JP2001050136A - Fuel injection pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the entry of foreign matter into a pump housing and to always and smoothly keep a control operation (sliding) in the longitudinal direction of a fuel control rack. SOLUTION: In a pump housing 1, a plunger which is capable of forcibly feeding fuel by a reciprocating operation and automatically adjusts forcibly fed fuel amount is provided by being internally mounted. The plunger is constituted so as to be controllable by a fuel control rack 4 inserted from an opening 3 formed on a side part of the pump housing 1 via a pinion member. The opening 3 is constituted so as to prevent the entry of foreign matter by a closing member 6 mounted on the pump housing 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection pump and belongs to the technical field of an engine.

[0002]

2. Description of the Related Art Conventionally, a fuel injection pump has a structure in which fuel is pumped by reciprocating a plunger, and by rotating the plunger, a fuel supply port and a drain port formed in a barrel and a plunger outer surface. The fuel supply amount is controlled by changing the relative position with respect to the provided lead. The barrel provided with the fuel supply port and the oil discharge port can be moved up and down, and the lower end surface of the barrel is used as an inclined cam surface, and the inclined cam surface is rotated in accordance with the movement of the brake control rack. A technology has been disclosed in which a static injection timing is controlled by abutting a projection provided on an upper end surface of a pinion gear to change a prestroke by rotating a sliding barrel up and down by rotation of the pinion gear. .

[0003]

In the above-described fuel injection pump, a fuel control rack is inserted into a pump housing through an opening provided on a side portion, and a control link is connected from the outside. It is configured to be controlled. In this conventional configuration, the opening at the side of the pump housing is always open, and foreign matter mixed into the lubricating oil supplied by scattering enters the inside and slides the fuel control rack. There was a problem that caused obstacles.

[0004]

SUMMARY OF THE INVENTION The present invention takes the following technical means in order to solve the above-mentioned problems. That is, the pump housing 1 has a plunger 2 having a function of pumping fuel and a function of adjusting the amount of fuel.
The plunger 2 is connected to a fuel control rack 4 inserted through an opening 3 formed in a side portion of the pump housing 1 via a pinion member 5 so as to be controllable. The opening 3 is a fuel injection pump configured to prevent foreign matter from entering by a closing member 6 attached to the pump housing 1.

[0005]

The present invention has been configured as described above.
Prevents foreign matter from entering the pump housing,
The control operation (sliding) in the longitudinal direction of the fuel control rack is always kept smooth.

[0006]

Embodiments of the present invention will be described below. First, the injection pump 7 is shown in FIG.
As shown in FIG. 5 and FIG. 5, it is provided in a part of the engine body 10 to supply fuel to the engine.
The injection pump 7 is provided at an upper position of the pump housing 1 as shown in FIG. 6, and a camshaft 8 for driving the same is provided with a lower cam chamber 9.
It is configured with an interior shaft. And the fuel control
Lulac 4 is arranged above the cam chamber 9 so as to control the fuel injection amount of the injection pump 7.

[0007] As shown in FIG. 6, a cam gear 11 is provided on a gear case provided on the front side of the pump housing 1.
The camshaft 8 is extended in a space (see FIG. 10 showing another embodiment 1), and a governor weight 12 is provided by being axially mounted on the extension shaft 8a. And tension arm 1
3 and Floating Team 14 are slide peaks to be described later.
At the front side of the switch 17, the base is pivotally supported on the arm shaft 15, and the distal end is connected by a buffer mechanism (see FIG. 10) so that the control can be integrally rotated. As shown in FIG. 6, the control link 16 is formed by connecting the upper end of the flooring 14 to the fuel control rack 4 above the cam chamber 9. In this case, as shown in FIG. 3, the control link 16 is connected to a rack pin 18 which is fixed at an intermediate position of the fuel control rack 4 and protrudes outward.

As shown in FIG. 6, the governor weight 12 is provided with an extension shaft 8a provided on the front side of the cam gear 11.
The slide piece 17 slidably provided on the distal end side of the slidably moves back and forth by a centrifugal force that operates in association with a change in rotation speed. The flooring 14 is pressed by the operation of the slide piece 17 to rotate about the arm shaft 15 of the base portion as a fulcrum to push and pull the control link 16. When the rotation of the camshaft 8 is reduced and the governor weight 12 is centrifugally moved inward, the control link 16 operates in the direction of arrow A in FIG. As a result, the fuel control rack 4 is controlled and operated.

The tension arm 13 has a full-load stopper and a shock-absorbing mechanism of a gear case provided for restricting the operation of the distal end. This will be described in another embodiment 1 described later. Next, as shown in FIG. 3, the fuel control rack 4 is disposed inside the pump housing 1.
The pinion member 5 is locked so as to be movable in the longitudinal direction. As conventionally known, the mechanism for adjusting the amount of fuel injection relates to the rotation of the plunger 2 between the fuel supply port and the oil discharge port formed in the barrel and the lead provided on the outer surface of the plunger. The relative oil volume is adjusted by changing the relative relationship. In the case of the embodiment, the control mechanism of the fuel injection amount is such that when the control link 16 moves in the direction of arrow A in FIG. 6 and the fuel control rack 4 operates in the same direction, the amount of fuel increases. It is configured so that when operated in the opposite direction, the amount is reduced.

In other words, when the rotation of the camshaft 8 shown in FIG. 6 is accelerated, the fuel control rack 4 causes the slide piece 17, the floating gum 14, Control is performed on the fuel decreasing side (the direction of the opposite arrow A in FIG. 6) via the control link 16, and conversely, when the speed becomes low, each member operates in the opposite manner to increase the amount.

As shown in FIGS. 1 and 2, the fuel control rack 4 is inserted through an opening 3 provided on the side of the pump housing 1 and slidably mounted in the longitudinal direction. Control by rack pin 18
And is slid (controlled) in the longitudinal direction in connection with the lubrication link 16. Then, as shown in FIG. 2, the opening 3 is formed in a side portion (outer corner portion) of the pump housing 1.
The metal plate is bent and welded to form a closing member 6 so that foreign matter does not enter the inside from the outside.

As shown in FIGS. 7 and 8, the closing member 6 is formed by forming the closing member 6 made of a resin, inserted into the projection 19 of the pump housing 1, and mounted. 3 is closed. Further, as another configuration example, as shown in FIG.
The pump housing 1 is formed in a clip shape by being inserted into the projection 19 of the pump housing 1 and mounted to close the opening 3.

As described above, according to the present invention, since the opening 3 of the pump housing 1 is closed by the closing member 6 as described in the embodiment, it is possible to prevent foreign matter from entering the inside from the opening 3 beforehand. Can be prevented. Accordingly, the fuel control rack 4 operates smoothly and accurately controls the fuel injection amount without the problem that the foreign matter that has penetrated is clogged in the guide groove and causes a sliding obstacle as in the prior art. can do.

Another Embodiment 1 Next, another embodiment 1 will be described with reference to FIGS. Conventionally, this type of injection pump is configured to control the engine output while automatically adjusting the fuel injection amount by a governor mechanism. In the conventional configuration, the upper limit of the injected fuel is regulated by the full load stopper, and the injected fuel cannot be injected beyond a certain amount. Therefore, it is extremely difficult to use a working machine that requires a higher output of the engine. Was.

In order to solve the above-mentioned problems, another embodiment 1 has improved a full load stopper,
It is possible to adjust the upper limit of the fuel injection amount, and in some cases, exceptionally remove (eliminate) the upper limit. First, as shown in FIG. 10, the injection pump 30 is provided at an upper position of a pump housing 31, and a camshaft 32 for driving the pump is internally mounted on a lower cam chamber 33. I have. The fuel control rack 34 is arranged above the cam chamber 33 so as to control the fuel injection amount of the injection pump 30.

As shown in FIG. 10, the cam gear 35 extends the cam shaft 32 into a gear case 36 provided on the front side of the pump housing 31, and is mounted on an extension shaft 32a. , Governor weight 3 on the front side
7 is equipped. The tension arm 38 and the floating arm 39 are configured so that their bases are pivotally supported on an arm shaft 40 and their distal ends are connected by a buffer mechanism 41 so that the control can be rotated. That is,
The flooring 39 is formed by connecting a control link 42 having a leading end connected to the fuel control rack 34.

The tension arm 38 has a stopper receiving surface 42 formed at an upper portion thereof, and receives the stop lot 44 of the full load stopper 43. As shown in FIGS. 10 to 12, the full-load stopper 43 is provided with a solenoid 45 at the upper end to electromagnetically control the expansion and contraction of the stopper lot 44. In addition, the solenoid 45 has a conventionally known configuration that is operated by turning on and off a switch.

Further, the full load stopper 43 is provided as shown in FIG.
In the case of the embodiment shown in FIG. 2, the outer stopper 43a and the inner stopper lot 44 are double-structured, and the difference between them and the dimension "h" are used as a part for improving the output (only the width "h"). The upper limit has been relaxed.) As is well known in the art, the governor weight 37 is provided with an extension shaft 32 provided on the front side of the cam gear 35 as shown in FIG.
a slide piece 46 slidably provided on the tip side of
It is configured to slide back and forth by the action of the centrifugal force that operates in association with the change in the rotation speed. The flooring 39 is pressed by the operation of the slide piece 46 to rotate about the arm shaft 40 at the base as a fulcrum so that the control link 42 can be pushed and pulled to adjust. . When the rotation of the camshaft 32 decreases and the governor weight 37 moves inward due to the centrifugal force, the control link 42 slides the slide piece 4.
6. Floating arm 39 (tension arm 38)
10 to operate the fuel control rack 34 in the direction of arrow A in FIG.

The movement of the tension arm 38 is restricted by the stopper receiving surface 42 at the tip end receiving the stop lot 44 of the full load stopper 43, and the upper limit of the fuel injection amount is regulated. Chingua
The configuration is linked to the system 39. The fuel control rack 34 is configured to lock the pinion member and move in the longitudinal direction inside the pump housing 31 to adjust the fuel injection amount, as is conventionally known. I have. In the case of the embodiment, as described above, the control mechanism moves the control link 42 in the direction of the arrow A in FIG. 10 and operates the fuel control rack 34 in the same direction. And when operated in the opposite direction, the weight is reduced.

In the first embodiment configured as described above, when the work is performed with a working machine that requires an engine output higher than the conventional regulation value, the solenoid 45 is operated in advance by a switch operation to perform the work. Full load stopper 43
The stop lot 44 is shortened and moved upward from the stopper receiving surface 42 (see FIG. 11) to start the engine. Then, the tension arm 38 is retracted to the position where the stopper lot 44 pressing the stopper receiving surface 42 has escaped, so that the rotation of the fuel injection amount is increased, so that the engine output can be increased.

In this case, the full load stopper 43 may be set by the designer to set the upper limit position of the fuel supply amount or to set the fuel supply amount to the unlimited position. In another embodiment 1, the engine output shown in FIG. As shown in the characteristic graph, the output range (B zone) is higher than the conventional output range (A zone).
) Can be increased, and a work machine that requires a high output can be used.

[Brief description of the drawings]

FIG. 1 is a front view of a pump housing according to an embodiment of the present invention.

FIG. 2 is an embodiment of the present invention and is an internal plan view showing a main part.

FIG. 3 is an internal plan view of the embodiment of the present invention.

FIG. 4 is a plan view of the embodiment of the present invention.

FIG. 5 is a front view of the embodiment of the present invention.

FIG. 6 is a side view of the embodiment of the present invention.

FIG. 7 is an internal plan view showing another embodiment of the present invention.

FIG. 8 is a front view of FIG. 7, which is an embodiment of the present invention.

FIG. 9 is an internal plan view showing another embodiment of the present invention.

FIG. 10 is an internal side view of another embodiment 1 of the present invention.

FIG. 11 is another embodiment 1 of the present invention and is an operation diagram of main parts.

FIG. 12 is a cut-away side view of a full-load stopper, which is Embodiment 1 of the present invention.

FIG. 13 is a graph of output characteristics, which is another example 1 of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Pump housing 2 Plunger 3 Opening 4 Fuel control rack 5 Pinion member 6 Closing member 7 Injection pump 8 Camshaft 12 Governor weight 13 Tension arm 14 Flowing arm 16 Control link 17 Slide piece.

Claims (1)

[Claims] 1. A pump housing 1 is provided with a plunger 2 internally provided with a pumping function of sending out fuel and a function of adjusting the amount of fuel, and the plunger 2 is provided on a side portion of the pump housing 1. A fuel control rack 4 inserted from the formed opening 3 is connected so as to be controllable via a pinion member 5, and the opening 3 is penetrated by foreign substances by a closing member 6 attached to the pump housing 1. A fuel injection pump configured to prevent the fuel injection.