US2886057A - Fuel injection filter system - Google Patents

Description

May 12, 1959 J. DOLZA ET AL 2,886057 FUEL INJECTION FILTER SYSTEM Filed June 12, 1957 IN V EN TORS HTTOlM/E) 2,886,057 3 FUEL nvrncrroiv FILTER SYSTEM 1 r John Dolza, Fenton, and WilliamH. Kolbe, Huntington Woods, Mich., assignors to General MotorszCorporation, Detroit, Mich., a corporation of Delaware Application June 12, 1957, sm ling. 665,299 b T 3 Claims. rel. 137-434) The present device relates to a filter system for a fiiel injection system of the type shown in copending applica- 2,886,057 Patented May 1 2, 1959,

. trolled lever 38 suitably pivoted at 48 to a bracket depending from cover 30. Thus as the fuel level in the reservoir varies the flow of fuel past the inlet valve 34 similarly varies in a well known manner.

The cover casing 30 is formed to provideacup -shaped receptacle 44 which projects ,within the fuel reservoir 14.

A filtering element 46 is disposed within the receptacle 44 and retained therewithin through a filter cover 48 which seats upon an upstanding wall 31 formed on cover 30. be

The fuel inlet passage 32 permits fuel to flow into the.

1 fuel receptacle 44 where it passes throughfilter 46 to flow tion Serial No. 608,853 Dolza, filed September 10,1956

and now Patent No. 2,843,098, issued July 15, 1958., ,I

In injection type fuel. systems fuel nozzles are utilized which incorporate extremely small orifices thereinl As a consequence such systems are extremely vulnerable to malfunctioning due to the fouling or blocking up of such orifices. The meteringvalve in such system is also very susceptible to fouling by impurities carried" by the fuel stream. i j j It is a further necessity in a fuel injection system to prevent dirt of a particle size larger than the end clearance of the metering pump from reaching the pump. Any such dirt particle is likely to become lodged between the gears and end plate in such a way as to increase the pump end clearance and thereby reduce the pumps volumetric efiiciency. Accordingly, great caremust be taken in a fuel injection system to provide suitable filtering means in advance of the points where impurities may impair the operation of a fuel injection system.

One of the most troublesome problems with such filtering systems has been the inability to provide filtering elements which may be removed or replaced without causing impurities to be set free in the system.

The present invention is directed to a filter device which provides satisfactory filtering of the fuel in the system and further which filter is capable of being removed from the system without danger of losing impurities therein. The present filter is of the cartridge type which is disposed in the fuel metering casing and easily accessible for removal purposes.

The details of the present invention as well as other objects and advantages are set forth in the description which follows. b i

The drawing relates to a fuel injection system embodying the subject filter device.

The fuel injection system as such constitutes no part of the present invention and functions in the same manner as described in the aforenoted copending application. In general, a fuel metering unit is shown at 10 and includes a casing 12 within which a fuel reservoir 14 is formed. An engine speed responsive pump 16 is submerged in the fuel reservoir 14 and supplies fuel under pressure to a conduit 18 leading to a fuel metering valve 20. Metering valve 20 is controlled by a diaphragm 22 suitably connected thereto through linkage 24 and which diaphragm is actuated in response to the mass of air flow through said system. Metered fuel from valve .20 is upwardly through a hollow portion50 thereof to com municate with apassage 52 in cover 48.; Passage 52 in turn communicates with a downwardly extending passage 54. -A chamber 56 is formed in reservoir cover 30 and. includes a secondary filter element 58 disposed therein. The chamber 56 communicates with the passage 36 lead-; ing to inlet valve 34. Thus, as the float controlled valve 34. is opened in response to a need for fuel in the reservoir, 14, fuel will flow through the inlet passage 32 into i the receptacle 44 through the filtering element 46 passing supplied to conduits 26 which terminate in nozzles 28 for delivery of fuel engine.

A casing 30 is adapted to. cover or enclose casing 12. A fuel inlet opening'32 is provided in cover casing 30. A fuel inlet valve 34 is slidably disposed in cover casing 30 and is adapted to coact. with a passage 36 to control the admission of fuel into the reservoir 14. The position of the fuel inlet valve 34 is controlled by a float conto the individual cylinders of the through passages 52 and 54 and secondaryfilter 58.

. The filter element 46 comprises acylindrical. filtering element 60 which is suitably connected, as by cementing, to an end plate 62.. Plate 62 is fixed to an upstruck por tion or boss 64 of a cup-shaped casing 66. The filter element 60 is thus supported within the casing 66 in spaced relation thereto. An upper end cap 68 is similarly fixed to the filtering element 60 and includes an upwardly extending neck portion 70 adapted to slide within a counterbore 72 of the filter cover 48.

The cup-shaped filter supporting casing 66 includes a radiallyextending flange 74 adapted to seat upon a gasketed annular shoulder 76formed internally of wall 31. A spring element 78 is adapted to seat against an annular seat 80 formed in cover 48 and bias upper end cap 68 downwardly causing the flange 74 of the casing 66 to sit tightly against shoulder 76.

With the filter 46 in position fuel will actually flow into be removed from casing 30 permitting the withdrawal of i the filter 60 and the integral sediment catching casing 66. In this Way the filter may be changed without any impurities being set free in the fuel system. Receptacle 44 provides a further safeguard against impurities entering reservoir 14 during the change of filters.

The secondary filter 58 'is intended to intercept any microscopic particles which may pass through filter element 60.

A conduit 80 communicates the metering valve 20 with a passage 82 in cover 30 to return bypassed fuel to the reservoir 14.

We claim:

1. A fuel injection system comprising a casing, a fuel reservoir formed in said casing, a cover for said casing, a fuel inlet passage disposed in said cover, a fuel inlet valve movably mounted in said cover, a float mechanism for controlling saidvalve mechanism in accordance with the fuel level within said reservoir, a receptacle formed in said cover, a filter device disposed in said receptacle, said device including a casing member supported upon said cover, a filtering element supported by said casing and projecting therewithin, a cover for said filtering element, said filter cover being adapted to be secured to said casingcover, said fuel inlet passage being adapted to deliver fuel within said filter casing whereby fuel will flow through said filtering element, passage means formed in said filter cover, said cover passage means communi- 3 eating with said inlet valve whereby the filtered fuel flowing through said filtering element is conveyed to said fuel inlet valve, and a secondary filter intermediate said cover passage means and said fuel inlet valve.

2. A fuel injection system comprising a casing, a fuel reservoir formed in said casing, a cover for said casing, a fuel inlet passage disposed in said cover, a fuel inlet valve movably mounted in said cover, a float mechanism for controlling said valve mechanism in accordance with the fuel level Within said reservoir, a receptacle formed in said cover and projecting within said reservoir, a filter device disposed in said receptacle, said device including a cup-shaped casing member, a flange on said member for supporting the member upon said cover, a filtering element supported in radially spaced relation within said cas ng, a cover having a counterbored portion for supporting said filtering element, said filter cover being adapted to be secured to said casing cover, said fuel inlet passage communicating with said filter device to deliver fuel Within said filter casing permitting fuel to flow through said filtering element, passage means formed in said filter cover, said cover passage means communicating with said inlet valve whereby the filtered fuel flowing through said filtering element is conveyed to said fuel inletvalve, and a secondary filter intermediate said cover passage means and said fuel inlet valve.

3. A fuel injection system comprising a casing, a fuel reservoir formed in said casing, a cover for said casing, a fuel inlet passage disposed in said cover, a fuel inlet t 4 valve movably mounted in said cover, a float mechanism for controlling said valve mechanism in accordance with the fuel level within said reservoir, a receptacle formed in said cover and projecting within said reservoir, a filter device disposed in said receptacle, said device including a cup-shaped casing member, a flange on said member for supporting the member upon said cover, a cylindrical filtering element supported in radially spaced relation within said casing, a cover having a counterhored portion for supporting said filtering element, a pair of end plates fixed to said element, one end plate being fixed to a boss centrally formed in the closed end of said cup-shaped casing, the other end cap including a longitudinally extending neck portion adapted to project within the cover counterbore, spring means seating on said filter cover and biasing said casing flange into engagement with the casing cover, said filter cover being adapted to be secured to said casing cover, said fuel inlet passage communicating with said filter device to deliver fuel within said filter casing permitting fuel to flow through said filtering element, passage means formed in said filter cover, said cover passage means communicating with said inlet valve whereby the filtered fuel flowing through said filtering element is conveyed to said fuel inlet valve.

References Cited in the file of this patent UNITED STATES PATENTS l,709,576 Hvoslef Apr. 16, 1929

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