CN216342519U - Conduit oil outlet throttling structure and fuel prefilter shell assembly - Google Patents

Abstract

The utility model discloses a conduit oil outlet throttling structure and a fuel prefilter shell assembly.A conduit is provided with a fuel oil channel and an air flow channel, the wall surface of the air flow channel is provided with an exhaust small hole, and the exhaust small hole is positioned below an oil outlet port of the fuel oil channel; a throttling channel is arranged below an oil outlet port of the fuel oil channel, the throttling channel is positioned outside the small exhaust hole and communicated with the small exhaust hole, and the throttling channel comprises an upper overflowing section with the through-flow sectional area gradually reduced from top to bottom; an oil outlet is formed at the bottom of the throttling channel. According to the utility model, the throttling structure is arranged below the conduit fuel oil channel, when fuel oil flows through the throttling structure, the fuel oil flow rate is increased, the fuel oil static pressure is reduced, the pressure difference at two sides of the exhaust small hole is increased, and even if the fuel oil flow rate in the fuel oil channel is low, the fuel oil can be accelerated to a higher flow rate level after flowing through the throttling structure, so that the gas in the airflow channel can be smoothly and continuously exhausted, and the fuel oil liquid level can be ensured to be raised to a satisfactory height.

Description

Conduit oil outlet throttling structure and fuel prefilter shell assembly

Technical Field

The utility model relates to the technical field of fuel filters, in particular to a conduit oil outlet throttling structure and a fuel prefilter shell assembly.

Background

The fuel prefilter is arranged in an engine fuel supply system and is used for filtering impurities, water and other pollutants in fuel and inputting the filtered fuel into the fuel delivery pump and the fuel injector, so that the problems of excessive wear or blockage of important parts such as the fuel delivery pump and the fuel injector are avoided, and the normal work of an engine is ensured. An exhaust structure is usually arranged in the fuel prefilter with an electric pump, so that gas at the upper end of the main shell can still be exhausted through the oil outlet even after the electric pump stops working, the fuel liquid level of the fuel prefilter is raised, and the utilization rate of the filter element is improved.

The Chinese patent application 201910943490.1 of the applicant discloses an exhaust structure of a fuel prefilter, wherein a central pipe is provided with a first channel for exhausting air and a second channel for discharging oil, the lower part of the first channel is positioned below the second channel and is provided with at least one small exhaust hole for communicating the first channel with the second channel, and when an oil way of the second channel discharges oil, negative pressure is formed at the small exhaust hole, so that air at the upper end of a main shell forms small bubbles and is pumped out along the oil way, and the normal operation of an engine cannot be influenced. This exhaust structure has the following disadvantages: when the fuel flow rate of the fuel prefilter is low, for example, the fuel flow rate is 50L/min to 250L/min, because the fuel flow rate is low, according to bernoulli's theorem, the flow rate of the fluid is inversely proportional to the static pressure of the fluid, when the fluid flow rate is reduced, the static pressure of the fluid is increased, that is, when the fuel flow rate is low, the static pressure is increased, the internal and external pressure difference of the exhaust small hole is reduced, which is not beneficial to the exhaust of the gas in the first passage, and the exhaust effect of the first passage is poor, thereby affecting the rise of the fuel level and making the fuel level unable to rise to a satisfactory height.

The mounting position of the fuel prefilter is usually higher than that of an automobile fuel tank, if leakage occurs due to sealing failure at an oil outlet pipe opening of the fuel prefilter or a pipeline at the rear end of the oil outlet pipe opening, after an engine stops working, external gas possibly enters the oil outlet pipe from the leakage position, and then enters the prefilter from a guide pipe through an electric pump, so that the excessive gas enters the prefilter, the fuel liquid level is reduced, the utilization rate of a filter element is reduced, and the service life of the filter element is shortened.

SUMMERY OF THE UTILITY MODEL

The applicant provides a conduit oil outlet throttling structure with a reasonable structure and a fuel prefilter shell assembly aiming at the defects of the existing fuel prefilter, so that the flow speed of the conduit oil outlet is improved, the static pressure of fuel at an exhaust small hole is reduced, the internal and external pressure difference of the exhaust small hole is increased, and the gas in an air flow channel is favorably discharged; the bottom of the guide pipe is provided with a one-way valve to prevent external air from entering the interior of the prefilter.

The technical scheme adopted by the utility model is as follows:

a conduit oil outlet throttling structure is characterized in that a fuel oil channel and an air flow channel are arranged on a conduit, an exhaust small hole is formed in the wall surface of the air flow channel, and the exhaust small hole is located below an oil outlet port of the fuel oil channel; a throttling channel is arranged below an oil outlet port of the fuel oil channel, the throttling channel is positioned outside the small exhaust hole and communicated with the small exhaust hole, and the throttling channel comprises an upper overflowing section with the through-flow sectional area gradually reduced from top to bottom; an oil outlet is formed at the bottom of the throttling channel.

As a further improvement of the above technical solution:

the throttling channel also comprises a middle overflowing section with the same flow cross section area, the flow cross section area of the middle overflowing section is consistent with the flow cross section area of the small-diameter end of the upper overflowing section, and the middle overflowing section is over against the small exhaust hole.

The lower part of the throttling channel is a lower overflowing section with the flow area gradually increasing from top to bottom, and the flow cross section of the small-diameter end of the lower transition section is consistent with the flow cross section of the middle overflowing section; the oil outlet is transversely arranged at the bottom of the throttling channel, and the throttling channel is transited to the oil outlet through the lower overflowing section.

The upper overflowing section comprises a conical surface section with a large upper part and a small lower part, and the outline size of the large-diameter end of the conical surface section is consistent with the outline size of the oil outlet port of the fuel oil channel; the included angle alpha between the generatrix of the conical surface section and the vertical line ranges from 10 degrees to 15 degrees.

A blocking block or a throttling pipe part is arranged below the fuel oil channel and outside the small exhaust hole, a first throttling surface is arranged on the blocking block or the throttling pipe part, and a gap is formed between the first throttling surface and the outer wall surface of the airflow channel to form the throttling channel; the first throttling surface comprises a first conical surface section, a first cylindrical surface section and a first cambered surface section which are sequentially connected from top to bottom, and the throttling channel comprises an upper overflowing section corresponding to the first conical surface section, a middle overflowing section corresponding to the first cylindrical surface section and a lower overflowing section corresponding to the first cambered surface section; the blocking block is provided with a first opening on the circumferential wall surface on the other side opposite to the first throttling surface, the first opening corresponds to the positioning rib of the conduit, and the positioning rib is inserted in the first opening to form a positioning structure; the outer wall surface of the lower part of the blocking block at the same side with the first oil outlet is provided with a sunken part.

A plugging block component is sleeved outside the exhaust small hole below the fuel oil channel and comprises a seat body, an adjusting plate and a spring, the adjusting plate is inserted in the seat body, and the spring is arranged between the seat body and the adjusting plate; a second throttling surface is arranged on the inner side of the adjusting plate, and a throttling channel is formed between the second throttling surface and the outer wall surface of the airflow channel; the second throttling surface comprises a second conical surface section with a large upper part and a small lower part, a second cylindrical surface section and a second cambered surface section with a large upper part and a small lower part, and the throttling channel comprises an upper overflowing section corresponding to the second conical surface section, a middle overflowing section corresponding to the second cylindrical surface section and a lower overflowing section corresponding to the second cambered surface section.

The base body is provided with a second opening, the second opening corresponds to the positioning rib of the conduit, and the positioning rib is inserted into the second opening for positioning; the wall surfaces of two opposite sides of the upper part of the seat body are provided with insertion holes, the upper part of the adjusting plate is provided with insertion columns, the insertion columns are inserted in the insertion holes, and the insertion columns are in clearance fit with the insertion holes; a blind hole is formed in the inner wall surface of the middle part of the seat body and the other side opposite to the second opening, a guide pillar is correspondingly arranged on the wall surface of the middle part of the adjusting plate, one end of the spring is sleeved on the guide pillar, and the other end of the spring is inserted into the blind hole; a notch is formed in the bottom of the seat body on the same side as the blind hole, a turned edge is arranged at the bottom of the adjusting plate, the turned edge is a U-shaped edge with a downward opening, and a second oil outlet is formed at the lower side of the turned edge; the inner side surface of the upper end part of the seat body is provided with a limiting surface, and the limiting surface is positioned above the adjusting plate and limits the adjusting plate.

A fuel prefilter shell assembly comprises the conduit oil outlet throttling structure, wherein a conduit is inserted in the center of a shell, and an oil inlet pipe orifice and an oil outlet pipe orifice are arranged on the shell.

As a further improvement of the above technical solution:

and a second one-way valve assembly is arranged at the air outlet port of the air flow channel of the guide pipe or on the oil outlet pipe orifice and is opened towards the air outlet direction or the oil outlet direction in a one-way mode.

A valve seat of the second one-way valve component is fixed in a mounting hole of the shell or an airflow channel of the guide pipe, a plurality of airflow through holes are formed in the valve seat, and the valve plate is inserted in the valve seat; or the air outlet port of the air flow channel of the guide pipe is integrally formed with a valve seat part, a plurality of air flow through holes are vertically formed in the valve seat part, and the valve plate is inserted into the valve seat part.

The utility model has the following beneficial effects:

(1) the lower part of the conduit fuel oil channel is provided with the flow passage with the gradually reduced flow cross section area as the throttling structure, when the fuel oil flows through the throttling structure, the flow rate of the fuel oil is increased, the static pressure of the fuel oil is reduced, and the pressure difference at two sides of the small exhaust hole is increased, so that even if the flow rate of the fuel oil in the fuel oil channel is lower, the fuel oil can also be accelerated to the level of higher flow rate after flowing through the throttling structure, the two sides of the small exhaust hole have larger pressure difference values, the gas in the air flow channel can be continuously and smoothly discharged, the liquid level of the fuel oil can be ensured to be raised to the satisfactory height, and the utilization rate of the filter element is ensured.

(2) The middle overflowing section of the throttling channel, which is right opposite to the small exhaust hole, of the throttling channel has a narrower through-flow sectional area which is equal up and down, and when fuel flows through the middle overflowing section (namely the small exhaust hole), the fuel flows downwards at a higher flow speed stably, so that the pressure difference between two sides (the airflow channel and the throttling channel) of the small exhaust hole is kept at a higher difference value stably, and the airflow in the airflow channel 22 is more favorably and continuously discharged.

(3) The flow area of the lower overflowing section of the throttling channel is gradually increased from top to bottom, and when fuel flows through the lower overflowing section, the fuel can be more smoothly turned and transited to the fuel outlet, so that the turbulence of the fuel can be reduced.

(4) The conical surface section ensures that the flow velocity of the fuel oil is improved after the fuel oil flows through the conical surface section, and simultaneously, the fuel oil has more smooth transition, so that the energy loss and the flow resistance of the fuel oil are kept in an allowable reasonable increase range, and the smoothness of the flow of the fuel oil is ensured.

(5) The opening of the plugging block is matched with the positioning rib of the conduit to form a positioning structure, so that the plugging block is positioned, the plugging block is ensured to be installed in place, and dislocation is avoided. The concave part of the block increases the distance between the block and the first one-way valve assembly, namely, the fuel flowing space between the block and the first one-way valve assembly is increased, so that the flow resistance of fuel is favorably reduced, and the fuel flows more smoothly.

(6) The throttling structure comprises a base body, an adjusting plate and a spring, wherein the adjusting plate is connected with the base body through the spring, the adjusting plate can adjust the through-flow sectional area of the second throttling channel through the compression amount of the spring, when the fuel flow rate of the prefilter is lower, the spring is in an uncompressed state or the compression amount is very small, the through-flow sectional area of the second throttling channel is smaller, when the fuel passes through the second throttling channel, the flow rate is accelerated, the pressure difference at two sides of an exhaust small hole is increased, the gas in the air flow channel can be smoothly and continuously exhausted, the gas is taken away along with the fuel, the liquid level of the fuel is ensured to be at a higher position, and the use efficiency of the filter element is improved; when the fuel flow rate of the prefilter is high, under the impact of the fuel oil pressure, the spring is compressed, the through-flow sectional area of the second throttling channel is increased, the situation that the fuel resistance is too large due to the fact that the through-flow sectional area is too small is avoided, in addition, due to the fact that the fuel flow rate is high, the pressure difference between the two sides of the small exhaust hole is large, gas in the air flow channel can be continuously exhausted smoothly, the fuel is taken away together, the fuel liquid level is guaranteed to be at a high position, and the using efficiency of the filter element is improved.

(7) The limiting surface of the base body can limit the adjusting plate, so that the situation that the flow cross section area of the second throttling channel is too small due to the fact that the adjusting plate is overturned excessively, and further the oil resistance of fuel oil is too large is avoided, and smooth circulation of the fuel oil is guaranteed.

(8) According to the utility model, the second check valve component is arranged at the air outlet port of the air flow channel or the oil outlet pipe opening of the shell, so that one-way air outlet of the air flow channel can be realized, the air flow is prevented from reversely entering the air flow channel from the air outlet port, even if external air enters the shell due to the fact that the pipeline at the oil outlet pipe opening or the rear end of the oil outlet pipe opening is sealed, the entered air cannot reversely enter the air flow channel through the air outlet port to cause the reduction of the liquid level of fuel oil, the liquid level of the fuel oil is ensured to be at a higher level when the pre-filter works normally, the filter element is ensured to have higher utilization rate, and the service life of the filter element is prolonged. The second check valve component is arranged at the air outlet port of the air flow channel, so that interference on the fuel channel can be avoided, the flow of fuel can not be influenced, and the smooth circulation of the fuel can be ensured when the pre-filter works normally.

Drawings

Fig. 1 is a sectional view of a housing assembly according to a first embodiment of the present invention.

Fig. 2 is an enlarged view of a portion a in fig. 1.

Fig. 3 is a sectional view of section B-B in fig. 1.

Fig. 4 is an enlarged view of a portion C in fig. 3.

Fig. 5 is a perspective view of a closure of the first embodiment.

Fig. 6 is a perspective view of another angle of the block of the first embodiment.

Fig. 7 is a cross-sectional view of the second embodiment.

Fig. 8 is a sectional view of the third embodiment.

Fig. 9 is a sectional view of the fourth embodiment.

Fig. 10 is an exploded view of the blockout assembly of the fifth embodiment.

Fig. 11 is a perspective view of a seat body of the fifth embodiment.

FIG. 12 is a cross-sectional view of the fifth embodiment with a low fuel flow rate and the spring of the plunger assembly in an uncompressed state.

FIG. 13 is a cross-sectional view of the fifth embodiment with a high fuel flow rate and the spring of the plunger assembly in a compressed state.

FIG. 14 is a partial cross-sectional view of the housing assembly of the sixth embodiment.

Fig. 15 is an enlarged view of a portion D in fig. 12.

In the figure: 1. a housing; 11. an oil inlet pipe orifice; 12. an oil outlet pipe orifice; 2. a conduit; 21. a fuel passage; 211. an oil inlet port; 212. an oil outlet port; 22. an air flow channel; 221. an air inlet port; 222. an air outlet port; 23. an exhaust aperture; 24. positioning ribs; 25. a throttle pipe portion; 26. a valve seat portion; 3. an electric pump; 4. a first one-way valve assembly; 5. a second one-way valve assembly; 51. a valve seat; 52. a valve plate;

6. blocking; 61. a first throttle surface; 611. a first conical surface section; 612. a first cylindrical section; 613. a first arc surface section; 62. a first throttle channel; 63. a first opening; 64. a first oil outlet; 65. a recessed portion;

7. a blockout component; 71. a base body; 711. inserting holes; 712. blind holes; 713. a second opening; 714. a notch; 715. a limiting surface; 72. an adjusting plate; 721. a second throttle surface; 7211. a second conical surface section; 7212. a second cylindrical section; 7213. a second arc surface section; 722. a second throttling passage; 723. inserting a column; 724. a guide post; 725. flanging; 726. a second oil outlet; 73. a spring.

Detailed Description

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

The first embodiment:

as shown in fig. 1, the housing 1 of the present invention is provided with an oil inlet pipe orifice 11 and an oil outlet pipe orifice 12, and the housing 1 is provided with a conduit 2, an electric pump 3 and a first check valve assembly 4; the conduit 2 is vertically inserted in the center of the shell 1, the electric pump 3 is transversely inserted below the conduit 2, and the first check valve assembly 4 is arranged between the conduit 2 and the oil outlet pipe orifice 12 and can be opened towards the oil outlet pipe orifice 12 in a one-way mode.

As shown in fig. 1 and 2, a through fuel oil channel 21 and an air flow channel 22 are vertically formed on the guide tube 2, an upper port of the fuel oil channel 21 is an oil inlet port 211, a lower port of the fuel oil channel is an oil outlet port 212, an upper port of the air flow channel 22 is an air inlet port 221, and a lower port of the air flow channel is an air outlet port 222; the height of the oil inlet port 211 of the fuel channel 21 is shorter than that of the air inlet port 221 of the air flow channel 22, and the height of the oil outlet port 212 of the fuel channel 21 is higher than that of the air outlet port 222 of the air flow channel 22. A second check valve assembly 5 is arranged at an air outlet port 222 of the air flow channel 22, the second check valve assembly 5 comprises a valve seat 51 and a valve plate 52, the valve seat 51 is fixedly inserted into the mounting hole of the shell 1, and a sealing element is arranged between the valve seat 51 and the wall surface of the mounting hole of the shell 1; in other embodiments, the valve seat 51 may also be fixedly inserted into the airflow channel 22 of the duct 2, and a sealing member is disposed between the valve seat 51 and the wall surface of the airflow channel 22; a plurality of air flow through holes (not shown in the figure) are vertically formed in the valve seat 51, and the valve plate 52 vertically penetrates through the valve seat 51 and can be opened downwards in a one-way mode towards the air outlet direction; the second check valve assembly 5 is arranged at the air outlet port 222 of the air flow channel 22, so that one-way air outlet of the air flow channel 22 can be realized, and the air flow is prevented from reversely entering the air flow channel 22 from the air outlet port 222, even if external air enters the shell 1 due to the fact that pipelines at the oil outlet pipe orifice 12 or at the rear end of the oil outlet pipe orifice 12 are sealed, the entered air cannot reversely enter the air flow channel 22 through the air outlet port 222 to cause the reduction of the liquid level of fuel, the liquid level of the fuel is ensured to be at a higher level when the pre-filter works normally, the filter element is ensured to have higher utilization rate, and the service life of the filter element is prolonged; the second check valve assembly 5 is arranged at the air outlet port 222 of the air flow channel 22, so that interference on the fuel channel 21 is avoided, the flow of fuel is not influenced, and the smooth circulation of the fuel is ensured when the prefilter works normally.

As shown in fig. 1 and 2, at least one through small vent hole 23 is radially opened on the wall surface of the air flow channel 22 on one side of the fuel channel 21, and the small vent hole 23 is located below the fuel outlet 212 of the fuel channel 21. The blocking block 6 is sleeved on the outer side of the small exhaust hole 23 below the fuel oil channel 21, as shown in fig. 5 and 6, a first throttling surface 61 is arranged on the inner side of the blocking block 6, as shown in fig. 2, a gap is formed between the first throttling surface 61 and the outer wall surface of the air flow channel 22 to form a first throttling channel 62, and the first throttling channel 62 is communicated with the fuel oil channel 21 and the small exhaust hole 23. As shown in fig. 6, a first oil outlet 64 is transversely formed in the bottom of the first throttle surface 61 on the blocking block 6, and the first oil outlet 64 is communicated with the first throttle passage 62; the first throttle surface 61, the first outlet port 64 and the airflow passage 22 are located on opposite sides. The outer wall surface of the lower portion of the upper portion of the blocking block 6 and the outer wall surface of the lower portion of the same side of the first oil outlet 64 are inwards recessed to form a recessed portion 65, as shown in fig. 2, the recessed direction of the recessed portion 65 deviates from the first check valve assembly 4, the distance between the blocking block 6 and the first check valve assembly 4 is increased, namely, a fuel flowing space between the blocking block 6 and the first check valve assembly 4 is increased, the flow resistance of fuel is favorably reduced, and the fuel flows more smoothly. As shown in fig. 5 and 6, the blocking piece 6 is a C-shaped piece, and a first opening 63 is formed in the circumferential wall surface of the other side opposite to the first throttling surface 61, as shown in fig. 3 and 4, a positioning rib 24 protrudes outwards from the outer wall surface of the conduit 2 at a position corresponding to the first opening 63, and the positioning rib 24 is inserted into the first opening 63 to form a positioning structure, so that the blocking piece 6 is positioned, the blocking piece 6 is ensured to be installed in place, and dislocation is avoided.

As shown in fig. 2, the first throttling surface 61 of the block 6 includes a first conical surface section 611, a first cylindrical surface section 612 and a first arc surface section 613 which are sequentially connected from top to bottom, and the first throttling channel 62 includes an upper flow passing section corresponding to the first conical surface section 611, a middle flow passing section corresponding to the first cylindrical surface section 612 and a lower flow passing section corresponding to the first arc surface section 613. The first conical surface section 611 is a conical surface with a large upper part and a small lower part, the upper port is a large-diameter end, and the lower port is a small-diameter end; the contour size of the large diameter end of the first conical surface section 611 is consistent with the contour size of the oil outlet port 212 of the fuel oil channel 21, and the contour size of the small diameter end is consistent with the contour size of the first cylindrical surface section 612; the included angle alpha between the bus of the first conical surface section 611 and the vertical line is in the range of 10-15 degrees, so that the flow speed of the fuel oil is improved after the fuel oil flows through the conical surface section, the fuel oil is in relatively smooth transition, the energy loss and the flow resistance of the fuel oil are kept in an allowable reasonable increase range, and the smoothness of the fuel oil flow is ensured; the first conical surface section 611 enables the cross-sectional area of the flow passage of the upper flow passage section of the first throttling channel 62 to be gradually reduced from top to bottom, the flow rate is gradually increased from top to bottom when fuel flows through the upper flow passage section, and the flow rate is increased to the maximum when fuel flows to the lower port of the first conical surface section 611. According to bernoulli's theorem, the flow velocity of a fluid is inversely proportional to the static pressure of the fluid, and the static pressure of the fluid is smaller when the flow velocity of the fluid is higher, whereas the static pressure of the fluid is larger when the flow velocity of the fluid is lower. When the prefilter works normally, the air in the air flow channel 22 basically tends to be in a static state when the prefilter works normally, the air flow speed is very low, and the air in the air flow channel 22 has a higher static pressure; when the fuel flows through the upper overflowing section, because the flow rate of the fuel is increased, the static pressure of the fuel is reduced, a large positive pressure difference is generated between the air flow channel 22 and the first throttling channel 62, under the action of the positive pressure difference, air in the air flow channel 22 is continuously discharged to the first throttling channel 62 through the small exhaust holes 23 and flows along with the fuel to be taken away, the pressure in the pre-filter is reduced, the liquid level of the fuel can rise and be kept at a high position, the filter paper layer participates in the filtering action more, the service rate of the filter element is improved, the service life of the filter element is prolonged, and the replacement frequency and the use cost are reduced. The first cylindrical section 612 is a cylindrical surface and is positioned on the outer side opposite to the small exhaust hole 23; the cross-sectional flow area of the first cylindrical section 612 is the same as that of the small-diameter end of the first conical section 611, that is, the middle flow section of the first throttling channel 62 facing the small vent hole 23 has a vertically equal and narrower cross-sectional flow area, and when the fuel flows through the middle flow section (i.e., the small vent hole 23), the fuel flows downwards at a higher flow rate, so that the pressure difference between the two sides of the small vent hole 23 (the air flow channel 22 and the first throttling channel 62) is stably maintained at a higher difference, and the air flow in the air flow channel 22 is more beneficial to being continuously discharged. The first arc surface section 613 is an outer convex arc surface with a small upper part and a large lower part, the contour size of the small diameter part at the upper end is consistent with the contour size of the first cylindrical surface section 612, and the large diameter part at the lower end is in smooth transition to the first oil outlet 64; the first arc surface section 613 gradually increases the flow area of the lower flow passage section of the first throttling channel 62 from top to bottom, so that the fuel can be more smoothly turned and transited to the first fuel outlet 64 when flowing through the lower flow passage section, and the turbulence of the fuel can be reduced. The lower part of the fuel oil channel 21 is provided with a flow passage with gradually reduced through-flow sectional area as a throttling structure, when fuel oil flows through the throttling structure, the flow rate of the fuel oil is increased, the static pressure of the fuel oil is reduced, the pressure difference on two sides of the small exhaust hole 23 is increased, even if the flow rate of the fuel oil in the fuel oil channel 21 is lower, the fuel oil can also be accelerated to the level of higher flow rate after flowing through the throttling structure, so that the two sides of the small exhaust hole 23 have larger pressure difference values, the gas of the air flow channel 22 can be continuously and smoothly discharged, the liquid level of the fuel oil can be ensured to rise to the satisfactory height, and the utilization rate of the filter element is ensured.

Second embodiment:

as shown in fig. 7, unlike the first embodiment, the throttle structure of the present embodiment is directly integrated with the duct 2. A throttle pipe part 25 extends downwards along the axial direction on the conduit 2 and below the fuel oil channel 21, the same as the block 6 of the first embodiment, a first throttle surface 61 and a first oil outlet 64 are arranged on the throttle pipe part 25, and a first throttle channel 62 is arranged between the first throttle surface 61 and the outer wall surface of the air flow channel 22; the first throttling surface 61 includes a first conical surface section 611 with a large top and a small bottom, a first cylindrical surface section 612, and a first arc surface section 613 with a large top and a small bottom, and an upper flow passage section with a gradually decreasing flow cross-sectional area from top to bottom, a middle flow passage section with a constant and narrow flow cross-sectional area, and a lower flow passage section with a gradually increasing flow area from top to bottom are respectively formed in the first throttling channel 62.

The third embodiment:

as shown in fig. 8, the second check valve assembly 5 of the present embodiment is directly integrated on the guide duct 2, unlike the first embodiment. The valve seat 26 is integrally formed on the air outlet port 222 of the air flow channel 22 of the conduit 2, a plurality of air flow through holes (not shown in the figure) are vertically formed on the valve seat 26, and the valve plate 52 of the second check valve assembly 5 vertically penetrates through the valve seat 26 and can be opened downwards in a single direction towards the electric pump 3.

The fourth embodiment:

as shown in fig. 9, the present embodiment integrates the throttling structure and the second check valve assembly 5 directly into the conduit 2.

Fifth embodiment:

as shown in fig. 10 to 13, in the present embodiment, different from the previous embodiments, the blocking piece assembly 7 is sleeved below the fuel passage 21 and outside the small exhaust hole 23.

As shown in fig. 10, the plugging block assembly 7 comprises a seat body 71, an adjusting plate 72 and a spring 73, wherein the adjusting plate 72 is vertically inserted into the seat body 71, and the spring 73 is transversely arranged between the seat body 71 and the adjusting plate 72.

As shown in fig. 10 and 11, the seat body 71 is a C-shaped block, a second opening 713 is formed on a circumferential wall surface of the seat body, the second opening 713 corresponds to the positioning rib 24 on the outer wall surface of the conduit 2, and the positioning rib 24 is inserted into the second opening 713 to position the seat body 71. Through insertion holes 711 are symmetrically formed in the wall surfaces of the two opposite sides of the upper portion of the seat body 71, and blind holes 712 are formed in the inner wall surface of the middle portion of the seat body 71 on the other side opposite to the second opening 713. The bottom of the seat body 71 on the same side as the blind hole 712 is provided with a notch 714.

As shown in fig. 10, the adjusting plate 72 is a conical cylindrical plate having a minor arc, and the inner side surface of the adjusting plate 72 is a second throttle surface 721, and as shown in fig. 12 and 13, a second throttle passage 722 is formed between the second throttle surface 721 and the outer wall surface of the gas flow passage 22. As shown in fig. 10, insertion posts 723 respectively extend outward from two opposite sides of the upper portion of the adjustment plate 72 and correspond to the insertion holes 711 of the housing 71, the insertion posts 723 are inserted into the insertion holes 711, and the insertion posts 723 are in clearance fit with the insertion holes 711 and can rotate in the insertion holes 711. A guide post 724 extends from the outer side wall surface of the middle portion of the adjusting plate 72 and corresponds to the blind hole 712 of the seat body 71, as shown in fig. 12 and 13, one end of the spring 73 is sleeved on the guide post 724, the other end of the spring 73 is inserted into the blind hole 712, and the flow cross-sectional area of the second throttling channel 722 can be adjusted by the adjusting plate 72 through the compression amount of the spring 73 under the action of oil pressure. A flange 725 transversely extends from the bottom of the adjusting plate 72, the flange 725 is a downward-opening U-shaped edge, a transverse second oil outlet 726 is formed at the lower side of the flange 725, and the second oil outlet 726 is communicated with the second throttling channel 722. The adjusting plate 72 is inserted upwards from one side of the seat body 71 provided with the notch 714, and the notch 714 can give way to the flanging 725. The inner side surface of the upper end of the seat body 71 is provided with a limiting surface 715 above the adjusting plate 72, and the limiting surface 715 can limit the adjusting plate 72, so that the situation that the adjusting plate 72 is overturned excessively to cause the flow cross-sectional area of the second throttling channel 722 to be too small and further cause the oil resistance of fuel oil to be too large is prevented, and the smooth circulation of the fuel oil is ensured.

As shown in fig. 12 and 13, the second throttle surface 721 includes a second conical surface section 7211 having a large top and a small bottom, a second conical surface section 7212, and a second arc surface section 7213 having a large top and a small bottom, and the second throttle passage 722 includes an upper flow passing section corresponding to the second conical surface section 7211, a middle flow passing section corresponding to the second conical surface section 7212, and a lower flow passing section corresponding to the second arc surface section 7213.

The throttling structure of the embodiment comprises a base body 71, an adjusting plate 72 and a spring 73, wherein the adjusting plate 72 is connected with the base body 71 through the spring 73, and the adjusting plate 72 can adjust the cross-sectional flow area of the second throttling channel 722 through the compression amount of the spring 73, as shown in fig. 12, when the fuel flow rate of the prefilter is low (the fuel flow rate is 50L/min-250L/min), the spring 73 is in an uncompressed state or the compression amount is small, the cross-sectional flow area of the second throttling channel 722 is small, when the fuel passes through the second throttling channel 722, the flow rate is accelerated, the pressure difference on two sides of the small exhaust hole 23 is increased, the gas in the air flow channel 22 can be continuously and smoothly discharged, the fuel is taken away together, the fuel liquid level is ensured to be at a high position, and the use efficiency of the filter element is improved; as shown in fig. 13, when the fuel flow rate of the pre-filter is high (the fuel flow rate is greater than 250L/min), under the impact of the fuel pressure, the spring 73 is compressed, the flow cross-sectional area of the second throttling channel 722 is increased, so that the fuel resistance is prevented from being too large due to the small flow cross-sectional area, moreover, because the fuel flow rate is high, the pressure difference between two sides of the small exhaust hole 23 is large, the gas in the air flow channel 22 can be continuously and smoothly discharged, the fuel is taken away together, the fuel liquid level is ensured to be at a high position, and the service efficiency of the filter element is improved.

Sixth embodiment:

as shown in fig. 14 and 15, unlike the first embodiment, in this embodiment, the second check valve assembly 5 is not disposed at the bottom of the air flow passage 22 of the duct 2, but the second check valve assembly 5 is disposed on the oil outlet pipe orifice 12 of the housing 1, the valve seat 51 of the second check valve assembly 5 is fixedly inserted into the inner end of the oil outlet pipe orifice 12, the valve sheet 52 is inserted into the valve seat 51, and can be opened in one way toward the oil outlet direction of the oil outlet pipe orifice 12, and also can prevent external air from entering the air flow passage 22 to cause the fuel level to drop, so as to ensure that the fuel level is at a higher level when the prefilter is in normal operation, ensure that the filter element has a higher utilization rate, and prolong the service life of the filter element.

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

Claims (10)

1. A conduit oil outlet throttling structure is characterized in that a conduit (2) is provided with a fuel oil channel (21) and an air flow channel (22), the wall surface of the air flow channel (22) is provided with an exhaust small hole (23), and the exhaust small hole (23) is positioned below an oil outlet port (212) of the fuel oil channel (21); the method is characterized in that: a throttling channel is arranged below an oil outlet port (212) of the fuel oil channel (21), the throttling channel is positioned outside the small exhaust hole (23) and communicated with the small exhaust hole (23), and the throttling channel comprises an upper overflowing section with the through-flow cross-sectional area gradually reduced from top to bottom; an oil outlet is formed at the bottom of the throttling channel.

2. A conduit outlet throttling arrangement as set forth in claim 1 wherein: the throttling channel also comprises a middle overflowing section with the same flow cross section area, the flow cross section area of the middle overflowing section is consistent with the flow cross section area of the small-diameter end of the upper overflowing section, and the middle overflowing section is over against the small vent hole (23).

3. A conduit outlet throttling arrangement as set forth in claim 1 wherein: the lower part of the throttling channel is a lower overflowing section with the flow area gradually increasing from top to bottom, and the flow cross section of the small-diameter end of the lower transition section is consistent with the flow cross section of the middle overflowing section; the oil outlet is transversely arranged at the bottom of the throttling channel, and the throttling channel is transited to the oil outlet through the lower overflowing section.

4. A conduit outlet throttling arrangement as set forth in claim 1 wherein: the upper overflowing section comprises a conical surface section with a large upper part and a small lower part, and the outline size of the large-diameter end of the conical surface section is consistent with the outline size of an oil outlet port (212) of the fuel oil channel (21); the included angle alpha between the generatrix of the conical surface section and the vertical line ranges from 10 degrees to 15 degrees.

5. A conduit outlet throttling arrangement according to any one of claims 1 to 4, wherein: a plugging block (6) or a throttling pipe part (25) is arranged below the fuel oil channel (21) and positioned outside the small exhaust hole (23), a first throttling surface (61) is arranged on the plugging block (6) or the throttling pipe part (25), and a gap is formed between the first throttling surface (61) and the outer wall surface of the air flow channel (22) to form the throttling channel; the first throttling surface (61) comprises a first conical surface section (611), a first cylindrical surface section (612) and a first arc surface section (613) which are sequentially connected from top to bottom, and the throttling channel comprises an upper overflowing section corresponding to the first conical surface section (611), a middle overflowing section corresponding to the first cylindrical surface section (612) and a lower overflowing section corresponding to the first arc surface section (613); the other side circumferential wall surface of the blocking block (6) opposite to the first throttling surface (61) is provided with a first opening (63), the first opening (63) corresponds to the positioning rib (24) of the conduit (2), and the positioning rib (24) is inserted into the first opening (63) to form a positioning structure; the outer wall surface of the lower part of the blocking block (6) on the same side with the first oil outlet (64) is provided with a concave part (65).

6. A conduit outlet throttling arrangement according to any one of claims 1 to 4, wherein: a plugging block component (7) is sleeved on the outer side of the small exhaust hole (23) below the fuel oil channel (21), the plugging block component (7) comprises a base body (71), an adjusting plate (72) and a spring (73), the adjusting plate (72) is inserted into the base body (71), and the spring (73) is arranged between the base body (71) and the adjusting plate (72); a second throttling surface (721) is arranged on the inner side of the adjusting plate (72), and a throttling channel is formed between the second throttling surface (721) and the outer wall surface of the airflow channel (22); the second throttling surface (721) comprises a second conical surface section (7211) with a large upper part and a small lower part, a second conical surface section (7212) and a second cambered surface section (7213) with a large upper part and a small lower part, and the throttling channel comprises an upper overflowing section corresponding to the second conical surface section (7211), a middle overflowing section corresponding to the second conical surface section (7212) and a lower overflowing section corresponding to the second cambered surface section (7213).

7. The conduit outlet flow restriction of claim 6, wherein: the seat body (71) is provided with a second opening (713), the second opening (713) corresponds to the positioning rib (24) of the guide pipe (2), and the positioning rib (24) is inserted into the second opening (713) for positioning; the wall surfaces of two opposite sides of the upper part of the seat body (71) are provided with insertion holes (711), the upper part of the adjusting plate (72) is provided with insertion columns (723), the insertion columns (723) are inserted in the insertion holes (711), and the insertion columns (723) are in clearance fit with the insertion holes (711); a blind hole (712) is formed in the inner wall surface of the middle part of the seat body (71) and the other side opposite to the second opening (713), a guide post (724) is correspondingly arranged on the wall surface of the middle part of the adjusting plate (72), one end of the spring (73) is sleeved on the guide post (724), and the other end of the spring (73) is inserted into the blind hole (712); a notch (714) is formed in the bottom of the base body (71) on the same side as the blind hole (712), a flanging (725) is arranged at the bottom of the adjusting plate (72), the flanging (725) is a U-shaped edge with a downward opening, and a second oil outlet (726) is formed in the lower side of the flanging (725); the inner side surface of the upper end part of the seat body (71) is provided with a limiting surface (715), and the limiting surface (715) is positioned above the adjusting plate (72) and limits the adjusting plate (72).

8. A fuel prefilter housing assembly characterized by: the guide pipe oil outlet throttling structure comprises the guide pipe oil outlet throttling structure in claim 1, wherein the guide pipe (2) is inserted in the center of the shell (1), and the shell (1) is provided with an oil inlet pipe orifice (11) and an oil outlet pipe orifice (12).

9. The pre-filter housing assembly as set forth in claim 8 wherein: a second one-way valve assembly (5) is arranged at an air outlet port (222) of an air flow channel (22) of the guide pipe (2) or on the oil outlet pipe orifice (12), and the second one-way valve assembly (5) is opened towards the air outlet direction or the oil outlet direction in a one-way mode.

10. The pre-filter housing assembly as set forth in claim 8 wherein: a valve seat (51) of the second one-way valve component (5) is fixed in a mounting hole of the shell (1) or on an airflow channel (22) of the guide pipe (2), a plurality of airflow through holes are formed in the valve seat (51), and the valve plate (52) is inserted in the valve seat (51); or the air outlet port (222) of the air flow channel (22) of the conduit (2) is integrally formed with the valve seat part (26), a plurality of air flow through holes are vertically formed in the valve seat part (26), and the valve plate (52) is inserted in the valve seat part (26).

Images