JP4355418B2 - Fuel injection pump for diesel engines - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fuel injection pump used for an internal combustion engine such as a diesel engine.
[0002]
[Prior art]
Generally, in a diesel engine fuel injection pump, the rotational force of a camshaft is transmitted to a governor lever in a governor device using the centrifugal force of the governor weight, and the control rack position in the pump device is determined via the governor lever. The fuel injection amount is controlled by a plunger that is operated and interlocked with the control rack.
[0003]
In such a fuel injection pump, the position of the control rack at the rated engine output (hereinafter referred to as “rated rack position”) depends on the difference in the injection characteristics of the fuel injection pump, the combustion characteristics of the engine, and the processing accuracy of the governor components. ) Are different, the range of action of the governor weight on the governor lever (hereinafter referred to as “the governor weight use range”) varies, and the regulation varies. Therefore, in the conventional governor device, at the time of assembly, for example, the length of the link is changed, the governor weight usage range is adjusted, and the variation in regulation is reduced.
[0004]
[Problems to be solved by the invention]
If the governor weight usage range is not adjusted as described above, even if governor springs of the same standard are used, variations in regulation cannot be avoided. Especially when the high idle speed is fixed, the rated speed There is a problem that even if the number is set, the rated output cannot be obtained and the output becomes insufficient. In order to improve this, it is necessary to prepare and replace several types of links having different lengths, and there is a problem that the number of parts and the number of replacement man-hours are large.
[0005]
[Means for Solving the Problems]
The problems to be solved by the present invention are as described above. Next, means for solving the problems will be described.
That is, according to the first aspect of the present invention, in the fuel injection pump provided with the link member that connects the plunger of the pump device for pumping and metering the fuel and the governor lever of the mechanical governor device, the link member has an inclined guide. The inclined guide is slidably engaged with a rack pin protruding from the control rack of the plunger, and an elevating mechanism capable of moving up and down is provided.
[0006]
According to a second aspect of the present invention, the lifting mechanism according to the first aspect is provided with a pivotable lift pin below the link member, and a lift portion protruding from an eccentric position of the lift pin end surface. It is abutted against the lower side of the link member.
[0007]
In Claim 3, the rotation range of the lift part of Claim 2 is comprised so that regulation is possible.
[0008]
According to a fourth aspect of the present invention, the rack pin is configured to be detachable from the inclined guide by the rotation of the lift portion according to the second aspect.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
1 is a side view of an engine equipped with a fuel injection pump, FIG. 2 is also a rear view, FIG. 3 is an overall side view of the fuel injection pump, FIG. 4 is a front view of a governor device, and FIG. 5 is a front view of the pump device. FIG. 6 is an overall side view showing the adjustment mechanism according to the present invention for moving the link connecting the control rack and the governor lever to the left and right. FIG. 7 is an explanatory view of the adjustment mechanism capable of regulating the rotation range. FIG. 8B is an explanatory diagram when the rack pin is closest to the plunger side, FIG. 8B is an explanatory diagram when the rack pin is at an intermediate position, FIG. 8C is an explanatory diagram when the rack pin is most spaced from the plunger side, and FIG. It is explanatory drawing of the detachable adjustment mechanism, (a) is explanatory drawing when a rack pin fully engages with a guide groove, (b) is explanatory drawing when the rack pin is in the middle of removing from a guide groove, (c) Is a rack Down is a diagram for describing a case in which deviates completely from the guide groove.
[0010]
First, the overall configuration of an engine equipped with a fuel injection pump according to the present invention will be described with reference to FIGS.
The engine 61 includes a crankcase 62, a cylinder portion 63, and a cylinder head portion 64. An exhaust device 65 is disposed on the side of the cylinder head portion 64 of the engine 61. A fuel injection pump 1 is disposed on the side of the engine 61 so that fuel supplied from a fuel tank (not shown) can be supplied into each cylinder at a high pressure.
[0011]
Fuel is supplied to the engine 61 from the fuel injection pump 1, and the fuel is introduced into the cylinder portion 63 together with air. Plural or single cylinders and pistons (not shown) are arranged in the cylinder part 63, and the introduced fuel and air are compressed by the pistons (not shown) in the cylinder and explode after exhausting from the cylinder part 63 as exhaust gas. Is done. The exhaust gas discharged from the cylinder part 63 is discharged from the cylinder head part 64.
[0012]
The cylinder head portion 64 is provided with a valve mechanism (not shown), and the exhaust gas generated in the cylinder portion 64 passes into the exhaust manifold 66 provided in the cylinder head portion 64 via the valve mechanism. Discharged. The exhaust gas discharged from each cylinder gathers in the exhaust manifold 66, and the exhaust device 65 is connected to the exhaust manifold 66.
In this configuration, the exhaust gas collected in the exhaust manifold 66 is introduced into the exhaust device 65.
[0013]
A driving force from the engine 61 is transmitted to the fuel injection pump 1, and fuel injection timing for each cylinder of the engine 61 is adjusted by the fuel injection pump 1. The power transmitted to the fuel injection pump 1 is synchronized with the crankshaft contained in the crankcase 62 of the engine 61, and the fuel injection pump 1 adjusts the fuel injection timing so as to be built in the cylinder portion 63. It is possible to inject fuel corresponding to the sliding of the piston.
The fuel injected from the fuel injection pump 1 in this way is injected into each cylinder housed in the cylinder portion 63 via an unillustrated oil valve.
[0014]
Next, the overall configuration of the distributed fuel injection pump will be described with reference to FIGS.
The fuel injection pump 1 includes a governor device 71 and a pump device 72. First, the pump device 72 will be described.
As shown in FIGS. 3 and 5, a cam shaft 4 having a cam 5 is provided in the lower portion of the pump device 72, and the drive side 4 a of the cam shaft 4 rotates to the main body housing 28 via the cam bearing 12. It is supported freely. A positioning key 13 for positioning the cam 5 is attached to the driving side 4 a end of the cam shaft 4.
[0015]
Above the cam 5, a plunger 7 fitted into the plunger barrel 8 so as to be slidable up and down is disposed, and a tappet 11 is attached to the lower end of the plunger 7. The plunger 7 and the tappet 11 are biased downward by a biasing means such as a spring 22, and the tappet 11 is in contact with the cam 5. The spring 22 is interposed between the upper receiving member 23 and the lower receiving member 24.
The plunger 7 is configured to move up and down by the rotation of the cam 5.
[0016]
A distribution shaft 9 is disposed on the side of the plunger 7 in parallel with the plunger 7, and the distribution shaft 9 is rotatably inserted into the distribution shaft sleeve 10 and the distribution shaft 9 is disposed. It is rotationally driven by a distribution drive shaft 19 connected to the lower end of the shaft 9. The distribution drive shaft 19 and the distribution shaft 9 are arranged in a direction orthogonal to the cam shaft 4.
A feed pump 6 is attached to the side of the camshaft 4 and is driven by the rotation of the camshaft 4 so that fuel is supplied to the fuel gallery 43 in the head housing 28a from a pipe joint 6a incorporating a filter. Yes.
[0017]
In the fuel injection pump 1 configured as described above, when the plunger 7 is positioned at the lower end of the vertical movement range, the fuel pumped to the fuel gallery 43 by the feed pump 6 is pumped into the plunger barrel 8 through the suction port 14. The
When the plunger 7 is pushed up by the cam 5 and rises, the fuel in the plunger barrel 8 is pumped to the delivery valve 18 through the distribution shaft sleeve 10 and the distribution shaft 9 and injected from the fuel injection valve connected to the delivery valve 18. The In this case, the fuel is distributed and pumped to the plurality of delivery valves 18 by the distribution shaft 9 that rotates in conjunction with the cam shaft 4.
[0018]
The plunger 7 can be rotated integrally with the control sleeve 17 on the outer periphery of the plunger 7 around the shaft center. By rotating the control sleeve 17 by a governor device 71 described later, the plunger 7 The amount of fuel injected from the fuel injection valve can be adjusted by changing the position of the plunger lead 16 formed in the above.
[0019]
Next, the governor device 71 will be described.
As shown in FIGS. 3 and 4, one end of the cam shaft 4 protrudes into a governor housing 36 of a governor device 71 that is attached and fixed to the main body housing 28. A governor weight 31 is attached to one end of the cam shaft 4, and when the cam shaft 4 rotates, the governor weight 31 is rotated outward by centrifugal force and the sleeve 30 is pushed out to contact the sleeve 30. The lower end of the first governor lever 29a moves. That is, the movement of the governor weight 31 due to the centrifugal force is transmitted to the lower end portion of the first governor lever 29a via the sleeve 30. And the lower end part of this 1st governor lever 29a is urged | biased from the non-sleeve 30 side by the lower end part of the 2nd governor lever 29b via the spring mechanism which is not shown in figure.
[0020]
The upper and lower intermediate portions of the first governor lever 29a are rotatably supported by a rotating shaft 29c, and the upper end portion of the first governor lever 29a is controlled via a link 27 having an adjusting mechanism 73 according to the present invention. The rack 21 is connected. Then, by moving the control rack 21, the control sleeve 17 is rotated to change the fuel injection amount.
[0021]
On the other hand, the upper and lower intermediate portions of the second governor lever 29b are rotatably supported by a rotating shaft 29c, and a hook 29d is projected from the right end portion of the second governor lever 29b. It is connected to the hook 75 a of the lever 75 via a governor spring 74. The base end portion of the lever 75 is fixed to one end portion of a control lever shaft 76 disposed in parallel with the rotating shaft 29c, and the control lever 84 is fixed to the other end portion of the control lever shaft 76. The control lever 84 is connected to an operation mechanism (not shown).
[0022]
That is, when the control lever 84 is operated to rotate the control lever shaft 76 by the operation mechanism, the second governor lever 29b is rotated via the lever 75 and the governor spring 74, and the spring mechanism (not shown) is used. When the first governor lever 29a is rotated, the control rack 21 is moved via the link 27, and the fuel injection amount is changed.
[0023]
Next, the adjusting mechanism according to the present invention in such a distributed fuel injection pump will be described with reference to FIGS. 3 and 6 to 8.
As shown in FIGS. 3 and 6, in the state where the link 27 is inserted from the governor device 71 into the pump device 72, a lift pin 77 is provided below the link 27 in a direction substantially orthogonal to the link 27. The lift pin 77 is rotatably provided from the outside of the pump device 72.
[0024]
A lift part 77a protrudes from the eccentric position of the front end surface of the lift pin 77, and the lower surface of the link 27 is brought into contact with the lift part 77a. The lower center portion of the plate 79 is fixed by external fitting. An arcuate guide groove 79a is opened in the upper part of the guide plate 79, and a guide pin 78 projecting from the main body housing 28 in parallel with the lift pin 77 is inserted into the guide groove 79a. ing.
[0025]
In the elevating mechanism 81 having such a configuration, as shown in FIG. 7, when the lift pin 77 is rotated from the outside during assembly, the lift portion 77a rises and pushes the link 27 upward. At the same time, the guide plate 79 also slides along the guide groove 79 a and rotates together with the lift pin 77. Since the rotation range of the guide plate 79 is regulated by the guide pins 78, the elevation range of the link 27 is also regulated to a certain range.
[0026]
Here, a guide groove 27a is formed obliquely at the tip of the link 27, and a rack pin 80 protruding from the control rack 21 is disposed above the guide groove 27a (FIG. 7 ( a)).
Accordingly, when the link 27 is raised by the lifting mechanism 81, the guide groove 27a of the link 27 engages with the rack pin 80 of the control rack 21, and at the same time, the rack pin 80 is moved in the horizontal direction by the lower side 27b of the guide groove 27a. The position of the control rack 21 provided with the rack pins 80 is also moved (FIG. 7B). When the link 27 is further lifted, the rack pin 80 is further pushed in the left-right direction and is completely engaged with the guide groove 27a (FIG. 7C).
[0027]
In this way, the link 27 is provided with the inclined guide groove 27a, and the rack pin 80 protruding from the control rack 21 of the plunger 7 is slidably engaged with the inclined guide groove 27a. Since the adjusting mechanism 73 having the vertically moving mechanism 81 is provided, it is possible to move only the position of the control rack 21 to the actual rated rack position while keeping the governor weight usage range constant. Can be prevented. In particular, since the governor weight usage range is kept constant, even when the high idle speed is fixed, it is possible to converge to the rated output and to prevent the output from becoming insufficient.
[0028]
Specifically, the position of the control rack 21 may be adjusted so that the rated output is obtained when the sleeve 30 pushed out by the governor weight 31 is in a specific position, thereby absorbing individual differences between the fuel injection pumps. can do.
In the present embodiment, since the rotation range of the lift portion 77a can be restricted, the lifting range of the link 27 can also be limited to a certain range, and the rack pin 80 can be operated when operating the lifting mechanism 81. Inadvertent removal from the guide groove 27a can also be prevented. Further, it can be easily adjusted from the outside.
[0029]
As shown in FIG. 8, the adjusting mechanism 83 having the lifting mechanism 82 of another form is provided with a lift pin 77 horizontally below the link 27 in a direction substantially perpendicular to the link 27, as in the lifting mechanism 81. The lift pin 77 is rotatably provided from the outside of the pump device 72. A lift portion 77a having a substantially circular cross section protrudes from an eccentric position of the tip surface of the lift pin 77, and the lower surface of the link 27 is in contact with the lift portion 77a.
[0030]
In the elevating mechanism 82 having such a configuration, the guide plate 79 is not provided and the rotation range of the lift pin 77 is not restricted at all. Therefore, the elevating range of the link 27 coincides with the upper and lower limit positions of the lift portion 77a. As a result, the link 27 can be moved up and down larger than the lifting mechanism 81.
Accordingly, after adjusting the position of the control rack 21 by engaging the rack pin 80 with the guide groove 27a provided obliquely at the tip of the link 27 (FIGS. 8A and 8B), the lift pin 77 is further rotated. When the link 27 is lowered, the guide groove 27a can be detached from the rack pin 80 while pushing the rack pin 80 in the left-right direction by the upper side 27c (FIG. 8C).
[0031]
That is, an inclined guide groove 27a is provided in the link 27, and a rack pin 80 protruding from the control rack 21 of the plunger 7 is slidably engaged with the inclined guide groove 27a, and the link 27 is moved up and down. An adjustment mechanism 73 having a movable elevating mechanism 81 is provided. In addition, since the rack pin 80 is configured to be detachable from the guide groove 27a by the rotation of the lift portion 77a, the control is performed while keeping the governor weight usage range constant. Not only can the position of the rack 21 be moved to the actual rated rack position, but the adjustment mechanism 83 can also be used as an attaching / detaching mechanism for the control rack 21 with a simple configuration, and the assembly structure can be simplified and reduced. Cost can be reduced.
[0032]
【The invention's effect】
Since the present invention is configured as described above, the following effects can be obtained.
That is, as in claim 1, in the fuel injection pump provided with the link member that connects the plunger of the pump device for pumping and metering the fuel and the governor lever of the mechanical governor device, the link member has an inclined shape. A guide is provided, and a rack pin projecting from the control rack of the plunger is slidably engaged with the inclined guide, and an elevating mechanism that can move up and down is provided. It is possible to move only the position of the control rack while keeping the governor weight usage range constant, absorb differences between fuel injection pumps, and prevent variation in regulation. In particular, even when the high idle speed is fixed, it is possible to prevent the output from becoming insufficient.
[0033]
According to a second aspect of the present invention, in the lifting mechanism according to the first aspect, a pivotable lift pin is provided below the link member, and a lift portion is provided at an eccentric position of the lift pin end surface so as to project the lift portion. Since the link member is brought into contact with the lower side of the link member, the link member can be moved up and down with a simple configuration, so that the cost of parts can be reduced and the adjustment efficiency can be improved by enabling adjustment from the outside. it can.
[0034]
Since the rotation range of the lift part according to claim 2 can be regulated as in claim 3, the rack pin can be prevented from being inadvertently detached from the guide groove.
[0035]
Since the rack pin is configured to be detachable from the inclined guide by turning the lift portion according to claim 2, only the position of the control rack can be moved while keeping the governor weight usage range constant. In addition, since the same mechanism can also be used for the attachment / detachment function of the control rack, the assembly structure can be simplified and the cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a side view of an engine equipped with a fuel injection pump.
FIG. 2 is also a rear view.
FIG. 3 is an overall side view of the fuel injection pump.
FIG. 4 is a front view of the governor device.
FIG. 5 is a front view of the pump device.
FIG. 6 is an overall side view showing an adjusting mechanism according to the present invention for moving a link connecting a control rack and a governor lever to the left and right.
7A and 7B are explanatory diagrams of an adjustment mechanism capable of regulating a rotation range, where FIG. 7A is an explanatory diagram when the rack pin is closest to the plunger side, and FIG. 7B is an explanatory diagram when the rack pin is at an intermediate position; (C) is explanatory drawing when a rack pin is most separated from the plunger side.
FIGS. 8A and 8B are explanatory views of an adjustment mechanism in which a rack pin can be attached and detached, where FIG. 8A is an explanatory view when the rack pin is completely engaged with the guide groove, and FIG. Explanatory drawing, (c) is explanatory drawing when a rack pin completely remove | deviates from a guide groove.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Fuel injection pump 7 Plunger 21 Control rack 27 Link member 27a Inclined guide 29 Governor lever 71 Governor apparatus 72 Pump apparatus 77 Lift pin 77a Lift part 80 Rack pin 81 * 82 Lifting mechanism

Claims (4)

In a fuel injection pump provided with a link member that connects a plunger of a pump device for pumping and metering fuel and a governor lever of a mechanical governor device, the link member is provided with an inclined guide, and the inclined guide is provided on the inclined guide. Is a fuel injection pump for a diesel engine, in which a rack pin projecting from the control rack of the plunger is slidably engaged and an elevating mechanism that can move up and down is provided. The lifting mechanism is provided with a pivotable lift pin below the link member, a lift portion projecting at an eccentric position of the end surface of the lift pin, and the lift portion contacting the lower side of the link member The fuel injection pump for a diesel engine according to claim 1, wherein The fuel injection pump for a diesel engine according to claim 2, wherein the rotation range of the lift portion can be regulated. The fuel injection pump for a diesel engine according to claim 2, wherein the rack pin is configured to be detachable from the inclined guide by rotation of the lift portion.

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