JP2000170616A - Fuel filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent corrosion from being generated on a body bottom part, by elastically supporting a filtering element without using a filtering supporting coil spring or a retainer causing corrosion of the body bottom part, in a fuel filter. SOLUTION: A deep pan-shaped elastic body 16 made of urethane foam and having a recessed part 16a at its central part is integrally mounted on the bottom part of a cup-shaped body 11 formed of a hot-dip galvanized steel plate. A cylindrical filtering element 13 is housed in the body 11, an projecting part 13e provided on a lower end plate 13c is fitted to the recessed part 16a of the elastic body 16 to support the element 13, a sheet plate 12 having an inlet through hole 12a and a boss part 12b and a cover plate 14 are superimposed and arranged on the releasing end of the body 11, and the peripheral edge of the cover plate 14 and the upper edge of the body 11 are caulked to close the body. No clearance through which foreign matter in fuel enters is formed between the bottom part of the body 11 and the elastic body 16 to prevent corrosion of the body bottom part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cartridge type fuel filter mainly used for a diesel engine.

[0002]

2. Description of the Related Art An example of a cartridge type (disposable type) fuel filter used in a diesel engine is shown in FIG. 4, which is a filter medium 3a in which filter paper or non-woven fabric is formed into a chrysanthemum flower shape or roll shape. Perforated inner cylinder 3 inside
b, the upper end of which is fitted with an annular upper end plate 3c, and the lower end of which is fitted with a dish-shaped lower end plate 3c, is accommodated in a cup-shaped body 1, The open end has a boss portion 2b screwed to a pipe Bp for removing purified fuel from the engine side bracket B, and has a plurality of inlet holes 2a around the boss portion 2b communicating with the inflow passage Ba of the bracket B. And a cover plate 4 on which an annular packing 5 made of a flexible rubber material and having a ball-shaped cross section is provided on the inner peripheral portion, and the peripheral edge of the cover plate 4 and the body 1 The upper edge is swaged, a lid-shaped annular retainer 6 is disposed on the bottom of the body 1, and a coil spring 7 is disposed between the retainer 6 and the lower end plate 3c. 3
Is pressed upward, and the flexible ring-shaped packing 8 fitted to the boss portion 2b of the sheet plate is pressed against the lower surface of the sheet plate 2 by the rising inner peripheral edge of the upper end plate 3c to seal the inside and outside of the filtration element 3. Has been made.

[0003] The components such as the body 1, the seat plate 2, the porous inner cylinder 3, the cover plate 4, and the coil spring 7 are plated with zinc (by electroplating to a film thickness of 5 to 5 mm).
(Approximately 8 μm), and an epoxy-based paint is applied to the outer surface of the body 1 and a lower portion of the inner surface (a portion where water contained in light oil as a processing fuel accumulates). The retainer 6, which is used to prevent the spring 7 from damaging the bottom of the body, is made of nylon-based synthetic resin or oil-resistant synthetic rubber.

[0004]

When the above filter is used, fuel (light oil) flows from the inflow passage Ba of the bracket B through the through hole 2a of the seat plate 2, and enters the periphery of the filter element 3 in the body 1. Is purified across the element 3 and gathers at the center to flow from the take-out pipe Bp to the injection pump side. However, in the above-mentioned conventional filter, the spring receiving retainer 6 has no fixed relation to the body 1 and can float. In such a state, a gap is easily formed between the body and the bottom of the body, and foreign matter (dust or metal powder generated in a fuel tank or a pipe) and contaminated moisture enter the gap. As a result, the paint film and the plating film on the bottom of the body are destroyed by the striking action of the retainer 6 due to the vibration of the engine and the pulsation based on the change in the pressure of the fuel, and the metal substrate is exposed. It occurs, which leads to fuel leakage.

In view of this, the present invention provides a filter element that is elastically supported to seal the inside and outside of the element without using a coil spring or a retainer that causes corrosion of the body bottom, and that the metal base on the body bottom is exposed. And to prevent corrosion.

[0006]

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the present invention provides a fuel filter comprising a foamed polyurethane formed at the bottom of a cup-shaped body made of a steel sheet surface-treated by hot-dip galvanizing, and a circular projection formed at the center. A deep dish-shaped elastic body with a recess surrounded by a strip is integrally attached, and a cylindrical filter medium made of filter paper or non-woven fabric, a porous inner cylinder, and a cylinder composed of upper and lower end plates are installed inside the body. Containing a filtration element,
The downward bulging portion provided on the lower end plate is fitted into the recess of the elastic body to support the filtering element by the elastic body, and the open end of the body has a boss at the center for removing the purified fuel. A sheet plate and a cover plate having a portion and having a plurality of entrance through-holes are arranged in an overlapping manner, and a peripheral edge of the cover plate is caulked to an upper edge of the body,
The packing is pressed between the boss portion of the sheet plate and the rising portion of the upper end plate to seal the filtration element.

[0007]

FIG. 1 shows an example of a fuel filter according to the present invention. Inside a cup-shaped body 11, a filter medium in which filter paper or non-woven fabric is formed in a chrysanthemum-shaped cylindrical or roll-like shape is shown. Insert a porous inner cylinder 13b inside 13a,
At its upper end, an annular upper end plate 13c having a rising portion 13d at the center is attached, and at the lower end, a dish-shaped lower end plate 13c having a downwardly bulging portion 13e at the center is attached. The opening end of the body 11 accommodates the element 13 and is provided with a boss portion 12b screwed to a pipe for taking out the purified fuel of the engine side bracket, and a plurality of entrance through holes 12a around the boss portion 12b communicating with the inflow passage of the bracket. A thick disk-shaped sheet plate 12 having an annular packing 15 having a ball-shaped cross section made of a flexible rubber material on an inner peripheral portion thereof.
A thin annular cover plate 14 on which the body 11 is mounted is superposed and arranged.
And crimp the upper edge.

A deep dish-shaped elastic body 16 made of closed-cell foamed polyurethane is provided on the bottom inner surface of the body 11 in a range where water in the fuel is collected (about 3 to 4 cm in height) in a predetermined use period. Are attached integrally as described later. The deep dish-shaped elastic body 16 has a thick central portion, and has a circular shape on the upper surface so as to match the shape of the central portion of the lower end plate 13c of the element. A recess 16a surrounded by the ridge 16b is provided, and a portion 1 around the circular ridge 16a is provided.
6c gradually becomes thinner and extends along the inner surface of the bottom of the body.

The filter element 13 housed in the body 11 is supported by a lower bulging portion 13e of the lower end plate 13c fitted into the recess 16b of the deep dish-like elastic body 16, and the upper end plate 1
The edge of the rising portion 13d of 3c presses the flexible rubber packing 17 fitted into the boss portion 12b of the sheet plate 12 between the boss portion 12b to seal the inside and outside of the element.

The body 11, which is a component of the fuel filter, is formed by drawing a steel plate having a relatively thick plating film (about 15 to 20 μm) and surface-treated by hot-dip galvanizing having excellent corrosion resistance. The other sheet plate 12, porous inner cylinder 13b, end plate 13c, cover plate 14 and the like are made of a steel plate or a steel material (with a film thickness of about 5 μm to 8 μm) surface-treated by electrogalvanizing.

A deep dish-shaped elastic body 16 for supporting the filter element 13 is mounted on the bottom of the body 11 as follows. That is, first, as shown in FIG. 2, a body 11 having a hot-dip galvanized inner and outer surface is disposed under a resin injector F, and isocyanate (liquid) is taken in from one inlet pipe Fa of the injector F. A mixed liquid of a polyol, a catalyst, and a blowing agent is taken in from the other inlet pipe Fb, and a predetermined amount of the mixed liquid M is injected from the nozzle Fn while mixing the two liquids in the cylinder.

Next, the body 11 is moved from the injection machine F to below the molding machine (not shown) as shown in FIG. 3, and the lower surface of the elastic body 16 has a projection Da for forming a recess and a circular projection for forming a ridge. An aluminum mold D having a groove portion Db and an arc-shaped portion Dc for forming a peripheral portion is inserted into the body 11 to a predetermined depth to lightly press the mixture M, and the mold D is heated to about 60 ° C. to 70 ° C. The mixture is reacted for a predetermined period of time (5 to 6 minutes) while heating the mixture, and the mixture reacts to form flexible urethane foam having closed cells. Thus, the mold D (wax, A mold release agent such as silicon is applied and can be easily separated from urethane.) By pulling up, a deep dish-shaped elastic body made of a non-breathable flexible foamed polyurethane is formed on the inner surface of the bottom of the body 11. 16 are integrally mounted.

Thus, the cylindrical filter element 13 is inserted into the body 11, and the downwardly bulging portion 13e of the lower end plate 13c is fitted and supported in the recess 16c of the elastic body 16,
On the upper side, the boss portion 1 is provided with a sheet plate 12 in which the cover plate 14 is integrated by projection welding.
The fuel filter is assembled by arranging 2b so as to enter the rising portion 13d of the element upper end plate 13c and caulking the peripheral edge of the cover plate 14 to the upper edge of the body 11. At this time, the packing 17 fitted to the boss portion 12b is connected to the boss portion 12b and the rising portion 1 of the upper end plate 13c.
3d and the element 13 is sealed.

The fuel filter is used by screwing the boss 12b of the seat plate 12 to the pipe for taking out the bracket on the engine side as described above, and the processing fuel flows from the inlet passage of the bracket to the inlet hole 12a of the seat plate 12. Through the filter element 13 and into the perimeter of the filter element 13 where it is purified by crossing the element 13 and gathers in the center,
The purified fuel flows out of the pipe for taking out the bracket. In this case, a deep dish-shaped flexible elastic body 16 is mounted on the bottom of the body 11, and the elastic body has a recess 16a.
Since the filter element 13 is directly supported by the elastic body 16 with the fitting relationship of fitting the downward bulging portion 13e of the lower end plate to the lower end plate, a gap is formed between the bottom part of the body 11 and the elastic body 16. There is no room for contaminants mixed in the fuel to enter, and there is no danger of exposing the metal base due to the tapping action of the retainer as before.
No corrosion at the bottom of the body.

[0015]

According to the present invention, as a fuel filter for a diesel engine, the fuel filter is constructed as described above. Therefore, a gap is formed between the bottom of the body and the elastic body supporting the filter element so that contaminants in the fuel can enter. And does not corrode the bottom of the body where water accumulates, without fear of destroying the plating layer on the bottom of the body and exposing the metal substrate. And
There is no need for anti-rust coating as post-processing on the inner and outer surfaces of the body, and the coil springs and retainers that support the filtration element as before can be omitted, and the number of parts is reduced, making it easier to manufacture. Have.

[Brief description of the drawings]

FIG. 1 is a sectional view of an example of a fuel filter according to the present invention.

FIG. 2 is an explanatory view of injecting an elastic body-forming resin into a body.

FIG. 3 is an explanatory view in which an elastic body is molded by a mold.

FIG. 4 is a sectional view of a conventional fuel filter.

[Description of Signs] 11 Body 12 Seat plate 12a Inlet through hole 12b Boss 13 Filtration element 13a Filter medium 13b Inner cylinder 13c Upper and lower end plates 13e Downward bulging part 14 Cover plate 16 Elastic body 16a Depression

Claims (1)

[Claims] 1. A deep dish-shaped elastic body made of foamed polyurethane and having a central portion surrounded by a circular ridge at the bottom of a cup-shaped body made of a steel sheet surface-treated by hot-dip galvanizing. And a cylindrical filter element made of filter paper or non-woven fabric, a porous inner cylinder, and a cylindrical filter element composed of upper and lower end plates are housed inside the body. Are fitted in the recesses of the elastic body, the filter element is supported by the elastic body, and the open end of the body has a boss at the center for removing the purified fuel and a plurality of inlets around the boss. A sheet plate having a through hole and a cover plate are arranged in an overlapping manner, the peripheral edge of the cover plate is caulked to the upper edge of the body, and the packing is pressed between the boss portion of the sheet plate and the rising portion of the upper end plate. Filter element A fuel filter characterized by being sealed.