CN114382622A - Double-stage filtering fuel filter - Google Patents

Abstract

The invention discloses a two-stage fuel filtering filter, wherein a filter element assembly is inserted in a shell assembly, the lower end part of the shell assembly is connected with a water collecting cup assembly, and a shell main body of the shell assembly is provided with an oil inlet and an oil outlet; the filter element assembly comprises a coarse filtering part and a fine filtering part which are arranged in a stacking mode, the coarse filtering layer of the coarse filtering part is connected with the fine filtering layer of the fine filtering part through a middle end cover, the upper portion of the middle end cover is covered at the bottom of the fine filtering layer, a middle through hole is formed in the lower portion of the middle end cover, and a flow passage communicated with the middle through hole and the fine filtering dirty side is arranged in the middle of the middle end cover. The coarse filter layer and the fine filter layer of the filter element assembly are connected through the same middle end cover, so that the arrangement of a matching structure is reduced, the structure is simplified, and the requirements on the machining precision and the assembling precision of each part are lowered. The rough filtering part is combined with a clean side double-stage water separating structure through a dirty side water separating structure to realize water separating and filtering, the water separating efficiency is high, water is separated and filtered more thoroughly, and cleaner fuel oil is provided for an engine.

Description

Double-stage filtering fuel filter

Technical Field

The invention relates to the technical field of engine fuel filters, in particular to a double-stage filtering fuel filter.

Background

The fuel filter is connected in series in the engine fuel system and used for filtering impurities and water in the fuel and then providing clean fuel for the fuel delivery pump and the high-pressure common rail system, so that the impurities and the water are prevented from being worn and corroded to precision parts in the engine fuel system, and the normal work of the engine is ensured.

In order to meet the requirements of the sixth country, a commercial vehicle usually adopts a fuel filter with double-stage filtration, a filter element assembly of the fuel filter comprises a coarse filtration assembly and a fine filtration assembly which are arranged in series, and the existing double-stage filtration fuel filter has the following defects:

(1) the structure of the rough filtering assembly and the fine filtering assembly is basically the same, the filtering layer is sleeved on the periphery of the central net pipe, the upper end part and the lower end part of the filtering layer are respectively provided with an upper end cover and a lower end cover, the rough filtering assembly and the fine filtering assembly are connected in series through connecting pieces, the filter element assembly comprises more parts and has higher cost, the whole structure is not compact enough, the volume is relatively larger, and the filter element assembly is heavier; and the matching structures are required to be independently arranged between the filter layer of the coarse filter assembly and the upper end cover thereof, between the filter layer of the fine filter assembly and the lower end cover thereof, between the upper end cover of the coarse filter assembly and the connecting part, and between the lower end cover of the fine filter assembly and the connecting part, so that the requirements on the processing precision of each part and the assembly precision of the three parts are high.

(2) The existing coarse filtering assembly usually only relies on a water repelling net to separate water in fuel oil, and the water separation efficiency is relatively low.

(3) The existing filter assembly with the hand pump is generally formed by connecting a base with the hand pump and a fuel filter, when fuel flows, larger particle impurities in the fuel can be possibly adhered to a one-way valve in the base with the hand pump, so that the base hand pump fails, and the fuel cannot be pumped; and the filter assembly with the hand pump base used in the market has a complex structure, wastes time and labor when cleaning particle impurities, and cannot timely treat the particle impurities.

(4) The water collecting cup of the existing fuel filter usually only has one water collecting cavity, water filtered from the dirty side and the clean side of the filter element assembly is collected into the same water collecting cavity, and oil and water collected from the dirty side easily causes secondary pollution to subsequent fuel oil, so that the filtering burden of the filter element assembly is increased, the filtering efficiency is reduced, and the service life of the fuel filter is also shortened.

Disclosure of Invention

The applicant aims at the defects of the existing double-stage filtering fuel filter, and provides a double-stage filtering fuel filter with a reasonable structure, so that the use of parts is reduced, the cost is reduced, the structure is more compact, and the water separation function is not attenuated in the whole service life.

The technical scheme adopted by the invention is as follows:

a fuel filter with double-stage filtration comprises a shell assembly, a filter element assembly is inserted in the shell assembly, the lower end part of the shell assembly is connected with a water collecting cup assembly, and a shell main body of the shell assembly is provided with an oil inlet and an oil outlet; the filter element assembly comprises a coarse filtering part and a fine filtering part which are arranged in a stacked mode, wherein the outer side of the coarse filtering part is a coarse filtering dirty side, and the center of the coarse filtering part is a coarse filtering clean side; the outer side of the fine filtering part is a fine filtering dirty side, the center of the fine filtering part is a fine filtering clean side, the coarse filtering dirty side is communicated with the oil inlet, and the fine filtering clean side is communicated with the oil outlet; the coarse filtering layer of the coarse filtering part is connected with the fine filtering layer of the fine filtering part through a middle end cover, and the middle end cover isolates the coarse filtering part from the fine filtering part; the upper part of the middle end cover is covered at the bottom of the fine filtration layer in a sealing manner, the lower part of the middle end cover is provided with a middle through hole communicated with the coarse filtration side, and the middle part of the middle end cover is provided with a flow passage communicated with the middle through hole and the fine filtration dirty side.

As a further improvement of the above technical solution:

the rough filtering part of the filter element assembly comprises a rough filtering layer, a central net pipe and a water collecting cylinder, wherein the rough filtering layer is sleeved on the periphery of the central net pipe, a water repellent net is nested on the central net pipe, the water collecting cylinder is inserted between the rough filtering layer and the central net pipe, and an annular cavity between the water collecting cylinder and the water repellent net forms a water repellent cavity; the outer surface of the rough filtering layer is coated with a water repellent coating; the lower end part of the coarse filtration layer is provided with a lower end cover, the center of the lower end cover is provided with a lower through hole, and the lower through hole is communicated with the drainage cavity; the fine filtering part of the filter element assembly comprises a fine filtering layer, an upper end cover is fixedly bonded at the upper end part of the fine filtering layer, an upper through hole is formed in the center of the upper end cover, and the upper through hole is communicated with the fine filtering side; the periphery of the middle lower part of the fine filtering layer is sleeved with a cover cylinder.

The middle end cover comprises an upper cover plate part, a lower cover plate part and a plurality of connecting ribs which are integrally formed, the connecting ribs are vertically arranged between the upper cover plate part and the lower cover plate part, and an overflowing channel is formed between the adjacent connecting ribs; the upper cover plate part is covered at the lower end part of the fine filtering layer and is provided with a closed bottom surface; the lower cover plate part is covered on the upper end part of the rough filtering layer, and a middle through hole is formed in the center of the lower cover plate part.

The middle end cover comprises an upper cover plate and a lower cover plate which are designed in a split mode, the upper cover plate and the lower cover plate are connected through a clamping structure, a plurality of transverse ribs are arranged between the upper cover plate and the lower cover plate, an overflowing channel is formed between every two adjacent transverse ribs, and a middle through hole is formed in the center of the lower cover plate; the upper cover plate is covered at the lower end part of the fine filtering layer, and the lower cover plate is covered at the upper end part of the coarse filtering layer.

The middle part of the inner side of the shell main body is vertically provided with an outer cylinder, and the outer cylinder extends into the fine filtration side and is supported at the inner side of the fine filtration layer; the outer cylinder and the upper end cover are in interference fit to form an interference sealing surface.

The inner side of the shell main body is also vertically provided with an inner cylinder which is positioned at the inner side of the outer cylinder; the valve ball is placed in the valve seat and can form one-way valve seal with the valve seat, the push-pull rod is inserted in the center of the inner cylinder, the valve frame and the valve block are fixed at the lower end part of the push-pull rod, and the valve block is sealed and covered at the upper side of the valve frame; the upper end part of the push-pull rod penetrates out of the shell main body, and the hand grab handle is fixed at the upper end part of the push-pull rod.

The upper end part of the inner cylinder is provided with a convex part which extends out of the oil outlet; the lower end part of the inner cylinder is provided with a plurality of guide ribs.

A nested piece is arranged in the through hole of the shell main body, a plurality of reinforcing ribs are arranged on the outer peripheral surface of the lower end part of the nested piece, and an upper second sealing ring and a lower second sealing ring are arranged between the nested piece and the push-pull rod; the inner side surface of the grab handle is provided with a first sealing ring, and the first sealing ring is opposite to the upper side of the matching surface of the nesting piece and the push-pull rod; the lower end part of the push-pull rod is provided with a large-diameter part, the upper end face of the large-diameter part is a limiting face, and the height of the large-diameter part is equal to or larger than the vertical distance between the upper end face of the protruding part of the inner cylinder and the lower end face of the nesting piece.

A separating ring is arranged in a cup body of the water collecting cup assembly, the separating ring separates a cavity body in the cup body into a clean side water collecting cavity and a dirty side water collecting cavity, the clean side water collecting cavity is communicated with a drainage cavity in a rough filtering part of the filter element assembly, and the dirty side water collecting cavity is communicated with a rough filtering dirty side outside the rough filtering part.

A drain hole is formed in the bottom surface of the cup body, the upper portion of the drain hole is divided into a clean side hole and a dirty side hole by a separating ring, the lower portion of the drain hole is an insertion hole portion, a water drainage screw sleeve is connected in the insertion hole portion, a sealing gasket is sleeved at the upper end of the water drainage screw sleeve, and a drain valve is sleeved on the periphery of the water drainage screw sleeve; a water guide groove is transversely formed in the inner side of the bottom surface of the water collecting cavity corresponding to the clean side on the cup body and is communicated with the clean side hole; a plurality of drainage channels are arranged on the drainage screw sleeve; the sealing gasket is provided with an axial sealing surface and a radial sealing ring.

The invention has the following beneficial effects:

the coarse filter layer and the fine filter layer of the filter element assembly are connected through the same middle end cover, and the matching precision between the coarse filter layer and the middle end cover and between the fine filter layer and the middle end cover only needs to be ensured, so that the arrangement of matching structures is reduced, the structure is simplified, and the requirements on the processing precision and the assembly precision of each part are lowered. The water repellent coating on the outer surface of the rough filtering layer forms a water separation structure on the rough filtering dirty side, and most of water particles in the fuel oil on the rough filtering dirty side are intercepted and filtered, so that water separation and filtration on the rough filtering dirty side are realized; the water collecting cylinder and the water repellent net form a two-stage water separating structure at the rough filtering side, the water collecting cylinder intercepts water particles passing through a rough filtering layer and coalesces the water particles into large-particle water drops which slide downwards, and the water repellent net further intercepts and filters a small amount of water particles driven by the flowing inertia of fuel oil to realize the water separating and filtering at the rough filtering side; the rough filtering part is combined with a clean side double-stage water separating structure through a dirty side water separating structure to realize water separating and filtering, the water separating efficiency is high, water is separated and filtered more thoroughly, and cleaner fuel oil is provided for an engine. The cover cylinder at the middle lower part of the fine filtering layer can force the fuel liquid level to climb and cross the upper port of the cover cylinder before reaching the fine filtering layer, so that the fuel oil level is always stably kept above the upper port of the cover cylinder, and the stability of the oil level is ensured; in addition, corresponding customer information, product information and the like can be printed on the outer surface of the cover cylinder, and the advertising effect is achieved.

The outer cylinder of the shell assembly is inserted in the center of the fine filter layer and can support the fine filter layer to prevent the fine filter layer from collapsing, and the outer cylinder is integrally formed on the shell main body and replaces a traditional central net support piece to support the fine filter layer, so that the use of the support piece is reduced, the cost of parts is reduced, the structure of the fine filter part is simplified, and the filter element assembly is more compact in integral structure, smaller in volume and lighter. The outer wall surface of the outer barrel and the upper end cover are sealed through the interference sealing surface, the interference sealing surface replaces the traditional sealing element to seal, the use of the sealing element is reduced, and the cost of parts is reduced. The bulge of the inner cylinder vertically extends out of the oil outlet, so that the space of the oil outlet can be reasonably and effectively utilized, the effective stroke cavity of the push-pull rod is increased as much as possible in the limited design space, and the oil pumping efficiency of the hand pump assembly is improved. The guide ribs at the lower end part of the inner cylinder enable the valve frame to move on the central axis of the inner cylinder all the time, and abnormal abrasion of the push-pull rod caused by shaking of the valve frame is avoided. An upper second sealing ring and a lower second sealing ring are arranged between the nesting piece and the push-pull rod, so that the sealing reliability and the product stability are improved. Half and the contact of shell main part, half and the nested contact of the first sealing washer of grab handle medial surface can seal the fitting surface of shell main part and nested, prevent to reveal the realization because of nested and the not hard up product that causes of shell main part life-span fatigue, improved the sealed reliability and the stability of product. The limiting surface of the large-diameter part of the push-pull rod limits the maximum stroke of the push-pull rod, so that abnormal abrasion of the valve plate caused by direct collision of the valve plate with the embedded part is avoided, the valve frame and the valve plate are still kept in the inner cylinder after the push-pull rod is lifted to the highest position, and the valve plate is prevented from sliding out of the inner cylinder to cause abnormal abrasion of the valve plate. The rib plate of the valve frame can improve the supporting strength of the valve frame and prevent the valve frame from collapsing. The external hexagonal mounting posts of the valve seat facilitate mounting of the valve seat to the housing body with the aid of an auxiliary tool.

According to the water collecting cup assembly, the cup body is separated into the two water collecting cavities through the separating ring, the water collecting cavity on the clean side only collects water on the clean side, the water collecting cavity on the dirty side only collects water on the dirty side, the water in the two water collecting cavities are not interfered with each other, secondary pollution of oil water on the dirty side to subsequent fuel oil is prevented, the filtering burden of the filter element assembly is reduced, the filtering efficiency is improved, and the service life of the fuel oil filter is prolonged. The water in the clean side water collecting cavity and the water in the dirty side water collecting cavity are collected to the lower part of the water discharging hole together and discharged through the same water discharging threaded sleeve and the water discharging valve, so that the water in the two water collecting cavities is discharged simultaneously by using one water discharging valve, the use of parts is reduced, the cost of the parts is reduced, the structure of the water collecting cup assembly is simplified, and the whole structure is more compact and light. The guiding gutter can lead the water in the clean side water collecting cavity to the clean side hole, and is favorable for thoroughly discharging the water in the clean side water collecting cavity. The water discharging threaded sleeve simultaneously realizes axial sealing and radial sealing through a sealing gasket, so that the sealing is more reliable, and the leakage risk of the product is lower. The lower end cover of the filter element assembly and the separating ring are sealed through the interference sealing surface, the interference sealing surface replaces the traditional sealing element to seal, the use of the sealing element is reduced, and the cost of parts is reduced. The convex ribs and the concave ribs of the cup body can improve the strength of the cup body.

Drawings

Fig. 1 is a perspective view of the present invention.

Fig. 2 is a cross-sectional view of the present invention.

Fig. 3 is a perspective view of the cartridge assembly.

Fig. 4 is a cross-sectional view of the cartridge assembly.

Fig. 5 is a perspective view of one embodiment of a center cap.

Fig. 6 is an exploded view of another embodiment of the middle cap.

Fig. 7 is a perspective cutaway view of another embodiment of the middle end cap.

FIG. 8 is a perspective cutaway view of the housing assembly.

Fig. 9 is a perspective view of the valve seat.

Fig. 10 is a perspective view of the valve frame.

FIG. 11 is a perspective view of a nest.

Fig. 12 is a perspective view of the water collection cup assembly.

FIG. 13 is a cross-sectional view of the water collection cup assembly.

Fig. 14 is an enlarged view of a portion a in fig. 13.

Fig. 15 is a perspective view of the water discharging screw sleeve.

Fig. 16 is a schematic view of the working principle of the fuel oil of the present invention.

Fig. 17 is a schematic view of the exhaust operation of the present invention, wherein the push-pull rod of the hand pump assembly is pulled up.

Fig. 18 is a schematic view of the exhaust operation of the present invention, wherein the push-pull rod of the hand pump assembly is depressed.

In the figure: 1. a housing assembly; 11. a housing main body; 12. an oil inlet; 13. an oil outlet; 14. an inner barrel; 141. a projection; 142. a guide rib; 15. an outer cylinder; 151. an oil passing channel; 16. a hand pump assembly; 161. a valve seat; 1611. mounting a column; 162. a valve ball; 163. a push-pull rod; 1631. a large diameter part; 1632. a limiting surface; 164. a valve frame; 1641. an oil passing hole; 1642. a rib plate; 165. a valve plate; 166. a grab handle; 167. a first seal ring; 17. nesting; 171. reinforcing ribs; 172. a second seal ring; 18. limiting ribs; 19. an exhaust valve;

2. a filter element assembly; 10. a coarse filtration part; 20. a fine filtering part; 21. a coarse filtration layer; 22. a fine filtering layer; 23. an upper end cover; 231. an upper through hole; 232. a first convex ring; 24. a middle end cover; 241. an upper cover plate portion; 242. a lower cover plate portion; 2421. a middle through hole; 243. connecting ribs; 244. an overflow channel; 245. an upper cover plate; 2451. a hook; 2452. transverse ribs; 246. a lower cover plate; 2461. a middle through hole; 2462. an axial convex ring; 25. a lower end cover; 251. a lower through hole; 252. a second convex ring; 26. a central network management; 261. water passing holes; 27. a water repellent net; 28. a water collecting cylinder; 29. a cover cylinder;

3. a water collection cup assembly; 31. a cup body; 311. a rib is protruded; 312. concave ribs; 32. a spacer ring; 33. a clean side water collection cavity; 34. a dirty side water collection chamber; 35. a drain hole; 351. a side hole is cleaned; 352. a side dirty hole; 353. an insertion hole portion; 354. a step surface; 36. a water chute; 37. a water discharging screw sleeve; 371. a water discharge tank; 38. a gasket; 381. an axial sealing surface; 382. a radial seal ring; 39. a drain valve;

100. coarse filtering dirty side; 200. coarse filtering and cleaning the side; 300. finely filtering the dirty side; 400. finely filtering the side; 500. a hydrophobic cavity.

Detailed Description

The following describes embodiments of the present invention with reference to the drawings.

As shown in fig. 1 and 2, the fuel filter with double-stage filtration according to the present invention includes a housing assembly 1, a filter element assembly 2 and a water collecting cup assembly 3, wherein the filter element assembly 2 is inserted into an inner cavity of the housing assembly 1, and the water collecting cup assembly 3 is fixed at a lower end of the housing assembly 1 by a threaded connection.

As shown in fig. 3 and 4, the filter element assembly 2 is a dual-stage filter element, and includes a coarse filter part 10 and a fine filter part 20 which are stacked from bottom to top; the outer side of the coarse filtering layer 21 of the coarse filtering part 10 is a coarse filtering dirty side 100, and the center of the coarse filtering layer 21 is a coarse filtering clean side 200; the outer side of the fine filter layer 22 of the fine filter part 20 is a fine filth filter side 300, and the center of the fine filter layer 22 is a fine filth filter side 400.

As shown in fig. 4, the coarse filter part 10 of the filter element assembly 2 comprises a coarse filter layer 21, a central mesh tube 26 and a water collecting cylinder 28; the coarse filter layer 21 is sleeved on the periphery of the central mesh pipe 26, the water repellent net 27 is nested on the circumferential surface of the central mesh pipe 26, the water collecting cylinder 28 is inserted between the coarse filter layer 21 and the central mesh pipe 26, the water collecting cylinder 28 is a cylindrical cotton cylinder, and an annular cavity between the water collecting cylinder 28 and the water repellent net 27 forms a hydrophobic cavity 500; the outer surface of the coarse filter layer 21 is coated with a layer of water repellent paint; the water repellent paint on the outer surface of the coarse filtering layer 21 forms a water separation structure of the coarse filtering dirty side 100, and most of water particles in the fuel oil on the coarse filtering dirty side 100 are intercepted and filtered, so that water separation and filtration of the coarse filtering dirty side 100 are realized; the water collecting cylinder 28 and the water repellent net 27 form a double-stage water separating structure of the rough filtering side 200, water particles passing through the rough filtering layer 21 are intercepted by the water collecting cylinder 28 and coalesced into large-particle water drops which slide downwards, and a small amount of water particles driven by the flowing inertia of fuel oil are further intercepted and filtered by the water repellent net 27, so that the rough filtering side 200 is separated from water and filtered; the rough filtering part 10 combines the dirty side water separating structure and the clean side double-stage water separating structure to realize water separation and filtration, the water separation efficiency is high, the water is separated and filtered more thoroughly, and cleaner fuel oil is provided for an engine. The top surface of the central net pipe 26 is open, the middle part of the bottom surface is blocked at the bottom of the rough filtering side 200, and the outer side part of the bottom surface of the central net pipe 26 is provided with a plurality of water through holes 261 communicated with the drainage cavity 500. The lower end part of the coarse filtration layer 21 is fixedly bonded with a lower end cover 25, the center of the lower end cover 25 is provided with a lower through hole 251, and the lower through hole 251 is communicated with the drainage cavity 500; the lower outer circumferential surface of the lower end cover 25 is provided with a plurality of second convex rings 252 which are protruded outwards along the radial direction.

As shown in fig. 4, the fine filtering part 20 of the filter element assembly 2 comprises a fine filtering layer 22, an upper end cover 23 is fixedly bonded to the upper end of the fine filtering layer 22, an upper through hole 231 is formed in the center of the upper end cover 23, and the upper through hole 231 is communicated with the fine filtering side 400; the inner circumferential surface of the upper through hole 231 is protruded radially inward with a plurality of first protruding rings 232. As shown in fig. 3 and 4, a cover cylinder 29 is sleeved on the periphery of the middle lower part of the fine filter layer 22, the cover cylinder 29 is a paper sleeve, the cover cylinder 29 can force the fuel liquid level to climb over the upper port of the cover cylinder 29 and then reach the fine filter layer 22, so that the fuel oil level is always stably kept above the upper port of the cover cylinder 29, and the stability of the oil level is ensured; in addition, corresponding customer information, product information and the like can be printed on the outer surface of the cover cylinder 29, and the advertising effect can be achieved.

As shown in fig. 3 and 4, the upper end of the coarse filter layer 21 of the coarse filter part 10 of the filter element assembly 2 is connected with the lower end of the fine filter layer 22 of the fine filter part 20 through a middle end cap 24, and the coarse filter layer 21, the fine filter layer 22 and the middle end cap 24 are fixed by adhesion; the coarse filter layer 21 and the fine filter layer 22 are connected through the same middle end cover 24, and the matching precision between the coarse filter layer 21 and the middle end cover 24 and between the fine filter layer 22 and the middle end cover 24 only need to be ensured, so that the arrangement of a matching structure is reduced, the structure is simplified, and the requirements on the processing precision and the assembling precision of each part are reduced. As shown in fig. 2, after the filter element assembly 2 is inserted into the housing assembly 1, a sealing member is disposed between the outer peripheral surface of the middle end cap 24 and the inner peripheral surface of the housing main body 11, so as to seal and isolate the coarse dirty filter side 100 of the coarse filter part 10 from the fine dirty filter side 300 of the fine filter part 20, and prevent the fuel on the coarse dirty filter side 100 from leaking to the fine dirty filter side 300 to affect the filtering efficiency.

As shown in fig. 5, which is a schematic view of an embodiment of the middle end cap 24, the middle end cap 24 includes an upper cover plate portion 241, a lower cover plate portion 242, and a plurality of connecting ribs 243, the connecting ribs 243 are vertically disposed between the upper cover plate portion 241 and the lower cover plate portion 242, and an overflow channel 244 for fuel flowing is formed between adjacent connecting ribs 243. The upper cover plate portion 241 has a closed bottom surface, and the center of the lower cover plate portion 242 is opened with a middle through hole 2421, and the middle through hole 2421 is communicated with the flow passage 244. As shown in fig. 4, the upper cover plate portion 241 of the middle cover 24 covers the lower end of the fine filter layer 22 and covers the bottom of the fine filter side 400 at the center of the fine filter layer 22; the lower cover plate part 242 of the middle cover 24 is covered on the upper end part of the coarse filter layer 21, and the middle through hole 2421 of the lower cover plate part 242 is communicated with the coarse filter clean side 200 at the center of the coarse filter layer 21; the flow passage 244 of the center cap 24 communicates with the dirty side 300 of the fine filter layer 22.

As shown in fig. 6 and 7, another embodiment of the middle end cap 24 is schematically illustrated, the middle end cap 24 includes an upper cover plate 245 and a lower cover plate 246 which are separately designed, the upper cover plate 245 covers the lower end of the fine filter layer 22, and the lower cover plate 246 covers the upper end of the coarse filter layer 21; the upper cover plate 245 and the lower cover plate 246 are connected by a snap structure. A plurality of hooks 2451 and a plurality of transverse ribs 2452 vertically extend downwards from the bottom surface of the upper cover plate 245; a middle through hole 2461 is formed in the center of the lower cover plate 246, and an axial convex ring 2462 vertically extends downwards from the lower cover plate 246; the hooks 2451 of the upper cover plate 245 are clamped on the axial convex ring 2462 of the lower cover plate 246, the transverse ribs 2452 are abutted on the lower cover plate 246, and the flow passage 244 is formed between the adjacent transverse ribs 2452. In other embodiments, cross rib 2452 may be integrally formed on lower cover plate 246.

As shown in fig. 8, an oil inlet 12 is disposed at the middle lower portion of the shell main body 11 of the housing assembly 1, and an oil outlet 13 is disposed at the top of the shell main body 11, as shown in fig. 2 and 16, the oil inlet 12 is communicated with the coarse filtration side 100, and the oil outlet 13 is communicated with the fine filtration side 400. As shown in fig. 8, an inner cylinder 14 and an outer cylinder 15 vertically extend downward from the middle part of the inner side of the top surface of the shell main body 11, the inner cylinder 14 and the outer cylinder 15 are coaxially arranged with an annular space therebetween, and the height of the outer cylinder 15 is greater than that of the inner cylinder 14. As shown in fig. 2, the outer cylinder 15 and the inner cylinder 14 pass through the upper through hole 231 of the upper end cover 23 of the filter element assembly 2 and extend into the fine filtration side 400, and a gap is formed between the lower port of the outer cylinder 15 and the upper surface of the middle end cover 24 of the filter element assembly 2 to form an oil passage 151; the outer cylinder 15 is inserted into the inner side of the fine filtering layer 22 and can support the fine filtering layer 22 to prevent the fine filtering layer 22 from collapsing, the outer cylinder 15 is integrally formed on the shell main body 11 and replaces a traditional central net support member to support the fine filtering layer 22, the use of the support member is reduced, the cost of parts is reduced, the structure of the fine filtering part 20 is simplified, and the filter element assembly 2 is more compact in overall structure, smaller in volume and more portable. The outer wall surface of the outer cylinder 15 is in interference fit with the first convex rings 232 of the upper end cover 23 to form an interference sealing surface, the matching surface of the outer cylinder 15 and the upper end cover 23 is sealed, the interference sealing surface replaces a traditional sealing piece to seal, the use of the sealing piece is reduced, and the cost of parts is reduced. The inner side of the top surface of the shell main body 11 and the outer side of the outer barrel 15 are provided with a plurality of limiting ribs 18, the limiting ribs 18 are abutted against the upper end cover 23 of the filter element assembly 2, and the strength of the shell main body 11 can be improved while the filter element assembly 2 is axially limited. The top surface of the case main body 11 is provided with a discharge valve 19.

As shown in fig. 8, the hand pump assembly 16 is disposed inside the inner cylinder 14 and the outer cylinder 15, and the hand pump assembly 16 includes a valve seat 161, a valve ball 162, a push-pull rod 163, a valve frame 164, a valve plate 165, and a hand grip 166. The valve seat 161 is screwed and fixed at the lower end opening of the outer cylinder 15, as shown in fig. 2, a space is provided between the lower surface of the valve seat 161 and the upper surface of the middle end cap 24 of the filter cartridge assembly 2, so as to ensure that the fuel has enough flowing space. As shown in fig. 8, the valve ball 162 is placed in the valve seat 161, and the valve ball 162 presses against the inner surface of the valve seat 161 under the action of its own weight to form a one-way valve seal with the valve seat 161, so that the valve ball can cooperate with the push-pull rod 163 to perform an oil pumping function and also can prevent the fuel from flowing back in a shutdown state. The push-pull rod 163 vertically penetrates through the center of the inner barrel 14, the valve frame 164 and the valve plate 165 are fixed at the lower end part of the push-pull rod 163, and the valve plate 165 covers the upper side of the valve frame 164 in a sealing mode; the upper end part of the push-pull rod 163 penetrates out of the top surface of the shell main body 11, the hand grab handle 166 is fixed at the upper end part of the push-pull rod 163, and the hand grab handle 166 and the shell main body 11 can be screwed and fixed through threads; as shown in fig. 17 and 18, after the handle 166 is released from the housing body 11, the handle 166 is pulled and pressed, and the push-pull rod 163 drives the valve frame 164 and the valve plate 165 to move up and down along the inner tube 14. As shown in fig. 2 and 8, a protruding portion 141 is formed by extending upward toward the oil outlet 13 at a position of the upper end portion of the inner cylinder 14, which is communicated with the oil outlet 13, and the protruding portion 141 vertically extends into the oil outlet 13, so that the space of the oil outlet 13 can be reasonably and effectively utilized, an effective stroke cavity of the push-pull rod 163 is increased as much as possible in a limited design space, and the oil pumping efficiency of the hand pump assembly 16 is improved. As shown in fig. 2, when the push-pull rod 163 is pressed to the lowest position and in the locked state, the valve holder 164 is still kept within the range of the guide rib 142, that is, the guide rib 142 enables the valve holder 164 to move on the central axis of the inner cylinder 14, so as to prevent the push-pull rod 163 from being abnormally worn due to shaking of the valve holder 164. A cylindrical nest 17 is embedded in a through hole penetrating through the push-pull rod 163 on the top surface of the shell main body 11, as shown in fig. 11, a plurality of reinforcing ribs 171 are convexly arranged on the outer peripheral surface of the lower end part of the nest 17, and the reinforcing ribs 171 can enable the nest 17 to be connected with the shell main body 11 more tightly, so that the nest 17 is not easy to peel off from the shell main body 11 to cause failure; an upper second sealing ring 172 and a lower second sealing ring 172 are arranged between the inner peripheral surface of the nesting piece 17 and the outer surface of the push-pull rod 163, and the nesting piece 17 and the push-pull rod 163 are sealed twice, so that the sealing reliability and the product stability are improved. The inside surface of the hand grab handle 166 is provided with a first sealing ring 167, the first sealing ring 167 is just opposite to the upside of the matching surface of the nesting piece 17 and the push-pull rod 163, when the hand grab handle 166 is screwed on the shell main body 11, half of the first sealing ring 167 contacts with the shell main body 11, the other half contacts with the nesting piece 17, the matching surface of the shell main body 11 and the nesting piece 17 can be sealed, the product leakage caused by fatigue looseness in the service life of the nesting piece 17 and the shell main body 11 is prevented, and the sealing reliability and stability of the product are improved.

As shown in fig. 9, the lower portion of the valve seat 161 is provided with an externally hexagonal mounting post 1611 to facilitate mounting of the valve seat 161 to the housing body 11 by an auxiliary tool.

As shown in fig. 8, the lower end portion of the push-pull rod 163 is provided with a large-diameter portion 1631 located above the valve plate 165, the valve plate 165 is pressed onto the valve frame 164 by the lower end surface of the large-diameter portion 1631, and the upper end surface of the large-diameter portion 1631 is a limiting surface 1632, as shown in fig. 18, when the push-pull rod 163 is pulled to the highest position, the limiting surface 1632 of the large-diameter portion 1631 abuts against the lower end surface of the nest 17 to limit the maximum stroke of the push-pull rod 163, so that abnormal wear of the valve plate 165 due to the fact that the valve plate 165 directly collides with the nest 17 is avoided. The height of the large-diameter part 1631 is equal to or greater than the vertical distance between the upper end surface of the protrusion 141 of the inner cylinder 14 and the lower end surface of the nesting piece 17, so that the valve frame 164 and the valve plate 165 are still kept in the inner cylinder 14 after the push-pull rod 163 is lifted to the highest position, and abnormal abrasion of the valve plate 165 caused by sliding of the valve plate 165 from the inner cylinder 14 is avoided.

As shown in fig. 10, a plurality of oil passing holes 1641 are formed in the valve frame 164 along the circumferential direction, triangular rib plates 1642 are vertically arranged on the bottom surface of the valve frame 164 and between two adjacent oil passing holes 1641, and the rib plates 1642 can improve the supporting strength of the valve frame 164 and prevent the valve frame 164 from collapsing.

As shown in fig. 12 and 13, a separating ring 32 vertically extends upwards from the middle part of the inner side of the bottom surface of the cup body 31 of the water collecting cup assembly 3, the separating ring 32 separates the cavity in the cup body 31 into a clean side water collecting cavity 33 and a dirty side water collecting cavity 34 which are arranged at the inner side and the outer side, as shown in fig. 2, the clean side water collecting cavity 33 is communicated with a water drainage cavity 500 in the coarse filtering part 10 of the filter element assembly 2, and the water separated and filtered by the coarse filtering side 200 slides downwards and is collected into the clean side water collecting cavity 33; the dirty-side water collecting chamber 34 is communicated with a coarse dirty-side filter 100 outside the coarse filter part 10, and water separated and filtered by the coarse dirty-side filter 100 slides downwards to be collected in the dirty-side water collecting chamber 34. As shown in fig. 2, the lower end cap 25 of the filter element assembly 2 is inserted into the inner side of the spacer ring 32, the second convex ring 252 of the lower end cap 25 is in interference fit with the spacer ring 32 to form an interference sealing surface, so as to seal the matching surface of the lower end cap 25 and the spacer ring 32, and the interference sealing surface replaces the conventional sealing member to seal, thereby reducing the use of the sealing member and reducing the cost of parts.

As shown in fig. 12 and 13, a water discharge hole 35 is vertically formed in the bottom surface of the cup body 31, an upper portion of the water discharge hole 35 is partitioned by a partition ring 32 into a clean side hole 351 communicating with the clean side water collection chamber 33 and a dirty side hole 352 communicating with the dirty side water collection chamber 34, a lower portion of the water discharge hole 35 is a plug-in hole portion 353, and a step surface 354 is formed between the plug-in hole portion 353 and the clean side hole 351 and the dirty side hole 352. As shown in fig. 13, a water discharge screw 37 is fixedly connected to the insertion hole portion 353 through a screw, a gasket 38 is fitted over an upper end portion of the water discharge screw 37, and a drain valve 39 is fitted over an outer periphery of the water discharge screw 37. The water collecting cup assembly 3 is divided into two water collecting cavities through the separating ring 32, the water collecting cavity 33 on the clean side only collects water on the clean side, the water collecting cavity 34 on the dirty side only collects water on the dirty side, the water in the two water collecting cavities is not interfered with each other, secondary pollution of oil water on the dirty side to subsequent fuel oil is prevented, the filtering burden of the filter element assembly 2 is reduced, and the filtering efficiency and the service life of the fuel oil filter are improved. The water in the clean side water collecting cavity 33 and the dirty side water collecting cavity 34 is separately discharged from the upper part of the water discharging hole 35, and then is collected to the lower part of the water discharging hole 35 together, and is discharged through the same water discharging threaded sleeve 37 and the water discharging valve 39, so that the water in the clean side water collecting cavity 33 and the dirty side water collecting cavity 34 is discharged simultaneously through one water discharging valve 39, the water discharging threaded sleeve 37 and the water discharging valve 39 are reduced, the part cost is reduced, the structure of the water collecting cup assembly 3 is simplified, and the whole structure is more compact and light.

As shown in fig. 12 and 13, the cup body 31 is transversely provided with a water guiding groove 36 corresponding to the inner side of the bottom surface of the clean side water collecting cavity 33, the water guiding groove 36 is communicated with the clean side hole 351, so that the water in the clean side water collecting cavity 33 can be guided to the clean side hole 351, and the water in the clean side water collecting cavity 33 can be completely discharged. As shown in fig. 15, a plurality of drainage grooves 371 are uniformly and vertically arranged on the upper portion of the water discharging screw sleeve 37 along the circumferential direction, in this embodiment, three drainage grooves 371 are arranged along the circumferential direction, so as to facilitate the drainage of the water collected in the cup body 31. As shown in fig. 13 and 14, the top surface of the gasket 38 is an axial sealing surface 381, and the axial sealing surface 381 presses against the step surface 354 of the drainage hole 35 to realize axial sealing; the outer peripheral surface of the sealing gasket 38 is provided with a ring of raised rings which form a radial sealing ring 382, and the radial sealing ring 382 is pressed on the inner peripheral surface of the insertion hole part 353 to realize radial sealing; the water discharging screw sleeve 37 simultaneously realizes axial sealing and radial sealing through the sealing gasket 38, so that the sealing is more reliable, and the product leakage risk is lower.

As shown in fig. 12, the circumferential wall surface of the cup body 31 is provided with a plurality of convex ribs 311 and a plurality of concave ribs 312, and the convex ribs 311 and the concave ribs 312 can improve the strength of the cup body 31.

When the invention is actually used:

(1) as shown in fig. 16, during fuel filtration, as shown by arrows in the figure, fuel enters the coarse filtration dirty side 100 from the oil inlet 12 of the housing assembly 1, enters the coarse filtration clean side 200 after being filtered by the coarse filtration layer 21 of the coarse filtration part 10, flows to the fine filtration dirty side 300 from the overflow channel 244, enters the fine filtration clean side 400 after being filtered by the fine filtration layer 22 of the fine filtration part 20, and overcomes the gravity of the valve ball 162 to push the valve ball 162 open to enter the inner cylinder 14, so as to flow out from the oil outlet 13. When the fuel oil flows through the coarse filter layer 21, most of moisture particles in the fuel oil are intercepted and filtered by the water repellent coating on the outer surface of the coarse filter layer 21, and the filtered dirty side moisture slides downwards and is collected to the dirty side water collecting cavity 34 of the water collecting cup assembly 3; when the fuel oil flows through the water collecting cylinder 28 and the water repelling net 27, the water collecting cylinder 28 and the water repelling net 27 further intercept and filter water particles in the fuel oil, and the filtered clean side water slides downwards and collects to the clean side water collecting cavity 33 of the water collecting cup assembly 3.

(2) After the fuel filter assembly is installed for the first time or periodically maintained, the gas in the fuel filter assembly needs to be exhausted and the fuel needs to be pumped, as shown in fig. 17 and 18, when exhausting: firstly, the oil pipe of the oil outlet 13 is disconnected, then the hand holding handle 166 of the hand pump assembly 16 is unscrewed from the shell main body 11, the hand holding handle 166 is held by hand to be pulled upwards, the valve plate 165 tightly clings to and blocks the oil passing hole 1641 of the valve frame 164, negative pressure is formed in the lower space of the valve plate 165, and therefore the valve ball 162 is sucked and exhausted, and air in the upper space of the valve plate 165 is discharged along the oil outlet 13; after the push-pull rod 163 is pulled up to the maximum stroke, the hand holding handle 166 is held and pressed downwards, the valve ball 162 falls back to the valve seat 161 under the self weight to form check seal, air or fuel can not flow backwards, the air or fuel in the lower space of the valve plate 165 props the valve plate 165 to reach the inner cavity of the inner cylinder 14 through the oil passing hole 1641 of the valve frame 164, the reciprocating motion is carried out in such a way, the fuel can flow out from the oil outlet 13, the oil pumping is stopped, the oil pipe of the oil outlet 13 is connected again, and the hand holding handle 166 is screwed onto the shell main body 11 again to finish the oil pumping and exhausting.

(3) And (3) draining periodically: the water separated by the filter element assembly 2 is deposited in the water collecting cup assembly 3, when the water in the water collecting cup assembly 3 is fully stored, the water discharge valve 39 is opened to discharge the water, and after the water discharge is finished, the water discharge valve 39 is screwed down.

The foregoing description is illustrative of the present invention and is not to be construed as limiting thereof, as the invention may be modified in any manner without departing from the spirit thereof.

Claims (10)

1. A double-stage fuel filtering filter is characterized in that a filter element assembly (2) is inserted in a shell assembly (1), the lower end part of the shell assembly (1) is connected with a water collecting cup assembly (3), and a shell main body (11) of the shell assembly (1) is provided with an oil inlet (12) and an oil outlet (13); the method is characterized in that: the filter element assembly (2) comprises a coarse filtering part (10) and a fine filtering part (20) which are arranged in a stacked mode, wherein the outer side of the coarse filtering part (10) is a coarse filtering dirty side (100), and the center of the coarse filtering part (10) is a coarse filtering clean side (200); the outer side of the fine filtering part (20) is a fine filtering dirty side (300), the center of the fine filtering part (20) is a fine filtering clean side (400), the coarse filtering dirty side (100) is communicated with the oil inlet (12), and the fine filtering clean side (400) is communicated with the oil outlet (13);

the coarse filtration layer (21) of the coarse filtration part (10) is connected with the fine filtration layer (22) of the fine filtration part (20) through a middle end cover (24), and the middle end cover (24) isolates the coarse filtration part (10) from the fine filtration part (20); the upper part of the middle end cover (24) is covered at the bottom of the fine filtration layer (22), the lower part of the middle end cover (24) is provided with a middle through hole communicated with the coarse filtration side (200), and the middle part of the middle end cover (24) is provided with a flow passage (244) communicated with the middle through hole and the fine filtration side (300).

2. The dual stage filtration fuel filter of claim 1 wherein: the rough filtering part (10) of the filter element assembly (2) comprises a rough filtering layer (21), a central net pipe (26) and a water collecting cylinder (28), wherein the rough filtering layer (21) is sleeved on the periphery of the central net pipe (26), the central net pipe (26) is nested with a water repelling net (27), the water collecting cylinder (28) is inserted between the rough filtering layer (21) and the central net pipe (26), and an annular cavity between the water collecting cylinder (28) and the water repelling net (27) forms a water repelling cavity (500); the outer surface of the coarse filter layer (21) is coated with a water repellent coating; a lower end cover (25) is arranged at the lower end part of the coarse filtration layer (21), a lower through hole (251) is formed in the center of the lower end cover (25), and the lower through hole (251) is communicated with the drainage cavity (500); the fine filtering part (20) of the filter element assembly (2) comprises a fine filtering layer (22), an upper end cover (23) is fixedly bonded at the upper end part of the fine filtering layer (22), an upper through hole (231) is formed in the center of the upper end cover (23), and the upper through hole (231) is communicated with the fine filtering side (400); the periphery of the middle lower part of the fine filtering layer (22) is sleeved with a cover cylinder (29).

3. The dual stage filtration fuel filter of claim 1 wherein: the middle end cover (24) comprises an upper cover plate part (241), a lower cover plate part (242) and a plurality of connecting ribs (243) which are integrally formed, the connecting ribs (243) are vertically arranged between the upper cover plate part (241) and the lower cover plate part (242), and an overflowing channel (244) is formed between the adjacent connecting ribs (243); the upper cover plate part (241) is covered at the lower end part of the fine filter layer (22) and is provided with a closed bottom surface; the lower cover plate part (242) is covered on the upper end part of the coarse filter layer (21), and a central through hole (2421) is formed in the center of the lower cover plate part (242).

4. The dual stage filtration fuel filter of claim 1 wherein: the middle end cover (24) comprises an upper cover plate (245) and a lower cover plate (246) which are designed in a split mode, the upper cover plate (245) is connected with the lower cover plate (246) through a clamping structure, a plurality of transverse ribs (2452) are arranged between the upper cover plate (245) and the lower cover plate (246), a flow passage (244) is formed between every two adjacent transverse ribs (2452), and a middle through hole (2461) is formed in the center of the lower cover plate (246); the upper cover plate (245) is arranged at the lower end part of the fine filtering layer (22) in a covering way, and the lower cover plate (246) is arranged at the upper end part of the coarse filtering layer (21) in a covering way.

5. The dual stage filtration fuel filter of claim 1 wherein: an outer cylinder (15) is vertically arranged in the middle of the inner side of the shell main body (11), and the outer cylinder (15) extends into the fine filtration side (400) and is supported on the inner side of the fine filtration layer (22); the outer cylinder (15) and the upper end cover (23) are in interference fit to form an interference sealing surface.

6. The dual stage filtration fuel filter of claim 1 wherein: an inner cylinder (14) is also vertically arranged on the inner side of the shell main body (11), and the inner cylinder (14) is positioned on the inner side of the outer cylinder (15); a hand pump assembly (16) is arranged in the inner cylinder (14) and the outer cylinder (15), a valve seat (161) of the hand pump assembly (16) is fixed at the lower end part of the outer cylinder (15), a valve ball (162) is placed in the valve seat (161) and can form one-way valve seal with the valve seat (161), a push-pull rod (163) is inserted in the center of the inner cylinder (14), a valve frame (164) and a valve plate (165) are fixed at the lower end part of the push-pull rod (163), and the valve plate (165) covers the upper side of the valve frame (164); the upper end of the push-pull rod (163) penetrates out of the shell body (11), and the hand grab handle (166) is fixed at the upper end of the push-pull rod (163).

7. The dual stage filtration fuel filter of claim 6 wherein: the upper end part of the inner cylinder (14) is provided with a convex part (141), and the convex part (141) extends out of the oil outlet (13); the lower end part of the inner cylinder (14) is provided with a plurality of guide ribs (142).

8. The dual stage filtration fuel filter of claim 6 wherein: an embedded piece (17) is arranged in a through hole of the shell main body (11), a plurality of reinforcing ribs (171) are arranged on the outer peripheral surface of the lower end part of the embedded piece (17), and an upper second sealing ring (172) and a lower second sealing ring (172) are arranged between the embedded piece (17) and the push-pull rod (163); a first sealing ring (167) is arranged on the inner side surface of the grab handle (166), and the first sealing ring (167) is opposite to the upper side of the matching surface of the nested piece (17) and the push-pull rod (163); the lower end part of the push-pull rod (163) is provided with a large-diameter part (1631), the upper end face of the large-diameter part (1631) is a limiting face (1632), and the height of the large-diameter part (1631) is equal to or greater than the vertical distance between the upper end face of the protruding part (141) of the inner cylinder (14) and the lower end face of the nesting piece (17).

9. The dual stage filtration fuel filter of claim 1 wherein: a separating ring (32) is arranged in a cup body (31) of the water collecting cup assembly (3), the separating ring (32) divides a cavity in the cup body (31) into a clean side water collecting cavity (33) and a dirty side water collecting cavity (34), the clean side water collecting cavity (33) is communicated with a drain cavity (500) in a rough filtering part (10) of the filter element assembly (2), and the dirty side water collecting cavity (34) is communicated with a rough filtering dirty side (100) on the outer side of the rough filtering part (10).

10. The dual stage filtration fuel filter of claim 9 wherein: a drain hole (35) is formed in the bottom surface of the cup body (31), the upper portion of the drain hole (35) is divided into a clean side hole (351) and a dirty side hole (352) by a separating ring (32), the lower portion of the drain hole (35) is a plug-in hole portion (353), a water discharging threaded sleeve (37) is connected in the plug-in hole portion (353), a sealing gasket (38) is sleeved on the upper end portion of the water discharging threaded sleeve (37), and a drain valve (39) is sleeved on the periphery of the water discharging threaded sleeve (37); a water guide groove (36) is transversely formed in the inner side of the bottom surface of the water collecting cavity (33) corresponding to the clean side on the cup body (31), and the water guide groove (36) is communicated with the clean side hole (351); a plurality of drainage grooves (371) are arranged on the water discharging screw sleeve (37); the seal (38) is provided with an axial seal surface (381) and a radial seal ring (382).

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