CN113685291B - Oil tank isolating valve - Google Patents
Oil tank isolating valve Download PDFInfo
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- CN113685291B CN113685291B CN202110888965.9A CN202110888965A CN113685291B CN 113685291 B CN113685291 B CN 113685291B CN 202110888965 A CN202110888965 A CN 202110888965A CN 113685291 B CN113685291 B CN 113685291B
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M25/00—Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture
- F02M25/08—Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture adding fuel vapours drawn from engine fuel reservoir
- F02M25/0854—Details of the absorption canister
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M25/00—Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture
- F02M25/08—Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture adding fuel vapours drawn from engine fuel reservoir
- F02M25/0836—Arrangement of valves controlling the admission of fuel vapour to an engine, e.g. valve being disposed between fuel tank or absorption canister and intake manifold
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/60—Other road transportation technologies with climate change mitigation effect
- Y02T10/62—Hybrid vehicles
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- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Cooling, Air Intake And Gas Exhaust, And Fuel Tank Arrangements In Propulsion Units (AREA)
Abstract
The invention discloses an oil tank isolating valve. The two-way valve assembly is arranged in the valve body and divides the valve body into a first cavity and a second cavity, the pilot cavity is fixed on one side of the valve body to seal one side of the valve body, the two-way valve assembly comprises a positive pressure valve rod, a negative pressure valve rod, a positive pressure spring and a negative pressure spring, one end of the positive pressure valve rod is a positioning rod, a ventilation cavity is arranged in the middle of the positive pressure valve rod, and a negative pressure valve cavity is arranged in the other end of the positive pressure valve rod; the positive pressure spring is sleeved outside the other end of the positive pressure valve rod, one end of the positive pressure spring is contacted with the disc, and the other end of the positive pressure spring is contacted with the inner wall of the valve body; the negative pressure valve rod is arranged inside the negative pressure valve cavity, and the negative pressure spring is sleeved outside the negative pressure valve rod. The invention can reduce the work load of the carbon canister, and the carbon canister realizes the function of low HC emission under the condition of low desorption.
Description
Technical Field
The invention belongs to the technical field of fuel evaporation control systems, and particularly relates to an oil tank isolation valve.
Background
The carbon canister can adsorb fuel steam volatilized from the fuel tank, and the negative pressure in the air inlet manifold can convey the fuel steam adsorbed in the carbon canister to the combustion chamber to participate in combustion when the engine works, so that the volatilization of the fuel steam is reduced, and the aim of saving energy is fulfilled. Along with the requirements of China on energy conservation and emission reduction, the hybrid vehicles are more and more. The vehicle type is mainly characterized in that the working time of the engine is shorter and shorter, so that fuel steam adsorbed in the carbon canister cannot be completely desorbed, and the fuel steam volatilized from the carbon canister is more when the vehicle stops. To solve this problem, there are two main solutions to the fuel evaporation control system:
1. for PHEV (plug-in hybrid electric) vehicle models: the high-pressure oil tank and the fuel evaporation control system are separated by adopting the high-pressure isolating valve, so that the volatilization amount of fuel steam in the high-pressure oil tank is obviously reduced, and the fuel amount entering the carbon canister is less. Therefore, the problem that the carbon tank causes excessive discharge of a fuel system due to the fact that the desorption volume is reduced can be solved. However, not only the cost of the tank isolation valve is high, but also the fuel tank needs to be a high-pressure fuel tank, active air pumping devices need to be adopted for OBD leakage detection, and the cost of the whole fuel evaporation control system is high.
2. For HEV (non plug-in hybrid) vehicle models: whole fuel evaporation control system is unanimous with traditional fuel car, and direct intercommunication between oil tank and the charcoal jar can increase the honeycomb formula charcoal stick with the atmospheric end department at the charcoal jar in order to reduce the charcoal jar evaporation emission volume, because desorption volume is low excessively, can use many honeycomb charcoal sticks usually. The cost is high due to the factors of complex manufacturing process, technical monopoly and the like of the honeycomb carbon rod, the honeycomb carbon rod can be divided into different specifications, and the different specifications and the different costs have larger differences.
Disclosure of Invention
The invention aims to solve the defects of the background technology, and provides an oil tank isolation valve which can be used in an HEV (electric vehicle) type, can reduce the emission of a carbon canister and can reduce the cost.
The technical scheme adopted by the invention is as follows: an oil tank isolation valve comprises a valve body, a two-way valve component and a pilot cavity, wherein the two-way valve component is arranged in the valve body and divides the valve body into a first cavity and a second cavity, the pilot cavity is fixed on one side of the valve body and seals one side of the valve body, the two-way valve component comprises a positive pressure valve rod, a negative pressure valve rod, a positive pressure spring and a negative pressure spring,
one end of the positive pressure valve rod is a positioning rod, a ventilation cavity is arranged in the middle of the positive pressure valve rod, a negative pressure valve cavity is arranged in the other end of the positive pressure valve rod, the positioning rod penetrates through one side of the valve body to be in contact with the elastic side of the pilot cavity, one end of the negative pressure valve cavity is communicated with the ventilation cavity, the other end of the negative pressure valve cavity is provided with a negative pressure end cover, a second ventilation hole communicated with the ventilation cavity is formed in the positioning rod, a disc connected with the valve body is arranged outside the middle of the positive pressure valve rod, and a third ventilation hole is formed in the negative pressure end cover; the positive pressure spring is sleeved outside the other end of the positive pressure valve rod, one end of the positive pressure spring is contacted with the disc, and the other end of the positive pressure spring is contacted with the inner wall of the valve body; the negative pressure valve rod is arranged in the negative pressure valve cavity, and the negative pressure spring is sleeved outside the negative pressure valve rod.
The two-way valve assembly is a mechanical normally-closed pressure valve and is provided with two pipe joints which are respectively connected with a steam pipe orifice of an oil tank and an adsorption pipe orifice of a carbon canister, the opening pressure of a channel of the steam pipe of the oil tank to the adsorption pipe orifice of the carbon canister can be designed to be below 35kPa or below 15kPa, and the opening pressure of a channel of the adsorption pipe orifice of the carbon canister to the steam pipe of the oil tank is designed to be below 6 kPa. Two connectors are arranged on the upper portion of the pilot cavity, one connector is designed to be in a closed form and can be detached, the connector is conveniently connected with other equipment in a matched mode, and the other connector is connected with a desorption pipe opening of the carbon tank. The lower part of the pilot cavity is provided with a rubber diaphragm which can be transmitted to the two-way valve assembly when acting, and the carbon canister can deform the rubber diaphragm when desorbing, so that the opening or closing function of the two-way valve assembly is realized.
Further, the valve body includes axial one end confined changeover portion, is located the radial both sides of changeover portion and coaxial arrangement's first coupling and second coupling respectively, the radial one side of changeover portion and first coupling intercommunication, the changeover portion axial other end and second coupling intercommunication, be equipped with annular linkage segment on the pipe outer wall of first coupling and second coupling, connect first support on the linkage segment, on the guide's cavity is fixed in first support, be equipped with first air vent on the first support, the two-way valve subassembly is installed on the changeover portion, and two-way valve subassembly one end is located inside the changeover portion, the other end passes first support center and contacts with the guide's cavity.
Further, first support includes cylindrical supporter, and the inside fixedly connected with of supporter crosses the cab apron with supporter inner wall vertically, supporter axial one end sets up flange, flange with linkage segment fixed connection, the supporter axial other end set up annular first recess, and first recess edge is equipped with a plurality of first buckles along the circumference, guide's cavity and first buckle and first groove connection, cross cab apron center and set up the shaft hole that is used for the locating lever to pass, the shaft hole is around setting up a plurality of first air vents all around.
Furthermore, one end of the negative pressure valve rod is in sealing contact with the axial limiting surface of the inner wall of the positive pressure valve rod to separate the ventilation cavity from the negative pressure valve cavity, the outer diameter of one end of the negative pressure valve rod is smaller than the inner diameter of the negative pressure valve cavity, and the other end of the negative pressure valve rod penetrates through the negative pressure end cover.
Furthermore, the pilot cavity comprises a first end cover, a first diaphragm and a first compression spring, the first end cover is of an arch structure, a movable closed control joint is arranged on the first end cover, and first buckling holes connected with the valve body are formed in the peripheral edge of the first end cover; the outer edge of the first diaphragm is in sealing contact with the edge of the valve body and the edge of the first end cover, a guide groove matched with the positioning rod is formed in the center of one side of the first diaphragm, one end of the first compression spring is in center contact with the inner wall of the first end cover, and the other end of the first compression spring is in center contact with the other side of the first diaphragm.
Further, first diaphragm includes base and annular flexure strip, and flexure strip one side is inwards sunken to form the protruding portion, flexure strip inner ring border and base edge fixed connection all around, flexure strip outer loop edge and valve body and first end cover edge sealing contact, a base side is equipped with the indent and locating lever complex guide slot, base another side be equipped with first compression spring complex spring groove.
Furthermore, a desorption joint communicated with a desorption pipe orifice of the carbon canister is arranged on the first end cover.
The isolating valve is installed between the common oil tank and the carbon canister, and can be opened when the engine is started, and the valve is closed under other working conditions. Because the valve is in a closed state, the aim of reducing fuel evaporation and emission can be achieved, and the aim of polluting the carbon canister by separating out liquid fuel due to shaking of the vehicle can be avoided.
When the engine works: the oil pump pumps fuel oil into the engine for combustion, negative pressure can be generated in a closed oil tank system to open the check valve of the device, and the carbon tank supplies air to the oil tank, so that the function of normally pumping the oil is realized.
When the engine stops working: the liquid fuel is converted into gaseous fuel due to the higher pressure in the fuel tank, and the gaseous fuel is low in quantity, so that the fuel can be absorbed by the carbon canister when the pressure of the fuel in the fuel tank exceeds the set opening pressure upper limit along with the increase of time. Therefore, the work load of the carbon tank can be greatly reduced, so that the carbon tank realizes the function of low HC emission under the condition of low desorption, and simultaneously, the use of honeycomb carbon rods can be cancelled or reduced, and the purpose of reducing the cost of a fuel evaporation control system is realized.
During fuel system leakage check: the ECU sends out an instruction to close a CVS valve of a large air port of the carbon tank; when the pressure at the desorption end of the carbon canister reaches a set pressure value, the pressure in the fuel evaporation control system is kept consistent together with the pressure in the carbon canister after the device is opened, so that the ECU can judge whether the system leaks or not through the pressure change rate in the pressure sensor.
The invention has the beneficial effects that: the invention can reduce the work load of the carbon canister, the carbon canister realizes the function of low HC emission under the condition of low desorption, and compared with the oil tank isolating valve which realizes the same function, the invention has the following advantages:
1. more energy-saving. The common oil tank isolation valve controls the electromagnetic valve through electric energy in an automobile to achieve the opening and closing functions of the pressure valve, and the invention controls the opening and closing of the pressure valve by utilizing a pneumatic transmission mode, so that the common oil tank isolation valve is more energy-saving compared with the common oil tank isolation valve.
2. And is safer. The tank isolation valve is typically disposed between the high pressure tank and the canister such that the fuel concentration in the tank isolation valve is relatively high, and the tank isolation valve is controlled by electrical power, which may present an uncontrolled safety problem if a short circuit occurs or the coil is damaged by overheating. The control mode of the invention does not use electric energy, and is safer compared with the common oil tank isolating valve.
3. The cost is more excellent. The common oil tank isolation valve uses an electromagnetic coil with higher power, but the invention does not need the part, and the manufacturing cost of the part is low; the common oil tank isolation valve can be used only after a user calibrates a whole vehicle system, if a vehicle is replaced, the calibration program is rewritten, so that the development cost is increased, and the invention directly and automatically controls the pressure in the system, thereby improving the universality. The vehicle can be directly used on different vehicle types, the whole vehicle program does not need to be rewritten, and the development cost is reduced.
Drawings
Fig. 1 is a schematic structural diagram of the oil tank isolating valve.
Fig. 2 is a schematic structural diagram of the oil tank isolating valve body.
Fig. 3 is a schematic structural diagram of a first bracket of the fuel tank isolating valve.
Fig. 4 is a schematic structural diagram of a two-way valve assembly of the tank isolation valve (a positive pressure spring is not shown in the figure).
FIG. 5 is a cross-sectional view of a two-way valve assembly of the tank isolation valve of the present invention (the positive pressure spring is not shown).
Fig. 6 is a schematic structural diagram of a first end cover of the oil tank isolating valve.
Fig. 7 is a partial enlarged view of a portion a in fig. 6.
Fig. 8 is a schematic structural view of a first diaphragm of the tank isolation valve of the present invention.
FIG. 9 is a schematic representation of the operation of an engine incorporating the control system of the present invention during operation.
Fig. 10 is a schematic diagram of the operation of the fuel vaporization incorporating the control system of the present invention.
FIG. 11 is a schematic diagram of the operation of a fuel system leak check incorporating the control system of the present invention.
In the figure: 100-tank isolation valve; 200-an engine control unit; 300-a tank assembly; 400-a pressure detection module; 500-carbon canister; 600-desorption control valve; 700-a vent solenoid valve; 800-ash filter; 10-a valve body; 11-a transition section; 11 a-the radial side; 11 b-axial other end; 11 c-sealing step; 12-a first pipe joint; 13-a second pipe joint; 14-a connecting segment; 14 a-welding ribs; 20-a first scaffold; 21-a support; 22-a transition plate; 23-a connecting flange; 24-a first groove; 25-a first buckle; 26-shaft hole; 27-a first vent; 30-a two-way valve assembly; 31-positive pressure valve stem; 31 a-positioning rod; 31 b-a ventilation lumen; 31 c-negative pressure valve cavity; 31 d-negative pressure end cover; 31 e-a second vent; 31 f-disc; 31 g-a third vent; 31 h-positive pressure gasket; 31 i-U-shaped groove; 32-a negative pressure valve stem; 32 a-one end; 32 b-the other end; 32 c-negative pressure gasket; 33-a positive pressure spring; 34-a negative pressure spring; 40-a first end cap; 41-control connection; 42-desorption joint; 43-first snap hole; 44-a first sealing rib; 45-a first guide boss; 46-a first compression spring; 50-a first membrane; 51-a base; 51 a-a guide groove; 51 b-spring groove; 52-an elastic sheet; 52 a-inner ring edge; 52 b-outer ring edge; 52 c-sealing flange; 52 d-projection.
Detailed Description
The following further describes embodiments of the present invention with reference to the drawings. It should be noted that the description of the embodiments is provided to help understanding of the present invention, but the present invention is not limited thereto. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.
As shown in fig. 1 to 8, the present invention provides a tank isolation valve, which is assembled by a valve body 10, a first bracket 20, a first end cap 43, a first compression spring 46, a first diaphragm 50, and a two-way valve assembly 30, wherein the first diaphragm 50, the first compression spring 46, and the first end cap 40 form a pilot chamber after assembly. The two-way valve assembly 30 is installed inside the valve body 1 to divide the valve body 1 into a first cavity A and a second cavity B, the pilot cavity is fixed on one side of the valve body 1 to seal one side of the valve body 1, a positioning rod 31a of the two-way valve assembly 30 penetrates through one side of the valve body 1 to be in contact with the elastic side of the pilot cavity, and the two-way valve assembly 30 is driven to act through pressure change of the first cavity A or the second cavity B to enable the first cavity A and the second cavity B to be communicated or disconnected.
The working principle of the invention is as follows: the spring force of the first compression spring 46 in the pilot chamber > the spring force of the positive pressure spring 33; under a normal condition, the elastic force of the first compression spring 46 is transmitted to the two-way valve assembly 30 through the diaphragm 50, so that the two-way valve assembly is attached to the sealing step 11c on the transition section 11 of the valve body 10 to form a function of closing an air flow channel, the valve body 10 is divided into a first cavity A and a second cavity B, when negative pressure is generated in the pilot cavity, the first diaphragm 50 deforms and displaces, and the elastic force of the positive pressure spring 33 pushes the positive pressure valve rod 31 of the two-way valve assembly 30 to move to realize a function of communicating the first cavity A with the second cavity B; when positive pressure is generated in the first cavity A, and resultant force formed by the pressure and the positive pressure spring 33 is larger than the elastic force of the first compression spring 46, the positive pressure valve rod 31 of the two-way valve assembly 30 moves to realize the function of communicating the first cavity A with the second cavity A; when negative pressure is generated in the first cavity A, the negative pressure overcomes the elasticity of the negative pressure spring 34 in the two-way valve assembly 30, and the negative pressure valve rod 32 moves to realize the function of communicating the first cavity A with the second cavity A.
As shown in fig. 2, the valve body 10 includes a transition section 11 with one end in the axial direction being closed, a first pipe joint 12 and a second pipe joint 13 which are respectively located on two sides of the transition section 11 in the radial direction and are coaxially arranged, the transition section 11, the first pipe joint 12 and the second pipe joint 13 are integrally connected, the transition section 11 is perpendicular to the first pipe joint 12 and is arranged, one side 11a of the transition section 11 in the radial direction is communicated with the first pipe joint 12, the other end 11b of the transition section 11 in the axial direction is communicated with the second pipe joint 13, an annular connecting section 14 is arranged on the outer wall of the first pipe joint 12 and the second pipe joint 13, a first bracket 20 is connected to the connecting section 14, the pilot cavity is fixed on the first bracket 20, a first vent 27 is arranged on the first bracket 20, a two-way valve assembly 30 is installed on the transition section 11, one end of the two-way valve assembly 30 is located inside the transition section 11, and the other end of the first bracket 20 passes through the center and contacts with the pilot cavity. The first pipe joint 11 and the second pipe joint 12 are both quick-insertion male joints of SAE standard, the first pipe joint 11 is used for connecting with the pressure sensor 400, and the second pipe joint 13 is used for communicating with the adsorption pipe orifice of the carbon canister 500. A raised circular ring structure is arranged on the sealing step 11c at the other axial end of the transition section 11 and used for realizing the function of sealing a cavity with the positive pressure sealing gasket 31 h. The welding rib 14a arranged on the connecting section 14 is a raised circular ring step for welding with the connecting flange 23 of the first bracket 20.
As shown in fig. 3, the first bracket 20 includes a cylindrical support 21, a transition plate 22 is fixedly connected inside the support 21 and perpendicular to the inner wall of the support 21, the support 21 and the longitudinal section of the transition plate 22 form an H-shaped structure, an integrated connecting flange 23 is arranged at one axial end of the support 21, the connecting flange 23 is fixedly connected to the connecting section 14, an annular first groove 24 is arranged at the other axial end of the support 21, a plurality of first buckles 25 are arranged at the edge of the first groove 24 along the circumference, the pilot cavity is connected to the first buckles 25 and the first groove 24, a shaft hole 26 for the positioning rod to pass through is arranged at the center of the transition plate 22, and a plurality of first vent holes 27 are arranged around the shaft hole 26. The width of the connecting flange 23 of the first bracket 20 is more than 3mm, so that the clamping of the tool is convenient to use during welding; the first groove 24 is provided for the function of a sealing flange 52c for fixing the first membrane 50, the width of the first groove 24 being greater than the width of the sealing flange 52c, and the depth of the first groove 24 being less than the height of the sealing flange 52 c. The first buckle 25 is a conventional buckle structure and is designed to play a role of fixing the first end cap 40 after being assembled with the first buckle hole; the inner diameter of the shaft hole 26 is larger than the outer diameter of the positioning rod 31a of the positive pressure valve rod 31, and the clearance is controlled within 0.5mm, so that the degree of freedom of the positioning rod 31a is only left in the axial direction.
As shown in fig. 4 and 5, the two-way valve assembly 30 includes a positive pressure valve rod 31, a negative pressure valve rod 32, a positive pressure spring 33 and a negative pressure spring 34, one end of the positive pressure valve rod 31 is a positioning rod 31a, a vent cavity 31b is arranged in the middle of the positive pressure valve rod 31, a negative pressure valve cavity 31c is arranged in the other end of the positive pressure valve rod 31, one end of the negative pressure valve cavity 31c is communicated with the vent cavity 31b, and the other end is provided with a negative pressure end cap 31d, except the negative pressure end cap, the positive pressure valve rod 31 can be integrally formed; a second vent hole 31e communicated with the vent cavity 31b is formed in the positioning rod 31a, a disc 31f connected with the valve body is arranged outside the middle of the positive pressure valve rod 31, a U-shaped groove 31i is formed in one side, close to the negative pressure valve cavity, of the disc 31f, a positive pressure sealing gasket 31h is arranged in the U-shaped groove 31i and used for being in sealing fit with a sealing step 11c of the transition section 11, and a third vent hole 31g is formed in the negative pressure end cover 31d; the positive pressure spring 33 is sleeved outside the other end of the positive pressure valve rod 31, one end of the positive pressure spring 33 is in contact with the disc 31f (when the positive pressure sealing gasket 31h is arranged, the positive pressure spring is in contact with the positive pressure sealing gasket 31 h), and the other end of the positive pressure spring 33 is in contact with the inner wall of the valve body 10 (namely, the inner wall of the axial end part of the transition section 11).
The negative pressure valve rod 32 is arranged in the negative pressure valve cavity 31c, one end 32a of the negative pressure valve rod 32 is in sealing contact with the axial limiting surface of the inner wall of the positive pressure valve rod 31 to separate the vent cavity 31b from the negative pressure valve cavity 31c, the outer diameter of one end 32a of the negative pressure valve rod 32 is smaller than the inner diameter of the negative pressure valve cavity 31c, and the other end 32b of the negative pressure valve rod 32 penetrates through the negative pressure end cover 31d; the negative pressure spring 34 is sleeved outside the negative pressure valve rod 21, one end of the negative pressure spring 43 is in contact with the end limiting surface of the negative pressure valve rod 32, and the other end of the negative pressure spring is in contact with the negative pressure end cover 31 d.
The positioning rod 31a is matched with the guide groove 51a on the first membrane 50, and the shaft end of the positioning rod 31a is designed to be spherical so that the stress is uniform. The second vent hole 31e is directly communicated with the vent cavity 31b, the vent cavity 31b and the negative pressure valve cavity 31c are coaxial, the inner diameter of the vent cavity 31b is smaller than that of the negative pressure valve cavity 31c, and the vent cavity 31b is directly communicated with the negative pressure valve cavity 31c when the negative pressure valve rod 32 and the negative pressure sealing gasket 32c are not assembled; the outer diameter of the U-shaped groove 31i for assembling the positive pressure sealing gasket 31h is larger than or equal to the inner hole of the positive pressure sealing gasket 31h, and the disc 31f and the positive pressure sealing gasket 31h can be designed into an integral piece or a split piece; the positive pressure sealing gasket 31h is annular, is made of a flexible material, and is preferably made of rubber materials such as NBR (nitrile butadiene rubber), FKM (FKM) and the like; the negative pressure valve rod 31 and the negative pressure sealing gasket 32c can be designed to be an integral piece or a split piece, and the material of the negative pressure sealing gasket 32c is consistent with that of the positive pressure sealing gasket 31 h. The central hole of the structure of the negative pressure end cover 31d has the guiding function of the negative pressure valve rod 32, and a plurality of third vent holes 31g for ventilation can be designed besides the central hole. The negative pressure spring 34 can be a tower spring or a cylinder type spring, and the installation elastic force of the negative pressure spring 34 is designed by fully considering the influence of the gravity and the sealing area of the negative pressure valve rod 32 and the negative pressure sealing gasket 32 c.
As shown in fig. 6 and 7, the first end cover 40 is of an arch structure, the first end cover 40 is provided with a movable closed control joint 41 and a desorption joint 42 for communicating with a desorption nozzle of the carbon canister, the control joint 41 is in a closed state in a normal state, and when communication with other equipment is required, the end part of the control joint can be opened to form a channel. The first end cover 40 is provided with a first snap hole 43 connected with the first bracket 20 at the peripheral edge, a raised first sealing rib 44 is arranged at the inner side edge of the first snap hole 43, and a first guide boss 45 is arranged at the coaxial position of the inner wall center of the first end cover 30 and the control joint 41; the control joint 41 is a pipe opening which can be forcibly disconnected and is communicated with the communication joint 71 of the second end cover 70 through a pipeline; the desorption joint 42 is a strong desorption pipe orifice which can be communicated with the desorption pipe orifice of the carbon canister 500 through a pipeline; the first fastening hole 43 is designed to have a larger taper to facilitate the assembly of the first fastener 25, and the minimum width is larger than the width of the first fastener 25; the first sealing ribs 44 are continuous semicircular bulges, and the height of the bulges is 10-20% of the thickness of the sealing flange 52 c; the first guide boss 45 is designed to limit the moving direction of the first compression spring 46 and to prevent the first compression spring 46 from falling down.
As shown in fig. 8, the first diaphragm 50 includes a base 51 and a ring-shaped elastic sheet 52, one or more positions on one side of the elastic sheet 52 are recessed inward to form a protrusion 52d to improve the strength of the elastic sheet, an inner ring edge 52a of the elastic sheet 52 is fixedly connected to the peripheral edge of the base 51, an outer ring edge 52b of the elastic sheet 52 is provided with a sealing flange 52c and is in sealing contact with the edges of the first bracket 20 and the first end cap 40, one side of the base 51 is provided with a recessed guide groove 51a matched with the positioning rod 31a, and the other side of the base 51 is provided with a spring groove 51b matched with the first compression spring 46. The elastic sheet 52 is made of a flexible material, preferably a rubber material such as NBR or FKM, and in order to increase the service life, it is preferable to add a woven polyester yarn inside or outside the material. The base 51 is made of a rigid material, preferably plastic. The thickness of the sealing flange 52c is greater than the height of the first groove 24; the inner ring edge 52a of the elastic sheet and the peripheral edge of the base 51 are combined into a whole part through processes such as vulcanization or glue injection. The thickness of the middle portion of the elastic sheet 52 is designed to be as thin as possible under the condition of ensuring the compression, so that the sensitivity of the device can be ensured, and the thickness is preferably between 0.2 and 1 mm. The guide groove 51a is designed to be arched to better fit with the positioning rod 31a of the positive pressure valve rod 31, the inner diameter of the spring groove 51b is larger than the outer diameter of the first compression spring 46, and the height of the step arched in the spring groove 51b is larger than 5 times the wire diameter of the first compression spring 46.
As shown in fig. 9 to 11, when the present invention is applied to a fuel evaporation control system, the present invention includes an engine control unit ECU 200, a desorption control valve 600, an ash filter 800, a vent solenoid valve 700, a canister 500, an isolation valve assembly, a pressure detection module 400, and a fuel tank assembly 300, which are sequentially connected to each other, wherein the engine control unit controls the vent solenoid valve 700, the desorption control valve 600, and the pressure detection module 400, the desorption control valve 600 is connected to the canister 500, the isolation valve assembly is the fuel tank isolation valve 100, the first cavity a is connected to the fuel tank assembly 300, and the second cavity B is connected to the canister 500.
The following explains the principle of the fuel evaporation control system in different working modes:
fig. 9 shows the working principle of the engine in the control system of the invention. After the desorption control valve 600 is opened, 1, the air inlet manifold of the engine is in a negative pressure state, air in the atmosphere is filtered by the ash filter 800, clean air enters the carbon canister 500 through the ventilation electromagnetic valve 700, and then fuel steam adsorbed by the air enters the engine to participate in combustion; although a small negative pressure is introduced into the tank isolation valve 100, it is not sufficient to change its normally closed state to an open state. 2. Because the oil pump in the oil tank works, negative pressure can be generated in the oil tank assembly 300, and the negative pressure can be transmitted into the oil tank isolation valve 100 through the pressure detection module 400 to open the negative pressure valve; the gas in the canister 500 is supplemented to the tank assembly 300 to form a pressure balance.
Referring to fig. 10, the operating principle of the control system of the present invention is shown when fuel is vaporized, and the liquid fuel in the fuel tank assembly 300 is converted into gaseous vapor to form positive pressure due to temperature change or long-term storage. Because the fuel tank isolation valve 100 is in a normally closed state, fuel vapor cannot directly enter the carbon canister 500, but when the pressure in the fuel tank assembly 300 reaches a set pressure, the fuel vapor is adsorbed by activated carbon powder in the carbon canister 500 after forcibly opening the fuel tank isolation valve 100, and a small amount of escaped fuel vapor is released to the atmosphere after passing through the ventilation solenoid valve 700 and the ash filter 800. Since the amount of the converted liquid fuel into gaseous state is smaller under the high pressure than under the normal pressure, the work load of the canister 500 is smaller, and the HC discharge amount is reduced.
Referring to fig. 11, which shows the working principle of the fuel system leakage check of the control system of the present invention, the ECU issues a leakage check command, and the vent solenoid valve 700 receives an electrical signal and changes from a normal open state to a closed state, where the entire fuel evaporation control system is an independent space. The desorption control valve 600 is powered on to be in an open state, and the engine pumps air into the fuel evaporation control system, so that negative pressure is formed in a system pipeline. When the negative pressure reaches a set value, the desorption control valve 600 is powered off to be in a closed state; the ECU determines whether there is a leak in the fuel evaporation control system by monitoring the rate of change of the pressure detection module 400 with time.
According to the oil tank isolation valve 100, the desorption joint 42 is arranged to be communicated with the carbon tank 500, when air in a system is pumped, after the carbon tank 500 and the desorption control valve 66 generate negative pressure, the negative pressure in the pilot cavity acts on the first diaphragm 50 in a one-step mode, so that the first cavity A is communicated with the second cavity B, the pressure in the carbon tank 500, the oil tank isolation valve 100 and the oil tank assembly 300 can be kept synchronous as soon as possible, the generation of back pressure is avoided, the pressure detection result is inaccurate, and the leakage judgment result is further influenced.
If the oil tank isolating valve 100 is not provided with the desorption connector 42, after the first cavity A needs to reach a certain negative pressure value, the negative pressure spring 33 can be compressed, the first cavity A and the second cavity B can be communicated, the pressure difference between the two sides of the oil tank isolating valve 100 is large, the back pressure can be generated, the pressure detection change is large, and the situation of leakage caused by misjudgment can be caused.
The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are also within the scope of the present invention. Those not described in detail in this specification are well within the skill of the art.
Claims (7)
1. An oil tank isolation valve, characterized in that: the two-way valve assembly is arranged in the valve body and divides the valve body into a first cavity and a second cavity, the pilot cavity is fixed on one side of the valve body and seals one side of the valve body, the two-way valve assembly comprises a positive pressure valve rod, a negative pressure valve rod, a positive pressure spring and a negative pressure spring,
one end of the positive pressure valve rod is a positioning rod, a vent cavity is arranged in the middle of the positive pressure valve rod, a negative pressure valve cavity is arranged in the other end of the positive pressure valve rod, the positioning rod penetrates through one side of the valve body and is in contact with the elastic side of the pilot cavity, one end of the negative pressure valve cavity is communicated with the vent cavity, the other end of the negative pressure valve cavity is provided with a negative pressure end cover, a second vent hole communicated with the vent cavity is arranged on the positioning rod, a disc connected with the valve body is arranged outside the middle of the positive pressure valve rod, and a third vent hole is arranged on the negative pressure end cover; the positive pressure spring is sleeved outside the other end of the positive pressure valve rod, one end of the positive pressure spring is contacted with the disc, and the other end of the positive pressure spring is contacted with the inner wall of the valve body; the negative pressure valve rod is arranged inside the negative pressure valve cavity, and the negative pressure spring is sleeved outside the negative pressure valve rod.
2. A tank isolation valve as claimed in claim 1, wherein: the valve body includes axial one end confined changeover portion, is located the radial both sides of changeover portion and the first coupling and the second coupling of coaxial arrangement respectively, the radial one side of changeover portion and first coupling intercommunication, the changeover portion axial other end and second coupling intercommunication, be equipped with annular linkage segment on the pipe outer wall of first coupling and second coupling, connect first support on the linkage segment, on the guide's cavity is fixed in first support, be equipped with first air vent on the first support, the bi-pass valve subassembly is installed on the changeover portion, and bi-pass valve subassembly one end is located inside, the other end of changeover portion and passes first support center and guide's cavity contact.
3. A tank isolation valve as claimed in claim 2, wherein: the first support comprises a columnar support body, the inner portion of the support body is fixedly connected with a transition plate perpendicular to the inner wall of the support body, one end of the support body in the axial direction is provided with a connecting flange, the connecting flange is fixedly connected with a connecting section, the other end of the support body in the axial direction is provided with an annular first groove, the edge of the first groove is provided with a plurality of first buckles along the circumference, a pilot cavity is connected with the first buckles and the first groove, the center of the transition plate is provided with a shaft hole used for the positioning rod to pass through, and the shaft hole is surrounded with a plurality of first air vents.
4. A tank isolation valve as claimed in claim 1, wherein: one end of the negative pressure valve rod is in sealing contact with the axial limiting surface of the inner wall of the positive pressure valve rod to separate the ventilation cavity from the negative pressure valve cavity, the outer diameter of one end of the negative pressure valve rod is smaller than the inner diameter of the negative pressure valve cavity, and the other end of the negative pressure valve rod penetrates through the negative pressure end cover.
5. A tank isolation valve as claimed in claim 1, wherein: the pilot cavity comprises a first end cover, a first diaphragm and a first compression spring, the first end cover is of an arch structure, a movable closed control joint is arranged on the first end cover, and first buckling holes connected with the valve body are formed in the peripheral edge of the first end cover; the outer edge of the first diaphragm is in sealing contact with the edge of the valve body and the edge of the first end cover, a guide groove matched with the positioning rod is formed in the center of one side of the first diaphragm, one end of the first compression spring is in center contact with the inner wall of the first end cover, and the other end of the first compression spring is in center contact with the other side of the first diaphragm.
6. A tank isolation valve as claimed in claim 5, wherein: first diaphragm includes base and annular flexure strip, and flexure strip one side is inside sunken to form the protruding portion, flexure strip inner ring edge and base edge fixed connection all around, flexure strip outer loop edge and valve body and first end cover edge sealing contact, a base side be equipped with the indent with locating lever complex guide slot, base another side be equipped with first compression spring complex spring groove.
7. A tank isolation valve as claimed in claim 5, wherein: the first end cover is provided with a desorption joint communicated with a desorption pipe orifice of the carbon canister.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110888965.9A CN113685291B (en) | 2021-08-03 | 2021-08-03 | Oil tank isolating valve |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110888965.9A CN113685291B (en) | 2021-08-03 | 2021-08-03 | Oil tank isolating valve |
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| CN113685291A CN113685291A (en) | 2021-11-23 |
| CN113685291B true CN113685291B (en) | 2022-12-23 |
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| CN202110888965.9A Active CN113685291B (en) | 2021-08-03 | 2021-08-03 | Oil tank isolating valve |
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105402050A (en) * | 2015-12-24 | 2016-03-16 | 江苏奥力威传感高科股份有限公司 | Fuel tank isolation electromagnetic valve |
| CN109538945A (en) * | 2018-12-17 | 2019-03-29 | 东风富士汤姆森调温器有限公司 | Universal vehicle-mounted fuel systems leak detecting device |
| CN209431100U (en) * | 2018-12-17 | 2019-09-24 | 东风富士汤姆森调温器有限公司 | Universal vehicle-mounted fuel systems leak detecting device |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6601569B2 (en) * | 2000-08-08 | 2003-08-05 | Siemens Automotive Inc. | Evaporative emission control system including a fuel tank isolation valve and a canister vent valve |
| US6553975B2 (en) * | 2000-08-08 | 2003-04-29 | Siemens Automotive Inc. | Method of operating a fuel tank isolation valve |
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2021
- 2021-08-03 CN CN202110888965.9A patent/CN113685291B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105402050A (en) * | 2015-12-24 | 2016-03-16 | 江苏奥力威传感高科股份有限公司 | Fuel tank isolation electromagnetic valve |
| CN109538945A (en) * | 2018-12-17 | 2019-03-29 | 东风富士汤姆森调温器有限公司 | Universal vehicle-mounted fuel systems leak detecting device |
| CN209431100U (en) * | 2018-12-17 | 2019-09-24 | 东风富士汤姆森调温器有限公司 | Universal vehicle-mounted fuel systems leak detecting device |
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