JP2816594B2 - Spill deflector mounting device for fuel injection pump - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a spill deflector mounting device in a fuel injection pump used for a diesel engine or the like.

<Prior Art> As is well known, this type of fuel injection pump supplies fuel to a plunger chamber through a suction / discharge port provided in a plunger barrel, and pressurizes the plunger to feed it from an injection nozzle. When the lead of the plunger communicates with the suction / discharge port, the pressure in the plunger chamber is reduced, and the injection is stopped. At the moment when the reed reaches the suction / discharge port, high-pressure fuel is ejected, so that the ejection energy is very large, which causes erosion due to cavitation in the pump body, the plunger barrel and the like. Therefore, by providing a plate-shaped spill deflector on the outer periphery of the suction / discharge port, or by inserting a plug-shaped spill deflector into the suction / discharge port,
It is common practice to prevent cavitation corrosion by preventing the jet flow from directly hitting the pump body or the like (for example, see Japanese Patent Publication No. 2-14989, Japanese Utility Model Application Laid-Open No. 50173/1990).

<Problems to be Solved by the Invention> In the case of the spill deflector mounting structure as described above, it is necessary to provide a hole, a fixing means, or a sealing means for mounting the spill deflector in the pump body. For this reason, there are problems that the man-hour required for the processing work of the pump body and the replacement work of the spill deflector become large, and that the pump body tends to become large, especially in a multi-cylinder fuel injection pump, so that the pump becomes large.

The present invention has been made in view of such a problem, and an object of the present invention is to provide a spill deflector mounting device which does not require processing of a pump body and allows easy replacement of a spill deflector.

<Means for Solving the Problems> In order to achieve the above object, according to the present invention, the mounting device includes an inner ring body fitted on the outer periphery of the plunger barrel, and an outer ring fitted on the outer periphery of the inner ring body. The spill deflector is inserted into a mounting hole provided in the inner ring corresponding to the suction and discharge port of the plunger barrel, and the tip of the spill deflector faces the suction and discharge port. The large-diameter base of the spill deflector is located in a fixing groove formed in at least one of the rings, and the base is held between the inner ring and the outer ring to hold the spill deflector.

<Operation> The spill deflector is attached by the inner ring and the outer ring fitted to the outer periphery of the plunger barrel without having to provide a mounting hole, a fixing means, a sealing means, and the like for the spill deflector in the pump body.

<Example> Next, one example shown in the drawings will be described. FIG. 1 is a sectional view of a mounting device with a spill deflector mounted, FIG. 2 is an exploded perspective view of the same, FIG. 3 is an exploded perspective view of a main part of a fuel injection pump in which the device of the embodiment is incorporated, and FIG. The figure is a sectional view of a main part of the pump. FIG. 4 shows two pump sections of the row type fuel injection pump in different cross sections.

First, the overall configuration of the fuel injection pump will be described with reference to FIG. 1 is a pump body, 2 is a plunger barrel, 3 is a plunger, 5 is a suction / discharge port provided on the plunger barrel 2, 6 is a lead provided on the plunger 3, 7 is a delivery valve, 8 is a delivery port, and 9 is a plunger 3. Plunger chamber formed on the upper surface of the camshaft, 10 is a camshaft, 11 is a cam mounted on the camshaft 10, 12 is a fuel rack, 13 is a fuel rack
It is a pinion that meshes with 12.

The fuel sucked into the plunger chamber 9 from the suction / discharge port 5 is pressurized by the plunger 3 that slides up and down by the cam 11, and is fed to the fuel injection valve (not shown) through the delivery valve 7 and the delivery port 8. When the plunger 3 moves up and the lead 6 communicates with the suction / discharge port 5, the pressurized pressure feeding is stopped.
The timing of this stop is adjusted by driving the fuel rack 12 by a control means (not shown) to rotate the plunger 3 and changing the effective stroke until the lead 6 communicates with the suction / discharge port 5. The basic configuration and operation described above are the same as those of the well-known fuel injection pump, and further description is omitted.

Next, a portion according to the present invention will be described with reference to other drawings. In the figure, 21 is an inner ring, 22 is an outer ring, and 23 is a spill deflector.

The inner ring 21 is fitted around the portion of the plunger barrel 2 where the suction / discharge port 5 is provided.
As shown in the figure, a suction hole 24 is provided symmetrically at an interval of 180 °, and a mounting hole 25 provided at a position shifted by 90 ° with respect to these holes, for example. Is formed with a circumferential groove 26 communicating between the holes 24 and 25. The mounting holes 25 are provided corresponding to the respective suction / discharge ports 5 of the plunger barrel 2, and the circumferential grooves 26 are formed in the plunger barrel 2.
A fuel gallery 28 communicating between the suction and discharge ports 5 is formed integrally with a circumferential groove 27 provided on the outer periphery of the fuel cell.

The outer ring 22 is fitted on the outer periphery of the inner ring 21 and includes suction and discharge holes 31 at positions corresponding to the respective suction and discharge holes 24 of the inner ring 21 as shown in FIG. Further, fixing grooves 32 are formed in the inner surface at positions corresponding to the respective mounting holes 25 in the axial direction.

Further, the spill deflector 23 has a shaft portion 35 inserted into the mounting hole 25 of the inner ring 21, a tip portion 36 facing the suction / discharge port 5 in a state of being inserted into the hole 25 and closing a part thereof, and a shaft portion. Inner ring 21 with both flanges with a diameter larger than 35 cut off
And a base 37 abutting the flat surface 21a on the outer periphery of the base. The shape and dimensions of the flat surface 21a and the fixing groove 32 are such that the base 37 of the spill deflector 23 is held between the inner ring 21 and the outer ring 22 when the outer ring 22 is fitted to the inner ring 21. It is selected as follows.

Reference numeral 41 denotes a barrel collar, in which a concave portion 42 is formed on the upper edge, and a convex portion 43 is formed on the lower edge of the inner ring body 21 corresponding to the concave portion 42. The inner ring 21 is positioned by combining the convex portion 43 with 42. Reference numeral 45 denotes a return spring of the plunger 3, and reference numeral 46 denotes a spring receiver thereof. The spring receiver 46 is fitted to a lower portion of the barrel collar 41.

In this embodiment, the inner ring 21 is fitted into the plunger barrel 2 by assembling the mounting hole 25 with the suction / discharge port 5 of the plunger barrel 2 during assembly.
The shaft 35 of the spill deflector 23 is inserted into the mounting hole 25. When the outer ring 22 is fitted to the inner ring 21 by aligning the fixing groove 32 with the mounting hole 25, the base 37 is sandwiched between the inner ring 21 and the outer ring 22 to fix the spill deflector 23. Therefore, in this state, the barrel collar 41 is fitted to the plunger barrel 2 and fixed to each other by the pins 47, and further, the spring receiver 46, the return spring 45 and the like are incorporated into the pump body 1.

As described above, in this embodiment, special processing for attaching the spill deflector 23 to the pump body 1 is unnecessary, and the members such as the inner ring 21, the spill deflector 23 and the outer ring 22 are arranged in a predetermined order. They can be incorporated by combining them.

By displacing the center of the spill deflector 23 with respect to the suction / discharge port 5 as shown in FIG. 1, it is possible to enhance the effect of reducing the ejection energy of the high-pressure fuel or the effect of preventing the generation of bubbles. Becomes possible. Also,
In the embodiment, the fixing groove 32 is formed in the outer ring 22, but it can be formed on the outer surface of the inner ring 21, on both sides, or by spilling on the outer surface of the inner ring 21. It is also possible to form a concave groove into which the base 37 of the deflector 23 fits and use this as a fixing groove. Further, in the embodiment, the fuel gallery 28 is divided into the circumferential groove 26 of the inner ring 21 and the circumferential groove of the plunger barrel 2.
27, but it can also be composed of only one of them.

<Effects of the Invention> As is apparent from the above description, the present invention spills an inner ring fitted on the outer periphery of a plunger barrel and an outer ring fitted on the outer periphery of the inner ring. A spill deflector is inserted into a mounting hole provided in the inner ring body so that the tip thereof faces the suction / discharge port, and a fixing groove formed between the inner ring body and the outer ring body is formed. The base of the spill deflector is located at a position between the inner ring and the outer ring to attach the spill deflector.

Therefore, it is not necessary to provide a mounting hole, a fixing means, a sealing means, and the like for the spill deflector in the pump main body, so that it is possible to reduce the number of processing steps of the pump main body, thereby reducing costs, and also facilitate replacement work of the spill deflector. . Further, since there is no need to provide mounting holes, fixing means, and the like in the pump main body, the pump main body can be downsized. In particular, if the present invention is applied to a multi-cylinder fuel injection pump, there is a great effect on downsizing of the pump.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a state in which a spill deflector according to one embodiment of the present invention is mounted, FIG. 2 is an exploded perspective view thereof, and FIG. 3 is an exploded perspective view of a main part of a fuel injection pump in which the device of the embodiment is incorporated. FIG. 4 is a sectional view of a main part of the pump. DESCRIPTION OF SYMBOLS 1 ... Pump body, 2 ... Plunger barrel, 3 ... Plunger, 5 ... Suction / discharge port, 6 ... Lead, 9 ... Plunger chamber, 21 ... Inner ring, 22 ... Outer ring, 23 ... ... Spill deflector, 24 ... Suction and discharge hole, 25 ... Mounting hole, 31 ... Suction and discharge hole, 32 ... Fixed groove, 35 ... Shaft, 36 ... Tip, 37 ...
…base.

Claims (1)

(57) [Claims] 1. An inner ring body fitted on the outer periphery of a plunger barrel, and an outer ring body fitted on the outer periphery of the inner ring body, the inner ring body corresponding to a suction / discharge port of the plunger barrel. Insert the spill deflector into the mounting hole provided in the spill deflector so that the tip faces the suction / discharge port, and insert the large-diameter base of the spill deflector into a fixing groove formed in at least one of the inner ring and the outer ring. A spill deflector mounting device for a fuel injection pump, wherein the spill deflector is held by sandwiching the base between the inner ring and the outer ring.