Fuel tank control valve

Abstract

A control valve for a fuel tank is provided, which simultaneously reduces the noise from collisions between the auxiliary float and other components caused by engine purging and improves the responsiveness to dynamic displacement of the fuel level. The control valve for a fuel tank includes: a housing; a main float disposed within the housing; a plate forming the bottom of the housing via its upper surface and having a first gas storage chamber formed by a peripheral wall portion extending downward from the periphery of the upper surface; and an auxiliary float movably disposed on the plate, wherein a second gas storage chamber is disposed within a portion of the upper surface of the first gas storage chamber including a gas supply hole and a partition wall portion separated from the peripheral wall portion. A gap exists between the housing and the peripheral wall portion relative to the auxiliary float, allowing fuel to flow into the fuel tank. Furthermore, the upper surface has a convex seating portion that forms an inflow space allowing gas to flow into the gas supply hole when the auxiliary float is seated.

Description

Technical Field

[0001] This specification discloses a fuel tank control valve installed in the fuel tank of an automobile. Background Technology

[0002] The purpose of a car's fuel tank is to prevent fuel leakage during swaying, rollover, or fuel supply, to limit the fuel level when the tank is full, to allow fuel vapor (evaporation gas) to vent, to control pressure rise within the fuel tank, and to prevent over-fueling. This includes a fuel tank control valve.

[0003] A fuel tank control valve consists of a housing and a float. The housing is installed inside the fuel tank, and the float is disposed within the housing and has buoyancy relative to the fuel (a structure consisting of a single float or a structure consisting of a main float and a secondary float). For example, in the case of a fuel tank control valve consisting of the two floats, the upper part of the housing is connected to a venting path that connects the fuel tank to a canister that adsorbs vapors generated inside the fuel tank. The main float maintains a closed valve state for a relatively long time when the valve is closed. Inside the housing, the secondary float, disposed lower than the main float, floats on the fuel and closes the valve when the vehicle turns or during the automatic stop of the first fuel injection. At the end of the first fuel injection, the gas floating on the secondary float in the closed valve state is released, and the valve returns to the open state (for example, see Patent Document 1).

[0004] According to the described structure, the fuel tank control valve can supply fuel even when the fuel level in the fuel tank fluctuates significantly, such as when the vehicle equipped with the fuel tank turns before refueling, and can prevent fuel from overflowing from the fuel inlet during the initial refueling. In other words, the fuel tank control valve has a good tracking structure relative to the dynamic changes in the fuel level.

[0005] The auxiliary float moves not only according to the fuel level but also sometimes according to the flow of gas. For example, to achieve initial automatic shut-off, in addition to closing the fuel passage according to the fuel level, it sometimes moves according to the flow of evaporated gas. At this time, through the repeated introduction and release of negative pressure from the vapor treatment device (engine purging), when the negative pressure fluctuates, the auxiliary float is also affected by the negative pressure and moves up and down, thus colliding with other components. Moreover, the collision sound is continuously generated; therefore, the driver may mistake the collision sound for a vehicle malfunction or become distracted from driving operations, and repeated collisions may even cause damage to the collision site.

[0006] Therefore, a control valve for a fuel tank has been disclosed previously, comprising: a volume chamber, the volume of which changes in conjunction with the up-and-down movement of the auxiliary float between the auxiliary float and a plate that sits on the plate when the auxiliary float is in the open state; and a flow regulating mechanism, which consists of a through hole for supplying gas from the plate to the volume chamber and a control gap (void) for allowing fuel to flow in, wherein the volume chamber functions as a damper through the void (see Patent Document 2).

[0007] According to the structure, the gap, by forming a narrow gap to the extent that it restricts the flow of fuel, controls the inflow of fuel into and out of the volume chamber. Therefore, the auxiliary float becomes a damper structure that, due to the phase difference between the change in the liquid level in the fuel tank and the change in the auxiliary float, restricts the discharge of fuel from the volume chamber, thereby delaying the movement of the auxiliary float from the closed valve state to the open valve state. This suppresses overly sensitive opening and closing of the auxiliary float and suppresses the impact noise.

[0008] Existing technical documents

[0009] Patent documents

[0010] Patent Document 1: Japanese Patent Application Publication No. 2013-82427

[0011] Patent Document 2: Japanese Patent Application Publication No. 2019-124202 Summary of the Invention

[0012] The technical problem that the invention aims to solve

[0013] However, due to the damper structure, the auxiliary float does not react in time when there is intense swaying of the fuel level caused by the vehicle turning or other movements, i.e., dynamic displacement of the fuel level. Therefore, sometimes the fuel tank control valve fails to perform its intended function.

[0014] Figure 13A and Figure 13B This is a schematic diagram illustrating the auxiliary float 301 and plate 401 of a conventional fuel tank control valve. Figure 13A The diagram illustrates a state where fuel F in the fuel tank sways due to vehicle cornering or other factors and enters the gas storage chamber 405 of plate 401. For example, if, during fuel supply, the fuel level is... Figure 13A As the liquid level rises, the gas in the gas storage chamber 405 is pushed upwards and supplied from the gas supply port 403 to the side of the auxiliary float 301. The auxiliary float 301 functions by rising relative to the liquid surface and closing the valve through the supplied gas.

[0015] However, if the fuel F swings due to turning or other reasons, it flows rapidly into the gas storage chamber 405, and a portion of the liquid surface F1 rises from the auxiliary float 301 through the through-hole 302 to the position on the main float (not shown) side before the auxiliary float 301 rises. Furthermore, fuel F also intrudes into the main float side from the gap 404 or other fuel inflow paths (not shown). In the above situation, the amount of residual gas R in the gas storage chamber 405 becomes very small due to the inflowing fuel F. Moreover, as... Figure 13A As shown, when the residual gas R becomes non-existent near the gas supply hole 403, gas cannot be supplied to the auxiliary float 301 side. Therefore, the auxiliary float 301 cannot obtain buoyancy and thus cannot close the valve.

[0016] Furthermore, as mentioned earlier, if the auxiliary float 301 fails to close the valve, it will become seated on the side of the plate 401, specifically in the seat portion 402. The upper surface of the seat portion 402 is as follows... Figure 13B The structure shown is formed not only by the gas supply hole 403 with a central opening, but also by a flat plane that contacts the surface of the auxiliary float 301. Therefore, when the auxiliary float 301 is seated in the seat portion 402, the auxiliary float 301 and the seat portion 402 are in surface contact except for the gas supply hole 403. Furthermore, as explained, when the residual gas R is low, the state where gas is not supplied to the side of the auxiliary float 301 is maintained when the surface contact state is achieved, increasing the resistance of the damper and worsening the responsiveness of the auxiliary float 301. In particular, when fuel adheres to the surfaces of the surface-contacting auxiliary float 301 and seat portion 402, when the auxiliary float 301 is seated, surface tension causes adhesion between the two surfaces. Therefore, even if gas is supplied to the side of the auxiliary float 301, time is required before it leaves the seat, which may lead to a decrease in the responsiveness of the auxiliary float 301.

[0017] As described above, if a damper structure is installed as a countermeasure against collision noise, the responsiveness of the auxiliary float will deteriorate when the fuel level dynamically shifts, and the valve-closing function of the auxiliary float will deteriorate. Therefore, the liquid level outside (inside) the fuel tank control valve and the liquid level inside the fuel tank control valve may abruptly become the same level.

[0018] Furthermore, if the vehicle equipped with the fuel tank makes continuous turns, the main float reacts and remains in a closed valve state. As a result, the evaporated gas generated inside the fuel tank cannot be discharged and fills the tank, causing the internal pressure to rise. This may lead to deformation of the fuel tank and further rupture.

[0019] Furthermore, if the main float becomes closed immediately after turning, the fuel tank control valve will perform the same operation as when it is full, resulting in a situation where fuel cannot be supplied even though the fuel tank is not full.

[0020] On the other hand, there is also the possibility that if a vehicle equipped with the fuel tank makes continuous turns, fuel may flow out into the venting path connected to the upper part of the housing and reach the tank before the main float reacts (i.e., before the valve closes). In this case, if the fuel reaches the tank rapidly, it may exceed the tank's allowable adsorption capacity, potentially causing a sharp deterioration in the tank's performance.

[0021] The damper structure addresses the technical problem of the impact sound, but in the presence of dynamic fuel level displacement, it can cause a decrease in the responsiveness of the auxiliary float. That is, the damper structure and the following structure have a mutually compensating relationship. Furthermore, in Figure 13A and Figure 13B The technical problems of a fuel tank control valve consisting of two floats, a main float and a secondary float, are explained. However, even a fuel tank control valve consisting of a single float, when equipped with a damper structure, suffers from the same technical problem of decreased displacement responsiveness relative to the dynamic fuel level as described above.

[0022] Therefore, this specification is disclosed in order to eliminate the above-mentioned technical problems, and its purpose is to provide a control valve for a fuel tank that can simultaneously reduce the impact noise and improve the responsiveness to the dynamic displacement of the fuel level.

[0023] Technical solutions adopted to solve technical problems

[0024] To achieve the above-mentioned objective, this specification discloses a control valve for a fuel tank, comprising: a housing disposed inside a vehicle fuel tank, the housing having an upper portion connected to a venting path communicating with the fuel tank; a valve seat disposed inside the housing; a plate disposed opposite to the valve seat in a lower direction relative to the housing; a peripheral wall portion erected from the periphery of the plate in a lower direction; a first gas storage chamber formed by the plate and the peripheral wall portion; a gas supply orifice opening on the surface of the plate opposite to the valve seat portion, capable of supplying gas from the first gas storage chamber to a variable-volume space formed between the plate and the valve seat portion; and a gap formed between the housing and the valve seat portion. The space includes: a circumferential wall portion, allowing fuel from the fuel tank to flow in; a float, which has buoyancy relative to the fuel flowing in from the gap, floats in the variable volume space by supplementing gas supplied from the gas supply hole, and is configured to sit on the valve seat portion; a through hole, which opens into the float, suppresses the flow of fuel from the gap by sitting on it, and discharges gas supplied to the variable volume space towards the upper side of the variable volume space as the buoyancy decreases; and a second gas storage chamber, which is formed by a portion of the plate including the gas supply hole and a partition wall portion erected separately from the circumferential wall portion, and is disposed within the first gas storage chamber, controlling the opening and closing of the fuel flow path inside the housing by the sitting and unsitting of the float on the valve seat portion.

[0025] According to the structure, by maintaining the gap, which serves as a damper structure, and forming the second gas storage chamber, even if the fuel level dynamically shifts, the gas directly below the gas supply hole can remain and supply gas to the auxiliary float, thereby enabling the auxiliary float to close its valve following the displacement of the fuel level.

[0026] Another aspect disclosed in this specification provides a control valve for a fuel tank, wherein the upper surface of the plate has a convex seating portion that forms an inflow space for gas to flow in from the gas supply hole when the auxiliary float is seated.

[0027] According to the structure described above, even when the secondary float is seated on the plate, and gas is supplied to the secondary float from the second gas storage chamber via the gas supply hole, the presence of the inflow space allows for rapid supply of gas to lift the secondary float. Furthermore, the formation of the inflow space reduces the contact area between the secondary float and the plate, thereby decreasing the surface tension generated by the contact between the secondary float and the seated surface.

[0028] Furthermore, another aspect disclosed in this specification provides a control valve for a fuel tank, wherein the second gas storage chamber is formed by a portion of the upper surface including the gas supply hole and a partition wall portion separated from the peripheral wall portion, the gap being formed between the housing and the peripheral wall portion, and the upper surface of the plate having a convex seating portion, the seating portion forming an inflow space for gas to flow in from the gas supply hole when the auxiliary float is seated.

[0029] According to the structure, since a second gas storage chamber is provided inside the first gas storage chamber and has a seating portion including the inflow space, gas can be supplied from the second gas storage chamber to the auxiliary float side in response to the dynamic displacement of the fuel liquid level. Since the auxiliary float forms the inflow space between itself and the seating portion, it can receive the gas supply and obtain the valve-closing function of the auxiliary float with good responsiveness.

[0030] Invention Effects

[0031] The control valve for the fuel tank disclosed in this specification has the effect of simultaneously reducing the impact noise and improving the responsiveness to the dynamic displacement of the fuel level. Attached Figure Description

[0032] Figure 1 This is a schematic side sectional view of the fuel tank.

[0033] Figure 2 This is a schematic side sectional view showing the structural outline of the control valve for the fuel tank.

[0034] Figure 3 It is a side sectional view of the control valve for the fuel tank, including the main float and the auxiliary float.

[0035] Figure 4 This is a schematic side sectional view showing the function of the plate and auxiliary float of the fuel tank control valve in the first embodiment.

[0036] Figure 5A This is a perspective view of the bottom surface of the plate in the first modified example of the first embodiment.

[0037] Figure 5B This is a schematic bottom view of the plate of the first modified example of the first embodiment.

[0038] Figure 6 This is a diagram illustrating a second variation of the first embodiment.

[0039] Figure 7 This is a diagram illustrating a third variation of the first embodiment.

[0040] Figure 8 This is a diagram illustrating a fourth variation of the first embodiment.

[0041] Figure 9 This is a diagram illustrating a fifth variation of the first embodiment.

[0042] Figure 10A This is a perspective view of the upper surface of the plate according to the second embodiment.

[0043] Figure 10B This is a side sectional view of the plate and auxiliary float of the second embodiment.

[0044] Figure 11A This is a top view showing a first modified example of a convex seating portion formed on the surface of the plate.

[0045] Figure 11B This is a top view showing a second modified example of a convex seating portion formed on the surface of the plate.

[0046] Figure 11C This is a top view showing a third modified example of a convex seating portion formed on the surface of the plate.

[0047] Figure 12 This is a schematic side sectional view of the plate and auxiliary float of the third embodiment.

[0048] Figure 13A This is a side sectional view showing the state of fuel intrusion into the auxiliary float and plate during oscillation in a conventional fuel tank control valve.

[0049] Figure 13B This is a top view of the seat of a conventional fuel tank control valve. Detailed Implementation

[0050] Hereinafter, embodiments for carrying out the disclosures herein will be described with reference to the accompanying drawings. In subsequent embodiments where structural elements correspond to those of the previously described embodiments, the same reference numerals will be used and repeated descriptions will be omitted. Furthermore, where only a portion of the structure is described in each embodiment, reference numerals from the previously described embodiments will sometimes be used for other parts of the structure. Even where specific combinations are not explicitly indicated in each embodiment, embodiments can be partially combined with each other as long as such combination does not impede. Furthermore, the sizes of the components in the figures are appropriately emphasized for ease of explanation and do not represent actual dimensions or proportions between components. Further areas of application will become clear from the description in this specification. The brief descriptions and specific examples are intended for simple illustration and are not intended to limit the scope of this disclosure.

[0051] <Fuel Tank>

[0052] Figure 1This is a schematic side sectional view of a fuel tank T equipped with a fuel tank control valve 1. A pump unit P is installed inside the fuel tank T, and the fuel F in the fuel tank T is supplied to the engine system E by the pump unit P.

[0053] Fuel F is supplied from fuel nozzle N to fuel tank T via fuel inlet. In addition, the vapors generated from fuel F inside fuel tank T are also sent from fuel tank control valve 1 to tank C via venting path V.

[0054] After the evaporated gas introduced into tank C is temporarily adsorbed by the adsorbent inside tank C, fuel components are supplied to engine system E via purge line L when predetermined driving conditions are met. The fuel components flowing from tank C to engine system E are supplied with regulated flow through negative pressure switching valve S controlled by electronic control unit U.

[0055] <Structural Overview of Control Valves for Fuel Tanks>

[0056] Figure 1 This is a structural schematic diagram (side sectional view) of a fuel tank control valve 1 having a single float as disclosed in this specification. The fuel tank control valve 1 has a housing 111, a valve seat 112, a plate 113, and a float 119.

[0057] The housing 111 is disposed inside the fuel tank T, and the upper part of the housing 111 is connected to the ventilation path V that communicates with the fuel tank T (not shown).

[0058] The valve seat portion 112 is disposed inside the housing 111. The plate 113 is disposed opposite to the valve seat portion 112 in the lower direction of the housing 111, which is closer to the valve seat portion 112 than the valve seat portion 112.

[0059] Plate 113 has a peripheral wall portion 114, which is erected from the periphery along the lower direction of housing 111. In this embodiment, plate 113 and peripheral wall portion 114 are shown as integrally formed, but they can also be formed by joining two separate components. Plate 113 and peripheral wall portion 114 form a first gas storage chamber 115.

[0060] A gas supply hole 117 is provided on the surface of plate 113 opposite to valve seat portion 112. Gas supply hole 117 supplies gas from first gas storage chamber 115 to variable volume space 116 formed between plate 113 and valve seat portion 112.

[0061] A gap 118 is formed between the float 119 and the peripheral wall portion 114. As described later, the gap 118 is a flow control mechanism that allows fuel F to flow into the fuel tank T.

[0062] Float 119 generates buoyancy by the rise of the fuel F liquid level within housing 111, and floats through the variable volume space 116 by the replenishment of gas supplied from gap 118 and gas supply hole 117 to the variable volume space 116, and is configured to sit on valve seat 112. A through hole 120 is provided at the opening of float 119. Float 119 discharges gas supplied to the variable volume space 116 through the through hole 120 to a position further up than the valve seat 112. Thus, float 119 is configured to lose buoyancy and detach from valve seat 112. In the variable volume space 116... Figure 2 The double-headed arrow indicates whether it floats or sinks.

[0063] A partition wall 121 is formed separately from the peripheral wall 114 within the first gas storage chamber 115. A second gas storage chamber 122 is provided within the first gas storage chamber 115 through a portion of the plate 113 including the gas supply hole 117 and the partition wall 121.

[0064] A convex seating portion 123 is provided on the surface of the plate 113 with an opening for gas supply 117. When the float 119 settles due to the decrease in buoyancy, the seating portion 123 forms an inflow space 124 for gas to flow in from the gas supply 117. That is, as... Figure 2 As indicated by the arrow, the gas stored in the second gas storage chamber 122 is supplied from the gas supply port 117 to the variable volume space 116 via the inflow space 124.

[0065] As described above, the fuel tank control valve 1 controls the opening and closing of the fuel flow path inside the housing 111 by the seat position and departure of the float 119 to the valve seat 112.

[0066] <Control valves for fuel tanks, including main and auxiliary floats>

[0067] Figure 3 This is a side sectional view of the fuel tank control valve 2 disclosed in this specification. Hereinafter, it will be used... Figure 3 The structure and function of the control valve 2 for the fuel tank are explained.

[0068] The fuel tank control valve 2 consists of a housing 21, a main float 22 (equivalent to the upper float), a container body 23, a housing 24, a plate 25, and a float. Hereinafter, the float refers to the auxiliary float 26 relative to the main float 22.

[0069] The housing 21 consists of an upper housing portion 21A and a lower housing portion 21B that is coupled to the housing 24. The upper housing portion 21A is arranged in... Figure 1 The fuel tank T, as described, is positioned higher than the upper limit of the fuel level H (the so-called full fuel level) during fuel supply. The casing 21 is a hollow cylindrical body. The upper end of the upper part 21A of the casing (the top surface side of the fuel tank T) is connected to... Figure 1 The description shows one end of the ventilation path V that connects the fuel tank T to the tank C.

[0070] The upper housing 21A is connected to a flange (not shown) and is disposed in the fuel tank T, but is sealed to the flange by an O-ring 21F. A connecting hole 21E is provided on the side of the upper housing 21A, below the O-ring 21F. The connecting hole 21E communicates the interior of the housing 21A with the exterior (inside the fuel tank T). The connecting hole 21E allows fuel F to be discharged to the exterior of the upper housing 21A and gas to be supplied to the upper housing 21A.

[0071] A pressure relief valve 21G is provided at the upper end of the upper part 21A of the housing, together with the guide part 21C. The pressure relief valve 21G opens when the pressure in the fuel tank T is higher than a specified value, releasing the evaporated gas in the fuel tank T to the ventilation path V side.

[0072] An upward flow path 21H is formed between the shell 21 and the container body 23. Fuel F that enters from the lower part 21B of the shell passes through the upward flow path 21H in the direction shown by the arrow in the figure and is introduced into the container body 23.

[0073] The main float 22 is housed in such a way that it can move along the direction of the fuel F flowing into the container body 23 disposed inside the upper part 21A of the shell, i.e., the axial direction of the container body 23.

[0074] The main float 22 has a retainer 22A with an inverted T-shaped cross-section at its upper part via a connecting mechanism 22E. Specifically, the retainer 22A has: a protrusion 22B that protrudes towards the guide portion 21C and can be inserted into the guide portion 21C; and a base portion 22D that can sit on the main float seat portion 21D below the protrusion 22B. When the base portion 22D sits on the main float seat portion 21D, it retains the seal 22C that seals the base portion 22D and the main float seat portion 21D.

[0075] When the main float 22 rises and the seal 22C is seated in the main float seat 21D, the seal 22C blocks the flow path 22G, and the main float 22 becomes a closed valve. Figure 2 (The dashed line indicates the closed valve state of the main float 211). On the other hand, when the main float 22 sinks and the base portion 22D leaves the main float seating portion 21D, the seal 12C opens the flow path 22G, and the main float 12 becomes the open valve state.

[0076] In addition, a spring 22F is provided between the main float 22 and the container body 23. The spring 22F applies force to the main float 22 in the direction of the closed valve to supplement the buoyancy of the upward movement.

[0077] As described above, the main float 22 moves up and down with the liquid surface of the fuel F that has invaded the interior of the housing 21 from the lower part 21B of the housing, thereby opening and closing the flow path 22G of the housing 21 connected to the ventilation path V.

[0078] The container body 23 houses the main float 22 inside the upper part 21A of the shell and has an upper opening 23A that allows the main float 22 to move up and down. It is shaped like a bottomed cup that can store fuel F. The upper opening 23A is located at approximately the same height as the connecting hole 21E. The container body 23 is configured such that when the fuel F reaches the upper opening 23A through the rising flow path 21H, the fuel F is introduced into the interior through the upper opening 23A.

[0079] The container body 23 has: a side discharge port 23C disposed on the side 23B of the container body; and a bottom discharge port 23E disposed on the bottom 23D of the container body. When the fuel F introduced from the upper opening 23A reaches the height of the side discharge port 23C, the side discharge port 23C can discharge the fuel F to the outside of the container body 23. The bottom 23D of the container body is formed into an inclined funnel shape with the bottom discharge port 23E facing downwards towards the center. Inside the container body 23, there is a sphere 23F that can roll freely on the bottom 23D of the container body. The sphere 23F blocks the bottom discharge port 23E in a stationary state, and rolls open the bottom discharge port 23E when a swing is sensed. When the bottom discharge port 23E is opened by the rolling of the sphere 23F, the fuel F remaining at a position lower than the height of the side discharge port 23C is discharged to the outside of the container body 23.

[0080] As described above, the side discharge port 23C, the bottom discharge port 23E, and the sphere 23F are discharge means for discharging the fuel F stored in the container body 23.

[0081] The housing 24 has an opening that separates from the bottom surface 23D of the container body towards the lower part 21B of the housing, comprising an upper end 24A of the housing and a lower end 24B of the housing that allows the fuel F to enter. The lower part of the housing 21 is formed by engaging with the lower part 21B of the housing via a locking mechanism (buckle). In this embodiment, the lower part 21B of the housing is engaged with the housing 24 via the locking mechanism, but any connection between the two is acceptable and is not limited to the locking mechanism described above. Alternatively, the housing 21 and the housing 24 can be integrally formed, with the entire structure constituting the housing 21.

[0082] In this embodiment, the periphery of the upper end 24A of the housing 24 is formed into a flange shape, constituting the engagement mechanism. Furthermore, a valve seat portion 24C for the auxiliary float 26 when the valve is closed is formed from below the flange-shaped periphery toward the interior of the lower portion 21B of the housing. Additionally, a variable-volume space 24D, which is freely movable vertically by the auxiliary float 26, is formed between the upper end 24A (valve seat portion 24C) of the housing and the plate 25 (described later).

[0083] A peripheral wall portion 25B is erected from the periphery of the upper surface 25A toward the lower part 21B of the housing, i.e., in the horizontal direction of the upper limit of the liquid level in the fuel tank T, forming an inverted cup shape. The space formed by the upper surface 25A and the peripheral wall portion 25B becomes the first gas storage chamber 25C. In addition, in this embodiment, the peripheral wall portion 25B is folded back from its lower end in the erected direction toward the outside of the peripheral wall portion 25B to be fitted with a U-shaped fitting groove 25F.

[0084] Furthermore, plate 25 includes a gap 25E that allows fuel to intrude from fuel tank T into the interior of housing 24 (fuel intrusion along the fuel intrusion path indicated by the arrow in the figure), and the upper surface 25A is positioned at the opening of the lower end 24B of housing to form the bottom of the lower portion 21B of housing. In this embodiment, the lower end 24B of housing and the upper surface 25A are connected to the lower portion 21B of housing and housing 24 by a locking mechanism (fastener), but the connection means are not limited to this.

[0085] The upper surface 25A has a gas supply hole 25D, which supplies gas from the first gas storage chamber 25C to the interior of the housing 24 (secondary float 26).

[0086] In this embodiment, a first gas storage chamber 25C includes a partition wall 25G and a second gas storage chamber 25H. The partition wall 25G separates a portion of the plate 25 (upper surface 15A) including the gas supply hole 25D from the peripheral wall 25B. Furthermore, a gap 25E is formed between the auxiliary float 26 and the peripheral wall 25B.

[0087] The upper surface 25A has a seat portion 25I on the side of the housing 24, that is, on the surface opposite to the valve seat portion 24C, where the auxiliary float 26 is seated when the valve is opened. When the auxiliary float 26 is seated in the seat portion 25I, an inflow space 25J leading to the gas supply hole 25D is formed between the upper surface 25A and the auxiliary float 26.

[0088] in addition, Figure 3The plate 25 disclosed herein, as described above, has a partition wall 25G and a second gas storage chamber 25 and an inflow space 25J, but the fuel tank control valve 2 disclosed herein, as described below, also has only one of these features.

[0089] The auxiliary float 26 is disposed between the upper end 24A and the upper surface 25A of the containment body, and moves up and down following the liquid surface of the fuel F that enters from the gap 25E and the fuel intrusion path 25L, freely moving up and down to separate and form a variable volume space 24D.

[0090] In this embodiment, the auxiliary float 26 is composed of an auxiliary float body 26A, an auxiliary float outer peripheral component 26C, and an auxiliary float seal 26B.

[0091] The auxiliary float body 26A forms the center of the auxiliary float 26 and faces the valve seat portion 24C of the upper end 24A of the housing and the seating portion 25I of the plate 25. Multiple units for temporary gas storage are located on the side opposite to the seating portion 25I. In this embodiment, each unit is a structure in which a peripheral wall is provided on the top plate-like planar member of the auxiliary float body 26A, separating concentric circular spaces of different diameters (in... Figure 2 (Forming a unit group with a comb-like cross-section).

[0092] A secondary float outer peripheral component 26C extends from the outer edge of the secondary float body 26A. The secondary float outer peripheral component 26C has a central insertion hole for mounting the secondary float body 26A. A circumferential flange is formed at the edge of the insertion hole. The outermost peripheral wall of the secondary float body 26A is formed further inward than the edge of the planar component, forming an inverted L-shaped stepped portion through the outermost peripheral wall and the edge of the planar component. The secondary float body 26A is inserted into the insertion hole of the secondary float outer peripheral component 26C, with the edge of the planar component forming the stepped portion resting on the circumferential flange of the secondary float outer peripheral component 26C and fixed by a locking mechanism. The circumferential flange of the secondary float outer peripheral component 26C and the edge of the planar component of the secondary float body 26A form a circumferential groove through this resting. Furthermore, the auxiliary float outer peripheral member 26C extends radially from the edge of the planar member with a layered structure to form a notch-shaped shoulder. An auxiliary float seal 26B, circumferentially fitted along the circumferential groove, is mounted on the shoulder.

[0093] The outer peripheral component 26C of the auxiliary float, which extends from the auxiliary float body 26A, has its opposite surface to the upper surface 25A arranged in a continuous manner with the units of the auxiliary float body 26A. The outermost peripheral wall of the auxiliary float outer peripheral component 26C extends downwards compared to the other peripheral walls constituting the unit, and circumferentially fits into the fitting groove 25F and gap 25E of the plate 25.

[0094] The auxiliary float 26 has a through hole 26D, which allows gas accumulated on one side of the plate 25 and exerting buoyancy on the auxiliary float 26 to be released towards the upper end 24A of the housing, so as to introduce fuel F towards the plate 25. Therefore, the through hole 26D provides a means of reducing the buoyancy of the auxiliary float 26.

[0095] As fuel F enters through the gap 25E, gas is supplied from the first gas storage chamber 25C to the variable volume space 24D via the gas supply port 25D, causing the auxiliary float 26 to rise. When it reaches the valve seat 24C at the upper end 24A of the housing and sits down, the valve closes, cutting off the intrusion of fuel F into the upper part 21A of the housing. Figure 2 The dashed line indicates the state of the auxiliary float at position 216 when the valve is closed.

[0096] As fuel F is discharged from the gap 25E, the gas supplied from the variable volume space 24D through the through hole 26D is discharged to the upper end 24A of the housing, thereby reducing buoyancy. As a result, the gas reaches the seating portion 25I on the upper surface 15A and sits down, opening the valve to allow fuel F to enter the upper part 11A of the housing.

[0097] The operation of the fuel tank control valve 2 during fuel supply will be explained below. Before fuel supply, both the main float 22 and the auxiliary float 26 are in the open state. When fuel supply begins, when the fuel F level reaches the upper limit level H, the liquid level rises rapidly through the fuel intrusion path 25L because the gap 25E is formed by tiny gaps. As the liquid level rises, gas is supplied from the first gas storage chamber 25C to the auxiliary float 26 through the gas supply hole 25D, and the auxiliary float 26 gains buoyancy and floats in the variable volume space 24D. When the auxiliary float 26 reaches the valve seat 24C, the valve seat 24C is blocked and becomes the closed valve state, preventing fuel intrusion to the upper part 21A of the housing, thus entering the initial automatic shutdown state where fuel supply implemented by the fuel supply device (not shown) stops.

[0098] Subsequently, due to the pressure relief within the fuel tank T, as the pressure decreases due to the gas venting through the connecting hole 21E, the liquid level of the intruding fuel F drops, and the auxiliary float 26 descends within the variable volume space 24D. When the auxiliary float 26 reaches the seating portion 25I, the valve seat portion 24C is opened, becoming an open valve state, and the gas vents from the through hole 26D towards the upper end 24A of the housing. If the valve is opened after the initial automatic shutdown when the valve is closed and the gas has vented from the through hole 26D, the auxiliary float 26 will become an open valve state in the absence of buoyant gas, and the auxiliary float 26 will not operate.

[0099] When fuel supply resumes after the initial automatic shutdown, the fuel F level will exceed the upper end 24A of the containment body and enter the rising flow path 21H. Then, when fuel F reaches the upper opening 23A, it will flow into the container 23. When fuel F accumulates in the container 23, the main float 22 will rise, and when it reaches the main float seat 21D, it will close, maintaining the internal pressure of the fuel tank control valve 2 for a specified time, preventing fuel supply and thus preventing over-fueling.

[0100] Fuel F accumulated in container 23 is discharged through side discharge port 23C. When the water level of fuel F in container 23 is lower than that in side discharge port 23C, it cannot be discharged through side discharge port 23C. However, when the vehicle starts moving, the ball 23F inside container 23 will roll due to the swaying motion, opening the bottom discharge port 23E and discharging the fuel F. Furthermore, with the discharge of fuel F from container 23, the main float 22 will lose buoyancy and descend again, becoming an open valve.

[0101] Next, the operation of the noise reduction mechanism of the fuel tank control valve 2 will be explained. Due to the repeated engine purging, a pulsating negative pressure will be generated, which will be transmitted to the fuel tank T. As a result, the fuel tank control valve 2 will also be affected, causing the auxiliary float 26 to generate noise when it collides with other components.

[0102] The fuel tank control valve 2 disclosed in this specification creates resistance to the inflow and outflow of fuel F and gas into and out of the gap 25E by narrowing the flow path of the gap 25E that controls the buoyancy of the auxiliary float 26. That is, the gap 25E creates a phase difference between the period of fluctuation of the pulsating negative pressure and the speed of vertical movement of the auxiliary float 26. This phase difference controls the auxiliary float 26 to move slowly relative to the fluctuation of the pulsating negative pressure, thereby reducing the energy of the impact and suppressing noise generation. The auxiliary float 26 operates as a movable cylinder, and the plate 25 functions as a damper, which acts as a fixed piston that moves relative to the movable cylinder.

[0103] Hereinafter, an embodiment of the fuel tank control valve 2 disclosed in this specification will be described. (Although the following embodiment uses the plate 25 and the auxiliary float 26 of the fuel tank control valve 2 for description, the same embodiment can also be applied to the plate 113 and the float 119 of the fuel tank control valve 1).

[0104] <First Implementation>

[0105] Figure 4 This is a schematic side sectional view showing the function of the plate 25 and the auxiliary float 26 of the fuel tank control valve 2 in the first embodiment.

[0106] Figure 4This shows the state of fuel F rapidly entering the fuel tank control valve 2 before the auxiliary float 26 closes when the vehicle equipped with the fuel tank control valve 2 turns during driving (showing the liquid level state when the vehicle is swaying).

[0107] Due to the rapid intrusion of fuel F from gap 25E, the liquid surface F1 does not swing horizontally relative to plate 25 and auxiliary float 26. Then, the highest point of the swinging liquid surface F2 exceeds the auxiliary float 26 and enters the main float side. However, as... Figure 3 As explained, the auxiliary float 26 is a damper structure; therefore, rapid changes in the liquid level F1 are slow and do not directly close the valve. Furthermore, if the vehicle makes continuous turns and the auxiliary float 26 remains open, failing to prevent the intrusion of fuel F, the main float closing the valve could cause the pressure inside the fuel tank T to rise, potentially leading to deformation or damage.

[0108] At this time, although fuel F also enters the first gas storage chamber 25C, the residual gas R in the second gas storage chamber 25H, which is located within the first gas storage chamber 25C, is retained in the space including the gas supply hole 25D by a portion of the upper surface 25A of the gas supply hole 25D (including plate 25) and the partition wall 25G. Therefore, even if fuel F rapidly enters the main float side beyond the auxiliary float 26, the residual gas R will be supplied to the auxiliary float 26 side via the gas supply hole 25D. Furthermore, a gap 25E is formed on the outside of the second gas storage chamber 25H.

[0109] The residual gas R supplied from the second gas storage chamber 25H to the auxiliary float 26 applies buoyancy to the auxiliary float 26. Therefore, even with the damper structure, the auxiliary float 26 can maintain good responsiveness to close valve operation in the event of the intrusion of the rapid fuel F.

[0110] <First Modification of the First Embodiment>

[0111] Figure 5A and Figure 5B This is a diagram illustrating a first variation of the first embodiment. Figure 5A This is a three-dimensional view of the bottom surface of the board. Figure 5B This is a schematic bottom view of the board.

[0112] In a first variation of the first embodiment, the second gas storage chamber 251H, formed by the partition wall portion 251G provided on the plate 25, is cylindrical. Due to continuous turning of the vehicle, the direction in which the fuel F rises and enters the fuel tank control valve 2 varies. The oscillation of the fuel F caused by the continuous turning results in gas loss and fuel F rising in various directions inside the second gas storage chamber 251H. Therefore, in order to minimize differences in the amount of gas loss and the rising speed of the fuel F due to the directions, the inner surface of the second gas storage chamber 251H is preferably curved. Therefore, the second gas storage chamber 251H formed by the partition wall portion 251G is cylindrical.

[0113] Moreover, such as Figure 5B As shown, the peripheral wall portion 251B is also cylindrical, the gas supply hole 25D is located at the center of the upper surface 251A, and a portion of the upper surface 251A constituting the second gas storage chamber 251H is formed as a circle concentric with the upper surface 251A. Therefore, within the second gas storage chamber 251H, the radial distance from the partition wall portion 251G to the gas supply hole 25D is equal in any direction. Thus, when the fuel F oscillates within the fuel tank T due to continuous turns, the amount of gas lost within the second gas storage chamber 251H is less likely to differ due to the oscillation direction of the fuel F caused by the turns, thereby ensuring a stable gas supply to the auxiliary float 26.

[0114] <Second variation of the first embodiment>

[0115] The second deformation is, for example Figure 6 The diagram shows the second gas storage chamber 252H formed in a direction from a portion of the upper surface 25A toward the lower portion of the vertical partition wall 252G. Figure 6 The second gas storage chamber 252H is a tapered inverted cone shape (not shown in the lower part of the housing 21) that tapers at the front end. By forming the second gas storage chamber 252H into this inverted cone shape, the opening area at the lower end of the second gas storage chamber 252H opposite to the upper surface 25A is reduced, making gas leakage less likely, and the volume near the gas supply hole 25D is larger than the volume near the opening at the lower end. Therefore, the gas supplied to the auxiliary float 26 can be easily stored on the side of the gas supply hole 25D, and good responsiveness in supplying gas to the auxiliary float 26 can be maintained even in the event of dynamic fuel leakage.

[0116] <Third variation of the first embodiment>

[0117] The third deformation, for example Figure 7The diagram shows an embodiment in which the opening at the lower end of the partition wall portion 253G, which forms the second gas storage chamber 253H and is opposite to a portion of the upper surface 25A, is bent in an L-shape toward the interior space of the second gas storage chamber 253H. By bending the lower end of the partition wall portion 253G in this L-shape, the opening area at the lower end of the second gas storage chamber 252H opposite to the upper surface 25A is reduced. Even if the fuel F inside the fuel tank T swings due to continuous turning or the like, the gas inside the second gas storage chamber 252H can be easily ensured, thereby enabling a stable gas supply to the auxiliary float 26.

[0118] <Fourth variation of the first embodiment>

[0119] Fourth transformation, for example Figure 8 The embodiment shown is in which the lower open end of the partition wall portion 254G protrudes further downward than the open end of the peripheral wall portion 25B. By making the lower end of the partition wall portion 254G protrude as described above, the volume of the second gas storage chamber 254H is increased, making it easy to ensure the gas inside the second gas storage chamber 254H, thereby enabling a stable gas supply to the auxiliary float 26.

[0120] <Fifth variation of the first embodiment>

[0121] Fifth variation, for example Figure 9 The embodiment shown has not only a gas supply hole 5D, but also gas supply holes 251D and 252D provided on a portion of the upper surface 25A constituting the second gas storage chamber 25H. By providing multiple gas supply holes 25D, 251D, and 252D on a portion of the upper surface 25A constituting the second gas storage chamber 25H, even if the residual gas R inside the second gas storage chamber 25H tilts steeply due to continuous turns or the like, gas can be supplied to the auxiliary float 26 with good responsiveness and stability.

[0122] <Second Implementation>

[0123] Figure 10A and Figure 10B This is a diagram showing the control valve 2 for the fuel tank according to the second embodiment. Figure 10A This is a three-dimensional view of the upper surface of the plate. Figure 10B This is a side sectional view of the plate and the auxiliary float.

[0124] The upper surface 25A of the plate 25 has a convex seating portion 25I, which forms an inflow space 25J for gas to flow in from the gas supply hole 25D when the auxiliary float 26 is seated.

[0125] Even when the auxiliary float 26 is seated in the seating portion 25I of the plate 25, and gas is supplied to the auxiliary float 26 from the gas storage chamber 25C through the gas supply hole 25D, the inflow space 25J is formed, thus enabling... Figure 10B The arrow indicates the supply of gas that causes the secondary float 26 to rise rapidly.

[0126] Furthermore, due to the formation of the inflow space 25J, the contact area between the seating portion 25I and the auxiliary float 26 is smaller compared to the case where the inflow space 25J is not formed. Therefore, the surface tension of the fuel generated by the surface contact between the auxiliary float 26 and the seating portion 25I can be reduced. Thus, even if the vehicle makes continuous turns causing the fuel F to rapidly enter the main float side beyond the auxiliary float 26, the inflow space 25J can maintain good responsiveness, allowing the auxiliary float 26 to float and perform the valve closing action.

[0127] The following uses Figure 11A , Figure 11B and Figure 11C A variation of the second embodiment will be described.

[0128] <First variation of the second embodiment>

[0129] Figure 11A This is a schematic top view of the seating portion 251I in the first modification. In the first modification, a plurality of ribs radiating radially from the gas supply hole 25D to the outer periphery of the upper surface 25A are provided to form the seating portion 251I, and an inflow space 251J is provided between adjacent ribs. In this modification, three ribs are formed at equal intervals along the circumference, but the number, height, and spacing of the ribs are not intended to be limited thereto.

[0130] <Second variation of the second embodiment>

[0131] Figure 11B This is a schematic top view of the seating portion 252I in the second variation. In the second variation, a plurality of slits constituting the inflow space 252J are arranged radially from the gas supply hole 25D to the outer periphery of the upper surface 25A, and the convex seating portions 252I are formed between adjacent slits. In this variation, three slits are formed at equal intervals along the circumference, but the number, height, and spacing of the slits are not intended to be limited thereto.

[0132] <Third variation of the second embodiment>

[0133] Figure 11CThis is a schematic top view of the seating portion 253I in the third variation. In the third variation, a plurality of columnar protrusions erected from the upper surface 25A toward the auxiliary float 26 are designated as the seating portion 253I when the valve is opened, and the space between the columnar protrusions is designated as the inflow space 253J. In this variation, three columnar protrusions are erected at equal intervals along the circumference, but the number, height, and spacing of the columnar protrusions are not intended to be limited thereto.

[0134] <Third Implementation Method>

[0135] Figure 12 This is a schematic side sectional view of the plate 25 and the auxiliary float 26 according to the third embodiment. In this embodiment, the plate 25 has a second gas storage chamber 25 as described in the first embodiment, and a convex seating portion 25I forming the inflow space 25J as described in the second embodiment. That is, even if the fuel F exceeds the auxiliary float 26 and is about to rapidly enter the main float side, firstly, the residual gas R in the second gas storage chamber 25H can be supplied to the auxiliary float 26 side from the gas supply hole 25D, and the supplied gas can be introduced into the inflow space 25J, causing the auxiliary float 26 to rise rapidly. Therefore, even when the vehicle is in a swaying state, even if there is resistance to the valve closing action realized by the damper structure, the auxiliary float 26 can be closed with good responsiveness to prevent dynamic fuel leakage.

[0136] <Other Implementation Methods>

[0137] The plate 25 of the third embodiment may also have multiple ribs protruding from the first modification of the second embodiment as seating portions when the valve is opened, and the space between adjacent ribs may be the inflow space. Furthermore, the plate 25 of the third embodiment may have multiple slits from the second modification of the second embodiment as the inflow space, and the space between adjacent slits may be the convex seating portion. Moreover, the plate 25 of the third embodiment may also have multiple columnar protrusions erected as seating portions, and the space between the columnar protrusions may be the inflow space. Furthermore, each plate 25 of the other embodiments described may include a second gas storage chamber from any one of the first to fourth modifications of the first embodiment, or have multiple gas supply holes as in the fifth modification.

[0138] The technology disclosed in this specification is not limited to the described embodiments. That is, it includes the illustrative embodiments and variations that would be conceived by those skilled in the art based on these embodiments. Furthermore, it includes embodiments obtained by substituting or combining components or elements between one embodiment and other embodiments. Moreover, the scope of the disclosed technology is not limited to the described embodiments. The scope of the disclosed technology is indicated by the claims, and includes all modifications within the meaning and scope equivalent to the claims.

[0139] (Symbol Explanation)

[0140] T fuel tank

[0141] C can

[0142] V Ventilation Path

[0143] 1. Control valves for fuel tanks 1 and 2

[0144] 21, 111 casing

[0145] 21A Upper part of the casing

[0146] 21B Lower part of the casing

[0147] 21C Guidance Section

[0148] 22 Main Float

[0149] 23 container body

[0150] 24 containment bodies

[0151] 24C, 112 valve seat section

[0152] 24D, 116 volume variable space

[0153] 25, 113 boards

[0154] 25A upper surface

[0155] 25B, 114 circumferential wall

[0156] 25C, 115 First Gas Storage Chamber

[0157] 25D, 117 gas supply port

[0158] 25E, 118 gap

[0159] 25G, 121 partition wall

[0160] 25H, 122 Second Gas Storage Chamber

[0161] 25I Seating Section

[0162] 25J, 124 flow space

[0163] 25K fuel intrusion path

[0164] 26 auxiliary floats

[0165] 26D, 120 through hole

[0166] 119 floats

Claims

1. A control valve for a fuel tank, comprising: A housing, which is disposed inside the fuel tank of a vehicle, and whose upper part is connected to a venting path leading to the fuel tank; Valve seat portion, the valve seat portion being disposed inside the housing; A plate, which is disposed opposite to the valve seat portion in a lower direction relative to the housing, and forms the bottom of the housing; A peripheral wall portion, which extends from the periphery of the plate toward the lower part; A first gas storage chamber, the first gas storage chamber being formed by the plate and the peripheral wall portion; A gas supply port is provided, which opens on the surface of the plate opposite to the valve seat portion, and can supply gas from the first gas storage chamber to a variable volume space formed between the plate and the valve seat portion. A gap is formed between the housing and the peripheral wall portion, and allows fuel from the fuel tank to flow in; A float, which has buoyancy relative to the fuel flowing in from the gap, floats in the variable volume space by the replenishment of gas supplied from the gas supply hole, and is configured to sit on the valve seat. A through hole, which opens into the float, suppresses the inflow of fuel from the gap by the seat, and allows the gas supplied to the variable volume space to be discharged to the upper side, which is closer to the valve seat, as the buoyancy decreases. as well as The second gas storage chamber is formed by a portion of the plate including the gas supply hole and a partition wall portion that is erected separately from the peripheral wall portion, and is disposed inside the first gas storage chamber. The opening and closing of the fuel flow path inside the housing is controlled by the float's seating and unseatment at the valve seat.

2. The control valve for a fuel tank as described in claim 1, characterized in that, The second gas storage chamber is cylindrical, consisting of an upper surface formed by a portion of a plate including the gas supply hole and a side surface formed by the partition wall portion.

3. The control valve for a fuel tank as described in claim 2, characterized in that, The first gas storage chamber is cylindrical, consisting of an upper surface formed by the plate and a side surface formed by the peripheral wall, and the gas supply hole is set in a concentric circle at the center of the upper surface of the plate and the upper surface formed by a part of the plate.

4. The control valve for a fuel tank as described in any one of claims 1 to 3, characterized in that, The partition wall portion is formed in an inverted cone shape from a portion of the plate toward the lower part.

5. The control valve for a fuel tank as described in any one of claims 1 to 3, characterized in that, The open end of the partition wall is L-shaped and bends towards the interior space of the second gas storage chamber.

6. The control valve for a fuel tank as described in any one of claims 1 to 3, characterized in that, The open end of the partition wall protrudes further downward than the open end of the peripheral wall.

7. The control valve for a fuel tank as described in any one of claims 1 to 3, characterized in that, The gas supply holes are provided in two or more locations on a portion of the plate.

8. The control valve for a fuel tank as described in any one of claims 1 to 3, characterized in that, The upper surface of the plate has a convex seating portion, which forms an inflow space that allows gas to flow in from the gas supply hole when the float is seated.

9. The control valve for a fuel tank as described in claim 8, characterized in that, The seating portion has multiple ribs that protrude radially from the gas supply hole toward the outer periphery of the plate, and the inflow space is formed between adjacent ribs.

10. The control valve for a fuel tank as described in claim 8, characterized in that, The seating portion is arranged radially from the gas supply hole toward the outer periphery of the upper surface, forming a plurality of slits that constitute the inflow space, with convex seating portions formed between adjacent slits.

11. The control valve for a fuel tank as described in claim 8, characterized in that, The seating portion has a plurality of columnar protrusions erected from the upper surface toward the float, and the inflow space is formed by the space between the columnar protrusions.

12. The control valve for a fuel tank as claimed in any one of claims 1 to 3, characterized in that, An upper float and an upper valve seat are provided on the upper side of the housing, which are closer to the valve seat portion of the float, to prevent over-supply of oil.

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