US3923026A

US3923026A - Diesel engine fuel injection pump governor

Info

Publication number: US3923026A
Application number: US472331A
Authority: US
Inventors: Hachiro Aoki
Original assignee: Diesel Kiki Co Ltd
Current assignee: Bosch Corp
Priority date: 1973-06-01
Filing date: 1974-05-22
Publication date: 1975-12-02
Anticipated expiration: 1992-12-02
Also published as: JPS5236215B2; JPS508927A

Abstract

A control lever and a flyweight assembly move a floating lever which determines the position of a control rod which controls the fuel injection volume. Novel means are provided to limit the fuel injection volume during starting to prevent smoky exhaust, and to prevent the control lever from being displaced by the floating lever during engine braking.

Description

United States Patent 1 1 Aoki 1 1 Dec. 2, 1975 [54] DIESEL ENGINE FUEL INJECTION PUMP 3,577,968 5/1971 Staudt ct al. 123/140 R GOV O 3,613,651 10/1971 Snyder et a1. 123/140 R 3,759,236 9/1973 Staudt et a1. 123/140 J [75] Inventor: Hachiro Aoki, Higashimatsuyama,

% Japan Primary ExaminerWendell E. Burns [73] Asslgnee' Dlesel Tokyo Japan Assistant E.raminer.lames Winthrop Cranson, Jr. [22] Filed: May 22, 1974 Attorney, Agent, or Firm-Frank J. Jordan [21] Appl. No.: 472,331

[57] ABSTRACT [30] Forelgn Application Priority Data June 1, 1973 Japan 48-60781 A control lever and a flyw eight assembly move a floating lever which determines the position of a control [52] US. Cl 123/140 J; 123/98; 123/140 R rod which controls the fuel injection volume. Novel [51] Int. Cl. F02D 1/04; F02D 1/06 means are provided to limit the fuel injection volume [58] Field of Search 123/140 R, 140 MC, 98, during starting to prevent smoky exhaust, and to pre- 123/140 .1 vent the control lever from being displaced by the floating lever during engine braking. [56 1 References Cited UNITED STATES PATENTS 13 Claims, 3Drawing Figures 3,370,579 2/1968 Nozawa et al. 123/140 R INCREASE DIESEL ENGINE FUEL INJECTION PUMP GOVERNOR The present invention relates to a governor for a fuel injection pump for a Diesel internal combustion en gine.

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 lever and a flyweight assembly and which moves a control rod which controls the fuel injection volume. However, there are several problems in the prior art design. Firstly, in a case in which the flyweights are engageable with both a high speed spring and an idling spring and the control lever is moved to a starting position to provide maximum fuel injection volume for starting the engine, as the engine speed rises, the flyweights engage with both the high speed spring and the idling spring with the result that the fuel injection volume is not properly reduced as the engine speed rises. Smoky exhaust gases are thereby produced which pollute the environment, and another important disadvantage is that fuel is wasted since the smoky exhaust gases are produced as the result of incomplete combustion. The latter is especially important in view of the radially rising cost and depletion of supply of fuel oil suitable for powering a Diesel engine. The present invention intends to eliminate this drawback by the use of novel means to disconnect the flyweights from the idling spring during engine starting.

Another problem with this type of governor is that when engine braking is being employed to slow down the vehicle, such as when moving downhill in low gear, although the vehicle operator has moved the control lever to the idling position, the action of the flyweights on the floating lever is such that the control lever will be moved thereby away from the idling position in the accelerating direction. This results in an unnatural sensation for the vehicle operator, and interferes with the engine braking operation. The present invention intends to provide novel means by which the control lever will not unnaturally be moved by the floating lever during engine braking.

It is therefore an important object of the present invention to provide a governor for a fuel injection pump for a Diesel internal combustion engine by which smoky exhaust gases are not produced while the engine is being started and efficient use of fuel is therefore assured.

It is another important object of the present invention to provide a governor for a fuel injection pump for a Diesel internal combustion engine by which the engine speed control lever and accelerator pedal are not moved from their idling position by the action of the governor floating lever during engine braking conditions.

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

FIG. 1 is a longitudinal sectional view of a governor embodying the present invention;

FIG. 2 is a top view, partly in section, of a portion of the governor of FIG. 1; and i O 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 a spring seat 22 is urged into engagement by an idling spring 24. 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 other side of which is engagable with a medium speed governor spring 36 and a high speed governor spring 38. A spring seat 40 is engageable with the other 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 slidably supported by the casing 10 and has a shoulder 42a formed near its right end which is engagable with the left side of a spring seat 44 which is also engagable with a shoulder 10a of the casing 10.

A bushing 46 is fixed to the casing 10 and receives the rod 42 therethrough. A compensating compression spring 48 is disposed inside the bushing 46, and engages at its right end with a nut 50 fixed to the end of the rod 42 and at its left end with the right side of the spring seat 44. The nut 50 is screwable along the rod 42 to provide a stroke S between its left side and the right side of the bushing 46. A spring 52 urges the spring seat 40 rightwards to eliminate play, and the rod 42 is formed with a shoulder 42b which is engagable with the left side of the spring seat 40.

A stopper lever 54 is manually rotatable to stop the engine, and has an extension.56 extending integrally therefrom and carrying at its end a pin 58. A link 60 is pivotally carried by the pin 58, and carries a pin 62 at its one end. The pin 62 is engagable with the left side of the spring seat 40, and the right side of the other end of the link 60 is engagable with the left side of a pin 64 fixed to a control rod 66. The cntrol 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 rotatable about the fulcrum pin 30, and engages at its lower end with a circumferential groove (no numeral) formed in the spring seat 22. The guide lever 68 is biased clockwise against the pin 32 of the tension lever 28 by a tension 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.

3 A pin 80 is fixed to the control rod 66, and pivotally supports the link 78.

Referring now also to FIG. 2, the floating lever 74 is formed with a longitudinal slot 74a, in which a pin 82 of an arm 84 is movably received. A control member or lever 86, which may be connected to an accelerator pedal of a vehicle through a suitable linkage (not shown), is fixed on a shaft 88 which is rotatably supported by the casing by a bushing 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.

The operation of the governor will now be described.

When the engine is shut down, the control lever 86 will be in its maximum counterclockwise position and the control rod 66 will be in its maximum upward position as shown in FIG. 2. To start the engine, the control lever 86 is rotated to its maximum clockwise position to provide maximum fuel injection volume for starting. In

, FIG. 2, the control lever 86 is rotated clockwise and the arm 92 engages with the pin 94 to move the arm 84 and thereby the pin 82 clockwise. Since the engine speed is almost zero, the flyweights 14 will not be moved and the shifter rod 16 will assume its maximum leftward position in FIG. 1. Also as viewed in FIG. 1, the tension lever 28 will assume its maximum clockwise position.

Initially, the guide lever 68 will assume its maximum clockwise position as viewed in FIG. 1, and the ball 72 will serve as a fixed pivot point for the floating lever 74. Referring now to FIG. 2, as the pin 82 is moved clockwise, it will exert a force on the floating lever 72 to pivot the same clockwise about the ball 72. This will cause the control rod 66 to be moved downward in the direction to increase the fuel injection volume by means of the link 78 and the starting spring 98. When the position of maximum fuel injection volume is reached, the pin 64 of the control rod 66 will abut against the link 60, which will in turn be rotated about the pin 58 until the pin 62 abuts against the spring seat 40. Due to the high stiffness of the

springs

36 and 38, further movement of the control rod 66 will be prevented and the pin 80 will then serve as a fixed pivot. Further clockwise rotation of the pin 82 will subsequently cause the floating lever 74 to pivot counterclockwise about the pin 76, and the guide lever 68 will be thereby rotated counterclockwise as viewed in FIG. 1 away from the tension lever 28. The lower end of the guide lever 68 will move the spring seat 22 axially rightward against the force of the idling spring 24 and out of engagement with the flyweights l4 and shifter rod 16.

If the engine were started without disengaging the idling spring 24 from the flyweights 14, the

springs

36 and 38 would be mechanically connected in parallel with the idling spring 24. Under starting conditions, in which the control lever 86 is moved past a full load position to the starting position, the

springs

36, 38 and 24, which normally serve to reduce the fuel injection volume in combination as the engine speed rises with the control lever 86 in a useful power producing position will provide too much resistance to reduction of the fuel injection volume, and the fuel injection volume will be too great and smoky exhaust will be produced. As described, however, the guide lever 68 disconnects the idling spring 24 from the flyweights l4, and the problem is eliminated.

After starting, the control lever 86 is rotated counterclockwise in FIG. 2 to an idling vposition. The arm 84 is urged by the spring 96.to follow the arm 92, and the floating lever 74 is pivoted counterclockwise about the ball 72 by the pin 82. The control rod 66 is pulled upward thereby to an idling position. As the floating lever 74 is rotated to the idling position, the guide lever 68 and thereby the ball 72 itself will be rotated clockwise in FIG. 1 by the idling spring 24 and the spring until the guide lever 68 engages with the pin 32 of the tension lever 28. The spring seat 22 will then engage with the shoulder 16a of the shifter rod 16.

The tension lever 28 and guide lever 68 will then rotate as a unit. As the engine speed approaches the idling speed, the flyweights l4 expand and the shifter rod 16 is moved rightward in FIG. 1 against the force of the idling spring 24. The guide lever 68 and tension lever 28 will then rotate counterclockwise. Referring to FIG. 2, counterclockwise rotation of the guide lever 68 will cause counterclockwise rotation of the floating lever 74 about the pin 82. The control rod 66 will thereby be moved upward to reduce the fuel injection volume.

As the control lever 86 is rotated clockwise in FIG. 2 to increase the engine speed, the floating lever 74 is pivoted clockwise thereby about the ball 72, and the control rod 66 is moved downward to increase the fuel injection volume. As viewed in FIG. 1, as the engine speed increases, the tension lever 28 and guide lever 68 will be rotated counterclockwise by the flyweights 14 and the shifter rod 16. The pin 32 will urge the spring seat 34, springs 36 and 38 and spring seat 40 leftward against the force of the spring 52, which is weak, until the left side of the spring seat 40 abuts against the shoulder 42b of the rod 42. The rod 42 will then be moved leftward against the force of the compensating spring 48, which serves to correctly determine the maximum fuel injection volume during the transition between idling and medium speed engine operation. After the rod 42 has been moved leftward by a distance corresponding to the stroke S, the left side of the nut 50 will abut against the right side of the bushing 46, and further movement of the rod 42 will be prevented. At or slightly before this point, the left side of the spring seat 40 will engage with the pin 62 and rotate the link 60 clockwise. If the control rod 66 should be thereafter moved leftward into engagement with the link 60, further movement thereof will be prevented. It will be understood that the tension lever 28, spring seats 34 and 40, springs 36, 38, 48 and 52, rod 42 and link 60 serve to limit the maximum fuel injection volume to a point above which smoky exhaust gas would be produced, and that the floating lever 74 and associated parts serve to suitably adjust the fuel injection volume to an optimum value below the maximum allowable value based on the engine speed demand and instantaneous engine speed.

As the engine speed increases and the tension lever 28 rotates further counterclockwise, the spring 36 and thereafter the spring 38 will be compressed between the spring seats 34 and 40. The maximum clockwise position of the link 60 will not change, however, indicating that the maximum fuel injection volume not producing smoky exhaust is constant above the engine speed at which the nut 50 engages with the bushing 46. The guide lever 68 rotating counterclockwise will rotate the floating lever 74 counterclockwise as viewed in FIG. 2 about the pin 82. The control rod 66 will be thereby moved upward to decrease the fuel injection volume as the engine speed increases since extra fuel is not required for further acceleration. v

The condition of engine braking, such as when the vehicle is moving downhill, is illustrated in FIG. 3. Under this condition, the engine speed is high and the control lever 86 is in the idling position. The positions of the parts shown in solid line correspond to normal idling conditions, and the positions shown in broken line correspond to engine braking conditions, under which the engine is being used as a brake to slow down the vehicle. For simplicity of description, it will be assumed that the vehicle is initially coasting on a'level portion of a highway with the control lever 86 in the idling position, and then starts moving downhill. The guide lever 68 will be rotated by the flyweights 14 from the position is solid line to the position in broken line since the engine will be driven by the vehicle wheels and the engine speed will increase. Since the control rod 66 is in the minimum fuel injection position andcannot be moved farther to decrease the fuel injection volume, the pin 80 will serve as a fixed pivot point. The floating lever 74 and link 78 will move as shown. Since the pin 82 must at all times be within the slot 74a, the pin 82 and arm 84 will be rotated clockwise. If the control lever 86 was fixedly rotatable with the arm 84 as in the prior art, the control lever 86 would be rotated by the floating lever 74 clockwise in the direction to increase the fuel injection volume as described above. However, with the provision of yieldable means including the spring 96, the arm 84 is able to rotate clockwise but the control lever 86 will remain in the position shown in solid line. Thus, the unnatural phenomenon of the control lever 86 being moved by the floating lever 74 during engine braking is eliminated by the present invention.

To shut down the engine, the stopper lever 54 is rotated clockwise as shown in FIG. 1 to move the link 60 and control rod 66 to maximum rightward positions to completely shut off fuel injection.

What is claimed is:

l. A fuel injection pump governor comprising a fuel control rod, flyweights displaceable upon rotation thereof, first linkage means operably connecting said flyweights to said control rod, governor spring means and an idling spring connected to said first linkage means and operable to biasingly oppose displacement of said flyweights upon rotational speed increase of the latter, said first linkage means comprising linkage elements operable to disengage said idling spring from said flyweights when the flyweight rotational speed is below a predetermined value.

2. A fuel injection pump according to claim 1, further comprising a control member manually movable to engage said first linkage means and thereby move said control rod, and yieldable means normally operatively connecting said control member to said first linkage means and being arranged to yield when a force is applied to said control member by said first linkage means in a direction urging said control member toward a maximum fuel position.

3. A fuel injection pump governor according to claim 2, in which said yieldable means comprises an arm rotatable about a fixed axis and carrying a first pin connected to said first linkage means, said arm also carrying a second pin, said control member being engagable with said second pin when rotated toward said maximum fuel position, and biasing means urging said arm 6 in a direction to engage said second pin with said control member.

4.'A fuel injection pump governor according to claim 1, further comprising a second linkage means engagable with said flyweights and said control rod to limit movement of said control rod toward a maximum fuel position as a predetermined function of the flyweight rotational speed, said first linkage means being arranged to disengage said idling spring from said flyweights when the movement of said control rod is being limitedby said second linkage means and the flyweight rotational speed is below said predetermined value.

5. A fuel injection pump governor according to claim 4, in which said first linkage means comprises a first rod axially movable by said flyweights, a first spring seat slidable on said first rod and engaging at one end with said idling spring and engagable at its other end with said first rod, a tension lever having an intermediate fulcrum and being pivotally connectedat one end to said first rod, a second rod slidably carrying thereon said governor spring means, said second rod also slidably carrying thereon second and third spring seats engagable with the opposite ends of said governor spring means, the other end of said tension lever being engagable with said second spring seat, a guide lever having an intermediate fulcrum at the same axis of rotation as said tension lever and having one end engaging with said first spring seat, a floating lever, the other end of said guide lever pivotally engaging with one end of said floating lever, a link, the other end of said floating lever pivotally engaging with one end of said link, the other end of saidlink pivotally engaging with said control rod, said second linkage means comprising a second link having an intermediate fulcrum and pivotally engaging at one end with said third spring seat and at the other end with said control rod.

6. A fuel injection pump governor according to claim 5, further comprising a compensating spring, said second rod being movable within a limited range and being engagable with said compensating spring in such a manner that said flyweights move against the biasing forces of said idling and compensating springs prior to moving against the biasing force of said governor spring means as the flyweight rotational speed increases.

7. A fuel injection pump governor according to claim 18, further comprising a stopper member pivotally connected to said fulcrum of said second link and being manually movable to move said fulcrum of said second link and thereby said control rod to a minimum fuel position.

8. A fuel injection pump governor according to claim 1, in which said governor spring means is in a substantially free state when the flyweight rotational speed is zero.

9. A fuel injection pump governor comprising a fuel control rod, flyweights disp aceable upon rotation thereof, a first linkage means operably connecting said flyweights to said control rod, governor spring means and an idling spring connected to said first linkage means and operable to biasingly oppose displacement of said flyweights upon rotational speed increase of the latter, a control member manually movable to engage said first linkage means and thereby move said control rod, a second linkage means engagable with said flyweights and said control rod to limit movement of said control rod toward a maximum fuel position as a predetermined function of the flyweight rotational speed, said first linkage means comprising linkage elements operable to disengage said idling spring from said flyweights when said control rod is moved by said control member through said first linkage toward said maximum fuel position to an extent that the movement of said control rod is limited by said second linkage means and the flyweight rotational speed is below a predetermined value, and yieldable means for connecting said control member to said first linkage means, said yieldable means normally operatively connecting said control member to said first linkage means and being arranged to yield when a force is applied to said control member by said first linkage means in a direction urging said control member toward said maximum fuel position.

10. A fuel injection pump governor according to claim 9, in which said first linkage means comprises a first rod axially movable by said flyweights, a first spring seat slidable on said first rod and engaging at one end with said idling spring and engagable at its other end with said first rod, a tension lever having an intermediate fulcrum and being pivotally connected at one end to said first rod, a second rod slidably carrying thereon said governor spring means, said second rod also slidably carrying thereon second and third spring seats engagable with the opposite ends of said governor spring means, the other end of said tension lever being engagable with said second spring seat, a guide lever having an intermediate fulcrum at the same axis as said tension lever and one end engaging with said first spring seat, a floating lever, the other end of said guide lever pivotally engaging with one end of said floating lever, a first link, the other end of said floating lever pivotally engaging with one end of said first link, the

8 other end of said first link pivotally engaging with said control rod, said second linkage means comprising a second link having an intermediate fulcrum and pivotally engaging at one end with said third spring seat and at the other end with said control rod, said yieldable means comprising an arm rotatable about a fixed axis and carrying a first pin slidable in a longitudinal slot formed through said floating lever, said arm also carrying a second pin, said control member being engagable with said second pin when rotated toward said maximum fuel position, and biasing means urging said arm in a direction to engage said second pin with said control member.

11. A fuel injection pump governor according to claim 10, further comprising a compensating spring, said second rod being movable within a limited range and being engagable with said compensating spring in such a manner that said flyweights move against the biasing forces of said idling and compensating springs prior to moving against the biasing force of said governor spring means as the flyweight rotational speed increases.

12. A fuel injection pump governor according to claim 10, further comprising a stopper member pivotally connected to said fulcrum of said second link and being manually movable to move said fulcrum of said second link and thereby said control rod to a minimum fuel position.

13. A fuel injection pump governor according to claim 9, in which said governor spring means is in a substantially free state when the flyweight rotational speed is zero.

Claims

1. A fuel injection pump governor comprising a fuel control rod, flyweights displaceable upon rotation thereof, first linkage means operably connecting said flyweights to said control rod, governor spring means and an idling spring connected to said first linkage means and operable to biasingly oppose displacement of said flyweights upon rotational speed increase of the latter, said first linkage means comprising linkage elements operable to disengage said idling spring from said flyweights when the flyweight rotational speed is below a predetermined value.

3. A fuel injection pump governor according to claim 2, in which said yieldable means comprises an arm rotatable about a fixed axis and carrying a first pin connected to said first linkage means, said arm also carrying a second pin, said control member being engagable with said second pin when rotated toward said maximum fuel position, and biasing means urging said arm in a direction to engage said second pin with said control member.

4. A fuel injection pump governor according to claim 1, further comprising a second linkage means engagable with said flyweights and said control rod to limit movement of said control rod toward a maximum fuel position as a predetermined function of the flyweight rotational speed, said first linkage means being arranged to disengage said idling spring from said flyweights when the movement of said control rod is being limited by said second linkage means and the flyweight rotational speed is below said predetermined value.

5. A fuel injection pump governor according to claim 4, in which said first linkage means comprises a first rod axially movable by said flyweights, a first spring seat slidable on said first rod and engaging at one end with said idling spring and engagable at its other end with said first rod, a tension lever having an intermediate fulcrum and being pivotally connected at one end to said first rod, a second rod slidably carrying thereon said governor spring means, said second rod also slidably carrying thereon second and third spring seats engagable with the opposite ends of said governor spring means, the other end of said tension lever being engagable with said second spring seat, a guide lever having an intermediate fulcrum at the same axis of rotation as said tension lever and having one end engaging with said first spring seat, a floating lever, the other end of said guide lever pivotally engaging with one eNd of said floating lever, a link, the other end of said floating lever pivotally engaging with one end of said link, the other end of said link pivotally engaging with said control rod, said second linkage means comprising a second link having an intermediate fulcrum and pivotally engaging at one end with said third spring seat and at the other end with said control rod.

9. A fuel injection pump governor comprising a fuel control rod, flyweights displaceable upon rotation thereof, a first linkage means operably connecting said flyweights to said control rod, governor spring means and an idling spring connected to said first linkage means and operable to biasingly oppose displacement of said flyweights upon rotational speed increase of the latter, a control member manually movable to engage said first linkage means and thereby move said control rod, a second linkage means engagable with said flyweights and said control rod to limit movement of said control rod toward a maximum fuel position as a predetermined function of the flyweight rotational speed, said first linkage means comprising linkage elements operable to disengage said idling spring from said flyweights when said control rod is moved by said control member through said first linkage toward said maximum fuel position to an extent that the movement of said control rod is limited by said second linkage means and the flyweight rotational speed is below a predetermined value, and yieldable means for connecting said control member to said first linkage means, said yieldable means normally operatively connecting said control member to said first linkage means and being arranged to yield when a force is applied to said control member by said first linkage means in a direction urging said control member toward said maximum fuel position.

10. A fuel injection pump governor according to claim 9, in which said first linkage means comprises a first rod axially movable by said flyweights, a first spring seat slidable on said first rod and engaging at one end with said idling spring and engagable at its other end with said first rod, a tension lever having an intermediate fulcrum and being pivotally connected at one end to said first rod, a second rod slidably carrying thereon said governor spring means, said second rod also slidably carrying thereon second and third spring seats engagable with the opposite ends of said governor spring means, the other end of said tension lever being engagable with said second spring seat, a guide lever having an intermediate fulcrum at the same axis as said tension lever and one end engaging with said first spring seat, a floating lever, the other end of said guide lever pivotally engaging with one end of said floating lever, a first link, the other end of said floating lever pivotally engaging with one end of said first link, the other end of said first link pivotally engaging with said control rod, said second linkage means comprising a second link having an intermediate fulcrum and pivotally engaging at one end with said third spring seat and at the other end with said control rod, said yieldable means comprising an arm rotatabLe about a fixed axis and carrying a first pin slidable in a longitudinal slot formed through said floating lever, said arm also carrying a second pin, said control member being engagable with said second pin when rotated toward said maximum fuel position, and biasing means urging said arm in a direction to engage said second pin with said control member.