Oil tank isolating valve

Abstract

The utility model provides an oil tank isolating valve which comprises a valve body, a positive pressure valve unit, a negative pressure valve unit and an electromagnetic valve unit. The interior of the valve body is a hollow cavity, a partition plate is arranged in the valve body to divide the hollow cavity into a first cavity and a second cavity which are distributed from bottom to top, and a first air hole and a second air hole are formed in the partition plate; the positive pressure valve unit comprises a positive pressure valve seat, a positive pressure spring and a sealing gasket, and the positive pressure valve seat is located in the first cavity; the positive pressure spring abuts against the bottom of the first cavity and the positive pressure valve seat. The sealing gasket is hermetically attached to the partition plate so as to seal the second air hole; the negative pressure valve unit is used for being attached to the partition plate in a sealed mode so as to seal the first air hole. And the electromagnetic valve unit is connected with the negative pressure valve unit. Due to the fact that the partition plate is arranged in the valve body, when medium pressure pushes the positive pressure valve seat to move downwards, the negative pressure valve unit cannot move downwards along with the positive pressure valve seat, the acting force of the negative pressure valve unit does not need to be overcome, the smaller the elastic force needed by the positive pressure spring is, the smaller the size specification is, and the cost can be reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of valves, in particular to an oil tank isolation valve. Background Art

[0002] In a gasoline vapor emission system, gasoline vapor generated in the fuel tank is discharged through an exhaust valve into the carbon canister, where it is effectively adsorbed by the activated carbon inside. After the engine is started, fresh air is drawn into the carbon canister, and the fuel vapor adsorbed by the activated carbon in the canister is re-introduced into the engine for combustion, improving fuel efficiency. However, plug-in hybrid vehicles sometimes operate in electric drive mode for extended periods. In this mode, the carbon canister lacks a desorption function, which can easily lead to saturation of the canister's adsorption capacity. Fuel vapor is then directly released into the atmosphere, causing environmental pollution and fuel waste. Furthermore, when the vehicle is in electric drive mode for extended periods, fuel vaporization and accumulation can lead to excessive pressure in the fuel tank, potentially damaging it. In these cases, the valve requires an automatic pressure relief function. Alternatively, if the fuel in the tank is used rapidly, the internal pressure may be too low, causing damage due to compression from external atmospheric pressure. In these cases, the valve requires an automatic pressure boost function.

[0003] In the prior art, the negative pressure valve moves with the positive pressure valve. When the positive pressure valve moves, the positive pressure spring needs to overcome the force of the negative pressure valve. Therefore, the greater the elastic force required by the positive pressure spring, the larger the size of the positive pressure spring and the higher the cost. Utility Model Content

[0004] In view of this, the present invention proposes a fuel tank isolation valve to solve the technical problem proposed in the above background technology that the negative pressure valve moves together with the positive pressure valve. When the positive pressure valve moves, the positive pressure spring needs to overcome the force of the negative pressure valve. Therefore, the greater the elastic force required by the positive pressure spring, the larger the size of the positive pressure spring and the higher the cost.

[0005] The technical solution of the present utility model is achieved as follows:

[0006] The utility model provides a fuel tank isolation valve, comprising a valve body, a positive pressure valve unit, a negative pressure valve unit and a solenoid valve unit, wherein:

[0007] The interior of the valve body is a hollow cavity. A partition plate is provided within the valve body to separate the hollow cavity into a first cavity and a second cavity disposed in a lower and upper direction. The partition plate is provided with a first air hole and a second air hole. The first cavity is connected to a first channel for connecting to a carbon canister, and the second cavity is connected to a second channel for connecting to a fuel tank.

[0008] The positive pressure valve unit includes a positive pressure valve seat, a positive pressure spring, and a sealing gasket. The positive pressure valve seat is located in the first cavity. One end of the positive pressure spring abuts against the bottom of the first cavity, and the other end abuts against the positive pressure valve seat. The lower surface of the sealing gasket is connected to the surface of the positive pressure valve seat away from the bottom of the first cavity, and the upper surface of the sealing gasket is used to seal with the partition plate to close the second air hole.

[0009] The negative pressure valve unit is located in the second cavity and is coaxial with the positive pressure valve seat, and is used to seal and fit with the partition plate to close the first air hole;

[0010] The solenoid valve unit is installed at one end of the second cavity away from the partition plate and is connected to the negative pressure valve unit;

[0011] Wherein: after the medium enters the second cavity from the second channel, it enters the first cavity from the second air hole and is discharged to the carbon canister through the first channel; or, after the medium enters the first cavity from the first channel, it enters the second cavity from the first air hole and is replenished to the fuel tank through the first channel.

[0012] Based on the above technical solution, preferably, the first air hole is located at the center of the partition plate, and a plurality of second air holes are provided, and the plurality of second air holes are arranged around the circumference of the first air hole;

[0013] The upper surface of the sealing gasket is provided with a first lip and a second lip respectively located on both sides of the second air hole, and the first lip and the second lip are used for sealing and fitting with the partition plate.

[0014] Based on the above technical solution, preferably, a second guide plate is provided at the bottom of the positive pressure valve seat, a first guide plate is provided at the bottom of the first cavity, the inner diameter of the first guide plate is larger than the inner diameter of the second guide plate, and the positive pressure spring is located between the second guide plate and the first guide plate.

[0015] On the basis of the above technical solution, preferably, a plurality of air holes are provided on the outer wall of the second guide plate, and the first guide plate includes at least two arc-shaped plates arranged at intervals.

[0016] On the basis of the above technical solution, preferably, the negative pressure valve unit includes a negative pressure valve seat and a negative pressure spring, the negative pressure valve seat is coaxial with the positive pressure valve seat, one end of the negative pressure spring abuts against the solenoid valve unit, and the other end of the negative pressure spring abuts against the negative pressure valve seat, so that the negative pressure valve seat abuts against the partition plate, and the negative pressure valve seat closes the first air hole.

[0017] Based on the above technical solution, preferably, the solenoid valve unit includes a shell, a coil and a guide rod; the shell is connected to the second cavity, and a sliding hole is provided inside the shell; the coil is provided at the top of the shell, and is used to magnetically attract the guide rod after power is turned on; the guide rod is made of magnetic material, and the guide rod is slidably installed in the sliding hole and is connected to the negative pressure valve seat.

[0018] On the basis of the above technical solution, preferably, the solenoid valve unit also includes a limit plate located in the shell and a guide seat located in the second cavity, and the guide seat includes a baffle and a guide cylinder; the guide rod abuts against the end of the baffle away from the guide cylinder, and the baffle can abut against the limit plate; the guide cylinder is connected to the end of the baffle away from the coil, and the negative pressure spring is sleeved on the guide rod and located in the guide cylinder.

[0019] On the basis of the above technical solution, preferably, the negative pressure valve seat includes a base and a connecting tube, the base is used to abut against the partition plate; the connecting tube is arranged on the top of the base, a connecting cavity is provided inside the connecting tube, and a mounting hole is provided on the top surface of the connecting tube, the diameter of the mounting hole is smaller than the diameter of the inner wall of the connecting cavity, and an axis groove section is provided at the end of the guide rod away from the coil, the axis groove section is provided in the mounting hole, and the end of the guide rod is located in the connecting cavity.

[0020] On the basis of the above technical solution, preferably, an outer wall of the connecting cylinder is provided with a mounting groove, the mounting groove communicates with the connecting cavity and the mounting hole, and the width of the mounting groove is greater than the bottom diameter of the shaft groove section.

[0021] On the basis of the above technical solution, preferably, a plurality of first ribs are further provided in the valve body, and the plurality of first ribs are arranged circumferentially along the inner wall of the second cavity. The first ribs extend from the inner wall of the second cavity along the diameter direction of the second cavity, and the end of the first rib away from the inner wall of the second cavity is used to guide the negative pressure valve seat.

[0022] The fuel tank isolation valve of the present invention has the following beneficial effects compared with the prior art:

[0023] (1) A partition plate is provided in the valve body, and a first air hole and a second air hole are provided on the partition plate. After the medium enters the second cavity from the second channel, it enters the first cavity from the second air hole, and in the process of driving the positive pressure valve seat to move downward, the negative pressure valve unit will not move downward with the positive pressure valve seat, and there is no need to overcome the force of the negative pressure valve unit. Therefore, the smaller the elastic force required by the positive pressure spring, the smaller the size of the positive pressure spring, which can reduce the cost;

[0024] (2) The first air hole is located at the center of the partition plate, and a plurality of second air holes are provided, and the plurality of second air holes are arranged around the circumference of the first air hole, thereby reducing space occupation and ensuring that the ventilation volume meets the requirements; the first lip and the second lip are located on both sides of the second air hole, and the first lip and the second lip are used to seal and fit with the partition plate to close the second air hole. The first air hole and the second air hole do not interfere with each other, and can ensure that the negative pressure valve unit and the positive pressure valve seat are coaxial;

[0025] (3) A second guide plate is provided at the bottom of the positive pressure valve seat, a first guide plate is provided at the bottom of the first cavity, the inner diameter of the first guide plate is larger than the inner diameter of the second guide plate, and the positive pressure spring is located between the second guide plate and the first guide plate, so that the elastic force direction of the positive pressure spring remains along the axial direction of the positive pressure valve seat, so that the first lip of the sealing gasket is more closely attached to the partition plate, thereby improving the sealing effect;

[0026] (4) A plurality of air holes are provided on the outer wall of the second guide plate, and the first guide plate includes at least two arc-shaped plates arranged at intervals, so that the air permeability area between the second guide plate and the first guide plate is increased, thereby avoiding affecting the flow of the gas medium and improving the efficiency of the medium flow, thereby improving the efficiency of pressure relief or gas replenishment;

[0027] (5) The baffle is connected to the guide rod through the baffle, and the baffle can abut against the end of the sliding hole; the guide cylinder is connected to the end of the baffle away from the magnet, and the negative pressure spring is sleeved on the guide rod and located in the guide cylinder, one end of the negative pressure spring abuts on the baffle, and the other end of the negative pressure spring abuts on the negative pressure valve seat. The baffle abuts on the end of the sliding hole, forming a support point for the negative pressure spring, and the elastic force of the negative pressure spring will not decrease as the guide rod rises. When the negative pressure is eliminated, the negative pressure spring can drive the negative pressure valve seat to descend and reset, thereby improving the stability and reliability of the device;

[0028] (6) A mounting groove is provided through the outer wall of the connecting tube, and the mounting groove connects the connecting cavity and the mounting hole. The width of the mounting groove is greater than the bottom diameter of the shaft groove section. When installing the guide rod, the shaft groove section area of ​​the guide rod is passed through the mounting groove, and the end of the guide rod can be placed in the connecting cavity, thereby improving the convenience of device installation and improving the reliability and stability of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0030] Figure 1 It is a cross-sectional view of the fuel tank isolation valve of the present utility model;

[0031] Figure 2 It is a three-dimensional diagram of the fuel tank isolation valve of the present utility model;

[0032] Figure 3 It is a cross-sectional view of the valve body of the present utility model;

[0033] Figure 4 The upper half of the valve body of the utility model is a three-dimensional Figure 1 ;

[0034] Figure 5 The upper half of the valve body of the utility model is a three-dimensional Figure 2 ;

[0035] Figure 6 It is a three-dimensional diagram of the lower half of the valve body of the present invention;

[0036] Figure 7 It is a three-dimensional diagram of the positive pressure valve unit of the present utility model;

[0037] Figure 8 This is a schematic structural diagram of the connection between the negative pressure valve seat and the solenoid valve unit of the present invention;

[0038] Figure 9 It is a three-dimensional diagram of the negative pressure valve seat of the present utility model;

[0039] Figure 10 It is a cross-sectional view of the solenoid valve unit of the present utility model;

[0040] Figure 11 This is a schematic diagram of the principle of the oil tank isolation valve of the utility model when working under positive pressure relief;

[0041] Figure 12 This is a schematic diagram of the principle of the oil tank isolation valve of the present utility model when working with negative pressure air supply.

[0042] Description of reference numerals: 1-valve body, 2-positive pressure valve unit, 3-negative pressure valve unit, 4-solenoid valve unit;

[0043] 11-first cavity, 111-first guide plate, 1111-arc-shaped plate, 12-second cavity, 13-partition plate, 131-first air hole, 132-second air hole, 14-first channel, 15-second channel, 16-first rib plate, 17-second rib plate;

[0044] 21 - positive pressure valve seat, 211 - second guide plate, 2111 - air vent, 22 - positive pressure spring, 23 - sealing gasket, 231 - first lip, 232 - second lip;

[0045] 31-negative pressure valve seat, 311-base, 312-connecting cylinder, 3121-connecting cavity, 3122-mounting hole, 3123-mounting groove, 32-negative pressure spring;

[0046] 41-shell, 411-slide hole, 412-limiting plate, 42-coil, 43-guide rod, 431-shaft groove section, 44-guide seat, 441-baffle, 442-guide cylinder. DETAILED DESCRIPTION

[0047] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0048] Reference Figures 1-12 As shown, the embodiment of the present utility model provides a fuel tank isolation valve, comprising a valve body 1, a positive pressure valve unit 2, a negative pressure valve unit 3 and a solenoid valve unit 4, wherein:

[0049] The interior of the valve body 1 is a hollow cavity. A partition plate 13 is provided in the valve body 1 to separate the hollow cavity into a first cavity 11 and a second cavity 12, which are arranged in a lower and upper direction. The partition plate 13 is provided with a first air hole 131 and a second air hole 132. The first cavity 11 is connected to a first channel 14 for connecting to a carbon canister, and the second cavity 12 is connected to a second channel 15 for connecting to a fuel tank.

[0050] The positive pressure valve unit 2 includes a positive pressure valve seat 21, a positive pressure spring 22 and a sealing gasket 23. The positive pressure valve seat 21 is located in the first cavity 11. One end of the positive pressure spring 22 abuts against the bottom of the first cavity 11, and the other end abuts against the positive pressure valve seat 21. The lower surface of the sealing gasket 23 is connected to the surface of the positive pressure valve seat 21 away from the bottom of the first cavity 11. The upper surface of the sealing gasket 23 is used to seal with the partition plate 13 to close the second air hole 132. The connection between the lower surface of the sealing gasket 23 and the top surface of the positive pressure valve seat 21 can be bonded by glue.

[0051] The negative pressure valve unit 3 includes a negative pressure valve seat 31 and a negative pressure spring 32. The negative pressure valve seat 31 is coaxial with the positive pressure valve seat 21. One end of the negative pressure spring 32 abuts against the solenoid valve unit 4, and the other end of the negative pressure spring 32 abuts against the negative pressure valve seat 31, so as to make the negative pressure valve seat 31 abut against the partition plate 13 to close the first air hole 131.

[0052] The solenoid valve unit 4 is installed at one end of the second cavity 12 away from the partition plate 13 and is connected to the negative pressure valve unit 3 to balance the elastic force of the negative pressure spring 32 through the magnetic field force;

[0053] in:

[0054] During positive pressure relief operation, after the medium enters the second chamber 12 from the second channel 15, the medium pressure pushes the sealing gasket 23 and the positive pressure valve seat 21 downward, the sealing gasket 23 disengages from the partition plate 13, and the second air hole 132 is opened. The solenoid valve unit 4 stops working, and the negative pressure valve seat 31 remains in contact with the partition plate 13 under the elastic force of the negative pressure spring 32. The medium enters the first chamber 11 from the second air hole 132 and is discharged into the carbon canister through the first channel 14.

[0055] When the negative pressure air replenishment is working, after the medium enters the first cavity 11 from the first channel 14, the positive pressure valve seat 21 keeps the sealing gasket 23 in contact with the partition plate 13 under the elastic force of the positive pressure spring 22, and the medium pressure pushes the negative pressure valve unit 3 to move upward, and the negative pressure valve unit 3 detaches from the partition plate 13, opening the first air hole 131, and the medium enters the second cavity 12 from the first air hole 131 and is replenished to the oil tank through the first channel 14.

[0056] The oil tank isolation valve provided in this embodiment is provided with a partition plate 13 in the valve body 1, and the partition plate 13 is provided with a first air hole 131 and a second air hole 132. After the medium enters the second cavity 12 from the second channel 15, it enters the first cavity 11 from the second air hole 132, driving the positive pressure valve seat 21 to move downward. In the process, the negative pressure valve seat 31 will not move downward with the positive pressure valve seat 21, and there is no need to overcome the force of the negative pressure valve seat 31. Therefore, the smaller the elastic force required by the positive pressure spring 22, the smaller the size of the positive pressure spring 22, which can reduce the cost.

[0057] In some embodiments, the first air hole 131 is located at the center of the partition plate 13, and a plurality of second air holes 132 are provided, and the plurality of second air holes 132 are arranged around the circumference of the first air hole 131; the upper surface of the sealing gasket 23 is provided with a first lip 231 and a second lip 232 respectively located on both sides of the second air hole 132, and the first lip 231 and the second lip 232 are used to seal and fit with the partition plate 13. The first air hole 131 is located at the center of the partition plate 13, and a plurality of second air holes 132 are provided. The plurality of second air holes 132 can be evenly arranged around the circumference of the first air hole 131, reducing space occupancy and ensuring that the ventilation volume meets the requirements. The medium pressure is more uniform when applied to the positive pressure valve seat 21, and the unidirectionality is better, providing stability and reliability; the first lip 231 and the second lip 232 are located on both sides of the second air hole 132, and the first lip 231 and the second lip 232 are used to seal and fit with the partition plate 13 to close the second air hole 132. The first air hole 131 and the second air hole 132 do not interfere with each other, and can ensure that the negative pressure valve unit 3 and the positive pressure valve seat 21 are coaxial.

[0058] In some embodiments, a second guide plate 211 is provided at the bottom of the positive pressure valve seat 21, a first guide plate 111 is provided at the bottom of the first cavity 11, the inner diameter of the first guide plate 111 is larger than the inner diameter of the second guide plate 211, and the positive pressure spring 22 is located between the second guide plate 211 and the first guide plate 111. By providing a second guide plate 211 at the bottom of the positive pressure valve seat 21, a first guide plate 111 is provided at the bottom of the first cavity 11, the inner diameter of the first guide plate 111 is larger than the inner diameter of the second guide plate 211, and the positive pressure spring 22 is located between the second guide plate 211 and the first guide plate 111, the elastic direction of the positive pressure spring 22 remains along the axial direction of the positive pressure valve seat 21, so that the first lip 231 of the sealing gasket 23 fits more closely with the partition plate 13, thereby improving the sealing effect.

[0059] In some embodiments, the outer wall of the second guide plate 211 is provided with a plurality of air holes 2111, and the first guide plate 111 includes at least two spaced-apart curved plates 1111. The plurality of air holes 2111 on the outer wall of the second guide plate 211 and the at least two spaced-apart curved plates 1111 of the first guide plate 111 increase the air permeability area between the second guide plate 211 and the first guide plate 111, thereby preventing interference with the flow of the gas medium and improving the efficiency of the medium flow, thereby improving the efficiency of pressure relief or gas replenishment.

[0060] In some embodiments, the solenoid valve unit 4 includes a housing 41, a coil 42, and a guide rod 43; the housing 41 is connected to the second cavity 12, and a sliding hole 411 is provided inside the housing 41; the coil 42 is provided at the top of the housing 41, and is used to magnetically attract the guide rod 43 when energized; the guide rod 43 is made of a magnetic material, is slidably installed in the sliding hole 411, and is connected to the negative pressure valve seat 31. The guide rod 43 is slidably installed in the sliding hole 411, and the sliding hole 411 guides the sliding of the guide rod 43. When energized, the coil 42 magnetically attracts the guide rod 43, and the upward magnetic attraction force of the coil 42 is applied to the guide rod 43 and transmitted to the negative pressure valve seat 31, balancing the downward elastic force of the negative pressure spring 32 on the negative pressure valve seat 31.

[0061] In some embodiments, the solenoid valve unit 4 also includes a limit plate 412 located in the shell 41 and a guide seat 44 located in the second cavity 12, the guide seat 44 includes a baffle 441 and a guide cylinder 442; the guide rod 43 abuts against the end of the baffle 441 away from the guide cylinder 442, and the baffle 441 can abut against the limit plate 412; the guide cylinder 442 is connected to the end of the baffle 441 away from the coil 42, and the negative pressure spring 32 is sleeved on the guide rod 43 and located in the guide cylinder 442. One end of the negative pressure spring 32 abuts against the baffle 441, and the other end of the negative pressure spring 32 abuts against the negative pressure valve seat 31. The baffle 441 abuts against the limit plate 412, forming a support point for the negative pressure spring 32. The elastic force of the negative pressure spring 32 will not decrease as the guide rod 43 rises. When the negative pressure is eliminated, the negative pressure spring 32 can drive the negative pressure valve seat 31 to descend and reset, thereby improving the stability and reliability of the device.

[0062] In some embodiments, the negative pressure valve seat 31 includes a base 311 and a connecting tube 312, the base 311 is used to abut against the partition plate 13; the connecting tube 312 is arranged at the top of the base 311, and a connecting cavity 3121 is provided inside the connecting tube 312, and a mounting hole 3122 is provided on the top surface of the connecting tube 312, and the diameter of the mounting hole 3122 is smaller than the diameter of the inner wall of the connecting cavity 3121, and an axis groove section 431 is provided at the end of the guide rod 43 away from the coil 42, and the axis groove section 431 is provided in the mounting hole 3122, and the end of the guide rod 43 is located in the connecting cavity 3121. The shaft groove section 431 is arranged in the mounting hole 3122, and the end of the guide rod 43 is located in the connecting cavity 3121. The diameter of the end of the guide rod 43 is larger than the diameter of the mounting hole 3122. The end of the guide rod 43 is limited by the mounting hole 3122, so that the guide rod 43 is connected to the negative pressure valve seat 31, and the guide rod 43 and the negative pressure valve seat 31 act together.

[0063] In some embodiments, the outer wall of the connecting tube 312 is provided with a mounting groove 3123, which connects the connecting cavity 3121 and the mounting hole 3122, and the width of the mounting groove 3123 is greater than the bottom diameter of the shaft groove section 431. Since the outer wall of the connecting tube 312 is provided with a mounting groove 3123, which connects the connecting cavity 3121 and the mounting hole 3122, and the width of the mounting groove 3123 is greater than the bottom diameter of the shaft groove section 431, when installing the guide rod 43, the shaft groove section 431 of the guide rod 43 is passed through the mounting groove 3123, and the end of the guide rod 43 is placed in the connecting cavity 3121, thereby improving the convenience of device installation and improving the reliability and stability of the device.

[0064] In some embodiments, the valve body 1 is further provided with a plurality of first ribs 16, which are arranged circumferentially along the inner wall of the second cavity 12. The first ribs 16 extend from the inner wall of the second cavity 12 along the diameter of the second cavity 12. The ends of the first ribs 16 distal from the inner wall of the second cavity 12 serve to guide the negative pressure valve seat 31. While guiding the negative pressure valve seat 31, the first ribs 16 can also strengthen the partition plate 13, preventing damage to the partition plate 13 due to excessive force, thereby improving the reliability and stability of the device.

[0065] In some embodiments, the valve body 1 is further provided with a plurality of second ribs 17, which are arranged circumferentially along the inner wall of the first cavity 11. The second ribs 17 are respectively connected to the inner wall of the first cavity 11 and the partition plate 13. The connection of the second ribs 17 to the inner wall of the first cavity 11 and the partition plate 13 further strengthens the strength of the partition plate 13, thereby further improving the reliability and stability of the device.

[0066] The working principle of the fuel tank isolation valve is:

[0067] During positive pressure relief operation, after the medium enters the second chamber 12 from the second channel 15, the medium pressure pushes the sealing gasket 23 and the positive pressure valve seat 21 downward, the sealing gasket 23 disengages from the partition plate 13, and the second air hole 132 is opened. The solenoid valve unit 4 stops working, and the negative pressure valve seat 31 remains in contact with the partition plate 13 under the elastic force of the negative pressure spring 32. The medium enters the first chamber 11 from the second air hole 132 and is discharged into the carbon canister through the first channel 14.

[0068] When the negative pressure air replenishment is working, after the medium enters the first cavity 11 from the first channel 14, the positive pressure valve seat 21 keeps the sealing gasket 23 in contact with the partition plate 13 under the elastic force of the positive pressure spring 22, and the medium pressure pushes the negative pressure valve unit 3 to move upward, and the negative pressure valve unit 3 detaches from the partition plate 13, opening the first air hole 131, and the medium enters the second cavity 12 from the first air hole 131 and is replenished to the oil tank through the first channel 14.

[0069] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A fuel tank isolation valve, characterized in that: It includes a valve body, a positive pressure valve unit, a negative pressure valve unit and a solenoid valve unit, wherein: The interior of the valve body is a hollow cavity. A partition plate is provided within the valve body to separate the hollow cavity into a first cavity and a second cavity disposed in a lower and upper direction. The partition plate is provided with a first air hole and a second air hole. The first cavity is connected to a first channel for connecting to a carbon canister, and the second cavity is connected to a second channel for connecting to a fuel tank. The positive pressure valve unit includes a positive pressure valve seat, a positive pressure spring, and a sealing gasket. The positive pressure valve seat is located in the first cavity. One end of the positive pressure spring abuts against the bottom of the first cavity, and the other end abuts against the positive pressure valve seat. The lower surface of the sealing gasket is connected to the surface of the positive pressure valve seat away from the bottom of the first cavity, and the upper surface of the sealing gasket is used to seal with the partition plate to close the second air hole. The negative pressure valve unit is located in the second cavity and is coaxial with the positive pressure valve seat, and is used to seal and fit with the partition plate to close the first air hole; The solenoid valve unit is installed at one end of the second cavity away from the partition plate and is connected to the negative pressure valve unit; Wherein: after the medium enters the second cavity from the second channel, it enters the first cavity from the second air hole and is discharged to the carbon canister through the first channel; or, after the medium enters the first cavity from the first channel, it enters the second cavity from the first air hole and is replenished to the fuel tank through the first channel.

2. The fuel tank isolation valve according to claim 1, characterized in that: The first air hole is located at the center of the partition plate, and a plurality of second air holes are provided, and the plurality of second air holes are arranged around the circumference of the first air hole; The upper surface of the sealing gasket is provided with a first lip and a second lip respectively located on both sides of the second air hole, and the first lip and the second lip are used for sealing and fitting with the partition plate.

3. The fuel tank isolation valve according to claim 1, characterized in that: A second guide plate is provided at the bottom of the positive pressure valve seat, and a first guide plate is provided at the bottom of the first cavity. The inner diameter of the first guide plate is larger than the inner diameter of the second guide plate, and the positive pressure spring is located between the second guide plate and the first guide plate.

4. The fuel tank isolation valve according to claim 3, characterized in that: A plurality of air holes are formed on the outer wall of the second guide plate, and the first guide plate includes at least two arc-shaped plates arranged at intervals.

5. The fuel tank isolation valve according to claim 1, characterized in that: The negative pressure valve unit includes a negative pressure valve seat and a negative pressure spring. The negative pressure valve seat is coaxial with the positive pressure valve seat. One end of the negative pressure spring abuts against the solenoid valve unit, and the other end of the negative pressure spring abuts against the negative pressure valve seat, so that the negative pressure valve seat abuts against the partition plate, and the negative pressure valve seat closes the first air hole.

6. The fuel tank isolation valve according to claim 5, characterized in that: The solenoid valve unit includes a shell, a coil and a guide rod; the shell is connected to the second cavity, and a sliding hole is provided inside the shell; the coil is arranged on the top of the shell, and is used to magnetically attract the guide rod after power is turned on; the guide rod is made of magnetic material, and the guide rod is slidably installed in the sliding hole and connected to the negative pressure valve seat.

7. The fuel tank isolation valve according to claim 6, characterized in that: The solenoid valve unit also includes a limit plate located in the shell and a guide seat located in the second cavity, the guide seat includes a baffle and a guide cylinder; the guide rod abuts against the end of the baffle away from the guide cylinder, and the baffle can abut against the limit plate; the guide cylinder is connected to the end of the baffle away from the coil, and the negative pressure spring is sleeved on the guide rod and located in the guide cylinder.

8. The fuel tank isolation valve according to claim 7, characterized in that: The negative pressure valve seat includes a base and a connecting tube, the base is used to abut against the partition plate; the connecting tube is arranged on the top of the base, a connecting cavity is provided inside the connecting tube, and a mounting hole is provided on the top surface of the connecting tube. The diameter of the mounting hole is smaller than the diameter of the inner wall of the connecting cavity. The guide rod is provided with an axis groove section at one end away from the coil, the axis groove section is provided in the mounting hole, and the end of the guide rod is located in the connecting cavity.

9. The fuel tank isolation valve according to claim 8, characterized in that: An outer wall of the connecting cylinder is provided with a mounting groove, the mounting groove communicates with the connecting cavity and the mounting hole, and the width of the mounting groove is greater than the bottom diameter of the shaft groove section.

10. The fuel tank isolation valve according to any one of claims 5 to 9, characterized in that: A plurality of first ribs are also provided in the valve body, and the plurality of first ribs are arranged circumferentially along the inner wall of the second cavity. The first ribs extend from the inner wall of the second cavity along the diameter direction of the second cavity, and the end of the first rib away from the inner wall of the second cavity is used to guide the negative pressure valve seat.

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