JP6249921B2 - Valve device for fuel tank - Google Patents

Description

  The present invention relates to an improvement of a valve device which is attached to a fuel tank of an automobile or a two-wheeled vehicle and forms a part of a ventilation passage of the fuel tank and which functions to communicate the inside and outside of the fuel tank in a valve open state .

  As a valve device for a fuel tank, there is one in which an opening for communicating the inside and outside of the fuel tank is closed by an upper part of the float by raising the float by fuel intrusion into the case (see Patent Document 1). This type of valve device incorporates a coil spring that assists in raising the float. As a result, the fuel level at which the float starts to rise can be adjusted, and the float can be raised when the vehicle tilts above a certain level.

  However, the coil spring is housed in a storage space that is formed in the float and is opened below, and the upper end of the spring is brought into contact with the inner back portion of the storage space, and the lower end of the spring is brought into contact with the bottom of the case. Thus, an upward biasing force is always applied to the float. For this reason, the outer diameter of the float has to be set including the dimensions of the storage space.

Japanese Patent No. 4869201

  The main problem to be solved by the present invention is that, in a valve device including this type of float and a coil spring that biases it, the outer diameter of the float can be appropriately and reasonably minimized, The valve device can be configured as compact as possible.

In order to achieve the above object, in the present invention, a fuel tank valve device is provided with a case having a valve port communicating between the inside and outside of the fuel tank;
A float in the case for opening and closing the valve opening;
A coil spring that encloses the float inside and biases the float toward the valve opening,
The upper end of the coil spring is brought into contact with a contact portion formed on the side of the float, and the lower end of the coil spring is supported by the case.

  Since the coil spring is placed inside the float, that is, wound around the outside of the float, the dimension in the direction perpendicular to the movement direction of the float, and hence the dimension of the valve device in this direction is the smallest. It becomes.

  One preferred aspect of the present invention is to provide a rib between the case and the float for guiding the movement of the float so as not to touch the coil spring. In this way, smooth movement of the float can be ensured even if the coil spring is positioned as if wound around the outside of the float as described above.

Further, it is one of preferred modes of the present invention that the rib is divided into an upper rib for the upper side of the float and a lower rib for the lower side of the float. In this case, it is one of preferred embodiments of the present invention that the upper rib is further provided on the float side and the lower rib is provided on the case side. Further, in this case, it is further preferable that the lower end of the coil spring is supported by a stepped portion formed on the lower rib and facing upward.

  Further, it is a preferable aspect of the present invention that the thickness of the upper rib is gradually reduced as it goes upward.

  Further, on the movement center axis of the float, the movement of the float may be guided through a guide hole provided in one of the float and the case through a guide shaft provided in the other of the float and the case. It is set as one of the preferable aspects. Even if it does in this way, even if it arrange | positions a coil spring so that it might be wound on the outer side of the float as mentioned above, the smooth movement of a float is securable.

  According to the present invention, in the valve device including this type of float and the coil spring that urges the float, the outer diameter of the float can be appropriately and reasonably minimized. It can be configured as compact as possible.

FIG. 1 is a side view of a valve device according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the valve device, in which the upper part of the fuel tank and the pipe connected to the valve device are represented by imaginary lines. FIG. 3 is a cross-sectional view of the valve device, showing the valve device in cross-section at a position 90 degrees different from FIG. 2, with the float in the lowered position. FIG. 4 is a cross-sectional view of the valve device, showing the valve device in cross-section at a position 90 degrees different from FIG. 2, with the float in the raised position. FIG. 5 is a cross-sectional view of the valve device, showing the valve device in cross section at a position 90 degrees different from FIG. 2, and showing a state immediately after the float starts to descend from the state of FIG. . FIG. 6 is a perspective view of the float and the lower body constituting the valve device. FIG. 7 is a perspective view of the main valve body constituting the float, and shows the state where the seal member is removed. FIG. 8 is a plan view of the main valve body constituting the float, and shows a state where the seal member is removed. FIG. 9 is a perspective view of a sub-valve element constituting the float. FIG. 10 is a perspective view of the lower body constituting the case. FIG. 11 is a plan view of the lower body constituting the case. FIG. 12 is a cross-sectional view of an essential part of a valve device (second example) according to one embodiment of the present invention. FIG. 13: is principal part sectional drawing of the valve apparatus (3rd example) concerning one Embodiment of this invention.

  Hereinafter, typical embodiments of the present invention will be described with reference to FIGS. The valve device B according to this embodiment is attached to a fuel tank T of an automobile or a two-wheeled automobile and forms a part of a ventilation passage of the fuel tank T, and communicates the inside and outside of the fuel tank T in a valve open state. Is to function as The valve device B is typically attached to the upper portion Ta of the fuel tank T, and constitutes a part of the ventilation passage of the fuel tank T. Such a valve device B uses an attachment hole Tb provided in the fuel tank T as in the illustrated example, or uses a bracket or the like provided in the fuel tank T (not shown). The fuel tank T can be provided.

  The valve device B includes a case 1 and a float 2 and a coil spring 3 that are accommodated in the case 1. In the illustrated example, the valve device B is combined with a member F having a flange Fa. The case 1 and the like can be easily imparted with a desired elastic deformation characteristic in a place where the elastic deformation characteristic should be provided by using a plastic molded product. The member F is formed on the outer side of the tubular portion Fb, a connecting tube portion Fc that is extended laterally with one end of the tube communicating with the upper end of the tubular portion Fb, and the tubular portion Fb. And a flange Fa. The inner diameter of the tubular portion Fb is substantially equal to the outer diameter of the case 1. The member F and the valve device B are combined with the upper side of the case 1 in the cylindrical portion Fb. The upper portion of the case 1 is abutted against an inner step surface Fd around one end of the connection pipe portion Fc in the member F, and the valve port 10 of the case 1 is communicated with one end of the connection pipe portion Fc. An outer wall 11 is formed on the outer side of the case 1 so as to form a gap for accommodating the lower end side of the cylindrical portion Fb. The cylindrical portion indicated by a symbol Fba in the window hole 11a of the outer wall 11 is formed. The combined state is maintained by engaging engagement protrusions formed on the outside of Fb. In the illustrated example, a portion positioned below the flange Fa is placed in a mounting hole Tb formed in the fuel tank T, and the flange Fa is welded to an outer surface portion of the fuel tank T. The valve device B can be attached to the. The connecting pipe portion Fc is inserted into a pipe P that constitutes the ventilation flow path, whereby the inside and outside of the fuel tank T are communicated via a valve device B. In FIG. 2, the symbol R is a seal ring between the outer surface of the case 1 and the inner surface of the member F.

  The case 1 is provided with a valve port 10 that communicates the inside and outside of the fuel tank T. In the illustrated example, the case 1 is composed of an upper body 12 and a lower body 13.

  The upper body 12 has a substantially cylindrical shape. The lower end of the upper body 12 is open. A rotating rod 12a is formed at the upper end of the upper body 12 so as to protrude toward the central axis of the upper body 12, and the inside of the rotating rod 12a functions as the valve port 10.

  The lower body 13 includes an upper annular body 130, a bottom 131, and a plurality of lower ribs 132 that connect the two. The upper annular body 130 has a short cylindrical shape. The bottom 131 includes a short cylindrical outer peripheral portion 131a and a circular dish-shaped central portion 131b. The outer peripheral part 131a has an inner flange 131c at the lower end thereof. The center part 131b is located in the inner collar 131c of the outer peripheral part 131a. The lower rib 132 has a lower end integrated with the inner flange 131c of the outer peripheral portion 131a, an outer edge portion on the lower end side integrated with an inner surface of the outer peripheral portion 131a, an upper end integrated with an inner surface of the upper annular body 130, and an inner edge on the lower end side. The part is integrated with the edge of the central part 131b.

  In the illustrated example, six lower ribs 132 are formed. Two of the six lower ribs 132... 132 are provided on both sides of the center on a virtual first straight line x1 passing through the center of the bottom 131. The two lower ribs 132, 132 are long plate-like and have a narrow plate shape formed so that the plate surface is parallel to the first straight line x1 (FIG. 11).

  The remaining lower ribs 132 are arranged on the third straight line x3 parallel to the second straight line x2 respectively located on both sides of the first straight line x1 across the virtual second straight line x2 orthogonal to the center. They are provided on both sides of the straight line x1. These remaining lower ribs 132 have a narrow plate shape that extends in the vertical direction and has a plate surface parallel to the third straight line x3 (FIG. 11).

  Each lower rib 132 has a stepped portion 132a facing upward at the inner edge at a position between the lower end of the upper annular body 130 and the upper end of the bottom portion 131. The level of the step 132a of each lower rib 132 is equal. Further, the upper edge of each lower rib 132 above the stepped portion 132a is inclined at the inner edge so as to decrease the plate width toward the upper end.

  The lower body 13 is fitted from the lower end of the upper body 12 until the positioning protrusion 133 formed on the outer side of the lower end of the bottom portion 131 comes into contact with the lower end of the upper body 12 and is combined with the upper body 12. Yes. This combined state is maintained by engaging an engagement protrusion 131d formed outside the bottom 131 of the lower body 13 with an engagement window 12b formed on the lower end side of the upper body.

  In the illustrated example, a circumferential step surface 12c facing downward is formed in the upper body 12 at a position approximately in the middle of the vertical direction. In the combined state, the upper end of the upper annular body 130 of the lower body 13 abuts on the circumferential step surface 12c and is opened downward by the outer surface of the upper annular body 130, the circumferential step surface, and the inner surface of the upper body 12. A circumferential recess 14 is formed.

  In this embodiment, when the fuel in the liquid state in the fuel tank T reaches the valve device B due to refueling or the inclination of the vehicle, the gap between the outer peripheral portion 131a and the central portion 131b of the bottom portion 131 of the lower body 13 is reached. The annular gap is entered into the case 1 as an inflow port 15. When the liquid level of the fuel flowing in reaches a predetermined level, the float 2 rises and closes the valve port 10 to prevent the fuel from flowing out of the fuel tank T (FIG. 4). In the illustrated example, part of the fuel that has flowed into the case 1 in this manner is temporarily trapped, that is, retained in the circumferential recess 14 formed above the inlet 15. ing. Thus, in this embodiment, when the fuel has entered the case 1 but has not reached the level at which the float 2 is raised, the fuel in the liquid state is supplied through the valve port 10 as fuel. The situation of leaking out of the tank T is prevented as much as possible.

  The float 2 is in the case 1 and opens and closes the valve port 10. The float 2 is housed in the case 1 so as to be movable up and down. At the same time, the float 2 is in the lowered position by its own weight until the fuel level in the case 1 reaches a predetermined level, and the upper portion thereof does not block the valve port 10. That is, the valve port 10 is not closed, and the valve device B is opened (FIGS. 2 and 3). On the other hand, the float 2 rises when the fuel level in the case 1 reaches a predetermined level and closes the valve port 10. That is, the valve port 10 is closed and the valve device B is closed (FIG. 4).

  In this embodiment, the float 2 includes a float main body 20, a sub-valve body 21 that is tiltably combined with the upper portion of the float main body 20, and the float main body 20 on the sub-valve body 21. A main valve body 22 is provided on the upper part so as to be movable up and down.

  The float main body 20 has a cylindrical shape. At the center of the float main body 20, a ventilation portion 20c is formed extending over the upper end 20a and the lower end 20b. The ventilation portion 20c has a large cross-sectional area from the lower end 20b of the float main body 20 to the vicinity of the upper end 20a, a small cross-sectional area on the upper end 20a side of the float main body 20, and an upper end 20a of the float main body 20 having an orifice shape. ing. Further, on the outer surface of the float main body 20 and on the upper end 20 a side of the float main body 20, a contact portion 20 d that forms a stepped surface facing downward is formed so as to go around the center of the float main body 20.

  The sub-valve element 21 includes a central portion 21a having a disk shape and three arm portions 21b... 21b protruding in a radial direction from the central portion 21a. An interval of about 120 degrees is provided between any adjacent arm portions 21b, 21b in the direction of circling the central portion 21a. Claw portions 21c protruding downward are formed at the two tips of the three arm portions 21b ... 21b. The central portion 21a of the sub-valve body 21 has a size that closes the ventilation portion 20c of the upper end 20a of the float main body 20 from above and sits on a later-described valve seat 22i of the main valve body 22 to block it. . Further, the claw portion 21c of the sub-valve body 21 seems to be caught at a corner between the upper end 20a of the float main body 20 and the side portion 20e in a state where the central portion 21a is positioned at the center of the upper end 20a of the float main body 20. It has become. Of the three arm portions 21b... 21b of the sub-valve body 21, the arm portion 21b where the claw portion 21c is not formed is passed through a holding hole 20f formed in a protruding piece protruding upward from the corner. As a result, the sub-valve element 21 can be tilted with the tip end side of the arm portion 21b passed through the holding hole 20f as the tilting center.

  The main valve body 22 includes a disk-shaped portion 22a, a seal member 22c, an upper rib 22f, and a leg portion 22g.

  A through hole 22b is formed at the center of the disc-like portion 22a. The seal member 22c has a disk shape having a size substantially equal to that of the disk-shaped portion 22a, and has a protrusion 22d at the center of the lower surface, and a ventilation hole 22e between the upper surface and the lower end of the protrusion 22d. It has. The seal member 22c is typically made of a soft synthetic resin. The protrusion 22d of the seal member 22c is fitted into the through hole 22b of the disk-like portion 22a, and both are integrated. The upper surface of the disk-shaped part 22a is covered with a seal member 22c, and the protrusion 22d of the seal member 22c protrudes from the lower surface of the disk-shaped part 22a. The protrusion 22d functions as a valve seat 22i for the sub valve body 21.

  The upper rib 22f has an upper end integrated with the outer edge of the disc-like portion 22a, and has a narrow plate shape extending downward. The upper rib 22f has a length that extends below the contact portion 20d of the float main body 20 at the maximum lowered position of the main valve body 22. In the example shown in the figure, six upper ribs 22f are provided at intervals between adjacent upper ribs 22f and 22f in the direction around the center of the disk-shaped portion 22a. Each of the upper ribs 22f is formed so that its plate surface is along a virtual straight line (not shown) extending in the radial direction from the center of the disk-like portion 22a. The diameter of a virtual circle r1 (see FIG. 8) circumscribing the inner edge of each upper rib 22f is larger than the outer diameter of the float main body 20, and the inner edge of each upper rib 22f houses the float 2 inside as will be described later. The coil spring 3 is not touched. Further, the diameter of a virtual circle r2 (see FIG. 8) inscribed in the outer edge portion of each upper rib 22f is slightly smaller than the inner diameter of the upper body 12.

  The leg part 22g protrudes downward from the outer edge of the disk-like part 22a. Three leg portions 22g are provided at intervals between adjacent leg portions 22g and 22g in a direction around the center of the disk-shaped portion 22a. Each leg portion 22g has a length positioned on the contact portion 20d of the float main body 20 at the maximum lowered position of the main valve body 22, and is provided on the side portion 20e of the float main body 20 on the contact portion 20d. It is stored in a groove-shaped guide portion 20g along the vertical direction. One of the three leg portions 22g... 22g is provided with a claw portion 22h, and a hooking portion 20h with respect to the claw portion 22h is formed at the upper end of the corresponding guide portion 20g. The valve body 22 is combined with the upper part of the float main body 20 so as to be movable up and down and tiltable about the leg 22g side provided with the claw portion 22h.

  When the float 2 is in the lowered position, the central portion 21a of the sub-valve element 21 is horizontally oriented and closes the ventilation portion 20c of the float main body 20. The disc-like portion 22a of the main valve body 22 is positioned horizontally on the sub-valve body 21, and the central portion 21a of the sub-valve body 21 is seated on the valve seat 22i of the main valve body 22 (FIG. 2, FIG. 3). When the fuel liquid level in the case 1 reaches a predetermined level (not shown), the float 2 rises and the valve port 10 is closed by the seal member 22c of the main valve body 22 to create the closed valve state (FIG. 4). ). When the fuel flows out from the case 1, the float main body 20 descends. Due to the pressure difference between the inside and outside of the fuel tank T, the main valve element 22 is subjected to a force that is normally pressed against the valve port 10, but even if this force is large, the opening that is narrower than the valve port 10 is caused by the lowering of the float main body 20. The sub-valve body 21 seated on the valve seat 22i of the area can be separated from the valve seat 22i of the main valve body 22 by the tilting (FIG. 5). When the valve vents the inside and outside of the fuel tank T through the vent hole 22e and the valve port 10 of the seal member 22c, the force in the direction of pressing the main valve body 22 against the valve port 10 is relieved. 22 is also tilted away from the valve port 10 and the float 2 is lowered as a whole, and the valve device B is opened.

In this embodiment, even if the float 2 can be lowered, the float 2 is not immediately lowered. As a result, when the fuel in the liquid state still remains in the case 1, typically, when the fuel in the water droplet state remains in the vicinity of the valve port 10, the valve port 10 is opened. Therefore, the situation where the fuel leaks out of the fuel tank T is prevented as much as possible. That is, in the illustrated example, the ventilation small hole 16 is formed on the upper end side of the case 1. When the fuel level in the case 1 starts to drop below the predetermined level, the ventilation portion 20c of the float main body 20 becomes negative pressure from the inside of the upper end side of the case 1. As a result, immediately after the lowering of the fuel liquid level is started, a force in a direction in which the central portion 21a of the sub-valve body 21 is attached to the vent portion 20c at the upper end of the float main body 20 is applied to the sub-valve body 21. The tilting of the sub valve body 21 is not started immediately.

  The coil spring 3 encloses the float 2 inside and biases the float 2 toward the valve port 10 side. The coil spring 3 is provided to assist the raising of the float 2 and functions to raise the float 2 when the vehicle is tilted more than a certain amount. In the illustrated example, the coil spring 3 has an outer diameter substantially equal to the outer diameter on the contact portion 20d of the float main body 20, and the inner diameter is smaller than the outer diameter of the float main body 20 below the contact portion 20d. Somewhat larger.

The coil spring 3 has its upper end 3a abutted against an abutting portion 20d formed on the side of the float 2 and its lower end 3b supported by the case 1 to attach the float 2 as described above. It has come to force. In the illustrated example, the lower end 3 b of the coil spring 3 is supported by a step portion 132 a formed on each lower rib 132 of the lower body 13.

  In the state where the float 2 is in the lowered position, the coil spring 3 is compressed between the abutting portion 20d and the stepped portion 132a. Under the lower end 3b of the coil spring 3, the float 2 is moved to the inner surface of the case 1 by the lower rib 132. Are held in a state where a gap is formed between them. The upper side of the float 2 is held in a state where a gap is formed between the upper rib 22f and the inner surface of the case 1.

  Since the coil spring 3 is positioned so that the float 2 is housed inside, that is, wound outside the float 2, the dimension in the direction orthogonal to the moving direction of the float 2, and thus the valve device B in this direction. The dimensions of are minimized.

  The rib between the case 1 and the float 2 that guides the movement of the float 2 is divided into the lower rib 132 and the upper rib 22f, and provided so as not to touch the coil spring 3. Therefore, even if the coil spring 3 is positioned so as to be wound around the outside of the float 2 as described above, smooth movement of the float 2 can be ensured. Further, in this embodiment, the upper rib 22f is provided on the float 2 side, and the lower rib 132 is provided on the case 1 side.

  In this embodiment, the upper rib 22f is configured to gradually reduce its thickness as it goes upward (FIGS. 7 and 8). In the valve open state, the gas in the fuel tank T enters the case 1 from the inlet 15 of the case 1 and is sent out of the fuel tank T from the valve port 10 through the gap between the case 1 and the float 2. If the upper rib 22f is configured in the shape as described above, the upper rib 22f does not hinder the gas flow, and the float does not flow into the case 1 due to this flow. The situation where 2 floats can be prevented as much as possible.

  FIG. 12 shows an example in which the movement of the float 2 is guided through the guide shaft 17 provided in the case 1 in the guide hole 23 provided in the float 2 on the movement central axis of the float 2. Even in this case, even when the coil spring 3 is positioned so as to be wound around the outside of the float 2 as described above, smooth movement of the float 2 can be ensured. In this example, the ventilation portion 20c of the float main body 20 is used as the guide hole 23, and the guide shaft 17 extending upward from the central portion 131b of the bottom portion 131 of the lower body 13 is passed through the ventilation portion 20c.

   FIG. 13 shows an example in which the movement of the float 2 is guided through the guide shaft 24 provided in the float 2 through the guide hole 18 provided in the case 1 on the movement central axis of the float 2. ing. Even in this case, even when the coil spring 3 is positioned so as to be wound around the outside of the float 2 as described above, smooth movement of the float 2 can be ensured. In this example, the guide shaft 24 protruding downward from the lower end of the float main body 20 is passed through the guide hole 18 that vertically penetrates the central portion 131 b of the bottom portion 131 of the lower body 13.

  Of course, the present invention is not limited to the embodiments described above, but includes all embodiments that can achieve the object of the present invention.

T Fuel tank 1 Case 10 Valve port 2 Float 20d Contact part 3 Coil spring 3a Upper end 3b Lower end

Claims (3)

A case with a valve port communicating between the inside and outside of the fuel tank;
A float in the case for opening and closing the valve opening;
A coil spring that encloses the float inside and biases the float toward the valve opening,
The upper end of the coil spring is brought into contact with a contact portion formed on the side of the float, and the lower end of the coil spring is supported by the case .
A rib between the case and the float for guiding the movement of the float is provided so as not to touch the coil spring between its upper and lower ends,
The rib is divided into an upper rib for the upper side of the float provided on the float side and a lower rib for the lower side of the float provided on the case side,
A valve device for a fuel tank , wherein a lower end of the coil spring is supported by a step portion formed on the lower rib and facing upward .   2. The fuel tank valve device according to claim 1, wherein the upper rib is gradually reduced in thickness as it goes upward. 3.   2. The movement of the float is guided through a guide shaft provided in one of the float and the case through a guide shaft provided in the other of the float and the case on the movement central axis of the float. The fuel tank valve device.

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