US2481020A - Engine control means - Google Patents

Description

Se t. 6, 1949. J. E. JUSTUS ENGINE CONTROL MEANS Filed Oct. 31. 1945 .Z'NvE/vraR JAMES E. Jus'rus "'7 3 M K. /0.,-.. M flrroR'A/Ev 'IIIIIIIIIII FIGL.

Patented Sept. 6,

ENGINE CONTROL MEANS James E. Justus, Beloit, Wis assignor to Fairbanks, Morse & 00., Chicago, Ill., a corporation of Illinois Application October 31, 1945, Serial No. 625,727

2 Claims. (01. 264-3) This invention relates generally to control sys-- tems for internal combustion engines, and has particular reference to certain improvements in pneumatically operated control systems of a character suitable for effecting regulation of engine speed governor mechanism. The invention as will hereinafter appear, is applicable in particular to a pneumantically operated control system suitable for use with the governor mechanism of a Diesel engine serving as the power unit in a Diesel-electric locomotive or the like.

In the operation of Diesel-electric locomotives havin a pneumatic control embodying a servomotor through which the engine governor is adjusted to determine engine speed and power output in accordance with engine loading, the operator frequently applies full or nearly full air pressure to the servo-motor quite suddenly, with the consequence as heretofore found in practice, that the servo-motor force-transmitting element in its resultant displacement, undergoes an appreciable vibratory or oscillatory movement in the initial period of its actuation. As a direct consequence thereoi, the governor responds by assuming a so-called hunting action, with the result that the engine speed and power will vary correspondingly for an appreciable time, until the servo-motor becomes stabilized and the governor ceases hunting. Such reaction of the control motor and governor at least in the initial period of adjustment, is a distinct disadvantage in locomotive operation, as it tends to result in an uneven movement of the locomotive. Consequently, the object of the present invention is to afford an improvement in the pneumatic control system provided for engine governor regulation, which will obviate the disadvantageous reaction as above discussed.

This and other objects of the invention will appear readily from the following description of a preferred embodiment thereof as illustrated by the accompanying drawing, wherein:

Fig. 1 shows diagrammatically, an internal combustion engine and engine speed governor, and a pneumatic control system in regulating association with the governor, wherein is embodied the present improvements,

Fig. 2 illustrates in enlarged section, a control device of a presently preferred form, as utilized in the pneumatic control system shown in Fig. 1, and

Fig. 3 is a diagrammatic view of a throttling mechanism suitable for incorporation in the showing of Fig. 1.

Referring to the drawing and first to Fig. l,

movements of the weighted arms l8, in the usual I an internal combustion engine of a Diesel type, is indicated diagrammatically at Hi, the engine in accordance with present example, serving as a power unit of 'a Diesel-electric locomotive (not shown), as to drive through the engine shaft II, a suitable electric generator for supplying electric, power to drive motors in operative association with the locomotive wheels, the several last named elements being deemed unnecessary of present disclosure.

An engine control governor indicated generally at l2, includes a shaft [4 in driven connection with the engine shaft ll through gearing l5, governor weight l6 pivotally suspended from the shaft it through arms l8, and a tubular member I9 sleeved on shaft i4 and connected to the governor arms l8 by links 20, whereby to afford displacement of the member along shaft M in response to pivotal manner of centrifugal governor operation. A bell-crank lever 22 suitably pivotally supported as indicated at 23, has its long arm 24 extended to an operative connection 26 with the governor sleeve l9, and its short arm 21 connected to one end of a control rod 28. Rod 28 leads to the engine fuel pumps (not shown) for regulating the latter as to fuel delivery, in accordance with control positions of the governor-mechanism. Load ing of the governor to condition it for maintaining engine speed and power output under load, is effected by a suitable capacity compression spring 36, here shown arranged between the sleeve is and acollar 3i. According to the diagrammatic arrangement shown, altering the position of the collar 3i, as to points nearer to or more removed from the sleeve it, will produce correspondingly greater or lesser compression of the spring 3%, whereby the governor may be thus set to maintain engine speed and power output predetermined according to the compression adjustment of the loading spring.

Positionin of the collar iii to adjust the governor spring loading 30, is effected by a pneumatically operated control shown diagrammatically in Fig. i, as comprising a servo-motor 32 providing an air chamber 3t closed on one side by a yieldable diaphragm t5 urged to an intial position by a spring 36, a plunger or actuator element it connected to the diaphragm, and an operating arm 39 pivotally supported at til and extending therefrom in a position for abutment by the free end 412 of the plunger 38. A link t3 connects the free end M of arm 39 with the collar 3i associated with the governor loading spring 30.

A suitable source of fluid pressure as the compressed air tank 46, is connected with the servomotor chamber 34 by a conduit 41, and located in the conduit line is an air throttle or valve device 48 having an operating lever or handle 50. Handle 50 is shown in a position which may be said to be the oif position of the throttle, wherein compressed air is shut-off from delivery to the servo motor, while any air under pressure above atmospheric in the motor chamber 34 and the piping to the throttle 48, may exhaust through the throttle valve to atmosphere. By moving the lever 50 to the right as viewed in Fig. 1, from the off position to the end of the slot 52, air under the full source pressure, will be delivered to motor chamber 34, while disposing the lever in any position intermediate the above extremes, will condition the control 48 to throttle the air pressure to a degree corresponding to the lever position selected. The device 48 functioning as indicated, while well known in the art, is illustrated in Fig. 3 and described below in detail.

In the operation of the engine speed control arrangement as thus far described, assuming the engine in to be in operation without load and at normal idling speed, the operating parts of the governor I2 and servo-motor 32 willbe positioned substantially as shown in Fig. 1, while the air throttle valve 48 will be in off" position. Now. for example, when full load operation of the engine is desired, the lever or handle 50 of the air valve 48 is moved to full air pressure delivery position, as to the end 5! of the slot 52. In consequence thereof, full air pressure is applied to the diaphragm 35 in chamber 34 of the servomotor 32, with the result that the diaphragm will be thereby displaced in opposition to the spring 36, to actuate the plunger 38 against the arm 39. Arm 39 thus displaced about its pivotal support 40, will effect through the link 43, positionment of the collar 3| to increase the efiective compression of governor loading spring 36 such as will condition the governor mechanism for establishing full load running of the engine. Any intermediate positioning of the throttle lever 50 likewise will effect corresponding compression adjustments of the governor spring 30 to establish engine operation under intermediate loads.

The diagrammatic view of Fig. 3 shows a suitable form of pressure throttling member controlled by the throttle lever 50. This member is indicated at 48 in Fig. 1, and is connected between the supply conduit 41 and the delivery conduit 64. The conduit 41 is connected to open between opposed diaphragms 82 and 83 so that motion of the diaphragm 83, which carries "a valve seat 84, is responsive to the force of the throttle spring 85 as opposed by fluid pressure on its opposite side. A supply valve 86 cooperates with the seat 84, and this valve 86 is held in mechanical connection with a release valve 81 by the light spring 88. The release valve 81 cooperates with a suitable seat at the inner end of the tubular operating member 89 which is slidably mounted in a housing sleeve guide. The valve 81 is urged to unseat by a light spring 98. The member 89 carries an adjustable tappet element 9|- at its outer end for working engagement with the cam 92 on the throttle lever 50. The conduit 64 opens to a space between the small valves 86 and 81 so that fluid at the selected pressure flows therethrough toward the actuator 32. Upon lever 50 being moved to reduce speed the member 89 is backed off the valve 81 by action of spring 93 to open the release passage to atmosphere. and this condition maintains until the spring 86 can against the diaphragm 35, and an equally sudden reaction of the diaphragm, as displacement thereof in opposition to the sprin 36. As a consequence, a marked vibratory displacement is set up in both the diaphragm and the spring, which dependin upon the period of oscillation characteristics of these parts, may last for an appreciable time. The resultant vibratory or oscillatory impulses are transmitted directly to the governor loading spring 36 through the servo-motor plunger 38, lever 39, link 43 and collar 31, so that until the pneumatic system and the adjusted compression of spring 30 become stabilized, the initial reaction of the governor i2 is one producing an alternating over and under speed regulation, or governor "hunting" as it is frequently called. The usual consequence of this reaction of the governor, is an uneven or jerky movement of the locomotive particularly when under load.

As heretofore objectively stated, the principal purpose of the present invention, is to afford such improvements in a pneumatic regulator system for an engine governor, as will avoid governor hunting" reaction to regulator actuation. As shown by Fig. 1, the pneumatic regulator system includes an air flow control device positioned at a suitable point in the portion of the air conduit 41 extending between the servo-motor chamber 34 and the air throttle valve 48. The device 60 appears in section in Fig. 2, and comprises a casing 61 having a connection 62 to the section 64 of conduit 41 leading from the throttle 48, and an opposite connection 65 to the conduit sec- 4 tion 66 leading to the servo-motor chamber 34.

Within the casing 6| is a step-like partition or wall 63 provided in the portion 69 thereof, with a port 10 of a predetermined relatively large area, the port at its upper side presenting a valve seat 12 for a ball'check valve element 13. Port-opening displacement of the ball valve is adjustably limited by an abutment l4 constituted by the lower end of a bolt-like member 16 threaded through the upper wall '11 of casing 6|. In the partition wall portion 68 adjacent the casingconduit connection 62, is a port 88 of predetermined small area, for a purpose now to appear.

With the control device 60 in the pneumatic regulator system, the operator may now move the throttle valve lever 50 from its ofi position to the end 5| of slot 52 for full air pressure delivery, or to any intermediate throttled air pressure delivery position, by a quick actuation or "throw" thereof without fear of producing governor huntingj, since the device 60 prevents immediate application of air under full or throttled pressure, to the servo-motor chamber 32 and against the diaphragm 35. The action of the device 60 in this instance, is to retard or effect a time-delay in air pressure delivery to the servo-motor such as to permit only a relatively gradual application of air pressure on the diaphragm 35. Since the air pressure admitted to the conduit section 64 through the throttle valve 48, is efiective on the ball check 13 to hold it seated in closing relation mar-ps to the large port 10, the air is thereby constrained to passage through the small port 80, the latter being calibrated as to area, so as to afford the desired gradual build-up of air pressure in the servomotor chamber 34. In consequence of this, the response of the servo-motor is correspondingly gradual, and produces an equally gradual adjustment of the governor-loading spring 36. -Therefore, there is avoided in this manner, any appreciable vibratory impulsing reaction of the servomotor, so that governor "hunting will not occur.

When the throttle valve is returned toward oil position, the air pressure acting on the servo-motor will decrease correspondingly under the control eflect of the throttle valve 48 to reduce the air pressure in the line to the servomotor. Accordingly, the spring 35 may then act to return the diaphragm toward its normal inactive position, which thus effects through the plunger 38, a release of arm 89 for upward movement in response to expansion of the governor spring 30. The latter in expanding, readjusts the governor mechanism for operation to determine engine speed and power output in accordance with the extent to which the throttle arm 56 is moved toward ofl position. when the foregoing takes place, the return movement or the diaphragm assists air pressure relief in the conduit portions 58 and GI, the ball valve 13 in this instance, lifting to permit a more rapid air pressure release through the port II than would obtain otherwise, through the small port 86.

Having now described one preferred embodiment of my invention, what I desire to claim and secure by Letters Patent is:

1. The combination with an internal combustion engine speed governor having governor load- ,ing spring means adjustable for regulating the speed control action of the governor, of a fluidpressure actuated mechanism operatively connected with the governor spring loading means, a source 01' fluid under pressure having a conduit connected with said pressure actuated mechanism. a manual control valve inserted in said conduit to permit flow of pressure fluid toward said mechanism and to release such pressure fluid for purposes of adjusting the governor spring loading means, and a flow control device inserted in said conduit between said manual control and said mechanism, said control device being constructed and adapted to retard the flow of pressure fluid toward said mechanism to prevent vibratory impulsing reaction of said mechanism, and to permit rapid reverse flow of pressure fluid away from said mechanism.

2. Engine control means comprising the combination with an engine governor of the type permitting variations of engine speed and power output in accordance with engine loading and having a governor loading spring adjustably coacting with the governor to determine the engine speed and power output by increasing and decreasing the load on the governor; of a fluid-pressure actuated means operatively connected to the loading spring to adjust its load on the governor, a source of fluid under pressure connected to said pressure actuated means, and control means inserted in the connection between said fluid pressure source and said pressure actuated means, said control means including a manually adjustable valve for throttling the flow of pressure fluid to said pressure actuated means between oil and full on positions and for releasing the pressure fluid upon adjustments out of its full on position, and a flow control device adapted to provide a time-delay in the application of fluid pressure at said pressure actuated means whereby to effect a gradual adjustment of the loading spring to increase the load on the governor, and to eflect a rapid release oi the fluid pressure on said pressure actuated means to decrease the spring loading on the governor.

JAMES E. Jus'ros.

REFERENCES CITED The following references are of record in the flle of this patent:

' UNITED STATES PATENTS Number Name Date 586,561 Mosher July 20, 1897 749,810 Truman Jan. 19, 1904 845,500 Wilson Feb. 26, 1907 1,156,165 McManamy Oct. 12, 1915 1,788,358 Goerg Jan. 6, 1931 1,853,613 Herr Apr. 12, 1932 1,861,742 Hand June 7, 1932 1,941,500 Simmen Jan. 2, 1934 2,138,372 Davis Nov. 29, 1938 2,227,593 Lawrence Jan. 7, 1941 2,332,925 Martin Oct. 26, 1943 2,397,876 Martin Apr. 2, 1946

Images