Check valve

Abstract

To provide a check valve capable of smoothly supplying oil and confirming the existence of a hole in a fuel passage.SOLUTION: A check valve 10 is provided at a connection part with a fuel tank 11 in a filler pipe 12 connected to the fuel tank 11, and has a check valve plate 33 for opening and closing a flow passage from the filler pipe 12 to the fuel tank 11, and the check valve plate 33 has a vent hole 41 communicating the inside of the fuel tank 11 with the inside of the filler pipe 12, and a wall body 42 extending upward from the lower side of the vent hole 41 and arranged on the filler pipe 12 side in the vent hole 41.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a check valve. [Background technology]

[0002] Fuel tanks for automobiles and other vehicles are equipped with a check valve at the connection point of a filler pipe connected to the fuel tank to prevent backflow. However, if the fuel tank is sealed by the check valve, it is difficult to check for holes in the filler pipe when a key-off pump (KOP) is used to create negative pressure in the fuel line to check for holes in the fuel line.

[0003] Patent Document 1 discloses that a bypass hole communicating with the upstream and downstream sides of a check valve is formed in the valve body of the check valve provided at the end of the filler pipe on the fuel tank side. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-16097 Summary of the Invention [Problem to be solved by the invention]

[0005] According to the structure described in Patent Document 1, by forming a vent hole, which is a bypass hole that connects the upstream and downstream sides of the check valve, in the valve body, it is possible to check for the presence or absence of a hole on the filler pipe side using a key-off pump even when the check valve is closed. However, by providing a vent hole in the valve body, fuel may flow downstream through the vent hole during refueling, reducing the fuel supply pressure and preventing the check valve from opening sufficiently during refueling, which could result in smooth refueling.

[0006] The present invention has been made in view of the above circumstances, and has as its object to provide a check valve that allows smooth fuel supply and also makes it possible to check whether or not there is a hole in the fuel line. [Means for solving the problem]

[0007] In order to achieve the above object, the check valve of the present invention comprises: A check valve provided at a connection portion of a filler pipe connected to a fuel tank with the fuel tank, the check valve having a check valve plate for opening and closing a flow path connecting the filler pipe to the fuel tank, The check valve plate is an air vent that communicates the interior of the fuel tank with the interior of the filler pipe; a wall body extending upward from a lower side of the vent hole and disposed on the filler pipe side of the vent hole; It has.

[0008] This check valve configuration ensures that a vent hole is provided for detecting holes in the filler pipe, while also preventing fuel from flowing in through the vent hole during refueling, reducing the fuel supply pressure and preventing the check valve plate from opening. This allows for smooth refueling and makes it possible to check for holes in the fuel path. [Effects of the Invention]

[0009] According to the present invention, a check valve can be provided that allows smooth fuel supply and also makes it possible to check whether or not there is a hole in the fuel path. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram of a part of a fuel system of a vehicle in which a check valve according to this embodiment is provided in a filler pipe. [Figure 2] FIG. 2 is a schematic cross-sectional side view of the check valve according to this embodiment. [Figure 3] FIG. 3 is a schematic cross-sectional side view of a check valve according to a reference example. [Figure 4]FIG. 4 is a schematic cross-sectional side view of a tip portion of a check valve according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic diagram of a part of a fuel system of a vehicle in which a check valve 10 according to this embodiment is provided in a filler pipe 12. As shown in FIG. As shown in FIG. 1, a check valve 10 according to this embodiment is used in a fuel passage in a vehicle such as an automobile.

[0012] A vehicle is equipped with a fuel tank 11. A filler pipe 12 is connected to this fuel tank 11. The filler pipe 12 has a fuel filler port 13 at the end opposite to the end connected to the fuel tank 11. The filler pipe 12 is a pipe for sending fuel supplied from the fuel filler port 13 by a fuel gun into the fuel tank 11. The check valve 10 is provided at the connection portion of the filler pipe 12 with the fuel tank 11.

[0013] The fuel tank 11 is a sealed fuel tank that is sealed while the vehicle is running, for example. One end of a vapor passage 22 having a shut-off valve 21 is connected to the fuel tank 11. The other end of the vapor passage 22 is connected to a canister 23. One end of an atmospheric passage 24 is connected to the canister 23, and the other end of the atmospheric passage 24 is connected to the filler pipe 12 near the fuel filler opening 13. The fuel tank 11 is sealed when the shut-off valve 21 closes the vapor passage 22.

[0014] FIG. 2 is a schematic cross-sectional side view of the check valve 10 according to this embodiment. 2, the check valve 10 has a cylindrical main body 31, and a flange 32 is formed on the main body 31. The main body 31 is inserted into a mounting hole (not shown) formed in the fuel tank 11, and the flange 32 is fixed to the edge of the mounting hole of the fuel tank 11. In this way, the check valve 10 is attached to the fuel tank 11 in a liquid-tight manner. A filler pipe 12 is connected to the upstream end of the main body 31, which is located outside the fuel tank 11, of the check valve 10 attached to the fuel tank 11.

[0015] The check valve 10 has a check valve plate 33 at its downstream end located inside the fuel tank 11, which opens and closes the flow path connecting the filler pipe 12 to the fuel tank 11. This check valve plate 33 is supported at the lower end of the main body 31 and is able to swing around this support point as a fulcrum. In a normal state, this check valve plate 33 is located on the main body 31 side, and an opening 34 of the main body 31 on the fuel tank 11 side is closed by the check valve plate 33.

[0016] Furthermore, a swing limiting plate 35 is fixed to the lower end of the main body 31. This swing limiting plate 35 is gradually inclined in a direction away from the opening 34 of the main body 31 toward the upper end of the main body 31. As a result, the swing limiting plate 35 restricts the swing of the check valve plate 33 in a direction away from the opening 34 of the main body 31. In other words, the check valve plate 33 is swingable between the opening 34 of the main body 31 and the swing limiting plate 35.

[0017] The check valve plate 33 has a vent hole 41 near its upper end. As a result, when the check valve plate 33 is positioned on the main body 31 side and the opening 34 is closed, the inside of the fuel tank 11 and the inside of the filler pipe 12 are in communication with each other via the vent hole 41. The vent hole 41 formed in the check valve plate 33 is positioned above the liquid level L when the fuel tank 11 is full. As a result, even when the fuel tank is full, fuel in the fuel tank 11 does not flow into the filler pipe 12 through the vent hole 41.

[0018] The check valve plate 33 also has a wall 42. The wall 42 is formed in a plate shape and is formed integrally with the check valve plate 33 on the filler pipe 12 side. The wall 42 extends upward from a position below the vent hole 41 in the check valve plate 33. As a result, the wall 42 is disposed opposite the vent hole 41 in the check valve plate 33 on the filler pipe 12 side. The wall 42 is inclined relative to the check valve plate 33 in a direction gradually moving away from the check valve plate 33 as it extends upward.

[0019] In the check valve 10 having the above structure, when fuel is supplied from a fuel gun inserted into the fuel inlet 13 of the filler pipe 12, the supply oil pressure presses the check valve plate 33 toward the fuel tank 11 and causes it to swing. This opens the opening 34 of the main body 31 that was previously closed by the check valve plate 33, allowing fuel to be sent from the filler pipe 12 into the fuel tank 11.

[0020] After refueling is complete, the pressure in the fuel tank 11 is removed, causing the check valve plate 33, which had been pressed and swung, to return to its original position and close the opening 34 of the main body 31. This causes the check valve plate 33 to close the opening 34 of the main body 31, preventing the fuel in the fuel tank 11 from flowing back toward the filler pipe 12.

[0021] Furthermore, the check valve 10 has a vent hole 41 in the check valve plate 33, which allows ventilation between the interior of the fuel tank 11 and the interior of the filler pipe 12. Therefore, with the opening 34 of the main body 31 closed by the check valve plate 33, it is possible to check with the key-off pump whether or not there is a hole on the filler pipe 12 side.

[0022] FIG. 3 is a schematic cross-sectional view of a check valve 10R according to a reference example. 3, the check valve 10R according to the reference example includes a check valve plate 33A that does not have a wall body 42. In the case of this check valve 10R, the check valve plate 33A also has an air vent 41 that allows ventilation between the interior of the fuel tank 11 and the interior of the filler pipe 12. Therefore, with the opening 34 of the main body 31 closed by the check valve plate 33A, it is possible to check for the presence or absence of a hole on the filler pipe 12 side using a key-off pump.

[0023] However, with the check valve 10R according to this reference example, when fuel is filled using a fuel gun inserted into the fuel filler port 13 of the filler pipe 12, the fuel being fed into the filler pipe 12 flows into the fuel tank 11 through the vent 41. This reduces the fill pressure during fuel filling, and the check valve plate 33A is not sufficiently pressed toward the fuel tank 11. For example, the reduction in fill pressure caused by fuel flowing into the fuel tank 11 through the vent 41 reduces the pressing force that presses the check valve plate 33A by about 10%. This prevents the opening 34 of the main body 31 from opening sufficiently, causing the fuel being fed into the filler pipe 12 to flow back into the fuel filler port 13, activating the auto-stop mechanism of the fuel gun, stopping fuel filling using the fuel gun, and potentially resulting in insufficient fuel being filled into the fuel tank 11.

[0024] In contrast to this, with the check valve 10 according to this embodiment, the wall body 42 can prevent fuel sent to the filler pipe 12 from flowing into the fuel tank 11 through the vent hole 41. Therefore, it is possible to prevent the phenomenon in which fuel flows into the fuel tank 11 through the vent hole 41 during refueling, causing the fuel supply pressure to drop and preventing the check valve plate 33 from opening, thereby enabling smooth refueling.

[0025] FIG. 4 is a schematic cross-sectional side view of the tip portion of a check valve 10A according to a modified example. As shown in Fig. 4, the check valve 10A according to the modified example includes a check valve plate 33A without a wall 42. Furthermore, in the check valve 10A, a wall 51 is provided integrally with the main body 31 on the inner surface of the upper part of the main body 31. The wall 51 is disposed on the filler pipe 12 side of the check valve plate 33A. This wall 51 extends downward, and its lower end reaches a position below the air vent 41 in the check valve plate 33A. As a result, the wall 51 is disposed opposite the air vent 41 in the check valve plate 33A on the filler pipe 12 side.

[0026] In the case of the check valve 10A according to this modification, the check valve plate 33A also has the vent hole 41, which allows ventilation between the interior of the fuel tank 11 and the interior of the filler pipe 12. Therefore, with the opening 34 of the main body 31 closed by the check valve plate 33A, it is possible to check for the presence or absence of a hole on the filler pipe 12 side using the key-off pump.

[0027] Also, in the case of the check valve 10A according to the modified example, the wall body 51 can prevent fuel sent to the filler pipe 12 from flowing into the fuel tank 11 through the vent hole 41. Therefore, it is possible to prevent the phenomenon in which fuel flows into the fuel tank 11 through the vent hole 41 during refueling, causing the fuel supply pressure to drop and preventing the check valve plate 33A from opening, thereby enabling smooth refueling. [Explanation of symbols]

[0028] 11 Fuel tank 12 Filler pipe 33 Check valve plate 10. Check valve 41 Ventilation hole 42 Wall

Claims

[Claim 1] A check valve provided at a connection portion of a filler pipe connected to a fuel tank with the fuel tank, the check valve having a check valve plate for opening and closing a flow path connecting the filler pipe to the fuel tank, The check valve plate is an air vent that communicates the interior of the fuel tank with the interior of the filler pipe; a wall body extending upward from a lower side of the vent hole and disposed on the filler pipe side of the vent hole; having non-return valve.

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