GB2170618A

GB2170618A - Governor mechanism

Info

Publication number: GB2170618A
Application number: GB08602123A
Authority: GB
Inventors: Domingo Cabarrocas Pruneda
Original assignee: Lucas Industries Ltd
Current assignee: ZF International UK Ltd
Priority date: 1985-02-06
Filing date: 1986-01-29
Publication date: 1986-08-06
Also published as: GB2170618B; GB8602123D0; ES540158A0; JPS61187541A; US4694795A; ES8601394A1; DE3603778A1

Description

GB2170618A

SPECIFICATION for setting the maximum fuel stop.

According to one aspect of the invention in Governor tnechanism a governor mechanism of the kind specified said weight mechanism includes a further out This invention relates to a governor mecha- 70 put member which moves in accordance with nism for attachment in use to a fuel injection the speed at which the mechanism is driven, a pump used to supply fuel to an internal com- fluid pressure operable servo responsive to bustion engine, the governor mechanism being the movement of said further output member, of the so-called "two speed" type and includ- a cam the position of which is varied by said ing a centrifugal weight mechanism, a pivotal 75 servo and a lever mechanism including a fol lever coupled to the weight mechanism and to lower engaging said cam, said lever mecha an output member which in use is connected nism acting to determine the setting of said to a fuel control rod of the pump, the mecha- maximum fuel stop.

nism including a manually operable member According to another aspect of the inven connected to an adjustable pivot for the lever, 80 tion in a governor mechanism of the kind spe and the governor mechanism including resilient cified comprises a piston coupled to said max means opposing movement of the centrifugal imum fuel stop, a cylinder in which said piston weight mechanism, the arrangement being is slidable, passage means through which fluid such that the governor mechanism will control under pressure can be supplied to one end of the idling speed and the maximum speed of 85 the cylinder to effect movement of the maxi the associated engine, the rate of fuel supply mum fuel stop to its normal position against intermediate these speeds being controlled by the action of a spring.

the position'of said manually operable mem- An example of a governor mechanism in ac ber, the mechanism further including a maxi- cordance with the invention will now be de mum fuel stop to limit the maximum rate at 90 scribed with referer1ce to the accompanying which fuel can be supplied to the associated drawings in which:

engine.. - Figure 1 is a sectional side elevation through The purpose of the maximum fuel stop is to the mechanism with parts of the mechanism ensure that no more than a predetermined in outline only, level of smoke appears in the engine exhaust. 95 Figure 2 is a sectional side elevation of a With a turbo supercharged engine the amount weight mechanism which is shown in outline of fuel which can be supplied to the engine in Figure 1, while still maintaining the desired level of Figure 3 is an end elevation of part of the smoke will vary depending upon the pressure mechanism seen in Figure 1, of air in the inlet manifold of the engine. To a 100 Figure 4 is a sectional side elevation of part lesser extent the maximum amount of fuel of the mechanism which is shown in outline in which can be supplied to a normally aspirated Figure 1, engine depends upon the engine speed. It is Figure 5 is a sectional side elevation of a therefore necessary to be able to modify the portion of the mechanism of Figure 1 with maximum amount of fuel which can be sup- 105 parts removed for the sake of clarity, plied to the engine at least in accordance with Figure 6 is a sectional plan view of part of the engine speed and one aspect of the inven- the mechanism seen in Figure 1, tion resides is to provide for adjustment of Figure 7 is a view similar to Figure 6 show the maximum fuel stop in accordance with ing a modification, and speed. 110 Figures 8, 9 and 10 are further sectional For starting purposes the maximum fuel views showing minor details of construction.

stop must be temporarily disabled to enable With reference to Figure 1 of the drawings the fuel injection pump to supply an amount the governor mechanism is located in a hous of fuel in excess of the maximum amount of ing 10 which in use will be secured to the fuel which is allowed during normal operation 115 housing of the associated pump. A drive shaft of the engine. This disablement of the maxi- 11 extends into the housing 10, the drive mum fuel stop can be achieved by manual shaft being an extension of the cam shaft of means but it is essential to arrange that once the pump. The shaft within the housing carries the associated engine has started, the maxi- a weight mechanism shown in outline at 12 mum fuel stop should be brought back into 120 and which will be described with reference to operation otherwise damage may be caused Figure 2.

to the engine, and/or excessive smoke will Mounted within the housing 10 is a pivotal appear in the engine exhaust. It is therefore lever 14 an end view of which is seen in preferred that the disablement of the stop_ Figure 3. The lower end of the lever is bifur- should be achieved automatically and the gov- 125 cated to define a pair of legs 14 which are ernor mechanism should include an arrange- apertured and are pivotally mounted on a sup ment for automatically returning the stop to its port block 15 which is slidable on a pin 16 normal position once starting of the engine carried by the housing. Intermediate its ends has been achieved. Another aspect of the in- the lever is shaped to define a cylindrical elon- vention is therefore to provide a mechanism 130gated guide surface 17 in which is located a 2 GB2170618A 2 plunger 18. Formed in the guide surface is a end of each lever being pivotally connected to slot through which extends a peg 19 engaged the cross pin 45 and the other ends of the within the plunger the peg being mounted on levers being pivotally connected to the respec a lever 20 which is coupled to a manually tive weights 29.

operable lever on the exterior the housing. At 70 Theoperation of the governor mechanism its upper end the lever 13 is coupled to a thus far described is as follows. As illustrated linkage 21 which'in turn is coupled to a block the mechanism is at rest however when the 22 mounted on a control rod 23 which is engine has been started, the weights 29 will connected to the fuel quantity control ele- move outwardly under the action of centrifugal ments of the pump. 75 force, the movement being opposed by the The weight mechanism 12 comprises a respective spring assemblies. If the lever 20 is sleeve 24 having a tapered bore to receive positioned in the engine idling position, the the shaft 11 and is retained upon the shaft by weights will move in the idling range and their means of a nut 25 shown in outline in Figure outward movement will be opposed only by 2. The nut is provided with a flange between 80 the first springs 30. The idling range extends which and the end of the sleeve 24 is located from the innermost position as shown to the a rim formed on the internal surface of the position in which the flanges 32 engage the wall of a bore formed in a weight support 26. first abutment plates 33. During outward The weight support mounts a pair of radial movement of the weights in this range the pins 27 about which are located spring as- 85 levers 48 urge the rod 41 and sleeve 42 to semblies 28 the latter being surrounded by wards the left and the sleeve 37 or first out weights 29. Each spring assembly includes a put member follows this movement under the first spring 30 located between an inwardly action of the spring 44. When the flanges of extending flange 31 of the weight and a the weights engage the abutment plate 33 it spring abutment plate 32. The assembly in- 90 is arranged that the sleeve 37 engages the cludes a second spring 33A which is located abutment 46. Movement of the sleeve 37 to between first and second abutment plates 33, wards the left effects movenent of the lower 34, the first plate 33 being spaced ' outwardly end of the the pivotal lever 13 towards the from the flange 31 and the second plate 34 left causing the lever 13 to pivot about the being urged against a step defined on the pin 95 peg 19 in a clockwise direction. This move by a spring pack comprising springs 35 and ment of the lever is imparted by way of the 36. linkage 21 to the block 22 to effect move The governor mechanism includes a first merit of the control rod to decrease the output member in the form of a sleeve 37 amount of fuel supplied by the pump If the slidable in a bush 38 which is secured to a 100 engine speed should fall then movement of mouning 39 forming part of the weight sup- the various parts takes place in the opposite port 26. The sleeve 37 is provided with a directions and -the idling speed of the engine groove 40 in which is engaged the support is controlled.

block 15 as shown in Figure 1. The weight An increase in engine speed above its idling mechanism has a second output member in 105 speed is effected by moving the lever 20 in the form of a rod 41 which is surrounded by the anticlockwise direction and this causes the a sleeve 42 having a groove 43 formed lever 13 to move in the anticlockwise direc therein. The sleeve 42 is located on the rod tion about its pivotal connection with the sup by a circlip and interposed between the port block 15. As a result the control rod 23 sleeves 37 and 42 is a coiled compression 110 is moved in a direction to increase the rate of spring 44. fuel supply to the engine with the result that The rod 41 mounts a cross pin 45 which the engine speed increases. With an increase passes through open ended grooves in the in engine speed above the idling speed the bush 38 so as to allow movement of the rod weights move outwardly against the action of and cross pin towards the left as seen in 115 the first and second springs 30, 33A. This Figure 2. The sleeve 37 is also provided with further outward movement of the weights re open ended slots and in the rest position as suits in axial movement of the sleeve 37 shown in Figure 2 the bases of these slots which remains in engagement with the abut are pressed into engagement with the cross ment 46.

pin 45 by the spring 44. 120 When the abutments 33 and 34 engage The rod 41 has an abutment plate 46 slida- with each other further movement of the ble thereon this plate being biased by a spring weights takes place against the action of the 47 into engagement with the end of the bush spring 30 and the springs 35 and 36. During 38. Also provided are four belicrank levers, this range of movement the rod 41 continues the outline of one of the levers being seen at 125 to move and causes clockwise movement of 48 in Figure 2. Each weight 29 has two lev- the lever leading to a reduction in the quantity ers associated with it, the levers being located of fuel supplied by the associated pump. In on opposite sides of the axis of the shaft 11. this range of movement the maximum speed The levers are pivoted intermediate their ends of the associated engine is controlled.

on pins 49 secured in the mounting 39, one 130 The movement of sleeve 42 is utilized to 3 GB2170618A 3 control the setting of a maximum fuel stop ting of the lever 20. If the associated engine this being constituted by a lever 50 which is is not provided with a supercharger or a engageable by the block 22. The lever 50 is turbo-charger the air pressure sensor 55A will coupled to a further lever 51 the two levers be of a different type or may be omitted.

are pivtoally mounted about the axis 52. The 70 The extent of movement of the lever 68 is lever 51 mounts a pin 53 which can engage a limited by a stop 68A and to allow continued mushroom shaped head 54 carried by the out- movement of the lever 70 once the movement put member 55 of an air pressure sensor 55A of the lever 68 has been halted an overtravel which is shown in greater detail in Figure 4. spring 68B is provided between the levers.

The output member 55 includes a diaphragm 75 In order to provide an excess of fuel for 56 which forms one wall of a chamber 57, starting purposes the lever 50 is movable axi the chamber being connected in use to the ally in the direction of the axis 52. As seen in inlet manifold of the associated engine. The Figure 6, the lever 51 from which the lever 50 output member 55 is moved by air under depends, is in the so-called excess fuel posipressure in the chamber 57 against the action 80 tion. It is urged to this position by a light of a spring. With an increasing air pressure spring 71 and in this position the lever 50 is the head 54 is moved downwardly to allow aligned with a recessed surface 72 of the the block 22 to be moved further towards the block 22 thereby allowing the block to move left allowing an increasd quantity of fuel to be further to the left to increase the amount of supplied to the associated engine, this characfuel supplied by the associated pump. Once teristic being required for a turbo super- the engine has started the levers 50 and 51 charged engine. are restored to the normal position by fluid In order to control the maximum torque under pressure acting upon a piston 73 con which can be developed by the engine the pin tained within a cylinder 74. One end of the 53 can be engaged by a lever 58 which is 90 cylinder is connected to a source of fluid pres pivotal about an axis 59. The lever 58 is ad- sure which develops as soon as the associ justably coupled to a further lever 60 which is ated engine has started and the other end of engageable with the surface of a cam 61 the cylinder is vented to the interior of the which is pivotable about an axis 62. The cam housing of the mechanism. It is essential to is movable about the axis 62 by means of a 95 ensure that the piston cannot return to the piston slidable within a cylinder 64. The pis- excess fuel position when the engine is in ton is provided with a lateral pin which ex- use. The piston for this purpose may be dou tends into an aperture in the cam so that ble acting with the pressures in the one end movement of the piston will cause angular of the cylinder being greater so as to provide movement of the cam 6 1. The piston is bi- 100 a differential force on the piston. When the ased by a spring 65 and it is hollow. Slidable pressure difference increases to a sufficient within the piston is a servo valve member 66 value the piston will move against the spring which is coupled by means of a link 67 to the and it can be arranged that the piston cuts off lever 68. The lever 68 can be pivoted about the flow of fluid to the other end of the cylin an axis 69 and is adjustably coupled to a 105 der once the full movement of the piston has further lever 70 which carries a pin which is taken place. As an example the one end of located within the groove 43. The servo valve the cylinder can be supplied with fluid from member 66 controls the admission of fluid un- the source and the other end of the cylinder der pressure to the closed end of the cylinder from the source through a restricted passage and as the servo valve member is moved 110 means with a restricted drain from the other downwardly as occurs with increasing speed, end of the cylinder. The piston closes the re the piston 63 will follow the movement of the stricted passage means once the full range of valve and cause the cam 61 to be moved in movement has taken place.

the anticlockwise direction about the axis 62. Figure 7 shows an arrangement in which the The piston 63 and the servo valve member 115 selection of excess fuel for starting the asso form a follow up servo mechanism. ciated enginb is achieved by energising an The lever 60 is biased into engagement electromagnetic actuator 75, the latter having with the surface of the cam 61 by the action an output member 76 which supports the of a spring associated with the lever 58. As a lever 51. In this case a spring 77 urges the result the lever 58 is positioned in accordance 120 lever 51 to the normal fuel position and an with the profile of the surface of the cam 61 electrical switch must be provided to ensure and it therefore acts to limit the movement of that the actuator is deenergised once the en the actual stop lever 50. In this manner the gine is running.

maximum amount of fuel which can be sup- For example, the actuator may be connected plied by the associated pump in the engine 125 in circuit with the engine starter motor and working range between idling and maximum therefore be energised whenever the starter speed varies in accordance with the speed of switch is operated. Both the mechanisms as the associated engine. It will of course be un- shown in Figure 6 and in Figure 7 will act to derstood that the actual amount of fuel sup- cause excess fuel flow to the engine irrespec plied by the pump will depend upon the set- 130 tive of whether the engine is hot or cold.

4 GB2170618A 4 When the engine is hot, the injection pump moves the latter to the zero fuel flow posi need not provide an extra flow of fuel, betion. A stop 92 is provided to limit the move cause the normal operating flow of fuel will be ment of the lever.

sufficient to allow engine starting. Conse- Another way which can be used to cut off quently, if the engine is hot, it must be pos- 70 the supply of fuel by the pump involves the sible to put out of action the cold starting external idling stop for the lever 20. It, be mechanism. cause of an internal spring, allows lever 20 to In order to achieve this object the governor be moved to a position to displace the lever mechanism is provided in the top part of the 13 and the control rod, through the flexible housing, as shown in Figure 8, with a mecha- 75 connection 21, can be moved to the zero fuel nism including a temperature responsive capposition.

sule 78 located in a body 79 having an inlet

Claims

and an outlet for engine cooling water. The CLAIMS operation of this

mechanism is as follows: 1. A governor mechanism for attachment to When it is desired to start the engine from 80 a fuel injection pump for an internal combus cold, the mechanism including the pin 80, as tion engine, the governor mechanism being of shown in Figures 6 and 7, is in contact with the so-called "two speed" type and compris its upper stop, that is to say allowing the ing a centrifugal weight mechanism, a pivotal injection pump to supply an excess of fuel to lever coupled to the weight mechanism and to the engine for starting. Once starting has been 85 an output member which in use is connected effected, the pin will move to the left from to a fuel control rod of the pump, the mecha the position shown in Figure 8, to assume the nism including a manually operable member position in which a slot 81 in the pin faces connected to an adjustable pivot for the lever, the output member 82 of the capsule. As the and the governor mechanism including resilient engine water heats up, the capsule 78 starts 90 means opposing movement of the centrifugal to react, thus forcing the output member 82 weight mechanism, the arrangement being to extend from its housing, overcoming the such that the governor mechanism will control force of a spring 83, and to enter into the the idling speed and the maximum speed of groove 81 in the pin 80. If under these condi- the associated engine, the rate of fuel supply tions the engine is stopped, the movement of 95 intermediate these speeds being controlled by the rod 80 will be blocked by the output the position of said manually operable mem member 82 thereby preventing the supply of ber, the mechanism further including a maxi excess fuel. It will be necessary for the tem- mum fuel stop to limit the maximum rate at perature of the water to fall sufficiently to re- which fuel can be supplied to the associated tract the output member before excess fuel 100 engine, said weight mechanism including an can be supplied to the engine. output member which moves in accordance The regulator also incorporates a shutdown with the speed at which the mechanism is mechanism connected to the main engine con- driven, a fluid pressure operable servo respon trol switch and which uses, as its source of sive to the movement of said further output power, compressed air from the vehicle brak- 105 member, a cam the position of which is varied ing system. As shown in Figures 9 and 10: by said servo and a lever mechanism including an electromagnetic valve 84 is connected to a follower engaging said cam, said lever the control switch and when the switch is in mechanism acting to determine the setting of the engine run setting, prevents air under said maximum fuel stop.

pressure from a supply duct 85 from passing 110
2. A mechanism according to Claim 1 in into a cylinder containing a piston 86. The which the servo includes a piston coupled to latter is in its most retracted position as a said cam, and a servo valve member slidable consequence of the tension applied by a re- within said piston for controlling the applica storing spring 87, and an exhaust duct 88 is tion of fluid under pressure to said piston, provided for decompressing the cylinder. 115 said piston and said valve member forming a When the switch is moved to the stop posi- follow up servo mechanism.

tion, the valve member closes the duct 88
3. A mechanism according to Claim 2 in and transmits air under pressure to the piston cluding a stop to limit the movement of the 86, which moves outwardly. The manner in servo valve member and a yieldable coupling which shutdown is achieved under these con- 120 interposed between the further output member ditions is the result of the action of a lever and the servo valve member whereby the out 89, which pivots about a screw 90 and is put member can continue to move after the always in contact at one end with the head of movement of the servo valve member has the piston 52 by virtue of a torsion spring 9 1. been halted.

The other end of the lever occupies a position 125
4. A mechanism according to Claim 3 in at the same level as the guide block 22, and cluding resilient means acting on said piston allows the latter to move to any position with- to oppose the movement thereof by fluid un out interference. When the piston 86 moves der pressure.

out of its cylinder, it pivots the lever 89 into
5. A mechanism according to Claim 1 in engagement with the guide block 22, and 130cluding means for displacing said maximum GB2170618A 5 fuel stop to a position to allow an excess of fuel to be supplied by the pump.
6. A mechanism according to Claim 1 or Claim 5 including air pressure responsive means for setting said maximum fuel stop in accordance with the pressure of air supplied to an air inlet manifold of the associated engine.
7. A governor mechanism for attachment to a fuel injection pump for an internal combustion engine, the governor being of the socalled---twospeedtype and comprising a centrifugal weight mechanism, a pivotal lever coupled to the weight mechanism and to an output member which in use is connected to a fuel control rod of the pump, the mechanism including a manually operable member connected to an adjustable pivot for the lever, and the governor mechanism including resilient means opposing movement of the centrifugal weight mechanism, the arrangement being such that the governor mechanism will control the idling speed and the maximum speed of the associated engine, the rate of fuel supply intermediate these speeds being controlled by the position of said manually operable member, the mechanism further including a maximum fuel stop to limit the maximum rate at which fuel can be supplied to the associated engine, a piston coupled to said maximum fuel stop, a cylinder in which said piston is slidable, passage means through which fluid under pressure can be supplied to one end of the cylinder to effect moverflent of the maximum fuel stop to its normal position against the action of a spring.
8. A mechanism according to Claim 7 including further passage means providing restricted communication between said one end of the cylinder and the other end thereof, a restricted outlet from the other end of the cylinder and valve means operable to close said further passage means after a predetermined movement of the piston against the ac- tion of the spring.
9. A mechanism according to Claim 8 including means responsive to the temperature of the associated engine for maintaining the maximum fuel stop in the normal fuel position until following the stopping of the engine, the engine cools to a temperature at which excess fuel is required for starting.
10. A governor mechanism for attachment to a fuel injection pump and comprising the combination and arrangement of parts substantially as hereinbefore described with reference to the accompanying drawings.

Printed in the United Kingdom for Her Majesty's Stationery Office, Dd 8818935, 1986, 4235. Published at The Patent Office, 25 Southampton Buildings, London, WC2A 'I AY, from which copies may be obtained.