JP2006046136A - Roll-over valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a roll-over valve capable of stabilizing an operation point of a valve element while dispensing with a spring for energizing the valve element. <P>SOLUTION: An operation chamber S1 in which the valve element 10 is guided and a float chamber S2 storing a float 20 so as to swing are provided in an upper part and a lower part of a valve case 2, respectively. The valve element 10 is formed by a material being heavier than the float 20 and having larger specific gravity than that of fuel. When the valve case 2 is at upward facing attitude, the valve element 10 floats by buoyancy of the float 20 when a liquid level of fuel exceeds a predetermined level. When the valve case 2 is at side facing attitude, the float 20 is guided by a conical face 2d and the valve element 10 is pressed to close an inlet opening part of a passage 3a by moving force of the float 20 when a liquid level of fuel exceeds the predetermined level. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a rollover valve for preventing fuel leakage from a fuel tank.

  An automobile or the like is equipped with an adsorption device called a canister for preventing the evaporated fuel generated from the fuel in the fuel tank from being released into the atmosphere. Since the function of this adsorbing device is impaired when the fuel liquid itself comes into contact, a valve is provided in the fuel tank at one end of the passage leading to the canister. Further, the valve must have a function for preventing fuel from leaking out of the fuel tank when the vehicle rolls over. As such a valve, a special valve called a rollover valve is used.

As this rollover valve, for example, the one described in Patent Document 1 is disclosed. Referring to FIG. 7, the rollover valve described in Patent Document 1 is housed in the valve case 102 in a state where the valve body 100 having a specific gravity larger than that of the fuel is urged upward by the coil spring 101. . Further, in this rollover valve, as shown in FIG. 7A, when the valve case 102 is in the upward posture and the fuel F is not in contact with the valve body 100, the gravity f1 of the valve body 100 is the elastic return force of the coil spring 101. The valve opening state is set to be larger than f2. Further, as shown in FIG. 7B, when the valve case 102 is in the upward posture and the liquid level of the fuel F exceeds a predetermined level, the buoyancy f3 received by the valve body 100 and the elastic return force f2 of the coil spring 101 are used. When the valve is closed and the fuel tank T rolls over as shown in FIG. 7C and the valve case 102 is in the horizontal posture and the liquid level of the fuel F exceeds a predetermined level, the coil spring 101 The closed state is set by the elastic return force f2, and as shown in FIG. 7D, the liquid level of the fuel F reaches a predetermined level when the fuel tank T is turned upside down and the valve case 102 is inverted. When exceeded, the valve body 100 is set in a closed state by being lowered by the gravity f1 of the valve body 100 and the elastic return force f2 of the coil spring 101.
Japanese Patent No. 2513537 (paragraphs 0014 and 0015, FIG. 1)

  However, the rollover valve described in Patent Document 1 can set the mass tolerance small for a valve body manufactured by molding or the like, but there is a problem that the yield deteriorates if the manufacturing tolerance of the coil spring is set small. Therefore, if the manufacturing tolerance of the coil spring is set large, the operating point of the valve body will vary, and the operating timing of the valve body will be too early or conversely, the operating timing of the valve body will be delayed, impairing the valve function. There is a fear.

  In addition, in order to open the valve body after the valve body is operated and closed, it is necessary to set the mass of the valve body, the amount of immersion of the valve body with respect to the fuel, and the spring force of the coil spring. May increase in size.

  The present invention solves the above-described conventional problems, and an object thereof is to provide a rollover valve that can stabilize the operating point of the valve body and prevent the valve body from becoming large. .

  The present invention provides a valve case having a valve seat to which a passage leading to the outside of a fuel tank is connected, a float provided in the valve case, which is lighter than the fuel in the fuel tank, and the passage and the float. A valve body that is guided in a direction to open and close the passage between them and is heavier than the float and larger in specific gravity than the fuel, and the liquid level of the fuel within a range of the valve case from an upward posture to a substantially lateral posture When the pressure exceeds a predetermined level, the valve element is configured to close the passage based on the buoyancy of the float.

  In the present invention, a spring having a large tolerance in the manufacturing process can be eliminated, so that the operating point of the valve body can be stabilized. In addition, since only the valve body and the float are required to open the valve after the valve is closed, the setting is facilitated and the enlargement of the valve body can be prevented. In addition, the valve case is in an upward posture means that the valve body and the float are respectively located on the vertical line, the valve body is on the upper side, and the float is located on the lower side. A state in which the robot is tilted about 90 degrees from the upward posture.

  The valve case includes a working chamber in which the valve body is guided and a float chamber in which the float can swing, and the fuel is placed in the float chamber with the valve case in a substantially horizontal posture. A structure is provided in which when the surface exceeds a predetermined level, the float moves while abutting, and guide means is provided to press the valve body in the direction of closing the passage based on the moving force of the float. Can be.

  By providing the guide means, it is possible to press the valve body in the direction of closing the passage by the moving force of the float when the valve case is in a substantially horizontal posture.

  For example, the guide surface is a conical surface that expands toward the valve body.

  As a result, the valve body can be operated in the same manner even when the valve case reaches a substantially lateral orientation in any direction.

  According to the present invention, since it is not necessary to provide a spring, the operating point of the valve body can be stabilized and the setting can be facilitated, so that an increase in the size of the valve body can be prevented. Even if the fuel tank is turned sideways, the valve can be closed only by the buoyancy of the float.

  1 is an exploded perspective view showing the rollover valve of the present embodiment, FIG. 2 is a cross-sectional view showing the opened state of the rollover valve of the present embodiment, and FIG. 3 is an upward view of the rollover valve of the present embodiment. FIG. 4 is a cross-sectional view showing the valve closing state when the rollover valve according to the present embodiment is in the horizontal position, and FIG. 5 is a cross-sectional view showing the valve closing state when the rollover valve according to the present embodiment is in the horizontal posture. FIG. 6 is a schematic view showing an example of a configuration around a fuel tank equipped with a rollover valve.

  For example, as shown in FIG. 6, the rollover valve 1 is installed at an upper portion in a fuel tank T such as an automobile. A pipe 3 is connected to the fuel tank T, one end of the pipe 3 is connected to the rollover valve 1, and the other end of the pipe 3 is connected to the canister C. The fuel tank T is provided with an oil supply pipe 11 for supplying the fuel F to the fuel tank T and a breather pipe 12.

  As shown in FIG. 1, the rollover valve 1 includes a valve case 2, a valve body 10, and a float 20. The valve case 2 is formed of a material such as metal or synthetic resin, and is configured by combining an upper case 2A and a lower case 2B. A valve seat 2V is formed on the inner surface of the upper case 2A.

  The upper case 2A has a cylindrical body 2a, and a circular flange 2b is formed at the lower peripheral edge of the cylindrical body 2a. Further, the cylindrical body 2a is connected to the pipe 3 in such a state that its upper portion is gradually reduced in inner diameter, and the internal space of the cylindrical body 2a and the passage 3a of the pipe 3 communicate with each other. The internal space of the cylindrical body 2a corresponds to the working chamber S1 in this embodiment. A plurality of through holes 2a1 are formed at equal intervals along the circumferential direction on the peripheral surface of the cylindrical body 2a. The shape and number of the through holes 2a1 can be changed as appropriate.

  The lower case 2B is formed in a substantially mortar shape, and on its inner wall surface, a cylindrical surface 2c extending along the vertical direction at the upper part, a conical surface (guide means) 2d expanding upward at the lower part, and a lowermost part And a horizontal bottom surface 2e. A plurality of through holes 2d1 are formed in the conical surface 2d at an equal pitch along the circumferential direction. Further, a through hole 2e1 is formed at the center of the bottom surface 2e. Note that a portion surrounded by the flange 2b and the lower case 2B of the upper case 2A corresponds to the float chamber S2 of the present embodiment.

  Opposing portions of the peripheral portion of the flange portion 2b of the upper case 2A and the upper edge portion of the lower case 2B are joined by uneven fitting. Note that the joint portion between the upper case 2A and the lower case 2B may be joined through a sealing material such as a gasket or sealed by welding.

  In the present embodiment, after the valve body 10 and the float 20 are inserted into the valve case 2, the upper case 2A and the lower case 2B are joined. At this time, the valve body 10 is accommodated in the working chamber S1, and the float 20 is accommodated in the float chamber S2.

  The valve body 10 is formed of a spherical member, and is formed of a material having a specific gravity greater than that of the fuel F, that is, a material that sinks with respect to the fuel F. Further, the valve body 10 has a mass such that when the float 20 receives buoyancy from the fuel F, the float 20 can be lifted with the valve body 10 on the buoyancy. Further, the valve body 10 is formed so that its diameter is slightly smaller than the diameter of the working chamber S1, and the valve body 10 can be smoothly guided in the vertical direction within the working chamber S1. The valve body 10 is not limited to being formed from a single material, and may be formed by combining a plurality of types of materials. Further, the valve body 10 is not limited to a sphere, and may be, for example, a cylindrical shape. As will be described later, when the valve body 10 abuts on a valve seat 2V formed on the inner surface of the upper case 2A, the valve body 10 closes the inlet of the passage 3a.

  The float 20 is formed of a substantially piece-shaped member, is formed of a material lighter than the fuel F, and floats by obtaining buoyancy with respect to the fuel F. In addition, the float 20 may be entirely formed of the same material, or may be a hollow shape. The float 20 has a vertical surface 20a parallel to the cylindrical surface 2c, an inclined surface 20b parallel to the conical surface 2d, and a horizontal surface 20c parallel to the bottom surface 2e on the bottom surface. Has been. The float 20 has a pressing portion 20d at the center of the upper surface thereof. The pressing portion 20d has a cylindrical shape and has a diameter that can move in the radial direction of the working chamber S1 in the working chamber S1.

  Furthermore, the shape of the float 20 and the shape of the internal space of the float chamber S2 will be described. As shown in FIG. 1, when the height dimension of the vertical surface 20a of the float 20 is H1, and the height dimension of the cylindrical surface 2c of the valve case 2 is H2, H2> H1 is set. . Further, when the length dimension from the upper end to the lower end of the inclined surface 20b of the float 20 is L1, and the length dimension from the upper end to the lower end of the conical surface 2d of the valve case 2 is L2, L2> L1 is satisfied. Is set to Further, when the diameter dimension of the horizontal surface 20c of the float 20 is R1, and the diameter dimension of the bottom surface 2e of the valve case 2 is R2, R1> R2 is set. Further, when the diameter dimension of the upper surface 20a1 of the float 20 is R3 and the inner diameter dimension of the cylindrical surface 2c of the valve case 2 is R4, R4> R3 is set. The overall height dimension of the float 20 in the vertical direction (distance from the upper surface of the pressing portion 20d to the horizontal surface 20c) is H3, and the height dimension of the float chamber S2 of the valve case 2 (from the lower surface of the flange portion 2b to the bottom surface 2e). Is set so that H4> H3. Thus, since the float 20 is formed in a shape sufficiently smaller than the float chamber S2, the float 20 is vertically and horizontally in the float chamber S2 of the valve case 2 as shown in FIG. It can swing.

Next, the operation of the rollover valve 1 of this embodiment will be described.
As shown in FIG. 2, when the valve case 2 is in the upward posture and the fuel F does not touch the float 20 (valve case 2), the valve body 10 and the float 20 are lowered by receiving gravity F1 and F2, respectively. With the inclined surface 20b of the float 20 in contact with the conical surface 2d of the valve case 2 and the valve body 10 in contact with the upper surface of the pressing portion 20d of the float 20, the valve body 10 is separated from the inlet opening of the passage 3a. The valve opens. At this time, the evaporated fuel Fv formed by vaporizing the fuel F is discharged from the through hole 2a1 to the outside of the fuel tank T through the passage 3a. Then, the evaporated fuel Fv is adsorbed to the canister C (see FIG. 4) mounted outside the fuel tank T.

  When the vehicle F is positioned on an inclined road surface, accelerated or decelerated, or turned, the fuel F swings and the liquid level La of the fuel F exceeds a predetermined level as shown in FIG. The fuel F enters the valve case 2 through the through holes 2d1 and 2e1. When the fuel F enters the valve case 2, the float 20 receives buoyancy F3 from the fuel F. However, the buoyancy F3 generated at this time needs to be set larger than the resultant force of the gravity F1 of the valve body 10 and the gravity F2 of the float 20. As a result, the valve body 10 is lifted in the direction of closing the passage 3a, contacts the valve seat 2V (see FIG. 2) formed on the inner surface of the upper case 2A, closes the inlet of the passage 3a, and is in a closed state. . Therefore, since the fuel F does not flow out of the fuel tank T, the liquid of the fuel F itself can be prevented from flowing into the canister C.

  In the state shown in FIG. 3, even if the float 20 moves in the float chamber S2 of the valve case 2 in the direction along the liquid level La, the peripheral surface 20d1 of the pressing portion 20d formed on the float 20 is not in the working chamber. Since the vertical surface 20a of the float 20 abuts on the cylindrical surface 2c of the float chamber S2 and the height of the float 20 relative to the liquid surface La does not change, the valve body 10 is in contact with the circumferential surface 2a2 of S1. The valve can be kept closed without leaving the seal portion.

  Further, as shown in FIG. 4, the vehicle is laid sideways, and the fuel tank T is in a sideways posture (state rotated 90 degrees with respect to the upward posture shown in FIGS. 2 and 3), and the liquid level of the fuel F When Lb exceeds a predetermined level shown in the figure, the fuel F enters the valve case 2 from a part of the through holes 2a1, a part of the through holes 2d1, and the through holes 2e1. When the fuel F enters the valve case 2, the float 20 receives buoyancy F3 from the fuel F. Since the buoyancy F3 at this time is larger than the gravity F2 of the float 20, it floats upward in the float chamber S2. When the inclined surface 20b formed on the float 20 comes into contact with the conical surface 2d of the valve case 2, the component force F4 of the component forces F4 and F5 of the buoyancy F3 causes the component to be inclined obliquely upward from the center side. Slide outward. At this time, since the float 20 slides in the aforementioned direction and moves in a direction approaching the valve body 10, the valve body 10 presses the pressing portion 20d with the force Fa, and the valve body 10 seals the passage 3a. The valve is closed. Further, at this time, as shown in FIG. 4, the peripheral surface 20d1 of the pressing portion 20d is in contact with the peripheral surface 2a2 of the working chamber S1, and the vertical surface 20a of the float 20 is in contact with the cylindrical surface 2c of the float chamber S2. Since the vertical surface 20a, the inclined surface 20b, and the pressing portion 20d are supported by the valve case 2, the valve closed state can be stably maintained. Therefore, even if the valve case 2 is in the horizontal posture, the fuel F does not leak from the fuel tank T.

  In the above description, the state inclined 90 degrees from the upward posture shown in FIGS. 2 and 3 has been described. However, it does not necessarily operate unless it is 90 degrees, and in a state inclined slightly upward from 90 degrees. Even if it is, or even if it is in a state inclined slightly downward from 90 degrees, it can be closed in the same manner as described above. Further, since the conical surface 2d is set as the guide means formed in the valve case 2, it is about 90 degrees in the clockwise direction on the paper surface opposite to FIG. 3 with respect to the upward posture shown in FIGS. The float 20 is conical in the same manner as in FIG. 4, whether it is tilted, tilted about 90 degrees to the back in the vertical direction of the paper, or tilted about 90 degrees to the front in the vertical direction of the paper. It can be slid while abutting 2d and operated in the valve closing direction.

  Further, the vehicle is turned upside down, and as shown in FIG. 5, the fuel tank T is in a downward posture (state rotated 90 degrees counterclockwise from sideways), and the liquid level Lc of the fuel F is illustrated. When the predetermined level is exceeded, the fuel F enters the valve case 2 through the through hole 2a1 and the through holes 2d1 and 2e1. When the fuel F enters the valve case 2, the float 20 receives buoyancy F3 from the fuel F. Since the buoyancy F3 at this time is larger than the gravity F2 of the float 20, the float 20 floats in the inverted float chamber S2, and the inclined surface 20b of the float 20 contacts the conical surface 2d of the float chamber S2. On the other hand, since the specific gravity of the valve body 10 is greater than that of the fuel F, the valve body 10 moves down (sinks) away from the float 20 and the valve body 10 is formed on the inner surface of the upper case 2A (see FIG. 2). And the valve 3 is closed. Therefore, even when the fuel tank T is turned upside down and the valve case 2 is in the downward posture, the fuel F does not flow out of the fuel tank T.

  Although not shown, for example, even when the liquid level of the fuel F exceeds a predetermined level in a state where it is inclined 45 degrees from the upward posture, the buoyancy of the float 20 is maintained in a state where the valve case 2 is inclined 45 degrees. Since the valve body 10 is pressed, it can be set to a valve-closed state. Further, even in a state where, for example, 45 degrees is tilted downward from the lateral posture, the valve body 10 is moved away from the float 20 by the dead weight of the valve body 10 to be in a valve-closed state.

  In addition, this invention is not limited to above-described embodiment, The shape of the valve case 2, the valve body 10, and the float 20 can be variously changed in the range which does not deviate from the main point of this invention. Further, the sealing portion (inlet opening portion) of the passage 3a with which the valve body 10 hits may be formed of an elastic member such as rubber to improve the sealing performance. Further, the through hole 2a1 through which the evaporated fuel Fv passes may not be provided in the working chamber S1, but may be provided at a position penetrating the cylindrical surface 2c of the float chamber S2.

It is a disassembled perspective view which shows the roll over valve of this embodiment. It is sectional drawing which shows the valve opening state of the rollover valve of this embodiment. It is sectional drawing which shows a valve closing state when the rollover valve of this embodiment is an upward attitude | position. It is sectional drawing which shows a valve closing state when the roll over valve of this embodiment is a horizontal attitude | position. It is sectional drawing which shows a valve closing state when the roll over valve of this embodiment is a downward attitude | position. It is the schematic which shows an example of a structure of the periphery of the fuel tank equipped with the rollover valve. It is an operation | movement figure of the conventional rollover valve, (a) is a valve opening state, (b) is a valve closing state in an upward posture, (c) is a valve closing state in a lateral posture, (d) is a downward posture. The valve is closed.

Explanation of symbols

1 Rollover valve 2 Valve case 2A Upper case 2B Lower case 2V Valve seat 2c Cylindrical surface 2d Conical surface (guide means)
2e bottom surface 3a passage 10 valve body 20 float 20a vertical surface 20b inclined surface 20c horizontal surface 20d pressing portion F fuel Fv evaporated fuel S1 working chamber S2 float chamber T fuel tank

Claims (3)

  A valve case having a valve seat to which a passage leading to the outside of the fuel tank is connected; a float that is lighter than the fuel in the fuel tank; and the passage between the passage and the float A valve body that is heavier than the float and greater in specific gravity than the fuel, and the fuel level is within a predetermined level within a range of the valve case from an upward posture to a substantially horizontal posture. A rollover valve characterized in that the valve body is configured to close the passage based on the buoyancy of the float when exceeded.   The valve case has a working chamber in which the valve body is guided and a float chamber in which the float can swing. The float chamber has a substantially horizontal posture and the liquid level of the fuel. When the float exceeds a predetermined level, there is provided guide means for moving the abutment while abutting and pressing the valve body in a direction to close the passage based on a moving force of the float. The rollover valve according to claim 1.   The rollover valve according to claim 2, wherein the guide means is a conical surface that expands toward the valve body.

Images