US3028847A - Engine governor actuator - Google Patents

Description

April 10, 1962 i M. F. STERNER ENGINE GOVERNOR ACTUATOR Filed Dec. 2, 1957 INVENTOR. MELvlN ESTERNER BY W Y ATToRNE s tice vPatented Apr. 10, i962 3,023,847 ENGNE GOVERNOR ACTUATR Melvin F. Steruer, Blooxntieid Hilis, Mich., assgnor to Holley Carburetor Company, Van Dyke, Mich., a corporation of Michigan Fiied Dec. 2, 1957, Ser. No. 699,970 6 Claims. (Cl. 12S- 103) The present invention relates generally to engine governors, and more specifically to means for actuating such governors. y

In the past engine governors for internal combustion engines using carbureting means have been provided which employed vacuum as the source of power for operating the speed control means, usually the throttle. Under certain conditions it becamerditiicult and costly to produce a vacuum actuated governor having a low r.p.m. spread without at the same time having a tendency to surge.

This problem has been magnified in the recent past by the fact that the automotive industry is using a continually increasing percentage of multiple barrel carburetors. Because of this trend the vacuum available for operating the governor and other devices has diminished and the resulting forces are becoming insufficient for proper governor control.

With the foregoing in mind it is an object of the present invention to provide a means for actuating a governor which may he designed to have a very low r.p.m. spread.

It is a further object of the present invention to provide a governor as defined in the preceding paragraph characterized by the fact that any tendency to surge has been eliminated.

It is a further object of the present invention to provide a means for actuating the governor which is not dependent on a supply of vacuum.

It is a further object of the present invention to provide hydraulic fluid pressure actuated motive means for operating a speed control member, in combination with a source of hydraulic pressure variable in accordance with engine speed.

More specifically, it is an object of the present invention to provide a source of hydraulic fluid under a Variable pressure dependent on engine speed.

Still more specifically, it is an object of the present in vention to provide, for use in conjunction with an internal combustion engine, a source of hydraulic liuid under a Variable pressure dependent on engine speed, in combination with means to prevent supply of hydraulic uid at a pressure less than that corresponding to a predetermined minimum engine speed.

Other objects and features of the invention will become apparent as the description proceeds, especially when taken in conjunction with the accompanying drawing, illustrating preferred embodiments of the invention, where- FIGURE 1 is a schematic sectional View illustrating the present invention.

FIGURE 2 is a sectional View illustrating a modification of the control valve.

FGURE 3 is a sectional view of a modified pressure supply unit.

In the embodiment of the invention illustrated in FIG- URE 1 there is provided a unit for supplying hydraulic iluid under a variable pressure dependent on the speed of an internal combustion engine to be controlled. The internal combustion engine includes the usual air intake passage 12 associated with a carburetor for supplying fuel and having a throttle 14 associated therewith. The throttle 14 in the figure is shown in open position and is mounted for pivotal movement about a pivot support 16 and is provided with an operating arm j18 to which is connected a rod 20 the opposite end of which is in turn secured to a flexible diaphragm 22 mounted in a housing indicated generally at 24 and composed of housing sections 26 and 28 between which the edges of the diaphragm 22 are clamped. The diaphragm divides the interior of the housing 24 into chambers 30 and 32, the chamber 32 being a pressure chamber as will subsequently be described. The chamber 30 is vented to atmosphere as indicated at 34 and includes a compression spring 36 biasing the diaphragm to the right as viewed in FIGURE 1 and hence in a direction to maintain the governor throttle plate 14 in positively open position. It will be understood that suitable stop means (not shown) are provided to limit opening movement of the throttle plate 14 to the position shown. It will be apparent that when pressure is built up in the chamber 32, the diaphragm 22 moves to the left thus moving the governor throttle plate 14 toward closed position. Y

In accordance with the present invention the means for supplying hydraulic fluid to the chamber 32 comprises a unit indicated generally at 40 including a housing portion 41 having a pumping chamber 42 therein which receives a rotary impeller 44 connected to a drive shaft 46 which in turn is connected to a rotating part of the internal cornbustion engine to be controlled, such for example as its cam shaft. 'Ihe shaft 46 has an axially extending passage 48 communicating with radially extending passages 50 and these in turn communicate with an iniet port 52 supplied with hydraulic fluid through a fitting 54 connected to a conduit 56. The impeller 44 includes a radially extending passage 58 which communicates with the axially extending passage 48. Accordingly, as the shaft 46 is rotated by operation of the engine, pressure of the hydraulic uid in the chamber 42 is built up by centrifugal action resulting from rotation of the impeller 44.

The housing portion 41 includes a recess 60 enclosed by a cover portion 62 which clamps the edges of a ilexible diaphragm 64 thereby providing an internal pressure chamber 66. Between the flexible diaphragm 64 and the bottom of the recess 60 there is provided a compression spring 68 and the space containing the spring is Vented to atmosphere as indicated at 70. The flexible diaphragm 64 carries a valve element 72 cooperable with an outlet valve port 74. The pressure 0r pumping chamber 42 is connected by a conduit or passage 76 with the pressure chamber 66.

The unit 40 is connected to a supply conduit 78 to the interior of the pressure chamber 32. In addition a fluid return line St) is provided extending from the pressure chamber 32 to the reservoir or other source of hydraulic fluid. A restriction S2 is providediin the return passage 80 so as to establish some point of critical iiow.

With the foregoing construction in mind it will be observed that when the engine is started rotation is imparted to the shaft 46 and pressure of the hydraulic uid in the pressure chamber 42 increases as a result of the action of the impeller 44. This pressure is transmitted through the passage 7 6 to the pressure chamber 66. However, escape of lluid under pressure is prevented since the valve 72 is on its seat and remains in closed relation until the pressure within the pressure chamber 66 reaches a value as determined by the strength of the spring 68 which corresponds to some predetermined engine speed. At this time the valve 72 opens and hydraulic fluid under pressure is supplied to the pressure chamber 32 where it estab- Y lishes a force against the flexible diaphragm 22 tending to close the governor throttle plate 14. A continuous liow of fluid takes place through the pressure chamber 312, this flow being restricted by the restriction 82 to maintain the pressure within the chamber 32 at a value dependent upon the pressure developed by rotation of the impeller 44.

Accordingly, Abelow a predetermined engine speed, no

geraet? y apesar? pressure acts on the flexible diaphragm 22 and the throttle plate 14 remains in full open position. However, at some predetermined engine speed, the valve 72 opens and hydraulic fluid under pressure is admitted to the pressure chamber 32. The pressure within the pressure chamber 32 is dependent upon the pressure developed by the impeller 44 and the amount of opening of the valve 72. The valve 72 may move from fully closed to fully open position upon a very small change in pressure in the pressure chamber 66. The movement of the governor throttle plate 14 is controlled by pressure in the chamber 32 overcoming the effect of the spring 36 and accordingly, the throttle plate 14 may move from fully open to fully closed position with an extremely small r.p.m. spread. At the same time, the valve 72 has the elect of preventing a throttling action on the gear throttle plate 14 at speeds below the predetermined governed speed.

Referring now to FIGURE 2, there is illustrated a modication of the valve which prevents supply of fluid from the unit at speeds below a predetermined minimum speed. In this figure there is illustrated a cylindrical chamber 90 one end of which is vented to atmosphere as indicated at 92 and which contains a compression spring 94 engaging one end of a piston 96 movable longitudinally of the chamber. Connected to the chamber is a passage 9S corresponding to the passage 76 of FIGURE 1, and adapted to receive uid under pressure from a pumping chamber corresponding to the pumping chamber 42. At one side of the cylinder 90 is a port 160 to which is connected a fluid supply passage 162 corresponding to the passage 78 shown in FIGURE 1. It will be observed that the piston 96 operates as a valve in conjunction with the port 100. Thus, as pressure supplied through the lpassage 98 builds up the piston is moved upwardly against the spring 94 until the port 100 is uncovered and thereafter, hydraulic fluid under pressure is supplied to the speed control unit.

Referring now to FIGURE 3 there is illustrated a construction in which a separate return conduit such as shown at 80 in FIGURE 1 is eliminated. In this embodiment of the invention the unit is self-contained and includes a rst housing member 110 having a pumping chamber 112 therein in which is mounted a rotary impeller 114 connected to a shaft 116 which in turn is adapted to be connected to a rotating part of the engine such for example as its cam shaft. A uid supply passage 118 is provided which communicates with the axially extending passage 120 in the shaft 116, the latter in turn communicating with the radially extending passages 122 in the impeller. The unit includes a second housing assembly 124 connected to the first member 110 and having a chamber 126 therein divided by a exible diaphragm 128 into a pressure chamber 130 and a second chamber 132 vented to atmosphere as indicated at 134. The chambers 112 and 126 are connected by a passage 136 to deliver fluid from the chamber 112 to the pressure chamber 126. The chamber 126 is provided with a passage 138 which leads to the speed control mechanism. Carried by the flexible diaphragm 128 is a valve 140 adapted to prevent delivery of hydraulic uid under pressure to the passage 138 until pressure within the chamber 13) reaches a predetermined minimum value as determined by a compression spring 142 contained in the chamber 132.

Formed within the housing members 110 and 124 is a passage 144 extending from the outlet passage 133 to the inlet passage 118. The passage 144 is provided with a restriction 146 to establish a critical point of flow. It will of course be appreciated that the passage 144 and restriction 146 correspond functionally to the external passage or conduit 86 and its restriction 82.

The unit illustrated in FIGURE 3 is thus adapted to provide a supply of hydraulic fluid under a pressure which is determined by engine speed whenever the engine speed is at or above a predetermined minimum speed.

Operation As the engine speed increases the shaft 46 or 116, which is driven at some constant ratio to the engine speed, rotates the impeller 44 or 114. This in turn causes the pressure of the tiuid in the chamber 42 or 112 to increase and this pressure is transmitted to the chamber 66 or 130. When the engine has reached sufficient speed and the pressure reaches some predetermined corresponding value the spring 68 or 142 will be overcome by the pressure on the diaphragm 64 or 128. When this condition is reached the valve 72 or 140 opens and hydraulic huid under pressure then lows to the chamber 32. As the hydraulic uid reaches a point of critical low through the restriction 82 or 146, pressure will correspondingly increase in the chamber 42 with an increase in engine speed. As the pressure continues to increase the diaphragm 22 will be moved to the left as seen in FIGURE l, against spring 36, and rotate the governor throttle plate 14 so as to limit the intake of combustible mixture by the engine.

The drawing and the foregoing specification constitute a description of the improved engine governor actuator in such full, clear, concise and exact terms as to enable any person skilled in the art to practice the invention, the scope of which is indicated by the appended claims.

What I claim as my invention is:

1. An engine speed governor for an internal combustion engine having a movable speed control member, a hydraulic fluid motor comprising an operating pressure chamber having a movable wall, actuating means connected to said wall and adapted to move said speed control member in a speed reducing direction upon admission of pressure uid to said chamber, a hydraulic pump adapted to be driven at a speed dependent on engine speed and to develop a pressure dependent on engine speed, said pump having a single outlet port, a supply passage connecting the outlet port of said pump to said chamber to deliver the entire output of said pump to said chamber, a normally closed pressure responsive valve in said passage, said valve having means responsive to the pressure of hydraulic uid developed by said pump operable to open said valve at a uid pressure corresponding to a predetermined engine speed, said passage being relatively unrestricted, and a relatively restricted exhaust passage connected to said pressure chamber of the motor.

2. An engine speed governor for an internal com bustion engine having a movable speed control member, a hydraulic uid motor comprising an operating pressure chamber having a movable wall, actuating means connected to said wall and adapted to move said speed control member in a speed reducing direction upon admission of pressure uid to said chamber, a hydraulic pump adapted to be driven at a speed dependent on engine speed and to develop a pressure dependent on engine speed, said pump having a single outlet port, a normally closed valve having a pressure chamber, a valve element controlling discharge of fluid from said pressure chamber, a resilient means operatively connected to said valve element and urging said valve element toward closed position, a substantially unrestricted passage con necting the outlet port of said pump to said pressure chamber of said valve to deliver the entire output of said pump to said chamber of said Valve and effective to maintain the pressure of uid in said valve pressure chamber substantially at pump discharge pressure, a passage connecting the pressure chamber' of said valve and the operating pressure chamber of said fluid motor to deliver the entire output of said pump to said motor when said valve is open, and a relatively restricted exhaust passage connected to said operating pressure chamber.

3. An engine speed governor for an internal combbustion engine having a movable speed control member, a hydraulic uid motor comprising an operating pressure chamber having a movable wall, actuating means connected to said wall and adapted to move said speed control member in a speed reducing direction upon admission of pressure uid to said chamber, a hydraulic pump adapted to be driven at a speed dependent on engine speed and to deliver hydraulic fluid at a pressure dependent on engine speed, a normally closed valve having a pressure chamber, a valve element controlling discharge of fluid from said pressure chamber, resilient means operatively connected to said valve element and urging said valve element toward closed position, said pump having a single outlet port, a substantially unrestricted passage connecting the outlet port of said pump to said pressure chamber of said valve to deliver the entire output of said pump to said pressure chamber of said valve and eiective to maintain the pressure of fluid in said valve pressure chamber substantially at pump discharge pressure, a substantially unrestricted passage connecting said valve and the operating pressure chamber of said uid motor, and a relatively restricted exhaust passage connected to said operating pressure chamber.

4. A hydraulic engine speed governor for an internal combustion engine having a movablespeed control member, a hydraulic motor connected to said member and operable when supplied with hydraulic uid under pressure to move said member in speed reducing direction, a.

housing having a pump chamber therein, an inlet passage connected to said pump chamber, a centrifugal pump rotor in said chamber, means for connecting said rotor to the engine for rotation thereby at a speed dependent on engine speed to maintain hydraulic fluid in said pump chamber at a pressure dependent on engine speed, a valve chamber in said housing having a movable Wall therein, said pump having a single outlet port, a substantially unrestricted pump outlet passage connecting said pump outlet port and said valve chamber for delivery of the entire output of said pump to said valve chamber, a valve port in said valve chamber, a valve connected t said movable Wall for actuation thereby, resilient means urging said valve to closed position and yieldable to open said valve upon development of a predetermined elevated pressure of hydraulic fluid in said valve chamber, an unrestricted supply passage connecting said valve chamber to said motor, and a restricted return passage located downstream from said valve to establish a critical ilow point and to provide for delivery of hydraulic fluid to said motor when said valve is opened at pressure substantially equal to the pressure in said pump chamber and said valve chamber.

5. A governor as dened in claim 4 in which said rehydraulic uid motor comprising an operating pressure chamber having a movable Wall, actuating means connected to said wall and adapted to move said speed control member in a speed reducing direction upon attainment of a predetermined pressure in said operating pressure chamber, a centrifugal hydraulic pump adapted to be driven at a speed dependent on engine speed and to develop a pressure dependent On engine speed, said pump having a single outlet port, a normally closed valve having a pressure chamber including a movable Wall subjected at one side to hydraulic pressure Within the pressure chamber of said valve and at the other side to atmospheric pressure, resilient means connected to said Wall to bias said wall in a direction opposing movement induced by an increase in pressure Within the pressure chamber of said valve, the pressure chamber of said valve having a single inlet port and a single outlet port, a valve element connected to said movable wall controlling the single outlet port of the pressure chamber of said valve and movable in opening direction upon attainment of a predetermined pressure Within the pressure chamber of said valve, a substantially unrestricted passage connecting the single outlet port of said pump to the single inlet port of the pressure chamber of said valve, a substantially unrestricted passage connecting the single outlet port of the pressure chamber of said valve to the operating pressure chamber of said motor, and a restricted exhaust passage connected to the operating pressure chamber of said motor. v

(Addition to No. 941,544)

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