setting will be made by remote control.

Many variations may be effected without departing from the spirit of the present invention. It is to be understood that these, together with other variation in details, are anticipated by the appended claims.

lclaim:

1. A hydraulic governor for controlling the rate of rotation of a shaft powered by an engine including fuel injection means; comprising a power piston for controlling the rate of fuel introduced into said engine through said fuel injection means; first and second gears comprising a hydraulic gear pump; a rotatable bushing including moveable weights; said first gear being secured to said shaft and said second gear being secured to said rotatable bushing for rotation thereof with rotation of said shaft whereupon said weights are moveable by centrifugal forces; hydraulic inlet means on the inlet side of said pump; a pilot valve member moveable in said bushing in one axial direction under the influence of the movement of said weights; speeder spring means urging said pilot valve member in the opposite axial direction; conduit means connecting the outlet of said gear pump to one side of said power piston by a path passing through said bushing, said pilot valve member being moveable axially in said bushing to close and open said path for moving said power iston in a first introduced to direction under the influence of hydraulic flui said one side of said piston from said gear pump; power spring means on the other side of said power piston urging the piston for motion in a second direction; a first lever connected intermediate its ends to said speeder spring for positioning said speeder spring relative to said bushing, the position of one end fulcrum of said lever being adjustable to adjust the position of said speeder spring relative to said bushing; a floating lever connected at its one end to the other end of said first lever and at its other end for motion with said power cylinder, said floating lever including a moveable fulcrum intermediate its ends, whereby motion of said piston induces motion of said first lever about its intermediate fulcrum, the amount of said motion being dependent upon the amount of motion of said piston and upon the location of said moveable fulcrum; and means for adjusting the position of said moveable fulcrum.

2. A governor according to claim 1 further including an oil reservoir, further conduit means communicating said oil reservoir with said other side of said power piston and with the end of said pilot valve member remote from said speeder spring, and valve means regulating the flow of hydraulic flow through said further conduit means.

3. A governor according to claim 1 further including a speed control lever secured to said one end of said first lever for adjusting the position of said speeder spring relative to said bushing.

4. A governor according to claim 1 further including speed limiting means comprising a valve located in a conduit connecting said one side of said power piston and said reservoir, said valve being actuated by motion of said power piston to open at a desired position of said power piston.

5. A governor according to claim 4 wherein said speed limiting means comprises a further lever for actuating said valve, the position of said further lever being adjustable to thereby adjust the actuation of said valve relative to motion of said power piston.

6. A governor according to claim 5 including adjustable cam means for adjusting the position of said further lever.

7. A governor according to claim 1 including cam means for moving said moveable fulcrum.

Claims

1. A hydraulic governor for controlling the rate of rotation of a shaft powered by an engine including fuel injection means; comprising a power piston for controlling the rate of fuel introduced into said engine through said fuel injection means; first and second gears comprising a hydraulic gear pump; a rotatable bushing including moveable weights; said first gear being secured to said shaft and said second gear being secured to said rotatable bushing for rotation thereof with rotation of said shaft whereupon said weights are moveable by centrifugal forces; hydraulic inlet means on the inlet side of said pump; a pilot valve member moveable in said bushing in one axial direction under the influence of the movement of said weights; speeder spring means urging said pilot valve member in the opposite axial direction; conduit means connecting the outlet of said gear pump to one side of said power piston by a path passing through said bushing, said pilot valve member being moveable axially in said bushing to close and open said path for moving said power piston in a first direction under the influence of hydraulic fluid introduced to said one side of said piston from said gear pump; power spring means on the other side of said power piston urging the piston for motion in a second direction; a first lever connected intermediate its ends to said speeder spring for positioning said speeder spring relative to said bushing, the position of one end fulcrum of said lever being adjustable to adjust the position of said speeder spring relative to said bushing; a floating lever connected at its one end to the other end of said first lever and at its other end for motion with said power cylinder, said floating lever including a moveable fulcrum intermediate its ends, whereby motion of said piston induces motion of said first lever about its intermediate fulcrum, the amount of said motion being dependent upon the amount of motion of said piston and upon the location of said moveable fulcrum; and means for adjusting the position of said moveable fulcrum.