CN114458496B

CN114458496B - Fuel filter exhaust structure, fuel filter and engine oil supply system

Info

Publication number: CN114458496B
Application number: CN202210141302.5A
Authority: CN
Inventors: 尹燕升; 张驰; 朱宏志; 张贵华; 郭平
Original assignee: FAW Jiefang Automotive Co Ltd
Current assignee: FAW Jiefang Automotive Co Ltd
Priority date: 2022-02-16
Filing date: 2022-02-16
Publication date: 2023-05-23
Anticipated expiration: 2042-02-16
Also published as: CN114458496A

Abstract

The invention relates to the field of vehicles, and discloses a fuel filter exhaust structure, a fuel filter and an engine oil supply system. The invention provides an exhaust structure of a fuel filter, which is provided with a gas guide channel and a vent pipe, wherein the gas in a top gas cavity is sent to an oil outlet channel through the gas guide channel by the vent pipe. In the working process of the fuel filter, the gas in the top gas cavity contains oil mist, so that the recycling of the gaseous fuel in the gas in the top gas cavity can be realized, and the fuel waste, air pollution and the like caused by directly discharging the gas in the top gas cavity into the atmosphere can be avoided. The upper end of the gas guide channel is higher than the top wall of the filter element, and the fuel filter is inclined or blocked, so that the probability that fuel in the oil cavity before filtering and fuel in the oil cavity after filtering are mutually mixed through the top gas cavity can be reduced, and the filtering effect of the fuel filter is ensured.

Description

Fuel filter exhaust structure, fuel filter and engine oil supply system

Technical Field

The invention relates to the field of vehicles, in particular to a fuel filter exhaust structure, a fuel filter and an engine oil supply system.

Background

The fuel supply oil way of the engine is provided with a filter for filtering fuel oil, so as to prevent the fuel oil from blocking the fuel supply oil way. The top of the filter is filled with air, the presence of which reduces the fuel capacity of the filter, for which purpose the air at the top of the filter needs to be evacuated. The top of the filter is provided with a manual exhaust valve, and the manual exhaust valve can be opened periodically to exhaust most of air in the filter. But typically the venting operation is performed when the filter is not in operation; in the working process of the filter, the fuel also contains air, so that the air accumulation in the filter is increased continuously, and if the air is not timely discharged, the fuel capacity of the filter is greatly reduced.

In order to solve the problem, an exhaust device is arranged at the top of the filter so as to exhaust the air at the top of the filter through the exhaust device. Meanwhile, when the temperature of the fuel is higher in the working process of the fuel filter, the gas accumulated at the top of the inner cavity of the filter contains oil mist, so that the gas at the top of the inner cavity of the filter is usually sent to an oil outlet channel of the filter through a filtered oil cavity of the filter to be discharged. In general, the liquid level in the filter is lower than the top of the filter element, and when the filter is inclined, the filter element of the filter is blocked, and the like, the fuel in the pre-filter oil cavity and the fuel in the post-filter oil cavity can cross each other through the gas cavity at the top of the filter, so that the filtering effect of the filter is affected.

Disclosure of Invention

The invention aims to provide a fuel filter exhaust structure, a fuel filter and an engine oil supply system, which can improve the selection of an exhaust mode according to actual conditions and avoid the mutual channeling of fuel in a pre-filter oil cavity and fuel in a post-filter oil cavity through a top gas cavity.

To achieve the purpose, the invention adopts the following technical scheme:

the utility model provides a fuel filter exhaust structure, includes filtration casing and filter core, the filter core is installed in filtration casing, and will filter the inner chamber of casing and divide into before-filter oil pocket and after-filter oil pocket, be equipped with the oil outlet channel on the filtration casing, the roof of filter core with the inner wall of filtration casing encloses into the top gas chamber with before-filter oil pocket intercommunication;

the fuel filter exhaust structure further includes:

the upper end of the gas guide channel is communicated with the top gas cavity, and the upper end of the gas guide channel is higher than the top wall of the filter element;

and the upper end of the vent pipe is communicated with the lower end of the gas guide channel, and the vent pipe can convey the gas in the top gas cavity to the oil outlet channel through the gas guide channel.

Optionally, the fuel filter exhaust structure further includes:

the guide cover is positioned in the top gas cavity, and the gas guide channel is formed in the guide cover;

and the guide elastic reset piece is used for pressing the guide cover to the top wall of the filter element.

Optionally, a guiding seal is provided between the lower end face of the guiding cap and the top wall of the filter cartridge.

Optionally, the upper end of the guiding elastic resetting piece is fixedly connected with the filtering shell, and the lower end of the guiding elastic resetting piece is fixedly connected with the guiding cover.

Optionally, the guide cover passes through a plurality of circumference interval distribution's buckle structure with the lower extreme joint of direction elasticity return piece.

Optionally, the fuel filter exhaust structure further includes:

and a vent valve capable of selectively connecting or disconnecting the top gas chamber to the outside atmosphere.

Optionally, an assembly through hole is formed in the top of the filtering shell, and the lower end of the exhaust valve is in threaded connection with the assembly through hole.

Optionally, a counter bore is arranged at the lower end of the exhaust valve, the upper end of the guide cover is inserted into the counter bore, and an air guide channel is formed between the inner wall of the counter bore and the outer wall of the upper end of the guide cover at intervals;

The lower end of the air guide channel is communicated with the top air cavity, and the upper end of the air guide channel is communicated with the air guide channel.

The invention also provides a fuel filter which is characterized by comprising the fuel filter exhaust structure.

The invention also provides an engine oil supply system which is characterized by comprising the fuel filter exhaust structure.

The invention has the beneficial effects that: the invention provides a fuel filter exhaust structure, a fuel filter and an engine oil supply system, wherein a gas guide channel and a vent pipe are arranged, the upper end of the gas guide channel is communicated with a top gas cavity, the lower end of the gas guide channel is communicated with the vent pipe, and the vent pipe is used for conveying gas in the top gas cavity to an oil outlet channel through the gas guide channel. In the working process of the fuel filter, the gas in the top gas cavity contains oil mist, so that the recycling of the gaseous fuel in the gas in the top gas cavity can be realized, and the fuel waste, air pollution and the like caused by directly discharging the gas in the top gas cavity into the atmosphere can be avoided. The upper end of the gas guide channel is higher than the top wall of the filter element, and the fuel filter is inclined or blocked, so that the probability that fuel in the oil cavity before filtering and fuel in the oil cavity after filtering are mutually mixed through the top gas cavity can be reduced, and the filtering effect of the fuel filter is ensured.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following description will briefly explain the drawings needed in the description of the embodiments of the present invention, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to the contents of the embodiments of the present invention and these drawings without inventive effort for those skilled in the art.

FIG. 1 is a cross-sectional view of a fuel filter according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a temperature control device according to a first embodiment of the present invention;

FIG. 3 is a schematic diagram of a temperature control device according to other embodiments of the present invention;

fig. 4 is a front view of an upper cover according to a first embodiment of the present invention;

FIG. 5 is a cross-sectional view of an upper cover provided in accordance with a first embodiment of the present invention;

FIG. 6 is a schematic diagram of a fuel filter according to a first embodiment of the present invention;

FIG. 7 is a schematic view showing a bypass thermostatic valve when a sealing rod is at a low temperature communication position according to the first embodiment of the present invention;

FIG. 8 is a schematic view illustrating a bypass thermostatic valve when a sealing rod is at a temperature-adaptive blocking position according to an embodiment of the present invention;

FIG. 9 is a side view of a bypass thermostatic valve provided in accordance with an embodiment of the present invention;

FIG. 10 is a cross-sectional view of a venturi structure provided in accordance with an embodiment of the present invention;

FIG. 11 is a top view of a venturi structure provided in accordance with an embodiment of the present invention;

FIG. 12 is a schematic view of an exhaust structure according to a first embodiment of the present invention;

FIG. 13 is a schematic view of a part of an exhaust structure according to a first embodiment of the present invention;

FIG. 14 is an internal schematic view of a top cover according to a first embodiment of the present invention;

FIG. 15 is a graph comparing analysis results of finite element analysis of the upper cover and the existing upper cover according to the first embodiment of the present invention;

fig. 16 to 20 are state diagrams of a bypass thermo valve when a sealing rod provided in the second embodiment of the present invention is moved from a low temperature communication position to a high temperature pressure release position.

In the figure: 1. a filter housing; 11. an upper cover; 111. an external thread; 112. sealing the groove; 113. a limit boss; 114. a top vent; 115. a first annular boss; 116. a second annular boss; 117. a first inner reinforcing rib; 118. a second inner reinforcing rib; 119. an outer reinforcing rib; 12. a case main body;

2. a filter element; 21. a top cover; 22. a mounting bracket; 23. a cartridge body; 24. a base; 3. a bypass temperature control valve; 31. a valve body; 311. an external oil port; 312. an oil outlet; 313. a pressure relief hole; 314. a valve housing; 3141. temperature control card is convex; 315. a valve cover; 3151. a temperature control clamping hole; 32. a sealing rod; 33. a temperature-sensitive wax valve; 331. an induction end; 332. a push rod; 34. a temperature-controlled elastic reset piece; 35. a bushing; 351. an internal oil port; 36. an assembly space; 37. a temperature control seal;

4. A temperature control device; 41. a temperature detection unit; 42. a heating unit; 43. a temperature control module; 44. a relay; 441. a state feedback end; 442. a first terminal; 443. a second terminal; 444. an electromagnetic trigger switch; 445. a positive electrical terminal; 446. a negative electrical terminal;

5. a heat insulating member; 6. an exhaust structure; 61. an oil drain pipe; 611. a third anti-swing part; 62. an exhaust pipe; 621. a top air tube; 6211. a first anti-swing portion; 622. a bottom air tube; 6221. an exhaust through hole; 6222. a second anti-swing portion; 63. a venturi passage; 71. a guide cover; 711. a gas guide channel; 72. a guide seal; 73. an elastic plate; 74. an exhaust valve; 741. an exhaust seal; 75. a guiding elastic resetting piece; 100. a pre-filtration oil chamber; 200. a filtered oil cavity; 300. a bypass oil passage; 400. a top gas chamber; 500. and an air guide channel.

Detailed Description

In order to make the technical problems solved, the technical scheme adopted and the technical effects achieved by the invention more clear, the technical scheme of the invention is further described below by a specific embodiment in combination with the attached drawings. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting thereof. It should be further noted that, for convenience of description, only some, but not all of the drawings related to the present invention are shown.

The present embodiment provides an engine oil supply system for supplying fuel in a fuel tank to an engine, where the fuel refers to diesel fuel. The engine oil supply system comprises a preheater, an electric pump and a high-pressure oil pump, wherein the preheater can be an electric heater, and is used for heating a small amount of solidified diesel oil near an inlet of the electric pump to enable solid fuel oil to be liquefied when the engine is started under the condition that the diesel oil in an oil tank is waxed. After the electric pump builds pressure, the liquid fuel around the electric pump is pushed to the engine through the high-pressure oil pump and returned to the oil tank through the oil return pipe, so that the solid fuel in the circulating oil path is replaced by the liquid fuel, and then the engine can be started normally. Compared with the prior art that 35# diesel is adopted to solve the problem of low-temperature starting of the engine, the method can not only effectively solve the problem of influencing the starting of the engine when zero # diesel is subjected to low-temperature waxing, but also greatly reduce the cost.

In order to avoid clogging of the high-pressure oil pump with impurities in the diesel oil, a fuel filter is generally provided between the high-pressure oil pump and the electric pump to filter the fuel to be sent to the high-pressure oil pump. However, when diesel oil is waxed, the resistance of the fuel oil passing through the filter element of the fuel oil filter is high due to the existence of the waxed fuel oil on the filter element, so that the liquid fuel oil provided by the electric pump can not push the solid fuel oil in the fuel oil filter to pass through the filter element. Therefore, the embodiment provides a fuel filter to solve the problem that the filter affects the engine start when the diesel oil is waxed at low temperature.

As shown in fig. 1, the fuel filter provided in this embodiment includes a filter housing 1 and a filter element 2, the filter element 2 being installed in the filter housing 1 and dividing an inner cavity of the filter housing 1 into a pre-filter oil chamber 100 and a post-filter oil chamber 200; the filtering shell 1 is provided with an oil outlet channel communicated with the oil cavity 200 after filtering, and the oil outlet channel is used for being connected with a high-pressure oil pump. Illustratively, the filter element 2 has a hollow structure, the pre-filtration oil cavity 100 is formed between the filter element 2 and the inner wall of the filter housing 1, and the post-filtration oil cavity 200 is formed in the filter element 2.

As shown in fig. 2, the fuel filter further includes a temperature control device 4, where the temperature control device 4 is configured to heat the fuel in the filter housing 1. When the engine is started at a low temperature, the fuel in the filter housing 1 is heated by the temperature control device 4 to melt the solid fuel in the filter housing 1, so that the solid fuel in the filter housing 1 is liquefied. Specifically, the temperature control device 4 includes a temperature detection unit 41, a heating unit 42, a temperature control module 43, and a relay 44, wherein the temperature detection unit 41 is used for detecting the temperature in the fuel filter, and the heating unit 42 is used for heating the fuel in the fuel filter; the temperature control module 43 is used for controlling the heating unit 42 to start and stop according to the detection result of the temperature detection unit 41; relay 44 includes a positive electrical terminal 445, a negative electrical terminal 446, and a status feedback terminal 441, relay 44 being configured to power temperature control module 43 when both positive electrical terminal 445 and negative electrical terminal 446 are energized, and status feedback terminal 441 feeding back the power state of temperature control module 43.

In this embodiment, the temperature detecting unit is a 41 temperature sensor, the heating unit 42 is an electric heater, the heating unit 42 is disposed in the pre-filter oil chamber 100, and the temperature control module 43 and the relay 44 are disposed outside the filter housing 1. In order to improve the heating efficiency of the heating unit 42, the heating unit 42 has a ring structure, so that the heating area is large, and the time consumption for melting the solid fuel is shortened.

In this embodiment, temperature control device 4 further includes a power source, negative terminal 446 is connected to a negative electrode of the power source, and positive terminal 445 is selectively connected to or disconnected from a positive electrode of the power source. The power source may be a 24V low voltage power source on the vehicle. The negative terminal of the temperature control module 43 is connected to the negative electrode of the power supply, the relay 44 comprises a first terminal 442, a second terminal 443 and an electromagnetic trigger switch 444, the first terminal 442 is connected to the positive terminal of the temperature control module 43, and the second terminal 443 is connected to the positive electrode of the power supply; the coil ends of the electromagnetic trigger switch 444 are connected to the positive and

negative terminals

445 and 446, respectively, and the electromagnetic trigger switch 444 is capable of operating when both the positive and

negative terminals

445 and 446 are energized to bring the first and

second terminals

442 and 443 into conduction and to bring the first and

second terminals

442 and 443 out of conduction when at least one of the positive and

negative terminals

445 and 446 is de-energized. It should be noted that the electromagnetic trigger switch 444 is a prior art, and will not be described in detail herein.

When the temperature detection unit 41 detects that the temperature in the fuel filter is lower than the target temperature, it indicates that fuel is about to be or has been waxed, in order to avoid that the fuel in the fuel filter is waxed to increase the resistance of the fuel in the fuel filter passing through the filter core 2, the positive electrode terminal 445 is conducted with the positive electrode of the power supply, the coil of the electromagnetic trigger switch 444 forms a passage with the power supply, and a current is generated in the coil, so that electromagnetic force is generated, the iron core of the electromagnetic trigger switch 444 stretches and contracts, the first terminal 442 and the second terminal 443 are conducted through the electromagnetic trigger switch 444, the positive electrode of the power supply is conducted through the second terminal 443, the first terminal 442 and the positive electrode of the temperature control module 43, at this time, the positive electrode of the temperature control module 43 is conducted with the positive electrode of the power supply, and the temperature control module 43 controls the heating unit 42 to start to work so as to heat the fuel in the fuel filter. At this time, the status feedback terminal 441 will be able to detect that the positive voltage of the temperature control module 43 is 24V, thereby determining that the heating unit 42 is operating.

When the temperature in the fuel filter detected by the temperature detecting unit 41 is not lower than the target temperature, it indicates that the fuel is not waxed, and the fuel in the fuel filter is not required to be heated, at this time, the positive electrode terminal 445 is disconnected from the positive electrode of the power supply, the electromagnetic trigger switch 444 cannot generate electromagnetic force, the first terminal 442 and the second terminal 443 are disconnected, at this time, the positive electrode of the power supply cannot be conducted with the positive electrode of the temperature control module 43, only the negative electrode of the temperature control module 43 is conducted with the negative electrode of the power supply, and the temperature control module 43 cannot control the heating unit 42 to work. At this time, the state feedback terminal 441 can detect that the positive voltage of the temperature control module 43 is 0V, thereby determining that the heating unit 42 is not operated.

In other embodiments, positive electrical terminal 445 may also be connected to the positive electrode of the power supply and negative electrical terminal 446 may be selectively connected to or disconnected from the negative electrode of the power supply, as shown in fig. 3. When the temperature detection unit 41 detects that the temperature in the fuel filter is lower than the target temperature, the negative electric terminal 446 will be conducted with the negative electrode of the power supply, thereby enabling the temperature control module 43 to control the operation of the heating unit 42. When the temperature detection unit 41 detects that the temperature in the fuel filter is not lower than the target temperature, the negative electric terminal 446 will be disconnected from the negative electrode of the power supply, so that the temperature control module 43 cannot control the operation of the heating unit 42. The target temperature may be set according to actual requirements, and optionally, the target temperature is less than or equal to 10 ℃. Preferably, -5 ℃ to-5 ℃.

Further, the filter housing 1 includes an upper cover 11 and a housing main body 12, and the upper cover 11 and the housing main body 12 are detachably connected to form a mounting cavity, and the filter element 2 is mounted in the mounting cavity. Because the filter element 2 needs to be replaced periodically, the upper cover 11 and the shell main body 12 are detachably connected, so that the filter element 2 is convenient to replace. As shown in fig. 1, 4 and 5, it is preferable that the upper cover 11 is screw-coupled with the case main body 12, specifically, an outer circumferential wall of a lower end of the upper cover 11 is provided with an outer screw 111, an inner circumferential wall of an upper end of the case main body 12 is provided with an inner screw, and the outer screw 111 on the upper cover 11 is engaged with the inner screw on the case main body 12. In order to prevent fuel leakage, the outer peripheral wall of the lower end of the upper cover 11 is provided with a seal groove 112, a seal member is provided in the seal groove 112, the seal member is sandwiched between the outer peripheral wall of the upper cover 11 and the inner peripheral wall of the case main body 12, and the seal groove 112 is located above the external screw thread 111 on the upper cover 11. The outer peripheral wall of the lower end of the upper cover 11 is convexly provided with a limiting boss 113, and the limiting boss 113 is higher than the external thread 111 on the upper cover 11, so that the shell main body 12 is limited by the limiting boss 113 when the upper cover 11 and the shell main body 12 are connected in a threaded manner.

Further, in practical applications, the fuel filter is arranged vertically, and the liquid level in the fuel filter is usually too low to be used for a large part above the middle of the filter element 2. Therefore, the upper cover 11 is of a transparent structure, so that the liquid level and the blocking condition in the filter shell 1 can be observed conveniently, the liquid level in the filter shell 1 meets the requirements, the liquid level in the filter shell 1 is not too low, the liquid level in the filter shell 1 is not too high, the filter element 2 is fully utilized, and the filtering efficiency of the fuel filter is improved.

Further, the shell main body 12 is an aluminum casting, so that the processing is convenient, the cost is low, the temperature of fuel oil can be gradually increased after the engine works for a period of time, and the aluminum shell main body 12 also has the advantage of good heat dissipation effect. In order to reduce the amount of heat dissipation during operation of the heating unit 42, a heat shield 5 is provided between the inner wall of the filter housing 1 and the heating unit 42. In this embodiment, the heat insulating member 5 has a ring-like structure, and the inner peripheral wall of the heat insulating member 5 completely covers the outer peripheral wall of the heating member to enhance the heat insulating effect.

Further, as shown in fig. 6, the fuel filter further includes a bypass oil passage 300, one end of the bypass oil passage 300 is communicated with the pre-filter oil chamber 100, and the other end is communicated with the oil outlet passage; the bypass oil passage 300 can be selectively opened or closed according to the temperature inside the pre-filter oil chamber 100.

When the engine is started by adopting the method under the condition of diesel oil waxing, in order to avoid that the resistance of the fuel passing through the filter element 2 is larger due to the fuel waxing, so that the liquid fuel provided by the electric pump can not push the solid fuel in the fuel filter to pass through the filter element 2, at the moment, the pre-filter oil cavity 100 and the oil outlet channel can be communicated through the bypass oil channel 300, and most of the fuel in the pre-filter oil cavity 100 directly enters the oil outlet channel through the bypass oil channel 300, so that compared with the flow of the fuel in the pre-filter oil cavity 100 from the filter element 2 to the oil outlet channel through the oil cavity 200 after filtering, the flow resistance of the fuel is greatly reduced. When the fuel in the pre-filter oil chamber 100 is not waxed and the fuel is not affected to pass, the bypass oil duct 300 is disconnected, and at the moment, the fuel in the pre-filter oil chamber 100 is filtered by the filter element 2 and then enters the post-filter oil chamber 200.

By adopting the fuel filter provided by the embodiment, the bypass oil duct 300 can be selectively connected or disconnected according to the temperature in the pre-filter oil cavity 100, when the temperature is low, the filtering of fuel is ignored, and the bypass oil duct 300 is communicated, so that the smooth oil path from the electric pump to the high-pressure oil pump is ensured to be mainly; when the temperature is relatively high and the fuel in the pre-filtration oil cavity 100 is not waxed, the bypass oil duct 300 is disconnected, and the smooth oil path from the electric pump to the high-pressure oil pump is ensured while the fuel is filtered. In order to shorten the preparation work before starting the engine in a low temperature environment, when the bypass passage 300 is communicated due to the wax deposition of the fuel, the heating unit 42 is controlled to operate to heat the fuel in the fuel filter so as to disconnect the bypass passage 300 as early as possible.

Further, as shown in fig. 1 and 6, in order to achieve automatic on-off of the bypass oil passage 300, the fuel filter further includes a bypass thermo valve 3 for selectively connecting or disconnecting the bypass oil passage 300 according to the temperature in the pre-filter oil chamber 100. In order to reduce the occupation space of the fuel filter, the bypass temperature control valve 3 is arranged in the oil cavity 100 before filtration, optionally, the bypass temperature control valve 3 is arranged in the shell main body 12, and the bypass temperature control valve 3 can be installed in the shell main body 12 by means of fasteners such as bolts or clamping, so that the bypass temperature control valve has the effects of convenient replacement and no additional increase of the occupation space of the fuel filter. Illustratively, a temperature control threaded hole is provided in the valve body 31 of the bypass thermo valve 3, securing the bypass thermo valve 3 to the housing body 12 of the fuel filter. The inner diameter of the temperature control threaded hole is 6 mm-12 mm.

As shown in fig. 7 to 9, the bypass thermostatic valve 3 provided in this embodiment includes a valve body 31, a sealing rod 32, and a temperature-sensitive wax valve 33, wherein an external oil port 311 and an oil outlet 312 are provided on the valve body 31, wherein the external oil port 311 is used for communicating with the pre-filter oil chamber 100 of the fuel filter, and the oil outlet 312 is used for communicating with the post-filter oil chamber 200 of the fuel filter. The temperature-sensitive wax valve 33 is capable of contacting the fuel in the pre-filter oil chamber 100 to contract to axially move the seal rod 32 in the valve body 31 when the temperature of the fuel in the pre-filter oil chamber 100 is not higher than a preset temperature, to communicate the outer oil port 311 with the oil outlet 312, and to expand to axially move the seal rod 32 in the valve body 31 when the temperature of the fuel in the pre-filter oil chamber 100 is higher than a preset temperature, to disconnect the outer oil port 311 from the oil outlet 312.

In this embodiment, when the temperature-sensitive wax valve 33 drives the sealing rod 32 to axially move in the valve body 31, the sealing rod 32 can be located at a low-temperature communication position and a temperature-adaptive blocking position which are sequentially distributed along the axial direction of the sealing rod; wherein, when the sealing rod 32 is at the low-temperature communication position, the external oil port 311 is communicated with the oil outlet 312; when the sealing rod 32 is in the proper-temperature blocking position, the external oil port 311 and the oil outlet 312 are disconnected. Specifically, the sensing end 331 of the temperature-sensitive wax valve 33 passes through the valve body 31 and extends into the pre-filter oil chamber 100, and the push rod 332 of the temperature-sensitive wax valve 33 is connected to the seal rod 32. The construction of the temperature-sensitive wax valve 33 is well known in the art and will not be described in detail herein. In order to simplify the connection, in the present embodiment, the push rod 332 of the temperature-sensitive wax valve 33 is inserted into the sealing rod 32. Illustratively, one end of the sealing rod 32 is provided with a wax valve mating portion into which the push rod 332 of the temperature-sensitive wax valve 33 is inserted.

The temperature-sensitive wax valve 33 can accurately sense the temperature change in the pre-filter oil chamber 100, and when the oil temperature in the pre-filter oil chamber 100 is reduced, the push rod 332 drives the sealing rod 32 to axially move and gradually approach the temperature-sensitive wax valve 33, so that the external oil port 311 is communicated with the oil outlet 312. When the oil temperature in the pre-filter oil chamber 100 increases, the push rod 332 pushes the seal rod 32 to move axially and gradually away from the temperature-sensitive wax valve 33, so that the external oil port 311 and the oil outlet 312 are disconnected. The number of the external oil ports 311 is not less than one, and when the number of the external oil ports 311 is greater than or equal to two, at least two external oil ports 311 are arranged at intervals along the circumferential direction of the valve body 31. Illustratively, the number of the external oil ports 311 is four, and the external oil ports 311 are arc-shaped holes extending along the circumferential direction of the outer wall of the valve body 31; the flow area of the outer oil port 311 is 100mm ² ～200mm ² The method comprises the steps of carrying out a first treatment on the surface of the The flow area of the oil outlet 312 is 100mm ² ～200mm ² 。

Further, when the push rod 332 of the temperature-sensitive wax valve 33 and the wax valve mating portion of the sealing rod 32 are connected in a plugging manner, the push rod 332 of the temperature-sensitive wax valve 33 and the wax valve mating portion of the sealing rod 32 may be separated during the temperature reduction process, so that the sealing rod 32 cannot be automatically reset, and therefore, the bypass temperature control valve 3 provided in this embodiment further includes a temperature-controlled elastic reset member 34 for enabling the sealing rod 32 to have a tendency to move to a position where the external oil port 311 is communicated with the oil outlet 312. Illustratively, the temperature-controlled elastic restoring member 34 is a compression spring. During the temperature decrease, the temperature-controlled elastic restoring member 34 provides a restoring force to gradually move the sealing rod 32 to a position where the external oil port 311 and the oil outlet port 312 communicate, so that the fit clearance between the push rod 332 of the temperature-sensitive wax valve 33 and the wax valve fitting portion of the sealing rod 32 can be appropriately increased. Alternatively, the fit clearance between the wax valve fitting portion and the push rod 332 of the temperature-sensitive wax valve 33 is 0.1mm to 1mm.

Further, the bypass thermostatic valve 3 further includes a bushing 35, the bushing 35 is sleeved outside the sealing rod 32 and fixed in the valve body 31, an inner oil port 351 communicated with the outer oil port 311 is provided on the bushing 35, and the sealing rod 32 is axially slidably matched with the inner wall of the bushing 35. In the embodiment, an inner oil port 351 corresponding to the outer oil port 311 one by one is arranged on the bushing 35, the inner oil port 351 and the corresponding outer oil port 311 are arranged opposite to each other, the bushing 35 comprises an oil port section, a bushing limiting section and a resetting limiting section which are coaxially arranged and integrally formed, wherein the inner oil port 351 is arranged on the oil port section, the outer diameter of the oil port section and the outer diameter of the resetting limiting section are smaller than the outer diameter of the bushing limiting section, a bushing limiting surface is arranged on the inner wall of the valve body 31, and the side surface of the bushing limiting section, which is close to one side of the oil port section, is abutted to the bushing limiting surface; one end of the temperature control elastic resetting piece 34 is sleeved on the resetting limiting section and is abutted to the side surface of one side, close to the resetting limiting section, of the lining limiting section. Illustratively, the flow area of the internal oil port 351 is 100mm ² ～200mm ² The inner diameter of the bushing 35 is 7 mm-15 mm, the wall thickness of the oil port section is 1 mm-3 mm, and the axial length of the oil port section is 6 mm-20 mm; the axial length of the bushing limiting section is 1 mm-5 mm, and the outer diameter of the bushing limiting section is 15 mm-25 mm; the axial length of the reset limiting section is 1 mm-5 mm, and the wall thickness of the lining limiting section is 1 mm-3 mm.

Further, the sliding fit of the sealing rod 32 and the bushing 35 forms an assembling space 36 on one side of the inner cavity of the valve body 31, and during the sliding fit of the sealing rod 32 and the bushing 35, a small amount of fuel enters the assembling space 36, and the resetting of the sealing rod 32 during low temperature will be affected as the fuel in the assembling space 36 increases gradually. For this purpose, a relief hole 313 communicating with the fitting space 36 is provided in the valve body 31, and the relief hole 313 communicates with the pre-filter oil chamber 100.

Further, the bypass thermo valve 3 further includes a temperature control seal 37 for being interposed between the outer peripheral wall of the seal rod 32 and the inner peripheral wall of the bush 35 when the outer oil port 311 is disconnected from the oil outlet port 312, preventing oil leakage. Illustratively, the temperature control seal 37 is an O-ring seal. In order to ensure smoothness when the seal rod 32 slides relative to the bush 35, the fit clearance between the inner wall of the bush 35 and the outer wall of the seal rod 32 is 50 μm to 1mm. In other embodiments, since the high temperature resistance of the temperature control seal 37 is required at high temperature of the fuel, the temperature control seal 37 may be omitted, and the fit gap between the inner wall of the bush 35 and the outer wall of the seal rod 32 may be reduced, for example, the fit gap between the inner wall of the bush 35 and the outer wall of the seal rod 32 may be 10 μm to 50 μm, and the seal effect may be achieved by controlling the fit gap.

In order to improve the stability of the sealing rod 32 during axial movement, both ends of the sealing rod 32 are slidably engaged with the inner wall of the bush 35 and the inner wall of the valve body 31, respectively. The engagement between the seal rod 32 and the valve body 31 is only to improve the stability of the seal rod 32 when it moves axially, and thus there is no need for sealability. Therefore, the fit clearance between the outer wall of the seal rod 32 and the inner wall of the valve body 31 can be properly increased, and the processing requirement on the surface accuracy of the inner wall of the valve body 31 can be reduced. Alternatively, the fit clearance between the outer wall of the sealing rod 32 and the inner wall of the valve body 31 is 0.2mm to 1mm. Illustratively, the valve body 31 is an aluminum casting, which is convenient to process and low in cost.

Further, the valve body 31 includes a valve housing 314 and a valve cap 315, and the valve housing 314 and the valve cap 315 are detachably connected to facilitate the installation of various components in the valve body 31. In this embodiment, the valve housing 314 is engaged with the valve cap 315. Specifically, the outer peripheral wall of the valve housing 314 is provided with five temperature control clamping protrusions 3141 circumferentially distributed at intervals, the valve cover 315 is provided with temperature control clamping holes 3151 corresponding to the temperature control clamping protrusions 3141 one by one, and the temperature control clamping protrusions 3141 are clamped with the corresponding temperature control clamping holes 3151.

The valve cover 315 is provided with a wax valve penetrating hole, and the temperature-sensing wax valve 33 comprises a sensing end 331, a first matching section, a second matching section and the push rod 332 which are sequentially arranged along the axial direction of the temperature-sensing wax valve 33, wherein one end of the sensing end 331 penetrates through the wax valve penetrating hole and is arranged in the pre-filtering oil cavity 100, so that the temperature-sensing wax valve 33 can accurately sense the temperature in the pre-filtering oil cavity 100; the other end of the sensing end 331 is connected with the first matching section to form a wax valve matching surface, the wax valve penetrating hole is a stepped hole, and a wax valve limiting surface facing the sealing rod 32 is formed on the inner wall of the wax valve penetrating hole and axially abuts against the wax valve matching surface to axially limit the temperature-sensing wax valve 33. Illustratively, the fit clearance between the small diameter bore of the wax valve through bore and the sensing end 331 is 0.1mm to 1mm. The length of the induction end 331 is 5 mm-25 mm, and the diameter of the induction end 331 is 7 mm-9 mm; the first matching section is matched with a large-diameter hole of the through hole of the wax valve, the length of the first matching section is 5-10 mm, and the diameter of the first matching section is 10-15 mm; the second matching section is connected with the push rod 332, the second matching section is matched with the first matching section, the length of the second matching section is 2 mm-5 mm, and the diameter of the second matching section is 7 mm-9 mm; the telescopic length of the push rod 332 is 3 mm-20 mm, and the diameter of the push rod 332 is 2 mm-5 mm.

Further, the sealing rod 32 further comprises a plugging part and a reset limiting part, the plugging part is connected with the reset limiting part through a connecting rod, the wax valve matching part is arranged on one side of the reset limiting part, which is opposite to the connecting rod, and the wax valve matching part is provided with a plug hole for plugging the push rod 332; the plugging part is in sliding fit with the bushing 35, and one end, away from the bushing 35, of the elastic resetting piece is abutted to the resetting limiting part. In this embodiment, the plugging portion, the connecting rod, the reset limiting portion and the wax valve mating portion are axially and sequentially arranged and integrally formed. The outer diameter of the plugging part is 7-15 mm, the axial length of the plugging part is 3-20 mm, the plugging part is of a circular ring structure, the weight reduction effect is achieved, and the wall thickness of the plugging part is 1-2 mm; the outer diameter of the wax valve matching part is 15 mm-25 mm, and the wall thickness of the wax valve matching part is 2 mm-6 mm.

In order to improve stability in the axial movement process of the seal rod 32, the outer peripheral wall of the connecting rod is convexly provided with rod reinforcing ribs, the rod reinforcing ribs are provided with a plurality of rod reinforcing ribs, and the plurality of rod reinforcing ribs are distributed at intervals along the circumferential direction of the connecting rod. The connecting rod has first end and the second end of setting relatively along its axial, and first end links to each other and does not bulge in the shutoff portion with shutoff portion, and the second end links to each other and does not bulge in the spacing portion that resets with spacing portion that resets to avoid the strengthening rib to cause the interference to the flexible of control by temperature change elasticity reset piece 34. Illustratively, four bar reinforcing ribs are provided, and the wall thickness of the bar reinforcing ribs is 1 mm-4 mm.

Further, the filter element 2 comprises a top cover 21, a mounting bracket 22, a base 24 and a filter element main body 23, wherein the top cover 21 is connected with the base 24 through the mounting bracket 22, and the filter element main body 23 is mounted on the mounting bracket 22; the top cover 21 is connected to the upper cover 11, and the base 24 is connected to the case main body 12. Preferably, the top cover 21 is detachably connected to the upper cover 11, and the base 24 is detachably connected to the case main body 12. When the filter element 2 needs to be replaced, the mounting bracket 22 for mounting the filter element 2 is only required to be disassembled and assembled. For a fuel filter, the filter element body 23 may be filter paper, or may be another type of filter element.

The top wall of the top cover 21 and the inner wall of the upper cover 11 above it enclose a top gas chamber 400, the top gas chamber 400 communicating with the pre-filter oil chamber 100. During operation of the fuel filter, the top gas chamber 400 is filled with a gas, including air, oil mist, etc. As the fuel filter continues to operate, the amount of gas above the filter housing 1 increases, which directly affects the amount of fuel that can be contained within the filter housing 1, as the fuel may contain air. To this end, the fuel filter provided in this embodiment further includes a gas exhaust structure 6 for exhausting the gas in the top gas chamber 400.

As shown in fig. 4, 10 and 11, the exhaust structure 6 is a venturi structure through which the filtered oil chamber 200 communicates with the oil outlet passage, and an inlet of the venturi structure communicates with the top gas chamber 400. When the fuel passes through the venturi tube structure, negative pressure is formed in the venturi tube structure, so that the gas in the top gas cavity 400 is sucked into the venturi tube structure and flows to the oil outlet channel along with the fuel, the automatic exhaust of the fuel filter is realized, the structure is simple, the cost is low, and the fuel waste, the air pollution and the like caused by directly exhausting the gas in the top gas cavity 400 into the atmosphere can be avoided; recycling of the oil mist in the top gas chamber 400 is achieved.

Specifically, the venturi structure includes an exhaust pipe 62 and an exhaust pipe 61, wherein an upper inlet of the exhaust pipe 62 is communicated with the top gas cavity 400, the exhaust pipe 61 is sleeved outside the exhaust pipe 62, a venturi channel 63 is formed between the exhaust pipe 61 and the exhaust pipe 62, an upper inlet of the venturi channel 63 is communicated with the filtered oil cavity 200, and a lower outlet of the venturi channel 63 is communicated with the oil outlet channel.

When the fuel in the filtered oil chamber 200 is introduced into the annular region between the exhaust pipe 62 and the oil discharge pipe 61, the flow area of the fuel decreases, and when the fuel in the annular region enters the oil discharge passage, the flow area increases, so that negative pressure is formed in the annular region. The inner hole of the oil drain pipe 61 may be set as a variable diameter hole, and the diameter of the variable diameter hole may be changed from large to small and then be changed from large to large in the top-to-bottom direction; the exhaust pipe 62 may be a stepped pipe having an outer diameter which varies, and the outer diameter of the exhaust pipe 62 located in the exhaust pipe 61 in the up-down direction may be changed from small to large. Illustratively, the inner bore of the oil drain tube 61 is provided as a variable diameter bore.

The specific exhaust process is as follows: in the process of the operation of the fuel filter, the filtered fuel enters the filtered fuel cavity 200 and flows to the fuel outlet channel through the venturi channel 63, in the process of the fuel flowing through the venturi channel 63, negative pressure is formed in the venturi channel 63 according to the venturi principle, the pressure in the top gas cavity 400 is equal to or higher than the atmospheric pressure, and the gas in the top gas cavity 400 enters the venturi channel 63 through the exhaust pipe 62 and enters the fuel outlet channel through the venturi channel 63 together with the fuel.

The lower end of the exhaust pipe 62 is always located below the liquid level in the post-filter oil chamber 200 when the fuel filter is in operation, so that a negative pressure can be formed in the venturi passage 63 to introduce the gas in the top gas chamber 400 into the venturi passage 63 through the exhaust pipe 62. When the engine is started by adopting the method under the condition of diesel oil waxing, the venturi tube structure provided by the embodiment is matched for exhausting, so that the oil way from the oil tank to the engine is ensured to be in a closed state, and the method for starting the engine can be effectively implemented.

In the present embodiment, the side wall of the exhaust pipe 62 is provided with an exhaust through hole 6221 that communicates with the venturi passage 63. Specifically, the lower end of the exhaust pipe 62 is disposed through the exhaust pipe 61, and an exhaust through hole 6221 is provided on the side wall of the exhaust pipe 62 forming the venturi passage 63 with the exhaust pipe 61, so as to ensure that the gas in the top gas chamber 400 can enter the venturi passage 63 through the exhaust pipe 62 and the exhaust through hole 6221 thereon in the process of fuel flowing through the venturi passage 63.

Further, since the length of the exhaust pipe 62 is very long due to the height limitation of the fuel filter, the pipe processing is inconvenient, and for this purpose, the exhaust pipe 62 in this embodiment includes a top air pipe 621 and a bottom air pipe 622 separately provided, the upper end of the top air pipe 621 communicates with the top air chamber 400, the lower end of the top air pipe 621 communicates with the upper end of the bottom air pipe 622, and the lower end of the bottom air pipe 622 extends into the exhaust pipe 61 from the upper end of the exhaust pipe 61. The split arrangement of the exhaust pipe 62 can greatly reduce the difficulty in processing the exhaust pipe 62.

In this embodiment, the upper end of the top air pipe 621 is fixedly connected with the upper end of the filter element 2, and the lower end of the oil drain pipe 61 is fixedly connected with the lower end of the filter element 2. Specifically, the top air pipe 621 is a rubber pipe, a through hole is formed in the top cover 21 of the filter element 2, the through hole is a stepped hole, and the upper end of the top air pipe 621 is inserted into a large-diameter section of the through hole and is abutted against a stepped surface in the through hole so as to plug the top air pipe 621 into the top cover 21. Because the top air pipe 621 is a rubber pipe, sealing connection between the top air pipe 621 and the top cover 21 can be realized, and a sealing piece is not required. The top air pipe 621 and the top cover 21 are connected in a plugging manner, and the installation manner is simple and quick. The bottom air pipe 622 is a plastic pipe, the base 24 of the filter element 2 is of a metal structure, and the lower end of the bottom air pipe 622 can be connected to the base 24 of the filter element 2 in a threaded connection mode.

Further, in order to prevent the bottom air tube 622 and the top air tube 621 from swinging, a first anti-swing portion 6211 is interposed between the outer peripheral surface of the air discharge tube 62 and the inner peripheral surface of the oil discharge tube 61; the upper end of the exhaust pipe 62 extends out of the exhaust pipe 61, and a second anti-swing portion 6222 is interposed between the outer peripheral surface of the exhaust pipe 62 located outside the exhaust pipe 61 and the inner peripheral surface of the hollow structure. In order to prevent the oil drain pipe 61 from swinging, a third anti-swing portion 611 is interposed between the outer peripheral surface of the upper end of the oil drain pipe 61 and the inner peripheral surface of the hollow structure. Specifically, the outer peripheral wall of the bottom air pipe 622 is convexly provided with a plurality of first anti-swing parts 6211 which are circumferentially distributed at intervals, the outer peripheral wall of the top air pipe 621 is convexly provided with a plurality of second anti-swing parts 6222 which are circumferentially distributed at intervals, and the outer peripheral wall of the upper end of the oil drain pipe 61 is convexly provided with a plurality of third anti-swing parts 611 which are circumferentially distributed at intervals. It should be noted that the first anti-swing portion 6211, the second anti-swing portion 6222, and the third anti-swing portion 611 may be provided with more than one turn. In the present embodiment, the exhaust through hole 6221 is located between the first anti-sway portion 6211 and the second anti-sway portion 6222.

It should be noted that, the upper end of the oil drain pipe 61 may be opened to form an inlet of the venturi channel 63, or the top of the oil drain pipe 61 may be sealed, and an oil drain through hole may be provided on the oil drain pipe 61, so that the fuel in the filtered oil chamber 200 enters the oil drain pipe 61 through the oil drain through hole, and at this time, the position of the oil drain through hole is required to be higher than that of the exhaust through hole 6221. Illustratively, the height difference between the oil drain through hole and the exhaust through hole 6221 is 5 mm-10 mm, and the flow area of the oil drain through hole is 100mm ² ～300mm ² The method comprises the steps of carrying out a first treatment on the surface of the The pipe section of the annular region formed by the inner wall of the oil drain pipe 61 and the outer wall of the exhaust pipe 62 and capable of forming negative pressure is denoted as a negative pressure pipe section, the outer diameter of the negative pressure pipe section is 10 mm-40 mm, the wall thickness of the negative pressure pipe section is 1 mm-2 mm, and the axial length of the negative pressure pipe section is 5 mm-200 mm; the radial clearance between the inner wall of the negative pressure pipe section and the outer wall of the exhaust pipe 62 is 1mm to 10mm. The inner diameter of the top air pipe 621 is 2 mm-19 mm, and the wall thickness of the top air pipe 621 is 1 mm-2 mm. The inner diameter of the bottom air pipe 622 is 1 mm-15 mm, and the wall thickness of the bottom air pipe 622 is 1 mm-2 mm; the number of the first anti-swing portion 6211 and the second anti-swing portion 6222 is 4, and the radial thickness of the first anti-swing portion 6211 and the second anti-swing portion 6222 is 1mm to 10mm. The flow area of the exhaust through hole 6221 is 20mm ² ～200mm ² . In this embodiment, the upper end of the oil discharge pipe 61 is opened to form an inlet of the venturi passage 63.

Further, as shown in fig. 12 and 13, when the filter is inclined, the filter element 2 of the filter is clogged, etc., the fuel in the pre-filter oil chamber 100 and the fuel in the post-filter oil chamber 200 may cross each other through the top gas chamber 400, so that the filtering effect of the filter is affected. To solve this problem, the fuel filter provided in the present embodiment further includes a gas guide passage 711, wherein an upper end of the gas guide passage 711 communicates with the top gas chamber 400, and an upper end of the gas guide passage 711 is higher than a top wall of the filter cartridge 2; the upper end of the vent pipe communicates with the lower end of the gas guide channel 711, and the vent pipe can send the gas in the top gas chamber 400 to the oil outlet channel through the gas guide channel 711. In this embodiment, the vent pipe has the venturi structure described above. Specifically, the fuel filter further includes a guide cover 71 and a guide elastic restoring member 75, wherein the guide cover 71 is located in the top gas chamber 400, and a gas guide passage 711 is provided in the guide cover 71; the guide elastic restoring member 75 is used to press the guide housing 71 against the top wall of the cartridge 2 to simplify the manner of fixing the guide housing 71. In this embodiment, the guiding elastic restoring member 75 is a compression spring, the guiding elastic restoring member 75 is sleeved outside the guiding cover 71, and the guiding elastic restoring member 75 is sandwiched between the inner top wall of the filtering housing 1 and the guiding cover 71.

Since the upper end of the gas guide channel 711 is higher than the top wall of the filter element 2, the fuel filter is inclined or blocked, so that the probability of mutual channeling of the fuel in the pre-filter oil chamber 100 and the fuel in the post-filter oil chamber 200 through the top gas chamber 400 can be reduced, and the filtering effect of the fuel filter can be ensured.

In this embodiment, the gas guide channel 711 is a vertical channel, the upper and lower ends of the guide cover 71 are opened to form the gas guide channel 711, and a guide seal member 72 is provided between the lower end surface of the guide cover 71 and the top wall of the filter element 2. Specifically, the inner peripheral surface of the guide seal member 72 is provided with an annular groove, the lower end of the guide cover 71 is formed with an annular boss, the guide seal member 72 is sleeved outside the annular boss and is inserted into the annular groove, the upper end and the lower end of the guide elastic reset member 75 are respectively abutted against the inner top wall of the filter housing 1 and the annular boss, and the annular boss is used for crimping the guide seal member 72 to the top wall of the filter element 2 so as to prevent the guide seal member 72 from loosening. In order to improve the sealing effect, the lower surface of the guide sealing piece 72 is provided with two sealing convex rings, the two sealing convex rings are sleeved and distributed along the radial direction of the guide sealing piece 72, and the guide sealing piece 72 below the annular groove is clamped between the annular boss and the top wall of the filter element 2, so that the sealing effect is good.

Further, the upper portion of the guiding elastic restoring member 75 is abutted against the filter housing 1, and the lower portion of the guiding elastic restoring member 75 is fixedly connected to the guiding cover 71, so that the guiding elastic restoring member 75 is prevented from being separated from the filter cartridge 2 when maintenance is performed on the filter cartridge 2. In this embodiment, the upper surface of the annular boss is provided with a plurality of fastening structures distributed at intervals in the circumferential direction, and the guide cover 71 is fastened to the lower end of the guide elastic restoring member 75 through the fastening structures. Specifically, the fastening structure is two elastic plates 73 distributed along the radial direction of the annular boss at intervals, the upper parts of the opposite side surfaces of the two elastic plates 73 are convexly provided with anti-falling parts, and the lower end of the guiding elastic reset piece 75 is limited between the two elastic plates 73 below the guiding elastic reset piece through the two anti-falling parts.

Further, the fuel filter also includes a vent valve 74, wherein the vent valve 74 enables the top gas chamber 400 to be selectively vented to or disconnected from the outside atmosphere. The exhaust valve 74 may be used as a backup, and the exhaust may be periodically performed by the exhaust valve 74 when the exhaust structure 6 fails. In this embodiment, the exhaust valve 74 includes an exhaust plug screw, the lower end of which is screwed with the internal thread of the top exhaust hole 114, and the operating end of the exhaust plug screw is screwed to allow the top gas chamber 400 to communicate with the outside atmosphere through the top exhaust hole 114 when the fuel filter needs to be exhausted. In order to facilitate operation, the operation end of the exhaust screw plug is of an inner hexagonal wrench structure. The operating end may also be configured to facilitate direct screwing by a human hand, and is not particularly limited herein.

In order to prevent air leakage, an air bleed seal 741, such as an O-ring seal, is interposed between the air bleed screw and the filter housing 1. Specifically, the outer wall of the vent plug screw is provided with a vent seal groove in which a vent seal 741 is installed. Preferably, the air exhaust sealing member 741 is positioned at the upper part of the top air exhaust hole 114, the internal thread is positioned at the lower part of the top air exhaust hole 114, and the air exhaust sealing member 741 is used for sealing while the air exhaust valve 74 and the lower part of the top air exhaust hole 114 are matched by threads for sealing, so that double sealing is realized, and the sealing effect is improved.

Further, a counter bore is provided at the lower end of the exhaust valve 74, the upper end of the guide cover 71 is inserted into the counter bore, an air guide channel 500 is formed between the inner wall of the counter bore and the outer wall of the upper end of the guide cover 71, the lower end of the air guide channel 500 is communicated with the top gas chamber 400, and the upper end of the air guide channel 500 is communicated with the gas guide channel 711. Preferably, the vent valve 74 is provided at the highest position of the filter housing 1. With the above arrangement, the height of the upper opening of the gas guide channel 711 can be increased as much as possible, so that the possibility that the fuel in the pre-filter oil chamber 100 and the fuel in the post-filter oil chamber 200 cross each other through the top gas chamber 400 is greatly reduced in the use process of the fuel filter; the above arrangement can substantially prevent the fuel in the pre-filter oil chamber 100 and the fuel in the post-filter oil chamber 200 from channeling each other through the top gas chamber 400 due to tilting or shaking during the normal process of the fuel filter, considering that the fuel filter is vertically installed during the actual use. In this embodiment, the upper end of the guide cover 71 is a tube-shaped air duct, and the top of the air duct is inserted into the counter bore. Illustratively, the external thread on the vent valve 74 is a B20X 2 serration thread, which represents a nominal diameter of 20mm and a thread pitch of 2mm. The counter bore diameter on the exhaust valve 74 is 11mm, the inner diameter of the air duct is 4mm, the outer diameter of the air duct is 8mm, and the gap between the top wall of the guide cover 71 and the inner bottom wall of the counter bore is 2 mm-5 mm.

Further, as shown in fig. 4, 5 and 14, the upper cover 11 of the filter housing 1 includes an upper cover body, and the top vent 114 is disposed on the upper cover body and penetrates through the top inner and outer walls thereof. In order to meet the installation requirement of the exhaust screw plug, the inner top wall of the upper cover body is convexly provided with a first annular boss 115, and an inner hole of the first annular boss 115 forms the top exhaust hole 114. The first annular boss 115 further has the function of improving the structural strength of the upper cover 11, and in order to further improve the structural strength of the upper cover 11, the inner top wall of the upper cover body is convexly provided with a second annular boss 116 sleeved outside the first annular boss 115 and arranged at intervals with the first annular boss 115. Because the top vent 114 reduces the structural strength of the upper cover 11, the inner top wall of the upper cover body is provided with a first inner reinforcing rib 117, one end of the first inner reinforcing rib 117 is connected to the outer circumferential wall of the first annular boss 115, and the other end is connected to the inner circumferential wall of the second annular boss 116. The inner wall of the upper cover body is provided with a second inner side reinforcing rib 118, one end of the second inner side reinforcing rib 118 is connected to the outer peripheral wall of the second annular boss 116, and the other end extends to the inner side wall of the upper cover 11 along the inner top wall of the upper cover body. In order to stably guide the elastic restoring member 75, an annular mounting cavity is formed between the first annular boss 115 and the second annular boss 116, and the upper end of the temperature-controlled elastic restoring member 34 is inserted into the annular mounting cavity and abuts against the first inner reinforcing rib 117.

In order to further improve the structural strength of the upper cover 11, a plurality of outer reinforcing ribs 119 are provided on the outer wall of the upper cover body at intervals in the circumferential direction. The outer reinforcing rib 119 extends from the outer top wall of the upper cover body to the outer side wall of the upper cover body. The upper cover body, the first inner reinforcement 117, the second inner reinforcement 118, and the outer reinforcement 119 are integrally formed to reduce costs. The upper cover in the prior art does not have the first inner reinforcing rib 117 connecting the first annular boss 115 and the second annular boss 116, and the upper cover in the prior art and the upper cover 11 provided in this embodiment perform finite element simulation under the oil pressure effect of 10Bar at 23 ℃, and it should be noted that the upper cover 11 is made of a TPU material, and the yield strength of the TPU material at 23 ℃ is 83MPa, and the yield strain is 0.09. Referring to fig. 15, the first line in fig. 15 is a stress concentration analysis chart, a strain analysis chart and a deformation analysis chart of the existing upper cover, and the second line is a stress concentration analysis chart, a strain analysis chart and a deformation analysis chart of the upper cover 11 provided by the present embodiment, respectively, and compared with the upper cover in the prior art, the maximum stress concentration of the upper cover 11 provided by the present embodiment is reduced from 179.7Mpa to 45.52Mpa, the maximum strain is reduced from 0.103 to 0.025, and the maximum deformation is reduced from 6.96mm to 1.208mm, so that it is obvious that the structural strength of the upper cover 11 provided by the present embodiment can more satisfy the use requirement.

The fuel filter can be used as a coarse filter of an engine oil supply system, and can also be used as a fine filter of the engine oil supply system by replacing the filter element 2 with higher filtering precision.

Example two

As shown in fig. 16 to 20, the difference between the present embodiment and the first embodiment is that the relief hole 313 is eliminated, so that when the temperature-sensitive wax valve 33 drives the sealing rod 32 to move axially in the valve body 31, the sealing rod 32 can be located at a low-temperature communication position, a temperature-adaptive blocking position and a high-temperature relief position which are distributed in sequence along the axial direction of the sealing rod 32, wherein when the sealing rod 32 is located at the low-temperature communication position, the external oil port 311 and the oil outlet 312 are communicated, and the external oil port 311 is disconnected from the assembly space 36; when the sealing rod 32 is at the proper-temperature blocking position, the external oil port 311 and the oil outlet 312 are disconnected, and the external oil port 311 is disconnected from the assembly space 36; when the seal rod 32 is in the high-temperature pressure relief position, the external oil port 311 and the oil outlet 312 are disconnected and the external oil port 311 is communicated with the assembly space 36.

During normal engine operation, the diesel temperature is typically high, at which point bypass gallery 300 is closed. Since diesel waxing usually occurs at low temperature and under the condition that the engine is not started, and diesel in the fuel filter gradually decreases in the process of flameout of the engine, although the diesel is inevitably present on the filter element 2, the height of the residual diesel liquid level in the fuel filter is not high, and after the pressure relief hole 313 is eliminated, the sealing rod 32 is higher than the diesel liquid level in the fuel filter when the liquid level in the fuel filter is not changed any more after flameout of the engine by adjusting the installation height of the bypass temperature control valve 3.

During normal operation of the engine, the sealing rod 32 is in a high-temperature pressure relief position, and the assembly space 36 is communicated with the pre-filter oil chamber 100 through the external oil port 311, so that the oil pressure in the assembly space 36 is prevented from being too high. After the engine is turned off, as the temperature of the diesel oil decreases, the seal rod 32 gradually moves to the temperature-suitable blocking position, and even in a low-temperature environment, the seal rod 32 moves to the low-temperature communication position. Since the diesel oil in the fuel filter is cooled down in the process of engine flameout, the sealing rod 32 is gradually reset in the process of cooling the diesel oil, the liquid level of the diesel oil in the fuel filter is gradually reduced, and the external oil port 311 is communicated with the assembly space 36 when the sealing rod 32 is positioned at the high-temperature pressure relief position, the liquid level of the assembly space 36 and the liquid level in the pre-filter oil cavity 100 are basically positioned at the same height in the process of resetting the sealing rod 32, and the sealing rod 32 is gradually reset along with the continuous decrease of the temperature in the pre-filter oil cavity 100, and most of the diesel oil in the assembly space 36 is returned into the pre-filter oil cavity 100 from the external oil port 311 before the sealing rod 32 is moved to the temperature-adapting blocking position by limiting the length of the sealing rod 32 and the position of the external oil port 311; when the sealing rod 32 moves to the proper temperature blocking position, the external oil port 311 is disconnected from the assembly space 36, and at this time, residual fuel in the assembly space 36 is less, so that even if the temperature continues to be reduced, the residual fuel in the assembly space 36 is waxed, and the sealing rod 32 is not affected to move to the low-temperature communication position.

When the sealing rod 32 moves between the temperature-suitable blocking position and the low-temperature communication position, the pressure change in the assembly space 36 is not obvious at low temperature, so that the movement of the sealing rod 32 is basically not influenced, and the pressure release problem of the assembly space 36 can be avoided. Illustratively, the temperature in the pre-filter oil chamber 100 is T, and as shown in FIG. 16, at T.ltoreq.20 ℃, the seal rod 32 is in the low temperature communication position, at which the communication opening degree of the external oil port 311 and the oil outlet port 312 is maximum and the external oil port 311 and the fitting space 36 are completely disconnected; as shown in fig. 17, when-20 ℃ is less than T < -13 ℃, the outer oil port 311 and the oil outlet 312 are partially communicated and the outer oil port 311 and the assembly space 36 are completely disconnected; as shown in fig. 18, when-13 ℃ is less than or equal to T is less than or equal to 25 ℃, the sealing rod 32 is in the temperature-suitable blocking position, at the moment, the outer oil port 311 and the oil outlet 312 are completely disconnected, and the outer oil port 311 and the assembly space 36 are completely disconnected; as shown in fig. 19, when 25 ℃ < T < 80 ℃, the outer oil port 311 is partially communicated with the fitting space 36 and the outer oil port 311 and the oil outlet 312 are completely disconnected; as shown in FIG. 20, when T is not less than 80 ℃, the communication opening between the outer oil port 311 and the fitting space 36 is maximum and the outer oil port 311 and the oil outlet 312 are completely disconnected.

It should be noted that, the relationship between the position of the sealing rod 32 and the temperature in the pre-filter oil chamber 100 is not limited to the above arrangement, and other arrangements may be adopted, which are not illustrated here.

Claims

1. The utility model provides a fuel filter exhaust structure, includes filtration casing (1) and filter core (2), filter core (2) install in filtration casing (1) in and with the inner chamber of filtration casing (1) divide into before-filter oil pocket (100) and after-filter oil pocket (200), be equipped with the oil outlet channel on filtration casing (1), the roof of filter core (2) with the inner wall of filtration casing (1) encloses into have with top gas chamber (400) of before-filter oil pocket (100) intercommunication;

the fuel filter exhaust structure is characterized by further comprising:

a gas guiding passage (711), an upper end of the gas guiding passage (711) communicating with the top gas chamber (400), and an upper end of the gas guiding passage (711) being higher than a top wall of the cartridge (2);

the upper end of the vent pipe is communicated with the lower end of the gas guide channel (711), the vent pipe can convey gas in the top gas cavity (400) to the oil outlet channel through the gas guide channel (711), the vent pipe is of a venturi structure, the venturi structure comprises an exhaust pipe (62) and an exhaust pipe (61), an upper end inlet of the exhaust pipe (62) is communicated with the top gas cavity (400), the exhaust pipe (61) is sleeved outside the exhaust pipe (62), a venturi channel (63) is formed between the exhaust pipe (61) and the exhaust pipe (62), an upper end inlet of the venturi channel (63) is communicated with the filtered oil cavity (200), a lower end outlet of the venturi channel (63) is communicated with the oil outlet channel, and an exhaust through hole (6221) communicated with the venturi channel (63) is formed in the side wall of the exhaust pipe (62);

The fuel filter exhaust structure further includes:

a guide cover (71), wherein the guide cover (71) is positioned in the top gas cavity (400), and the gas guide channel (711) is arranged in the guide cover (71);

a guide elastic return member (75) for pressing the guide cap (71) against the top wall of the cartridge (2);

a vent valve (74), the vent valve (74) being capable of selectively connecting or disconnecting the top gas chamber (400) to the outside atmosphere; the top of the filtering shell (1) is provided with an assembly through hole, and the lower end of the exhaust valve (74) is in threaded connection with the assembly through hole; the lower end of the exhaust valve (74) is provided with a counter bore, the upper end of the guide cover (71) is inserted into the counter bore, and an air guide channel (500) is formed between the inner wall of the counter bore and the outer wall of the upper end of the guide cover (71); the lower end of the gas guide channel (500) is communicated with the top gas cavity (400), and the upper end of the gas guide channel (500) is communicated with the gas guide channel (711).

2. A fuel filter exhaust structure according to claim 1, characterized in that a guide seal (72) is provided between the lower end face of the guide cap (71) and the top wall of the filter cartridge (2).

3. The fuel filter exhaust structure according to claim 1, wherein an upper end of the guide elastic restoring member (75) is fixedly connected with the filter housing (1), and a lower end of the guide elastic restoring member (75) is fixedly connected with the guide cover (71).

4. A fuel filter exhaust structure according to claim 3, wherein the guide cover (71) is engaged with the lower end of the guide elastic restoring member (75) by a plurality of circumferentially spaced snap-fit structures.

5. A fuel filter comprising the fuel filter exhaust structure of any one of claims 1 to 4.

6. An engine fueling system comprising the fuel filter of claim 5.