Fuel tank isolation valve for a vehicle

Abstract

The present invention relates to a fuel tank isolation valve for a vehicle. A valve opening operation or a valve closing operation is performed using a guide protrusion configured to move along a guide groove in response to upward movement or downward movement of a plunger. The present invention prevents battery discharge. Also, the present invention prevents sudden changes in fuel tank pressure.

Description

Technical Field

[0001] The present invention generally relates to a fuel tank isolation valve for a vehicle, and more specifically to a fuel tank isolation valve for a vehicle in which a valve opening operation or a valve closing operation can be performed using a guide protrusion configured to move along a guide groove in response to upward or downward movement of a plunger, thereby preventing battery discharge and preventing sudden changes in fuel tank pressure. Background Technology

[0002] refer to Figure 1 According to relevant technology, a carbon canister 20 is connected to the vehicle's fuel tank 10. The carbon canister 20 collects fuel vapors and then purifies the collected fuel vapors to make them combustible in the combustion chamber of the engine 30. In this respect, the inlet 21 of the carbon canister 20 is connected to the fuel tank 10 via an exhaust line 13, and the outlet 22 of the carbon canister 20 is connected to the engine intake manifold 31 via a purification line 14.

[0003] Furthermore, a collector (not shown) for collecting evaporated gases by adsorption is disposed inside the carbon canister 20. The collector collects the evaporated gases inside the carbon canister 20, and an exhaust port 23 for discharging the purified gases is disposed on the carbon canister 20. Therefore, in response to the operation of the fuel pump 11 installed inside the fuel tank 10, fuel is supplied to the engine 30 along the fuel supply line 12, making the fuel combustible. Furthermore, after the evaporated gases from the fuel in the fuel tank 10 are collected in the carbon canister 20 through the exhaust line 13, the evaporated gases can be supplied to the engine 30 along the purification line 14 under the negative intake pressure of the engine, making the evaporated gases combustible.

[0004] However, in hybrid vehicles, particularly plug-in hybrid electric vehicles (PHEVs) that are primarily driven in electric vehicle (EV) mode by operating a drive motor, the following limitations exist. When the carbon canister 20 has already collected its maximum amount of evaporated gases, any further amount of evaporated gases continuously entering from the fuel tank 10 may not be collected. When the hybrid vehicle switches to engine-operated hybrid electric vehicle (HEV) mode, the evaporated gases collected in the carbon canister 20 are purified to make them combustible in the engine. However, during vehicle parking or engine shutdown, and in EV mode, evaporated gases exceeding the collection capacity of the carbon canister 20 continuously enter from the fuel tank 10.

[0005] Therefore, when the maximum amount of evaporated gas has already been collected in the carbon canister 20, and evaporated gas continues to enter the carbon canister 20 from the fuel tank 10, the evaporated gas exceeding the collection capacity of the carbon canister 20 will not be collected but will be emitted into the air through the exhaust port 23, causing air pollution. This is problematic. To overcome these problems, an isolation valve 200 is installed on the exhaust line 13, as per relevant technology. Figure 2 As shown. The isolation valve 200 is configured to open or close to allow or prevent evaporated gas from flowing from the fuel tank 10 to the carbon canister 20.

[0006] Isolation valve 200 is a solenoid valve that opens when energized. Isolation valve 200 is normally closed and only opens when the engine is running or fuel is supplied to the fuel tank. More specifically, isolation valve 200 remains closed under normal conditions when the engine is not running, such as during parking or engine shutdown, or in EV drive mode. When the engine is running, isolation valve 200 can open using energized power in response to a signal from a controller (e.g., engine control unit (ECU)). During fuel supply, isolation valve 200 can open using energized power in response to a signal from a controller (e.g., body control module (BCM)).

[0007] Therefore, when the isolation valve 200 remains closed, the evaporated gases in the fuel tank 10 are isolated and stored within the fuel tank 10 without flowing to the carbon canister 20. This prevents the evaporated gases from being released into the air through the carbon canister 20. Conversely, when the isolation valve 200 is opened during engine operation, the evaporated gases in the fuel tank 10 are collected in the carbon canister 20 by passing through the open isolation valve 200. The collected evaporated gases can be purified by the engine's negative intake pressure to make them combustible in the engine.

[0008] Alternatively, when the isolation valve 200 is opened during fuel supply to the fuel tank, the vaporized gases in the fuel tank 10 are collected in the carbon canister 20 as they pass through the opened isolation valve 200, thereby relieving internal pressure in the fuel tank 10 and facilitating fuel supply to the fuel tank 10. At this time, when the user presses the fuel door button in the vehicle compartment, the controller (e.g., BCM) determines to open the isolation valve 200 to relieve internal pressure in the fuel tank 10, and then operates to open the electric fuel tank cap 40.

[0009] In the following text, reference will be made to relevant technologies. Figures 3 to 5 This describes the construction and operation of a related isolation valve. Referring to the exterior of isolation valve 200, an upper housing 210 and a lower housing 230 are connected to each other. A first passage 231 communicating with a fuel tank and a second passage 232 communicating with a carbon canister are located inside the lower housing 230. An open / close passage 233 is provided at the boundary between the first passage 231 and the second passage 232, configured to be opened and closed by a valve body 217.

[0010] A hollow spool 212 with a coil 211 wound around it is mounted on the inner wall of the upper housing 210, and a core 213 is disposed inside the spool 212. Furthermore, the core 213 has a bottom-open plunger lifting path 214, and a plunger 215 is disposed within the plunger lifting path 214 for vertical movement. Additionally, a bottom-open valve lifting path 216 is disposed within the plunger 215. A valve body 217 configured to open and close the open / close passage 233 is disposed within the valve lifting path 216 for vertical movement.

[0011] Furthermore, the evaporation gas path 218 extends vertically through the valve body 217, allowing the evaporation gas to pass through it. Specifically, the first spring 219 is connected to the bottom surface of the core 213 and the bottom end of the plunger 215, and the second spring 220 is connected to the bottom surface of the valve body 217 and the opening / closing passage 233.

[0012] Closing operation of isolation valve

[0013] refer to Figure 3 When no power is applied to coil 211, as plunger 215 moves downwards due to the elastic restoring force of first spring 219 in the tension direction, plunger 215 presses down on valve body 217. Therefore, valve body 217 closes open / close passage 233 while compressing second spring 220, preventing evaporated gas in fuel tank from flowing to carbon canister. In this way, isolation valve 200 is closed.

[0014] Then, when the engine is not running, such as during parking or when the engine is off, or in EV drive mode, the isolation valve 200 remains closed. Therefore, the evaporated gases within the fuel tank 10 can be isolated and stored in the fuel tank 10 without flowing to the carbon canister 20, thus preventing them from being emitted into the air through the carbon canister 20.

[0015] Opening operation of isolation valve

[0016] refer to Figure 4 When power is applied to coil 211, plunger 215 moves instantaneously upward along plunger lifting path 214 of core 213 by magnetic attraction. Therefore, the path is primarily defined by the gap between plunger 215 and valve body 217.

[0017] Therefore, the evaporated gas in the fuel tank flows sequentially through the first passage 231 of the lower housing 230, the gap passage between the plunger 215 and the valve body 217, the evaporated gas passage 218 of the valve body 217, and the second passage 232 of the lower housing 230, thereby flowing to the carbon canister connected to the second passage 232, where the evaporated gas is collected. Subsequently, as... Figure 5As shown, the valve body 217 moves upward along the valve lifting path 216 of the plunger 215 due to the elastic restoring force of the second spring 220 in the tension direction, thereby opening the open / close passage 233. Therefore, the evaporated gas in the fuel tank flows sequentially through the first passage 231, the open / close passage 233, and the second passage 232 of the lower housing 230, and then flows to the carbon canister to collect the evaporated gas.

[0018] Therefore, when the engine of the hybrid vehicle is running, the vaporized gases in the fuel tank 10 can pass through the open isolation valve 200 and be collected in the carbon canister 20. The collected vaporized gases can be purified by the negative intake pressure of the engine to make them combustible in the engine. In addition, during fuel supply to the fuel tank, while the vaporized gases in the fuel tank 10 are being collected in the carbon canister 20 through the open isolation valve 200, the internal pressure in the fuel tank 10 can be removed, thereby facilitating fuel supply to the fuel tank.

[0019] However, the aforementioned isolation valves in the related technologies have the following problems.

[0020] First, when the isolation valve operates to open in response to the power applied to the coil, current is continuously supplied to the coil to maintain the open position, thereby discharging the battery.

[0021] Secondly, since the current is continuously supplied to the coil, it may cause malfunctions or fires due to overheating.

[0022] Third, in a configuration where the isolation valve is forcibly closed by stopping power to the coil when the isolation valve's opening limit time has been exceeded, the internal pressure of the fuel tank may increase during fuel supply due to the sudden closure of the isolation valve. This could potentially cause damage, such as fuel overflow from the fuel tank.

[0023] Fourth, the plunger, valve body, and other components used to open and close the isolation valve may not be reliably fixed in the open or closed position, thereby reducing the valve's performance or durability.

[0024] The above description is intended only to help understand the background of the present invention and is not intended to imply that the present invention falls within the scope of related technologies known to those skilled in the art. Summary of the Invention

[0025] Therefore, the present invention has taken into account the aforementioned problems in related technologies, and aims to provide a fuel tank isolation valve (FTIV) for a vehicle that uses a protruding unit structure as a configuration for opening and closing the isolation valve. The protruding unit structure is configured to selectively press a plunger and a pressing element unit, the plunger being configured to rotate and move vertically along a guide groove. Therefore, the valve can be maintained in both the open and closed positions even without applied current. Thus, battery discharge can be prevented by preventing continuous current supply to the coil. Furthermore, the opening operation of the isolation valve can be divided into two independent operations, thereby preventing sudden changes in fuel tank pressure.

[0026] According to one aspect of the invention, a fuel tank isolation valve for a vehicle is provided. The isolation valve may include: an upper housing; a spool wound with a coil, the spool being mounted inside the upper housing; a core having a plunger lifting path with an open bottom in the plunger lifting path, the core being mounted inside the spool; a lower housing having a first passage communicating with a fuel tank, a second passage communicating with a carbon canister, and an open / close passage formed between the first and second passages, the lower housing being fitted to the upper housing; a plunger disposed in the plunger lifting path and configured to rotate and move vertically along a guide groove in response to an applied current to the coil, the guide groove being disposed in the outer circumferential surface of the plunger lifting path; a protruding unit protruding from the lower part of the plunger; and a pressing unit disposed below the plunger lifting path. When the plunger moves vertically, the pressing unit selectively opens the valve by receiving pressure applied thereto by the protruding unit. The fuel tank isolation valve for a vehicle further includes a first spring compressed between a plunger and a spring support plate; a valve drive plate disposed at the bottom end of the core for vertical movement while sealingly isolating the plunger lifting path; and a valve body configured such that its orifice allows communication between the first passage and the second passage, and is disposed in the open / close passage for vertical movement.

[0027] The plunger may include a plurality of guide protrusions projecting from its outer periphery toward a surface, the guide protrusions being configured to insert into guide grooves. The guide grooves may include: a plurality of standby sections in which the guide protrusions engage; a plurality of first inclined sections extending downwardly from corresponding standby sections, allowing the plunger to rotate and move; a plurality of vertical sections branching off from corresponding first inclined sections and configured to guide vertical movement of the plunger; and a plurality of second inclined sections extending upwardly above corresponding vertical sections and toward adjacent standby sections, thereby guiding the guide protrusions toward adjacent standby sections when the plunger returns after the valve has opened or closed.

[0028] Each standby segment may be spaced 90° from an adjacent standby segment along the outer circumferential surface of the plunger's lifting path. The protruding unit may include: a valve opening protrusion configured to press both sides of the pressing unit to maintain the valve in an open position; and a valve closing protrusion configured to press the upper part of the pressing unit in response to rotation and movement of the plunger, thereby changing the valve open position to the valve closed position.

[0029] The length of the valve opening protrusion may be longer than the length of the valve closing protrusion. The pressing unit may include: a main body connected to be vertically movable in the spring support plate; a first pressing part disposed on both sides of the main body and configured to selectively disengage from the slot disposed in the spring support plate when pressed by the valve opening protrusion; and a second pressing part disposed on the upper part of the main body and configured to move downward when pressed by the valve closing protrusion and selectively engage the first pressing part with the slot.

[0030] The second pressing portion may include an insertion groove configured to selectively prevent interference from the downwardly moving valve closing protrusion when the first pressing portion is pressed by the valve opening protrusion, and the second pressing portion is selectively configured to move downward upon contact with the valve closing protrusion. As the plunger rotates and moves along a guide groove at 90°, the valve closing protrusion may, in response to the valve opening protrusion pressing the first pressing portion, insert into the insertion groove to maintain the valve in the open position, and selectively press and move the second pressing portion downward, thereby switching to the valve closed position.

[0031] The plunger may include a stop configured to contact the top surface of the plunger's lifting path while providing cushioning when returned to its original position by the first spring. The fuel tank isolation valve for a vehicle may further include: a second spring compressed between the valve actuation plate and the valve body; and a third spring disposed between the bottom surface of the valve body and the bottom surface of the opening / closing passage. The valve actuation plate may be mounted on the lower end of the core via a diaphragm to maintain a sealed state.

[0032] In the fuel tank isolation valve for a vehicle according to the invention, the protruding unit is configured to have a structure for opening and closing the isolation valve. The protruding unit is configured to selectively press a plunger and a pressing element unit, the plunger being configured to rotate and move vertically along a guide groove. Therefore, the valve can be maintained in both the open and closed positions even without an applied current. Thus, battery discharge can be prevented by preventing continuous current supply to the coil.

[0033] Furthermore, the opening operation of the isolation valve can be divided into two independent operations: first, opening the valve body orifice, and then actually opening the valve body, thereby preventing sudden changes in tank pressure. In addition, according to the present invention, sudden changes in fuel tank pressure are prevented. Therefore, it is possible to prevent the fuel tank vent valve from becoming clogged or experiencing fuel cavitation due to increased discharge flow caused by sudden pressure changes under overpressure conditions in the fuel tank. It is also possible to prevent problems in the fuel pump caused by fuel cavitation, such as reduced flow or fuel pump shutdown. Attached Figure Description

[0034] The above and other objects, features, and other advantages of the invention will become clearer from the detailed description that follows in conjunction with the accompanying drawings, in which:

[0035] Figure 1 A schematic diagram illustrating the collection of evaporated gases in the fuel tank into a carbon canister and then purification before being sent to the engine, according to the relevant technology;

[0036] Figure 2 A schematic diagram illustrating the state of an isolation valve installed between the fuel tank and the carbon canister according to relevant technology;

[0037] Figure 3 To illustrate the construction of the isolation valve according to the related art and a cross-sectional view of the isolation valve closing operation according to the related art;

[0038] Figure 4 and Figure 5 To illustrate the construction of the isolation valve according to the related art and a cross-sectional view of the opening operation of the isolation valve according to the related art;

[0039] Figure 6 A cross-sectional view of a fuel tank isolation valve for a vehicle according to the present invention is shown.

[0040] Figure 7 A perspective view showing the plunger structure and protruding unit structure of the fuel tank isolation valve for a vehicle according to the present invention;

[0041] Figure 8 A perspective view showing the arrangement of a fuel tank isolation valve for a vehicle according to the present invention, wherein a plunger and a pressing element unit are assembled;

[0042] Figure 9 A perspective view showing the operation of the plunger of the fuel tank isolation valve for a vehicle according to the present invention when an electric current is applied;

[0043] Figure 10 A perspective view showing the operation of the plunger of the fuel tank isolation valve for a vehicle according to the present invention when the applied current is removed;

[0044] Figure 11AA perspective view showing the operation of the plunger bringing the fuel tank isolation valve for a vehicle according to the invention to the valve open position;

[0045] Figure 11B A perspective view showing the operation of the valve closing protrusion to bring the fuel tank isolation valve for a vehicle according to the invention to the valve open position;

[0046] Figure 12A A perspective view showing the operation of the plunger bringing the fuel tank isolation valve for a vehicle according to the invention to the valve closed position;

[0047] Figure 12B A perspective view showing the operation of the valve closing protrusion to bring the fuel tank isolation valve for a vehicle according to the invention to the valve closed position;

[0048] Figures 13A to 13C A cross-sectional view showing the operation of the fuel tank isolation valve for a vehicle according to the invention, which is in the valve closed position, changing from the valve closed position to the valve open position;

[0049] Figures 14A to 14C A cross-sectional view showing the operation of the fuel tank isolation valve for a vehicle according to the invention, which is in the valve closed position, changing from the valve open position to the valve closed position;

[0050] Figure 15 A perspective view of a fuel tank isolation valve for a vehicle according to the present invention, wherein the first pressing part is disengaged from the slot;

[0051] Figure 16 A perspective view of a fuel tank isolation valve for a vehicle according to the present invention, wherein the first pressing part is engaged by a slot;

[0052] Figure 17 To illustrate, compared to related technologies, a diagram shows that the fuel tank isolation valve for a vehicle according to the present invention can remain in the open position when no power is applied to it; and

[0053] Figure 18 A diagram illustrating the operation of a fuel tank isolation valve for a vehicle according to the invention to open via two separate operations, thereby preventing sudden changes in fuel tank pressure. Detailed Implementation

[0054] Exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0055] The advantages and features of the present invention, as well as the methods of implementing it, will be more clearly understood from the following detailed description of the embodiments in conjunction with the accompanying drawings.

[0056] It should be understood that, as used herein, the terms "vehicle" or "of a vehicle" or other similar terms generally include motor vehicles, such as passenger vehicles including sport utility vehicles (SUVs), buses, trucks, various commercial vehicles, vessels including various boats and ships, aircraft, etc., and include hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles, and other vehicles powered by alternative fuels (e.g., fuels derived from non-petroleum sources). As mentioned herein, a hybrid vehicle is a vehicle with two or more power sources, such as a vehicle that combines gasoline and electric power.

[0057] Although exemplary embodiments are described as using multiple units to perform exemplary processes, it should be understood that exemplary processes can also be performed by one or more modules. Furthermore, it should be understood that the term controller / control unit refers to a hardware device including a memory and a processor, specifically programmed to perform the processes described herein. The memory is configured to store modules, and the processor is specifically configured to execute said modules to perform one or more processes, as will be further described below.

[0058] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” as used herein are intended to include the plural forms as well. When the terms “comprising” and / or “including” are used in this specification, they specify the presence of the stated features, values, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, values, steps, operations, elements, components, and / or combinations thereof. The term “and / or” as used herein includes any and all combinations of one or more of the listed related items.

[0059] Unless otherwise specified or obvious from the context, the term “about” as used herein is understood to mean within the normal tolerance range in the field, such as within 2 standard deviations of the mean. “About” can be understood as within 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, 0.1%, 0.05%, or 0.01% of the stated value. All numerical values ​​provided herein are modified by the term “about” unless the context clearly indicates otherwise.

[0060] However, the invention is not limited to the specific embodiments described below, but can be embodied in various different forms. Rather, these embodiments are provided to make the description of the invention complete and to fully convey the scope of the invention to those skilled in the art. The invention should be defined by the scope of the claims.

[0061] Furthermore, in the following description of the present invention, detailed descriptions of known technologies, etc., will be omitted where such descriptions might make the subject matter of the present invention quite unclear. Figure 6 As shown, referring to the exterior of the isolation valve 100 according to the present invention, the isolation valve 100 includes an upper housing 110 and a lower housing 120 connected to the upper housing 110.

[0062] A first passage 121 communicating with the fuel tank and a second passage 122 communicating with the carbon canister are located inside the lower housing 120. An open / close passage 123 is provided at the boundary between the first passage 121 and the second passage 122, which is configured to be opened and closed by a valve body 170. A hollow spool 112 with a coil 111 wound around it can be mounted on the inner wall of the upper housing 110, and a core 113 can be located inside the spool 112.

[0063] A bottom-open plunger lifting path 114 can be disposed within the core 113. The plunger 116 can be received within the plunger lifting path 114 of the core 113 and can be configured to move vertically in response to a current applied to the coil. Specifically, a stop 117 can be mounted on the top surface of the plunger 116. The stop 117 can contact the top surface of the plunger lifting path 114 while providing cushioning, thereby limiting the distance the plunger 116 is allowed to move vertically and cushioning the plunger 116.

[0064] In addition, such as Figure 7 As shown, the protruding unit 118 protrudes from the lower part of the plunger 116. When the plunger 116 moves downward in response to an applied current, the pressing unit 130 is selectively pressed, thereby opening or closing the valve. Furthermore, the plunger 116 can rotate or move vertically along a guide groove 140, which forms a path on the outer circumferential surface of the plunger lifting path 114. This rotation and upward and downward (e.g., vertical) movement of the plunger 116 can occur as a plurality of guide protrusions 116a move along the path while being received by the guide groove 140.

[0065] like Figures 8 to 10 As shown, the guide groove 140 may include a standby section 141, a first inclined section 142, a vertical section 143, and a second inclined section 144. The standby section 141 is the section corresponding to the stop position of the guide protrusion 116a. The standby section 141 can be the initial standby position of the plunger 116.

[0066] like Figure 9 As shown, the first inclined section 142 extends downward from the standby section 141 to allow the plunger 116 to rotate and move along the first inclined section 142. Since the guide protrusion 116a, which moves downward in the standby section 141, firstly contacts the first inclined section 142, the first inclined section 142 guides the guide protrusion 116a to move along its inclined surface.

[0067] The vertical section 143 branches off from the first inclined section 142, guiding the vertical movement of the plunger 116 to open or close the valve in the vertical direction, or to return to its original position after opening or closing the valve in the vertical direction. The second inclined section 144 extends upward above the vertical section 143 and inclined toward the adjacent standby section 141, thereby guiding the plunger 116 to move toward the adjacent standby section 141 when the plunger 116 returns after the valve has opened or closed.

[0068] Specifically, each portion between adjacent standby sections 141 is perpendicular to each other, approximately 90°, along the outer circumference of the plunger lifting path 114. Therefore, the plunger 116 moves while rotating in one direction at approximately 90° intervals. When current is applied, the valve can switch from the valve open position to the valve closed position or vice versa whenever the plunger 116 moves vertically. In other words, when current is applied to the coil 111 to switch to the valve open position, the guide protrusion 116a located in the standby section 141 moves sequentially to the first inclined section 142, as... Figure 9 As shown. Subsequently, the guide protrusion 116a moves through the vertical section 143, and then the valve-opening protrusion 118a of the protrusion unit 118 presses the first pressing part 132 of the pressing part unit 130. This causes the body 131 to move vertically within the spring support plate 150, thereby placing it in the valve-open position.

[0069] like Figure 10 As shown, even if the current applied to the coil 111 is removed, the elastic restoring force of the first spring 151 will cause the guide protrusion 116a to move along the vertical section 143 and the second inclined section 144, thereby positioning it in the adjacent standby section 141. Therefore, even when the applied current is removed, the valve can remain in the open position when the guide protrusion 116a is in the standby section 141. Furthermore, the protrusion unit 118 includes a valve opening protrusion 118a and a valve closing protrusion 118b. The pressing unit 130 may include a first pressing portion 132 and a second pressing portion 133.

[0070] In this structure, the valve opening protrusion 118a presses down on both sides of the pressing member unit 130 (i.e., the first pressing member portion 132), thereby maintaining the valve in the open position. When the first pressing member portion 132 is pressed down by the valve opening protrusion 118a, the first pressing member portion 132 selectively disengages from the slot 150a provided in the spring support plate 150 (see...). Figure 11A and Figure 15 Therefore, the main body 131 of the pressing unit 130 can move vertically within the spring support plate 150, thereby putting the valve in the open position (i.e., the first operation).

[0071] Furthermore, as the plunger 116 rotates and moves, the valve closing protrusion 118b presses against the upper part of the pressing member unit 130 (i.e., the second pressing member portion 133), such as Figure 12A As shown, this changes the valve from the open position to the closed position. At this time, the second pressing part 133 is pressed downwards by the valve closing protrusion 118b, causing the first pressing part 132 and the pressing auxiliary part 132a to be selectively engaged by the slot 150a, which is provided within the spring support plate 150 (see...). Figure 16 Therefore, the main body 131 of the pressing unit 130 can put the valve in the spring support plate 150 in the closed position (i.e., the second operation).

[0072] Specifically, the second pressing portion 133 has an insertion groove 133a configured to selectively prevent interference from the downwardly moving valve closing protrusion 118b when the first pressing portion 132 is pressed by the valve opening protrusion 118a. In the first operation, the valve closing protrusion 118b can be inserted into the insertion groove 133a, thereby causing the valve opening protrusion 118a to press the first pressing portion 132 (see...). Figure 11B In the second operation, the plunger 116, which has already rotated and moved at 90° intervals in the first operation, allows the valve closing protrusion 118b to press against the top surface of the second pressing portion 133 (see...). Figure 12B ).

[0073] In the following text, the first operation of putting the valve in the open position and the transition from the first operation to the second operation of putting the valve in the closed position will be described based on the above structure.

[0074] First operation

[0075] In such Figure 6 In the valve closed position shown, in response to the current applied to the coil 111, the guide protrusion 116a located in the standby section 141 moves along the first inclined section 142 and the vertical section 143. Then, the plunger 116 rotates and moves downward within the plunger lifting path 114, causing the valve opening protrusion 118a to press the first pressing part 132.

[0076] In particular, such as Figures 13A to 13C As indicated by the middle arrow, the gas above the diaphragm 161 located at the bottom of the core 113 is discharged through the vent 162 and impurity filter 163 in the valve drive plate 160. When the second spring 152 moves the valve drive plate 160 vertically, the first pressing part 132, which disengages from the slot 150a, pushes the lower part of the main body 131 upward, thereby opening the orifice 171 of the valve body 170.

[0077] Therefore, the first passage 121, which connects to the fuel tank, is connected to the second passage 122, which connects to the carbon canister, via the open orifice 171. In this case, the pressure inside the fuel tank can gradually be applied to the second passage 122 through the first passage 121 and the orifice 171, thereby preventing sudden changes in the pressure inside the fuel tank. This may result in the opening operation of the isolation valve being divided into two independent operations: the operation of opening the orifice of the valve body first and the operation of actually opening the valve body, such as... Figure 18 As shown, this prevents sudden changes in fuel tank pressure.

[0078] Subsequently, when the pressure inside the fuel tank acting on the valve body 170 through the first passage 121 is less than the elastic restoring force of the third spring 153 disposed between the bottom surface of the valve body 170 and the bottom surface of the opening / closing passage 123, the elastic restoring force of the third spring 153 causes the valve body 170 to move upward. Then, as... Figure 13C As shown, the valve body 170 moves upward, and the valve seat 173, which has been attached to the valve plate 172, disengages from the outer periphery of the open / close passage 123, thereby opening the open / close passage 123. In this way, the isolation valve is switched to the open position.

[0079] Therefore, the evaporated gas in the fuel tank can more easily flow sequentially through the first passage 121, the open / close passage 123, and the second passage 122 to the carbon canister. When the current to the coil 111 is stopped, the guide protrusion 116a moves along the vertical section 143 and the second inclined section 144 to be positioned in the adjacent standby section 141, thereby performing a second operation when the current is reapplied later. Thus, in the valve open position, the plunger 116 moves vertically to its original position.

[0080] As described above, even when the current to coil 111 is stopped, the isolation valve can remain in the open position. Therefore, as Figure 17 As shown, this can prevent battery discharge that occurs in related technologies due to continuous current supply to the coil when the isolation valve is in the open position.

[0081] Second operation

[0082] like Figures 14A to 14C As shown, when current is applied to coil 111 to switch from valve open to valve closed, the guide protrusion 116a located in standby section 141 moves along the first inclined section 142 and the vertical section 143. Then, plunger 116 rotates and moves downward at approximately 90° intervals within plunger lifting path 114, causing valve closing protrusion 118b to press against the second pressing portion 133, as... Figure 14B As shown.

[0083] Then, the gas present in the plunger lifting path 114 along... Figure 14BThe airflow, as indicated by the middle arrow, passes through the vent 162 and impurity filter 163 of the valve drive plate 160 and discharges into the first passage 121, which communicates with the fuel tank. Specifically, when the second pressing part 133 is pressed, as... Figure 14C As shown, the main body 131 moves downward to press the valve drive plate 160, causing the valve drive plate 160 to move downward while compressing the second spring 152. At the same time, the valve drive plate 160 presses the valve body 170, causing the valve body 170 to move downward while compressing the third spring 153.

[0084] Then, the valve body 170 moves downward, and the valve seat 173, attached to the valve plate 172 of the valve body 170, comes into close contact with the outer periphery of the opening / closing passage 123. Therefore, the opening / closing passage 123 is closed, thereby preventing evaporated gas from the fuel tank from flowing into the carbon canister. In other words, the isolation valve is in the closed position. Subsequently, when the current applied to the coil 111 is removed, the guide protrusion 116a moves along the vertical section 143 and the second inclined section 144 in the same manner as in the first operation to be positioned in the standby section 141, thereby allowing the first operation to be performed when the current is later reapplied. Therefore, in the valve closed position, the plunger 116 moves vertically to the initial position.

[0085] As described above, the isolation valve can remain in the closed position even when current to coil 111 is blocked and no current is applied. Therefore, as Figure 17 As shown, this can prevent battery discharge that occurs in related technologies due to continuous current supply to the coil when the isolation valve is in the open position.

[0086] According to the present invention, the protruding unit is configured for opening and closing an isolation valve. The protruding unit is configured to selectively press a plunger and a pressing element unit, the plunger being configured to rotate and move vertically along a guide groove. Therefore, the valve can be maintained in both the open and closed positions even without an applied current. Thus, battery discharge can be prevented by preventing continuous current supply to the coil.

[0087] Furthermore, the opening operation of the isolation valve can be divided into two independent operations: first, opening the valve body orifice, and then actually opening the valve body, thereby preventing sudden changes in tank pressure. In addition, according to the present invention, sudden changes in fuel tank pressure are prevented. Therefore, it is possible to prevent the fuel tank vent valve from becoming clogged or experiencing fuel cavitation due to increased discharge flow caused by sudden pressure changes under overpressure conditions in the fuel tank. It is also possible to prevent problems in the fuel pump caused by fuel cavitation, such as reduced flow or fuel pump shutdown.

[0088] Although exemplary embodiments of the invention have been described for illustrative purposes, those skilled in the art will understand that various modifications, additions, and substitutions can be made therein. It will also be apparent to those skilled in the art that all or some of the above embodiments can be selectively combined. Therefore, the true scope of protection of the invention should be defined by the technical concept of the appended claims.

Claims

1. A fuel tank isolation valve for a vehicle, comprising: Upper shell; A bobbin with a coil wound on it is installed inside the upper housing; The core has a plunger lifting path, in which an opening bottom is provided, and the core is installed inside the spool; The lower housing has a first passage communicating with a fuel tank, a second passage communicating with a carbon canister, and an open / close passage formed between the first and second passages, the lower housing being assembled to the upper housing; A plunger disposed in the plunger lifting path and configured to rotate and move vertically along a guide groove in response to an applied current to a coil, the guide groove being disposed in the outer circumferential surface of the plunger lifting path; A protruding unit that protrudes from the lower part of the plunger; A pressing unit, disposed below the plunger's lifting path, selectively positions the valve in the open position by receiving pressure applied to it by the protruding unit when the plunger moves vertically. A first spring is compressedly disposed between the plunger and the spring support plate; A valve drive plate is disposed at the bottom end of the core to be able to move vertically while sealingly isolating the plunger lifting path; as well as A valve body having an orifice and disposed in the open / close passage to enable vertical movement, the orifice allowing the first passage to communicate with the second passage.

2. The fuel tank isolation valve for a vehicle according to claim 1, wherein, The plunger includes a plurality of guide protrusions projecting from its outer periphery toward a surface, the guide protrusions being configured to insert into guide grooves.

3. The fuel tank isolation valve for a vehicle according to claim 2, wherein, The guide groove includes: Multiple standby segments, with the guide protrusion engaged within each standby segment; Multiple first inclined sections extend downward from corresponding standby sections, enabling the plunger to rotate and move; Multiple vertical sections, each branching from a corresponding first inclined section and configured to guide the plunger upward or downward; and Multiple second inclined sections extend upward at an angle above a corresponding vertical section and toward an adjacent standby section, thereby guiding the guide protrusion toward the adjacent standby section as the plunger returns after the valve is opened or closed.

4. The fuel tank isolation valve for a vehicle according to claim 3, wherein, Each standby segment has a 90° gap between its outer circumferential surface along the plunger lifting path and the adjacent standby segment.

5. The fuel tank isolation valve for a vehicle according to claim 1, wherein, The protruding unit includes: A valve opening protrusion is configured to press both sides of the pressing element unit to maintain the valve in the open position; and A valve closing protrusion is configured to press the upper part of the pressing unit in response to the rotation and movement of the plunger, thereby changing the valve open position to the valve closed position.

6. The fuel tank isolation valve for a vehicle according to claim 5, wherein, The length of the valve opening protrusion is longer than the length of the valve closing protrusion.

7. The fuel tank isolation valve for a vehicle according to claim 5, wherein, The pressing unit includes: The main body is connected in a manner that allows it to move vertically within the spring support plate; The first pressing element is located on both sides of the main body and is configured to selectively disengage from a slot in the spring support plate when pressed by the valve opening protrusion; and The second pressing part is disposed on the upper part of the main body and configured to move downward when pressed by the valve closing protrusion and selectively cause the first pressing part to be locked by the slot.

8. The fuel tank isolation valve for a vehicle according to claim 7, wherein, The second pressing part includes an insertion groove configured to selectively prevent interference from the downwardly moving valve closing protrusion when the first pressing part is pressed by the valve opening protrusion, and the second pressing part is selectively configured to move downward when in contact with the valve closing protrusion.

9. The fuel tank isolation valve for a vehicle according to claim 8, wherein, When the plunger rotates and moves along the guide groove at 90°, the valve closing protrusion is inserted into the insertion groove in response to the valve opening protrusion pressing the first pressing part to maintain the valve in the open position, and selectively presses and moves the second pressing part downward to switch to the valve closing position.

10. The fuel tank isolation valve for a vehicle according to claim 1, wherein, The plunger includes a stop configured to contact the top surface of the plunger's lifting path while providing cushioning when the plunger returns to its original position via the first spring.

11. The fuel tank isolation valve for a vehicle according to claim 1, further comprising: A second spring is compressedly disposed between the valve drive plate and the valve body; as well as A third spring is disposed between the bottom surface of the valve body and the bottom surface of the opening / closing passage.

12. The fuel tank isolation valve for a vehicle according to claim 1, wherein, The valve drive plate is mounted on the lower end of the core via a diaphragm to maintain a sealed state.

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