Fuel shutoff valve

Abstract

The present invention provides a fuel shut-off valve that can reduce the pressure inside the fuel tank when the pressure inside the fuel tank is higher than a preset pressure. [Solution] The fuel shut-off valve comprises a cap located on the outside of the fuel tank, a case located on the inside of the fuel tank, and a float housed in an internal space formed inside the case. The float has a float portion and a valve portion extending from the float portion toward the contact surface. The float portion has a first chamber located on the valve portion side and a second chamber isolated from the first chamber. The valve portion has a second communication hole that penetrates the first chamber along the extension direction of the valve portion. The float portion is provided with a first valve that connects the first chamber and the second chamber when the pressure inside the fuel tank is higher than a preset pressure.

Description

Technical Field

[0001] The present disclosure relates to a fuel cut-off valve.

Background Art

[0002] Patent Document 1 discloses a fuel cut-off valve attached to the upper part of a fuel tank. Such a fuel cut-off valve includes a casing having a valve chamber connected to the fuel tank and a connection passage connecting the valve chamber to the outside, and a float housed in the valve chamber that opens and closes the connection passage by rising and falling according to the fuel liquid level in the valve chamber. According to such a fuel cut-off valve, the float rises and falls according to the fuel liquid level in the fuel tank, and the float opens and closes the connection passage to prevent fuel from flowing out of the fuel tank.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, when the temperature in the fuel tank rises while the float closes the connection passage, the pressure in the fuel tank also rises. Therefore, it is necessary to install an internal pressure regulating valve or the like separately from the fuel cut-off valve. However, installing an internal pressure regulating valve or the like separately from the fuel cut-off valve has problems such as restrictions on the layout of the internal pressure regulating valve or the like and increased costs.

[0005] In view of the above circumstances, at least one embodiment of the present invention aims to provide a fuel cut-off valve that can reduce the pressure in the fuel tank when the pressure in the fuel tank is higher than a preset pressure.

Means for Solving the Problems

[0006] A fuel shut-off valve according to at least one embodiment of the present invention is a fuel shut-off valve installed in a fuel tank, comprising: a cap located on the outside of the fuel tank; a case located on the inside of the fuel tank; and a float housed in an internal space formed inside the case, wherein the cap has a first communication hole that communicates from the internal space to the outside of the fuel tank, and a contact surface surrounding the upstream opening of the first communication hole; the case has a communication port that communicates with the inside of the fuel tank; and the float has a float portion and a valve portion that extends from the float portion toward the contact surface. The float portion has a first chamber located on the valve portion side and a second chamber isolated from the first chamber. The valve portion has a second communication hole that penetrates the valve portion along the extending direction of the valve portion. The case has a first air hole that communicates with the inside of the fuel tank and the internal space at a position closer to the outer wall of the fuel tank than the communication hole. The float portion has a second air hole that communicates with the internal space and the second chamber. The float portion is provided with a first valve that connects the first chamber and the second chamber when the pressure inside the fuel tank is higher than a preset pressure.

[0007] According to the above configuration, when the pressure inside the fuel tank is higher than a predetermined pressure, the first valve connects the first chamber and the second chamber, so that the inside of the fuel tank communicates with the outside of the fuel tank through the first air vent, the second air vent, the second chamber, the first chamber, the second connecting hole, and the first connecting hole. This makes it possible to lower the pressure inside the fuel tank when it is higher than a predetermined pressure. [Effects of the Invention]

[0008] According to at least one embodiment of the present invention, the pressure inside the fuel tank can be reduced when the pressure inside the fuel tank is higher than a preset pressure. [Brief explanation of the drawing]

[0009] [Figure 1]This is a schematic cross-sectional view showing the configuration of a fuel shut-off valve according to an embodiment. [Figure 2] This is a cross-sectional view of the fuel shutoff valve shown in Figure 1, taken along line II-II. [Figure 3] This is a cross-sectional view of a fuel shut-off valve according to an embodiment, showing a state in which the fuel level in the fuel tank has risen. [Figure 4] This is a cross-sectional view of a fuel shut-off valve according to an embodiment, showing a state in which the pressure inside the fuel tank has risen above a preset pressure. [Figure 5] This is a cross-sectional view of a fuel shut-off valve according to an embodiment, showing a state in which the pressure inside the fuel tank has fallen below a preset pressure. [Modes for carrying out the invention]

[0010] Hereinafter, several embodiments of the present invention will be described with reference to the attached drawings. However, the dimensions, materials, shapes, relative arrangements, etc., of the components described as embodiments or shown in the drawings are not intended to limit the scope of the present invention, but are merely illustrative examples.

[0011] [Configuration of fuel shutoff valve 1] Figure 1 is a schematic cross-sectional view showing the configuration of the fuel shut-off valve 1 according to an embodiment, and Figure 2 is a cross-sectional view of the fuel shut-off valve 1 shown in Figure 1, taken along line II-II.

[0012] As shown in Figure 1, the fuel shut-off valve 1 according to this embodiment is a fuel shut-off valve installed in a fuel tank 100, and is installed on the outer wall 110 of the fuel tank 100. The fuel shut-off valve 1 comprises a cap 10 installed on the outside of the fuel tank 100, a case 12 installed on the inside of the fuel tank 100, and a float 16 housed in an internal space 14 formed inside the case 12. The cap 10 may be mostly located on the outside of the fuel tank 100, or a portion of it may be located on the inside of the fuel tank 100. Similarly, the case 12 may be mostly located on the inside of the fuel tank 100, or a portion of it may be located on the outside of the fuel tank 100.

[0013] The cap 10 is disc-shaped with a smaller diameter portion superimposed on a larger diameter portion, and a tube 18 extends radially outward from the side of the smaller diameter portion. The case 12 is cylindrical and has a closed bottom with one end open.

[0014] The cap 10 is joined to the outer wall 110 of the fuel tank 100, and the case 12 is joined to the cap 10. However, the case 12 may be joined to the outer wall 110 of the fuel tank 100 and the cap 10 may be joined to the case 12, or the cap 10 and the case 12 may each be joined to the outer wall 110 of the fuel tank 100.

[0015] The cap 10 has a communication hole (first communication hole) 20 that connects the internal space 14 to the outside of the fuel tank 100, and a contact surface 22 that surrounds the upstream opening of the first communication hole 20. The first communication hole 20 is composed of a cylindrical vertical hole space 24 extending axially from a space in the cap 10 where a small diameter space is superimposed on a large diameter space, a horizontal hole space 26 extending radially outward from the vertical hole space 24, and the internal space 28 of the pipe 18. The contact surface 22 is a flat surface provided around the vertical hole space 24, but it may also be a conical tapered surface that narrows towards the back.

[0016] The case 12 has a communication port 30 that communicates with the inside of the fuel tank 100. The communication port 30 is a circular hole provided at the bottom of the case 12, but it may also be provided on the side of the case 12 near the bottom.

[0017] The float 16 has a float portion 32 and a valve portion 34 that extends from the float portion 32 toward the contact surface 22. The float portion 32 is formed in a cylindrical shape with a diameter slightly smaller than the internal space 14 of the case 12. The valve portion 34 is formed in a cylindrical shape with a diameter larger than the vertical hole space 24. The tip of the valve portion 34 is a flat surface that contacts the contact surface 22, but if the contact surface 22 is a tapered surface, the tip may be a tapered surface that becomes smaller in diameter toward the tip.

[0018] In the float portion 32, a first chamber 36 located on the valve portion 34 side and a second chamber 38 separated from the first chamber 36 are formed. The first chamber 36 and the second chamber 38 are cylindrical spaces, and the first chamber 36 and the second chamber 38 are formed along the axial direction of the float portion 32. Incidentally, although the bottom side of the case 12 of the second chamber 38 is blocked, it may be open.

[0019] In the valve portion 34, a communication hole (second communication hole) 40 penetrating the valve portion 34 along the extending direction of the valve portion 34 is formed. The second communication hole 40 is cylindrical and communicates with the first chamber 36.

[0020] In the case 12, an air hole (first air hole) 42 that communicates with the inside of the fuel tank 100 and the internal space 14 is formed at a position closer to the outer wall 110 of the fuel tank 100 than the communication port 30. The first air hole 42 is formed outside the fuel tank 100, but may be formed inside the fuel tank 100.

[0021] In the float portion 32, an air hole (second air hole) 44 that communicates with the internal space 14 of the case 12 and the second chamber 38 is formed. The second air hole 44 is provided on the side surface of the float portion 32, on the side closer to the outer wall 110 of the fuel tank 100.

[0022] The float section 32 is provided with a valve (first valve) 46 that connects the first chamber 36 and the second chamber 38 when the pressure inside the fuel tank 100 is higher than a preset pressure. In the example shown in Figure 1, the float section 32 has a passage (first passage) 48 that communicates with the first chamber 36 and the second chamber 38, and the first valve 46 is provided in the first passage 48. The first passage 48 is a valve chamber (first valve chamber) 50 formed between the first chamber 36 and the second chamber 38, and communication holes 56 and 58 are formed in a partition wall 52 provided between the first chamber 36 and the first valve chamber 50 and in a partition wall 54 provided between the second chamber 38 and the first valve chamber 50, respectively. The first valve 46 is composed of a ball 60 located on the second chamber 38 side and a compression spring 62 located on the first chamber 36 side. The ball 60, due to the elastic restoring force of the compression spring 62, closes the communication hole 58 formed in the partition wall 54 on the second chamber 38 side, blocking communication between the first chamber 36 and the second chamber 38. On the other hand, when the pressure inside the second chamber 38 increases and the ball 60 is pressed against the elastic restoring force of the compression spring 62, the ball 60 separates from the partition wall 54 on the second chamber 38 side, the communication hole 58 opens, and the first chamber 36 and the second chamber 38 become connected.

[0023] The float section 32 is provided with a valve (second valve) 64 that connects the first chamber 36 and the second chamber 38 when the pressure inside the fuel tank 100 is lower than a preset pressure. In the example shown in Figure 1, the float section 32 has a passage (second passage) 66 that connects the first chamber 36 and the second chamber 38, separate from the first passage 48, and the second valve 64 is provided in the second passage 66. The second passage 66 is a valve chamber (second valve chamber) 68 formed between the first chamber 36 and the second chamber 38, and as shown in Figure 2, it is provided separately from the first valve chamber 50. In the second valve chamber 68, similar to the first valve chamber 50, communication holes 74 and 76 are formed in the partition wall 70 provided between the first chamber 36 and the second valve chamber 68, and in the partition wall 72 provided between the second chamber 38 and the second valve chamber 68, respectively. The second valve 64 consists of a ball 78 located on the first chamber 36 side and a compression spring 80 located on the second chamber 38 side. The ball 78 closes the communication hole 74 formed on the first chamber 36 side by the elastic restoring force of the compression spring 80, blocking communication between the first chamber 36 and the second chamber 38. On the other hand, when the pressure in the second chamber 38 decreases and the ball 78 is attracted against the elastic restoring force of the compression spring 80, and the ball 78 moves away from the partition wall 70 on the first chamber 36 side, the communication hole 74 opens, and the first chamber 36 and the second chamber 38 communicate with each other.

[0024] [Operation of fuel shutoff valve 1] [The fuel level in the fuel tank 100 has risen.] Figure 3 is a cross-sectional view of the fuel shut-off valve 1 according to an embodiment, showing a state in which the liquid level of fuel in the fuel tank 100 has risen.

[0025] As shown in Figure 3, when the fuel level in the fuel tank 100 rises, fuel enters the internal space 14 through the communication port 30 formed in the case 12, causing the float 16 to rise. When the float 16 rises, the valve portion 34 contacts the contact surface 22 surrounding the upstream opening of the first communication hole 20, and the valve portion 34 closes the upstream opening of the first communication hole 20. This blocks the internal space 14 of the case 12 from the first communication hole 20, preventing fuel from flowing from inside the fuel tank 100 through the internal space 14 of the case 12 to the first communication hole 20.

[0026] [Condition: High pressure inside fuel tank 100] Figure 4 is a cross-sectional view of the fuel shut-off valve 1 according to an embodiment, showing a state in which the pressure inside the fuel tank 100 has become higher than a preset pressure.

[0027] As shown in Figure 4, when the pressure inside the fuel tank 100 increases with the valve section 34 blocking the upstream opening of the first communication hole 20, the first valve 46 opens the first chamber 36 and the second chamber 38. As a result, air inside the fuel tank 100 flows out of the fuel tank 100 from the second chamber 38 through the first chamber 36. Consequently, the pressure inside the fuel tank 100 decreases. Then, when the pressure inside the fuel tank 100 decreases, the first valve 46 shuts off the communication between the first chamber 36 and the second chamber 38 (see Figure 3).

[0028] In the example shown in Figure 4, when the pressure inside the fuel tank 100 increases, air inside the fuel tank 100 flows into the second chamber 38 through the first air hole 42 formed in the case 12 and the second air hole 44 formed in the float section 32, increasing the pressure inside the second chamber 38. As the pressure inside the second chamber 38 increases, the ball 60 is pressed against the elastic restoring force of the compression spring 62, and when the ball 60 separates from the partition wall 54 on the second chamber 38 side, the communication hole 58 opens, and the first chamber 36 and the second chamber 38 communicate with each other. As a result, air inside the fuel tank 100 flows out of the fuel tank 100 from the second chamber 38 through the first chamber 36, the second communication hole 40, and the first communication hole 20. Consequently, the pressure inside the second chamber 38 decreases, and the pressure inside the fuel tank 100 also decreases. When the pressure inside the second chamber 38 decreases, the elastic restoring force of the compression spring 62 causes the ball 60 to close the communication hole 58 formed in the partition wall 54 on the second chamber 38 side, thereby blocking communication between the first chamber 36 and the second chamber 38.

[0029] [Condition: Low pressure inside fuel tank 100] Figure 5 is a cross-sectional view of the fuel shut-off valve 1 according to an embodiment, showing a state in which the pressure inside the fuel tank has fallen below a preset pressure.

[0030] As shown in Figure 5, when the pressure inside the fuel tank 100 decreases while the valve section 34 is blocking the upstream opening of the first communication hole 20, the second valve 64 opens the first chamber 36 and the second chamber 38. As a result, air from outside the fuel tank 100 flows from the first chamber 36 through the second chamber 38 into the fuel tank 100. This increases the pressure inside the fuel tank 100. When the pressure inside the fuel tank 100 increases, the second valve 64 shuts off the communication between the first chamber 36 and the second chamber 38 (see Figure 3).

[0031] In the example shown in Figure 5, when the pressure inside the fuel tank 100 decreases (becomes negative pressure), air in the second chamber 38 flows into the fuel tank 100 through the second air hole 44 formed in the float section 32 and the first air hole 42 formed in the case 12, causing the pressure inside the second chamber 38 to decrease. As the pressure inside the second chamber 38 decreases, the ball 78 is drawn in against the elastic restoring force of the compression spring 80, and when the ball 78 separates from the partition wall 70 on the first chamber 36 side, the communication hole 74 opens, and the first chamber 36 and the second chamber 38 communicate with each other. As a result, air from outside the fuel tank 100 flows into the fuel tank 100 from the first chamber 36 through the second chamber 38, the second air hole 44, and the first air hole 42. Consequently, the pressure inside the second chamber 38 increases, and the pressure inside the fuel tank 100 also increases. When the pressure in the second chamber 38 increases, the elastic restoring force of the compression spring 80 causes the ball 78 to block the communication hole 74 formed in the partition wall 70 on the first chamber 36 side, thereby blocking communication between the first chamber 36 and the second chamber 38.

[0032] [Effect of fuel shutoff valve 1] According to the fuel shut-off valve 1 of this embodiment, when the pressure inside the fuel tank 100 is higher than a predetermined pressure, the first valve 46 connects the first chamber 36 and the second chamber 38, so that the inside of the fuel tank 100 is connected to the outside of the fuel tank 100 through the first air hole 42, the second air hole 44, the second chamber 38, the first chamber 36, the second communication hole 40, and the first communication hole 20. As a result, the pressure inside the fuel tank 100 can be reduced when the pressure inside the fuel tank 100 is higher than a predetermined pressure.

[0033] Furthermore, when the pressure inside the fuel tank 100 is lower than a predetermined pressure, the second valve 64 connects the first chamber 36 and the second chamber 38, so that the inside of the fuel tank 100 is connected to the outside of the fuel tank 100 through the first air hole 42, the second air hole 44, the second chamber 38, the first chamber 36, the second communication hole 40, and the first communication hole 20. This makes it possible to increase the pressure inside the fuel tank 100 when the pressure inside the fuel tank 100 is lower than a predetermined pressure.

[0034] The present invention is not limited to the embodiments described above, and includes modified forms of the embodiments described above, as well as forms that combine these forms as appropriate. [Explanation of Symbols]

[0035] 1. Fuel shutoff valve 10 caps 12 cases 14 Interior space 16 floats 20 1st communication hole 22 Contact surface 30 connecting ports 32 Float section 34 Valve section 36 Room 1 38 Room 2 40 2nd communication hole 42 First air vent 44 Second air vent 46. ​​Valve No. 1 64. Second valve 100 Fuel Tank 110 Fuel tank outer wall

Claims

1. A fuel shut-off valve installed in a fuel tank, A cap located on the outside of the aforementioned fuel tank, A case located inside the aforementioned fuel tank, A float housed in an internal space formed inside the case, Equipped with, The cap is formed with a first communication hole that connects the internal space to the outside of the fuel tank, and a contact surface that surrounds the upstream opening of the first communication hole. The case has a communication port that communicates with the inside of the fuel tank. The float is formed with a float portion and a valve portion extending from the float portion toward the contact surface. The float portion is formed with a first chamber located on the valve portion side and a second chamber isolated from the first chamber. The valve portion has a second communication hole that penetrates the valve portion along the extending direction of the valve portion. The case has a first air hole that communicates with the inside of the fuel tank and the internal space, located closer to the outer wall of the fuel tank than the communication opening. The float portion has a second air hole that communicates with the internal space and the second chamber. A fuel shut-off valve is provided in the float section, which includes a first valve that connects the first chamber and the second chamber when the pressure in the fuel tank is higher than a preset pressure.

2. The float portion has a first passage that communicates with the first chamber and the second chamber. The first valve is provided in the first passage, The fuel shut-off valve according to claim 1.

3. The fuel shut-off valve according to claim 1 or 2, wherein the float portion is provided with a second valve that connects the first chamber and the second chamber when the pressure in the fuel tank is lower than a preset pressure.

4. The float portion has a second passage that communicates with the first chamber and the second chamber. The fuel shut-off valve according to claim 3, wherein the first valve is provided in the second passage.

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