Fuel tank isolation solenoid for a vehicle

Abstract

A fuel tank isolation solenoid for a vehicle includes a plunger disposed in the isolation solenoid to move vertically and having a first vent hole for releasing overpressure or underpressure, and a valve body disposed in the isolation solenoid to move vertically and having a second vent hole for releasing overpressure or underpressure.

Description

Technical Field

[0001] This disclosure relates to a fuel tank isolation solenoid valve for a vehicle, wherein a positive and negative pressure relief valve is integrally integrated. Background Technology

[0002] The statements in this section are provided only as background information in connection with this disclosure and may not constitute prior art.

[0003] refer to Figure 1 The fuel tank 10 for the vehicle is connected to a canister 20, which is configured to collect the evaporated gas of the fuel and purge the evaporated gas into the combustion chamber in the engine 30, so that the evaporated gas is burned in the combustion chamber.

[0004] For this purpose, the inlet 21 of the tank 20 and the fuel tank 10 are connected to each other via a discharge line 13 disposed therebetween, and the outlet 22 of the tank 20 and the engine intake pipe are connected to each other via a purge line 14 disposed therebetween.

[0005] The tank 20 is provided with a collector (not shown) configured to adsorb and collect evaporated gas, and is provided with an exhaust port 23 through which the remaining purified air, except for the evaporated gas collected at the collector, is discharged to the outside.

[0006] Therefore, the fuel in the fuel tank 10 is supplied to the engine 30 through the fuel supply line 12 so as to be burned by the operation of the fuel pump 11 installed in the fuel tank 10. The vapors from the fuel in the fuel tank 10 are collected in the tank 20 through the discharge line 13 and supplied to the engine 30 through the purge line 14 so as to be burned due to the negative intake pressure of the engine.

[0007] Hybrid vehicles, especially plug-in hybrid electric vehicles (PHEVs), use a drive motor to operate in EV driving mode. However, the collection of evaporative gases continuously introduced from the fuel tank 10 is limited when the evaporative gases are collected to the maximum extent in the tank 20.

[0008] Although the vapors collected in tank 20 are purged to the engine for combustion when the hybrid vehicle switches to HEV driving mode with the engine running, the vapors continuously introduced from fuel tank 10 exceed the collection capacity of tank 20 when the vehicle is parked or stopped or in EV driving mode.

[0009] Therefore, when the evaporated gas is collected to the maximum extent in the tank 20, when the evaporated gas is continuously introduced into the tank 20 from the fuel tank 10, the evaporated gas exceeding the collection capacity of the tank 20 is not collected in the tank, but is discharged into the atmosphere through the exhaust port 23, thereby causing air pollution problems.

[0010] A fuel tank isolation solenoid valve (FTIV) 200 is installed on the discharge line 13 connecting the inlet 21 of both fuel tank 10 and tank 20. This FTIV 200 closes or opens, thereby preventing or allowing the flow of vaporized gas from fuel tank 10 to tank 20. Figure 2 As shown.

[0011] The isolating solenoid valve 200 is a solenoid-type isolating solenoid valve configured to open when power is applied. This isolating solenoid valve is normally kept closed, but opens only when the engine is running or the fuel tank is being filled.

[0012] More specifically, under normal conditions when the engine is not running (such as in a parked or stopped state or in EV driving mode), the isolation solenoid valve 200 remains closed. However, when power is applied in response to a signal from a controller (e.g., engine control unit; ECU) when the engine is running, or when power is applied in response to a signal from a controller (e.g., body control unit; BCM) during acceleration, the isolation solenoid valve 200 opens.

[0013] Therefore, when the isolation solenoid valve 200 remains closed, the evaporated gas in the fuel tank 10 is sealed and stored in the fuel tank 10 without flowing into the tank 20, thereby preventing the evaporated gas from being discharged into the atmosphere through the tank 20.

[0014] Meanwhile, when the isolation solenoid valve 200 is opened while the engine is running, the evaporated gas in the fuel tank 10 is collected in the canister 20 through the opened isolation solenoid valve 200, and the evaporated gas collected in the canister 20 is purged to the engine so that it can be burned due to the negative intake pressure of the engine.

[0015] Furthermore, when the isolation solenoid valve 200 is opened during refueling, the evaporated gas in the fuel tank 10 is collected in the tank 20 through the opened isolation solenoid valve 200, and the internal pressure in the fuel tank 10 is released, thereby allowing the fuel tank to be easily refueled.

[0016] At this time, when the user presses the refueling button in the vehicle, the controller (e.g., the body control unit; BCM) checks whether the isolation solenoid valve 200 is open to release the internal pressure in the fuel tank and opens the electric fuel valve 40.

[0017] like Figure 3 As shown, the isolation solenoid valve 200 is further provided with a positive and negative pressure relief valve 210 on one side, which is a safety valve.

[0018] The relief valve 210 is normally kept closed. However, when an overpressure (positive pressure) above the reference pressure acts on the isolation solenoid valve 200 from the fuel tank 10, the relief valve 210 operates to open a bypass path provided in the relief valve toward the tank 20 to release the overpressure. Furthermore, when a negative pressure below the reference pressure acts on the isolation solenoid valve 200 from the tank 20, the relief valve 210 operates to open a bypass path toward the fuel tank 10 to release the negative pressure.

[0019] However, we have found that traditional isolation solenoid valves have the following disadvantages because they are further equipped with a release valve.

[0020] First, because the release valve is located on one side of the isolating solenoid valve so as to protrude laterally, the overall size of the isolating solenoid valve is increased, and it is desirable to mount the isolating solenoid valve, including the release valve, into the vehicle body's encapsulation layout.

[0021] Second, because the release valve is separately installed on the isolation solenoid valve, the number of components and manufacturing costs increase.

[0022] The information disclosed in this background section is only intended to enhance the understanding of the background of this disclosure, and therefore may contain information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0023] This disclosure provides a fuel tank isolation solenoid valve for a vehicle. The fuel tank isolation solenoid valve includes: an upper housing; a spool mounted in the upper housing; a coil wound around the spool; a core mounted in the spool, the core having a plunger channel open at its lower end; a lower housing coupled to the upper housing, the lower housing including a first channel communicating with a fuel tank, a second channel communicating with a canister, and a communication channel defined between the first channel and the second channel; and a plunger having a lower open space formed therein and a plurality of first vent holes configured to allow communication between the first channel and the lower open space, the plunger being disposed in the plunger channel. The valve body is vertically movable and has a plurality of second vent holes formed vertically through the valve body to allow communication between the first and second channels. A sealing plate is mounted on the lower housing at the outer periphery of the communication channel to provide airtight contact with both the lower surface of the main seal and the upper surface of the valve body. A first spring is disposed between the lower surface of the core and the lower end of the plunger, and a second spring is disposed between the lower surface of the valve body and the bottom surface of the communication channel.

[0024] A diaphragm can be provided between the outer surface of the plunger and the inner surface of the core, and the diaphragm can be connected to prevent foreign objects from entering the valve.

[0025] The plunger may also have vents formed therein to allow communication between the upper space in the diaphragm and the lower open space in the plunger.

[0026] The plunger may have a first spring retaining groove formed in the outer periphery of its lower end, and a first spring is fitted and retained in the first spring retaining groove.

[0027] The plunger may have a stop on its upper surface that contacts the upper surface of the plunger channel formed in the core and cushions the upper surface.

[0028] The valve body may include a sealing wall that protrudes from the upper surface of the valve body at an inner periphery spaced inward from the second vent, the sealing wall being in airtight contact with the main seal.

[0029] The valve body may include a vertical guide pin formed at the center of its upper surface, which enters and exits the lower open space in the plunger.

[0030] The valve body may have a second spring retaining groove formed in the outer periphery of its lower surface, and the second spring is assembled and retained in the second spring retaining groove.

[0031] The sealing plate may include a mating wall formed on its lower surface, and the lower housing may have a mating groove formed in the outer periphery of the communicating channel, the mating wall fitting and being held in the mating groove.

[0032] When an overpressure, which is higher than the reference pressure, acts on the valve body from the fuel tank through the first channel and the first vent in the plunger, the valve body can be lowered, compressing the second spring. The overpressure can then be released by passing sequentially through the first vent in the plunger and the lower open space, as well as the second vent in the valve body and acting on the second channel.

[0033] When an excessive negative pressure below the reference pressure acts on the lower part of the plunger through the second vent in the valve body, the plunger can rise and compress the first spring. The excessive negative pressure can then be released through the second vent in the valve body and act on the first channel communicating with the fuel tank.

[0034] Other application areas will become apparent from the description provided herein. It should be understood that the descriptions and specific examples are intended for illustrative purposes only and are not intended to limit the scope of this disclosure. Attached Figure Description

[0035] To facilitate a good understanding of this disclosure, various forms of the disclosure, given by way of example, will now be described with reference to the accompanying drawings, in which:

[0036] Figure 1This is a schematic diagram illustrating the process by which evaporated gases in the fuel tank are collected in a canister and subsequently purged to the engine;

[0037] Figure 2 This is a schematic diagram showing a structure in which an isolation solenoid valve is installed between the fuel tank and the reservoir;

[0038] Figure 3 This is a perspective view showing the appearance of a conventional isolation solenoid valve equipped with a release valve;

[0039] Figure 4 This is a perspective view showing the appearance of a fuel tank isolation solenoid valve for a vehicle according to one form of the present disclosure;

[0040] Figure 5 This is a cross-sectional view showing one form of a fuel tank isolation solenoid valve for a vehicle according to the present disclosure;

[0041] Figure 6 This is a perspective view showing the plunger between the components of a fuel tank isolation solenoid valve for a vehicle according to one form of the present disclosure;

[0042] Figure 7 This is a perspective view showing the valve body between the components of a fuel tank isolation solenoid valve for a vehicle according to one form of the present disclosure;

[0043] Figure 8 This is a perspective view showing the assembled state of the internal components (including plunger and valve body) of a fuel tank isolation solenoid valve for a vehicle according to one form of the present disclosure;

[0044] Figure 9 It is a cross-sectional view showing the operation of opening a fuel tank isolation solenoid valve for a vehicle according to one form of the present disclosure when power is applied;

[0045] Figure 10 This is a cross-sectional view showing the operation of releasing overpressure through a fuel tank isolation solenoid valve for a vehicle according to one form of this disclosure; and

[0046] Figure 11 This is a cross-sectional view showing the operation of releasing negative pressure through a fuel tank isolation solenoid valve for a vehicle according to one form of the present disclosure.

[0047] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of this disclosure in any way. Detailed Implementation

[0048] In the following, reference will now be made in detail to various forms of this disclosure, examples of which are illustrated in the accompanying drawings and described below. Although this disclosure is described in conjunction with exemplary forms, it should be understood that this description is not intended to limit this disclosure to these exemplary forms. Rather, this disclosure is intended not only to cover the exemplary forms, but also to cover various alternatives, modifications, equivalents, and other forms that may be included within the spirit and scope of this disclosure.

[0049] It should be understood that the accompanying drawings are not necessarily to scale and present a simplified representation to some extent of the various preferred features illustrating the basic principles of this disclosure. Specific design features of this disclosure (including, for example, specific dimensions, orientations, locations, and shapes) will be determined in part by the particular intended application and environment of use.

[0050] In the following, preferred forms of the present disclosure will be described in detail with reference to the accompanying drawings.

[0051] Figure 4 and Figure 5 A form of fuel tank isolation solenoid valve for a vehicle according to this disclosure is shown.

[0052] like Figure 4 and Figure 5 As shown, the fuel tank isolation solenoid valve 100 includes an upper housing 110 and a lower housing 120, which are coupled to each other to define the appearance of the valve 100.

[0053] The lower housing 120 has a first channel 121 communicating with the fuel tank and a second channel 122 communicating with the tank formed therein. The communication channel 123 is defined in the boundary portion between the first channel 121 and the second channel 122.

[0054] A hollow spool 112 is mounted on the inner wall of the upper housing 110. A coil 111 is wound around the spool, which is a solenoid type for raising and lowering the plunger, and a core 113 is installed in the spool 112.

[0055] The core 113 has a plunger channel 114 therein, which is open at its lower end.

[0056] The plunger 130 is disposed in the plunger channel 114 in the core 113 so as to protrude downward from the core 113. Specifically, the upper end of the plunger 130 is inserted into the plunger channel 114 to be able to move vertically, while the lower end of the plunger 130 is positioned below the core 113.

[0057] like Figure 5 and Figure 6 As shown, the plunger 130 has a cylindrical shape, wherein the diameter of its lower portion is larger than the diameter of its upper portion. The plunger has a lower open space 131 formed therein.

[0058] Specifically, the lower part of the plunger 130 is provided with a plurality of first vent holes 132 to allow the lower open space 131 to communicate with the first channel 121 in the lower housing 120.

[0059] like Figure 5 and Figure 8 As shown, a diaphragm 136 is disposed between the outer surface of the plunger 130 and the inner surface of the core 113, and is connected to the outer surface of the plunger and the inner surface of the core. The diaphragm 136 is used to prevent foreign objects from entering the plunger channel 114 in the core 113.

[0060] More specifically, the diaphragm 136 is used to prevent the plunger 130 from getting stuck in the plunger channel 114 and thus from being unable to rise or fall due to foreign matter entering the plunger channel 114 in the core 113.

[0061] The plunger 130 is further provided with a vent 133 to allow the upper space in the diaphragm 136 to communicate with the lower open space 131.

[0062] Therefore, when the plunger 130 rises, the air in the upper space of the diaphragm 136 and the air in the plunger channel 114 are discharged into the lower open space 131 through the vent 133, thereby allowing the plunger 130 to rise easily without resisting the air.

[0063] A first spring 140 is disposed between the lower surface of the core 113 and the lower end of the plunger 130 so that it can be compressed. For this purpose, a first spring retaining groove 134 is provided at the outer periphery of the lower end of the plunger 130, and the first spring 140 is fitted and retained in the first spring retaining groove.

[0064] Therefore, the first spring 140 is compressed when the plunger 130 rises, and provides an elastic restoring force to the plunger 130 when the plunger 130 falls.

[0065] Preferably, the plunger 130 is provided with a rubber stop 135 on its upper surface, which contacts the upper end surface of the plunger channel 114 formed in the core 113, thereby limiting the distance the plunger 130 rises and cushioning the plunger 130.

[0066] A main seal 150 is mounted on the lower surface of the plunger 130. The main seal 150 is in close contact with the sealing plate 170 (described later) in an airtight manner to block the first passage 121 communicating with the fuel tank and the second passage 122 communicating with the tank.

[0067] The valve body 160 is disposed in the communication channel 123 in the lower housing 120 so that it can move vertically.

[0068] See Figure 5 and Figure 7 The valve body 160 has a plurality of second vent holes 161 formed therein to allow communication between the first channel 121 and the second channel 122. The valve body 160 is disposed in the communication channel 123 to be vertically movable.

[0069] A sealing wall 162 is provided on the upper surface of the valve body 160 at a peripheral position spaced inward from the second vent 161. The sealing wall protrudes upward so as to make airtight and tight contact with the lower surface of the main seal 150.

[0070] In addition, a vertical guide pin 163 is provided at the center of the upper surface of the valve body 160. The vertical guide pin protrudes upward and enters and exits the lower open space 131 in the plunger 130.

[0071] The second spring 180 is disposed between the lower surface of the valve body 160 and the bottom surface of the communicating channel 123 so that it can be compressed. For this purpose, the lower surface of the valve body 160 is provided with a second spring retaining groove 164 on its outer periphery, and the second spring 180 is assembled and retained in the second spring retaining groove.

[0072] The second spring 180 is compressed when the valve body 160 is lowered, and provides elastic restoring force when the valve body 160 is raised.

[0073] The lower housing 120 is provided with an annular sealing plate 170 on the outer periphery of the connecting channel 123. The annular sealing plate is in airtight contact with the lower surface of the main sealing element 150 and the upper surface of the valve body 160.

[0074] For this purpose, the lower surface of the sealing plate 170 is provided with a mating wall 171, and the lower housing 120 is provided with a mating groove 124 in the outer periphery of the connecting channel 123, and the mating wall 171 is mated in the mating groove.

[0075] Here, the sealing plate 170 is in airtight contact with both the lower surface of the main seal 150 and the upper surface of the valve body 160, and is configured to have an annular shape to prevent the second vent hole 161 in the valve body 160 from being blocked by the sealing plate 170, such as... Figure 5 and Figure 8 As shown.

[0076] The operation of a fuel tank isolation solenoid valve constructed in the manner described above, according to one form of the present disclosure, will now be described.

[0077] [Closed state of the insulated solenoid valve]

[0078] like Figure 5 As shown, under normal conditions when the engine is not running (such as in parked or stopped state and EV driving mode), the isolation solenoid valve 100 remains in the closed state.

[0079] More specifically, when the isolating solenoid valve 100 is closed, the plunger 130 rises to its maximum height due to the elastic restoring force of the first spring 140, and the valve body 160 rises to its maximum height due to the elastic restoring force of the second spring 180. Therefore, the lower surface of the main seal 150 mounted on the plunger 130 is in airtight contact with the upper surface of the sealing plate 170, and the upper surface of the valve body 160 is in airtight contact with the lower surface of the sealing plate 170.

[0080] Therefore, since the connecting passage 123, which is limited to the first passage 121 communicating with the fuel tank and the second passage 122 communicating with the tank, is closed, the evaporated gas in the fuel tank cannot flow to the tank.

[0081] When the isolation solenoid valve 100 remains closed, the evaporated gas in the fuel tank cannot flow to the can and is sealed and stored in the fuel tank, thereby preventing the evaporated gas from being discharged into the atmosphere through the can.

[0082] [Operation to open the insulated solenoid valve]

[0083] Figure 9 This is a cross-sectional view showing the operation of opening an isolation solenoid valve for a vehicle according to one form of the present disclosure when power is applied.

[0084] When the engine is running, refueling is being done, or fuel tank leaks are being checked, the isolation solenoid valve 100 opens.

[0085] When power is applied to coil 111, plunger 130 rises along plunger channel 114 in core 113 due to magnetic attraction, and first spring 140 is compressed.

[0086] like Figure 9 As indicated by arrow "A", when the plunger 130 rises, the air in the upper space of the diaphragm 136 and the plunger channel 114 is discharged through the vent 133 into the lower open space 131 and the first vent 132, thereby allowing the plunger 130 to rise easily without resisting the air.

[0087] Furthermore, when the plunger 130 is raised, the main seal 150 mounted on the plunger 130 separates from and is spaced apart from the upper surface of the sealing plate 170.

[0088] Therefore, since the second vent 161 in the valve body 160 is opened, the first channel 121 communicating with the fuel tank is connected to the second channel 122 communicating with the tank via the second vent 161. Thus, the connecting channel 123 between the first channel 121 communicating with the fuel tank and the second channel 122 communicating with the tank is switched to the open state.

[0089] In other words, such as Figure 9As indicated by arrow "B", the first channel 121, which communicates with the fuel tank, and the second channel 122, which communicates with the tank, are connected to each other via the second vent 161.

[0090] When the isolation solenoid valve 100 is opened during engine operation, the vaporized gas in the fuel tank passes sequentially through the first channel 121, the second vent 161 in the valve body 160, and the second channel 122 and is collected in the tank. The vaporized gas collected in the tank is then purged into the engine so that it can be burned due to the negative intake pressure of the engine.

[0091] When the isolation solenoid valve 100 opens during refueling, the vapors in the fuel tank pass sequentially through the first channel 121, the second vent 161 in the valve body 160, and the second channel 122, and are collected in the tank. At this time, the internal pressure of the fuel tank is released, thereby allowing the fuel tank to be easily refueled.

[0092] [Operation of the isolation solenoid valve used to release overpressure]

[0093] Figure 10 This is a cross-sectional view showing the operation of releasing overpressure through a fuel tank isolation solenoid valve for a vehicle according to the form of this disclosure.

[0094] When the pressure in the fuel tank increases to a level higher than the reference pressure due to factors such as the amount of vaporized gas in the fuel tank and the external temperature, the overpressure in the fuel tank acts on the first channel 121.

[0095] Overpressure, which is higher than the reference pressure and acts on the first channel 121, acts on the valve body 160 through the first vent 132 in the plunger 130.

[0096] Therefore, due to the overpressure exceeding the reference pressure, the valve body 160 lowers, simultaneously compressing the second spring 180. At the same time, the sealing wall 162 of the valve body 160 separates and spacees from the lower surface of the main seal 150, and the upper surface of the valve body 160 separates and spacees from the lower surface of the sealing plate 170. Thus, the first channel 121 communicating with the fuel tank and the second channel 122 communicating with the tank are connected to each other via the second vent 161 in the valve body 160.

[0097] Therefore, the overpressure in the fuel tank passes sequentially through the first channel 121, the first vent 132 in the plunger 130, the lower open space, and the second vent 161 in the valve body 160, and then acts on the second channel 122 communicating with the tank, thereby easily releasing the overpressure, as if by Figure 10 The arrow "C" indicates this.

[0098] When the overpressure is released, the valve body 160 rises to its initial position and makes airtight contact with both the sealing plate 170 and the main seal 150, thereby closing the isolation solenoid valve 100.

[0099] Figure 11 This is a cross-sectional view showing the operation of releasing negative pressure using a fuel tank isolation solenoid valve for a vehicle according to one form of the present disclosure.

[0100] When the pressure in the fuel tank drops below the reference pressure, the engine's negative pressure acts on the tank, and the excessive negative pressure acts from the tank on the second channel 122.

[0101] The negative pressure in the second channel 122 from the tank acts on the lower part of the plunger 130 through the second vent 161 in the valve body 160.

[0102] Therefore, due to the excessive negative pressure, the plunger 130 rises, simultaneously compressing the first spring 140, and the main seal 150 mounted on the plunger 130 separates from and is spaced apart from the sealing plate 170, as... Figure 11 As shown. Therefore, the first channel 121, which communicates with the fuel tank, and the second channel 122, which communicates with the tank, are connected to each other via the second vent 161 in the valve body 160.

[0103] Therefore, the excessive negative pressure in the tank passes sequentially through the second channel 122 and the second vent 161 in the valve body 160, and then acts on the first channel 121 connected to the fuel tank, thereby easily releasing the excessive negative pressure, as if by Figure 11 The arrow "D" indicates this.

[0104] When the negative pressure is released as described above, the plunger 130 is lowered to its initial position by the elastic restoring force of the first spring 140, and the main seal 150 mounted on the plunger 130 is in airtight contact with the sealing plate 170 and the sealing wall 162, thereby closing the isolation solenoid valve 100.

[0105] Therefore, since overpressure (positive pressure) or overpressure (negative pressure) acting on the isolating solenoid valve 100 is easily released, damage and failure of the internal components of the isolating solenoid valve can be prevented, and the durability of the fuel tank and the isolating solenoid valve can be increased.

[0106] Will Figure 3 The conventional isolation solenoid valve 200 shown includes a release valve 210 and... Figure 4Compared to the isolation solenoid valve 100 of this form according to the present disclosure, the size of the isolation solenoid valve 100 is reduced to less than that of a conventional isolation solenoid valve 200 because the release valve is omitted in the isolation solenoid valve 100. Therefore, the isolation solenoid valve according to the present disclosure offers advantages in the design of the package layout in which the isolation solenoid valve is to be mounted to the vehicle body, and provides the effects of reducing the number of parts, saving costs and reducing weight by eliminating the release valve.

[0107] Through the above construction, this disclosure provides the following effects.

[0108] First, when an overpressure (positive pressure) acting from the fuel tank acts on the isolation solenoid valve as a pressure higher than the reference pressure, the overpressure can be easily released because the valve body in the isolation solenoid valve is lowered to limit the path for releasing the overpressure.

[0109] Second, when overpressure (positive pressure) acts on the isolation solenoid valve from the tank, the overpressure can be easily released because the plunger in the isolation solenoid valve rises to limit the path for releasing the overpressure.

[0110] Third, since overpressure (positive pressure) and overpressure (negative pressure) acting on the isolating solenoid valve are easily released, it is possible to prevent malfunctions of the isolating solenoid valve and increase its durability.

[0111] Fourth, since the isolation solenoid valve remains closed when the engine is not running, it ensures the function of preventing evaporated gases from escaping to the atmosphere. Since the isolation solenoid valve opens when the engine is running, it ensures the function of collecting evaporated gases in the fuel tank into the canister and purging the evaporated gases into the engine for combustion. And since the isolation solenoid valve opens when the fuel tank is being refueled, it ensures the function of releasing the internal pressure in the fuel tank for refueling.

[0112] Fifth, compared to conventional isolating solenoid valves that include a release valve, the isolating solenoid valve according to this disclosure can reduce its overall size, and therefore offers advantages in the design of packaging layouts where the isolating solenoid valve is intended to be mounted in the vehicle body. Furthermore, by eliminating the release valve, it provides the effects of reducing the number of parts, saving costs, and reducing weight.

[0113] This disclosure has been described in detail with reference to its preferred forms. However, those skilled in the art will understand that changes can be made to these forms without departing from the principles and spirit of this disclosure.

Claims

1. A fuel tank isolation solenoid valve for a vehicle, wherein, The fuel tank isolation solenoid valve includes: Upper casing; The spool is installed in the upper housing; A coil, wound around the spool; A core, installed in the spool, having a plunger channel that opens at its lower end; A lower housing, coupled to the upper housing, the lower housing comprising: The first channel is configured to connect to the fuel tank; The second channel is configured to connect to the tank; and The connecting channel is defined between the first channel and the second channel; A plunger having a lower open space formed in the plunger and a plurality of first vent holes configured to allow the first channel to communicate with the lower open space, the plunger being disposed in the plunger channel and configured to move vertically; The main seal is mounted on the lower surface of the plunger; A valve body, disposed in the communicating channel for vertical movement and having a plurality of second vent holes, wherein the plurality of second vent holes are vertically formed through the valve body and configured to allow communication between the first channel and the second channel; A sealing plate is mounted on the lower housing at the outer periphery of the communication channel so as to make airtight contact with both the lower surface of the main seal and the upper surface of the valve body. The sealing plate is configured to have an annular shape to prevent the second vent in the valve body from being blocked by the sealing plate. A first spring is disposed between the lower surface of the core and the lower end of the plunger; and The second spring is disposed between the lower surface of the valve body and the bottom surface of the communication channel.

2. The fuel tank isolation solenoid valve according to claim 1 further includes: A diaphragm is disposed between the outer surface of the plunger and the inner surface of the core and is connected to the outer surface of the plunger and the inner surface of the core.

3. The fuel tank isolation solenoid valve according to claim 2, wherein, The plunger also has a vent formed in the plunger, the vent being configured to allow communication between the upper space in the diaphragm and the lower open space in the plunger.

4. The fuel tank isolation solenoid valve according to claim 1, wherein, The plunger has a first spring retaining groove formed in the outer periphery of the lower end of the plunger, the first spring being configured to be fitted and retained in the first spring retaining groove.

5. The fuel tank isolation solenoid valve according to claim 1, wherein, The plunger includes a stop on its upper surface, and the stop is configured to contact the upper end surface of the plunger channel formed in the core, while cushioning the upper end surface of the plunger.

6. The fuel tank isolation solenoid valve according to claim 1, wherein, The valve body includes a sealing wall that protrudes from the upper surface of the valve body at an inner periphery spaced inward from the second vent, the sealing wall being configured to make airtight contact with the main seal.

7. The fuel tank isolation solenoid valve according to claim 1, wherein, The valve body includes a vertical guide pin formed at the center of the upper surface of the valve body and configured to enter and exit the lower open space in the plunger.

8. The fuel tank isolation solenoid valve according to claim 1, wherein, The valve body has a second spring retaining groove formed in the outer periphery of the lower surface of the valve body, and the second spring is configured to be fitted and retained in the second spring retaining groove.

9. The fuel tank isolation solenoid valve according to claim 1, wherein, The sealing plate includes a mating wall formed on the lower surface of the sealing plate, and the lower housing has a mating groove formed in the outer periphery of the communicating channel, the mating wall being configured to fit and be held in the mating groove.

10. The fuel tank isolation solenoid valve according to claim 1, wherein: When an overpressure, which is a pressure higher than the reference pressure, acts on the valve body from the fuel tank through the first channel and the first vent in the plunger... The valve body lowers, simultaneously compressing the second spring. The overpressure passes sequentially through the first vent in the plunger, the lower open space, and the second vent in the valve body, and acts on the second channel. The overpressure was released.

11. The fuel tank isolation solenoid valve according to claim 1, wherein: When an excessive negative pressure, which is lower than the reference pressure, acts on the lower part of the plunger from the tank through the second vent in the valve body, The plunger rises, simultaneously compressing the first spring. The negative pressure passes through the second vent in the valve body and acts on the first channel communicating with the fuel tank. The excessive negative pressure is released.

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