JPS636454Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a distributed fuel injection device for a multi-cylinder internal combustion engine, and in particular, a pump mechanism that pumps fuel to be delivered to each cylinder, and a pump mechanism that pumps fuel that is pumped from this pump mechanism. The present invention relates to a distribution type fuel injection device including a pressure distribution mechanism that pressurizes and injects into each cylinder sequentially in synchronization with the rotation of an internal combustion engine.

In one conventional example of this type of distribution type fuel injection device, the pressurized distribution mechanism has fuel supplied thereinto from the pump mechanism via a valve means that opens and closes in synchronization with the rotation of the internal combustion engine. cylinder and
The engine includes a plunger that is provided within the cylinder and moves in synchronization with the rotation of the internal combustion engine. This plunger has holes that open at both ends of the plunger at the tip and side surfaces of the plunger inside the cylinder, and on the other hand, the side wall of the cylinder has a plurality of holes each communicating with the cylinder via a valve. The plunger is provided so that when the plunger rotates within the cylinder, the hole in the plunger is sequentially communicated with each cylinder through the plurality of holes in the cylinder side wall. The plunger also makes reciprocating motion within the cylinder in response to the rotation of the internal combustion engine, and its forward movement, that is, the movement that reduces the fuel volume within the cylinder, causes the hole in the plunger and the plunger to The fuel in the cylinder is forced out of the cylinder and injected into the cylinder through a hole in the cylinder side wall that communicates with the hole in the cylinder and the above-mentioned valve.

In this conventional distribution type fuel injection device, foreign particles such as minute fragments of the members constituting the pump mechanism may get mixed into the fuel and reach the fuel pressurization distribution mechanism including the plunger and cylinder described above from the pump mechanism. However, there was a drawback that such foreign particles accelerated the wear of members such as the plunger and cylinder.

Therefore, an object of the present invention is to provide a distributed fuel injection system configured to prevent foreign particles from reaching the plunger, cylinder, valves, etc. located downstream thereof, which have a fairly wide friction surface, from the pump means. The purpose is to provide equipment.

For this purpose, in the distribution type fuel injection device of the present invention, a filtering means is provided in the fuel feed path from the pump mechanism to the pressure distribution mechanism including the plunger and cylinder.

Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a cross section of a pressure distribution mechanism of a distribution type fuel injection device which is an embodiment of the present invention. This pressure distribution mechanism includes a cylindrical cylinder 10,
The plunger 12 has a cylindrical shape and is engaged with a shaft hole having a circular cross section of the cylinder. The cylinder 10 is fitted into a through hole 16 of a member 14 forming a housing of the fuel injection device. A closing member 18 is screwed into the outer end of the through hole 16.
An O-ring seal 20 is provided in an annular groove formed on the circumferential side of the closing member 18 and the O-ring seal 20.
The ring seal 20 closes the outer end of the through hole 16 in a liquid-tight manner. A hole 22 that communicates between the inside and outside of the cylinder 10 is formed in a portion of the cylinder 10 near the closing member 18, and through this hole 22 and a hole 24 of the member 14, a Internal combustion engine cylinders (not shown)
Fuel is fed into the cylinder 10 from a pump mechanism P (not shown) that pumps fuel to be fed to the cylinder 10 .

The plunger 12 has a hole 26 extending along its central axis from its distal end facing the closing member 18, and the hole 26 has an opening 28 on the circumferential side of the plunger 12. A plurality of grooves 30 (only one shown) are provided on the circumferential side of the tip of the plunger 12, spaced apart from each other in the circumferential direction and extending in the longitudinal direction of the plunger 12, respectively. On the other hand, in the side wall of the cylinder 10, holes 3 having the same number as the grooves 30 and similarly spaced apart from each other in the circumferential direction so as to communicate the inside and outside of the cylinder 10 at an axial position that can communicate with the hole 26 of the plunger.
2 (only one shown) is provided. The members 14 each communicate with the bore 32 of the cylinder 10.
The holes 34 (only one is shown) formed in the cylinders communicate with the cylinders of the internal combustion engine through valves V (not shown), respectively.

Since the configuration of the above-described distributed fuel injection device is well known, its operation will only be briefly described.
That is, the plunger 12 repeats reciprocating motion and rotational motion in synchronization with the rotation of the internal combustion engine, and increases the volume of the high pressure chamber 36 defined by the cylinder 10 and the plunger 12 when moving straight in the direction of arrow R. This allows fuel to flow from the pump mechanism P into the high pressure chamber 36 via the hole 22 of the cylinder 10 and the groove 30 of the plunger 12. The plunger 12 is then rotated and moved straight in the direction of arrow F to reduce the volume of the high pressure chamber 36 and open the holes 26, 2 of the plunger 12.
8. Fuel in the high pressure chamber 36 is injected into the cylinder via the hole 34 of the member 14 and the valve V.

A solenoid valve S is provided in a fuel supply path between a pressure distribution mechanism consisting of a cylinder 10 and a plunger 12 and a pump mechanism P. This electromagnetic valve is energized to open the fuel supply passage when the ignition switch is in a conductive state, and closes the fuel supply passage when it is in a non-conductive state.

As already mentioned, in order to prevent foreign particles from getting into the fuel from a member having a friction surface of the pump mechanism P and reaching the pressurizing distribution mechanism consisting of the cylinder 10 and the plunger 12, the fuel injection according to the present invention is used. A filtration device 38 is provided in the device. The filter device 38 is fixed to the member 14 by a solenoid valve S. The filtration device 38 includes a cylindrical member 42 disposed in the hole 24 of the member 14 so as to surround the valve body 40 of the solenoid valve S, and a cylindrical member 42 disposed in the hole 24 of the member 14 so as to surround the valve body 40 of the solenoid valve S, and a cylindrical member 42 disposed in the hole 24 of the cylindrical member 42 so as to cover the opening 44 on the side surface of the cylindrical member 42. The fuel flows into the inside of the cylindrical member 42 through the opening 44 on the side of the cylindrical member 42 through the mesh member 46 and exits the cylindrical member 42 through the opening 48 on the bottom. It's starting to leak out. Valve body 4
0 is movable in parallel to the central axis of the cylindrical member 42, and the valve seat that cooperates with this valve body is the cylindrical member 42.
The hole 24 is defined at the periphery of the opening 48 at the bottom of the member 14 or in the vicinity of the opening 48 of the member 14.

As mentioned above, in the distribution type fuel injection device according to the present invention, since a filtration device is provided in the fuel supply path between the pump mechanism and the pressurized distribution mechanism, even if debris from friction points of the pump mechanism is The filtration device removes such foreign matter even if it gets mixed in with the pressure distribution mechanism, so foreign matter will not enter the pressurized distribution mechanism and wear out its cylinder, plunger, and valves downstream from these components. .
Therefore, according to the present invention, the life of the distributed fuel injection device is extended and the reliability is improved.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of a pressurizing distribution mechanism of a distribution type fuel injection device which is an embodiment of the present invention, Fig. 2 is a front view of a filtration device used in the device of Fig. 1, and Fig. 3 is a perspective view of the filtration device. Explanation of symbols of main parts, 10...Cylinder, 1
2... Plunger, 38... Filtration device, 46...
...Mesh member, S... Solenoid valve.

Claims (1)

[Scope of utility model registration request] a pump mechanism that pumps fuel to be fed to the cylinders of an internal combustion engine having a plurality of cylinders; and a pump mechanism that pressurizes the fuel pumped from the pump mechanism in synchronization with the rotation of the internal combustion engine to sequentially feed the fuel to the plurality of cylinders. a pressurizing distribution mechanism that periodically injects fuel; a member forming a fuel feed path from the pump mechanism to the pressurizing distribution mechanism; a filtering means provided in the fuel feeding path; and a valve means for keeping the fuel feed passage closed when the ignition switch is in a non-conducting state, the filtering means is configured to pass through the interior through an opening formed in a side surface. a cylindrical member disposed in the fuel feed passage so that the fuel flows to one end opened in the axial direction; and a filterable member fixed to the inner surface of the cylindrical member so as to cover the opening in the side surface. The cylindrical member is fixed to the member forming the fuel feed path by the valve means, and the valve body of the valve means is housed inside the cylindrical member. Distributed fuel injection system for multi-cylinder internal combustion engines.