US3924594A

US3924594A - Diesel engine fuel injection pump governor

Info

Publication number: US3924594A
Application number: US472396A
Authority: US
Inventors: Hachiro Aoki
Original assignee: Diesel Kiki Co Ltd
Current assignee: Bosch Corp
Priority date: 1973-06-23
Filing date: 1974-05-22
Publication date: 1975-12-09
Anticipated expiration: 1992-12-09
Also published as: JPS544580Y2; JPS5020925U

Abstract

A control lever and flyweight assembly move a floating lever which determines the position of a control rod which controls the fuel injection volume. A novel linkage including a profiled cam is engagable with the flyweight assembly and the control rod to limit the fuel injection volume to a level at which smoky exhaust gases are not produced. Compensating means are engagable with the linkage to compensate for variations in temperature and pressure.

Description

United States Patent Aoki [ Dec. 9, 1975 3,766,899 10/1973 Isselhorst 123/140 CC [75] Inventor: Hachiro Aoki, Higashimatsuyama, Primary Examiner-Wendell 5- urns Japan Assistant ExaminerJames W. Cranson, Jr. [73] Assignee: Diesel Kiki Co., Ltd., Tokyo, Japan Attorney Agent or FlrmFrank Jordan [22] Filed: May 22, 1974 21 Appl. No.: 472,396 [57] ABSIRACT A control lever and flyweight assembly move a float- [30] Foreign Application Priority Data ing lever which determines the position of a control J 23 1973 J 4 rod WhlCh controls the fuel m ectlon volume. A novel une apan 8-74075[U] linkage including a profiled cam is engagable with the flyweight assembly and the control rod to limit the 82 fuel injection volume to a level at which smoky exhaust gases are not produced. Compensating means [58] Field of Search 123/140 140 CC are engagable with the linkage to compensate for vari- [56] References Cited atlons 1n temperature and pressure.

3,727,598 4/1973 Knapp 123/140 MC INCREASE I I .1111/ 4.- r-l 7 w 0 O u i llllfiin nfl 68 420. '.'I l 1 I g 1 \T '10 O 3O U, a C

U.S. Patent Dec. 9, 1975 Sheet 1 of2 3,924,594

Fig.

INCREASE U.S. Patant Dec. 9, 1975 Sheet 2 of2 3,924,594

Fig. 3

IN GREASE DIESEL ENGINE FUEL INJECTION PUMP GOVERNOR The present invention relates to a governor for a fuel injection pump for a Diesel engine.

It has been proposed in the prior art to provide a governor assembly including a floating lever, the position of which is determined by a manual speed control member and a flyweight assembly and which moves a control rod which controls the fuel injection volume. The flyweights are movable against an idling spring and a governor spring as the engine speed rises to decrease the fuel injection volume as an acceleration demand condition ends. Means are also provided to limit the maximum fuel injection volume to a level below which smoky exhaust gases are produced, which include a compensating spring to control the maximum fuel injection volume during the transition between idling and medium speed operation. However, the fuel injection characteristics are nonlinear in this region, and a simple spring is not able to satisfactorily control the maximum fuel injection volume. Thus, smoky exhaust gases are often produced, especially during severe acceleration from idling speed, which pollute the atmosphere and constitute a waste of valuable fuel. The latter problem is especially acute in view of the drastically rising cost of fuel suitable for powering a Diesel engine and the depletion of the supply.

It is therefore an important object of the present invention to provide an improved governor for a fuel injection pump for a Diesel engine comprising novel means to positively prevent emission of smoky exhaust gases.

It is a further object of the present invention to provide an improved governor for a fuel injection pump for a Diesel engine comprising novel means including a cam to positively limit the fuel injection volume to a level at which smoky exhaust gases are not produced at all engine speeds.

It is a still further object of the present invention to provide an improved governor for a fuel injection pump for a Diesel engine comprising novel means to optimally control the maximum fuel injection volume which varies in a non-linear manner as a function of engine speed, temperature and pressure.

The above and other objects, features and advantages of the present invention will become clear from the following detailed description taken with the accompanying drawings in which directions such as clockwise and rightward refer to the invention as viewed in the respective drawings, and in which:

FIG. 1 is a graph illustrating the non-linear variation in the optimum maximum fuel injection volume of a Diesel engine as a function as engine speed;

FIG. 2 is a partial longitudinal section view of a governor for an engine fuel injection pump embodying the present invention;

FIG. 3 is a fragmentary top view, partly in section, of the governor shown in FIG. 2; and

FIG. 4 is a fragmentary side view, partly in section, of a portion. of a governor embodying the present invention to be used in combination with the portion shown in FIG. 2.

Referring now to FIG. 1, the ordinate N represents the engine speed and the abcissa q represents the maximum fuel injection volume not producing smoky exhaust gases. N represents the normal idling speed and N represents the beginning of medium speed operation. As shown, a maximum fuel injection volume is required for starting, and the volume varies nonlinearly in a region a between idling and medium speed engine operation. Obviously, a simple compensating spring can not produce the non-linear function illustrated in the region a and as a result smoky exhaust gases are produced by engines employing fuel injection pump governors utilizing simple compensating springs. It is the primary object of the present invention to provide a governor which can positively produce the curve a, and also compensate for variations in temperature and pressure which are not shown but are known in the art and will not be described in detail so as not to introduce unnecessary complication into the description.

Referring now to FIG. 2, a governor embodying the present invention includes a casing 10 rotatably supporting therein a shaft 12 rotatably driven by a camshaft of a Diesel engine fuel injection pump (not shown). The shaft 12 carries flyweights 14 which are arranged to expand by centrifugal force developed by rotation thereof by the shaft 12 and axially move a shifter rod 16 rightward as the engine speed increases. The shifter rod 16 engages with the flyweights 14 by means of a thrust bearing 18, and carries a pin 20. The shifter rod 16 is also formed with a right shoulder 16a, with which an idling spring 24 engages. The preload of the idling spring 24 is adjustable by means of an adjusting nut 26. A tension lever 28 is rotatable about a fulcrum pin 30 supported by the casing 10, and is pivotally connected at one end to the pin 20. A pin 32 carried by the other end of the tension lever 28 is engagable with the right side of a spring seat 34, the left side of which is engagable with a medium speed governor spring 36 and a high speed governor spring 38. A spring seat 40 is engagable with the left ends of the springs 36 and 38, and is slidable on a shaft or rod 42 as is the spring seat 34. The rod 42 is fixedly supported within the casing 10.

A spring 52 urges the spring seat 40 rightwards to eliminate play, and the rod 42 is formed with a shoulder 42a which is engagable with the left side of the spring seat 40.

A control rod 66 is formed with a rack (not shown) which is operatively connected to the fuel injection pump to control the volume of fuel injected therefrom into the Diesel engine. The rack of the control rod 66 may engage with control quadrants of control sleeves of fuel injection valves (not shown) of the fuel injection pump, or be connected to control the fuel injection pump in any other manner. The control rod 66 is moved leftward as shown by an arrow to increase the fuel injection volume.

A guide lever 68 is pivotal about the fulcrum pin 30, and is biased counterclockwise against the pin 32 of the tension lever 28 by a spring 70, and a ball 72 fixed to the upper end of the guide lever 68 pivotally engages in a hole (no numeral) formed through one end of a floating lever 74. A ball 76 fixed to one end of a link 78 pivotally engages in a hole (no numeral) formed through the other end of the floating lever 74. A pin 80 is fixed to the control rod 66, and pivotally supports the link shown), is fixed on a shaft 88 which is rotatably supported by the casing by a busing 90. An arm 92 is fixed to the shaft 88 and is engagable with a pin 94 extending from the arm 84. The arm 84 is urged by a spring 96 so that the pin 94 engages with the arm 92. The control rod 66 is urged leftward by a starting spring 98.

Referring now to FIG. 4, a bell crank lever or link 100 is rotatable about a pin 102 fixed within the casing 10. A bolt 104 screwably extending through the link 100 is biased into engagement with the pin 32 of the tension lever 28 opposite to the spring seat 34 by a cancelling spring 106. The initial position of the link 100 is adjustable by means of a locknut 108. A cam 110 is rotatable about a pin 112 fixed within the casing 10 and carries a pin 114 which engages in a slot 100a formed through the link 100. The cam 110 has a cam profile surface 110a. A link 116 is rotatable about a pin 118 fixed within the casing 10, and carries a pin 120 at its end. A cam follower 122 is rotatably supported by the pin 120, and has a pin 124 at its end which is engagable with the cam surface 110a of the cam 110. The other end of the cam follower 122 is engagable with the left side of a pin 126 fixed to the control rod 66. A stopper arm 128 is manually rotatable about the pin 118 and carries a stopper pin 130 engagable with the right side of the link 116. Compensating means 132 of any known type are fixed to the casing 10 and engage with the top of the link 1 16. The initial position of the compensating means 132 is adjustable by means of an adjusting nut 134. The compensating means 132 are operative to sense temperature and/or pressure, and expand and contract in response thereto to rotate the link 116 about the pin 118. The compensating means 132 may be arranged to sense the ambient temperature and/or pressure within the casing 10, or may be connected by a pipe (not shown) to a selected portion of the Diesel engine such as the combustion chamber.

The operation of the governor will now be described. When the engine is at rest, the control member 86 is rotated to its maximum counterclockwise position as shown in FIG. 3, and the control rod 66 is at its uppermost position to provide substantially zero fuel injection volume. Referring now to FIG. 2, the flyweights 14 are not expanded and the shifter rod 16 is in its leftmost position. The tension lever 28 and the guide lever 68 are in their maximum clockwise positions and the springs 36 and 38 are substantially unloaded. The pin 126 of the control rod 66 is disengaged from the cam follower 122.

To start the engine, the control member 86 is rotated to its maximum clockwise position as viewed in FIG. 3. The arm 84 will be urged by the spring 96 to rotate clockwise, and the pin 82 engaging in the slot 743 of the floating lever 74 will cause the floating lever 74 to I rotate clockwise about the ball 72. This and the spring 98 will cause the control rod 66 to move downward to its position of maximum fuel injection volume for starting the engine.

Since the engine speed is close to zero, the force developed by the flyweights 14 will be very low and the shifter rod 16 and thereby the tension lever 28 will not substantially move. As viewed in FIG. 4, the link 100 will be in its maximum clockwise position, the cam 1 10 will be in its maximum counterclockwise position and the cam follower 122 will be in its maximum counterclockwise position. The point of engagement between the cam follower 122 and the pin 126 of the control rod 66 will be in its leftmost possible position, thus providing maximum fuel injection volume for starting the engme.

As the control member 86 is rotated clockwise in FIG. 3 to increase the fuel injection volume, the pin 126 of the control rod will eventually abut against the cam follower 122, and the movement of the control rod 66 in the direction to increase the fuel injection volume (downward) will be stopped. Further rotation of the control member 86 will not produce movement of the floating lever 74, because the ball 72 and the pin are prevented from moving. The arm 92 will then disengage from the pin 94 against the force of the spring 96, because the arm 84 is prevented from movement by engagement of the pin 82 in the slot 74a. The spring 96 and associated parts thus serve as yieldable means to prevent breakage of the floating lever 74 and the link.

As combustion begins in the engine and the engine speed increases, the flyweights 14 will expand and the shifter rod 16 will be moved rightward in FIG. 2. The tension lever 28 and the guide lever 68 will be rotated counterclockwise as a unit. As a result, the floating lever 74 will be rotated as viewed in FIG. 3 by the ball 72 about the pin 82, and the control rod 66' will be urged upward to decrease the fuel injection volume as the engine speed increases. Simultaneously, as viewed in FIG. 4, since the tension lever 28 rotated counterclockwise about the pin 30, the link 100 will be rotated counterclockwise about the pin 102 by the pin 32. The cam will rotate clockwise, and through engagement of the cam surface 110a with the pin 124, the cam follower 122 will be rotated clockwise about the pin 120. The point of engagement of the cam follower 122 and pin 126 of the control rod 66 will then move rightward, to reduce the level of the maximum allowable fuel injection volume.

After the engine has been started, the vehicle operator will rotate the control member 86 counterclockwise in FIG. 3 to the idling position. When the arm 92 contacts the pin 94 the arm 84 and thereby the pin 82 will be rotated counterclockwise. As a result, the floating lever 74 will be rotated counterclockwise about the ball 72 and the control rod 66 will be moved upward to reduce the fuel injection volume. The pin 126 will disengage from the cam follower 122, and the fuel injection volume will be controlled by the flyweights 14 and the idling spring 24 through the guide lever 68 and floating lever 74.

As the control member 86 is rotated clockwise in FIG. 3 to accelerate the engine, the floating lever '74 will be pivoted by the pin 82 about the ball 72 clockwise to move the control rod 66 downward to increase the fuel injection volume. At a certain point, the pin 126 of the control rod 66 will abut against the cam follower 122 and further movement of the control rod 66 in the direction to increase the fuel injection volume will be prevented. The arm 92 will then disengage from the pin 94 against the force of the spring 96, but the floating lever 74 will continue to be urged clockwise by the spring 96. As the engine speed rises above the normal idling speed, the spring'seat 34, springs 36 and consequently 38 and the spring seat 40 will be urged leftward in FIG. 2 against the force of the spring 52, which is weak. The left side of the spring seat 40 will then abut against the shoulder 42a of the rod 42 and be stopped. The movement of the tension lever 28 will thereafter the controlled by the force of the flyweights 14 balanced against the springs 36 and 38.

5 Referring now to FIG. 3, the guide lever 68 will be urged to rotate with the tension lever 28 by the spring 7%. The floating lever '74 will then be urged to simultaneously pivot about the ball72 and the ball 76 in a generally counterclockwise direction since the pin 80 is prevented from movement by the engagement of the pin 126 of the control rod 66 with the cam follower 122. The result of this combined "movement of the floating lever. 74 is simultaneous clockwise rotation of the pin 82 about the shaft 88. The arm 84 will also rotate clockwise and the pin 94- will approach the arm 92. As the pin 94 engages with the arm 92, rotation of the arm 34 will be stopped and the pin 82 will become a fixed pivot point for the floating lever 74. At this point, the pin 1126 of the control rod 66 will disengage from the cam follower 1 .22, as the floating lever 74 is rotated counterclockwise about the pin 82 by the ball 72. The fuel injection volume will then be less than the maximum allowable, and will be controlled by the flyweights l4, floating lever 74l, etc.

Simultaneously, as the engine speed increases and the tension lever 28 rotates counterclockwise as viewed in H6. t, the link 100 will be rotated counterclockwise about the pin T02. The cam 110 will be rotated clockwise and engagement of the cam surface 110a with the pin 124 will cause the cam follower 122 to rotate clockwise about the pin 120.,The point of engagement of the cam follower 122 and the pin 126 of the control rod 66 will move further rightward to further decrease the maximum allowable fuel injection volume as shown in FIG. 1. Thus, the cam M and associated parts can produce the predetermined function represented by the curve of FIG. 1 exactly by suitable design of the profile of the cam surface 110a.

To stop the engine, the stopper arm 128 is rotated counterclockwise by the vehicle operator. The stopper pin 13% will abut against the right side (in FIG. 4) of the link H6 and rotate the same counterclockwise about the pin 118. The pin 120 will thereby be rotated counterclockwise and the cam follower 122 will be rotated clockwise about the pin 120. The pin 126 and the control rod 66 will thereby be moved rightward to a position of essentially zero fuel injection volume to stop the engine.

The springs 70 and W6 are cancelling springs to prevent breakage of parts of the governor due to forced movement beyond maximum operating limits. The spring 7th also serves to prevent the control member 86 from being rotated in the accelerating direction by the floating lever 7'4 during engine braking conditions by allowing the guide lever 63 to remain stationary even though the tension lever 28 is rotated counterclockwise in FIG. 2.

Many modifications are possible by those skilled in the art within the scope of the present invention. For example, the link llflfi may be omitted and the cam 100 be directly engagable with the tension lever 28. Also, the stopper arm 128 may be arranged to engage with the cam follower 122 directly instead of through the link 266.

What is claimed is:

1. An engine fuel injection pump governor comprismg:

a fuel injection control rod;

flyweights displaceable upon rotation thereof;

first linkage means operatively connecting said flyweights to said control rod;

governor spring means connected to said first linkage means and operable to biasingly oppose displacement of said flyweights upon rotational speed increase of the latter; and

second linkage means connected to and movable by said first linkage means, said control rod being engagable with said second linkage means during movement of said control rod in a fuel injection increasing direction to limit the movement of said control rod in accordance with a predetermined function of flyweight rotational speed, said second linkage means including a cam having a profile selected to provide said predetermined function.

2. A governor according to claim 1, further comprising compensating means connected to said second linkage means to compensate the predetermined function thereof in response to sensed parameters including at least one of temperature and pressure.

3. A governor according to claim 1, further comprising a manually movable speed control member, and in which:

said first linkage means comprises a tension lever having an intermediate fulcrum and being rotatable by said flyweights against the biasing force of said governor spring means as the flyweight rotational speed increases, a guide lever rotatable with said tension lever and a floating lever pivotally connected at its opposite ends to said guide lever and said control rod respectively and being rotatable by said control member; and

said second linkage means, comprising said cam which is rotatable by said tension lever and a cam follower engagable with a profile surface on said cam and with said control rod to limit movement of said control rod in the fuel injection increasing direction in dependence on the angular position of said cam.

4. A governor according to claim 3, further comprising compensating means arranged to move said cam follower and thereby compensate the predetermined function of said second linkage means in response to sensed parameters including at least one of temperature and pressure.

5. A governor according to claim 3, in which said second linkage means further comprises a link pivotally connecting said tension lever to said cam.

6. A governor according to claim 3, further comprising yieldable means normally operatively connecting said control member to said floating lever and being arranged to yield when the movement of said control rod is limited by said cam follower and said control member is moved in a fuel injection increasing direction.

7. An engine fuel injection pump governor comprising a fuel injection control rod, flyweights displaceable upon rotation thereof, first linkage means operatively connecting said flyweights to said control rod, governor spring means connected to said first linkage means and operable to biasingly oppose displacement of said flyweights upon rotational speed increase of the latter, a manually movable speed control member, yieldable means connecting said control member to said first linkage means, second linkage means connected to and movable by said first linkage means, said control rod being engagable with said second linkage means during movement of said control rod in a fuel injecting direction to limit movement of said control rod in accordance with a predetermined function of flyweight rotational speed, said second linkage means including a cam having a profile to provide the predetermined function, said yieldable means normally operatively connecting said control member to move said first linkage means and being arranged to yield when the movement of said control rod is limited by said second linkage means and said control member is moved in a fuel injection increasing direction.

8. A governor according to claim 7, further comprising compensating means connected to said second linkage means to compensate the predetermined function thereof in response to sensed parameters including at least one of temperature and pressure.

9. A governor according to claim 7, wherein said first linkage means comprises a tension lever having an intermediate fulcrum and being rotatable by said flyweights against the biasing force of said governor spring means as the flyweight rotational speed increases, a guide lever rotatable with said tension lever and a floating lever pivotally connected at its opposite ends to said guide lever and said control rod respectively and being rotatably connected for rotation by said control member by said yieldable means; and said second linkage means comprises said cam which is rotatable by said tension lever and a cam follower engagable with said profile surface of said cam and with said control rod to limit movement of said control rod in the fuel injection increasing direction in dependence on the angular position of said cam.

10. A governor according to claim 9, further comprising compensating means connected to said second linkage means to compensate the predetermined function thereof in response to sensed parameters including at least one of temperature and pressure.

11. A governor according to claim 9 in which said second linkage means further comprises a link pivotally connecting said tension lever to said cam. I

12. A governor according to claim 7, in which said governor spring means is in an unloaded state when the flyweight rotational speed is zero, and which further comprises an idling spring, said flyweights being connected to move against the biasing force of said idling spring when the flyweight rotational speed is below a predetermined value and move against the biasing forces of both said idling spring and said governor spring means when the flyweight rotational speed is above said predetermined value.

13. A governor according to claim 7, further comprising stopper means being manually movable to en gage with and move said second linkage means and thereby said control rod to a substantially zero fuel injection position.

14. A governor according to claim 7, in which said second linkage means comprises a spring which is yieldable to prevent breakage of said second linkage means due to forced movement beyond a maximum operating position.

Claims

1. An engine fuel injection pump governor comprising: a fuel injection control rod; flyweights displaceable upon rotation thereof; first linkage means operatively connecting said flyweights to said control rod; governor spring means connected to said first linkage means and operable to biasingly oppose displacement of said flyweights upon rotational speed increase of the latter; and second linkage means connected to and movable by said first linkage means, said control rod being engagable with said second linkage means during movement of said control rod in a fuel injection increasing direction to limit the movement of said control rod in accordance with a predetermined function of flyweight rotational speed, said second linkage means including a cam having a profile selected to provide said predetermined function.

3. A governor according to claim 1, further comprising a manually movable speed control member, and in which: said first linkage means comprises a tension lever having an intermediate fulcrum and being rotatable by said flyweights against the biasing force of said governor spring means as the flyweight rotational speed increases, a guide lever rotatable with said tension lever and a floating lever pivotally connected at its opposite ends to said guide lever and said control rod respectively and being rotatable by said control member; and said second linkage means, comprising said cam which is rotatable by said tension lever and a cam follower engagable with a profile surface on said cam and with said control rod to limit movement of said control rod in the fuel injection increasing direction in dependence on the angular position of said cam.

11. A governor according to claim 9 in which said second linkage means further comprises a link pivotally connecting said tension lever to said cam.

13. A governor according to claim 7, further comprising stopper means being manually movable to engage with and move saId second linkage means and thereby said control rod to a substantially zero fuel injection position.